rtc: alarm: Add in-kernel alarm interface

Drivers can now create alarms that will use an hrtimer while the
system is running and the rtc to wake up from suspend.

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

4 files changed, 638 insertions, 325 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 7f1abd6949e8..411c83d391ff 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -113,9 +113,17 @@ config RTC_INTF_ALARM
 	help
 	  Provides non-wakeup and rtc backed wakeup alarms based on rtc or
 	  elapsed realtime, and a non-wakeup alarm on the monotonic clock.
-	  Also provides an ioctl to set the wall time which must be used
+	  Also provides an interface to set the wall time which must be used
 	  for elapsed realtime to work.
 
+config RTC_INTF_ALARM_DEV
+	bool "Android alarm device"
+	depends on RTC_INTF_ALARM
+	default y
+	help
+	  Exports the alarm interface to user-space.
+
+
 config RTC_DRV_TEST
 	tristate "Test driver/device"
 	help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 0ea84a0612a8..9a4882ed8b47 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -9,7 +9,8 @@ obj-$(CONFIG_RTC_HCTOSYS)	+= hctosys.o
 obj-$(CONFIG_RTC_CLASS)		+= rtc-core.o
 rtc-core-y			:= class.o interface.o
 
-rtc-core-$(CONFIG_RTC_INTF_ALARM) += alarm.o
+obj-$(CONFIG_RTC_INTF_ALARM) += alarm.o
+obj-$(CONFIG_RTC_INTF_ALARM_DEV) += alarm-dev.o
 rtc-core-$(CONFIG_RTC_INTF_DEV)	+= rtc-dev.o
 rtc-core-$(CONFIG_RTC_INTF_PROC) += rtc-proc.o
 rtc-core-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o
diff --git a/drivers/rtc/alarm-dev.c b/drivers/rtc/alarm-dev.c
new file mode 100644
index 000000000000..686e6f7ed480
--- /dev/null
+++ b/drivers/rtc/alarm-dev.c
@@ -0,0 +1,286 @@
+/* drivers/rtc/alarm-dev.c
+ *
+ * Copyright (C) 2007-2009 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 <asm/mach/time.h>
+#include <linux/android_alarm.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/sysdev.h>
+#include <linux/uaccess.h>
+#include <linux/wakelock.h>
+
+#define ANDROID_ALARM_PRINT_INFO (1U << 0)
+#define ANDROID_ALARM_PRINT_IO (1U << 1)
+#define ANDROID_ALARM_PRINT_INT (1U << 2)
+
+static int debug_mask = ANDROID_ALARM_PRINT_INFO;
+module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+#define pr_alarm(debug_level_mask, args...) \
+	do { \
+		if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) { \
+			pr_info(args); \
+		} \
+	} while (0)
+
+#define ANDROID_ALARM_WAKEUP_MASK ( \
+	ANDROID_ALARM_RTC_WAKEUP_MASK | \
+	ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
+
+/* support old usespace code */
+#define ANDROID_ALARM_SET_OLD               _IOW('a', 2, time_t) /* set alarm */
+#define ANDROID_ALARM_SET_AND_WAIT_OLD      _IOW('a', 3, time_t)
+
+static int alarm_opened;
+static DEFINE_SPINLOCK(alarm_slock);
+static struct wake_lock alarm_wake_lock;
+static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
+static uint32_t alarm_pending;
+static uint32_t alarm_enabled;
+static uint32_t wait_pending;
+
+static struct alarm alarms[ANDROID_ALARM_TYPE_COUNT];
+
+static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	int rv = 0;
+	unsigned long flags;
+	struct timespec new_alarm_time;
+	struct timespec new_rtc_time;
+	struct timespec tmp_time;
+	enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
+	uint32_t alarm_type_mask = 1U << alarm_type;
+
+	if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
+		return -EINVAL;
+
+	if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
+		if ((file->f_flags & O_ACCMODE) == O_RDONLY)
+			return -EPERM;
+		if (file->private_data == NULL &&
+		    cmd != ANDROID_ALARM_SET_RTC) {
+			spin_lock_irqsave(&alarm_slock, flags);
+			if (alarm_opened) {
+				spin_unlock_irqrestore(&alarm_slock, flags);
+				return -EBUSY;
+			}
+			alarm_opened = 1;
+			file->private_data = (void *)1;
+			spin_unlock_irqrestore(&alarm_slock, flags);
+		}
+	}
+
+	switch (ANDROID_ALARM_BASE_CMD(cmd)) {
+	case ANDROID_ALARM_CLEAR(0):
+		spin_lock_irqsave(&alarm_slock, flags);
+		pr_alarm(IO, "alarm %d clear\n", alarm_type);
+		alarm_try_to_cancel(&alarms[alarm_type]);
+		if (alarm_pending) {
+			alarm_pending &= ~alarm_type_mask;
+			if (!alarm_pending && !wait_pending)
+				wake_unlock(&alarm_wake_lock);
+		}
+		alarm_enabled &= ~alarm_type_mask;
+		spin_unlock_irqrestore(&alarm_slock, flags);
+		break;
+
+	case ANDROID_ALARM_SET_OLD:
+	case ANDROID_ALARM_SET_AND_WAIT_OLD:
+		if (get_user(new_alarm_time.tv_sec, (int __user *)arg)) {
+			rv = -EFAULT;
+			goto err1;
+		}
+		new_alarm_time.tv_nsec = 0;
+		goto from_old_alarm_set;
+
+	case ANDROID_ALARM_SET_AND_WAIT(0):
+	case ANDROID_ALARM_SET(0):
+		if (copy_from_user(&new_alarm_time, (void __user *)arg,
+		    sizeof(new_alarm_time))) {
+			rv = -EFAULT;
+			goto err1;
+		}
+from_old_alarm_set:
+		spin_lock_irqsave(&alarm_slock, flags);
