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>

1 files changed, 318 insertions, 0 deletions

diff --git a/drivers/dma/coh901318_lli.c b/drivers/dma/coh901318_lli.c
new file mode 100644
index 0000000..f5120f2
--- /dev/null
+++ 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;
+}