[deliverable/linux.git] / drivers / staging / android / alarm.c

/* drivers/rtc/alarm.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 <linux/time.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/wakelock.h>
#include "android_alarm.h"

#define ANDROID_ALARM_PRINT_ERROR (1U << 0)
#define ANDROID_ALARM_PRINT_INIT_STATUS (1U << 1)
#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 (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)

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 DEFINE_SPINLOCK(alarm_slock);
static DEFINE_MUTEX(alarm_setrtc_mutex);
static struct wake_lock alarm_rtc_wake_lock;
static struct platform_device *alarm_platform_dev;
struct alarm_queue alarms[ANDROID_ALARM_TYPE_COUNT];
static bool suspended;

static void update_timer_locked(struct alarm_queue *base, bool head_removed)
{
	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;

	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 void alarm_enqueue_locked(struct alarm *alarm)
{
	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);
	}

	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);
	}

	rb_link_node(&alarm->node, parent, link);
	rb_insert_color(&alarm->node, &base->alarms);
}

/**
 * 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;

	pr_alarm(FLOW, "created alarm, type %d, func %pF\n", type, function);
}


/**
 * 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);
}

/**
 * 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)
{
	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;
}

/**
 * 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);
	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);
	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;
}

/**
 * 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;
	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;

	spin_lock_irqsave(&alarm_slock, flags);

	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;
}

static void alarm_triggered_func(void *p)
{
	struct rtc_device *rtc = alarm_rtc_dev;
	if (!(rtc->irq_data & RTC_AF))
		return;
	pr_alarm(INT, "rtc alarm triggered\n");
	wake_lock_timeout(&alarm_rtc_wake_lock, 1 * HZ);
}

static int alarm_suspend(struct platform_device *pdev, pm_message_t state)
{
	int                 err = 0;
	unsigned long       flags;
	struct rtc_wkalrm   rtc_alarm;
	struct rtc_time     rtc_current_rtc_time;
	unsigned long       rtc_current_time;
	unsigned long       rtc_alarm_time;
	struct timespec     rtc_delta;
	struct timespec     wall_time;
	struct alarm_queue *wakeup_queue = NULL;
	struct alarm_queue *tmp_queue = NULL;

	pr_alarm(SUSPEND, "alarm_suspend(%p, %d)\n", pdev, state.event);

	spin_lock_irqsave(&alarm_slock, flags);
	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);
		getnstimeofday(&wall_time);
		rtc_tm_to_time(&rtc_current_rtc_time, &rtc_current_time);
		set_normalized_timespec(&rtc_delta,
					wall_time.tv_sec - rtc_current_time,
					wall_time.tv_nsec);

		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);
		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) {
			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);
			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);
		}
	}
	return err;
}

static int alarm_resume(struct platform_device *pdev)
{
	struct rtc_wkalrm alarm;
	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;
}

static struct rtc_task alarm_rtc_task = {
	.func = alarm_triggered_func
};

static int rtc_alarm_add_device(struct device *dev,
				struct class_interface *class_intf)
{
	int err;
	struct rtc_device *rtc = to_rtc_device(dev);

	mutex_lock(&alarm_setrtc_mutex);

	if (alarm_rtc_dev) {
		err = -EBUSY;
		goto err1;
	}

	alarm_platform_dev =
		platform_device_register_simple("alarm", -1, NULL, 0);
	if (IS_ERR(alarm_platform_dev)) {
		err = PTR_ERR(alarm_platform_dev);
		goto err2;
	}
	err = rtc_irq_register(rtc, &alarm_rtc_task);
	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);

	return 0;

err3:
	platform_device_unregister(alarm_platform_dev);
err2:
err1:
	mutex_unlock(&alarm_setrtc_mutex);
	return err;
}

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);
		alarm_rtc_dev = NULL;
	}
}

static struct class_interface rtc_alarm_interface = {
	.add_dev = &rtc_alarm_add_device,
	.remove_dev = &rtc_alarm_remove_device,
};

static struct platform_driver alarm_driver = {
	.suspend = alarm_suspend,
	.resume = alarm_resume,
	.driver = {
		.name = "alarm"
	}
};

static int __init alarm_late_init(void)
{
	unsigned long   flags;
	struct timespec tmp_time, system_time;

