1 files changed, 369 insertions, 176 deletions

diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index b06cd4ca626..ead491346da 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -22,11 +22,16 @@
 #include <linux/platform_device.h>
 #include <linux/dmaengine.h>
 #include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/stmp_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
+#include <linux/list.h>
 
 #include <asm/irq.h>
-#include <mach/mxs.h>
-#include <mach/dma.h>
-#include <mach/common.h>
+
+#include "dmaengine.h"
 
 /*
  * NOTE: The term "PIO" throughout the mxs-dma implementation means
@@ -34,12 +39,8 @@
  * dma can program the controller registers of peripheral devices.
  */
 
-#define MXS_DMA_APBH		0
-#define MXS_DMA_APBX		1
-#define dma_is_apbh()		(mxs_dma->dev_id == MXS_DMA_APBH)
-
-#define APBH_VERSION_LATEST	3
-#define apbh_is_old()		(mxs_dma->version < APBH_VERSION_LATEST)
+#define dma_is_apbh(mxs_dma)	((mxs_dma)->type == MXS_DMA_APBH)
+#define apbh_is_old(mxs_dma)	((mxs_dma)->dev_id == IMX23_DMA)
 
 #define HW_APBHX_CTRL0				0x000
 #define BM_APBH_CTRL0_APB_BURST8_EN		(1 << 29)
@@ -49,13 +50,17 @@
 #define HW_APBHX_CTRL2				0x020
 #define HW_APBHX_CHANNEL_CTRL			0x030
 #define BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL	16
-#define HW_APBH_VERSION				(cpu_is_mx23() ? 0x3f0 : 0x800)
-#define HW_APBX_VERSION				0x800
-#define BP_APBHX_VERSION_MAJOR			24
-#define HW_APBHX_CHn_NXTCMDAR(n) \
-	(((dma_is_apbh() && apbh_is_old()) ? 0x050 : 0x110) + (n) * 0x70)
-#define HW_APBHX_CHn_SEMA(n) \
-	(((dma_is_apbh() && apbh_is_old()) ? 0x080 : 0x140) + (n) * 0x70)
+/*
+ * The offset of NXTCMDAR register is different per both dma type and version,
+ * while stride for each channel is all the same 0x70.
+ */
+#define HW_APBHX_CHn_NXTCMDAR(d, n) \
+	(((dma_is_apbh(d) && apbh_is_old(d)) ? 0x050 : 0x110) + (n) * 0x70)
+#define HW_APBHX_CHn_SEMA(d, n) \
+	(((dma_is_apbh(d) && apbh_is_old(d)) ? 0x080 : 0x140) + (n) * 0x70)
+#define HW_APBHX_CHn_BAR(d, n) \
+	(((dma_is_apbh(d) && apbh_is_old(d)) ? 0x070 : 0x130) + (n) * 0x70)
+#define HW_APBX_CHn_DEBUG1(d, n) (0x150 + (n) * 0x70)
 
 /*
  * ccw bits definitions
@@ -100,47 +105,149 @@ struct mxs_dma_ccw {
 	u32		pio_words[MXS_PIO_WORDS];
 };
 
-#define NUM_CCW	(int)(PAGE_SIZE / sizeof(struct mxs_dma_ccw))
+#define CCW_BLOCK_SIZE	(4 * PAGE_SIZE)
+#define NUM_CCW	(int)(CCW_BLOCK_SIZE / sizeof(struct mxs_dma_ccw))
 
 struct mxs_dma_chan {
 	struct mxs_dma_engine		*mxs_dma;
 	struct dma_chan			chan;
 	struct dma_async_tx_descriptor	desc;
 	struct tasklet_struct		tasklet;
-	int				chan_irq;
+	unsigned int			chan_irq;
 	struct mxs_dma_ccw		*ccw;
 	dma_addr_t			ccw_phys;
 	int				desc_count;
-	dma_cookie_t			last_completed;
 	enum dma_status			status;
 	unsigned int			flags;
+	bool				reset;
 #define MXS_DMA_SG_LOOP			(1 << 0)
+#define MXS_DMA_USE_SEMAPHORE		(1 << 1)
 };
 