+		pr_alarm(IO, "alarm %d set %ld.%09ld\n", alarm_type,
+			new_alarm_time.tv_sec, new_alarm_time.tv_nsec);
+		alarm_enabled |= alarm_type_mask;
+		alarm_start_range(&alarms[alarm_type],
+			timespec_to_ktime(new_alarm_time),
+			timespec_to_ktime(new_alarm_time));
+		spin_unlock_irqrestore(&alarm_slock, flags);
+		if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_SET_AND_WAIT(0)
+		    && cmd != ANDROID_ALARM_SET_AND_WAIT_OLD)
+			break;
+		/* fall though */
+	case ANDROID_ALARM_WAIT:
+		spin_lock_irqsave(&alarm_slock, flags);
+		pr_alarm(IO, "alarm wait\n");
+		if (!alarm_pending && wait_pending) {
+			wake_unlock(&alarm_wake_lock);
+			wait_pending = 0;
+		}
+		spin_unlock_irqrestore(&alarm_slock, flags);
+		rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
+		if (rv)
+			goto err1;
+		spin_lock_irqsave(&alarm_slock, flags);
+		rv = alarm_pending;
+		wait_pending = 1;
+		alarm_pending = 0;
+		spin_unlock_irqrestore(&alarm_slock, flags);
+		break;
+	case ANDROID_ALARM_SET_RTC:
+		if (copy_from_user(&new_rtc_time, (void __user *)arg,
+		    sizeof(new_rtc_time))) {
+			rv = -EFAULT;
+			goto err1;
+		}
+		rv = alarm_set_rtc(new_rtc_time);
+		spin_lock_irqsave(&alarm_slock, flags);
+		alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
+		wake_up(&alarm_wait_queue);
+		spin_unlock_irqrestore(&alarm_slock, flags);
+		if (rv < 0)
+			goto err1;
+		break;
+	case ANDROID_ALARM_GET_TIME(0):
+		switch (alarm_type) {
+		case ANDROID_ALARM_RTC_WAKEUP:
+		case ANDROID_ALARM_RTC:
+			getnstimeofday(&tmp_time);
+			break;
+		case ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP:
+		case ANDROID_ALARM_ELAPSED_REALTIME:
+			tmp_time =
+				ktime_to_timespec(alarm_get_elapsed_realtime());
+			break;
+		case ANDROID_ALARM_TYPE_COUNT:
+		case ANDROID_ALARM_SYSTEMTIME:
+			ktime_get_ts(&tmp_time);
+			break;
+		}
+		if (copy_to_user((void __user *)arg, &tmp_time,
+		    sizeof(tmp_time))) {
+			rv = -EFAULT;
+			goto err1;
+		}
+		break;
+
+	default:
+		rv = -EINVAL;
+		goto err1;
+	}
+err1:
+	return rv;
+}
+
+static int alarm_open(struct inode *inode, struct file *file)
+{
+	file->private_data = NULL;
+	return 0;
+}
+
+static int alarm_release(struct inode *inode, struct file *file)
+{
+	int i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&alarm_slock, flags);
+	if (file->private_data != 0) {
+		for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
+			uint32_t alarm_type_mask = 1U << i;
+			if (alarm_enabled & alarm_type_mask) {
+				pr_alarm(INFO, "alarm_release: clear alarm, "
+					"pending %d\n",
+					!!(alarm_pending & alarm_type_mask));
+				alarm_enabled &= ~alarm_type_mask;
+			}
+			spin_unlock_irqrestore(&alarm_slock, flags);
+			alarm_cancel(&alarms[i]);
+			spin_lock_irqsave(&alarm_slock, flags);
+		}
+		if (alarm_pending | wait_pending) {
+			if (alarm_pending)
+				pr_alarm(INFO, "alarm_release: clear "
+					"pending alarms %x\n", alarm_pending);
+			wake_unlock(&alarm_wake_lock);
+			wait_pending = 0;
+			alarm_pending = 0;
+		}
+		alarm_opened = 0;
+	}
+	spin_unlock_irqrestore(&alarm_slock, flags);
+	return 0;
+}
+
+static void alarm_triggered(struct alarm *alarm)
+{
+	unsigned long flags;
+	uint32_t alarm_type_mask = 1U << alarm->type;
+
+	pr_alarm(INT, "alarm_triggered type %d\n", alarm->type);
+	spin_lock_irqsave(&alarm_slock, flags);
+	if (alarm_enabled & alarm_type_mask) {
+		wake_lock_timeout(&alarm_wake_lock, 5 * HZ);
+		alarm_enabled &= ~alarm_type_mask;
+		alarm_pending |= alarm_type_mask;
+		wake_up(&alarm_wait_queue);
+	}
+	spin_unlock_irqrestore(&alarm_slock, flags);
+}
+
+static const struct file_operations alarm_fops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = alarm_ioctl,
+	.open = alarm_open,
+	.release = alarm_release,
+};
+
+static struct miscdevice alarm_device = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "alarm",
+	.fops = &alarm_fops,
+};
+
+static int __init alarm_dev_init(void)
+{
+	int err;
+	int i;
+
+	err = misc_register(&alarm_device);
+	if (err)
+		return err;
+
+	for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++)
+		alarm_init(&alarms[i], i, alarm_triggered);
+	wake_lock_init(&alarm_wake_lock, WAKE_LOCK_SUSPEND, "alarm");
+
+	return 0;
+}
+
+static void  __exit alarm_dev_exit(void)
+{
+	misc_deregister(&alarm_device);
+	wake_lock_destroy(&alarm_wake_lock);
+}
+
+module_init(alarm_dev_init);
+module_exit(alarm_dev_exit);
+
diff --git a/drivers/rtc/alarm.c b/drivers/rtc/alarm.c
index cd660eee3b27..18492fded494 100644
--- a/drivers/rtc/alarm.c
+++ b/drivers/rtc/alarm.c
@@ -1,6 +1,6 @@
 /* drivers/rtc/alarm.c
  *
- * Copyright (C) 2007 Google, Inc.
+ * Copyright (C) 2007-2009 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
@@ -24,24 +24,24 @@
 #include <linux/sysdev.h>
 #include <linux/wakelock.h>
 