	/* this needs to run after the rtc is read at boot */
	spin_lock_irqsave(&alarm_slock, flags);
	/* We read the current rtc and system time so we can later calulate
	 * elasped realtime to be (boot_systemtime + rtc - boot_rtc) ==
	 * (rtc - (boot_rtc - boot_systemtime))
	 */
	getnstimeofday(&tmp_time);
	ktime_get_ts(&system_time);
	alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].delta =
		alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta =
			timespec_to_ktime(timespec_sub(tmp_time, system_time));

	spin_unlock_irqrestore(&alarm_slock, flags);
	return 0;
}

static int __init alarm_driver_init(void)
{
	int err;
	int i;

	for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
		hrtimer_init(&alarms[i].timer,
				CLOCK_REALTIME, HRTIMER_MODE_ABS);
		alarms[i].timer.function = alarm_timer_triggered;
	}
	hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].timer,
		     CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
	alarms[ANDROID_ALARM_SYSTEMTIME].timer.function = alarm_timer_triggered;
	err = platform_driver_register(&alarm_driver);
	if (err < 0)
		goto err1;
	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);
	if (err < 0)
		goto err2;

	return 0;

err2:
	wake_lock_destroy(&alarm_rtc_wake_lock);
	platform_driver_unregister(&alarm_driver);
err1:
	return err;
}

static void  __exit alarm_exit(void)
{
	class_interface_unregister(&rtc_alarm_interface);
	wake_lock_destroy(&alarm_rtc_wake_lock);
	platform_driver_unregister(&alarm_driver);
}

