dmaengine: add CSR SiRFprimaII DMAC driver

Cc: Jassi Brar <jaswinder.singh@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rongjun Ying <rongjun.ying@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
[fixed direction enums and cyclic api based on changes
 already merged]
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

MAINTAINERS

@@ -749,6 +749,7 @@ M:	Barry Song <baohua.song@csr.com>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	arch/arm/mach-prima2/
+F:	drivers/dma/sirf-dma*
 
 ARM/EBSA110 MACHINE SUPPORT
 M:	Russell King <linux@arm.linux.org.uk>

drivers/dma/Kconfig

@@ -187,6 +187,13 @@ config TIMB_DMA
 	help
 	  Enable support for the Timberdale FPGA DMA engine.
 
+config SIRF_DMA
+	tristate "CSR SiRFprimaII DMA support"
+	depends on ARCH_PRIMA2
+	select DMA_ENGINE
+	help
+	  Enable support for the CSR SiRFprimaII DMA engine.
+
 config ARCH_HAS_ASYNC_TX_FIND_CHANNEL
 	bool
 

drivers/dma/Makefile

@@ -21,6 +21,7 @@ obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
 obj-$(CONFIG_IMX_DMA) += imx-dma.o
 obj-$(CONFIG_MXS_DMA) += mxs-dma.o
 obj-$(CONFIG_TIMB_DMA) += timb_dma.o
+obj-$(CONFIG_SIRF_DMA) += sirf-dma.o
 obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_PL330_DMA) += pl330.o
 obj-$(CONFIG_PCH_DMA) += pch_dma.o