 #define MXS_DMA_CHANNELS		16
 #define MXS_DMA_CHANNELS_MASK		0xffff
 
+enum mxs_dma_devtype {
+	MXS_DMA_APBH,
+	MXS_DMA_APBX,
+};
+
+enum mxs_dma_id {
+	IMX23_DMA,
+	IMX28_DMA,
+};
+
 struct mxs_dma_engine {
-	int				dev_id;
-	unsigned int			version;
+	enum mxs_dma_id			dev_id;
+	enum mxs_dma_devtype		type;
 	void __iomem			*base;
 	struct clk			*clk;
 	struct dma_device		dma_device;
 	struct device_dma_parameters	dma_parms;
 	struct mxs_dma_chan		mxs_chans[MXS_DMA_CHANNELS];
+	struct platform_device		*pdev;
+	unsigned int			nr_channels;
+};
+
+struct mxs_dma_type {
+	enum mxs_dma_id id;
+	enum mxs_dma_devtype type;
 };
 
+static struct mxs_dma_type mxs_dma_types[] = {
+	{
+		.id = IMX23_DMA,
+		.type = MXS_DMA_APBH,
+	}, {
+		.id = IMX23_DMA,
+		.type = MXS_DMA_APBX,
+	}, {
+		.id = IMX28_DMA,
+		.type = MXS_DMA_APBH,
+	}, {
+		.id = IMX28_DMA,
+		.type = MXS_DMA_APBX,
+	}
+};
+
+static struct platform_device_id mxs_dma_ids[] = {
+	{
+		.name = "imx23-dma-apbh",
+		.driver_data = (kernel_ulong_t) &mxs_dma_types[0],
+	}, {
+		.name = "imx23-dma-apbx",
+		.driver_data = (kernel_ulong_t) &mxs_dma_types[1],
+	}, {
+		.name = "imx28-dma-apbh",
+		.driver_data = (kernel_ulong_t) &mxs_dma_types[2],
+	}, {
+		.name = "imx28-dma-apbx",
+		.driver_data = (kernel_ulong_t) &mxs_dma_types[3],
+	}, {
+		/* end of list */
+	}
+};
+
+static const struct of_device_id mxs_dma_dt_ids[] = {
+	{ .compatible = "fsl,imx23-dma-apbh", .data = &mxs_dma_ids[0], },
+	{ .compatible = "fsl,imx23-dma-apbx", .data = &mxs_dma_ids[1], },
+	{ .compatible = "fsl,imx28-dma-apbh", .data = &mxs_dma_ids[2], },
+	{ .compatible = "fsl,imx28-dma-apbx", .data = &mxs_dma_ids[3], },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxs_dma_dt_ids);
+
+static struct mxs_dma_chan *to_mxs_dma_chan(struct dma_chan *chan)
+{
+	return container_of(chan, struct mxs_dma_chan, chan);
+}
+
 static void mxs_dma_reset_chan(struct mxs_dma_chan *mxs_chan)
 {
 	struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
 	int chan_id = mxs_chan->chan.chan_id;
 
-	if (dma_is_apbh() && apbh_is_old())
+	/*
+	 * mxs dma channel resets can cause a channel stall. To recover from a
+	 * channel stall, we have to reset the whole DMA engine. To avoid this,
+	 * we use cyclic DMA with semaphores, that are enhanced in
+	 * mxs_dma_int_handler. To reset the channel, we can simply stop writing
+	 * into the semaphore counter.
+	 */
+	if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE &&
+			mxs_chan->flags & MXS_DMA_SG_LOOP) {
+		mxs_chan->reset = true;
+	} else if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma)) {
 		writel(1 << (chan_id + BP_APBH_CTRL0_RESET_CHANNEL),
-			mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
-	else
+			mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
+	} else {
+		unsigned long elapsed = 0;
+		const unsigned long max_wait = 50000; /* 50ms */
+		void __iomem *reg_dbg1 = mxs_dma->base +
+				HW_APBX_CHn_DEBUG1(mxs_dma, chan_id);
+
+		/*
+		 * On i.MX28 APBX, the DMA channel can stop working if we reset
+		 * the channel while it is in READ_FLUSH (0x08) state.
+		 * We wait here until we leave the state. Then we trigger the
+		 * reset. Waiting a maximum of 50ms, the kernel shouldn't crash
+		 * because of this.
+		 */
+		while ((readl(reg_dbg1) & 0xf) == 0x8 && elapsed < max_wait) {
+			udelay(100);
+			elapsed += 100;
+		}
+
+		if (elapsed >= max_wait)
+			dev_err(&mxs_chan->mxs_dma->pdev->dev,
+					"Failed waiting for the DMA channel %d to leave state READ_FLUSH, trying to reset channel in READ_FLUSH state now\n",
+					chan_id);
+
 		writel(1 << (chan_id + BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL),
-			mxs_dma->base + HW_APBHX_CHANNEL_CTRL + MXS_SET_ADDR);
+			mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET);
+	}
+
+	mxs_chan->status = DMA_COMPLETE;
 }
 