late_initcall(alarm_late_init);
module_init(alarm_driver_init);
module_exit(alarm_exit);
Commit	Line	Data
841cb11c AH	1	/* drivers/rtc/alarm.c
	2	*
	3	* Copyright (C) 2007-2009 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
d47908b2	16	#include <linux/time.h>
bf647ea7	17	#include <linux/module.h>
841cb11c AH	18	#include <linux/device.h>
	19	#include <linux/miscdevice.h>
	20	#include <linux/platform_device.h>
	21	#include <linux/rtc.h>
	22	#include <linux/sched.h>
	23	#include <linux/spinlock.h>
841cb11c AH	24	#include <linux/wakelock.h>
	25	#include "android_alarm.h"
	26
	27	#define ANDROID_ALARM_PRINT_ERROR (1U << 0)
	28	#define ANDROID_ALARM_PRINT_INIT_STATUS (1U << 1)
	29	#define ANDROID_ALARM_PRINT_TSET (1U << 2)
	30	#define ANDROID_ALARM_PRINT_CALL (1U << 3)
	31	#define ANDROID_ALARM_PRINT_SUSPEND (1U << 4)
	32	#define ANDROID_ALARM_PRINT_INT (1U << 5)
	33	#define ANDROID_ALARM_PRINT_FLOW (1U << 6)
	34
	35	static int debug_mask = ANDROID_ALARM_PRINT_ERROR \| \
	36	ANDROID_ALARM_PRINT_INIT_STATUS;
	37	module_param_named(debug_mask, debug_mask, int, S_IRUGO \| S_IWUSR \| S_IWGRP);
	38
	39	#define pr_alarm(debug_level_mask, args...) \
	40	do { \
	41	if (debug_mask & ANDROID_ALARM_PRINT_##debug_level_mask) { \
	42	pr_info(args); \
	43	} \
	44	} while (0)
	45
	46	#define ANDROID_ALARM_WAKEUP_MASK ( \
	47	ANDROID_ALARM_RTC_WAKEUP_MASK \| \
	48	ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK)
	49
	50	/* support old usespace code */
	51	#define ANDROID_ALARM_SET_OLD _IOW('a', 2, time_t) /* set alarm */
	52	#define ANDROID_ALARM_SET_AND_WAIT_OLD _IOW('a', 3, time_t)
	53
	54	struct alarm_queue {
	55	struct rb_root alarms;
	56	struct rb_node *first;
	57	struct hrtimer timer;
	58	ktime_t delta;
	59	bool stopped;
	60	ktime_t stopped_time;
	61	};
	62
	63	static struct rtc_device *alarm_rtc_dev;
	64	static DEFINE_SPINLOCK(alarm_slock);
	65	static DEFINE_MUTEX(alarm_setrtc_mutex);
	66	static struct wake_lock alarm_rtc_wake_lock;
	67	static struct platform_device *alarm_platform_dev;
	68	struct alarm_queue alarms[ANDROID_ALARM_TYPE_COUNT];
	69	static bool suspended;
	70
	71	static void update_timer_locked(struct alarm_queue *base, bool head_removed)
	72	{
	73	struct alarm *alarm;
	74	bool is_wakeup = base == &alarms[ANDROID_ALARM_RTC_WAKEUP] \|\|
	75	base == &alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP];
	76
	77	if (base->stopped) {
	78	pr_alarm(FLOW, "changed alarm while setting the wall time\n");
	79	return;
	80	}
	81
	82	if (is_wakeup && !suspended && head_removed)
	83	wake_unlock(&alarm_rtc_wake_lock);
	84
	85	if (!base->first)
	86	return;
	87
88	alarm = container_of(base->first, struct alarm, node);
89
90	pr_alarm(FLOW, "selected alarm, type %d, func %pF at %lld\n",
91	alarm->type, alarm->function, ktime_to_ns(alarm->expires));
92
93	if (is_wakeup && suspended) {
94	pr_alarm(FLOW, "changed alarm while suspened\n");
95	wake_lock_timeout(&alarm_rtc_wake_lock, 1 * HZ);
96	return;
97	}
98
99	hrtimer_try_to_cancel(&base->timer);
100	base->timer.node.expires = ktime_add(base->delta, alarm->expires);
101	base->timer._softexpires = ktime_add(base->delta, alarm->softexpires);
102	hrtimer_start_expires(&base->timer, HRTIMER_MODE_ABS);
103	}
104
105	static void alarm_enqueue_locked(struct alarm *alarm)
106	{
107	struct alarm_queue *base = &alarms[alarm->type];
108	struct rb_node **link = &base->alarms.rb_node;
109	struct rb_node *parent = NULL;
110	struct alarm *entry;
111	int leftmost = 1;
112
113	pr_alarm(FLOW, "added alarm, type %d, func %pF at %lld\n",
114	alarm->type, alarm->function, ktime_to_ns(alarm->expires));
115
