Patchwork [V3,resend,2/2] pata_arasan_cf: Adding support for arasan compact flash host controller

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Submitter Viresh KUMAR
Date Feb. 22, 2011, 10:16 a.m.
Message ID <3f8cc4d5b94214f4746f55427e43ca4cd6df6a27.1298369157.git.viresh.kumar@st.com>
Download mbox | patch
Permalink /patch/83944/
State Not Applicable
Delegated to: David Miller
Headers show

Comments

Viresh KUMAR - Feb. 22, 2011, 10:16 a.m.
The Arasan CompactFlash Device Controller has three basic modes of
operation: PC card ATA using I/O mode, PC card ATA using memory mode, PC card
ATA using true IDE modes.

Currently driver supports only True IDE mode.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
---
 MAINTAINERS                         |    7 +
 drivers/ata/Kconfig                 |    6 +
 drivers/ata/Makefile                |    1 +
 drivers/ata/pata_arasan_cf.c        |  977 +++++++++++++++++++++++++++++++++++
 include/linux/pata_arasan_cf_data.h |   47 ++
 5 files changed, 1038 insertions(+), 0 deletions(-)
 create mode 100644 drivers/ata/pata_arasan_cf.c
 create mode 100644 include/linux/pata_arasan_cf_data.h
Tejun Heo - Feb. 22, 2011, 10:43 a.m.
On Tue, Feb 22, 2011 at 03:46:07PM +0530, Viresh Kumar wrote:
> The Arasan CompactFlash Device Controller has three basic modes of
> operation: PC card ATA using I/O mode, PC card ATA using memory mode, PC card
> ATA using true IDE modes.
> 
> Currently driver supports only True IDE mode.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@st.com>

Alright, looks good to me.

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 916f561..98bc389 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -485,6 +485,13 @@  S:	Maintained
 F:	drivers/net/appletalk/
 F:	net/appletalk/
 
+ARASAN COMPACT FLASH PATA CONTROLLER
+M:	Viresh Kumar <viresh.kumar@st.com>
+L:	linux-ide@vger.kernel.org
+S:	Maintained
+F:	include/linux/pata_arasan_cf_data.h
+F:	drivers/ata/pata_arasan_cf.c
+
 ARC FRAMEBUFFER DRIVER
 M:	Jaya Kumar <jayalk@intworks.biz>
 S:	Maintained
diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 36e2319..5dd1e4c 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -283,6 +283,12 @@  config PATA_AMD
 
 	  If unsure, say N.
 
+config PATA_ARASAN_CF
+	tristate "ARASAN CompactFlash PATA Controller Support"
+	select DMA_ENGINE
+	help
+	  Say Y here to support the ARASAN CompactFlash PATA controller
+
 config PATA_ARTOP
 	tristate "ARTOP 6210/6260 PATA support"
 	depends on PCI
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 2b67c90..0da42cb 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -11,6 +11,7 @@  obj-$(CONFIG_SATA_DWC)		+= sata_dwc_460ex.o
 
 # SFF w/ custom DMA
 obj-$(CONFIG_PDC_ADMA)		+= pdc_adma.o
+obj-$(CONFIG_PATA_ARASAN_CF)	+= pata_arasan_cf.o
 obj-$(CONFIG_PATA_OCTEON_CF)	+= pata_octeon_cf.o
 obj-$(CONFIG_SATA_QSTOR)	+= sata_qstor.o
 obj-$(CONFIG_SATA_SX4)		+= sata_sx4.o
diff --git a/drivers/ata/pata_arasan_cf.c b/drivers/ata/pata_arasan_cf.c
new file mode 100644
index 0000000..b99b3fc
--- /dev/null
+++ b/drivers/ata/pata_arasan_cf.c
@@ -0,0 +1,977 @@ 
+/*
+ * drivers/ata/pata_arasan_cf.c
+ *
+ * Arasan Compact Flash host controller source file
+ *
+ * Copyright (C) 2011 ST Microelectronics
+ * Viresh Kumar <viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+/*
+ * The Arasan CompactFlash Device Controller IP core has three basic modes of
+ * operation: PC card ATA using I/O mode, PC card ATA using memory mode, PC card
+ * ATA using true IDE modes. This driver supports only True IDE mode currently.
+ *
+ * Arasan CF Controller shares global irq register with Arasan XD Controller.
