[PATCH v2 2/2] ARM: dts: at_xdmac: add bindings documentation

[mark.rutland@arm.com (Mark Rutland)]

On Fri, Jul 04, 2014 at 08:36:10AM +0100, Ludovic Desroches wrote:
> Add bindings documentation for the new Atmel DMA controller (XDMAC)
> introduced with SAMA5D4.
> 
> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
> ---
>  .../devicetree/bindings/dma/atmel-xdma.txt         |   39 ++++++++++++++++++++
>  1 file changed, 39 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/atmel-xdma.txt
> 
> diff --git a/Documentation/devicetree/bindings/dma/atmel-xdma.txt b/Documentation/devicetree/bindings/dma/atmel-xdma.txt
> new file mode 100644
> index 0000000..1e09fda
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt
> @@ -0,0 +1,39 @@
> +* Atmel Extensible Direct Memory Access Controller (XDMAC)
> +
> +Required properties:
> +- 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.

Could you please move the description of the two cells in the
dma-specifier here? It makes it far easier to read the binding.

Cheers,
Mark.

> +
> +Example:
> +
> +dma1: dma-controller at f0004000 {
> +	compatible = "atmel,sama5d4-dma";
> +	reg = <0xf0004000 0x200>;
> +	interrupts = <50 4 0>;
> +	#dma-cells = <2>;
> +};
> +
> +DMA clients connected to the Atmel XDMA controller must use the format
> +described in the dma.txt file, using a three-cell specifier for each channel:
> +a phandle plus two integer cells.
> +The two 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. Channel configuration register. Configurable fields are:
> +  - bit 30-24: PERID, peripheral identifier.
> +
> +Example:
> +
> +i2c2: i2c at f8024000 {
> +	compatible = "atmel,at91sam9x5-i2c";
> +	reg = <0xf8024000 0x4000>;
> +	interrupts = <34 4 6>;
> +	dmas = <&dma0 0x00000001 0x06000000>,
> +	       <&dma0 0x00000001 0x07000000>;
> +	dma-names = "tx", "rx";
> +};
> -- 
> 1.7.9.5
> 
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