ALSA: usb-audio: refactor code

Clean up the usb audio driver by factoring out a lot of functions to
separate files. Code for procfs, quirks, urbs, format parsers etc all
got a new home now.

Moved almost all special quirk handling to quirks.c and introduced new
generic functions to handle them, so the exceptions do not pollute the
whole driver.

Renamed usbaudio.c to card.c because this is what it actually does now.
Renamed usbmidi.c to midi.c for namespace clarity.
Removed more things from usbaudio.h.

The non-standard drivers were adopted accordingly.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

27 files changed, 4411 insertions, 4095 deletions

diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index 423d829056f..0758d8dc8cd 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -2,8 +2,17 @@
 # Makefile for ALSA
 #
 
-snd-usb-audio-objs := usbaudio.o usbmixer.o
-snd-usbmidi-lib-objs := usbmidi.o
+snd-usb-audio-objs := 	card.o \
+			usbmixer.o \
+			proc.o \
+			quirks.o \
+			format.o \
+			endpoint.o \
+			urb.o \
+			pcm.o \
+			helper.o
+
+snd-usbmidi-lib-objs := midi.o
 
 # Toplevel Module Dependency
 obj-$(CONFIG_SND_USB_AUDIO) += snd-usb-audio.o snd-usbmidi-lib.o
diff --git a/sound/usb/card.c b/sound/usb/card.c
new file mode 100644
index 00000000000..426aabc729d
--- /dev/null
+++ b/sound/usb/card.c
@@ -0,0 +1,648 @@
+/*
+ *   (Tentative) USB Audio Driver for ALSA
+ *
+ *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
+ *
+ *   Many codes borrowed from audio.c by
+ *	    Alan Cox (alan@lxorguk.ukuu.org.uk)
+ *	    Thomas Sailer (sailer@ife.ee.ethz.ch)
+ *
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ *
+ *  NOTES:
+ *
+ *   - async unlink should be used for avoiding the sleep inside lock.
+ *     2.4.22 usb-uhci seems buggy for async unlinking and results in
+ *     oops.  in such a cse, pass async_unlink=0 option.
+ *   - the linked URBs would be preferred but not used so far because of
+ *     the instability of unlinking.
+ *   - type II is not supported properly.  there is no device which supports
+ *     this type *correctly*.  SB extigy looks as if it supports, but it's
+ *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
+ */
+
+
+#include <linux/bitops.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/usb.h>
+#include <linux/moduleparam.h>
+#include <linux/mutex.h>
+#include <linux/usb/audio.h>
+
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/initval.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "midi.h"
+#include "usbmixer.h"
+#include "proc.h"
+#include "quirks.h"
+#include "endpoint.h"
+#include "helper.h"
+#include "debug.h"
+#include "pcm.h"
+#include "urb.h"
+#include "format.h"
+
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("USB Audio");
+MODULE_LICENSE("GPL");
+MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
+
+
+static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
+static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
+static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
+/* Vendor/product IDs for this card */
+static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
+static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
+static int nrpacks = 8;		/* max. number of packets per urb */
+static int async_unlink = 1;
+static int device_setup[SNDRV_CARDS]; /* device parameter for this card */
+static int ignore_ctl_error;
+
+module_param_array(index, int, NULL, 0444);
+MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
+module_param_array(id, charp, NULL, 0444);
+MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
+module_param_array(enable, bool, NULL, 0444);
+MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
+module_param_array(vid, int, NULL, 0444);
+MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
+module_param_array(pid, int, NULL, 0444);
+MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
+module_param(nrpacks, int, 0644);
+MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB.");
+module_param(async_unlink, bool, 0444);
+MODULE_PARM_DESC(async_unlink, "Use async unlink mode.");
+module_param_array(device_setup, int, NULL, 0444);
+MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
+module_param(ignore_ctl_error, bool, 0444);
+MODULE_PARM_DESC(ignore_ctl_error,
+		 "Ignore errors from USB controller for mixer interfaces.");
+
+/*
+ * we keep the snd_usb_audio_t instances by ourselves for merging
+ * the all interfaces on the same card as one sound device.
+ */
+
+static DEFINE_MUTEX(register_mutex);
+static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
+static struct usb_driver usb_audio_driver;
+
+/*
+ * disconnect streams
+ * called from snd_usb_audio_disconnect()
+ */
+static void snd_usb_stream_disconnect(struct list_head *head)
+{
+	int idx;
+	struct snd_usb_stream *as;
+	struct snd_usb_substream *subs;
+
+	as = list_entry(head, struct snd_usb_stream, list);
+	for (idx = 0; idx < 2; idx++) {
+		subs = &as->substream[idx];
+		if (!subs->num_formats)
+			return;
+		snd_usb_release_substream_urbs(subs, 1);
+		subs->interface = -1;
+	}
+}
+
+static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
+{
+	struct usb_device *dev = chip->dev;
+	struct usb_host_interface *alts;
+	struct usb_interface_descriptor *altsd;
+	struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
+
+	if (!iface) {
+		snd_printk(KERN_ERR "%d:%u:%d : does not exist\n",
+			   dev->devnum, ctrlif, interface);
+		return -EINVAL;
+	}
+
+	if (usb_interface_claimed(iface)) {
+		snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
+						dev->devnum, ctrlif, interface);
+		return -EINVAL;
+	}
+
+	alts = &iface->altsetting[0];
+	altsd = get_iface_desc(alts);
+	if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
+	     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
+	    altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
+		int err = snd_usbmidi_create(chip->card, iface,
+					     &chip->midi_list, NULL);
+		if (err < 0) {
+			snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n",
+						dev->devnum, ctrlif, interface);
+			return -EINVAL;
+		}
+		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
+
+		return 0;
+	}
+
+	if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
+	     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
+	    altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
+		snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n",
+					dev->devnum, ctrlif, interface, altsd->bInterfaceClass);
+		/* skip non-supported classes */
+		return -EINVAL;
+	}
+
+	if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
+		snd_printk(KERN_ERR "low speed audio streaming not supported\n");
+		return -EINVAL;
+	}
+
+	if (! snd_usb_parse_audio_endpoints(chip, interface)) {
+		usb_set_interface(dev, interface, 0); /* reset the current interface */
+		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * parse audio control descriptor and create pcm/midi streams
+ */
+static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
+{
+	struct usb_device *dev = chip->dev;
+	struct usb_host_interface *host_iface;
+	struct usb_interface_descriptor *altsd;
+	void *control_header;
+	int i, protocol;
+
+	/* find audiocontrol interface */
+	host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
+	control_header = snd_usb_find_csint_desc(host_iface->extra,
+						 host_iface->extralen,
+						 NULL, UAC_HEADER);
+	altsd = get_iface_desc(host_iface);
+	protocol = altsd->bInterfaceProtocol;
+
+	if (!control_header) {
+		snd_printk(KERN_ERR "cannot find UAC_HEADER\n");
+		return -EINVAL;
+	}
+
+	switch (protocol) {
+	case UAC_VERSION_1: {
+		struct uac_ac_header_descriptor_v1 *h1 = control_header;
+
+		if (!h1->bInCollection) {
+			snd_printk(KERN_INFO "skipping empty audio interface (v1)\n");
+			return -EINVAL;
+		}
+
+		if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
+			snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n");
+			return -EINVAL;
+		}
+
+		for (i = 0; i < h1->bInCollection; i++)
+			snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
+
+		break;
+	}
+
+	case UAC_VERSION_2: {
+		struct uac_clock_source_descriptor *cs;
+		struct usb_interface_assoc_descriptor *assoc =
+			usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
+
+		if (!assoc) {
+			snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");
+			return -EINVAL;
+		}
+
+		/* FIXME: for now, we expect there is at least one clock source
+		 * descriptor and we always take the first one.
+		 * We should properly support devices with multiple clock sources,
+		 * clock selectors and sample rate conversion units. */
+
+		cs = snd_usb_find_csint_desc(host_iface->extra, host_iface->extralen,
+						NULL, UAC_CLOCK_SOURCE);
+
+		if (!cs) {
+			snd_printk(KERN_ERR "CLOCK_SOURCE descriptor not found\n");
+			return -EINVAL;
+		}
+
+		chip->clock_id = cs->bClockID;
+
+		for (i = 0; i < assoc->bInterfaceCount; i++) {
+			int intf = assoc->bFirstInterface + i;
+
+			if (intf != ctrlif)
+				snd_usb_create_stream(chip, ctrlif, intf);
+		}
+
+		break;
+	}
+
+	default:
+		snd_printk(KERN_ERR "unknown protocol version 0x%02x\n", protocol);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * free the chip instance
+ *
+ * here we have to do not much, since pcm and controls are already freed
+ *
+ */
+
+static int snd_usb_audio_free(struct snd_usb_audio *chip)
+{
+	kfree(chip);
+	return 0;
+}
+
+static int snd_usb_audio_dev_free(struct snd_device *device)
+{
+	struct snd_usb_audio *chip = device->device_data;
+	return snd_usb_audio_free(chip);
+}
+
+
+/*
+ * create a chip instance and set its names.
+ */
+static int snd_usb_audio_create(struct usb_device *dev, int idx,
+				const struct snd_usb_audio_quirk *quirk,
+				struct snd_usb_audio **rchip)
+{
+	struct snd_card *card;
+	struct snd_usb_audio *chip;
+	int err, len;
+	char component[14];
+	static struct snd_device_ops ops = {
+		.dev_free =	snd_usb_audio_dev_free,
+	};
+
+	*rchip = NULL;
+
+	if (snd_usb_get_speed(dev) != USB_SPEED_LOW &&
+	    snd_usb_get_speed(dev) != USB_SPEED_FULL &&
+	    snd_usb_get_speed(dev) != USB_SPEED_HIGH) {
+		snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev));
+		return -ENXIO;
+	}
+
+	err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card);
+	if (err < 0) {
+		snd_printk(KERN_ERR "cannot create card instance %d\n", idx);
+		return err;
+	}
+
+	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+	if (! chip) {
+		snd_card_free(card);
+		return -ENOMEM;
+	}
+
+	chip->index = idx;
+	chip->dev = dev;
+	chip->card = card;
+	chip->setup = device_setup[idx];
+	chip->nrpacks = nrpacks;
+	chip->async_unlink = async_unlink;
+
+	chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
+			      le16_to_cpu(dev->descriptor.idProduct));
+	INIT_LIST_HEAD(&chip->pcm_list);
+	INIT_LIST_HEAD(&chip->midi_list);
+	INIT_LIST_HEAD(&chip->mixer_list);
+
+	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
+		snd_usb_audio_free(chip);
+		snd_card_free(card);
+		return err;
+	}
+
+	strcpy(card->driver, "USB-Audio");
+	sprintf(component, "USB%04x:%04x",
+		USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
+	snd_component_add(card, component);
+
+	/* retrieve the device string as shortname */
+	if (quirk && quirk->product_name) {
+		strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
+	} else {
+		if (!dev->descriptor.iProduct ||
+		    usb_string(dev, dev->descriptor.iProduct,
+		    card->shortname, sizeof(card->shortname)) <= 0) {
+			/* no name available from anywhere, so use ID */
+			sprintf(card->shortname, "USB Device %#04x:%#04x",
+				USB_ID_VENDOR(chip->usb_id),
+				USB_ID_PRODUCT(chip->usb_id));
+		}
+	}
+
+	/* retrieve the vendor and device strings as longname */
+	if (quirk && quirk->vendor_name) {
+		len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
+	} else {
+		if (dev->descriptor.iManufacturer)
+			len = usb_string(dev, dev->descriptor.iManufacturer,
+					 card->longname, sizeof(card->longname));
+		else
+			len = 0;
+		/* we don't really care if there isn't any vendor string */
+	}
+	if (len > 0)
+		strlcat(card->longname, " ", sizeof(card->longname));
+
+	strlcat(card->longname, card->shortname, sizeof(card->longname));
+
+	len = strlcat(card->longname, " at ", sizeof(card->longname));
+
+	if (len < sizeof(card->longname))
+		usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
+
+	strlcat(card->longname,
+		snd_usb_get_speed(dev) == USB_SPEED_LOW ? ", low speed" :
+		snd_usb_get_speed(dev) == USB_SPEED_FULL ? ", full speed" :
+		", high speed",
+		sizeof(card->longname));
+
+	snd_usb_audio_create_proc(chip);
+
+	*rchip = chip;
+	return 0;
+}
+
+/*
+ * probe the active usb device
+ *
+ * note that this can be called multiple times per a device, when it
+ * includes multiple audio control interfaces.
+ *
+ * thus we check the usb device pointer and creates the card instance
+ * only at the first time.  the successive calls of this function will
+ * append the pcm interface to the corresponding card.
+ */
+static void *snd_usb_audio_probe(struct usb_device *dev,
+				 struct usb_interface *intf,
+				 const struct usb_device_id *usb_id)
+{
+	const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info;
+	int i, err;
+	struct snd_usb_audio *chip;
+	struct usb_host_interface *alts;
+	int ifnum;
+	u32 id;
+
+	alts = &intf->altsetting[0];
+	ifnum = get_iface_desc(alts)->bInterfaceNumber;
+	id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
+		    le16_to_cpu(dev->descriptor.idProduct));
+	if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
+		goto __err_val;
+
+	if (snd_usb_apply_boot_quirk(dev, intf, quirk) < 0)
+		goto __err_val;
+
+	/*
+	 * found a config.  now register to ALSA
+	 */
+
+	/* check whether it's already registered */
+	chip = NULL;
+	mutex_lock(&register_mutex);
+	for (i = 0; i < SNDRV_CARDS; i++) {
+		if (usb_chip[i] && usb_chip[i]->dev == dev) {
+			if (usb_chip[i]->shutdown) {
+				snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n");
+				goto __error;
+			}
+			chip = usb_chip[i];
+			break;
+		}
+	}
+	if (! chip) {
+		/* it's a fresh one.
+		 * now look for an empty slot and create a new card instance
+		 */
+		for (i = 0; i < SNDRV_CARDS; i++)
+			if (enable[i] && ! usb_chip[i] &&
+			    (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
+			    (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
+				if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) {
+					goto __error;
+				}
+				snd_card_set_dev(chip->card, &intf->dev);
+				break;
+			}
+		if (!chip) {
+			printk(KERN_ERR "no available usb audio device\n");
+			goto __error;
+		}
+	}
+
+	chip->txfr_quirk = 0;
+	err = 1; /* continue */
+	if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
+		/* need some special handlings */
+		if ((err = snd_usb_create_quirk(chip, intf, &usb_audio_driver, quirk)) < 0)
+			goto __error;
+	}
+
+	if (err > 0) {
+		/* create normal USB audio interfaces */
+		if (snd_usb_create_streams(chip, ifnum) < 0 ||
+		    snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
+			goto __error;
+		}
+	}
+
+	/* we are allowed to call snd_card_register() many times */
+	if (snd_card_register(chip->card) < 0) {
+		goto __error;
+	}
+
+	usb_chip[chip->index] = chip;
+	chip->num_interfaces++;
+	mutex_unlock(&register_mutex);
+	return chip;
+
+ __error:
+	if (chip && !chip->num_interfaces)
+		snd_card_free(chip->card);
+	mutex_unlock(&register_mutex);
+ __err_val:
+	return NULL;
+}
+
+/*
+ * we need to take care of counter, since disconnection can be called also
+ * many times as well as usb_audio_probe().
+ */
+static void snd_usb_audio_disconnect(struct usb_device *dev, void *ptr)
+{
+	struct snd_usb_audio *chip;
+	struct snd_card *card;
+	struct list_head *p;
+
+	if (ptr == (void *)-1L)
+		return;
+
+	chip = ptr;
+	card = chip->card;
+	mutex_lock(&register_mutex);
+	chip->shutdown = 1;
+	chip->num_interfaces--;
+	if (chip->num_interfaces <= 0) {
+		snd_card_disconnect(card);
+		/* release the pcm resources */
+		list_for_each(p, &chip->pcm_list) {
+			snd_usb_stream_disconnect(p);
+		}
+		/* release the midi resources */
+		list_for_each(p, &chip->midi_list) {
+			snd_usbmidi_disconnect(p);
+		}
+		/* release mixer resources */
+		list_for_each(p, &chip->mixer_list) {
+			snd_usb_mixer_disconnect(p);
+		}
+		usb_chip[chip->index] = NULL;
+		mutex_unlock(&register_mutex);
+		snd_card_free_when_closed(card);
+	} else {
+		mutex_unlock(&register_mutex);
+	}
+}
+
+/*
+ * new 2.5 USB kernel API
+ */
+static int usb_audio_probe(struct usb_interface *intf,
+			   const struct usb_device_id *id)
+{
+	void *chip;
+	chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
+	if (chip) {
+		usb_set_intfdata(intf, chip);
+		return 0;
+	} else
+		return -EIO;
+}
+
+static void usb_audio_disconnect(struct usb_interface *intf)
+{
+	snd_usb_audio_disconnect(interface_to_usbdev(intf),
+				 usb_get_intfdata(intf));
+}
+
+#ifdef CONFIG_PM
+static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct snd_usb_audio *chip = usb_get_intfdata(intf);
+	struct list_head *p;
+	struct snd_usb_stream *as;
+
+	if (chip == (void *)-1L)
+		return 0;
+
+	snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
+	if (!chip->num_suspended_intf++) {
+		list_for_each(p, &chip->pcm_list) {
+			as = list_entry(p, struct snd_usb_stream, list);
+			snd_pcm_suspend_all(as->pcm);
+		}
+	}
+
+	return 0;
+}
+
+static int usb_audio_resume(struct usb_interface *intf)
+{
+	struct snd_usb_audio *chip = usb_get_intfdata(intf);
+
+	if (chip == (void *)-1L)
+		return 0;
+	if (--chip->num_suspended_intf)
+		return 0;
+	/*
+	 * ALSA leaves material resumption to user space
+	 * we just notify
+	 */
+
+	snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
+
+	return 0;
+}
+#endif		/* CONFIG_PM */
+
+static struct usb_device_id usb_audio_ids [] = {
+#include "quirks-table.h"
+    { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
+      .bInterfaceClass = USB_CLASS_AUDIO,
+      .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
+    { }						/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE (usb, usb_audio_ids);
+
+/*
+ * entry point for linux usb interface
+ */
+
+static struct usb_driver usb_audio_driver = {
+	.name =		"snd-usb-audio",
+	.probe =	usb_audio_probe,
+	.disconnect =	usb_audio_disconnect,
+	.suspend =	usb_audio_suspend,
+	.resume =	usb_audio_resume,
+	.id_table =	usb_audio_ids,
+};
+
+static int __init snd_usb_audio_init(void)
+{
+	if (nrpacks < 1 || nrpacks > MAX_PACKS) {
+		printk(KERN_WARNING "invalid nrpacks value.\n");
+		return -EINVAL;
+	}
+	return usb_register(&usb_audio_driver);
+}
+
+static void __exit snd_usb_audio_cleanup(void)
+{
+	usb_deregister(&usb_audio_driver);
+}
+
+module_init(snd_usb_audio_init);
+module_exit(snd_usb_audio_cleanup);
diff --git a/sound/usb/card.h b/sound/usb/card.h
new file mode 100644
index 00000000000..71f03c15103
--- /dev/null
+++ b/sound/usb/card.h
@@ -0,0 +1,105 @@
+#ifndef __USBAUDIO_CARD_H
+#define __USBAUDIO_CARD_H
+
+#define MAX_PACKS	20
+#define MAX_PACKS_HS	(MAX_PACKS * 8)	/* in high speed mode */
+#define MAX_URBS	8
+#define SYNC_URBS	4	/* always four urbs for sync */
+#define MAX_QUEUE	24	/* try not to exceed this queue length, in ms */
+
+struct audioformat {
+	struct list_head list;
+	snd_pcm_format_t format;	/* format type */
+	unsigned int channels;		/* # channels */
+	unsigned int fmt_type;		/* USB audio format type (1-3) */
+	unsigned int frame_size;	/* samples per frame for non-audio */
+	int iface;			/* interface number */
+	unsigned char altsetting;	/* corresponding alternate setting */
+	unsigned char altset_idx;	/* array index of altenate setting */
+	unsigned char attributes;	/* corresponding attributes of cs endpoint */
+	unsigned char endpoint;		/* endpoint */
+	unsigned char ep_attr;		/* endpoint attributes */
+	unsigned char datainterval;	/* log_2 of data packet interval */
+	unsigned int maxpacksize;	/* max. packet size */
+	unsigned int rates;		/* rate bitmasks */
+	unsigned int rate_min, rate_max;	/* min/max rates */
+	unsigned int nr_rates;		/* number of rate table entries */
+	unsigned int *rate_table;	/* rate table */
+};
+
+struct snd_usb_substream;
+
+struct snd_urb_ctx {
+	struct urb *urb;
+	unsigned int buffer_size;	/* size of data buffer, if data URB */
+	struct snd_usb_substream *subs;
+	int index;	/* index for urb array */
+	int packets;	/* number of packets per urb */
+};
+
+struct snd_urb_ops {
+	int (*prepare)(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime, struct urb *u);
+	int (*retire)(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime, struct urb *u);
+	int (*prepare_sync)(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime, struct urb *u);
+	int (*retire_sync)(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime, struct urb *u);
+};
+
+struct snd_usb_substream {
+	struct snd_usb_stream *stream;
+	struct usb_device *dev;
+	struct snd_pcm_substream *pcm_substream;
+	int direction;	/* playback or capture */
+	int interface;	/* current interface */
+	int endpoint;	/* assigned endpoint */
+	struct audioformat *cur_audiofmt;	/* current audioformat pointer (for hw_params callback) */
+	unsigned int cur_rate;		/* current rate (for hw_params callback) */
+	unsigned int period_bytes;	/* current period bytes (for hw_params callback) */
+	unsigned int format;     /* USB data format */
+	unsigned int datapipe;   /* the data i/o pipe */
+	unsigned int syncpipe;   /* 1 - async out or adaptive in */
+	unsigned int datainterval;	/* log_2 of data packet interval */
+	unsigned int syncinterval;  /* P for adaptive mode, 0 otherwise */
+	unsigned int freqn;      /* nominal sampling rate in fs/fps in Q16.16 format */
+	unsigned int freqm;      /* momentary sampling rate in fs/fps in Q16.16 format */
+	unsigned int freqmax;    /* maximum sampling rate, used for buffer management */
+	unsigned int phase;      /* phase accumulator */
+	unsigned int maxpacksize;	/* max packet size in bytes */
+	unsigned int maxframesize;	/* max packet size in frames */
+	unsigned int curpacksize;	/* current packet size in bytes (for capture) */
+	unsigned int curframesize;	/* current packet size in frames (for capture) */
+	unsigned int fill_max: 1;	/* fill max packet size always */
+	unsigned int txfr_quirk:1;	/* allow sub-frame alignment */
+	unsigned int fmt_type;		/* USB audio format type (1-3) */
+
+	unsigned int running: 1;	/* running status */
+
+	unsigned int hwptr_done;	/* processed byte position in the buffer */
+	unsigned int transfer_done;		/* processed frames since last period update */
+	unsigned long active_mask;	/* bitmask of active urbs */
+	unsigned long unlink_mask;	/* bitmask of unlinked urbs */
+
+	unsigned int nurbs;			/* # urbs */
+	struct snd_urb_ctx dataurb[MAX_URBS];	/* data urb table */
+	struct snd_urb_ctx syncurb[SYNC_URBS];	/* sync urb table */
+	char *syncbuf;				/* sync buffer for all sync URBs */
+	dma_addr_t sync_dma;			/* DMA address of syncbuf */
+
+	u64 formats;			/* format bitmasks (all or'ed) */
+	unsigned int num_formats;		/* number of supported audio formats (list) */
+	struct list_head fmt_list;	/* format list */
+	struct snd_pcm_hw_constraint_list rate_list;	/* limited rates */
+	spinlock_t lock;
+
+	struct snd_urb_ops ops;		/* callbacks (must be filled at init) */
+};
+
+struct snd_usb_stream {
+	struct snd_usb_audio *chip;
+	struct snd_pcm *pcm;
+	int pcm_index;
+	unsigned int fmt_type;		/* USB audio format type (1-3) */
+	struct snd_usb_substream substream[2];
+	struct list_head list;
+};
+
+#endif /* __USBAUDIO_CARD_H */
diff --git a/sound/usb/debug.h b/sound/usb/debug.h
new file mode 100644
index 00000000000..343ec2d9ee6
--- /dev/null
+++ b/sound/usb/debug.h
@@ -0,0 +1,15 @@
+#ifndef __USBAUDIO_DEBUG_H
+#define __USBAUDIO_DEBUG_H
+
+/*
+ * h/w constraints
+ */
+
+#ifdef HW_CONST_DEBUG
+#define hwc_debug(fmt, args...) printk(KERN_DEBUG fmt, ##args)
+#else
+#define hwc_debug(fmt, args...) /**/
+#endif
+
+#endif /* __USBAUDIO_DEBUG_H */
+
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
new file mode 100644
index 00000000000..3f53dee1270
--- /dev/null
+++ b/sound/usb/endpoint.c
@@ -0,0 +1,358 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "proc.h"
+#include "quirks.h"
+#include "endpoint.h"
+#include "urb.h"
+#include "pcm.h"
+#include "helper.h"
+#include "format.h"
+
+/*
+ * free a substream
+ */
+static void free_substream(struct snd_usb_substream *subs)
+{
+	struct list_head *p, *n;
+
+	if (!subs->num_formats)
+		return; /* not initialized */
+	list_for_each_safe(p, n, &subs->fmt_list) {
+		struct audioformat *fp = list_entry(p, struct audioformat, list);
+		kfree(fp->rate_table);
+		kfree(fp);
+	}
+	kfree(subs->rate_list.list);
+}
+
+
+/*
+ * free a usb stream instance
+ */
+static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
+{
+	free_substream(&stream->substream[0]);
+	free_substream(&stream->substream[1]);
+	list_del(&stream->list);
+	kfree(stream);
+}
+
+static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
+{
+	struct snd_usb_stream *stream = pcm->private_data;
+	if (stream) {
+		stream->pcm = NULL;
+		snd_usb_audio_stream_free(stream);
+	}
+}
+
+
+/*
+ * add this endpoint to the chip instance.
+ * if a stream with the same endpoint already exists, append to it.
+ * if not, create a new pcm stream.
+ */
+int snd_usb_add_audio_endpoint(struct snd_usb_audio *chip, int stream, struct audioformat *fp)
+{
+	struct list_head *p;
+	struct snd_usb_stream *as;
+	struct snd_usb_substream *subs;
+	struct snd_pcm *pcm;
+	int err;
+
+	list_for_each(p, &chip->pcm_list) {
+		as = list_entry(p, struct snd_usb_stream, list);
+		if (as->fmt_type != fp->fmt_type)
+			continue;
+		subs = &as->substream[stream];
+		if (!subs->endpoint)
+			continue;
+		if (subs->endpoint == fp->endpoint) {
+			list_add_tail(&fp->list, &subs->fmt_list);
+			subs->num_formats++;
+			subs->formats |= 1ULL << fp->format;
+			return 0;
+		}
+	}
+	/* look for an empty stream */
+	list_for_each(p, &chip->pcm_list) {
+		as = list_entry(p, struct snd_usb_stream, list);
+		if (as->fmt_type != fp->fmt_type)
+			continue;
+		subs = &as->substream[stream];
+		if (subs->endpoint)
+			continue;
+		err = snd_pcm_new_stream(as->pcm, stream, 1);
+		if (err < 0)
+			return err;
+		snd_usb_init_substream(as, stream, fp);
+		return 0;
+	}
+
+	/* create a new pcm */
+	as = kzalloc(sizeof(*as), GFP_KERNEL);
+	if (!as)
+		return -ENOMEM;
+	as->pcm_index = chip->pcm_devs;
+	as->chip = chip;
+	as->fmt_type = fp->fmt_type;
+	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
+			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
+			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
+			  &pcm);
+	if (err < 0) {
+		kfree(as);
+		return err;
+	}
+	as->pcm = pcm;
+	pcm->private_data = as;
+	pcm->private_free = snd_usb_audio_pcm_free;
+	pcm->info_flags = 0;
+	if (chip->pcm_devs > 0)
+		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
+	else
+		strcpy(pcm->name, "USB Audio");
+
+	snd_usb_init_substream(as, stream, fp);
+
+	list_add(&as->list, &chip->pcm_list);
+	chip->pcm_devs++;
+
+	snd_usb_proc_pcm_format_add(as);
+
+	return 0;
+}
+
+int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
+{
+	struct usb_device *dev;
+	struct usb_interface *iface;
+	struct usb_host_interface *alts;
+	struct usb_interface_descriptor *altsd;
+	int i, altno, err, stream;
+	int format = 0, num_channels = 0;
+	struct audioformat *fp = NULL;
+	unsigned char *fmt, *csep;
+	int num, protocol;
+
+	dev = chip->dev;
+
+	/* parse the interface's altsettings */
+	iface = usb_ifnum_to_if(dev, iface_no);
+
+	num = iface->num_altsetting;
+
+	/*
+	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
+	 * one misses syncpipe, and does not produce any sound.
+	 */
+	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
+		num = 4;
+
+	for (i = 0; i < num; i++) {
+		alts = &iface->altsetting[i];
+		altsd = get_iface_desc(alts);
+		protocol = altsd->bInterfaceProtocol;
+		/* skip invalid one */
+		if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
+		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
+		    (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
+		     altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC) ||
+		    altsd->bNumEndpoints < 1 ||
+		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
+			continue;
+		/* must be isochronous */
+		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
+		    USB_ENDPOINT_XFER_ISOC)
+			continue;
+		/* check direction */
+		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
+			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
+		altno = altsd->bAlternateSetting;
+
+		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
+			continue;
+
+		/* get audio formats */
+		switch (protocol) {
+		case UAC_VERSION_1: {
+			struct uac_as_header_descriptor_v1 *as =
+				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
+
+			if (!as) {
+				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
+					   dev->devnum, iface_no, altno);
+				continue;
+			}
+
+			if (as->bLength < sizeof(*as)) {
+				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
+					   dev->devnum, iface_no, altno);
+				continue;
+			}
+
+			format = le16_to_cpu(as->wFormatTag); /* remember the format value */
+			break;
+		}
+
+		case UAC_VERSION_2: {
+			struct uac_as_header_descriptor_v2 *as =
+				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
+
+			if (!as) {
+				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
+					   dev->devnum, iface_no, altno);
+				continue;
+			}
+
+			if (as->bLength < sizeof(*as)) {
+				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
+					   dev->devnum, iface_no, altno);
+				continue;
+			}
+
+			num_channels = as->bNrChannels;
+			format = le32_to_cpu(as->bmFormats);
+
+			break;
+		}
+
+		default:
+			snd_printk(KERN_ERR "%d:%u:%d : unknown interface protocol %04x\n",
+				   dev->devnum, iface_no, altno, protocol);
+			continue;
+		}
+
+		/* get format type */
+		fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_FORMAT_TYPE);
+		if (!fmt) {
+			snd_printk(KERN_ERR "%d:%u:%d : no UAC_FORMAT_TYPE desc\n",
+				   dev->devnum, iface_no, altno);
+			continue;
+		}
+		if (((protocol == UAC_VERSION_1) && (fmt[0] < 8)) ||
+		    ((protocol == UAC_VERSION_2) && (fmt[0] != 6))) {
+			snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_FORMAT_TYPE desc\n",
+				   dev->devnum, iface_no, altno);
+			continue;
+		}
+
+		/*
+		 * Blue Microphones workaround: The last altsetting is identical
+		 * with the previous one, except for a larger packet size, but
+		 * is actually a mislabeled two-channel setting; ignore it.
+		 */
+		if (fmt[4] == 1 && fmt[5] == 2 && altno == 2 && num == 3 &&
+		    fp && fp->altsetting == 1 && fp->channels == 1 &&
+		    fp->format == SNDRV_PCM_FORMAT_S16_LE &&
+		    protocol == UAC_VERSION_1 &&
+		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
+							fp->maxpacksize * 2)
+			continue;
+
+		csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
+		/* Creamware Noah has this descriptor after the 2nd endpoint */
+		if (!csep && altsd->bNumEndpoints >= 2)
+			csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
+		if (!csep || csep[0] < 7 || csep[2] != UAC_EP_GENERAL) {
+			snd_printk(KERN_WARNING "%d:%u:%d : no or invalid"
+				   " class specific endpoint descriptor\n",
+				   dev->devnum, iface_no, altno);
+			csep = NULL;
+		}
+
+		fp = kzalloc(sizeof(*fp), GFP_KERNEL);
+		if (! fp) {
+			snd_printk(KERN_ERR "cannot malloc\n");
+			return -ENOMEM;
+		}
+
+		fp->iface = iface_no;
+		fp->altsetting = altno;
+		fp->altset_idx = i;
+		fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
+		fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
+		fp->datainterval = snd_usb_parse_datainterval(chip, alts);
+		fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
+		/* num_channels is only set for v2 interfaces */
+		fp->channels = num_channels;
+		if (snd_usb_get_speed(dev) == USB_SPEED_HIGH)
+			fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
+					* (fp->maxpacksize & 0x7ff);
+		fp->attributes = csep ? csep[3] : 0;
+
+		/* some quirks for attributes here */
+
+		switch (chip->usb_id) {
+		case USB_ID(0x0a92, 0x0053): /* AudioTrak Optoplay */
+			/* Optoplay sets the sample rate attribute although
+			 * it seems not supporting it in fact.
+			 */
+			fp->attributes &= ~UAC_EP_CS_ATTR_SAMPLE_RATE;
+			break;
+		case USB_ID(0x041e, 0x3020): /* Creative SB Audigy 2 NX */
+		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
+			/* doesn't set the sample rate attribute, but supports it */
+			fp->attributes |= UAC_EP_CS_ATTR_SAMPLE_RATE;
+			break;
+		case USB_ID(0x047f, 0x0ca1): /* plantronics headset */
+		case USB_ID(0x077d, 0x07af): /* Griffin iMic (note that there is
+						an older model 77d:223) */
+		/*
+		 * plantronics headset and Griffin iMic have set adaptive-in
+		 * although it's really not...
+		 */
+			fp->ep_attr &= ~USB_ENDPOINT_SYNCTYPE;
+			if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+				fp->ep_attr |= USB_ENDPOINT_SYNC_ADAPTIVE;
+			else
+				fp->ep_attr |= USB_ENDPOINT_SYNC_SYNC;
+			break;
+		}
+
+		/* ok, let's parse further... */
+		if (snd_usb_parse_audio_format(chip, fp, format, fmt, stream, alts) < 0) {
+			kfree(fp->rate_table);
+			kfree(fp);
+			continue;
+		}
+
+		snd_printdd(KERN_INFO "%d:%u:%d: add audio endpoint %#x\n", dev->devnum, iface_no, altno, fp->endpoint);
+		err = snd_usb_add_audio_endpoint(chip, stream, fp);
+		if (err < 0) {
+			kfree(fp->rate_table);
+			kfree(fp);
+			return err;
+		}
+		/* try to set the interface... */
+		usb_set_interface(chip->dev, iface_no, altno);
+		snd_usb_init_pitch(chip->dev, iface_no, alts, fp);
+		snd_usb_init_sample_rate(chip->dev, iface_no, alts, fp, fp->rate_max);
+	}
+	return 0;
+}
+
diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h
new file mode 100644
index 00000000000..64dd0db023b
--- /dev/null
+++ b/sound/usb/endpoint.h
@@ -0,0 +1,11 @@
+#ifndef __USBAUDIO_ENDPOINT_H
+#define __USBAUDIO_ENDPOINT_H
+
+int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip,
+				  int iface_no);
+
+int snd_usb_add_audio_endpoint(struct snd_usb_audio *chip,
+			       int stream,
+			       struct audioformat *fp);
+
+#endif /* __USBAUDIO_ENDPOINT_H */
diff --git a/sound/usb/format.c b/sound/usb/format.c
new file mode 100644
index 00000000000..cbfe0c23dbd
--- /dev/null
+++ b/sound/usb/format.c
@@ -0,0 +1,445 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "quirks.h"
+#include "helper.h"
+#include "debug.h"
+
+/*
+ * parse the audio format type I descriptor
+ * and returns the corresponding pcm format
+ *
+ * @dev: usb device
+ * @fp: audioformat record
+ * @format: the format tag (wFormatTag)
+ * @fmt: the format type descriptor
+ */
+static int parse_audio_format_i_type(struct snd_usb_audio *chip,
+				     struct audioformat *fp,
+				     int format, void *_fmt,
+				     int protocol)
+{
+	int pcm_format, i;
+	int sample_width, sample_bytes;
+
+	switch (protocol) {
+	case UAC_VERSION_1: {
+		struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
+		sample_width = fmt->bBitResolution;
+		sample_bytes = fmt->bSubframeSize;
+		break;
+	}
+
+	case UAC_VERSION_2: {
+		struct uac_format_type_i_ext_descriptor *fmt = _fmt;
+		sample_width = fmt->bBitResolution;
+		sample_bytes = fmt->bSubslotSize;
+
+		/*
+		 * FIXME
+		 * USB audio class v2 devices specify a bitmap of possible
+		 * audio formats rather than one fix value. For now, we just
+		 * pick one of them and report that as the only possible
+		 * value for this setting.
+		 * The bit allocation map is in fact compatible to the
+		 * wFormatTag of the v1 AS streaming descriptors, which is why
+		 * we can simply map the matrix.
+		 */
+
+		for (i = 0; i < 5; i++)
+			if (format & (1UL << i)) {
+				format = i + 1;
+				break;
+			}
+
+		break;
+	}
+
+	default:
+		return -EINVAL;
+	}
+
+	/* FIXME: correct endianess and sign? */
+	pcm_format = -1;
+
+	switch (format) {
+	case UAC_FORMAT_TYPE_I_UNDEFINED: /* some devices don't define this correctly... */
+		snd_printdd(KERN_INFO "%d:%u:%d : format type 0 is detected, processed as PCM\n",
+			    chip->dev->devnum, fp->iface, fp->altsetting);
+		/* fall-through */
+	case UAC_FORMAT_TYPE_I_PCM:
+		if (sample_width > sample_bytes * 8) {
+			snd_printk(KERN_INFO "%d:%u:%d : sample bitwidth %d in over sample bytes %d\n",
+				   chip->dev->devnum, fp->iface, fp->altsetting,
+				   sample_width, sample_bytes);
+		}
+		/* check the format byte size */
+		switch (sample_bytes) {
+		case 1:
+			pcm_format = SNDRV_PCM_FORMAT_S8;
+			break;
+		case 2:
+			if (snd_usb_is_big_endian_format(chip, fp))
+				pcm_format = SNDRV_PCM_FORMAT_S16_BE; /* grrr, big endian!! */
+			else
+				pcm_format = SNDRV_PCM_FORMAT_S16_LE;
+			break;
+		case 3:
+			if (snd_usb_is_big_endian_format(chip, fp))
+				pcm_format = SNDRV_PCM_FORMAT_S24_3BE; /* grrr, big endian!! */
+			else
+				pcm_format = SNDRV_PCM_FORMAT_S24_3LE;
+			break;
+		case 4:
+			pcm_format = SNDRV_PCM_FORMAT_S32_LE;
+			break;
+		default:
+			snd_printk(KERN_INFO "%d:%u:%d : unsupported sample bitwidth %d in %d bytes\n",
+				   chip->dev->devnum, fp->iface, fp->altsetting,
+				   sample_width, sample_bytes);
+			break;
+		}
+		break;
+	case UAC_FORMAT_TYPE_I_PCM8:
+		pcm_format = SNDRV_PCM_FORMAT_U8;
+
+		/* Dallas DS4201 workaround: it advertises U8 format, but really
+		   supports S8. */
+		if (chip->usb_id == USB_ID(0x04fa, 0x4201))
+			pcm_format = SNDRV_PCM_FORMAT_S8;
+		break;
+	case UAC_FORMAT_TYPE_I_IEEE_FLOAT:
+		pcm_format = SNDRV_PCM_FORMAT_FLOAT_LE;
+		break;
+	case UAC_FORMAT_TYPE_I_ALAW:
+		pcm_format = SNDRV_PCM_FORMAT_A_LAW;
+		break;
+	case UAC_FORMAT_TYPE_I_MULAW:
+		pcm_format = SNDRV_PCM_FORMAT_MU_LAW;
+		break;
+	default:
+		snd_printk(KERN_INFO "%d:%u:%d : unsupported format type %d\n",
+			   chip->dev->devnum, fp->iface, fp->altsetting, format);
+		break;
+	}
+	return pcm_format;
+}
+
+
+/*
+ * parse the format descriptor and stores the possible sample rates
+ * on the audioformat table (audio class v1).
+ *
+ * @dev: usb device
+ * @fp: audioformat record
+ * @fmt: the format descriptor
+ * @offset: the start offset of descriptor pointing the rate type
+ *          (7 for type I and II, 8 for type II)
+ */
+static int parse_audio_format_rates_v1(struct snd_usb_audio *chip, struct audioformat *fp,
+				       unsigned char *fmt, int offset)
+{
+	int nr_rates = fmt[offset];
+
+	if (fmt[0] < offset + 1 + 3 * (nr_rates ? nr_rates : 2)) {
+		snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_FORMAT_TYPE desc\n",
+				   chip->dev->devnum, fp->iface, fp->altsetting);
+		return -1;
+	}
+
+	if (nr_rates) {
+		/*
+		 * build the rate table and bitmap flags
+		 */
+		int r, idx;
+
+		fp->rate_table = kmalloc(sizeof(int) * nr_rates, GFP_KERNEL);
+		if (fp->rate_table == NULL) {
+			snd_printk(KERN_ERR "cannot malloc\n");
+			return -1;
+		}
+
+		fp->nr_rates = 0;
+		fp->rate_min = fp->rate_max = 0;
+		for (r = 0, idx = offset + 1; r < nr_rates; r++, idx += 3) {
+			unsigned int rate = combine_triple(&fmt[idx]);
+			if (!rate)
+				continue;
+			/* C-Media CM6501 mislabels its 96 kHz altsetting */
+			if (rate == 48000 && nr_rates == 1 &&
+			    (chip->usb_id == USB_ID(0x0d8c, 0x0201) ||
+			     chip->usb_id == USB_ID(0x0d8c, 0x0102)) &&
+			    fp->altsetting == 5 && fp->maxpacksize == 392)
+				rate = 96000;
+			/* Creative VF0470 Live Cam reports 16 kHz instead of 8kHz */
+			if (rate == 16000 && chip->usb_id == USB_ID(0x041e, 0x4068))
+				rate = 8000;
+
+			fp->rate_table[fp->nr_rates] = rate;
+			if (!fp->rate_min || rate < fp->rate_min)
+				fp->rate_min = rate;
+			if (!fp->rate_max || rate > fp->rate_max)
+				fp->rate_max = rate;
+			fp->rates |= snd_pcm_rate_to_rate_bit(rate);
+			fp->nr_rates++;
+		}
+		if (!fp->nr_rates) {
+			hwc_debug("All rates were zero. Skipping format!\n");
+			return -1;
+		}
+	} else {
+		/* continuous rates */
+		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
+		fp->rate_min = combine_triple(&fmt[offset + 1]);
+		fp->rate_max = combine_triple(&fmt[offset + 4]);
+	}
+	return 0;
+}
+
+/*
+ * parse the format descriptor and stores the possible sample rates
+ * on the audioformat table (audio class v2).
+ */
+static int parse_audio_format_rates_v2(struct snd_usb_audio *chip,
+				       struct audioformat *fp,
+				       struct usb_host_interface *iface)
+{
+	struct usb_device *dev = chip->dev;
+	unsigned char tmp[2], *data;
+	int i, nr_rates, data_size, ret = 0;
+
+	/* get the number of sample rates first by only fetching 2 bytes */
+	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
+			      USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
+			      0x0100, chip->clock_id << 8, tmp, sizeof(tmp), 1000);
+
+	if (ret < 0) {
+		snd_printk(KERN_ERR "unable to retrieve number of sample rates\n");
+		goto err;
+	}
+
+	nr_rates = (tmp[1] << 8) | tmp[0];
+	data_size = 2 + 12 * nr_rates;
+	data = kzalloc(data_size, GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	/* now get the full information */
+	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
+			       USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
+			       0x0100, chip->clock_id << 8, data, data_size, 1000);
+
+	if (ret < 0) {
+		snd_printk(KERN_ERR "unable to retrieve sample rate range\n");
+		ret = -EINVAL;
+		goto err_free;
+	}
+
+	fp->rate_table = kmalloc(sizeof(int) * nr_rates, GFP_KERNEL);
+	if (!fp->rate_table) {
+		ret = -ENOMEM;
+		goto err_free;
+	}
+
+	fp->nr_rates = 0;
+	fp->rate_min = fp->rate_max = 0;
+
+	for (i = 0; i < nr_rates; i++) {
+		int rate = combine_quad(&data[2 + 12 * i]);
+
+		fp->rate_table[fp->nr_rates] = rate;
+		if (!fp->rate_min || rate < fp->rate_min)
+			fp->rate_min = rate;
+		if (!fp->rate_max || rate > fp->rate_max)
+			fp->rate_max = rate;
+		fp->rates |= snd_pcm_rate_to_rate_bit(rate);
+		fp->nr_rates++;
+	}
+
+err_free:
+	kfree(data);
+err:
+	return ret;
+}
+
+/*
+ * parse the format type I and III descriptors
+ */
+static int parse_audio_format_i(struct snd_usb_audio *chip,
+				struct audioformat *fp,
+				int format, void *_fmt,
+				struct usb_host_interface *iface)
+{
+	struct usb_interface_descriptor *altsd = get_iface_desc(iface);
+	struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
+	int protocol = altsd->bInterfaceProtocol;
+	int pcm_format, ret;
+
+	if (fmt->bFormatType == UAC_FORMAT_TYPE_III) {
+		/* FIXME: the format type is really IECxxx
+		 *        but we give normal PCM format to get the existing
+		 *        apps working...
+		 */
+		switch (chip->usb_id) {
+
+		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
+			if (chip->setup == 0x00 && 
+			    fp->altsetting == 6)
+				pcm_format = SNDRV_PCM_FORMAT_S16_BE;
+			else
+				pcm_format = SNDRV_PCM_FORMAT_S16_LE;
+			break;
+		default:
+			pcm_format = SNDRV_PCM_FORMAT_S16_LE;
+		}
+	} else {
+		pcm_format = parse_audio_format_i_type(chip, fp, format, fmt, protocol);
+		if (pcm_format < 0)
+			return -1;
+	}
+
+	fp->format = pcm_format;
+
+	/* gather possible sample rates */
+	/* audio class v1 reports possible sample rates as part of the
+	 * proprietary class specific descriptor.
+	 * audio class v2 uses class specific EP0 range requests for that.
+	 */
+	switch (protocol) {
+	case UAC_VERSION_1:
+		fp->channels = fmt->bNrChannels;
+		ret = parse_audio_format_rates_v1(chip, fp, _fmt, 7);
+		break;
+	case UAC_VERSION_2:
+		/* fp->channels is already set in this case */
+		ret = parse_audio_format_rates_v2(chip, fp, iface);
+		break;
+	}
+
+	if (fp->channels < 1) {
+		snd_printk(KERN_ERR "%d:%u:%d : invalid channels %d\n",
+			   chip->dev->devnum, fp->iface, fp->altsetting, fp->channels);
+		return -1;
+	}
+
+	return ret;
+}
+
+/*
+ * parse the format type II descriptor
+ */
+static int parse_audio_format_ii(struct snd_usb_audio *chip,
+				 struct audioformat *fp,
+				 int format, void *_fmt,
+				 struct usb_host_interface *iface)
+{
+	int brate, framesize, ret;
+	struct usb_interface_descriptor *altsd = get_iface_desc(iface);
+	int protocol = altsd->bInterfaceProtocol;
+
+	switch (format) {
+	case UAC_FORMAT_TYPE_II_AC3:
+		/* FIXME: there is no AC3 format defined yet */
+		// fp->format = SNDRV_PCM_FORMAT_AC3;
+		fp->format = SNDRV_PCM_FORMAT_U8; /* temporarily hack to receive byte streams */
+		break;
+	case UAC_FORMAT_TYPE_II_MPEG:
+		fp->format = SNDRV_PCM_FORMAT_MPEG;
+		break;
+	default:
+		snd_printd(KERN_INFO "%d:%u:%d : unknown format tag %#x is detected.  processed as MPEG.\n",
+			   chip->dev->devnum, fp->iface, fp->altsetting, format);
+		fp->format = SNDRV_PCM_FORMAT_MPEG;
+		break;
+	}
+
+	fp->channels = 1;
+
+	switch (protocol) {
+	case UAC_VERSION_1: {
+		struct uac_format_type_ii_discrete_descriptor *fmt = _fmt;
+		brate = le16_to_cpu(fmt->wMaxBitRate);
+		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
+		snd_printd(KERN_INFO "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
+		fp->frame_size = framesize;
+		ret = parse_audio_format_rates_v1(chip, fp, _fmt, 8); /* fmt[8..] sample rates */
+		break;
+	}
+	case UAC_VERSION_2: {
+		struct uac_format_type_ii_ext_descriptor *fmt = _fmt;
+		brate = le16_to_cpu(fmt->wMaxBitRate);
+		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
+		snd_printd(KERN_INFO "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
+		fp->frame_size = framesize;
+		ret = parse_audio_format_rates_v2(chip, fp, iface);
+		break;
+	}
+	}
+
+	return ret;
+}
+
+int snd_usb_parse_audio_format(struct snd_usb_audio *chip, struct audioformat *fp,
+		       int format, unsigned char *fmt, int stream,
+		       struct usb_host_interface *iface)
+{
+	int err;
+
+	switch (fmt[3]) {
+	case UAC_FORMAT_TYPE_I:
+	case UAC_FORMAT_TYPE_III:
+		err = parse_audio_format_i(chip, fp, format, fmt, iface);
+		break;
+	case UAC_FORMAT_TYPE_II:
+		err = parse_audio_format_ii(chip, fp, format, fmt, iface);
+		break;
+	default:
+		snd_printd(KERN_INFO "%d:%u:%d : format type %d is not supported yet\n",
+			   chip->dev->devnum, fp->iface, fp->altsetting, fmt[3]);
+		return -1;
+	}
+	fp->fmt_type = fmt[3];
+	if (err < 0)
+		return err;
+#if 1
+	/* FIXME: temporary hack for extigy/audigy 2 nx/zs */
+	/* extigy apparently supports sample rates other than 48k
+	 * but not in ordinary way.  so we enable only 48k atm.
+	 */
+	if (chip->usb_id == USB_ID(0x041e, 0x3000) ||
+	    chip->usb_id == USB_ID(0x041e, 0x3020) ||
+	    chip->usb_id == USB_ID(0x041e, 0x3061)) {
+		if (fmt[3] == UAC_FORMAT_TYPE_I &&
+		    fp->rates != SNDRV_PCM_RATE_48000 &&
+		    fp->rates != SNDRV_PCM_RATE_96000)
+			return -1;
+	}
+#endif
+	return 0;
+}
+
diff --git a/sound/usb/format.h b/sound/usb/format.h
new file mode 100644
index 00000000000..8298c4e8ddf
--- /dev/null
+++ b/sound/usb/format.h
@@ -0,0 +1,8 @@
+#ifndef __USBAUDIO_FORMAT_H
+#define __USBAUDIO_FORMAT_H
+
+int snd_usb_parse_audio_format(struct snd_usb_audio *chip, struct audioformat *fp,
+			       int format, unsigned char *fmt, int stream,
+			       struct usb_host_interface *iface);
+
+#endif /*  __USBAUDIO_FORMAT_H */
diff --git a/sound/usb/helper.c b/sound/usb/helper.c
new file mode 100644
index 00000000000..ba7dba4d5cf
--- /dev/null
+++ b/sound/usb/helper.c
@@ -0,0 +1,112 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/usb.h>
+
+#include "usbaudio.h"
+#include "helper.h"
+
+/*
+ * combine bytes and get an integer value
+ */
+unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size)
+{
+	switch (size) {
+	case 1:  return *bytes;
+	case 2:  return combine_word(bytes);
+	case 3:  return combine_triple(bytes);
+	case 4:  return combine_quad(bytes);
+	default: return 0;
+	}
+}
+
+/*
+ * parse descriptor buffer and return the pointer starting the given
+ * descriptor type.
+ */
+void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype)
+{
+	u8 *p, *end, *next;
+
+	p = descstart;
+	end = p + desclen;
+	for (; p < end;) {
+		if (p[0] < 2)
+			return NULL;
+		next = p + p[0];
+		if (next > end)
+			return NULL;
+		if (p[1] == dtype && (!after || (void *)p > after)) {
+			return p;
+		}
+		p = next;
+	}
+	return NULL;
+}
+
+/*
+ * find a class-specified interface descriptor with the given subtype.
+ */
+void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype)
+{
+	unsigned char *p = after;
+
+	while ((p = snd_usb_find_desc(buffer, buflen, p,
+				      USB_DT_CS_INTERFACE)) != NULL) {
+		if (p[0] >= 3 && p[2] == dsubtype)
+			return p;
+	}
+	return NULL;
+}
+
+/*
+ * Wrapper for usb_control_msg().
+ * Allocates a temp buffer to prevent dmaing from/to the stack.
+ */
+int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
+		    __u8 requesttype, __u16 value, __u16 index, void *data,
+		    __u16 size, int timeout)
+{
+	int err;
+	void *buf = NULL;
+
+	if (size > 0) {
+		buf = kmemdup(data, size, GFP_KERNEL);
+		if (!buf)
+			return -ENOMEM;
+	}
+	err = usb_control_msg(dev, pipe, request, requesttype,
+			      value, index, buf, size, timeout);
+	if (size > 0) {
+		memcpy(data, buf, size);
+		kfree(buf);
+	}
+	return err;
+}
+
+unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
+					 struct usb_host_interface *alts)
+{
+	if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH &&
+	    get_endpoint(alts, 0)->bInterval >= 1 &&
+	    get_endpoint(alts, 0)->bInterval <= 4)
+		return get_endpoint(alts, 0)->bInterval - 1;
+	else
+		return 0;
+}
+
diff --git a/sound/usb/helper.h b/sound/usb/helper.h
new file mode 100644
index 00000000000..a6b0e51b3a9
--- /dev/null
+++ b/sound/usb/helper.h
@@ -0,0 +1,32 @@
+#ifndef __USBAUDIO_HELPER_H
+#define __USBAUDIO_HELPER_H
+
+unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size);
+
+void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype);
+void *snd_usb_find_csint_desc(void *descstart, int desclen, void *after, u8 dsubtype);
+
+int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe,
+		    __u8 request, __u8 requesttype, __u16 value, __u16 index,
+		    void *data, __u16 size, int timeout);
+
+unsigned char snd_usb_parse_datainterval(struct snd_usb_audio *chip,
+					 struct usb_host_interface *alts);
+
+/*
+ * retrieve usb_interface descriptor from the host interface
+ * (conditional for compatibility with the older API)
+ */
+#ifndef get_iface_desc
+#define get_iface_desc(iface)	(&(iface)->desc)
+#define get_endpoint(alt,ep)	(&(alt)->endpoint[ep].desc)
+#define get_ep_desc(ep)		(&(ep)->desc)
+#define get_cfg_desc(cfg)	(&(cfg)->desc)
+#endif
+
+#ifndef snd_usb_get_speed
+#define snd_usb_get_speed(dev) ((dev)->speed)
+#endif
+
+
+#endif /* __USBAUDIO_HELPER_H */
diff --git a/sound/usb/usbmidi.c b/sound/usb/midi.c
index 5915a04cdb9..c6ee4a18e51 100644
--- a/sound/usb/usbmidi.c
+++ b/sound/usb/midi.c
@@ -53,8 +53,8 @@
 #include <sound/rawmidi.h>
 #include <sound/asequencer.h>
 #include "usbaudio.h"
-#include "usbmidi.h"
-
+#include "midi.h"
+#include "helper.h"
 