+ *
+ * Tested on arch/arm/mach-spear13xx
+ */
+
+#include <linux/ata.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/libata.h>
+#include <linux/module.h>
+#include <linux/pata_arasan_cf_data.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#define DRIVER_NAME	"arasan_cf"
+#define TIMEOUT		msecs_to_jiffies(3000)
+
+/* Registers */
+/* CompactFlash Interface Status */
+#define CFI_STS			0x000
+	#define STS_CHG				(1)
+	#define BIN_AUDIO_OUT			(1 << 1)
+	#define CARD_DETECT1			(1 << 2)
+	#define CARD_DETECT2			(1 << 3)
+	#define INP_ACK				(1 << 4)
+	#define CARD_READY			(1 << 5)
+	#define IO_READY			(1 << 6)
+	#define B16_IO_PORT_SEL			(1 << 7)
+/* IRQ */
+#define IRQ_STS			0x004
+/* Interrupt Enable */
+#define IRQ_EN			0x008
+	#define CARD_DETECT_IRQ			(1)
+	#define STATUS_CHNG_IRQ			(1 << 1)
+	#define MEM_MODE_IRQ			(1 << 2)
+	#define IO_MODE_IRQ			(1 << 3)
+	#define TRUE_IDE_MODE_IRQ		(1 << 8)
+	#define PIO_XFER_ERR_IRQ		(1 << 9)
+	#define BUF_AVAIL_IRQ			(1 << 10)
+	#define XFER_DONE_IRQ			(1 << 11)
+	#define IGNORED_IRQS	(STATUS_CHNG_IRQ | MEM_MODE_IRQ | IO_MODE_IRQ |\
+					TRUE_IDE_MODE_IRQ)
+	#define TRUE_IDE_IRQS	(CARD_DETECT_IRQ | PIO_XFER_ERR_IRQ |\
+					BUF_AVAIL_IRQ | XFER_DONE_IRQ)
+/* Operation Mode */
+#define OP_MODE			0x00C
+	#define CARD_MODE_MASK			(0x3)
+	#define MEM_MODE			(0x0)
+	#define IO_MODE				(0x1)
+	#define TRUE_IDE_MODE			(0x2)
+
+	#define CARD_TYPE_MASK			(1 << 2)
+	#define CF_CARD				(0)
+	#define CF_PLUS_CARD			(1 << 2)
+
+	#define CARD_RESET			(1 << 3)
+	#define CFHOST_ENB			(1 << 4)
+	#define OUTPUTS_TRISTATE		(1 << 5)
+	#define ULTRA_DMA_ENB			(1 << 8)
+	#define MULTI_WORD_DMA_ENB		(1 << 9)
+	#define DRQ_BLOCK_SIZE_MASK		(0x3 << 11)
+	#define DRQ_BLOCK_SIZE_512		(0)
+	#define DRQ_BLOCK_SIZE_1024		(1 << 11)
+	#define DRQ_BLOCK_SIZE_2048		(2 << 11)
+	#define DRQ_BLOCK_SIZE_4096		(3 << 11)
+/* CF Interface Clock Configuration */
+#define CLK_CFG			0x010
+	#define CF_IF_CLK_MASK			(0XF)
+/* CF Timing Mode Configuration */
+#define TM_CFG			0x014
+	#define MEM_MODE_TIMING_MASK		(0x3)
+	#define MEM_MODE_TIMING_250NS		(0x0)
+	#define MEM_MODE_TIMING_120NS		(0x1)
+	#define MEM_MODE_TIMING_100NS		(0x2)
+	#define MEM_MODE_TIMING_80NS		(0x3)
+
+	#define IO_MODE_TIMING_MASK		(0x3 << 2)
+	#define IO_MODE_TIMING_250NS		(0x0 << 2)
+	#define IO_MODE_TIMING_120NS		(0x1 << 2)
+	#define IO_MODE_TIMING_100NS		(0x2 << 2)
+	#define IO_MODE_TIMING_80NS		(0x3 << 2)
+
+	#define TRUEIDE_PIO_TIMING_MASK		(0x7 << 4)
+	#define TRUEIDE_PIO_TIMING_SHIFT	4
+
+	#define TRUEIDE_MWORD_DMA_TIMING_MASK	(0x7 << 7)
+	#define TRUEIDE_MWORD_DMA_TIMING_SHIFT	7
+
+	#define ULTRA_DMA_TIMING_MASK		(0x7 << 10)
+	#define ULTRA_DMA_TIMING_SHIFT		10
+/* CF Transfer Address */
+#define XFER_ADDR		0x014
+	#define XFER_ADDR_MASK			(0x7FF)
+	#define MAX_XFER_COUNT			0x20000u
+/* Transfer Control */
+#define XFER_CTR		0x01C
+	#define XFER_COUNT_MASK			(0x3FFFF)
+	#define ADDR_INC_DISABLE		(1 << 24)
+	#define XFER_WIDTH_MASK			(1 << 25)
+	#define XFER_WIDTH_8B			(0)
+	#define XFER_WIDTH_16B			(1 << 25)
+
+	#define MEM_TYPE_MASK			(1 << 26)
+	#define MEM_TYPE_COMMON			(0)
+	#define MEM_TYPE_ATTRIBUTE		(1 << 26)
+
+	#define MEM_IO_XFER_MASK		(1 << 27)
+	#define MEM_XFER			(0)
+	#define IO_XFER				(1 << 27)
+
+	#define DMA_XFER_MODE			(1 << 28)
+
+	#define AHB_BUS_NORMAL_PIO_OPRTN	(~(1 << 29))
+	#define XFER_DIR_MASK			(1 << 30)
+	#define XFER_READ			(0)
+	#define XFER_WRITE			(1 << 30)
+
+	#define XFER_START			(1 << 31)
+/* Write Data Port */
+#define WRITE_PORT		0x024
+/* Read Data Port */
+#define READ_PORT		0x028
+/* ATA Data Port */
+#define ATA_DATA_PORT		0x030
+	#define ATA_DATA_PORT_MASK		(0xFFFF)
+/* ATA Error/Features */
+#define ATA_ERR_FTR		0x034
+/* ATA Sector Count */
+#define ATA_SC			0x038
+/* ATA Sector Number */
+#define ATA_SN			0x03C
+/* ATA Cylinder Low */
+#define ATA_CL			0x040
+/* ATA Cylinder High */
+#define ATA_CH			0x044
+/* ATA Select Card/Head */
+#define ATA_SH			0x048
+/* ATA Status-Command */
+#define ATA_STS_CMD		0x04C
+/* ATA Alternate Status/Device Control */
+#define ATA_ASTS_DCTR		0x050
