0001 # SPDX-License-Identifier: GPL-2.0
0002 %YAML 1.2
0003 ---
0004 $id: http://devicetree.org/schemas/i2c/i2c-mux.yaml#
0005 $schema: http://devicetree.org/meta-schemas/core.yaml#
0006
0007 title: Common i2c bus multiplexer/switch properties.
0008
0009 maintainers:
0010 - Peter Rosin <peda@axentia.se>
0011
0012 description: |+
0013 An i2c bus multiplexer/switch will have several child busses that are numbered
0014 uniquely in a device dependent manner. The nodes for an i2c bus
0015 multiplexer/switch will have one child node for each child bus.
0016
0017 For i2c multiplexers/switches that have child nodes that are a mixture of both
0018 i2c child busses and other child nodes, the 'i2c-mux' subnode can be used for
0019 populating the i2c child busses. If an 'i2c-mux' subnode is present, only
0020 subnodes of this will be considered as i2c child busses.
0021
0022 properties:
0023 $nodename:
0024 pattern: '^(i2c-?)?mux'
0025
0026 '#address-cells':
0027 const: 1
0028
0029 '#size-cells':
0030 const: 0
0031
0032 patternProperties:
0033 '^i2c@[0-9a-f]+$':
0034 $ref: /schemas/i2c/i2c-controller.yaml
0035 unevaluatedProperties: false
0036
0037 properties:
0038 reg:
0039 description: The mux selector sub-bus number for the child I2C bus.
0040 maxItems: 1
0041
0042 additionalProperties: true
0043
0044 examples:
0045 - |
0046 /*
0047 * An NXP pca9548 8 channel I2C multiplexer at address 0x70
0048 * with two NXP pca8574 GPIO expanders attached, one each to
0049 * ports 3 and 4.
0050 */
0051 i2c {
0052 #address-cells = <1>;
0053 #size-cells = <0>;
0054
0055 i2c-mux@70 {
0056 compatible = "nxp,pca9548";
0057 reg = <0x70>;
0058 #address-cells = <1>;
0059 #size-cells = <0>;
0060
0061 i2c@3 {
0062 #address-cells = <1>;
0063 #size-cells = <0>;
0064 reg = <3>;
0065
0066 gpio@20 {
0067 compatible = "nxp,pca9555";
0068 gpio-controller;
0069 #gpio-cells = <2>;
0070 reg = <0x20>;
0071 };
0072 };
0073 i2c@4 {
0074 #address-cells = <1>;
0075 #size-cells = <0>;
0076 reg = <4>;
0077
0078 gpio@20 {
0079 compatible = "nxp,pca9555";
0080 gpio-controller;
0081 #gpio-cells = <2>;
0082 reg = <0x20>;
0083 };
0084 };
0085 };
0086 };
0087 ...