-#define ANDROID_ALARM_PRINT_ERRORS (1U << 0)
+#define ANDROID_ALARM_PRINT_ERROR (1U << 0)
 #define ANDROID_ALARM_PRINT_INIT_STATUS (1U << 1)
-#define ANDROID_ALARM_PRINT_INFO (1U << 2)
-#define ANDROID_ALARM_PRINT_IO (1U << 3)
-#define ANDROID_ALARM_PRINT_INT (1U << 4)
-#define ANDROID_ALARM_PRINT_FLOW (1U << 5)
-
-#if 0
-#define ANDROID_ALARM_DPRINTF_MASK (~0)
-#define ANDROID_ALARM_DPRINTF(debug_level_mask, args...) \
+#define ANDROID_ALARM_PRINT_TSET (1U << 2)
+#define ANDROID_ALARM_PRINT_CALL (1U << 3)
+#define ANDROID_ALARM_PRINT_SUSPEND (1U << 4)
+#define ANDROID_ALARM_PRINT_INT (1U << 5)
+#define ANDROID_ALARM_PRINT_FLOW (1U << 6)
+
+static int debug_mask = ANDROID_ALARM_PRINT_ERROR | \
+			ANDROID_ALARM_PRINT_INIT_STATUS;
+module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+#define pr_alarm(debug_level_mask, args...) \
 	do { \
-		if (ANDROID_ALARM_DPRINTF_MASK & debug_level_mask) { \
-			printk(args); \
+		if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) { \
+			pr_info(args); \
 		} \
 	} while (0)
-#else
-#define ANDROID_ALARM_DPRINTF(args...)
-#endif
 
 #define ANDROID_ALARM_WAKEUP_MASK ( \
 	ANDROID_ALARM_RTC_WAKEUP_MASK | \
@@ -51,264 +51,307 @@
 #define ANDROID_ALARM_SET_OLD               _IOW('a', 2, time_t) /* set alarm */
 #define ANDROID_ALARM_SET_AND_WAIT_OLD      _IOW('a', 3, time_t)
 
+struct alarm_queue {
+	struct rb_root alarms;
+	struct rb_node *first;
+	struct hrtimer timer;
+	ktime_t delta;
+	bool stopped;
+	ktime_t stopped_time;
+};
+
 static struct rtc_device *alarm_rtc_dev;
-static int alarm_opened;
 static DEFINE_SPINLOCK(alarm_slock);
 static DEFINE_MUTEX(alarm_setrtc_mutex);
-static struct wake_lock alarm_wake_lock;
 static struct wake_lock alarm_rtc_wake_lock;
-static DECLARE_WAIT_QUEUE_HEAD(alarm_wait_queue);
-static uint32_t alarm_pending;
-static uint32_t alarm_enabled;
-static uint32_t wait_pending;
 static struct platform_device *alarm_platform_dev;
-static struct hrtimer alarm_timer[ANDROID_ALARM_TYPE_COUNT];
-static struct timespec alarm_time[ANDROID_ALARM_TYPE_COUNT];
-static struct timespec elapsed_rtc_delta;
+struct alarm_queue alarms[ANDROID_ALARM_TYPE_COUNT];
+static bool suspended;
 
-static void alarm_start_hrtimer(enum android_alarm_type alarm_type)
+static void update_timer_locked(struct alarm_queue *base, bool head_removed)
 {
-	struct timespec hr_alarm_time;
-	if (!(alarm_enabled & (1U << alarm_type)))
+	struct alarm *alarm;
+	bool is_wakeup = base == &alarms[ANDROID_ALARM_RTC_WAKEUP] ||
+			base == &alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP];
+
+	if (base->stopped) {
+		pr_alarm(FLOW, "changed alarm while setting the wall time\n");
+		return;
+	}
+
+	if (is_wakeup && !suspended && head_removed)
+		wake_unlock(&alarm_rtc_wake_lock);
+
+	if (!base->first)
 		return;
-	hr_alarm_time = alarm_time[alarm_type];
-	if (alarm_type == ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP ||
-	    alarm_type == ANDROID_ALARM_ELAPSED_REALTIME)
-		set_normalized_timespec(&hr_alarm_time,
-			hr_alarm_time.tv_sec + elapsed_rtc_delta.tv_sec,
-			hr_alarm_time.tv_nsec + elapsed_rtc_delta.tv_nsec);
-	ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_FLOW,
-		"alarm start hrtimer %d at %ld.%09ld\n",
-		alarm_type, hr_alarm_time.tv_sec, hr_alarm_time.tv_nsec);
-	hrtimer_start(&alarm_timer[alarm_type],
-		      timespec_to_ktime(hr_alarm_time), HRTIMER_MODE_ABS);
+
+	alarm = container_of(base->first, struct alarm, node);
+
+	pr_alarm(FLOW, "selected alarm, type %d, func %pF at %lld\n",
+		alarm->type, alarm->function, ktime_to_ns(alarm->expires));
+
+	if (is_wakeup && suspended) {
+		pr_alarm(FLOW, "changed alarm while suspened\n");
+		wake_lock_timeout(&alarm_rtc_wake_lock, 1 * HZ);
+		return;
+	}
+
+	hrtimer_try_to_cancel(&base->timer);
+	base->timer.node.expires = ktime_add(base->delta, alarm->expires);
+	base->timer._softexpires = ktime_add(base->delta, alarm->softexpires);
+	hrtimer_start_expires(&base->timer, HRTIMER_MODE_ABS);
 }
 
-static long alarm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+static void alarm_enqueue_locked(struct alarm *alarm)
 {
-	int rv = 0;
-	unsigned long flags;
-	int i;
-	struct timespec new_alarm_time;
-	struct timespec new_rtc_time;
-	struct timespec tmp_time;
-	struct rtc_time rtc_new_rtc_time;
-	enum android_alarm_type alarm_type = ANDROID_ALARM_IOCTL_TO_TYPE(cmd);
-	uint32_t alarm_type_mask = 1U << alarm_type;
-
-	if (alarm_type >= ANDROID_ALARM_TYPE_COUNT)
-		return -EINVAL;
+	struct alarm_queue *base = &alarms[alarm->type];
+	struct rb_node **link = &base->alarms.rb_node;
+	struct rb_node *parent = NULL;
+	struct alarm *entry;
+	int leftmost = 1;
+
+	pr_alarm(FLOW, "added alarm, type %d, func %pF at %lld\n",
+		alarm->type, alarm->function, ktime_to_ns(alarm->expires));
+
+	if (base->first == &alarm->node)
+		base->first = rb_next(&alarm->node);
+	if (!RB_EMPTY_NODE(&alarm->node)) {
+		rb_erase(&alarm->node, &base->alarms);
+		RB_CLEAR_NODE(&alarm->node);
+	}
 
