dma: move shdma driver to an own directory

The shdma driver is going to be split into multiple files. To make this more
convenient move it to an own directory.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

3 files changed, 1591 insertions, 0 deletions

diff --git a/drivers/dma/sh/Makefile b/drivers/dma/sh/Makefile
new file mode 100644
index 000000000000..ad4981af38b2
--- /dev/null
+++ b/drivers/dma/sh/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_SH_DMAE) += shdma.o
diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
new file mode 100644
index 000000000000..8ab4a1f5d3c1
--- /dev/null
+++ b/drivers/dma/sh/shdma.c
@@ -0,0 +1,1524 @@
+/*
+ * Renesas SuperH DMA Engine support
+ *
+ * base is drivers/dma/flsdma.c
+ *
+ * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
+ * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
+ * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * - DMA of SuperH does not have Hardware DMA chain mode.
+ * - MAX DMA size is 16MB.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/sh_dma.h>
+#include <linux/notifier.h>
+#include <linux/kdebug.h>
+#include <linux/spinlock.h>
+#include <linux/rculist.h>
+
+#include "../dmaengine.h"
+#include "shdma.h"
+
+/* DMA descriptor control */
+enum sh_dmae_desc_status {
+	DESC_IDLE,
+	DESC_PREPARED,
+	DESC_SUBMITTED,
+	DESC_COMPLETED,	/* completed, have to call callback */
+	DESC_WAITING,	/* callback called, waiting for ack / re-submit */
+};
+
+#define NR_DESCS_PER_CHANNEL 32
+/* Default MEMCPY transfer size = 2^2 = 4 bytes */
+#define LOG2_DEFAULT_XFER_SIZE	2
+
+/*
+ * Used for write-side mutual exclusion for the global device list,
+ * read-side synchronization by way of RCU, and per-controller data.
+ */
+static DEFINE_SPINLOCK(sh_dmae_lock);
+static LIST_HEAD(sh_dmae_devices);
+
+/* A bitmask with bits enough for enum sh_dmae_slave_chan_id */
+static unsigned long sh_dmae_slave_used[BITS_TO_LONGS(SH_DMA_SLAVE_NUMBER)];
+
+static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all);
+static void sh_chan_xfer_ld_queue(struct sh_dmae_chan *sh_chan);
+
+static void chclr_write(struct sh_dmae_chan *sh_dc, u32 data)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
+
+	__raw_writel(data, shdev->chan_reg +
+		     shdev->pdata->channel[sh_dc->id].chclr_offset);
+}
+
+static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
+{
+	__raw_writel(data, sh_dc->base + reg / sizeof(u32));
+}
+
+static u32 sh_dmae_readl(struct sh_dmae_chan *sh_dc, u32 reg)
+{
+	return __raw_readl(sh_dc->base + reg / sizeof(u32));
+}
+
+static u16 dmaor_read(struct sh_dmae_device *shdev)
+{
+	u32 __iomem *addr = shdev->chan_reg + DMAOR / sizeof(u32);
+
+	if (shdev->pdata->dmaor_is_32bit)
+		return __raw_readl(addr);
+	else
+		return __raw_readw(addr);
+}
+
+static void dmaor_write(struct sh_dmae_device *shdev, u16 data)
+{
+	u32 __iomem *addr = shdev->chan_reg + DMAOR / sizeof(u32);
+
+	if (shdev->pdata->dmaor_is_32bit)
+		__raw_writel(data, addr);
+	else
+		__raw_writew(data, addr);
+}
+
+static void chcr_write(struct sh_dmae_chan *sh_dc, u32 data)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
+
+	__raw_writel(data, sh_dc->base + shdev->chcr_offset / sizeof(u32));
+}
+
+static u32 chcr_read(struct sh_dmae_chan *sh_dc)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
+
+	return __raw_readl(sh_dc->base + shdev->chcr_offset / sizeof(u32));
+}
+
+/*
+ * Reset DMA controller
+ *
+ * SH7780 has two DMAOR register
+ */
+static void sh_dmae_ctl_stop(struct sh_dmae_device *shdev)
+{
+	unsigned short dmaor;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sh_dmae_lock, flags);
+
+	dmaor = dmaor_read(shdev);
+	dmaor_write(shdev, dmaor & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME));
+
+	spin_unlock_irqrestore(&sh_dmae_lock, flags);
+}
+
+static int sh_dmae_rst(struct sh_dmae_device *shdev)
+{
+	unsigned short dmaor;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sh_dmae_lock, flags);
+
+	dmaor = dmaor_read(shdev) & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME);
+
+	if (shdev->pdata->chclr_present) {
+		int i;
+		for (i = 0; i < shdev->pdata->channel_num; i++) {
+			struct sh_dmae_chan *sh_chan = shdev->chan[i];
+			if (sh_chan)
+				chclr_write(sh_chan, 0);
+		}
+	}
+
+	dmaor_write(shdev, dmaor | shdev->pdata->dmaor_init);
+
+	dmaor = dmaor_read(shdev);
+
+	spin_unlock_irqrestore(&sh_dmae_lock, flags);
+
+	if (dmaor & (DMAOR_AE | DMAOR_NMIF)) {
+		dev_warn(shdev->common.dev, "Can't initialize DMAOR.\n");
+		return -EIO;
+	}
+	if (shdev->pdata->dmaor_init & ~dmaor)
+		dev_warn(shdev->common.dev,
+			 "DMAOR=0x%x hasn't latched the initial value 0x%x.\n",
+			 dmaor, shdev->pdata->dmaor_init);
+	return 0;
+}
+
+static bool dmae_is_busy(struct sh_dmae_chan *sh_chan)
+{
+	u32 chcr = chcr_read(sh_chan);
+
+	if ((chcr & (CHCR_DE | CHCR_TE)) == CHCR_DE)
+		return true; /* working */
+
+	return false; /* waiting */
+}
+
+static unsigned int calc_xmit_shift(struct sh_dmae_chan *sh_chan, u32 chcr)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	struct sh_dmae_pdata *pdata = shdev->pdata;
+	int cnt = ((chcr & pdata->ts_low_mask) >> pdata->ts_low_shift) |
+		((chcr & pdata->ts_high_mask) >> pdata->ts_high_shift);
+
+	if (cnt >= pdata->ts_shift_num)
+		cnt = 0;
+
+	return pdata->ts_shift[cnt];
+}
+
+static u32 log2size_to_chcr(struct sh_dmae_chan *sh_chan, int l2size)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	struct sh_dmae_pdata *pdata = shdev->pdata;
+	int i;
+
+	for (i = 0; i < pdata->ts_shift_num; i++)
+		if (pdata->ts_shift[i] == l2size)
+			break;
+
+	if (i == pdata->ts_shift_num)
+		i = 0;
+
+	return ((i << pdata->ts_low_shift) & pdata->ts_low_mask) |
+		((i << pdata->ts_high_shift) & pdata->ts_high_mask);
+}
+
+static void dmae_set_reg(struct sh_dmae_chan *sh_chan, struct sh_dmae_regs *hw)
+{
+	sh_dmae_writel(sh_chan, hw->sar, SAR);
+	sh_dmae_writel(sh_chan, hw->dar, DAR);
+	sh_dmae_writel(sh_chan, hw->tcr >> sh_chan->xmit_shift, TCR);
+}
+
+static void dmae_start(struct sh_dmae_chan *sh_chan)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	u32 chcr = chcr_read(sh_chan);
+
+	if (shdev->pdata->needs_tend_set)
+		sh_dmae_writel(sh_chan, 0xFFFFFFFF, TEND);
+
+	chcr |= CHCR_DE | shdev->chcr_ie_bit;
+	chcr_write(sh_chan, chcr & ~CHCR_TE);
+}
+
+static void dmae_halt(struct sh_dmae_chan *sh_chan)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	u32 chcr = chcr_read(sh_chan);
+
+	chcr &= ~(CHCR_DE | CHCR_TE | shdev->chcr_ie_bit);
+	chcr_write(sh_chan, chcr);
+}
+
+static void dmae_init(struct sh_dmae_chan *sh_chan)
+{
+	/*
+	 * Default configuration for dual address memory-memory transfer.
