target/linux/brcm2708/patches-4.4/0080-gpio-poweroff-Allow-it-to-work-on-Raspberry-Pi.patch

   1 From 5b9146b6d47d409c98832d67447a78246e203a36 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 080/381] 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  drivers/power/reset/gpio-poweroff.c | 4 +++-
  19  1 file changed, 3 insertions(+), 1 deletion(-)
  20
  21 --- a/drivers/power/reset/gpio-poweroff.c
  22 +++ b/drivers/power/reset/gpio-poweroff.c
  23 @@ -49,9 +49,11 @@ static int gpio_poweroff_probe(struct pl
  24  {
  25         bool input = false;
  26         enum gpiod_flags flags;
  27 +       bool force = false;
  28
  29         /* If a pm_power_off function has already been added, leave it alone */
  30 -       if (pm_power_off != NULL) {
  31 +       force = of_property_read_bool(pdev->dev.of_node, "force");
  32 +       if (!force && (pm_power_off != NULL)) {
  33                 dev_err(&pdev->dev,
  34                         "%s: pm_power_off function already registered",
  35                        __func__);