bindings/i2c/i2c-mux-pinctrl.yaml

1 # SPDX-License-Identifier: GPL-2.0-only
3 ---
4 $id: http://devicetree.org/schemas/i2c/i2c-mux-pinctrl.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
7 title: Pinctrl-based I2C Bus Mux
10   - Wolfram Sang <wsa@kernel.org>
13   This binding describes an I2C bus multiplexer that uses pin multiplexing to route the I2C
17                                  +-----+  +-----+
19     +------------------------+   +-----+  +-----+
21     |                   /----|------+--------+
22     |   +---+   +------+     | child bus A, on first set of pins
23     |   |I2C|---|Pinmux|     |
24     |   +---+   +------+     | child bus B, on second set of pins
25     |                   \----|------+--------+--------+
27     +------------------------+  +-----+  +-----+  +-----+
29                                 +-----+  +-----+  +-----+
31   For each named state defined in the pinctrl-names property, an I2C child bus will be created.
32   I2C child bus numbers are assigned based on the index into the pinctrl-names property.
34   The only exception is that no bus will be created for a state named "idle". If such a state is
35   defined, it must be the last entry in pinctrl-names. For example:
37     pinctrl-names = "ddc", "pta", "idle"  ->  ddc = bus 0, pta = bus 1
38     pinctrl-names = "ddc", "idle", "pta"  ->  Invalid ("idle" not last)
39     pinctrl-names = "idle", "ddc", "pta"  ->  Invalid ("idle" not last)
41   Whenever an access is made to a device on a child bus, the relevant pinctrl state will be
44   If an idle state is defined, whenever an access is not being made to a device on a child bus,
48   into hardware whenever no access is being made of a device on a child bus.
52     const: i2c-mux-pinctrl
54   i2c-parent:
56     description: The phandle of the I2C bus that this multiplexer's master-side port is connected
60   - $ref: i2c-mux.yaml
65   - compatible
66   - i2c-parent
69   - |
71       compatible = "i2c-mux-pinctrl";
72       #address-cells = <1>;
73       #size-cells = <0>;
75       i2c-parent = <&i2c1>;
77       pinctrl-names = "ddc", "pta", "idle";
78       pinctrl-0 = <&state_i2cmux_ddc>;
79       pinctrl-1 = <&state_i2cmux_pta>;
80       pinctrl-2 = <&state_i2cmux_idle>;
82       i2c@0 {
84         #address-cells = <1>;
85         #size-cells = <0>;
93       i2c@1 {
95         #address-cells = <1>;
96         #size-cells = <0>;