+	 * 0x400 represents auto-request.
+	 */
+	u32 chcr = DM_INC | SM_INC | 0x400 | log2size_to_chcr(sh_chan,
+						   LOG2_DEFAULT_XFER_SIZE);
+	sh_chan->xmit_shift = calc_xmit_shift(sh_chan, chcr);
+	chcr_write(sh_chan, chcr);
+}
+
+static int dmae_set_chcr(struct sh_dmae_chan *sh_chan, u32 val)
+{
+	/* If DMA is active, cannot set CHCR. TODO: remove this superfluous check */
+	if (dmae_is_busy(sh_chan))
+		return -EBUSY;
+
+	sh_chan->xmit_shift = calc_xmit_shift(sh_chan, val);
+	chcr_write(sh_chan, val);
+
+	return 0;
+}
+
+static int dmae_set_dmars(struct sh_dmae_chan *sh_chan, u16 val)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	struct sh_dmae_pdata *pdata = shdev->pdata;
+	const struct sh_dmae_channel *chan_pdata = &pdata->channel[sh_chan->id];
+	u16 __iomem *addr = shdev->dmars;
+	unsigned int shift = chan_pdata->dmars_bit;
+
+	if (dmae_is_busy(sh_chan))
+		return -EBUSY;
+
+	if (pdata->no_dmars)
+		return 0;
+
+	/* in the case of a missing DMARS resource use first memory window */
+	if (!addr)
+		addr = (u16 __iomem *)shdev->chan_reg;
+	addr += chan_pdata->dmars / sizeof(u16);
+
+	__raw_writew((__raw_readw(addr) & (0xff00 >> shift)) | (val << shift),
+		     addr);
+
+	return 0;
+}
+
+static dma_cookie_t sh_dmae_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct sh_desc *desc = tx_to_sh_desc(tx), *chunk, *last = desc, *c;
+	struct sh_dmae_chan *sh_chan = to_sh_chan(tx->chan);
+	struct sh_dmae_slave *param = tx->chan->private;
+	dma_async_tx_callback callback = tx->callback;
+	dma_cookie_t cookie;
+	bool power_up;
+
+	spin_lock_irq(&sh_chan->desc_lock);
+
+	if (list_empty(&sh_chan->ld_queue))
+		power_up = true;
+	else
+		power_up = false;
+
+	cookie = dma_cookie_assign(tx);
+
+	/* Mark all chunks of this descriptor as submitted, move to the queue */
+	list_for_each_entry_safe(chunk, c, desc->node.prev, node) {
+		/*
+		 * All chunks are on the global ld_free, so, we have to find
+		 * the end of the chain ourselves
+		 */
+		if (chunk != desc && (chunk->mark == DESC_IDLE ||
+				      chunk->async_tx.cookie > 0 ||
+				      chunk->async_tx.cookie == -EBUSY ||
+				      &chunk->node == &sh_chan->ld_free))
+			break;
+		chunk->mark = DESC_SUBMITTED;
+		/* Callback goes to the last chunk */
+		chunk->async_tx.callback = NULL;
+		chunk->cookie = cookie;
+		list_move_tail(&chunk->node, &sh_chan->ld_queue);
+		last = chunk;
+	}
+
+	last->async_tx.callback = callback;
+	last->async_tx.callback_param = tx->callback_param;
+
+	dev_dbg(sh_chan->dev, "submit #%d@%p on %d: %x[%d] -> %x\n",
+		tx->cookie, &last->async_tx, sh_chan->id,
+		desc->hw.sar, desc->hw.tcr, desc->hw.dar);
+
+	if (power_up) {
+		sh_chan->pm_state = DMAE_PM_BUSY;
+
+		pm_runtime_get(sh_chan->dev);
+
+		spin_unlock_irq(&sh_chan->desc_lock);
+
+		pm_runtime_barrier(sh_chan->dev);
+
+		spin_lock_irq(&sh_chan->desc_lock);
+
+		/* Have we been reset, while waiting? */
+		if (sh_chan->pm_state != DMAE_PM_ESTABLISHED) {
+			dev_dbg(sh_chan->dev, "Bring up channel %d\n",
+				sh_chan->id);
+			if (param) {
+				const struct sh_dmae_slave_config *cfg =
+					param->config;
+
+				dmae_set_dmars(sh_chan, cfg->mid_rid);
+				dmae_set_chcr(sh_chan, cfg->chcr);
+			} else {
+				dmae_init(sh_chan);
+			}
+
+			if (sh_chan->pm_state == DMAE_PM_PENDING)
+				sh_chan_xfer_ld_queue(sh_chan);
+			sh_chan->pm_state = DMAE_PM_ESTABLISHED;
+		}
+	} else {
+		sh_chan->pm_state = DMAE_PM_PENDING;
+	}
+
+	spin_unlock_irq(&sh_chan->desc_lock);
+
+	return cookie;
+}
+
+/* Called with desc_lock held */
+static struct sh_desc *sh_dmae_get_desc(struct sh_dmae_chan *sh_chan)
+{
+	struct sh_desc *desc;
+
+	list_for_each_entry(desc, &sh_chan->ld_free, node)
+		if (desc->mark != DESC_PREPARED) {
+			BUG_ON(desc->mark != DESC_IDLE);
+			list_del(&desc->node);
+			return desc;
+		}
+
+	return NULL;
+}
+
+static const struct sh_dmae_slave_config *sh_dmae_find_slave(
+	struct sh_dmae_chan *sh_chan, struct sh_dmae_slave *param)
+{
+	struct sh_dmae_device *shdev = to_sh_dev(sh_chan);
+	struct sh_dmae_pdata *pdata = shdev->pdata;
+	int i;
+
+	if (param->slave_id >= SH_DMA_SLAVE_NUMBER)
+		return NULL;
+
+	for (i = 0; i < pdata->slave_num; i++)
+		if (pdata->slave[i].slave_id == param->slave_id)
+			return pdata->slave + i;
+
+	return NULL;
+}
+
+static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
+	struct sh_desc *desc;
+	struct sh_dmae_slave *param = chan->private;
+	int ret;
+
+	/*
+	 * This relies on the guarantee from dmaengine that alloc_chan_resources
+	 * never runs concurrently with itself or free_chan_resources.