 /*
  * define this to log all USB packets
diff --git a/sound/usb/usbmidi.h b/sound/usb/midi.h
index 2089ec987c6..2089ec987c6 100644
--- a/sound/usb/usbmidi.h
+++ b/sound/usb/midi.h
diff --git a/sound/usb/misc/ua101.c b/sound/usb/misc/ua101.c
index b4a4cb46a17..796d8b25ee8 100644
--- a/sound/usb/misc/ua101.c
+++ b/sound/usb/misc/ua101.c
@@ -24,7 +24,7 @@
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include "../usbaudio.h"
-#include "../usbmidi.h"
+#include "../midi.h"
 
 MODULE_DESCRIPTION("Edirol UA-101/1000 driver");
 MODULE_AUTHOR("Clemens Ladisch <clemens@ladisch.de>");
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
new file mode 100644
index 00000000000..87863ccf906
--- /dev/null
+++ b/sound/usb/pcm.c
@@ -0,0 +1,845 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "quirks.h"
+#include "debug.h"
+#include "urb.h"
+#include "helper.h"
+#include "pcm.h"
+
+/*
+ * return the current pcm pointer.  just based on the hwptr_done value.
+ */
+static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_usb_substream *subs;
+	unsigned int hwptr_done;
+
+	subs = (struct snd_usb_substream *)substream->runtime->private_data;
+	spin_lock(&subs->lock);
+	hwptr_done = subs->hwptr_done;
+	spin_unlock(&subs->lock);
+	return hwptr_done / (substream->runtime->frame_bits >> 3);
+}
+
+/*
+ * find a matching audio format
+ */
+static struct audioformat *find_format(struct snd_usb_substream *subs, unsigned int format,
+				       unsigned int rate, unsigned int channels)
+{
+	struct list_head *p;
+	struct audioformat *found = NULL;
+	int cur_attr = 0, attr;
+
+	list_for_each(p, &subs->fmt_list) {
+		struct audioformat *fp;
+		fp = list_entry(p, struct audioformat, list);
+		if (fp->format != format || fp->channels != channels)
+			continue;
+		if (rate < fp->rate_min || rate > fp->rate_max)
+			continue;
+		if (! (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
+			unsigned int i;
+			for (i = 0; i < fp->nr_rates; i++)
+				if (fp->rate_table[i] == rate)
+					break;
+			if (i >= fp->nr_rates)
+				continue;
+		}
+		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
+		if (! found) {
+			found = fp;
+			cur_attr = attr;
+			continue;
+		}
+		/* avoid async out and adaptive in if the other method
+		 * supports the same format.
+		 * this is a workaround for the case like
+		 * M-audio audiophile USB.
+		 */
+		if (attr != cur_attr) {
+			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
+			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
+			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
+			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
+				continue;
+			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
+			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
+			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
+			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
+				found = fp;
+				cur_attr = attr;
+				continue;
+			}
+		}
+		/* find the format with the largest max. packet size */
+		if (fp->maxpacksize > found->maxpacksize) {
+			found = fp;
+			cur_attr = attr;
+		}
+	}
+	return found;
+}
+
+
+/*
+ * initialize the picth control and sample rate
+ */
+int snd_usb_init_pitch(struct usb_device *dev, int iface,
+		       struct usb_host_interface *alts,
+		       struct audioformat *fmt)
+{
+	unsigned int ep;
+	unsigned char data[1];
+	int err;
+
+	ep = get_endpoint(alts, 0)->bEndpointAddress;
+	/* if endpoint has pitch control, enable it */
+	if (fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL) {
+		data[0] = 1;
+		if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
+					   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
+					   UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep, data, 1, 1000)) < 0) {
+			snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH\n",
+				   dev->devnum, iface, ep);
+			return err;
+		}
+	}
+	return 0;
+}
+
+int snd_usb_init_sample_rate(struct usb_device *dev, int iface,
+			     struct usb_host_interface *alts,
+			     struct audioformat *fmt, int rate)
+{
+	unsigned int ep;
+	unsigned char data[3];
+	int err;
+
+	ep = get_endpoint(alts, 0)->bEndpointAddress;
+	/* if endpoint has sampling rate control, set it */
+	if (fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE) {
+		int crate;
+		data[0] = rate;
+		data[1] = rate >> 8;
+		data[2] = rate >> 16;
+		if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
+					   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
+					   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, data, 3, 1000)) < 0) {
+			snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
+				   dev->devnum, iface, fmt->altsetting, rate, ep);
+			return err;
+		}
+		if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
+					   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_IN,
+					   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, data, 3, 1000)) < 0) {
+			snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
+				   dev->devnum, iface, fmt->altsetting, ep);
+			return 0; /* some devices don't support reading */
+		}
+		crate = data[0] | (data[1] << 8) | (data[2] << 16);
+		if (crate != rate) {
+			snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
+			// runtime->rate = crate;
+		}
+	}
+	return 0;
+}
+
+/*
+ * find a matching format and set up the interface
+ */
+static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
+{
+	struct usb_device *dev = subs->dev;
+	struct usb_host_interface *alts;
+	struct usb_interface_descriptor *altsd;
+	struct usb_interface *iface;
+	unsigned int ep, attr;
+	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
+	int err;
+
+	iface = usb_ifnum_to_if(dev, fmt->iface);
+	if (WARN_ON(!iface))
+		return -EINVAL;
+	alts = &iface->altsetting[fmt->altset_idx];
+	altsd = get_iface_desc(alts);
+	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
+		return -EINVAL;
+
+	if (fmt == subs->cur_audiofmt)
+		return 0;
+
+	/* close the old interface */
+	if (subs->interface >= 0 && subs->interface != fmt->iface) {
+		if (usb_set_interface(subs->dev, subs->interface, 0) < 0) {
+			snd_printk(KERN_ERR "%d:%d:%d: return to setting 0 failed\n",
+				dev->devnum, fmt->iface, fmt->altsetting);
+			return -EIO;
+		}
+		subs->interface = -1;
+		subs->format = 0;
+	}
+
+	/* set interface */
+	if (subs->interface != fmt->iface || subs->format != fmt->altset_idx) {
+		if (usb_set_interface(dev, fmt->iface, fmt->altsetting) < 0) {
+			snd_printk(KERN_ERR "%d:%d:%d: usb_set_interface failed\n",
+				   dev->devnum, fmt->iface, fmt->altsetting);
+			return -EIO;
+		}
+		snd_printdd(KERN_INFO "setting usb interface %d:%d\n", fmt->iface, fmt->altsetting);
+		subs->interface = fmt->iface;
+		subs->format = fmt->altset_idx;
+	}
+
+	/* create a data pipe */
+	ep = fmt->endpoint & USB_ENDPOINT_NUMBER_MASK;
+	if (is_playback)
+		subs->datapipe = usb_sndisocpipe(dev, ep);
+	else
+		subs->datapipe = usb_rcvisocpipe(dev, ep);
+	subs->datainterval = fmt->datainterval;
+	subs->syncpipe = subs->syncinterval = 0;
+	subs->maxpacksize = fmt->maxpacksize;
+	subs->fill_max = 0;
+
+	/* we need a sync pipe in async OUT or adaptive IN mode */
+	/* check the number of EP, since some devices have broken
+	 * descriptors which fool us.  if it has only one EP,
+	 * assume it as adaptive-out or sync-in.
+	 */
+	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
+	if (((is_playback && attr == USB_ENDPOINT_SYNC_ASYNC) ||
+	     (! is_playback && attr == USB_ENDPOINT_SYNC_ADAPTIVE)) &&
+	    altsd->bNumEndpoints >= 2) {
+		/* check sync-pipe endpoint */
+		/* ... and check descriptor size before accessing bSynchAddress
+		   because there is a version of the SB Audigy 2 NX firmware lacking
+		   the audio fields in the endpoint descriptors */
+		if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != 0x01 ||
+		    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
+		     get_endpoint(alts, 1)->bSynchAddress != 0)) {
+			snd_printk(KERN_ERR "%d:%d:%d : invalid synch pipe\n",
+				   dev->devnum, fmt->iface, fmt->altsetting);
+			return -EINVAL;
+		}
+		ep = get_endpoint(alts, 1)->bEndpointAddress;
+		if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
+		    (( is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
+		     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
+			snd_printk(KERN_ERR "%d:%d:%d : invalid synch pipe\n",
+				   dev->devnum, fmt->iface, fmt->altsetting);
+			return -EINVAL;
+		}
+		ep &= USB_ENDPOINT_NUMBER_MASK;
+		if (is_playback)
+			subs->syncpipe = usb_rcvisocpipe(dev, ep);
+		else
+			subs->syncpipe = usb_sndisocpipe(dev, ep);
+		if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
+		    get_endpoint(alts, 1)->bRefresh >= 1 &&
+		    get_endpoint(alts, 1)->bRefresh <= 9)
+			subs->syncinterval = get_endpoint(alts, 1)->bRefresh;
+		else if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
+			subs->syncinterval = 1;
+		else if (get_endpoint(alts, 1)->bInterval >= 1 &&
+			 get_endpoint(alts, 1)->bInterval <= 16)
+			subs->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
+		else
+			subs->syncinterval = 3;
+	}
+
+	/* always fill max packet size */
+	if (fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX)
+		subs->fill_max = 1;
+
+	if ((err = snd_usb_init_pitch(dev, subs->interface, alts, fmt)) < 0)
+		return err;
+
+	subs->cur_audiofmt = fmt;
+
+	snd_usb_set_format_quirk(subs, fmt);
+
+#if 0
+	printk(KERN_DEBUG
+	       "setting done: format = %d, rate = %d..%d, channels = %d\n",
+	       fmt->format, fmt->rate_min, fmt->rate_max, fmt->channels);
+	printk(KERN_DEBUG
+	       "  datapipe = 0x%0x, syncpipe = 0x%0x\n",
+	       subs->datapipe, subs->syncpipe);
+#endif
+
+	return 0;
+}
+
+/*
+ * hw_params callback
+ *
+ * allocate a buffer and set the given audio format.
+ *
+ * so far we use a physically linear buffer although packetize transfer
+ * doesn't need a continuous area.
+ * if sg buffer is supported on the later version of alsa, we'll follow
+ * that.
+ */
+static int snd_usb_hw_params(struct snd_pcm_substream *substream,
+			     struct snd_pcm_hw_params *hw_params)
+{
+	struct snd_usb_substream *subs = substream->runtime->private_data;
+	struct audioformat *fmt;
+	unsigned int channels, rate, format;
+	int ret, changed;
+
+	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
+					       params_buffer_bytes(hw_params));
+	if (ret < 0)
+		return ret;
+
+	format = params_format(hw_params);
+	rate = params_rate(hw_params);
+	channels = params_channels(hw_params);
+	fmt = find_format(subs, format, rate, channels);
+	if (!fmt) {
+		snd_printd(KERN_DEBUG "cannot set format: format = %#x, rate = %d, channels = %d\n",
+			   format, rate, channels);
+		return -EINVAL;
+	}
+
+	changed = subs->cur_audiofmt != fmt ||
+		subs->period_bytes != params_period_bytes(hw_params) ||
+		subs->cur_rate != rate;
+	if ((ret = set_format(subs, fmt)) < 0)
+		return ret;
+
+	if (subs->cur_rate != rate) {
+		struct usb_host_interface *alts;
+		struct usb_interface *iface;
+		iface = usb_ifnum_to_if(subs->dev, fmt->iface);
+		alts = &iface->altsetting[fmt->altset_idx];
+		ret = snd_usb_init_sample_rate(subs->dev, subs->interface, alts, fmt, rate);
+		if (ret < 0)
+			return ret;
+		subs->cur_rate = rate;
+	}
+
+	if (changed) {
+		/* format changed */
+		snd_usb_release_substream_urbs(subs, 0);
+		/* influenced: period_bytes, channels, rate, format, */
+		ret = snd_usb_init_substream_urbs(subs, params_period_bytes(hw_params),
+						  params_rate(hw_params),
+						  snd_pcm_format_physical_width(params_format(hw_params)) *
+							params_channels(hw_params));
+	}
+
+	return ret;
+}
+
+/*
+ * hw_free callback
+ *
+ * reset the audio format and release the buffer
+ */
+static int snd_usb_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_usb_substream *subs = substream->runtime->private_data;
+
+	subs->cur_audiofmt = NULL;
+	subs->cur_rate = 0;
+	subs->period_bytes = 0;
+	if (!subs->stream->chip->shutdown)
+		snd_usb_release_substream_urbs(subs, 0);
+	return snd_pcm_lib_free_vmalloc_buffer(substream);
+}
+
+/*
+ * prepare callback
+ *
+ * only a few subtle things...
+ */
+static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usb_substream *subs = runtime->private_data;
+
+	if (! subs->cur_audiofmt) {
+		snd_printk(KERN_ERR "usbaudio: no format is specified!\n");
+		return -ENXIO;
+	}
+
+	/* some unit conversions in runtime */
+	subs->maxframesize = bytes_to_frames(runtime, subs->maxpacksize);
+	subs->curframesize = bytes_to_frames(runtime, subs->curpacksize);
+
+	/* reset the pointer */
+	subs->hwptr_done = 0;
+	subs->transfer_done = 0;
+	subs->phase = 0;
+	runtime->delay = 0;
+
+	return snd_usb_substream_prepare(subs, runtime);
+}
+
+static struct snd_pcm_hardware snd_usb_hardware =
+{
+	.info =			SNDRV_PCM_INFO_MMAP |
+				SNDRV_PCM_INFO_MMAP_VALID |
+				SNDRV_PCM_INFO_BATCH |
+				SNDRV_PCM_INFO_INTERLEAVED |
+				SNDRV_PCM_INFO_BLOCK_TRANSFER |
+				SNDRV_PCM_INFO_PAUSE,
+	.buffer_bytes_max =	1024 * 1024,
+	.period_bytes_min =	64,
+	.period_bytes_max =	512 * 1024,
+	.periods_min =		2,
+	.periods_max =		1024,
+};
+
+static int hw_check_valid_format(struct snd_usb_substream *subs,
+				 struct snd_pcm_hw_params *params,
+				 struct audioformat *fp)
+{
+	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
+	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
+	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
+	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
+	unsigned int ptime;
+
+	/* check the format */
+	if (!snd_mask_test(fmts, fp->format)) {
+		hwc_debug("   > check: no supported format %d\n", fp->format);
+		return 0;
+	}
+	/* check the channels */
+	if (fp->channels < ct->min || fp->channels > ct->max) {
+		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
+		return 0;
+	}
+	/* check the rate is within the range */
+	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
+		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
+		return 0;
+	}
+	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
+		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
+		return 0;
+	}
+	/* check whether the period time is >= the data packet interval */
+	if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH) {
+		ptime = 125 * (1 << fp->datainterval);
+		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
+			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
+			return 0;
+		}
+	}
+	return 1;
+}
+
+static int hw_rule_rate(struct snd_pcm_hw_params *params,
+			struct snd_pcm_hw_rule *rule)
+{
+	struct snd_usb_substream *subs = rule->private;
+	struct list_head *p;
+	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
+	unsigned int rmin, rmax;
+	int changed;
+
+	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
+	changed = 0;
+	rmin = rmax = 0;
+	list_for_each(p, &subs->fmt_list) {
+		struct audioformat *fp;
+		fp = list_entry(p, struct audioformat, list);
+		if (!hw_check_valid_format(subs, params, fp))
+			continue;
+		if (changed++) {
+			if (rmin > fp->rate_min)
+				rmin = fp->rate_min;
+			if (rmax < fp->rate_max)
+				rmax = fp->rate_max;
+		} else {
+			rmin = fp->rate_min;
+			rmax = fp->rate_max;
+		}
+	}
+
+	if (!changed) {
+		hwc_debug("  --> get empty\n");
+		it->empty = 1;
+		return -EINVAL;
+	}
+
+	changed = 0;
+	if (it->min < rmin) {
+		it->min = rmin;
+		it->openmin = 0;
+		changed = 1;
+	}
+	if (it->max > rmax) {
+		it->max = rmax;
+		it->openmax = 0;
+		changed = 1;
+	}
+	if (snd_interval_checkempty(it)) {
+		it->empty = 1;
+		return -EINVAL;
+	}
+	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
+	return changed;
+}
+
+
+static int hw_rule_channels(struct snd_pcm_hw_params *params,
+			    struct snd_pcm_hw_rule *rule)
+{
+	struct snd_usb_substream *subs = rule->private;
+	struct list_head *p;
+	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
+	unsigned int rmin, rmax;
+	int changed;
+
+	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
+	changed = 0;
+	rmin = rmax = 0;
+	list_for_each(p, &subs->fmt_list) {
+		struct audioformat *fp;
+		fp = list_entry(p, struct audioformat, list);
+		if (!hw_check_valid_format(subs, params, fp))
+			continue;
+		if (changed++) {
+			if (rmin > fp->channels)
+				rmin = fp->channels;
+			if (rmax < fp->channels)
+				rmax = fp->channels;
+		} else {
+			rmin = fp->channels;
+			rmax = fp->channels;
+		}
+	}
+
+	if (!changed) {
+		hwc_debug("  --> get empty\n");
+		it->empty = 1;
+		return -EINVAL;
+	}
+
+	changed = 0;
+	if (it->min < rmin) {
+		it->min = rmin;
+		it->openmin = 0;
+		changed = 1;
+	}
+	if (it->max > rmax) {
+		it->max = rmax;
+		it->openmax = 0;
+		changed = 1;
+	}
+	if (snd_interval_checkempty(it)) {
+		it->empty = 1;
+		return -EINVAL;
+	}
+	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
+	return changed;
+}
+
+static int hw_rule_format(struct snd_pcm_hw_params *params,
+			  struct snd_pcm_hw_rule *rule)
+{
+	struct snd_usb_substream *subs = rule->private;
+	struct list_head *p;
+	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
+	u64 fbits;
+	u32 oldbits[2];
+	int changed;
+
+	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
+	fbits = 0;
+	list_for_each(p, &subs->fmt_list) {
+		struct audioformat *fp;
+		fp = list_entry(p, struct audioformat, list);
+		if (!hw_check_valid_format(subs, params, fp))
+			continue;
+		fbits |= (1ULL << fp->format);
+	}
+
+	oldbits[0] = fmt->bits[0];
+	oldbits[1] = fmt->bits[1];
+	fmt->bits[0] &= (u32)fbits;
+	fmt->bits[1] &= (u32)(fbits >> 32);
+	if (!fmt->bits[0] && !fmt->bits[1]) {
+		hwc_debug("  --> get empty\n");
+		return -EINVAL;
+	}
+	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
+	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
+	return changed;
+}
+
+static int hw_rule_period_time(struct snd_pcm_hw_params *params,
+			       struct snd_pcm_hw_rule *rule)
+{
+	struct snd_usb_substream *subs = rule->private;
+	struct audioformat *fp;
+	struct snd_interval *it;
+	unsigned char min_datainterval;
+	unsigned int pmin;
+	int changed;
+
+	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
+	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
+	min_datainterval = 0xff;
+	list_for_each_entry(fp, &subs->fmt_list, list) {
+		if (!hw_check_valid_format(subs, params, fp))
+			continue;
+		min_datainterval = min(min_datainterval, fp->datainterval);
+	}
+	if (min_datainterval == 0xff) {
+		hwc_debug("  --> get emtpy\n");
+		it->empty = 1;
+		return -EINVAL;
+	}
+	pmin = 125 * (1 << min_datainterval);
+	changed = 0;
+	if (it->min < pmin) {
+		it->min = pmin;
+		it->openmin = 0;
+		changed = 1;
+	}
+	if (snd_interval_checkempty(it)) {
+		it->empty = 1;
+		return -EINVAL;
+	}
+	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
+	return changed;
+}
+
+/*
+ *  If the device supports unusual bit rates, does the request meet these?
+ */
+static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
+				  struct snd_usb_substream *subs)
+{
+	struct audioformat *fp;
+	int count = 0, needs_knot = 0;
+	int err;
+
+	list_for_each_entry(fp, &subs->fmt_list, list) {
+		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
+			return 0;
+		count += fp->nr_rates;
+		if (fp->rates & SNDRV_PCM_RATE_KNOT)
+			needs_knot = 1;
+	}
+	if (!needs_knot)
+		return 0;
+
+	subs->rate_list.count = count;
+	subs->rate_list.list = kmalloc(sizeof(int) * count, GFP_KERNEL);
+	subs->rate_list.mask = 0;
+	count = 0;
+	list_for_each_entry(fp, &subs->fmt_list, list) {
+		int i;
+		for (i = 0; i < fp->nr_rates; i++)
+			subs->rate_list.list[count++] = fp->rate_table[i];
+	}
+	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+					 &subs->rate_list);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+
+/*
+ * set up the runtime hardware information.
+ */
+
+static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
+{
+	struct list_head *p;
+	unsigned int pt, ptmin;
+	int param_period_time_if_needed;
+	int err;
+
+	runtime->hw.formats = subs->formats;
+
+	runtime->hw.rate_min = 0x7fffffff;
+	runtime->hw.rate_max = 0;
+	runtime->hw.channels_min = 256;
+	runtime->hw.channels_max = 0;
+	runtime->hw.rates = 0;
+	ptmin = UINT_MAX;
+	/* check min/max rates and channels */
+	list_for_each(p, &subs->fmt_list) {
+		struct audioformat *fp;
+		fp = list_entry(p, struct audioformat, list);
+		runtime->hw.rates |= fp->rates;
+		if (runtime->hw.rate_min > fp->rate_min)
+			runtime->hw.rate_min = fp->rate_min;
+		if (runtime->hw.rate_max < fp->rate_max)
+			runtime->hw.rate_max = fp->rate_max;
+		if (runtime->hw.channels_min > fp->channels)
+			runtime->hw.channels_min = fp->channels;
+		if (runtime->hw.channels_max < fp->channels)
+			runtime->hw.channels_max = fp->channels;
+		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
+			/* FIXME: there might be more than one audio formats... */
+			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
+				fp->frame_size;
+		}
+		pt = 125 * (1 << fp->datainterval);
+		ptmin = min(ptmin, pt);
+	}
+
+	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
+	if (snd_usb_get_speed(subs->dev) != USB_SPEED_HIGH)
+		/* full speed devices have fixed data packet interval */
+		ptmin = 1000;
+	if (ptmin == 1000)
+		/* if period time doesn't go below 1 ms, no rules needed */
+		param_period_time_if_needed = -1;
+	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
+				     ptmin, UINT_MAX);
+
+	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+				       hw_rule_rate, subs,
+				       SNDRV_PCM_HW_PARAM_FORMAT,
+				       SNDRV_PCM_HW_PARAM_CHANNELS,
+				       param_period_time_if_needed,
+				       -1)) < 0)
+		return err;
+	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
+				       hw_rule_channels, subs,
+				       SNDRV_PCM_HW_PARAM_FORMAT,
+				       SNDRV_PCM_HW_PARAM_RATE,
+				       param_period_time_if_needed,
+				       -1)) < 0)
+		return err;
+	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
+				       hw_rule_format, subs,
+				       SNDRV_PCM_HW_PARAM_RATE,
+				       SNDRV_PCM_HW_PARAM_CHANNELS,
+				       param_period_time_if_needed,
+				       -1)) < 0)
+		return err;
+	if (param_period_time_if_needed >= 0) {
+		err = snd_pcm_hw_rule_add(runtime, 0,
+					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
+					  hw_rule_period_time, subs,
+					  SNDRV_PCM_HW_PARAM_FORMAT,
+					  SNDRV_PCM_HW_PARAM_CHANNELS,
+					  SNDRV_PCM_HW_PARAM_RATE,
+					  -1);
+		if (err < 0)
+			return err;
+	}
+	if ((err = snd_usb_pcm_check_knot(runtime, subs)) < 0)
+		return err;
+	return 0;
+}
+
+static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
+{
+	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_usb_substream *subs = &as->substream[direction];
+
+	subs->interface = -1;
+	subs->format = 0;
+	runtime->hw = snd_usb_hardware;
+	runtime->private_data = subs;
+	subs->pcm_substream = substream;
+	return setup_hw_info(runtime, subs);
+}
+
+static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
+{
+	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
+	struct snd_usb_substream *subs = &as->substream[direction];
+
+	if (!as->chip->shutdown && subs->interface >= 0) {
+		usb_set_interface(subs->dev, subs->interface, 0);
+		subs->interface = -1;
+	}
+	subs->pcm_substream = NULL;
+	return 0;
+}
+
+static int snd_usb_playback_open(struct snd_pcm_substream *substream)
+{
+	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_PLAYBACK);
+}
+
+static int snd_usb_playback_close(struct snd_pcm_substream *substream)
+{
+	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_PLAYBACK);
+}
+
+static int snd_usb_capture_open(struct snd_pcm_substream *substream)
+{
+	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_CAPTURE);
+}
+
+static int snd_usb_capture_close(struct snd_pcm_substream *substream)
+{
+	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_CAPTURE);
+}
+
+static struct snd_pcm_ops snd_usb_playback_ops = {
+	.open =		snd_usb_playback_open,
+	.close =	snd_usb_playback_close,
+	.ioctl =	snd_pcm_lib_ioctl,
+	.hw_params =	snd_usb_hw_params,
+	.hw_free =	snd_usb_hw_free,
+	.prepare =	snd_usb_pcm_prepare,
+	.trigger =	snd_usb_substream_playback_trigger,
+	.pointer =	snd_usb_pcm_pointer,
+	.page =		snd_pcm_lib_get_vmalloc_page,
+	.mmap =		snd_pcm_lib_mmap_vmalloc,
+};
+
+static struct snd_pcm_ops snd_usb_capture_ops = {
+	.open =		snd_usb_capture_open,
+	.close =	snd_usb_capture_close,
+	.ioctl =	snd_pcm_lib_ioctl,
+	.hw_params =	snd_usb_hw_params,
+	.hw_free =	snd_usb_hw_free,
+	.prepare =	snd_usb_pcm_prepare,
+	.trigger =	snd_usb_substream_capture_trigger,
+	.pointer =	snd_usb_pcm_pointer,
+	.page =		snd_pcm_lib_get_vmalloc_page,
+	.mmap =		snd_pcm_lib_mmap_vmalloc,
+};
+
+void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream)
+{
+	snd_pcm_set_ops(pcm, stream,
+			stream == SNDRV_PCM_STREAM_PLAYBACK ?
+			&snd_usb_playback_ops : &snd_usb_capture_ops);
+}
diff --git a/sound/usb/pcm.h b/sound/usb/pcm.h
new file mode 100644
index 00000000000..85856016e05
--- /dev/null
+++ b/sound/usb/pcm.h
@@ -0,0 +1,14 @@
+#ifndef __USBAUDIO_PCM_H
+#define __USBAUDIO_PCM_H
+
+void snd_usb_set_pcm_ops(struct snd_pcm *pcm, int stream);
+
+int snd_usb_init_pitch(struct usb_device *dev, int iface,
+		       struct usb_host_interface *alts,
+		       struct audioformat *fmt);
+
+int snd_usb_init_sample_rate(struct usb_device *dev, int iface,
+			     struct usb_host_interface *alts,
+			     struct audioformat *fmt, int rate);
+
+#endif /* __USBAUDIO_PCM_H */
diff --git a/sound/usb/proc.c b/sound/usb/proc.c
new file mode 100644
index 00000000000..be3065ea1af
--- /dev/null
+++ b/sound/usb/proc.c
@@ -0,0 +1,163 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/usb.h>
+
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/pcm.h>
+
+#include "usbaudio.h"
+#include "helper.h"
+#include "card.h"
+#include "proc.h"
+
+/* convert our full speed USB rate into sampling rate in Hz */
+static inline unsigned get_full_speed_hz(unsigned int usb_rate)
+{
+	return (usb_rate * 125 + (1 << 12)) >> 13;
+}
+
+/* convert our high speed USB rate into sampling rate in Hz */
+static inline unsigned get_high_speed_hz(unsigned int usb_rate)
+{
+	return (usb_rate * 125 + (1 << 9)) >> 10;
+}
+
+/*
+ * common proc files to show the usb device info
+ */
+static void proc_audio_usbbus_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
+{
+	struct snd_usb_audio *chip = entry->private_data;
+	if (!chip->shutdown)
+		snd_iprintf(buffer, "%03d/%03d\n", chip->dev->bus->busnum, chip->dev->devnum);
+}
+
+static void proc_audio_usbid_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
+{
+	struct snd_usb_audio *chip = entry->private_data;
+	if (!chip->shutdown)
+		snd_iprintf(buffer, "%04x:%04x\n", 
+			    USB_ID_VENDOR(chip->usb_id),
+			    USB_ID_PRODUCT(chip->usb_id));
+}
+
+void snd_usb_audio_create_proc(struct snd_usb_audio *chip)
+{
+	struct snd_info_entry *entry;
+	if (!snd_card_proc_new(chip->card, "usbbus", &entry))
+		snd_info_set_text_ops(entry, chip, proc_audio_usbbus_read);
+	if (!snd_card_proc_new(chip->card, "usbid", &entry))
+		snd_info_set_text_ops(entry, chip, proc_audio_usbid_read);
+}
+
+/*
+ * proc interface for list the supported pcm formats
+ */
+static void proc_dump_substream_formats(struct snd_usb_substream *subs, struct snd_info_buffer *buffer)
+{
+	struct list_head *p;
+	static char *sync_types[4] = {
+		"NONE", "ASYNC", "ADAPTIVE", "SYNC"
+	};
+
+	list_for_each(p, &subs->fmt_list) {
+		struct audioformat *fp;
+		fp = list_entry(p, struct audioformat, list);
+		snd_iprintf(buffer, "  Interface %d\n", fp->iface);
+		snd_iprintf(buffer, "    Altset %d\n", fp->altsetting);
+		snd_iprintf(buffer, "    Format: %s\n",
+			    snd_pcm_format_name(fp->format));
+		snd_iprintf(buffer, "    Channels: %d\n", fp->channels);
+		snd_iprintf(buffer, "    Endpoint: %d %s (%s)\n",
+			    fp->endpoint & USB_ENDPOINT_NUMBER_MASK,
+			    fp->endpoint & USB_DIR_IN ? "IN" : "OUT",
+			    sync_types[(fp->ep_attr & USB_ENDPOINT_SYNCTYPE) >> 2]);
+		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS) {
+			snd_iprintf(buffer, "    Rates: %d - %d (continuous)\n",
+				    fp->rate_min, fp->rate_max);
+		} else {
+			unsigned int i;
+			snd_iprintf(buffer, "    Rates: ");
+			for (i = 0; i < fp->nr_rates; i++) {
+				if (i > 0)
+					snd_iprintf(buffer, ", ");
+				snd_iprintf(buffer, "%d", fp->rate_table[i]);
+			}
+			snd_iprintf(buffer, "\n");
+		}
+		if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH)
+			snd_iprintf(buffer, "    Data packet interval: %d us\n",
+				    125 * (1 << fp->datainterval));
+		// snd_iprintf(buffer, "    Max Packet Size = %d\n", fp->maxpacksize);
+		// snd_iprintf(buffer, "    EP Attribute = %#x\n", fp->attributes);
+	}
+}
+
+static void proc_dump_substream_status(struct snd_usb_substream *subs, struct snd_info_buffer *buffer)
+{
+	if (subs->running) {
+		unsigned int i;
+		snd_iprintf(buffer, "  Status: Running\n");
+		snd_iprintf(buffer, "    Interface = %d\n", subs->interface);
+		snd_iprintf(buffer, "    Altset = %d\n", subs->format);
+		snd_iprintf(buffer, "    URBs = %d [ ", subs->nurbs);
+		for (i = 0; i < subs->nurbs; i++)
+			snd_iprintf(buffer, "%d ", subs->dataurb[i].packets);
+		snd_iprintf(buffer, "]\n");
+		snd_iprintf(buffer, "    Packet Size = %d\n", subs->curpacksize);
+		snd_iprintf(buffer, "    Momentary freq = %u Hz (%#x.%04x)\n",
+			    snd_usb_get_speed(subs->dev) == USB_SPEED_FULL
+			    ? get_full_speed_hz(subs->freqm)
+			    : get_high_speed_hz(subs->freqm),
+			    subs->freqm >> 16, subs->freqm & 0xffff);
+	} else {
+		snd_iprintf(buffer, "  Status: Stop\n");
+	}
+}
+
+static void proc_pcm_format_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
+{
+	struct snd_usb_stream *stream = entry->private_data;
+
+	snd_iprintf(buffer, "%s : %s\n", stream->chip->card->longname, stream->pcm->name);
+
+	if (stream->substream[SNDRV_PCM_STREAM_PLAYBACK].num_formats) {
+		snd_iprintf(buffer, "\nPlayback:\n");
+		proc_dump_substream_status(&stream->substream[SNDRV_PCM_STREAM_PLAYBACK], buffer);
+		proc_dump_substream_formats(&stream->substream[SNDRV_PCM_STREAM_PLAYBACK], buffer);
+	}
+	if (stream->substream[SNDRV_PCM_STREAM_CAPTURE].num_formats) {
+		snd_iprintf(buffer, "\nCapture:\n");
+		proc_dump_substream_status(&stream->substream[SNDRV_PCM_STREAM_CAPTURE], buffer);
+		proc_dump_substream_formats(&stream->substream[SNDRV_PCM_STREAM_CAPTURE], buffer);
+	}
+}
+
+void snd_usb_proc_pcm_format_add(struct snd_usb_stream *stream)
+{
+	struct snd_info_entry *entry;
+	char name[32];
+	struct snd_card *card = stream->chip->card;
+
+	sprintf(name, "stream%d", stream->pcm_index);
+	if (!snd_card_proc_new(card, name, &entry))
+		snd_info_set_text_ops(entry, stream, proc_pcm_format_read);
+}
+
diff --git a/sound/usb/proc.h b/sound/usb/proc.h
new file mode 100644
index 00000000000..a45b765e4cf
--- /dev/null
+++ b/sound/usb/proc.h
@@ -0,0 +1,8 @@
+#ifndef __USBAUDIO_PROC_H
+#define __USBAUDIO_PROC_H
+
+void snd_usb_audio_create_proc(struct snd_usb_audio *chip);
+void snd_usb_proc_pcm_format_add(struct snd_usb_stream *stream);
+
+#endif /* __USBAUDIO_PROC_H */
+
diff --git a/sound/usb/usbquirks.h b/sound/usb/quirks-table.h
index 2b426c1fd0e..2b426c1fd0e 100644
--- a/sound/usb/usbquirks.h
+++ b/sound/usb/quirks-table.h
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
new file mode 100644
index 00000000000..4c16920844e
--- /dev/null
+++ b/sound/usb/quirks.c
@@ -0,0 +1,592 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/pcm.h>
+
+#include "usbaudio.h"
+#include "card.h"
+#include "usbmixer.h"
+#include "midi.h"
+#include "quirks.h"
+#include "helper.h"
+#include "endpoint.h"
+#include "pcm.h"
+
+/*
+ * handle the quirks for the contained interfaces
+ */
+static int create_composite_quirk(struct snd_usb_audio *chip,
+				  struct usb_interface *iface,
+				  struct usb_driver *driver,
+				  const struct snd_usb_audio_quirk *quirk)
+{
+	int probed_ifnum = get_iface_desc(iface->altsetting)->bInterfaceNumber;
+	int err;
+
+	for (quirk = quirk->data; quirk->ifnum >= 0; ++quirk) {
+		iface = usb_ifnum_to_if(chip->dev, quirk->ifnum);
+		if (!iface)
+			continue;
+		if (quirk->ifnum != probed_ifnum &&
+		    usb_interface_claimed(iface))
+			continue;
+		err = snd_usb_create_quirk(chip, iface, driver, quirk);
+		if (err < 0)
+			return err;
+		if (quirk->ifnum != probed_ifnum)
+			usb_driver_claim_interface(driver, iface, (void *)-1L);
+	}
+	return 0;
+}
+
+static int ignore_interface_quirk(struct snd_usb_audio *chip,
+				  struct usb_interface *iface,
+				  struct usb_driver *driver,
+				  const struct snd_usb_audio_quirk *quirk)
+{
+	return 0;
+}
+
+
+/*
+ * Allow alignment on audio sub-slot (channel samples) rather than
+ * on audio slots (audio frames)
+ */
+static int create_align_transfer_quirk(struct snd_usb_audio *chip,
+				       struct usb_interface *iface,
+				       struct usb_driver *driver,
+				       const struct snd_usb_audio_quirk *quirk)
+{
+	chip->txfr_quirk = 1;
+	return 1;	/* Continue with creating streams and mixer */
