Release 4.14 drivers/rtc/interface.c

/*
 * RTC subsystem, interface functions
 *
 * Copyright (C) 2005 Tower Technologies
 * Author: Alessandro Zummo <a.zummo@towertech.it>
 *
 * based on arch/arm/common/rtctime.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
*/

#include <linux/rtc.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/log2.h>
#include <linux/workqueue.h>

static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);
static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);



static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
{
	int err;
	if (!rtc->ops)
		err = -ENODEV;
	else if (!rtc->ops->read_time)
		err = -EINVAL;
	else {
		memset(tm, 0, sizeof(struct rtc_time));
		err = rtc->ops->read_time(rtc->dev.parent, tm);
		if (err < 0) {
			dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
				err);
			return err;
		}

		err = rtc_valid_tm(tm);
		if (err < 0)
			dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n");
	}
	return err;
}

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int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
{
	int err;

	err = mutex_lock_interruptible(&rtc->ops_lock);
	if (err)
		return err;

	err = __rtc_read_time(rtc, tm);
	mutex_unlock(&rtc->ops_lock);
	return err;
}
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EXPORT_SYMBOL_GPL(rtc_read_time);



int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
{
	int err;

	err = rtc_valid_tm(tm);
	if (err != 0)
		return err;

	err = mutex_lock_interruptible(&rtc->ops_lock);
	if (err)
		return err;

	if (!rtc->ops)
		err = -ENODEV;
	else if (rtc->ops->set_time)
		err = rtc->ops->set_time(rtc->dev.parent, tm);
	else if (rtc->ops->set_mmss64) {
		time64_t secs64 = rtc_tm_to_time64(tm);

		err = rtc->ops->set_mmss64(rtc->dev.parent, secs64);
	} else if (rtc->ops->set_mmss) {
		time64_t secs64 = rtc_tm_to_time64(tm);
		err = rtc->ops->set_mmss(rtc->dev.parent, secs64);
	} else
		err = -EINVAL;

	pm_stay_awake(rtc->dev.parent);
	mutex_unlock(&rtc->ops_lock);
	/* A timer might have just expired */
	schedule_work(&rtc->irqwork);
	return err;
}
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6
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3
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EXPORT_SYMBOL_GPL(rtc_set_time);



static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
	int err;

	err = mutex_lock_interruptible(&rtc->ops_lock);
	if (err)
		return err;

	if (rtc->ops == NULL)
		err = -ENODEV;
	else if (!rtc->ops->read_alarm)
		err = -EINVAL;
	else {
		alarm->enabled = 0;
		alarm->pending = 0;
		alarm->time.tm_sec = -1;
		alarm->time.tm_min = -1;
		alarm->time.tm_hour = -1;
		alarm->time.tm_mday = -1;
		alarm->time.tm_mon = -1;
		alarm->time.tm_year = -1;
		alarm->time.tm_wday = -1;
		alarm->time.tm_yday = -1;
		alarm->time.tm_isdst = -1;
		err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
	}

	mutex_unlock(&rtc->ops_lock);
	return err;
}

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int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
	int err;
	struct rtc_time before, now;
	int first_time = 1;
	time64_t t_now, t_alm;
	enum { none, day, month, year } missing = none;
	unsigned days;

	/* The lower level RTC driver may return -1 in some fields,
         * creating invalid alarm->time values, for reasons like:
         *
         *   - The hardware may not be capable of filling them in;
         *     many alarms match only on time-of-day fields, not
         *     day/month/year calendar data.
         *
         *   - Some hardware uses illegal values as "wildcard" match
         *     values, which non-Linux firmware (like a BIOS) may try
         *     to set up as e.g. "alarm 15 minutes after each hour".
         *     Linux uses only oneshot alarms.
         *
         * When we see that here, we deal with it by using values from
         * a current RTC timestamp for any missing (-1) values.  The
         * RTC driver prevents "periodic alarm" modes.
         *
         * But this can be racey, because some fields of the RTC timestamp
         * may have wrapped in the interval since we read the RTC alarm,
         * which would lead to us inserting inconsistent values in place
         * of the -1 fields.
         *
         * Reading the alarm and timestamp in the reverse sequence
         * would have the same race condition, and not solve the issue.
         *
         * So, we must first read the RTC timestamp,
         * then read the RTC alarm value,
         * and then read a second RTC timestamp.
         *
         * If any fields of the second timestamp have changed
         * when compared with the first timestamp, then we know
         * our timestamp may be inconsistent with that used by
         * the low-level rtc_read_alarm_internal() function.
         *
         * So, when the two timestamps disagree, we just loop and do
         * the process again to get a fully consistent set of values.
         *
         * This could all instead be done in the lower level driver,
         * but since more than one lower level RTC implementation needs it,
         * then it's probably best best to do it here instead of there..
         */

