From 31ef9134eb52636d383a7d0626cbbd345cb94f2f Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Tue, 15 Mar 2011 07:53:21 +0100 Subject: ALSA: add LaCie FireWire Speakers/Griffin FireWave Surround driver Add a driver for two playback-only FireWire devices based on the OXFW970 chip. v2: better AMDTP API abstraction; fix fw_unit leak; small fixes v3: cache the iPCR value v4: FireWave constraints; fix fw_device reference counting; fix PCR caching; small changes and fixes v5: volume/mute support; fix crashing due to pcm stop races v6: fix build; one-channel volume for LaCie v7: use signed values to make volume (range checks) work; fix function block IDs for volume/mute; always use channel 0 for LaCie volume Signed-off-by: Clemens Ladisch Acked-by: Stefan Richter Tested-by: Jay Fenlason Signed-off-by: Takashi Iwai --- sound/firewire/lib.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 sound/firewire/lib.c (limited to 'sound/firewire/lib.c') diff --git a/sound/firewire/lib.c b/sound/firewire/lib.c new file mode 100644 index 00000000000..4750cea2210 --- /dev/null +++ b/sound/firewire/lib.c @@ -0,0 +1,85 @@ +/* + * miscellaneous helper functions + * + * Copyright (c) Clemens Ladisch + * Licensed under the terms of the GNU General Public License, version 2. + */ + +#include +#include +#include +#include +#include "lib.h" + +#define ERROR_RETRY_DELAY_MS 5 + +/** + * rcode_string - convert a firewire result code to a string + * @rcode: the result + */ +const char *rcode_string(unsigned int rcode) +{ + static const char *const names[] = { + [RCODE_COMPLETE] = "complete", + [RCODE_CONFLICT_ERROR] = "conflict error", + [RCODE_DATA_ERROR] = "data error", + [RCODE_TYPE_ERROR] = "type error", + [RCODE_ADDRESS_ERROR] = "address error", + [RCODE_SEND_ERROR] = "send error", + [RCODE_CANCELLED] = "cancelled", + [RCODE_BUSY] = "busy", + [RCODE_GENERATION] = "generation", + [RCODE_NO_ACK] = "no ack", + }; + + if (rcode < ARRAY_SIZE(names) && names[rcode]) + return names[rcode]; + else + return "unknown"; +} +EXPORT_SYMBOL(rcode_string); + +/** + * snd_fw_transaction - send a request and wait for its completion + * @unit: the driver's unit on the target device + * @tcode: the transaction code + * @offset: the address in the target's address space + * @buffer: input/output data + * @length: length of @buffer + * + * Submits an asynchronous request to the target device, and waits for the + * response. The node ID and the current generation are derived from @unit. + * On a bus reset or an error, the transaction is retried a few times. + * Returns zero on success, or a negative error code. + */ +int snd_fw_transaction(struct fw_unit *unit, int tcode, + u64 offset, void *buffer, size_t length) +{ + struct fw_device *device = fw_parent_device(unit); + int generation, rcode, tries = 0; + + for (;;) { + generation = device->generation; + smp_rmb(); /* node_id vs. generation */ + rcode = fw_run_transaction(device->card, tcode, + device->node_id, generation, + device->max_speed, offset, + buffer, length); + + if (rcode == RCODE_COMPLETE) + return 0; + + if (rcode_is_permanent_error(rcode) || ++tries >= 3) { + dev_err(&unit->device, "transaction failed: %s\n", + rcode_string(rcode)); + return -EIO; + } + + msleep(ERROR_RETRY_DELAY_MS); + } +} +EXPORT_SYMBOL(snd_fw_transaction); + +MODULE_DESCRIPTION("FireWire audio helper functions"); +MODULE_AUTHOR("Clemens Ladisch "); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3