drivers/dma/sirf-dma.c

+/*
+ * DMA controller driver for CSR SiRFprimaII
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/sirfsoc_dma.h>
+
+#define SIRFSOC_DMA_DESCRIPTORS                 16
+#define SIRFSOC_DMA_CHANNELS                    16
+
+#define SIRFSOC_DMA_CH_ADDR                     0x00
+#define SIRFSOC_DMA_CH_XLEN                     0x04
+#define SIRFSOC_DMA_CH_YLEN                     0x08
+#define SIRFSOC_DMA_CH_CTRL                     0x0C
+
+#define SIRFSOC_DMA_WIDTH_0                     0x100
+#define SIRFSOC_DMA_CH_VALID                    0x140
+#define SIRFSOC_DMA_CH_INT                      0x144
+#define SIRFSOC_DMA_INT_EN                      0x148
+#define SIRFSOC_DMA_CH_LOOP_CTRL                0x150
+
+#define SIRFSOC_DMA_MODE_CTRL_BIT               4
+#define SIRFSOC_DMA_DIR_CTRL_BIT                5
+
+/* xlen and dma_width register is in 4 bytes boundary */
+#define SIRFSOC_DMA_WORD_LEN			4
+
+struct sirfsoc_dma_desc {
+	struct dma_async_tx_descriptor	desc;
+	struct list_head		node;
+
+	/* SiRFprimaII 2D-DMA parameters */
+
+	int             xlen;           /* DMA xlen */
+	int             ylen;           /* DMA ylen */
+	int             width;          /* DMA width */
+	int             dir;
+	bool            cyclic;         /* is loop DMA? */
+	u32             addr;		/* DMA buffer address */
+};
+
+struct sirfsoc_dma_chan {
+	struct dma_chan			chan;
+	struct list_head		free;
+	struct list_head		prepared;
+	struct list_head		queued;
+	struct list_head		active;
+	struct list_head		completed;
+	dma_cookie_t			completed_cookie;
+	unsigned long			happened_cyclic;
+	unsigned long			completed_cyclic;
+
+	/* Lock for this structure */
+	spinlock_t			lock;
+
+	int				mode;
+};
+
+struct sirfsoc_dma {
+	struct dma_device		dma;
+	struct tasklet_struct		tasklet;
+	struct sirfsoc_dma_chan		channels[SIRFSOC_DMA_CHANNELS];
+	void __iomem			*base;
+	int				irq;
+};
+
+#define DRV_NAME	"sirfsoc_dma"
+
+/* Convert struct dma_chan to struct sirfsoc_dma_chan */
+static inline
+struct sirfsoc_dma_chan *dma_chan_to_sirfsoc_dma_chan(struct dma_chan *c)
+{
+	return container_of(c, struct sirfsoc_dma_chan, chan);
+}
+
+/* Convert struct dma_chan to struct sirfsoc_dma */
+static inline struct sirfsoc_dma *dma_chan_to_sirfsoc_dma(struct dma_chan *c)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(c);
+	return container_of(schan, struct sirfsoc_dma, channels[c->chan_id]);
+}
+
+/* Execute all queued DMA descriptors */
+static void sirfsoc_dma_execute(struct sirfsoc_dma_chan *schan)
+{
+	struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(&schan->chan);
+	int cid = schan->chan.chan_id;
+	struct sirfsoc_dma_desc *sdesc = NULL;
+
+	/*
+	 * lock has been held by functions calling this, so we don't hold
+	 * lock again
+	 */
+
+	sdesc = list_first_entry(&schan->queued, struct sirfsoc_dma_desc,
+		node);
+	/* Move the first queued descriptor to active list */
+	list_move_tail(&schan->queued, &schan->active);
+
+	/* Start the DMA transfer */
+	writel_relaxed(sdesc->width, sdma->base + SIRFSOC_DMA_WIDTH_0 +
+		cid * 4);
+	writel_relaxed(cid | (schan->mode << SIRFSOC_DMA_MODE_CTRL_BIT) |
+		(sdesc->dir << SIRFSOC_DMA_DIR_CTRL_BIT),
+		sdma->base + cid * 0x10 + SIRFSOC_DMA_CH_CTRL);
+	writel_relaxed(sdesc->xlen, sdma->base + cid * 0x10 +
+		SIRFSOC_DMA_CH_XLEN);
+	writel_relaxed(sdesc->ylen, sdma->base + cid * 0x10 +
+		SIRFSOC_DMA_CH_YLEN);
+	writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN) |
+		(1 << cid), sdma->base + SIRFSOC_DMA_INT_EN);
+
+	/*
+	 * writel has an implict memory write barrier to make sure data is
+	 * flushed into memory before starting DMA
+	 */
+	writel(sdesc->addr >> 2, sdma->base + cid * 0x10 + SIRFSOC_DMA_CH_ADDR);
+
+	if (sdesc->cyclic) {
+		writel((1 << cid) | 1 << (cid + 16) |
+			readl_relaxed(sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL),
+			sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
