Add the rt linux 4.1.3-rt3 as base

Import the rt linux 4.1.3-rt3 as OPNFV kvm base.

It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:

commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date:   Sat Jul 25 12:13:34 2015 +0200

    Prepare v4.1.3-rt3

    Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.

Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>

1 files changed, 931 insertions, 0 deletions

diff --git a/kernel/drivers/dma/sirf-dma.c b/kernel/drivers/dma/sirf-dma.c
new file mode 100644
index 000000000..a1afda43b
--- /dev/null
+++ b/kernel/drivers/dma/sirf-dma.c
@@ -0,0 +1,931 @@
+/*
+ * 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/pm_runtime.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/clk.h>
+#include <linux/of_dma.h>
+#include <linux/sirfsoc_dma.h>
+
+#include "dmaengine.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_INT_EN_CLR			0x14C
+#define SIRFSOC_DMA_CH_LOOP_CTRL                0x150
+#define SIRFSOC_DMA_CH_LOOP_CTRL_CLR            0x15C
+
+#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;
+	unsigned long			happened_cyclic;
+	unsigned long			completed_cyclic;
+
+	/* Lock for this structure */
+	spinlock_t			lock;
+
+	int				mode;
+};
+
+struct sirfsoc_dma_regs {
+	u32				ctrl[SIRFSOC_DMA_CHANNELS];
+	u32				interrupt_en;
+};
+
+struct sirfsoc_dma {
+	struct dma_device		dma;
+	struct tasklet_struct		tasklet;
+	struct sirfsoc_dma_chan		channels[SIRFSOC_DMA_CHANNELS];
+	void __iomem			*base;
+	int				irq;
+	struct clk			*clk;
+	bool				is_marco;
+	struct sirfsoc_dma_regs		regs_save;
+};
+
+#define DRV_NAME	"sirfsoc_dma"
+
+static int sirfsoc_dma_runtime_suspend(struct device *dev);
+
+/* 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(&sdesc->node, &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->chan.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);
+
+	cookie = dma_cookie_assign(txd);
+
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	return cookie;
+}
+
+static int sirfsoc_dma_slave_config(struct dma_chan *chan,
+				    struct dma_slave_config *config)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	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 dma_chan *chan)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(&schan->chan);
+	int cid = schan->chan.chan_id;
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->lock, flags);
+
+	if (!sdma->is_marco) {
+		writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN) &
+			~(1 << cid), sdma->base + SIRFSOC_DMA_INT_EN);
+		writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL)
+			& ~((1 << cid) | 1 << (cid + 16)),
+			sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
+	} else {
+		writel_relaxed(1 << cid, sdma->base + SIRFSOC_DMA_INT_EN_CLR);
+		writel_relaxed((1 << cid) | 1 << (cid + 16),
+			sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL_CLR);
+	}
+
+	writel_relaxed(1 << cid, sdma->base + SIRFSOC_DMA_CH_VALID);
+
+	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_pause_chan(struct dma_chan *chan)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(&schan->chan);
+	int cid = schan->chan.chan_id;
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->lock, flags);
+
+	if (!sdma->is_marco)
+		writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL)
+			& ~((1 << cid) | 1 << (cid + 16)),
+			sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
+	else
+		writel_relaxed((1 << cid) | 1 << (cid + 16),
+			sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL_CLR);
+
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	return 0;
+}
+
+static int sirfsoc_dma_resume_chan(struct dma_chan *chan)
+{
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(&schan->chan);
+	int cid = schan->chan.chan_id;
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->lock, flags);
+
+	if (!sdma->is_marco)
+		writel_relaxed(readl_relaxed(sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL)
+			| ((1 << cid) | 1 << (cid + 16)),
+			sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
+	else
+		writel_relaxed((1 << cid) | 1 << (cid + 16),
+			sdma->base + SIRFSOC_DMA_CH_LOOP_CTRL);
+
