PM: Implement wakelock api.

PM: wakelock: Replace expire work with a timer

The expire work function did not work in the normal case.

Signed-off-by: Arve Hjønnevåg <arve@android.com>

4 files changed, 629 insertions, 0 deletions

diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 87f4d24..1c04e80 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -18,6 +18,25 @@ config SUSPEND_FREEZER
 
 	  Turning OFF this setting is NOT recommended! If in doubt, say Y.
 
+config HAS_WAKELOCK
+	bool
+
+config WAKELOCK
+	bool "Wake lock"
+	depends on PM && RTC_CLASS
+	default n
+	select HAS_WAKELOCK
+	---help---
+	  Enable wakelocks. When user space request a sleep state the
+	  sleep request will be delayed until no wake locks are held.
+
+config WAKELOCK_STAT
+	bool "Wake lock stats"
+	depends on WAKELOCK
+	default y
+	---help---
+	  Report wake lock stats in /proc/wakelocks
+
 config HIBERNATE_CALLBACKS
 	bool
 
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index c5ebc6a..e58fcac 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -8,5 +8,6 @@ obj-$(CONFIG_SUSPEND)		+= suspend.o
 obj-$(CONFIG_PM_TEST_SUSPEND)	+= suspend_test.o
 obj-$(CONFIG_HIBERNATION)	+= hibernate.o snapshot.o swap.o user.o \
 				   block_io.o
+obj-$(CONFIG_WAKELOCK)		+= wakelock.o
 
 obj-$(CONFIG_MAGIC_SYSRQ)	+= poweroff.o
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 9a00a0a..a48dd02 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -245,3 +245,10 @@ static inline void suspend_thaw_processes(void)
 {
 }
 #endif
+
+#ifdef CONFIG_WAKELOCK
+/* kernel/power/wakelock.c */
+extern struct workqueue_struct *suspend_work_queue;
+extern struct wake_lock main_wake_lock;
+extern suspend_state_t requested_suspend_state;
+#endif
diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c
new file mode 100644
index 0000000..b24eb75
--- /dev/null
+++ b/kernel/power/wakelock.c
@@ -0,0 +1,602 @@
+/* kernel/power/wakelock.c
+ *
+ * Copyright (C) 2005-2008 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/suspend.h>
+#include <linux/syscalls.h> /* sys_sync */
+#include <linux/wakelock.h>
+#ifdef CONFIG_WAKELOCK_STAT
+#include <linux/proc_fs.h>
+#endif
+#include "power.h"
+
+enum {
+	DEBUG_EXIT_SUSPEND = 1U << 0,
+	DEBUG_WAKEUP = 1U << 1,
+	DEBUG_SUSPEND = 1U << 2,
+	DEBUG_EXPIRE = 1U << 3,
+	DEBUG_WAKE_LOCK = 1U << 4,
+};
+static int debug_mask = DEBUG_EXIT_SUSPEND | DEBUG_WAKEUP;
+module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+#define WAKE_LOCK_TYPE_MASK              (0x0f)
+#define WAKE_LOCK_INITIALIZED            (1U << 8)
+#define WAKE_LOCK_ACTIVE                 (1U << 9)
+#define WAKE_LOCK_AUTO_EXPIRE            (1U << 10)
+#define WAKE_LOCK_PREVENTING_SUSPEND     (1U << 11)
+
+static DEFINE_SPINLOCK(list_lock);
+static LIST_HEAD(inactive_locks);
+static struct list_head active_wake_locks[WAKE_LOCK_TYPE_COUNT];
+static int current_event_num;
+struct workqueue_struct *suspend_work_queue;
+struct wake_lock main_wake_lock;
+suspend_state_t requested_suspend_state = PM_SUSPEND_MEM;
+static struct wake_lock unknown_wakeup;
+
+#ifdef CONFIG_WAKELOCK_STAT
+static struct wake_lock deleted_wake_locks;
+static ktime_t last_sleep_time_update;