 static void mxs_dma_enable_chan(struct mxs_dma_chan *mxs_chan)
@@ -150,15 +257,24 @@ static void mxs_dma_enable_chan(struct mxs_dma_chan *mxs_chan)
 
 	/* set cmd_addr up */
 	writel(mxs_chan->ccw_phys,
-		mxs_dma->base + HW_APBHX_CHn_NXTCMDAR(chan_id));
+		mxs_dma->base + HW_APBHX_CHn_NXTCMDAR(mxs_dma, chan_id));
 
 	/* write 1 to SEMA to kick off the channel */
-	writel(1, mxs_dma->base + HW_APBHX_CHn_SEMA(chan_id));
+	if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE &&
+			mxs_chan->flags & MXS_DMA_SG_LOOP) {
+		/* A cyclic DMA consists of at least 2 segments, so initialize
+		 * the semaphore with 2 so we have enough time to add 1 to the
+		 * semaphore if we need to */
+		writel(2, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id));
+	} else {
+		writel(1, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id));
+	}
+	mxs_chan->reset = false;
 }
 
 static void mxs_dma_disable_chan(struct mxs_dma_chan *mxs_chan)
 {
-	mxs_chan->status = DMA_SUCCESS;
+	mxs_chan->status = DMA_COMPLETE;
 }
 
 static void mxs_dma_pause_chan(struct mxs_dma_chan *mxs_chan)
@@ -167,12 +283,12 @@ static void mxs_dma_pause_chan(struct mxs_dma_chan *mxs_chan)
 	int chan_id = mxs_chan->chan.chan_id;
 
 	/* freeze the channel */
-	if (dma_is_apbh() && apbh_is_old())
+	if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma))
 		writel(1 << chan_id,
-			mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
+			mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
 	else
 		writel(1 << chan_id,
-			mxs_dma->base + HW_APBHX_CHANNEL_CTRL + MXS_SET_ADDR);
+			mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET);
 
 	mxs_chan->status = DMA_PAUSED;
 }
@@ -183,41 +299,19 @@ static void mxs_dma_resume_chan(struct mxs_dma_chan *mxs_chan)
 	int chan_id = mxs_chan->chan.chan_id;
 
 	/* unfreeze the channel */
-	if (dma_is_apbh() && apbh_is_old())
+	if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma))
 		writel(1 << chan_id,
-			mxs_dma->base + HW_APBHX_CTRL0 + MXS_CLR_ADDR);
+			mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_CLR);
 	else
 		writel(1 << chan_id,
-			mxs_dma->base + HW_APBHX_CHANNEL_CTRL + MXS_CLR_ADDR);
+			mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_CLR);
 
 	mxs_chan->status = DMA_IN_PROGRESS;
 }
 
-static dma_cookie_t mxs_dma_assign_cookie(struct mxs_dma_chan *mxs_chan)
-{
-	dma_cookie_t cookie = mxs_chan->chan.cookie;
-
-	if (++cookie < 0)
-		cookie = 1;
-
-	mxs_chan->chan.cookie = cookie;
-	mxs_chan->desc.cookie = cookie;
-
-	return cookie;
-}
-
-static struct mxs_dma_chan *to_mxs_dma_chan(struct dma_chan *chan)
-{
-	return container_of(chan, struct mxs_dma_chan, chan);
-}
-
 static dma_cookie_t mxs_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 {
-	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(tx->chan);
-
-	mxs_dma_enable_chan(mxs_chan);
-
-	return mxs_dma_assign_cookie(mxs_chan);
+	return dma_cookie_assign(tx);
 }
 
 static void mxs_dma_tasklet(unsigned long data)
@@ -228,81 +322,106 @@ static void mxs_dma_tasklet(unsigned long data)
 		mxs_chan->desc.callback(mxs_chan->desc.callback_param);
 }
 
