1# Copyright 2023 Google LLC
2# SPDX-License-Identifier: Apache-2.0
3
4description: |
5  GPIO based QDEC input device
6
7  Implement an input device generating relative axis event reports for a rotary
8  encoder connected to two GPIOs. The driver is normally idling until it sees a
9  transition on any of the encoder signal lines, then switches to polling mode
10  and samples the two signal lines periodically to track the encoder position,
11  and goes back to idling after the specified timeout.
12
13  Example configuration:
14
15  #include <zephyr/dt-bindings/input/input-event-codes.h>
16
17  qdec {
18          compatible = "gpio-qdec";
19          gpios = <&gpio0 14 (GPIO_PULL_UP | GPIO_ACTIVE_HIGH)>,
20                  <&gpio0 13 (GPIO_PULL_UP | GPIO_ACTIVE_HIGH)>;
21          steps-per-period = <4>;
22          zephyr,axis = <INPUT_REL_WHEEL>;
23          sample-time-us = <2000>;
24          idle-timeout-ms = <200>;
25  };
26
27compatible: "gpio-qdec"
28
29include: base.yaml
30
31properties:
32  gpios:
33    type: phandle-array
34    required: true
35    description: |
36      GPIO for the A and B encoder signals.
37
38  steps-per-period:
39    type: int
40    required: true
41    description: |
42      How many steps to count before reporting an input event.
43
44  zephyr,axis:
45    type: int
46    required: true
47    description: |
48      The input code for the axis to report for the device, typically any of
49      INPUT_REL_*.
50
51  sample-time-us:
52    type: int
53    required: true
54    description: |
55      How often to sample the A and B signal lines when tracking the encoder
56      movement.
57
58  idle-timeout-ms:
59    type: int
60    required: true
61    description: |
62      Timeout for the last detected transition before stopping the sampling
63      timer and going back to idle state.
64