[PATCH v8 01/10] dt-bindings: display: rockchip: analogix-dp: Fix hclk as third clock for RK3588
Conor Dooley
conor at kernel.org
Tue May 26 09:39:42 PDT 2026
On Tue, May 26, 2026 at 07:27:55PM +0800, Damon Ding wrote:
> Hi Conor,
>
> On 5/26/2026 8:54 AM, Damon Ding wrote:
> > Hi Conor,
> >
> > On 5/26/2026 12:54 AM, Conor Dooley wrote:
> > > On Mon, May 25, 2026 at 08:53:22PM +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 at 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.
> > > >
> > > > Changes in v7:
> > > > - List all valid clock names at the top level, and constrain the clock
> > > > count for each platform with minItems/maxItems in allOf.
> > > >
> > > > Changes in v8:
> > > > - Fix indentation to 10 for enum in clock-names property.
> > > > ---
> > > > .../rockchip/rockchip,analogix-dp.yaml | 34 ++++++++++++++++++-
> > > > 1 file changed, 33 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/display/rockchip/
> > > > rockchip,analogix-dp.yaml b/Documentation/devicetree/bindings/
> > > > display/rockchip/rockchip,analogix-dp.yaml
> > > > index d99b23b88cc5..a1ab7a77bdd3 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
> > > > power-domains:
> > > > maxItems: 1
> > > > @@ -60,6 +62,32 @@ required:
> > > > allOf:
> > > > - $ref: /schemas/display/bridge/analogix,dp.yaml#
> > > > + - if:
> > > > + properties:
> > > > + compatible:
> > > > + contains:
> > > > + enum:
> > > > + - rockchip,rk3288-dp
> > > > + then:
> > > > + properties:
> > > > + clocks:
> > > > + maxItems: 2
> > > > + clock-names:
> > > > + maxItems: 2
> > > > +
> > > > + - if:
> > > > + properties:
> > > > + compatible:
> > > > + contains:
> > > > + enum:
> > > > + - rockchip,rk3399-edp
> > > > + then:
> > > > + properties:
> > > > + clocks:
> > > > + minItems: 3
> > > > + clock-names:
> > > > + minItems: 3
> > >
> > > If you go back to v6, you'll see that I never asked you to remove the
> > > explict clock-names from here or below. Only the one from the 3288
> > > section. The minItems was an addition, not a replacement.
> > >
> > > pw-bot: changes-requested
> > >
> >
> > Sorry for the misunderstanding. I will restore the explicit clock-names
> > definitions and fix this in next version.
> >
>
> Sorry to bother you. I attempted to place the explicit clock-names under
> minItems:
>
> diff --git a/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml b/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
> index a1ab7a77bdd3..ef03edf52de8 100644
> --- a/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
> +++ b/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
> @@ -87,6 +87,10 @@ allOf:
> minItems: 3
> clock-names:
> minItems: 3
> + items:
> + - const: dp
> + - const: pclk
> + - const: grf
>
> - if:
> properties:
> @@ -100,6 +104,10 @@ allOf:
> minItems: 3
> clock-names:
> minItems: 3
> + items:
> + - const: dp
> + - const: pclk
> + - const: hclk
> resets:
> minItems: 2
> reset-names:
>
> make dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml
>
> Then the following errors occurred:
>
> SCHEMA Documentation/devicetree/bindings/processed-schema.json
> CHKDT ./Documentation/devicetree/bindings
> /home/ding/drm-misc/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml:
> allOf:2:then:properties:clock-names: 'oneOf' conditional failed, one must be
> fixed:
> False schema does not allow 3
> [{'const': 'dp'}, {'const': 'pclk'}, {'const': 'grf'}] is too long
> [{'const': 'dp'}, {'const': 'pclk'}, {'const': 'grf'}] is too short
> 1 was expected
> 3 is greater than the maximum of 2
> hint: "minItems" is only needed if less than the "items" list length
> from schema $id: http://devicetree.org/meta-schemas/items.yaml
> /home/ding/drm-misc/Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.yaml:
> allOf:3:then:properties:clock-names: 'oneOf' conditional failed, one must be
> fixed:
> False schema does not allow 3
> [{'const': 'dp'}, {'const': 'pclk'}, {'const': 'hclk'}] is too long
> [{'const': 'dp'}, {'const': 'pclk'}, {'const': 'hclk'}] is too short
> 1 was expected
> 3 is greater than the maximum of 2
> hint: "minItems" is only needed if less than the "items" list length
> from schema $id: http://devicetree.org/meta-schemas/items.yaml
> LINT ./Documentation/devicetree/bindings
> DTEX Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.example.dts
> DTC [C] Documentation/devicetree/bindings/display/rockchip/rockchip,analogix-dp.example.dtb
>
> Neither keeping only minItems nor only the explicit clock-names causes any
> errors. Would it be a better idea to keep just the explicit clock-names
> here?
Sure.
This feels like a bug because I have no idea where the "maximum of 2" is
coming from. I'll ask Rob about it.
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