+}
+
+static int create_any_midi_quirk(struct snd_usb_audio *chip,
+				 struct usb_interface *intf,
+				 struct usb_driver *driver,
+				 const struct snd_usb_audio_quirk *quirk)
+{
+	return snd_usbmidi_create(chip->card, intf, &chip->midi_list, quirk);
+}
+
+/*
+ * create a stream for an interface with proper descriptors
+ */
+static int create_standard_audio_quirk(struct snd_usb_audio *chip,
+				       struct usb_interface *iface,
+				       struct usb_driver *driver,
+				       const struct snd_usb_audio_quirk *quirk)
+{
+	struct usb_host_interface *alts;
+	struct usb_interface_descriptor *altsd;
+	int err;
+
+	alts = &iface->altsetting[0];
+	altsd = get_iface_desc(alts);
+	err = snd_usb_parse_audio_endpoints(chip, altsd->bInterfaceNumber);
+	if (err < 0) {
+		snd_printk(KERN_ERR "cannot setup if %d: error %d\n",
+			   altsd->bInterfaceNumber, err);
+		return err;
+	}
+	/* reset the current interface */
+	usb_set_interface(chip->dev, altsd->bInterfaceNumber, 0);
+	return 0;
+}
+
+/*
+ * create a stream for an endpoint/altsetting without proper descriptors
+ */
+static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
+				     struct usb_interface *iface,
+				     struct usb_driver *driver,
+				     const struct snd_usb_audio_quirk *quirk)
+{
+	struct audioformat *fp;
+	struct usb_host_interface *alts;
+	int stream, err;
+	unsigned *rate_table = NULL;
+
+	fp = kmemdup(quirk->data, sizeof(*fp), GFP_KERNEL);
+	if (! fp) {
+		snd_printk(KERN_ERR "cannot memdup\n");
+		return -ENOMEM;
+	}
+	if (fp->nr_rates > 0) {
+		rate_table = kmalloc(sizeof(int) * fp->nr_rates, GFP_KERNEL);
+		if (!rate_table) {
+			kfree(fp);
+			return -ENOMEM;
+		}
+		memcpy(rate_table, fp->rate_table, sizeof(int) * fp->nr_rates);
+		fp->rate_table = rate_table;
+	}
+
+	stream = (fp->endpoint & USB_DIR_IN)
+		? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
+	err = snd_usb_add_audio_endpoint(chip, stream, fp);
+	if (err < 0) {
+		kfree(fp);
+		kfree(rate_table);
+		return err;
+	}
+	if (fp->iface != get_iface_desc(&iface->altsetting[0])->bInterfaceNumber ||
+	    fp->altset_idx >= iface->num_altsetting) {
+		kfree(fp);
+		kfree(rate_table);
+		return -EINVAL;
+	}
+	alts = &iface->altsetting[fp->altset_idx];
+	fp->datainterval = snd_usb_parse_datainterval(chip, alts);
+	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
+	usb_set_interface(chip->dev, fp->iface, 0);
+	snd_usb_init_pitch(chip->dev, fp->iface, alts, fp);
+	snd_usb_init_sample_rate(chip->dev, fp->iface, alts, fp, fp->rate_max);
+	return 0;
+}
+
+/*
+ * Create a stream for an Edirol UA-700/UA-25/UA-4FX interface.  
+ * The only way to detect the sample rate is by looking at wMaxPacketSize.
+ */
+static int create_uaxx_quirk(struct snd_usb_audio *chip,
+			     struct usb_interface *iface,
+			     struct usb_driver *driver,
+			     const struct snd_usb_audio_quirk *quirk)
+{
+	static const struct audioformat ua_format = {
+		.format = SNDRV_PCM_FORMAT_S24_3LE,
+		.channels = 2,
+		.fmt_type = UAC_FORMAT_TYPE_I,
+		.altsetting = 1,
+		.altset_idx = 1,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+	};
+	struct usb_host_interface *alts;
+	struct usb_interface_descriptor *altsd;
+	struct audioformat *fp;
+	int stream, err;
+
+	/* both PCM and MIDI interfaces have 2 or more altsettings */
+	if (iface->num_altsetting < 2)
+		return -ENXIO;
+	alts = &iface->altsetting[1];
+	altsd = get_iface_desc(alts);
+
+	if (altsd->bNumEndpoints == 2) {
+		static const struct snd_usb_midi_endpoint_info ua700_ep = {
+			.out_cables = 0x0003,
+			.in_cables  = 0x0003
+		};
+		static const struct snd_usb_audio_quirk ua700_quirk = {
+			.type = QUIRK_MIDI_FIXED_ENDPOINT,
+			.data = &ua700_ep
+		};
+		static const struct snd_usb_midi_endpoint_info uaxx_ep = {
+			.out_cables = 0x0001,
+			.in_cables  = 0x0001
+		};
+		static const struct snd_usb_audio_quirk uaxx_quirk = {
+			.type = QUIRK_MIDI_FIXED_ENDPOINT,
+			.data = &uaxx_ep
+		};
+		const struct snd_usb_audio_quirk *quirk =
+			chip->usb_id == USB_ID(0x0582, 0x002b)
+			? &ua700_quirk : &uaxx_quirk;
+		return snd_usbmidi_create(chip->card, iface,
+					  &chip->midi_list, quirk);
+	}
+
+	if (altsd->bNumEndpoints != 1)
+		return -ENXIO;
+
+	fp = kmalloc(sizeof(*fp), GFP_KERNEL);
+	if (!fp)
+		return -ENOMEM;
+	memcpy(fp, &ua_format, sizeof(*fp));
+
+	fp->iface = altsd->bInterfaceNumber;
+	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
+	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
+	fp->datainterval = 0;
+	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
+
+	switch (fp->maxpacksize) {
+	case 0x120:
+		fp->rate_max = fp->rate_min = 44100;
+		break;
+	case 0x138:
+	case 0x140:
+		fp->rate_max = fp->rate_min = 48000;
+		break;
+	case 0x258:
+	case 0x260:
+		fp->rate_max = fp->rate_min = 96000;
+		break;
+	default:
+		snd_printk(KERN_ERR "unknown sample rate\n");
+		kfree(fp);
+		return -ENXIO;
+	}
+
+	stream = (fp->endpoint & USB_DIR_IN)
+		? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
+	err = snd_usb_add_audio_endpoint(chip, stream, fp);
+	if (err < 0) {
+		kfree(fp);
+		return err;
+	}
+	usb_set_interface(chip->dev, fp->iface, 0);
+	return 0;
+}
+
+/*
+ * audio-interface quirks
+ *
+ * returns zero if no standard audio/MIDI parsing is needed.
+ * returns a postive value if standard audio/midi interfaces are parsed
+ * after this.
+ * returns a negative value at error.
+ */
+int snd_usb_create_quirk(struct snd_usb_audio *chip,
+			 struct usb_interface *iface,
+			 struct usb_driver *driver,
+			 const struct snd_usb_audio_quirk *quirk)
+{
+	typedef int (*quirk_func_t)(struct snd_usb_audio *,
+				    struct usb_interface *,
+				    struct usb_driver *,
+				    const struct snd_usb_audio_quirk *);
+	static const quirk_func_t quirk_funcs[] = {
+		[QUIRK_IGNORE_INTERFACE] = ignore_interface_quirk,
+		[QUIRK_COMPOSITE] = create_composite_quirk,
+		[QUIRK_MIDI_STANDARD_INTERFACE] = create_any_midi_quirk,
+		[QUIRK_MIDI_FIXED_ENDPOINT] = create_any_midi_quirk,
+		[QUIRK_MIDI_YAMAHA] = create_any_midi_quirk,
+		[QUIRK_MIDI_MIDIMAN] = create_any_midi_quirk,
+		[QUIRK_MIDI_NOVATION] = create_any_midi_quirk,
+		[QUIRK_MIDI_FASTLANE] = create_any_midi_quirk,
+		[QUIRK_MIDI_EMAGIC] = create_any_midi_quirk,
+		[QUIRK_MIDI_CME] = create_any_midi_quirk,
+		[QUIRK_AUDIO_STANDARD_INTERFACE] = create_standard_audio_quirk,
+		[QUIRK_AUDIO_FIXED_ENDPOINT] = create_fixed_stream_quirk,
+		[QUIRK_AUDIO_EDIROL_UAXX] = create_uaxx_quirk,
+		[QUIRK_AUDIO_ALIGN_TRANSFER] = create_align_transfer_quirk
+	};
+
+	if (quirk->type < QUIRK_TYPE_COUNT) {
+		return quirk_funcs[quirk->type](chip, iface, driver, quirk);
+	} else {
+		snd_printd(KERN_ERR "invalid quirk type %d\n", quirk->type);
+		return -ENXIO;
+	}
+}
+
+/*
+ * boot quirks
+ */
+
+#define EXTIGY_FIRMWARE_SIZE_OLD 794
+#define EXTIGY_FIRMWARE_SIZE_NEW 483
+
+static int snd_usb_extigy_boot_quirk(struct usb_device *dev, struct usb_interface *intf)
+{
+	struct usb_host_config *config = dev->actconfig;
+	int err;
+
+	if (le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_OLD ||
+	    le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_NEW) {
+		snd_printdd("sending Extigy boot sequence...\n");
+		/* Send message to force it to reconnect with full interface. */
+		err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev,0),
+				      0x10, 0x43, 0x0001, 0x000a, NULL, 0, 1000);
+		if (err < 0) snd_printdd("error sending boot message: %d\n", err);
+		err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
+				&dev->descriptor, sizeof(dev->descriptor));
+		config = dev->actconfig;
+		if (err < 0) snd_printdd("error usb_get_descriptor: %d\n", err);
+		err = usb_reset_configuration(dev);
+		if (err < 0) snd_printdd("error usb_reset_configuration: %d\n", err);
+		snd_printdd("extigy_boot: new boot length = %d\n",
+			    le16_to_cpu(get_cfg_desc(config)->wTotalLength));
+		return -ENODEV; /* quit this anyway */
+	}
+	return 0;
+}
+
+static int snd_usb_audigy2nx_boot_quirk(struct usb_device *dev)
+{
+	u8 buf = 1;
+
+	snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), 0x2a,
+			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
+			0, 0, &buf, 1, 1000);
+	if (buf == 0) {
+		snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0x29,
+				USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
+				1, 2000, NULL, 0, 1000);
+		return -ENODEV;
+	}
+	return 0;
+}
+
+/*
+ * C-Media CM106/CM106+ have four 16-bit internal registers that are nicely
+ * documented in the device's data sheet.
+ */
+static int snd_usb_cm106_write_int_reg(struct usb_device *dev, int reg, u16 value)
+{
+	u8 buf[4];
+	buf[0] = 0x20;
+	buf[1] = value & 0xff;
+	buf[2] = (value >> 8) & 0xff;
+	buf[3] = reg;
+	return snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_CONFIGURATION,
+			       USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
+			       0, 0, &buf, 4, 1000);
+}
+
+static int snd_usb_cm106_boot_quirk(struct usb_device *dev)
+{
+	/*
+	 * Enable line-out driver mode, set headphone source to front
+	 * channels, enable stereo mic.
+	 */
+	return snd_usb_cm106_write_int_reg(dev, 2, 0x8004);
+}
+
+/*
+ * C-Media CM6206 is based on CM106 with two additional
+ * registers that are not documented in the data sheet.
+ * Values here are chosen based on sniffing USB traffic
+ * under Windows.
+ */
+static int snd_usb_cm6206_boot_quirk(struct usb_device *dev)
+{
+	int err, reg;
+	int val[] = {0x200c, 0x3000, 0xf800, 0x143f, 0x0000, 0x3000};
+
+	for (reg = 0; reg < ARRAY_SIZE(val); reg++) {
+		err = snd_usb_cm106_write_int_reg(dev, reg, val[reg]);
+		if (err < 0)
+			return err;
+	}
+
+	return err;
+}
+
+/*
+ * This call will put the synth in "USB send" mode, i.e it will send MIDI
+ * messages through USB (this is disabled at startup). The synth will
+ * acknowledge by sending a sysex on endpoint 0x85 and by displaying a USB
+ * sign on its LCD. Values here are chosen based on sniffing USB traffic
+ * under Windows.
+ */
+static int snd_usb_accessmusic_boot_quirk(struct usb_device *dev)
+{
+	int err, actual_length;
+
+	/* "midi send" enable */
+	static const u8 seq[] = { 0x4e, 0x73, 0x52, 0x01 };
+
+	void *buf = kmemdup(seq, ARRAY_SIZE(seq), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+	err = usb_interrupt_msg(dev, usb_sndintpipe(dev, 0x05), buf,
+			ARRAY_SIZE(seq), &actual_length, 1000);
+	kfree(buf);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+/*
+ * Setup quirks
+ */
+#define AUDIOPHILE_SET			0x01 /* if set, parse device_setup */
+#define AUDIOPHILE_SET_DTS              0x02 /* if set, enable DTS Digital Output */
+#define AUDIOPHILE_SET_96K              0x04 /* 48-96KHz rate if set, 8-48KHz otherwise */
+#define AUDIOPHILE_SET_24B		0x08 /* 24bits sample if set, 16bits otherwise */
+#define AUDIOPHILE_SET_DI		0x10 /* if set, enable Digital Input */
+#define AUDIOPHILE_SET_MASK		0x1F /* bit mask for setup value */
+#define AUDIOPHILE_SET_24B_48K_DI	0x19 /* value for 24bits+48KHz+Digital Input */
+#define AUDIOPHILE_SET_24B_48K_NOTDI	0x09 /* value for 24bits+48KHz+No Digital Input */
+#define AUDIOPHILE_SET_16B_48K_DI	0x11 /* value for 16bits+48KHz+Digital Input */
+#define AUDIOPHILE_SET_16B_48K_NOTDI	0x01 /* value for 16bits+48KHz+No Digital Input */
+
+static int audiophile_skip_setting_quirk(struct snd_usb_audio *chip,
+					 int iface,
+					 int altno)
+{
+	/* Reset ALL ifaces to 0 altsetting.
+	 * Call it for every possible altsetting of every interface.
+	 */
+	usb_set_interface(chip->dev, iface, 0);
+
+	if (chip->setup & AUDIOPHILE_SET) {
+		if ((chip->setup & AUDIOPHILE_SET_DTS)
+		    && altno != 6)
+			return 1; /* skip this altsetting */
+		if ((chip->setup & AUDIOPHILE_SET_96K)
+		    && altno != 1)
+			return 1; /* skip this altsetting */
+		if ((chip->setup & AUDIOPHILE_SET_MASK) ==
+		    AUDIOPHILE_SET_24B_48K_DI && altno != 2)
+			return 1; /* skip this altsetting */
+		if ((chip->setup & AUDIOPHILE_SET_MASK) ==
+		    AUDIOPHILE_SET_24B_48K_NOTDI && altno != 3)
+			return 1; /* skip this altsetting */
+		if ((chip->setup & AUDIOPHILE_SET_MASK) ==
+		    AUDIOPHILE_SET_16B_48K_DI && altno != 4)
+			return 1; /* skip this altsetting */
+		if ((chip->setup & AUDIOPHILE_SET_MASK) ==
+		    AUDIOPHILE_SET_16B_48K_NOTDI && altno != 5)
+			return 1; /* skip this altsetting */
+	}
+
+	return 0; /* keep this altsetting */
+}
+
+int snd_usb_apply_interface_quirk(struct snd_usb_audio *chip,
+				  int iface,
+				  int altno)
+{
+	/* audiophile usb: skip altsets incompatible with device_setup */
+	if (chip->usb_id == USB_ID(0x0763, 0x2003))
+		return audiophile_skip_setting_quirk(chip, iface, altno);
+
+	return 0;
+}
+
+int snd_usb_apply_boot_quirk(struct usb_device *dev,
+			     struct usb_interface *intf,
+			     const struct snd_usb_audio_quirk *quirk)
+{
+	u32 id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
+			le16_to_cpu(dev->descriptor.idProduct));
+
+	/* SB Extigy needs special boot-up sequence */
+	/* if more models come, this will go to the quirk list. */
+	if (id == USB_ID(0x041e, 0x3000))
+		return snd_usb_extigy_boot_quirk(dev, intf);
+
+	/* SB Audigy 2 NX needs its own boot-up magic, too */
+	if (id == USB_ID(0x041e, 0x3020))
+		return snd_usb_audigy2nx_boot_quirk(dev);
+
+	/* C-Media CM106 / Turtle Beach Audio Advantage Roadie */
+	if (id == USB_ID(0x10f5, 0x0200))
+		return snd_usb_cm106_boot_quirk(dev);
+
+	/* C-Media CM6206 / CM106-Like Sound Device */
+	if (id == USB_ID(0x0d8c, 0x0102))
+		return snd_usb_cm6206_boot_quirk(dev);
+
+	/* Access Music VirusTI Desktop */
+	if (id == USB_ID(0x133e, 0x0815))
+		return snd_usb_accessmusic_boot_quirk(dev);
+
+	return 0;
+}
+
+/*
+ * check if the device uses big-endian samples
+ */
+int snd_usb_is_big_endian_format(struct snd_usb_audio *chip, struct audioformat *fp)
+{
+	switch (chip->usb_id) {
+	case USB_ID(0x0763, 0x2001): /* M-Audio Quattro: captured data only */
+		if (fp->endpoint & USB_DIR_IN)
+			return 1;
+		break;
+	case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
+		if (chip->setup == 0x00 ||
+		    fp->altsetting==1 || fp->altsetting==2 || fp->altsetting==3)
+			return 1;
+	}
+	return 0;
+}
+
+/*
+ * For E-Mu 0404USB/0202USB/TrackerPre sample rate should be set for device,
+ * not for interface.
+ */
+
+enum {
+	EMU_QUIRK_SR_44100HZ = 0,
+	EMU_QUIRK_SR_48000HZ,
+	EMU_QUIRK_SR_88200HZ,
+	EMU_QUIRK_SR_96000HZ,
+	EMU_QUIRK_SR_176400HZ,
+	EMU_QUIRK_SR_192000HZ
+};
+
+static void set_format_emu_quirk(struct snd_usb_substream *subs,
+				 struct audioformat *fmt)
+{
+	unsigned char emu_samplerate_id = 0;
+
+	/* When capture is active
+	 * sample rate shouldn't be changed
+	 * by playback substream
+	 */
+	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
+		if (subs->stream->substream[SNDRV_PCM_STREAM_CAPTURE].interface != -1)
+			return;
+	}
+
+	switch (fmt->rate_min) {
+	case 48000:
+		emu_samplerate_id = EMU_QUIRK_SR_48000HZ;
+		break;
+	case 88200:
+		emu_samplerate_id = EMU_QUIRK_SR_88200HZ;
+		break;
+	case 96000:
+		emu_samplerate_id = EMU_QUIRK_SR_96000HZ;
+		break;
+	case 176400:
+		emu_samplerate_id = EMU_QUIRK_SR_176400HZ;
+		break;
+	case 192000:
+		emu_samplerate_id = EMU_QUIRK_SR_192000HZ;
+		break;
+	default:
+		emu_samplerate_id = EMU_QUIRK_SR_44100HZ;
+		break;
+	}
+	snd_emuusb_set_samplerate(subs->stream->chip, emu_samplerate_id);
+}
+
+void snd_usb_set_format_quirk(struct snd_usb_substream *subs,
+			      struct audioformat *fmt)
+{
+	switch (subs->stream->chip->usb_id) {
+	case USB_ID(0x041e, 0x3f02): /* E-Mu 0202 USB */
+	case USB_ID(0x041e, 0x3f04): /* E-Mu 0404 USB */
+	case USB_ID(0x041e, 0x3f0a): /* E-Mu Tracker Pre */
+		set_format_emu_quirk(subs, fmt);
+		break;
+	}
+}
+
diff --git a/sound/usb/quirks.h b/sound/usb/quirks.h
new file mode 100644
index 00000000000..03e5e94098c
--- /dev/null
+++ b/sound/usb/quirks.h
@@ -0,0 +1,23 @@
+#ifndef __USBAUDIO_QUIRKS_H
+#define __USBAUDIO_QUIRKS_H
+
+int snd_usb_create_quirk(struct snd_usb_audio *chip,
+			 struct usb_interface *iface,
+			 struct usb_driver *driver,
+			 const struct snd_usb_audio_quirk *quirk);
+
+int snd_usb_apply_interface_quirk(struct snd_usb_audio *chip,
+				  int iface,
+				  int altno);
+
+int snd_usb_apply_boot_quirk(struct usb_device *dev,
+			     struct usb_interface *intf,
+			     const struct snd_usb_audio_quirk *quirk);
+
+void snd_usb_set_format_quirk(struct snd_usb_substream *subs,
+			      struct audioformat *fmt);
+
+int snd_usb_is_big_endian_format(struct snd_usb_audio *chip,
+				 struct audioformat *fp);
+
+#endif /* __USBAUDIO_QUIRKS_H */
diff --git a/sound/usb/urb.c b/sound/usb/urb.c
new file mode 100644
index 00000000000..e9c339f7586
--- /dev/null
+++ b/sound/usb/urb.c
@@ -0,0 +1,989 @@
+/*
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+
+#include "usbaudio.h"
+#include "helper.h"
+#include "card.h"
+#include "urb.h"
+#include "pcm.h"
+
+/*
+ * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
+ * this will overflow at approx 524 kHz
+ */
+static inline unsigned get_usb_full_speed_rate(unsigned int rate)
+{
+	return ((rate << 13) + 62) / 125;
+}
+
+/*
+ * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
+ * this will overflow at approx 4 MHz
+ */
+static inline unsigned get_usb_high_speed_rate(unsigned int rate)
+{
+	return ((rate << 10) + 62) / 125;
+}
+
+/*
+ * unlink active urbs.
+ */
+static int deactivate_urbs(struct snd_usb_substream *subs, int force, int can_sleep)
+{
+	struct snd_usb_audio *chip = subs->stream->chip;
+	unsigned int i;
+	int async;
+
+	subs->running = 0;
+
+	if (!force && subs->stream->chip->shutdown) /* to be sure... */
+		return -EBADFD;
+
+	async = !can_sleep && chip->async_unlink;
+
+	if (!async && in_interrupt())
+		return 0;
+
+	for (i = 0; i < subs->nurbs; i++) {
+		if (test_bit(i, &subs->active_mask)) {
+			if (!test_and_set_bit(i, &subs->unlink_mask)) {
+				struct urb *u = subs->dataurb[i].urb;
+				if (async)
+					usb_unlink_urb(u);
+				else
+					usb_kill_urb(u);
+			}
+		}
+	}
+	if (subs->syncpipe) {
+		for (i = 0; i < SYNC_URBS; i++) {
+			if (test_bit(i+16, &subs->active_mask)) {
+				if (!test_and_set_bit(i+16, &subs->unlink_mask)) {
+					struct urb *u = subs->syncurb[i].urb;
+					if (async)
+						usb_unlink_urb(u);
+					else
+						usb_kill_urb(u);
+				}
+			}
+		}
+	}
+	return 0;
+}
+
+
+/*
+ * release a urb data
+ */
+static void release_urb_ctx(struct snd_urb_ctx *u)
+{
+	if (u->urb) {
+		if (u->buffer_size)
+			usb_buffer_free(u->subs->dev, u->buffer_size,
+					u->urb->transfer_buffer,
+					u->urb->transfer_dma);
+		usb_free_urb(u->urb);
+		u->urb = NULL;
+	}
+}
+
+/*
+ *  wait until all urbs are processed.
+ */
+static int wait_clear_urbs(struct snd_usb_substream *subs)
+{
+	unsigned long end_time = jiffies + msecs_to_jiffies(1000);
+	unsigned int i;
+	int alive;
+
+	do {
+		alive = 0;
+		for (i = 0; i < subs->nurbs; i++) {
+			if (test_bit(i, &subs->active_mask))
+				alive++;
+		}
+		if (subs->syncpipe) {
+			for (i = 0; i < SYNC_URBS; i++) {
+				if (test_bit(i + 16, &subs->active_mask))
+					alive++;
+			}
+		}
+		if (! alive)
+			break;
+		schedule_timeout_uninterruptible(1);
+	} while (time_before(jiffies, end_time));
+	if (alive)
+		snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
+	return 0;
+}
+
+/*
+ * release a substream
+ */
+void snd_usb_release_substream_urbs(struct snd_usb_substream *subs, int force)
+{
+	int i;
+
+	/* stop urbs (to be sure) */
+	deactivate_urbs(subs, force, 1);
+	wait_clear_urbs(subs);
+
+	for (i = 0; i < MAX_URBS; i++)
+		release_urb_ctx(&subs->dataurb[i]);
+	for (i = 0; i < SYNC_URBS; i++)
+		release_urb_ctx(&subs->syncurb[i]);
+	usb_buffer_free(subs->dev, SYNC_URBS * 4,
+			subs->syncbuf, subs->sync_dma);
+	subs->syncbuf = NULL;
+	subs->nurbs = 0;
+}
+
+/*
+ * complete callback from data urb
+ */
+static void snd_complete_urb(struct urb *urb)
+{
+	struct snd_urb_ctx *ctx = urb->context;
+	struct snd_usb_substream *subs = ctx->subs;
+	struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
+	int err = 0;
+
+	if ((subs->running && subs->ops.retire(subs, substream->runtime, urb)) ||
+	    !subs->running || /* can be stopped during retire callback */
+	    (err = subs->ops.prepare(subs, substream->runtime, urb)) < 0 ||
+	    (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
+		clear_bit(ctx->index, &subs->active_mask);
+		if (err < 0) {
+			snd_printd(KERN_ERR "cannot submit urb (err = %d)\n", err);
+			snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+		}
+	}
+}
+
+
+/*
+ * complete callback from sync urb
+ */
+static void snd_complete_sync_urb(struct urb *urb)
+{
+	struct snd_urb_ctx *ctx = urb->context;
+	struct snd_usb_substream *subs = ctx->subs;
+	struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
+	int err = 0;
+
+	if ((subs->running && subs->ops.retire_sync(subs, substream->runtime, urb)) ||
+	    !subs->running || /* can be stopped during retire callback */
+	    (err = subs->ops.prepare_sync(subs, substream->runtime, urb)) < 0 ||
+	    (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
+		clear_bit(ctx->index + 16, &subs->active_mask);
+		if (err < 0) {
+			snd_printd(KERN_ERR "cannot submit sync urb (err = %d)\n", err);
+			snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+		}
+	}
+}
+
+
+/*
+ * initialize a substream for plaback/capture
+ */
+int snd_usb_init_substream_urbs(struct snd_usb_substream *subs,
+				unsigned int period_bytes,
+				unsigned int rate,
+				unsigned int frame_bits)
+{
+	unsigned int maxsize, i;
+	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
+	unsigned int urb_packs, total_packs, packs_per_ms;
+	struct snd_usb_audio *chip = subs->stream->chip;
+
+	/* calculate the frequency in 16.16 format */
+	if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
+		subs->freqn = get_usb_full_speed_rate(rate);
+	else
+		subs->freqn = get_usb_high_speed_rate(rate);
+	subs->freqm = subs->freqn;
+	/* calculate max. frequency */
+	if (subs->maxpacksize) {
+		/* whatever fits into a max. size packet */
+		maxsize = subs->maxpacksize;
+		subs->freqmax = (maxsize / (frame_bits >> 3))
+				<< (16 - subs->datainterval);
+	} else {
+		/* no max. packet size: just take 25% higher than nominal */
+		subs->freqmax = subs->freqn + (subs->freqn >> 2);
+		maxsize = ((subs->freqmax + 0xffff) * (frame_bits >> 3))
+				>> (16 - subs->datainterval);
+	}
+	subs->phase = 0;
+
+	if (subs->fill_max)
+		subs->curpacksize = subs->maxpacksize;
+	else
+		subs->curpacksize = maxsize;
+
+	if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH)
+		packs_per_ms = 8 >> subs->datainterval;
+	else
+		packs_per_ms = 1;
+
+	if (is_playback) {
+		urb_packs = max(chip->nrpacks, 1);
+		urb_packs = min(urb_packs, (unsigned int)MAX_PACKS);
+	} else
+		urb_packs = 1;
+	urb_packs *= packs_per_ms;
+	if (subs->syncpipe)
+		urb_packs = min(urb_packs, 1U << subs->syncinterval);
+
+	/* decide how many packets to be used */
+	if (is_playback) {
+		unsigned int minsize, maxpacks;
+		/* determine how small a packet can be */
+		minsize = (subs->freqn >> (16 - subs->datainterval))
+			  * (frame_bits >> 3);
+		/* with sync from device, assume it can be 12% lower */
+		if (subs->syncpipe)
+			minsize -= minsize >> 3;
+		minsize = max(minsize, 1u);
+		total_packs = (period_bytes + minsize - 1) / minsize;
+		/* we need at least two URBs for queueing */
+		if (total_packs < 2) {
+			total_packs = 2;
+		} else {
+			/* and we don't want too long a queue either */
+			maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2);
+			total_packs = min(total_packs, maxpacks);
+		}
+	} else {
+		while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
+			urb_packs >>= 1;
+		total_packs = MAX_URBS * urb_packs;
+	}
+	subs->nurbs = (total_packs + urb_packs - 1) / urb_packs;
+	if (subs->nurbs > MAX_URBS) {
+		/* too much... */
+		subs->nurbs = MAX_URBS;
+		total_packs = MAX_URBS * urb_packs;
+	} else if (subs->nurbs < 2) {
+		/* too little - we need at least two packets
+		 * to ensure contiguous playback/capture
+		 */
+		subs->nurbs = 2;
+	}
+
+	/* allocate and initialize data urbs */
+	for (i = 0; i < subs->nurbs; i++) {
+		struct snd_urb_ctx *u = &subs->dataurb[i];
+		u->index = i;
+		u->subs = subs;
+		u->packets = (i + 1) * total_packs / subs->nurbs
+			- i * total_packs / subs->nurbs;
+		u->buffer_size = maxsize * u->packets;
+		if (subs->fmt_type == UAC_FORMAT_TYPE_II)
+			u->packets++; /* for transfer delimiter */
+		u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
+		if (!u->urb)
+			goto out_of_memory;
+		u->urb->transfer_buffer =
+			usb_buffer_alloc(subs->dev, u->buffer_size, GFP_KERNEL,
+					 &u->urb->transfer_dma);
+		if (!u->urb->transfer_buffer)
+			goto out_of_memory;
+		u->urb->pipe = subs->datapipe;
+		u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
+		u->urb->interval = 1 << subs->datainterval;
+		u->urb->context = u;
+		u->urb->complete = snd_complete_urb;
+	}
+
+	if (subs->syncpipe) {
+		/* allocate and initialize sync urbs */
+		subs->syncbuf = usb_buffer_alloc(subs->dev, SYNC_URBS * 4,
+						 GFP_KERNEL, &subs->sync_dma);
+		if (!subs->syncbuf)
+			goto out_of_memory;
+		for (i = 0; i < SYNC_URBS; i++) {
+			struct snd_urb_ctx *u = &subs->syncurb[i];
+			u->index = i;
+			u->subs = subs;
+			u->packets = 1;
+			u->urb = usb_alloc_urb(1, GFP_KERNEL);
+			if (!u->urb)
+				goto out_of_memory;
+			u->urb->transfer_buffer = subs->syncbuf + i * 4;
+			u->urb->transfer_dma = subs->sync_dma + i * 4;
+			u->urb->transfer_buffer_length = 4;
+			u->urb->pipe = subs->syncpipe;
+			u->urb->transfer_flags = URB_ISO_ASAP |
+						 URB_NO_TRANSFER_DMA_MAP;
+			u->urb->number_of_packets = 1;
+			u->urb->interval = 1 << subs->syncinterval;
+			u->urb->context = u;
+			u->urb->complete = snd_complete_sync_urb;
+		}
+	}
+	return 0;
+
+out_of_memory:
+	snd_usb_release_substream_urbs(subs, 0);
+	return -ENOMEM;
+}
+
+/*
+ * prepare urb for full speed capture sync pipe
+ *
+ * fill the length and offset of each urb descriptor.
+ * the fixed 10.14 frequency is passed through the pipe.
+ */
+static int prepare_capture_sync_urb(struct snd_usb_substream *subs,
+				    struct snd_pcm_runtime *runtime,
+				    struct urb *urb)
+{
+	unsigned char *cp = urb->transfer_buffer;
+	struct snd_urb_ctx *ctx = urb->context;
+
+	urb->dev = ctx->subs->dev; /* we need to set this at each time */
+	urb->iso_frame_desc[0].length = 3;
+	urb->iso_frame_desc[0].offset = 0;
+	cp[0] = subs->freqn >> 2;
+	cp[1] = subs->freqn >> 10;
+	cp[2] = subs->freqn >> 18;
+	return 0;
+}
+
+/*
+ * prepare urb for high speed capture sync pipe
+ *
+ * fill the length and offset of each urb descriptor.
+ * the fixed 12.13 frequency is passed as 16.16 through the pipe.
+ */
+static int prepare_capture_sync_urb_hs(struct snd_usb_substream *subs,
+				       struct snd_pcm_runtime *runtime,
+				       struct urb *urb)
+{
+	unsigned char *cp = urb->transfer_buffer;
+	struct snd_urb_ctx *ctx = urb->context;
+
+	urb->dev = ctx->subs->dev; /* we need to set this at each time */
+	urb->iso_frame_desc[0].length = 4;
+	urb->iso_frame_desc[0].offset = 0;
+	cp[0] = subs->freqn;
+	cp[1] = subs->freqn >> 8;
+	cp[2] = subs->freqn >> 16;
+	cp[3] = subs->freqn >> 24;
+	return 0;
+}
+
+/*
+ * process after capture sync complete
+ * - nothing to do
+ */
+static int retire_capture_sync_urb(struct snd_usb_substream *subs,
+				   struct snd_pcm_runtime *runtime,
+				   struct urb *urb)
+{
+	return 0;
+}
+
+/*
+ * prepare urb for capture data pipe
+ *
+ * fill the offset and length of each descriptor.
+ *
+ * we use a temporary buffer to write the captured data.
+ * since the length of written data is determined by host, we cannot
+ * write onto the pcm buffer directly...  the data is thus copied
+ * later at complete callback to the global buffer.
+ */
+static int prepare_capture_urb(struct snd_usb_substream *subs,
+			       struct snd_pcm_runtime *runtime,
+			       struct urb *urb)
+{
+	int i, offs;
+	struct snd_urb_ctx *ctx = urb->context;
+
+	offs = 0;
+	urb->dev = ctx->subs->dev; /* we need to set this at each time */
+	for (i = 0; i < ctx->packets; i++) {
+		urb->iso_frame_desc[i].offset = offs;
+		urb->iso_frame_desc[i].length = subs->curpacksize;
+		offs += subs->curpacksize;
+	}
+	urb->transfer_buffer_length = offs;
+	urb->number_of_packets = ctx->packets;
+	return 0;
+}
+
+/*
+ * process after capture complete
+ *
+ * copy the data from each desctiptor to the pcm buffer, and
+ * update the current position.
+ */
+static int retire_capture_urb(struct snd_usb_substream *subs,
+			      struct snd_pcm_runtime *runtime,
+			      struct urb *urb)
+{
+	unsigned long flags;
+	unsigned char *cp;
+	int i;
+	unsigned int stride, frames, bytes, oldptr;
+	int period_elapsed = 0;
+
+	stride = runtime->frame_bits >> 3;
+
+	for (i = 0; i < urb->number_of_packets; i++) {
+		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
+		if (urb->iso_frame_desc[i].status) {
+			snd_printd(KERN_ERR "frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
+			// continue;
+		}
+		bytes = urb->iso_frame_desc[i].actual_length;
+		frames = bytes / stride;
+		if (!subs->txfr_quirk)
+			bytes = frames * stride;
+		if (bytes % (runtime->sample_bits >> 3) != 0) {
+#ifdef CONFIG_SND_DEBUG_VERBOSE
+			int oldbytes = bytes;
+#endif
+			bytes = frames * stride;
+			snd_printdd(KERN_ERR "Corrected urb data len. %d->%d\n",
+							oldbytes, bytes);
+		}
+		/* update the current pointer */
+		spin_lock_irqsave(&subs->lock, flags);
+		oldptr = subs->hwptr_done;
+		subs->hwptr_done += bytes;
+		if (subs->hwptr_done >= runtime->buffer_size * stride)
+			subs->hwptr_done -= runtime->buffer_size * stride;
+		frames = (bytes + (oldptr % stride)) / stride;
+		subs->transfer_done += frames;
+		if (subs->transfer_done >= runtime->period_size) {
+			subs->transfer_done -= runtime->period_size;
+			period_elapsed = 1;
+		}
+		spin_unlock_irqrestore(&subs->lock, flags);
+		/* copy a data chunk */
+		if (oldptr + bytes > runtime->buffer_size * stride) {
+			unsigned int bytes1 =
+					runtime->buffer_size * stride - oldptr;
+			memcpy(runtime->dma_area + oldptr, cp, bytes1);
+			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
+		} else {
+			memcpy(runtime->dma_area + oldptr, cp, bytes);
+		}
+	}
+	if (period_elapsed)
+		snd_pcm_period_elapsed(subs->pcm_substream);
+	return 0;
+}
+
+/*
+ * Process after capture complete when paused.  Nothing to do.
+ */
+static int retire_paused_capture_urb(struct snd_usb_substream *subs,
+				     struct snd_pcm_runtime *runtime,
+				     struct urb *urb)
+{
+	return 0;
+}
+
+
+/*
+ * prepare urb for full speed playback sync pipe
+ *
+ * set up the offset and length to receive the current frequency.
+ */
+
+static int prepare_playback_sync_urb(struct snd_usb_substream *subs,
+				     struct snd_pcm_runtime *runtime,
+				     struct urb *urb)
+{
+	struct snd_urb_ctx *ctx = urb->context;
+
+	urb->dev = ctx->subs->dev; /* we need to set this at each time */
+	urb->iso_frame_desc[0].length = 3;
+	urb->iso_frame_desc[0].offset = 0;
+	return 0;
+}
+
+/*
+ * prepare urb for high speed playback sync pipe
+ *
+ * set up the offset and length to receive the current frequency.
+ */
+
+static int prepare_playback_sync_urb_hs(struct snd_usb_substream *subs,
+					struct snd_pcm_runtime *runtime,
+					struct urb *urb)
+{
+	struct snd_urb_ctx *ctx = urb->context;
+
+	urb->dev = ctx->subs->dev; /* we need to set this at each time */
+	urb->iso_frame_desc[0].length = 4;
+	urb->iso_frame_desc[0].offset = 0;
+	return 0;
+}
+
+/*
+ * process after full speed playback sync complete
+ *
+ * retrieve the current 10.14 frequency from pipe, and set it.
+ * the value is referred in prepare_playback_urb().
+ */
+static int retire_playback_sync_urb(struct snd_usb_substream *subs,
+				    struct snd_pcm_runtime *runtime,
+				    struct urb *urb)
+{
+	unsigned int f;
+	unsigned long flags;
+
+	if (urb->iso_frame_desc[0].status == 0 &&
+	    urb->iso_frame_desc[0].actual_length == 3) {
+		f = combine_triple((u8*)urb->transfer_buffer) << 2;
+		if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
+			spin_lock_irqsave(&subs->lock, flags);
+			subs->freqm = f;
+			spin_unlock_irqrestore(&subs->lock, flags);
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * process after high speed playback sync complete
+ *
+ * retrieve the current 12.13 frequency from pipe, and set it.
+ * the value is referred in prepare_playback_urb().
+ */
+static int retire_playback_sync_urb_hs(struct snd_usb_substream *subs,
+				       struct snd_pcm_runtime *runtime,
+				       struct urb *urb)
+{
+	unsigned int f;
+	unsigned long flags;
+
+	if (urb->iso_frame_desc[0].status == 0 &&
+	    urb->iso_frame_desc[0].actual_length == 4) {
+		f = combine_quad((u8*)urb->transfer_buffer) & 0x0fffffff;
+		if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
+			spin_lock_irqsave(&subs->lock, flags);
+			subs->freqm = f;
+			spin_unlock_irqrestore(&subs->lock, flags);
+		}
+	}
+
+	return 0;
