On Thu, Aug 21, 2025 at 03:53:26PM +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 > > And the layout of the lanes can be swpped depending of an > eventual USB-C connector orientation. > > Nevertheless those QMP Comby PHY can be statically used to > drive a DisplayPort connector, DP->HDMI bridge, USB3 A Connector... > > But if a 4lanes DP->HDMI bridge is directly connected to the > QMP Comby PHY lanes, in the default routing 2 or the 4 lanes would > probbaly be USB3, making the DP->HDMI bridge non functional. > > Add a property to hint in which layout mode the QMP Comby PHY > should be as startup. > > Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> > --- > .../bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > 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 c8bc512df08b5694c8599f475de78679a4438449..129475a1d9527733e43ded5a38aad766f9810fe7 100644 > --- a/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml > +++ b/Documentation/devicetree/bindings/phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml > @@ -76,6 +76,19 @@ properties: > mode-switch: true > orientation-switch: true > > + qcom,combo-initial-mode: > + description: > + Describe the initial mode of the Combo PHY configuration. > + The Combo PHY is a wrapper on top of a DP PHY and an USB3 PHY, > + sharing the same SuperSpeed lanes with either DisplayPort over > + the 4 lanes (dp), USB3 on a pair of lanes (usb3) or both > + technologies in a 2+2 configuration (usb3+dp) as default. SPecifying this as an initial mode means that it can be switched later. Should we generalize this and desribe it as bus-type (from video-interfaces.yaml) and allow it to be present only if there is no mode-switch property? > + default: usb3+dp > + enum: > + - usb3+dp > + - usb3 > + - dp > + > ports: > $ref: /schemas/graph.yaml#/properties/ports > properties: > > -- > 2.34.1 > -- With best wishes Dmitry
