Kernel-4.18.0-80.el8_rotary-encoder

Rotary encoder DT bindings

Required properties:

  • gpios: a spec for at least two GPIOs to be used, most significant first

Optional properties:

  • linux,axis: the input subsystem axis to map to this rotary encoder.
    Defaults to 0 (ABS_X / REL_X)
  • rotary-encoder,steps: Number of steps in a full turnaround of the
    encoder. Only relevant for absolute axis. Defaults to 24 which is a
    typical value for such devices.
  • rotary-encoder,relative-axis: register a relative axis rather than an
    absolute one. Relative axis will only generate +1/-1 events on the input
    device, hence no steps need to be passed.
  • rotary-encoder,rollover: Automatic rollover when the rotary value becomes
    greater than the specified steps or smaller than 0. For absolute axis only.
  • rotary-encoder,steps-per-period: Number of steps (stable states) per period.
    The values have the following meaning:
    1: Full-period mode (default)
    2: Half-period mode
    4: Quarter-period mode
  • wakeup-source: Boolean, rotary encoder can wake up the system.
  • rotary-encoder,encoding: String, the method used to encode steps.
    Supported are “gray” (the default and more common) and “binary”.

Deprecated properties:

  • rotary-encoder,half-period: Makes the driver work on half-period mode.
    This property is deprecated. Instead, a ‘steps-per-period ‘ value should
    be used, such as “rotary-encoder,steps-per-period = <2>”.

See Documentation/input/devices/rotary-encoder.rst for more information.

Example:

    rotary@0 {
        compatible = "rotary-encoder";
        gpios = <&gpio 19 1>, <&gpio 20 0>; /* GPIO19 is inverted */
        linux,axis = <0>; /* REL_X */
        rotary-encoder,encoding = "gray";
        rotary-encoder,relative-axis;
    };

    rotary@1 {
        compatible = "rotary-encoder";
        gpios = <&gpio 21 0>, <&gpio 22 0>;
        linux,axis = <1>; /* ABS_Y */
        rotary-encoder,steps = <24>;
        rotary-encoder,encoding = "binary";
        rotary-encoder,rollover;
    };