Add COH 901 318 DMA block driver v5

This patch adds support for the ST-Ericsson COH 901 318 DMA block, found in the U300 series platforms. It registers a DMA slave for device I/O and also a memcpy slave for memcpy. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2024-11-11 12:28:41 +08:00 · 2009-11-19 19:49:17 +01:00 · 2009-11-19 19:49:17 +01:00 · 61f135b92f
commit 61f135b92f
parent b419148e56
6 changed files with 2056 additions and 0 deletions
--- a/arch/arm/mach-u300/include/mach/coh901318.h
+++ b/arch/arm/mach-u300/include/mach/coh901318.h
@ -0,0 +1,281 @@
+/*
+ *
+ * include/linux/coh901318.h
+ *
+ *
+ * Copyright (C) 2007-2009 ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ * DMA driver for COH 901 318
+ * Author: Per Friden <per.friden@stericsson.com>
+ */
+
+#ifndef COH901318_H
+#define COH901318_H
+
+#include <linux/device.h>
+#include <linux/dmaengine.h>
+
+#define MAX_DMA_PACKET_SIZE_SHIFT 11
+#define MAX_DMA_PACKET_SIZE (1 << MAX_DMA_PACKET_SIZE_SHIFT)
+
+/**
+ * struct coh901318_lli - linked list item for DMAC
+ * @control: control settings for DMAC
+ * @src_addr: transfer source address
+ * @dst_addr: transfer destination address
+ * @link_addr:  physical address to next lli
+ * @virt_link_addr: virtual addres of next lli (only used by pool_free)
+ * @phy_this: physical address of current lli (only used by pool_free)
+ */
+struct coh901318_lli {
+	u32 control;
+	dma_addr_t src_addr;
+	dma_addr_t dst_addr;
+	dma_addr_t link_addr;
+
+	void *virt_link_addr;
+	dma_addr_t phy_this;
+};
+/**
+ * struct coh901318_params - parameters for DMAC configuration
+ * @config: DMA config register
+ * @ctrl_lli_last: DMA control register for the last lli in the list
+ * @ctrl_lli: DMA control register for an lli
+ * @ctrl_lli_chained: DMA control register for a chained lli
+ */
+struct coh901318_params {
+	u32 config;
+	u32 ctrl_lli_last;
+	u32 ctrl_lli;
+	u32 ctrl_lli_chained;
+};
+/**
+ * struct coh_dma_channel - dma channel base
+ * @name: ascii name of dma channel
+ * @number: channel id number
+ * @desc_nbr_max: number of preallocated descriptortors
+ * @priority_high: prio of channel, 0 low otherwise high.
+ * @param: configuration parameters
+ * @dev_addr: physical address of periphal connected to channel
+ */
+struct coh_dma_channel {
+	const char name[32];
+	const int number;
+	const int desc_nbr_max;
+	const int priority_high;
+	const struct coh901318_params param;
+	const dma_addr_t dev_addr;
+};
+
+/**
+ * dma_access_memory_state_t - register dma for memory access
+ *
+ * @dev: The dma device
+ * @active:  1 means dma intends to access memory
+ *           0 means dma wont access memory
+ */
+typedef void (*dma_access_memory_state_t)(struct device *dev,
+					  bool active);
+
+/**
+ * struct powersave - DMA power save structure
+ * @lock: lock protecting data in this struct
+ * @started_channels: bit mask indicating active dma channels
+ */
+struct powersave {
+	spinlock_t lock;
+	u64 started_channels;
+};
+/**
+ * struct coh901318_platform - platform arch structure
+ * @chans_slave: specifying dma slave channels
+ * @chans_memcpy: specifying dma memcpy channels
+ * @access_memory_state: requesting DMA memeory access (on / off)
+ * @chan_conf: dma channel configurations
+ * @max_channels: max number of dma chanenls
+ */
+struct coh901318_platform {
+	const int *chans_slave;
+	const int *chans_memcpy;
+	const dma_access_memory_state_t access_memory_state;
+	const struct coh_dma_channel *chan_conf;
+	const int max_channels;
+};
+
+/**
+ * coh901318_get_bytes_left() - Get number of bytes left on a current transfer
+ * @chan: dma channel handle
+ * return number of bytes left, or negative on error
+ */
+u32 coh901318_get_bytes_left(struct dma_chan *chan);
+
+/**
+ * coh901318_stop() - Stops dma transfer
+ * @chan: dma channel handle
+ * return 0 on success otherwise negative value
+ */
+void coh901318_stop(struct dma_chan *chan);
+
+/**
+ * coh901318_continue() - Resumes a stopped dma transfer
+ * @chan: dma channel handle
+ * return 0 on success otherwise negative value
+ */
+void coh901318_continue(struct dma_chan *chan);
+
+/**
+ * coh901318_filter_id() - DMA channel filter function
+ * @chan: dma channel handle
+ * @chan_id: id of dma channel to be filter out
+ *
+ * In dma_request_channel() it specifies what channel id to be requested
+ */
+bool coh901318_filter_id(struct dma_chan *chan, void *chan_id);
+
+/*
+ * DMA Controller - this access the static mappings of the coh901318 dma.
