kernel/power/poweroff.c

   1 /*
   2  * poweroff.c - sysrq handler to gracefully power down machine.
   3  *
   4  * This file is released under the GPL v2
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/sysrq.h>
   9 #include <linux/init.h>
  10 #include <linux/pm.h>
  11 #include <linux/workqueue.h>
  12
  13 /*
  14  * When the user hits Sys-Rq o to power down the machine this is the
  15  * callback we use.
  16  */
  17
  18 static void do_poweroff(void *dummy)
  19 {
  20         if (pm_power_off)
  21                 pm_power_off();
  22 }
  23
  24 static DECLARE_WORK(poweroff_work, do_poweroff, NULL);
  25
  26 static void handle_poweroff(int key, struct pt_regs *pt_regs,
  27                                 struct tty_struct *tty)
  28 {
  29         schedule_work(&poweroff_work);
  30 }
  31
  32 static struct sysrq_key_op      sysrq_poweroff_op = {
  33         .handler        = handle_poweroff,
  34         .help_msg       = "powerOff",
  35         .action_msg     = "Power Off",
  36         .enable_mask    = SYSRQ_ENABLE_BOOT,
  37 };
  38
  39 static int pm_sysrq_init(void)
  40 {
  41         register_sysrq_key('o', &sysrq_poweroff_op);
  42         return 0;
  43 }
  44
  45 subsys_initcall(pm_sysrq_init);