Documentation/devicetree/bindings/input/rotary-encoder.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/input/rotary-encoder.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Rotary encoder

maintainers:
  - Frank Li <Frank.Li@nxp.com>

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

properties:
  compatible:
    const: rotary-encoder

  gpios:
    minItems: 2

  linux,axis:
    default: 0
    description:
      the input subsystem axis to map to this rotary encoder.
      Defaults to 0 (ABS_X / REL_X)

  rotary-encoder,steps:
    $ref: /schemas/types.yaml#/definitions/uint32
    default: 24
    description:
      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:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      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:
    $ref: /schemas/types.yaml#/definitions/int32
    description:
      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:
    $ref: /schemas/types.yaml#/definitions/uint32
    default: 1
    enum: [1, 2, 4]
    description: |
      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: true

  rotary-encoder,encoding:
    $ref: /schemas/types.yaml#/definitions/string
    description: the method used to encode steps.
    enum: [gray, binary]

  rotary-encoder,half-period:
    $ref: /schemas/types.yaml#/definitions/flag
    deprecated: true
    description:
      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>".

required:
  - compatible
  - gpios

additionalProperties: false

examples:
  - |
    rotary {
        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;
    };