Kernel-4.18.0-80.el8_gpio-matrix-keypa

• GPIO driven matrix keypad device tree bindings

GPIO driven matrix keypad is used to interface a SoC with a matrix keypad.
The matrix keypad supports multiple row and column lines, a key can be
placed at each intersection of a unique row and a unique column. The matrix
keypad can sense a key-press and key-release by means of GPIO lines and
report the event using GPIO interrupts to the cpu.

Required Properties:

• compatible: Should be “gpio-matrix-keypad”
• row-gpios: List of gpios used as row lines. The gpio specifier

        for this property depends on the gpio controller to
        which these row lines are connected.
  

• col-gpios: List of gpios used as column lines. The gpio specifier

        for this property depends on the gpio controller to
        which these column lines are connected.
  

• linux,keymap: The definition can be found at

        bindings/input/matrix-keymap.txt
  

Optional Properties:

• linux,no-autorepeat: do no enable autorepeat feature.
• wakeup-source: use any event on keypad as wakeup event.

        (Legacy property supported: "linux,wakeup")
  

• debounce-delay-ms: debounce interval in milliseconds
• col-scan-delay-us: delay, measured in microseconds, that is needed

        before we can scan keypad after activating column gpio
  

• drive-inactive-cols: drive inactive columns during scan,

        default is to turn inactive columns into inputs.
  

Example:
matrix-keypad {
compatible = “gpio-matrix-keypad”;
debounce-delay-ms = <5>;
col-scan-delay-us = <2>;

    row-gpios = <&gpio2 25 0
             &gpio2 26 0
             &gpio2 27 0>;

    col-gpios = <&gpio2 21 0
             &gpio2 22 0>;

    linux,keymap = <0x0000008B
            0x0100009E
            0x02000069
            0x0001006A
            0x0101001C
            0x0201006C>;
};