Re: [PATCH v3 04/21] dt-bindings: reset: renesas,rzv2h-usb2phy: Document VBUS_SEL mux

[Conor Dooley <conor@kernel.org>]

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Tommaso, Rob,

On Mon, Nov 10, 2025 at 11:43:37PM +0100, Tommaso Merciai wrote:
> Hi Conor,
> Thanks for your comment!
> 
> On Mon, Nov 10, 2025 at 06:56:31PM +0000, Conor Dooley wrote:
> > On Mon, Nov 10, 2025 at 01:08:04PM +0100, Tommaso Merciai wrote:
> > > Document the 'mux-controller' child node in the Renesas RZ/V2H(P)
> > > USB2PHY reset binding to support describing the USB VBUS_SEL
> > > multiplexer as a mux-controller.
> > > 
> > > This is required to properly configure the USB PHY VBUS source on
> > > RZ/V2H(P), RZ/G3E SoCs.
> > > 
> > > Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
> > > ---
> > > v2->v3:
> > >  - Manipulate mux-controller as an internal node.
> > 
> > Why is it a child node, rather than just putting the cell in the parent
> > reset node?
> 
> Getting "make dt_binding_check errors" [1] in v2
> Adding #mux-state-cells = <1> into:
> 
> 	usb20phyrst: reset-controller@15830000
> 	usb21phyrst: reset-controller@15840000
> 
> Nodes.
> 
> Please correct me if I'm wrong.

I think that that binding is not working as intended. Why require a
node-name pattern, when it matches on other things too:
select:
  anyOf:
    - properties:
        $nodename:
          pattern: '^mux-controller'
    - required:
        - '#mux-control-cells'
    - required:
        - '#mux-state-cells'
if the node name always contained mux-controller, the second two here
would not be needed. Looks to me like the intention was for it to allow
putting these control/state-cells properties into mfd type nodes.

I'd delete the node name property tbh. Rob, you converted this to
schema, what do you think?

Cheers,
Conor.
 
> [1] https://patchwork.kernel.org/project/linux-renesas-soc/patch/961741af7d4ec945945164759fe0d78bb3cf4d9d.1762354366.git.tommaso.merciai.xr@bp.renesas.com/
> 
> > 
> > >  - Improved commit body.
> > > 
> > > v1->v2:
> > >  - New patch
> > > 
> > >  .../bindings/reset/renesas,rzv2h-usb2phy-reset.yaml   | 11 +++++++++++
> > >  1 file changed, 11 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/reset/renesas,rzv2h-usb2phy-reset.yaml b/Documentation/devicetree/bindings/reset/renesas,rzv2h-usb2phy-reset.yaml
> > > index c1b800a10b53..03da74ff2d08 100644
> > > --- a/Documentation/devicetree/bindings/reset/renesas,rzv2h-usb2phy-reset.yaml
> > > +++ b/Documentation/devicetree/bindings/reset/renesas,rzv2h-usb2phy-reset.yaml
> > > @@ -37,6 +37,12 @@ properties:
> > >    '#reset-cells':
> > >      const: 0
> > >  
> > > +  mux-controller:
> > > +    $ref: /schemas/mux/mux-controller.yaml#
> > > +    description: Mux controller for USB VBUS source selection.
> > > +    type: object
> > > +    unevaluatedProperties: false
> > > +
> > >  required:
> > >    - compatible
> > >    - reg
> > > @@ -44,6 +50,7 @@ required:
> > >    - resets
> > >    - power-domains
> > >    - '#reset-cells'
> > > +  - mux-controller
> > >  
> > >  additionalProperties: false
> > >  
> > > @@ -58,4 +65,8 @@ examples:
> > >          resets = <&cpg 0xaf>;
> > >          power-domains = <&cpg>;
> > >          #reset-cells = <0>;
> > > +
> > > +        mux-controller {
> > > +          #mux-state-cells = <1>;
> > > +        };
> > >      };
> > > -- 
> > > 2.43.0
> > > 
> 
> 

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