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Date: Wed, 02 Apr 2014 20:17:00 -0700 (PDT)
From: Kuninori Morimoto <kuninori.morimoto.gx@...il.com>
To: Vinod Koul <vinod.koul@...el.com>
Cc: Linux-SH <linux-sh@...r.kernel.org>, linux-kernel@...r.kernel.org,
dmaengine@...r.kernel.org
Subject: [PATCH 2/2] DMA: shdma: add cyclic transfer support
From: Kuninori Morimoto <kuninori.morimoto.gx@...esas.com>
This patch add cyclic transfer support
and enables dmaengine_prep_dma_cyclic()
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@...esas.com>
---
drivers/dma/sh/shdma-base.c | 72 ++++++++++++++++++++++++++++++++++++++-----
include/linux/shdma-base.h | 1 +
2 files changed, 66 insertions(+), 7 deletions(-)
diff --git a/drivers/dma/sh/shdma-base.c b/drivers/dma/sh/shdma-base.c
index 6786ecb..974794c 100644
--- a/drivers/dma/sh/shdma-base.c
+++ b/drivers/dma/sh/shdma-base.c
@@ -304,6 +304,7 @@ static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all)
dma_async_tx_callback callback = NULL;
void *param = NULL;
unsigned long flags;
+ LIST_HEAD(cyclic_list);
spin_lock_irqsave(&schan->chan_lock, flags);
list_for_each_entry_safe(desc, _desc, &schan->ld_queue, node) {
@@ -369,10 +370,16 @@ static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all)
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, &schan->ld_free);
+ if (all || !desc->cyclic) {
+ /* Remove from ld_queue list */
+ desc->mark = DESC_IDLE;
+ list_move(&desc->node, &schan->ld_free);
+ } else {
+ /* reuse as cyclic */
+ desc->mark = DESC_SUBMITTED;
+ list_move_tail(&desc->node, &cyclic_list);
+ }
if (list_empty(&schan->ld_queue)) {
dev_dbg(schan->dev, "Bring down channel %d\n", schan->id);
@@ -389,6 +396,8 @@ static dma_async_tx_callback __ld_cleanup(struct shdma_chan *schan, bool all)
*/
schan->dma_chan.completed_cookie = schan->dma_chan.cookie;
+ list_splice_tail(&cyclic_list, &schan->ld_queue);
+
spin_unlock_irqrestore(&schan->chan_lock, flags);
if (callback)
@@ -521,7 +530,7 @@ static struct shdma_desc *shdma_add_desc(struct shdma_chan *schan,
*/
static struct dma_async_tx_descriptor *shdma_prep_sg(struct shdma_chan *schan,
struct scatterlist *sgl, unsigned int sg_len, dma_addr_t *addr,
- enum dma_transfer_direction direction, unsigned long flags)
+ enum dma_transfer_direction direction, unsigned long flags, bool cyclic)
{
struct scatterlist *sg;
struct shdma_desc *first = NULL, *new = NULL /* compiler... */;
@@ -569,7 +578,11 @@ static struct dma_async_tx_descriptor *shdma_prep_sg(struct shdma_chan *schan,
if (!new)
goto err_get_desc;
- new->chunks = chunks--;
+ new->cyclic = cyclic;
+ if (cyclic)
+ new->chunks = 1;
+ else
+ new->chunks = chunks--;
list_add_tail(&new->node, &tx_list);
} while (len);
}
@@ -612,7 +625,8 @@ static struct dma_async_tx_descriptor *shdma_prep_memcpy(
sg_dma_address(&sg) = dma_src;
sg_dma_len(&sg) = len;
- return shdma_prep_sg(schan, &sg, 1, &dma_dest, DMA_MEM_TO_MEM, flags);
+ return shdma_prep_sg(schan, &sg, 1, &dma_dest, DMA_MEM_TO_MEM,
+ flags, false);
}
static struct dma_async_tx_descriptor *shdma_prep_slave_sg(
@@ -640,7 +654,50 @@ static struct dma_async_tx_descriptor *shdma_prep_slave_sg(
slave_addr = ops->slave_addr(schan);
return shdma_prep_sg(schan, sgl, sg_len, &slave_addr,
- direction, flags);
+ direction, flags, false);
+}
+
+struct dma_async_tx_descriptor *shdma_prep_dma_cyclic(
+ struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
+ size_t period_len, enum dma_transfer_direction direction,
+ unsigned long flags, void *context)
+{
+ struct shdma_chan *schan = to_shdma_chan(chan);
+ struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
+ const struct shdma_ops *ops = sdev->ops;
+ unsigned int sg_len = buf_len / period_len;
+ int slave_id = schan->slave_id;
+ dma_addr_t slave_addr;
+ struct scatterlist sgl[sg_len];
+ int i;
+
+ if (!chan)
+ return NULL;
+
+ BUG_ON(!schan->desc_num);
+
+ /* Someone calling slave DMA on a generic channel? */
+ if (slave_id < 0 || (buf_len < period_len)) {
+ dev_warn(schan->dev,
+ "%s: bad parameter: buf_len=%d, period_len=%d, id=%d\n",
+ __func__, buf_len, period_len, slave_id);
+ return NULL;
+ }
+
+ slave_addr = ops->slave_addr(schan);
+
+ sg_init_table(sgl, sg_len);
+ for (i = 0; i < sg_len; i++) {
+ dma_addr_t src = buf_addr + (period_len * i);
+
+ sg_set_page(&sgl[i], pfn_to_page(PFN_DOWN(src)), period_len,
+ offset_in_page(src));
+ sg_dma_address(&sgl[i]) = src;
+ sg_dma_len(&sgl[i]) = period_len;
+ }
+
+ return shdma_prep_sg(schan, sgl, sg_len, &slave_addr,
+ direction, flags, true);
}
static int shdma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
@@ -915,6 +972,7 @@ int shdma_init(struct device *dev, struct shdma_dev *sdev,
/* Compulsory for DMA_SLAVE fields */
dma_dev->device_prep_slave_sg = shdma_prep_slave_sg;
+ dma_dev->device_prep_dma_cyclic = shdma_prep_dma_cyclic;
dma_dev->device_control = shdma_control;
dma_dev->dev = dev;
diff --git a/include/linux/shdma-base.h b/include/linux/shdma-base.h
index f92c0a4..abdf1f2 100644
--- a/include/linux/shdma-base.h
+++ b/include/linux/shdma-base.h
@@ -54,6 +54,7 @@ struct shdma_desc {
dma_cookie_t cookie;
int chunks;
int mark;
+ bool cyclic; /* used as cyclic transfer */
};
struct shdma_chan {
--
1.7.9.5
--
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