target/linux/brcm2708/patches-4.1/0087-gpio-poweroff-Allow-it-to-work-on-Raspberry-Pi.patch

   1 From 842fe412d512dabb76d169395086b6337150015a Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Thu, 25 Jun 2015 12:16:11 +0100
   4 Subject: [PATCH 087/121] gpio-poweroff: Allow it to work on Raspberry Pi
   5
   6 The Raspberry Pi firmware manages the power-down and reboot
   7 process. To do this it installs a pm_power_off handler, causing
   8 the gpio-poweroff module to abort the probe function.
   9
  10 This patch introduces a "force" DT property that overrides that
  11 behaviour, and also adds a DT overlay to enable and control it.
  12
  13 Note that running in an active-low configuration (DT parameter
  14 "active_low") requires a custom dt-blob.bin and probably won't
  15 allow a reboot without switching off, so an external inversion
  16 of the trigger signal may be preferable.
  17 ---
  18  arch/arm/boot/dts/overlays/Makefile                |  1 +
  19  arch/arm/boot/dts/overlays/README                  | 13 +++++++++
  20  .../boot/dts/overlays/gpio-poweroff-overlay.dts    | 34 ++++++++++++++++++++++
  21  drivers/power/reset/gpio-poweroff.c                |  4 ++-
  22  4 files changed, 51 insertions(+), 1 deletion(-)
  23  create mode 100644 arch/arm/boot/dts/overlays/gpio-poweroff-overlay.dts
  24
  25 --- a/arch/arm/boot/dts/overlays/Makefile
  26 +++ b/arch/arm/boot/dts/overlays/Makefile
  27 @@ -16,6 +16,7 @@ dtb-$(RPI_DT_OVERLAYS) += ads7846-overla
  28  dtb-$(RPI_DT_OVERLAYS) += bmp085_i2c-sensor-overlay.dtb
  29  dtb-$(RPI_DT_OVERLAYS) += dht11-overlay.dtb
  30  dtb-$(RPI_DT_OVERLAYS) += enc28j60-overlay.dtb
  31 +dtb-$(RPI_DT_OVERLAYS) += gpio-poweroff-overlay.dtb
  32  dtb-$(RPI_DT_OVERLAYS) += hifiberry-amp-overlay.dtb
  33  dtb-$(RPI_DT_OVERLAYS) += hifiberry-dac-overlay.dtb
  34  dtb-$(RPI_DT_OVERLAYS) += hifiberry-dacplus-overlay.dtb
  35 --- a/arch/arm/boot/dts/overlays/README
  36 +++ b/arch/arm/boot/dts/overlays/README
  37 @@ -192,6 +192,19 @@ Params: int_pin                  GPIO us
  38          speed                    SPI bus speed (default 12000000)
  39
  40
  41 +Name:   gpio-poweroff
  42 +Info:   Drives a GPIO high or low on reboot
  43 +Load:   gpio-poweroff,<param>=<val>
  44 +Params: gpiopin                  GPIO for signalling (default 26)
  45 +
  46 +        active_low               Set if the power control device requires a
  47 +                                 high->low transition to trigger a power-down.
  48 +                                 Note that this will require the support of a
  49 +                                 custom dt-blob.bin to prevent a power-down
  50 +                                 during the boot process, and that a reboot
  51 +                                 will also cause the pin to go low.
  52 +
  53 +
  54  Name:   hifiberry-amp
  55  Info:   Configures the HifiBerry Amp and Amp+ audio cards
  56  Load:   dtoverlay=hifiberry-amp
  57 --- /dev/null
  58 +++ b/arch/arm/boot/dts/overlays/gpio-poweroff-overlay.dts
  59 @@ -0,0 +1,34 @@
  60 +// Definitions for gpio-poweroff module
  61 +/dts-v1/;
  62 +/plugin/;
  63 +
  64 +/ {
  65 +       compatible = "brcm,bcm2708";
  66 +
  67 +       fragment@0 {
  68 +               target-path = "/";
  69 +               __overlay__ {
  70 +                       power_ctrl: power_ctrl {
  71 +                               compatible = "gpio-poweroff";
  72 +                               gpios = <&gpio 26 0>;
  73 +                               force;
  74 +                       };
  75 +               };
  76 +       };
  77 +
  78 +       fragment@1 {
  79 +               target = <&gpio>;
  80 +               __overlay__ {
  81 +                       power_ctrl_pins: power_ctrl_pins {
  82 +                               brcm,pins = <26>;
  83 +                               brcm,function = <1>; // out
  84 +                       };
  85 +               };
  86 +       };
  87 +
  88 +       __overrides__ {
  89 +               gpiopin =       <&power_ctrl>,"gpios:4",
  90 +                               <&power_ctrl_pins>,"brcm,pins:0";
  91 +               active_low =    <&power_ctrl>,"gpios:8";
  92 +       };
  93 +};
  94 --- a/drivers/power/reset/gpio-poweroff.c
  95 +++ b/drivers/power/reset/gpio-poweroff.c
  96 @@ -48,9 +48,11 @@ static void gpio_poweroff_do_poweroff(vo
  97  static int gpio_poweroff_probe(struct platform_device *pdev)
  98  {
  99         bool input = false;
 100 +       bool force = false;
 101
 102         /* If a pm_power_off function has already been added, leave it alone */
 103 -       if (pm_power_off != NULL) {
 104 +       force = of_property_read_bool(pdev->dev.of_node, "force");
 105 +       if (!force && (pm_power_off != NULL)) {
 106                 dev_err(&pdev->dev,
 107                         "%s: pm_power_off function already registered",
 108                        __func__);