+ *
+ */
+
+#define COH901318_MOD32_MASK					(0x1F)
+#define COH901318_WORD_MASK					(0xFFFFFFFF)
+/* INT_STATUS - Interrupt Status Registers 32bit (R/-) */
+#define COH901318_INT_STATUS1					(0x0000)
+#define COH901318_INT_STATUS2					(0x0004)
+/* TC_INT_STATUS - Terminal Count Interrupt Status Registers 32bit (R/-) */
+#define COH901318_TC_INT_STATUS1				(0x0008)
+#define COH901318_TC_INT_STATUS2				(0x000C)
+/* TC_INT_CLEAR - Terminal Count Interrupt Clear Registers 32bit (-/W) */
+#define COH901318_TC_INT_CLEAR1					(0x0010)
+#define COH901318_TC_INT_CLEAR2					(0x0014)
+/* RAW_TC_INT_STATUS - Raw Term Count Interrupt Status Registers 32bit (R/-) */
+#define COH901318_RAW_TC_INT_STATUS1				(0x0018)
+#define COH901318_RAW_TC_INT_STATUS2				(0x001C)
+/* BE_INT_STATUS - Bus Error Interrupt Status Registers 32bit (R/-) */
+#define COH901318_BE_INT_STATUS1				(0x0020)
+#define COH901318_BE_INT_STATUS2				(0x0024)
+/* BE_INT_CLEAR - Bus Error Interrupt Clear Registers 32bit (-/W) */
+#define COH901318_BE_INT_CLEAR1					(0x0028)
+#define COH901318_BE_INT_CLEAR2					(0x002C)
+/* RAW_BE_INT_STATUS - Raw Term Count Interrupt Status Registers 32bit (R/-) */
+#define COH901318_RAW_BE_INT_STATUS1				(0x0030)
+#define COH901318_RAW_BE_INT_STATUS2				(0x0034)
+
+/*
+ * CX_CFG - Channel Configuration Registers 32bit (R/W)
+ */
+#define COH901318_CX_CFG					(0x0100)
+#define COH901318_CX_CFG_SPACING				(0x04)
+/* Channel enable activates tha dma job */
+#define COH901318_CX_CFG_CH_ENABLE				(0x00000001)
+#define COH901318_CX_CFG_CH_DISABLE				(0x00000000)
+/* Request Mode */
+#define COH901318_CX_CFG_RM_MASK				(0x00000006)
+#define COH901318_CX_CFG_RM_MEMORY_TO_MEMORY			(0x0 << 1)
+#define COH901318_CX_CFG_RM_PRIMARY_TO_MEMORY			(0x1 << 1)
+#define COH901318_CX_CFG_RM_MEMORY_TO_PRIMARY			(0x1 << 1)
+#define COH901318_CX_CFG_RM_PRIMARY_TO_SECONDARY		(0x3 << 1)
+#define COH901318_CX_CFG_RM_SECONDARY_TO_PRIMARY		(0x3 << 1)
+/* Linked channel request field. RM must == 11 */
+#define COH901318_CX_CFG_LCRF_SHIFT				3
+#define COH901318_CX_CFG_LCRF_MASK				(0x000001F8)
+#define COH901318_CX_CFG_LCR_DISABLE				(0x00000000)
+/* Terminal Counter Interrupt Request Mask */
+#define COH901318_CX_CFG_TC_IRQ_ENABLE				(0x00000200)
+#define COH901318_CX_CFG_TC_IRQ_DISABLE				(0x00000000)
+/* Bus Error interrupt Mask */
+#define COH901318_CX_CFG_BE_IRQ_ENABLE				(0x00000400)
+#define COH901318_CX_CFG_BE_IRQ_DISABLE				(0x00000000)
+
+/*
+ * CX_STAT - Channel Status Registers 32bit (R/-)
+ */
+#define COH901318_CX_STAT					(0x0200)
+#define COH901318_CX_STAT_SPACING				(0x04)
+#define COH901318_CX_STAT_RBE_IRQ_IND				(0x00000008)
+#define COH901318_CX_STAT_RTC_IRQ_IND				(0x00000004)
+#define COH901318_CX_STAT_ACTIVE				(0x00000002)
+#define COH901318_CX_STAT_ENABLED				(0x00000001)
+
+/*
+ * CX_CTRL - Channel Control Registers 32bit (R/W)
+ */
+#define COH901318_CX_CTRL					(0x0400)
+#define COH901318_CX_CTRL_SPACING				(0x10)
+/* Transfer Count Enable */