-	if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_GET_TIME(0)) {
-		if ((file->f_flags & O_ACCMODE) == O_RDONLY)
-			return -EPERM;
-		if (file->private_data == NULL &&
-		    cmd != ANDROID_ALARM_SET_RTC) {
-			spin_lock_irqsave(&alarm_slock, flags);
-			if (alarm_opened) {
-				spin_unlock_irqrestore(&alarm_slock, flags);
-				return -EBUSY;
-			}
-			alarm_opened = 1;
-			file->private_data = (void *)1;
-			spin_unlock_irqrestore(&alarm_slock, flags);
+	while (*link) {
+		parent = *link;
+		entry = rb_entry(parent, struct alarm, node);
+		/*
+		* We dont care about collisions. Nodes with
+		* the same expiry time stay together.
+		*/
+		if (alarm->expires.tv64 < entry->expires.tv64) {
+			link = &(*link)->rb_left;
+		} else {
+			link = &(*link)->rb_right;
+			leftmost = 0;
 		}
 	}
+	if (leftmost) {
+		base->first = &alarm->node;
+		update_timer_locked(base, false);
+	}
 
-	switch (ANDROID_ALARM_BASE_CMD(cmd)) {
-	case ANDROID_ALARM_CLEAR(0):
-		spin_lock_irqsave(&alarm_slock, flags);
-		ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_IO,
-				      "alarm %d clear\n", alarm_type);
-		hrtimer_try_to_cancel(&alarm_timer[alarm_type]);
-		if (alarm_pending) {
-			alarm_pending &= ~alarm_type_mask;
-			if (!alarm_pending && !wait_pending)
-				wake_unlock(&alarm_wake_lock);
-		}
-		alarm_enabled &= ~alarm_type_mask;
-		spin_unlock_irqrestore(&alarm_slock, flags);
-		break;
+	rb_link_node(&alarm->node, parent, link);
+	rb_insert_color(&alarm->node, &base->alarms);
+}
 
-	case ANDROID_ALARM_SET_OLD:
-	case ANDROID_ALARM_SET_AND_WAIT_OLD:
-		if (get_user(new_alarm_time.tv_sec, (int __user *)arg)) {
-			rv = -EFAULT;
-			goto err1;
-		}
-		new_alarm_time.tv_nsec = 0;
-		goto from_old_alarm_set;
-
-	case ANDROID_ALARM_SET_AND_WAIT(0):
-	case ANDROID_ALARM_SET(0):
-		if (copy_from_user(&new_alarm_time, (void __user *)arg,
-		    sizeof(new_alarm_time))) {
-			rv = -EFAULT;
-			goto err1;
-		}
-from_old_alarm_set:
-		spin_lock_irqsave(&alarm_slock, flags);
-		ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_IO,
-			"alarm %d set %ld.%09ld\n", alarm_type,
-			new_alarm_time.tv_sec, new_alarm_time.tv_nsec);
-		alarm_time[alarm_type] = new_alarm_time;
-		alarm_enabled |= alarm_type_mask;
-		alarm_start_hrtimer(alarm_type);
-		spin_unlock_irqrestore(&alarm_slock, flags);
-		if (ANDROID_ALARM_BASE_CMD(cmd) != ANDROID_ALARM_SET_AND_WAIT(0)
-		    && cmd != ANDROID_ALARM_SET_AND_WAIT_OLD)
-			break;
-		/* fall though */
-	case ANDROID_ALARM_WAIT:
-		spin_lock_irqsave(&alarm_slock, flags);
-		ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_IO, "alarm wait\n");
-		if (!alarm_pending && wait_pending) {
-			wake_unlock(&alarm_wake_lock);
-			wait_pending = 0;
-		}
-		spin_unlock_irqrestore(&alarm_slock, flags);
-		rv = wait_event_interruptible(alarm_wait_queue, alarm_pending);
-		if (rv)
-			goto err1;
-		spin_lock_irqsave(&alarm_slock, flags);
-		rv = alarm_pending;
-		wait_pending = 1;
-		alarm_pending = 0;
-		if (rv & ANDROID_ALARM_WAKEUP_MASK)
-			wake_unlock(&alarm_rtc_wake_lock);
-		spin_unlock_irqrestore(&alarm_slock, flags);
-		break;
-	case ANDROID_ALARM_SET_RTC:
-		if (copy_from_user(&new_rtc_time, (void __user *)arg,
-		    sizeof(new_rtc_time))) {
-			rv = -EFAULT;
-			goto err1;
-		}
-		rtc_time_to_tm(new_rtc_time.tv_sec, &rtc_new_rtc_time);
+/**
+ * alarm_init - initialize an alarm
+ * @alarm:	the alarm to be initialized
+ * @type:	the alarm type to be used
+ * @function:	alarm callback function
+ */
+void alarm_init(struct alarm *alarm,
+	enum android_alarm_type type, void (*function)(struct alarm *))
+{
+	RB_CLEAR_NODE(&alarm->node);
+	alarm->type = type;
+	alarm->function = function;
 
-		ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_IO,
-			"set rtc %ld %ld - rtc %02d:%02d:%02d %02d/%02d/%04d\n",
-			new_rtc_time.tv_sec, new_rtc_time.tv_nsec,
-			rtc_new_rtc_time.tm_hour, rtc_new_rtc_time.tm_min,
-			rtc_new_rtc_time.tm_sec, rtc_new_rtc_time.tm_mon + 1,
-			rtc_new_rtc_time.tm_mday,
-			rtc_new_rtc_time.tm_year + 1900);
+	pr_alarm(FLOW, "created alarm, type %d, func %pF\n", type, function);
+}
 
