Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | # SPDX-License-Identifier: GPL-2.0 |
| 2 | %YAML 1.2 |
| 3 | --- |
| 4 | $id: http://devicetree.org/schemas/input/adc-keys.yaml# |
| 5 | $schema: http://devicetree.org/meta-schemas/core.yaml# |
| 6 | |
| 7 | title: ADC attached resistor ladder buttons |
| 8 | |
| 9 | maintainers: |
| 10 | - Alexandre Belloni <alexandre.belloni@bootlin.com> |
| 11 | |
| 12 | allOf: |
| 13 | - $ref: input.yaml# |
| 14 | |
| 15 | properties: |
| 16 | compatible: |
| 17 | const: adc-keys |
| 18 | |
| 19 | io-channels: |
| 20 | maxItems: 1 |
| 21 | |
| 22 | io-channel-names: |
| 23 | const: buttons |
| 24 | |
| 25 | keyup-threshold-microvolt: |
| 26 | description: |
| 27 | Voltage above or equal to which all the keys are considered up. |
| 28 | |
| 29 | poll-interval: true |
| 30 | autorepeat: true |
| 31 | |
| 32 | patternProperties: |
| 33 | '^button-': |
| 34 | type: object |
| 35 | $ref: input.yaml# |
| 36 | additionalProperties: false |
| 37 | description: |
| 38 | Each button (key) is represented as a sub-node. |
| 39 | |
| 40 | properties: |
| 41 | label: true |
| 42 | |
| 43 | linux,code: true |
| 44 | |
| 45 | press-threshold-microvolt: |
| 46 | description: |
| 47 | Voltage above or equal to which this key is considered pressed. No |
| 48 | two values of press-threshold-microvolt may be the same. All values |
| 49 | of press-threshold-microvolt must be less than |
| 50 | keyup-threshold-microvolt. |
| 51 | |
| 52 | required: |
| 53 | - linux,code |
| 54 | - press-threshold-microvolt |
| 55 | |
| 56 | required: |
| 57 | - compatible |
| 58 | - io-channels |
| 59 | - io-channel-names |
| 60 | - keyup-threshold-microvolt |
| 61 | |
| 62 | additionalProperties: false |
| 63 | |
| 64 | examples: |
| 65 | - | |
| 66 | #include <dt-bindings/input/input.h> |
| 67 | // +--------------------------------+------------------------+ |
| 68 | // | 2.000.000 <= value | no key pressed | |
| 69 | // +--------------------------------+------------------------+ |
| 70 | // | 1.500.000 <= value < 2.000.000 | KEY_VOLUMEUP pressed | |
| 71 | // +--------------------------------+------------------------+ |
| 72 | // | 1.000.000 <= value < 1.500.000 | KEY_VOLUMEDOWN pressed | |
| 73 | // +--------------------------------+------------------------+ |
| 74 | // | 500.000 <= value < 1.000.000 | KEY_ENTER pressed | |
| 75 | // +--------------------------------+------------------------+ |
| 76 | // | value < 500.000 | no key pressed | |
| 77 | // +--------------------------------+------------------------+ |
| 78 | |
| 79 | adc-keys { |
| 80 | compatible = "adc-keys"; |
| 81 | io-channels = <&lradc 0>; |
| 82 | io-channel-names = "buttons"; |
| 83 | keyup-threshold-microvolt = <2000000>; |
| 84 | |
| 85 | button-up { |
| 86 | label = "Volume Up"; |
| 87 | linux,code = <KEY_VOLUMEUP>; |
| 88 | press-threshold-microvolt = <1500000>; |
| 89 | }; |
| 90 | |
| 91 | button-down { |
| 92 | label = "Volume Down"; |
| 93 | linux,code = <KEY_VOLUMEDOWN>; |
| 94 | press-threshold-microvolt = <1000000>; |
| 95 | }; |
| 96 | |
| 97 | button-enter { |
| 98 | label = "Enter"; |
| 99 | linux,code = <KEY_ENTER>; |
| 100 | press-threshold-microvolt = <500000>; |
| 101 | }; |
| 102 | }; |
| 103 | ... |