bindings/i2c/i2c-mux-pinctrl.txt

1 Pinctrl-based I2C Bus Mux
3 This binding describes an I2C bus multiplexer that uses pin multiplexing to
4 route the I2C signals, and represents the pin multiplexing configuration
7                                  +-----+  +-----+
9     +------------------------+   +-----+  +-----+
11     |                   /----|------+--------+
12     |   +---+   +------+     | child bus A, on first set of pins
13     |   |I2C|---|Pinmux|     |
14     |   +---+   +------+     | child bus B, on second set of pins
15     |                   \----|------+--------+--------+
17     +------------------------+  +-----+  +-----+  +-----+
19                                 +-----+  +-----+  +-----+
22 - compatible: i2c-mux-pinctrl
23 - i2c-parent: The phandle of the I2C bus that this multiplexer's master-side
29   bus. See ../pinctrl/pinctrl-bindings.txt.
31 * Standard I2C mux properties. See i2c-mux.txt in this directory.
33 * I2C child bus nodes. See i2c-mux.txt in this directory.
35 For each named state defined in the pinctrl-names property, an I2C child bus
36 will be created. I2C child bus numbers are assigned based on the index into
37 the pinctrl-names property.
39 The only exception is that no bus will be created for a state named "idle". If
40 such a state is defined, it must be the last entry in pinctrl-names. For
43 	pinctrl-names = "ddc", "pta", "idle"  ->  ddc = bus 0, pta = bus 1
44 	pinctrl-names = "ddc", "idle", "pta"  ->  Invalid ("idle" not last)
45 	pinctrl-names = "idle", "ddc", "pta"  ->  Invalid ("idle" not last)
47 Whenever an access is made to a device on a child bus, the relevant pinctrl
51 on a child bus, the idle pinctrl state will be programmed into hardware.
55 a child bus.
60 		compatible = "i2c-mux-pinctrl";
61 		#address-cells = <1>;
62 		#size-cells = <0>;
64 		i2c-parent = <&i2c1>;
66 		pinctrl-names = "ddc", "pta", "idle";
67 		pinctrl-0 = <&state_i2cmux_ddc>;
68 		pinctrl-1 = <&state_i2cmux_pta>;
69 		pinctrl-2 = <&state_i2cmux_idle>;
71 		i2c@0 {
73 			#address-cells = <1>;
74 			#size-cells = <0>;
82 		i2c@1 {
84 			#address-cells = <1>;
85 			#size-cells = <0>;