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 <linux/resume-trace.h>
  13 #include "../base.h"
  14 #include "power.h"
  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         TRACE_DEVICE(dev);
  28         TRACE_RESUME(0);
  29         down(&dev->sem);
  30         if (dev->power.pm_parent
  31                         && dev->power.pm_parent->power.power_state.event) {
  32                 dev_err(dev, "PM: resume from %d, parent %s still %d\n",
  33                         dev->power.power_state.event,
  34                         dev->power.pm_parent->bus_id,
  35                         dev->power.pm_parent->power.power_state.event);
  36         }
  37         if (dev->bus && dev->bus->resume) {
  38                 dev_dbg(dev,"resuming\n");
  39                 error = dev->bus->resume(dev);
  40         }
  41         up(&dev->sem);
  42         TRACE_RESUME(error);
  43         return error;
  44 }
  45
  46
  47
  48 void dpm_resume(void)
  49 {
  50         down(&dpm_list_sem);
  51         while(!list_empty(&dpm_off)) {
  52                 struct list_head * entry = dpm_off.next;
  53                 struct device * dev = to_device(entry);
  54
  55                 get_device(dev);
  56                 list_move_tail(entry, &dpm_active);
  57
  58                 up(&dpm_list_sem);
  59                 if (!dev->power.prev_state.event)
  60                         resume_device(dev);
  61                 down(&dpm_list_sem);
  62                 put_device(dev);
  63         }
  64         up(&dpm_list_sem);
  65 }
  66
  67
  68 /**
  69  *      device_resume - Restore state of each device in system.
  70  *
  71  *      Walk the dpm_off list, remove each entry, resume the device,
  72  *      then add it to the dpm_active list.
  73  */
  74
  75 void device_resume(void)
  76 {
  77         down(&dpm_sem);
  78         dpm_resume();
  79         up(&dpm_sem);
  80 }
  81
  82 EXPORT_SYMBOL_GPL(device_resume);
  83
  84
  85 /**
  86  *      device_power_up_irq - Power on some devices.
  87  *
  88  *      Walk the dpm_off_irq list and power each device up. This
  89  *      is used for devices that required they be powered down with
  90  *      interrupts disabled. As devices are powered on, they are moved to
  91  *      the dpm_suspended list.
  92  *
  93  *      Interrupts must be disabled when calling this.
  94  */
  95
  96 void dpm_power_up(void)
  97 {
  98         while(!list_empty(&dpm_off_irq)) {
  99                 struct list_head * entry = dpm_off_irq.next;
 100                 struct device * dev = to_device(entry);
 101
 102                 get_device(dev);
 103                 list_move_tail(entry, &dpm_active);
 104                 resume_device(dev);
 105                 put_device(dev);
 106         }
 107 }
 108
 109
 110 /**
 111  *      device_pm_power_up - Turn on all devices that need special attention.
 112  *
 113  *      Power on system devices then devices that required we shut them down
 114  *      with interrupts disabled.
 115  *      Called with interrupts disabled.
 116  */
 117
 118 void device_power_up(void)
 119 {
 120         sysdev_resume();
 121         dpm_power_up();
 122 }
 123
 124 EXPORT_SYMBOL_GPL(device_power_up);
 125
 126