Re: [PATCH v2 1/2] dt-bindings: usb: Introduce GPIO-based SBU mux

Rob Herring
2023-01-17T18:26:01Z

On Thu, Jan 12, 2023 at 08:11:14PM -0800, Bjorn Andersson wrote:
> From: Bjorn Andersson <bjorn.andersson@linaro.org>
>
> Introduce a binding for GPIO-based mux hardware used for connecting,
> disconnecting and switching orientation of the SBU lines in USB Type-C
> applications.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
> ---
>
> Changes since v1:
> - Expanded the example to indicate how this fits with the TCPM
> - Updated maintainer email address.
>
> .../devicetree/bindings/usb/gpio-sbu-mux.yaml | 110 ++++++++++++++++++
> 1 file changed, 110 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/usb/gpio-sbu-mux.yaml
>
> diff --git a/Documentation/devicetree/bindings/usb/gpio-sbu-mux.yaml b/Documentation/devicetree/bindings/usb/gpio-sbu-mux.yaml
> new file mode 100644
> index 000000000000..bf4b1d016e1f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/gpio-sbu-mux.yaml
> @@ -0,0 +1,110 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/usb/gpio-sbu-mux.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: GPIO-based SBU mux
> +
> +maintainers:
> + - Bjorn Andersson <andersson@kernel.org>
> +
> +description:
> + In USB Type-C applications the SBU lines needs to be connected, disconnected
> + and swapped depending on the altmode and orientation. This binding describes
> + a family of hardware solutions which switches between these modes using GPIO
> + signals.
> +
> +properties:
> + compatible:
> + items:
> + - enum:
> + - onnn,fsusb43l10x
> + - pericom,pi3usb102
> + - const: gpio-sbu-mux
> +
> + enable-gpios:
> + description: Switch enable GPIO
> +
> + select-gpios:
> + description: Orientation select
> +
> + vcc-supply:
> + description: power supply
> +
> + mode-switch:
> + description: Flag the port as possible handle of altmode switching
> + type: boolean
> +
> + orientation-switch:
> + description: Flag the port as possible handler of orientation switching
> + type: boolean
> +
> + port:
> + $ref: /schemas/graph.yaml#/properties/port
> + description:
> + A port node to link the SBU mux to a TypeC controller for the purpose of
> + handling altmode muxing and orientation switching.
> +
> +required:
> + - compatible
> + - enable-gpios
> + - select-gpios
> + - mode-switch
> + - orientation-switch
> + - port
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> +
> + tcpm {
> + connector {
> + compatible = "usb-c-connector";
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port@0 {
> + reg = <0>;
> + tcpm_hs_out: endpoint {
> + remote-endpoint = <&usb_hs_phy_in>;
> + };
> + };
> +
> + port@1 {
> + reg = <1>;
> + tcpm_ss_out: endpoint {
> + remote-endpoint = <&usb_ss_phy_in>;
> + };
> + };
> +
> + port@2 {
> + reg = <2>;
> + tcpm_sbu_out: endpoint {
> + remote-endpoint = <&sbu_mux_in>;
> + };
> + };
> + };
> + };
> + };
> +
> + sbu-mux {
> + compatible = "pericom,pi3usb102", "gpio-sbu-mux";
> +
> + enable-gpios = <&tlmm 101 GPIO_ACTIVE_LOW>;
> + select-gpios = <&tlmm 164 GPIO_ACTIVE_HIGH>;
> +
> + mode-switch;
> + orientation-switch;
> +
> + port {
> + sbu_mux_in: endpoint {
> + remote-endpoint = <&tcpm_sbu_out>;
> + };

Don't you need a connection to whatever drives SBU? Maybe your case is
fixed because the phy does the DP/USB muxing? But the binding needs to
support the worst case which I guess would be all the muxing/switching
is done by separate board level components.

Rob