+		schan->happened_cyclic = schan->completed_cyclic = 0;
+	}
+}
+
+/* Interrupt handler */
+static irqreturn_t sirfsoc_dma_irq(int irq, void *data)
+{
+	struct sirfsoc_dma *sdma = data;
+	struct sirfsoc_dma_chan *schan;
+	struct sirfsoc_dma_desc *sdesc = NULL;
+	u32 is;
+	int ch;
+
+	is = readl(sdma->base + SIRFSOC_DMA_CH_INT);
+	while ((ch = fls(is) - 1) >= 0) {
+		is &= ~(1 << ch);
+		writel_relaxed(1 << ch, sdma->base + SIRFSOC_DMA_CH_INT);
+		schan = &sdma->channels[ch];
+
+		spin_lock(&schan->lock);
+
+		sdesc = list_first_entry(&schan->active, struct sirfsoc_dma_desc,
+			node);
+		if (!sdesc->cyclic) {
+			/* Execute queued descriptors */
+			list_splice_tail_init(&schan->active, &schan->completed);
+			if (!list_empty(&schan->queued))
+				sirfsoc_dma_execute(schan);
+		} else
+			schan->happened_cyclic++;
+
+		spin_unlock(&schan->lock);
+	}
+
+	/* Schedule tasklet */
+	tasklet_schedule(&sdma->tasklet);
+
+	return IRQ_HANDLED;
+}
+
+/* process completed descriptors */
+static void sirfsoc_dma_process_completed(struct sirfsoc_dma *sdma)
+{
+	dma_cookie_t last_cookie = 0;
+	struct sirfsoc_dma_chan *schan;
+	struct sirfsoc_dma_desc *sdesc;
+	struct dma_async_tx_descriptor *desc;
+	unsigned long flags;
+	unsigned long happened_cyclic;
+	LIST_HEAD(list);
+	int i;
+
+	for (i = 0; i < sdma->dma.chancnt; i++) {
+		schan = &sdma->channels[i];
+
+		/* Get all completed descriptors */
+		spin_lock_irqsave(&schan->lock, flags);
+		if (!list_empty(&schan->completed)) {
+			list_splice_tail_init(&schan->completed, &list);
+			spin_unlock_irqrestore(&schan->lock, flags);
+
+			/* Execute callbacks and run dependencies */
+			list_for_each_entry(sdesc, &list, node) {
+				desc = &sdesc->desc;
+
+				if (desc->callback)
+					desc->callback(desc->callback_param);
+
+				last_cookie = desc->cookie;
+				dma_run_dependencies(desc);
+			}
+
+			/* Free descriptors */
+			spin_lock_irqsave(&schan->lock, flags);
+			list_splice_tail_init(&list, &schan->free);
+			schan->completed_cookie = last_cookie;
+			spin_unlock_irqrestore(&schan->lock, flags);
+		} else {
+			/* for cyclic channel, desc is always in active list */
+			sdesc = list_first_entry(&schan->active, struct sirfsoc_dma_desc,
+				node);
+
+			if (!sdesc || (sdesc && !sdesc->cyclic)) {
+				/* without active cyclic DMA */
+				spin_unlock_irqrestore(&schan->lock, flags);
+				continue;
+			}
+
+			/* cyclic DMA */
+			happened_cyclic = schan->happened_cyclic;
+			spin_unlock_irqrestore(&schan->lock, flags);
+
+			desc = &sdesc->desc;
+			while (happened_cyclic != schan->completed_cyclic) {
+				if (desc->callback)
+					desc->callback(desc->callback_param);
+				schan->completed_cyclic++;
+			}
+		}
+	}
+}
+
+/* DMA Tasklet */
+static void sirfsoc_dma_tasklet(unsigned long data)
+{
+	struct sirfsoc_dma *sdma = (void *)data;
+
+	sirfsoc_dma_process_completed(sdma);
+}
+
+/* Submit descriptor to hardware */
+static dma_cookie_t sirfsoc_dma_tx_submit(struct dma_async_tx_descriptor *txd)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(txd->chan);
+	struct sirfsoc_dma_desc *sdesc;
+	unsigned long flags;
+	dma_cookie_t cookie;
+
+	sdesc = container_of(txd, struct sirfsoc_dma_desc, desc);
+
+	spin_lock_irqsave(&schan->lock, flags);
+
+	/* Move descriptor to queue */
+	list_move_tail(&sdesc->node, &schan->queued);
+
+	/* Update cookie */
+	cookie = schan->chan.cookie + 1;
+	if (cookie <= 0)
+		cookie = 1;
+
+	schan->chan.cookie = cookie;
+	sdesc->desc.cookie = cookie;
+
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	return cookie;
+}
+
+static int sirfsoc_dma_slave_config(struct sirfsoc_dma_chan *schan,
+	struct dma_slave_config *config)
+{
+	unsigned long flags;
+
+	if ((config->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ||
+		(config->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES))
+		return -EINVAL;
+
+	spin_lock_irqsave(&schan->lock, flags);
