[PATCH v3 3/5] dt-bindings: phy: qcom,sc8280xp-qmp-usb43dp-phy: Document lanes mapping when not using in USB-C complex

[Dmitry Baryshkov]

On Tue, Sep 09, 2025 at 09:14:49AM +0200, Neil Armstrong wrote:
> On 08/09/2025 23:14, Dmitry Baryshkov wrote:
> > On Mon, Sep 08, 2025 at 03:04:20PM +0200, Neil Armstrong wrote:
> > > The QMP USB3/DP Combo PHY hosts an USB3 phy and a DP PHY on top
> > > of a combo glue to route either lanes to the 4 shared physical lanes.
> > > 
> > > The routing of the lanes can be:
> > > - 2 DP + 2 USB3
> > > - 4 DP
> > > - 2 USB3
> > > 
> > > The layout of the lanes was designed to be mapped and swapped
> > > related to the USB-C Power Delivery negociation, so it supports
> > > a finite set of mappings inherited by the USB-C Altmode layouts.
> > > 
> > > Nevertheless those QMP Comby PHY can be used to drive a DisplayPort
> > > connector, DP->HDMI bridge, USB3 A Connector, etc... without
> > > an USB-C connector and no PD events.
> > > 
> > > Document the data-lanes on numbered port at 0 out endpoints,
> > > allowing us to document the lanes mapping to DisplayPort
> > > and/or USB3 connectors/peripherals.
> > > 
> > > Signed-off-by: Neil Armstrong <neil.armstrong at linaro.org>
> > > ---
> > >   .../phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml         | 59 +++++++++++++++++++++-
> > >   1 file changed, 58 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
> > > index 5005514d7c3a1e4a8893883497fd204bc04e12be..51e0d0983091af0b8a5170ac34a05ab0acc435a3 100644
> > > --- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
> > > +++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml
> > > @@ -81,10 +81,67 @@ properties:
> > >     ports:
> > >       $ref: /schemas/graph.yaml#/properties/ports
> > > +
> > >       properties:
> > >         port at 0:
> > > -        $ref: /schemas/graph.yaml#/properties/port
> > > +        $ref: /schemas/graph.yaml#/$defs/port-base
> > >           description: Output endpoint of the PHY
> > > +        unevaluatedProperties: false
> > > +
> > > +        properties:
> > > +          endpoint:
> > > +            $ref: /schemas/graph.yaml#/$defs/endpoint-base
> > > +            unevaluatedProperties: false
> > > +
> > > +          endpoint at 0:
> > > +            $ref: /schemas/graph.yaml#/$defs/endpoint-base
> > > +            description: Display Port Output lanes of the PHY when used with static mapping
> > > +            unevaluatedProperties: false
> > > +
> > > +            properties:
> > > +              data-lanes:
> > > +                $ref: /schemas/types.yaml#/definitions/uint32-array
> > > +                minItems: 2
> > 
> > Nit: DP can work in a 1-lane mode. Do we nned to support that in the PHY?
> 
> So the PHY already supports 1-lane, but the QMP Combo only supports
> mapping 2+2 or 4, but nevetheless we can still decscribe 1 lane in DT
> int both in & out endpoint and still should work fine.
> 
> Do you think this should be done now ?

Do we support it in the PHY hardware?

> 
> Neil
> 
> > 
> > > +                maxItems: 4
> > > +                oneOf:
> > > +                  - items: # DisplayPort 2 lanes, normal orientation
> > > +                      - const: 0
> > > +                      - const: 1
> > > +                  - items: # DisplayPort 2 lanes, flipped orientation
> > > +                      - const: 3
> > > +                      - const: 2
> > > +                  - items: # DisplayPort 4 lanes, normal orientation
> > > +                      - const: 0
> > > +                      - const: 1
> > > +                      - const: 2
> > > +                      - const: 3
> > > +                  - items: # DisplayPort 4 lanes, flipped orientation
> > > +                      - const: 3
> > > +                      - const: 2
> > > +                      - const: 1
> > > +                      - const: 0
> > > +            required:
> > > +              - data-lanes
> > > +
> > > +          endpoint at 1:
> > > +            $ref: /schemas/graph.yaml#/$defs/endpoint-base
> > > +            description: USB Output lanes of the PHY when used with static mapping
> > > +            unevaluatedProperties: false
> > > +
> > > +            properties:
> > > +              data-lanes:
> > > +                $ref: /schemas/types.yaml#/definitions/uint32-array
> > > +                minItems: 2
> > > +                oneOf:
> > > +                  - items: # USB3, normal orientation
> > > +                      - const: 1
> > > +                      - const: 0
> > > +                  - items: # USB3, flipped orientation
> > > +                      - const: 2
> > > +                      - const: 3
> > > +
> > > +            required:
> > > +              - data-lanes
> > >         port at 1:
> > >           $ref: /schemas/graph.yaml#/properties/port
> > > 
> > > -- 
> > > 2.34.1
> > > 
> > 
> 

-- 
With best wishes
Dmitry