libata: New driver for OCTEON SOC Compact Flash interface (v7).

Cavium OCTEON processor support was recently merged, so now we have
this CF driver for your consideration.

Most OCTEON variants have *no* DMA or interrupt support on the CF
interface so for these, only PIO is supported.  Although if DMA is
available, we do take advantage of it.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

3 files changed, 975 insertions, 0 deletions

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 1a7be96d627..503a908afc8 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -698,6 +698,15 @@ config PATA_IXP4XX_CF
 
 	  If unsure, say N.
 
+config PATA_OCTEON_CF
+	tristate "OCTEON Boot Bus Compact Flash support"
+	depends on CPU_CAVIUM_OCTEON
+	help
+	  This option enables a polled compact flash driver for use with
+	  compact flash cards attached to the OCTEON boot bus.
+
+	  If unsure, say N.
+
 config PATA_SCC
 	tristate "Toshiba's Cell Reference Set IDE support"
 	depends on PCI && PPC_CELLEB
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 674965fa326..7f1ecf99528 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_PATA_IXP4XX_CF)	+= pata_ixp4xx_cf.o
 obj-$(CONFIG_PATA_SCC)		+= pata_scc.o
 obj-$(CONFIG_PATA_SCH)		+= pata_sch.o
 obj-$(CONFIG_PATA_BF54X)	+= pata_bf54x.o
+obj-$(CONFIG_PATA_OCTEON_CF)	+= pata_octeon_cf.o
 obj-$(CONFIG_PATA_PLATFORM)	+= pata_platform.o
 obj-$(CONFIG_PATA_OF_PLATFORM)	+= pata_of_platform.o
 obj-$(CONFIG_PATA_ICSIDE)	+= pata_icside.o
diff --git a/drivers/ata/pata_octeon_cf.c b/drivers/ata/pata_octeon_cf.c
new file mode 100644
index 00000000000..0fe4ef309c6
--- /dev/null
+++ b/drivers/ata/pata_octeon_cf.c
@@ -0,0 +1,965 @@
+/*
+ * Driver for the Octeon bootbus compact flash.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2005 - 2009 Cavium Networks
+ * Copyright (C) 2008 Wind River Systems
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/libata.h>
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+#include <scsi/scsi_host.h>
+
+#include <asm/octeon/octeon.h>
+
+/*
+ * The Octeon bootbus compact flash interface is connected in at least
+ * 3 different configurations on various evaluation boards:
+ *
+ * -- 8  bits no irq, no DMA
+ * -- 16 bits no irq, no DMA
+ * -- 16 bits True IDE mode with DMA, but no irq.
+ *
+ * In the last case the DMA engine can generate an interrupt when the
+ * transfer is complete.  For the first two cases only PIO is supported.
+ *
+ */
+
+#define DRV_NAME	"pata_octeon_cf"
+#define DRV_VERSION	"2.1"
+
+
+struct octeon_cf_port {
+	struct workqueue_struct *wq;
+	struct delayed_work delayed_finish;
+	struct ata_port *ap;
+	int dma_finished;
+};
+
+static struct scsi_host_template octeon_cf_sht = {
+	ATA_PIO_SHT(DRV_NAME),
+};
+
+/**
+ * Convert nanosecond based time to setting used in the
+ * boot bus timing register, based on timing multiple
+ */
+static unsigned int ns_to_tim_reg(unsigned int tim_mult, unsigned int nsecs)
+{
+	unsigned int val;
+
+	/*
+	 * Compute # of eclock periods to get desired duration in
+	 * nanoseconds.
+	 */
+	val = DIV_ROUND_UP(nsecs * (octeon_get_clock_rate() / 1000000),
+			  1000 * tim_mult);
+
+	return val;
+}
+
+static void octeon_cf_set_boot_reg_cfg(int cs)
+{
+	union cvmx_mio_boot_reg_cfgx reg_cfg;
+	reg_cfg.u64 = cvmx_read_csr(CVMX_MIO_BOOT_REG_CFGX(cs));
+	reg_cfg.s.dmack = 0;	/* Don't assert DMACK on access */
+	reg_cfg.s.tim_mult = 2;	/* Timing mutiplier 2x */
+	reg_cfg.s.rd_dly = 0;	/* Sample on falling edge of BOOT_OE */
+	reg_cfg.s.sam = 0;	/* Don't combine write and output enable */
+	reg_cfg.s.we_ext = 0;	/* No write enable extension */
+	reg_cfg.s.oe_ext = 0;	/* No read enable extension */
+	reg_cfg.s.en = 1;	/* Enable this region */
+	reg_cfg.s.orbit = 0;	/* Don't combine with previous region */
+	reg_cfg.s.ale = 0;	/* Don't do address multiplexing */
+	cvmx_write_csr(CVMX_MIO_BOOT_REG_CFGX(cs), reg_cfg.u64);
+}
+
+/**
+ * Called after libata determines the needed PIO mode. This
+ * function programs the Octeon bootbus regions to support the
+ * timing requirements of the PIO mode.
