[PATCH 4/5] dt-bindings: input: Add docs for ADC driven joystick.

Artur Rojek
2020-01-05T00:10:47Z

Add documentation for the adc-joystick driver, used to provide support
for joysticks connected over ADC.

Signed-off-by: Artur Rojek <contact@artur-rojek.eu>
Tested-by: Paul Cercueil <paul@crapouillou.net>
---
.../bindings/input/adc-joystick.yaml | 100 ++++++++++++++++++
1 file changed, 100 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/adc-joystick.yaml

diff --git a/Documentation/devicetree/bindings/input/adc-joystick.yaml b/Documentation/devicetree/bindings/input/adc-joystick.yaml
new file mode 100644
index 000000000000..97ae797348c7
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/adc-joystick.yaml
@@ -0,0 +1,100 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2019-2020 Artur Rojek
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/bindings/input/adc-joystick.yaml#"
+$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:
+ 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.
+
+required:
+ - compatible
+ - io-channels
+
+additionalProperties: false
+
+patternProperties:
+ "^axis@([0-9])$":
+ 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
+ index must be specified.
+
+ properties:
+ linux,abs-code:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: EV_ABS specific event code generated by the axis.
+
+ linux,abs-range:
+ $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.
+
+ linux,abs-fuzz:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: |
+ Amount of noise in the input value.
+ Omitting this property indicates the axis is precise.
+
+ linux,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:
+ - linux,abs-code
+ - linux,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>;
+
+ axis@0 {
+ linux,abs-code = <ABS_X>;
+ linux,abs-range = <3300 0>;
+ linux,abs-fuzz = <4>;
+ linux,abs-flat = <200>;
+ };
+ axis@1 {
+ linux,abs-code = <ABS_Y>;
+ linux,abs-range = <0 3300>;
+ linux,abs-fuzz = <4>;
+ linux,abs-flat = <200>;
+ };
+ };
--
2.24.1