kernel/power/earlysuspend.c

   1 /* kernel/power/earlysuspend.c
   2  *
   3  * Copyright (C) 2005-2008 Google, Inc.
   4  *
   5  * This software is licensed under the terms of the GNU General Public
   6  * License version 2, as published by the Free Software Foundation, and
   7  * may be copied, distributed, and modified under those terms.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15
  16 #include <linux/earlysuspend.h>
  17 #include <linux/module.h>
  18 #include <linux/mutex.h>
  19 #include <linux/rtc.h>
  20 #include <linux/syscalls.h> /* sys_sync */
  21 #include <linux/wakelock.h>
  22 #include <linux/workqueue.h>
  23
  24 #include "power.h"
  25
  26 enum {
  27         DEBUG_USER_STATE = 1U << 0,
  28         DEBUG_SUSPEND = 1U << 2,
  29 };
  30 static int debug_mask = DEBUG_USER_STATE;
  31 module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
  32
  33 static DEFINE_MUTEX(early_suspend_lock);
  34 static LIST_HEAD(early_suspend_handlers);
  35 static void early_suspend(struct work_struct *work);
  36 static void late_resume(struct work_struct *work);
  37 static DECLARE_WORK(early_suspend_work, early_suspend);
  38 static DECLARE_WORK(late_resume_work, late_resume);
  39 static DEFINE_SPINLOCK(state_lock);
  40 enum {
  41         SUSPEND_REQUESTED = 0x1,
  42         SUSPENDED = 0x2,
  43         SUSPEND_REQUESTED_AND_SUSPENDED = SUSPEND_REQUESTED | SUSPENDED,
  44 };
  45 static int state;
  46
  47 void register_early_suspend(struct early_suspend *handler)
  48 {
  49         struct list_head *pos;
  50
  51         mutex_lock(&early_suspend_lock);
  52         list_for_each(pos, &early_suspend_handlers) {
  53                 struct early_suspend *e;
  54                 e = list_entry(pos, struct early_suspend, link);
  55                 if (e->level > handler->level)
  56                         break;
  57         }
  58         list_add_tail(&handler->link, pos);
  59         if ((state & SUSPENDED) && handler->suspend)
  60                 handler->suspend(handler);
  61         mutex_unlock(&early_suspend_lock);
  62 }
  63 EXPORT_SYMBOL(register_early_suspend);
  64
  65 void unregister_early_suspend(struct early_suspend *handler)
  66 {
  67         mutex_lock(&early_suspend_lock);
  68         list_del(&handler->link);
  69         mutex_unlock(&early_suspend_lock);
  70 }
  71 EXPORT_SYMBOL(unregister_early_suspend);
  72
  73 static void early_suspend(struct work_struct *work)
  74 {
  75         struct early_suspend *pos;
  76         unsigned long irqflags;
  77         int abort = 0;
  78
  79         mutex_lock(&early_suspend_lock);
  80         spin_lock_irqsave(&state_lock, irqflags);
  81         if (state == SUSPEND_REQUESTED)
  82                 state |= SUSPENDED;
  83         else
  84                 abort = 1;
  85         spin_unlock_irqrestore(&state_lock, irqflags);
  86
  87         if (abort) {
  88                 if (debug_mask & DEBUG_SUSPEND)
  89                         pr_info("early_suspend: abort, state %d\n", state);
  90                 mutex_unlock(&early_suspend_lock);
  91                 goto abort;
  92         }
  93
  94         if (debug_mask & DEBUG_SUSPEND)
  95                 pr_info("early_suspend: call handlers\n");
  96         list_for_each_entry(pos, &early_suspend_handlers, link) {
  97                 if (pos->suspend != NULL)
  98                         pos->suspend(pos);
  99         }
 100         mutex_unlock(&early_suspend_lock);
 101
 102         if (debug_mask & DEBUG_SUSPEND)
 103                 pr_info("early_suspend: sync\n");
 104
 105         sys_sync();
 106 abort:
 107         spin_lock_irqsave(&state_lock, irqflags);
 108         if (state == SUSPEND_REQUESTED_AND_SUSPENDED)
 109                 wake_unlock(&main_wake_lock);
 110         spin_unlock_irqrestore(&state_lock, irqflags);
 111 }
 112
 113 static void late_resume(struct work_struct *work)
 114 {
 115         struct early_suspend *pos;
 116         unsigned long irqflags;
 117         int abort = 0;
 118
 119         mutex_lock(&early_suspend_lock);
 120         spin_lock_irqsave(&state_lock, irqflags);
 121         if (state == SUSPENDED)
 122                 state &= ~SUSPENDED;
 123         else
 124                 abort = 1;
 125         spin_unlock_irqrestore(&state_lock, irqflags);
 126
 127         if (abort) {
 128                 if (debug_mask & DEBUG_SUSPEND)
 129                         pr_info("late_resume: abort, state %d\n", state);
 130                 goto abort;
 131         }
 132         if (debug_mask & DEBUG_SUSPEND)
 133                 pr_info("late_resume: call handlers\n");
 134         list_for_each_entry_reverse(pos, &early_suspend_handlers, link)
 135                 if (pos->resume != NULL)
 136                         pos->resume(pos);
 137         if (debug_mask & DEBUG_SUSPEND)
 138                 pr_info("late_resume: done\n");
 139 abort:
 140         mutex_unlock(&early_suspend_lock);
 141 }
 142
 143 void request_suspend_state(suspend_state_t new_state)
 144 {
 145         unsigned long irqflags;
 146         int old_sleep;
 147
 148         spin_lock_irqsave(&state_lock, irqflags);
 149         old_sleep = state & SUSPEND_REQUESTED;
 150         if (debug_mask & DEBUG_USER_STATE) {
 151                 struct timespec ts;
 152                 struct rtc_time tm;
 153                 getnstimeofday(&ts);
 154                 rtc_time_to_tm(ts.tv_sec, &tm);
 155                 pr_info("request_suspend_state: %s (%d->%d) at %lld "
 156                         "(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n",
 157                         new_state != PM_SUSPEND_ON ? "sleep" : "wakeup",
 158                         requested_suspend_state, new_state,
 159                         ktime_to_ns(ktime_get()),
 160                         tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 161                         tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
 162         }
 163         if (!old_sleep && new_state != PM_SUSPEND_ON) {
 164                 state |= SUSPEND_REQUESTED;
 165                 queue_work(suspend_work_queue, &early_suspend_work);
 166         } else if (old_sleep && new_state == PM_SUSPEND_ON) {
 167                 state &= ~SUSPEND_REQUESTED;
 168                 wake_lock(&main_wake_lock);
 169                 queue_work(suspend_work_queue, &late_resume_work);
 170         }
 171         requested_suspend_state = new_state;
 172         spin_unlock_irqrestore(&state_lock, irqflags);
 173 }
 174
 175 suspend_state_t get_suspend_state(void)
 176 {
 177         return requested_suspend_state;
 178 }