Re: [PATCH 2/7] dt-bindings: display: mediatek: dpi: add binding for MT8365

[CK Hu]

Hi, Fabien:

On Mon, 2022-05-30 at 22:14 +0200, Fabien Parent wrote:
> DPI for MT8365 is compatible with MT8192 but requires an additional
> clock. Modify the documentation to requires this clock only on MT8365
> SoCs.
> 
> Signed-off-by: Fabien Parent <fparent@xxxxxxxxxxxx>
> ---
>  .../display/mediatek/mediatek,dpi.yaml        | 44 ++++++++++++++++-
> --
>  1 file changed, 37 insertions(+), 7 deletions(-)
> 
> diff --git
> a/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.yam
> l
> b/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.yam
> l
> index caf4c88708f4..c9c9f4d5ebe7 100644
> ---
> a/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.yam
> l
> +++
> b/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.yam
> l
> @@ -17,13 +17,18 @@ description: |
>  
>  properties:
>    compatible:
> -    enum:
> -      - mediatek,mt2701-dpi
> -      - mediatek,mt7623-dpi
> -      - mediatek,mt8173-dpi
> -      - mediatek,mt8183-dpi
> -      - mediatek,mt8186-dpi
> -      - mediatek,mt8192-dpi
> +    oneOf:
> +      - enum:
> +          - mediatek,mt2701-dpi
> +          - mediatek,mt7623-dpi
> +          - mediatek,mt8173-dpi
> +          - mediatek,mt8183-dpi
> +          - mediatek,mt8186-dpi
> +          - mediatek,mt8192-dpi
> +      - items:
> +          - enum:
> +              - mediatek,mt8365-dpi
> +          - const: mediatek,mt8192-dpi
>  
>    reg:
>      maxItems: 1
> @@ -32,16 +37,20 @@ properties:
>      maxItems: 1
>  
>    clocks:
> +    minItems: 3
>      items:
>        - description: Pixel Clock
>        - description: Engine Clock
>        - description: DPI PLL
> +      - description: DPI Clock

Why MT8365 has this additional clock? What is the new hardware block
(compared with other SoC) need this clock? Why this is different than
other SoC?

Is this case the same as [1]? If so, I think you should not add this
clock.

[1] 
https://patchwork.kernel.org/project/linux-mediatek/patch/20220613064841.10481-2-rex-bc.chen@xxxxxxxxxxxx/

Regards,
CK

>  
>    clock-names:
> +    minItems: 3
>      items:
>        - const: pixel
>        - const: engine
>        - const: pll
> +      - const: dpi
>  
>    pinctrl-0: true
>    pinctrl-1: true
> @@ -71,6 +80,27 @@ required:
>  
>  additionalProperties: false
>  
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: mediatek,mt8365-dpi
> +
> +    then:
> +      properties:
> +        clocks:
> +          maxItems: 4
> +        clock-names:
> +          maxItems: 4
> +
> +    else:
> +      properties:
> +        clocks:
> +          maxItems: 3
> +        clock-names:
> +          maxItems: 3
> +
>  examples:
>    - |
>      #include <dt-bindings/interrupt-controller/arm-gic.h>