+static int mxs_dma_irq_to_chan(struct mxs_dma_engine *mxs_dma, int irq)
+{
+	int i;
+
+	for (i = 0; i != mxs_dma->nr_channels; ++i)
+		if (mxs_dma->mxs_chans[i].chan_irq == irq)
+			return i;
+
+	return -EINVAL;
+}
+
 static irqreturn_t mxs_dma_int_handler(int irq, void *dev_id)
 {
 	struct mxs_dma_engine *mxs_dma = dev_id;
-	u32 stat1, stat2;
+	struct mxs_dma_chan *mxs_chan;
+	u32 completed;
+	u32 err;
+	int chan = mxs_dma_irq_to_chan(mxs_dma, irq);
+
+	if (chan < 0)
+		return IRQ_NONE;
 
 	/* completion status */
-	stat1 = readl(mxs_dma->base + HW_APBHX_CTRL1);
-	stat1 &= MXS_DMA_CHANNELS_MASK;
-	writel(stat1, mxs_dma->base + HW_APBHX_CTRL1 + MXS_CLR_ADDR);
+	completed = readl(mxs_dma->base + HW_APBHX_CTRL1);
+	completed = (completed >> chan) & 0x1;
+
+	/* Clear interrupt */
+	writel((1 << chan),
+			mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_CLR);
 
 	/* error status */
-	stat2 = readl(mxs_dma->base + HW_APBHX_CTRL2);
-	writel(stat2, mxs_dma->base + HW_APBHX_CTRL2 + MXS_CLR_ADDR);
+	err = readl(mxs_dma->base + HW_APBHX_CTRL2);
+	err &= (1 << (MXS_DMA_CHANNELS + chan)) | (1 << chan);
+
+	/*
+	 * error status bit is in the upper 16 bits, error irq bit in the lower
+	 * 16 bits. We transform it into a simpler error code:
+	 * err: 0x00 = no error, 0x01 = TERMINATION, 0x02 = BUS_ERROR
+	 */
+	err = (err >> (MXS_DMA_CHANNELS + chan)) + (err >> chan);
+
+	/* Clear error irq */
+	writel((1 << chan),
+			mxs_dma->base + HW_APBHX_CTRL2 + STMP_OFFSET_REG_CLR);
 
 	/*
 	 * When both completion and error of termination bits set at the
 	 * same time, we do not take it as an error.  IOW, it only becomes
-	 * an error we need to handle here in case of either it's (1) a bus
-	 * error or (2) a termination error with no completion.
+	 * an error we need to handle here in case of either it's a bus
+	 * error or a termination error with no completion. 0x01 is termination
+	 * error, so we can subtract err & completed to get the real error case.
 	 */
-	stat2 = ((stat2 >> MXS_DMA_CHANNELS) & stat2) | /* (1) */
-		(~(stat2 >> MXS_DMA_CHANNELS) & stat2 & ~stat1); /* (2) */
-
-	/* combine error and completion status for checking */
-	stat1 = (stat2 << MXS_DMA_CHANNELS) | stat1;
-	while (stat1) {
-		int channel = fls(stat1) - 1;
-		struct mxs_dma_chan *mxs_chan =
-			&mxs_dma->mxs_chans[channel % MXS_DMA_CHANNELS];
-
-		if (channel >= MXS_DMA_CHANNELS) {
-			dev_dbg(mxs_dma->dma_device.dev,
-				"%s: error in channel %d\n", __func__,
-				channel - MXS_DMA_CHANNELS);
-			mxs_chan->status = DMA_ERROR;
-			mxs_dma_reset_chan(mxs_chan);
-		} else {
-			if (mxs_chan->flags & MXS_DMA_SG_LOOP)
-				mxs_chan->status = DMA_IN_PROGRESS;
-			else
-				mxs_chan->status = DMA_SUCCESS;
-		}
+	err -= err & completed;
 