+	schan->mode = (config->src_maxburst == 4 ? 1 : 0);
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	return 0;
+}
+
+static int sirfsoc_dma_terminate_all(struct sirfsoc_dma_chan *schan)
+{
+	struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(&schan->chan);
+	int cid = schan->chan.chan_id;
+	unsigned long flags;
+
+	writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN) &
+		~(1 << cid), sdma->base + SIRFSOC_DMA_INT_EN);
+	writel_relaxed(1 << cid, sdma->base + SIRFSOC_DMA_CH_VALID);
+
+	writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL)
+		& ~((1 << cid) | 1 << (cid + 16)),
+			sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
+
+	spin_lock_irqsave(&schan->lock, flags);
+	list_splice_tail_init(&schan->active, &schan->free);
+	list_splice_tail_init(&schan->queued, &schan->free);
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	return 0;
+}
+
+static int sirfsoc_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+	unsigned long arg)
+{
+	struct dma_slave_config *config;
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+
+	switch (cmd) {
+	case DMA_TERMINATE_ALL:
+		return sirfsoc_dma_terminate_all(schan);
+	case DMA_SLAVE_CONFIG:
+		config = (struct dma_slave_config *)arg;
+		return sirfsoc_dma_slave_config(schan, config);
+
+	default:
+		break;
+	}
+
+	return -ENOSYS;
+}
+
+/* Alloc channel resources */
+static int sirfsoc_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	struct sirfsoc_dma_desc *sdesc;
+	unsigned long flags;
+	LIST_HEAD(descs);
+	int i;
+
+	/* Alloc descriptors for this channel */
+	for (i = 0; i < SIRFSOC_DMA_DESCRIPTORS; i++) {
+		sdesc = kzalloc(sizeof(*sdesc), GFP_KERNEL);
+		if (!sdesc) {
+			dev_notice(sdma->dma.dev, "Memory allocation error. "
+				"Allocated only %u descriptors\n", i);
+			break;
+		}
+
+		dma_async_tx_descriptor_init(&sdesc->desc, chan);
+		sdesc->desc.flags = DMA_CTRL_ACK;
+		sdesc->desc.tx_submit = sirfsoc_dma_tx_submit;
+
+		list_add_tail(&sdesc->node, &descs);
+	}
+
+	/* Return error only if no descriptors were allocated */
+	if (i == 0)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&schan->lock, flags);
+
+	list_splice_tail_init(&descs, &schan->free);
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	return i;
+}
+
+/* Free channel resources */
+static void sirfsoc_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	struct sirfsoc_dma_desc *sdesc, *tmp;
+	unsigned long flags;
+	LIST_HEAD(descs);
+
+	spin_lock_irqsave(&schan->lock, flags);
+
+	/* Channel must be idle */
+	BUG_ON(!list_empty(&schan->prepared));
+	BUG_ON(!list_empty(&schan->queued));
+	BUG_ON(!list_empty(&schan->active));
+	BUG_ON(!list_empty(&schan->completed));
+
+	/* Move data */
+	list_splice_tail_init(&schan->free, &descs);
+
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	/* Free descriptors */
+	list_for_each_entry_safe(sdesc, tmp, &descs, node)
+		kfree(sdesc);
+}
+
+/* Send pending descriptor to hardware */
+static void sirfsoc_dma_issue_pending(struct dma_chan *chan)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->lock, flags);
+
+	if (list_empty(&schan->active) && !list_empty(&schan->queued))
+		sirfsoc_dma_execute(schan);
+
+	spin_unlock_irqrestore(&schan->lock, flags);
+}
+
+/* Check request completion status */
+static enum dma_status
+sirfsoc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
+	struct dma_tx_state *txstate)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	unsigned long flags;
+	dma_cookie_t last_used;
+	dma_cookie_t last_complete;
+
+	spin_lock_irqsave(&schan->lock, flags);
+	last_used = schan->chan.cookie;
+	last_complete = schan->completed_cookie;
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	dma_set_tx_state(txstate, last_complete, last_used, 0);
+	return dma_async_is_complete(cookie, last_complete, last_used);
+}
+
+static struct dma_async_tx_descriptor *sirfsoc_dma_prep_interleaved(
