Re: [PATCH 1/4] dt-bindings: display: renesas,rzg2l-du: Add RZ/T2H and RZ/N2H support

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Prabhakar,

Thank you for the patch.

On Wed, Apr 29, 2026 at 06:00:09PM +0100, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Document the Display Unit (DU) support for the RZ/T2H and RZ/N2H SoCs.
> 
> The DU block on RZ/T2H is functionally equivalent to the RZ/G2UL DU and
> supports the DPI interface, but includes SoC-specific register differences.
> Add a dedicated compatible string to represent this variant.
> 
> As the DU implementation on RZ/N2H matches RZ/T2H, describe it using an
> RZ/N2H specific compatible string with the RZ/T2H compatible as fallback.
> 
> Unlike other DU variants which use a multi-port model, the RZ/T2H and
> RZ/N2H DU has a single output and is modelled using a single port node
> with one endpoint. Add a port property to support this and update the
> allOf constraints accordingly.

Wouldn't it be simpler to always have a "ports" node, even for variants
with a single port ?

> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
>  .../bindings/display/renesas,rzg2l-du.yaml    | 24 +++++++++++++++++--
>  1 file changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml b/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml
> index 2cc66dcef870..45678d536a75 100644
> --- a/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml
> +++ b/Documentation/devicetree/bindings/display/renesas,rzg2l-du.yaml
> @@ -21,6 +21,7 @@ properties:
>            - renesas,r9a07g043u-du # RZ/G2UL
>            - renesas,r9a07g044-du # RZ/G2{L,LC}
>            - renesas,r9a09g057-du # RZ/V2H(P)
> +          - renesas,r9a09g077-du # RZ/T2H
>        - items:
>            - enum:
>                - renesas,r9a07g054-du    # RZ/V2L
> @@ -28,6 +29,9 @@ properties:
>        - items:
>            - const: renesas,r9a09g056-du # RZ/V2N
>            - const: renesas,r9a09g057-du # RZ/V2H(P) fallback
> +      - items:
> +          - const: renesas,r9a09g087-du # RZ/N2H
> +          - const: renesas,r9a09g077-du # RZ/T2H fallback
>  
>    reg:
>      maxItems: 1
> @@ -53,6 +57,10 @@ properties:
>    power-domains:
>      maxItems: 1
>  
> +  port:
> +    $ref: /schemas/graph.yaml#/properties/port
> +    description: Single output port for single-output DU variants.
> +
>    ports:
>      $ref: /schemas/graph.yaml#/properties/ports
>      description: |
> @@ -83,9 +91,7 @@ required:
>    - interrupts
>    - clocks
>    - clock-names
> -  - resets
>    - power-domains
> -  - ports
>    - renesas,vsps
>  
>  additionalProperties: false
> @@ -137,6 +143,20 @@ allOf:
>  
>            required:
>              - port@0
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: renesas,r9a09g077-du
> +    then:
> +      properties:
> +        resets: false
> +      required:
> +        - port
> +    else:
> +      required:
> +        - resets
> +        - ports
>  
>  examples:
>    # RZ/G2L DU

-- 
Regards,

Laurent Pinchart