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 "../base.h"
  13 #include "power.h"
  14
  15
  16 /**
  17  *      resume_device - Restore state for one device.
  18  *      @dev:   Device.
  19  *
  20  */
  21
  22 int resume_device(struct device * dev)
  23 {
  24         int error = 0;
  25
  26         down(&dev->sem);
  27         if (dev->power.pm_parent
  28                         && dev->power.pm_parent->power.power_state.event) {
  29                 dev_err(dev, "PM: resume from %d, parent %s still %d\n",
  30                         dev->power.power_state.event,
  31                         dev->power.pm_parent->bus_id,
  32                         dev->power.pm_parent->power.power_state.event);
  33         }
  34         if (dev->bus && dev->bus->resume) {
  35                 dev_dbg(dev,"resuming\n");
  36                 error = dev->bus->resume(dev);
  37         }
  38         up(&dev->sem);
  39         return error;
  40 }
  41
  42
  43
  44 void dpm_resume(void)
  45 {
  46         down(&dpm_list_sem);
  47         while(!list_empty(&dpm_off)) {
  48                 struct list_head * entry = dpm_off.next;
  49                 struct device * dev = to_device(entry);
  50
  51                 get_device(dev);
  52                 list_del_init(entry);
  53                 list_add_tail(entry, &dpm_active);
  54
  55                 up(&dpm_list_sem);
  56                 if (!dev->power.prev_state.event)
  57                         resume_device(dev);
  58                 down(&dpm_list_sem);
  59                 put_device(dev);
  60         }
  61         up(&dpm_list_sem);
  62 }
  63
  64
  65 /**
  66  *      device_resume - Restore state of each device in system.
  67  *
  68  *      Walk the dpm_off list, remove each entry, resume the device,
  69  *      then add it to the dpm_active list.
  70  */
  71
  72 void device_resume(void)
  73 {
  74         down(&dpm_sem);
  75         dpm_resume();
  76         up(&dpm_sem);
  77 }
  78
  79 EXPORT_SYMBOL_GPL(device_resume);
  80
  81
  82 /**
  83  *      device_power_up_irq - Power on some devices.
  84  *
  85  *      Walk the dpm_off_irq list and power each device up. This
  86  *      is used for devices that required they be powered down with
  87  *      interrupts disabled. As devices are powered on, they are moved to
  88  *      the dpm_suspended list.
  89  *
  90  *      Interrupts must be disabled when calling this.
  91  */
  92
  93 void dpm_power_up(void)
  94 {
  95         while(!list_empty(&dpm_off_irq)) {
  96                 struct list_head * entry = dpm_off_irq.next;
  97                 struct device * dev = to_device(entry);
  98
  99                 get_device(dev);
 100                 list_del_init(entry);
 101                 list_add_tail(entry, &dpm_active);
 102                 resume_device(dev);
 103                 put_device(dev);
 104         }
 105 }
 106
 107
 108 /**
 109  *      device_pm_power_up - Turn on all devices that need special attention.
 110  *
 111  *      Power on system devices then devices that required we shut them down
 112  *      with interrupts disabled.
 113  *      Called with interrupts disabled.
 114  */
 115
 116 void device_power_up(void)
 117 {
 118         sysdev_resume();
 119         dpm_power_up();
 120 }
 121
 122 EXPORT_SYMBOL_GPL(device_power_up);
 123
 124