+/* Extended Write Data Port 0x200-0x3FC */
+#define EXT_WRITE_PORT		0x200
+/* Extended Read Data Port 0x400-0x5FC */
+#define EXT_READ_PORT		0x400
+	#define FIFO_SIZE	0x200u
+/* Global Interrupt Status */
+#define GIRQ_STS		0x800
+/* Global Interrupt Status enable */
+#define GIRQ_STS_EN		0x804
+/* Global Interrupt Signal enable */
+#define GIRQ_SGN_EN		0x808
+	#define GIRQ_CF		(1)
+	#define GIRQ_XD		(1 << 1)
+
+/* Compact Flash Controller Dev Structure */
+struct arasan_cf_dev {
+	/* pointer to ata_host structure */
+	struct ata_host *host;
+	/* clk structure, only if HAVE_CLK is defined */
+#ifdef CONFIG_HAVE_CLK
+	struct clk *clk;
+#endif
+
+	/* physical base address of controller */
+	dma_addr_t pbase;
+	/* virtual base address of controller */
+	void __iomem *vbase;
+	/* irq number*/
+	int irq;
+
+	/* status to be updated to framework regarding DMA transfer */
+	u8 dma_status;
+	/* Card is present or Not */
+	u8 card_present;
+
+	/* dma specific */
+	/* Completion for transfer complete interrupt from controller */
+	struct completion cf_completion;
+	/* Completion for DMA transfer complete. */
+	struct completion dma_completion;
+	/* Dma channel allocated */
+	struct dma_chan *dma_chan;
+	/* Mask for DMA transfers */
+	dma_cap_mask_t mask;
+	/* DMA transfer work */
+	struct work_struct work;
+	/* DMA delayed finish work */
+	struct delayed_work dwork;
+	/* qc to be transferred using DMA */
+	struct ata_queued_cmd *qc;
+};
+
+static struct scsi_host_template arasan_cf_sht = {
+	ATA_BASE_SHT(DRIVER_NAME),
+	.sg_tablesize = SG_NONE,
+	.dma_boundary = 0xFFFFFFFFUL,
+};
+
+static void cf_dumpregs(struct arasan_cf_dev *acdev)
+{
+	struct device *dev = acdev->host->dev;
+
+	dev_dbg(dev, ": =========== REGISTER DUMP ===========");
+	dev_dbg(dev, ": CFI_STS: %x", readl(acdev->vbase + CFI_STS));
+	dev_dbg(dev, ": IRQ_STS: %x", readl(acdev->vbase + IRQ_STS));
+	dev_dbg(dev, ": IRQ_EN: %x", readl(acdev->vbase + IRQ_EN));
+	dev_dbg(dev, ": OP_MODE: %x", readl(acdev->vbase + OP_MODE));
+	dev_dbg(dev, ": CLK_CFG: %x", readl(acdev->vbase + CLK_CFG));
+	dev_dbg(dev, ": TM_CFG: %x", readl(acdev->vbase + TM_CFG));
+	dev_dbg(dev, ": XFER_CTR: %x", readl(acdev->vbase + XFER_CTR));
+	dev_dbg(dev, ": GIRQ_STS: %x", readl(acdev->vbase + GIRQ_STS));
+	dev_dbg(dev, ": GIRQ_STS_EN: %x", readl(acdev->vbase + GIRQ_STS_EN));
+	dev_dbg(dev, ": GIRQ_SGN_EN: %x", readl(acdev->vbase + GIRQ_SGN_EN));
+	dev_dbg(dev, ": =====================================");
+}
+
+/* Enable/Disable global interrupts shared between CF and XD ctrlr. */
+static void cf_ginterrupt_enable(struct arasan_cf_dev *acdev, bool enable)
+{
+	/* enable should be 0 or 1 */
+	writel(enable, acdev->vbase + GIRQ_STS_EN);
+	writel(enable, acdev->vbase + GIRQ_SGN_EN);
+}
+
+/* Enable/Disable CF interrupts */
+static inline void
+cf_interrupt_enable(struct arasan_cf_dev *acdev, u32 mask, bool enable)
+{
+	u32 val = readl(acdev->vbase + IRQ_EN);
+	/* clear & enable/disable irqs */
+	if (enable) {
+		writel(mask, acdev->vbase + IRQ_STS);
+		writel(val | mask, acdev->vbase + IRQ_EN);
+	} else
+		writel(val & ~mask, acdev->vbase + IRQ_EN);
+}
+
+static inline void cf_card_reset(struct arasan_cf_dev *acdev)
+{
+	u32 val = readl(acdev->vbase + OP_MODE);
+
+	writel(val | CARD_RESET, acdev->vbase + OP_MODE);
+	udelay(200);
+	writel(val & ~CARD_RESET, acdev->vbase + OP_MODE);
+}
+
+static inline void cf_ctrl_reset(struct arasan_cf_dev *acdev)
+{
+	writel(readl(acdev->vbase + OP_MODE) & ~CFHOST_ENB,
+			acdev->vbase + OP_MODE);
+	writel(readl(acdev->vbase + OP_MODE) | CFHOST_ENB,
+			acdev->vbase + OP_MODE);
+}
+
+static void cf_card_detect(struct arasan_cf_dev *acdev, bool hotplugged)
+{
+	struct ata_port *ap = acdev->host->ports[0];
+	struct ata_eh_info *ehi = &ap->link.eh_info;
+	u32 val = readl(acdev->vbase + CFI_STS);
+
+	/* Both CD1 & CD2 should be low if card inserted completely */
+	if (!(val & (CARD_DETECT1 | CARD_DETECT2))) {
+		if (acdev->card_present)
+			return;
+		acdev->card_present = 1;
+		cf_card_reset(acdev);
+	} else {
+		if (!acdev->card_present)
+			return;
