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Diffstat (limited to 'Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml')
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diff --git a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml new file mode 100644 index 000000000000..7023e8c73a7b --- /dev/null +++ b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml @@ -0,0 +1,219 @@ +# SPDX-License-Identifier: GPL-2.0 +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/input/touchscreen/touchscreen.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Common touchscreen + +maintainers: + - Dmitry Torokhov <dmitry.torokhov@gmail.com> + +properties: + panel: + description: If this touchscreen is integrally connected to a panel, this + is a reference to that panel. The presence of this reference indicates + that the touchscreen should be power sequenced together with the panel + and that they may share power and/or reset signals. + $ref: /schemas/types.yaml#/definitions/phandle + + touchscreen-min-x: + description: minimum x coordinate reported + $ref: /schemas/types.yaml#/definitions/uint32 + default: 0 + + touchscreen-min-y: + description: minimum y coordinate reported + $ref: /schemas/types.yaml#/definitions/uint32 + default: 0 + + touchscreen-size-x: + description: horizontal resolution of touchscreen (maximum x coordinate reported + 1) + $ref: /schemas/types.yaml#/definitions/uint32 + + touchscreen-size-y: + description: vertical resolution of touchscreen (maximum y coordinate reported + 1) + $ref: /schemas/types.yaml#/definitions/uint32 + + touchscreen-max-pressure: + description: maximum reported pressure (arbitrary range dependent on the controller) + $ref: /schemas/types.yaml#/definitions/uint32 + + touchscreen-min-pressure: + description: minimum pressure on the touchscreen to be achieved in order + for the touchscreen driver to report a touch event. + $ref: /schemas/types.yaml#/definitions/uint32 + + touchscreen-fuzz-x: + description: horizontal noise value of the absolute input device (in pixels) + $ref: /schemas/types.yaml#/definitions/uint32 + + touchscreen-fuzz-y: + description: vertical noise value of the absolute input device (in pixels) + $ref: /schemas/types.yaml#/definitions/uint32 + + touchscreen-fuzz-pressure: + description: pressure noise value of the absolute input device (arbitrary + range dependent on the controller) + $ref: /schemas/types.yaml#/definitions/uint32 + + touchscreen-average-samples: + description: Number of data samples which are averaged for each read (valid + values dependent on the controller) + $ref: /schemas/types.yaml#/definitions/uint32 + + touchscreen-inverted-x: + description: X axis is inverted + type: boolean + + touchscreen-inverted-y: + description: Y axis is inverted + type: boolean + + touchscreen-swapped-x-y: + description: X and Y axis are swapped + Swapping is done after inverting the axis + type: boolean + + touchscreen-x-mm: + description: horizontal length in mm of the touchscreen + + touchscreen-y-mm: + description: vertical length in mm of the touchscreen + + touchscreen-x-plate-ohms: + description: Resistance of the X-plate in Ohms + + touchscreen-y-plate-ohms: + description: Resistance of the Y-plate in Ohms + + touch-overlay: + description: | + List of nodes defining segments (touch areas) on the touchscreen. + + This object can be used to describe a series of segments to restrict + the region within touch events are reported or buttons with a specific + functionality. + + This is of special interest if the touchscreen is shipped with a physical + overlay on top of it with a frame that hides some part of the original + touchscreen area. Printed buttons on that overlay are also a typical + use case. + + A new touchscreen area is defined as a sub-node without a key code. If a + key code is defined in the sub-node, it will be interpreted as a button. + + The x-origin and y-origin properties of a touchscreen area define the + offset of a new origin from where the touchscreen events are referenced. + This offset is applied to the events accordingly. The x-size and y-size + properties define the size of the touchscreen effective area. + + The following example shows a new touchscreen area with the new origin + (0',0') for the touch events generated by the device. + + Touchscreen (full area) + ┌────────────────────────────────────────┐ + │ ┌───────────────────────────────┐ │ + │ │ │ │ + │ ├ y-size │ │ + │ │ │ │ + │ │ touchscreen area │ │ + │ │ (no key code) │ │ + │ │ │ │ + │ │ x-size │ │ + │ ┌└──────────────┴────────────────┘ │ + │(0',0') │ + ┌└────────────────────────────────────────┘ + (0,0) + + where (0',0') = (0+x-origin,0+y-origin) + + Sub-nodes with key codes report the touch events on their surface as key + events instead. + + The following example shows a touchscreen with a single button on it. + + Touchscreen (full area) + ┌───────────────────────────────────┐ + │ │ + │ │ + │ ┌─────────┐ │ + │ │button 0 │ │ + │ │KEY_POWER│ │ + │ └─────────┘ │ + │ │ + │ │ + ┌└───────────────────────────────────┘ + (0,0) + + Segments defining buttons and clipped toushcreen areas can be combined + as shown in the following example. + In that case only the events within the touchscreen area are reported + as touch events. Events within the button areas report their associated + key code. Any events outside the defined areas are ignored. + + Touchscreen (full area) + ┌─────────┬──────────────────────────────┐ + │ │ │ + │ │ ┌───────────────────────┐ │ + │ button 0│ │ │ │ + │KEY_POWER│ │ │ │ + │ │ │ │ │ + ├─────────┤ │ touchscreen area │ │ + │ │ │ (no key code) │ │ + │ │ │ │ │ + │ button 1│ │ │ │ + │ KEY_INFO│ ┌└───────────────────────┘ │ + │ │(0',0') │ + ┌└─────────┴──────────────────────────────┘ + (0,0) + + type: object + + patternProperties: + '^segment-': + type: object + description: + Each segment is represented as a sub-node. + properties: + x-origin: + description: horizontal origin of the node area + $ref: /schemas/types.yaml#/definitions/uint32 + + y-origin: + description: vertical origin of the node area + $ref: /schemas/types.yaml#/definitions/uint32 + + x-size: + description: horizontal resolution of the node area + $ref: /schemas/types.yaml#/definitions/uint32 + + y-size: + description: vertical resolution of the node area + $ref: /schemas/types.yaml#/definitions/uint32 + + label: + description: descriptive name of the segment + $ref: /schemas/types.yaml#/definitions/string + + linux,code: true + + required: + - x-origin + - y-origin + - x-size + - y-size + + unevaluatedProperties: false + + debounce-delay-us: + description: Minimum duration in microseconds a signal must remain stable + to be considered valid. + +dependencies: + touchscreen-size-x: [ touchscreen-size-y ] + touchscreen-size-y: [ touchscreen-size-x ] + touchscreen-x-mm: [ touchscreen-y-mm ] + touchscreen-y-mm: [ touchscreen-x-mm ] + +additionalProperties: true |