+	 */
+	if (param) {
+		const struct sh_dmae_slave_config *cfg;
+
+		cfg = sh_dmae_find_slave(sh_chan, param);
+		if (!cfg) {
+			ret = -EINVAL;
+			goto efindslave;
+		}
+
+		if (test_and_set_bit(param->slave_id, sh_dmae_slave_used)) {
+			ret = -EBUSY;
+			goto etestused;
+		}
+
+		param->config = cfg;
+	}
+
+	while (sh_chan->descs_allocated < NR_DESCS_PER_CHANNEL) {
+		desc = kzalloc(sizeof(struct sh_desc), GFP_KERNEL);
+		if (!desc)
+			break;
+		dma_async_tx_descriptor_init(&desc->async_tx,
+					&sh_chan->common);
+		desc->async_tx.tx_submit = sh_dmae_tx_submit;
+		desc->mark = DESC_IDLE;
+
+		list_add(&desc->node, &sh_chan->ld_free);
+		sh_chan->descs_allocated++;
+	}
+
+	if (!sh_chan->descs_allocated) {
+		ret = -ENOMEM;
+		goto edescalloc;
+	}
+
+	return sh_chan->descs_allocated;
+
+edescalloc:
+	if (param)
+		clear_bit(param->slave_id, sh_dmae_slave_used);
+etestused:
+efindslave:
+	chan->private = NULL;
+	return ret;
+}
+
+/*
+ * sh_dma_free_chan_resources - Free all resources of the channel.
+ */
+static void sh_dmae_free_chan_resources(struct dma_chan *chan)
+{
+	struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
+	struct sh_desc *desc, *_desc;
+	LIST_HEAD(list);
+
+	/* Protect against ISR */
+	spin_lock_irq(&sh_chan->desc_lock);
+	dmae_halt(sh_chan);
+	spin_unlock_irq(&sh_chan->desc_lock);
+
+	/* Now no new interrupts will occur */
+
+	/* Prepared and not submitted descriptors can still be on the queue */
+	if (!list_empty(&sh_chan->ld_queue))
+		sh_dmae_chan_ld_cleanup(sh_chan, true);
+
+	if (chan->private) {
+		/* The caller is holding dma_list_mutex */
+		struct sh_dmae_slave *param = chan->private;
+		clear_bit(param->slave_id, sh_dmae_slave_used);
+		chan->private = NULL;
+	}
+
+	spin_lock_irq(&sh_chan->desc_lock);
+
+	list_splice_init(&sh_chan->ld_free, &list);
+	sh_chan->descs_allocated = 0;
+
+	spin_unlock_irq(&sh_chan->desc_lock);
+
+	list_for_each_entry_safe(desc, _desc, &list, node)
+		kfree(desc);
+}
+
+/**
+ * sh_dmae_add_desc - get, set up and return one transfer descriptor
+ * @sh_chan:	DMA channel
+ * @flags:	DMA transfer flags
+ * @dest:	destination DMA address, incremented when direction equals
+ *		DMA_DEV_TO_MEM
+ * @src:	source DMA address, incremented when direction equals
+ *		DMA_MEM_TO_DEV
+ * @len:	DMA transfer length
+ * @first:	if NULL, set to the current descriptor and cookie set to -EBUSY
+ * @direction:	needed for slave DMA to decide which address to keep constant,
+ *		equals DMA_MEM_TO_MEM for MEMCPY
+ * Returns 0 or an error
+ * Locks: called with desc_lock held
+ */
+static struct sh_desc *sh_dmae_add_desc(struct sh_dmae_chan *sh_chan,
+	unsigned long flags, dma_addr_t *dest, dma_addr_t *src, size_t *len,
+	struct sh_desc **first, enum dma_transfer_direction direction)
+{
+	struct sh_desc *new;
+	size_t copy_size;
+
+	if (!*len)
+		return NULL;
+
+	/* Allocate the link descriptor from the free list */
+	new = sh_dmae_get_desc(sh_chan);
+	if (!new) {
+		dev_err(sh_chan->dev, "No free link descriptor available\n");
+		return NULL;
+	}
+
+	copy_size = min(*len, (size_t)SH_DMA_TCR_MAX + 1);
+
+	new->hw.sar = *src;
+	new->hw.dar = *dest;
+	new->hw.tcr = copy_size;
+
+	if (!*first) {
+		/* First desc */
+		new->async_tx.cookie = -EBUSY;
+		*first = new;
+	} else {
+		/* Other desc - invisible to the user */
+		new->async_tx.cookie = -EINVAL;
+	}
+
+	dev_dbg(sh_chan->dev,
+		"chaining (%u/%u)@%x -> %x with %p, cookie %d, shift %d\n",
+		copy_size, *len, *src, *dest, &new->async_tx,
+		new->async_tx.cookie, sh_chan->xmit_shift);
+
+	new->mark = DESC_PREPARED;
+	new->async_tx.flags = flags;
+	new->direction = direction;
+
+	*len -= copy_size;
+	if (direction == DMA_MEM_TO_MEM || direction == DMA_MEM_TO_DEV)
+		*src += copy_size;
+	if (direction == DMA_MEM_TO_MEM || direction == DMA_DEV_TO_MEM)
+		*dest += copy_size;
+
+	return new;
+}
+
+/*
+ * sh_dmae_prep_sg - prepare transfer descriptors from an SG list
+ *
+ * Common routine for public (MEMCPY) and slave DMA. The MEMCPY case is also
+ * converted to scatter-gather to guarantee consistent locking and a correct
+ * list manipulation. For slave DMA direction carries the usual meaning, and,
+ * logically, the SG list is RAM and the addr variable contains slave address,
+ * e.g., the FIFO I/O register. For MEMCPY direction equals DMA_MEM_TO_MEM
+ * and the SG list contains only one element and points at the source buffer.
