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->bus && dev->bus->resume)
  26                 return dev->bus->resume(dev);
  27         return 0;
  28 }
  29
  30
  31
  32 void dpm_resume(void)
  33 {
  34         down(&dpm_list_sem);
  35         while(!list_empty(&dpm_off)) {
  36                 struct list_head * entry = dpm_off.next;
  37                 struct device * dev = to_device(entry);
  38
  39                 get_device(dev);
  40                 list_del_init(entry);
  41                 list_add_tail(entry, &dpm_active);
  42
  43                 up(&dpm_list_sem);
  44                 if (!dev->power.prev_state)
  45                         resume_device(dev);
  46                 down(&dpm_list_sem);
  47                 put_device(dev);
  48         }
  49         up(&dpm_list_sem);
  50 }
  51
  52
  53 /**
  54  *      device_resume - Restore state of each device in system.
  55  *
  56  *      Walk the dpm_off list, remove each entry, resume the device,
  57  *      then add it to the dpm_active list.
  58  */
  59
  60 void device_resume(void)
  61 {
  62         down(&dpm_sem);
  63         dpm_resume();
  64         up(&dpm_sem);
  65 }
  66
  67 EXPORT_SYMBOL_GPL(device_resume);
  68
  69
  70 /**
  71  *      device_power_up_irq - Power on some devices.
  72  *
  73  *      Walk the dpm_off_irq list and power each device up. This
  74  *      is used for devices that required they be powered down with
  75  *      interrupts disabled. As devices are powered on, they are moved to
  76  *      the dpm_suspended list.
  77  *
  78  *      Interrupts must be disabled when calling this.
  79  */
  80
  81 void dpm_power_up(void)
  82 {
  83         while(!list_empty(&dpm_off_irq)) {
  84                 struct list_head * entry = dpm_off_irq.next;
  85                 struct device * dev = to_device(entry);
  86
  87                 get_device(dev);
  88                 list_del_init(entry);
  89                 list_add_tail(entry, &dpm_active);
  90                 resume_device(dev);
  91                 put_device(dev);
  92         }
  93 }
  94
  95
  96 /**
  97  *      device_pm_power_up - Turn on all devices that need special attention.
  98  *
  99  *      Power on system devices then devices that required we shut them down
 100  *      with interrupts disabled.
 101  *      Called with interrupts disabled.
 102  */
 103
 104 void device_power_up(void)
 105 {
 106         sysdev_resume();
 107         dpm_power_up();
 108 }
 109
 110 EXPORT_SYMBOL_GPL(device_power_up);
 111
 112