+		acdev->card_present = 0;
+	}
+
+	if (hotplugged) {
+		ata_ehi_hotplugged(ehi);
+		ata_port_freeze(ap);
+	}
+}
+
+static int cf_init(struct arasan_cf_dev *acdev)
+{
+	struct arasan_cf_pdata *pdata = dev_get_platdata(acdev->host->dev);
+	unsigned long flags;
+	int ret = 0;
+
+#ifdef CONFIG_HAVE_CLK
+	ret = clk_enable(acdev->clk);
+	if (ret) {
+		dev_dbg(acdev->host->dev, "clock enable failed");
+		return ret;
+	}
+#endif
+
+	spin_lock_irqsave(&acdev->host->lock, flags);
+	/* configure CF interface clock */
+	writel((pdata->cf_if_clk <= CF_IF_CLK_200M) ? pdata->cf_if_clk :
+			CF_IF_CLK_166M, acdev->vbase + CLK_CFG);
+
+	writel(TRUE_IDE_MODE | CFHOST_ENB, acdev->vbase + OP_MODE);
+	cf_interrupt_enable(acdev, CARD_DETECT_IRQ, 1);
+	cf_ginterrupt_enable(acdev, 1);
+	spin_unlock_irqrestore(&acdev->host->lock, flags);
+
+	return ret;
+}
+
+static void cf_exit(struct arasan_cf_dev *acdev)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&acdev->host->lock, flags);
+	cf_ginterrupt_enable(acdev, 0);
+	cf_interrupt_enable(acdev, TRUE_IDE_IRQS, 0);
+	cf_card_reset(acdev);
+	writel(readl(acdev->vbase + OP_MODE) & ~CFHOST_ENB,
+			acdev->vbase + OP_MODE);
+	spin_unlock_irqrestore(&acdev->host->lock, flags);
+#ifdef CONFIG_HAVE_CLK
+	clk_disable(acdev->clk);
+#endif
+}
+
+static void dma_callback(void *dev)
+{
+	struct arasan_cf_dev *acdev = (struct arasan_cf_dev *) dev;
+
+	complete(&acdev->dma_completion);
+}
+
+static bool filter(struct dma_chan *chan, void *slave)
+{
+	return true;
+}
+
+static inline void dma_complete(struct arasan_cf_dev *acdev)
+{
+	struct ata_queued_cmd *qc = acdev->qc;
+	unsigned long flags;
+
+	acdev->qc = NULL;
+	ata_sff_interrupt(acdev->irq, acdev->host);
+
+	spin_lock_irqsave(&acdev->host->lock, flags);
+	if (unlikely(qc->err_mask) && ata_is_dma(qc->tf.protocol))
+		ata_ehi_push_desc(&qc->ap->link.eh_info, "DMA Failed: Timeout");
+	spin_unlock_irqrestore(&acdev->host->lock, flags);
+}
+
+static inline int wait4buf(struct arasan_cf_dev *acdev)
+{
+	if (!wait_for_completion_timeout(&acdev->cf_completion, TIMEOUT)) {
+		u32 rw = acdev->qc->tf.flags & ATA_TFLAG_WRITE;
+
+		dev_err(acdev->host->dev, "%s TimeOut", rw ? "write" : "read");
+		return -ETIMEDOUT;
+	}
+
+	/* Check if PIO Error interrupt has occured */
+	if (acdev->dma_status & ATA_DMA_ERR)
+		return -EAGAIN;
+
+	return 0;
+}
+
+static int
+dma_xfer(struct arasan_cf_dev *acdev, dma_addr_t src, dma_addr_t dest, u32 len)
+{
+	struct dma_async_tx_descriptor *tx;
+	struct dma_chan *chan = acdev->dma_chan;
+	dma_cookie_t cookie;
+	unsigned long flags = DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_SRC_UNMAP |
+		DMA_COMPL_SKIP_DEST_UNMAP;
+	int ret = 0;
+
+	tx = chan->device->device_prep_dma_memcpy(chan, dest, src, len, flags);
+	if (!tx) {
+		dev_err(acdev->host->dev, "device_prep_dma_memcpy failed\n");
+		return -EAGAIN;
+	}
+
+	tx->callback = dma_callback;
+	tx->callback_param = acdev;
+	cookie = tx->tx_submit(tx);
+
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dev_err(acdev->host->dev, "dma_submit_error\n");
+		return ret;
+	}
+
+	chan->device->device_issue_pending(chan);
+
+	/* Wait for DMA to complete */
+	if (!wait_for_completion_timeout(&acdev->dma_completion, TIMEOUT)) {
+		chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
+		dev_err(acdev->host->dev, "wait_for_completion_timeout\n");
+		return -ETIMEDOUT;
+	}
+
+	return ret;
+}
+
+static int sg_xfer(struct arasan_cf_dev *acdev, struct scatterlist *sg)
+{
+	dma_addr_t dest = 0, src = 0;
+	u32 xfer_cnt, sglen, dma_len, xfer_ctr;
+	u32 write = acdev->qc->tf.flags & ATA_TFLAG_WRITE;
+	unsigned long flags;
+	int ret = 0;
+
+	sglen = sg_dma_len(sg);
+	if (write) {
+		src = sg_dma_address(sg);
+		dest = acdev->pbase + EXT_WRITE_PORT;
+	} else {
+		dest = sg_dma_address(sg);
+		src = acdev->pbase + EXT_READ_PORT;
+	}
+
+	/*
+	 * For each sg:
+	 * MAX_XFER_COUNT data will be transferred before we get transfer
+	 * complete interrupt. Inbetween after FIFO_SIZE data
+	 * buffer available interrupt will be generated. At this time we will
+	 * fill FIFO again: max FIFO_SIZE data.
