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 #include <linux/kallsyms.h>
  24
  25 #include "power.h"
  26
  27 enum {
  28         DEBUG_USER_STATE = 1U << 0,
  29         DEBUG_SUSPEND = 1U << 2,
  30 };
  31 #ifdef DEBUG
  32 static int debug_mask = DEBUG_USER_STATE | DEBUG_SUSPEND;
  33 #else
  34 static int debug_mask = DEBUG_USER_STATE;
  35 #endif
  36 module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
  37
  38 static DEFINE_MUTEX(early_suspend_lock);
  39 static LIST_HEAD(early_suspend_handlers);
  40 static void early_suspend(struct work_struct *work);
  41 static void late_resume(struct work_struct *work);
  42 static DECLARE_WORK(early_suspend_work, early_suspend);
  43 static DECLARE_WORK(late_resume_work, late_resume);
  44 static DEFINE_SPINLOCK(state_lock);
  45 enum {
  46         SUSPEND_REQUESTED = 0x1,
  47         SUSPENDED = 0x2,
  48         SUSPEND_REQUESTED_AND_SUSPENDED = SUSPEND_REQUESTED | SUSPENDED,
  49 };
  50 static int state;
  51
  52 void register_early_suspend(struct early_suspend *handler)
  53 {
  54         struct list_head *pos;
  55
  56         mutex_lock(&early_suspend_lock);
  57         list_for_each(pos, &early_suspend_handlers) {
  58                 struct early_suspend *e;
  59                 e = list_entry(pos, struct early_suspend, link);
  60                 if (e->level > handler->level)
  61                         break;
  62         }
  63         list_add_tail(&handler->link, pos);
  64         if ((state & SUSPENDED) && handler->suspend)
  65                 handler->suspend(handler);
  66         mutex_unlock(&early_suspend_lock);
  67 }
  68 EXPORT_SYMBOL(register_early_suspend);
  69
  70 void unregister_early_suspend(struct early_suspend *handler)
  71 {
  72         mutex_lock(&early_suspend_lock);
  73         list_del(&handler->link);
  74         mutex_unlock(&early_suspend_lock);
  75 }
  76 EXPORT_SYMBOL(unregister_early_suspend);
  77
  78 static void early_suspend(struct work_struct *work)
  79 {
  80         struct early_suspend *pos;
  81         unsigned long irqflags;
  82         int abort = 0;
  83
  84         mutex_lock(&early_suspend_lock);
  85         spin_lock_irqsave(&state_lock, irqflags);
  86         if (state == SUSPEND_REQUESTED)
  87                 state |= SUSPENDED;
  88         else
  89                 abort = 1;
  90         spin_unlock_irqrestore(&state_lock, irqflags);
  91
  92         if (abort) {
  93                 if (debug_mask & DEBUG_SUSPEND)
  94                         pr_info("early_suspend: abort, state %d\n", state);
  95                 mutex_unlock(&early_suspend_lock);
  96                 goto abort;
  97         }
  98
  99         if (debug_mask & DEBUG_SUSPEND)
 100                 pr_info("early_suspend: call handlers\n");
 101         list_for_each_entry(pos, &early_suspend_handlers, link) {
 102                 if (debug_mask & DEBUG_SUSPEND)
 103                         print_symbol("early_suspend: call %s\n", (unsigned long)pos->suspend);
 104                 if (pos->suspend != NULL)
 105                         pos->suspend(pos);
 106         }
 107         mutex_unlock(&early_suspend_lock);
 108
 109         if (debug_mask & DEBUG_SUSPEND)
 110                 pr_info("early_suspend: sync\n");
 111
 112         sys_sync();
 113 abort:
 114         spin_lock_irqsave(&state_lock, irqflags);
 115         if (state == SUSPEND_REQUESTED_AND_SUSPENDED)
 116                 wake_unlock(&main_wake_lock);
 117         spin_unlock_irqrestore(&state_lock, irqflags);
 118 }
 119
 120 static void late_resume(struct work_struct *work)
 121 {
 122         struct early_suspend *pos;
 123         unsigned long irqflags;
 124         int abort = 0;
 125
 126         mutex_lock(&early_suspend_lock);
 127         spin_lock_irqsave(&state_lock, irqflags);
 128         if (state == SUSPENDED)
 129                 state &= ~SUSPENDED;
 130         else
 131                 abort = 1;
 132         spin_unlock_irqrestore(&state_lock, irqflags);
 133
 134         if (abort) {
 135                 if (debug_mask & DEBUG_SUSPEND)
 136                         pr_info("late_resume: abort, state %d\n", state);
 137                 goto abort;
 138         }
 139         if (debug_mask & DEBUG_SUSPEND)
 140                 pr_info("late_resume: call handlers\n");
 141         list_for_each_entry_reverse(pos, &early_suspend_handlers, link) {
 142                 if (debug_mask & DEBUG_SUSPEND)
 143                         print_symbol("late_resume: call %s\n", (unsigned long)pos->resume);
 144                 if (pos->resume != NULL)
 145                         pos->resume(pos);
 146         }
 147         if (debug_mask & DEBUG_SUSPEND)
 148                 pr_info("late_resume: done\n");
 149 abort:
 150         mutex_unlock(&early_suspend_lock);
 151 }
 152
 153 void request_suspend_state(suspend_state_t new_state)
 154 {
 155         unsigned long irqflags;
 156         int old_sleep;
 157
 158         spin_lock_irqsave(&state_lock, irqflags);
 159         old_sleep = state & SUSPEND_REQUESTED;
 160         if (debug_mask & DEBUG_USER_STATE) {
 161                 struct timespec ts;
 162                 struct rtc_time tm;
 163                 getnstimeofday(&ts);
 164                 rtc_time_to_tm(ts.tv_sec, &tm);
 165                 pr_info("request_suspend_state: %s (%d->%d) at %lld "
 166                         "(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n",
 167                         new_state != PM_SUSPEND_ON ? "sleep" : "wakeup",
 168                         requested_suspend_state, new_state,
 169                         ktime_to_ns(ktime_get()),
 170                         tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 171                         tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
 172         }
 173         if (!old_sleep && new_state != PM_SUSPEND_ON) {
 174                 state |= SUSPEND_REQUESTED;
 175                 queue_work(suspend_work_queue, &early_suspend_work);
 176         } else if (old_sleep && new_state == PM_SUSPEND_ON) {
 177                 state &= ~SUSPEND_REQUESTED;
 178                 wake_lock(&main_wake_lock);
 179                 queue_work(suspend_work_queue, &late_resume_work);
 180         }
 181         requested_suspend_state = new_state;
 182         spin_unlock_irqrestore(&state_lock, irqflags);
 183 }
 184
 185 suspend_state_t get_suspend_state(void)
 186 {
 187         return requested_suspend_state;
 188 }