Re: [PATCH v2 1/4] dt-bindings: dma: Add binding for Actions Semi Owl SoCs

[Vinod]

Hi Mani,

Patch title should be dmaengine: ... Please always use the apt tags and
one can find them using git log <subsystem>

On 23-07-18, 09:47, Manivannan Sadhasivam wrote:
> Add devicetree binding for Actions Semi Owl SoCs DMA controller.


It would help for review to describe the controller here

> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> ---
>  .../devicetree/bindings/dma/owl-dma.txt       | 46 +++++++++++++++++++
>  1 file changed, 46 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/dma/owl-dma.txt
> 
> diff --git a/Documentation/devicetree/bindings/dma/owl-dma.txt b/Documentation/devicetree/bindings/dma/owl-dma.txt
> new file mode 100644
> index 000000000000..dd6ce237b216
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/dma/owl-dma.txt
> @@ -0,0 +1,46 @@
> +* Actions Semi Owl SoCs DMA controller
> +
> +This binding follows the generic DMA bindings defined in dma.txt.
> +
> +Required properties:
> +- compatible: Should be "actions,s900-dma".
> +- reg: Should contain DMA registers location and length.
> +- interrupts: Should contain 4 interrupts shared by all channel.
> +- #dma-cells: Must be <1>. Used to represent the number of integer
> +              cells in the dmas property of client device.
> +- dma-channels: Physical channels supported.
> +- dma-requests: Virtual channels supported.

not really, virtual channel is a software concepts. On the other hand
you may have request lines in hw and you can describe that, if not skip
this one

> +- clocks: Phandle and Specifier of the clock feeding the DMA controller.
> +
> +Example:
> +
> +Controller:
> +                dma: dma-controller@e0260000 {
> +                        compatible = "actions,s900-dma";
> +                        reg = <0x0 0xe0260000 0x0 0x1000>;
> +                        interrupts = <GIC_SPI 57 IRQ_TYPE_LEVEL_HIGH>,
> +                                     <GIC_SPI 58 IRQ_TYPE_LEVEL_HIGH>,
> +                                     <GIC_SPI 59 IRQ_TYPE_LEVEL_HIGH>,
> +                                     <GIC_SPI 60 IRQ_TYPE_LEVEL_HIGH>;
> +                        #dma-cells = <1>;
> +                        dma-channels = <12>;
> +                        dma-requests = <46>;
> +                        clocks = <&clock CLK_DMAC>;
> +                };
> +
> +Client:
> +
> +DMA clients connected to the Actions Semi Owl SoCs DMA controller must
> +use the format described in the dma.txt file, using a two-cell specifier
> +for each channel.
> +
> +The two cells in order are:
> +1. A phandle pointing to the DMA controller.
> +2. The channel id.
> +
> +uart5: serial@e012a000 {
> +        ...
> +        dma-names = "tx", "rx";
> +        dmas = <&dma 26>, <&dma 27>;
> +        ...
> +};
> -- 
> 2.17.1

-- 
~Vinod