	/* Get the "before" timestamp */
	err = rtc_read_time(rtc, &before);
	if (err < 0)
		return err;
	do {
		if (!first_time)
			memcpy(&before, &now, sizeof(struct rtc_time));
		first_time = 0;

		/* get the RTC alarm values, which may be incomplete */
		err = rtc_read_alarm_internal(rtc, alarm);
		if (err)
			return err;

		/* full-function RTCs won't have such missing fields */
		if (rtc_valid_tm(&alarm->time) == 0)
			return 0;

		/* get the "after" timestamp, to detect wrapped fields */
		err = rtc_read_time(rtc, &now);
		if (err < 0)
			return err;

		/* note that tm_sec is a "don't care" value here: */
	} while (   before.tm_min   != now.tm_min
		 || before.tm_hour  != now.tm_hour
		 || before.tm_mon   != now.tm_mon
		 || before.tm_year  != now.tm_year);

	/* Fill in the missing alarm fields using the timestamp; we
         * know there's at least one since alarm->time is invalid.
         */
	if (alarm->time.tm_sec == -1)
		alarm->time.tm_sec = now.tm_sec;
	if (alarm->time.tm_min == -1)
		alarm->time.tm_min = now.tm_min;
	if (alarm->time.tm_hour == -1)
		alarm->time.tm_hour = now.tm_hour;

	/* For simplicity, only support date rollover for now */
	if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) {
		alarm->time.tm_mday = now.tm_mday;
		missing = day;
	}
	if ((unsigned)alarm->time.tm_mon >= 12) {
		alarm->time.tm_mon = now.tm_mon;
		if (missing == none)
			missing = month;
	}
	if (alarm->time.tm_year == -1) {
		alarm->time.tm_year = now.tm_year;
		if (missing == none)
			missing = year;
	}

	/* Can't proceed if alarm is still invalid after replacing
         * missing fields.
         */
	err = rtc_valid_tm(&alarm->time);
	if (err)
		goto done;

	/* with luck, no rollover is needed */
	t_now = rtc_tm_to_time64(&now);
	t_alm = rtc_tm_to_time64(&alarm->time);
	if (t_now < t_alm)
		goto done;

	switch (missing) {

	/* 24 hour rollover ... if it's now 10am Monday, an alarm that
         * that will trigger at 5am will do so at 5am Tuesday, which
         * could also be in the next month or year.  This is a common
         * case, especially for PCs.
         */
	case day:
		dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
		t_alm += 24 * 60 * 60;
		rtc_time64_to_tm(t_alm, &alarm->time);
		break;

	/* Month rollover ... if it's the 31th, an alarm on the 3rd will
         * be next month.  An alarm matching on the 30th, 29th, or 28th
         * may end up in the month after that!  Many newer PCs support
         * this type of alarm.
         */
	case month:
		dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
		do {
			if (alarm->time.tm_mon < 11)
				alarm->time.tm_mon++;
			else {
				alarm->time.tm_mon = 0;
				alarm->time.tm_year++;
			}
			days = rtc_month_days(alarm->time.tm_mon,
					alarm->time.tm_year);
		} while (days < alarm->time.tm_mday);
		break;

	/* Year rollover ... easy except for leap years! */
	case year:
		dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
		do {
			alarm->time.tm_year++;
		} while (!is_leap_year(alarm->time.tm_year + 1900)
			&& rtc_valid_tm(&alarm->time) != 0);
		break;

	default:
		dev_warn(&rtc->dev, "alarm rollover not handled\n");
	}

	err = rtc_valid_tm(&alarm->time);

done:
	if (err) {
		dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n",
			alarm->time.tm_year + 1900, alarm->time.tm_mon + 1,
			alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min,
			alarm->time.tm_sec);
	}

	return err;
}

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int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
	int err;

	err = mutex_lock_interruptible(&rtc->ops_lock);
	if (err)
		return err;
	if (rtc->ops == NULL)
		err = -ENODEV;
	else if (!rtc->ops->read_alarm)
		err = -EINVAL;
	else {
		memset(alarm, 0, sizeof(struct rtc_wkalrm));
		alarm->enabled = rtc->aie_timer.enabled;
		alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
	}
	mutex_unlock(&rtc->ops_lock);

	return err;
}
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EXPORT_SYMBOL_GPL(rtc_read_alarm);



static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
	struct rtc_time tm;
	time64_t now, scheduled;
	int err;

	err = rtc_valid_tm(&alarm->time);
	if (err)
		return err;
	scheduled = rtc_tm_to_time64(&alarm->time);