+ *
+ * @ap:     ATA port information
+ * @dev:    ATA device
+ */
+static void octeon_cf_set_piomode(struct ata_port *ap, struct ata_device *dev)
+{
+	struct octeon_cf_data *ocd = ap->dev->platform_data;
+	union cvmx_mio_boot_reg_timx reg_tim;
+	int cs = ocd->base_region;
+	int T;
+	struct ata_timing timing;
+
+	int use_iordy;
+	int trh;
+	int pause;
+	/* These names are timing parameters from the ATA spec */
+	int t1;
+	int t2;
+	int t2i;
+
+	T = (int)(2000000000000LL / octeon_get_clock_rate());
+
+	if (ata_timing_compute(dev, dev->pio_mode, &timing, T, T))
+		BUG();
+
+	t1 = timing.setup;
+	if (t1)
+		t1--;
+	t2 = timing.active;
+	if (t2)
+		t2--;
+	t2i = timing.act8b;
+	if (t2i)
+		t2i--;
+
+	trh = ns_to_tim_reg(2, 20);
+	if (trh)
+		trh--;
+
+	pause = timing.cycle - timing.active - timing.setup - trh;
+	if (pause)
+		pause--;
+
+	octeon_cf_set_boot_reg_cfg(cs);
+	if (ocd->dma_engine >= 0)
+		/* True IDE mode, program both chip selects.  */
+		octeon_cf_set_boot_reg_cfg(cs + 1);
+
+
+	use_iordy = ata_pio_need_iordy(dev);
+
+	reg_tim.u64 = cvmx_read_csr(CVMX_MIO_BOOT_REG_TIMX(cs));
+	/* Disable page mode */
+	reg_tim.s.pagem = 0;
+	/* Enable dynamic timing */
+	reg_tim.s.waitm = use_iordy;
+	/* Pages are disabled */
+	reg_tim.s.pages = 0;
+	/* We don't use multiplexed address mode */
+	reg_tim.s.ale = 0;
+	/* Not used */
+	reg_tim.s.page = 0;
+	/* Time after IORDY to coninue to assert the data */
+	reg_tim.s.wait = 0;
+	/* Time to wait to complete the cycle. */
+	reg_tim.s.pause = pause;
+	/* How long to hold after a write to de-assert CE. */
+	reg_tim.s.wr_hld = trh;
+	/* How long to wait after a read to de-assert CE. */
+	reg_tim.s.rd_hld = trh;
+	/* How long write enable is asserted */
+	reg_tim.s.we = t2;
+	/* How long read enable is asserted */
+	reg_tim.s.oe = t2;
+	/* Time after CE that read/write starts */
+	reg_tim.s.ce = ns_to_tim_reg(2, 5);
+	/* Time before CE that address is valid */
+	reg_tim.s.adr = 0;
+
+	/* Program the bootbus region timing for the data port chip select. */
+	cvmx_write_csr(CVMX_MIO_BOOT_REG_TIMX(cs), reg_tim.u64);
+	if (ocd->dma_engine >= 0)
+		/* True IDE mode, program both chip selects.  */
+		cvmx_write_csr(CVMX_MIO_BOOT_REG_TIMX(cs + 1), reg_tim.u64);
+}
+
+static void octeon_cf_set_dmamode(struct ata_port *ap, struct ata_device *dev)
+{
+	struct octeon_cf_data *ocd = dev->link->ap->dev->platform_data;
+	union cvmx_mio_boot_dma_timx dma_tim;
+	unsigned int oe_a;
+	unsigned int oe_n;
+	unsigned int dma_ackh;
+	unsigned int dma_arq;
+	unsigned int pause;
+	unsigned int T0, Tkr, Td;
+	unsigned int tim_mult;
+
+	const struct ata_timing *timing;
+
+	timing = ata_timing_find_mode(dev->dma_mode);
+	T0	= timing->cycle;
+	Td	= timing->active;
+	Tkr	= timing->recover;
+	dma_ackh = timing->dmack_hold;
+
+	dma_tim.u64 = 0;
+	/* dma_tim.s.tim_mult = 0 --> 4x */
+	tim_mult = 4;
+
+	/* not spec'ed, value in eclocks, not affected by tim_mult */
+	dma_arq = 8;
+	pause = 25 - dma_arq * 1000 /
+		(octeon_get_clock_rate() / 1000000); /* Tz */
+
+	oe_a = Td;
+	/* Tkr from cf spec, lengthened to meet T0 */
+	oe_n = max(T0 - oe_a, Tkr);
+
+	dma_tim.s.dmack_pi = 1;
+
+	dma_tim.s.oe_n = ns_to_tim_reg(tim_mult, oe_n);
+	dma_tim.s.oe_a = ns_to_tim_reg(tim_mult, oe_a);
+
+	/*
+	 * This is tI, C.F. spec. says 0, but Sony CF card requires
+	 * more, we use 20 nS.
