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         if (dev->class && dev->class->resume) {
  42                 dev_dbg(dev,"class resume\n");
  43                 error = dev->class->resume(dev);
  44         }
  45         up(&dev->sem);
  46         TRACE_RESUME(error);
  47         return error;
  48 }
  49
  50
  51 static int resume_device_early(struct device * dev)
  52 {
  53         int error = 0;
  54
  55         TRACE_DEVICE(dev);
  56         TRACE_RESUME(0);
  57         if (dev->bus && dev->bus->resume_early) {
  58                 dev_dbg(dev,"EARLY resume\n");
  59                 error = dev->bus->resume_early(dev);
  60         }
  61         TRACE_RESUME(error);
  62         return error;
  63 }
  64
  65 /*
  66  * Resume the devices that have either not gone through
  67  * the late suspend, or that did go through it but also
  68  * went through the early resume
  69  */
  70 void dpm_resume(void)
  71 {
  72         down(&dpm_list_sem);
  73         while(!list_empty(&dpm_off)) {
  74                 struct list_head * entry = dpm_off.next;
  75                 struct device * dev = to_device(entry);
  76
  77                 get_device(dev);
  78                 list_move_tail(entry, &dpm_active);
  79
  80                 up(&dpm_list_sem);
  81                 if (!dev->power.prev_state.event)
  82                         resume_device(dev);
  83                 down(&dpm_list_sem);
  84                 put_device(dev);
  85         }
  86         up(&dpm_list_sem);
  87 }
  88
  89
  90 /**
  91  *      device_resume - Restore state of each device in system.
  92  *
  93  *      Walk the dpm_off list, remove each entry, resume the device,
  94  *      then add it to the dpm_active list.
  95  */
  96
  97 void device_resume(void)
  98 {
  99         might_sleep();
 100         down(&dpm_sem);
 101         dpm_resume();
 102         up(&dpm_sem);
 103 }
 104
 105 EXPORT_SYMBOL_GPL(device_resume);
 106
 107
 108 /**
 109  *      dpm_power_up - Power on some devices.
 110  *
 111  *      Walk the dpm_off_irq list and power each device up. This
 112  *      is used for devices that required they be powered down with
 113  *      interrupts disabled. As devices are powered on, they are moved
 114  *      to the dpm_active list.
 115  *
 116  *      Interrupts must be disabled when calling this.
 117  */
 118
 119 void dpm_power_up(void)
 120 {
 121         while(!list_empty(&dpm_off_irq)) {
 122                 struct list_head * entry = dpm_off_irq.next;
 123                 struct device * dev = to_device(entry);
 124
 125                 list_move_tail(entry, &dpm_off);
 126                 resume_device_early(dev);
 127         }
 128 }
 129
 130
 131 /**
 132  *      device_power_up - Turn on all devices that need special attention.
 133  *
 134  *      Power on system devices then devices that required we shut them down
 135  *      with interrupts disabled.
 136  *      Called with interrupts disabled.
 137  */
 138
 139 void device_power_up(void)
 140 {
 141         sysdev_resume();
 142         dpm_power_up();
 143 }
 144
 145 EXPORT_SYMBOL_GPL(device_power_up);
 146
 147