+	 */
+	while (sglen) {
+		xfer_cnt = min(sglen, MAX_XFER_COUNT);
+		spin_lock_irqsave(&acdev->host->lock, flags);
+		xfer_ctr = readl(acdev->vbase + XFER_CTR) &
+			~XFER_COUNT_MASK;
+		writel(xfer_ctr | xfer_cnt | XFER_START,
+				acdev->vbase + XFER_CTR);
+		spin_unlock_irqrestore(&acdev->host->lock, flags);
+
+		/* continue dma xfers untill current sg is completed */
+		while (xfer_cnt) {
+			/* wait for read to complete */
+			if (!write) {
+				ret = wait4buf(acdev);
+				if (ret)
+					goto fail;
+			}
+
+			/* read/write FIFO in chunk of FIFO_SIZE */
+			dma_len = min(xfer_cnt, FIFO_SIZE);
+			ret = dma_xfer(acdev, src, dest, dma_len);
+			if (ret) {
+				dev_err(acdev->host->dev, "dma failed");
+				goto fail;
+			}
+
+			if (write)
+				src += dma_len;
+			else
+				dest += dma_len;
+
+			sglen -= dma_len;
+			xfer_cnt -= dma_len;
+
+			/* wait for write to complete */
+			if (write) {
+				ret = wait4buf(acdev);
+				if (ret)
+					goto fail;
+			}
+		}
+	}
+
+fail:
+	spin_lock_irqsave(&acdev->host->lock, flags);
+	writel(readl(acdev->vbase + XFER_CTR) & ~XFER_START,
+			acdev->vbase + XFER_CTR);
+	spin_unlock_irqrestore(&acdev->host->lock, flags);
+
+	return ret;
+}
+
+/*
+ * This routine uses External DMA controller to read/write data to FIFO of CF
+ * controller. There are two xfer related interrupt supported by CF controller:
+ * - buf_avail: This interrupt is generated as soon as we have buffer of 512
+ *	bytes available for reading or empty buffer available for writing.
+ * - xfer_done: This interrupt is generated on transfer of "xfer_size" amount of
+ *	data to/from FIFO. xfer_size is programmed in XFER_CTR register.
+ *
+ * Max buffer size = FIFO_SIZE = 512 Bytes.
+ * Max xfer_size = MAX_XFER_COUNT = 256 KB.
+ */
+static void data_xfer(struct work_struct *work)
+{
+	struct arasan_cf_dev *acdev = container_of(work, struct arasan_cf_dev,
+			work);
+	struct ata_queued_cmd *qc = acdev->qc;
+	struct scatterlist *sg;
+	unsigned long flags;
+	u32 temp;
+	int ret = 0;
+
+	/* request dma channels */
+	/* dma_request_channel may sleep, so calling from process context */
+	acdev->dma_chan = dma_request_channel(acdev->mask, filter, NULL);
+	if (!acdev->dma_chan) {
+		dev_err(acdev->host->dev, "Unable to get dma_chan\n");
+		goto chan_request_fail;
+	}
+
+	for_each_sg(qc->sg, sg, qc->n_elem, temp) {
+		ret = sg_xfer(acdev, sg);
+		if (ret)
+			break;
+	}
+
+	dma_release_channel(acdev->dma_chan);
+
+	/* data xferred successfully */
+	if (!ret) {
+		u32 status;
+
+		spin_lock_irqsave(&acdev->host->lock, flags);
+		status = ioread8(qc->ap->ioaddr.altstatus_addr);
+		spin_unlock_irqrestore(&acdev->host->lock, flags);
+		if (status & (ATA_BUSY | ATA_DRQ)) {
+			ata_sff_queue_delayed_work(&acdev->dwork, 1);
+			return;
+		}
+
+		goto sff_intr;
+	}
+
+	cf_dumpregs(acdev);
+
+chan_request_fail:
+	spin_lock_irqsave(&acdev->host->lock, flags);
+	/* error when transfering data to/from memory */
+	qc->err_mask |= AC_ERR_HOST_BUS;
+	qc->ap->hsm_task_state = HSM_ST_ERR;
+
+	cf_ctrl_reset(acdev);
+	spin_unlock_irqrestore(qc->ap->lock, flags);
+sff_intr:
+	dma_complete(acdev);
+}
+
+static void delayed_finish(struct work_struct *work)
+{
+	struct arasan_cf_dev *acdev = container_of(work, struct arasan_cf_dev,
+			dwork.work);
+	struct ata_queued_cmd *qc = acdev->qc;
+	unsigned long flags;
+	u8 status;
+
+	spin_lock_irqsave(&acdev->host->lock, flags);
+	status = ioread8(qc->ap->ioaddr.altstatus_addr);
+	spin_unlock_irqrestore(&acdev->host->lock, flags);
+
+	if (status & (ATA_BUSY | ATA_DRQ))
+		ata_sff_queue_delayed_work(&acdev->dwork, 1);
+	else
+		dma_complete(acdev);
+}
+
+static irqreturn_t arasan_cf_interrupt(int irq, void *dev)
+{
+	struct arasan_cf_dev *acdev = ((struct ata_host *)dev)->private_data;
+	unsigned long flags;
+	u32 irqsts;
+
+	irqsts = readl(acdev->vbase + GIRQ_STS);
+	if (!(irqsts & GIRQ_CF))