+	 */
+	dma_tim.s.dmack_s = ns_to_tim_reg(tim_mult, 20);;
+	dma_tim.s.dmack_h = ns_to_tim_reg(tim_mult, dma_ackh);
+
+	dma_tim.s.dmarq = dma_arq;
+	dma_tim.s.pause = ns_to_tim_reg(tim_mult, pause);
+
+	dma_tim.s.rd_dly = 0;	/* Sample right on edge */
+
+	/*  writes only */
+	dma_tim.s.we_n = ns_to_tim_reg(tim_mult, oe_n);
+	dma_tim.s.we_a = ns_to_tim_reg(tim_mult, oe_a);
+
+	pr_debug("ns to ticks (mult %d) of %d is: %d\n", tim_mult, 60,
+		 ns_to_tim_reg(tim_mult, 60));
+	pr_debug("oe_n: %d, oe_a: %d, dmack_s: %d, dmack_h: "
+		 "%d, dmarq: %d, pause: %d\n",
+		 dma_tim.s.oe_n, dma_tim.s.oe_a, dma_tim.s.dmack_s,
+		 dma_tim.s.dmack_h, dma_tim.s.dmarq, dma_tim.s.pause);
+
+	cvmx_write_csr(CVMX_MIO_BOOT_DMA_TIMX(ocd->dma_engine),
+		       dma_tim.u64);
+
+}
+
+/**
+ * Handle an 8 bit I/O request.
+ *
+ * @dev:        Device to access
+ * @buffer:     Data buffer
+ * @buflen:     Length of the buffer.
+ * @rw:         True to write.
+ */
+static unsigned int octeon_cf_data_xfer8(struct ata_device *dev,
+					 unsigned char *buffer,
+					 unsigned int buflen,
+					 int rw)
+{
+	struct ata_port *ap		= dev->link->ap;
+	void __iomem *data_addr		= ap->ioaddr.data_addr;
+	unsigned long words;
+	int count;
+
+	words = buflen;
+	if (rw) {
+		count = 16;
+		while (words--) {
+			iowrite8(*buffer, data_addr);
+			buffer++;
+			/*
+			 * Every 16 writes do a read so the bootbus
+			 * FIFO doesn't fill up.
+			 */
+			if (--count == 0) {
+				ioread8(ap->ioaddr.altstatus_addr);
+				count = 16;
+			}
+		}
+	} else {
+		ioread8_rep(data_addr, buffer, words);
+	}
+	return buflen;
+}
+
+/**
+ * Handle a 16 bit I/O request.
+ *
+ * @dev:        Device to access
+ * @buffer:     Data buffer
+ * @buflen:     Length of the buffer.
+ * @rw:         True to write.
+ */
+static unsigned int octeon_cf_data_xfer16(struct ata_device *dev,
+					  unsigned char *buffer,
+					  unsigned int buflen,
+					  int rw)
+{
+	struct ata_port *ap		= dev->link->ap;
+	void __iomem *data_addr		= ap->ioaddr.data_addr;
+	unsigned long words;
+	int count;
+
+	words = buflen / 2;
+	if (rw) {
+		count = 16;
+		while (words--) {
+			iowrite16(*(uint16_t *)buffer, data_addr);
+			buffer += sizeof(uint16_t);
+			/*
+			 * Every 16 writes do a read so the bootbus
+			 * FIFO doesn't fill up.
+			 */
+			if (--count == 0) {
+				ioread8(ap->ioaddr.altstatus_addr);
+				count = 16;
+			}
+		}
+	} else {
+		while (words--) {
+			*(uint16_t *)buffer = ioread16(data_addr);
+			buffer += sizeof(uint16_t);
+		}
+	}
+	/* Transfer trailing 1 byte, if any. */
+	if (unlikely(buflen & 0x01)) {
+		__le16 align_buf[1] = { 0 };
+
+		if (rw == READ) {
+			align_buf[0] = cpu_to_le16(ioread16(data_addr));
+			memcpy(buffer, align_buf, 1);
+		} else {
+			memcpy(align_buf, buffer, 1);
+			iowrite16(le16_to_cpu(align_buf[0]), data_addr);
+		}
+		words++;
+	}
+	return buflen;
+}
+
+/**
+ * Read the taskfile for 16bit non-True IDE only.