-		mutex_lock(&alarm_setrtc_mutex);
-		spin_lock_irqsave(&alarm_slock, flags);
-		for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++)
-			hrtimer_try_to_cancel(&alarm_timer[i]);
-		getnstimeofday(&tmp_time);
-		elapsed_rtc_delta = timespec_sub(elapsed_rtc_delta,
-					timespec_sub(tmp_time, new_rtc_time));
-		spin_unlock_irqrestore(&alarm_slock, flags);
-		rv = do_settimeofday(&new_rtc_time);
-		spin_lock_irqsave(&alarm_slock, flags);
-		for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++)
-			alarm_start_hrtimer(i);
-		spin_unlock_irqrestore(&alarm_slock, flags);
-		if (rv < 0) {
-			ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_ERRORS,
-					      "Failed to set time\n");
-			mutex_unlock(&alarm_setrtc_mutex);
-			goto err1;
-		}
-		rv = rtc_set_time(alarm_rtc_dev, &rtc_new_rtc_time);
-		spin_lock_irqsave(&alarm_slock, flags);
-		alarm_pending |= ANDROID_ALARM_TIME_CHANGE_MASK;
-		wake_up(&alarm_wait_queue);
-		spin_unlock_irqrestore(&alarm_slock, flags);
-		mutex_unlock(&alarm_setrtc_mutex);
-		if (rv < 0) {
-			ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_ERRORS,
-			    "Failed to set RTC, time will be lost on reboot\n");
-			goto err1;
-		}
-		break;
-	case ANDROID_ALARM_GET_TIME(0):
-		mutex_lock(&alarm_setrtc_mutex);
-		spin_lock_irqsave(&alarm_slock, flags);
-		if (alarm_type != ANDROID_ALARM_SYSTEMTIME) {
-			getnstimeofday(&tmp_time);
-			if (alarm_type >= ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP)
-				tmp_time = timespec_sub(tmp_time,
-							elapsed_rtc_delta);
-		} else
-			ktime_get_ts(&tmp_time);
-		spin_unlock_irqrestore(&alarm_slock, flags);
-		mutex_unlock(&alarm_setrtc_mutex);
-		if (copy_to_user((void __user *)arg, &tmp_time,
-		    sizeof(tmp_time))) {
-			rv = -EFAULT;
-			goto err1;
-		}
-		break;
 
-	default:
-		rv = -EINVAL;
-		goto err1;
-	}
-err1:
-	return rv;
+/**
+ * alarm_start_range - (re)start an alarm
+ * @alarm:	the alarm to be added
+ * @start:	earliest expiry time
+ * @end:	expiry time
+ */
+void alarm_start_range(struct alarm *alarm, ktime_t start, ktime_t end)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&alarm_slock, flags);
+	alarm->softexpires = start;
+	alarm->expires = end;
+	alarm_enqueue_locked(alarm);
+	spin_unlock_irqrestore(&alarm_slock, flags);
 }
 
-static int alarm_open(struct inode *inode, struct file *file)
+/**
+ * alarm_try_to_cancel - try to deactivate an alarm
+ * @alarm:	alarm to stop
+ *
+ * Returns:
+ *  0 when the alarm was not active
+ *  1 when the alarm was active
+ * -1 when the alarm may currently be excuting the callback function and
+ *    cannot be stopped (it may also be inactive)
+ */
+int alarm_try_to_cancel(struct alarm *alarm)
 {
-	file->private_data = NULL;
-	return 0;
+	struct alarm_queue *base = &alarms[alarm->type];
+	unsigned long flags;
+	bool first = false;
+	int ret = 0;
+
+	spin_lock_irqsave(&alarm_slock, flags);
+	if (!RB_EMPTY_NODE(&alarm->node)) {
+		pr_alarm(FLOW, "canceled alarm, type %d, func %pF at %lld\n",
+			alarm->type, alarm->function,
+			ktime_to_ns(alarm->expires));
+		ret = 1;
+		if (base->first == &alarm->node) {
+			base->first = rb_next(&alarm->node);
+			first = true;
+		}
+		rb_erase(&alarm->node, &base->alarms);
+		RB_CLEAR_NODE(&alarm->node);
+		if (first)
+			update_timer_locked(base, true);
+	} else
+		pr_alarm(FLOW, "tried to cancel alarm, type %d, func %pF\n",
+			alarm->type, alarm->function);
+	spin_unlock_irqrestore(&alarm_slock, flags);
+	if (!ret && hrtimer_callback_running(&base->timer))
+		ret = -1;
+	return ret;
 }
 
-static int alarm_release(struct inode *inode, struct file *file)
+/**
+ * alarm_cancel - cancel an alarm and wait for the handler to finish.
+ * @alarm:	the alarm to be cancelled
+ *
+ * Returns:
+ *  0 when the alarm was not active
+ *  1 when the alarm was active
+ */
+int alarm_cancel(struct alarm *alarm)
+{
+	for (;;) {
+		int ret = alarm_try_to_cancel(alarm);
+		if (ret >= 0)
+			return ret;
+		cpu_relax();
+	}
+}
+
+/**
+ * alarm_set_rtc - set the kernel and rtc walltime
+ * @new_time:	timespec value containing the new time
+ */
+int alarm_set_rtc(struct timespec new_time)
 {
 	int i;
+	int ret;
 	unsigned long flags;
+	struct rtc_time rtc_new_rtc_time;
+	struct timespec tmp_time;
+
+	rtc_time_to_tm(new_time.tv_sec, &rtc_new_rtc_time);
+
+	pr_alarm(TSET, "set rtc %ld %ld - rtc %02d:%02d:%02d %02d/%02d/%04d\n",
+		new_time.tv_sec, new_time.tv_nsec,
+		rtc_new_rtc_time.tm_hour, rtc_new_rtc_time.tm_min,
+		rtc_new_rtc_time.tm_sec, rtc_new_rtc_time.tm_mon + 1,
+		rtc_new_rtc_time.tm_mday,
+		rtc_new_rtc_time.tm_year + 1900);
 
