Device-Tree bindings for input/gpio_keys_polled.c keyboard driver
Required properties:
- compatible = “gpio-keys-polled”;
- poll-interval: Poll interval time in milliseconds
Optional properties:
- autorepeat: Boolean, Enable auto repeat feature of Linux input
subsystem.
Each button (key) is represented as a sub-node of “gpio-keys-polled”:
Subnode properties:
- gpios: OF device-tree gpio specification.
- label: Descriptive name of the key.
- linux,code: Key / Axis code to emit.
Optional subnode-properties:
- linux,input-type: Specify event type this button/key generates.
If not specified defaults to <1> == EV_KEY.
- linux,input-value: If linux,input-type is EV_ABS or EV_REL then this
value is sent for events this button generates when pressed.
EV_ABS/EV_REL axis will generate an event with a value of 0 when
all buttons with linux,input-type == type and linux,code == axis
are released. This value is interpreted as a signed 32 bit value,
e.g. to make a button generate a value of -1 use:
linux,input-value = <0xffffffff>; /* -1 */
- debounce-interval: Debouncing interval time in milliseconds.
If not specified defaults to 5.
- wakeup-source: Boolean, button can wake-up the system.
(Legacy property supported: “gpio-key,wakeup”)
Example nodes:
gpio_keys_polled {
compatible = "gpio-keys-polled";
poll-interval = <100>;
autorepeat;
button21 {
label = "GPIO Key UP";
linux,code = <103>;
gpios = <&gpio1 0 1>;
};
...
