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.
Signed-off-by: Paul Cercueil <p...@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);
struct dma_async_tx_descriptor *(*device_prep_slave_sg)(
struct dma_chan *chan, struct scatterlist *sgl,
unsigned int sg_len, enum dma_transfer_direction direction,
@@ -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
