84bed51dcdce79503d718186775e690560d4637b
[linux-2.6.git] / 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 }