+ */
+static struct dma_async_tx_descriptor *sh_dmae_prep_sg(struct sh_dmae_chan *sh_chan,
+	struct scatterlist *sgl, unsigned int sg_len, dma_addr_t *addr,
+	enum dma_transfer_direction direction, unsigned long flags)
+{
+	struct scatterlist *sg;
+	struct sh_desc *first = NULL, *new = NULL /* compiler... */;
+	LIST_HEAD(tx_list);
+	int chunks = 0;
+	unsigned long irq_flags;
+	int i;
+
+	if (!sg_len)
+		return NULL;
+
+	for_each_sg(sgl, sg, sg_len, i)
+		chunks += (sg_dma_len(sg) + SH_DMA_TCR_MAX) /
+			(SH_DMA_TCR_MAX + 1);
+
+	/* Have to lock the whole loop to protect against concurrent release */
+	spin_lock_irqsave(&sh_chan->desc_lock, irq_flags);
+
+	/*
+	 * Chaining:
+	 * first descriptor is what user is dealing with in all API calls, its
+	 *	cookie is at first set to -EBUSY, at tx-submit to a positive
+	 *	number
+	 * if more than one chunk is needed further chunks have cookie = -EINVAL
+	 * the last chunk, if not equal to the first, has cookie = -ENOSPC
+	 * all chunks are linked onto the tx_list head with their .node heads
+	 *	only during this function, then they are immediately spliced
+	 *	back onto the free list in form of a chain
+	 */
+	for_each_sg(sgl, sg, sg_len, i) {
+		dma_addr_t sg_addr = sg_dma_address(sg);
+		size_t len = sg_dma_len(sg);
+
+		if (!len)
+			goto err_get_desc;
+
+		do {
+			dev_dbg(sh_chan->dev, "Add SG #%d@%p[%d], dma %llx\n",
+				i, sg, len, (unsigned long long)sg_addr);
+
+			if (direction == DMA_DEV_TO_MEM)
+				new = sh_dmae_add_desc(sh_chan, flags,
+						&sg_addr, addr, &len, &first,
+						direction);
+			else
+				new = sh_dmae_add_desc(sh_chan, flags,
+						addr, &sg_addr, &len, &first,
+						direction);
+			if (!new)
+				goto err_get_desc;
+
+			new->chunks = chunks--;
+			list_add_tail(&new->node, &tx_list);
+		} while (len);
+	}
+
+	if (new != first)
+		new->async_tx.cookie = -ENOSPC;
+
+	/* Put them back on the free list, so, they don't get lost */
+	list_splice_tail(&tx_list, &sh_chan->ld_free);
+
+	spin_unlock_irqrestore(&sh_chan->desc_lock, irq_flags);
+
+	return &first->async_tx;
+
+err_get_desc:
+	list_for_each_entry(new, &tx_list, node)
+		new->mark = DESC_IDLE;
+	list_splice(&tx_list, &sh_chan->ld_free);
+
+	spin_unlock_irqrestore(&sh_chan->desc_lock, irq_flags);
+
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *sh_dmae_prep_memcpy(
+	struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src,
+	size_t len, unsigned long flags)
+{
+	struct sh_dmae_chan *sh_chan;
+	struct scatterlist sg;
+
+	if (!chan || !len)
+		return NULL;
+
+	sh_chan = to_sh_chan(chan);
+
+	sg_init_table(&sg, 1);
+	sg_set_page(&sg, pfn_to_page(PFN_DOWN(dma_src)), len,
+		    offset_in_page(dma_src));
+	sg_dma_address(&sg) = dma_src;
+	sg_dma_len(&sg) = len;
+
+	return sh_dmae_prep_sg(sh_chan, &sg, 1, &dma_dest, DMA_MEM_TO_MEM,
+			       flags);
+}
+
+static struct dma_async_tx_descriptor *sh_dmae_prep_slave_sg(
+	struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len,
+	enum dma_transfer_direction direction, unsigned long flags,
+	void *context)
+{
+	struct sh_dmae_slave *param;
+	struct sh_dmae_chan *sh_chan;
+	dma_addr_t slave_addr;
+
+	if (!chan)
+		return NULL;
+
+	sh_chan = to_sh_chan(chan);
+	param = chan->private;
+
+	/* Someone calling slave DMA on a public channel? */
+	if (!param || !sg_len) {
+		dev_warn(sh_chan->dev, "%s: bad parameter: %p, %d, %d\n",
+			 __func__, param, sg_len, param ? param->slave_id : -1);
+		return NULL;
+	}
+
+	slave_addr = param->config->addr;
+
+	/*
+	 * if (param != NULL), this is a successfully requested slave channel,
+	 * therefore param->config != NULL too.
+	 */
+	return sh_dmae_prep_sg(sh_chan, sgl, sg_len, &slave_addr,
+			       direction, flags);
+}
+
+static int sh_dmae_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+			   unsigned long arg)
+{
+	struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
+	unsigned long flags;
+
+	/* Only supports DMA_TERMINATE_ALL */
+	if (cmd != DMA_TERMINATE_ALL)
+		return -ENXIO;
+
+	if (!chan)
+		return -EINVAL;
+
+	spin_lock_irqsave(&sh_chan->desc_lock, flags);
+	dmae_halt(sh_chan);
+
+	if (!list_empty(&sh_chan->ld_queue)) {
+		/* Record partial transfer */
+		struct sh_desc *desc = list_entry(sh_chan->ld_queue.next,
+						  struct sh_desc, node);
+		desc->partial = (desc->hw.tcr - sh_dmae_readl(sh_chan, TCR)) <<
+			sh_chan->xmit_shift;
+	}
+	spin_unlock_irqrestore(&sh_chan->desc_lock, flags);
+
+	sh_dmae_chan_ld_cleanup(sh_chan, true);
+
+	return 0;
+}
+
+static dma_async_tx_callback __ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
+{
+	struct sh_desc *desc, *_desc;
+	/* Is the "exposed" head of a chain acked? */
+	bool head_acked = false;
+	dma_cookie_t cookie = 0;
+	dma_async_tx_callback callback = NULL;
+	void *param = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sh_chan->desc_lock, flags);
+	list_for_each_entry_safe(desc, _desc, &sh_chan->ld_queue, node) {
+		struct dma_async_tx_descriptor *tx = &desc->async_tx;
+
+		BUG_ON(tx->cookie > 0 && tx->cookie != desc->cookie);
+		BUG_ON(desc->mark != DESC_SUBMITTED &&
+		       desc->mark != DESC_COMPLETED &&
+		       desc->mark != DESC_WAITING);
+
+		/*
+		 * queue is ordered, and we use this loop to (1) clean up all
+		 * completed descriptors, and to (2) update descriptor flags of
+		 * any chunks in a (partially) completed chain
+		 */
+		if (!all && desc->mark == DESC_SUBMITTED &&
+		    desc->cookie != cookie)
+			break;
+
+		if (tx->cookie > 0)
+			cookie = tx->cookie;
+
+		if (desc->mark == DESC_COMPLETED && desc->chunks == 1) {
+			if (sh_chan->common.completed_cookie != desc->cookie - 1)
+				dev_dbg(sh_chan->dev,
+					"Completing cookie %d, expected %d\n",
+					desc->cookie,
+					sh_chan->common.completed_cookie + 1);
+			sh_chan->common.completed_cookie = desc->cookie;
+		}
+
+		/* Call callback on the last chunk */
+		if (desc->mark == DESC_COMPLETED && tx->callback) {
+			desc->mark = DESC_WAITING;
+			callback = tx->callback;
+			param = tx->callback_param;
+			dev_dbg(sh_chan->dev, "descriptor #%d@%p on %d callback\n",
+				tx->cookie, tx, sh_chan->id);
+			BUG_ON(desc->chunks != 1);
+			break;
+		}
+
+		if (tx->cookie > 0 || tx->cookie == -EBUSY) {
+			if (desc->mark == DESC_COMPLETED) {
+				BUG_ON(tx->cookie < 0);
+				desc->mark = DESC_WAITING;
+			}
+			head_acked = async_tx_test_ack(tx);
+		} else {
+			switch (desc->mark) {
+			case DESC_COMPLETED:
+				desc->mark = DESC_WAITING;
+				/* Fall through */
+			case DESC_WAITING:
+				if (head_acked)
+					async_tx_ack(&desc->async_tx);
+			}
+		}
+
+		dev_dbg(sh_chan->dev, "descriptor %p #%d completed.\n",
+			tx, tx->cookie);
+
+		if (((desc->mark == DESC_COMPLETED ||
+		      desc->mark == DESC_WAITING) &&
+		     async_tx_test_ack(&desc->async_tx)) || all) {
+			/* Remove from ld_queue list */
+			desc->mark = DESC_IDLE;
+
+			list_move(&desc->node, &sh_chan->ld_free);
+
+			if (list_empty(&sh_chan->ld_queue)) {
+				dev_dbg(sh_chan->dev, "Bring down channel %d\n", sh_chan->id);
+				pm_runtime_put(sh_chan->dev);
+			}
+		}
+	}
+
+	if (all && !callback)
+		/*
+		 * Terminating and the loop completed normally: forgive
+		 * uncompleted cookies
+		 */
+		sh_chan->common.completed_cookie = sh_chan->common.cookie;
+
+	spin_unlock_irqrestore(&sh_chan->desc_lock, flags);
+
+	if (callback)
+		callback(param);
+
+	return callback;
+}
+
+/*
+ * sh_chan_ld_cleanup - Clean up link descriptors
+ *
+ * This function cleans up the ld_queue of DMA channel.
