dmaengine: add driver for Freescale MPC85xx DMA controller

The driver implements DMA engine API for Freescale MPC85xx DMA controller,
which could be used by devices in the silicon.  The driver supports the
Basic mode of Freescale MPC85xx DMA controller.  The MPC85xx processors
supported include MPC8540/60, MPC8555, MPC8548, MPC8641 and so on.

The MPC83xx(MPC8349, MPC8360) are also supported.

[kamalesh@linux.vnet.ibm.com: build fix]
[dan.j.williams@intel.com: merge mm fixes, rebase on async_tx-2.6.25]
Signed-off-by: Zhang Wei <wei.zhang@freescale.com>
Signed-off-by: Ebony Zhu <ebony.zhu@freescale.com>
Acked-by: Kumar Gala <galak@gate.crashing.org>
Cc: Shannon Nelson <shannon.nelson@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 1068 insertions, 0 deletions

diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
new file mode 100644
index 000000000000..902e852571a8
--- /dev/null
+++ b/drivers/dma/fsldma.c
@@ -0,0 +1,1068 @@
+/*
+ * Freescale MPC85xx, MPC83xx DMA Engine support
+ *
+ * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * Author:
+ *   Zhang Wei <wei.zhang@freescale.com>, Jul 2007
+ *   Ebony Zhu <ebony.zhu@freescale.com>, May 2007
+ *
+ * Description:
+ *   DMA engine driver for Freescale MPC8540 DMA controller, which is
+ *   also fit for MPC8560, MPC8555, MPC8548, MPC8641, and etc.
+ *   The support for MPC8349 DMA contorller is also added.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/dmaengine.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/of_platform.h>
+
+#include "fsldma.h"
+
+static void dma_init(struct fsl_dma_chan *fsl_chan)
+{
+	/* Reset the channel */
+	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, 0, 32);
+
+	switch (fsl_chan->feature & FSL_DMA_IP_MASK) {
+	case FSL_DMA_IP_85XX:
+		/* Set the channel to below modes:
+		 * EIE - Error interrupt enable
+		 * EOSIE - End of segments interrupt enable (basic mode)
+		 * EOLNIE - End of links interrupt enable
+		 */
+		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, FSL_DMA_MR_EIE
+				| FSL_DMA_MR_EOLNIE | FSL_DMA_MR_EOSIE, 32);
+		break;
+	case FSL_DMA_IP_83XX:
+		/* Set the channel to below modes:
+		 * EOTIE - End-of-transfer interrupt enable
+		 */
+		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, FSL_DMA_MR_EOTIE,
+				32);
+		break;
+	}
+
+}
+
+static void set_sr(struct fsl_dma_chan *fsl_chan, dma_addr_t val)
+{
+	DMA_OUT(fsl_chan, &fsl_chan->reg_base->sr, val, 32);
+}
+
+static dma_addr_t get_sr(struct fsl_dma_chan *fsl_chan)
+{
+	return DMA_IN(fsl_chan, &fsl_chan->reg_base->sr, 32);
+}
+
+static void set_desc_cnt(struct fsl_dma_chan *fsl_chan,
+				struct fsl_dma_ld_hw *hw, u32 count)
+{
+	hw->count = CPU_TO_DMA(fsl_chan, count, 32);
+}
+
+static void set_desc_src(struct fsl_dma_chan *fsl_chan,
+				struct fsl_dma_ld_hw *hw, dma_addr_t src)
+{
+	u64 snoop_bits;
+
+	snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+		? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
+	hw->src_addr = CPU_TO_DMA(fsl_chan, snoop_bits | src, 64);
+}
+
+static void set_desc_dest(struct fsl_dma_chan *fsl_chan,
+				struct fsl_dma_ld_hw *hw, dma_addr_t dest)
+{
+	u64 snoop_bits;
+
+	snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+		? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
+	hw->dst_addr = CPU_TO_DMA(fsl_chan, snoop_bits | dest, 64);
+}
+
+static void set_desc_next(struct fsl_dma_chan *fsl_chan,
+				struct fsl_dma_ld_hw *hw, dma_addr_t next)
+{
+	u64 snoop_bits;
+
+	snoop_bits = ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
+		? FSL_DMA_SNEN : 0;
+	hw->next_ln_addr = CPU_TO_DMA(fsl_chan, snoop_bits | next, 64);
+}
+
+static void set_cdar(struct fsl_dma_chan *fsl_chan, dma_addr_t addr)
+{
+	DMA_OUT(fsl_chan, &fsl_chan->reg_base->cdar, addr | FSL_DMA_SNEN, 64);
+}
+
+static dma_addr_t get_cdar(struct fsl_dma_chan *fsl_chan)
+{
+	return DMA_IN(fsl_chan, &fsl_chan->reg_base->cdar, 64) & ~FSL_DMA_SNEN;
+}
+