+}
+
+/*
+ * process after E-Mu 0202/0404/Tracker Pre high speed playback sync complete
+ *
+ * These devices return the number of samples per packet instead of the number
+ * of samples per microframe.
+ */
+static int retire_playback_sync_urb_hs_emu(struct snd_usb_substream *subs,
+					   struct snd_pcm_runtime *runtime,
+					   struct urb *urb)
+{
+	unsigned int f;
+	unsigned long flags;
+
+	if (urb->iso_frame_desc[0].status == 0 &&
+	    urb->iso_frame_desc[0].actual_length == 4) {
+		f = combine_quad((u8*)urb->transfer_buffer) & 0x0fffffff;
+		f >>= subs->datainterval;
+		if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
+			spin_lock_irqsave(&subs->lock, flags);
+			subs->freqm = f;
+			spin_unlock_irqrestore(&subs->lock, flags);
+		}
+	}
+
+	return 0;
+}
+
+/* determine the number of frames in the next packet */
+static int snd_usb_audio_next_packet_size(struct snd_usb_substream *subs)
+{
+	if (subs->fill_max)
+		return subs->maxframesize;
+	else {
+		subs->phase = (subs->phase & 0xffff)
+			+ (subs->freqm << subs->datainterval);
+		return min(subs->phase >> 16, subs->maxframesize);
+	}
+}
+
+/*
+ * Prepare urb for streaming before playback starts or when paused.
+ *
+ * We don't have any data, so we send silence.
+ */
+static int prepare_nodata_playback_urb(struct snd_usb_substream *subs,
+				       struct snd_pcm_runtime *runtime,
+				       struct urb *urb)
+{
+	unsigned int i, offs, counts;
+	struct snd_urb_ctx *ctx = urb->context;
+	int stride = runtime->frame_bits >> 3;
+
+	offs = 0;
+	urb->dev = ctx->subs->dev;
+	for (i = 0; i < ctx->packets; ++i) {
+		counts = snd_usb_audio_next_packet_size(subs);
+		urb->iso_frame_desc[i].offset = offs * stride;
+		urb->iso_frame_desc[i].length = counts * stride;
+		offs += counts;
+	}
+	urb->number_of_packets = ctx->packets;
+	urb->transfer_buffer_length = offs * stride;
+	memset(urb->transfer_buffer,
+	       subs->cur_audiofmt->format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0,
+	       offs * stride);
+	return 0;
+}
+
+/*
+ * prepare urb for playback data pipe
+ *
+ * Since a URB can handle only a single linear buffer, we must use double
+ * buffering when the data to be transferred overflows the buffer boundary.
+ * To avoid inconsistencies when updating hwptr_done, we use double buffering
+ * for all URBs.
+ */
+static int prepare_playback_urb(struct snd_usb_substream *subs,
+				struct snd_pcm_runtime *runtime,
+				struct urb *urb)
+{
+	int i, stride;
+	unsigned int counts, frames, bytes;
+	unsigned long flags;
+	int period_elapsed = 0;
+	struct snd_urb_ctx *ctx = urb->context;
+
+	stride = runtime->frame_bits >> 3;
+
+	frames = 0;
+	urb->dev = ctx->subs->dev; /* we need to set this at each time */
+	urb->number_of_packets = 0;
+	spin_lock_irqsave(&subs->lock, flags);
+	for (i = 0; i < ctx->packets; i++) {
+		counts = snd_usb_audio_next_packet_size(subs);
+		/* set up descriptor */
+		urb->iso_frame_desc[i].offset = frames * stride;
+		urb->iso_frame_desc[i].length = counts * stride;
+		frames += counts;
+		urb->number_of_packets++;
+		subs->transfer_done += counts;
+		if (subs->transfer_done >= runtime->period_size) {
+			subs->transfer_done -= runtime->period_size;
+			period_elapsed = 1;
+			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
+				if (subs->transfer_done > 0) {
+					/* FIXME: fill-max mode is not
+					 * supported yet */
+					frames -= subs->transfer_done;
+					counts -= subs->transfer_done;
+					urb->iso_frame_desc[i].length =
+						counts * stride;
+					subs->transfer_done = 0;
+				}
+				i++;
+				if (i < ctx->packets) {
+					/* add a transfer delimiter */
+					urb->iso_frame_desc[i].offset =
+						frames * stride;
+					urb->iso_frame_desc[i].length = 0;
+					urb->number_of_packets++;
+				}
+				break;
+			}
+		}
+		if (period_elapsed) /* finish at the period boundary */
+			break;
+	}
+	bytes = frames * stride;
+	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
+		/* err, the transferred area goes over buffer boundary. */
+		unsigned int bytes1 =
+			runtime->buffer_size * stride - subs->hwptr_done;
+		memcpy(urb->transfer_buffer,
+		       runtime->dma_area + subs->hwptr_done, bytes1);
+		memcpy(urb->transfer_buffer + bytes1,
+		       runtime->dma_area, bytes - bytes1);
+	} else {
+		memcpy(urb->transfer_buffer,
+		       runtime->dma_area + subs->hwptr_done, bytes);
+	}
+	subs->hwptr_done += bytes;
+	if (subs->hwptr_done >= runtime->buffer_size * stride)
+		subs->hwptr_done -= runtime->buffer_size * stride;
+	runtime->delay += frames;
+	spin_unlock_irqrestore(&subs->lock, flags);
+	urb->transfer_buffer_length = bytes;
+	if (period_elapsed)
+		snd_pcm_period_elapsed(subs->pcm_substream);
+	return 0;
+}
+
+/*
+ * process after playback data complete
+ * - decrease the delay count again
+ */
+static int retire_playback_urb(struct snd_usb_substream *subs,
+			       struct snd_pcm_runtime *runtime,
+			       struct urb *urb)
+{
+	unsigned long flags;
+	int stride = runtime->frame_bits >> 3;
+	int processed = urb->transfer_buffer_length / stride;
+
+	spin_lock_irqsave(&subs->lock, flags);
+	if (processed > runtime->delay)
+		runtime->delay = 0;
+	else
+		runtime->delay -= processed;
+	spin_unlock_irqrestore(&subs->lock, flags);
+	return 0;
+}
+
+static const char *usb_error_string(int err)
+{
+	switch (err) {
+	case -ENODEV:
+		return "no device";
+	case -ENOENT:
+		return "endpoint not enabled";
+	case -EPIPE:
+		return "endpoint stalled";
+	case -ENOSPC:
+		return "not enough bandwidth";
+	case -ESHUTDOWN:
+		return "device disabled";
+	case -EHOSTUNREACH:
+		return "device suspended";
+	case -EINVAL:
+	case -EAGAIN:
+	case -EFBIG:
+	case -EMSGSIZE:
+		return "internal error";
+	default:
+		return "unknown error";
+	}
+}
+
+/*
+ * set up and start data/sync urbs
+ */
+static int start_urbs(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime)
+{
+	unsigned int i;
+	int err;
+
+	if (subs->stream->chip->shutdown)
+		return -EBADFD;
+
+	for (i = 0; i < subs->nurbs; i++) {
+		if (snd_BUG_ON(!subs->dataurb[i].urb))
+			return -EINVAL;
+		if (subs->ops.prepare(subs, runtime, subs->dataurb[i].urb) < 0) {
+			snd_printk(KERN_ERR "cannot prepare datapipe for urb %d\n", i);
+			goto __error;
+		}
+	}
+	if (subs->syncpipe) {
+		for (i = 0; i < SYNC_URBS; i++) {
+			if (snd_BUG_ON(!subs->syncurb[i].urb))
+				return -EINVAL;
+			if (subs->ops.prepare_sync(subs, runtime, subs->syncurb[i].urb) < 0) {
+				snd_printk(KERN_ERR "cannot prepare syncpipe for urb %d\n", i);
+				goto __error;
+			}
+		}
+	}
+
+	subs->active_mask = 0;
+	subs->unlink_mask = 0;
+	subs->running = 1;
+	for (i = 0; i < subs->nurbs; i++) {
+		err = usb_submit_urb(subs->dataurb[i].urb, GFP_ATOMIC);
+		if (err < 0) {
+			snd_printk(KERN_ERR "cannot submit datapipe "
+				   "for urb %d, error %d: %s\n",
+				   i, err, usb_error_string(err));
+			goto __error;
+		}
+		set_bit(i, &subs->active_mask);
+	}
+	if (subs->syncpipe) {
+		for (i = 0; i < SYNC_URBS; i++) {
+			err = usb_submit_urb(subs->syncurb[i].urb, GFP_ATOMIC);
+			if (err < 0) {
+				snd_printk(KERN_ERR "cannot submit syncpipe "
+					   "for urb %d, error %d: %s\n",
+					   i, err, usb_error_string(err));
+				goto __error;
+			}
+			set_bit(i + 16, &subs->active_mask);
+		}
+	}
+	return 0;
+
+ __error:
+	// snd_pcm_stop(subs->pcm_substream, SNDRV_PCM_STATE_XRUN);
+	deactivate_urbs(subs, 0, 0);
+	return -EPIPE;
+}
+
+
+/*
+ */
+static struct snd_urb_ops audio_urb_ops[2] = {
+	{
+		.prepare =	prepare_nodata_playback_urb,
+		.retire =	retire_playback_urb,
+		.prepare_sync =	prepare_playback_sync_urb,
+		.retire_sync =	retire_playback_sync_urb,
+	},
+	{
+		.prepare =	prepare_capture_urb,
+		.retire =	retire_capture_urb,
+		.prepare_sync =	prepare_capture_sync_urb,
+		.retire_sync =	retire_capture_sync_urb,
+	},
+};
+
+static struct snd_urb_ops audio_urb_ops_high_speed[2] = {
+	{
+		.prepare =	prepare_nodata_playback_urb,
+		.retire =	retire_playback_urb,
+		.prepare_sync =	prepare_playback_sync_urb_hs,
+		.retire_sync =	retire_playback_sync_urb_hs,
+	},
+	{
+		.prepare =	prepare_capture_urb,
+		.retire =	retire_capture_urb,
+		.prepare_sync =	prepare_capture_sync_urb_hs,
+		.retire_sync =	retire_capture_sync_urb,
+	},
+};
+
+/*
+ * initialize the substream instance.
+ */
+
+void snd_usb_init_substream(struct snd_usb_stream *as,
+			    int stream, struct audioformat *fp)
+{
+	struct snd_usb_substream *subs = &as->substream[stream];
+
+	INIT_LIST_HEAD(&subs->fmt_list);
+	spin_lock_init(&subs->lock);
+
+	subs->stream = as;
+	subs->direction = stream;
+	subs->dev = as->chip->dev;
+	subs->txfr_quirk = as->chip->txfr_quirk;
+	if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL) {
+		subs->ops = audio_urb_ops[stream];
+	} else {
+		subs->ops = audio_urb_ops_high_speed[stream];
+		switch (as->chip->usb_id) {
+		case USB_ID(0x041e, 0x3f02): /* E-Mu 0202 USB */
+		case USB_ID(0x041e, 0x3f04): /* E-Mu 0404 USB */
+		case USB_ID(0x041e, 0x3f0a): /* E-Mu Tracker Pre */
+			subs->ops.retire_sync = retire_playback_sync_urb_hs_emu;
+			break;
+		}
+	}
+
+	snd_usb_set_pcm_ops(as->pcm, stream);
+
+	list_add_tail(&fp->list, &subs->fmt_list);
+	subs->formats |= 1ULL << fp->format;
+	subs->endpoint = fp->endpoint;
+	subs->num_formats++;
+	subs->fmt_type = fp->fmt_type;
+}
+
+int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_usb_substream *subs = substream->runtime->private_data;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		subs->ops.prepare = prepare_playback_urb;
+		return 0;
+	case SNDRV_PCM_TRIGGER_STOP:
+		return deactivate_urbs(subs, 0, 0);
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		subs->ops.prepare = prepare_nodata_playback_urb;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_usb_substream *subs = substream->runtime->private_data;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		subs->ops.retire = retire_capture_urb;
+		return start_urbs(subs, substream->runtime);
+	case SNDRV_PCM_TRIGGER_STOP:
+		return deactivate_urbs(subs, 0, 0);
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		subs->ops.retire = retire_paused_capture_urb;
+		return 0;
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		subs->ops.retire = retire_capture_urb;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+int snd_usb_substream_prepare(struct snd_usb_substream *subs,
+			      struct snd_pcm_runtime *runtime)
+{
+	/* clear urbs (to be sure) */
+	deactivate_urbs(subs, 0, 1);
+	wait_clear_urbs(subs);
+
+	/* for playback, submit the URBs now; otherwise, the first hwptr_done
+	 * updates for all URBs would happen at the same time when starting */
+	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
+		subs->ops.prepare = prepare_nodata_playback_urb;
+		return start_urbs(subs, runtime);
+	}
+
+	return 0;
+}
+
diff --git a/sound/usb/urb.h b/sound/usb/urb.h
new file mode 100644
index 00000000000..888da38079c
--- /dev/null
+++ b/sound/usb/urb.h
@@ -0,0 +1,21 @@
+#ifndef __USBAUDIO_URB_H
+#define __USBAUDIO_URB_H
+
+void snd_usb_init_substream(struct snd_usb_stream *as,
+			    int stream,
+			    struct audioformat *fp);
+
+int snd_usb_init_substream_urbs(struct snd_usb_substream *subs,
+				unsigned int period_bytes,
+				unsigned int rate,
+				unsigned int frame_bits);
+
+void snd_usb_release_substream_urbs(struct snd_usb_substream *subs, int force);
+
+int snd_usb_substream_prepare(struct snd_usb_substream *subs,
+			      struct snd_pcm_runtime *runtime);
+
+int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substream, int cmd);
+int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream, int cmd);
+
+#endif /* __USBAUDIO_URB_H */
diff --git a/sound/usb/usbaudio.c b/sound/usb/usbaudio.c
deleted file mode 100644
index 5b91aa02b40..00000000000
--- a/sound/usb/usbaudio.c
+++ /dev/null
@@ -1,4051 +0,0 @@
-/*
- *   (Tentative) USB Audio Driver for ALSA
- *
- *   Main and PCM part
- *
- *   Copyright (c) 2002 by Takashi Iwai <tiwai@suse.de>
- *
- *   Many codes borrowed from audio.c by
- *	    Alan Cox (alan@lxorguk.ukuu.org.uk)
- *	    Thomas Sailer (sailer@ife.ee.ethz.ch)
- *
- *
- *   This program is free software; you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *   GNU General Public License for more details.
- *
- *   You should have received a copy of the GNU General Public License
- *   along with this program; if not, write to the Free Software
- *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
- *
- *
- *  NOTES:
- *
- *   - async unlink should be used for avoiding the sleep inside lock.
- *     2.4.22 usb-uhci seems buggy for async unlinking and results in
- *     oops.  in such a cse, pass async_unlink=0 option.
- *   - the linked URBs would be preferred but not used so far because of
- *     the instability of unlinking.
- *   - type II is not supported properly.  there is no device which supports
- *     this type *correctly*.  SB extigy looks as if it supports, but it's
- *     indeed an AC3 stream packed in SPDIF frames (i.e. no real AC3 stream).
- */
-
-
-#include <linux/bitops.h>
-#include <linux/init.h>
-#include <linux/list.h>
-#include <linux/slab.h>
-#include <linux/string.h>
-#include <linux/usb.h>
-#include <linux/moduleparam.h>
-#include <linux/mutex.h>
-#include <linux/usb/audio.h>
-#include <linux/usb/ch9.h>
-
-#include <sound/core.h>
-#include <sound/info.h>
-#include <sound/pcm.h>
-#include <sound/pcm_params.h>
-#include <sound/initval.h>
-
-#include "usbaudio.h"
-#include "usbmidi.h"
-#include "usbmixer.h"
-
-MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
-MODULE_DESCRIPTION("USB Audio");
-MODULE_LICENSE("GPL");
-MODULE_SUPPORTED_DEVICE("{{Generic,USB Audio}}");
-
-
-static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
-static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
-static int enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;/* Enable this card */
-/* Vendor/product IDs for this card */
-static int vid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
-static int pid[SNDRV_CARDS] = { [0 ... (SNDRV_CARDS-1)] = -1 };
-static int nrpacks = 8;		/* max. number of packets per urb */
-static int async_unlink = 1;
-static int device_setup[SNDRV_CARDS]; /* device parameter for this card*/
-static int ignore_ctl_error;
-
-module_param_array(index, int, NULL, 0444);
-MODULE_PARM_DESC(index, "Index value for the USB audio adapter.");
-module_param_array(id, charp, NULL, 0444);
-MODULE_PARM_DESC(id, "ID string for the USB audio adapter.");
-module_param_array(enable, bool, NULL, 0444);
-MODULE_PARM_DESC(enable, "Enable USB audio adapter.");
-module_param_array(vid, int, NULL, 0444);
-MODULE_PARM_DESC(vid, "Vendor ID for the USB audio device.");
-module_param_array(pid, int, NULL, 0444);
-MODULE_PARM_DESC(pid, "Product ID for the USB audio device.");
-module_param(nrpacks, int, 0644);
-MODULE_PARM_DESC(nrpacks, "Max. number of packets per URB.");
-module_param(async_unlink, bool, 0444);
-MODULE_PARM_DESC(async_unlink, "Use async unlink mode.");
-module_param_array(device_setup, int, NULL, 0444);
-MODULE_PARM_DESC(device_setup, "Specific device setup (if needed).");
-module_param(ignore_ctl_error, bool, 0444);
-MODULE_PARM_DESC(ignore_ctl_error,
-		 "Ignore errors from USB controller for mixer interfaces.");
-
-/*
- * debug the h/w constraints
- */
-/* #define HW_CONST_DEBUG */
-
-
-/*
- *
- */
-
-#define MAX_PACKS	20
-#define MAX_PACKS_HS	(MAX_PACKS * 8)	/* in high speed mode */
-#define MAX_URBS	8
-#define SYNC_URBS	4	/* always four urbs for sync */
-#define MAX_QUEUE	24	/* try not to exceed this queue length, in ms */
-
-struct audioformat {
-	struct list_head list;
-	snd_pcm_format_t format;	/* format type */
-	unsigned int channels;		/* # channels */
-	unsigned int fmt_type;		/* USB audio format type (1-3) */
-	unsigned int frame_size;	/* samples per frame for non-audio */
-	int iface;			/* interface number */
-	unsigned char altsetting;	/* corresponding alternate setting */
-	unsigned char altset_idx;	/* array index of altenate setting */
-	unsigned char attributes;	/* corresponding attributes of cs endpoint */
-	unsigned char endpoint;		/* endpoint */
-	unsigned char ep_attr;		/* endpoint attributes */
-	unsigned char datainterval;	/* log_2 of data packet interval */
-	unsigned int maxpacksize;	/* max. packet size */
-	unsigned int rates;		/* rate bitmasks */
-	unsigned int rate_min, rate_max;	/* min/max rates */
-	unsigned int nr_rates;		/* number of rate table entries */
-	unsigned int *rate_table;	/* rate table */
-};
-
-struct snd_usb_substream;
-
-struct snd_urb_ctx {
-	struct urb *urb;
-	unsigned int buffer_size;	/* size of data buffer, if data URB */
-	struct snd_usb_substream *subs;
-	int index;	/* index for urb array */
-	int packets;	/* number of packets per urb */
-};
-
-struct snd_urb_ops {
-	int (*prepare)(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime, struct urb *u);
-	int (*retire)(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime, struct urb *u);
-	int (*prepare_sync)(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime, struct urb *u);
-	int (*retire_sync)(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime, struct urb *u);
-};
-
-struct snd_usb_substream {
-	struct snd_usb_stream *stream;
-	struct usb_device *dev;
-	struct snd_pcm_substream *pcm_substream;
-	int direction;	/* playback or capture */
-	int interface;	/* current interface */
-	int endpoint;	/* assigned endpoint */
-	struct audioformat *cur_audiofmt;	/* current audioformat pointer (for hw_params callback) */
-	unsigned int cur_rate;		/* current rate (for hw_params callback) */
-	unsigned int period_bytes;	/* current period bytes (for hw_params callback) */
-	unsigned int format;     /* USB data format */
-	unsigned int datapipe;   /* the data i/o pipe */
-	unsigned int syncpipe;   /* 1 - async out or adaptive in */
-	unsigned int datainterval;	/* log_2 of data packet interval */
-	unsigned int syncinterval;  /* P for adaptive mode, 0 otherwise */
-	unsigned int freqn;      /* nominal sampling rate in fs/fps in Q16.16 format */
-	unsigned int freqm;      /* momentary sampling rate in fs/fps in Q16.16 format */
-	unsigned int freqmax;    /* maximum sampling rate, used for buffer management */
-	unsigned int phase;      /* phase accumulator */
-	unsigned int maxpacksize;	/* max packet size in bytes */
-	unsigned int maxframesize;	/* max packet size in frames */
-	unsigned int curpacksize;	/* current packet size in bytes (for capture) */
-	unsigned int curframesize;	/* current packet size in frames (for capture) */
-	unsigned int fill_max: 1;	/* fill max packet size always */
-	unsigned int txfr_quirk:1;	/* allow sub-frame alignment */
-	unsigned int fmt_type;		/* USB audio format type (1-3) */
-
-	unsigned int running: 1;	/* running status */
-
-	unsigned int hwptr_done;	/* processed byte position in the buffer */
-	unsigned int transfer_done;		/* processed frames since last period update */
-	unsigned long active_mask;	/* bitmask of active urbs */
-	unsigned long unlink_mask;	/* bitmask of unlinked urbs */
-
-	unsigned int nurbs;			/* # urbs */
-	struct snd_urb_ctx dataurb[MAX_URBS];	/* data urb table */
-	struct snd_urb_ctx syncurb[SYNC_URBS];	/* sync urb table */
-	char *syncbuf;				/* sync buffer for all sync URBs */
-	dma_addr_t sync_dma;			/* DMA address of syncbuf */
-
-	u64 formats;			/* format bitmasks (all or'ed) */
-	unsigned int num_formats;		/* number of supported audio formats (list) */
-	struct list_head fmt_list;	/* format list */
-	struct snd_pcm_hw_constraint_list rate_list;	/* limited rates */
-	spinlock_t lock;
-
-	struct snd_urb_ops ops;		/* callbacks (must be filled at init) */
-};
-
-
-struct snd_usb_stream {
-	struct snd_usb_audio *chip;
-	struct snd_pcm *pcm;
-	int pcm_index;
-	unsigned int fmt_type;		/* USB audio format type (1-3) */
-	struct snd_usb_substream substream[2];
-	struct list_head list;
-};
-
-
-/*
- * we keep the snd_usb_audio_t instances by ourselves for merging
- * the all interfaces on the same card as one sound device.
- */
-
-static DEFINE_MUTEX(register_mutex);
-static struct snd_usb_audio *usb_chip[SNDRV_CARDS];
-
-
-/*
- * convert a sampling rate into our full speed format (fs/1000 in Q16.16)
- * this will overflow at approx 524 kHz
- */
-static inline unsigned get_usb_full_speed_rate(unsigned int rate)
-{
-	return ((rate << 13) + 62) / 125;
-}
-
-/*
- * convert a sampling rate into USB high speed format (fs/8000 in Q16.16)
- * this will overflow at approx 4 MHz
- */
-static inline unsigned get_usb_high_speed_rate(unsigned int rate)
-{
-	return ((rate << 10) + 62) / 125;
-}
-
-/* convert our full speed USB rate into sampling rate in Hz */
-static inline unsigned get_full_speed_hz(unsigned int usb_rate)
-{
-	return (usb_rate * 125 + (1 << 12)) >> 13;
-}
-
-/* convert our high speed USB rate into sampling rate in Hz */
-static inline unsigned get_high_speed_hz(unsigned int usb_rate)
-{
-	return (usb_rate * 125 + (1 << 9)) >> 10;
-}
-
-
-/*
- * prepare urb for full speed capture sync pipe
- *
- * fill the length and offset of each urb descriptor.
- * the fixed 10.14 frequency is passed through the pipe.
- */
-static int prepare_capture_sync_urb(struct snd_usb_substream *subs,
-				    struct snd_pcm_runtime *runtime,
-				    struct urb *urb)
-{
-	unsigned char *cp = urb->transfer_buffer;
-	struct snd_urb_ctx *ctx = urb->context;
-
-	urb->dev = ctx->subs->dev; /* we need to set this at each time */
-	urb->iso_frame_desc[0].length = 3;
-	urb->iso_frame_desc[0].offset = 0;
-	cp[0] = subs->freqn >> 2;
-	cp[1] = subs->freqn >> 10;
-	cp[2] = subs->freqn >> 18;
-	return 0;
-}
-
-/*
- * prepare urb for high speed capture sync pipe
- *
- * fill the length and offset of each urb descriptor.
- * the fixed 12.13 frequency is passed as 16.16 through the pipe.
- */
-static int prepare_capture_sync_urb_hs(struct snd_usb_substream *subs,
-				       struct snd_pcm_runtime *runtime,
-				       struct urb *urb)
-{
-	unsigned char *cp = urb->transfer_buffer;
-	struct snd_urb_ctx *ctx = urb->context;
-
-	urb->dev = ctx->subs->dev; /* we need to set this at each time */
-	urb->iso_frame_desc[0].length = 4;
-	urb->iso_frame_desc[0].offset = 0;
-	cp[0] = subs->freqn;
-	cp[1] = subs->freqn >> 8;
-	cp[2] = subs->freqn >> 16;
-	cp[3] = subs->freqn >> 24;
-	return 0;
-}
-
-/*
- * process after capture sync complete
- * - nothing to do
- */
-static int retire_capture_sync_urb(struct snd_usb_substream *subs,
-				   struct snd_pcm_runtime *runtime,
-				   struct urb *urb)
-{
-	return 0;
-}
-
-/*
- * prepare urb for capture data pipe
- *
- * fill the offset and length of each descriptor.
- *
- * we use a temporary buffer to write the captured data.
- * since the length of written data is determined by host, we cannot
- * write onto the pcm buffer directly...  the data is thus copied
- * later at complete callback to the global buffer.
- */
-static int prepare_capture_urb(struct snd_usb_substream *subs,
-			       struct snd_pcm_runtime *runtime,
-			       struct urb *urb)
-{
-	int i, offs;
-	struct snd_urb_ctx *ctx = urb->context;
-
-	offs = 0;
-	urb->dev = ctx->subs->dev; /* we need to set this at each time */
-	for (i = 0; i < ctx->packets; i++) {
-		urb->iso_frame_desc[i].offset = offs;
-		urb->iso_frame_desc[i].length = subs->curpacksize;
-		offs += subs->curpacksize;
-	}
-	urb->transfer_buffer_length = offs;
-	urb->number_of_packets = ctx->packets;
-	return 0;
-}
-
-/*
- * process after capture complete
- *
- * copy the data from each desctiptor to the pcm buffer, and
- * update the current position.
- */
-static int retire_capture_urb(struct snd_usb_substream *subs,
-			      struct snd_pcm_runtime *runtime,
-			      struct urb *urb)
-{
-	unsigned long flags;
-	unsigned char *cp;
-	int i;
-	unsigned int stride, frames, bytes, oldptr;
-	int period_elapsed = 0;
-
-	stride = runtime->frame_bits >> 3;
-
-	for (i = 0; i < urb->number_of_packets; i++) {
-		cp = (unsigned char *)urb->transfer_buffer + urb->iso_frame_desc[i].offset;
-		if (urb->iso_frame_desc[i].status) {
-			snd_printd(KERN_ERR "frame %d active: %d\n", i, urb->iso_frame_desc[i].status);
-			// continue;
-		}
-		bytes = urb->iso_frame_desc[i].actual_length;
-		frames = bytes / stride;
-		if (!subs->txfr_quirk)
-			bytes = frames * stride;
-		if (bytes % (runtime->sample_bits >> 3) != 0) {
-#ifdef CONFIG_SND_DEBUG_VERBOSE
-			int oldbytes = bytes;
-#endif
-			bytes = frames * stride;
-			snd_printdd(KERN_ERR "Corrected urb data len. %d->%d\n",
-							oldbytes, bytes);
-		}
-		/* update the current pointer */
-		spin_lock_irqsave(&subs->lock, flags);
-		oldptr = subs->hwptr_done;
-		subs->hwptr_done += bytes;
-		if (subs->hwptr_done >= runtime->buffer_size * stride)
-			subs->hwptr_done -= runtime->buffer_size * stride;
-		frames = (bytes + (oldptr % stride)) / stride;
-		subs->transfer_done += frames;
-		if (subs->transfer_done >= runtime->period_size) {
-			subs->transfer_done -= runtime->period_size;
-			period_elapsed = 1;
-		}
-		spin_unlock_irqrestore(&subs->lock, flags);
-		/* copy a data chunk */
-		if (oldptr + bytes > runtime->buffer_size * stride) {
-			unsigned int bytes1 =
-					runtime->buffer_size * stride - oldptr;
-			memcpy(runtime->dma_area + oldptr, cp, bytes1);
-			memcpy(runtime->dma_area, cp + bytes1, bytes - bytes1);
-		} else {
-			memcpy(runtime->dma_area + oldptr, cp, bytes);
-		}
-	}
-	if (period_elapsed)
-		snd_pcm_period_elapsed(subs->pcm_substream);
-	return 0;
-}
-
-/*
- * Process after capture complete when paused.  Nothing to do.
- */
-static int retire_paused_capture_urb(struct snd_usb_substream *subs,
-				     struct snd_pcm_runtime *runtime,
-				     struct urb *urb)
-{
-	return 0;
-}
-
-
-/*
- * prepare urb for full speed playback sync pipe
- *
- * set up the offset and length to receive the current frequency.
- */
-
-static int prepare_playback_sync_urb(struct snd_usb_substream *subs,
-				     struct snd_pcm_runtime *runtime,
-				     struct urb *urb)
-{
-	struct snd_urb_ctx *ctx = urb->context;
-
-	urb->dev = ctx->subs->dev; /* we need to set this at each time */
-	urb->iso_frame_desc[0].length = 3;
-	urb->iso_frame_desc[0].offset = 0;
-	return 0;
-}
-
-/*
- * prepare urb for high speed playback sync pipe
- *
- * set up the offset and length to receive the current frequency.
- */
-
-static int prepare_playback_sync_urb_hs(struct snd_usb_substream *subs,
-					struct snd_pcm_runtime *runtime,
-					struct urb *urb)
-{
-	struct snd_urb_ctx *ctx = urb->context;
-
-	urb->dev = ctx->subs->dev; /* we need to set this at each time */
-	urb->iso_frame_desc[0].length = 4;
-	urb->iso_frame_desc[0].offset = 0;
-	return 0;
-}
-
-/*
- * process after full speed playback sync complete
- *
- * retrieve the current 10.14 frequency from pipe, and set it.
- * the value is referred in prepare_playback_urb().
- */
-static int retire_playback_sync_urb(struct snd_usb_substream *subs,
-				    struct snd_pcm_runtime *runtime,
-				    struct urb *urb)
-{
-	unsigned int f;
-	unsigned long flags;
-
-	if (urb->iso_frame_desc[0].status == 0 &&
-	    urb->iso_frame_desc[0].actual_length == 3) {
-		f = combine_triple((u8*)urb->transfer_buffer) << 2;
-		if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
-			spin_lock_irqsave(&subs->lock, flags);
-			subs->freqm = f;
-			spin_unlock_irqrestore(&subs->lock, flags);
-		}
-	}
-
-	return 0;
-}
-
-/*
- * process after high speed playback sync complete
- *
- * retrieve the current 12.13 frequency from pipe, and set it.
- * the value is referred in prepare_playback_urb().
- */
-static int retire_playback_sync_urb_hs(struct snd_usb_substream *subs,
-				       struct snd_pcm_runtime *runtime,
-				       struct urb *urb)
-{
-	unsigned int f;
-	unsigned long flags;
-
-	if (urb->iso_frame_desc[0].status == 0 &&
-	    urb->iso_frame_desc[0].actual_length == 4) {
-		f = combine_quad((u8*)urb->transfer_buffer) & 0x0fffffff;
-		if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
-			spin_lock_irqsave(&subs->lock, flags);
-			subs->freqm = f;
-			spin_unlock_irqrestore(&subs->lock, flags);
-		}
-	}
-
-	return 0;
-}
-
-/*
- * process after E-Mu 0202/0404/Tracker Pre high speed playback sync complete
- *
- * These devices return the number of samples per packet instead of the number
- * of samples per microframe.
- */
-static int retire_playback_sync_urb_hs_emu(struct snd_usb_substream *subs,
-					   struct snd_pcm_runtime *runtime,
-					   struct urb *urb)
-{
-	unsigned int f;
-	unsigned long flags;
-
-	if (urb->iso_frame_desc[0].status == 0 &&
-	    urb->iso_frame_desc[0].actual_length == 4) {
-		f = combine_quad((u8*)urb->transfer_buffer) & 0x0fffffff;
-		f >>= subs->datainterval;
-		if (f >= subs->freqn - subs->freqn / 8 && f <= subs->freqmax) {
-			spin_lock_irqsave(&subs->lock, flags);
-			subs->freqm = f;
-			spin_unlock_irqrestore(&subs->lock, flags);
-		}
-	}
-
-	return 0;
-}
-
-/* determine the number of frames in the next packet */
-static int snd_usb_audio_next_packet_size(struct snd_usb_substream *subs)
-{
-	if (subs->fill_max)
-		return subs->maxframesize;
-	else {
-		subs->phase = (subs->phase & 0xffff)
-			+ (subs->freqm << subs->datainterval);
-		return min(subs->phase >> 16, subs->maxframesize);
-	}
-}
-
-/*
- * Prepare urb for streaming before playback starts or when paused.
- *
- * We don't have any data, so we send silence.
- */
-static int prepare_nodata_playback_urb(struct snd_usb_substream *subs,
-				       struct snd_pcm_runtime *runtime,
-				       struct urb *urb)
-{
-	unsigned int i, offs, counts;
-	struct snd_urb_ctx *ctx = urb->context;
-	int stride = runtime->frame_bits >> 3;
-
-	offs = 0;
-	urb->dev = ctx->subs->dev;
-	for (i = 0; i < ctx->packets; ++i) {
-		counts = snd_usb_audio_next_packet_size(subs);
-		urb->iso_frame_desc[i].offset = offs * stride;
-		urb->iso_frame_desc[i].length = counts * stride;
-		offs += counts;
-	}
-	urb->number_of_packets = ctx->packets;
-	urb->transfer_buffer_length = offs * stride;
-	memset(urb->transfer_buffer,
-	       subs->cur_audiofmt->format == SNDRV_PCM_FORMAT_U8 ? 0x80 : 0,
-	       offs * stride);
-	return 0;
-}
-
-/*
- * prepare urb for playback data pipe
- *
- * Since a URB can handle only a single linear buffer, we must use double
- * buffering when the data to be transferred overflows the buffer boundary.
- * To avoid inconsistencies when updating hwptr_done, we use double buffering
- * for all URBs.
- */
-static int prepare_playback_urb(struct snd_usb_substream *subs,
-				struct snd_pcm_runtime *runtime,
-				struct urb *urb)
-{
-	int i, stride;
-	unsigned int counts, frames, bytes;
-	unsigned long flags;
-	int period_elapsed = 0;
-	struct snd_urb_ctx *ctx = urb->context;
-
-	stride = runtime->frame_bits >> 3;
-
-	frames = 0;
-	urb->dev = ctx->subs->dev; /* we need to set this at each time */
-	urb->number_of_packets = 0;
-	spin_lock_irqsave(&subs->lock, flags);
-	for (i = 0; i < ctx->packets; i++) {
-		counts = snd_usb_audio_next_packet_size(subs);
-		/* set up descriptor */
-		urb->iso_frame_desc[i].offset = frames * stride;
-		urb->iso_frame_desc[i].length = counts * stride;
-		frames += counts;
-		urb->number_of_packets++;
-		subs->transfer_done += counts;
-		if (subs->transfer_done >= runtime->period_size) {
-			subs->transfer_done -= runtime->period_size;
-			period_elapsed = 1;
-			if (subs->fmt_type == UAC_FORMAT_TYPE_II) {
-				if (subs->transfer_done > 0) {
-					/* FIXME: fill-max mode is not
-					 * supported yet */
-					frames -= subs->transfer_done;
-					counts -= subs->transfer_done;
-					urb->iso_frame_desc[i].length =
-						counts * stride;
-					subs->transfer_done = 0;
-				}
-				i++;
-				if (i < ctx->packets) {
-					/* add a transfer delimiter */
-					urb->iso_frame_desc[i].offset =
-						frames * stride;
-					urb->iso_frame_desc[i].length = 0;
-					urb->number_of_packets++;
-				}
-				break;
-			}
- 		}
-		if (period_elapsed) /* finish at the period boundary */
-			break;
-	}
-	bytes = frames * stride;
-	if (subs->hwptr_done + bytes > runtime->buffer_size * stride) {
-		/* err, the transferred area goes over buffer boundary. */
-		unsigned int bytes1 =
-			runtime->buffer_size * stride - subs->hwptr_done;
-		memcpy(urb->transfer_buffer,
-		       runtime->dma_area + subs->hwptr_done, bytes1);
-		memcpy(urb->transfer_buffer + bytes1,
-		       runtime->dma_area, bytes - bytes1);
-	} else {
-		memcpy(urb->transfer_buffer,
-		       runtime->dma_area + subs->hwptr_done, bytes);
-	}
-	subs->hwptr_done += bytes;
-	if (subs->hwptr_done >= runtime->buffer_size * stride)
-		subs->hwptr_done -= runtime->buffer_size * stride;
-	runtime->delay += frames;
-	spin_unlock_irqrestore(&subs->lock, flags);
-	urb->transfer_buffer_length = bytes;
-	if (period_elapsed)
-		snd_pcm_period_elapsed(subs->pcm_substream);
-	return 0;
-}
-
-/*
- * process after playback data complete
- * - decrease the delay count again
- */
-static int retire_playback_urb(struct snd_usb_substream *subs,
-			       struct snd_pcm_runtime *runtime,
