Commit 7956b0d4 authored by Artur Rojek's avatar Artur Rojek Committed by Dmitry Torokhov

dt-bindings: input: Add docs for ADC driven joystick

Add documentation for the adc-joystick driver, used to provide support
for joysticks connected over ADC.
Signed-off-by: default avatarArtur Rojek <contact@artur-rojek.eu>
Tested-by: default avatarPaul Cercueil <paul@crapouillou.net>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20200927123302.31062-1-contact@artur-rojek.euSigned-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent cafb3abe
# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
# Copyright 2019-2020 Artur Rojek
%YAML 1.2
---
$id: "http://devicetree.org/schemas/input/adc-joystick.yaml#"
$schema: "http://devicetree.org/meta-schemas/core.yaml#"
title: ADC attached joystick
maintainers:
- Artur Rojek <contact@artur-rojek.eu>
description: >
Bindings for joystick devices connected to ADC controllers supporting
the Industrial I/O subsystem.
properties:
compatible:
const: adc-joystick
io-channels:
minItems: 1
maxItems: 1024
description: >
List of phandle and IIO specifier pairs.
Each pair defines one ADC channel to which a joystick axis is connected.
See Documentation/devicetree/bindings/iio/iio-bindings.txt for details.
'#address-cells':
const: 1
'#size-cells':
const: 0
required:
- compatible
- io-channels
- '#address-cells'
- '#size-cells'
additionalProperties: false
patternProperties:
"^axis@[0-9a-f]+$":
type: object
description: >
Represents a joystick axis bound to the given ADC channel.
For each entry in the io-channels list, one axis subnode with a matching
reg property must be specified.
properties:
reg:
minimum: 0
maximum: 1023
description: Index of an io-channels list entry bound to this axis.
linux,code:
$ref: /schemas/types.yaml#/definitions/uint32
description: EV_ABS specific event code generated by the axis.
abs-range:
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32-array
- items:
- description: minimum value
- description: maximum value
description: >
Minimum and maximum values produced by the axis.
For an ABS_X axis this will be the left-most and right-most
inclination of the joystick. If min > max, it is left to userspace to
treat the axis as inverted.
This property is interpreted as two signed 32 bit values.
abs-fuzz:
$ref: /schemas/types.yaml#/definitions/uint32
description: >
Amount of noise in the input value.
Omitting this property indicates the axis is precise.
abs-flat:
$ref: /schemas/types.yaml#/definitions/uint32
description: >
Axial "deadzone", or area around the center position, where the axis
is considered to be at rest.
Omitting this property indicates the axis always returns to exactly
the center position.
required:
- reg
- linux,code
- abs-range
additionalProperties: false
examples:
- |
#include <dt-bindings/iio/adc/ingenic,adc.h>
#include <dt-bindings/input/input.h>
joystick: adc-joystick {
compatible = "adc-joystick";
io-channels = <&adc INGENIC_ADC_TOUCH_XP>,
<&adc INGENIC_ADC_TOUCH_YP>;
#address-cells = <1>;
#size-cells = <0>;
axis@0 {
reg = <0>;
linux,code = <ABS_X>;
abs-range = <3300 0>;
abs-fuzz = <4>;
abs-flat = <200>;
};
axis@1 {
reg = <1>;
linux,code = <ABS_Y>;
abs-range = <0 3300>;
abs-fuzz = <4>;
abs-flat = <200>;
};
};
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