Ken Van Hoeylandt c729e8340f
Trackball rewrite (#600)
- Implement generic trackball settings
- Refactor T-Deck trackball driver into generic driver at `Drivers/gpio-trackball-module`
- Automatically bind/unbind trackball devices with LVGL
- Automatically load settings for trackball devices on boot
2026-07-30 13:38:19 +02:00

830 B

GPIO Trackball

Kernel driver for a 5-way GPIO trackball (4 direction pins + a click button), exposing a TRACKBALL_TYPE device (tactility/drivers/trackball.h).

Devicetree binding: tactility,gpio-trackball (see bindings/tactility,gpio-trackball.yaml).

Each direction pin is wired to a falling-edge interrupt that accumulates a signed delta; the click pin is active-low and read on any edge. read_delta() drains and resets the accumulated delta on each call.

Example

trackball {
    compatible = "tactility,gpio-trackball";
    pin-right = <&gpio0 1 GPIO_FLAG_NONE>;
    pin-up = <&gpio0 2 GPIO_FLAG_NONE>;
    pin-left = <&gpio0 3 GPIO_FLAG_NONE>;
    pin-down = <&gpio0 4 GPIO_FLAG_NONE>;
    pin-click = <&gpio0 5 GPIO_FLAG_NONE>;
};

License

Apache License Version 2.0