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-rw-r--r--Documentation/dmaengine/provider.txt7
-rw-r--r--include/linux/dmaengine.h4
2 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/dmaengine/provider.txt b/Documentation/dmaengine/provider.txt
index e33bc1c8ed2c..bfadbfdf13ed 100644
--- a/Documentation/dmaengine/provider.txt
+++ b/Documentation/dmaengine/provider.txt
@@ -395,6 +395,13 @@ where to put them)
when DMA_CTRL_REUSE is already set
- Terminating the channel
+ * DMA_PREP_CMD
+ - If set, the client driver tells DMA controller that passed data in DMA
+ API is command data.
+ - Interpretation of command data is DMA controller specific. It can be
+ used for issuing commands to other peripherals/register reads/register
+ writes for which the descriptor should be in different format from
+ normal data descriptors.
General Design Notes
--------------------
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 533680860865..dd4de1d40166 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -186,6 +186,9 @@ struct dma_interleaved_template {
* on the result of this operation
* @DMA_CTRL_REUSE: client can reuse the descriptor and submit again till
* cleared or freed
+ * @DMA_PREP_CMD: tell the driver that the data passed to DMA API is command
+ * data and the descriptor should be in different format from normal
+ * data descriptors.
*/
enum dma_ctrl_flags {
DMA_PREP_INTERRUPT = (1 << 0),
@@ -195,6 +198,7 @@ enum dma_ctrl_flags {
DMA_PREP_CONTINUE = (1 << 4),
DMA_PREP_FENCE = (1 << 5),
DMA_CTRL_REUSE = (1 << 6),
+ DMA_PREP_CMD = (1 << 7),
};
/**