+static int wait_for_wakeup;
+
+int get_expired_time(struct wake_lock *lock, ktime_t *expire_time)
+{
+	struct timespec ts;
+	struct timespec kt;
+	struct timespec tomono;
+	struct timespec delta;
+	unsigned long seq;
+	long timeout;
+
+	if (!(lock->flags & WAKE_LOCK_AUTO_EXPIRE))
+		return 0;
+	do {
+		seq = read_seqbegin(&xtime_lock);
+		timeout = lock->expires - jiffies;
+		if (timeout > 0)
+			return 0;
+		kt = current_kernel_time();
+		tomono = wall_to_monotonic;
+	} while (read_seqretry(&xtime_lock, seq));
+	jiffies_to_timespec(-timeout, &delta);
+	set_normalized_timespec(&ts, kt.tv_sec + tomono.tv_sec - delta.tv_sec,
+				kt.tv_nsec + tomono.tv_nsec - delta.tv_nsec);
+	*expire_time = timespec_to_ktime(ts);
+	return 1;
+}
+
+
+static int print_lock_stat(char *buf, struct wake_lock *lock)
+{
+	int lock_count = lock->stat.count;
+	int expire_count = lock->stat.expire_count;
+	ktime_t active_time = ktime_set(0, 0);
+	ktime_t total_time = lock->stat.total_time;
+	ktime_t max_time = lock->stat.max_time;
+	ktime_t prevent_suspend_time = lock->stat.prevent_suspend_time;
+	if (lock->flags & WAKE_LOCK_ACTIVE) {
+		ktime_t now, add_time;
+		int expired = get_expired_time(lock, &now);
+		if (!expired)
+			now = ktime_get();
+		add_time = ktime_sub(now, lock->stat.last_time);
+		lock_count++;
+		if (!expired)
+			active_time = add_time;
+		else
+			expire_count++;
+		total_time = ktime_add(total_time, add_time);
+		if (lock->flags & WAKE_LOCK_PREVENTING_SUSPEND)
+			prevent_suspend_time = ktime_add(prevent_suspend_time,
+					ktime_sub(now, last_sleep_time_update));
+		if (add_time.tv64 > max_time.tv64)
+			max_time = add_time;
+	}
+
+	return sprintf(buf, "\"%s\"\t%d\t%d\t%d\t%lld\t%lld\t%lld\t%lld\t"
+		       "%lld\n", lock->name, lock_count, expire_count,
+		       lock->stat.wakeup_count, ktime_to_ns(active_time),
+		       ktime_to_ns(total_time),
+		       ktime_to_ns(prevent_suspend_time), ktime_to_ns(max_time),
+		       ktime_to_ns(lock->stat.last_time));
+}
+
+
+static int wakelocks_read_proc(char *page, char **start, off_t off,
+			       int count, int *eof, void *data)
+{
+	unsigned long irqflags;
+	struct wake_lock *lock;
+	int len = 0;
+	char *p = page;
+	int type;
+
+	spin_lock_irqsave(&list_lock, irqflags);
+
+	p += sprintf(p, "name\tcount\texpire_count\twake_count\tactive_since"
+		     "\ttotal_time\tsleep_time\tmax_time\tlast_change\n");
+	list_for_each_entry(lock, &inactive_locks, link) {
+		p += print_lock_stat(p, lock);
+	}
+	for (type = 0; type < WAKE_LOCK_TYPE_COUNT; type++) {
+		list_for_each_entry(lock, &active_wake_locks[type], link)
+			p += print_lock_stat(p, lock);
+	}
+	spin_unlock_irqrestore(&list_lock, irqflags);
+
+	*start = page + off;
+
+	len = p - page;
+	if (len > off)
+		len -= off;
+	else
+		len = 0;
+
+	return len < count ? len  : count;
+}
+
+static void wake_unlock_stat_locked(struct wake_lock *lock, int expired)
+{
+	ktime_t duration;
+	ktime_t now;
+	if (!(lock->flags & WAKE_LOCK_ACTIVE))
+		return;
+	if (get_expired_time(lock, &now))
+		expired = 1;
+	else
+		now = ktime_get();
+	lock->stat.count++;
+	if (expired)
+		lock->stat.expire_count++;
+	duration = ktime_sub(now, lock->stat.last_time);