+static void set_ndar(struct fsl_dma_chan *fsl_chan, dma_addr_t addr)
+{
+	DMA_OUT(fsl_chan, &fsl_chan->reg_base->ndar, addr, 64);
+}
+
+static dma_addr_t get_ndar(struct fsl_dma_chan *fsl_chan)
+{
+	return DMA_IN(fsl_chan, &fsl_chan->reg_base->ndar, 64);
+}
+
+static int dma_is_idle(struct fsl_dma_chan *fsl_chan)
+{
+	u32 sr = get_sr(fsl_chan);
+	return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
+}
+
+static void dma_start(struct fsl_dma_chan *fsl_chan)
+{
+	u32 mr_set = 0;;
+
+	if (fsl_chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
+		DMA_OUT(fsl_chan, &fsl_chan->reg_base->bcr, 0, 32);
+		mr_set |= FSL_DMA_MR_EMP_EN;
+	} else
+		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
+			DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32)
+				& ~FSL_DMA_MR_EMP_EN, 32);
+
+	if (fsl_chan->feature & FSL_DMA_CHAN_START_EXT)
+		mr_set |= FSL_DMA_MR_EMS_EN;
+	else
+		mr_set |= FSL_DMA_MR_CS;
+
+	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
+			DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32)
+			| mr_set, 32);
+}
+
+static void dma_halt(struct fsl_dma_chan *fsl_chan)
+{
+	int i = 0;
+	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
+		DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) | FSL_DMA_MR_CA,
+		32);
+	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
+		DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) & ~(FSL_DMA_MR_CS
+		| FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA), 32);
+
+	while (!dma_is_idle(fsl_chan) && (i++ < 100))
+		udelay(10);
+	if (i >= 100 && !dma_is_idle(fsl_chan))
+		dev_err(fsl_chan->dev, "DMA halt timeout!\n");
+}
+
+static void set_ld_eol(struct fsl_dma_chan *fsl_chan,
+			struct fsl_desc_sw *desc)
+{
+	desc->hw.next_ln_addr = CPU_TO_DMA(fsl_chan,
+		DMA_TO_CPU(fsl_chan, desc->hw.next_ln_addr, 64)	| FSL_DMA_EOL,
+		64);
+}
+
+static void append_ld_queue(struct fsl_dma_chan *fsl_chan,
+		struct fsl_desc_sw *new_desc)
+{
+	struct fsl_desc_sw *queue_tail = to_fsl_desc(fsl_chan->ld_queue.prev);
+
+	if (list_empty(&fsl_chan->ld_queue))
+		return;
+
+	/* Link to the new descriptor physical address and
+	 * Enable End-of-segment interrupt for
+	 * the last link descriptor.
+	 * (the previous node's next link descriptor)
+	 *
+	 * For FSL_DMA_IP_83xx, the snoop enable bit need be set.
+	 */
+	queue_tail->hw.next_ln_addr = CPU_TO_DMA(fsl_chan,
+			new_desc->async_tx.phys | FSL_DMA_EOSIE |
+			(((fsl_chan->feature & FSL_DMA_IP_MASK)
+				== FSL_DMA_IP_83XX) ? FSL_DMA_SNEN : 0), 64);
+}
+
+/**
+ * fsl_chan_set_src_loop_size - Set source address hold transfer size
+ * @fsl_chan : Freescale DMA channel
+ * @size     : Address loop size, 0 for disable loop
+ *
+ * The set source address hold transfer size. The source
+ * address hold or loop transfer size is when the DMA transfer
+ * data from source address (SA), if the loop size is 4, the DMA will
+ * read data from SA, SA + 1, SA + 2, SA + 3, then loop back to SA,
+ * SA + 1 ... and so on.
+ */
+static void fsl_chan_set_src_loop_size(struct fsl_dma_chan *fsl_chan, int size)
+{
+	switch (size) {
+	case 0:
+		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
+			DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) &
+			(~FSL_DMA_MR_SAHE), 32);
+		break;
+	case 1:
+	case 2:
+	case 4:
+	case 8:
+		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
+			DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) |
+			FSL_DMA_MR_SAHE | (__ilog2(size) << 14),
+			32);
+		break;
+	}
+}
+
+/**
+ * fsl_chan_set_dest_loop_size - Set destination address hold transfer size
+ * @fsl_chan : Freescale DMA channel
+ * @size     : Address loop size, 0 for disable loop
+ *
+ * The set destination address hold transfer size. The destination
+ * address hold or loop transfer size is when the DMA transfer
+ * data to destination address (TA), if the loop size is 4, the DMA will
+ * write data to TA, TA + 1, TA + 2, TA + 3, then loop back to TA,
+ * TA + 1 ... and so on.
