Re: [PATCH v4 13/18] dt-bindings: usb-switch: Extend for DisplayPort altmode

[Stephen Boyd]

Quoting Dmitry Baryshkov (2024-09-19 03:40:19)
> On Sat, Aug 31, 2024 at 09:06:51PM GMT, Stephen Boyd wrote:
> > diff --git a/Documentation/devicetree/bindings/usb/usb-switch.yaml b/Documentation/devicetree/bindings/usb/usb-switch.yaml
> > index f5dc7e23b134..816f295f322f 100644
> > --- a/Documentation/devicetree/bindings/usb/usb-switch.yaml
> > +++ b/Documentation/devicetree/bindings/usb/usb-switch.yaml
> > @@ -52,6 +52,14 @@ properties:
> >            endpoint:
> >              $ref: '#/$defs/usbc-in-endpoint'
> >
> > +      port@2:
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > +        unevaluatedProperties: false
> > +
> > +        properties:
> > +          endpoint:
> > +            $ref: '#/$defs/dp-endpoint'
>
> Is it a separate port or is it an endpoint of the same upstream-facing
> (non-connector-facing) SS port?

I don't quite follow this comment. This is an input DP endpoint/port.

>
> > +
> >  oneOf:
> >    - required:
> >        - port
> > @@ -65,6 +73,19 @@ $defs:
> >      $ref: /schemas/graph.yaml#/$defs/endpoint-base
> >      description: Super Speed (SS) output endpoint to a type-c connector
> >      unevaluatedProperties: false
> > +    properties:
> > +      data-lanes:
> > +        $ref: /schemas/types.yaml#/definitions/uint32-array
> > +        description: |
> > +          An array of physical USB Type-C data lane indexes.
> > +          - 0 is SSRX1 lane
> > +          - 1 is SSTX1 lane
> > +          - 2 is SSTX2 lane
> > +          - 3 is SSRX2 lane
> > +        minItems: 4
> > +        maxItems: 4
> > +        items:
> > +          maximum: 3
>
> What is the usecase to delare less than 4 lanes going to the USB-C
> connector?

I'm not aware of any usecase. The 'maximum: 3' is the max value in the
cell, i.e. 0, 1, 2, or 3.