+ */
+static void octeon_cf_tf_read16(struct ata_port *ap, struct ata_taskfile *tf)
+{
+	u16 blob;
+	/* The base of the registers is at ioaddr.data_addr. */
+	void __iomem *base = ap->ioaddr.data_addr;
+
+	blob = __raw_readw(base + 0xc);
+	tf->feature = blob >> 8;
+
+	blob = __raw_readw(base + 2);
+	tf->nsect = blob & 0xff;
+	tf->lbal = blob >> 8;
+
+	blob = __raw_readw(base + 4);
+	tf->lbam = blob & 0xff;
+	tf->lbah = blob >> 8;
+
+	blob = __raw_readw(base + 6);
+	tf->device = blob & 0xff;
+	tf->command = blob >> 8;
+
+	if (tf->flags & ATA_TFLAG_LBA48) {
+		if (likely(ap->ioaddr.ctl_addr)) {
+			iowrite8(tf->ctl | ATA_HOB, ap->ioaddr.ctl_addr);
+
+			blob = __raw_readw(base + 0xc);
+			tf->hob_feature = blob >> 8;
+
+			blob = __raw_readw(base + 2);
+			tf->hob_nsect = blob & 0xff;
+			tf->hob_lbal = blob >> 8;
+
+			blob = __raw_readw(base + 4);
+			tf->hob_lbam = blob & 0xff;
+			tf->hob_lbah = blob >> 8;
+
+			iowrite8(tf->ctl, ap->ioaddr.ctl_addr);
+			ap->last_ctl = tf->ctl;
+		} else {
+			WARN_ON(1);
+		}
+	}
+}
+
+static u8 octeon_cf_check_status16(struct ata_port *ap)
+{
+	u16 blob;
+	void __iomem *base = ap->ioaddr.data_addr;
+
+	blob = __raw_readw(base + 6);
+	return blob >> 8;
+}
+
+static int octeon_cf_softreset16(struct ata_link *link, unsigned int *classes,
+				 unsigned long deadline)
+{
+	struct ata_port *ap = link->ap;
+	void __iomem *base = ap->ioaddr.data_addr;
+	int rc;
+	u8 err;
+
+	DPRINTK("about to softreset\n");
+	__raw_writew(ap->ctl, base + 0xe);
+	udelay(20);
+	__raw_writew(ap->ctl | ATA_SRST, base + 0xe);
+	udelay(20);
+	__raw_writew(ap->ctl, base + 0xe);
+
+	rc = ata_sff_wait_after_reset(link, 1, deadline);
+	if (rc) {
+		ata_link_printk(link, KERN_ERR, "SRST failed (errno=%d)\n", rc);
+		return rc;
+	}
+
+	/* determine by signature whether we have ATA or ATAPI devices */
+	classes[0] = ata_sff_dev_classify(&link->device[0], 1, &err);
+	DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
+	return 0;
+}
+
+/**
+ * Load the taskfile for 16bit non-True IDE only.  The device_addr is
+ * not loaded, we do this as part of octeon_cf_exec_command16.
+ */
+static void octeon_cf_tf_load16(struct ata_port *ap,
+				const struct ata_taskfile *tf)
+{
+	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
+	/* The base of the registers is at ioaddr.data_addr. */
+	void __iomem *base = ap->ioaddr.data_addr;
+
+	if (tf->ctl != ap->last_ctl) {
+		iowrite8(tf->ctl, ap->ioaddr.ctl_addr);
+		ap->last_ctl = tf->ctl;
+		ata_wait_idle(ap);
+	}
+	if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
+		__raw_writew(tf->hob_feature << 8, base + 0xc);
+		__raw_writew(tf->hob_nsect | tf->hob_lbal << 8, base + 2);
+		__raw_writew(tf->hob_lbam | tf->hob_lbah << 8, base + 4);
+		VPRINTK("hob: feat 0x%X nsect 0x%X, lba 0x%X 0x%X 0x%X\n",
+			tf->hob_feature,
+			tf->hob_nsect,
+			tf->hob_lbal,
+			tf->hob_lbam,
+			tf->hob_lbah);
+	}
+	if (is_addr) {
+		__raw_writew(tf->feature << 8, base + 0xc);
+		__raw_writew(tf->nsect | tf->lbal << 8, base + 2);
+		__raw_writew(tf->lbam | tf->lbah << 8, base + 4);
+		VPRINTK("feat 0x%X nsect 0x%X, lba 0x%X 0x%X 0x%X\n",
+			tf->feature,
+			tf->nsect,
+			tf->lbal,
+			tf->lbam,
+			tf->lbah);
+	}
+	ata_wait_idle(ap);
+}
+
+
+static void octeon_cf_dev_select(struct ata_port *ap, unsigned int device)
+{
+/*  There is only one device, do nothing. */
+	return;
+}
+
+/*
+ * Issue ATA command to host controller.  The device_addr is also sent
+ * as it must be written in a combined write with the command.