+#define COH901318_CX_CTRL_TC_ENABLE				(0x00001000)
+#define COH901318_CX_CTRL_TC_DISABLE				(0x00000000)
+/* Transfer Count Value 0 - 4095 */
+#define COH901318_CX_CTRL_TC_VALUE_MASK				(0x00000FFF)
+/* Burst count */
+#define COH901318_CX_CTRL_BURST_COUNT_MASK			(0x0000E000)
+#define COH901318_CX_CTRL_BURST_COUNT_64_BYTES			(0x7 << 13)
+#define COH901318_CX_CTRL_BURST_COUNT_48_BYTES			(0x6 << 13)
+#define COH901318_CX_CTRL_BURST_COUNT_32_BYTES			(0x5 << 13)
+#define COH901318_CX_CTRL_BURST_COUNT_16_BYTES			(0x4 << 13)
+#define COH901318_CX_CTRL_BURST_COUNT_8_BYTES			(0x3 << 13)
+#define COH901318_CX_CTRL_BURST_COUNT_4_BYTES			(0x2 << 13)
+#define COH901318_CX_CTRL_BURST_COUNT_2_BYTES			(0x1 << 13)
+#define COH901318_CX_CTRL_BURST_COUNT_1_BYTE			(0x0 << 13)
+/* Source bus size  */
+#define COH901318_CX_CTRL_SRC_BUS_SIZE_MASK			(0x00030000)
+#define COH901318_CX_CTRL_SRC_BUS_SIZE_32_BITS			(0x2 << 16)
+#define COH901318_CX_CTRL_SRC_BUS_SIZE_16_BITS			(0x1 << 16)
+#define COH901318_CX_CTRL_SRC_BUS_SIZE_8_BITS			(0x0 << 16)
+/* Source address increment */
+#define COH901318_CX_CTRL_SRC_ADDR_INC_ENABLE			(0x00040000)
+#define COH901318_CX_CTRL_SRC_ADDR_INC_DISABLE			(0x00000000)
+/* Destination Bus Size */
+#define COH901318_CX_CTRL_DST_BUS_SIZE_MASK			(0x00180000)
+#define COH901318_CX_CTRL_DST_BUS_SIZE_32_BITS			(0x2 << 19)
+#define COH901318_CX_CTRL_DST_BUS_SIZE_16_BITS			(0x1 << 19)
+#define COH901318_CX_CTRL_DST_BUS_SIZE_8_BITS			(0x0 << 19)
+/* Destination address increment */
+#define COH901318_CX_CTRL_DST_ADDR_INC_ENABLE			(0x00200000)
+#define COH901318_CX_CTRL_DST_ADDR_INC_DISABLE			(0x00000000)
+/* Master Mode (Master2 is only connected to MSL) */
+#define COH901318_CX_CTRL_MASTER_MODE_MASK			(0x00C00000)
+#define COH901318_CX_CTRL_MASTER_MODE_M2R_M1W			(0x3 << 22)
+#define COH901318_CX_CTRL_MASTER_MODE_M1R_M2W			(0x2 << 22)
+#define COH901318_CX_CTRL_MASTER_MODE_M2RW			(0x1 << 22)
+#define COH901318_CX_CTRL_MASTER_MODE_M1RW			(0x0 << 22)
+/* Terminal Count flag to PER enable */
+#define COH901318_CX_CTRL_TCP_ENABLE				(0x01000000)
+#define COH901318_CX_CTRL_TCP_DISABLE				(0x00000000)
+/* Terminal Count flags to CPU enable */
+#define COH901318_CX_CTRL_TC_IRQ_ENABLE				(0x02000000)
+#define COH901318_CX_CTRL_TC_IRQ_DISABLE			(0x00000000)
+/* Hand shake to peripheral */
+#define COH901318_CX_CTRL_HSP_ENABLE				(0x04000000)
+#define COH901318_CX_CTRL_HSP_DISABLE				(0x00000000)
+#define COH901318_CX_CTRL_HSS_ENABLE				(0x08000000)
+#define COH901318_CX_CTRL_HSS_DISABLE				(0x00000000)
+/* DMA mode */
+#define COH901318_CX_CTRL_DDMA_MASK				(0x30000000)
+#define COH901318_CX_CTRL_DDMA_LEGACY				(0x0 << 28)
+#define COH901318_CX_CTRL_DDMA_DEMAND_DMA1			(0x1 << 28)
+#define COH901318_CX_CTRL_DDMA_DEMAND_DMA2			(0x2 << 28)
+/* Primary Request Data Destination */
+#define COH901318_CX_CTRL_PRDD_MASK				(0x40000000)
+#define COH901318_CX_CTRL_PRDD_DEST				(0x1 << 30)
+#define COH901318_CX_CTRL_PRDD_SOURCE				(0x0 << 30)
+
