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/sched.h>
  16 #include <linux/sysdev.h>
  17 #include <asm/io.h>
  18 #include "sleep.h"
  19
  20 int acpi_sleep_prepare(u32 acpi_state)
  21 {
  22 #ifdef CONFIG_ACPI_SLEEP
  23         /* do we have a wakeup address for S2 and S3? */
  24         /* Here, we support only S4BIOS, those we set the wakeup address */
  25         /* S4OS is only supported for now via swsusp.. */
  26         if (acpi_state == ACPI_STATE_S3 || acpi_state == ACPI_STATE_S4) {
  27                 if (!acpi_wakeup_address) {
  28                         return -EFAULT;
  29                 }
  30                 acpi_set_firmware_waking_vector((acpi_physical_address)
  31                                                 virt_to_phys((void *)
  32                                                              acpi_wakeup_address));
  33
  34         }
  35         ACPI_FLUSH_CPU_CACHE();
  36         acpi_enable_wakeup_device_prep(acpi_state);
  37 #endif
  38         if (acpi_state == ACPI_STATE_S5) {
  39                 acpi_wakeup_gpe_poweroff_prepare();
  40         }
  41         acpi_enter_sleep_state_prep(acpi_state);
  42         return 0;
  43 }
  44
  45 #ifdef CONFIG_PM
  46
  47 void acpi_power_off(void)
  48 {
  49         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
  50         printk("%s called\n", __FUNCTION__);
  51         local_irq_disable();
  52         /* Some SMP machines only can poweroff in boot CPU */
  53         acpi_enter_sleep_state(ACPI_STATE_S5);
  54 }
  55
  56 static int acpi_shutdown(struct sys_device *x)
  57 {
  58         if (system_state == SYSTEM_POWER_OFF) {
  59                 /* Prepare if we are going to power off the system */
  60                 return acpi_sleep_prepare(ACPI_STATE_S5);
  61         }
  62         return 0;
  63 }
  64
  65 static struct sysdev_class acpi_sysclass = {
  66         set_kset_name("acpi"),
  67         .shutdown = acpi_shutdown
  68 };
  69
  70 static struct sys_device device_acpi = {
  71         .id = 0,
  72         .cls = &acpi_sysclass,
  73 };
  74
  75 static int acpi_poweroff_init(void)
  76 {
  77         if (!acpi_disabled) {
  78                 u8 type_a, type_b;
  79                 acpi_status status;
  80
  81                 status =
  82                     acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
  83                 if (ACPI_SUCCESS(status)) {
  84                         int error;
  85                         error = sysdev_class_register(&acpi_sysclass);
  86                         if (!error)
  87                                 error = sysdev_register(&device_acpi);
  88                         if (!error)
  89                                 pm_power_off = acpi_power_off;
  90                         return error;
  91                 }
  92         }
  93         return 0;
  94 }
  95
  96 late_initcall(acpi_poweroff_init);
  97
  98 #endif                          /* CONFIG_PM */