+	lock->stat.total_time = ktime_add(lock->stat.total_time, duration);
+	if (ktime_to_ns(duration) > ktime_to_ns(lock->stat.max_time))
+		lock->stat.max_time = duration;
+	lock->stat.last_time = ktime_get();
+	if (lock->flags & WAKE_LOCK_PREVENTING_SUSPEND) {
+		duration = ktime_sub(now, last_sleep_time_update);
+		lock->stat.prevent_suspend_time = ktime_add(
+			lock->stat.prevent_suspend_time, duration);
+		lock->flags &= ~WAKE_LOCK_PREVENTING_SUSPEND;
+	}
+}
+
+static void update_sleep_wait_stats_locked(int done)
+{
+	struct wake_lock *lock;
+	ktime_t now, etime, elapsed, add;
+	int expired;
+
+	now = ktime_get();
+	elapsed = ktime_sub(now, last_sleep_time_update);
+	list_for_each_entry(lock, &active_wake_locks[WAKE_LOCK_SUSPEND], link) {
+		expired = get_expired_time(lock, &etime);
+		if (lock->flags & WAKE_LOCK_PREVENTING_SUSPEND) {
+			if (expired)
+				add = ktime_sub(etime, last_sleep_time_update);
+			else
+				add = elapsed;
+			lock->stat.prevent_suspend_time = ktime_add(
+				lock->stat.prevent_suspend_time, add);
+		}
+		if (done || expired)
+			lock->flags &= ~WAKE_LOCK_PREVENTING_SUSPEND;
+		else
+			lock->flags |= WAKE_LOCK_PREVENTING_SUSPEND;
+	}
+	last_sleep_time_update = now;
+}
+#endif
+
+
+static void expire_wake_lock(struct wake_lock *lock)
+{
+#ifdef CONFIG_WAKELOCK_STAT
+	wake_unlock_stat_locked(lock, 1);
+#endif
+	lock->flags &= ~(WAKE_LOCK_ACTIVE | WAKE_LOCK_AUTO_EXPIRE);
+	list_del(&lock->link);
+	list_add(&lock->link, &inactive_locks);
+	if (debug_mask & (DEBUG_WAKE_LOCK | DEBUG_EXPIRE))
+		pr_info("expired wake lock %s\n", lock->name);
+}
+
+static void print_active_locks(int type)
+{
+	unsigned long irqflags;
+	struct wake_lock *lock;
+
+	BUG_ON(type >= WAKE_LOCK_TYPE_COUNT);
+	spin_lock_irqsave(&list_lock, irqflags);
+	list_for_each_entry(lock, &active_wake_locks[type], link) {
+		if (lock->flags & WAKE_LOCK_AUTO_EXPIRE) {
+			long timeout = lock->expires - jiffies;
+			if (timeout <= 0)
+				pr_info("wake lock %s, expired\n", lock->name);
+			else
+				pr_info("active wake lock %s, time left %ld\n",
+					lock->name, timeout);
+		} else
+			pr_info("active wake lock %s\n", lock->name);
+	}
+	spin_unlock_irqrestore(&list_lock, irqflags);
+}
+
+static long has_wake_lock_locked(int type)
+{
+	struct wake_lock *lock, *n;
+	long max_timeout = 0;
+
+	BUG_ON(type >= WAKE_LOCK_TYPE_COUNT);
+	list_for_each_entry_safe(lock, n, &active_wake_locks[type], link) {
+		if (lock->flags & WAKE_LOCK_AUTO_EXPIRE) {
+			long timeout = lock->expires - jiffies;
+			if (timeout <= 0)
+				expire_wake_lock(lock);
+			else if (timeout > max_timeout)
+				max_timeout = timeout;
+		} else
+			return -1;
+	}
+	return max_timeout;
+}
+
+long has_wake_lock(int type)
+{
+	long ret;
+	unsigned long irqflags;
+	spin_lock_irqsave(&list_lock, irqflags);
+	ret = has_wake_lock_locked(type);
+	spin_unlock_irqrestore(&list_lock, irqflags);
+	return ret;
+}
+
+static void suspend(struct work_struct *work)
+{
+	int ret;
+	int entry_event_num;
+
+	if (has_wake_lock(WAKE_LOCK_SUSPEND)) {
+		if (debug_mask & DEBUG_SUSPEND)
+			pr_info("suspend: abort suspend\n");
+		return;
+	}
+
+	entry_event_num = current_event_num;
+	sys_sync();
