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- wakeup-source: use any event on keypad as wakeup event. 23 (Legacy property supported: "linux,wakeup") 24- debounce-delay-ms: debounce interval in milliseconds 25- col-scan-delay-us: delay, measured in microseconds, that is needed 26 before we can scan keypad after activating column gpio 27 28Example: 29 matrix-keypad { 30 compatible = "gpio-matrix-keypad"; 31 debounce-delay-ms = <5>; 32 col-scan-delay-us = <2>; 33 34 row-gpios = <&gpio2 25 0 35 &gpio2 26 0 36 &gpio2 27 0>; 37 38 col-gpios = <&gpio2 21 0 39 &gpio2 22 0>; 40 41 linux,keymap = <0x0000008B 42 0x0100009E 43 0x02000069 44 0x0001006A 45 0x0101001C 46 0x0201006C>; 47 }; 48