116	if (base->first == &alarm->node)
117	base->first = rb_next(&alarm->node);
118	if (!RB_EMPTY_NODE(&alarm->node)) {
119	rb_erase(&alarm->node, &base->alarms);
120	RB_CLEAR_NODE(&alarm->node);
121	}
122
123	while (*link) {
124	parent = *link;
125	entry = rb_entry(parent, struct alarm, node);
126	/*
127	* We dont care about collisions. Nodes with
128	* the same expiry time stay together.
129	*/
130	if (alarm->expires.tv64 < entry->expires.tv64) {
131	link = &(*link)->rb_left;
132	} else {
133	link = &(*link)->rb_right;
134	leftmost = 0;
135	}
136	}
137	if (leftmost) {
138	base->first = &alarm->node;
139	update_timer_locked(base, false);
140	}
141
142	rb_link_node(&alarm->node, parent, link);
143	rb_insert_color(&alarm->node, &base->alarms);
144	}
145
146	/**
147	* alarm_init - initialize an alarm
148	* @alarm: the alarm to be initialized
149	* @type: the alarm type to be used
150	* @function: alarm callback function
151	*/
152	void alarm_init(struct alarm *alarm,
153	enum android_alarm_type type, void (function)(struct alarm ))
154	{
155	RB_CLEAR_NODE(&alarm->node);
156	alarm->type = type;
157	alarm->function = function;
158
159	pr_alarm(FLOW, "created alarm, type %d, func %pF\n", type, function);
160	}
161
162
163	/**
164	* alarm_start_range - (re)start an alarm
165	* @alarm: the alarm to be added
166	* @start: earliest expiry time
167	* @end: expiry time
168	*/
169	void alarm_start_range(struct alarm *alarm, ktime_t start, ktime_t end)
170	{
171	unsigned long flags;
172
173	spin_lock_irqsave(&alarm_slock, flags);
174	alarm->softexpires = start;
175	alarm->expires = end;
176	alarm_enqueue_locked(alarm);
177	spin_unlock_irqrestore(&alarm_slock, flags);
178	}
179
180	/**
181	* alarm_try_to_cancel - try to deactivate an alarm
182	* @alarm: alarm to stop
183	*
184	* Returns:
185	* 0 when the alarm was not active
186	* 1 when the alarm was active
187	* -1 when the alarm may currently be excuting the callback function and
188	* cannot be stopped (it may also be inactive)
189	*/
190	int alarm_try_to_cancel(struct alarm *alarm)
191	{
192	struct alarm_queue *base = &alarms[alarm->type];
193	unsigned long flags;
194	bool first = false;
195	int ret = 0;
196
197	spin_lock_irqsave(&alarm_slock, flags);
198	if (!RB_EMPTY_NODE(&alarm->node)) {
199	pr_alarm(FLOW, "canceled alarm, type %d, func %pF at %lld\n",
200	alarm->type, alarm->function,
201	ktime_to_ns(alarm->expires));
202	ret = 1;
203	if (base->first == &alarm->node) {
204	base->first = rb_next(&alarm->node);
205	first = true;
206	}
207	rb_erase(&alarm->node, &base->alarms);
208	RB_CLEAR_NODE(&alarm->node);
209	if (first)
210	update_timer_locked(base, true);
211	} else
212	pr_alarm(FLOW, "tried to cancel alarm, type %d, func %pF\n",
213	alarm->type, alarm->function);
214	spin_unlock_irqrestore(&alarm_slock, flags);
215	if (!ret && hrtimer_callback_running(&base->timer))
216	ret = -1;
217	return ret;
218	}
219
220	/**
221	* alarm_cancel - cancel an alarm and wait for the handler to finish.
222	* @alarm: the alarm to be cancelled
223	*
224	* Returns:
225	* 0 when the alarm was not active
226	* 1 when the alarm was active
227	*/
228	int alarm_cancel(struct alarm *alarm)
229	{
230	for (;;) {
231	int ret = alarm_try_to_cancel(alarm);
232	if (ret >= 0)
233	return ret;
234	cpu_relax();
235	}
236	}
237
238	/**
239	* alarm_set_rtc - set the kernel and rtc walltime
240	* @new_time: timespec value containing the new time
241	*/
242	int alarm_set_rtc(struct timespec new_time)
243	{
244	int i;
245	int ret;
246	unsigned long flags;
247	struct rtc_time rtc_new_rtc_time;
248	struct timespec tmp_time;
249
250	rtc_time_to_tm(new_time.tv_sec, &rtc_new_rtc_time);
