Re: [PATCH v2 2/3] dt-bindings: arm: mediatek: mmsys: Add OF graph support for board path

[Rob Herring <robh@kernel.org>]

On Tue, Apr 09, 2024 at 02:02:10PM +0200, AngeloGioacchino Del Regno wrote:
> Document OF graph on MMSYS/VDOSYS: this supports up to three DDP paths
> per HW instance (so potentially up to six displays for multi-vdo SoCs).
> 
> The MMSYS or VDOSYS is always the first component in the DDP pipeline,
> so it only supports an output port with multiple endpoints - where each
> endpoint defines the starting point for one of the (currently three)
> possible hardware paths.
> 
> Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
> ---
>  .../bindings/arm/mediatek/mediatek,mmsys.yaml | 23 +++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yaml b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yaml
> index b3c6888c1457..4e9acd966aa5 100644
> --- a/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yaml
> +++ b/Documentation/devicetree/bindings/arm/mediatek/mediatek,mmsys.yaml
> @@ -93,6 +93,29 @@ properties:
>    '#reset-cells':
>      const: 1
>  
> +  port:
> +    $ref: /schemas/graph.yaml#/properties/port
> +    description:
> +      Output port node. This port connects the MMSYS/VDOSYS output to
> +      the first component of one display pipeline, for example one of
> +      the available OVL or RDMA blocks.
> +      Some MediaTek SoCs support up to three display outputs per MMSYS.

I'm have a hard time understanding this, but is it 3 outputs 
simultaneously or connect mmsys to 1 of 3. Generally it's multiple ports 
for the former and endpoints for the latter.

> +    properties:
> +      endpoint@0:
> +        $ref: /schemas/graph.yaml#/properties/endpoint
> +        description: Output to the primary display pipeline
> +
> +      endpoint@1:
> +        $ref: /schemas/graph.yaml#/properties/endpoint
> +        description: Output to the secondary display pipeline
> +
> +      endpoint@2:
> +        $ref: /schemas/graph.yaml#/properties/endpoint
> +        description: Output to the tertiary display pipeline
> +
> +    required:
> +      - endpoint@0
> +
>  required:
>    - compatible
>    - reg
> -- 
> 2.44.0
>