-		stat1 &= ~(1 << channel);
+	mxs_chan = &mxs_dma->mxs_chans[chan];
 
-		if (mxs_chan->status == DMA_SUCCESS)
-			mxs_chan->last_completed = mxs_chan->desc.cookie;
+	if (err) {
+		dev_dbg(mxs_dma->dma_device.dev,
+			"%s: error in channel %d\n", __func__,
+			chan);
+		mxs_chan->status = DMA_ERROR;
+		mxs_dma_reset_chan(mxs_chan);
+	} else if (mxs_chan->status != DMA_COMPLETE) {
+		if (mxs_chan->flags & MXS_DMA_SG_LOOP) {
+			mxs_chan->status = DMA_IN_PROGRESS;
+			if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE)
+				writel(1, mxs_dma->base +
+					HW_APBHX_CHn_SEMA(mxs_dma, chan));
+		} else {
+			mxs_chan->status = DMA_COMPLETE;
+		}
+	}
 
-		/* schedule tasklet on this channel */
-		tasklet_schedule(&mxs_chan->tasklet);
+	if (mxs_chan->status == DMA_COMPLETE) {
+		if (mxs_chan->reset)
+			return IRQ_HANDLED;
+		dma_cookie_complete(&mxs_chan->desc);
 	}
 
+	/* schedule tasklet on this channel */
+	tasklet_schedule(&mxs_chan->tasklet);
+
 	return IRQ_HANDLED;
 }
 
 static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
 {
 	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
-	struct mxs_dma_data *data = chan->private;
 	struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
 	int ret;
 
-	if (!data)
-		return -EINVAL;
-
-	mxs_chan->chan_irq = data->chan_irq;
-
-	mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,
-				&mxs_chan->ccw_phys, GFP_KERNEL);
+	mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev,
+				CCW_BLOCK_SIZE, &mxs_chan->ccw_phys,
+				GFP_KERNEL);
 	if (!mxs_chan->ccw) {
 		ret = -ENOMEM;
 		goto err_alloc;
 	}
 
-	memset(mxs_chan->ccw, 0, PAGE_SIZE);
+	memset(mxs_chan->ccw, 0, CCW_BLOCK_SIZE);
 
 	if (mxs_chan->chan_irq != NO_IRQ) {
 		ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler,
@@ -328,7 +447,7 @@ static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
 err_clk:
 	free_irq(mxs_chan->chan_irq, mxs_dma);
 err_irq:
-	dma_free_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,
+	dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
 			mxs_chan->ccw, mxs_chan->ccw_phys);
 err_alloc:
 	return ret;
@@ -343,23 +462,46 @@ static void mxs_dma_free_chan_resources(struct dma_chan *chan)
 
 	free_irq(mxs_chan->chan_irq, mxs_dma);
 
-	dma_free_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,
+	dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE,
 			mxs_chan->ccw, mxs_chan->ccw_phys);
 
 	clk_disable_unprepare(mxs_dma->clk);
 }
 
+/*
+ * How to use the flags for ->device_prep_slave_sg() :
+ *    [1] If there is only one DMA command in the DMA chain, the code should be:
+ *            ......
+ *            ->device_prep_slave_sg(DMA_CTRL_ACK);
+ *            ......
+ *    [2] If there are two DMA commands in the DMA chain, the code should be
+ *            ......
+ *            ->device_prep_slave_sg(0);
+ *            ......
+ *            ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ *            ......
+ *    [3] If there are more than two DMA commands in the DMA chain, the code
+ *        should be:
+ *            ......
+ *            ->device_prep_slave_sg(0);                                // First
+ *            ......
+ *            ->device_prep_slave_sg(DMA_PREP_INTERRUPT [| DMA_CTRL_ACK]);
+ *            ......
+ *            ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK); // Last
+ *            ......
+ */
 static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 		struct dma_chan *chan, struct scatterlist *sgl,
 		unsigned int sg_len, enum dma_transfer_direction direction,
-		unsigned long append)
+		unsigned long flags, void *context)
 {
 	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
 	struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
 	struct mxs_dma_ccw *ccw;
 	struct scatterlist *sg;
-	int i, j;
+	u32 i, j;
 	u32 *pio;
+	bool append = flags & DMA_PREP_INTERRUPT;
 	int idx = append ? mxs_chan->desc_count : 0;
 