+	mutex_lock(&alarm_setrtc_mutex);
 	spin_lock_irqsave(&alarm_slock, flags);
-	if (file->private_data != 0) {
-		for (i = 0; i < ANDROID_ALARM_TYPE_COUNT; i++) {
-			uint32_t alarm_type_mask = 1U << i;
-			if (alarm_enabled & alarm_type_mask) {
-				ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_INFO,
-					"alarm_release: clear alarm, "
-					"pending %d\n",
-					!!(alarm_pending & alarm_type_mask));
-				alarm_enabled &= ~alarm_type_mask;
-			}
-			spin_unlock_irqrestore(&alarm_slock, flags);
-			hrtimer_cancel(&alarm_timer[i]);
-			spin_lock_irqsave(&alarm_slock, flags);
-		}
-		if (alarm_pending | wait_pending) {
-			if (alarm_pending)
-				ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_INFO,
-					"alarm_release: clear pending alarms "
-					"%x\n", alarm_pending);
-			wake_unlock(&alarm_wake_lock);
-			wait_pending = 0;
-			alarm_pending = 0;
-		}
-		alarm_opened = 0;
+	wake_lock(&alarm_rtc_wake_lock);
+	getnstimeofday(&tmp_time);
+	for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
+		hrtimer_try_to_cancel(&alarms[i].timer);
+		alarms[i].stopped = true;
+		alarms[i].stopped_time = timespec_to_ktime(tmp_time);
 	}
+	alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].delta =
+		alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta =
+		ktime_sub(alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta,
+			timespec_to_ktime(timespec_sub(tmp_time, new_time)));
 	spin_unlock_irqrestore(&alarm_slock, flags);
-	return 0;
+	ret = do_settimeofday(&new_time);
+	spin_lock_irqsave(&alarm_slock, flags);
+	for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
+		alarms[i].stopped = false;
+		update_timer_locked(&alarms[i], false);
+	}
+	spin_unlock_irqrestore(&alarm_slock, flags);
+	if (ret < 0) {
+		pr_alarm(ERROR, "alarm_set_rtc: Failed to set time\n");
+		goto err;
+	}
+	if (!alarm_rtc_dev) {
+		pr_alarm(ERROR,
+			"alarm_set_rtc: no RTC, time will be lost on reboot\n");
+		goto err;
+	}
+	ret = rtc_set_time(alarm_rtc_dev, &rtc_new_rtc_time);
+	if (ret < 0)
+		pr_alarm(ERROR, "alarm_set_rtc: "
+			"Failed to set RTC, time will be lost on reboot\n");
+err:
+	wake_unlock(&alarm_rtc_wake_lock);
+	mutex_unlock(&alarm_setrtc_mutex);
+	return ret;
 }
 
-static enum hrtimer_restart alarm_timer_triggered(struct hrtimer *timer)
+/**
+ * alarm_get_elapsed_realtime - get the elapsed real time in ktime_t format
+ *
+ * returns the time in ktime_t format
+ */
+ktime_t alarm_get_elapsed_realtime(void)
 {
+	ktime_t now;
 	unsigned long flags;
-	enum android_alarm_type alarm_type = (timer - alarm_timer);
-	uint32_t alarm_type_mask = 1U << alarm_type;
+	struct alarm_queue *base = &alarms[ANDROID_ALARM_ELAPSED_REALTIME];
 
+	spin_lock_irqsave(&alarm_slock, flags);
+	now = base->stopped ? base->stopped_time : ktime_get_real();
+	now = ktime_sub(now, base->delta);
+	spin_unlock_irqrestore(&alarm_slock, flags);
+	return now;
+}
+
+static enum hrtimer_restart alarm_timer_triggered(struct hrtimer *timer)
+{
+	struct alarm_queue *base;
+	struct alarm *alarm;
+	unsigned long flags;
+	ktime_t now;
 
-	ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_INT,
-			      "alarm_timer_triggered type %d\n", alarm_type);
 	spin_lock_irqsave(&alarm_slock, flags);
-	if (alarm_enabled & alarm_type_mask) {
-		wake_lock_timeout(&alarm_wake_lock, 5 * HZ);
-		alarm_enabled &= ~alarm_type_mask;
-		alarm_pending |= alarm_type_mask;
-		wake_up(&alarm_wait_queue);
+
+	base = container_of(timer, struct alarm_queue, timer);
+	now = base->stopped ? base->stopped_time : hrtimer_cb_get_time(timer);
+	now = ktime_sub(now, base->delta);
+
+	pr_alarm(INT, "alarm_timer_triggered type %d at %lld\n",
+		base - alarms, ktime_to_ns(now));
+
+	while (base->first) {
+		alarm = container_of(base->first, struct alarm, node);
+		if (alarm->softexpires.tv64 > now.tv64) {
+			pr_alarm(FLOW, "don't call alarm, %pF, %lld (s %lld)\n",
+				alarm->function, ktime_to_ns(alarm->expires),
+				ktime_to_ns(alarm->softexpires));
+			break;
+		}
+		base->first = rb_next(&alarm->node);
+		rb_erase(&alarm->node, &base->alarms);
+		RB_CLEAR_NODE(&alarm->node);
+		pr_alarm(CALL, "call alarm, type %d, func %pF, %lld (s %lld)\n",
+			alarm->type, alarm->function,
+			ktime_to_ns(alarm->expires),
+			ktime_to_ns(alarm->softexpires));
+		spin_unlock_irqrestore(&alarm_slock, flags);
+		alarm->function(alarm);
+		spin_lock_irqsave(&alarm_slock, flags);
 	}
+	if (!base->first)
+		pr_alarm(FLOW, "no more alarms of type %d\n", base - alarms);
+	update_timer_locked(base, true);
 	spin_unlock_irqrestore(&alarm_slock, flags);
 	return HRTIMER_NORESTART;
 }
@@ -318,11 +361,11 @@ static void alarm_triggered_func(void *p)
 	struct rtc_device *rtc = alarm_rtc_dev;
 	if (!(rtc->irq_data & RTC_AF))
 		return;
-	ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_INT, "rtc alarm triggered\n");
+	pr_alarm(INT, "rtc alarm triggered\n");
 	wake_lock_timeout(&alarm_rtc_wake_lock, 1 * HZ);
 }
 