+/*
+ * CX_SRC_ADDR - Channel Source Address Registers 32bit (R/W)
+ */
+#define COH901318_CX_SRC_ADDR					(0x0404)
+#define COH901318_CX_SRC_ADDR_SPACING				(0x10)
+
+/*
+ * CX_DST_ADDR - Channel Destination Address Registers 32bit R/W
+ */
+#define COH901318_CX_DST_ADDR					(0x0408)
+#define COH901318_CX_DST_ADDR_SPACING				(0x10)
+
+/*
+ * CX_LNK_ADDR - Channel Link Address Registers 32bit (R/W)
+ */
+#define COH901318_CX_LNK_ADDR					(0x040C)
+#define COH901318_CX_LNK_ADDR_SPACING				(0x10)
+#define COH901318_CX_LNK_LINK_IMMEDIATE				(0x00000001)
+#endif /* COH901318_H */
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@ -109,6 +109,13 @@ config SH_DMAE
 	help
 	  Enable support for the Renesas SuperH DMA controllers.

+config COH901318
+	bool "ST-Ericsson COH901318 DMA support"
+	select DMA_ENGINE
+	depends on ARCH_U300
+	help
+	  Enable support for ST-Ericsson COH 901 318 DMA.
+
 config DMA_ENGINE
 	bool

--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@ -10,3 +10,4 @@ obj-$(CONFIG_AT_HDMAC) += at_hdmac.o
 obj-$(CONFIG_MX3_IPU) += ipu/
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
 obj-$(CONFIG_SH_DMAE) += shdma.o
+obj-$(CONFIG_COH901318) += coh901318.o coh901318_lli.o
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
--- a/drivers/dma/coh901318_lli.c
+++ b/drivers/dma/coh901318_lli.c
@ -0,0 +1,318 @@
+/*
+ * driver/dma/coh901318_lli.c
+ *
+ * Copyright (C) 2007-2009 ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ * Support functions for handling lli for dma
+ * Author: Per Friden <per.friden@stericsson.com>
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/spinlock.h>
+#include <linux/dmapool.h>
+#include <linux/memory.h>
+#include <mach/coh901318.h>
+
+#include "coh901318_lli.h"
+
+#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_U300_DEBUG))
+#define DEBUGFS_POOL_COUNTER_RESET(pool) (pool->debugfs_pool_counter = 0)
+#define DEBUGFS_POOL_COUNTER_ADD(pool, add) (pool->debugfs_pool_counter += add)
+#else
+#define DEBUGFS_POOL_COUNTER_RESET(pool)
+#define DEBUGFS_POOL_COUNTER_ADD(pool, add)
+#endif
+
+static struct coh901318_lli *
+coh901318_lli_next(struct coh901318_lli *data)
+{
+	if (data == NULL || data->link_addr == 0)
+		return NULL;
+
+	return (struct coh901318_lli *) data->virt_link_addr;
+}
+
+int coh901318_pool_create(struct coh901318_pool *pool,
+			  struct device *dev,
+			  size_t size, size_t align)
+{
+	spin_lock_init(&pool->lock);
+	pool->dev = dev;
+	pool->dmapool = dma_pool_create("lli_pool", dev, size, align, 0);
+
+	DEBUGFS_POOL_COUNTER_RESET(pool);
+	return 0;
+}
+
+int coh901318_pool_destroy(struct coh901318_pool *pool)
+{
+
+	dma_pool_destroy(pool->dmapool);
+	return 0;
+}
+
+struct coh901318_lli *
+coh901318_lli_alloc(struct coh901318_pool *pool, unsigned int len)
+{
+	int i;
+	struct coh901318_lli *head;
+	struct coh901318_lli *lli;
+	struct coh901318_lli *lli_prev;
+	dma_addr_t phy;
+
+	if (len == 0)
+		goto err;
+
+	spin_lock(&pool->lock);
+
