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1# SPDX-License-Identifier: GPL-2.02%YAML 1.23---4$id: http://devicetree.org/schemas/i2c/i2c-mux-gpmux.yaml#5$schema: http://devicetree.org/meta-schemas/core.yaml#6 7title: General Purpose I2C Bus Mux8 9maintainers:10 - Peter Rosin <peda@axentia.se>11 12description: |+13 This binding describes an I2C bus multiplexer that uses a mux controller14 from the mux subsystem to route the I2C signals.15 16 .-----. .-----.17 | dev | | dev |18 .------------. '-----' '-----'19 | SoC | | |20 | | .--------+--------'21 | .------. | .------+ child bus A, on MUX value set to 022 | | I2C |-|--| Mux |23 | '------' | '--+---+ child bus B, on MUX value set to 124 | .------. | | '----------+--------+--------.25 | | MUX- | | | | | |26 | | Ctrl |-|-----+ .-----. .-----. .-----.27 | '------' | | dev | | dev | | dev |28 '------------' '-----' '-----' '-----'29 30 31allOf:32 - $ref: /schemas/i2c/i2c-mux.yaml#33 34properties:35 compatible:36 const: i2c-mux37 38 i2c-parent:39 $ref: /schemas/types.yaml#/definitions/phandle40 description:41 The phandle of the I2C bus that this multiplexer's master-side port is42 connected to.43 44 mux-controls:45 maxItems: 146 description:47 The mux-controller states are the I2C sub-bus numbers.48 49 mux-locked:50 type: boolean51 description: |52 Explicitly allow unrelated I2C transactions on the parent I2C adapter at53 these times:54 - during setup of the multiplexer55 - between setup of the multiplexer and the child bus I2C transaction56 - between the child bus I2C transaction and releasing of the multiplexer57 - during releasing of the multiplexer58 59 However, I2C transactions to devices behind all I2C multiplexers connected60 to the same parent adapter that this multiplexer is connected to are blocked61 for the full duration of the complete multiplexed I2C transaction (i.e.62 including the times covered by the above list).63 If mux-locked is not present, the multiplexer is assumed to be parent-locked.64 This means that no unrelated I2C transactions are allowed on the parent I2C65 adapter for the complete multiplexed I2C transaction.66 The properties of mux-locked and parent-locked multiplexers are discussed67 in more detail in Documentation/i2c/i2c-topology.rst.68 69required:70 - compatible71 - i2c-parent72 - mux-controls73 74unevaluatedProperties: false75 76examples:77 - |78 #include <dt-bindings/gpio/gpio.h>79 mux: mux-controller {80 compatible = "gpio-mux";81 #mux-control-cells = <0>;82 83 mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,84 <&pioA 1 GPIO_ACTIVE_HIGH>;85 };86 87 i2c-mux {88 compatible = "i2c-mux";89 mux-locked;90 i2c-parent = <&i2c1>;91 92 mux-controls = <&mux>;93 94 #address-cells = <1>;95 #size-cells = <0>;96 97 i2c@1 {98 reg = <1>;99 #address-cells = <1>;100 #size-cells = <0>;101 102 gpio@20 {103 compatible = "nxp,pca9555";104 gpio-controller;105 #gpio-cells = <2>;106 reg = <0x20>;107 };108 };109 110 i2c@3 {111 reg = <3>;112 #address-cells = <1>;113 #size-cells = <0>;114 115 gpio@20 {116 compatible = "nxp,pca9555";117 gpio-controller;118 #gpio-cells = <2>;119 reg = <0x20>;120 };121 };122 };123...124