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&acdev->host->lock, flags);
+	irqsts = readl(acdev->vbase + IRQ_STS);
+	writel(irqsts, acdev->vbase + IRQ_STS);		/* clear irqs */
+	writel(GIRQ_CF, acdev->vbase + GIRQ_STS);	/* clear girqs */
+
+	/* handle only relevant interrupts */
+	irqsts &= ~IGNORED_IRQS;
+
+	if (irqsts & CARD_DETECT_IRQ) {
+		cf_card_detect(acdev, 1);
+		spin_unlock_irqrestore(&acdev->host->lock, flags);
+		return IRQ_HANDLED;
+	}
+
+	if (irqsts & PIO_XFER_ERR_IRQ) {
+		acdev->dma_status = ATA_DMA_ERR;
+		writel(readl(acdev->vbase + XFER_CTR) & ~XFER_START,
+				acdev->vbase + XFER_CTR);
+		spin_unlock_irqrestore(&acdev->host->lock, flags);
+		complete(&acdev->cf_completion);
+		dev_err(acdev->host->dev, "pio xfer err irq\n");
+		return IRQ_HANDLED;
+	}
+
+	spin_unlock_irqrestore(&acdev->host->lock, flags);
+
+	if (irqsts & BUF_AVAIL_IRQ) {
+		complete(&acdev->cf_completion);
+		return IRQ_HANDLED;
+	}
+
+	if (irqsts & XFER_DONE_IRQ) {
+		struct ata_queued_cmd *qc = acdev->qc;
+
+		/* Send Complete only for write */
+		if (qc->tf.flags & ATA_TFLAG_WRITE)
+			complete(&acdev->cf_completion);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void arasan_cf_freeze(struct ata_port *ap)
+{
+	struct arasan_cf_dev *acdev = ap->host->private_data;
+
+	/* stop transfer and reset controller */
+	writel(readl(acdev->vbase + XFER_CTR) & ~XFER_START,
+			acdev->vbase + XFER_CTR);
+	cf_ctrl_reset(acdev);
+	acdev->dma_status = ATA_DMA_ERR;
+
+	ata_sff_dma_pause(ap);
+	ata_sff_freeze(ap);
+}
+
+void arasan_cf_error_handler(struct ata_port *ap)
+{
+	struct arasan_cf_dev *acdev = ap->host->private_data;
+
+	/*
+	 * DMA transfers using an external DMA controller may be scheduled.
+	 * Abort them before handling error. Refer data_xfer() for further
+	 * details.
+	 */
+	cancel_work_sync(&acdev->work);
+	cancel_delayed_work_sync(&acdev->dwork);
+	return ata_sff_error_handler(ap);
+}
+
+static void arasan_cf_dma_start(struct arasan_cf_dev *acdev)
+{
+	u32 xfer_ctr = readl(acdev->vbase + XFER_CTR) & ~XFER_DIR_MASK;
+	u32 write = acdev->qc->tf.flags & ATA_TFLAG_WRITE;
+
+	xfer_ctr |= write ? XFER_WRITE : XFER_READ;
+	writel(xfer_ctr, acdev->vbase + XFER_CTR);
+
+	acdev->qc->ap->ops->sff_exec_command(acdev->qc->ap, &acdev->qc->tf);
+	ata_sff_queue_work(&acdev->work);
+}
+
+unsigned int arasan_cf_qc_issue(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+	struct arasan_cf_dev *acdev = ap->host->private_data;
+
+	/* defer PIO handling to sff_qc_issue */
+	if (!ata_is_dma(qc->tf.protocol))
+		return ata_sff_qc_issue(qc);
+
+	/* select the device */
+	ata_wait_idle(ap);
+	ata_sff_dev_select(ap, qc->dev->devno);
+	ata_wait_idle(ap);
+
+	/* start the command */
+	switch (qc->tf.protocol) {
+	case ATA_PROT_DMA:
+		WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
+
+		ap->ops->sff_tf_load(ap, &qc->tf);
+		acdev->dma_status = 0;
+		acdev->qc = qc;
+		arasan_cf_dma_start(acdev);
+		ap->hsm_task_state = HSM_ST_LAST;
+		break;
+
+	default:
+		WARN_ON(1);
+		return AC_ERR_SYSTEM;
+	}
+
+	return 0;
+}
+
+static void arasan_cf_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+	struct arasan_cf_dev *acdev = ap->host->private_data;
+	u8 pio = adev->pio_mode - XFER_PIO_0;
+	unsigned long flags;
+	u32 val;
+
+	/* Arasan ctrl supports Mode0 -> Mode6 */
+	if (pio > 6) {
+		dev_err(ap->dev, "Unknown PIO mode\n");
+		return;
+	}
+
+	spin_lock_irqsave(&acdev->host->lock, flags);
+	val = readl(acdev->vbase + OP_MODE) &
+		~(ULTRA_DMA_ENB | MULTI_WORD_DMA_ENB | DRQ_BLOCK_SIZE_MASK);
+	writel(val, acdev->vbase + OP_MODE);
+	val = readl(acdev->vbase + TM_CFG) & ~TRUEIDE_PIO_TIMING_MASK;
+	val |= pio << TRUEIDE_PIO_TIMING_SHIFT;
+	writel(val, acdev->vbase + TM_CFG);
+
+	cf_interrupt_enable(acdev, BUF_AVAIL_IRQ | XFER_DONE_IRQ, 0);
+	cf_interrupt_enable(acdev, PIO_XFER_ERR_IRQ, 1);
+	spin_unlock_irqrestore(&acdev->host->lock, flags);