+	head = dma_pool_alloc(pool->dmapool, GFP_NOWAIT, &phy);
+
+	if (head == NULL)
+		goto err;
+
+	DEBUGFS_POOL_COUNTER_ADD(pool, 1);
+
+	lli = head;
+	lli->phy_this = phy;
+
+	for (i = 1; i < len; i++) {
+		lli_prev = lli;
+
+		lli = dma_pool_alloc(pool->dmapool, GFP_NOWAIT, &phy);
+
+		if (lli == NULL)
+			goto err_clean_up;
+
+		DEBUGFS_POOL_COUNTER_ADD(pool, 1);
+		lli->phy_this = phy;
+
+		lli_prev->link_addr = phy;
+		lli_prev->virt_link_addr = lli;
+	}
+
+	lli->link_addr = 0x00000000U;
+
+	spin_unlock(&pool->lock);
+
+	return head;
+
+ err:
+	spin_unlock(&pool->lock);
+	return NULL;
+
+ err_clean_up:
+	lli_prev->link_addr = 0x00000000U;
+	spin_unlock(&pool->lock);
+	coh901318_lli_free(pool, &head);
+	return NULL;
+}
+
+void coh901318_lli_free(struct coh901318_pool *pool,
+			struct coh901318_lli **lli)
+{
+	struct coh901318_lli *l;
+	struct coh901318_lli *next;
+
+	if (lli == NULL)
+		return;
+
+	l = *lli;
+
+	if (l == NULL)
+		return;
+
+	spin_lock(&pool->lock);
+
+	while (l->link_addr) {
+		next = l->virt_link_addr;
+		dma_pool_free(pool->dmapool, l, l->phy_this);
+		DEBUGFS_POOL_COUNTER_ADD(pool, -1);
+		l = next;
+	}
+	dma_pool_free(pool->dmapool, l, l->phy_this);
+	DEBUGFS_POOL_COUNTER_ADD(pool, -1);
+
+	spin_unlock(&pool->lock);
+	*lli = NULL;
+}
+
+int
+coh901318_lli_fill_memcpy(struct coh901318_pool *pool,
+			  struct coh901318_lli *lli,
+			  dma_addr_t source, unsigned int size,
+			  dma_addr_t destination, u32 ctrl_chained,
+			  u32 ctrl_eom)
+{
+	int s = size;
+	dma_addr_t src = source;
+	dma_addr_t dst = destination;
+
+	lli->src_addr = src;
+	lli->dst_addr = dst;
+
+	while (lli->link_addr) {
+		lli->control = ctrl_chained | MAX_DMA_PACKET_SIZE;
+		lli->src_addr = src;
+		lli->dst_addr = dst;
+
+		s -= MAX_DMA_PACKET_SIZE;
+		lli = coh901318_lli_next(lli);
+
+		src += MAX_DMA_PACKET_SIZE;
+		dst += MAX_DMA_PACKET_SIZE;
+	}
+
+	lli->control = ctrl_eom | s;
+	lli->src_addr = src;
+	lli->dst_addr = dst;
+
+	/* One irq per single transfer */
+	return 1;
+}
+
+int
+coh901318_lli_fill_single(struct coh901318_pool *pool,
+			  struct coh901318_lli *lli,
+			  dma_addr_t buf, unsigned int size,
+			  dma_addr_t dev_addr, u32 ctrl_chained, u32 ctrl_eom,
+			  enum dma_data_direction dir)
+{
+	int s = size;
+	dma_addr_t src;
+	dma_addr_t dst;
+
+
+	if (dir == DMA_TO_DEVICE) {
+		src = buf;
+		dst = dev_addr;
+
+	} else if (dir == DMA_FROM_DEVICE) {
+
+		src = dev_addr;
+		dst = buf;
+	} else {
+		return -EINVAL;
+	}
+
+	while (lli->link_addr) {
+		size_t block_size = MAX_DMA_PACKET_SIZE;
+		lli->control = ctrl_chained | MAX_DMA_PACKET_SIZE;
+
+		/* If we are on the next-to-final block and there will
+		 * be less than half a DMA packet left for the last
+		 * block, then we want to make this block a little
+		 * smaller to balance the sizes. This is meant to
+		 * avoid too small transfers if the buffer size is
+		 * (MAX_DMA_PACKET_SIZE*N + 1) */
+		if (s < (MAX_DMA_PACKET_SIZE + MAX_DMA_PACKET_SIZE/2))
+			block_size = MAX_DMA_PACKET_SIZE/2;
