mirror of
https://github.com/ByteWelder/Tactility.git
synced 2026-10-17 19:05:07 +00:00
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>;
};