+ */
+static void fsl_chan_set_dest_loop_size(struct fsl_dma_chan *fsl_chan, int size)
+{
+	switch (size) {
+	case 0:
+		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
+			DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) &
+			(~FSL_DMA_MR_DAHE), 32);
+		break;
+	case 1:
+	case 2:
+	case 4:
+	case 8:
+		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
+			DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32) |
+			FSL_DMA_MR_DAHE | (__ilog2(size) << 16),
+			32);
+		break;
+	}
+}
+
+/**
+ * fsl_chan_toggle_ext_pause - Toggle channel external pause status
+ * @fsl_chan : Freescale DMA channel
+ * @size     : Pause control size, 0 for disable external pause control.
+ *             The maximum is 1024.
+ *
+ * The Freescale DMA channel can be controlled by the external
+ * signal DREQ#. The pause control size is how many bytes are allowed
+ * to transfer before pausing the channel, after which a new assertion
+ * of DREQ# resumes channel operation.
+ */
+static void fsl_chan_toggle_ext_pause(struct fsl_dma_chan *fsl_chan, int size)
+{
+	if (size > 1024)
+		return;
+
+	if (size) {
+		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr,
+			DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32)
+				| ((__ilog2(size) << 24) & 0x0f000000),
+			32);
+		fsl_chan->feature |= FSL_DMA_CHAN_PAUSE_EXT;
+	} else
+		fsl_chan->feature &= ~FSL_DMA_CHAN_PAUSE_EXT;
+}
+
+/**
+ * fsl_chan_toggle_ext_start - Toggle channel external start status
+ * @fsl_chan : Freescale DMA channel
+ * @enable   : 0 is disabled, 1 is enabled.
+ *
+ * If enable the external start, the channel can be started by an
+ * external DMA start pin. So the dma_start() does not start the
+ * transfer immediately. The DMA channel will wait for the
+ * control pin asserted.
+ */
+static void fsl_chan_toggle_ext_start(struct fsl_dma_chan *fsl_chan, int enable)
+{
+	if (enable)
+		fsl_chan->feature |= FSL_DMA_CHAN_START_EXT;
+	else
+		fsl_chan->feature &= ~FSL_DMA_CHAN_START_EXT;
+}
+
+static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
+	struct fsl_dma_chan *fsl_chan = to_fsl_chan(tx->chan);
+	unsigned long flags;
+	dma_cookie_t cookie;
+
+	/* cookie increment and adding to ld_queue must be atomic */
+	spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+
+	cookie = fsl_chan->common.cookie;
+	cookie++;
+	if (cookie < 0)
+		cookie = 1;
+	desc->async_tx.cookie = cookie;
+	fsl_chan->common.cookie = desc->async_tx.cookie;
+
+	append_ld_queue(fsl_chan, desc);
+	list_splice_init(&desc->async_tx.tx_list, fsl_chan->ld_queue.prev);
+
+	spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+
+	return cookie;
+}
+
+/**
+ * fsl_dma_alloc_descriptor - Allocate descriptor from channel's DMA pool.
+ * @fsl_chan : Freescale DMA channel
+ *
+ * Return - The descriptor allocated. NULL for failed.
+ */
+static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
+					struct fsl_dma_chan *fsl_chan)
+{
+	dma_addr_t pdesc;
+	struct fsl_desc_sw *desc_sw;
+
+	desc_sw = dma_pool_alloc(fsl_chan->desc_pool, GFP_ATOMIC, &pdesc);
+	if (desc_sw) {
+		memset(desc_sw, 0, sizeof(struct fsl_desc_sw));
+		dma_async_tx_descriptor_init(&desc_sw->async_tx,
+						&fsl_chan->common);
+		desc_sw->async_tx.tx_submit = fsl_dma_tx_submit;
+		INIT_LIST_HEAD(&desc_sw->async_tx.tx_list);
+		desc_sw->async_tx.phys = pdesc;
+	}
+
+	return desc_sw;
+}
+
+
+/**
+ * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
+ * @fsl_chan : Freescale DMA channel
+ *
+ * This function will create a dma pool for descriptor allocation.
+ *
+ * Return - The number of descriptors allocated.
+ */
+static int fsl_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
+	LIST_HEAD(tmp_list);
+
+	/* We need the descriptor to be aligned to 32bytes
+	 * for meeting FSL DMA specification requirement.
+	 */
+	fsl_chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool",
+			fsl_chan->dev, sizeof(struct fsl_desc_sw),
+			32, 0);
+	if (!fsl_chan->desc_pool) {
+		dev_err(fsl_chan->dev, "No memory for channel %d "
+			"descriptor dma pool.\n", fsl_chan->id);
+		return 0;
+	}
+
+	return 1;
+}
+
+/**
+ * fsl_dma_free_chan_resources - Free all resources of the channel.
