dmaengine: sprd: Support DMA 2-stage transfer mode

The Spreadtrum DMA controller supports channel 2-stage tansfer mode,
that means we can request 2 dma channels, one for source channel, and
another one for destination channel. Once the source channel's transaction
is done, it will trigger the destination channel's transaction automatically
by hardware signal.

Signed-off-by: Eric Long <eric.long@spreadtrum.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 59 insertions, 3 deletions

diff --git a/include/linux/dma/sprd-dma.h b/include/linux/dma/sprd-dma.h
index b42b80e52cc2..ab82df64682a 100644
--- a/include/linux/dma/sprd-dma.h
+++ b/include/linux/dma/sprd-dma.h
@@ -3,9 +3,65 @@
 #ifndef _SPRD_DMA_H_
 #define _SPRD_DMA_H_
 
-#define SPRD_DMA_REQ_SHIFT 16
-#define SPRD_DMA_FLAGS(req_mode, int_type) \
-	((req_mode) << SPRD_DMA_REQ_SHIFT | (int_type))
+#define SPRD_DMA_REQ_SHIFT	8
+#define SPRD_DMA_TRG_MODE_SHIFT	16
+#define SPRD_DMA_CHN_MODE_SHIFT	24
+#define SPRD_DMA_FLAGS(chn_mode, trg_mode, req_mode, int_type) \
+	((chn_mode) << SPRD_DMA_CHN_MODE_SHIFT | \
+	(trg_mode) << SPRD_DMA_TRG_MODE_SHIFT | \
+	(req_mode) << SPRD_DMA_REQ_SHIFT | (int_type))
+
+/*
+ * The Spreadtrum DMA controller supports channel 2-stage tansfer, that means
+ * we can request 2 dma channels, one for source channel, and another one for
+ * destination channel. Each channel is independent, and has its own
+ * configurations. Once the source channel's transaction is done, it will
+ * trigger the destination channel's transaction automatically by hardware
+ * signal.
+ *
+ * To support 2-stage tansfer, we must configure the channel mode and trigger
+ * mode as below definition.
+ */
+
+/*
+ * enum sprd_dma_chn_mode: define the DMA channel mode for 2-stage transfer
+ * @SPRD_DMA_CHN_MODE_NONE: No channel mode setting which means channel doesn't
+ * support the 2-stage transfer.
+ * @SPRD_DMA_SRC_CHN0: Channel used as source channel 0.
+ * @SPRD_DMA_SRC_CHN1: Channel used as source channel 1.
+ * @SPRD_DMA_DST_CHN0: Channel used as destination channel 0.
+ * @SPRD_DMA_DST_CHN1: Channel used as destination channel 1.
+ *
+ * Now the DMA controller can supports 2 groups 2-stage transfer.
+ */
+enum sprd_dma_chn_mode {
+	SPRD_DMA_CHN_MODE_NONE,
+	SPRD_DMA_SRC_CHN0,
+	SPRD_DMA_SRC_CHN1,
+	SPRD_DMA_DST_CHN0,
+	SPRD_DMA_DST_CHN1,
+};
+
+/*
+ * enum sprd_dma_trg_mode: define the DMA channel trigger mode for 2-stage
+ * transfer
+ * @SPRD_DMA_NO_TRG: No trigger setting.
+ * @SPRD_DMA_FRAG_DONE_TRG: Trigger the transaction of destination channel
+ * automatically once the source channel's fragment request is done.
+ * @SPRD_DMA_BLOCK_DONE_TRG: Trigger the transaction of destination channel
+ * automatically once the source channel's block request is done.
+ * @SPRD_DMA_TRANS_DONE_TRG: Trigger the transaction of destination channel
+ * automatically once the source channel's transfer request is done.
+ * @SPRD_DMA_LIST_DONE_TRG: Trigger the transaction of destination channel
+ * automatically once the source channel's link-list request is done.
+ */
+enum sprd_dma_trg_mode {
+	SPRD_DMA_NO_TRG,
+	SPRD_DMA_FRAG_DONE_TRG,
+	SPRD_DMA_BLOCK_DONE_TRG,
+	SPRD_DMA_TRANS_DONE_TRG,
+	SPRD_DMA_LIST_DONE_TRG,
+};
 
 /*
  * enum sprd_dma_req_mode: define the DMA request mode