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

From: Rob Herring
Date: Tue Aug 14 2018 - 12:13:31 EST


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@xxxxxxxxxx>
> ---
> 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
>
> --
> To unsubscribe from this list: send the line "unsubscribe devicetree" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html