+
+		s -= block_size;
+		lli->src_addr = src;
+		lli->dst_addr = dst;
+
+		lli = coh901318_lli_next(lli);
+
+		if (dir == DMA_TO_DEVICE)
+			src += block_size;
+		else if (dir == DMA_FROM_DEVICE)
+			dst += block_size;
+	}
+
+	lli->control = ctrl_eom | s;
+	lli->src_addr = src;
+	lli->dst_addr = dst;
+
+	/* One irq per single transfer */
+	return 1;
+}
+
+int
+coh901318_lli_fill_sg(struct coh901318_pool *pool,
+		      struct coh901318_lli *lli,
+		      struct scatterlist *sgl, unsigned int nents,
+		      dma_addr_t dev_addr, u32 ctrl_chained, u32 ctrl,
+		      u32 ctrl_last,
+		      enum dma_data_direction dir, u32 ctrl_irq_mask)
+{
+	int i;
+	struct scatterlist *sg;
+	u32 ctrl_sg;
+	dma_addr_t src = 0;
+	dma_addr_t dst = 0;
+	int nbr_of_irq = 0;
+	u32 bytes_to_transfer;
+	u32 elem_size;
+
+	if (lli == NULL)
+		goto err;
+
+	spin_lock(&pool->lock);
+
+	if (dir == DMA_TO_DEVICE)
+		dst = dev_addr;
+	else if (dir == DMA_FROM_DEVICE)
+		src = dev_addr;
+	else
+		goto err;
+
+	for_each_sg(sgl, sg, nents, i) {
+		if (sg_is_chain(sg)) {
+			/* sg continues to the next sg-element don't
+			 * send ctrl_finish until the last
+			 * sg-element in the chain
+			 */
+			ctrl_sg = ctrl_chained;
+		} else if (i == nents - 1)
+			ctrl_sg = ctrl_last;
+		else
+			ctrl_sg = ctrl ? ctrl : ctrl_last;
+
+
+		if ((ctrl_sg & ctrl_irq_mask))
+			nbr_of_irq++;
+
+		if (dir == DMA_TO_DEVICE)
+			/* increment source address */
+			src = sg_dma_address(sg);
+		else
+			/* increment destination address */
+			dst =  sg_dma_address(sg);
+
+		bytes_to_transfer = sg_dma_len(sg);
+
+		while (bytes_to_transfer) {
+			u32 val;
+
+			if (bytes_to_transfer > MAX_DMA_PACKET_SIZE) {
+				elem_size = MAX_DMA_PACKET_SIZE;
+				val = ctrl_chained;
+			} else {
+				elem_size = bytes_to_transfer;
+				val = ctrl_sg;
+			}
+
+			lli->control = val | elem_size;
+			lli->src_addr = src;
+			lli->dst_addr = dst;
+
+			if (dir == DMA_FROM_DEVICE)
+				dst += elem_size;
+			else
+				src += elem_size;
+
+			BUG_ON(lli->link_addr & 3);
+
+			bytes_to_transfer -= elem_size;
+			lli = coh901318_lli_next(lli);
+		}
+
+	}
+	spin_unlock(&pool->lock);
+
+	/* There can be many IRQs per sg transfer */
+	return nbr_of_irq;
+ err:
+	spin_unlock(&pool->lock);
+	return -EINVAL;
+}
--- a/drivers/dma/coh901318_lli.h
+++ b/drivers/dma/coh901318_lli.h
@ -0,0 +1,124 @@
+/*
+ * driver/dma/coh901318_lli.h
+ *
+ * Copyright (C) 2007-2009 ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ * Support functions for handling lli for coh901318
+ * Author: Per Friden <per.friden@stericsson.com>
+ */
+
+#ifndef COH901318_LLI_H
+#define COH901318_LLI_H
+
+#include <mach/coh901318.h>
+
+struct device;
+
+struct coh901318_pool {
+	spinlock_t lock;
+	struct dma_pool *dmapool;
+	struct device *dev;
+
+#ifdef CONFIG_DEBUG_FS
+	int debugfs_pool_counter;
+#endif
+};
+
+struct device;
+/**
+ * coh901318_pool_create() - Creates an dma pool for lli:s
+ * @pool: pool handle
+ * @dev: dma device
