diff options
Diffstat (limited to 'Documentation/devicetree/bindings/mux/mux-controller.yaml')
| -rw-r--r-- | Documentation/devicetree/bindings/mux/mux-controller.yaml | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mux/mux-controller.yaml b/Documentation/devicetree/bindings/mux/mux-controller.yaml new file mode 100644 index 0000000000..8b943082a2 --- /dev/null +++ b/Documentation/devicetree/bindings/mux/mux-controller.yaml @@ -0,0 +1,206 @@ +# 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 + +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>; + }; +... |