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	return 0;
+}
+
+/* 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;
+
+	pm_runtime_get_sync(sdma->dma.dev);
+
+	/* 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 *sdma = dma_chan_to_sirfsoc_dma(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);
+
+	pm_runtime_put(sdma->dma.dev);
+}
+
+/* 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 *sdma = dma_chan_to_sirfsoc_dma(chan);
+	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
+	unsigned long flags;
+	enum dma_status ret;
+	struct sirfsoc_dma_desc *sdesc;
+	int cid = schan->chan.chan_id;
+	unsigned long dma_pos;
+	unsigned long dma_request_bytes;
+	unsigned long residue;
+
+	spin_lock_irqsave(&schan->lock, flags);
+
+	sdesc = list_first_entry(&schan->active, struct sirfsoc_dma_desc,
+			node);
+	dma_request_bytes = (sdesc->xlen + 1) * (sdesc->ylen + 1) *
+		(sdesc->width * SIRFSOC_DMA_WORD_LEN);
+
+	ret = dma_cookie_status(chan, cookie, txstate);
+	dma_pos = readl_relaxed(sdma->base + cid * 0x10 + SIRFSOC_DMA_CH_ADDR)
+		<< 2;
+	residue = dma_request_bytes - (dma_pos - sdesc->addr);
+	dma_set_residue(txstate, residue);
+
+	spin_unlock_irqrestore(&schan->lock, flags);
+
+	return ret;
+}
+
+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, unsigned long flags)
+{
+	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 NULL;
+
+	/* 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);
+
+#define SIRFSOC_DMA_BUSWIDTHS \
+	(BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
+	BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
+	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
+	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | \
+	BIT(DMA_SLAVE_BUSWIDTH_8_BYTES))
+
+static struct dma_chan *of_dma_sirfsoc_xlate(struct of_phandle_args *dma_spec,
+	struct of_dma *ofdma)
+{
+	struct sirfsoc_dma *sdma = ofdma->of_dma_data;
+	unsigned int request = dma_spec->args[0];
+
+	if (request >= SIRFSOC_DMA_CHANNELS)
+		return NULL;
+
+	return dma_get_slave_channel(&sdma->channels[request].chan);
+}
+
+static int 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_device_is_compatible(dn, "sirf,marco-dmac"))
+		sdma->is_marco = true;
+
+	if (of_property_read_u32(dn, "cell-index", &id)) {
+		dev_err(dev, "Fail to get DMAC index\n");
+		return -ENODEV;
+	}
+
+	sdma->irq = irq_of_parse_and_map(dn, 0);
+	if (sdma->irq == NO_IRQ) {
+		dev_err(dev, "Error mapping IRQ!\n");
+		return -EINVAL;
+	}
+
+	sdma->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(sdma->clk)) {
+		dev_err(dev, "failed to get a clock.\n");
+		return PTR_ERR(sdma->clk);
+	}
+
+	ret = of_address_to_resource(dn, 0, &res);
+	if (ret) {
+		dev_err(dev, "Error parsing memory region!\n");
+		goto irq_dispose;
+	}
+
+	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 = request_irq(sdma->irq, &sirfsoc_dma_irq, 0, DRV_NAME, sdma);
+	if (ret) {
+		dev_err(dev, "Error requesting IRQ!\n");
+		ret = -EINVAL;
+		goto irq_dispose;
+	}
+
+	dma = &sdma->dma;
+	dma->dev = dev;
+
+	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_config = sirfsoc_dma_slave_config;
+	dma->device_pause = sirfsoc_dma_pause_chan;
+	dma->device_resume = sirfsoc_dma_resume_chan;
+	dma->device_terminate_all = sirfsoc_dma_terminate_all;
+	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;
+	dma->src_addr_widths = SIRFSOC_DMA_BUSWIDTHS;
+	dma->dst_addr_widths = SIRFSOC_DMA_BUSWIDTHS;
+	dma->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+
+	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 < SIRFSOC_DMA_CHANNELS; i++) {
+		schan = &sdma->channels[i];
+
+		schan->chan.device = dma;
+		dma_cookie_init(&schan->chan);
+
+		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;
+
+	/* Device-tree DMA controller registration */
+	ret = of_dma_controller_register(dn, of_dma_sirfsoc_xlate, sdma);
+	if (ret) {
+		dev_err(dev, "failed to register DMA controller\n");
+		goto unreg_dma_dev;
+	}
+
+	pm_runtime_enable(&op->dev);
+	dev_info(dev, "initialized SIRFSOC DMAC driver\n");
+
+	return 0;
+
+unreg_dma_dev:
+	dma_async_device_unregister(dma);
+free_irq:
+	free_irq(sdma->irq, sdma);
+irq_dispose:
+	irq_dispose_mapping(sdma->irq);