-int alarm_suspend(struct platform_device *pdev, pm_message_t state)
+static int alarm_suspend(struct platform_device *pdev, pm_message_t state)
 {
 	int                 err = 0;
 	unsigned long       flags;
@@ -332,89 +375,85 @@ int alarm_suspend(struct platform_device *pdev, pm_message_t state)
 	unsigned long       rtc_alarm_time;
 	struct timespec     rtc_current_timespec;
 	struct timespec     rtc_delta;
-	struct timespec     elapsed_realtime_alarm_time;
+	struct alarm_queue *wakeup_queue = NULL;
+	struct alarm_queue *tmp_queue = NULL;
+
+	pr_alarm(SUSPEND, "alarm_suspend(%p, %d)\n", pdev, state.event);
 
-	ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_FLOW,
-			      "alarm_suspend(%p, %d)\n", pdev, state.event);
 	spin_lock_irqsave(&alarm_slock, flags);
-	if (alarm_pending && !wake_lock_active(&alarm_wake_lock)) {
-		ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_INFO,
-				      "alarm pending\n");
-		err = -EBUSY;
-		goto err1;
-	}
-	if (alarm_enabled & ANDROID_ALARM_WAKEUP_MASK) {
-		spin_unlock_irqrestore(&alarm_slock, flags);
-		if (alarm_enabled & ANDROID_ALARM_RTC_WAKEUP_MASK)
-			hrtimer_cancel(&alarm_timer[ANDROID_ALARM_RTC_WAKEUP]);
-		if (alarm_enabled & ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
-			hrtimer_cancel(&alarm_timer[
-					ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP]);
+	suspended = true;
+	spin_unlock_irqrestore(&alarm_slock, flags);
 
+	hrtimer_cancel(&alarms[ANDROID_ALARM_RTC_WAKEUP].timer);
+	hrtimer_cancel(&alarms[
+			ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK].timer);
+
+	tmp_queue = &alarms[ANDROID_ALARM_RTC_WAKEUP];
+	if (tmp_queue->first)
+		wakeup_queue = tmp_queue;
+	tmp_queue = &alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP];
+	if (tmp_queue->first && (!wakeup_queue ||
+				hrtimer_get_expires(&tmp_queue->timer).tv64 <
+				hrtimer_get_expires(&wakeup_queue->timer).tv64))
+		wakeup_queue = tmp_queue;
+	if (wakeup_queue) {
 		rtc_read_time(alarm_rtc_dev, &rtc_current_rtc_time);
 		rtc_current_timespec.tv_nsec = 0;
 		rtc_tm_to_time(&rtc_current_rtc_time,
 			       &rtc_current_timespec.tv_sec);
 		save_time_delta(&rtc_delta, &rtc_current_timespec);
-		set_normalized_timespec(&elapsed_realtime_alarm_time,
-			alarm_time[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP]
-			.tv_sec + elapsed_rtc_delta.tv_sec,
-			alarm_time[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP]
-			.tv_nsec + elapsed_rtc_delta.tv_nsec);
-		if ((alarm_enabled & ANDROID_ALARM_RTC_WAKEUP_MASK) &&
-		    (!(alarm_enabled &
-		       ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK) ||
-		     timespec_compare(&alarm_time[ANDROID_ALARM_RTC_WAKEUP],
-				      &elapsed_realtime_alarm_time) < 0))
-			rtc_alarm_time = timespec_sub(
-					alarm_time[ANDROID_ALARM_RTC_WAKEUP],
-					rtc_delta).tv_sec;
-		else
-			rtc_alarm_time = timespec_sub(
-				elapsed_realtime_alarm_time, rtc_delta).tv_sec;
+
+		rtc_alarm_time = timespec_sub(ktime_to_timespec(
+			hrtimer_get_expires(&wakeup_queue->timer)),
+			rtc_delta).tv_sec;
+
 		rtc_time_to_tm(rtc_alarm_time, &rtc_alarm.time);
 		rtc_alarm.enabled = 1;
 		rtc_set_alarm(alarm_rtc_dev, &rtc_alarm);
 		rtc_read_time(alarm_rtc_dev, &rtc_current_rtc_time);
 		rtc_tm_to_time(&rtc_current_rtc_time, &rtc_current_time);
-		ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_INFO,
+		pr_alarm(SUSPEND,
 			"rtc alarm set at %ld, now %ld, rtc delta %ld.%09ld\n",
 			rtc_alarm_time, rtc_current_time,
 			rtc_delta.tv_sec, rtc_delta.tv_nsec);
 		if (rtc_current_time + 1 >= rtc_alarm_time) {
-			ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_INFO,
-					      "alarm about to go off\n");
+			pr_alarm(SUSPEND, "alarm about to go off\n");
 			memset(&rtc_alarm, 0, sizeof(rtc_alarm));
 			rtc_alarm.enabled = 0;
 			rtc_set_alarm(alarm_rtc_dev, &rtc_alarm);
 
 			spin_lock_irqsave(&alarm_slock, flags);
+			suspended = false;
 			wake_lock_timeout(&alarm_rtc_wake_lock, 2 * HZ);
-			alarm_start_hrtimer(ANDROID_ALARM_RTC_WAKEUP);
-			alarm_start_hrtimer(
-				ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP);
+			update_timer_locked(&alarms[ANDROID_ALARM_RTC_WAKEUP],
+									false);
+			update_timer_locked(&alarms[
+				ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP], false);
 			err = -EBUSY;
 			spin_unlock_irqrestore(&alarm_slock, flags);
 		}
-	} else {
-err1:
-		spin_unlock_irqrestore(&alarm_slock, flags);
 	}
 	return err;
 }
 
-int alarm_resume(struct platform_device *pdev)
+static int alarm_resume(struct platform_device *pdev)
 {
 	struct rtc_wkalrm alarm;
-	ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_FLOW,
-			      "alarm_resume(%p)\n", pdev);
-	if (alarm_enabled & ANDROID_ALARM_WAKEUP_MASK) {
-		memset(&alarm, 0, sizeof(alarm));
-		alarm.enabled = 0;
-		rtc_set_alarm(alarm_rtc_dev, &alarm);
-		alarm_start_hrtimer(ANDROID_ALARM_RTC_WAKEUP);
-		alarm_start_hrtimer(ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP);
-	}
+	unsigned long       flags;
+
+	pr_alarm(SUSPEND, "alarm_resume(%p)\n", pdev);
+
+	memset(&alarm, 0, sizeof(alarm));
+	alarm.enabled = 0;
+	rtc_set_alarm(alarm_rtc_dev, &alarm);
+
+	spin_lock_irqsave(&alarm_slock, flags);
+	suspended = false;
+	update_timer_locked(&alarms[ANDROID_ALARM_RTC_WAKEUP], false);
+	update_timer_locked(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP],
+									false);
+	spin_unlock_irqrestore(&alarm_slock, flags);
+
 	return 0;
 }
 
