1 files changed, 30 insertions, 5 deletions

diff --git a/Documentation/devicetree/bindings/dma/atmel-dma.txt b/Documentation/devicetree/bindings/dma/atmel-dma.txt
index 3c046ee6e8b5..c80e8a3402f0 100644
--- a/Documentation/devicetree/bindings/dma/atmel-dma.txt
+++ b/Documentation/devicetree/bindings/dma/atmel-dma.txt
@@ -1,14 +1,39 @@
 * Atmel Direct Memory Access Controller (DMA)
 
 Required properties:
-- compatible: Should be "atmel,<chip>-dma"
-- reg: Should contain DMA registers location and length
-- interrupts: Should contain DMA interrupt
+- compatible: Should be "atmel,<chip>-dma".
+- reg: Should contain DMA registers location and length.
+- interrupts: Should contain DMA interrupt.
+- #dma-cells: Must be <2>, used to represent the number of integer cells in
+the dmas property of client devices.
 
-Examples:
+Example:
 
-dma@ffffec00 {
+dma0: dma@ffffec00 {
         compatible = "atmel,at91sam9g45-dma";
         reg = <0xffffec00 0x200>;
         interrupts = <21>;
+        #dma-cells = <2>;
+};
+
+DMA clients connected to the Atmel DMA controller must use the format
+described in the dma.txt file, using a three-cell specifier for each channel:
+a phandle plus two interger cells.
+The three cells in order are:
+
+1. A phandle pointing to the DMA controller.
+2. The memory interface (16 most significant bits), the peripheral interface
+(16 less significant bits).
+3. The peripheral identifier for the hardware handshaking interface. The
+identifier can be different for tx and rx.
+
+Example:
+
+i2c0@i2c@f8010000 {
+        compatible = "atmel,at91sam9x5-i2c";
+        reg = <0xf8010000 0x100>;
+        interrupts = <9 4 6>;
+        dmas = <&dma0 1 7>,
+               <&dma0 1 8>;
+        dma-names = "tx", "rx";
 };