[PATCH v3 1/3] dma: Support multiple interleaved frames with non-contiguous memory

From: Srikanth Thokala
Date: Sat Feb 15 2014 - 07:00:58 EST


The current implementation of interleaved DMA API support multiple
frames only when the memory is contiguous by incrementing src_start/
dst_start members of interleaved template.

But, when the memory is non-contiguous it will restrict slave device
to not submit multiple frames in a batch. This patch handles this
issue by allowing the slave device to send array of interleaved dma
templates each having a different memory location.

Signed-off-by: Srikanth Thokala <sthokal@xxxxxxxxxx>
---
Documentation/dmaengine.txt | 2 +-
drivers/dma/imx-dma.c | 3 ++-
drivers/dma/sirf-dma.c | 3 ++-
drivers/media/platform/m2m-deinterlace.c | 2 +-
include/linux/dmaengine.h | 6 +++---
5 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/Documentation/dmaengine.txt b/Documentation/dmaengine.txt
index 879b6e3..c642614 100644
--- a/Documentation/dmaengine.txt
+++ b/Documentation/dmaengine.txt
@@ -94,7 +94,7 @@ The slave DMA usage consists of following steps:
size_t period_len, enum dma_data_direction direction);

struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)(
- struct dma_chan *chan, struct dma_interleaved_template *xt,
+ struct dma_chan *chan, struct dma_interleaved_template **xts,
unsigned long flags);

The peripheral driver is expected to have mapped the scatterlist for
diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
index 6f9ac20..e2c52ce 100644
--- a/drivers/dma/imx-dma.c
+++ b/drivers/dma/imx-dma.c
@@ -954,12 +954,13 @@ static struct dma_async_tx_descriptor *imxdma_prep_dma_memcpy(
}

static struct dma_async_tx_descriptor *imxdma_prep_dma_interleaved(
- struct dma_chan *chan, struct dma_interleaved_template *xt,
+ struct dma_chan *chan, struct dma_interleaved_template **xts,
unsigned long flags)
{
struct imxdma_channel *imxdmac = to_imxdma_chan(chan);
struct imxdma_engine *imxdma = imxdmac->imxdma;
struct imxdma_desc *desc;
+ struct dma_interleaved_template *xt = *xts;

dev_dbg(imxdma->dev, "%s channel: %d src_start=0x%llx dst_start=0x%llx\n"
" src_sgl=%s dst_sgl=%s numf=%zu frame_size=%zu\n", __func__,
diff --git a/drivers/dma/sirf-dma.c b/drivers/dma/sirf-dma.c
index d4d3a31..b6a150b 100644
--- a/drivers/dma/sirf-dma.c
+++ b/drivers/dma/sirf-dma.c
@@ -509,12 +509,13 @@ sirfsoc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
}

static struct dma_async_tx_descriptor *sirfsoc_dma_prep_interleaved(
- struct dma_chan *chan, struct dma_interleaved_template *xt,
+ struct dma_chan *chan, struct dma_interleaved_template **xts,
unsigned long flags)
{
struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
struct sirfsoc_dma_desc *sdesc = NULL;
+ struct dma_interleaved_template *xt = *xts;
unsigned long iflags;
int ret;

diff --git a/drivers/media/platform/m2m-deinterlace.c b/drivers/media/platform/m2m-deinterlace.c
index 6bb86b5..468110a 100644
--- a/drivers/media/platform/m2m-deinterlace.c
+++ b/drivers/media/platform/m2m-deinterlace.c
@@ -343,7 +343,7 @@ static void deinterlace_issue_dma(struct deinterlace_ctx *ctx, int op,
ctx->xt->dst_sgl = true;
flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;

- tx = dmadev->device_prep_interleaved_dma(chan, ctx->xt, flags);
+ tx = dmadev->device_prep_interleaved_dma(chan, &ctx->xt, flags);
if (tx == NULL) {
v4l2_warn(&pcdev->v4l2_dev, "DMA interleaved prep error\n");
return;
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index c5c92d5..2f77a9a 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -675,7 +675,7 @@ struct dma_device {
size_t period_len, enum dma_transfer_direction direction,
unsigned long flags, void *context);
struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)(
- struct dma_chan *chan, struct dma_interleaved_template *xt,
+ struct dma_chan *chan, struct dma_interleaved_template **xts,
unsigned long flags);
int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg);
@@ -752,10 +752,10 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic(
}

static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma(
- struct dma_chan *chan, struct dma_interleaved_template *xt,
+ struct dma_chan *chan, struct dma_interleaved_template **xts,
unsigned long flags)
{
- return chan->device->device_prep_interleaved_dma(chan, xt, flags);
+ return chan->device->device_prep_interleaved_dma(chan, xts, flags);
}

static inline int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
--
1.7.9.5

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