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-rw-r--r--include/linux/dmaengine.h17
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 6283917edd90..abd8cffdf202 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -61,6 +61,8 @@ enum dma_transaction_type {
DMA_SLAVE,
DMA_CYCLIC,
DMA_INTERLEAVE,
+ DMA_REPEAT,
+ DMA_LOAD_EOT,
/* last transaction type for creation of the capabilities mask */
DMA_TX_TYPE_END,
};
@@ -176,6 +178,16 @@ struct dma_interleaved_template {
* @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.
+ * @DMA_PREP_REPEAT: tell the driver that the transaction shall be automatically
+ * repeated when it ends until a transaction is issued on the same channel
+ * with the DMA_PREP_LOAD_EOT flag set. This flag is only applicable to
+ * interleaved transactions and is ignored for all other transaction types.
+ * @DMA_PREP_LOAD_EOT: tell the driver that the transaction shall replace any
+ * active repeated (as indicated by DMA_PREP_REPEAT) transaction when the
+ * repeated transaction ends. Not setting this flag when the previously queued
+ * transaction is marked with DMA_PREP_REPEAT will cause the new transaction
+ * to never be processed and stay in the issued queue forever. The flag is
+ * ignored if the previous transaction is not a repeated transaction.
*/
enum dma_ctrl_flags {
DMA_PREP_INTERRUPT = (1 << 0),
@@ -186,6 +198,8 @@ enum dma_ctrl_flags {
DMA_PREP_FENCE = (1 << 5),
DMA_CTRL_REUSE = (1 << 6),
DMA_PREP_CMD = (1 << 7),
+ DMA_PREP_REPEAT = (1 << 8),
+ DMA_PREP_LOAD_EOT = (1 << 9),
};
/**
@@ -980,6 +994,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma(
{
if (!chan || !chan->device || !chan->device->device_prep_interleaved_dma)
return NULL;
+ if (flags & DMA_PREP_REPEAT &&
+ !test_bit(DMA_REPEAT, chan->device->cap_mask.bits))
+ return NULL;
return chan->device->device_prep_interleaved_dma(chan, xt, flags);
}