+	return ret;
+}
+
+static int sirfsoc_dma_remove(struct platform_device *op)
+{
+	struct device *dev = &op->dev;
+	struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+
+	of_dma_controller_free(op->dev.of_node);
+	dma_async_device_unregister(&sdma->dma);
+	free_irq(sdma->irq, sdma);
+	irq_dispose_mapping(sdma->irq);
+	pm_runtime_disable(&op->dev);
+	if (!pm_runtime_status_suspended(&op->dev))
+		sirfsoc_dma_runtime_suspend(&op->dev);
+
+	return 0;
+}
+
+static int sirfsoc_dma_runtime_suspend(struct device *dev)
+{
+	struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(sdma->clk);
+	return 0;
+}
+
+static int sirfsoc_dma_runtime_resume(struct device *dev)
+{
+	struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(sdma->clk);
+	if (ret < 0) {
+		dev_err(dev, "clk_enable failed: %d\n", ret);
+		return ret;
+	}
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int sirfsoc_dma_pm_suspend(struct device *dev)
+{
+	struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+	struct sirfsoc_dma_regs *save = &sdma->regs_save;
+	struct sirfsoc_dma_desc *sdesc;
+	struct sirfsoc_dma_chan *schan;
+	int ch;
+	int ret;
+
+	/*
+	 * if we were runtime-suspended before, resume to enable clock
+	 * before accessing register
+	 */
+	if (pm_runtime_status_suspended(dev)) {
+		ret = sirfsoc_dma_runtime_resume(dev);
+		if (ret < 0)
+			return ret;
+	}
+
+	/*
+	 * DMA controller will lose all registers while suspending
+	 * so we need to save registers for active channels
+	 */
+	for (ch = 0; ch < SIRFSOC_DMA_CHANNELS; ch++) {
+		schan = &sdma->channels[ch];
+		if (list_empty(&schan->active))
+			continue;
+		sdesc = list_first_entry(&schan->active,
+			struct sirfsoc_dma_desc,
+			node);
+		save->ctrl[ch] = readl_relaxed(sdma->base +
+			ch * 0x10 + SIRFSOC_DMA_CH_CTRL);
+	}
+	save->interrupt_en = readl_relaxed(sdma->base + SIRFSOC_DMA_INT_EN);
+
+	/* Disable clock */
+	sirfsoc_dma_runtime_suspend(dev);
+
+	return 0;
+}
+
+static int sirfsoc_dma_pm_resume(struct device *dev)
+{
+	struct sirfsoc_dma *sdma = dev_get_drvdata(dev);
+	struct sirfsoc_dma_regs *save = &sdma->regs_save;
+	struct sirfsoc_dma_desc *sdesc;
+	struct sirfsoc_dma_chan *schan;
+	int ch;
+	int ret;
+
+	/* Enable clock before accessing register */
+	ret = sirfsoc_dma_runtime_resume(dev);
+	if (ret < 0)
+		return ret;
+
+	writel_relaxed(save->interrupt_en, sdma->base + SIRFSOC_DMA_INT_EN);
+	for (ch = 0; ch < SIRFSOC_DMA_CHANNELS; ch++) {
+		schan = &sdma->channels[ch];
+		if (list_empty(&schan->active))
+			continue;
+		sdesc = list_first_entry(&schan->active,
+			struct sirfsoc_dma_desc,
+			node);
+		writel_relaxed(sdesc->width,
+			sdma->base + SIRFSOC_DMA_WIDTH_0 + ch * 4);
+		writel_relaxed(sdesc->xlen,
+			sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_XLEN);
+		writel_relaxed(sdesc->ylen,
+			sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_YLEN);
+		writel_relaxed(save->ctrl[ch],
+			sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_CTRL);
+		writel_relaxed(sdesc->addr >> 2,
+			sdma->base + ch * 0x10 + SIRFSOC_DMA_CH_ADDR);
+	}
+
+	/* if we were runtime-suspended before, suspend again */
+	if (pm_runtime_status_suspended(dev))
+		sirfsoc_dma_runtime_suspend(dev);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops sirfsoc_dma_pm_ops = {
+	SET_RUNTIME_PM_OPS(sirfsoc_dma_runtime_suspend, sirfsoc_dma_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(sirfsoc_dma_pm_suspend, sirfsoc_dma_pm_resume)
+};
+
+static const struct of_device_id sirfsoc_dma_match[] = {
+	{ .compatible = "sirf,prima2-dmac", },
+	{ .compatible = "sirf,marco-dmac", },
+	{},
+};
+
+static struct platform_driver sirfsoc_dma_driver = {
+	.probe		= sirfsoc_dma_probe,
+	.remove		= sirfsoc_dma_remove,
+	.driver = {
+		.name = DRV_NAME,
+		.pm = &sirfsoc_dma_pm_ops,
+		.of_match_table	= sirfsoc_dma_match,
+	},
+};
+
+static __init int sirfsoc_dma_init(void)
+{
+	return platform_driver_register(&sirfsoc_dma_driver);
+}
+
+static void __exit sirfsoc_dma_exit(void)
+{
+	platform_driver_unregister(&sirfsoc_dma_driver);
+}
+
+subsys_initcall(sirfsoc_dma_init);
+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");