+ * @fsl_chan : Freescale DMA channel
+ */
+static void fsl_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
+	struct fsl_desc_sw *desc, *_desc;
+	unsigned long flags;
+
+	dev_dbg(fsl_chan->dev, "Free all channel resources.\n");
+	spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+	list_for_each_entry_safe(desc, _desc, &fsl_chan->ld_queue, node) {
+#ifdef FSL_DMA_LD_DEBUG
+		dev_dbg(fsl_chan->dev,
+				"LD %p will be released.\n", desc);
+#endif
+		list_del(&desc->node);
+		/* free link descriptor */
+		dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys);
+	}
+	spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+	dma_pool_destroy(fsl_chan->desc_pool);
+}
+
+static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
+	struct dma_chan *chan, dma_addr_t dma_dest, dma_addr_t dma_src,
+	size_t len, unsigned long flags)
+{
+	struct fsl_dma_chan *fsl_chan;
+	struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
+	size_t copy;
+	LIST_HEAD(link_chain);
+
+	if (!chan)
+		return NULL;
+
+	if (!len)
+		return NULL;
+
+	fsl_chan = to_fsl_chan(chan);
+
+	do {
+
+		/* Allocate the link descriptor from DMA pool */
+		new = fsl_dma_alloc_descriptor(fsl_chan);
+		if (!new) {
+			dev_err(fsl_chan->dev,
+					"No free memory for link descriptor\n");
+			return NULL;
+		}
+#ifdef FSL_DMA_LD_DEBUG
+		dev_dbg(fsl_chan->dev, "new link desc alloc %p\n", new);
+#endif
+
+		copy = min(len, FSL_DMA_BCR_MAX_CNT);
+
+		set_desc_cnt(fsl_chan, &new->hw, copy);
+		set_desc_src(fsl_chan, &new->hw, dma_src);
+		set_desc_dest(fsl_chan, &new->hw, dma_dest);
+
+		if (!first)
+			first = new;
+		else
+			set_desc_next(fsl_chan, &prev->hw, new->async_tx.phys);
+
+		new->async_tx.cookie = 0;
+		new->async_tx.ack = 1;
+
+		prev = new;
+		len -= copy;
+		dma_src += copy;
+		dma_dest += copy;
+
+		/* Insert the link descriptor to the LD ring */
+		list_add_tail(&new->node, &first->async_tx.tx_list);
+	} while (len);
+
+	new->async_tx.ack = 0; /* client is in control of this ack */
+	new->async_tx.cookie = -EBUSY;
+
+	/* Set End-of-link to the last link descriptor of new list*/
+	set_ld_eol(fsl_chan, new);
+
+	return first ? &first->async_tx : NULL;
+}
+
+/**
+ * fsl_dma_update_completed_cookie - Update the completed cookie.
+ * @fsl_chan : Freescale DMA channel
+ */
+static void fsl_dma_update_completed_cookie(struct fsl_dma_chan *fsl_chan)
+{
+	struct fsl_desc_sw *cur_desc, *desc;
+	dma_addr_t ld_phy;
+
+	ld_phy = get_cdar(fsl_chan) & FSL_DMA_NLDA_MASK;
+
+	if (ld_phy) {
+		cur_desc = NULL;
+		list_for_each_entry(desc, &fsl_chan->ld_queue, node)
+			if (desc->async_tx.phys == ld_phy) {
+				cur_desc = desc;
+				break;
+			}
+
+		if (cur_desc && cur_desc->async_tx.cookie) {
+			if (dma_is_idle(fsl_chan))
+				fsl_chan->completed_cookie =
+					cur_desc->async_tx.cookie;
+			else
+				fsl_chan->completed_cookie =
+					cur_desc->async_tx.cookie - 1;
+		}
+	}
+}
+
+/**
+ * fsl_chan_ld_cleanup - Clean up link descriptors
+ * @fsl_chan : Freescale DMA channel
+ *
+ * This function clean up the ld_queue of DMA channel.
+ * If 'in_intr' is set, the function will move the link descriptor to
+ * the recycle list. Otherwise, free it directly.
+ */
+static void fsl_chan_ld_cleanup(struct fsl_dma_chan *fsl_chan)
+{
+	struct fsl_desc_sw *desc, *_desc;
+	unsigned long flags;
+
+	spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+
+	fsl_dma_update_completed_cookie(fsl_chan);
+	dev_dbg(fsl_chan->dev, "chan completed_cookie = %d\n",
+			fsl_chan->completed_cookie);
+	list_for_each_entry_safe(desc, _desc, &fsl_chan->ld_queue, node) {
+		dma_async_tx_callback callback;
+		void *callback_param;
+
+		if (dma_async_is_complete(desc->async_tx.cookie,
+			    fsl_chan->completed_cookie, fsl_chan->common.cookie)
+				== DMA_IN_PROGRESS)
+			break;
+
+		callback = desc->async_tx.callback;
+		callback_param = desc->async_tx.callback_param;
+
+		/* Remove from ld_queue list */
+		list_del(&desc->node);
+
+		dev_dbg(fsl_chan->dev, "link descriptor %p will be recycle.\n",
+				desc);
+		dma_pool_free(fsl_chan->desc_pool, desc, desc->async_tx.phys);
+
+		/* Run the link descriptor callback function */
+		if (callback) {
+			spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+			dev_dbg(fsl_chan->dev, "link descriptor %p callback\n",
+					desc);
+			callback(callback_param);
+			spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+		}
+	}
+	spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+}
+
+/**
+ * fsl_chan_xfer_ld_queue - Transfer link descriptors in channel ld_queue.