+ */
+static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all)
+{
+	while (__ld_cleanup(sh_chan, all))
+		;
+}
+
+/* Called under spin_lock_irq(&sh_chan->desc_lock) */
+static void sh_chan_xfer_ld_queue(struct sh_dmae_chan *sh_chan)
+{
+	struct sh_desc *desc;
+
+	/* DMA work check */
+	if (dmae_is_busy(sh_chan))
+		return;
+
+	/* Find the first not transferred descriptor */
+	list_for_each_entry(desc, &sh_chan->ld_queue, node)
+		if (desc->mark == DESC_SUBMITTED) {
+			dev_dbg(sh_chan->dev, "Queue #%d to %d: %u@%x -> %x\n",
+				desc->async_tx.cookie, sh_chan->id,
+				desc->hw.tcr, desc->hw.sar, desc->hw.dar);
+			/* Get the ld start address from ld_queue */
+			dmae_set_reg(sh_chan, &desc->hw);
+			dmae_start(sh_chan);
+			break;
+		}
+}
+
+static void sh_dmae_memcpy_issue_pending(struct dma_chan *chan)
+{
+	struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
+
+	spin_lock_irq(&sh_chan->desc_lock);
+	if (sh_chan->pm_state == DMAE_PM_ESTABLISHED)
+		sh_chan_xfer_ld_queue(sh_chan);
+	else
+		sh_chan->pm_state = DMAE_PM_PENDING;
+	spin_unlock_irq(&sh_chan->desc_lock);
+}
+
+static enum dma_status sh_dmae_tx_status(struct dma_chan *chan,
+					dma_cookie_t cookie,
+					struct dma_tx_state *txstate)
+{
+	struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
+	enum dma_status status;
+	unsigned long flags;
+
+	sh_dmae_chan_ld_cleanup(sh_chan, false);
+
+	spin_lock_irqsave(&sh_chan->desc_lock, flags);
+
+	status = dma_cookie_status(chan, cookie, txstate);
+
+	/*
+	 * If we don't find cookie on the queue, it has been aborted and we have
+	 * to report error
+	 */
+	if (status != DMA_SUCCESS) {
+		struct sh_desc *desc;
+		status = DMA_ERROR;
+		list_for_each_entry(desc, &sh_chan->ld_queue, node)
+			if (desc->cookie == cookie) {
+				status = DMA_IN_PROGRESS;
+				break;
+			}
+	}
+
+	spin_unlock_irqrestore(&sh_chan->desc_lock, flags);
+
+	return status;
+}
+
+static irqreturn_t sh_dmae_interrupt(int irq, void *data)
+{
+	irqreturn_t ret = IRQ_NONE;
+	struct sh_dmae_chan *sh_chan = data;
+	u32 chcr;
+
+	spin_lock(&sh_chan->desc_lock);
+
+	chcr = chcr_read(sh_chan);
+
+	if (chcr & CHCR_TE) {
+		/* DMA stop */
+		dmae_halt(sh_chan);
+
+		ret = IRQ_HANDLED;
+		tasklet_schedule(&sh_chan->tasklet);
+	}
+
+	spin_unlock(&sh_chan->desc_lock);
+
+	return ret;
+}
+
+/* Called from error IRQ or NMI */
+static bool sh_dmae_reset(struct sh_dmae_device *shdev)
+{
+	unsigned int handled = 0;
+	int i;
+
+	/* halt the dma controller */
+	sh_dmae_ctl_stop(shdev);
+
+	/* We cannot detect, which channel caused the error, have to reset all */
+	for (i = 0; i < SH_DMAC_MAX_CHANNELS; i++) {
+		struct sh_dmae_chan *sh_chan = shdev->chan[i];
+		struct sh_desc *desc;
+		LIST_HEAD(dl);
+
+		if (!sh_chan)
+			continue;
+
+		spin_lock(&sh_chan->desc_lock);
+
+		/* Stop the channel */
+		dmae_halt(sh_chan);
+
+		list_splice_init(&sh_chan->ld_queue, &dl);
+
+		if (!list_empty(&dl)) {
+			dev_dbg(sh_chan->dev, "Bring down channel %d\n", sh_chan->id);
+			pm_runtime_put(sh_chan->dev);
+		}
+		sh_chan->pm_state = DMAE_PM_ESTABLISHED;
+
+		spin_unlock(&sh_chan->desc_lock);
+
+		/* Complete all  */
+		list_for_each_entry(desc, &dl, node) {
+			struct dma_async_tx_descriptor *tx = &desc->async_tx;
+			desc->mark = DESC_IDLE;
+			if (tx->callback)
+				tx->callback(tx->callback_param);
+		}
+
+		spin_lock(&sh_chan->desc_lock);
+		list_splice(&dl, &sh_chan->ld_free);
+		spin_unlock(&sh_chan->desc_lock);
+
+		handled++;
+	}
+
+	sh_dmae_rst(shdev);
+
+	return !!handled;
+}
+
+static irqreturn_t sh_dmae_err(int irq, void *data)
+{
+	struct sh_dmae_device *shdev = data;
+
+	if (!(dmaor_read(shdev) & DMAOR_AE))
+		return IRQ_NONE;
+
+	sh_dmae_reset(data);
+	return IRQ_HANDLED;
+}
+
+static void dmae_do_tasklet(unsigned long data)
+{
+	struct sh_dmae_chan *sh_chan = (struct sh_dmae_chan *)data;
+	struct sh_desc *desc;
+	u32 sar_buf = sh_dmae_readl(sh_chan, SAR);
+	u32 dar_buf = sh_dmae_readl(sh_chan, DAR);
+
+	spin_lock_irq(&sh_chan->desc_lock);
+	list_for_each_entry(desc, &sh_chan->ld_queue, node) {
+		if (desc->mark == DESC_SUBMITTED &&
+		    ((desc->direction == DMA_DEV_TO_MEM &&
+		      (desc->hw.dar + desc->hw.tcr) == dar_buf) ||
+		     (desc->hw.sar + desc->hw.tcr) == sar_buf)) {
+			dev_dbg(sh_chan->dev, "done #%d@%p dst %u\n",
+				desc->async_tx.cookie, &desc->async_tx,
+				desc->hw.dar);
+			desc->mark = DESC_COMPLETED;
+			break;
+		}
+	}
+	/* Next desc */
+	sh_chan_xfer_ld_queue(sh_chan);
+	spin_unlock_irq(&sh_chan->desc_lock);
+
+	sh_dmae_chan_ld_cleanup(sh_chan, false);
+}
+
+static bool sh_dmae_nmi_notify(struct sh_dmae_device *shdev)
+{
+	/* Fast path out if NMIF is not asserted for this controller */
+	if ((dmaor_read(shdev) & DMAOR_NMIF) == 0)
+		return false;
+
+	return sh_dmae_reset(shdev);
+}
+
+static int sh_dmae_nmi_handler(struct notifier_block *self,
+			       unsigned long cmd, void *data)
+{
+	struct sh_dmae_device *shdev;
+	int ret = NOTIFY_DONE;
+	bool triggered;
+
+	/*
+	 * Only concern ourselves with NMI events.