+}
+
+static void arasan_cf_set_dmamode(struct ata_port *ap, struct ata_device *adev)
+{
+	struct arasan_cf_dev *acdev = ap->host->private_data;
+	u32 opmode, tmcfg, dma_mode = adev->dma_mode;
+	unsigned long flags;
+
+	spin_lock_irqsave(&acdev->host->lock, flags);
+	opmode = readl(acdev->vbase + OP_MODE) &
+		~(MULTI_WORD_DMA_ENB | ULTRA_DMA_ENB);
+	tmcfg = readl(acdev->vbase + TM_CFG);
+
+	if ((dma_mode >= XFER_UDMA_0) && (dma_mode <= XFER_UDMA_6)) {
+		opmode |= ULTRA_DMA_ENB;
+		tmcfg &= ~ULTRA_DMA_TIMING_MASK;
+		tmcfg |= (dma_mode - XFER_UDMA_0) << ULTRA_DMA_TIMING_SHIFT;
+	} else if ((dma_mode >= XFER_MW_DMA_0) && (dma_mode <= XFER_MW_DMA_4)) {
+		opmode |= MULTI_WORD_DMA_ENB;
+		tmcfg &= ~TRUEIDE_MWORD_DMA_TIMING_MASK;
+		tmcfg |= (dma_mode - XFER_MW_DMA_0) <<
+			TRUEIDE_MWORD_DMA_TIMING_SHIFT;
+	} else {
+		dev_err(ap->dev, "Unknown DMA mode\n");
+		spin_unlock_irqrestore(&acdev->host->lock, flags);
+		return;
+	}
+
+	writel(opmode, acdev->vbase + OP_MODE);
+	writel(tmcfg, acdev->vbase + TM_CFG);
+	writel(DMA_XFER_MODE, acdev->vbase + XFER_CTR);
+
+	cf_interrupt_enable(acdev, PIO_XFER_ERR_IRQ, 0);
+	cf_interrupt_enable(acdev, BUF_AVAIL_IRQ | XFER_DONE_IRQ, 1);
+	spin_unlock_irqrestore(&acdev->host->lock, flags);
+}
+
+static struct ata_port_operations arasan_cf_ops = {
+	.inherits = &ata_sff_port_ops,
+	.freeze = arasan_cf_freeze,
+	.error_handler = arasan_cf_error_handler,
+	.qc_issue = arasan_cf_qc_issue,
+	.set_piomode = arasan_cf_set_piomode,
+	.set_dmamode = arasan_cf_set_dmamode,
+};
+
+static int __devinit arasan_cf_probe(struct platform_device *pdev)
+{
+	struct arasan_cf_dev *acdev;
+	struct arasan_cf_pdata *pdata = dev_get_platdata(&pdev->dev);
+	struct ata_host *host;
+	struct ata_port *ap;
+	struct resource *res;
+	irq_handler_t irq_handler = NULL;
+	int ret = 0;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	if (!devm_request_mem_region(&pdev->dev, res->start, resource_size(res),
+				DRIVER_NAME)) {
+		dev_warn(&pdev->dev, "Failed to get memory region resource\n");
+		return -ENOENT;
+	}
+
+	acdev = devm_kzalloc(&pdev->dev, sizeof(*acdev), GFP_KERNEL);
+	if (!acdev) {
+		dev_warn(&pdev->dev, "kzalloc fail\n");
+		return -ENOMEM;
+	}
+
+	/* if irq is 0, support only PIO */
+	acdev->irq = platform_get_irq(pdev, 0);
+	if (acdev->irq)
+		irq_handler = arasan_cf_interrupt;
+	else
+		pdata->quirk |= CF_BROKEN_MWDMA | CF_BROKEN_UDMA;
+
+	acdev->pbase = res->start;
+	acdev->vbase = devm_ioremap_nocache(&pdev->dev, res->start,
+			resource_size(res));
+	if (!acdev->vbase) {
+		dev_warn(&pdev->dev, "ioremap fail\n");
+		return -ENOMEM;
+	}
+
+#ifdef CONFIG_HAVE_CLK
+	acdev->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(acdev->clk)) {
+		dev_warn(&pdev->dev, "Clock not found\n");
+		return PTR_ERR(acdev->clk);
+	}
+#endif
+
+	/* allocate host */
+	host = ata_host_alloc(&pdev->dev, 1);
+	if (!host) {
+		ret = -ENOMEM;
+		dev_warn(&pdev->dev, "alloc host fail\n");
+		goto free_clk;
+	}
+
+	ap = host->ports[0];
+	host->private_data = acdev;
+	acdev->host = host;
+	ap->ops = &arasan_cf_ops;
+	ap->pio_mask = ATA_PIO6;
+	ap->mwdma_mask = ATA_MWDMA4;
+	ap->udma_mask = ATA_UDMA6;
+
+	init_completion(&acdev->cf_completion);
+	init_completion(&acdev->dma_completion);
+	INIT_WORK(&acdev->work, data_xfer);
+	INIT_DELAYED_WORK(&acdev->dwork, delayed_finish);
+	dma_cap_set(DMA_MEMCPY, acdev->mask);
+
+	/* Handle platform specific quirks */
+	if (pdata->quirk) {
+		if (pdata->quirk & CF_BROKEN_PIO) {
+			ap->ops->set_piomode = NULL;
+			ap->pio_mask = 0;
+		}
+		if (pdata->quirk & CF_BROKEN_MWDMA)
+			ap->mwdma_mask = 0;
+		if (pdata->quirk & CF_BROKEN_UDMA)
+			ap->udma_mask = 0;
+	}
+	ap->flags |= ATA_FLAG_PIO_POLLING | ATA_FLAG_NO_ATAPI;
+
+	ap->ioaddr.cmd_addr = acdev->vbase + ATA_DATA_PORT;
+	ap->ioaddr.data_addr = acdev->vbase + ATA_DATA_PORT;
+	ap->ioaddr.error_addr = acdev->vbase + ATA_ERR_FTR;
