Re: [PATCH v2 02/12] dt-bindings: display: mediatek: add MT8195 hdmi bindings

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 14/10/2022 11:15, Guillaume Ranquet wrote:
> Add mt8195 SoC bindings for hdmi and hdmi-ddc
> 
> Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
> ---
>  .../bindings/display/mediatek/mediatek,hdmi.yaml   | 67 +++++++++++++++++-----
>  .../display/mediatek/mediatek,mt8195-hdmi-ddc.yaml | 51 ++++++++++++++++
>  2 files changed, 104 insertions(+), 14 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,hdmi.yaml b/Documentation/devicetree/bindings/display/mediatek/mediatek,hdmi.yaml
> index bdaf0b51e68c..955026cd7ca5 100644
> --- a/Documentation/devicetree/bindings/display/mediatek/mediatek,hdmi.yaml
> +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,hdmi.yaml
> @@ -21,26 +21,21 @@ properties:
>        - mediatek,mt7623-hdmi
>        - mediatek,mt8167-hdmi
>        - mediatek,mt8173-hdmi
> +      - mediatek,mt8195-hdmi
>  
>    reg:
>      maxItems: 1
>  
> -  interrupts:
> -    maxItems: 1
> -

This change is not really explained in commit msg...

>    clocks:
> -    items:
> -      - description: Pixel Clock
> -      - description: HDMI PLL
> -      - description: Bit Clock
> -      - description: S/PDIF Clock
> +    minItems: 4
> +    maxItems: 4
>  
>    clock-names:
> -    items:
> -      - const: pixel
> -      - const: pll
> -      - const: bclk
> -      - const: spdif
> +    minItems: 4
> +    maxItems: 4
> +
> +  interrupts:
> +    maxItems: 1
>  
>    phys:
>      maxItems: 1
> @@ -58,6 +53,9 @@ properties:
>      description: |
>        phandle link and register offset to the system configuration registers.
>  
> +  power-domains:
> +    maxItems: 1
> +
>    ports:
>      $ref: /schemas/graph.yaml#/properties/ports
>  
> @@ -86,9 +84,50 @@ required:
>    - clock-names
>    - phys
>    - phy-names
> -  - mediatek,syscon-hdmi
>    - ports
>  
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: mediatek,mt8195-hdmi
> +    then:
> +      properties:
> +        clocks:
> +          items:
> +            - description: APB
> +            - description: HDCP
> +            - description: HDCP 24M
> +            - description: Split HDMI
> +        clock-names:
> +          items:
> +            - const: hdmi_apb_sel
> +            - const: hdcp_sel
> +            - const: hdcp24_sel
> +            - const: split_hdmi
> +
> +      required:
> +        - power-domains
> +    else:
> +      properties:
> +        clocks:
> +          items:
> +            - description: Pixel Clock
> +            - description: HDMI PLL
> +            - description: Bit Clock
> +            - description: S/PDIF Clock
> +
> +        clock-names:
> +          items:
> +            - const: pixel
> +            - const: pll
> +            - const: bclk
> +            - const: spdif
> +
> +      required:
> +        - mediatek,syscon-hdmi
> +
>  additionalProperties: false
>  
>  examples:
> diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,mt8195-hdmi-ddc.yaml b/Documentation/devicetree/bindings/display/mediatek/mediatek,mt8195-hdmi-ddc.yaml
> new file mode 100644
> index 000000000000..0fe0a2a2f17f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,mt8195-hdmi-ddc.yaml
> @@ -0,0 +1,51 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/mediatek/mediatek,mt8195-hdmi-ddc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Mediatek HDMI DDC for mt8195
> +
> +maintainers:
> +  - CK Hu <ck.hu@mediatek.com>
> +  - Jitao shi <jitao.shi@mediatek.com>
> +
> +description: |
> +  The HDMI DDC i2c controller is used to interface with the HDMI DDC pins.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - mediatek,mt8195-hdmi-ddc

I think I wrote it - you already have bindings for HDMI DDC. I doubt
that these are different and it looks like you model the bindings
according to your driver. That's not the way.

> +
> +  clocks:
> +    maxItems: 1
> +
> +  clock-names:
> +    items:
> +      - const: ddc
> +
> +  mediatek,hdmi:
> +    $ref: /schemas/types.yaml#/definitions/phandle
> +    description:
> +      A phandle to the mt8195 hdmi controller
> +
> +required:
> +  - compatible
> +  - clocks
> +  - clock-names
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    hdmiddc0: ddc_i2c {

Node names should be generic - ddc.
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

No underscores in node names.

Additionally I2C devices have addresses on the bus. Why this one doesn't?

> +      compatible = "mediatek,mt8195-hdmi-ddc";
> +      mediatek,hdmi = <&hdmi0>;
> +      clocks = <&clk26m>;
> +      clock-names = "ddc";
> +    };
> +
> +...
> 

Best regards,
Krzysztof