	/* Make sure we're not setting alarms in the past */
	err = __rtc_read_time(rtc, &tm);
	if (err)
		return err;
	now = rtc_tm_to_time64(&tm);
	if (scheduled <= now)
		return -ETIME;
	/*
         * XXX - We just checked to make sure the alarm time is not
         * in the past, but there is still a race window where if
         * the is alarm set for the next second and the second ticks
         * over right here, before we set the alarm.
         */

	if (!rtc->ops)
		err = -ENODEV;
	else if (!rtc->ops->set_alarm)
		err = -EINVAL;
	else
		err = rtc->ops->set_alarm(rtc->dev.parent, alarm);

	return err;
}

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int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
	int err;

	err = rtc_valid_tm(&alarm->time);
	if (err != 0)
		return err;

	err = mutex_lock_interruptible(&rtc->ops_lock);
	if (err)
		return err;
	if (rtc->aie_timer.enabled)
		rtc_timer_remove(rtc, &rtc->aie_timer);

	rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
	rtc->aie_timer.period = 0;
	if (alarm->enabled)
		err = rtc_timer_enqueue(rtc, &rtc->aie_timer);

	mutex_unlock(&rtc->ops_lock);
	return err;
}
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EXPORT_SYMBOL_GPL(rtc_set_alarm);

/* Called once per device from rtc_device_register */


int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
	int err;
	struct rtc_time now;

	err = rtc_valid_tm(&alarm->time);
	if (err != 0)
		return err;

	err = rtc_read_time(rtc, &now);
	if (err)
		return err;

	err = mutex_lock_interruptible(&rtc->ops_lock);
	if (err)
		return err;

	rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
	rtc->aie_timer.period = 0;

	/* Alarm has to be enabled & in the future for us to enqueue it */
	if (alarm->enabled && (rtc_tm_to_ktime(now) <
			 rtc->aie_timer.node.expires)) {

		rtc->aie_timer.enabled = 1;
		timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
	}
	mutex_unlock(&rtc->ops_lock);
	return err;
}
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EXPORT_SYMBOL_GPL(rtc_initialize_alarm);



int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
{
	int err = mutex_lock_interruptible(&rtc->ops_lock);
	if (err)
		return err;

	if (rtc->aie_timer.enabled != enabled) {
		if (enabled)
			err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
		else
			rtc_timer_remove(rtc, &rtc->aie_timer);
	}

	if (err)
		/* nothing */;
	else if (!rtc->ops)
		err = -ENODEV;
	else if (!rtc->ops->alarm_irq_enable)
		err = -EINVAL;
	else
		err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);

	mutex_unlock(&rtc->ops_lock);
	return err;
}
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EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);



int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
{
	int err = mutex_lock_interruptible(&rtc->ops_lock);
	if (err)
		return err;

#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	if (enabled == 0 && rtc->uie_irq_active) {
		mutex_unlock(&rtc->ops_lock);
		return rtc_dev_update_irq_enable_emul(rtc, 0);
	}
#endif
	/* make sure we're changing state */
	if (rtc->uie_rtctimer.enabled == enabled)
		goto out;

	if (rtc->uie_unsupported) {
		err = -EINVAL;
		goto out;
	}

	if (enabled) {
		struct rtc_time tm;
		ktime_t now, onesec;

		__rtc_read_time(rtc, &tm);
		onesec = ktime_set(1, 0);
		now = rtc_tm_to_ktime(tm);
		rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
		rtc->uie_rtctimer.period = ktime_set(1, 0);
		err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
	} else
		rtc_timer_remove(rtc, &rtc->uie_rtctimer);

out:
	mutex_unlock(&rtc->ops_lock);
#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	/*
         * Enable emulation if the driver did not provide
         * the update_irq_enable function pointer or if returned
         * -EINVAL to signal that it has been configured without
         * interrupts or that are not available at the moment.
         */
	if (err == -EINVAL)
		err = rtc_dev_update_irq_enable_emul(rtc, enabled);
#endif
	return err;

}
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EXPORT_SYMBOL_GPL(rtc_update_irq_enable);


/**
 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
 * @rtc: pointer to the rtc device
 *
 * This function is called when an AIE, UIE or PIE mode interrupt
 * has occurred (or been emulated).
 *
 * Triggers the registered irq_task function callback.
 */


void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
{
	unsigned long flags;

	/* mark one irq of the appropriate mode */
	spin_lock_irqsave(&rtc->irq_lock, flags);
	rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
	spin_unlock_irqrestore(&rtc->irq_lock, flags);

