target/linux/brcm2708/patches-4.14/950-0157-add-gpio-key-overlay-2329.patch

   1 From e8a650fc27bf1e7d858c997fddd9944e6c222260 Mon Sep 17 00:00:00 2001
   2 From: Aaron Shaw <shawaj@gmail.com>
   3 Date: Thu, 4 Jan 2018 15:02:16 +0000
   4 Subject: [PATCH 157/454] add gpio-key overlay (#2329)
   5
   6 An overlay that allows a Linux key to be bound to a GPIO.
   7 ---
   8  arch/arm/boot/dts/overlays/Makefile           |  1 +
   9  arch/arm/boot/dts/overlays/README             | 21 ++++++++
  10  .../boot/dts/overlays/gpio-key-overlay.dts    | 48 +++++++++++++++++++
  11  3 files changed, 70 insertions(+)
  12  create mode 100644 arch/arm/boot/dts/overlays/gpio-key-overlay.dts
  13
  14 --- a/arch/arm/boot/dts/overlays/Makefile
  15 +++ b/arch/arm/boot/dts/overlays/Makefile
  16 @@ -31,6 +31,7 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
  17         googlevoicehat-soundcard.dtbo \
  18         gpio-ir.dtbo \
  19         gpio-ir-tx.dtbo \
  20 +       gpio-key.dtbo \
  21         gpio-poweroff.dtbo \
  22         gpio-shutdown.dtbo \
  23         hifiberry-amp.dtbo \
  24 --- a/arch/arm/boot/dts/overlays/README
  25 +++ b/arch/arm/boot/dts/overlays/README
  26 @@ -515,6 +515,27 @@ Params: gpio_pin                Output G
  27                                  Default is "0" (active-high).
  28
  29
  30 +Name:   gpio-key
  31 +Info:   This is a generic overlay for activating GPIO keypresses using
  32 +        the gpio-keys library and this dtoverlay. Multiple keys can be
  33 +        set up using multiple calls to the overlay for configuring
  34 +        additional buttons or joysticks. You can see available keycodes
  35 +        at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
  36 +        linux/input-event-codes.h#L64
  37 +Load:   dtoverlay=gpio-key,<param>=<val>
  38 +Params: gpio                    GPIO pin to trigger on (default 3)
  39 +        active_low              When this is 1 (active low), a falling
  40 +                                edge generates a key down event and a
  41 +                                rising edge generates a key up event.
  42 +                                When this is 0 (active high), this is
  43 +                                reversed. The default is 1 (active low)
  44 +        gpio_pull               Desired pull-up/down state (off, down, up)
  45 +                                Default is "up". Note that the default pin
  46 +                                (GPIO3) has an external pullup
  47 +        label                   Set a label for the key
  48 +        keycode                 Set the key code for the button
  49 +
  50 +
  51  Name:   gpio-poweroff
  52  Info:   Drives a GPIO high or low on poweroff (including halt). Enabling this
  53          overlay will prevent the ability to boot by driving GPIO3 low.
  54 --- /dev/null
  55 +++ b/arch/arm/boot/dts/overlays/gpio-key-overlay.dts
  56 @@ -0,0 +1,48 @@
  57 +// Definitions for gpio-key module
  58 +/dts-v1/;
  59 +/plugin/;
  60 +
  61 +/ {
  62 +       compatible = "brcm,bcm2708";
  63 +
  64 +       fragment@0 {
  65 +               // Configure the gpio pin controller
  66 +               target = <&gpio>;
  67 +               __overlay__ {
  68 +                       pin_state: button_pins@0 {
  69 +                               brcm,pins = <3>; // gpio number
  70 +                               brcm,function = <0>; // 0 = input, 1 = output
  71 +                               brcm,pull = <2>; // 0 = none, 1 = pull down, 2 = pull up
  72 +                       };
  73 +               };
  74 +       };
  75 +       fragment@1 {
  76 +               target-path = "/";
  77 +               __overlay__ {
  78 +                       button: button@0 {
  79 +                               compatible = "gpio-keys";
  80 +                               pinctrl-names = "default";
  81 +                               pinctrl-0 = <&pin_state>;
  82 +                               status = "okay";
  83 +
  84 +                               key: key {
  85 +                                       linux,code = <116>;
  86 +                                       gpios = <&gpio 3 1>;
  87 +                                       label = "KEY_POWER";
  88 +                               };
  89 +                       };
  90 +               };
  91 +       };
  92 +
  93 +       __overrides__ {
  94 +               gpio =       <&key>,"gpios:4",
  95 +                            <&button>,"reg:0",
  96 +                            <&pin_state>,"brcm,pins:0",
  97 +                            <&pin_state>,"reg:0";
  98 +               label =      <&key>,"label";
  99 +               keycode =    <&key>,"linux,code:0";
 100 +               gpio_pull =  <&pin_state>,"brcm,pull:0";
 101 +               active_low = <&key>,"gpios:8";
 102 +       };
 103 +
 104 +};