+ */
+static void octeon_cf_exec_command16(struct ata_port *ap,
+				const struct ata_taskfile *tf)
+{
+	/* The base of the registers is at ioaddr.data_addr. */
+	void __iomem *base = ap->ioaddr.data_addr;
+	u16 blob;
+
+	if (tf->flags & ATA_TFLAG_DEVICE) {
+		VPRINTK("device 0x%X\n", tf->device);
+		blob = tf->device;
+	} else {
+		blob = 0;
+	}
+
+	DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command);
+	blob |= (tf->command << 8);
+	__raw_writew(blob, base + 6);
+
+
+	ata_wait_idle(ap);
+}
+
+static u8 octeon_cf_irq_on(struct ata_port *ap)
+{
+	return 0;
+}
+
+static void octeon_cf_irq_clear(struct ata_port *ap)
+{
+	return;
+}
+
+static void octeon_cf_dma_setup(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+	struct octeon_cf_port *cf_port;
+
+	cf_port = (struct octeon_cf_port *)ap->private_data;
+	DPRINTK("ENTER\n");
+	/* issue r/w command */
+	qc->cursg = qc->sg;
+	cf_port->dma_finished = 0;
+	ap->ops->sff_exec_command(ap, &qc->tf);
+	DPRINTK("EXIT\n");
+}
+
+/**
+ * Start a DMA transfer that was already setup
+ *
+ * @qc:     Information about the DMA
+ */
+static void octeon_cf_dma_start(struct ata_queued_cmd *qc)
+{
+	struct octeon_cf_data *ocd = qc->ap->dev->platform_data;
+	union cvmx_mio_boot_dma_cfgx mio_boot_dma_cfg;
+	union cvmx_mio_boot_dma_intx mio_boot_dma_int;
+	struct scatterlist *sg;
+
+	VPRINTK("%d scatterlists\n", qc->n_elem);
+
+	/* Get the scatter list entry we need to DMA into */
+	sg = qc->cursg;
+	BUG_ON(!sg);
+
+	/*
+	 * Clear the DMA complete status.
+	 */
+	mio_boot_dma_int.u64 = 0;
+	mio_boot_dma_int.s.done = 1;
+	cvmx_write_csr(CVMX_MIO_BOOT_DMA_INTX(ocd->dma_engine),
+		       mio_boot_dma_int.u64);
+
+	/* Enable the interrupt.  */
+	cvmx_write_csr(CVMX_MIO_BOOT_DMA_INT_ENX(ocd->dma_engine),
+		       mio_boot_dma_int.u64);
+
+	/* Set the direction of the DMA */
+	mio_boot_dma_cfg.u64 = 0;
+	mio_boot_dma_cfg.s.en = 1;
+	mio_boot_dma_cfg.s.rw = ((qc->tf.flags & ATA_TFLAG_WRITE) != 0);
+
+	/*
+	 * Don't stop the DMA if the device deasserts DMARQ. Many
+	 * compact flashes deassert DMARQ for a short time between
+	 * sectors. Instead of stopping and restarting the DMA, we'll
+	 * let the hardware do it. If the DMA is really stopped early
+	 * due to an error condition, a later timeout will force us to
+	 * stop.
+	 */
+	mio_boot_dma_cfg.s.clr = 0;
+
+	/* Size is specified in 16bit words and minus one notation */
+	mio_boot_dma_cfg.s.size = sg_dma_len(sg) / 2 - 1;
+
+	/* We need to swap the high and low bytes of every 16 bits */
+	mio_boot_dma_cfg.s.swap8 = 1;
+
+	mio_boot_dma_cfg.s.adr = sg_dma_address(sg);
+
+	VPRINTK("%s %d bytes address=%p\n",
+		(mio_boot_dma_cfg.s.rw) ? "write" : "read", sg->length,
+		(void *)(unsigned long)mio_boot_dma_cfg.s.adr);
+
+	cvmx_write_csr(CVMX_MIO_BOOT_DMA_CFGX(ocd->dma_engine),
+		       mio_boot_dma_cfg.u64);
+}
+
+/**
+ *
+ *	LOCKING:
+ *	spin_lock_irqsave(host lock)
+ *
+ */
+static unsigned int octeon_cf_dma_finished(struct ata_port *ap,
+					struct ata_queued_cmd *qc)
+{
+	struct ata_eh_info *ehi = &ap->link.eh_info;
+	struct octeon_cf_data *ocd = ap->dev->platform_data;
+	union cvmx_mio_boot_dma_cfgx dma_cfg;
+	union cvmx_mio_boot_dma_intx dma_int;
+	struct octeon_cf_port *cf_port;
+	u8 status;
+
+	VPRINTK("ata%u: protocol %d task_state %d\n",
+		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
+
+
+	if (ap->hsm_task_state != HSM_ST_LAST)
+		return 0;
+
+	cf_port = (struct octeon_cf_port *)ap->private_data;
+
+	dma_cfg.u64 = cvmx_read_csr(CVMX_MIO_BOOT_DMA_CFGX(ocd->dma_engine));
+	if (dma_cfg.s.size != 0xfffff) {
+		/* Error, the transfer was not complete.  */
+		qc->err_mask |= AC_ERR_HOST_BUS;
+		ap->hsm_task_state = HSM_ST_ERR;
+	}
+
+	/* Stop and clear the dma engine.  */
+	dma_cfg.u64 = 0;
+	dma_cfg.s.size = -1;
+	cvmx_write_csr(CVMX_MIO_BOOT_DMA_CFGX(ocd->dma_engine), dma_cfg.u64);
+
+	/* Disable the interrupt.  */
+	dma_int.u64 = 0;
+	cvmx_write_csr(CVMX_MIO_BOOT_DMA_INT_ENX(ocd->dma_engine), dma_int.u64);
+
+	/* Clear the DMA complete status */
+	dma_int.s.done = 1;
+	cvmx_write_csr(CVMX_MIO_BOOT_DMA_INTX(ocd->dma_engine), dma_int.u64);
+
+	status = ap->ops->sff_check_status(ap);
+
+	ata_sff_hsm_move(ap, qc, status, 0);
+
+	if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA))
+		ata_ehi_push_desc(ehi, "DMA stat 0x%x", status);
+
+	return 1;
+}
+
+/*
+ * Check if any queued commands have more DMAs, if so start the next
+ * transfer, else do end of transfer handling.