+ * @fsl_chan : Freescale DMA channel
+ */
+static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan)
+{
+	struct list_head *ld_node;
+	dma_addr_t next_dest_addr;
+	unsigned long flags;
+
+	if (!dma_is_idle(fsl_chan))
+		return;
+
+	dma_halt(fsl_chan);
+
+	/* If there are some link descriptors
+	 * not transfered in queue. We need to start it.
+	 */
+	spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+
+	/* Find the first un-transfer desciptor */
+	for (ld_node = fsl_chan->ld_queue.next;
+		(ld_node != &fsl_chan->ld_queue)
+			&& (dma_async_is_complete(
+				to_fsl_desc(ld_node)->async_tx.cookie,
+				fsl_chan->completed_cookie,
+				fsl_chan->common.cookie) == DMA_SUCCESS);
+		ld_node = ld_node->next);
+
+	spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+
+	if (ld_node != &fsl_chan->ld_queue) {
+		/* Get the ld start address from ld_queue */
+		next_dest_addr = to_fsl_desc(ld_node)->async_tx.phys;
+		dev_dbg(fsl_chan->dev, "xfer LDs staring from 0x%016llx\n",
+				(u64)next_dest_addr);
+		set_cdar(fsl_chan, next_dest_addr);
+		dma_start(fsl_chan);
+	} else {
+		set_cdar(fsl_chan, 0);
+		set_ndar(fsl_chan, 0);
+	}
+}
+
+/**
+ * fsl_dma_memcpy_issue_pending - Issue the DMA start command
+ * @fsl_chan : Freescale DMA channel
+ */
+static void fsl_dma_memcpy_issue_pending(struct dma_chan *chan)
+{
+	struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
+
+#ifdef FSL_DMA_LD_DEBUG
+	struct fsl_desc_sw *ld;
+	unsigned long flags;
+
+	spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+	if (list_empty(&fsl_chan->ld_queue)) {
+		spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+		return;
+	}
+
+	dev_dbg(fsl_chan->dev, "--memcpy issue--\n");
+	list_for_each_entry(ld, &fsl_chan->ld_queue, node) {
+		int i;
+		dev_dbg(fsl_chan->dev, "Ch %d, LD %08x\n",
+				fsl_chan->id, ld->async_tx.phys);
+		for (i = 0; i < 8; i++)
+			dev_dbg(fsl_chan->dev, "LD offset %d: %08x\n",
+					i, *(((u32 *)&ld->hw) + i));
+	}
+	dev_dbg(fsl_chan->dev, "----------------\n");
+	spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
+#endif
+
+	fsl_chan_xfer_ld_queue(fsl_chan);
+}
+
+static void fsl_dma_dependency_added(struct dma_chan *chan)
+{
+	struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
+
+	fsl_chan_ld_cleanup(fsl_chan);
+}
+
+/**
+ * fsl_dma_is_complete - Determine the DMA status
+ * @fsl_chan : Freescale DMA channel
+ */
+static enum dma_status fsl_dma_is_complete(struct dma_chan *chan,
+					dma_cookie_t cookie,
+					dma_cookie_t *done,
+					dma_cookie_t *used)
+{
+	struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
+	dma_cookie_t last_used;
+	dma_cookie_t last_complete;
+
+	fsl_chan_ld_cleanup(fsl_chan);
+
+	last_used = chan->cookie;
+	last_complete = fsl_chan->completed_cookie;
+
+	if (done)
+		*done = last_complete;
+
+	if (used)
+		*used = last_used;
+
+	return dma_async_is_complete(cookie, last_complete, last_used);
+}
+
+static irqreturn_t fsl_dma_chan_do_interrupt(int irq, void *data)
+{
+	struct fsl_dma_chan *fsl_chan = (struct fsl_dma_chan *)data;
+	dma_addr_t stat;
+
+	stat = get_sr(fsl_chan);
+	dev_dbg(fsl_chan->dev, "event: channel %d, stat = 0x%x\n",
+						fsl_chan->id, stat);
+	set_sr(fsl_chan, stat);		/* Clear the event register */
+
+	stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
+	if (!stat)
+		return IRQ_NONE;
+
+	if (stat & FSL_DMA_SR_TE)
+		dev_err(fsl_chan->dev, "Transfer Error!\n");
+
+	/* If the link descriptor segment transfer finishes,
+	 * we will recycle the used descriptor.