+	if (debug_mask & DEBUG_SUSPEND)
+		pr_info("suspend: enter suspend\n");
+	ret = pm_suspend(requested_suspend_state);
+	if (debug_mask & DEBUG_EXIT_SUSPEND) {
+		struct timespec ts;
+		struct rtc_time tm;
+		getnstimeofday(&ts);
+		rtc_time_to_tm(ts.tv_sec, &tm);
+		pr_info("suspend: exit suspend, ret = %d "
+			"(%d-%02d-%02d %02d:%02d:%02d.%09lu UTC)\n", ret,
+			tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+			tm.tm_hour, tm.tm_min, tm.tm_sec, ts.tv_nsec);
+	}
+	if (current_event_num == entry_event_num) {
+		if (debug_mask & DEBUG_SUSPEND)
+			pr_info("suspend: pm_suspend returned with no event\n");
+		wake_lock_timeout(&unknown_wakeup, HZ / 2);
+	}
+}
+static DECLARE_WORK(suspend_work, suspend);
+
+static void expire_wake_locks(unsigned long data)
+{
+	long has_lock;
+	unsigned long irqflags;
+	if (debug_mask & DEBUG_EXPIRE)
+		pr_info("expire_wake_locks: start\n");
+	if (debug_mask & DEBUG_SUSPEND)
+		print_active_locks(WAKE_LOCK_SUSPEND);
+	spin_lock_irqsave(&list_lock, irqflags);
+	has_lock = has_wake_lock_locked(WAKE_LOCK_SUSPEND);
+	if (debug_mask & DEBUG_EXPIRE)
+		pr_info("expire_wake_locks: done, has_lock %ld\n", has_lock);
+	if (has_lock == 0)
+		queue_work(suspend_work_queue, &suspend_work);
+	spin_unlock_irqrestore(&list_lock, irqflags);
+}
+static DEFINE_TIMER(expire_timer, expire_wake_locks, 0, 0);
+
+static int power_suspend_late(struct device *dev)
+{
+	int ret = has_wake_lock(WAKE_LOCK_SUSPEND) ? -EAGAIN : 0;
+#ifdef CONFIG_WAKELOCK_STAT
+	wait_for_wakeup = 1;
+#endif
+	if (debug_mask & DEBUG_SUSPEND)
+		pr_info("power_suspend_late return %d\n", ret);
+	return ret;
+}
+
+static struct dev_pm_ops power_driver_pm_ops = {
+	.suspend_noirq = power_suspend_late,
+};
+
+static struct platform_driver power_driver = {
+	.driver.name = "power",
+	.driver.pm = &power_driver_pm_ops,
+};
+static struct platform_device power_device = {
+	.name = "power",
+};
+
+void wake_lock_init(struct wake_lock *lock, int type, const char *name)
+{
+	unsigned long irqflags = 0;
+
+	if (name)
+		lock->name = name;
+	BUG_ON(!lock->name);
+
+	if (debug_mask & DEBUG_WAKE_LOCK)
+		pr_info("wake_lock_init name=%s\n", lock->name);
+#ifdef CONFIG_WAKELOCK_STAT
+	lock->stat.count = 0;
+	lock->stat.expire_count = 0;
+	lock->stat.wakeup_count = 0;
+	lock->stat.total_time = ktime_set(0, 0);
+	lock->stat.prevent_suspend_time = ktime_set(0, 0);
+	lock->stat.max_time = ktime_set(0, 0);
+	lock->stat.last_time = ktime_set(0, 0);
+#endif
+	lock->flags = (type & WAKE_LOCK_TYPE_MASK) | WAKE_LOCK_INITIALIZED;
+
+	INIT_LIST_HEAD(&lock->link);
+	spin_lock_irqsave(&list_lock, irqflags);
+	list_add(&lock->link, &inactive_locks);
+	spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(wake_lock_init);
+
+void wake_lock_destroy(struct wake_lock *lock)
+{
+	unsigned long irqflags;
+	if (debug_mask & DEBUG_WAKE_LOCK)
+		pr_info("wake_lock_destroy name=%s\n", lock->name);
+	spin_lock_irqsave(&list_lock, irqflags);
+	lock->flags &= ~WAKE_LOCK_INITIALIZED;
+#ifdef CONFIG_WAKELOCK_STAT
+	if (lock->stat.count) {
+		deleted_wake_locks.stat.count += lock->stat.count;
+		deleted_wake_locks.stat.expire_count += lock->stat.expire_count;
+		deleted_wake_locks.stat.total_time =
