Re: [PATCH v6 01/10] dt-bindings: display: rockchip: analogix-dp: Fix hclk as third clock for RK3588

[Krzysztof Kozlowski <krzk@kernel.org>]

On Thu, May 21, 2026 at 04:08:26PM +0800, Damon Ding wrote:
> RK3588 eDP controller requires HCLK_VO1 to access the VO1 GRF
> registers and enable the video datapath.
> 
> Previously, the clock was enabled implicitly via the 'rockchip,vo-grf'
> phandle reference, which allowed the eDP to work without explicitly
> managing the hclk_vo1 clock. However, this is not safe or explicit.
> 
> To make the clock dependency explicit, enforce per-SoC clock-names
> requirements:
>  - RK3288: 2 clocks (dp, pclk)
>  - RK3399: 3 clocks (dp, pclk, grf)
>  - RK3588: 3 clocks (dp, pclk, hclk)
> 
> Do not reuse the 'grf' clock name for RK3588 because it represents
> a different clock with distinct control logic:
> - The 'grf' clock is only for GRF register access and is toggled
>   dynamically during register access.
> - The 'hclk' clock controls both GRF access and video datapath
>   gating, and must remain enabled during probe.
> 
> Fixes: f855146263b1 ("dt-bindings: display: rockchip: analogix-dp: Add support for RK3588")
> Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
> 
> ---
> 
> Changes in v4:
> - Modify the commit msg.
> 
> Changes in v5:
> - Enforce the correct third clock name on a per-compatible basis.
> - Modify the commit msg simultaneously.
> 
> Changes in v6:
> - Expand more detail commit msg about using hclk instead of grf clock.
> ---
>  .../rockchip/rockchip,analogix-dp.yaml        | 37 +++++++++++++++++--
>  1 file changed, 33 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml b/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
> index d99b23b88cc5..8001c1facf98 100644
> --- a/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
> +++ b/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
> @@ -23,10 +23,7 @@ properties:
>  
>    clock-names:
>      minItems: 2
> -    items:
> -      - const: dp
> -      - const: pclk
> -      - const: grf
> +    maxItems: 3
>  
>    power-domains:
>      maxItems: 1
> @@ -60,6 +57,33 @@ required:
>  allOf:
>    - $ref: /schemas/display/bridge/analogix,dp.yaml#
>  
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - rockchip,rk3288-dp
> +    then:
> +      properties:
> +        clock-names:
> +          items:
> +            - const: dp
> +            - const: pclk

Why aren't there constraints for clocks? They always must come together.

Please open any other binding and look how it is done there.

Best regards,
Krzysztof