+	 */
+	if (stat & FSL_DMA_SR_EOSI) {
+		dev_dbg(fsl_chan->dev, "event: End-of-segments INT\n");
+		dev_dbg(fsl_chan->dev, "event: clndar 0x%016llx, "
+				"nlndar 0x%016llx\n", (u64)get_cdar(fsl_chan),
+				(u64)get_ndar(fsl_chan));
+		stat &= ~FSL_DMA_SR_EOSI;
+		fsl_chan_ld_cleanup(fsl_chan);
+	}
+
+	/* If it current transfer is the end-of-transfer,
+	 * we should clear the Channel Start bit for
+	 * prepare next transfer.
+	 */
+	if (stat & (FSL_DMA_SR_EOLNI | FSL_DMA_SR_EOCDI)) {
+		dev_dbg(fsl_chan->dev, "event: End-of-link INT\n");
+		stat &= ~FSL_DMA_SR_EOLNI;
+		fsl_chan_xfer_ld_queue(fsl_chan);
+	}
+
+	if (stat)
+		dev_dbg(fsl_chan->dev, "event: unhandled sr 0x%02x\n",
+					stat);
+
+	dev_dbg(fsl_chan->dev, "event: Exit\n");
+	tasklet_schedule(&fsl_chan->tasklet);
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t fsl_dma_do_interrupt(int irq, void *data)
+{
+	struct fsl_dma_device *fdev = (struct fsl_dma_device *)data;
+	u32 gsr;
+	int ch_nr;
+
+	gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->reg_base)
+			: in_le32(fdev->reg_base);
+	ch_nr = (32 - ffs(gsr)) / 8;
+
+	return fdev->chan[ch_nr] ? fsl_dma_chan_do_interrupt(irq,
+			fdev->chan[ch_nr]) : IRQ_NONE;
+}
+
+static void dma_do_tasklet(unsigned long data)
+{
+	struct fsl_dma_chan *fsl_chan = (struct fsl_dma_chan *)data;
+	fsl_chan_ld_cleanup(fsl_chan);
+}
+
+static void fsl_dma_callback_test(struct fsl_dma_chan *fsl_chan)
+{
+	if (fsl_chan)
+		dev_info(fsl_chan->dev, "selftest: callback is ok!\n");
+}
+
+static int fsl_dma_self_test(struct fsl_dma_chan *fsl_chan)
+{
+	struct dma_chan *chan;
+	int err = 0;
+	dma_addr_t dma_dest, dma_src;
+	dma_cookie_t cookie;
+	u8 *src, *dest;
+	int i;
+	size_t test_size;
+	struct dma_async_tx_descriptor *tx1, *tx2, *tx3;
+
+	test_size = 4096;
+
+	src = kmalloc(test_size * 2, GFP_KERNEL);
+	if (!src) {
+		dev_err(fsl_chan->dev,
+				"selftest: Cannot alloc memory for test!\n");
+		err = -ENOMEM;
+		goto out;
+	}
+
+	dest = src + test_size;
+
+	for (i = 0; i < test_size; i++)
+		src[i] = (u8) i;
+
+	chan = &fsl_chan->common;
+
+	if (fsl_dma_alloc_chan_resources(chan) < 1) {
+		dev_err(fsl_chan->dev,
+				"selftest: Cannot alloc resources for DMA\n");
+		err = -ENODEV;
+		goto out;
+	}
+
+	/* TX 1 */
+	dma_src = dma_map_single(fsl_chan->dev, src, test_size / 2,
+				 DMA_TO_DEVICE);
+	dma_dest = dma_map_single(fsl_chan->dev, dest, test_size / 2,
+				  DMA_FROM_DEVICE);
+	tx1 = fsl_dma_prep_memcpy(chan, dma_dest, dma_src, test_size / 2, 0);
+	async_tx_ack(tx1);
+
+	cookie = fsl_dma_tx_submit(tx1);
+	fsl_dma_memcpy_issue_pending(chan);
+	msleep(2);
+
+	if (fsl_dma_is_complete(chan, cookie, NULL, NULL) != DMA_SUCCESS) {
+		dev_err(fsl_chan->dev, "selftest: Time out!\n");
+		err = -ENODEV;
+		goto out;
+	}
+
+	/* Test free and re-alloc channel resources */
+	fsl_dma_free_chan_resources(chan);
+
+	if (fsl_dma_alloc_chan_resources(chan) < 1) {
+		dev_err(fsl_chan->dev,
+				"selftest: Cannot alloc resources for DMA\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+
+	/* Continue to test
+	 * TX 2
+	 */
+	dma_src = dma_map_single(fsl_chan->dev, src + test_size / 2,
+					test_size / 4, DMA_TO_DEVICE);
+	dma_dest = dma_map_single(fsl_chan->dev, dest + test_size / 2,
+					test_size / 4, DMA_FROM_DEVICE);
+	tx2 = fsl_dma_prep_memcpy(chan, dma_dest, dma_src, test_size / 4, 0);
+	async_tx_ack(tx2);
+
+	/* TX 3 */
+	dma_src = dma_map_single(fsl_chan->dev, src + test_size * 3 / 4,
+					test_size / 4, DMA_TO_DEVICE);
+	dma_dest = dma_map_single(fsl_chan->dev, dest + test_size * 3 / 4,
+					test_size / 4, DMA_FROM_DEVICE);