+ */
+static irqreturn_t octeon_cf_interrupt(int irq, void *dev_instance)
+{
+	struct ata_host *host = dev_instance;
+	struct octeon_cf_port *cf_port;
+	int i;
+	unsigned int handled = 0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	DPRINTK("ENTER\n");
+	for (i = 0; i < host->n_ports; i++) {
+		u8 status;
+		struct ata_port *ap;
+		struct ata_queued_cmd *qc;
+		union cvmx_mio_boot_dma_intx dma_int;
+		union cvmx_mio_boot_dma_cfgx dma_cfg;
+		struct octeon_cf_data *ocd;
+
+		ap = host->ports[i];
+		ocd = ap->dev->platform_data;
+		if (!ap || (ap->flags & ATA_FLAG_DISABLED))
+			continue;
+
+		ocd = ap->dev->platform_data;
+		cf_port = (struct octeon_cf_port *)ap->private_data;
+		dma_int.u64 =
+			cvmx_read_csr(CVMX_MIO_BOOT_DMA_INTX(ocd->dma_engine));
+		dma_cfg.u64 =
+			cvmx_read_csr(CVMX_MIO_BOOT_DMA_CFGX(ocd->dma_engine));
+
+		qc = ata_qc_from_tag(ap, ap->link.active_tag);
+
+		if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
+		    (qc->flags & ATA_QCFLAG_ACTIVE)) {
+			if (dma_int.s.done && !dma_cfg.s.en) {
+				if (!sg_is_last(qc->cursg)) {
+					qc->cursg = sg_next(qc->cursg);
+					handled = 1;
+					octeon_cf_dma_start(qc);
+					continue;
+				} else {
+					cf_port->dma_finished = 1;
+				}
+			}
+			if (!cf_port->dma_finished)
+				continue;
+			status = ioread8(ap->ioaddr.altstatus_addr);
+			if (status & (ATA_BUSY | ATA_DRQ)) {
+				/*
+				 * We are busy, try to handle it
+				 * later.  This is the DMA finished
+				 * interrupt, and it could take a
+				 * little while for the card to be
+				 * ready for more commands.
+				 */
+				/* Clear DMA irq. */
+				dma_int.u64 = 0;
+				dma_int.s.done = 1;
+				cvmx_write_csr(CVMX_MIO_BOOT_DMA_INTX(ocd->dma_engine),
+					       dma_int.u64);
+
+				queue_delayed_work(cf_port->wq,
+						   &cf_port->delayed_finish, 1);
+				handled = 1;
+			} else {
+				handled |= octeon_cf_dma_finished(ap, qc);
+			}
+		}
+	}
+	spin_unlock_irqrestore(&host->lock, flags);
+	DPRINTK("EXIT\n");
+	return IRQ_RETVAL(handled);
+}
+
+static void octeon_cf_delayed_finish(struct work_struct *work)
+{
+	struct octeon_cf_port *cf_port = container_of(work,
+						      struct octeon_cf_port,
+						      delayed_finish.work);
+	struct ata_port *ap = cf_port->ap;
+	struct ata_host *host = ap->host;
+	struct ata_queued_cmd *qc;
+	unsigned long flags;
+	u8 status;
+
+	spin_lock_irqsave(&host->lock, flags);
+
+	/*
+	 * If the port is not waiting for completion, it must have
+	 * handled it previously.  The hsm_task_state is
+	 * protected by host->lock.