 	if (mxs_chan->status == DMA_IN_PROGRESS && !append)
@@ -386,7 +528,6 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 		ccw->bits |= CCW_CHAIN;
 		ccw->bits &= ~CCW_IRQ;
 		ccw->bits &= ~CCW_DEC_SEM;
-		ccw->bits &= ~CCW_WAIT4END;
 	} else {
 		idx = 0;
 	}
@@ -401,16 +542,17 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 		ccw->bits = 0;
 		ccw->bits |= CCW_IRQ;
 		ccw->bits |= CCW_DEC_SEM;
-		ccw->bits |= CCW_WAIT4END;
+		if (flags & DMA_CTRL_ACK)
+			ccw->bits |= CCW_WAIT4END;
 		ccw->bits |= CCW_HALT_ON_TERM;
 		ccw->bits |= CCW_TERM_FLUSH;
 		ccw->bits |= BF_CCW(sg_len, PIO_NUM);
 		ccw->bits |= BF_CCW(MXS_DMA_CMD_NO_XFER, COMMAND);
 	} else {
 		for_each_sg(sgl, sg, sg_len, i) {
-			if (sg->length > MAX_XFER_BYTES) {
+			if (sg_dma_len(sg) > MAX_XFER_BYTES) {
 				dev_err(mxs_dma->dma_device.dev, "maximum bytes for sg entry exceeded: %d > %d\n",
-						sg->length, MAX_XFER_BYTES);
+						sg_dma_len(sg), MAX_XFER_BYTES);
 				goto err_out;
 			}
 
@@ -418,7 +560,7 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 
 			ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx;
 			ccw->bufaddr = sg->dma_address;
-			ccw->xfer_bytes = sg->length;
+			ccw->xfer_bytes = sg_dma_len(sg);
 
 			ccw->bits = 0;
 			ccw->bits |= CCW_CHAIN;
@@ -432,7 +574,8 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 				ccw->bits &= ~CCW_CHAIN;
 				ccw->bits |= CCW_IRQ;
 				ccw->bits |= CCW_DEC_SEM;
-				ccw->bits |= CCW_WAIT4END;
+				if (flags & DMA_CTRL_ACK)
+					ccw->bits |= CCW_WAIT4END;
 			}
 		}
 	}
@@ -447,18 +590,20 @@ err_out:
 
 static struct dma_async_tx_descriptor *mxs_dma_prep_dma_cyclic(
 		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
-		size_t period_len, enum dma_transfer_direction direction)
+		size_t period_len, enum dma_transfer_direction direction,
+		unsigned long flags, void *context)
 {
 	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
 	struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
-	int num_periods = buf_len / period_len;
-	int i = 0, buf = 0;
+	u32 num_periods = buf_len / period_len;
+	u32 i = 0, buf = 0;
 
 	if (mxs_chan->status == DMA_IN_PROGRESS)
 		return NULL;
 
 	mxs_chan->status = DMA_IN_PROGRESS;
 	mxs_chan->flags |= MXS_DMA_SG_LOOP;
+	mxs_chan->flags |= MXS_DMA_USE_SEMAPHORE;
 
 	if (num_periods > NUM_CCW) {
 		dev_err(mxs_dma->dma_device.dev,
@@ -490,6 +635,7 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_dma_cyclic(
 		ccw->bits |= CCW_IRQ;
 		ccw->bits |= CCW_HALT_ON_TERM;
 		ccw->bits |= CCW_TERM_FLUSH;
+		ccw->bits |= CCW_DEC_SEM;
 		ccw->bits |= BF_CCW(direction == DMA_DEV_TO_MEM ?
 				MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ, COMMAND);
 
@@ -535,19 +681,33 @@ static enum dma_status mxs_dma_tx_status(struct dma_chan *chan,
 			dma_cookie_t cookie, struct dma_tx_state *txstate)
 {
 	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
-	dma_cookie_t last_used;
+	struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+	u32 residue = 0;
 
