1 files changed, 92 insertions, 7 deletions

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 75f53f874b24..679b349d9b66 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -23,7 +23,6 @@
 
 #include <linux/device.h>
 #include <linux/uio.h>
-#include <linux/dma-direction.h>
 #include <linux/scatterlist.h>
 #include <linux/bitmap.h>
 #include <asm/page.h>
@@ -72,11 +71,93 @@ enum dma_transaction_type {
         DMA_ASYNC_TX,
         DMA_SLAVE,
         DMA_CYCLIC,
+        DMA_INTERLEAVE,
+/* last transaction type for creation of the capabilities mask */
+        DMA_TX_TYPE_END,
 };
 
-/* last transaction type for creation of the capabilities mask */
-#define DMA_TX_TYPE_END (DMA_CYCLIC + 1)
+/**
+ * enum dma_transfer_direction - dma transfer mode and direction indicator
+ * @DMA_MEM_TO_MEM: Async/Memcpy mode
+ * @DMA_MEM_TO_DEV: Slave mode & From Memory to Device
+ * @DMA_DEV_TO_MEM: Slave mode & From Device to Memory
+ * @DMA_DEV_TO_DEV: Slave mode & From Device to Device
+ */
+enum dma_transfer_direction {
+        DMA_MEM_TO_MEM,
+        DMA_MEM_TO_DEV,
+        DMA_DEV_TO_MEM,
+        DMA_DEV_TO_DEV,
+        DMA_TRANS_NONE,
+};
+
+/**
+ * Interleaved Transfer Request
+ * ----------------------------
+ * A chunk is collection of contiguous bytes to be transfered.
+ * The gap(in bytes) between two chunks is called inter-chunk-gap(ICG).
+ * ICGs may or maynot change between chunks.
+ * A FRAME is the smallest series of contiguous {chunk,icg} pairs,
+ *  that when repeated an integral number of times, specifies the transfer.
+ * A transfer template is specification of a Frame, the number of times
+ *  it is to be repeated and other per-transfer attributes.
+ *
+ * Practically, a client driver would have ready a template for each
+ *  type of transfer it is going to need during its lifetime and
+ *  set only 'src_start' and 'dst_start' before submitting the requests.
+ *
+ *
+ *  |      Frame-1        |       Frame-2       | ~ |       Frame-'numf'  |
+ *  |====....==.===...=...|====....==.===...=...| ~ |====....==.===...=...|
+ *
+ *    ==  Chunk size
+ *    ... ICG
+ */
+
+/**
+ * struct data_chunk - Element of scatter-gather list that makes a frame.
+ * @size: Number of bytes to read from source.
+ *        size_dst := fn(op, size_src), so doesn't mean much for destination.
+ * @icg: Number of bytes to jump after last src/dst address of this
+ *       chunk and before first src/dst address for next chunk.
+ *       Ignored for dst(assumed 0), if dst_inc is true and dst_sgl is false.
+ *       Ignored for src(assumed 0), if src_inc is true and src_sgl is false.
+ */
+struct data_chunk {
+        size_t size;
+        size_t icg;
+};
 
+/**
+ * struct dma_interleaved_template - Template to convey DMAC the transfer pattern
+ *       and attributes.
+ * @src_start: Bus address of source for the first chunk.
+ * @dst_start: Bus address of destination for the first chunk.
+ * @dir: Specifies the type of Source and Destination.
+ * @src_inc: If the source address increments after reading from it.
+ * @dst_inc: If the destination address increments after writing to it.
+ * @src_sgl: If the 'icg' of sgl[] applies to Source (scattered read).
+ *              Otherwise, source is read contiguously (icg ignored).
+ *              Ignored if src_inc is false.
+ * @dst_sgl: If the 'icg' of sgl[] applies to Destination (scattered write).
+ *              Otherwise, destination is filled contiguously (icg ignored).
+ *              Ignored if dst_inc is false.
+ * @numf: Number of frames in this template.
+ * @frame_size: Number of chunks in a frame i.e, size of sgl[].
+ * @sgl: Array of {chunk,icg} pairs that make up a frame.
+ */
+struct dma_interleaved_template {
+        dma_addr_t src_start;
+        dma_addr_t dst_start;
+        enum dma_transfer_direction dir;
+        bool src_inc;
+        bool dst_inc;
+        bool src_sgl;
+        bool dst_sgl;
+        size_t numf;
+        size_t frame_size;
+        struct data_chunk sgl[0];
+};
 
 /**
  * enum dma_ctrl_flags - DMA flags to augment operation preparation,
@@ -269,7 +350,7 @@ enum dma_slave_buswidth {
  * struct, if applicable.
  */
 struct dma_slave_config {
-        enum dma_data_direction direction;
+        enum dma_transfer_direction direction;
         dma_addr_t src_addr;
         dma_addr_t dst_addr;
         enum dma_slave_buswidth src_addr_width;
@@ -433,6 +514,7 @@ struct dma_tx_state {
  * @device_prep_dma_cyclic: prepare a cyclic dma operation suitable for audio.
  *      The function takes a buffer of size buf_len. The callback function will
  *      be called after period_len bytes have been transferred.
+ * @device_prep_interleaved_dma: Transfer expression in a generic way.
  * @device_control: manipulate all pending operations on a channel, returns
  *      zero or error code
  * @device_tx_status: poll for transaction completion, the optional
@@ -492,11 +574,14 @@ struct dma_device {
 
         struct dma_async_tx_descriptor *(*device_prep_slave_sg)(
                 struct dma_chan *chan, struct scatterlist *sgl,
-                unsigned int sg_len, enum dma_data_direction direction,
+                unsigned int sg_len, enum dma_transfer_direction direction,
                 unsigned long flags);
         struct dma_async_tx_descriptor *(*device_prep_dma_cyclic)(
                 struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
-                size_t period_len, enum dma_data_direction direction);
+                size_t period_len, enum dma_transfer_direction direction);
+        struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)(
+                struct dma_chan *chan, struct dma_interleaved_template *xt,
+                unsigned long flags);
         int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
                 unsigned long arg);
 
@@ -522,7 +607,7 @@ static inline int dmaengine_slave_config(struct dma_chan *chan,
 
 static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single(
         struct dma_chan *chan, void *buf, size_t len,
-        enum dma_data_direction dir, unsigned long flags)
+        enum dma_transfer_direction dir, unsigned long flags)
 {
         struct scatterlist sg;
         sg_init_one(&sg, buf, len);