| Message ID | 20220520164810.141400-1-bjorn.andersson@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [PATCH/RFC] dt-bindings: connector: Add port for OOB notifications | expand |
diff --git a/Documentation/devicetree/bindings/connector/usb-connector.yaml b/Documentation/devicetree/bindings/connector/usb-connector.yaml index 0420fa563532..99d4aeb233e5 100644 --- a/Documentation/devicetree/bindings/connector/usb-connector.yaml +++ b/Documentation/devicetree/bindings/connector/usb-connector.yaml @@ -189,6 +189,12 @@ properties: description: Sideband Use (SBU), present in USB-C. This describes the alternate mode connection of which SBU is a part. + port@3: + $ref: /schemas/graph.yaml#/properties/port + description: Out-of-band notifications. This describes the logical + connection to e.g. a DisplayPort controller that should be notified + about hot plug events. + required: - port@0
In USB Type-C altmode hot plug interrupts are transferred using sideband channels. Introduce an additional port in the usb-c-connector to allow referencing the recipient of these notifications. A typical node to be referred is a DisplayPort controller. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> --- I have a USB Type-C port manager with two usb-c-connector child nodes and I have two display-port controller nodes. I need a way to link each port with it's related displayport controller, for the purpose of passing hot-plug events from USB PD to the dp driver. The displayport binding [1] specifies port@1 as "Output endpoint of the controller" and in case of being connected to an eDP panel or a dp-controller this links the node with whatever the output is. It has been suggested by some to describe the link from the usb-c-connector add a displayport = <&phandle> to each usb-c-connector node, but the proposed solution here would make the usb-c-connector case follow the same scheme as these other cases. Also, using the graph would allow an implementation of either the tcpm just notifying the referenced displayport-controller, or following the dp-controller implementation in Linux implement a drm_bridge and use the reference in the other direction. To clarify the end result would look something like: tcpm { connector@0 { compatible = "usb-c-connector"; reg = <0>; ports { port@0 { reg = <0>; endpoint { remote-endpoint = <&usb0_hs_mux>; }; }; port@1 { reg = <1>; endpoint { remote-endpoint = <&usb0_ss_mux>; }; }; port@2 { reg = <2>; endpoint { remote-endpoint = <&usb0_sbu_switch>; }; }; connector0_dp0: port@3 { reg = <1>; endpoint { remote-endpoint = <&dp0_connector0>; }; }; }; }; connector@1 { compatible = "usb-c-connector"; reg = <1>; ports { port@0 { reg = <0>; endpoint { remote-endpoint = <&usb1_hs_mux>; }; }; port@1 { reg = <1>; endpoint { remote-endpoint = <&usb1_ss_mux>; }; }; port@2 { reg = <2>; endpoint { remote-endpoint = <&usb1_sbu_switch>; }; }; connector1_dp1: port@3 { reg = <1>; endpoint { remote-endpoint = <&dp1_connector1>; }; }; }; }; } displayport-controller@0 { reg = <0x0>; ports { port@1 { reg = <1>; dp0_connector0: endpoint { remote-endpoint = <&connector0_dp0>; }; }; }; }; displayport-controller@1 { reg = <0x1>; ports { port@1 { reg = <1>; dp1_connector1: endpoint { remote-endpoint = <&connector1_dp1>; }; }; }; }; [1] https://www.kernel.org/doc/Documentation/devicetree/bindings/display/msm/dp-controller.yaml .../devicetree/bindings/connector/usb-connector.yaml | 6 ++++++ 1 file changed, 6 insertions(+)