drivers/acpi/sleep/poweroff.c

   1 /*
   2  * poweroff.c - ACPI handler for powering off the system.
   3  *
   4  * AKA S5, but it is independent of whether or not the kernel supports
   5  * any other sleep support in the system.
   6  *
   7  * Copyright (c) 2005 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   8  *
   9  * This file is released under the GPLv2.
  10  */
  11
  12 #include <linux/pm.h>
  13 #include <linux/init.h>
  14 #include <acpi/acpi_bus.h>
  15 #include <linux/sysdev.h>
  16 #include <asm/io.h>
  17 #include "sleep.h"
  18
  19 int acpi_sleep_prepare(u32 acpi_state)
  20 {
  21 #ifdef CONFIG_ACPI_SLEEP
  22         /* do we have a wakeup address for S2 and S3? */
  23         if (acpi_state == ACPI_STATE_S3) {
  24                 if (!acpi_wakeup_address) {
  25                         return -EFAULT;
  26                 }
  27                 acpi_set_firmware_waking_vector((acpi_physical_address)
  28                                                 virt_to_phys((void *)
  29                                                              acpi_wakeup_address));
  30
  31         }
  32         ACPI_FLUSH_CPU_CACHE();
  33         acpi_enable_wakeup_device_prep(acpi_state);
  34 #endif
  35         acpi_gpe_sleep_prepare(acpi_state);
  36         acpi_enter_sleep_state_prep(acpi_state);
  37         return 0;
  38 }
  39
  40 #ifdef CONFIG_PM
  41
  42 void acpi_power_off(void)
  43 {
  44         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
  45         printk("%s called\n", __FUNCTION__);
  46         local_irq_disable();
  47         /* Some SMP machines only can poweroff in boot CPU */
  48         acpi_enter_sleep_state(ACPI_STATE_S5);
  49 }
  50
  51 static int acpi_shutdown(struct sys_device *x)
  52 {
  53         switch (system_state) {
  54         case SYSTEM_POWER_OFF:
  55                 /* Prepare to power off the system */
  56                 return acpi_sleep_prepare(ACPI_STATE_S5);
  57         default:
  58                 return 0;
  59         }
  60 }
  61
  62 static struct sysdev_class acpi_sysclass = {
  63         set_kset_name("acpi"),
  64         .shutdown = acpi_shutdown
  65 };
  66
  67 static struct sys_device device_acpi = {
  68         .id = 0,
  69         .cls = &acpi_sysclass,
  70 };
  71
  72 static int acpi_poweroff_init(void)
  73 {
  74         if (!acpi_disabled) {
  75                 u8 type_a, type_b;
  76                 acpi_status status;
  77
  78                 status =
  79                     acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
  80                 if (ACPI_SUCCESS(status)) {
  81                         int error;
  82                         error = sysdev_class_register(&acpi_sysclass);
  83                         if (!error)
  84                                 error = sysdev_register(&device_acpi);
  85                         if (!error)
  86                                 pm_power_off = acpi_power_off;
  87                         return error;
  88                 }
  89         }
  90         return 0;
  91 }
  92
  93 late_initcall(acpi_poweroff_init);
  94
  95 #endif                          /* CONFIG_PM */