xref: /linux/Documentation/devicetree/bindings/input/adc-joystick.yaml (revision da1d9caf95def6f0320819cf941c9fd1069ba9e1) 
1# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
2# Copyright 2019-2020 Artur Rojek
3%YAML 1.2
4---
5$id: "http://devicetree.org/schemas/input/adc-joystick.yaml#"
6$schema: "http://devicetree.org/meta-schemas/core.yaml#"
7
8title: ADC attached joystick
9
10maintainers:
11  - Artur Rojek <contact@artur-rojek.eu>
12
13description: >
14  Bindings for joystick devices connected to ADC controllers supporting
15  the Industrial I/O subsystem.
16
17properties:
18  compatible:
19    const: adc-joystick
20
21  io-channels:
22    minItems: 1
23    maxItems: 1024
24    description: >
25      List of phandle and IIO specifier pairs.
26      Each pair defines one ADC channel to which a joystick axis is connected.
27      See
28      https://github.com/devicetree-org/dt-schema/blob/master/schemas/iio/iio-consumer.yaml
29      for details.
30
31  '#address-cells':
32    const: 1
33
34  '#size-cells':
35    const: 0
36
37required:
38  - compatible
39  - io-channels
40  - '#address-cells'
41  - '#size-cells'
42
43additionalProperties: false
44
45patternProperties:
46  "^axis@[0-9a-f]+$":
47    type: object
48    description: >
49      Represents a joystick axis bound to the given ADC channel.
50      For each entry in the io-channels list, one axis subnode with a matching
51      reg property must be specified.
52
53    properties:
54      reg:
55        minimum: 0
56        maximum: 1023
57        description: Index of an io-channels list entry bound to this axis.
58
59      linux,code:
60        $ref: /schemas/types.yaml#/definitions/uint32
61        description: EV_ABS specific event code generated by the axis.
62
63      abs-range:
64        $ref: /schemas/types.yaml#/definitions/uint32-array
65        items:
66          - description: minimum value
67          - description: maximum value
68        description: >
69          Minimum and maximum values produced by the axis.
70          For an ABS_X axis this will be the left-most and right-most
71          inclination of the joystick. If min > max, it is left to userspace to
72          treat the axis as inverted.
73          This property is interpreted as two signed 32 bit values.
74
75      abs-fuzz:
76        $ref: /schemas/types.yaml#/definitions/uint32
77        description: >
78          Amount of noise in the input value.
79          Omitting this property indicates the axis is precise.
80
81      abs-flat:
82        $ref: /schemas/types.yaml#/definitions/uint32
83        description: >
84          Axial "deadzone", or area around the center position, where the axis
85          is considered to be at rest.
86          Omitting this property indicates the axis always returns to exactly
87          the center position.
88
89    required:
90      - reg
91      - linux,code
92      - abs-range
93
94    additionalProperties: false
95
96examples:
97  - |
98    #include <dt-bindings/iio/adc/ingenic,adc.h>
99    #include <dt-bindings/input/input.h>
100
101    joystick: adc-joystick {
102      compatible = "adc-joystick";
103      io-channels = <&adc INGENIC_ADC_TOUCH_XP>,
104                    <&adc INGENIC_ADC_TOUCH_YP>;
105      #address-cells = <1>;
106      #size-cells = <0>;
107
108      axis@0 {
109              reg = <0>;
110              linux,code = <ABS_X>;
111              abs-range = <3300 0>;
112              abs-fuzz = <4>;
113              abs-flat = <200>;
114      };
115      axis@1 {
116              reg = <1>;
117              linux,code = <ABS_Y>;
118              abs-range = <0 3300>;
119              abs-fuzz = <4>;
120              abs-flat = <200>;
121      };
122    };
123