+	struct dma_chan *chan, struct dma_interleaved_template *xt,
+	unsigned long flags)
+{
+	struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	struct sirfsoc_dma_desc *sdesc = NULL;
+	unsigned long iflags;
+	int ret;
+
+	if ((xt->dir != DMA_MEM_TO_DEV) || (xt->dir != DMA_DEV_TO_MEM)) {
+		ret = -EINVAL;
+		goto err_dir;
+	}
+
+	/* Get free descriptor */
+	spin_lock_irqsave(&schan->lock, iflags);
+	if (!list_empty(&schan->free)) {
+		sdesc = list_first_entry(&schan->free, struct sirfsoc_dma_desc,
+			node);
+		list_del(&sdesc->node);
+	}
+	spin_unlock_irqrestore(&schan->lock, iflags);
+
+	if (!sdesc) {
+		/* try to free completed descriptors */
+		sirfsoc_dma_process_completed(sdma);
+		ret = 0;
+		goto no_desc;
+	}
+
+	/* Place descriptor in prepared list */
+	spin_lock_irqsave(&schan->lock, iflags);
+
+	/*
+	 * Number of chunks in a frame can only be 1 for prima2
+	 * and ylen (number of frame - 1) must be at least 0
+	 */
+	if ((xt->frame_size == 1) && (xt->numf > 0)) {
+		sdesc->cyclic = 0;
+		sdesc->xlen = xt->sgl[0].size / SIRFSOC_DMA_WORD_LEN;
+		sdesc->width = (xt->sgl[0].size + xt->sgl[0].icg) /
+				SIRFSOC_DMA_WORD_LEN;
+		sdesc->ylen = xt->numf - 1;
+		if (xt->dir == DMA_MEM_TO_DEV) {
+			sdesc->addr = xt->src_start;
+			sdesc->dir = 1;
+		} else {
+			sdesc->addr = xt->dst_start;
+			sdesc->dir = 0;
+		}
+
+		list_add_tail(&sdesc->node, &schan->prepared);
+	} else {
+		pr_err("sirfsoc DMA Invalid xfer\n");
+		ret = -EINVAL;
+		goto err_xfer;
+	}
+	spin_unlock_irqrestore(&schan->lock, iflags);
+
+	return &sdesc->desc;
+err_xfer:
+	spin_unlock_irqrestore(&schan->lock, iflags);
+no_desc:
+err_dir:
+	return ERR_PTR(ret);
+}
+
+static struct dma_async_tx_descriptor *
+sirfsoc_dma_prep_cyclic(struct dma_chan *chan, dma_addr_t addr,
+	size_t buf_len, size_t period_len,
+	enum dma_transfer_direction direction)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	struct sirfsoc_dma_desc *sdesc = NULL;
+	unsigned long iflags;
+
+	/*
+	 * we only support cycle transfer with 2 period
+	 * If the X-length is set to 0, it would be the loop mode.
+	 * The DMA address keeps increasing until reaching the end of a loop
+	 * area whose size is defined by (DMA_WIDTH x (Y_LENGTH + 1)). Then
+	 * the DMA address goes back to the beginning of this area.
+	 * In loop mode, the DMA data region is divided into two parts, BUFA
+	 * and BUFB. DMA controller generates interrupts twice in each loop:
+	 * when the DMA address reaches the end of BUFA or the end of the
+	 * BUFB
+	 */
+	if (buf_len !=  2 * period_len)
+		return ERR_PTR(-EINVAL);
+
+	/* Get free descriptor */
+	spin_lock_irqsave(&schan->lock, iflags);
+	if (!list_empty(&schan->free)) {
+		sdesc = list_first_entry(&schan->free, struct sirfsoc_dma_desc,
+			node);
+		list_del(&sdesc->node);
+	}
+	spin_unlock_irqrestore(&schan->lock, iflags);
+
+	if (!sdesc)
+		return 0;
+
+	/* Place descriptor in prepared list */
+	spin_lock_irqsave(&schan->lock, iflags);
+	sdesc->addr = addr;
+	sdesc->cyclic = 1;
+	sdesc->xlen = 0;
+	sdesc->ylen = buf_len / SIRFSOC_DMA_WORD_LEN - 1;
+	sdesc->width = 1;
+	list_add_tail(&sdesc->node, &schan->prepared);
+	spin_unlock_irqrestore(&schan->lock, iflags);
+
+	return &sdesc->desc;
+}
+
+/*
+ * The DMA controller consists of 16 independent DMA channels.
+ * Each channel is allocated to a different function
+ */
+bool sirfsoc_dma_filter_id(struct dma_chan *chan, void *chan_id)
+{
+	unsigned int ch_nr = (unsigned int) chan_id;
+
+	if (ch_nr == chan->chan_id +
+		chan->device->dev_id * SIRFSOC_DMA_CHANNELS)
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL(sirfsoc_dma_filter_id);
+
+static int __devinit sirfsoc_dma_probe(struct platform_device *op)
+{
+	struct device_node *dn = op->dev.of_node;
+	struct device *dev = &op->dev;
+	struct dma_device *dma;
+	struct sirfsoc_dma *sdma;
+	struct sirfsoc_dma_chan *schan;
+	struct resource res;
+	ulong regs_start, regs_size;
+	u32 id;
+	int ret, i;
+
