Documentation/devicetree/bindings/input/microchip,cap11xx.yaml

# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/input/microchip,cap11xx.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Microchip CAP11xx based capacitive touch sensors

description: |
  The Microchip CAP1xxx Family of RightTouchTM multiple-channel capacitive
  touch controllers and LED drivers. The device communication via I2C only.

maintainers:
  - Rob Herring <robh@kernel.org>

properties:
  compatible:
    enum:
      - microchip,cap1106
      - microchip,cap1126
      - microchip,cap1188
      - microchip,cap1203
      - microchip,cap1206
      - microchip,cap1293
      - microchip,cap1298

  reg:
    maxItems: 1

  '#address-cells':
    const: 1

  '#size-cells':
    const: 0

  interrupts:
    maxItems: 1
    description: |
      Property describing the interrupt line the
      device's ALERT#/CM_IRQ# pin is connected to.
      The device only has one interrupt source.

  autorepeat:
    description: |
      Enables the Linux input system's autorepeat feature on the input device.

  linux,keycodes:
    minItems: 3
    maxItems: 8
    description: |
      Specifies an array of numeric keycode values to
      be used for the channels. If this property is
      omitted, KEY_A, KEY_B, etc are used as defaults.
      The number of entries must correspond to the number of channels.

  microchip,sensor-gain:
    $ref: /schemas/types.yaml#/definitions/uint32
    default: 1
    enum: [1, 2, 4, 8]
    description: |
      Defines the gain of the sensor circuitry. This
      effectively controls the sensitivity, as a
      smaller delta capacitance is required to
      generate the same delta count values.

  microchip,irq-active-high:
    type: boolean
    description: |
      By default the interrupt pin is active low
      open drain. This property allows using the active
      high push-pull output.

  microchip,sensitivity-delta-sense:
    $ref: /schemas/types.yaml#/definitions/uint32
    default: 32
    enum: [1, 2, 4, 8, 16, 32, 64, 128]
    description:
      Controls the sensitivity multiplier of a touch detection.
      Higher value means more sensitive settings.
      At the more sensitive settings, touches are detected for a smaller delta
      capacitance corresponding to a "lighter" touch.

  microchip,signal-guard:
    $ref: /schemas/types.yaml#/definitions/uint32-array
    minItems: 3
    maxItems: 8
    items:
      enum: [0, 1]
    description: |
      0 - off
      1 - on
      The signal guard isolates the signal from virtual grounds.
      If enabled then the behavior of the channel is changed to signal guard.
      The number of entries must correspond to the number of channels.

  microchip,input-threshold:
    $ref: /schemas/types.yaml#/definitions/uint32-array
    minItems: 3
    maxItems: 8
    items:
      minimum: 0
      maximum: 127
    description:
      Specifies the delta threshold that is used to determine if a touch has
      been detected. A higher value means a larger difference in capacitance
      is required for a touch to be registered, making the touch sensor less
      sensitive.
      The number of entries must correspond to the number of channels.

  microchip,calib-sensitivity:
    $ref: /schemas/types.yaml#/definitions/uint32-array
    minItems: 3
    maxItems: 8
    items:
      enum: [1, 2, 4]
    description: |
      Specifies an array of numeric values that controls the gain
      used by the calibration routine to enable sensor inputs
      to be more sensitive for proximity detection.
      Gain is based on touch pad capacitance range
      1 - 5-50pF
      2 - 0-25pF
      4 - 0-12.5pF
      The number of entries must correspond to the number of channels.

patternProperties:
  "^led@[0-7]$":
    type: object
    description: CAP11xx LEDs
    $ref: /schemas/leds/common.yaml#

    properties:
      reg:
        enum: [0, 1, 2, 3, 4, 5, 6, 7]

      label: true

      linux,default-trigger: true

      default-state: true

    required:
      - reg

    additionalProperties: false

allOf:
  - $ref: input.yaml
  - if:
      properties:
        compatible:
          contains:
            enum:
              - microchip,cap1106
              - microchip,cap1203
              - microchip,cap1206
              - microchip,cap1293
              - microchip,cap1298
    then:
      patternProperties:
        "^led@[0-7]$": false

  - if:
      properties:
        compatible:
          contains:
            enum:
              - microchip,cap1106
              - microchip,cap1126
              - microchip,cap1188
              - microchip,cap1203
              - microchip,cap1206
    then:
      properties:
        microchip,signal-guard: false
        microchip,calib-sensitivity: false

required:
  - compatible
  - interrupts

additionalProperties: false

examples:
  - |
    i2c {
      #address-cells = <1>;
      #size-cells = <0>;

      touch@28 {
        compatible = "microchip,cap1188";
        interrupt-parent = <&gpio1>;
        interrupts = <0 0>;
        reg = <0x28>;
        autorepeat;
        microchip,sensor-gain = <2>;
        microchip,sensitivity-delta-sense = <16>;
        microchip,input-threshold = <21>, <18>, <46>, <46>, <46>, <21>;

        linux,keycodes = <103>,	/* KEY_UP */
                         <106>,	/* KEY_RIGHT */
                         <108>,	/* KEY_DOWN */
                         <105>,	/* KEY_LEFT */
                         <109>,	/* KEY_PAGEDOWN */
                         <104>;	/* KEY_PAGEUP */

        #address-cells = <1>;
        #size-cells = <0>;

        led@0 {
                label = "cap11xx:green:usr0";
                reg = <0>;
        };

        led@1 {
                label = "cap11xx:green:usr1";
                reg = <1>;
        };

        led@2 {
                label = "cap11xx:green:alive";
                reg = <2>;
                linux,default-trigger = "heartbeat";
        };
      };
    };