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

[Dmitry Baryshkov]

On Thu, Oct 10, 2024 at 06:43:35PM -0400, Stephen Boyd wrote:
> 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.

This is the question: is this a separate port or just an endpoint on the
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.

-- 
With best wishes
Dmitry