-			       struct urb *urb)
-{
-	unsigned long flags;
-	int stride = runtime->frame_bits >> 3;
-	int processed = urb->transfer_buffer_length / stride;
-
-	spin_lock_irqsave(&subs->lock, flags);
-	if (processed > runtime->delay)
-		runtime->delay = 0;
-	else
-		runtime->delay -= processed;
-	spin_unlock_irqrestore(&subs->lock, flags);
-	return 0;
-}
-
-
-/*
- */
-static struct snd_urb_ops audio_urb_ops[2] = {
-	{
-		.prepare =	prepare_nodata_playback_urb,
-		.retire =	retire_playback_urb,
-		.prepare_sync =	prepare_playback_sync_urb,
-		.retire_sync =	retire_playback_sync_urb,
-	},
-	{
-		.prepare =	prepare_capture_urb,
-		.retire =	retire_capture_urb,
-		.prepare_sync =	prepare_capture_sync_urb,
-		.retire_sync =	retire_capture_sync_urb,
-	},
-};
-
-static struct snd_urb_ops audio_urb_ops_high_speed[2] = {
-	{
-		.prepare =	prepare_nodata_playback_urb,
-		.retire =	retire_playback_urb,
-		.prepare_sync =	prepare_playback_sync_urb_hs,
-		.retire_sync =	retire_playback_sync_urb_hs,
-	},
-	{
-		.prepare =	prepare_capture_urb,
-		.retire =	retire_capture_urb,
-		.prepare_sync =	prepare_capture_sync_urb_hs,
-		.retire_sync =	retire_capture_sync_urb,
-	},
-};
-
-/*
- * complete callback from data urb
- */
-static void snd_complete_urb(struct urb *urb)
-{
-	struct snd_urb_ctx *ctx = urb->context;
-	struct snd_usb_substream *subs = ctx->subs;
-	struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
-	int err = 0;
-
-	if ((subs->running && subs->ops.retire(subs, substream->runtime, urb)) ||
-	    !subs->running || /* can be stopped during retire callback */
-	    (err = subs->ops.prepare(subs, substream->runtime, urb)) < 0 ||
-	    (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
-		clear_bit(ctx->index, &subs->active_mask);
-		if (err < 0) {
-			snd_printd(KERN_ERR "cannot submit urb (err = %d)\n", err);
-			snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
-		}
-	}
-}
-
-
-/*
- * complete callback from sync urb
- */
-static void snd_complete_sync_urb(struct urb *urb)
-{
-	struct snd_urb_ctx *ctx = urb->context;
-	struct snd_usb_substream *subs = ctx->subs;
-	struct snd_pcm_substream *substream = ctx->subs->pcm_substream;
-	int err = 0;
-
-	if ((subs->running && subs->ops.retire_sync(subs, substream->runtime, urb)) ||
-	    !subs->running || /* can be stopped during retire callback */
-	    (err = subs->ops.prepare_sync(subs, substream->runtime, urb)) < 0 ||
-	    (err = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
-		clear_bit(ctx->index + 16, &subs->active_mask);
-		if (err < 0) {
-			snd_printd(KERN_ERR "cannot submit sync urb (err = %d)\n", err);
-			snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
-		}
-	}
-}
-
-
-/*
- * unlink active urbs.
- */
-static int deactivate_urbs(struct snd_usb_substream *subs, int force, int can_sleep)
-{
-	unsigned int i;
-	int async;
-
-	subs->running = 0;
-
-	if (!force && subs->stream->chip->shutdown) /* to be sure... */
-		return -EBADFD;
-
-	async = !can_sleep && async_unlink;
-
-	if (!async && in_interrupt())
-		return 0;
-
-	for (i = 0; i < subs->nurbs; i++) {
-		if (test_bit(i, &subs->active_mask)) {
-			if (!test_and_set_bit(i, &subs->unlink_mask)) {
-				struct urb *u = subs->dataurb[i].urb;
-				if (async)
-					usb_unlink_urb(u);
-				else
-					usb_kill_urb(u);
-			}
-		}
-	}
-	if (subs->syncpipe) {
-		for (i = 0; i < SYNC_URBS; i++) {
-			if (test_bit(i+16, &subs->active_mask)) {
-				if (!test_and_set_bit(i+16, &subs->unlink_mask)) {
-					struct urb *u = subs->syncurb[i].urb;
-					if (async)
-						usb_unlink_urb(u);
-					else
-						usb_kill_urb(u);
-				}
-			}
-		}
-	}
-	return 0;
-}
-
-
-static const char *usb_error_string(int err)
-{
-	switch (err) {
-	case -ENODEV:
-		return "no device";
-	case -ENOENT:
-		return "endpoint not enabled";
-	case -EPIPE:
-		return "endpoint stalled";
-	case -ENOSPC:
-		return "not enough bandwidth";
-	case -ESHUTDOWN:
-		return "device disabled";
-	case -EHOSTUNREACH:
-		return "device suspended";
-	case -EINVAL:
-	case -EAGAIN:
-	case -EFBIG:
-	case -EMSGSIZE:
-		return "internal error";
-	default:
-		return "unknown error";
-	}
-}
-
-/*
- * set up and start data/sync urbs
- */
-static int start_urbs(struct snd_usb_substream *subs, struct snd_pcm_runtime *runtime)
-{
-	unsigned int i;
-	int err;
-
-	if (subs->stream->chip->shutdown)
-		return -EBADFD;
-
-	for (i = 0; i < subs->nurbs; i++) {
-		if (snd_BUG_ON(!subs->dataurb[i].urb))
-			return -EINVAL;
-		if (subs->ops.prepare(subs, runtime, subs->dataurb[i].urb) < 0) {
-			snd_printk(KERN_ERR "cannot prepare datapipe for urb %d\n", i);
-			goto __error;
-		}
-	}
-	if (subs->syncpipe) {
-		for (i = 0; i < SYNC_URBS; i++) {
-			if (snd_BUG_ON(!subs->syncurb[i].urb))
-				return -EINVAL;
-			if (subs->ops.prepare_sync(subs, runtime, subs->syncurb[i].urb) < 0) {
-				snd_printk(KERN_ERR "cannot prepare syncpipe for urb %d\n", i);
-				goto __error;
-			}
-		}
-	}
-
-	subs->active_mask = 0;
-	subs->unlink_mask = 0;
-	subs->running = 1;
-	for (i = 0; i < subs->nurbs; i++) {
-		err = usb_submit_urb(subs->dataurb[i].urb, GFP_ATOMIC);
-		if (err < 0) {
-			snd_printk(KERN_ERR "cannot submit datapipe "
-				   "for urb %d, error %d: %s\n",
-				   i, err, usb_error_string(err));
-			goto __error;
-		}
-		set_bit(i, &subs->active_mask);
-	}
-	if (subs->syncpipe) {
-		for (i = 0; i < SYNC_URBS; i++) {
-			err = usb_submit_urb(subs->syncurb[i].urb, GFP_ATOMIC);
-			if (err < 0) {
-				snd_printk(KERN_ERR "cannot submit syncpipe "
-					   "for urb %d, error %d: %s\n",
-					   i, err, usb_error_string(err));
-				goto __error;
-			}
-			set_bit(i + 16, &subs->active_mask);
-		}
-	}
-	return 0;
-
- __error:
-	// snd_pcm_stop(subs->pcm_substream, SNDRV_PCM_STATE_XRUN);
-	deactivate_urbs(subs, 0, 0);
-	return -EPIPE;
-}
-
-
-/*
- *  wait until all urbs are processed.
- */
-static int wait_clear_urbs(struct snd_usb_substream *subs)
-{
-	unsigned long end_time = jiffies + msecs_to_jiffies(1000);
-	unsigned int i;
-	int alive;
-
-	do {
-		alive = 0;
-		for (i = 0; i < subs->nurbs; i++) {
-			if (test_bit(i, &subs->active_mask))
-				alive++;
-		}
-		if (subs->syncpipe) {
-			for (i = 0; i < SYNC_URBS; i++) {
-				if (test_bit(i + 16, &subs->active_mask))
-					alive++;
-			}
-		}
-		if (! alive)
-			break;
-		schedule_timeout_uninterruptible(1);
-	} while (time_before(jiffies, end_time));
-	if (alive)
-		snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);
-	return 0;
-}
-
-
-/*
- * return the current pcm pointer.  just based on the hwptr_done value.
- */
-static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream)
-{
-	struct snd_usb_substream *subs;
-	unsigned int hwptr_done;
-	
-	subs = (struct snd_usb_substream *)substream->runtime->private_data;
-	spin_lock(&subs->lock);
-	hwptr_done = subs->hwptr_done;
-	spin_unlock(&subs->lock);
-	return hwptr_done / (substream->runtime->frame_bits >> 3);
-}
-
-
-/*
- * start/stop playback substream
- */
-static int snd_usb_pcm_playback_trigger(struct snd_pcm_substream *substream,
-					int cmd)
-{
-	struct snd_usb_substream *subs = substream->runtime->private_data;
-
-	switch (cmd) {
-	case SNDRV_PCM_TRIGGER_START:
-	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
-		subs->ops.prepare = prepare_playback_urb;
-		return 0;
-	case SNDRV_PCM_TRIGGER_STOP:
-		return deactivate_urbs(subs, 0, 0);
-	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
-		subs->ops.prepare = prepare_nodata_playback_urb;
-		return 0;
-	default:
-		return -EINVAL;
-	}
-}
-
-/*
- * start/stop capture substream
- */
-static int snd_usb_pcm_capture_trigger(struct snd_pcm_substream *substream,
-				       int cmd)
-{
-	struct snd_usb_substream *subs = substream->runtime->private_data;
-
-	switch (cmd) {
-	case SNDRV_PCM_TRIGGER_START:
-		subs->ops.retire = retire_capture_urb;
-		return start_urbs(subs, substream->runtime);
-	case SNDRV_PCM_TRIGGER_STOP:
-		return deactivate_urbs(subs, 0, 0);
-	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
-		subs->ops.retire = retire_paused_capture_urb;
-		return 0;
-	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
-		subs->ops.retire = retire_capture_urb;
-		return 0;
-	default:
-		return -EINVAL;
-	}
-}
-
-
-/*
- * release a urb data
- */
-static void release_urb_ctx(struct snd_urb_ctx *u)
-{
-	if (u->urb) {
-		if (u->buffer_size)
-			usb_buffer_free(u->subs->dev, u->buffer_size,
-					u->urb->transfer_buffer,
-					u->urb->transfer_dma);
-		usb_free_urb(u->urb);
-		u->urb = NULL;
-	}
-}
-
-/*
- * release a substream
- */
-static void release_substream_urbs(struct snd_usb_substream *subs, int force)
-{
-	int i;
-
-	/* stop urbs (to be sure) */
-	deactivate_urbs(subs, force, 1);
-	wait_clear_urbs(subs);
-
-	for (i = 0; i < MAX_URBS; i++)
-		release_urb_ctx(&subs->dataurb[i]);
-	for (i = 0; i < SYNC_URBS; i++)
-		release_urb_ctx(&subs->syncurb[i]);
-	usb_buffer_free(subs->dev, SYNC_URBS * 4,
-			subs->syncbuf, subs->sync_dma);
-	subs->syncbuf = NULL;
-	subs->nurbs = 0;
-}
-
-/*
- * initialize a substream for plaback/capture
- */
-static int init_substream_urbs(struct snd_usb_substream *subs, unsigned int period_bytes,
-			       unsigned int rate, unsigned int frame_bits)
-{
-	unsigned int maxsize, i;
-	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
-	unsigned int urb_packs, total_packs, packs_per_ms;
-
-	/* calculate the frequency in 16.16 format */
-	if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
-		subs->freqn = get_usb_full_speed_rate(rate);
-	else
-		subs->freqn = get_usb_high_speed_rate(rate);
-	subs->freqm = subs->freqn;
-	/* calculate max. frequency */
-	if (subs->maxpacksize) {
-		/* whatever fits into a max. size packet */
-		maxsize = subs->maxpacksize;
-		subs->freqmax = (maxsize / (frame_bits >> 3))
-				<< (16 - subs->datainterval);
-	} else {
-		/* no max. packet size: just take 25% higher than nominal */
-		subs->freqmax = subs->freqn + (subs->freqn >> 2);
-		maxsize = ((subs->freqmax + 0xffff) * (frame_bits >> 3))
-				>> (16 - subs->datainterval);
-	}
-	subs->phase = 0;
-
-	if (subs->fill_max)
-		subs->curpacksize = subs->maxpacksize;
-	else
-		subs->curpacksize = maxsize;
-
-	if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH)
-		packs_per_ms = 8 >> subs->datainterval;
-	else
-		packs_per_ms = 1;
-
-	if (is_playback) {
-		urb_packs = max(nrpacks, 1);
-		urb_packs = min(urb_packs, (unsigned int)MAX_PACKS);
-	} else
-		urb_packs = 1;
-	urb_packs *= packs_per_ms;
-	if (subs->syncpipe)
-		urb_packs = min(urb_packs, 1U << subs->syncinterval);
-
-	/* decide how many packets to be used */
-	if (is_playback) {
-		unsigned int minsize, maxpacks;
-		/* determine how small a packet can be */
-		minsize = (subs->freqn >> (16 - subs->datainterval))
-			  * (frame_bits >> 3);
-		/* with sync from device, assume it can be 12% lower */
-		if (subs->syncpipe)
-			minsize -= minsize >> 3;
-		minsize = max(minsize, 1u);
-		total_packs = (period_bytes + minsize - 1) / minsize;
-		/* we need at least two URBs for queueing */
-		if (total_packs < 2) {
-			total_packs = 2;
-		} else {
-			/* and we don't want too long a queue either */
-			maxpacks = max(MAX_QUEUE * packs_per_ms, urb_packs * 2);
-			total_packs = min(total_packs, maxpacks);
-		}
-	} else {
-		while (urb_packs > 1 && urb_packs * maxsize >= period_bytes)
-			urb_packs >>= 1;
-		total_packs = MAX_URBS * urb_packs;
-	}
-	subs->nurbs = (total_packs + urb_packs - 1) / urb_packs;
-	if (subs->nurbs > MAX_URBS) {
-		/* too much... */
-		subs->nurbs = MAX_URBS;
-		total_packs = MAX_URBS * urb_packs;
-	} else if (subs->nurbs < 2) {
-		/* too little - we need at least two packets
-		 * to ensure contiguous playback/capture
-		 */
-		subs->nurbs = 2;
-	}
-
-	/* allocate and initialize data urbs */
-	for (i = 0; i < subs->nurbs; i++) {
-		struct snd_urb_ctx *u = &subs->dataurb[i];
-		u->index = i;
-		u->subs = subs;
-		u->packets = (i + 1) * total_packs / subs->nurbs
-			- i * total_packs / subs->nurbs;
-		u->buffer_size = maxsize * u->packets;
-		if (subs->fmt_type == UAC_FORMAT_TYPE_II)
-			u->packets++; /* for transfer delimiter */
-		u->urb = usb_alloc_urb(u->packets, GFP_KERNEL);
-		if (!u->urb)
-			goto out_of_memory;
-		u->urb->transfer_buffer =
-			usb_buffer_alloc(subs->dev, u->buffer_size, GFP_KERNEL,
-					 &u->urb->transfer_dma);
-		if (!u->urb->transfer_buffer)
-			goto out_of_memory;
-		u->urb->pipe = subs->datapipe;
-		u->urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
-		u->urb->interval = 1 << subs->datainterval;
-		u->urb->context = u;
-		u->urb->complete = snd_complete_urb;
-	}
-
-	if (subs->syncpipe) {
-		/* allocate and initialize sync urbs */
-		subs->syncbuf = usb_buffer_alloc(subs->dev, SYNC_URBS * 4,
-						 GFP_KERNEL, &subs->sync_dma);
-		if (!subs->syncbuf)
-			goto out_of_memory;
-		for (i = 0; i < SYNC_URBS; i++) {
-			struct snd_urb_ctx *u = &subs->syncurb[i];
-			u->index = i;
-			u->subs = subs;
-			u->packets = 1;
-			u->urb = usb_alloc_urb(1, GFP_KERNEL);
-			if (!u->urb)
-				goto out_of_memory;
-			u->urb->transfer_buffer = subs->syncbuf + i * 4;
-			u->urb->transfer_dma = subs->sync_dma + i * 4;
-			u->urb->transfer_buffer_length = 4;
-			u->urb->pipe = subs->syncpipe;
-			u->urb->transfer_flags = URB_ISO_ASAP |
-						 URB_NO_TRANSFER_DMA_MAP;
-			u->urb->number_of_packets = 1;
-			u->urb->interval = 1 << subs->syncinterval;
-			u->urb->context = u;
-			u->urb->complete = snd_complete_sync_urb;
-		}
-	}
-	return 0;
-
-out_of_memory:
-	release_substream_urbs(subs, 0);
-	return -ENOMEM;
-}
-
-
-/*
- * find a matching audio format
- */
-static struct audioformat *find_format(struct snd_usb_substream *subs, unsigned int format,
-				       unsigned int rate, unsigned int channels)
-{
-	struct list_head *p;
-	struct audioformat *found = NULL;
-	int cur_attr = 0, attr;
-
-	list_for_each(p, &subs->fmt_list) {
-		struct audioformat *fp;
-		fp = list_entry(p, struct audioformat, list);
-		if (fp->format != format || fp->channels != channels)
-			continue;
-		if (rate < fp->rate_min || rate > fp->rate_max)
-			continue;
-		if (! (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)) {
-			unsigned int i;
-			for (i = 0; i < fp->nr_rates; i++)
-				if (fp->rate_table[i] == rate)
-					break;
-			if (i >= fp->nr_rates)
-				continue;
-		}
-		attr = fp->ep_attr & USB_ENDPOINT_SYNCTYPE;
-		if (! found) {
-			found = fp;
-			cur_attr = attr;
-			continue;
-		}
-		/* avoid async out and adaptive in if the other method
-		 * supports the same format.
-		 * this is a workaround for the case like
-		 * M-audio audiophile USB.
-		 */
-		if (attr != cur_attr) {
-			if ((attr == USB_ENDPOINT_SYNC_ASYNC &&
-			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
-			    (attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
-			     subs->direction == SNDRV_PCM_STREAM_CAPTURE))
-				continue;
-			if ((cur_attr == USB_ENDPOINT_SYNC_ASYNC &&
-			     subs->direction == SNDRV_PCM_STREAM_PLAYBACK) ||
-			    (cur_attr == USB_ENDPOINT_SYNC_ADAPTIVE &&
-			     subs->direction == SNDRV_PCM_STREAM_CAPTURE)) {
-				found = fp;
-				cur_attr = attr;
-				continue;
-			}
-		}
-		/* find the format with the largest max. packet size */
-		if (fp->maxpacksize > found->maxpacksize) {
-			found = fp;
-			cur_attr = attr;
-		}
-	}
-	return found;
-}
-
-
-/*
- * initialize the picth control and sample rate
- */
-static int init_usb_pitch(struct usb_device *dev, int iface,
-			  struct usb_host_interface *alts,
-			  struct audioformat *fmt)
-{
-	unsigned int ep;
-	unsigned char data[1];
-	int err;
-
-	ep = get_endpoint(alts, 0)->bEndpointAddress;
-	/* if endpoint has pitch control, enable it */
-	if (fmt->attributes & UAC_EP_CS_ATTR_PITCH_CONTROL) {
-		data[0] = 1;
-		if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
-					   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
-					   UAC_EP_CS_ATTR_PITCH_CONTROL << 8, ep, data, 1, 1000)) < 0) {
-			snd_printk(KERN_ERR "%d:%d:%d: cannot set enable PITCH\n",
-				   dev->devnum, iface, ep);
-			return err;
-		}
-	}
-	return 0;
-}
-
-static int init_usb_sample_rate(struct usb_device *dev, int iface,
-				struct usb_host_interface *alts,
-				struct audioformat *fmt, int rate)
-{
-	unsigned int ep;
-	unsigned char data[3];
-	int err;
-
-	ep = get_endpoint(alts, 0)->bEndpointAddress;
-	/* if endpoint has sampling rate control, set it */
-	if (fmt->attributes & UAC_EP_CS_ATTR_SAMPLE_RATE) {
-		int crate;
-		data[0] = rate;
-		data[1] = rate >> 8;
-		data[2] = rate >> 16;
-		if ((err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), UAC_SET_CUR,
-					   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_OUT,
-					   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, data, 3, 1000)) < 0) {
-			snd_printk(KERN_ERR "%d:%d:%d: cannot set freq %d to ep %#x\n",
-				   dev->devnum, iface, fmt->altsetting, rate, ep);
-			return err;
-		}
-		if ((err = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC_GET_CUR,
-					   USB_TYPE_CLASS|USB_RECIP_ENDPOINT|USB_DIR_IN,
-					   UAC_EP_CS_ATTR_SAMPLE_RATE << 8, ep, data, 3, 1000)) < 0) {
-			snd_printk(KERN_WARNING "%d:%d:%d: cannot get freq at ep %#x\n",
-				   dev->devnum, iface, fmt->altsetting, ep);
-			return 0; /* some devices don't support reading */
-		}
-		crate = data[0] | (data[1] << 8) | (data[2] << 16);
-		if (crate != rate) {
-			snd_printd(KERN_WARNING "current rate %d is different from the runtime rate %d\n", crate, rate);
-			// runtime->rate = crate;
-		}
-	}
-	return 0;
-}
-
-/*
- * For E-Mu 0404USB/0202USB/TrackerPre sample rate should be set for device,
- * not for interface.
- */
-static void set_format_emu_quirk(struct snd_usb_substream *subs,
-				 struct audioformat *fmt)
-{
-	unsigned char emu_samplerate_id = 0;
-
-	/* When capture is active
-	 * sample rate shouldn't be changed
-	 * by playback substream
-	 */
-	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
-		if (subs->stream->substream[SNDRV_PCM_STREAM_CAPTURE].interface != -1)
-			return;
-	}
-
-	switch (fmt->rate_min) {
-	case 48000:
-		emu_samplerate_id = EMU_QUIRK_SR_48000HZ;
-		break;
-	case 88200:
-		emu_samplerate_id = EMU_QUIRK_SR_88200HZ;
-		break;
-	case 96000:
-		emu_samplerate_id = EMU_QUIRK_SR_96000HZ;
-		break;
-	case 176400:
-		emu_samplerate_id = EMU_QUIRK_SR_176400HZ;
-		break;
-	case 192000:
-		emu_samplerate_id = EMU_QUIRK_SR_192000HZ;
-		break;
-	default:
-		emu_samplerate_id = EMU_QUIRK_SR_44100HZ;
-		break;
-	}
-	snd_emuusb_set_samplerate(subs->stream->chip, emu_samplerate_id);
-}
-
-/*
- * find a matching format and set up the interface
- */
-static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
-{
-	struct usb_device *dev = subs->dev;
-	struct usb_host_interface *alts;
-	struct usb_interface_descriptor *altsd;
-	struct usb_interface *iface;
-	unsigned int ep, attr;
-	int is_playback = subs->direction == SNDRV_PCM_STREAM_PLAYBACK;
-	int err;
-
-	iface = usb_ifnum_to_if(dev, fmt->iface);
-	if (WARN_ON(!iface))
-		return -EINVAL;
-	alts = &iface->altsetting[fmt->altset_idx];
-	altsd = get_iface_desc(alts);
-	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
-		return -EINVAL;
-
-	if (fmt == subs->cur_audiofmt)
-		return 0;
-
-	/* close the old interface */
-	if (subs->interface >= 0 && subs->interface != fmt->iface) {
-		if (usb_set_interface(subs->dev, subs->interface, 0) < 0) {
-			snd_printk(KERN_ERR "%d:%d:%d: return to setting 0 failed\n",
-				dev->devnum, fmt->iface, fmt->altsetting);
-			return -EIO;
-		}
-		subs->interface = -1;
-		subs->format = 0;
-	}
-
-	/* set interface */
-	if (subs->interface != fmt->iface || subs->format != fmt->altset_idx) {
-		if (usb_set_interface(dev, fmt->iface, fmt->altsetting) < 0) {
-			snd_printk(KERN_ERR "%d:%d:%d: usb_set_interface failed\n",
-				   dev->devnum, fmt->iface, fmt->altsetting);
-			return -EIO;
-		}
-		snd_printdd(KERN_INFO "setting usb interface %d:%d\n", fmt->iface, fmt->altsetting);
-		subs->interface = fmt->iface;
-		subs->format = fmt->altset_idx;
-	}
-
-	/* create a data pipe */
-	ep = fmt->endpoint & USB_ENDPOINT_NUMBER_MASK;
-	if (is_playback)
-		subs->datapipe = usb_sndisocpipe(dev, ep);
-	else
-		subs->datapipe = usb_rcvisocpipe(dev, ep);
-	subs->datainterval = fmt->datainterval;
-	subs->syncpipe = subs->syncinterval = 0;
-	subs->maxpacksize = fmt->maxpacksize;
-	subs->fill_max = 0;
-
-	/* we need a sync pipe in async OUT or adaptive IN mode */
-	/* check the number of EP, since some devices have broken
-	 * descriptors which fool us.  if it has only one EP,
-	 * assume it as adaptive-out or sync-in.
-	 */
-	attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
-	if (((is_playback && attr == USB_ENDPOINT_SYNC_ASYNC) ||
-	     (! is_playback && attr == USB_ENDPOINT_SYNC_ADAPTIVE)) &&
-	    altsd->bNumEndpoints >= 2) {
-		/* check sync-pipe endpoint */
-		/* ... and check descriptor size before accessing bSynchAddress
-		   because there is a version of the SB Audigy 2 NX firmware lacking
-		   the audio fields in the endpoint descriptors */
-		if ((get_endpoint(alts, 1)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != 0x01 ||
-		    (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
-		     get_endpoint(alts, 1)->bSynchAddress != 0)) {
-			snd_printk(KERN_ERR "%d:%d:%d : invalid synch pipe\n",
-				   dev->devnum, fmt->iface, fmt->altsetting);
-			return -EINVAL;
-		}
-		ep = get_endpoint(alts, 1)->bEndpointAddress;
-		if (get_endpoint(alts, 0)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
-		    (( is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress | USB_DIR_IN)) ||
-		     (!is_playback && ep != (unsigned int)(get_endpoint(alts, 0)->bSynchAddress & ~USB_DIR_IN)))) {
-			snd_printk(KERN_ERR "%d:%d:%d : invalid synch pipe\n",
-				   dev->devnum, fmt->iface, fmt->altsetting);
-			return -EINVAL;
-		}
-		ep &= USB_ENDPOINT_NUMBER_MASK;
-		if (is_playback)
-			subs->syncpipe = usb_rcvisocpipe(dev, ep);
-		else
-			subs->syncpipe = usb_sndisocpipe(dev, ep);
-		if (get_endpoint(alts, 1)->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE &&
-		    get_endpoint(alts, 1)->bRefresh >= 1 &&
-		    get_endpoint(alts, 1)->bRefresh <= 9)
-			subs->syncinterval = get_endpoint(alts, 1)->bRefresh;
-		else if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
-			subs->syncinterval = 1;
-		else if (get_endpoint(alts, 1)->bInterval >= 1 &&
-			 get_endpoint(alts, 1)->bInterval <= 16)
-			subs->syncinterval = get_endpoint(alts, 1)->bInterval - 1;
-		else
-			subs->syncinterval = 3;
-	}
-
-	/* always fill max packet size */
-	if (fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX)
-		subs->fill_max = 1;
-
-	if ((err = init_usb_pitch(dev, subs->interface, alts, fmt)) < 0)
-		return err;
-
-	subs->cur_audiofmt = fmt;
-
-	switch (subs->stream->chip->usb_id) {
-	case USB_ID(0x041e, 0x3f02): /* E-Mu 0202 USB */
-	case USB_ID(0x041e, 0x3f04): /* E-Mu 0404 USB */
-	case USB_ID(0x041e, 0x3f0a): /* E-Mu Tracker Pre */
-		set_format_emu_quirk(subs, fmt);
-		break;
-	}
-
-#if 0
-	printk(KERN_DEBUG
-	       "setting done: format = %d, rate = %d..%d, channels = %d\n",
-	       fmt->format, fmt->rate_min, fmt->rate_max, fmt->channels);
-	printk(KERN_DEBUG
-	       "  datapipe = 0x%0x, syncpipe = 0x%0x\n",
-	       subs->datapipe, subs->syncpipe);
-#endif
-
-	return 0;
-}
-
-/*
- * hw_params callback
- *
- * allocate a buffer and set the given audio format.
- *
- * so far we use a physically linear buffer although packetize transfer
- * doesn't need a continuous area.
- * if sg buffer is supported on the later version of alsa, we'll follow
- * that.
- */
-static int snd_usb_hw_params(struct snd_pcm_substream *substream,
-			     struct snd_pcm_hw_params *hw_params)
-{
-	struct snd_usb_substream *subs = substream->runtime->private_data;
-	struct audioformat *fmt;
-	unsigned int channels, rate, format;
-	int ret, changed;
-
-	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
-					       params_buffer_bytes(hw_params));
-	if (ret < 0)
-		return ret;
-
-	format = params_format(hw_params);
-	rate = params_rate(hw_params);
-	channels = params_channels(hw_params);
-	fmt = find_format(subs, format, rate, channels);
-	if (!fmt) {
-		snd_printd(KERN_DEBUG "cannot set format: format = %#x, rate = %d, channels = %d\n",
-			   format, rate, channels);
-		return -EINVAL;
-	}
-
-	changed = subs->cur_audiofmt != fmt ||
-		subs->period_bytes != params_period_bytes(hw_params) ||
-		subs->cur_rate != rate;
-	if ((ret = set_format(subs, fmt)) < 0)
-		return ret;
-
-	if (subs->cur_rate != rate) {
-		struct usb_host_interface *alts;
-		struct usb_interface *iface;
-		iface = usb_ifnum_to_if(subs->dev, fmt->iface);
-		alts = &iface->altsetting[fmt->altset_idx];
-		ret = init_usb_sample_rate(subs->dev, subs->interface, alts, fmt, rate);
-		if (ret < 0)
-			return ret;
-		subs->cur_rate = rate;
-	}
-
-	if (changed) {
-		/* format changed */
-		release_substream_urbs(subs, 0);
-		/* influenced: period_bytes, channels, rate, format, */
-		ret = init_substream_urbs(subs, params_period_bytes(hw_params),
-					  params_rate(hw_params),
-					  snd_pcm_format_physical_width(params_format(hw_params)) * params_channels(hw_params));
-	}
-
-	return ret;
-}
-
-/*
- * hw_free callback
- *
- * reset the audio format and release the buffer
- */
-static int snd_usb_hw_free(struct snd_pcm_substream *substream)
-{
-	struct snd_usb_substream *subs = substream->runtime->private_data;
-
-	subs->cur_audiofmt = NULL;
-	subs->cur_rate = 0;
-	subs->period_bytes = 0;
-	if (!subs->stream->chip->shutdown)
-		release_substream_urbs(subs, 0);
-	return snd_pcm_lib_free_vmalloc_buffer(substream);
-}
-
-/*
- * prepare callback
- *
- * only a few subtle things...
- */
-static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
-{
-	struct snd_pcm_runtime *runtime = substream->runtime;
-	struct snd_usb_substream *subs = runtime->private_data;
-
-	if (! subs->cur_audiofmt) {
-		snd_printk(KERN_ERR "usbaudio: no format is specified!\n");
-		return -ENXIO;
-	}
-
-	/* some unit conversions in runtime */
-	subs->maxframesize = bytes_to_frames(runtime, subs->maxpacksize);
-	subs->curframesize = bytes_to_frames(runtime, subs->curpacksize);
-
-	/* reset the pointer */
-	subs->hwptr_done = 0;
-	subs->transfer_done = 0;
-	subs->phase = 0;
-	runtime->delay = 0;
-
-	/* clear urbs (to be sure) */
-	deactivate_urbs(subs, 0, 1);
-	wait_clear_urbs(subs);
-
-	/* for playback, submit the URBs now; otherwise, the first hwptr_done
-	 * updates for all URBs would happen at the same time when starting */
-	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK) {
-		subs->ops.prepare = prepare_nodata_playback_urb;
-		return start_urbs(subs, runtime);
-	} else
-		return 0;
-}
-
-static struct snd_pcm_hardware snd_usb_hardware =
-{
-	.info =			SNDRV_PCM_INFO_MMAP |
-				SNDRV_PCM_INFO_MMAP_VALID |
-				SNDRV_PCM_INFO_BATCH |
-				SNDRV_PCM_INFO_INTERLEAVED |
-				SNDRV_PCM_INFO_BLOCK_TRANSFER |
-				SNDRV_PCM_INFO_PAUSE,
-	.buffer_bytes_max =	1024 * 1024,
-	.period_bytes_min =	64,
-	.period_bytes_max =	512 * 1024,
-	.periods_min =		2,
-	.periods_max =		1024,
-};
-
-/*
- * h/w constraints
- */
-
-#ifdef HW_CONST_DEBUG
-#define hwc_debug(fmt, args...) printk(KERN_DEBUG fmt, ##args)
-#else
-#define hwc_debug(fmt, args...) /**/
-#endif
-
-static int hw_check_valid_format(struct snd_usb_substream *subs,
-				 struct snd_pcm_hw_params *params,
-				 struct audioformat *fp)
-{
-	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
-	struct snd_interval *ct = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
-	struct snd_mask *fmts = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
-	struct snd_interval *pt = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
-	unsigned int ptime;
-
-	/* check the format */
-	if (!snd_mask_test(fmts, fp->format)) {
-		hwc_debug("   > check: no supported format %d\n", fp->format);
-		return 0;
-	}
-	/* check the channels */
-	if (fp->channels < ct->min || fp->channels > ct->max) {
-		hwc_debug("   > check: no valid channels %d (%d/%d)\n", fp->channels, ct->min, ct->max);
-		return 0;
-	}
-	/* check the rate is within the range */
-	if (fp->rate_min > it->max || (fp->rate_min == it->max && it->openmax)) {
-		hwc_debug("   > check: rate_min %d > max %d\n", fp->rate_min, it->max);
-		return 0;
-	}
-	if (fp->rate_max < it->min || (fp->rate_max == it->min && it->openmin)) {
-		hwc_debug("   > check: rate_max %d < min %d\n", fp->rate_max, it->min);
-		return 0;
-	}
-	/* check whether the period time is >= the data packet interval */
-	if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH) {
-		ptime = 125 * (1 << fp->datainterval);
-		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
-			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
-			return 0;
-		}
-	}
-	return 1;
-}
-
-static int hw_rule_rate(struct snd_pcm_hw_params *params,
-			struct snd_pcm_hw_rule *rule)
-{
-	struct snd_usb_substream *subs = rule->private;
-	struct list_head *p;
-	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
-	unsigned int rmin, rmax;
-	int changed;
-
-	hwc_debug("hw_rule_rate: (%d,%d)\n", it->min, it->max);
-	changed = 0;
-	rmin = rmax = 0;
-	list_for_each(p, &subs->fmt_list) {
-		struct audioformat *fp;
-		fp = list_entry(p, struct audioformat, list);
-		if (!hw_check_valid_format(subs, params, fp))
-			continue;
-		if (changed++) {
-			if (rmin > fp->rate_min)
-				rmin = fp->rate_min;
-			if (rmax < fp->rate_max)
-				rmax = fp->rate_max;
-		} else {
-			rmin = fp->rate_min;
-			rmax = fp->rate_max;
-		}
-	}
-
-	if (!changed) {
-		hwc_debug("  --> get empty\n");
-		it->empty = 1;
-		return -EINVAL;
-	}
-
-	changed = 0;
-	if (it->min < rmin) {
-		it->min = rmin;
-		it->openmin = 0;
-		changed = 1;
-	}
-	if (it->max > rmax) {
-		it->max = rmax;
-		it->openmax = 0;
-		changed = 1;
-	}
-	if (snd_interval_checkempty(it)) {
-		it->empty = 1;
-		return -EINVAL;
-	}
-	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
-	return changed;
-}
-
-
-static int hw_rule_channels(struct snd_pcm_hw_params *params,
-			    struct snd_pcm_hw_rule *rule)
-{
-	struct snd_usb_substream *subs = rule->private;
-	struct list_head *p;
-	struct snd_interval *it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
-	unsigned int rmin, rmax;
-	int changed;
-
-	hwc_debug("hw_rule_channels: (%d,%d)\n", it->min, it->max);
-	changed = 0;
-	rmin = rmax = 0;
-	list_for_each(p, &subs->fmt_list) {
-		struct audioformat *fp;
-		fp = list_entry(p, struct audioformat, list);
-		if (!hw_check_valid_format(subs, params, fp))
-			continue;
-		if (changed++) {
-			if (rmin > fp->channels)
-				rmin = fp->channels;
-			if (rmax < fp->channels)
-				rmax = fp->channels;
-		} else {
-			rmin = fp->channels;
-			rmax = fp->channels;
-		}
-	}
-
-	if (!changed) {
-		hwc_debug("  --> get empty\n");
-		it->empty = 1;
-		return -EINVAL;
-	}
-
-	changed = 0;
-	if (it->min < rmin) {
-		it->min = rmin;
-		it->openmin = 0;
-		changed = 1;
-	}
-	if (it->max > rmax) {
-		it->max = rmax;
-		it->openmax = 0;
-		changed = 1;
-	}
-	if (snd_interval_checkempty(it)) {
-		it->empty = 1;
-		return -EINVAL;
-	}
-	hwc_debug("  --> (%d, %d) (changed = %d)\n", it->min, it->max, changed);
-	return changed;
-}
-
-static int hw_rule_format(struct snd_pcm_hw_params *params,
-			  struct snd_pcm_hw_rule *rule)
-{
-	struct snd_usb_substream *subs = rule->private;
-	struct list_head *p;
-	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
-	u64 fbits;
-	u32 oldbits[2];
-	int changed;
-
-	hwc_debug("hw_rule_format: %x:%x\n", fmt->bits[0], fmt->bits[1]);
-	fbits = 0;
-	list_for_each(p, &subs->fmt_list) {
-		struct audioformat *fp;
-		fp = list_entry(p, struct audioformat, list);
-		if (!hw_check_valid_format(subs, params, fp))
-			continue;
-		fbits |= (1ULL << fp->format);
-	}
-
-	oldbits[0] = fmt->bits[0];
-	oldbits[1] = fmt->bits[1];
-	fmt->bits[0] &= (u32)fbits;
-	fmt->bits[1] &= (u32)(fbits >> 32);
-	if (!fmt->bits[0] && !fmt->bits[1]) {
-		hwc_debug("  --> get empty\n");
-		return -EINVAL;
-	}
-	changed = (oldbits[0] != fmt->bits[0] || oldbits[1] != fmt->bits[1]);
-	hwc_debug("  --> %x:%x (changed = %d)\n", fmt->bits[0], fmt->bits[1], changed);
-	return changed;
-}
-
-static int hw_rule_period_time(struct snd_pcm_hw_params *params,
-			       struct snd_pcm_hw_rule *rule)
-{
-	struct snd_usb_substream *subs = rule->private;
-	struct audioformat *fp;
-	struct snd_interval *it;
-	unsigned char min_datainterval;
-	unsigned int pmin;
-	int changed;
-
-	it = hw_param_interval(params, SNDRV_PCM_HW_PARAM_PERIOD_TIME);
-	hwc_debug("hw_rule_period_time: (%u,%u)\n", it->min, it->max);
-	min_datainterval = 0xff;
-	list_for_each_entry(fp, &subs->fmt_list, list) {
-		if (!hw_check_valid_format(subs, params, fp))
-			continue;
-		min_datainterval = min(min_datainterval, fp->datainterval);
-	}
-	if (min_datainterval == 0xff) {
-		hwc_debug("  --> get emtpy\n");
-		it->empty = 1;
-		return -EINVAL;
-	}
-	pmin = 125 * (1 << min_datainterval);
-	changed = 0;
-	if (it->min < pmin) {
