drivers/power/reset/restart-poweroff.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Power off by restarting and let u-boot keep hold of the machine
   4  * until the user presses a button for example.
   5  *
   6  * Andrew Lunn <andrew@lunn.ch>
   7  *
   8  * Copyright (C) 2012 Andrew Lunn
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/init.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/of_platform.h>
  14 #include <linux/module.h>
  15 #include <linux/reboot.h>
  16
  17 static void restart_poweroff_do_poweroff(void)
  18 {
  19         reboot_mode = REBOOT_HARD;
  20         machine_restart(NULL);
  21 }
  22
  23 static int restart_poweroff_probe(struct platform_device *pdev)
  24 {
  25         /* If a pm_power_off function has already been added, leave it alone */
  26         if (pm_power_off != NULL) {
  27                 dev_err(&pdev->dev,
  28                         "pm_power_off function already registered");
  29                 return -EBUSY;
  30         }
  31
  32         pm_power_off = &restart_poweroff_do_poweroff;
  33         return 0;
  34 }
  35
  36 static int restart_poweroff_remove(struct platform_device *pdev)
  37 {
  38         if (pm_power_off == &restart_poweroff_do_poweroff)
  39                 pm_power_off = NULL;
  40
  41         return 0;
  42 }
  43
  44 static const struct of_device_id of_restart_poweroff_match[] = {
  45         { .compatible = "restart-poweroff", },
  46         {},
  47 };
  48
  49 static struct platform_driver restart_poweroff_driver = {
  50         .probe = restart_poweroff_probe,
  51         .remove = restart_poweroff_remove,
  52         .driver = {
  53                 .name = "poweroff-restart",
  54                 .of_match_table = of_restart_poweroff_match,
  55         },
  56 };
  57 module_platform_driver(restart_poweroff_driver);
  58
  59 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch");
  60 MODULE_DESCRIPTION("restart poweroff driver");
  61 MODULE_LICENSE("GPL v2");
  62 MODULE_ALIAS("platform:poweroff-restart");