-	last_used = chan->cookie;
-	dma_set_tx_state(txstate, mxs_chan->last_completed, last_used, 0);
+	if (mxs_chan->status == DMA_IN_PROGRESS &&
+			mxs_chan->flags & MXS_DMA_SG_LOOP) {
+		struct mxs_dma_ccw *last_ccw;
+		u32 bar;
+
+		last_ccw = &mxs_chan->ccw[mxs_chan->desc_count - 1];
+		residue = last_ccw->xfer_bytes + last_ccw->bufaddr;
+
+		bar = readl(mxs_dma->base +
+				HW_APBHX_CHn_BAR(mxs_dma, chan->chan_id));
+		residue -= bar;
+	}
+
+	dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie,
+			residue);
 
 	return mxs_chan->status;
 }
 
 static void mxs_dma_issue_pending(struct dma_chan *chan)
 {
-	/*
-	 * Nothing to do. We only have a single descriptor.
-	 */
+	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
+
+	mxs_dma_enable_chan(mxs_chan);
 }
 
 static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
@@ -558,66 +718,111 @@ static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
 	if (ret)
 		return ret;
 
-	ret = mxs_reset_block(mxs_dma->base);
+	ret = stmp_reset_block(mxs_dma->base);
 	if (ret)
 		goto err_out;
 
-	/* only major version matters */
-	mxs_dma->version = readl(mxs_dma->base +
-				((mxs_dma->dev_id == MXS_DMA_APBX) ?
-				HW_APBX_VERSION : HW_APBH_VERSION)) >>
-				BP_APBHX_VERSION_MAJOR;
-
 	/* enable apbh burst */
-	if (dma_is_apbh()) {
+	if (dma_is_apbh(mxs_dma)) {
 		writel(BM_APBH_CTRL0_APB_BURST_EN,
-			mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
+			mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
 		writel(BM_APBH_CTRL0_APB_BURST8_EN,
-			mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
+			mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET);
 	}
 
 	/* enable irq for all the channels */
 	writel(MXS_DMA_CHANNELS_MASK << MXS_DMA_CHANNELS,
-		mxs_dma->base + HW_APBHX_CTRL1 + MXS_SET_ADDR);
+		mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_SET);
 
 err_out:
 	clk_disable_unprepare(mxs_dma->clk);
 	return ret;
 }
 
+struct mxs_dma_filter_param {
+	struct device_node *of_node;
+	unsigned int chan_id;
+};
+
+static bool mxs_dma_filter_fn(struct dma_chan *chan, void *fn_param)
+{
+	struct mxs_dma_filter_param *param = fn_param;
+	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
+	struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+	int chan_irq;
+
+	if (mxs_dma->dma_device.dev->of_node != param->of_node)
+		return false;
+
+	if (chan->chan_id != param->chan_id)
+		return false;
+
+	chan_irq = platform_get_irq(mxs_dma->pdev, param->chan_id);
+	if (chan_irq < 0)
+		return false;
+
+	mxs_chan->chan_irq = chan_irq;
+
+	return true;
+}
+
+static struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec,
+			       struct of_dma *ofdma)
+{
+	struct mxs_dma_engine *mxs_dma = ofdma->of_dma_data;
+	dma_cap_mask_t mask = mxs_dma->dma_device.cap_mask;
+	struct mxs_dma_filter_param param;
+
+	if (dma_spec->args_count != 1)
+		return NULL;
+
+	param.of_node = ofdma->of_node;
+	param.chan_id = dma_spec->args[0];
+
+	if (param.chan_id >= mxs_dma->nr_channels)
+		return NULL;
+
+	return dma_request_channel(mask, mxs_dma_filter_fn, &param);
+}
+
 static int __init mxs_dma_probe(struct platform_device *pdev)
 {
-	const struct platform_device_id *id_entry =
-				platform_get_device_id(pdev);
+	struct device_node *np = pdev->dev.of_node;
+	const struct platform_device_id *id_entry;
+	const struct of_device_id *of_id;
+	const struct mxs_dma_type *dma_type;
 	struct mxs_dma_engine *mxs_dma;
 	struct resource *iores;
 	int ret, i;
 
-	mxs_dma = kzalloc(sizeof(*mxs_dma), GFP_KERNEL);
+	mxs_dma = devm_kzalloc(&pdev->dev, sizeof(*mxs_dma), GFP_KERNEL);
 	if (!mxs_dma)
 		return -ENOMEM;
 
