1* GPIO driven matrix keypad device tree bindings 2 3GPIO driven matrix keypad is used to interface a SoC with a matrix keypad. 4The matrix keypad supports multiple row and column lines, a key can be 5placed at each intersection of a unique row and a unique column. The matrix 6keypad can sense a key-press and key-release by means of GPIO lines and 7report the event using GPIO interrupts to the cpu. 8 9Required Properties: 10- compatible: Should be "gpio-matrix-keypad" 11- row-gpios: List of gpios used as row lines. The gpio specifier 12 for this property depends on the gpio controller to 13 which these row lines are connected. 14- col-gpios: List of gpios used as column lines. The gpio specifier 15 for this property depends on the gpio controller to 16 which these column lines are connected. 17- linux,keymap: The definition can be found at 18 bindings/input/matrix-keymap.txt 19 20Optional Properties: 21- linux,no-autorepeat: do no enable autorepeat feature. 22- linux,wakeup: use any event on keypad as wakeup event. 23- debounce-delay-ms: debounce interval in milliseconds 24- col-scan-delay-us: delay, measured in microseconds, that is needed 25 before we can scan keypad after activating column gpio 26 27Example: 28 matrix-keypad { 29 compatible = "gpio-matrix-keypad"; 30 debounce-delay-ms = <5>; 31 col-scan-delay-us = <2>; 32 33 row-gpios = <&gpio2 25 0 34 &gpio2 26 0 35 &gpio2 27 0>; 36 37 col-gpios = <&gpio2 21 0 38 &gpio2 22 0>; 39 40 linux,keymap = <0x0000008B 41 0x0100009E 42 0x02000069 43 0x0001006A 44 0x0101001C 45 0x0201006C>; 46 }; 47