@@ -422,19 +461,6 @@ static struct rtc_task alarm_rtc_task = {
 	.func = alarm_triggered_func
 };
 
-static struct file_operations alarm_fops = {
-	.owner = THIS_MODULE,
-	.unlocked_ioctl = alarm_ioctl,
-	.open = alarm_open,
-	.release = alarm_release,
-};
-
-static struct miscdevice alarm_device = {
-	.minor = MISC_DYNAMIC_MINOR,
-	.name = "alarm",
-	.fops = &alarm_fops,
-};
-
 static int rtc_alarm_add_device(struct device *dev,
 				struct class_interface *class_intf)
 {
@@ -448,9 +474,6 @@ static int rtc_alarm_add_device(struct device *dev,
 		goto err1;
 	}
 
-	err = misc_register(&alarm_device);
-	if (err)
-		goto err1;
 	alarm_platform_dev =
 		platform_device_register_simple("alarm", -1, NULL, 0);
 	if (IS_ERR(alarm_platform_dev)) {
@@ -461,16 +484,14 @@ static int rtc_alarm_add_device(struct device *dev,
 	if (err)
 		goto err3;
 	alarm_rtc_dev = rtc;
+	pr_alarm(INIT_STATUS, "using rtc device, %s, for alarms", rtc->name);
 	mutex_unlock(&alarm_setrtc_mutex);
 
-	ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_INFO, "alarm: parent %p\n",
-			      alarm_platform_dev->dev.power.pm_parent);
 	return 0;
 
 err3:
 	platform_device_unregister(alarm_platform_dev);
 err2:
-	misc_deregister(&alarm_device);
 err1:
 	mutex_unlock(&alarm_setrtc_mutex);
 	return err;
@@ -480,9 +501,9 @@ static void rtc_alarm_remove_device(struct device *dev,
 				    struct class_interface *class_intf)
 {
 	if (dev == &alarm_rtc_dev->dev) {
+		pr_alarm(INIT_STATUS, "lost rtc device for alarms");
 		rtc_irq_unregister(alarm_rtc_dev, &alarm_rtc_task);
 		platform_device_unregister(alarm_platform_dev);
-		misc_deregister(&alarm_device);
 		alarm_rtc_dev = NULL;
 	}
 }
@@ -503,7 +524,7 @@ static struct platform_driver alarm_driver = {
 static int __init alarm_late_init(void)
 {
 	unsigned long   flags;
-	struct timespec system_time;
+	struct timespec tmp_time, system_time;
 
 	/* this needs to run after the rtc is read at boot */
 	spin_lock_irqsave(&alarm_slock, flags);
@@ -511,33 +532,32 @@ static int __init alarm_late_init(void)
 	 * elasped realtime to be (boot_systemtime + rtc - boot_rtc) ==
 	 * (rtc - (boot_rtc - boot_systemtime))
 	 */
-	getnstimeofday(&elapsed_rtc_delta);
+	getnstimeofday(&tmp_time);
 	ktime_get_ts(&system_time);
-	elapsed_rtc_delta = timespec_sub(elapsed_rtc_delta, system_time);
-	spin_unlock_irqrestore(&alarm_slock, flags);
+	alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].delta =
+		alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta =
+			timespec_to_ktime(timespec_sub(tmp_time, system_time));
 
-	ANDROID_ALARM_DPRINTF(ANDROID_ALARM_PRINT_INFO,
-		"alarm_late_init: rtc to elapsed realtime delta %ld.%09ld\n",
-		elapsed_rtc_delta.tv_sec, elapsed_rtc_delta.tv_nsec);
+	spin_unlock_irqrestore(&alarm_slock, flags);
 	return 0;
 }
 
-static int __init alarm_init(void)
+static int __init alarm_driver_init(void)
 {
 	int err;
 	int i;
 
 	for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
-		hrtimer_init(&alarm_timer[i], CLOCK_REALTIME, HRTIMER_MODE_ABS);
-		alarm_timer[i].function = alarm_timer_triggered;
+		hrtimer_init(&alarms[i].timer,
+				CLOCK_REALTIME, HRTIMER_MODE_ABS);
+		alarms[i].timer.function = alarm_timer_triggered;
 	}
-	hrtimer_init(&alarm_timer[ANDROID_ALARM_SYSTEMTIME],
+	hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].timer,
 		     CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
-	alarm_timer[ANDROID_ALARM_SYSTEMTIME].function = alarm_timer_triggered;
+	alarms[ANDROID_ALARM_SYSTEMTIME].timer.function = alarm_timer_triggered;
 	err = platform_driver_register(&alarm_driver);
 	if (err < 0)
 		goto err1;
-	wake_lock_init(&alarm_wake_lock, WAKE_LOCK_SUSPEND, "alarm");
 	wake_lock_init(&alarm_rtc_wake_lock, WAKE_LOCK_SUSPEND, "alarm_rtc");
 	rtc_alarm_interface.class = rtc_class;
 	err = class_interface_register(&rtc_alarm_interface);
@@ -548,7 +568,6 @@ static int __init alarm_init(void)
 
 err2:
 	wake_lock_destroy(&alarm_rtc_wake_lock);
-	wake_lock_destroy(&alarm_wake_lock);
 	platform_driver_unregister(&alarm_driver);
 err1:
 	return err;
@@ -558,11 +577,10 @@ static void  __exit alarm_exit(void)
 {
 	class_interface_unregister(&rtc_alarm_interface);
 	wake_lock_destroy(&alarm_rtc_wake_lock);
-	wake_lock_destroy(&alarm_wake_lock);
 	platform_driver_unregister(&alarm_driver);
 }
 
 late_initcall(alarm_late_init);
-module_init(alarm_init);
+module_init(alarm_driver_init);
 module_exit(alarm_exit);