dmaengine: add helper function for slave_single
For clients which require a single slave transfer and dont want to be bothered
about the scatterlist api, this helper gives simple API for this transfer and
creates single scatterlist for DMA API
Idea from Russell King
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 8fbf40e..0d738c9 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -24,6 +24,7 @@
#include <linux/device.h>
#include <linux/uio.h>
#include <linux/dma-direction.h>
+#include <linux/scatterlist.h>
struct scatterlist;
@@ -519,6 +520,16 @@
(unsigned long)config);
}
+static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single(
+ struct dma_chan *chan, void *buf, size_t len,
+ enum dma_data_direction dir, unsigned long flags)
+{
+ struct scatterlist sg;
+ sg_init_one(&sg, buf, len);
+
+ return chan->device->device_prep_slave_sg(chan, &sg, 1, dir, flags);
+}
+
static inline int dmaengine_terminate_all(struct dma_chan *chan)
{
return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0);