-		it->min = pmin;
-		it->openmin = 0;
-		changed = 1;
-	}
-	if (snd_interval_checkempty(it)) {
-		it->empty = 1;
-		return -EINVAL;
-	}
-	hwc_debug("  --> (%u,%u) (changed = %d)\n", it->min, it->max, changed);
-	return changed;
-}
-
-/*
- *  If the device supports unusual bit rates, does the request meet these?
- */
-static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
-				  struct snd_usb_substream *subs)
-{
-	struct audioformat *fp;
-	int count = 0, needs_knot = 0;
-	int err;
-
-	list_for_each_entry(fp, &subs->fmt_list, list) {
-		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
-			return 0;
-		count += fp->nr_rates;
-		if (fp->rates & SNDRV_PCM_RATE_KNOT)
-			needs_knot = 1;
-	}
-	if (!needs_knot)
-		return 0;
-
-	subs->rate_list.count = count;
-	subs->rate_list.list = kmalloc(sizeof(int) * count, GFP_KERNEL);
-	subs->rate_list.mask = 0;
-	count = 0;
-	list_for_each_entry(fp, &subs->fmt_list, list) {
-		int i;
-		for (i = 0; i < fp->nr_rates; i++)
-			subs->rate_list.list[count++] = fp->rate_table[i];
-	}
-	err = snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
-					 &subs->rate_list);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-
-
-/*
- * set up the runtime hardware information.
- */
-
-static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substream *subs)
-{
-	struct list_head *p;
-	unsigned int pt, ptmin;
-	int param_period_time_if_needed;
-	int err;
-
-	runtime->hw.formats = subs->formats;
-
-	runtime->hw.rate_min = 0x7fffffff;
-	runtime->hw.rate_max = 0;
-	runtime->hw.channels_min = 256;
-	runtime->hw.channels_max = 0;
-	runtime->hw.rates = 0;
-	ptmin = UINT_MAX;
-	/* check min/max rates and channels */
-	list_for_each(p, &subs->fmt_list) {
-		struct audioformat *fp;
-		fp = list_entry(p, struct audioformat, list);
-		runtime->hw.rates |= fp->rates;
-		if (runtime->hw.rate_min > fp->rate_min)
-			runtime->hw.rate_min = fp->rate_min;
-		if (runtime->hw.rate_max < fp->rate_max)
-			runtime->hw.rate_max = fp->rate_max;
-		if (runtime->hw.channels_min > fp->channels)
-			runtime->hw.channels_min = fp->channels;
-		if (runtime->hw.channels_max < fp->channels)
-			runtime->hw.channels_max = fp->channels;
-		if (fp->fmt_type == UAC_FORMAT_TYPE_II && fp->frame_size > 0) {
-			/* FIXME: there might be more than one audio formats... */
-			runtime->hw.period_bytes_min = runtime->hw.period_bytes_max =
-				fp->frame_size;
-		}
-		pt = 125 * (1 << fp->datainterval);
-		ptmin = min(ptmin, pt);
-	}
-
-	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
-	if (snd_usb_get_speed(subs->dev) != USB_SPEED_HIGH)
-		/* full speed devices have fixed data packet interval */
-		ptmin = 1000;
-	if (ptmin == 1000)
-		/* if period time doesn't go below 1 ms, no rules needed */
-		param_period_time_if_needed = -1;
-	snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_PERIOD_TIME,
-				     ptmin, UINT_MAX);
-
-	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
-				       hw_rule_rate, subs,
-				       SNDRV_PCM_HW_PARAM_FORMAT,
-				       SNDRV_PCM_HW_PARAM_CHANNELS,
-				       param_period_time_if_needed,
-				       -1)) < 0)
-		return err;
-	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
-				       hw_rule_channels, subs,
-				       SNDRV_PCM_HW_PARAM_FORMAT,
-				       SNDRV_PCM_HW_PARAM_RATE,
-				       param_period_time_if_needed,
-				       -1)) < 0)
-		return err;
-	if ((err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
-				       hw_rule_format, subs,
-				       SNDRV_PCM_HW_PARAM_RATE,
-				       SNDRV_PCM_HW_PARAM_CHANNELS,
-				       param_period_time_if_needed,
-				       -1)) < 0)
-		return err;
-	if (param_period_time_if_needed >= 0) {
-		err = snd_pcm_hw_rule_add(runtime, 0,
-					  SNDRV_PCM_HW_PARAM_PERIOD_TIME,
-					  hw_rule_period_time, subs,
-					  SNDRV_PCM_HW_PARAM_FORMAT,
-					  SNDRV_PCM_HW_PARAM_CHANNELS,
-					  SNDRV_PCM_HW_PARAM_RATE,
-					  -1);
-		if (err < 0)
-			return err;
-	}
-	if ((err = snd_usb_pcm_check_knot(runtime, subs)) < 0)
-		return err;
-	return 0;
-}
-
-static int snd_usb_pcm_open(struct snd_pcm_substream *substream, int direction)
-{
-	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
-	struct snd_pcm_runtime *runtime = substream->runtime;
-	struct snd_usb_substream *subs = &as->substream[direction];
-
-	subs->interface = -1;
-	subs->format = 0;
-	runtime->hw = snd_usb_hardware;
-	runtime->private_data = subs;
-	subs->pcm_substream = substream;
-	return setup_hw_info(runtime, subs);
-}
-
-static int snd_usb_pcm_close(struct snd_pcm_substream *substream, int direction)
-{
-	struct snd_usb_stream *as = snd_pcm_substream_chip(substream);
-	struct snd_usb_substream *subs = &as->substream[direction];
-
-	if (!as->chip->shutdown && subs->interface >= 0) {
-		usb_set_interface(subs->dev, subs->interface, 0);
-		subs->interface = -1;
-	}
-	subs->pcm_substream = NULL;
-	return 0;
-}
-
-static int snd_usb_playback_open(struct snd_pcm_substream *substream)
-{
-	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_PLAYBACK);
-}
-
-static int snd_usb_playback_close(struct snd_pcm_substream *substream)
-{
-	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_PLAYBACK);
-}
-
-static int snd_usb_capture_open(struct snd_pcm_substream *substream)
-{
-	return snd_usb_pcm_open(substream, SNDRV_PCM_STREAM_CAPTURE);
-}
-
-static int snd_usb_capture_close(struct snd_pcm_substream *substream)
-{
-	return snd_usb_pcm_close(substream, SNDRV_PCM_STREAM_CAPTURE);
-}
-
-static struct snd_pcm_ops snd_usb_playback_ops = {
-	.open =		snd_usb_playback_open,
-	.close =	snd_usb_playback_close,
-	.ioctl =	snd_pcm_lib_ioctl,
-	.hw_params =	snd_usb_hw_params,
-	.hw_free =	snd_usb_hw_free,
-	.prepare =	snd_usb_pcm_prepare,
-	.trigger =	snd_usb_pcm_playback_trigger,
-	.pointer =	snd_usb_pcm_pointer,
-	.page =		snd_pcm_lib_get_vmalloc_page,
-	.mmap =		snd_pcm_lib_mmap_vmalloc,
-};
-
-static struct snd_pcm_ops snd_usb_capture_ops = {
-	.open =		snd_usb_capture_open,
-	.close =	snd_usb_capture_close,
-	.ioctl =	snd_pcm_lib_ioctl,
-	.hw_params =	snd_usb_hw_params,
-	.hw_free =	snd_usb_hw_free,
-	.prepare =	snd_usb_pcm_prepare,
-	.trigger =	snd_usb_pcm_capture_trigger,
-	.pointer =	snd_usb_pcm_pointer,
-	.page =		snd_pcm_lib_get_vmalloc_page,
-	.mmap =		snd_pcm_lib_mmap_vmalloc,
-};
-
-
-
-/*
- * helper functions
- */
-
-/*
- * combine bytes and get an integer value
- */
-unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size)
-{
-	switch (size) {
-	case 1:  return *bytes;
-	case 2:  return combine_word(bytes);
-	case 3:  return combine_triple(bytes);
-	case 4:  return combine_quad(bytes);
-	default: return 0;
-	}
-}
-
-/*
- * parse descriptor buffer and return the pointer starting the given
- * descriptor type.
- */
-void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype)
-{
-	u8 *p, *end, *next;
-
-	p = descstart;
-	end = p + desclen;
-	for (; p < end;) {
-		if (p[0] < 2)
-			return NULL;
-		next = p + p[0];
-		if (next > end)
-			return NULL;
-		if (p[1] == dtype && (!after || (void *)p > after)) {
-			return p;
-		}
-		p = next;
-	}
-	return NULL;
-}
-
-/*
- * find a class-specified interface descriptor with the given subtype.
- */
-void *snd_usb_find_csint_desc(void *buffer, int buflen, void *after, u8 dsubtype)
-{
-	unsigned char *p = after;
-
-	while ((p = snd_usb_find_desc(buffer, buflen, p,
-				      USB_DT_CS_INTERFACE)) != NULL) {
-		if (p[0] >= 3 && p[2] == dsubtype)
-			return p;
-	}
-	return NULL;
-}
-
-/*
- * Wrapper for usb_control_msg().
- * Allocates a temp buffer to prevent dmaing from/to the stack.
- */
-int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe, __u8 request,
-		    __u8 requesttype, __u16 value, __u16 index, void *data,
-		    __u16 size, int timeout)
-{
-	int err;
-	void *buf = NULL;
-
-	if (size > 0) {
-		buf = kmemdup(data, size, GFP_KERNEL);
-		if (!buf)
-			return -ENOMEM;
-	}
-	err = usb_control_msg(dev, pipe, request, requesttype,
-			      value, index, buf, size, timeout);
-	if (size > 0) {
-		memcpy(data, buf, size);
-		kfree(buf);
-	}
-	return err;
-}
-
-
-/*
- * entry point for linux usb interface
- */
-
-static int usb_audio_probe(struct usb_interface *intf,
-			   const struct usb_device_id *id);
-static void usb_audio_disconnect(struct usb_interface *intf);
-
-#ifdef CONFIG_PM
-static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message);
-static int usb_audio_resume(struct usb_interface *intf);
-#else
-#define usb_audio_suspend NULL
-#define usb_audio_resume NULL
-#endif
-
-static struct usb_device_id usb_audio_ids [] = {
-#include "usbquirks.h"
-    { .match_flags = (USB_DEVICE_ID_MATCH_INT_CLASS | USB_DEVICE_ID_MATCH_INT_SUBCLASS),
-      .bInterfaceClass = USB_CLASS_AUDIO,
-      .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL },
-    { }						/* Terminating entry */
-};
-
-MODULE_DEVICE_TABLE (usb, usb_audio_ids);
-
-static struct usb_driver usb_audio_driver = {
-	.name =		"snd-usb-audio",
-	.probe =	usb_audio_probe,
-	.disconnect =	usb_audio_disconnect,
-	.suspend =	usb_audio_suspend,
-	.resume =	usb_audio_resume,
-	.id_table =	usb_audio_ids,
-};
-
-
-#if defined(CONFIG_PROC_FS) && defined(CONFIG_SND_VERBOSE_PROCFS)
-
-/*
- * proc interface for list the supported pcm formats
- */
-static void proc_dump_substream_formats(struct snd_usb_substream *subs, struct snd_info_buffer *buffer)
-{
-	struct list_head *p;
-	static char *sync_types[4] = {
-		"NONE", "ASYNC", "ADAPTIVE", "SYNC"
-	};
-
-	list_for_each(p, &subs->fmt_list) {
-		struct audioformat *fp;
-		fp = list_entry(p, struct audioformat, list);
-		snd_iprintf(buffer, "  Interface %d\n", fp->iface);
-		snd_iprintf(buffer, "    Altset %d\n", fp->altsetting);
-		snd_iprintf(buffer, "    Format: %s\n",
-			    snd_pcm_format_name(fp->format));
-		snd_iprintf(buffer, "    Channels: %d\n", fp->channels);
-		snd_iprintf(buffer, "    Endpoint: %d %s (%s)\n",
-			    fp->endpoint & USB_ENDPOINT_NUMBER_MASK,
-			    fp->endpoint & USB_DIR_IN ? "IN" : "OUT",
-			    sync_types[(fp->ep_attr & USB_ENDPOINT_SYNCTYPE) >> 2]);
-		if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS) {
-			snd_iprintf(buffer, "    Rates: %d - %d (continuous)\n",
-				    fp->rate_min, fp->rate_max);
-		} else {
-			unsigned int i;
-			snd_iprintf(buffer, "    Rates: ");
-			for (i = 0; i < fp->nr_rates; i++) {
-				if (i > 0)
-					snd_iprintf(buffer, ", ");
-				snd_iprintf(buffer, "%d", fp->rate_table[i]);
-			}
-			snd_iprintf(buffer, "\n");
-		}
-		if (snd_usb_get_speed(subs->dev) == USB_SPEED_HIGH)
-			snd_iprintf(buffer, "    Data packet interval: %d us\n",
-				    125 * (1 << fp->datainterval));
-		// snd_iprintf(buffer, "    Max Packet Size = %d\n", fp->maxpacksize);
-		// snd_iprintf(buffer, "    EP Attribute = %#x\n", fp->attributes);
-	}
-}
-
-static void proc_dump_substream_status(struct snd_usb_substream *subs, struct snd_info_buffer *buffer)
-{
-	if (subs->running) {
-		unsigned int i;
-		snd_iprintf(buffer, "  Status: Running\n");
-		snd_iprintf(buffer, "    Interface = %d\n", subs->interface);
-		snd_iprintf(buffer, "    Altset = %d\n", subs->format);
-		snd_iprintf(buffer, "    URBs = %d [ ", subs->nurbs);
-		for (i = 0; i < subs->nurbs; i++)
-			snd_iprintf(buffer, "%d ", subs->dataurb[i].packets);
-		snd_iprintf(buffer, "]\n");
-		snd_iprintf(buffer, "    Packet Size = %d\n", subs->curpacksize);
-		snd_iprintf(buffer, "    Momentary freq = %u Hz (%#x.%04x)\n",
-			    snd_usb_get_speed(subs->dev) == USB_SPEED_FULL
-			    ? get_full_speed_hz(subs->freqm)
-			    : get_high_speed_hz(subs->freqm),
-			    subs->freqm >> 16, subs->freqm & 0xffff);
-	} else {
-		snd_iprintf(buffer, "  Status: Stop\n");
-	}
-}
-
-static void proc_pcm_format_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
-{
-	struct snd_usb_stream *stream = entry->private_data;
-
-	snd_iprintf(buffer, "%s : %s\n", stream->chip->card->longname, stream->pcm->name);
-
-	if (stream->substream[SNDRV_PCM_STREAM_PLAYBACK].num_formats) {
-		snd_iprintf(buffer, "\nPlayback:\n");
-		proc_dump_substream_status(&stream->substream[SNDRV_PCM_STREAM_PLAYBACK], buffer);
-		proc_dump_substream_formats(&stream->substream[SNDRV_PCM_STREAM_PLAYBACK], buffer);
-	}
-	if (stream->substream[SNDRV_PCM_STREAM_CAPTURE].num_formats) {
-		snd_iprintf(buffer, "\nCapture:\n");
-		proc_dump_substream_status(&stream->substream[SNDRV_PCM_STREAM_CAPTURE], buffer);
-		proc_dump_substream_formats(&stream->substream[SNDRV_PCM_STREAM_CAPTURE], buffer);
-	}
-}
-
-static void proc_pcm_format_add(struct snd_usb_stream *stream)
-{
-	struct snd_info_entry *entry;
-	char name[32];
-	struct snd_card *card = stream->chip->card;
-
-	sprintf(name, "stream%d", stream->pcm_index);
-	if (!snd_card_proc_new(card, name, &entry))
-		snd_info_set_text_ops(entry, stream, proc_pcm_format_read);
-}
-
-#else
-
-static inline void proc_pcm_format_add(struct snd_usb_stream *stream)
-{
-}
-
-#endif
-
-/*
- * initialize the substream instance.
- */
-
-static void init_substream(struct snd_usb_stream *as, int stream, struct audioformat *fp)
-{
-	struct snd_usb_substream *subs = &as->substream[stream];
-
-	INIT_LIST_HEAD(&subs->fmt_list);
-	spin_lock_init(&subs->lock);
-
-	subs->stream = as;
-	subs->direction = stream;
-	subs->dev = as->chip->dev;
-	subs->txfr_quirk = as->chip->txfr_quirk;
-	if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL) {
-		subs->ops = audio_urb_ops[stream];
-	} else {
-		subs->ops = audio_urb_ops_high_speed[stream];
-		switch (as->chip->usb_id) {
-		case USB_ID(0x041e, 0x3f02): /* E-Mu 0202 USB */
-		case USB_ID(0x041e, 0x3f04): /* E-Mu 0404 USB */
-		case USB_ID(0x041e, 0x3f0a): /* E-Mu Tracker Pre */
-			subs->ops.retire_sync = retire_playback_sync_urb_hs_emu;
-			break;
-		}
-	}
-	snd_pcm_set_ops(as->pcm, stream,
-			stream == SNDRV_PCM_STREAM_PLAYBACK ?
-			&snd_usb_playback_ops : &snd_usb_capture_ops);
-
-	list_add_tail(&fp->list, &subs->fmt_list);
-	subs->formats |= 1ULL << fp->format;
-	subs->endpoint = fp->endpoint;
-	subs->num_formats++;
-	subs->fmt_type = fp->fmt_type;
-}
-
-
-/*
- * free a substream
- */
-static void free_substream(struct snd_usb_substream *subs)
-{
-	struct list_head *p, *n;
-
-	if (!subs->num_formats)
-		return; /* not initialized */
-	list_for_each_safe(p, n, &subs->fmt_list) {
-		struct audioformat *fp = list_entry(p, struct audioformat, list);
-		kfree(fp->rate_table);
-		kfree(fp);
-	}
-	kfree(subs->rate_list.list);
-}
-
-
-/*
- * free a usb stream instance
- */
-static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
-{
-	free_substream(&stream->substream[0]);
-	free_substream(&stream->substream[1]);
-	list_del(&stream->list);
-	kfree(stream);
-}
-
-static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
-{
-	struct snd_usb_stream *stream = pcm->private_data;
-	if (stream) {
-		stream->pcm = NULL;
-		snd_usb_audio_stream_free(stream);
-	}
-}
-
-
-/*
- * add this endpoint to the chip instance.
- * if a stream with the same endpoint already exists, append to it.
- * if not, create a new pcm stream.
- */
-static int add_audio_endpoint(struct snd_usb_audio *chip, int stream, struct audioformat *fp)
-{
-	struct list_head *p;
-	struct snd_usb_stream *as;
-	struct snd_usb_substream *subs;
-	struct snd_pcm *pcm;
-	int err;
-
-	list_for_each(p, &chip->pcm_list) {
-		as = list_entry(p, struct snd_usb_stream, list);
-		if (as->fmt_type != fp->fmt_type)
-			continue;
-		subs = &as->substream[stream];
-		if (!subs->endpoint)
-			continue;
-		if (subs->endpoint == fp->endpoint) {
-			list_add_tail(&fp->list, &subs->fmt_list);
-			subs->num_formats++;
-			subs->formats |= 1ULL << fp->format;
-			return 0;
-		}
-	}
-	/* look for an empty stream */
-	list_for_each(p, &chip->pcm_list) {
-		as = list_entry(p, struct snd_usb_stream, list);
-		if (as->fmt_type != fp->fmt_type)
-			continue;
-		subs = &as->substream[stream];
-		if (subs->endpoint)
-			continue;
-		err = snd_pcm_new_stream(as->pcm, stream, 1);
-		if (err < 0)
-			return err;
-		init_substream(as, stream, fp);
-		return 0;
-	}
-
-	/* create a new pcm */
-	as = kzalloc(sizeof(*as), GFP_KERNEL);
-	if (!as)
-		return -ENOMEM;
-	as->pcm_index = chip->pcm_devs;
-	as->chip = chip;
-	as->fmt_type = fp->fmt_type;
-	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
-			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
-			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
-			  &pcm);
-	if (err < 0) {
-		kfree(as);
-		return err;
-	}
-	as->pcm = pcm;
-	pcm->private_data = as;
-	pcm->private_free = snd_usb_audio_pcm_free;
-	pcm->info_flags = 0;
-	if (chip->pcm_devs > 0)
-		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
-	else
-		strcpy(pcm->name, "USB Audio");
-
-	init_substream(as, stream, fp);
-
-	list_add(&as->list, &chip->pcm_list);
-	chip->pcm_devs++;
-
-	proc_pcm_format_add(as);
-
-	return 0;
-}
-
-
-/*
- * check if the device uses big-endian samples
- */
-static int is_big_endian_format(struct snd_usb_audio *chip, struct audioformat *fp)
-{
-	switch (chip->usb_id) {
-	case USB_ID(0x0763, 0x2001): /* M-Audio Quattro: captured data only */
-		if (fp->endpoint & USB_DIR_IN)
-			return 1;
-		break;
-	case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
-		if (device_setup[chip->index] == 0x00 ||
-		    fp->altsetting==1 || fp->altsetting==2 || fp->altsetting==3)
-			return 1;
-	}
-	return 0;
-}
-
-/*
- * parse the audio format type I descriptor
- * and returns the corresponding pcm format
- *
- * @dev: usb device
- * @fp: audioformat record
- * @format: the format tag (wFormatTag)
- * @fmt: the format type descriptor
- */
-static int parse_audio_format_i_type(struct snd_usb_audio *chip,
-				     struct audioformat *fp,
-				     int format, void *_fmt,
-				     int protocol)
-{
-	int pcm_format, i;
-	int sample_width, sample_bytes;
-
-	switch (protocol) {
-	case UAC_VERSION_1: {
-		struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
-		sample_width = fmt->bBitResolution;
-		sample_bytes = fmt->bSubframeSize;
-		break;
-	}
-
-	case UAC_VERSION_2: {
-		struct uac_format_type_i_ext_descriptor *fmt = _fmt;
-		sample_width = fmt->bBitResolution;
-		sample_bytes = fmt->bSubslotSize;
-
-		/*
-		 * FIXME
-		 * USB audio class v2 devices specify a bitmap of possible
-		 * audio formats rather than one fix value. For now, we just
-		 * pick one of them and report that as the only possible
-		 * value for this setting.
-		 * The bit allocation map is in fact compatible to the
-		 * wFormatTag of the v1 AS streaming descriptors, which is why
-		 * we can simply map the matrix.
-		 */
-
-		for (i = 0; i < 5; i++)
-			if (format & (1UL << i)) {
-				format = i + 1;
-				break;
-			}
-
-		break;
-	}
-
-	default:
-		return -EINVAL;
-	}
-
-	/* FIXME: correct endianess and sign? */
-	pcm_format = -1;
-
-	switch (format) {
-	case UAC_FORMAT_TYPE_I_UNDEFINED: /* some devices don't define this correctly... */
-		snd_printdd(KERN_INFO "%d:%u:%d : format type 0 is detected, processed as PCM\n",
-			    chip->dev->devnum, fp->iface, fp->altsetting);
-		/* fall-through */
-	case UAC_FORMAT_TYPE_I_PCM:
-		if (sample_width > sample_bytes * 8) {
-			snd_printk(KERN_INFO "%d:%u:%d : sample bitwidth %d in over sample bytes %d\n",
-				   chip->dev->devnum, fp->iface, fp->altsetting,
-				   sample_width, sample_bytes);
-		}
-		/* check the format byte size */
-		switch (sample_bytes) {
-		case 1:
-			pcm_format = SNDRV_PCM_FORMAT_S8;
-			break;
-		case 2:
-			if (is_big_endian_format(chip, fp))
-				pcm_format = SNDRV_PCM_FORMAT_S16_BE; /* grrr, big endian!! */
-			else
-				pcm_format = SNDRV_PCM_FORMAT_S16_LE;
-			break;
-		case 3:
-			if (is_big_endian_format(chip, fp))
-				pcm_format = SNDRV_PCM_FORMAT_S24_3BE; /* grrr, big endian!! */
-			else
-				pcm_format = SNDRV_PCM_FORMAT_S24_3LE;
-			break;
-		case 4:
-			pcm_format = SNDRV_PCM_FORMAT_S32_LE;
-			break;
-		default:
-			snd_printk(KERN_INFO "%d:%u:%d : unsupported sample bitwidth %d in %d bytes\n",
-				   chip->dev->devnum, fp->iface, fp->altsetting,
-				   sample_width, sample_bytes);
-			break;
-		}
-		break;
-	case UAC_FORMAT_TYPE_I_PCM8:
-		pcm_format = SNDRV_PCM_FORMAT_U8;
-
-		/* Dallas DS4201 workaround: it advertises U8 format, but really
-		   supports S8. */
-		if (chip->usb_id == USB_ID(0x04fa, 0x4201))
-			pcm_format = SNDRV_PCM_FORMAT_S8;
-		break;
-	case UAC_FORMAT_TYPE_I_IEEE_FLOAT:
-		pcm_format = SNDRV_PCM_FORMAT_FLOAT_LE;
-		break;
-	case UAC_FORMAT_TYPE_I_ALAW:
-		pcm_format = SNDRV_PCM_FORMAT_A_LAW;
-		break;
-	case UAC_FORMAT_TYPE_I_MULAW:
-		pcm_format = SNDRV_PCM_FORMAT_MU_LAW;
-		break;
-	default:
-		snd_printk(KERN_INFO "%d:%u:%d : unsupported format type %d\n",
-			   chip->dev->devnum, fp->iface, fp->altsetting, format);
-		break;
-	}
-	return pcm_format;
-}
-
-
-/*
- * parse the format descriptor and stores the possible sample rates
- * on the audioformat table (audio class v1).
- *
- * @dev: usb device
- * @fp: audioformat record
- * @fmt: the format descriptor
- * @offset: the start offset of descriptor pointing the rate type
- *          (7 for type I and II, 8 for type II)
- */
-static int parse_audio_format_rates_v1(struct snd_usb_audio *chip, struct audioformat *fp,
-				       unsigned char *fmt, int offset)
-{
-	int nr_rates = fmt[offset];
-
-	if (fmt[0] < offset + 1 + 3 * (nr_rates ? nr_rates : 2)) {
-		snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_FORMAT_TYPE desc\n",
-				   chip->dev->devnum, fp->iface, fp->altsetting);
-		return -1;
-	}
-
-	if (nr_rates) {
-		/*
-		 * build the rate table and bitmap flags
-		 */
-		int r, idx;
-
-		fp->rate_table = kmalloc(sizeof(int) * nr_rates, GFP_KERNEL);
-		if (fp->rate_table == NULL) {
-			snd_printk(KERN_ERR "cannot malloc\n");
-			return -1;
-		}
-
-		fp->nr_rates = 0;
-		fp->rate_min = fp->rate_max = 0;
-		for (r = 0, idx = offset + 1; r < nr_rates; r++, idx += 3) {
-			unsigned int rate = combine_triple(&fmt[idx]);
-			if (!rate)
-				continue;
-			/* C-Media CM6501 mislabels its 96 kHz altsetting */
-			if (rate == 48000 && nr_rates == 1 &&
-			    (chip->usb_id == USB_ID(0x0d8c, 0x0201) ||
-			     chip->usb_id == USB_ID(0x0d8c, 0x0102)) &&
-			    fp->altsetting == 5 && fp->maxpacksize == 392)
-				rate = 96000;
-			/* Creative VF0470 Live Cam reports 16 kHz instead of 8kHz */
-			if (rate == 16000 && chip->usb_id == USB_ID(0x041e, 0x4068))
-				rate = 8000;
-			fp->rate_table[fp->nr_rates] = rate;
-			if (!fp->rate_min || rate < fp->rate_min)
-				fp->rate_min = rate;
-			if (!fp->rate_max || rate > fp->rate_max)
-				fp->rate_max = rate;
-			fp->rates |= snd_pcm_rate_to_rate_bit(rate);
-			fp->nr_rates++;
-		}
-		if (!fp->nr_rates) {
-			hwc_debug("All rates were zero. Skipping format!\n");
-			return -1;
-		}
-	} else {
-		/* continuous rates */
-		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
-		fp->rate_min = combine_triple(&fmt[offset + 1]);
-		fp->rate_max = combine_triple(&fmt[offset + 4]);
-	}
-	return 0;
-}
-
-/*
- * parse the format descriptor and stores the possible sample rates
- * on the audioformat table (audio class v2).
- */
-static int parse_audio_format_rates_v2(struct snd_usb_audio *chip,
-				       struct audioformat *fp,
-				       struct usb_host_interface *iface)
-{
-	struct usb_device *dev = chip->dev;
-	unsigned char tmp[2], *data;
-	int i, nr_rates, data_size, ret = 0;
-
-	/* get the number of sample rates first by only fetching 2 bytes */
-	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
-			       USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
-			       0x0100, chip->clock_id << 8, tmp, sizeof(tmp), 1000);
-
-	if (ret < 0) {
-		snd_printk(KERN_ERR "unable to retrieve number of sample rates\n");
-		goto err;
-	}
-
-	nr_rates = (tmp[1] << 8) | tmp[0];
-	data_size = 2 + 12 * nr_rates;
-	data = kzalloc(data_size, GFP_KERNEL);
-	if (!data) {
-		ret = -ENOMEM;
-		goto err;
-	}
-
-	/* now get the full information */
-	ret = snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), UAC2_CS_RANGE,
-			       USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_IN,
-			       0x0100, chip->clock_id << 8, data, data_size, 1000);
-
-	if (ret < 0) {
-		snd_printk(KERN_ERR "unable to retrieve sample rate range\n");
-		ret = -EINVAL;
-		goto err_free;
-	}
-
-	fp->rate_table = kmalloc(sizeof(int) * nr_rates, GFP_KERNEL);
-	if (!fp->rate_table) {
-		ret = -ENOMEM;
-		goto err_free;
-	}
-
-	fp->nr_rates = 0;
-	fp->rate_min = fp->rate_max = 0;
-
-	for (i = 0; i < nr_rates; i++) {
-		int rate = combine_quad(&data[2 + 12 * i]);
-
-		fp->rate_table[fp->nr_rates] = rate;
-		if (!fp->rate_min || rate < fp->rate_min)
-			fp->rate_min = rate;
-		if (!fp->rate_max || rate > fp->rate_max)
-			fp->rate_max = rate;
-		fp->rates |= snd_pcm_rate_to_rate_bit(rate);
-		fp->nr_rates++;
-	}
-
-err_free:
-	kfree(data);
-err:
-	return ret;
-}
-
-/*
- * parse the format type I and III descriptors
- */
-static int parse_audio_format_i(struct snd_usb_audio *chip,
-				struct audioformat *fp,
-				int format, void *_fmt,
-				struct usb_host_interface *iface)
-{
-	struct usb_interface_descriptor *altsd = get_iface_desc(iface);
-	struct uac_format_type_i_discrete_descriptor *fmt = _fmt;
-	int protocol = altsd->bInterfaceProtocol;
-	int pcm_format, ret;
-
-	if (fmt->bFormatType == UAC_FORMAT_TYPE_III) {
-		/* FIXME: the format type is really IECxxx
-		 *        but we give normal PCM format to get the existing
-		 *        apps working...
-		 */
-		switch (chip->usb_id) {
-
-		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
-			if (device_setup[chip->index] == 0x00 && 
-			    fp->altsetting == 6)
-				pcm_format = SNDRV_PCM_FORMAT_S16_BE;
-			else
-				pcm_format = SNDRV_PCM_FORMAT_S16_LE;
-			break;
-		default:
-			pcm_format = SNDRV_PCM_FORMAT_S16_LE;
-		}
-	} else {
-		pcm_format = parse_audio_format_i_type(chip, fp, format, fmt, protocol);
-		if (pcm_format < 0)
-			return -1;
-	}
-
-	fp->format = pcm_format;
-
-	/* gather possible sample rates */
-	/* audio class v1 reports possible sample rates as part of the
-	 * proprietary class specific descriptor.
-	 * audio class v2 uses class specific EP0 range requests for that.
-	 */
-	switch (protocol) {
-	case UAC_VERSION_1:
-		fp->channels = fmt->bNrChannels;
-		ret = parse_audio_format_rates_v1(chip, fp, _fmt, 7);
-		break;
-	case UAC_VERSION_2:
-		/* fp->channels is already set in this case */
-		ret = parse_audio_format_rates_v2(chip, fp, iface);
-		break;
-	}
-
-	if (fp->channels < 1) {
-		snd_printk(KERN_ERR "%d:%u:%d : invalid channels %d\n",
-			   chip->dev->devnum, fp->iface, fp->altsetting, fp->channels);
-		return -1;
-	}
-
-	return ret;
-}
-
-/*
- * parse the format type II descriptor
- */
-static int parse_audio_format_ii(struct snd_usb_audio *chip,
-				 struct audioformat *fp,
-				 int format, void *_fmt,
-				 struct usb_host_interface *iface)
-{
-	int brate, framesize, ret;
-	struct usb_interface_descriptor *altsd = get_iface_desc(iface);
-	int protocol = altsd->bInterfaceProtocol;
-
-	switch (format) {
-	case UAC_FORMAT_TYPE_II_AC3:
-		/* FIXME: there is no AC3 format defined yet */
-		// fp->format = SNDRV_PCM_FORMAT_AC3;
-		fp->format = SNDRV_PCM_FORMAT_U8; /* temporarily hack to receive byte streams */
-		break;
-	case UAC_FORMAT_TYPE_II_MPEG:
-		fp->format = SNDRV_PCM_FORMAT_MPEG;
-		break;
-	default:
-		snd_printd(KERN_INFO "%d:%u:%d : unknown format tag %#x is detected.  processed as MPEG.\n",
-			   chip->dev->devnum, fp->iface, fp->altsetting, format);
-		fp->format = SNDRV_PCM_FORMAT_MPEG;
-		break;
-	}
-
-	fp->channels = 1;
-
-	switch (protocol) {
-	case UAC_VERSION_1: {
-		struct uac_format_type_ii_discrete_descriptor *fmt = _fmt;
-		brate = le16_to_cpu(fmt->wMaxBitRate);
-		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
-		snd_printd(KERN_INFO "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
-		fp->frame_size = framesize;
-		ret = parse_audio_format_rates_v1(chip, fp, _fmt, 8); /* fmt[8..] sample rates */
-		break;
-	}
-	case UAC_VERSION_2: {
-		struct uac_format_type_ii_ext_descriptor *fmt = _fmt;
-		brate = le16_to_cpu(fmt->wMaxBitRate);
-		framesize = le16_to_cpu(fmt->wSamplesPerFrame);
-		snd_printd(KERN_INFO "found format II with max.bitrate = %d, frame size=%d\n", brate, framesize);
-		fp->frame_size = framesize;
-		ret = parse_audio_format_rates_v2(chip, fp, iface);
-		break;
-	}
-	}
-
-	return ret;
-}
-
-static int parse_audio_format(struct snd_usb_audio *chip, struct audioformat *fp,
-			      int format, unsigned char *fmt, int stream,
-			      struct usb_host_interface *iface)
-{
-	int err;
-
-	switch (fmt[3]) {
-	case UAC_FORMAT_TYPE_I:
-	case UAC_FORMAT_TYPE_III:
-		err = parse_audio_format_i(chip, fp, format, fmt, iface);
-		break;
-	case UAC_FORMAT_TYPE_II:
-		err = parse_audio_format_ii(chip, fp, format, fmt, iface);
-		break;
-	default:
-		snd_printd(KERN_INFO "%d:%u:%d : format type %d is not supported yet\n",
-			   chip->dev->devnum, fp->iface, fp->altsetting, fmt[3]);
-		return -1;
-	}
-	fp->fmt_type = fmt[3];
-	if (err < 0)
-		return err;
-#if 1
-	/* FIXME: temporary hack for extigy/audigy 2 nx/zs */
-	/* extigy apparently supports sample rates other than 48k
-	 * but not in ordinary way.  so we enable only 48k atm.
-	 */
-	if (chip->usb_id == USB_ID(0x041e, 0x3000) ||
-	    chip->usb_id == USB_ID(0x041e, 0x3020) ||
-	    chip->usb_id == USB_ID(0x041e, 0x3061)) {
-		if (fmt[3] == UAC_FORMAT_TYPE_I &&
-		    fp->rates != SNDRV_PCM_RATE_48000 &&
-		    fp->rates != SNDRV_PCM_RATE_96000)
-			return -1;
-	}
-#endif
-	return 0;
-}
-
-static unsigned char parse_datainterval(struct snd_usb_audio *chip,
-					struct usb_host_interface *alts)
-{
-	if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH &&
-	    get_endpoint(alts, 0)->bInterval >= 1 &&
-	    get_endpoint(alts, 0)->bInterval <= 4)
-		return get_endpoint(alts, 0)->bInterval - 1;
-	else
-		return 0;
-}
-
-static int audiophile_skip_setting_quirk(struct snd_usb_audio *chip,
-					 int iface, int altno);
-static int parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
-{
-	struct usb_device *dev;
-	struct usb_interface *iface;
-	struct usb_host_interface *alts;
-	struct usb_interface_descriptor *altsd;
-	int i, altno, err, stream;
-	int format = 0, num_channels = 0;
-	struct audioformat *fp = NULL;
-	unsigned char *fmt, *csep;
-	int num, protocol;
-
-	dev = chip->dev;
-
-	/* parse the interface's altsettings */
-	iface = usb_ifnum_to_if(dev, iface_no);
-
-	num = iface->num_altsetting;
-
-	/*
-	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
-	 * one misses syncpipe, and does not produce any sound.
-	 */
-	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
-		num = 4;
-
-	for (i = 0; i < num; i++) {
-		alts = &iface->altsetting[i];
-		altsd = get_iface_desc(alts);
-		protocol = altsd->bInterfaceProtocol;
-		/* skip invalid one */
-		if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
-		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
-		    (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
-		     altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC) ||
-		    altsd->bNumEndpoints < 1 ||
-		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
-			continue;
-		/* must be isochronous */
-		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
-		    USB_ENDPOINT_XFER_ISOC)
-			continue;
-		/* check direction */
-		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
-			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
-		altno = altsd->bAlternateSetting;
-	
-		/* audiophile usb: skip altsets incompatible with device_setup
-		 */
-		if (chip->usb_id == USB_ID(0x0763, 0x2003) && 
-		    audiophile_skip_setting_quirk(chip, iface_no, altno))
-			continue;
-
-		/* get audio formats */
-		switch (protocol) {
-		case UAC_VERSION_1: {
-			struct uac_as_header_descriptor_v1 *as =
-				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
-
-			if (!as) {
-				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
-					   dev->devnum, iface_no, altno);
-				continue;
-			}
-
-			if (as->bLength < sizeof(*as)) {
-				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
-					   dev->devnum, iface_no, altno);
-				continue;
-			}
-
-			format = le16_to_cpu(as->wFormatTag); /* remember the format value */
-			break;
-		}
-
-		case UAC_VERSION_2: {
-			struct uac_as_header_descriptor_v2 *as =
-				snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_AS_GENERAL);
-
-			if (!as) {
-				snd_printk(KERN_ERR "%d:%u:%d : UAC_AS_GENERAL descriptor not found\n",
-					   dev->devnum, iface_no, altno);
-				continue;
-			}
-
-			if (as->bLength < sizeof(*as)) {
-				snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_AS_GENERAL desc\n",
-					   dev->devnum, iface_no, altno);
-				continue;
-			}
-
-			num_channels = as->bNrChannels;
-			format = le32_to_cpu(as->bmFormats);
-
-			break;
-		}
-
-		default:
-			snd_printk(KERN_ERR "%d:%u:%d : unknown interface protocol %04x\n",
-				   dev->devnum, iface_no, altno, protocol);
-			continue;
-		}
-
-		/* get format type */
