On Tue, May 09, 2023 at 08:19:28PM -0700, Bjorn Andersson wrote: > The QMP combo PHY sits in an of_graph connected between the DisplayPort > controller and a USB Type-C connector (or possibly a redriver). > > The TCPM needs to be able to convey the HPD signal to the DisplayPort > controller, but no directly link is provided by DeviceTree so the signal > needs to "pass through" the QMP combo phy. > > Handle this by introducing a drm_bridge which upon initialization finds > the next bridge (i.e. the usb-c-connector) and chain this together. This > way HPD changes in the connector will propagate to the DisplayPort > driver. > > The connector bridge is resolved lazily, as the TCPM is expected to be > able to resolve the typec mux and switch at probe time, so the QMP combo > phy will probe before the TCPM. > > Signed-off-by: Bjorn Andersson <quic_bjorande@xxxxxxxxxxx> > Acked-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> > Tested-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx> > Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx> > Tested-by: Abel Vesa <abel.vesa@xxxxxxxxxx> > Tested-by: Steev Klimaszewski <steev@xxxxxxxx> > Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> # on HDK8450 > Tested-by: Johan Hovold <johan+linaro@xxxxxxxxxx> # X13s > --- > > Changes since v1: > - Wrap DRM-related code in CONFIG_DRM guard > - Inroduce DRM-dependencies in Kconfig > - Dropped dev_err_probe() usage Reviewed-by: Johan Hovold <johan+linaro@xxxxxxxxxx>