[RFC,1/2] dt-bindings: dmaengine: xilinx_dma: Add binding for Xilinx MCDMA IP

[Rob Herring <robh@kernel.org>]

On Tue, Jul 31, 2018 at 11:16:12PM +0530, Radhey Shyam Pandey wrote:
> Add devicetree binding for Xilinx AXI Multichannel Direct Memory Access
> (AXI MCDMA) IP. The AXI MCDMA provides high-bandwidth direct memory
> access between memory and AXI4-Stream target peripherals. The AXI MCDMA
> core provides scatter-gather interface with multiple channel support.
> 
> Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
> ---
>  Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
> index 174af2c..57bb02e 100644
> --- a/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
> +++ b/Documentation/devicetree/bindings/dma/xilinx/xilinx_dma.txt
> @@ -11,9 +11,13 @@ is to receive from the device.
>  Xilinx AXI CDMA engine, it does transfers between memory-mapped source
>  address and a memory-mapped destination address.
>  
> +Xilinx AXI MCDMA engine, it does transfer between memory and AXI4 stream
> +target devices. It can be configured to have up to 16 independent transmit
> +and receive channels.
> +
>  Required properties:
>  - compatible: Should be "xlnx,axi-vdma-1.00.a" or "xlnx,axi-dma-1.00.a" or
> -	      "xlnx,axi-cdma-1.00.a""
> +	      "xlnx,axi-cdma-1.00.a" or "xlnx,axi-mcdma-1.00.a".

Please reformat to 1 per line.

>  - #dma-cells: Should be <1>, see "dmas" property below
>  - reg: Should contain VDMA registers location and length.
>  - xlnx,addrwidth: Should be the vdma addressing size in bits(ex: 32 bits).
> @@ -56,6 +60,8 @@ Required child node properties:
>  	For CDMA: It should be "xlnx,axi-cdma-channel".
>  	For AXIDMA: It should be either "xlnx,axi-dma-mm2s-channel" or
>  	"xlnx,axi-dma-s2mm-channel".
> +	For MCDMA: It should be either "xlnx,axi-mcdma-mm2s-channel" or
> +	"xlnx,axi-mcdma-s2mm-channel".

What's wrong with reusing the existing xlnx,axi-dma-* names? 

>  - interrupts: Should contain per channel VDMA interrupts.
>  - xlnx,datawidth: Should contain the stream data width, take values
>  	{32,64...1024}.
> @@ -68,7 +74,7 @@ Optional child node properties for VDMA:
>  	enabled/disabled in hardware.
>  - xlnx,enable-vert-flip: Tells vertical flip is
>  	enabled/disabled in hardware(S2MM path).
> -Optional child node properties for AXI DMA:
> +Optional child node properties for AXI DMA and MCDMA:
>  -dma-channels: Number of dma channels in child node.
>  
>  Example:
> -- 
> 2.7.4
> 
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