[PATCH 1/3] dmaengine: Add support for 2D DMA operation

[Aatif Mushtaq <aatif4.m@xxxxxxxxxxx>]

Add a new dma engine API to support 2D DMA operations.
The API will be used to get the descriptor for 2D transfer based on
the 16-bit immediate to define the stride length between consecuitive
source address or destination address after every DMA load and
store instruction is processed.

Signed-off-by: Aatif Mushtaq <aatif4.m@xxxxxxxxxxx>
---
 include/linux/dmaengine.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index b137fdb56093..8a73b2147983 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -833,6 +833,7 @@ struct dma_filter {
  *	be called after period_len bytes have been transferred.
  * @device_prep_interleaved_dma: Transfer expression in a generic way.
  * @device_prep_dma_imm_data: DMA's 8 byte immediate data to the dst address
+ * @device_prep_2d_dma_memcpy: prepares a 2D memcpy operation
  * @device_caps: May be used to override the generic DMA slave capabilities
  *	with per-channel specific ones
  * @device_config: Pushes a new configuration to a channel, return 0 or an error
@@ -938,6 +939,9 @@ struct dma_device {
 	struct dma_async_tx_descriptor *(*device_prep_dma_imm_data)(
 		struct dma_chan *chan, dma_addr_t dst, u64 data,
 		unsigned long flags);
+	struct dma_async_tx_descriptor *(*device_prep_2d_dma_memcpy)(
+		struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+		size_t len, u16 src_imm, u16 dest_imm, unsigned long flags);
 
 	void (*device_caps)(struct dma_chan *chan, struct dma_slave_caps *caps);
 	int (*device_config)(struct dma_chan *chan, struct dma_slave_config *config);
@@ -1087,6 +1091,27 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_memcpy(
 						    len, flags);
 }
 
+/**
+ * device_prep_2d_dma_memcpy() - Prepare a DMA 2D memcpy descriptor.
+ * @chan: The channel to be used for this descriptor
+ * @dest: Address of the destination data for a DMA channel
+ * @src: Address of the source data for a DMA channel
+ * @len: The total size of data
+ * @src_imm: The immediate value to be added to the src address register
+ * @dest_imm: The immediate value to be added to the dst address register
+ * @flags: DMA engine flags
+ */
+static inline struct dma_async_tx_descriptor *device_prep_2d_dma_memcpy(
+		struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+		size_t len, u16 src_imm, u16 dest_imm, unsigned long flags)
+{
+	if (!chan || !chan->device || !chan->device->device_prep_2d_dma_memcpy)
+		return NULL;
+
+	return chan->device->device_prep_2d_dma_memcpy(chan, dest, src, len,
+						       src_imm, dest_imm, flags);
+}
+
 static inline bool dmaengine_is_metadata_mode_supported(struct dma_chan *chan,
 		enum dma_desc_metadata_mode mode)
 {
-- 
2.17.1