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

Rob Herring
2024-04-10T19:15:27Z

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
>