Re: [PATCH v2 1/9] dt-bindings: display: rockchip: analogix-dp: Expand clock-names "hclk" for the third clock

[Krzysztof Kozlowski <krzk@kernel.org>]

On 23/03/2026 09:49, Damon Ding wrote:
>>> diff --git a/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml b/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
>>> index d99b23b88cc5..d2bc8636b626 100644
>>> --- a/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
>>> +++ b/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
>>> @@ -26,7 +26,9 @@ properties:
>>>       items:
>>>         - const: dp
>>>         - const: pclk
>>> -      - const: grf
>>> +      - enum:
>>> +          - grf
>>> +          - hclk
>>
>> You just told me it is the same clock, no? I asked that and you
>> confirmed? Or you replied with an answer not relevant to the question?
>>
> 
> Aha, I may have misunderstood your earlier advice as meaning that since 
> the RK3576 and RK3588 platforms share the same design, their clock 
> dependencies should also be identical.
> 
> The 'grf' clock and 'hclk' clock are different.
> On RK3399, the GRF clock is for accessing VIO GRF registers.

OK

> On RK3588/RK3576, the eDP 'hclk' is required as it is the parent clock 
> of 'pclk' in the AHB bus topology.

Heh, device takes pclk, so you do not need to take its parent.

> 
>> If this device takes reference to grf, why does it also take grf clock?
>> Devices MUST NOT take clocks on behalf of other devices, so please
>> answer with a list of all clock inputs according to datasheet/manual.
>>
> 
> On earlier platforms, the GRF was not partitioned into separate 
> functional small GRF units as on newer designs. Therefore, the 'grf' 
> clock was designed as the clock dependency for all relevant modules.
> 
> For RK3588/RK3576 eDP module, the list of all clock inputs is:
> 
> CLK_EDP0_24M: Reference clock.
> PCLK_EDP0: AHB clock.
> HCLK_VO1/HCLK_VO0_ROOT: Video datapath clock.




Best regards,
Krzysztof