+ * @lli_nbr: number of lli:s in the pool
+ * @algin: adress alignemtn of lli:s
+ * returns 0 on success otherwise none zero
+ */
+int coh901318_pool_create(struct coh901318_pool *pool,
+			  struct device *dev,
+			  size_t lli_nbr, size_t align);
+
+/**
+ * coh901318_pool_destroy() - Destroys the dma pool
+ * @pool: pool handle
+ * returns 0 on success otherwise none zero
+ */
+int coh901318_pool_destroy(struct coh901318_pool *pool);
+
+/**
+ * coh901318_lli_alloc() - Allocates a linked list
+ *
+ * @pool: pool handle
+ * @len: length to list
+ * return: none NULL if success otherwise NULL
+ */
+struct coh901318_lli *
+coh901318_lli_alloc(struct coh901318_pool *pool,
+		    unsigned int len);
+
+/**
+ * coh901318_lli_free() - Returns the linked list items to the pool
+ * @pool: pool handle
+ * @lli: reference to lli pointer to be freed
+ */
+void coh901318_lli_free(struct coh901318_pool *pool,
+			struct coh901318_lli **lli);
+
+/**
+ * coh901318_lli_fill_memcpy() - Prepares the lli:s for dma memcpy
+ * @pool: pool handle
+ * @lli: allocated lli
+ * @src: src address
+ * @size: transfer size
+ * @dst: destination address
+ * @ctrl_chained: ctrl for chained lli
+ * @ctrl_last: ctrl for the last lli
+ * returns number of CPU interrupts for the lli, negative on error.
+ */
+int
+coh901318_lli_fill_memcpy(struct coh901318_pool *pool,
+			  struct coh901318_lli *lli,
+			  dma_addr_t src, unsigned int size,
+			  dma_addr_t dst, u32 ctrl_chained, u32 ctrl_last);
+
+/**
+ * coh901318_lli_fill_single() - Prepares the lli:s for dma single transfer
+ * @pool: pool handle
+ * @lli: allocated lli
+ * @buf: transfer buffer
+ * @size: transfer size
+ * @dev_addr: address of periphal
+ * @ctrl_chained: ctrl for chained lli
+ * @ctrl_last: ctrl for the last lli
+ * @dir: direction of transfer (to or from device)
+ * returns number of CPU interrupts for the lli, negative on error.
+ */
+int
+coh901318_lli_fill_single(struct coh901318_pool *pool,
+			  struct coh901318_lli *lli,
+			  dma_addr_t buf, unsigned int size,
+			  dma_addr_t dev_addr, u32 ctrl_chained, u32 ctrl_last,
+			  enum dma_data_direction dir);
+
+/**
+ * coh901318_lli_fill_single() - Prepares the lli:s for dma scatter list transfer
+ * @pool: pool handle
+ * @lli: allocated lli
+ * @sg: scatter gather list
+ * @nents: number of entries in sg
+ * @dev_addr: address of periphal
+ * @ctrl_chained: ctrl for chained lli
+ * @ctrl: ctrl of middle lli
+ * @ctrl_last: ctrl for the last lli
+ * @dir: direction of transfer (to or from device)
+ * @ctrl_irq_mask: ctrl mask for CPU interrupt
+ * returns number of CPU interrupts for the lli, negative on error.
+ */
+int
+coh901318_lli_fill_sg(struct coh901318_pool *pool,
+		      struct coh901318_lli *lli,
+		      struct scatterlist *sg, unsigned int nents,
+		      dma_addr_t dev_addr, u32 ctrl_chained,
+		      u32 ctrl, u32 ctrl_last,
+		      enum dma_data_direction dir, u32 ctrl_irq_mask);
+
+#endif /* COH901318_LLI_H */