+			ktime_add(deleted_wake_locks.stat.total_time,
+				  lock->stat.total_time);
+		deleted_wake_locks.stat.prevent_suspend_time =
+			ktime_add(deleted_wake_locks.stat.prevent_suspend_time,
+				  lock->stat.prevent_suspend_time);
+		deleted_wake_locks.stat.max_time =
+			ktime_add(deleted_wake_locks.stat.max_time,
+				  lock->stat.max_time);
+	}
+#endif
+	list_del(&lock->link);
+	spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(wake_lock_destroy);
+
+static void wake_lock_internal(
+	struct wake_lock *lock, long timeout, int has_timeout)
+{
+	int type;
+	unsigned long irqflags;
+	long expire_in;
+
+	spin_lock_irqsave(&list_lock, irqflags);
+	type = lock->flags & WAKE_LOCK_TYPE_MASK;
+	BUG_ON(type >= WAKE_LOCK_TYPE_COUNT);
+	BUG_ON(!(lock->flags & WAKE_LOCK_INITIALIZED));
+#ifdef CONFIG_WAKELOCK_STAT
+	if (type == WAKE_LOCK_SUSPEND && wait_for_wakeup) {
+		if (debug_mask & DEBUG_WAKEUP)
+			pr_info("wakeup wake lock: %s\n", lock->name);
+		wait_for_wakeup = 0;
+		lock->stat.wakeup_count++;
+	}
+	if ((lock->flags & WAKE_LOCK_AUTO_EXPIRE) &&
+	    (long)(lock->expires - jiffies) <= 0) {
+		wake_unlock_stat_locked(lock, 0);
+		lock->stat.last_time = ktime_get();
+	}
+#endif
+	if (!(lock->flags & WAKE_LOCK_ACTIVE)) {
+		lock->flags |= WAKE_LOCK_ACTIVE;
+#ifdef CONFIG_WAKELOCK_STAT
+		lock->stat.last_time = ktime_get();
+#endif
+	}
+	list_del(&lock->link);
+	if (has_timeout) {
+		if (debug_mask & DEBUG_WAKE_LOCK)
+			pr_info("wake_lock: %s, type %d, timeout %ld.%03lu\n",
+				lock->name, type, timeout / HZ,
+				(timeout % HZ) * MSEC_PER_SEC / HZ);
+		lock->expires = jiffies + timeout;
+		lock->flags |= WAKE_LOCK_AUTO_EXPIRE;
+		list_add_tail(&lock->link, &active_wake_locks[type]);
+	} else {
+		if (debug_mask & DEBUG_WAKE_LOCK)
+			pr_info("wake_lock: %s, type %d\n", lock->name, type);
+		lock->expires = LONG_MAX;
+		lock->flags &= ~WAKE_LOCK_AUTO_EXPIRE;
+		list_add(&lock->link, &active_wake_locks[type]);
+	}
+	if (type == WAKE_LOCK_SUSPEND) {
+		current_event_num++;
+#ifdef CONFIG_WAKELOCK_STAT
+		if (lock == &main_wake_lock)
+			update_sleep_wait_stats_locked(1);
+		else if (!wake_lock_active(&main_wake_lock))
+			update_sleep_wait_stats_locked(0);
+#endif
+		if (has_timeout)
+			expire_in = has_wake_lock_locked(type);
+		else
+			expire_in = -1;
+		if (expire_in > 0) {
+			if (debug_mask & DEBUG_EXPIRE)
+				pr_info("wake_lock: %s, start expire timer, "
+					"%ld\n", lock->name, expire_in);
+			mod_timer(&expire_timer, jiffies + expire_in);
+		} else {
+			if (del_timer(&expire_timer))
+				if (debug_mask & DEBUG_EXPIRE)
+					pr_info("wake_lock: %s, stop expire timer\n",
+						lock->name);
+			if (expire_in == 0)
+				queue_work(suspend_work_queue, &suspend_work);
+		}
+	}
+	spin_unlock_irqrestore(&list_lock, irqflags);
+}
+
+void wake_lock(struct wake_lock *lock)
+{
+	wake_lock_internal(lock, 0, 0);
+}
+EXPORT_SYMBOL(wake_lock);
+
+void wake_lock_timeout(struct wake_lock *lock, long timeout)
+{
+	wake_lock_internal(lock, timeout, 1);
+}
+EXPORT_SYMBOL(wake_lock_timeout);
+
+void wake_unlock(struct wake_lock *lock)
+{
+	int type;
+	unsigned long irqflags;
+	spin_lock_irqsave(&list_lock, irqflags);
