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         /* Flag to do not allow second time invocation for S5 state */
  23         static int shutdown_prepared = 0;
  24 #ifdef CONFIG_ACPI_SLEEP
  25         /* do we have a wakeup address for S2 and S3? */
  26         /* Here, we support only S4BIOS, those we set the wakeup address */
  27         /* S4OS is only supported for now via swsusp.. */
  28         if (acpi_state == ACPI_STATE_S3 || acpi_state == ACPI_STATE_S4) {
  29                 if (!acpi_wakeup_address) {
  30                         return -EFAULT;
  31                 }
  32                 acpi_set_firmware_waking_vector((acpi_physical_address)
  33                                                 virt_to_phys((void *)
  34                                                              acpi_wakeup_address));
  35
  36         }
  37         ACPI_FLUSH_CPU_CACHE();
  38         acpi_enable_wakeup_device_prep(acpi_state);
  39 #endif
  40         if (acpi_state == ACPI_STATE_S5) {
  41                 /* Check if we were already called */
  42                 if (shutdown_prepared)
  43                         return 0;
  44                 acpi_wakeup_gpe_poweroff_prepare();
  45                 shutdown_prepared = 1;
  46         }
  47         acpi_enter_sleep_state_prep(acpi_state);
  48         return 0;
  49 }
  50
  51 void acpi_power_off(void)
  52 {
  53         printk("%s called\n", __FUNCTION__);
  54         acpi_sleep_prepare(ACPI_STATE_S5);
  55         local_irq_disable();
  56         /* Some SMP machines only can poweroff in boot CPU */
  57         acpi_enter_sleep_state(ACPI_STATE_S5);
  58 }
  59
  60 #ifdef CONFIG_PM
  61
  62 static int acpi_shutdown(struct sys_device *x)
  63 {
  64         return acpi_sleep_prepare(ACPI_STATE_S5);
  65 }
  66
  67 static struct sysdev_class acpi_sysclass = {
  68         set_kset_name("acpi"),
  69         .shutdown = acpi_shutdown
  70 };
  71
  72 static struct sys_device device_acpi = {
  73         .id = 0,
  74         .cls = &acpi_sysclass,
  75 };
  76
  77 #endif
  78
  79 static int acpi_poweroff_init(void)
  80 {
  81         if (!acpi_disabled) {
  82                 u8 type_a, type_b;
  83                 acpi_status status;
  84
  85                 status =
  86                     acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
  87                 if (ACPI_SUCCESS(status)) {
  88                         pm_power_off = acpi_power_off;
  89 #ifdef CONFIG_PM
  90                         {
  91                                 int error;
  92                                 error = sysdev_class_register(&acpi_sysclass);
  93                                 if (!error)
  94                                         error = sysdev_register(&device_acpi);
  95                                 return error;
  96                         }
  97 #endif
  98                 }
  99         }
 100         return 0;
 101 }
 102
 103 late_initcall(acpi_poweroff_init);