	/* call the task func */
	spin_lock_irqsave(&rtc->irq_task_lock, flags);
	if (rtc->irq_task)
		rtc->irq_task->func(rtc->irq_task->private_data);
	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);

	wake_up_interruptible(&rtc->irq_queue);
	kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
}


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/**
 * rtc_aie_update_irq - AIE mode rtctimer hook
 * @private: pointer to the rtc_device
 *
 * This functions is called when the aie_timer expires.
 */


void rtc_aie_update_irq(void *private)
{
	struct rtc_device *rtc = (struct rtc_device *)private;
	rtc_handle_legacy_irq(rtc, 1, RTC_AF);
}


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/**
 * rtc_uie_update_irq - UIE mode rtctimer hook
 * @private: pointer to the rtc_device
 *
 * This functions is called when the uie_timer expires.
 */


void rtc_uie_update_irq(void *private)
{
	struct rtc_device *rtc = (struct rtc_device *)private;
	rtc_handle_legacy_irq(rtc, 1,  RTC_UF);
}


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/**
 * rtc_pie_update_irq - PIE mode hrtimer hook
 * @timer: pointer to the pie mode hrtimer
 *
 * This function is used to emulate PIE mode interrupts
 * using an hrtimer. This function is called when the periodic
 * hrtimer expires.
 */


enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
{
	struct rtc_device *rtc;
	ktime_t period;
	int count;
	rtc = container_of(timer, struct rtc_device, pie_timer);

	period = NSEC_PER_SEC / rtc->irq_freq;
	count = hrtimer_forward_now(timer, period);

	rtc_handle_legacy_irq(rtc, count, RTC_PF);

	return HRTIMER_RESTART;
}

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/**
 * rtc_update_irq - Triggered when a RTC interrupt occurs.
 * @rtc: the rtc device
 * @num: how many irqs are being reported (usually one)
 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
 * Context: any
 */


void rtc_update_irq(struct rtc_device *rtc,
		unsigned long num, unsigned long events)
{
	if (IS_ERR_OR_NULL(rtc))
		return;

	pm_stay_awake(rtc->dev.parent);
	schedule_work(&rtc->irqwork);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
26
60.47%
1
33.33%
Neil Brown
9
20.93%
1
33.33%
Alessandro Zummo
8
18.60%
1
33.33%
Total
43
100.00%
3
100.00%


EXPORT_SYMBOL_GPL(rtc_update_irq);



static int __rtc_match(struct device *dev, const void *data)
{
	const char *name = data;

	if (strcmp(dev_name(dev), name) == 0)
		return 1;
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
33
76.74%
1
20.00%
David Brownell
4
9.30%
1
20.00%
Mark Lord
3
6.98%
1
20.00%
Michał Mirosław
2
4.65%
1
20.00%
Alessandro Zummo
1
2.33%
1
20.00%
Total
43
100.00%
5
100.00%



struct rtc_device *rtc_class_open(const char *name)
{
	struct device *dev;
	struct rtc_device *rtc = NULL;

	dev = class_find_device(rtc_class, NULL, name, __rtc_match);
	if (dev)
		rtc = to_rtc_device(dev);

	if (rtc) {
		if (!try_module_get(rtc->owner)) {
			put_device(dev);
			rtc = NULL;
		}
	}

	return rtc;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
45
57.69%
1
20.00%
Alessandro Zummo
24
30.77%
1
20.00%
David Brownell
8
10.26%
2
40.00%
Michał Mirosław
1
1.28%
1
20.00%
Total
78
100.00%
5
100.00%


EXPORT_SYMBOL_GPL(rtc_class_open);



void rtc_class_close(struct rtc_device *rtc)
{
	module_put(rtc->owner);
	put_device(&rtc->dev);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
13
52.00%
1
33.33%
Alessandro Zummo
11
44.00%
1
33.33%
David Brownell
1
4.00%
1
33.33%
Total
25
100.00%
3
100.00%


EXPORT_SYMBOL_GPL(rtc_class_close);



int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
{
	int retval = -EBUSY;

	if (task == NULL || task->func == NULL)
		return -EINVAL;

	/* Cannot register while the char dev is in use */
	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
		return -EBUSY;

	spin_lock_irq(&rtc->irq_task_lock);
	if (rtc->irq_task == NULL) {
		rtc->irq_task = task;
		retval = 0;
	}
	spin_unlock_irq(&rtc->irq_task_lock);

	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);

	return retval;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
57
55.34%
1
50.00%
Alessandro Zummo
46
44.66%
1
50.00%
Total
103
100.00%
2
100.00%