+	tx3 = fsl_dma_prep_memcpy(chan, dma_dest, dma_src, test_size / 4, 0);
+	async_tx_ack(tx3);
+
+	/* Test exchanging the prepared tx sort */
+	cookie = fsl_dma_tx_submit(tx3);
+	cookie = fsl_dma_tx_submit(tx2);
+
+#ifdef FSL_DMA_CALLBACKTEST
+	if (dma_has_cap(DMA_INTERRUPT, ((struct fsl_dma_device *)
+	    dev_get_drvdata(fsl_chan->dev->parent))->common.cap_mask)) {
+		tx3->callback = fsl_dma_callback_test;
+		tx3->callback_param = fsl_chan;
+	}
+#endif
+	fsl_dma_memcpy_issue_pending(chan);
+	msleep(2);
+
+	if (fsl_dma_is_complete(chan, cookie, NULL, NULL) != DMA_SUCCESS) {
+		dev_err(fsl_chan->dev, "selftest: Time out!\n");
+		err = -ENODEV;
+		goto free_resources;
+	}
+
+	err = memcmp(src, dest, test_size);
+	if (err) {
+		for (i = 0; (*(src + i) == *(dest + i)) && (i < test_size);
+				i++);
+		dev_err(fsl_chan->dev, "selftest: Test failed, data %d/%d is "
+				"error! src 0x%x, dest 0x%x\n",
+				i, test_size, *(src + i), *(dest + i));
+	}
+
+free_resources:
+	fsl_dma_free_chan_resources(chan);
+out:
+	kfree(src);
+	return err;
+}
+
+static int __devinit of_fsl_dma_chan_probe(struct of_device *dev,
+			const struct of_device_id *match)
+{
+	struct fsl_dma_device *fdev;
+	struct fsl_dma_chan *new_fsl_chan;
+	int err;
+
+	fdev = dev_get_drvdata(dev->dev.parent);
+	BUG_ON(!fdev);
+
+	/* alloc channel */
+	new_fsl_chan = kzalloc(sizeof(struct fsl_dma_chan), GFP_KERNEL);
+	if (!new_fsl_chan) {
+		dev_err(&dev->dev, "No free memory for allocating "
+				"dma channels!\n");
+		err = -ENOMEM;
+		goto err;
+	}
+
+	/* get dma channel register base */
+	err = of_address_to_resource(dev->node, 0, &new_fsl_chan->reg);
+	if (err) {
+		dev_err(&dev->dev, "Can't get %s property 'reg'\n",
+				dev->node->full_name);
+		goto err;
+	}
+
+	new_fsl_chan->feature = *(u32 *)match->data;
+
+	if (!fdev->feature)
+		fdev->feature = new_fsl_chan->feature;
+
+	/* If the DMA device's feature is different than its channels',
+	 * report the bug.
+	 */
+	WARN_ON(fdev->feature != new_fsl_chan->feature);
+
+	new_fsl_chan->dev = &dev->dev;
+	new_fsl_chan->reg_base = ioremap(new_fsl_chan->reg.start,
+			new_fsl_chan->reg.end - new_fsl_chan->reg.start + 1);
+
+	new_fsl_chan->id = ((new_fsl_chan->reg.start - 0x100) & 0xfff) >> 7;
+	if (new_fsl_chan->id > FSL_DMA_MAX_CHANS_PER_DEVICE) {
+		dev_err(&dev->dev, "There is no %d channel!\n",
+				new_fsl_chan->id);
+		err = -EINVAL;
+		goto err;
+	}
+	fdev->chan[new_fsl_chan->id] = new_fsl_chan;
+	tasklet_init(&new_fsl_chan->tasklet, dma_do_tasklet,
+			(unsigned long)new_fsl_chan);
+
+	/* Init the channel */
+	dma_init(new_fsl_chan);
+
+	/* Clear cdar registers */
+	set_cdar(new_fsl_chan, 0);
+
+	switch (new_fsl_chan->feature & FSL_DMA_IP_MASK) {
+	case FSL_DMA_IP_85XX:
+		new_fsl_chan->toggle_ext_start = fsl_chan_toggle_ext_start;
+		new_fsl_chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
+	case FSL_DMA_IP_83XX:
+		new_fsl_chan->set_src_loop_size = fsl_chan_set_src_loop_size;
+		new_fsl_chan->set_dest_loop_size = fsl_chan_set_dest_loop_size;
+	}
+
+	spin_lock_init(&new_fsl_chan->desc_lock);
+	INIT_LIST_HEAD(&new_fsl_chan->ld_queue);
+
+	new_fsl_chan->common.device = &fdev->common;
+
+	/* Add the channel to DMA device channel list */
+	list_add_tail(&new_fsl_chan->common.device_node,
+			&fdev->common.channels);
+	fdev->common.chancnt++;
+
+	new_fsl_chan->irq = irq_of_parse_and_map(dev->node, 0);
+	if (new_fsl_chan->irq != NO_IRQ) {
+		err = request_irq(new_fsl_chan->irq,
+					&fsl_dma_chan_do_interrupt, IRQF_SHARED,
+					"fsldma-channel", new_fsl_chan);
+		if (err) {
+			dev_err(&dev->dev, "DMA channel %s request_irq error "
