drivers/acpi/wakeup.c

   1 /*
   2  * wakeup.c - support wakeup devices
   3  * Copyright (C) 2004 Li Shaohua <shaohua.li@intel.com>
   4  */
   5
   6 #include <linux/init.h>
   7 #include <linux/acpi.h>
   8 #include <acpi/acpi_drivers.h>
   9 #include <linux/kernel.h>
  10 #include <linux/types.h>
  11
  12 #include "internal.h"
  13 #include "sleep.h"
  14
  15 /*
  16  * We didn't lock acpi_device_lock in the file, because it invokes oops in
  17  * suspend/resume and isn't really required as this is called in S-state. At
  18  * that time, there is no device hotplug
  19  **/
  20 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
  21 ACPI_MODULE_NAME("wakeup_devices")
  22
  23 /**
  24  * acpi_enable_wakeup_device_prep - Prepare wake-up devices.
  25  * @sleep_state: ACPI system sleep state.
  26  *
  27  * Enable all wake-up devices' power, unless the requested system sleep state is
  28  * too deep.
  29  */
  30 void acpi_enable_wakeup_device_prep(u8 sleep_state)
  31 {
  32         struct list_head *node, *next;
  33
  34         list_for_each_safe(node, next, &acpi_wakeup_device_list) {
  35                 struct acpi_device *dev = container_of(node,
  36                                                        struct acpi_device,
  37                                                        wakeup_list);
  38
  39                 if (!dev->wakeup.flags.valid || !dev->wakeup.state.enabled
  40                     || (sleep_state > (u32) dev->wakeup.sleep_state))
  41                         continue;
  42
  43                 acpi_enable_wakeup_device_power(dev, sleep_state);
  44         }
  45 }
  46
  47 /**
  48  * acpi_enable_wakeup_device - Enable wake-up device GPEs.
  49  * @sleep_state: ACPI system sleep state.
  50  *
  51  * Enable all wake-up devices' GPEs, with the assumption that
  52  * acpi_disable_all_gpes() was executed before, so we don't need to disable any
  53  * GPEs here.
  54  */
  55 void acpi_enable_wakeup_device(u8 sleep_state)
  56 {
  57         struct list_head *node, *next;
  58
  59         /*
  60          * Caution: this routine must be invoked when interrupt is disabled
  61          * Refer ACPI2.0: P212
  62          */
  63         list_for_each_safe(node, next, &acpi_wakeup_device_list) {
  64                 struct acpi_device *dev =
  65                         container_of(node, struct acpi_device, wakeup_list);
  66
  67                 if (!dev->wakeup.flags.valid)
  68                         continue;
  69
  70                 if ((!dev->wakeup.state.enabled && !dev->wakeup.prepare_count)
  71                     || sleep_state > (u32) dev->wakeup.sleep_state)
  72                         continue;
  73
  74                 /* The wake-up power should have been enabled already. */
  75                 acpi_set_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
  76                                 ACPI_GPE_ENABLE);
  77         }
  78 }
  79
  80 /**
  81  * acpi_disable_wakeup_device - Disable devices' wakeup capability.
  82  * @sleep_state: ACPI system sleep state.
  83  *
  84  * This function only affects devices with wakeup.state.enabled set, which means
  85  * that it reverses the changes made by acpi_enable_wakeup_device_prep().
  86  */
  87 void acpi_disable_wakeup_device(u8 sleep_state)
  88 {
  89         struct list_head *node, *next;
  90
  91         list_for_each_safe(node, next, &acpi_wakeup_device_list) {
  92                 struct acpi_device *dev =
  93                         container_of(node, struct acpi_device, wakeup_list);
  94
  95                 if (!dev->wakeup.flags.valid || !dev->wakeup.state.enabled
  96                     || (sleep_state > (u32) dev->wakeup.sleep_state))
  97                         continue;
  98
  99                 acpi_disable_wakeup_device_power(dev);
 100         }
 101 }
 102
 103 int __init acpi_wakeup_device_init(void)
 104 {
 105         struct list_head *node, *next;
 106
 107         mutex_lock(&acpi_device_lock);
 108         list_for_each_safe(node, next, &acpi_wakeup_device_list) {
 109                 struct acpi_device *dev = container_of(node,
 110                                                        struct acpi_device,
 111                                                        wakeup_list);
 112                 /* In case user doesn't load button driver */
 113                 if (!dev->wakeup.flags.always_enabled ||
 114                     dev->wakeup.state.enabled)
 115                         continue;
 116                 acpi_enable_gpe(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
 117                                 ACPI_GPE_TYPE_WAKE);
 118                 dev->wakeup.state.enabled = 1;
 119         }
 120         mutex_unlock(&acpi_device_lock);
 121         return 0;
 122 }