+	 *
+	 * Normally we would check the die chain value, but as this needs
+	 * to be architecture independent, check for NMI context instead.
+	 */
+	if (!in_nmi())
+		return NOTIFY_DONE;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(shdev, &sh_dmae_devices, node) {
+		/*
+		 * Only stop if one of the controllers has NMIF asserted,
+		 * we do not want to interfere with regular address error
+		 * handling or NMI events that don't concern the DMACs.
+		 */
+		triggered = sh_dmae_nmi_notify(shdev);
+		if (triggered == true)
+			ret = NOTIFY_OK;
+	}
+	rcu_read_unlock();
+
+	return ret;
+}
+
+static struct notifier_block sh_dmae_nmi_notifier __read_mostly = {
+	.notifier_call	= sh_dmae_nmi_handler,
+
+	/* Run before NMI debug handler and KGDB */
+	.priority	= 1,
+};
+
+static int __devinit sh_dmae_chan_probe(struct sh_dmae_device *shdev, int id,
+					int irq, unsigned long flags)
+{
+	int err;
+	const struct sh_dmae_channel *chan_pdata = &shdev->pdata->channel[id];
+	struct platform_device *pdev = to_platform_device(shdev->common.dev);
+	struct sh_dmae_chan *new_sh_chan;
+
+	/* alloc channel */
+	new_sh_chan = kzalloc(sizeof(struct sh_dmae_chan), GFP_KERNEL);
+	if (!new_sh_chan) {
+		dev_err(shdev->common.dev,
+			"No free memory for allocating dma channels!\n");
+		return -ENOMEM;
+	}
+
+	new_sh_chan->pm_state = DMAE_PM_ESTABLISHED;
+
+	/* reference struct dma_device */
+	new_sh_chan->common.device = &shdev->common;
+	dma_cookie_init(&new_sh_chan->common);
+
+	new_sh_chan->dev = shdev->common.dev;
+	new_sh_chan->id = id;
+	new_sh_chan->irq = irq;
+	new_sh_chan->base = shdev->chan_reg + chan_pdata->offset / sizeof(u32);
+
+	/* Init DMA tasklet */
+	tasklet_init(&new_sh_chan->tasklet, dmae_do_tasklet,
+			(unsigned long)new_sh_chan);
+
+	spin_lock_init(&new_sh_chan->desc_lock);
+
+	/* Init descripter manage list */
+	INIT_LIST_HEAD(&new_sh_chan->ld_queue);
+	INIT_LIST_HEAD(&new_sh_chan->ld_free);
+
+	/* Add the channel to DMA device channel list */
+	list_add_tail(&new_sh_chan->common.device_node,
+			&shdev->common.channels);
+	shdev->common.chancnt++;
+
+	if (pdev->id >= 0)
+		snprintf(new_sh_chan->dev_id, sizeof(new_sh_chan->dev_id),
+			 "sh-dmae%d.%d", pdev->id, new_sh_chan->id);
+	else
+		snprintf(new_sh_chan->dev_id, sizeof(new_sh_chan->dev_id),
+			 "sh-dma%d", new_sh_chan->id);
+
+	/* set up channel irq */
+	err = request_irq(irq, &sh_dmae_interrupt, flags,
+			  new_sh_chan->dev_id, new_sh_chan);
+	if (err) {
+		dev_err(shdev->common.dev, "DMA channel %d request_irq error "
+			"with return %d\n", id, err);
+		goto err_no_irq;
+	}
+
+	shdev->chan[id] = new_sh_chan;
+	return 0;
+
+err_no_irq:
+	/* remove from dmaengine device node */
+	list_del(&new_sh_chan->common.device_node);
+	kfree(new_sh_chan);
+	return err;
+}
+
+static void sh_dmae_chan_remove(struct sh_dmae_device *shdev)
+{
+	int i;
+
+	for (i = shdev->common.chancnt - 1 ; i >= 0 ; i--) {
+		if (shdev->chan[i]) {
+			struct sh_dmae_chan *sh_chan = shdev->chan[i];
+
+			free_irq(sh_chan->irq, sh_chan);
+
+			list_del(&sh_chan->common.device_node);
+			kfree(sh_chan);
+			shdev->chan[i] = NULL;
+		}
+	}
+	shdev->common.chancnt = 0;
+}
+
+static int __init sh_dmae_probe(struct platform_device *pdev)
+{
+	struct sh_dmae_pdata *pdata = pdev->dev.platform_data;
+	unsigned long irqflags = IRQF_DISABLED,
+		chan_flag[SH_DMAC_MAX_CHANNELS] = {};
+	int errirq, chan_irq[SH_DMAC_MAX_CHANNELS];
+	int err, i, irq_cnt = 0, irqres = 0, irq_cap = 0;
+	struct sh_dmae_device *shdev;
+	struct resource *chan, *dmars, *errirq_res, *chanirq_res;
+
+	/* get platform data */
+	if (!pdata || !pdata->channel_num)
+		return -ENODEV;
+
+	chan = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	/* DMARS area is optional */
+	dmars = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	/*
+	 * IRQ resources:
+	 * 1. there always must be at least one IRQ IO-resource. On SH4 it is
+	 *    the error IRQ, in which case it is the only IRQ in this resource:
+	 *    start == end. If it is the only IRQ resource, all channels also
+	 *    use the same IRQ.