+	type = lock->flags & WAKE_LOCK_TYPE_MASK;
+#ifdef CONFIG_WAKELOCK_STAT
+	wake_unlock_stat_locked(lock, 0);
+#endif
+	if (debug_mask & DEBUG_WAKE_LOCK)
+		pr_info("wake_unlock: %s\n", lock->name);
+	lock->flags &= ~(WAKE_LOCK_ACTIVE | WAKE_LOCK_AUTO_EXPIRE);
+	list_del(&lock->link);
+	list_add(&lock->link, &inactive_locks);
+	if (type == WAKE_LOCK_SUSPEND) {
+		long has_lock = has_wake_lock_locked(type);
+		if (has_lock > 0) {
+			if (debug_mask & DEBUG_EXPIRE)
+				pr_info("wake_unlock: %s, start expire timer, "
+					"%ld\n", lock->name, has_lock);
+			mod_timer(&expire_timer, jiffies + has_lock);
+		} else {
+			if (del_timer(&expire_timer))
+				if (debug_mask & DEBUG_EXPIRE)
+					pr_info("wake_unlock: %s, stop expire "
+						"timer\n", lock->name);
+			if (has_lock == 0)
+				queue_work(suspend_work_queue, &suspend_work);
+		}
+		if (lock == &main_wake_lock) {
+			if (debug_mask & DEBUG_SUSPEND)
+				print_active_locks(WAKE_LOCK_SUSPEND);
+#ifdef CONFIG_WAKELOCK_STAT
+			update_sleep_wait_stats_locked(0);
+#endif
+		}
+	}
+	spin_unlock_irqrestore(&list_lock, irqflags);
+}
+EXPORT_SYMBOL(wake_unlock);
+
+int wake_lock_active(struct wake_lock *lock)
+{
+	return !!(lock->flags & WAKE_LOCK_ACTIVE);
+}
+EXPORT_SYMBOL(wake_lock_active);
+
+static int __init wakelocks_init(void)
+{
+	int ret;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(active_wake_locks); i++)
+		INIT_LIST_HEAD(&active_wake_locks[i]);
+
+#ifdef CONFIG_WAKELOCK_STAT
+	wake_lock_init(&deleted_wake_locks, WAKE_LOCK_SUSPEND,
+			"deleted_wake_locks");
+#endif
+	wake_lock_init(&main_wake_lock, WAKE_LOCK_SUSPEND, "main");
+	wake_lock(&main_wake_lock);
+	wake_lock_init(&unknown_wakeup, WAKE_LOCK_SUSPEND, "unknown_wakeups");
+
+	ret = platform_device_register(&power_device);
+	if (ret) {
+		pr_err("wakelocks_init: platform_device_register failed\n");
+		goto err_platform_device_register;
+	}
+	ret = platform_driver_register(&power_driver);
+	if (ret) {
+		pr_err("wakelocks_init: platform_driver_register failed\n");
+		goto err_platform_driver_register;
+	}
+
+	suspend_work_queue = create_singlethread_workqueue("suspend");
+	if (suspend_work_queue == NULL) {
+		ret = -ENOMEM;
+		goto err_suspend_work_queue;
+	}
+
+#ifdef CONFIG_WAKELOCK_STAT
+	create_proc_read_entry("wakelocks", S_IRUGO, NULL,
+				wakelocks_read_proc, NULL);
+#endif
+
+	return 0;
+
+err_suspend_work_queue:
+	platform_driver_unregister(&power_driver);
+err_platform_driver_register:
+	platform_device_unregister(&power_device);
+err_platform_device_register:
+	wake_lock_destroy(&unknown_wakeup);
+	wake_lock_destroy(&main_wake_lock);
+#ifdef CONFIG_WAKELOCK_STAT
+	wake_lock_destroy(&deleted_wake_locks);
+#endif
+	return ret;
+}
+
+static void  __exit wakelocks_exit(void)
+{
+#ifdef CONFIG_WAKELOCK_STAT
+	remove_proc_entry("wakelocks", NULL);
+#endif
+	destroy_workqueue(suspend_work_queue);
+	platform_driver_unregister(&power_driver);
+	platform_device_unregister(&power_device);
+	wake_lock_destroy(&unknown_wakeup);
+	wake_lock_destroy(&main_wake_lock);
+#ifdef CONFIG_WAKELOCK_STAT
+	wake_lock_destroy(&deleted_wake_locks);
+#endif
+}
+
+core_initcall(wakelocks_init);
+module_exit(wakelocks_exit);