Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma

[karo-tx-linux.git] / Documentation / devicetree / bindings / dma / atmel-dma.txt

diff --git a/Documentation/devicetree/bindings/dma/atmel-dma.txt b/Documentation/devicetree/bindings/dma/atmel-dma.txt
index 3c046ee6e8b5dd54e14f7fcc6fb8699792aa4b7d..c80e8a3402f0f5e744d323c0611dec9727f4930e 100644 (file)
--- 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";
 };