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- drive-inactive-cols: drive inactive columns during scan, 28 default is to turn inactive columns into inputs. 29 30Example: 31 matrix-keypad { 32 compatible = "gpio-matrix-keypad"; 33 debounce-delay-ms = <5>; 34 col-scan-delay-us = <2>; 35 36 row-gpios = <&gpio2 25 0 37 &gpio2 26 0 38 &gpio2 27 0>; 39 40 col-gpios = <&gpio2 21 0 41 &gpio2 22 0>; 42 43 linux,keymap = <0x0000008B 44 0x0100009E 45 0x02000069 46 0x0001006A 47 0x0101001C 48 0x0201006C>; 49 }; 50