251
252	pr_alarm(TSET, "set rtc %ld %ld - rtc %02d:%02d:%02d %02d/%02d/%04d\n",
253	new_time.tv_sec, new_time.tv_nsec,
254	rtc_new_rtc_time.tm_hour, rtc_new_rtc_time.tm_min,
255	rtc_new_rtc_time.tm_sec, rtc_new_rtc_time.tm_mon + 1,
256	rtc_new_rtc_time.tm_mday,
257	rtc_new_rtc_time.tm_year + 1900);
258
259	mutex_lock(&alarm_setrtc_mutex);
260	spin_lock_irqsave(&alarm_slock, flags);
261	wake_lock(&alarm_rtc_wake_lock);
262	getnstimeofday(&tmp_time);
263	for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
264	hrtimer_try_to_cancel(&alarms[i].timer);
265	alarms[i].stopped = true;
266	alarms[i].stopped_time = timespec_to_ktime(tmp_time);
267	}
268	alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].delta =
269	alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta =
270	ktime_sub(alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta,
271	timespec_to_ktime(timespec_sub(tmp_time, new_time)));
272	spin_unlock_irqrestore(&alarm_slock, flags);
273	ret = do_settimeofday(&new_time);
274	spin_lock_irqsave(&alarm_slock, flags);
275	for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
276	alarms[i].stopped = false;
277	update_timer_locked(&alarms[i], false);
278	}
279	spin_unlock_irqrestore(&alarm_slock, flags);
280	if (ret < 0) {
281	pr_alarm(ERROR, "alarm_set_rtc: Failed to set time\n");
282	goto err;
283	}
284	if (!alarm_rtc_dev) {
285	pr_alarm(ERROR,
286	"alarm_set_rtc: no RTC, time will be lost on reboot\n");
287	goto err;
288	}
289	ret = rtc_set_time(alarm_rtc_dev, &rtc_new_rtc_time);
290	if (ret < 0)
291	pr_alarm(ERROR, "alarm_set_rtc: "
292	"Failed to set RTC, time will be lost on reboot\n");
293	err:
294	wake_unlock(&alarm_rtc_wake_lock);
295	mutex_unlock(&alarm_setrtc_mutex);
296	return ret;
297	}
298
299	/**
300	* alarm_get_elapsed_realtime - get the elapsed real time in ktime_t format
301	*
302	* returns the time in ktime_t format
303	*/
304	ktime_t alarm_get_elapsed_realtime(void)
305	{
306	ktime_t now;
307	unsigned long flags;
308	struct alarm_queue *base = &alarms[ANDROID_ALARM_ELAPSED_REALTIME];
309
310	spin_lock_irqsave(&alarm_slock, flags);
311	now = base->stopped ? base->stopped_time : ktime_get_real();
312	now = ktime_sub(now, base->delta);
313	spin_unlock_irqrestore(&alarm_slock, flags);
314	return now;
315	}
316
317	static enum hrtimer_restart alarm_timer_triggered(struct hrtimer *timer)
318	{
319	struct alarm_queue *base;
320	struct alarm *alarm;
321	unsigned long flags;
322	ktime_t now;
323
324	spin_lock_irqsave(&alarm_slock, flags);
325
326	base = container_of(timer, struct alarm_queue, timer);
327	now = base->stopped ? base->stopped_time : hrtimer_cb_get_time(timer);
328	now = ktime_sub(now, base->delta);
329
330	pr_alarm(INT, "alarm_timer_triggered type %d at %lld\n",
331	base - alarms, ktime_to_ns(now));
332
333	while (base->first) {
334	alarm = container_of(base->first, struct alarm, node);
335	if (alarm->softexpires.tv64 > now.tv64) {
336	pr_alarm(FLOW, "don't call alarm, %pF, %lld (s %lld)\n",
337	alarm->function, ktime_to_ns(alarm->expires),
338	ktime_to_ns(alarm->softexpires));
339	break;
340	}
341	base->first = rb_next(&alarm->node);
342	rb_erase(&alarm->node, &base->alarms);
343	RB_CLEAR_NODE(&alarm->node);
344	pr_alarm(CALL, "call alarm, type %d, func %pF, %lld (s %lld)\n",
345	alarm->type, alarm->function,
346	ktime_to_ns(alarm->expires),
347	ktime_to_ns(alarm->softexpires));
348	spin_unlock_irqrestore(&alarm_slock, flags);
349	alarm->function(alarm);
350	spin_lock_irqsave(&alarm_slock, flags);
351	}
352	if (!base->first)
353	pr_alarm(FLOW, "no more alarms of type %d\n", base - alarms);
