On Mon, 19 Aug 2024 15:38:28 -0700, Stephen Boyd wrote: > Add a DT graph binding to google,cros-ec-typec so that it can combine > DisplayPort (DP) and USB SuperSpeed (SS) data into a USB type-c endpoint > that is connected to the usb-c-connector node's SS endpoint. This also > allows us to connect the DP and USB nodes in the graph to the USB type-c > connectors, providing the full picture of the USB type-c data flows in > the system. > > Allow there to be multiple typec nodes underneath the EC node so that > one DT graph exists per DP bridge. The EC is actually controlling TCPCs > and redrivers that combine the DP and USB signals together so this more > accurately reflects the hardware design without introducing yet another > DT node underneath the EC for USB type-c. > > If the type-c ports are being shared between a single DP controller then > the ports need to know about each other and determine a policy to drive > DP to one type-c port. If the type-c ports each have their own dedicated > DP controller then they're able to operate independently and enter/exit > DP altmode independently as well. We can't connect the DP controller's > endpoint to one usb-c-connector port@1 endpoint and the USB controller's > endpoint to another usb-c-connector port@1 endpoint either because the > DP muxing case would have DP connected to two usb-c-connector endpoints > which the graph binding doesn't support. > > Therefore, one typec node is required per the capabilities of the type-c > port(s) being managed. This also lets us indicate which type-c ports the > DP controller is wired to. For example, if DP was connected to ports 0 > and 2, while port 1 was connected to another DP controller we wouldn't > be able to implement that without having some other DT property to > indicate which output ports are connected to the DP endpoint. > > Cc: Rob Herring <robh+dt@xxxxxxxxxx> > Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx> > Cc: Conor Dooley <conor+dt@xxxxxxxxxx> > Cc: Lee Jones <lee@xxxxxxxxxx> > Cc: Benson Leung <bleung@xxxxxxxxxxxx> > Cc: Guenter Roeck <groeck@xxxxxxxxxxxx> > Cc: Prashant Malani <pmalani@xxxxxxxxxxxx> > Cc: Tzung-Bi Shih <tzungbi@xxxxxxxxxx> > Cc: <devicetree@xxxxxxxxxxxxxxx> > Cc: <chrome-platform@xxxxxxxxxxxxxxx> > Cc: Pin-yen Lin <treapking@xxxxxxxxxxxx> > Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> > --- > .../bindings/mfd/google,cros-ec.yaml | 7 +- > .../bindings/usb/google,cros-ec-typec.yaml | 229 ++++++++++++++++++ > 2 files changed, 233 insertions(+), 3 deletions(-) > Reviewed-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
