# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id:
http://devicetree.org/schemas/i2c/i2c-mux.yaml#
$schema:
http://devicetree.org/meta-schemas/core.yaml#
title: Common i2c bus multiplexer/switch properties.
maintainers:
- Peter Rosin <peda@axentia.se>
description: |+
An i2c bus multiplexer/switch will have several child busses that are numbered
uniquely in a device dependent manner. The nodes for an i2c bus
multiplexer/switch will have one child node for each child bus.
For i2c multiplexers/switches that have child nodes that are a mixture of both
i2c child busses and other child nodes, the 'i2c-mux' subnode can be used for
populating the i2c child busses. If an 'i2c-mux' subnode is present, only
subnodes of this will be considered as i2c child busses.
properties:
$nodename:
pattern: '^(i2c-?)?mux'
'#address-cells':
const: 1
'#size-cells':
const: 0
patternProperties:
'^i2c@[0-9a-f]+$':
$ref: /schemas/i2c/i2c-controller.yaml
unevaluatedProperties: false
properties:
reg:
description: The mux selector sub-bus number for the child I2C bus.
maxItems: 1
additionalProperties: true
examples:
- |
/*
* An NXP pca9548 8 channel I2C multiplexer at address 0x70
* with two NXP pca8574 GPIO expanders attached, one each to
* ports 3 and 4.
*/
i2c {
#address-cells = <1>;
#size-cells = <0>;
i2c-mux@70 {
compatible = "nxp,pca9548";
reg = <0x70>;
#address-cells = <1>;
#size-cells = <0>;
i2c@3 {
#address-cells = <1>;
#size-cells = <0>;
reg = <3>;
gpio@20 {
compatible = "nxp,pca9555";
gpio-controller;
#gpio-cells = <2>;
reg = <0x20>;
};
};
i2c@4 {
#address-cells = <1>;
#size-cells = <0>;
reg = <4>;
gpio@20 {
compatible = "nxp,pca9555";
gpio-controller;
#gpio-cells = <2>;
reg = <0x20>;
};
};
};
};
...
