drivers/base/power/resume.c

   1 /*
   2  * resume.c - Functions for waking devices up.
   3  *
   4  * Copyright (c) 2003 Patrick Mochel
   5  * Copyright (c) 2003 Open Source Development Labs
   6  *
   7  * This file is released under the GPLv2
   8  *
   9  */
  10
  11 #include <linux/device.h>
  12 #include "power.h"
  13
  14 extern int sysdev_resume(void);
  15
  16
  17 /**
  18  *      resume_device - Restore state for one device.
  19  *      @dev:   Device.
  20  *
  21  */
  22
  23 int resume_device(struct device * dev)
  24 {
  25         if (dev->power.pm_parent
  26                         && dev->power.pm_parent->power.power_state) {
  27                 dev_err(dev, "PM: resume from %d, parent %s still %d\n",
  28                         dev->power.power_state,
  29                         dev->power.pm_parent->bus_id,
  30                         dev->power.pm_parent->power.power_state);
  31         }
  32         if (dev->bus && dev->bus->resume) {
  33                 dev_dbg(dev,"resuming\n");
  34                 return dev->bus->resume(dev);
  35         }
  36         return 0;
  37 }
  38
  39
  40
  41 void dpm_resume(void)
  42 {
  43         down(&dpm_list_sem);
  44         while(!list_empty(&dpm_off)) {
  45                 struct list_head * entry = dpm_off.next;
  46                 struct device * dev = to_device(entry);
  47
  48                 get_device(dev);
  49                 list_del_init(entry);
  50                 list_add_tail(entry, &dpm_active);
  51
  52                 up(&dpm_list_sem);
  53                 if (!dev->power.prev_state)
  54                         resume_device(dev);
  55                 down(&dpm_list_sem);
  56                 put_device(dev);
  57         }
  58         up(&dpm_list_sem);
  59 }
  60
  61
  62 /**
  63  *      device_resume - Restore state of each device in system.
  64  *
  65  *      Walk the dpm_off list, remove each entry, resume the device,
  66  *      then add it to the dpm_active list.
  67  */
  68
  69 void device_resume(void)
  70 {
  71         down(&dpm_sem);
  72         dpm_resume();
  73         up(&dpm_sem);
  74 }
  75
  76 EXPORT_SYMBOL_GPL(device_resume);
  77
  78
  79 /**
  80  *      device_power_up_irq - Power on some devices.
  81  *
  82  *      Walk the dpm_off_irq list and power each device up. This
  83  *      is used for devices that required they be powered down with
  84  *      interrupts disabled. As devices are powered on, they are moved to
  85  *      the dpm_suspended list.
  86  *
  87  *      Interrupts must be disabled when calling this.
  88  */
  89
  90 void dpm_power_up(void)
  91 {
  92         while(!list_empty(&dpm_off_irq)) {
  93                 struct list_head * entry = dpm_off_irq.next;
  94                 struct device * dev = to_device(entry);
  95
  96                 get_device(dev);
  97                 list_del_init(entry);
  98                 list_add_tail(entry, &dpm_active);
  99                 resume_device(dev);
 100                 put_device(dev);
 101         }
 102 }
 103
 104
 105 /**
 106  *      device_pm_power_up - Turn on all devices that need special attention.
 107  *
 108  *      Power on system devices then devices that required we shut them down
 109  *      with interrupts disabled.
 110  *      Called with interrupts disabled.
 111  */
 112
 113 void device_power_up(void)
 114 {
 115         sysdev_resume();
 116         dpm_power_up();
 117 }
 118
 119 EXPORT_SYMBOL_GPL(device_power_up);
 120
 121