On 03-04-23, 17:47, Paul Cercueil wrote:
This function can be used to initiate a scatter-gather DMA transfer where the DMA addresses and lengths are located inside arrays.
The major difference with dmaengine_prep_slave_sg() is that it supports specifying the lengths of each DMA transfer; as trying to override the length of the transfer with dmaengine_prep_slave_sg() is a very tedious process. The introduction of a new API function is also justified by the fact that scatterlists are on their way out.
Do we need a new API for this? why not use device_prep_interleaved_dma?
Signed-off-by: Paul Cercueil paul@crapouillou.net
v3: New patch
include/linux/dmaengine.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index c3656e590213..62efa28c009a 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -912,6 +912,11 @@ struct dma_device { struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)( struct dma_chan *chan, unsigned long flags);
- struct dma_async_tx_descriptor *(*device_prep_slave_dma_array)(
struct dma_chan *chan, dma_addr_t *addrs,size_t *lengths, size_t nb,enum dma_transfer_direction direction,unsigned long flags);@@ -974,6 +979,17 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single( dir, flags, NULL); } +static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_dma_array(
- struct dma_chan *chan, dma_addr_t *addrs, size_t *lengths,
- size_t nb, enum dma_transfer_direction dir, unsigned long flags)
+{
- if (!chan || !chan->device || !chan->device->device_prep_slave_dma_array)
return NULL;- return chan->device->device_prep_slave_dma_array(chan, addrs, lengths,
nb, dir, flags);+}
static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg( struct dma_chan *chan, struct scatterlist *sgl, unsigned int sg_len, enum dma_transfer_direction dir, unsigned long flags) -- 2.39.2