On Sat, Dec 14, 2019 at 5:29 AM Rob Herring <robh+dt@xxxxxxxxxx> wrote: > > On Wed, Dec 11, 2019 at 12:19 AM Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> wrote: > > > > From: Nicolas Boichat <drinkcat@xxxxxxxxxxxx> > > > > Add bindings for Generic GPIO mux driver. > > > > Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx> > > Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx> > > --- > > Change from RFC to v1: > > - txt to yaml > > --- > > .../bindings/display/bridge/gpio-mux.yaml | 89 +++++++++++++++++++ > > 1 file changed, 89 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/display/bridge/gpio-mux.yaml > > > > diff --git a/Documentation/devicetree/bindings/display/bridge/gpio-mux.yaml b/Documentation/devicetree/bindings/display/bridge/gpio-mux.yaml > > new file mode 100644 > > index 000000000000..cef098749066 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/display/bridge/gpio-mux.yaml > > @@ -0,0 +1,89 @@ > > +# SPDX-License-Identifier: GPL-2.0 > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/display/bridge/gpio-mux.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Generic display mux (1 input, 2 outputs) > > What makes it generic? Doesn't the mux chip have power supply, > possibly a reset line or not, etc.? What about a mux where the GPIO > controls the mux? > > Generally, we avoid 'generic' bindings because h/w is rarely generic. > You can have a generic driver which works on multiple devices. > Then how about making it mt8173-oak-gpio-mux? Since this is currently only used in this board. > > + > > +maintainers: > > + - Nicolas Boichat <drinkcat@xxxxxxxxxxxx> > > + > > +description: | > > + This bindings describes a simple display (e.g. HDMI) mux, that has 1 > > + input, and 2 outputs. The mux status is controlled by hardware, and > > + its status is read back using a GPIO. > > + > > +properties: > > + compatible: > > + const: gpio-display-mux > > + > > + detect-gpios: > > + maxItems: 1 > > + description: GPIO that indicates the active output > > + > > + ports: > > + type: object > > + > > + properties: > > + port@0: > > + type: object > > + description: | > > + Video port for input. > > + > > + port@1: > > + type: object > > + description: | > > + 2 video ports for output. > > + The reg value in the endpoints matches the GPIO status: when > > + GPIO is asserted, endpoint with reg value <1> is selected. > > You should describe 'endpoint@0' and 'endpoint@1' here too. Will add in next version, thanks > > > + > > + required: > > + - port@0 > > + - port@1 > > + > > +required: > > + - compatible > > + - detect-gpios > > + - ports > > + > > +examples: > > + - | > > + hdmi_mux: hdmi_mux { > > + compatible = "gpio-display-mux"; > > + status = "okay"; > > Don't show status in examples. > > > + detect-gpios = <&pio 36 GPIO_ACTIVE_HIGH>; > > + pinctrl-names = "default"; > > + pinctrl-0 = <&hdmi_mux_pins>; > > + ddc-i2c-bus = <&hdmiddc0>; > > Not documented. Is the i2c bus muxed too? If not, then this is in the > wrong place. > It's muxed, but this is required because of [1], so it should be removed in this example. [1]https://elixir.bootlin.com/linux/v5.5-rc2/source/Documentation/devicetree/bindings/display/mediatek/mediatek,hdmi.txt#L24 > > + > > + ports { > > + #address-cells = <1>; > > + #size-cells = <0>; > > + > > + port@0 { /* input */ > > + reg = <0>; > > + > > + hdmi_mux_in: endpoint { > > + remote-endpoint = <&hdmi0_out>; > > + }; > > + }; > > + > > + port@1 { /* output */ > > + reg = <1>; > > + > > + #address-cells = <1>; > > + #size-cells = <0>; > > + > > + hdmi_mux_out_anx: endpoint@0 { > > + reg = <0>; > > + remote-endpoint = <&anx7688_in>; > > + }; > > + > > + hdmi_mux_out_hdmi: endpoint@1 { > > + reg = <1>; > > + remote-endpoint = <&hdmi_connector_in>; > > + }; > > + }; > > + }; > > + }; > > -- > > 2.24.0.525.g8f36a354ae-goog > >
