[alsa-devel] [PATCH 3/4] ARM: dts: Add #dma-cells for generic dma binding support

Arnd Bergmann arnd at arndb.de
Mon Jan 28 15:47:33 CET 2013

On Friday 18 January 2013, Padmavathi Venna wrote:
> diff --git a/Documentation/devicetree/bindings/dma/arm-pl330.txt b/Documentation/devicetree/bindings/dma/arm-pl330.txt
> index 36e27d5..457a233 100644
> --- a/Documentation/devicetree/bindings/dma/arm-pl330.txt
> +++ b/Documentation/devicetree/bindings/dma/arm-pl330.txt
> @@ -8,6 +8,8 @@ Required properties:
>    - reg: physical base address of the controller and length of memory mapped
>      region.
>    - interrupts: interrupt number to the cpu.
> +  - #dma-cells: must be at least 1. used to represent the number of integer
> +    cells in the dmas property of client device.

The wording 'at least' seems wrong here: that is what we use in the
generic DMA binding, but in the part that is specific to one
driver, I would expect to see

	- #dma-cells: must be <1>

Since that is what this particular driver requires.

>  Client drivers (device nodes requiring dma transfers from dev-to-mem or
> @@ -27,7 +30,7 @@ as shown below.
>    [property name]  = <[phandle of the dma controller] [dma request id]>;
>        where 'dma request id' is the dma request number which is connected
> -      to the client controller. The 'property name' is recommended to be
> -      of the form <name>-dma-channel.
> +      to the client controller. The 'property name' is 'dmas' as recommended
> +      by the generic dma device tree binding helpers.


Also, the "dma-names" property is required as well.


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