bindings/i2c/i2c-mux-gpmux.txt

1 General Purpose I2C Bus Mux
3 This binding describes an I2C bus multiplexer that uses a mux controller
4 from the mux subsystem to route the I2C signals.
6                                   .-----.  .-----.
8     .------------.                '-----'  '-----'
10     |            |          .--------+--------'
11     |   .------. |  .------+    child bus A, on MUX value set to 0
12     |   | I2C  |-|--| Mux  |
13     |   '------' |  '--+---+    child bus B, on MUX value set to 1
14     |   .------. |     |    '----------+--------+--------.
15     |   | MUX- | |     |               |        |        |
16     |   | Ctrl |-|-----+            .-----.  .-----.  .-----.
17     |   '------' |                  | dev |  | dev |  | dev |
18     '------------'                  '-----'  '-----'  '-----'
21 - compatible: i2c-mux
22 - i2c-parent: The phandle of the I2C bus that this multiplexer's master-side
24 - mux-controls: The phandle of the mux controller to use for operating the
25   mux.
26 * Standard I2C mux properties. See i2c-mux.txt in this directory.
27 * I2C child bus nodes. See i2c-mux.txt in this directory. The sub-bus number
28   is also the mux-controller state described in ../mux/mux-controller.txt
31 - mux-locked: If present, explicitly allow unrelated I2C transactions on the
41   If mux-locked is not present, the multiplexer is assumed to be parent-locked.
44   The properties of mux-locked and parent-locked multiplexers are discussed
45   in more detail in Documentation/i2c/i2c-topology.rst.
52 mux controller.
55 	mux: mux-controller {
56 		compatible = "gpio-mux";
57 		#mux-control-cells = <0>;
59 		mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
63 	i2c-mux {
64 		compatible = "i2c-mux";
65 		mux-locked;
66 		i2c-parent = <&i2c1>;
68 		mux-controls = <&mux>;
70 		#address-cells = <1>;
71 		#size-cells = <0>;
75 			#address-cells = <1>;
76 			#size-cells = <0>;
79 				compatible = "solomon,ssd1307fb-i2c";
82 				reset-gpios = <&gpio2 7 1>;
83 				reset-active-low;
89 			#address-cells = <1>;
90 			#size-cells = <0>;
94 				gpio-controller;
95 				#gpio-cells = <2>;