+	 * 2. DMA channel IRQ resources can be specified one per resource or in
+	 *    ranges (start != end)
+	 * 3. iff all events (channels and, optionally, error) on this
+	 *    controller use the same IRQ, only one IRQ resource can be
+	 *    specified, otherwise there must be one IRQ per channel, even if
+	 *    some of them are equal
+	 * 4. if all IRQs on this controller are equal or if some specific IRQs
+	 *    specify IORESOURCE_IRQ_SHAREABLE in their resources, they will be
+	 *    requested with the IRQF_SHARED flag
+	 */
+	errirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (!chan || !errirq_res)
+		return -ENODEV;
+
+	if (!request_mem_region(chan->start, resource_size(chan), pdev->name)) {
+		dev_err(&pdev->dev, "DMAC register region already claimed\n");
+		return -EBUSY;
+	}
+
+	if (dmars && !request_mem_region(dmars->start, resource_size(dmars), pdev->name)) {
+		dev_err(&pdev->dev, "DMAC DMARS region already claimed\n");
+		err = -EBUSY;
+		goto ermrdmars;
+	}
+
+	err = -ENOMEM;
+	shdev = kzalloc(sizeof(struct sh_dmae_device), GFP_KERNEL);
+	if (!shdev) {
+		dev_err(&pdev->dev, "Not enough memory\n");
+		goto ealloc;
+	}
+
+	shdev->chan_reg = ioremap(chan->start, resource_size(chan));
+	if (!shdev->chan_reg)
+		goto emapchan;
+	if (dmars) {
+		shdev->dmars = ioremap(dmars->start, resource_size(dmars));
+		if (!shdev->dmars)
+			goto emapdmars;
+	}
+
+	/* platform data */
+	shdev->pdata = pdata;
+
+	if (pdata->chcr_offset)
+		shdev->chcr_offset = pdata->chcr_offset;
+	else
+		shdev->chcr_offset = CHCR;
+
+	if (pdata->chcr_ie_bit)
+		shdev->chcr_ie_bit = pdata->chcr_ie_bit;
+	else
+		shdev->chcr_ie_bit = CHCR_IE;
+
+	platform_set_drvdata(pdev, shdev);
+
+	shdev->common.dev = &pdev->dev;
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
+	spin_lock_irq(&sh_dmae_lock);
+	list_add_tail_rcu(&shdev->node, &sh_dmae_devices);
+	spin_unlock_irq(&sh_dmae_lock);
+
+	/* reset dma controller - only needed as a test */
+	err = sh_dmae_rst(shdev);
+	if (err)
+		goto rst_err;
+
+	INIT_LIST_HEAD(&shdev->common.channels);
+
+	if (!pdata->slave_only)
+		dma_cap_set(DMA_MEMCPY, shdev->common.cap_mask);
+	if (pdata->slave && pdata->slave_num)
+		dma_cap_set(DMA_SLAVE, shdev->common.cap_mask);
+
+	shdev->common.device_alloc_chan_resources
+		= sh_dmae_alloc_chan_resources;
+	shdev->common.device_free_chan_resources = sh_dmae_free_chan_resources;
+	shdev->common.device_prep_dma_memcpy = sh_dmae_prep_memcpy;
+	shdev->common.device_tx_status = sh_dmae_tx_status;
+	shdev->common.device_issue_pending = sh_dmae_memcpy_issue_pending;
+
+	/* Compulsory for DMA_SLAVE fields */
+	shdev->common.device_prep_slave_sg = sh_dmae_prep_slave_sg;
+	shdev->common.device_control = sh_dmae_control;
+
+	/* Default transfer size of 32 bytes requires 32-byte alignment */
+	shdev->common.copy_align = LOG2_DEFAULT_XFER_SIZE;
+
+#if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
+	chanirq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
+
+	if (!chanirq_res)
+		chanirq_res = errirq_res;
+	else
+		irqres++;
+
+	if (chanirq_res == errirq_res ||
+	    (errirq_res->flags & IORESOURCE_BITS) == IORESOURCE_IRQ_SHAREABLE)
+		irqflags = IRQF_SHARED;
+
+	errirq = errirq_res->start;
+
+	err = request_irq(errirq, sh_dmae_err, irqflags,
+			  "DMAC Address Error", shdev);
+	if (err) {
+		dev_err(&pdev->dev,
+			"DMA failed requesting irq #%d, error %d\n",
+			errirq, err);
+		goto eirq_err;
+	}
+
+#else
+	chanirq_res = errirq_res;
+#endif /* CONFIG_CPU_SH4 || CONFIG_ARCH_SHMOBILE */
+
+	if (chanirq_res->start == chanirq_res->end &&
+	    !platform_get_resource(pdev, IORESOURCE_IRQ, 1)) {
+		/* Special case - all multiplexed */
+		for (; irq_cnt < pdata->channel_num; irq_cnt++) {
+			if (irq_cnt < SH_DMAC_MAX_CHANNELS) {
+				chan_irq[irq_cnt] = chanirq_res->start;
+				chan_flag[irq_cnt] = IRQF_SHARED;
+			} else {
+				irq_cap = 1;
+				break;
+			}
+		}
+	} else {
+		do {
+			for (i = chanirq_res->start; i <= chanirq_res->end; i++) {
+				if (irq_cnt >= SH_DMAC_MAX_CHANNELS) {
+					irq_cap = 1;
+					break;
+				}
+
+				if ((errirq_res->flags & IORESOURCE_BITS) ==
+				    IORESOURCE_IRQ_SHAREABLE)
+					chan_flag[irq_cnt] = IRQF_SHARED;
+				else
+					chan_flag[irq_cnt] = IRQF_DISABLED;
+				dev_dbg(&pdev->dev,
+					"Found IRQ %d for channel %d\n",
+					i, irq_cnt);
+				chan_irq[irq_cnt++] = i;
+			}
+
+			if (irq_cnt >= SH_DMAC_MAX_CHANNELS)
+				break;
+
+			chanirq_res = platform_get_resource(pdev,
+						IORESOURCE_IRQ, ++irqres);
+		} while (irq_cnt < pdata->channel_num && chanirq_res);
+	}
+
+	/* Create DMA Channel */
+	for (i = 0; i < irq_cnt; i++) {
+		err = sh_dmae_chan_probe(shdev, i, chan_irq[i], chan_flag[i]);
+		if (err)
+			goto chan_probe_err;
+	}
+
+	if (irq_cap)
+		dev_notice(&pdev->dev, "Attempting to register %d DMA "
+			   "channels when a maximum of %d are supported.\n",
+			   pdata->channel_num, SH_DMAC_MAX_CHANNELS);
+
+	pm_runtime_put(&pdev->dev);
+
+	dma_async_device_register(&shdev->common);
+
+	return err;
+
+chan_probe_err:
+	sh_dmae_chan_remove(shdev);
+
+#if defined(CONFIG_CPU_SH4) || defined(CONFIG_ARCH_SHMOBILE)
+	free_irq(errirq, shdev);
+eirq_err:
+#endif
+rst_err:
+	spin_lock_irq(&sh_dmae_lock);
+	list_del_rcu(&shdev->node);
+	spin_unlock_irq(&sh_dmae_lock);
+
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	if (dmars)
