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         pr_info("[R] early_suspend start\n");
  80         mutex_lock(&early_suspend_lock);
  81         spin_lock_irqsave(&state_lock, irqflags);
  82         if (state == SUSPEND_REQUESTED)
  83                 state |= SUSPENDED;
  84         else
  85                 abort = 1;
  86         spin_unlock_irqrestore(&state_lock, irqflags);
  87
  88         if (abort) {
  89                 if (debug_mask & DEBUG_SUSPEND)
  90                         pr_info("early_suspend: abort, state %d\n", state);
  91                 mutex_unlock(&early_suspend_lock);
  92                 goto abort;
  93         }
  94
  95         if (debug_mask & DEBUG_SUSPEND)
  96                 pr_info("early_suspend: call handlers\n");
  97         list_for_each_entry(pos, &early_suspend_handlers, link) {
  98                 if (pos->suspend != NULL)
  99                         pos->suspend(pos);
 100         }
 101         mutex_unlock(&early_suspend_lock);
 102
 103         if (debug_mask & DEBUG_SUSPEND)
 104                 pr_info("early_suspend: sync\n");
 105
 106         pr_info("[R] early_suspend: sync\n");
 107         sys_sync();
 108 abort:
 109         spin_lock_irqsave(&state_lock, irqflags);
 110         if (state == SUSPEND_REQUESTED_AND_SUSPENDED)
 111                 wake_unlock(&main_wake_lock);
 112         spin_unlock_irqrestore(&state_lock, irqflags);
 113         pr_info("[R] early_suspend end\n");
 114 }
 115
 116 static void late_resume(struct work_struct *work)
 117 {
 118         struct early_suspend *pos;
 119         unsigned long irqflags;
 120         int abort = 0;
 121
 122         pr_info("[R] late_resume start\n");
 123         mutex_lock(&early_suspend_lock);
 124         spin_lock_irqsave(&state_lock, irqflags);
 125         if (state == SUSPENDED)
 126                 state &= ~SUSPENDED;
 127         else
 128                 abort = 1;
 129         spin_unlock_irqrestore(&state_lock, irqflags);
 130
 131         if (abort) {
 132                 if (debug_mask & DEBUG_SUSPEND)
 133                         pr_info("late_resume: abort, state %d\n", state);
 134                 goto abort;
 135         }
 136         if (debug_mask & DEBUG_SUSPEND)
 137                 pr_info("late_resume: call handlers\n");
 138         list_for_each_entry_reverse(pos, &early_suspend_handlers, link)
 139                 if (pos->resume != NULL)
 140                         pos->resume(pos);
 141         if (debug_mask & DEBUG_SUSPEND)
 142                 pr_info("late_resume: done\n");
 143 abort:
 144         mutex_unlock(&early_suspend_lock);
 145         pr_info("[R] late_resume end\n");
 146 }
 147
 148 void request_suspend_state(suspend_state_t new_state)
 149 {
 150         unsigned long irqflags;
 151         int old_sleep;
 152
 153         spin_lock_irqsave(&state_lock, irqflags);
 154         old_sleep = state & SUSPEND_REQUESTED;
 155         if (debug_mask & DEBUG_USER_STATE) {
 156                 struct timespec ts;
 157                 struct rtc_time tm;
 158                 getnstimeofday(&ts);
 159                 rtc_time_to_tm(ts.tv_sec, &tm);
 160                 pr_info("request_suspend_state: %s (%d->%d) at %lld "
 161                         "(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n",
 162                         new_state != PM_SUSPEND_ON ? "sleep" : "wakeup",
 163                         requested_suspend_state, new_state,
 164                         ktime_to_ns(ktime_get()),
 165                         tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 166                         tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
 167         }
 168         if (!old_sleep && new_state != PM_SUSPEND_ON) {
 169                 state |= SUSPEND_REQUESTED;
 170                 queue_work(suspend_work_queue, &early_suspend_work);
 171         } else if (old_sleep && new_state == PM_SUSPEND_ON) {
 172                 state &= ~SUSPEND_REQUESTED;
 173                 wake_lock(&main_wake_lock);
 174                 queue_work(suspend_work_queue, &late_resume_work);
 175         }
 176         requested_suspend_state = new_state;
 177         spin_unlock_irqrestore(&state_lock, irqflags);
 178 }
 179
 180 suspend_state_t get_suspend_state(void)
 181 {
 182         return requested_suspend_state;
 183 }