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

[Padma Venkat]

Hi Rob,

On Wed, Feb 6, 2013 at 8:54 PM, Rob Herring <robherring2 at gmail.com> wrote:
> 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.
OK. I will fix this.
>
>>
>> Signed-off-by: Padmavathi Venna <padma.v at samsung.com>
>> Acked-by: Arnd Bergmann <arnd at 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.

In Exynos we have support for both peripheral to peripheral and memory
to memory.
So I made it as required property. Should I make this as optional?

>
> 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 at 121B0000 {
>>                       compatible = "arm,pl330", "arm,primecell";
>>                       reg = <0x121B0000 0x1000>;
>>                       interrupts = <0 35 0>;
>> +                     #dma-cells = <1>;
>>               };
>>
>>               mdma0: mdma at 10800000 {
>>                       compatible = "arm,pl330", "arm,primecell";
>>                       reg = <0x10800000 0x1000>;
>>                       interrupts = <0 33 0>;
>> +                     #dma-cells = <1>;
>>               };
>>
>>               mdma1: mdma at 11C10000 {
>>                       compatible = "arm,pl330", "arm,primecell";
>>                       reg = <0x11C10000 0x1000>;
>>                       interrupts = <0 124 0>;
>> +                     #dma-cells = <1>;
>>               };
>>       };
>>
>>
>

Thanks
Padma