DMAEngine: Define interleaved transfer request api

Define a new api that could be used for doing fancy data transfers
like interleaved to contiguous copy and vice-versa.
Traditional SG_list based transfers tend to be very inefficient in
such cases as where the interleave and chunk are only a few bytes,
which call for a very condensed api to convey pattern of the transfer.
This api supports all 4 variants of scatter-gather and contiguous transfer.

Of course, neither can this api help transfers that don't lend to DMA by
nature, i.e, scattered tiny read/writes with no periodic pattern.

Also since now we support SLAVE channels that might not provide
device_prep_slave_sg callback but device_prep_interleaved_dma,
remove the BUG_ON check.

Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Acked-by: Barry Song <Baohua.Song@csr.com>
[renamed dmaxfer_template to dma_interleaved_template
 did fixup after the enum dma_transfer_merge]
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index b48967b499da..a6c6051ec858 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -693,12 +693,12 @@ int dma_async_device_register(struct dma_device *device)
                 !device->device_prep_dma_interrupt);
         BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&
                 !device->device_prep_dma_sg);
-        BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
-                !device->device_prep_slave_sg);
         BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
                 !device->device_prep_dma_cyclic);
         BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
                 !device->device_control);
+        BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
+                !device->device_prep_interleaved_dma);
 
         BUG_ON(!device->device_alloc_chan_resources);
         BUG_ON(!device->device_free_chan_resources);