[PATCH v2 1/2] dmaengine: Add support for audio interleaved transfer

[Sugar Zhang]

This patch add support for interleaved transfer which used
for interleaved audio or 2d video data transfer.

for audio situation, we add 'nump' for number of period frames.

e.g. combine 2 stream into a union one by 2D dma.

DAI0: 16CH
+-------------------------------------------------------------+
| Frame-1 | Frame-2 | Frame-3 | Frame-4 | ...... Frame-'numf' |
+-------------------------------------------------------------+

DAI1: 16CH
+-------------------------------------------------------------+
| Frame-1 | Frame-2 | Frame-3 | Frame-4 | ...... Frame-'numf' |
+-------------------------------------------------------------+

DAI0 + DAI1: 32CH

+-------------------------------------------------------------+
| DAI0-F1 | DAI1-F1 | DAI0-F2 | DAI1-F2 | ......              |
+-------------------------------------------------------------+
|      Frame-1      |      Frame-2      | ...... Frame-'numf' |

For audio situation, we have buffer_size and period_size,
the 'numf' is the buffer_size. so, we need another one for
period_size, e.g. 'nump'.

| Frame-1 | ~ | Frame-'nump' | ~ | Frame-'nump+1' | ~ |  Frame-'numf' |
|

As the above shown:

each DAI0 transfer 1 Frame, should skip a gap size (DAI1-F1)
each DAI1 transfer 1 Frame, should skip a gap size (DAI0-F1)

So, the interleaved template describe as follows:

DAI0:

struct dma_interleaved_template *xt;

xt->sgl[0].size = DAI0-F1;
xt->sgl[0].icg =  DAI1-F1;
xt->nump = nump; //the period_size in frames
xt->numf = numf; //the buffer_size in frames

DAI1:

struct dma_interleaved_template *xt;

xt->sgl[0].size = DAI1-F1;
xt->sgl[0].icg =  DAI0-F1;
xt->nump = nump; //the period_size in frames
xt->numf = numf; //the buffer_size in frames

Signed-off-by: Sugar Zhang <sugar.zhang at rock-chips.com>
---

Changes in v2:
- Add the pl330 interleaved transfer

 include/linux/dmaengine.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 752dbde..5263cde 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -144,6 +144,7 @@ struct data_chunk {
  *		Otherwise, destination is filled contiguously (icg ignored).
  *		Ignored if dst_inc is false.
  * @numf: Number of frames in this template.
+ * @nump: Number of period frames in this template.
  * @frame_size: Number of chunks in a frame i.e, size of sgl[].
  * @sgl: Array of {chunk,icg} pairs that make up a frame.
  */
@@ -156,6 +157,7 @@ struct dma_interleaved_template {
 	bool src_sgl;
 	bool dst_sgl;
 	size_t numf;
+	size_t nump;
 	size_t frame_size;
 	struct data_chunk sgl[];
 };
-- 
2.7.4