+	sdma = devm_kzalloc(dev, sizeof(*sdma), GFP_KERNEL);
+	if (!sdma) {
+		dev_err(dev, "Memory exhausted!\n");
+		return -ENOMEM;
+	}
+
+	if (of_property_read_u32(dn, "cell-index", &id)) {
+		dev_err(dev, "Fail to get DMAC index\n");
+		ret = -ENODEV;
+		goto free_mem;
+	}
+
+	sdma->irq = irq_of_parse_and_map(dn, 0);
+	if (sdma->irq == NO_IRQ) {
+		dev_err(dev, "Error mapping IRQ!\n");
+		ret = -EINVAL;
+		goto free_mem;
+	}
+
+	ret = of_address_to_resource(dn, 0, &res);
+	if (ret) {
+		dev_err(dev, "Error parsing memory region!\n");
+		goto free_mem;
+	}
+
+	regs_start = res.start;
+	regs_size = resource_size(&res);
+
+	sdma->base = devm_ioremap(dev, regs_start, regs_size);
+	if (!sdma->base) {
+		dev_err(dev, "Error mapping memory region!\n");
+		ret = -ENOMEM;
+		goto irq_dispose;
+	}
+
+	ret = devm_request_irq(dev, sdma->irq, &sirfsoc_dma_irq, 0, DRV_NAME,
+		sdma);
+	if (ret) {
+		dev_err(dev, "Error requesting IRQ!\n");
+		ret = -EINVAL;
+		goto unmap_mem;
+	}
+
+	dma = &sdma->dma;
+	dma->dev = dev;
+	dma->chancnt = SIRFSOC_DMA_CHANNELS;
+
+	dma->device_alloc_chan_resources = sirfsoc_dma_alloc_chan_resources;
+	dma->device_free_chan_resources = sirfsoc_dma_free_chan_resources;
+	dma->device_issue_pending = sirfsoc_dma_issue_pending;
+	dma->device_control = sirfsoc_dma_control;
+	dma->device_tx_status = sirfsoc_dma_tx_status;
+	dma->device_prep_interleaved_dma = sirfsoc_dma_prep_interleaved;
+	dma->device_prep_dma_cyclic = sirfsoc_dma_prep_cyclic;
+
+	INIT_LIST_HEAD(&dma->channels);
+	dma_cap_set(DMA_SLAVE, dma->cap_mask);
+	dma_cap_set(DMA_CYCLIC, dma->cap_mask);
+	dma_cap_set(DMA_INTERLEAVE, dma->cap_mask);
+	dma_cap_set(DMA_PRIVATE, dma->cap_mask);
+
+	for (i = 0; i < dma->chancnt; i++) {
+		schan = &sdma->channels[i];
+
+		schan->chan.device = dma;
+		schan->chan.cookie = 1;
+		schan->completed_cookie = schan->chan.cookie;
+
+		INIT_LIST_HEAD(&schan->free);
+		INIT_LIST_HEAD(&schan->prepared);
+		INIT_LIST_HEAD(&schan->queued);
+		INIT_LIST_HEAD(&schan->active);
+		INIT_LIST_HEAD(&schan->completed);
+
+		spin_lock_init(&schan->lock);
+		list_add_tail(&schan->chan.device_node, &dma->channels);
+	}
+
+	tasklet_init(&sdma->tasklet, sirfsoc_dma_tasklet, (unsigned long)sdma);
+
+	/* Register DMA engine */
+	dev_set_drvdata(dev, sdma);
+	ret = dma_async_device_register(dma);
+	if (ret)
+		goto free_irq;
+
+	dev_info(dev, "initialized SIRFSOC DMAC driver\n");
+
+	return 0;
+
+free_irq:
+	devm_free_irq(dev, sdma->irq, sdma);
+irq_dispose:
+	irq_dispose_mapping(sdma->irq);
+unmap_mem:
+	iounmap(sdma->base);
+free_mem:
+	devm_kfree(dev, sdma);
+	return ret;
+}
+
+static int __devexit sirfsoc_dma_remove(struct platform_device *op)
+{
+	struct device *dev = &op->dev;
+	struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+
+	dma_async_device_unregister(&sdma->dma);
+	devm_free_irq(dev, sdma->irq, sdma);
+	irq_dispose_mapping(sdma->irq);
+	iounmap(sdma->base);
+	devm_kfree(dev, sdma);
+	return 0;
+}
+
+static struct of_device_id sirfsoc_dma_match[] = {
+	{ .compatible = "sirf,prima2-dmac", },
+	{},
+};
+
+static struct platform_driver sirfsoc_dma_driver = {
+	.probe		= sirfsoc_dma_probe,
+	.remove		= __devexit_p(sirfsoc_dma_remove),
+	.driver = {
+		.name = DRV_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table	= sirfsoc_dma_match,
+	},
+};
+
+static int __init sirfsoc_dma_init(void)
+{
+	return platform_driver_register(&sirfsoc_dma_driver);
+}
+module_init(sirfsoc_dma_init);
+
+static void __exit sirfsoc_dma_exit(void)
+{
+	platform_driver_unregister(&sirfsoc_dma_driver);
+}
+module_exit(sirfsoc_dma_exit);
+
+MODULE_AUTHOR("Rongjun Ying <rongjun.ying@csr.com>, "
+	"Barry Song <baohua.song@csr.com>");
+MODULE_DESCRIPTION("SIRFSOC DMA control driver");
+MODULE_LICENSE("GPL v2");

include/linux/sirfsoc_dma.h

+#ifndef _SIRFSOC_DMA_H_
+#define _SIRFSOC_DMA_H_
+
+bool sirfsoc_dma_filter_id(struct dma_chan *chan, void *chan_id);
+
+#endif