+		iounmap(shdev->dmars);
+
+	platform_set_drvdata(pdev, NULL);
+emapdmars:
+	iounmap(shdev->chan_reg);
+	synchronize_rcu();
+emapchan:
+	kfree(shdev);
+ealloc:
+	if (dmars)
+		release_mem_region(dmars->start, resource_size(dmars));
+ermrdmars:
+	release_mem_region(chan->start, resource_size(chan));
+
+	return err;
+}
+
+static int __exit sh_dmae_remove(struct platform_device *pdev)
+{
+	struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
+	struct resource *res;
+	int errirq = platform_get_irq(pdev, 0);
+
+	dma_async_device_unregister(&shdev->common);
+
+	if (errirq > 0)
+		free_irq(errirq, shdev);
+
+	spin_lock_irq(&sh_dmae_lock);
+	list_del_rcu(&shdev->node);
+	spin_unlock_irq(&sh_dmae_lock);
+
+	/* channel data remove */
+	sh_dmae_chan_remove(shdev);
+
+	pm_runtime_disable(&pdev->dev);
+
+	if (shdev->dmars)
+		iounmap(shdev->dmars);
+	iounmap(shdev->chan_reg);
+
+	platform_set_drvdata(pdev, NULL);
+
+	synchronize_rcu();
+	kfree(shdev);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res)
+		release_mem_region(res->start, resource_size(res));
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (res)
+		release_mem_region(res->start, resource_size(res));
+
+	return 0;
+}
+
+static void sh_dmae_shutdown(struct platform_device *pdev)
+{
+	struct sh_dmae_device *shdev = platform_get_drvdata(pdev);
+	sh_dmae_ctl_stop(shdev);
+}
+
+static int sh_dmae_runtime_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int sh_dmae_runtime_resume(struct device *dev)
+{
+	struct sh_dmae_device *shdev = dev_get_drvdata(dev);
+
+	return sh_dmae_rst(shdev);
+}
+
+#ifdef CONFIG_PM
+static int sh_dmae_suspend(struct device *dev)
+{
+	return 0;
+}
+
+static int sh_dmae_resume(struct device *dev)
+{
+	struct sh_dmae_device *shdev = dev_get_drvdata(dev);
+	int i, ret;
+
+	ret = sh_dmae_rst(shdev);
+	if (ret < 0)
+		dev_err(dev, "Failed to reset!\n");
+
+	for (i = 0; i < shdev->pdata->channel_num; i++) {
+		struct sh_dmae_chan *sh_chan = shdev->chan[i];
+		struct sh_dmae_slave *param = sh_chan->common.private;
+
+		if (!sh_chan->descs_allocated)
+			continue;
+
+		if (param) {
+			const struct sh_dmae_slave_config *cfg = param->config;
+			dmae_set_dmars(sh_chan, cfg->mid_rid);
+			dmae_set_chcr(sh_chan, cfg->chcr);
+		} else {
+			dmae_init(sh_chan);
+		}
+	}
+
+	return 0;
+}
+#else
+#define sh_dmae_suspend NULL
+#define sh_dmae_resume NULL
+#endif
+
+const struct dev_pm_ops sh_dmae_pm = {
+	.suspend		= sh_dmae_suspend,
+	.resume			= sh_dmae_resume,
+	.runtime_suspend	= sh_dmae_runtime_suspend,
+	.runtime_resume		= sh_dmae_runtime_resume,
+};
+
+static struct platform_driver sh_dmae_driver = {
+	.remove		= __exit_p(sh_dmae_remove),
+	.shutdown	= sh_dmae_shutdown,
+	.driver = {
+		.owner	= THIS_MODULE,
+		.name	= "sh-dma-engine",
+		.pm	= &sh_dmae_pm,
+	},
+};
+
+static int __init sh_dmae_init(void)
+{
+	/* Wire up NMI handling */
+	int err = register_die_notifier(&sh_dmae_nmi_notifier);
+	if (err)
+		return err;
+
+	return platform_driver_probe(&sh_dmae_driver, sh_dmae_probe);
+}
+module_init(sh_dmae_init);
+
+static void __exit sh_dmae_exit(void)
+{
+	platform_driver_unregister(&sh_dmae_driver);
+
+	unregister_die_notifier(&sh_dmae_nmi_notifier);
+}
+module_exit(sh_dmae_exit);
+
+MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>");
+MODULE_DESCRIPTION("Renesas SH DMA Engine driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:sh-dma-engine");
diff --git a/drivers/dma/sh/shdma.h b/drivers/dma/sh/shdma.h
new file mode 100644
index 000000000000..0b1d2c105f02
--- /dev/null
+++ b/drivers/dma/sh/shdma.h
@@ -0,0 +1,66 @@
+/*
+ * Renesas SuperH DMA Engine support
+ *
+ * Copyright (C) 2009 Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
+ * Copyright (C) 2009 Renesas Solutions, Inc. All rights reserved.
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+#ifndef __DMA_SHDMA_H
+#define __DMA_SHDMA_H
+
+#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+
+#define SH_DMAC_MAX_CHANNELS 20
+#define SH_DMA_SLAVE_NUMBER 256
+#define SH_DMA_TCR_MAX 0x00FFFFFF	/* 16MB */
+
+struct device;
+
+enum dmae_pm_state {
+	DMAE_PM_ESTABLISHED,
+	DMAE_PM_BUSY,
+	DMAE_PM_PENDING,
+};
+
+struct sh_dmae_chan {
+	spinlock_t desc_lock;		/* Descriptor operation lock */
+	struct list_head ld_queue;	/* Link descriptors queue */
+	struct list_head ld_free;	/* Link descriptors free */
+	struct dma_chan common;		/* DMA common channel */
+	struct device *dev;		/* Channel device */
+	struct tasklet_struct tasklet;	/* Tasklet */
+	int descs_allocated;		/* desc count */
+	int xmit_shift;			/* log_2(bytes_per_xfer) */
+	int irq;
+	int id;				/* Raw id of this channel */
+	u32 __iomem *base;
+	char dev_id[16];		/* unique name per DMAC of channel */
+	int pm_error;
+	enum dmae_pm_state pm_state;
+};
+
+struct sh_dmae_device {
+	struct dma_device common;
+	struct sh_dmae_chan *chan[SH_DMAC_MAX_CHANNELS];
+	struct sh_dmae_pdata *pdata;
+	struct list_head node;
+	u32 __iomem *chan_reg;
+	u16 __iomem *dmars;
+	unsigned int chcr_offset;
+	u32 chcr_ie_bit;
+};
+
+#define to_sh_chan(chan) container_of(chan, struct sh_dmae_chan, common)
+#define to_sh_desc(lh) container_of(lh, struct sh_desc, node)
+#define tx_to_sh_desc(tx) container_of(tx, struct sh_desc, async_tx)
+#define to_sh_dev(chan) container_of(chan->common.device,\
+				     struct sh_dmae_device, common)
+
+#endif	/* __DMA_SHDMA_H */