arch/arm/boot/dts/overlays/gpio-key-overlay.dts

   1 // Definitions for gpio-key module
   2 /dts-v1/;
   3 /plugin/;
   4
   5 / {
   6         compatible = "brcm,bcm2835";
   7
   8         fragment@0 {
   9                 // Configure the gpio pin controller
  10                 target = <&gpio>;
  11                 __overlay__ {
  12                         pin_state: button_pins@0 {
  13                                 brcm,pins = <3>; // gpio number
  14                                 brcm,function = <0>; // 0 = input, 1 = output
  15                                 brcm,pull = <2>; // 0 = none, 1 = pull down, 2 = pull up
  16                         };
  17                 };
  18         };
  19         fragment@1 {
  20                 target-path = "/";
  21                 __overlay__ {
  22                         button: button@0 {
  23                                 compatible = "gpio-keys";
  24                                 pinctrl-names = "default";
  25                                 pinctrl-0 = <&pin_state>;
  26                                 status = "okay";
  27
  28                                 key: key {
  29                                         linux,code = <116>;
  30                                         gpios = <&gpio 3 1>;
  31                                         label = "KEY_POWER";
  32                                 };
  33                         };
  34                 };
  35         };
  36
  37         __overrides__ {
  38                 gpio =       <&key>,"gpios:4",
  39                              <&button>,"reg:0",
  40                              <&pin_state>,"brcm,pins:0",
  41                              <&pin_state>,"reg:0";
  42                 label =      <&key>,"label";
  43                 keycode =    <&key>,"linux,code:0";
  44                 gpio_pull =  <&pin_state>,"brcm,pull:0";
  45                 active_low = <&key>,"gpios:8";
  46         };
  47
  48 };