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         int error = 0;
  26
  27         down(&dev->sem);
  28         if (dev->power.pm_parent
  29                         && dev->power.pm_parent->power.power_state) {
  30                 dev_err(dev, "PM: resume from %d, parent %s still %d\n",
  31                         dev->power.power_state,
  32                         dev->power.pm_parent->bus_id,
  33                         dev->power.pm_parent->power.power_state);
  34         }
  35         if (dev->bus && dev->bus->resume) {
  36                 dev_dbg(dev,"resuming\n");
  37                 error = dev->bus->resume(dev);
  38         }
  39         up(&dev->sem);
  40         return error;
  41 }
  42
  43
  44
  45 void dpm_resume(void)
  46 {
  47         down(&dpm_list_sem);
  48         while(!list_empty(&dpm_off)) {
  49                 struct list_head * entry = dpm_off.next;
  50                 struct device * dev = to_device(entry);
  51
  52                 get_device(dev);
  53                 list_del_init(entry);
  54                 list_add_tail(entry, &dpm_active);
  55
  56                 up(&dpm_list_sem);
  57                 if (!dev->power.prev_state)
  58                         resume_device(dev);
  59                 down(&dpm_list_sem);
  60                 put_device(dev);
  61         }
  62         up(&dpm_list_sem);
  63 }
  64
  65
  66 /**
  67  *      device_resume - Restore state of each device in system.
  68  *
  69  *      Walk the dpm_off list, remove each entry, resume the device,
  70  *      then add it to the dpm_active list.
  71  */
  72
  73 void device_resume(void)
  74 {
  75         down(&dpm_sem);
  76         dpm_resume();
  77         up(&dpm_sem);
  78 }
  79
  80 EXPORT_SYMBOL_GPL(device_resume);
  81
  82
  83 /**
  84  *      device_power_up_irq - Power on some devices.
  85  *
  86  *      Walk the dpm_off_irq list and power each device up. This
  87  *      is used for devices that required they be powered down with
  88  *      interrupts disabled. As devices are powered on, they are moved to
  89  *      the dpm_suspended list.
  90  *
  91  *      Interrupts must be disabled when calling this.
  92  */
  93
  94 void dpm_power_up(void)
  95 {
  96         while(!list_empty(&dpm_off_irq)) {
  97                 struct list_head * entry = dpm_off_irq.next;
  98                 struct device * dev = to_device(entry);
  99
 100                 get_device(dev);
 101                 list_del_init(entry);
 102                 list_add_tail(entry, &dpm_active);
 103                 resume_device(dev);
 104                 put_device(dev);
 105         }
 106 }
 107
 108
 109 /**
 110  *      device_pm_power_up - Turn on all devices that need special attention.
 111  *
 112  *      Power on system devices then devices that required we shut them down
 113  *      with interrupts disabled.
 114  *      Called with interrupts disabled.
 115  */
 116
 117 void device_power_up(void)
 118 {
 119         sysdev_resume();
 120         dpm_power_up();
 121 }
 122
 123 EXPORT_SYMBOL_GPL(device_power_up);
 124
 125