+	ap->ioaddr.feature_addr = acdev->vbase + ATA_ERR_FTR;
+	ap->ioaddr.nsect_addr = acdev->vbase + ATA_SC;
+	ap->ioaddr.lbal_addr = acdev->vbase + ATA_SN;
+	ap->ioaddr.lbam_addr = acdev->vbase + ATA_CL;
+	ap->ioaddr.lbah_addr = acdev->vbase + ATA_CH;
+	ap->ioaddr.device_addr = acdev->vbase + ATA_SH;
+	ap->ioaddr.status_addr = acdev->vbase + ATA_STS_CMD;
+	ap->ioaddr.command_addr = acdev->vbase + ATA_STS_CMD;
+	ap->ioaddr.altstatus_addr = acdev->vbase + ATA_ASTS_DCTR;
+	ap->ioaddr.ctl_addr = acdev->vbase + ATA_ASTS_DCTR;
+
+	ata_port_desc(ap, "phy_addr %x virt_addr %p", res->start, acdev->vbase);
+
+	ret = cf_init(acdev);
+	if (ret)
+		goto free_clk;
+
+	cf_card_detect(acdev, 0);
+
+	return ata_host_activate(host, acdev->irq, irq_handler, 0,
+			&arasan_cf_sht);
+
+free_clk:
+#ifdef CONFIG_HAVE_CLK
+	clk_put(acdev->clk);
+#endif
+	return ret;
+}
+
+static int __devexit arasan_cf_remove(struct platform_device *pdev)
+{
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	struct arasan_cf_dev *acdev = host->ports[0]->private_data;
+
+	ata_host_detach(host);
+	cf_exit(acdev);
+#ifdef CONFIG_HAVE_CLK
+	clk_put(acdev->clk);
+#endif
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int arasan_cf_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	struct arasan_cf_dev *acdev = host->ports[0]->private_data;
+
+	if (acdev->dma_chan) {
+		acdev->dma_chan->device->device_control(acdev->dma_chan,
+				DMA_TERMINATE_ALL, 0);
+		dma_release_channel(acdev->dma_chan);
+	}
+	cf_exit(acdev);
+	return ata_host_suspend(host, PMSG_SUSPEND);
+}
+
+static int arasan_cf_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	struct arasan_cf_dev *acdev = host->ports[0]->private_data;
+
+	cf_init(acdev);
+	ata_host_resume(host);
+
+	return 0;
+}
+
+static const struct dev_pm_ops arasan_cf_pm_ops = {
+	.suspend	= arasan_cf_suspend,
+	.resume		= arasan_cf_resume,
+};
+#endif
+
+static struct platform_driver arasan_cf_driver = {
+	.probe		= arasan_cf_probe,
+	.remove		= __devexit_p(arasan_cf_remove),
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+#ifdef CONFIG_PM
+		.pm		= &arasan_cf_pm_ops,
+#endif
+	},
+};
+
+static int __init arasan_cf_init(void)
+{
+	return platform_driver_register(&arasan_cf_driver);
+}
+module_init(arasan_cf_init);
+
+static void __exit arasan_cf_exit(void)
+{
+	platform_driver_unregister(&arasan_cf_driver);
+}
+module_exit(arasan_cf_exit);
+
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");
+MODULE_DESCRIPTION("Arasan ATA Compact Flash driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);
diff --git a/include/linux/pata_arasan_cf_data.h b/include/linux/pata_arasan_cf_data.h
new file mode 100644
index 0000000..d979fe6
--- /dev/null
+++ b/include/linux/pata_arasan_cf_data.h
@@ -0,0 +1,47 @@ 
+/*
+ * include/linux/pata_arasan_cf_data.h
+ *
+ * Arasan Compact Flash host controller platform data header file
+ *
+ * Copyright (C) 2011 ST Microelectronics
+ * Viresh Kumar <viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef _PATA_ARASAN_CF_DATA_H
+#define _PATA_ARASAN_CF_DATA_H
+
+#include <linux/platform_device.h>
+
+struct arasan_cf_pdata {
+	u8 cf_if_clk;
+	#define CF_IF_CLK_100M			(0x0)
+	#define CF_IF_CLK_75M			(0x1)
+	#define CF_IF_CLK_66M			(0x2)
+	#define CF_IF_CLK_50M			(0x3)
+	#define CF_IF_CLK_40M			(0x4)
+	#define CF_IF_CLK_33M			(0x5)
+	#define CF_IF_CLK_25M			(0x6)
+	#define CF_IF_CLK_125M			(0x7)
+	#define CF_IF_CLK_150M			(0x8)
+	#define CF_IF_CLK_166M			(0x9)
+	#define CF_IF_CLK_200M			(0xA)
+	/*
+	 * Platform specific incapabilities of CF controller is handled via
+	 * quirks
+	 */
+	u32 quirk;
+	#define CF_BROKEN_PIO			(1)
+	#define CF_BROKEN_MWDMA			(1 << 1)
+	#define CF_BROKEN_UDMA			(1 << 2)
+};
+
+static inline void
+set_arasan_cf_pdata(struct platform_device *pdev, struct arasan_cf_pdata *data)
+{
+	pdev->dev.platform_data = data;
+}
+#endif /* _PATA_ARASAN_CF_DATA_H */