354	update_timer_locked(base, true);
355	spin_unlock_irqrestore(&alarm_slock, flags);
356	return HRTIMER_NORESTART;
357	}
358
359	static void alarm_triggered_func(void *p)
360	{
361	struct rtc_device *rtc = alarm_rtc_dev;
362	if (!(rtc->irq_data & RTC_AF))
363	return;
364	pr_alarm(INT, "rtc alarm triggered\n");
365	wake_lock_timeout(&alarm_rtc_wake_lock, 1 * HZ);
366	}
367
368	static int alarm_suspend(struct platform_device *pdev, pm_message_t state)
369	{
370	int err = 0;
371	unsigned long flags;
372	struct rtc_wkalrm rtc_alarm;
373	struct rtc_time rtc_current_rtc_time;
374	unsigned long rtc_current_time;
375	unsigned long rtc_alarm_time;
841cb11c	376	struct timespec rtc_delta;
5dd12c29	377	struct timespec wall_time;
841cb11c AH	378	struct alarm_queue *wakeup_queue = NULL;
	379	struct alarm_queue *tmp_queue = NULL;
	380
	381	pr_alarm(SUSPEND, "alarm_suspend(%p, %d)\n", pdev, state.event);
	382
	383	spin_lock_irqsave(&alarm_slock, flags);
	384	suspended = true;
	385	spin_unlock_irqrestore(&alarm_slock, flags);
	386
	387	hrtimer_cancel(&alarms[ANDROID_ALARM_RTC_WAKEUP].timer);
	388	hrtimer_cancel(&alarms[
	389	ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP_MASK].timer);
	390
	391	tmp_queue = &alarms[ANDROID_ALARM_RTC_WAKEUP];
	392	if (tmp_queue->first)
	393	wakeup_queue = tmp_queue;
	394	tmp_queue = &alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP];
	395	if (tmp_queue->first && (!wakeup_queue \|\|
	396	hrtimer_get_expires(&tmp_queue->timer).tv64 <
	397	hrtimer_get_expires(&wakeup_queue->timer).tv64))
	398	wakeup_queue = tmp_queue;
	399	if (wakeup_queue) {
	400	rtc_read_time(alarm_rtc_dev, &rtc_current_rtc_time);
5dd12c29 AH	401	getnstimeofday(&wall_time);
	402	rtc_tm_to_time(&rtc_current_rtc_time, &rtc_current_time);
	403	set_normalized_timespec(&rtc_delta,
	404	wall_time.tv_sec - rtc_current_time,
	405	wall_time.tv_nsec);
841cb11c AH	406
	407	rtc_alarm_time = timespec_sub(ktime_to_timespec(
	408	hrtimer_get_expires(&wakeup_queue->timer)),
	409	rtc_delta).tv_sec;
	410
	411	rtc_time_to_tm(rtc_alarm_time, &rtc_alarm.time);
	412	rtc_alarm.enabled = 1;
	413	rtc_set_alarm(alarm_rtc_dev, &rtc_alarm);
	414	rtc_read_time(alarm_rtc_dev, &rtc_current_rtc_time);
	415	rtc_tm_to_time(&rtc_current_rtc_time, &rtc_current_time);
	416	pr_alarm(SUSPEND,
	417	"rtc alarm set at %ld, now %ld, rtc delta %ld.%09ld\n",
	418	rtc_alarm_time, rtc_current_time,
	419	rtc_delta.tv_sec, rtc_delta.tv_nsec);
	420	if (rtc_current_time + 1 >= rtc_alarm_time) {
	421	pr_alarm(SUSPEND, "alarm about to go off\n");
	422	memset(&rtc_alarm, 0, sizeof(rtc_alarm));
	423	rtc_alarm.enabled = 0;
	424	rtc_set_alarm(alarm_rtc_dev, &rtc_alarm);
	425
	426	spin_lock_irqsave(&alarm_slock, flags);
	427	suspended = false;
	428	wake_lock_timeout(&alarm_rtc_wake_lock, 2 * HZ);
	429	update_timer_locked(&alarms[ANDROID_ALARM_RTC_WAKEUP],
	430	false);
	431	update_timer_locked(&alarms[
	432	ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP], false);
	433	err = -EBUSY;
	434	spin_unlock_irqrestore(&alarm_slock, flags);
	435	}
	436	}
	437	return err;
	438	}
	439
	440	static int alarm_resume(struct platform_device *pdev)
	441	{
	442	struct rtc_wkalrm alarm;
	443	unsigned long flags;
	444
	445	pr_alarm(SUSPEND, "alarm_resume(%p)\n", pdev);
	446
	447	memset(&alarm, 0, sizeof(alarm));
	448	alarm.enabled = 0;
	449	rtc_set_alarm(alarm_rtc_dev, &alarm);
	450
	451	spin_lock_irqsave(&alarm_slock, flags);
	452	suspended = false;
	453	update_timer_locked(&alarms[ANDROID_ALARM_RTC_WAKEUP], false);
	454	update_timer_locked(&alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP],
	455	false);
