root/kernel/power/poweroff.c

DEFINITIONS

1. do_poweroff
2. handle_poweroff
3. pm_sysrq_init

/*
 * poweroff.c - sysrq handler to gracefully power down machine.
 *
 * This file is released under the GPL v2
 */

#include <linux/kernel.h>
#include <linux/sysrq.h>
#include <linux/init.h>
#include <linux/pm.h>
#include <linux/workqueue.h>
#include <linux/reboot.h>
#include <linux/cpumask.h>

/*
 * When the user hits Sys-Rq o to power down the machine this is the
 * callback we use.
 */

static void do_poweroff(struct work_struct *dummy)
{
        kernel_power_off();
}

static DECLARE_WORK(poweroff_work, do_poweroff);

static void handle_poweroff(int key, struct tty_struct *tty)
{
        /* run sysrq poweroff on boot cpu */
        schedule_work_on(first_cpu(cpu_online_map), &poweroff_work);
}

static struct sysrq_key_op      sysrq_poweroff_op = {
        .handler        = handle_poweroff,
        .help_msg       = "powerOff",
        .action_msg     = "Power Off",
        .enable_mask    = SYSRQ_ENABLE_BOOT,
};

static int pm_sysrq_init(void)
{
        register_sysrq_key('o', &sysrq_poweroff_op);
        return 0;
}

subsys_initcall(pm_sysrq_init);