-	mxs_dma->dev_id = id_entry->driver_data;
+	ret = of_property_read_u32(np, "dma-channels", &mxs_dma->nr_channels);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to read dma-channels\n");
+		return ret;
+	}
 
-	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	of_id = of_match_device(mxs_dma_dt_ids, &pdev->dev);
+	if (of_id)
+		id_entry = of_id->data;
+	else
+		id_entry = platform_get_device_id(pdev);
 
-	if (!request_mem_region(iores->start, resource_size(iores),
-				pdev->name)) {
-		ret = -EBUSY;
-		goto err_request_region;
-	}
+	dma_type = (struct mxs_dma_type *)id_entry->driver_data;
+	mxs_dma->type = dma_type->type;
+	mxs_dma->dev_id = dma_type->id;
 
-	mxs_dma->base = ioremap(iores->start, resource_size(iores));
-	if (!mxs_dma->base) {
-		ret = -ENOMEM;
-		goto err_ioremap;
-	}
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mxs_dma->base = devm_ioremap_resource(&pdev->dev, iores);
+	if (IS_ERR(mxs_dma->base))
+		return PTR_ERR(mxs_dma->base);
 
-	mxs_dma->clk = clk_get(&pdev->dev, NULL);
-	if (IS_ERR(mxs_dma->clk)) {
-		ret = PTR_ERR(mxs_dma->clk);
-		goto err_clk;
-	}
+	mxs_dma->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(mxs_dma->clk))
+		return PTR_ERR(mxs_dma->clk);
 
 	dma_cap_set(DMA_SLAVE, mxs_dma->dma_device.cap_mask);
 	dma_cap_set(DMA_CYCLIC, mxs_dma->dma_device.cap_mask);
@@ -630,6 +835,7 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
 
 		mxs_chan->mxs_dma = mxs_dma;
 		mxs_chan->chan.device = &mxs_dma->dma_device;
+		dma_cookie_init(&mxs_chan->chan);
 
 		tasklet_init(&mxs_chan->tasklet, mxs_dma_tasklet,
 			     (unsigned long) mxs_chan);
@@ -642,8 +848,9 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
 
 	ret = mxs_dma_init(mxs_dma);
 	if (ret)
-		goto err_init;
+		return ret;
 
+	mxs_dma->pdev = pdev;
 	mxs_dma->dma_device.dev = &pdev->dev;
 
 	/* mxs_dma gets 65535 bytes maximum sg size */
@@ -661,41 +868,27 @@ static int __init mxs_dma_probe(struct platform_device *pdev)
 	ret = dma_async_device_register(&mxs_dma->dma_device);
 	if (ret) {
 		dev_err(mxs_dma->dma_device.dev, "unable to register\n");
-		goto err_init;
+		return ret;
+	}
+
+	ret = of_dma_controller_register(np, mxs_dma_xlate, mxs_dma);
+	if (ret) {
+		dev_err(mxs_dma->dma_device.dev,
+			"failed to register controller\n");
+		dma_async_device_unregister(&mxs_dma->dma_device);
 	}
 
 	dev_info(mxs_dma->dma_device.dev, "initialized\n");
 
 	return 0;
-
-err_init:
-	clk_put(mxs_dma->clk);
-err_clk:
-	iounmap(mxs_dma->base);
-err_ioremap:
-	release_mem_region(iores->start, resource_size(iores));
-err_request_region:
-	kfree(mxs_dma);
-	return ret;
 }
 
-static struct platform_device_id mxs_dma_type[] = {
-	{
-		.name = "mxs-dma-apbh",
-		.driver_data = MXS_DMA_APBH,
-	}, {
-		.name = "mxs-dma-apbx",
-		.driver_data = MXS_DMA_APBX,
-	}, {
-		/* end of list */
-	}
-};
-
 static struct platform_driver mxs_dma_driver = {
 	.driver		= {
 		.name	= "mxs-dma",
+		.of_match_table = mxs_dma_dt_ids,
 	},
-	.id_table	= mxs_dma_type,
+	.id_table	= mxs_dma_ids,
 };
 
 static int __init mxs_dma_module_init(void)