+	 */
+	if (ap->hsm_task_state != HSM_ST_LAST || !cf_port->dma_finished)
+		goto out;
+
+	status = ioread8(ap->ioaddr.altstatus_addr);
+	if (status & (ATA_BUSY | ATA_DRQ)) {
+		/* Still busy, try again. */
+		queue_delayed_work(cf_port->wq,
+				   &cf_port->delayed_finish, 1);
+		goto out;
+	}
+	qc = ata_qc_from_tag(ap, ap->link.active_tag);
+	if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
+	    (qc->flags & ATA_QCFLAG_ACTIVE))
+		octeon_cf_dma_finished(ap, qc);
+out:
+	spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void octeon_cf_dev_config(struct ata_device *dev)
+{
+	/*
+	 * A maximum of 2^20 - 1 16 bit transfers are possible with
+	 * the bootbus DMA.  So we need to throttle max_sectors to
+	 * (2^12 - 1 == 4095) to assure that this can never happen.
+	 */
+	dev->max_sectors = min(dev->max_sectors, 4095U);
+}
+
+/*
+ * Trap if driver tries to do standard bmdma commands.  They are not
+ * supported.
+ */
+static void unreachable_qc(struct ata_queued_cmd *qc)
+{
+	BUG();
+}
+
+static u8 unreachable_port(struct ata_port *ap)
+{
+	BUG();
+}
+
+/*
+ * We don't do ATAPI DMA so return 0.
+ */
+static int octeon_cf_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+	return 0;
+}
+
+static unsigned int octeon_cf_qc_issue(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+
+	switch (qc->tf.protocol) {
+	case ATA_PROT_DMA:
+		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
+
+		ap->ops->sff_tf_load(ap, &qc->tf);  /* load tf registers */
+		octeon_cf_dma_setup(qc);	    /* set up dma */
+		octeon_cf_dma_start(qc);	    /* initiate dma */
+		ap->hsm_task_state = HSM_ST_LAST;
+		break;
+
+	case ATAPI_PROT_DMA:
+		dev_err(ap->dev, "Error, ATAPI not supported\n");
+		BUG();
+
+	default:
+		return ata_sff_qc_issue(qc);
+	}
+
+	return 0;
+}
+
+static struct ata_port_operations octeon_cf_ops = {
+	.inherits		= &ata_sff_port_ops,
+	.check_atapi_dma	= octeon_cf_check_atapi_dma,
+	.qc_prep		= ata_noop_qc_prep,
+	.qc_issue		= octeon_cf_qc_issue,
+	.sff_dev_select		= octeon_cf_dev_select,
+	.sff_irq_on		= octeon_cf_irq_on,
+	.sff_irq_clear		= octeon_cf_irq_clear,
+	.bmdma_setup		= unreachable_qc,
+	.bmdma_start		= unreachable_qc,
+	.bmdma_stop		= unreachable_qc,
+	.bmdma_status		= unreachable_port,
+	.cable_detect		= ata_cable_40wire,
+	.set_piomode		= octeon_cf_set_piomode,
+	.set_dmamode		= octeon_cf_set_dmamode,
+	.dev_config		= octeon_cf_dev_config,
+};
+
+static int __devinit octeon_cf_probe(struct platform_device *pdev)
+{
+	struct resource *res_cs0, *res_cs1;
+
+	void __iomem *cs0;
+	void __iomem *cs1 = NULL;
+	struct ata_host *host;
+	struct ata_port *ap;
+	struct octeon_cf_data *ocd;
+	int irq = 0;
+	irq_handler_t irq_handler = NULL;
+	void __iomem *base;
+	struct octeon_cf_port *cf_port;
+
+	res_cs0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	if (!res_cs0)
+		return -EINVAL;
+
+	ocd = pdev->dev.platform_data;
+
+	cs0 = devm_ioremap_nocache(&pdev->dev, res_cs0->start,
+				   res_cs0->end - res_cs0->start + 1);
+
+	if (!cs0)
+		return -ENOMEM;
+
+	/* Determine from availability of DMA if True IDE mode or not */
+	if (ocd->dma_engine >= 0) {
+		res_cs1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+		if (!res_cs1)
+			return -EINVAL;
+
+		cs1 = devm_ioremap_nocache(&pdev->dev, res_cs1->start,
+					   res_cs0->end - res_cs1->start + 1);
+
+		if (!cs1)
+			return -ENOMEM;
+	}
+
