dmaengine: qcom: bam_dma: add command descriptor flag

If DMA_PREP_CMD flag is passed in prep_slave_sg then peripheral
driver has passed the data is in BAM command descriptor format
and BAM driver should set CMD bit for each of the HW descriptors.

Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/qcom/bam_dma.c

@@ -65,6 +65,7 @@ struct bam_desc_hw {
 #define DESC_FLAG_EOT BIT(14)
 #define DESC_FLAG_EOB BIT(13)
 #define DESC_FLAG_NWD BIT(12)
+#define DESC_FLAG_CMD BIT(11)
 
 struct bam_async_desc {
 	struct virt_dma_desc vd;
@@ -645,6 +646,9 @@ static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan,
 		unsigned int curr_offset = 0;
 
 		do {
+			if (flags & DMA_PREP_CMD)
+				desc->flags |= cpu_to_le16(DESC_FLAG_CMD);
+
 			desc->addr = cpu_to_le32(sg_dma_address(sg) +
 						 curr_offset);
 
@@ -960,7 +964,7 @@ static void bam_start_dma(struct bam_chan *bchan)
 
 	/* set any special flags on the last descriptor */
 	if (async_desc->num_desc == async_desc->xfer_len)
-		desc[async_desc->xfer_len - 1].flags =
+		desc[async_desc->xfer_len - 1].flags |=
 					cpu_to_le16(async_desc->flags);
 	else
 		desc[async_desc->xfer_len - 1].flags |=