+				"with return %d\n", dev->node->full_name, err);
+			goto err;
+		}
+	}
+
+#ifdef CONFIG_FSL_DMA_SELFTEST
+	err = fsl_dma_self_test(new_fsl_chan);
+	if (err)
+		goto err;
+#endif
+
+	dev_info(&dev->dev, "#%d (%s), irq %d\n", new_fsl_chan->id,
+				match->compatible, new_fsl_chan->irq);
+
+	return 0;
+err:
+	dma_halt(new_fsl_chan);
+	iounmap(new_fsl_chan->reg_base);
+	free_irq(new_fsl_chan->irq, new_fsl_chan);
+	list_del(&new_fsl_chan->common.device_node);
+	kfree(new_fsl_chan);
+	return err;
+}
+
+const u32 mpc8540_dma_ip_feature = FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN;
+const u32 mpc8349_dma_ip_feature = FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN;
+
+static struct of_device_id of_fsl_dma_chan_ids[] = {
+	{
+		.compatible = "fsl,mpc8540-dma-channel",
+		.data = (void *)&mpc8540_dma_ip_feature,
+	},
+	{
+		.compatible = "fsl,mpc8349-dma-channel",
+		.data = (void *)&mpc8349_dma_ip_feature,
+	},
+	{}
+};
+
+static struct of_platform_driver of_fsl_dma_chan_driver = {
+	.name = "of-fsl-dma-channel",
+	.match_table = of_fsl_dma_chan_ids,
+	.probe = of_fsl_dma_chan_probe,
+};
+
+static __init int of_fsl_dma_chan_init(void)
+{
+	return of_register_platform_driver(&of_fsl_dma_chan_driver);
+}
+
+static int __devinit of_fsl_dma_probe(struct of_device *dev,
+			const struct of_device_id *match)
+{
+	int err;
+	unsigned int irq;
+	struct fsl_dma_device *fdev;
+
+	fdev = kzalloc(sizeof(struct fsl_dma_device), GFP_KERNEL);
+	if (!fdev) {
+		dev_err(&dev->dev, "No enough memory for 'priv'\n");
+		err = -ENOMEM;
+		goto err;
+	}
+	fdev->dev = &dev->dev;
+	INIT_LIST_HEAD(&fdev->common.channels);
+
+	/* get DMA controller register base */
+	err = of_address_to_resource(dev->node, 0, &fdev->reg);
+	if (err) {
+		dev_err(&dev->dev, "Can't get %s property 'reg'\n",
+				dev->node->full_name);
+		goto err;
+	}
+
+	dev_info(&dev->dev, "Probe the Freescale DMA driver for %s "
+			"controller at 0x%08x...\n",
+			match->compatible, fdev->reg.start);
+	fdev->reg_base = ioremap(fdev->reg.start, fdev->reg.end
+						- fdev->reg.start + 1);
+
+	dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
+	dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
+	fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
+	fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
+	fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
+	fdev->common.device_is_tx_complete = fsl_dma_is_complete;
+	fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
+	fdev->common.device_dependency_added = fsl_dma_dependency_added;
+	fdev->common.dev = &dev->dev;
+
+	irq = irq_of_parse_and_map(dev->node, 0);
+	if (irq != NO_IRQ) {
+		err = request_irq(irq, &fsl_dma_do_interrupt, IRQF_SHARED,
+					"fsldma-device", fdev);
+		if (err) {
+			dev_err(&dev->dev, "DMA device request_irq error "
+				"with return %d\n", err);
+			goto err;
+		}
+	}
+
+	dev_set_drvdata(&(dev->dev), fdev);
+	of_platform_bus_probe(dev->node, of_fsl_dma_chan_ids, &dev->dev);
+
+	dma_async_device_register(&fdev->common);
+	return 0;
+
+err:
+	iounmap(fdev->reg_base);
+	kfree(fdev);
+	return err;
+}
+
+static struct of_device_id of_fsl_dma_ids[] = {
+	{ .compatible = "fsl,mpc8540-dma", },
+	{ .compatible = "fsl,mpc8349-dma", },
+	{}
+};
+
+static struct of_platform_driver of_fsl_dma_driver = {
+	.name = "of-fsl-dma",
+	.match_table = of_fsl_dma_ids,
+	.probe = of_fsl_dma_probe,
+};
+
+static __init int of_fsl_dma_init(void)
+{
+	return of_register_platform_driver(&of_fsl_dma_driver);
+}
+
+subsys_initcall(of_fsl_dma_chan_init);
+subsys_initcall(of_fsl_dma_init);