+	cf_port = kzalloc(sizeof(*cf_port), GFP_KERNEL);
+	if (!cf_port)
+		return -ENOMEM;
+
+	/* allocate host */
+	host = ata_host_alloc(&pdev->dev, 1);
+	if (!host)
+		goto free_cf_port;
+
+	ap = host->ports[0];
+	ap->private_data = cf_port;
+	cf_port->ap = ap;
+	ap->ops = &octeon_cf_ops;
+	ap->pio_mask = 0x7f; /* Support PIO 0-6 */
+	ap->flags |= ATA_FLAG_MMIO | ATA_FLAG_NO_LEGACY
+		  | ATA_FLAG_NO_ATAPI | ATA_FLAG_PIO_POLLING;
+
+	base = cs0 + ocd->base_region_bias;
+	if (!ocd->is16bit) {
+		ap->ioaddr.cmd_addr	= base;
+		ata_sff_std_ports(&ap->ioaddr);
+
+		ap->ioaddr.altstatus_addr = base + 0xe;
+		ap->ioaddr.ctl_addr	= base + 0xe;
+		octeon_cf_ops.sff_data_xfer = octeon_cf_data_xfer8;
+	} else if (cs1) {
+		/* Presence of cs1 indicates True IDE mode.  */
+		ap->ioaddr.cmd_addr	= base + (ATA_REG_CMD << 1) + 1;
+		ap->ioaddr.data_addr	= base + (ATA_REG_DATA << 1);
+		ap->ioaddr.error_addr	= base + (ATA_REG_ERR << 1) + 1;
+		ap->ioaddr.feature_addr	= base + (ATA_REG_FEATURE << 1) + 1;
+		ap->ioaddr.nsect_addr	= base + (ATA_REG_NSECT << 1) + 1;
+		ap->ioaddr.lbal_addr	= base + (ATA_REG_LBAL << 1) + 1;
+		ap->ioaddr.lbam_addr	= base + (ATA_REG_LBAM << 1) + 1;
+		ap->ioaddr.lbah_addr	= base + (ATA_REG_LBAH << 1) + 1;
+		ap->ioaddr.device_addr	= base + (ATA_REG_DEVICE << 1) + 1;
+		ap->ioaddr.status_addr	= base + (ATA_REG_STATUS << 1) + 1;
+		ap->ioaddr.command_addr	= base + (ATA_REG_CMD << 1) + 1;
+		ap->ioaddr.altstatus_addr = cs1 + (6 << 1) + 1;
+		ap->ioaddr.ctl_addr	= cs1 + (6 << 1) + 1;
+		octeon_cf_ops.sff_data_xfer = octeon_cf_data_xfer16;
+
+		ap->mwdma_mask	= 0x1f; /* Support MWDMA 0-4 */
+		irq = platform_get_irq(pdev, 0);
+		irq_handler = octeon_cf_interrupt;
+
+		/* True IDE mode needs delayed work to poll for not-busy.  */
+		cf_port->wq = create_singlethread_workqueue(DRV_NAME);
+		if (!cf_port->wq)
+			goto free_cf_port;
+		INIT_DELAYED_WORK(&cf_port->delayed_finish,
+				  octeon_cf_delayed_finish);
+
+	} else {
+		/* 16 bit but not True IDE */
+		octeon_cf_ops.sff_data_xfer	= octeon_cf_data_xfer16;
+		octeon_cf_ops.softreset		= octeon_cf_softreset16;
+		octeon_cf_ops.sff_check_status	= octeon_cf_check_status16;
+		octeon_cf_ops.sff_tf_read	= octeon_cf_tf_read16;
+		octeon_cf_ops.sff_tf_load	= octeon_cf_tf_load16;
+		octeon_cf_ops.sff_exec_command	= octeon_cf_exec_command16;
+
+		ap->ioaddr.data_addr	= base + ATA_REG_DATA;
+		ap->ioaddr.nsect_addr	= base + ATA_REG_NSECT;
+		ap->ioaddr.lbal_addr	= base + ATA_REG_LBAL;
+		ap->ioaddr.ctl_addr	= base + 0xe;
+		ap->ioaddr.altstatus_addr = base + 0xe;
+	}
+
+	ata_port_desc(ap, "cmd %p ctl %p", base, ap->ioaddr.ctl_addr);
+
+
+	dev_info(&pdev->dev, "version " DRV_VERSION" %d bit%s.\n",
+		 (ocd->is16bit) ? 16 : 8,
+		 (cs1) ? ", True IDE" : "");
+
+
+	return ata_host_activate(host, irq, irq_handler, 0, &octeon_cf_sht);
+
+free_cf_port:
+	kfree(cf_port);
+	return -ENOMEM;
+}
+
+static struct platform_driver octeon_cf_driver = {
+	.probe		= octeon_cf_probe,
+	.driver		= {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init octeon_cf_init(void)
+{
+	return platform_driver_register(&octeon_cf_driver);
+}
+
+
+MODULE_AUTHOR("David Daney <ddaney@caviumnetworks.com>");
+MODULE_DESCRIPTION("low-level driver for Cavium OCTEON Compact Flash PATA");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);
+MODULE_ALIAS("platform:" DRV_NAME);
+
+module_init(octeon_cf_init);