-		fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen, NULL, UAC_FORMAT_TYPE);
-		if (!fmt) {
-			snd_printk(KERN_ERR "%d:%u:%d : no UAC_FORMAT_TYPE desc\n",
-				   dev->devnum, iface_no, altno);
-			continue;
-		}
-		if (((protocol == UAC_VERSION_1) && (fmt[0] < 8)) ||
-		    ((protocol == UAC_VERSION_2) && (fmt[0] != 6))) {
-			snd_printk(KERN_ERR "%d:%u:%d : invalid UAC_FORMAT_TYPE desc\n",
-				   dev->devnum, iface_no, altno);
-			continue;
-		}
-
-		/*
-		 * Blue Microphones workaround: The last altsetting is identical
-		 * with the previous one, except for a larger packet size, but
-		 * is actually a mislabeled two-channel setting; ignore it.
-		 */
-		if (fmt[4] == 1 && fmt[5] == 2 && altno == 2 && num == 3 &&
-		    fp && fp->altsetting == 1 && fp->channels == 1 &&
-		    fp->format == SNDRV_PCM_FORMAT_S16_LE &&
-		    protocol == UAC_VERSION_1 &&
-		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
-							fp->maxpacksize * 2)
-			continue;
-
-		csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
-		/* Creamware Noah has this descriptor after the 2nd endpoint */
-		if (!csep && altsd->bNumEndpoints >= 2)
-			csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
-		if (!csep || csep[0] < 7 || csep[2] != UAC_EP_GENERAL) {
-			snd_printk(KERN_WARNING "%d:%u:%d : no or invalid"
-				   " class specific endpoint descriptor\n",
-				   dev->devnum, iface_no, altno);
-			csep = NULL;
-		}
-
-		fp = kzalloc(sizeof(*fp), GFP_KERNEL);
-		if (! fp) {
-			snd_printk(KERN_ERR "cannot malloc\n");
-			return -ENOMEM;
-		}
-
-		fp->iface = iface_no;
-		fp->altsetting = altno;
-		fp->altset_idx = i;
-		fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
-		fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
-		fp->datainterval = parse_datainterval(chip, alts);
-		fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
-		/* num_channels is only set for v2 interfaces */
-		fp->channels = num_channels;
-		if (snd_usb_get_speed(dev) == USB_SPEED_HIGH)
-			fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
-					* (fp->maxpacksize & 0x7ff);
-		fp->attributes = csep ? csep[3] : 0;
-
-		/* some quirks for attributes here */
-
-		switch (chip->usb_id) {
-		case USB_ID(0x0a92, 0x0053): /* AudioTrak Optoplay */
-			/* Optoplay sets the sample rate attribute although
-			 * it seems not supporting it in fact.
-			 */
-			fp->attributes &= ~UAC_EP_CS_ATTR_SAMPLE_RATE;
-			break;
-		case USB_ID(0x041e, 0x3020): /* Creative SB Audigy 2 NX */
-		case USB_ID(0x0763, 0x2003): /* M-Audio Audiophile USB */
-			/* doesn't set the sample rate attribute, but supports it */
-			fp->attributes |= UAC_EP_CS_ATTR_SAMPLE_RATE;
-			break;
-		case USB_ID(0x047f, 0x0ca1): /* plantronics headset */
-		case USB_ID(0x077d, 0x07af): /* Griffin iMic (note that there is
-						an older model 77d:223) */
-		/*
-		 * plantronics headset and Griffin iMic have set adaptive-in
-		 * although it's really not...
-		 */
-			fp->ep_attr &= ~USB_ENDPOINT_SYNCTYPE;
-			if (stream == SNDRV_PCM_STREAM_PLAYBACK)
-				fp->ep_attr |= USB_ENDPOINT_SYNC_ADAPTIVE;
-			else
-				fp->ep_attr |= USB_ENDPOINT_SYNC_SYNC;
-			break;
-		}
-
-		/* ok, let's parse further... */
-		if (parse_audio_format(chip, fp, format, fmt, stream, alts) < 0) {
-			kfree(fp->rate_table);
-			kfree(fp);
-			continue;
-		}
-
-		snd_printdd(KERN_INFO "%d:%u:%d: add audio endpoint %#x\n", dev->devnum, iface_no, altno, fp->endpoint);
-		err = add_audio_endpoint(chip, stream, fp);
-		if (err < 0) {
-			kfree(fp->rate_table);
-			kfree(fp);
-			return err;
-		}
-		/* try to set the interface... */
-		usb_set_interface(chip->dev, iface_no, altno);
-		init_usb_pitch(chip->dev, iface_no, alts, fp);
-		init_usb_sample_rate(chip->dev, iface_no, alts, fp, fp->rate_max);
-	}
-	return 0;
-}
-
-
-/*
- * disconnect streams
- * called from snd_usb_audio_disconnect()
- */
-static void snd_usb_stream_disconnect(struct list_head *head)
-{
-	int idx;
-	struct snd_usb_stream *as;
-	struct snd_usb_substream *subs;
-
-	as = list_entry(head, struct snd_usb_stream, list);
-	for (idx = 0; idx < 2; idx++) {
-		subs = &as->substream[idx];
-		if (!subs->num_formats)
-			return;
-		release_substream_urbs(subs, 1);
-		subs->interface = -1;
-	}
-}
-
-static int snd_usb_create_stream(struct snd_usb_audio *chip, int ctrlif, int interface)
-{
-	struct usb_device *dev = chip->dev;
-	struct usb_host_interface *alts;
-	struct usb_interface_descriptor *altsd;
-	struct usb_interface *iface = usb_ifnum_to_if(dev, interface);
-
-	if (!iface) {
-		snd_printk(KERN_ERR "%d:%u:%d : does not exist\n",
-			   dev->devnum, ctrlif, interface);
-		return -EINVAL;
-	}
-
-	if (usb_interface_claimed(iface)) {
-		snd_printdd(KERN_INFO "%d:%d:%d: skipping, already claimed\n",
-						dev->devnum, ctrlif, interface);
-		return -EINVAL;
-	}
-
-	alts = &iface->altsetting[0];
-	altsd = get_iface_desc(alts);
-	if ((altsd->bInterfaceClass == USB_CLASS_AUDIO ||
-	     altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC) &&
-	    altsd->bInterfaceSubClass == USB_SUBCLASS_MIDISTREAMING) {
-		int err = snd_usbmidi_create(chip->card, iface,
-					     &chip->midi_list, NULL);
-		if (err < 0) {
-			snd_printk(KERN_ERR "%d:%u:%d: cannot create sequencer device\n",
-						dev->devnum, ctrlif, interface);
-			return -EINVAL;
-		}
-		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
-
-		return 0;
-	}
-
-	if ((altsd->bInterfaceClass != USB_CLASS_AUDIO &&
-	     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
-	    altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING) {
-		snd_printdd(KERN_ERR "%d:%u:%d: skipping non-supported interface %d\n",
-					dev->devnum, ctrlif, interface, altsd->bInterfaceClass);
-		/* skip non-supported classes */
-		return -EINVAL;
-	}
-
-	if (snd_usb_get_speed(dev) == USB_SPEED_LOW) {
-		snd_printk(KERN_ERR "low speed audio streaming not supported\n");
-		return -EINVAL;
-	}
-
-	if (! parse_audio_endpoints(chip, interface)) {
-		usb_set_interface(dev, interface, 0); /* reset the current interface */
-		usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-/*
- * parse audio control descriptor and create pcm/midi streams
- */
-static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif)
-{
-	struct usb_device *dev = chip->dev;
-	struct usb_host_interface *host_iface;
-	struct usb_interface_descriptor *altsd;
-	void *control_header;
-	int i, protocol;
-
-	/* find audiocontrol interface */
-	host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0];
-	control_header = snd_usb_find_csint_desc(host_iface->extra,
-						 host_iface->extralen,
-						 NULL, UAC_HEADER);
-	altsd = get_iface_desc(host_iface);
-	protocol = altsd->bInterfaceProtocol;
-
-	if (!control_header) {
-		snd_printk(KERN_ERR "cannot find UAC_HEADER\n");
-		return -EINVAL;
-	}
-
-	switch (protocol) {
-	case UAC_VERSION_1: {
-		struct uac_ac_header_descriptor_v1 *h1 = control_header;
-
-		if (!h1->bInCollection) {
-			snd_printk(KERN_INFO "skipping empty audio interface (v1)\n");
-			return -EINVAL;
-		}
-
-		if (h1->bLength < sizeof(*h1) + h1->bInCollection) {
-			snd_printk(KERN_ERR "invalid UAC_HEADER (v1)\n");
-			return -EINVAL;
-		}
-
-		for (i = 0; i < h1->bInCollection; i++)
-			snd_usb_create_stream(chip, ctrlif, h1->baInterfaceNr[i]);
-
-		break;
-	}
-
-	case UAC_VERSION_2: {
-		struct uac_clock_source_descriptor *cs;
-		struct usb_interface_assoc_descriptor *assoc =
-			usb_ifnum_to_if(dev, ctrlif)->intf_assoc;
-
-		if (!assoc) {
-			snd_printk(KERN_ERR "Audio class v2 interfaces need an interface association\n");
-			return -EINVAL;
-		}
-
-		/* FIXME: for now, we expect there is at least one clock source
-		 * descriptor and we always take the first one.
-		 * We should properly support devices with multiple clock sources,
-		 * clock selectors and sample rate conversion units. */
-
-		cs = snd_usb_find_csint_desc(host_iface->extra, host_iface->extralen,
-						NULL, UAC_CLOCK_SOURCE);
-
-		if (!cs) {
-			snd_printk(KERN_ERR "CLOCK_SOURCE descriptor not found\n");
-			return -EINVAL;
-		}
-
-		chip->clock_id = cs->bClockID;
-
-		for (i = 0; i < assoc->bInterfaceCount; i++) {
-			int intf = assoc->bFirstInterface + i;
-
-			if (intf != ctrlif)
-				snd_usb_create_stream(chip, ctrlif, intf);
-		}
-
-		break;
-	}
-
-	default:
-		snd_printk(KERN_ERR "unknown protocol version 0x%02x\n", protocol);
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-/*
- * create a stream for an endpoint/altsetting without proper descriptors
- */
-static int create_fixed_stream_quirk(struct snd_usb_audio *chip,
-				     struct usb_interface *iface,
-				     const struct snd_usb_audio_quirk *quirk)
-{
-	struct audioformat *fp;
-	struct usb_host_interface *alts;
-	int stream, err;
-	unsigned *rate_table = NULL;
-
-	fp = kmemdup(quirk->data, sizeof(*fp), GFP_KERNEL);
-	if (! fp) {
-		snd_printk(KERN_ERR "cannot memdup\n");
-		return -ENOMEM;
-	}
-	if (fp->nr_rates > 0) {
-		rate_table = kmalloc(sizeof(int) * fp->nr_rates, GFP_KERNEL);
-		if (!rate_table) {
-			kfree(fp);
-			return -ENOMEM;
-		}
-		memcpy(rate_table, fp->rate_table, sizeof(int) * fp->nr_rates);
-		fp->rate_table = rate_table;
-	}
-
-	stream = (fp->endpoint & USB_DIR_IN)
-		? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
-	err = add_audio_endpoint(chip, stream, fp);
-	if (err < 0) {
-		kfree(fp);
-		kfree(rate_table);
-		return err;
-	}
-	if (fp->iface != get_iface_desc(&iface->altsetting[0])->bInterfaceNumber ||
-	    fp->altset_idx >= iface->num_altsetting) {
-		kfree(fp);
-		kfree(rate_table);
-		return -EINVAL;
-	}
-	alts = &iface->altsetting[fp->altset_idx];
-	fp->datainterval = parse_datainterval(chip, alts);
-	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
-	usb_set_interface(chip->dev, fp->iface, 0);
-	init_usb_pitch(chip->dev, fp->iface, alts, fp);
-	init_usb_sample_rate(chip->dev, fp->iface, alts, fp, fp->rate_max);
-	return 0;
-}
-
-/*
- * create a stream for an interface with proper descriptors
- */
-static int create_standard_audio_quirk(struct snd_usb_audio *chip,
-				       struct usb_interface *iface,
-				       const struct snd_usb_audio_quirk *quirk)
-{
-	struct usb_host_interface *alts;
-	struct usb_interface_descriptor *altsd;
-	int err;
-
-	alts = &iface->altsetting[0];
-	altsd = get_iface_desc(alts);
-	err = parse_audio_endpoints(chip, altsd->bInterfaceNumber);
-	if (err < 0) {
-		snd_printk(KERN_ERR "cannot setup if %d: error %d\n",
-			   altsd->bInterfaceNumber, err);
-		return err;
-	}
-	/* reset the current interface */
-	usb_set_interface(chip->dev, altsd->bInterfaceNumber, 0);
-	return 0;
-}
-
-/*
- * Create a stream for an Edirol UA-700/UA-25/UA-4FX interface.  
- * The only way to detect the sample rate is by looking at wMaxPacketSize.
- */
-static int create_uaxx_quirk(struct snd_usb_audio *chip,
-			      struct usb_interface *iface,
-			      const struct snd_usb_audio_quirk *quirk)
-{
-	static const struct audioformat ua_format = {
-		.format = SNDRV_PCM_FORMAT_S24_3LE,
-		.channels = 2,
-		.fmt_type = UAC_FORMAT_TYPE_I,
-		.altsetting = 1,
-		.altset_idx = 1,
-		.rates = SNDRV_PCM_RATE_CONTINUOUS,
-	};
-	struct usb_host_interface *alts;
-	struct usb_interface_descriptor *altsd;
-	struct audioformat *fp;
-	int stream, err;
-
-	/* both PCM and MIDI interfaces have 2 or more altsettings */
-	if (iface->num_altsetting < 2)
-		return -ENXIO;
-	alts = &iface->altsetting[1];
-	altsd = get_iface_desc(alts);
-
-	if (altsd->bNumEndpoints == 2) {
-		static const struct snd_usb_midi_endpoint_info ua700_ep = {
-			.out_cables = 0x0003,
-			.in_cables  = 0x0003
-		};
-		static const struct snd_usb_audio_quirk ua700_quirk = {
-			.type = QUIRK_MIDI_FIXED_ENDPOINT,
-			.data = &ua700_ep
-		};
-		static const struct snd_usb_midi_endpoint_info uaxx_ep = {
-			.out_cables = 0x0001,
-			.in_cables  = 0x0001
-		};
-		static const struct snd_usb_audio_quirk uaxx_quirk = {
-			.type = QUIRK_MIDI_FIXED_ENDPOINT,
-			.data = &uaxx_ep
-		};
-		const struct snd_usb_audio_quirk *quirk =
-			chip->usb_id == USB_ID(0x0582, 0x002b)
-			? &ua700_quirk : &uaxx_quirk;
-		return snd_usbmidi_create(chip->card, iface,
-					  &chip->midi_list, quirk);
-	}
-
-	if (altsd->bNumEndpoints != 1)
-		return -ENXIO;
-
-	fp = kmalloc(sizeof(*fp), GFP_KERNEL);
-	if (!fp)
-		return -ENOMEM;
-	memcpy(fp, &ua_format, sizeof(*fp));
-
-	fp->iface = altsd->bInterfaceNumber;
-	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
-	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
-	fp->datainterval = 0;
-	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
-
-	switch (fp->maxpacksize) {
-	case 0x120:
-		fp->rate_max = fp->rate_min = 44100;
-		break;
-	case 0x138:
-	case 0x140:
-		fp->rate_max = fp->rate_min = 48000;
-		break;
-	case 0x258:
-	case 0x260:
-		fp->rate_max = fp->rate_min = 96000;
-		break;
-	default:
-		snd_printk(KERN_ERR "unknown sample rate\n");
-		kfree(fp);
-		return -ENXIO;
-	}
-
-	stream = (fp->endpoint & USB_DIR_IN)
-		? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
-	err = add_audio_endpoint(chip, stream, fp);
-	if (err < 0) {
-		kfree(fp);
-		return err;
-	}
-	usb_set_interface(chip->dev, fp->iface, 0);
-	return 0;
-}
-
-static int snd_usb_create_quirk(struct snd_usb_audio *chip,
-				struct usb_interface *iface,
-				const struct snd_usb_audio_quirk *quirk);
-
-/*
- * handle the quirks for the contained interfaces
- */
-static int create_composite_quirk(struct snd_usb_audio *chip,
-				  struct usb_interface *iface,
-				  const struct snd_usb_audio_quirk *quirk)
-{
-	int probed_ifnum = get_iface_desc(iface->altsetting)->bInterfaceNumber;
-	int err;
-
-	for (quirk = quirk->data; quirk->ifnum >= 0; ++quirk) {
-		iface = usb_ifnum_to_if(chip->dev, quirk->ifnum);
-		if (!iface)
-			continue;
-		if (quirk->ifnum != probed_ifnum &&
-		    usb_interface_claimed(iface))
-			continue;
-		err = snd_usb_create_quirk(chip, iface, quirk);
-		if (err < 0)
-			return err;
-		if (quirk->ifnum != probed_ifnum)
-			usb_driver_claim_interface(&usb_audio_driver, iface, (void *)-1L);
-	}
-	return 0;
-}
-
-static int ignore_interface_quirk(struct snd_usb_audio *chip,
-				  struct usb_interface *iface,
-				  const struct snd_usb_audio_quirk *quirk)
-{
-	return 0;
-}
-
-/*
- * Allow alignment on audio sub-slot (channel samples) rather than
- * on audio slots (audio frames)
- */
-static int create_align_transfer_quirk(struct snd_usb_audio *chip,
-				  struct usb_interface *iface,
-				  const struct snd_usb_audio_quirk *quirk)
-{
-	chip->txfr_quirk = 1;
-	return 1;	/* Continue with creating streams and mixer */
-}
-
-
-/*
- * boot quirks
- */
-
-#define EXTIGY_FIRMWARE_SIZE_OLD 794
-#define EXTIGY_FIRMWARE_SIZE_NEW 483
-
-static int snd_usb_extigy_boot_quirk(struct usb_device *dev, struct usb_interface *intf)
-{
-	struct usb_host_config *config = dev->actconfig;
-	int err;
-
-	if (le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_OLD ||
-	    le16_to_cpu(get_cfg_desc(config)->wTotalLength) == EXTIGY_FIRMWARE_SIZE_NEW) {
-		snd_printdd("sending Extigy boot sequence...\n");
-		/* Send message to force it to reconnect with full interface. */
-		err = snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev,0),
-				      0x10, 0x43, 0x0001, 0x000a, NULL, 0, 1000);
-		if (err < 0) snd_printdd("error sending boot message: %d\n", err);
-		err = usb_get_descriptor(dev, USB_DT_DEVICE, 0,
-				&dev->descriptor, sizeof(dev->descriptor));
-		config = dev->actconfig;
-		if (err < 0) snd_printdd("error usb_get_descriptor: %d\n", err);
-		err = usb_reset_configuration(dev);
-		if (err < 0) snd_printdd("error usb_reset_configuration: %d\n", err);
-		snd_printdd("extigy_boot: new boot length = %d\n",
-			    le16_to_cpu(get_cfg_desc(config)->wTotalLength));
-		return -ENODEV; /* quit this anyway */
-	}
-	return 0;
-}
-
-static int snd_usb_audigy2nx_boot_quirk(struct usb_device *dev)
-{
-	u8 buf = 1;
-
-	snd_usb_ctl_msg(dev, usb_rcvctrlpipe(dev, 0), 0x2a,
-			USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_OTHER,
-			0, 0, &buf, 1, 1000);
-	if (buf == 0) {
-		snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), 0x29,
-				USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
-				1, 2000, NULL, 0, 1000);
-		return -ENODEV;
-	}
-	return 0;
-}
-
-/*
- * C-Media CM106/CM106+ have four 16-bit internal registers that are nicely
- * documented in the device's data sheet.
- */
-static int snd_usb_cm106_write_int_reg(struct usb_device *dev, int reg, u16 value)
-{
-	u8 buf[4];
-	buf[0] = 0x20;
-	buf[1] = value & 0xff;
-	buf[2] = (value >> 8) & 0xff;
-	buf[3] = reg;
-	return snd_usb_ctl_msg(dev, usb_sndctrlpipe(dev, 0), USB_REQ_SET_CONFIGURATION,
-			       USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
-			       0, 0, &buf, 4, 1000);
-}
-
-static int snd_usb_cm106_boot_quirk(struct usb_device *dev)
-{
-	/*
-	 * Enable line-out driver mode, set headphone source to front
-	 * channels, enable stereo mic.
-	 */
-	return snd_usb_cm106_write_int_reg(dev, 2, 0x8004);
-}
-
-/*
- * C-Media CM6206 is based on CM106 with two additional
- * registers that are not documented in the data sheet.
- * Values here are chosen based on sniffing USB traffic
- * under Windows.
- */
-static int snd_usb_cm6206_boot_quirk(struct usb_device *dev)
-{
-	int err, reg;
-	int val[] = {0x200c, 0x3000, 0xf800, 0x143f, 0x0000, 0x3000};
-
-	for (reg = 0; reg < ARRAY_SIZE(val); reg++) {
-		err = snd_usb_cm106_write_int_reg(dev, reg, val[reg]);
-		if (err < 0)
-			return err;
-	}
-
-	return err;
-}
-
-/*
- * This call will put the synth in "USB send" mode, i.e it will send MIDI
- * messages through USB (this is disabled at startup). The synth will
- * acknowledge by sending a sysex on endpoint 0x85 and by displaying a USB
- * sign on its LCD. Values here are chosen based on sniffing USB traffic
- * under Windows.
- */
-static int snd_usb_accessmusic_boot_quirk(struct usb_device *dev)
-{
-	int err, actual_length;
-
-	/* "midi send" enable */
-	static const u8 seq[] = { 0x4e, 0x73, 0x52, 0x01 };
-
-	void *buf = kmemdup(seq, ARRAY_SIZE(seq), GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-	err = usb_interrupt_msg(dev, usb_sndintpipe(dev, 0x05), buf,
-			ARRAY_SIZE(seq), &actual_length, 1000);
-	kfree(buf);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-
-/*
- * Setup quirks
- */
-#define AUDIOPHILE_SET			0x01 /* if set, parse device_setup */
-#define AUDIOPHILE_SET_DTS              0x02 /* if set, enable DTS Digital Output */
-#define AUDIOPHILE_SET_96K              0x04 /* 48-96KHz rate if set, 8-48KHz otherwise */
-#define AUDIOPHILE_SET_24B		0x08 /* 24bits sample if set, 16bits otherwise */
-#define AUDIOPHILE_SET_DI		0x10 /* if set, enable Digital Input */
-#define AUDIOPHILE_SET_MASK		0x1F /* bit mask for setup value */
-#define AUDIOPHILE_SET_24B_48K_DI	0x19 /* value for 24bits+48KHz+Digital Input */
-#define AUDIOPHILE_SET_24B_48K_NOTDI	0x09 /* value for 24bits+48KHz+No Digital Input */
-#define AUDIOPHILE_SET_16B_48K_DI	0x11 /* value for 16bits+48KHz+Digital Input */
-#define AUDIOPHILE_SET_16B_48K_NOTDI	0x01 /* value for 16bits+48KHz+No Digital Input */
-
-static int audiophile_skip_setting_quirk(struct snd_usb_audio *chip,
-					 int iface, int altno)
-{
-	/* Reset ALL ifaces to 0 altsetting.
-	 * Call it for every possible altsetting of every interface.
-	 */
-	usb_set_interface(chip->dev, iface, 0);
-
-	if (device_setup[chip->index] & AUDIOPHILE_SET) {
-		if ((device_setup[chip->index] & AUDIOPHILE_SET_DTS)
-		    && altno != 6)
-			return 1; /* skip this altsetting */
-		if ((device_setup[chip->index] & AUDIOPHILE_SET_96K)
-		    && altno != 1)
-			return 1; /* skip this altsetting */
-		if ((device_setup[chip->index] & AUDIOPHILE_SET_MASK) ==
-		    AUDIOPHILE_SET_24B_48K_DI && altno != 2)
-			return 1; /* skip this altsetting */
-		if ((device_setup[chip->index] & AUDIOPHILE_SET_MASK) ==
-		    AUDIOPHILE_SET_24B_48K_NOTDI && altno != 3)
-			return 1; /* skip this altsetting */
-		if ((device_setup[chip->index] & AUDIOPHILE_SET_MASK) ==
-		    AUDIOPHILE_SET_16B_48K_DI && altno != 4)
-			return 1; /* skip this altsetting */
-		if ((device_setup[chip->index] & AUDIOPHILE_SET_MASK) ==
-		    AUDIOPHILE_SET_16B_48K_NOTDI && altno != 5)
-			return 1; /* skip this altsetting */
-	}	
-	return 0; /* keep this altsetting */
-}
-
-static int create_any_midi_quirk(struct snd_usb_audio *chip,
-				 struct usb_interface *intf,
-				 const struct snd_usb_audio_quirk *quirk)
-{
-	return snd_usbmidi_create(chip->card, intf, &chip->midi_list, quirk);
-}
-
-/*
- * audio-interface quirks
- *
- * returns zero if no standard audio/MIDI parsing is needed.
- * returns a postive value if standard audio/midi interfaces are parsed
- * after this.
- * returns a negative value at error.
- */
-static int snd_usb_create_quirk(struct snd_usb_audio *chip,
-				struct usb_interface *iface,
-				const struct snd_usb_audio_quirk *quirk)
-{
-	typedef int (*quirk_func_t)(struct snd_usb_audio *, struct usb_interface *,
-				    const struct snd_usb_audio_quirk *);
-	static const quirk_func_t quirk_funcs[] = {
-		[QUIRK_IGNORE_INTERFACE] = ignore_interface_quirk,
-		[QUIRK_COMPOSITE] = create_composite_quirk,
-		[QUIRK_MIDI_STANDARD_INTERFACE] = create_any_midi_quirk,
-		[QUIRK_MIDI_FIXED_ENDPOINT] = create_any_midi_quirk,
-		[QUIRK_MIDI_YAMAHA] = create_any_midi_quirk,
-		[QUIRK_MIDI_MIDIMAN] = create_any_midi_quirk,
-		[QUIRK_MIDI_NOVATION] = create_any_midi_quirk,
-		[QUIRK_MIDI_FASTLANE] = create_any_midi_quirk,
-		[QUIRK_MIDI_EMAGIC] = create_any_midi_quirk,
-		[QUIRK_MIDI_CME] = create_any_midi_quirk,
-		[QUIRK_AUDIO_STANDARD_INTERFACE] = create_standard_audio_quirk,
-		[QUIRK_AUDIO_FIXED_ENDPOINT] = create_fixed_stream_quirk,
-		[QUIRK_AUDIO_EDIROL_UAXX] = create_uaxx_quirk,
-		[QUIRK_AUDIO_ALIGN_TRANSFER] = create_align_transfer_quirk
-	};
-
-	if (quirk->type < QUIRK_TYPE_COUNT) {
-		return quirk_funcs[quirk->type](chip, iface, quirk);
-	} else {
-		snd_printd(KERN_ERR "invalid quirk type %d\n", quirk->type);
-		return -ENXIO;
-	}
-}
-
-
-/*
- * common proc files to show the usb device info
- */
-static void proc_audio_usbbus_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
-{
-	struct snd_usb_audio *chip = entry->private_data;
-	if (!chip->shutdown)
-		snd_iprintf(buffer, "%03d/%03d\n", chip->dev->bus->busnum, chip->dev->devnum);
-}
-
-static void proc_audio_usbid_read(struct snd_info_entry *entry, struct snd_info_buffer *buffer)
-{
-	struct snd_usb_audio *chip = entry->private_data;
-	if (!chip->shutdown)
-		snd_iprintf(buffer, "%04x:%04x\n", 
-			    USB_ID_VENDOR(chip->usb_id),
-			    USB_ID_PRODUCT(chip->usb_id));
-}
-
-static void snd_usb_audio_create_proc(struct snd_usb_audio *chip)
-{
-	struct snd_info_entry *entry;
-	if (!snd_card_proc_new(chip->card, "usbbus", &entry))
-		snd_info_set_text_ops(entry, chip, proc_audio_usbbus_read);
-	if (!snd_card_proc_new(chip->card, "usbid", &entry))
-		snd_info_set_text_ops(entry, chip, proc_audio_usbid_read);
-}
-
-/*
- * free the chip instance
- *
- * here we have to do not much, since pcm and controls are already freed
- *
- */
-
-static int snd_usb_audio_free(struct snd_usb_audio *chip)
-{
-	kfree(chip);
-	return 0;
-}
-
-static int snd_usb_audio_dev_free(struct snd_device *device)
-{
-	struct snd_usb_audio *chip = device->device_data;
-	return snd_usb_audio_free(chip);
-}
-
-
-/*
- * create a chip instance and set its names.
- */
-static int snd_usb_audio_create(struct usb_device *dev, int idx,
-				const struct snd_usb_audio_quirk *quirk,
-				struct snd_usb_audio **rchip)
-{
-	struct snd_card *card;
-	struct snd_usb_audio *chip;
-	int err, len;
-	char component[14];
-	static struct snd_device_ops ops = {
-		.dev_free =	snd_usb_audio_dev_free,
-	};
-
-	*rchip = NULL;
-
-	if (snd_usb_get_speed(dev) != USB_SPEED_LOW &&
-	    snd_usb_get_speed(dev) != USB_SPEED_FULL &&
-	    snd_usb_get_speed(dev) != USB_SPEED_HIGH) {
-		snd_printk(KERN_ERR "unknown device speed %d\n", snd_usb_get_speed(dev));
-		return -ENXIO;
-	}
-
-	err = snd_card_create(index[idx], id[idx], THIS_MODULE, 0, &card);
-	if (err < 0) {
-		snd_printk(KERN_ERR "cannot create card instance %d\n", idx);
-		return err;
-	}
-
-	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
-	if (! chip) {
-		snd_card_free(card);
-		return -ENOMEM;
-	}
-
-	chip->index = idx;
-	chip->dev = dev;
-	chip->card = card;
-	chip->usb_id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
-			      le16_to_cpu(dev->descriptor.idProduct));
-	INIT_LIST_HEAD(&chip->pcm_list);
-	INIT_LIST_HEAD(&chip->midi_list);
-	INIT_LIST_HEAD(&chip->mixer_list);
-
-	if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, chip, &ops)) < 0) {
-		snd_usb_audio_free(chip);
-		snd_card_free(card);
-		return err;
-	}
-
-	strcpy(card->driver, "USB-Audio");
-	sprintf(component, "USB%04x:%04x",
-		USB_ID_VENDOR(chip->usb_id), USB_ID_PRODUCT(chip->usb_id));
-	snd_component_add(card, component);
-
-	/* retrieve the device string as shortname */
- 	if (quirk && quirk->product_name) {
-		strlcpy(card->shortname, quirk->product_name, sizeof(card->shortname));
-	} else {
-		if (!dev->descriptor.iProduct ||
-		    usb_string(dev, dev->descriptor.iProduct,
-      			       card->shortname, sizeof(card->shortname)) <= 0) {
-			/* no name available from anywhere, so use ID */
-			sprintf(card->shortname, "USB Device %#04x:%#04x",
-				USB_ID_VENDOR(chip->usb_id),
-				USB_ID_PRODUCT(chip->usb_id));
-		}
-	}
-
-	/* retrieve the vendor and device strings as longname */
-	if (quirk && quirk->vendor_name) {
-		len = strlcpy(card->longname, quirk->vendor_name, sizeof(card->longname));
-	} else {
-		if (dev->descriptor.iManufacturer)
-			len = usb_string(dev, dev->descriptor.iManufacturer,
-					 card->longname, sizeof(card->longname));
-		else
-			len = 0;
-		/* we don't really care if there isn't any vendor string */
-	}
-	if (len > 0)
-		strlcat(card->longname, " ", sizeof(card->longname));
-
-	strlcat(card->longname, card->shortname, sizeof(card->longname));
-
-	len = strlcat(card->longname, " at ", sizeof(card->longname));
-
-	if (len < sizeof(card->longname))
-		usb_make_path(dev, card->longname + len, sizeof(card->longname) - len);
-
-	strlcat(card->longname,
-		snd_usb_get_speed(dev) == USB_SPEED_LOW ? ", low speed" :
-		snd_usb_get_speed(dev) == USB_SPEED_FULL ? ", full speed" :
-		", high speed",
-		sizeof(card->longname));
-
-	snd_usb_audio_create_proc(chip);
-
-	*rchip = chip;
-	return 0;
-}
-
-
-/*
- * probe the active usb device
- *
- * note that this can be called multiple times per a device, when it
- * includes multiple audio control interfaces.
- *
- * thus we check the usb device pointer and creates the card instance
- * only at the first time.  the successive calls of this function will
- * append the pcm interface to the corresponding card.
- */
-static void *snd_usb_audio_probe(struct usb_device *dev,
-				 struct usb_interface *intf,
-				 const struct usb_device_id *usb_id)
-{
-	const struct snd_usb_audio_quirk *quirk = (const struct snd_usb_audio_quirk *)usb_id->driver_info;
-	int i, err;
-	struct snd_usb_audio *chip;
-	struct usb_host_interface *alts;
-	int ifnum;
-	u32 id;
-
-	alts = &intf->altsetting[0];
-	ifnum = get_iface_desc(alts)->bInterfaceNumber;
-	id = USB_ID(le16_to_cpu(dev->descriptor.idVendor),
-		    le16_to_cpu(dev->descriptor.idProduct));
-	if (quirk && quirk->ifnum >= 0 && ifnum != quirk->ifnum)
-		goto __err_val;
-
-	/* SB Extigy needs special boot-up sequence */
-	/* if more models come, this will go to the quirk list. */
-	if (id == USB_ID(0x041e, 0x3000)) {
-		if (snd_usb_extigy_boot_quirk(dev, intf) < 0)
-			goto __err_val;
-	}
-	/* SB Audigy 2 NX needs its own boot-up magic, too */
-	if (id == USB_ID(0x041e, 0x3020)) {
-		if (snd_usb_audigy2nx_boot_quirk(dev) < 0)
-			goto __err_val;
-	}
-
-	/* C-Media CM106 / Turtle Beach Audio Advantage Roadie */
-	if (id == USB_ID(0x10f5, 0x0200)) {
-		if (snd_usb_cm106_boot_quirk(dev) < 0)
-			goto __err_val;
-	}
-
-	/* C-Media CM6206 / CM106-Like Sound Device */
-	if (id == USB_ID(0x0d8c, 0x0102)) {
-		if (snd_usb_cm6206_boot_quirk(dev) < 0)
-			goto __err_val;
-	}
-
-	/* Access Music VirusTI Desktop */
-	if (id == USB_ID(0x133e, 0x0815)) {
-		if (snd_usb_accessmusic_boot_quirk(dev) < 0)
-			goto __err_val;
-	}
-
-	/*
-	 * found a config.  now register to ALSA
-	 */
-
-	/* check whether it's already registered */
-	chip = NULL;
-	mutex_lock(&register_mutex);
-	for (i = 0; i < SNDRV_CARDS; i++) {
-		if (usb_chip[i] && usb_chip[i]->dev == dev) {
-			if (usb_chip[i]->shutdown) {
-				snd_printk(KERN_ERR "USB device is in the shutdown state, cannot create a card instance\n");
-				goto __error;
-			}
-			chip = usb_chip[i];
-			break;
-		}
-	}
-	if (! chip) {
-		/* it's a fresh one.
-		 * now look for an empty slot and create a new card instance
-		 */
-		for (i = 0; i < SNDRV_CARDS; i++)
-			if (enable[i] && ! usb_chip[i] &&
-			    (vid[i] == -1 || vid[i] == USB_ID_VENDOR(id)) &&
-			    (pid[i] == -1 || pid[i] == USB_ID_PRODUCT(id))) {
-				if (snd_usb_audio_create(dev, i, quirk, &chip) < 0) {
-					goto __error;
-				}
-				snd_card_set_dev(chip->card, &intf->dev);
-				break;
-			}
-		if (!chip) {
-			printk(KERN_ERR "no available usb audio device\n");
-			goto __error;
-		}
-	}
-
-	chip->txfr_quirk = 0;
-	err = 1; /* continue */
-	if (quirk && quirk->ifnum != QUIRK_NO_INTERFACE) {
-		/* need some special handlings */
-		if ((err = snd_usb_create_quirk(chip, intf, quirk)) < 0)
-			goto __error;
-	}
-
-	if (err > 0) {
-		/* create normal USB audio interfaces */
-		if (snd_usb_create_streams(chip, ifnum) < 0 ||
-		    snd_usb_create_mixer(chip, ifnum, ignore_ctl_error) < 0) {
-			goto __error;
-		}
-	}
-
-	/* we are allowed to call snd_card_register() many times */
-	if (snd_card_register(chip->card) < 0) {
-		goto __error;
-	}
-
-	usb_chip[chip->index] = chip;
-	chip->num_interfaces++;
-	mutex_unlock(&register_mutex);
-	return chip;
-
- __error:
-	if (chip && !chip->num_interfaces)
-		snd_card_free(chip->card);
-	mutex_unlock(&register_mutex);
- __err_val:
-	return NULL;
-}
-
-/*
- * we need to take care of counter, since disconnection can be called also
- * many times as well as usb_audio_probe().
- */
-static void snd_usb_audio_disconnect(struct usb_device *dev, void *ptr)
-{
-	struct snd_usb_audio *chip;
-	struct snd_card *card;
-	struct list_head *p;
-
-	if (ptr == (void *)-1L)
-		return;
-
-	chip = ptr;
-	card = chip->card;
-	mutex_lock(&register_mutex);
-	chip->shutdown = 1;
-	chip->num_interfaces--;
-	if (chip->num_interfaces <= 0) {
-		snd_card_disconnect(card);
-		/* release the pcm resources */
-		list_for_each(p, &chip->pcm_list) {
-			snd_usb_stream_disconnect(p);
-		}
-		/* release the midi resources */
-		list_for_each(p, &chip->midi_list) {
-			snd_usbmidi_disconnect(p);
-		}
-		/* release mixer resources */
-		list_for_each(p, &chip->mixer_list) {
-			snd_usb_mixer_disconnect(p);
-		}
-		usb_chip[chip->index] = NULL;
-		mutex_unlock(&register_mutex);
-		snd_card_free_when_closed(card);
-	} else {
-		mutex_unlock(&register_mutex);
-	}
-}
-
-/*
- * new 2.5 USB kernel API
- */
-static int usb_audio_probe(struct usb_interface *intf,
-			   const struct usb_device_id *id)
-{
-	void *chip;
-	chip = snd_usb_audio_probe(interface_to_usbdev(intf), intf, id);
-	if (chip) {
-		usb_set_intfdata(intf, chip);
-		return 0;
-	} else
-		return -EIO;
-}
-
-static void usb_audio_disconnect(struct usb_interface *intf)
-{
-	snd_usb_audio_disconnect(interface_to_usbdev(intf),
-				 usb_get_intfdata(intf));
-}
-
-#ifdef CONFIG_PM
-static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
-{
-	struct snd_usb_audio *chip = usb_get_intfdata(intf);
-	struct list_head *p;
-	struct snd_usb_stream *as;
-
-	if (chip == (void *)-1L)
-		return 0;
-
-	snd_power_change_state(chip->card, SNDRV_CTL_POWER_D3hot);
-	if (!chip->num_suspended_intf++) {
-		list_for_each(p, &chip->pcm_list) {
-			as = list_entry(p, struct snd_usb_stream, list);
-			snd_pcm_suspend_all(as->pcm);
-		}
-	}
-
-	return 0;
-}
-
-static int usb_audio_resume(struct usb_interface *intf)
-{
-	struct snd_usb_audio *chip = usb_get_intfdata(intf);
-
-	if (chip == (void *)-1L)
-		return 0;
-	if (--chip->num_suspended_intf)
-		return 0;
-	/*
-	 * ALSA leaves material resumption to user space
-	 * we just notify
-	 */
-
-	snd_power_change_state(chip->card, SNDRV_CTL_POWER_D0);
-
-	return 0;
-}
-#endif		/* CONFIG_PM */
-
-static int __init snd_usb_audio_init(void)
-{
-	if (nrpacks < 1 || nrpacks > MAX_PACKS) {
-		printk(KERN_WARNING "invalid nrpacks value.\n");
-		return -EINVAL;
-	}
-	return usb_register(&usb_audio_driver);
-}
-
-
-static void __exit snd_usb_audio_cleanup(void)
-{
-	usb_deregister(&usb_audio_driver);
-}
-
-module_init(snd_usb_audio_init);
-module_exit(snd_usb_audio_cleanup);
diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h
index 49a691a0b28..d679e72a3e5 100644
--- a/sound/usb/usbaudio.h
+++ b/sound/usb/usbaudio.h
@@ -27,6 +27,7 @@
 #define USB_ID_PRODUCT(id) ((u16)(id))
 
