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+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mux/mux-controller.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common multiplexer controller provider bindings
+
+maintainers:
+ - Peter Rosin <peda@axentia.se>
+
+description: |
+ A multiplexer (or mux) controller will have one, or several, consumer devices
+ that uses the mux controller. Thus, a mux controller can possibly control
+ several parallel multiplexers. Presumably there will be at least one
+ multiplexer needed by each consumer, but a single mux controller can of course
+ control several multiplexers for a single consumer.
+
+ A mux controller provides a number of states to its consumers, and the state
+ space is a simple zero-based enumeration. I.e. 0-1 for a 2-way multiplexer,
+ 0-7 for an 8-way multiplexer, etc.
+
+
+ Mux controller nodes
+ --------------------
+
+ Mux controller nodes must specify the number of cells used for the
+ specifier using the '#mux-control-cells' or '#mux-state-cells' property.
+ The value of '#mux-state-cells' will always be one greater than the value
+ of '#mux-control-cells'.
+
+ Optionally, mux controller nodes can also specify the state the mux should
+ have when it is idle. The idle-state property is used for this. If the
+ idle-state is not present, the mux controller is typically left as is when
+ it is idle. For multiplexer chips that expose several mux controllers, the
+ idle-state property is an array with one idle state for each mux controller.
+
+ The special value (-1) may be used to indicate that the mux should be left
+ as is when it is idle. This is the default, but can still be useful for
+ mux controller chips with more than one mux controller, particularly when
+ there is a need to "step past" a mux controller and set some other idle
+ state for a mux controller with a higher index.
+
+ Some mux controllers have the ability to disconnect the input/output of the
+ multiplexer. Using this disconnected high-impedance state as the idle state
+ is indicated with idle state (-2).
+
+ These constants are available in
+
+ #include <dt-bindings/mux/mux.h>
+
+ as MUX_IDLE_AS_IS (-1) and MUX_IDLE_DISCONNECT (-2).
+
+ An example mux controller node look like this (the adg972a chip is a triple
+ 4-way multiplexer):
+
+ mux: mux-controller@50 {
+ compatible = "adi,adg792a";
+ reg = <0x50>;
+ #mux-control-cells = <1>;
+
+ idle-state = <MUX_IDLE_DISCONNECT MUX_IDLE_AS_IS 2>;
+ };
+
+select:
+ anyOf:
+ - properties:
+ $nodename:
+ pattern: '^mux-controller'
+ - required:
+ - '#mux-control-cells'
+ - required:
+ - '#mux-state-cells'
+
+properties:
+ $nodename:
+ pattern: '^mux-controller(@.*|-[0-9a-f]+)?$'
+
+ '#mux-control-cells':
+ enum: [ 0, 1 ]
+
+ '#mux-state-cells':
+ enum: [ 1, 2 ]
+
+ idle-state:
+ $ref: /schemas/types.yaml#/definitions/int32
+ minimum: -2
+
+ idle-states:
+ description: |
+ Mux controller nodes can specify the state the mux should have when it is
+ idle. If the idle-state is not present, the mux controller is typically
+ left as is when it is idle. For multiplexer chips that expose several mux
+ controllers, the idle-state property is an array with one idle state for
+ each mux controller.
+
+ The special value (-1) may be used to indicate that the mux should be left
+ as is when it is idle. This is the default, but can still be useful for
+ mux controller chips with more than one mux controller, particularly when
+ there is a need to "step past" a mux controller and set some other idle
+ state for a mux controller with a higher index.
+
+ Some mux controllers have the ability to disconnect the input/output of the
+ multiplexer. Using this disconnected high-impedance state as the idle state
+ is indicated with idle state (-2).
+ $ref: /schemas/types.yaml#/definitions/int32-array
+ items:
+ minimum: -2
+
+additionalProperties: true
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ /* One consumer of a 2-way mux controller (one GPIO-line) */
+ mux: mux-controller {
+ compatible = "gpio-mux";
+ #mux-control-cells = <0>;
+
+ mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>;
+ };
+
+ adc-mux {
+ compatible = "io-channel-mux";
+ io-channels = <&adc 0>;
+ io-channel-names = "parent";
+
+ mux-controls = <&mux>;
+ mux-control-names = "adc";
+
+ channels = "sync", "in";
+ };
+
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ /*
+ * Two consumers (one for an ADC line and one for an i2c bus) of
+ * parallel 4-way multiplexers controlled by the same two GPIO-lines.
+ */
+ mux2: mux-controller {
+ compatible = "gpio-mux";
+ #mux-control-cells = <0>;
+
+ mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
+ <&pioA 1 GPIO_ACTIVE_HIGH>;
+ };
+
+ adc-mux {
+ compatible = "io-channel-mux";
+ io-channels = <&adc 0>;
+ io-channel-names = "parent";
+
+ mux-controls = <&mux2>;
+
+ channels = "sync-1", "in", "out", "sync-2";
+ };
+
+ i2c-mux {
+ compatible = "i2c-mux";
+ i2c-parent = <&i2c1>;
+
+ mux-controls = <&mux2>;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ i2c@0 {
+ reg = <0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ssd1307: oled@3c {
+ reg = <0x3c>;
+ };
+ };
+
+ i2c@3 {
+ reg = <3>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ pca9555: pca9555@20 {
+ reg = <0x20>;
+ };
+ };
+ };
+
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+
+ mux1: mux-controller {
+ compatible = "gpio-mux";
+ #mux-state-cells = <1>;
+ mux-gpios = <&exp_som 2 GPIO_ACTIVE_HIGH>;
+ };
+
+ transceiver4: can-phy4 {
+ compatible = "ti,tcan1042";
+ #phy-cells = <0>;
+ max-bitrate = <5000000>;
+ standby-gpios = <&exp_som 7 GPIO_ACTIVE_HIGH>;
+ mux-states = <&mux1 1>;
+ };
+...