Re: [PATCH V3 4/5] ARM: dts: Add #dma-cells for generic dma binding support

[Rob Herring <robherring2@gmail.com>]

On 02/06/2013 12:18 AM, Padmavathi Venna wrote:
> This patch adds #dma-cells property to PL330 DMA controller
> nodes for supporting generic dma dt bindings on samsung
> exynos5250 platform.

The subject doesn't reflect this is for pl330.

> 
> Signed-off-by: Padmavathi Venna <padma.v@samsung.com>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  .../devicetree/bindings/dma/arm-pl330.txt          |   15 +++++++++++----
>  arch/arm/boot/dts/exynos5250.dtsi                  |    4 ++++
>  2 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/arm-pl330.txt b/Documentation/devicetree/bindings/dma/arm-pl330.txt
> index 36e27d5..1fdbff6 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 <1>. used to represent the number of integer
> +    cells in the dmas property of client device.

This should be optional in the case of platforms supporting only memory
to memory xfers.

Rob

>  
>  Optional properties:
>  - dma-coherent      : Present if dma operations are coherent
> @@ -18,16 +20,21 @@ Example:
>  		compatible = "arm,pl330", "arm,primecell";
>  		reg = <0x12680000 0x1000>;
>  		interrupts = <99>;
> +		#dma-cells = <1>;
>  	};
>  
>  Client drivers (device nodes requiring dma transfers from dev-to-mem or
> -mem-to-dev) should specify the DMA channel numbers using a two-value pair
> +mem-to-dev) should specify the DMA channel numbers and dma channel names
>  as shown below.
>  
>    [property name]  = <[phandle of the dma controller] [dma request id]>;
> +  [property name]  = <[dma channel name]>
>  
>        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' 'dmas' and 'dma-names'
> +      as required by the generic dma device tree binding helpers. The dma
> +      names correspond 1:1 with the dma request ids in the dmas property.
>  
> -  Example:  tx-dma-channel = <&pdma0 12>;
> +  Example:  dmas = <&pdma0 12
> +		    &pdma1 11>;
> +	    dma-names = "tx", "rx";
> diff --git a/arch/arm/boot/dts/exynos5250.dtsi b/arch/arm/boot/dts/exynos5250.dtsi
> index f50b4e8..724f5bd 100644
> --- a/arch/arm/boot/dts/exynos5250.dtsi
> +++ b/arch/arm/boot/dts/exynos5250.dtsi
> @@ -312,24 +312,28 @@
>  			compatible = "arm,pl330", "arm,primecell";
>  			reg = <0x121A0000 0x1000>;
>  			interrupts = <0 34 0>;
> +			#dma-cells = <1>;
>  		};
>  
>  		pdma1: pdma@121B0000 {
>  			compatible = "arm,pl330", "arm,primecell";
>  			reg = <0x121B0000 0x1000>;
>  			interrupts = <0 35 0>;
> +			#dma-cells = <1>;
>  		};
>  
>  		mdma0: mdma@10800000 {
>  			compatible = "arm,pl330", "arm,primecell";
>  			reg = <0x10800000 0x1000>;
>  			interrupts = <0 33 0>;
> +			#dma-cells = <1>;
>  		};
>  
>  		mdma1: mdma@11C10000 {
>  			compatible = "arm,pl330", "arm,primecell";
>  			reg = <0x11C10000 0x1000>;
>  			interrupts = <0 124 0>;
> +			#dma-cells = <1>;
>  		};
>  	};
>  
>