xref: /linux/Documentation/devicetree/bindings/i2c/i2c-mux.yaml (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0) 
1# SPDX-License-Identifier: GPL-2.0
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/i2c/i2c-mux.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Common i2c bus multiplexer/switch properties.
8
9maintainers:
10  - Peter Rosin <peda@axentia.se>
11
12description: |+
13  An i2c bus multiplexer/switch will have several child busses that are numbered
14  uniquely in a device dependent manner.  The nodes for an i2c bus
15  multiplexer/switch will have one child node for each child bus.
16
17  For i2c multiplexers/switches that have child nodes that are a mixture of both
18  i2c child busses and other child nodes, the 'i2c-mux' subnode can be used for
19  populating the i2c child busses.  If an 'i2c-mux' subnode is present, only
20  subnodes of this will be considered as i2c child busses.
21
22properties:
23  $nodename:
24    pattern: '^(i2c-?)?mux'
25
26  '#address-cells':
27    const: 1
28
29  '#size-cells':
30    const: 0
31
32patternProperties:
33  '^i2c@[0-9a-f]+$':
34    $ref: /schemas/i2c/i2c-controller.yaml
35    unevaluatedProperties: false
36
37    properties:
38      reg:
39        description: The mux selector sub-bus number for the child I2C bus.
40        maxItems: 1
41
42additionalProperties: true
43
44examples:
45  - |
46    /*
47     * An NXP pca9548 8 channel I2C multiplexer at address 0x70
48     * with two NXP pca8574 GPIO expanders attached, one each to
49     * ports 3 and 4.
50     */
51    i2c {
52        #address-cells = <1>;
53        #size-cells = <0>;
54
55        i2c-mux@70 {
56            compatible = "nxp,pca9548";
57            reg = <0x70>;
58            #address-cells = <1>;
59            #size-cells = <0>;
60
61            i2c@3 {
62                #address-cells = <1>;
63                #size-cells = <0>;
64                reg = <3>;
65
66                gpio@20 {
67                    compatible = "nxp,pca9555";
68                    gpio-controller;
69                    #gpio-cells = <2>;
70                    reg = <0x20>;
71                };
72            };
73            i2c@4 {
74                #address-cells = <1>;
75                #size-cells = <0>;
76                reg = <4>;
77
78                gpio@20 {
79                    compatible = "nxp,pca9555";
80                    gpio-controller;
81                    #gpio-cells = <2>;
82                    reg = <0x20>;
83                };
84            };
85        };
86    };
87...
88