 /*
+ *
  */
 
 struct snd_usb_audio {
@@ -48,6 +49,10 @@ struct snd_usb_audio {
 	struct list_head midi_list;	/* list of midi interfaces */
 
 	struct list_head mixer_list;	/* list of mixer interfaces */
+
+	int setup;			/* from the 'device_setup' module param */
+	int nrpacks;			/* from the 'nrpacks' module param */
+	int async_unlink;		/* from the 'async_unlink' module param */
 };
 
 /*
@@ -86,45 +91,8 @@ struct snd_usb_audio_quirk {
 	const void *data;
 };
 
-/*
- */
-
-/*E-mu USB samplerate control quirk*/
-enum {
-	EMU_QUIRK_SR_44100HZ = 0,
-	EMU_QUIRK_SR_48000HZ,
-	EMU_QUIRK_SR_88200HZ,
-	EMU_QUIRK_SR_96000HZ,
-	EMU_QUIRK_SR_176400HZ,
-	EMU_QUIRK_SR_192000HZ
-};
-
 #define combine_word(s)    ((*(s)) | ((unsigned int)(s)[1] << 8))
 #define combine_triple(s)  (combine_word(s) | ((unsigned int)(s)[2] << 16))
 #define combine_quad(s)    (combine_triple(s) | ((unsigned int)(s)[3] << 24))
 
-unsigned int snd_usb_combine_bytes(unsigned char *bytes, int size);
-
-void *snd_usb_find_desc(void *descstart, int desclen, void *after, u8 dtype);
-void *snd_usb_find_csint_desc(void *descstart, int desclen, void *after, u8 dsubtype);
-
-int snd_usb_ctl_msg(struct usb_device *dev, unsigned int pipe,
-		    __u8 request, __u8 requesttype, __u16 value, __u16 index,
-		    void *data, __u16 size, int timeout);
-
-/*
- * retrieve usb_interface descriptor from the host interface
- * (conditional for compatibility with the older API)
- */
-#ifndef get_iface_desc
-#define get_iface_desc(iface)	(&(iface)->desc)
-#define get_endpoint(alt,ep)	(&(alt)->endpoint[ep].desc)
-#define get_ep_desc(ep)		(&(ep)->desc)
-#define get_cfg_desc(cfg)	(&(cfg)->desc)
-#endif
-
-#ifndef snd_usb_get_speed
-#define snd_usb_get_speed(dev) ((dev)->speed)
-#endif
-
 #endif /* __USBAUDIO_H */
diff --git a/sound/usb/usbmixer.c b/sound/usb/usbmixer.c
index 43d53a36249..5c056837594 100644
--- a/sound/usb/usbmixer.c
+++ b/sound/usb/usbmixer.c
@@ -42,6 +42,7 @@
 
 #include "usbaudio.h"
 #include "usbmixer.h"
+#include "helper.h"
 
 /*
  */
diff --git a/sound/usb/usx2y/us122l.c b/sound/usb/usx2y/us122l.c
index 4f6518c9b05..5f7b942ff57 100644
--- a/sound/usb/usx2y/us122l.c
+++ b/sound/usb/usx2y/us122l.c
@@ -25,7 +25,7 @@
 #define MODNAME "US122L"
 #include "usb_stream.c"
 #include "../usbaudio.h"
-#include "../usbmidi.h"
+#include "../midi.h"
 #include "us122l.h"
 
 MODULE_AUTHOR("Karsten Wiese <fzu@wemgehoertderstaat.de>");
diff --git a/sound/usb/usx2y/usbusx2y.h b/sound/usb/usx2y/usbusx2y.h
index 9ab97b40a35..e43c0a86441 100644
--- a/sound/usb/usx2y/usbusx2y.h
+++ b/sound/usb/usx2y/usbusx2y.h
@@ -1,7 +1,7 @@
 #ifndef USBUSX2Y_H
 #define USBUSX2Y_H
 #include "../usbaudio.h"
-#include "../usbmidi.h"
+#include "../midi.h"
 #include "usbus428ctldefs.h" 
 
 #define NRURBS	        2