	456	spin_unlock_irqrestore(&alarm_slock, flags);
	457
	458	return 0;
	459	}
	460
	461	static struct rtc_task alarm_rtc_task = {
	462	.func = alarm_triggered_func
	463	};
	464
	465	static int rtc_alarm_add_device(struct device *dev,
	466	struct class_interface *class_intf)
	467	{
	468	int err;
	469	struct rtc_device *rtc = to_rtc_device(dev);
470
471	mutex_lock(&alarm_setrtc_mutex);
472
473	if (alarm_rtc_dev) {
474	err = -EBUSY;
475	goto err1;
476	}
477
478	alarm_platform_dev =
479	platform_device_register_simple("alarm", -1, NULL, 0);
480	if (IS_ERR(alarm_platform_dev)) {
481	err = PTR_ERR(alarm_platform_dev);
482	goto err2;
483	}
484	err = rtc_irq_register(rtc, &alarm_rtc_task);
485	if (err)
486	goto err3;
487	alarm_rtc_dev = rtc;
488	pr_alarm(INIT_STATUS, "using rtc device, %s, for alarms", rtc->name);
489	mutex_unlock(&alarm_setrtc_mutex);
490
491	return 0;
492
493	err3:
494	platform_device_unregister(alarm_platform_dev);
495	err2:
496	err1:
497	mutex_unlock(&alarm_setrtc_mutex);
498	return err;
499	}
500
501	static void rtc_alarm_remove_device(struct device *dev,
502	struct class_interface *class_intf)
503	{
504	if (dev == &alarm_rtc_dev->dev) {
505	pr_alarm(INIT_STATUS, "lost rtc device for alarms");
506	rtc_irq_unregister(alarm_rtc_dev, &alarm_rtc_task);
507	platform_device_unregister(alarm_platform_dev);
508	alarm_rtc_dev = NULL;
509	}
510	}
511
512	static struct class_interface rtc_alarm_interface = {
513	.add_dev = &rtc_alarm_add_device,
514	.remove_dev = &rtc_alarm_remove_device,
515	};
516
517	static struct platform_driver alarm_driver = {
518	.suspend = alarm_suspend,
519	.resume = alarm_resume,
520	.driver = {
521	.name = "alarm"
522	}
523	};
524
525	static int __init alarm_late_init(void)
526	{
527	unsigned long flags;
528	struct timespec tmp_time, system_time;
529
530	/* this needs to run after the rtc is read at boot */
531	spin_lock_irqsave(&alarm_slock, flags);
532	/* We read the current rtc and system time so we can later calulate
533	* elasped realtime to be (boot_systemtime + rtc - boot_rtc) ==
534	* (rtc - (boot_rtc - boot_systemtime))
535	*/
536	getnstimeofday(&tmp_time);
537	ktime_get_ts(&system_time);
538	alarms[ANDROID_ALARM_ELAPSED_REALTIME_WAKEUP].delta =
539	alarms[ANDROID_ALARM_ELAPSED_REALTIME].delta =
540	timespec_to_ktime(timespec_sub(tmp_time, system_time));
541
542	spin_unlock_irqrestore(&alarm_slock, flags);
543	return 0;
544	}
545
546	static int __init alarm_driver_init(void)
547	{
548	int err;
549	int i;
550
551	for (i = 0; i < ANDROID_ALARM_SYSTEMTIME; i++) {
552	hrtimer_init(&alarms[i].timer,
553	CLOCK_REALTIME, HRTIMER_MODE_ABS);
554	alarms[i].timer.function = alarm_timer_triggered;
555	}
556	hrtimer_init(&alarms[ANDROID_ALARM_SYSTEMTIME].timer,
557	CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
558	alarms[ANDROID_ALARM_SYSTEMTIME].timer.function = alarm_timer_triggered;
559	err = platform_driver_register(&alarm_driver);
560	if (err < 0)
561	goto err1;
562	wake_lock_init(&alarm_rtc_wake_lock, WAKE_LOCK_SUSPEND, "alarm_rtc");
563	rtc_alarm_interface.class = rtc_class;
564	err = class_interface_register(&rtc_alarm_interface);
565	if (err < 0)
566	goto err2;
567
568	return 0;
569
570	err2:
571	wake_lock_destroy(&alarm_rtc_wake_lock);
572	platform_driver_unregister(&alarm_driver);
573	err1:
574	return err;
575	}
576
577	static void __exit alarm_exit(void)
578	{
579	class_interface_unregister(&rtc_alarm_interface);
580	wake_lock_destroy(&alarm_rtc_wake_lock);
581	platform_driver_unregister(&alarm_driver);
582	}
583
584	late_initcall(alarm_late_init);
585	module_init(alarm_driver_init);
586	module_exit(alarm_exit);
587