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