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| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.yaml | 172 |
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diff --git a/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.yaml b/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.yaml new file mode 100644 index 0000000000..2c08f2a7cf --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-demux-pinctrl.yaml @@ -0,0 +1,172 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/i2c/i2c-demux-pinctrl.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Pinctrl-based I2C Bus Demultiplexer + +maintainers: + - Wolfram Sang <wsa+renesas@sang-engineering.com> + +description: | + This binding describes an I2C bus demultiplexer that uses pin multiplexing to + route the I2C signals, and represents the pin multiplexing configuration + using the pinctrl device tree bindings. This may be used to select one I2C + IP core at runtime which may have a better feature set for a given task than + another I2C IP core on the SoC. The most simple example is to fall back to + GPIO bitbanging if your current runtime configuration hits an errata of the + internal IP core. + + +-------------------------------+ + | SoC | + | | +-----+ +-----+ + | +------------+ | | dev | | dev | + | |I2C IP Core1|--\ | +-----+ +-----+ + | +------------+ \-------+ | | | + | |Pinctrl|--|------+--------+ + | +------------+ +-------+ | + | |I2C IP Core2|--/ | + | +------------+ | + | | + +-------------------------------+ + +allOf: + - $ref: i2c-mux.yaml + - $ref: /schemas/i2c/i2c-controller.yaml# + +properties: + compatible: + const: i2c-demux-pinctrl + + i2c-parent: + $ref: /schemas/types.yaml#/definitions/phandle-array + description: + List of phandles of I2C masters available for selection. The first one + will be used as default. + + i2c-bus-name: + $ref: /schemas/types.yaml#/definitions/string + description: + The name of this bus. Also needed as pinctrl-name for the I2C parents. + +required: + - compatible + - i2c-parent + - i2c-bus-name + +unevaluatedProperties: false + +examples: + - | + #include <dt-bindings/gpio/gpio.h> + #include <dt-bindings/interrupt-controller/irq.h> + + gpioi2c2: i2c-9 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "i2c-gpio"; + scl-gpios = <&gpio5 5 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; + sda-gpios = <&gpio5 6 (GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN)>; + i2c-gpio,delay-us = <5>; + + // The I2C controller must have its status "disabled". The I2C bus + // demultiplexer will enable it at runtime when needed. + status = "disabled"; + }; + + iic2: i2c@e6520000 { + reg = <0xe6520000 0x425>; + pinctrl-0 = <&iic2_pins>; + // The pinctrl property for the parent I2C controller needs a pinctrl + // state with the same name as i2c-bus-name in the I2C bus demultiplexer + // node, not "default"! + pinctrl-names = "i2c-hdmi"; + + clock-frequency = <100000>; + + // The I2C controller must have its status "disabled". The I2C bus + // demultiplexer will enable it at runtime when needed. + status = "disabled"; + }; + + i2c2: i2c@e6530000 { + reg = <0 0xe6530000 0 0x40>; + pinctrl-0 = <&i2c2_pins>; + // The pinctrl property for the parent I2C controller needs a pinctrl + // state with the same name as i2c-bus-name in the I2C bus demultiplexer + // node, not "default"! + pinctrl-names = "i2c-hdmi"; + + clock-frequency = <100000>; + + // The I2C controller must have its status "disabled". The I2C bus + // demultiplexer will enable it at runtime when needed. + status = "disabled"; + }; + + // Example for a bus to be demuxed. It contains various I2C clients for + // HDMI, so the bus is named "i2c-hdmi": + i2chdmi: i2c-mux3 { + compatible = "i2c-demux-pinctrl"; + i2c-parent = <&iic2>, <&i2c2>, <&gpioi2c2>; + i2c-bus-name = "i2c-hdmi"; + #address-cells = <1>; + #size-cells = <0>; + + ak4643: codec@12 { + compatible = "asahi-kasei,ak4643"; + #sound-dai-cells = <0>; + reg = <0x12>; + }; + + composite-in@20 { + compatible = "adi,adv7180"; + reg = <0x20>; + + port { + adv7180: endpoint { + bus-width = <8>; + remote-endpoint = <&vin1ep0>; + }; + }; + }; + + hdmi@39 { + compatible = "adi,adv7511w"; + reg = <0x39>; + interrupt-parent = <&gpio1>; + interrupts = <15 IRQ_TYPE_LEVEL_LOW>; + clocks = <&cec_clock>; + clock-names = "cec"; + + avdd-supply = <&fixedregulator1v8>; + dvdd-supply = <&fixedregulator1v8>; + pvdd-supply = <&fixedregulator1v8>; + dvdd-3v-supply = <&fixedregulator3v3>; + bgvdd-supply = <&fixedregulator1v8>; + + adi,input-depth = <8>; + adi,input-colorspace = "rgb"; + adi,input-clock = "1x"; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + port@0 { + reg = <0>; + adv7511_in: endpoint { + remote-endpoint = <&lvds0_out>; + }; + }; + + port@1 { + reg = <1>; + adv7511_out: endpoint { + remote-endpoint = <&hdmi_con_out>; + }; + }; + }; + }; + }; |