EXPORT_SYMBOL_GPL(rtc_irq_register);



void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
{
	spin_lock_irq(&rtc->irq_task_lock);
	if (rtc->irq_task == task)
		rtc->irq_task = NULL;
	spin_unlock_irq(&rtc->irq_task_lock);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Alessandro Zummo
24
53.33%
1
50.00%
John Stultz
21
46.67%
1
50.00%
Total
45
100.00%
2
100.00%


EXPORT_SYMBOL_GPL(rtc_irq_unregister);



static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
{
	/*
         * We always cancel the timer here first, because otherwise
         * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
         * when we manage to start the timer before the callback
         * returns HRTIMER_RESTART.
         *
         * We cannot use hrtimer_cancel() here as a running callback
         * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
         * would spin forever.
         */
	if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
		return -1;

	if (enabled) {
		ktime_t period = NSEC_PER_SEC / rtc->irq_freq;

		hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
	}
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Thomas Gleixner
61
100.00%
1
100.00%
Total
61
100.00%
1
100.00%

/**
 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
 * @rtc: the rtc device
 * @task: currently registered with rtc_irq_register()
 * @enabled: true to enable periodic IRQs
 * Context: any
 *
 * Note that rtc_irq_set_freq() should previously have been used to
 * specify the desired frequency of periodic IRQ task->func() callbacks.
 */


int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
{
	int err = 0;
	unsigned long flags;

retry:
	spin_lock_irqsave(&rtc->irq_task_lock, flags);
	if (rtc->irq_task != NULL && task == NULL)
		err = -EBUSY;
	else if (rtc->irq_task != task)
		err = -EACCES;
	else {
		if (rtc_update_hrtimer(rtc, enabled) < 0) {
			spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
			cpu_relax();
			goto retry;
		}
		rtc->pie_enabled = enabled;
	}
	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
	return err;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
57
47.11%
1
20.00%
Alessandro Zummo
41
33.88%
1
20.00%
Thomas Gleixner
21
17.36%
2
40.00%
Chris Brand
2
1.65%
1
20.00%
Total
121
100.00%
5
100.00%


EXPORT_SYMBOL_GPL(rtc_irq_set_state);

/**
 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
 * @rtc: the rtc device
 * @task: currently registered with rtc_irq_register()
 * @freq: positive frequency with which task->func() will be called
 * Context: any
 *
 * Note that rtc_irq_set_state() is used to enable or disable the
 * periodic IRQs.
 */


int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
{
	int err = 0;
	unsigned long flags;

	if (freq <= 0 || freq > RTC_MAX_FREQ)
		return -EINVAL;
retry:
	spin_lock_irqsave(&rtc->irq_task_lock, flags);
	if (rtc->irq_task != NULL && task == NULL)
		err = -EBUSY;
	else if (rtc->irq_task != task)
		err = -EACCES;
	else {
		rtc->irq_freq = freq;
		if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
			spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
			cpu_relax();
			goto retry;
		}
	}
	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
	return err;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
55
39.57%
1
12.50%
Alessandro Zummo
41
29.50%
1
12.50%
Thomas Gleixner
22
15.83%
2
25.00%
Marcelo Roberto Jimenez
10
7.19%
1
12.50%
Atsushi Nemoto
7
5.04%
1
12.50%
Chris Brand
2
1.44%
1
12.50%
David Brownell
2
1.44%
1
12.50%
Total
139
100.00%
8
100.00%


EXPORT_SYMBOL_GPL(rtc_irq_set_freq);

/**
 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
 * @rtc rtc device
 * @timer timer being added.
 *
 * Enqueues a timer onto the rtc devices timerqueue and sets
 * the next alarm event appropriately.
 *
 * Sets the enabled bit on the added timer.
 *
 * Must hold ops_lock for proper serialization of timerqueue
 */


static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
{
	struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
	struct rtc_time tm;
	ktime_t now;

	timer->enabled = 1;
	__rtc_read_time(rtc, &tm);
	now = rtc_tm_to_ktime(tm);

	/* Skip over expired timers */
	while (next) {
		if (next->expires >= now)
			break;
		next = timerqueue_iterate_next(next);
	}

	timerqueue_add(&rtc->timerqueue, &timer->node);
	if (!next) {
		struct rtc_wkalrm alarm;
		int err;
		alarm.time = rtc_ktime_to_tm(timer->node.expires);
		alarm.enabled = 1;
		err = __rtc_set_alarm(rtc, &alarm);
		if (err == -ETIME) {
			pm_stay_awake(rtc->dev.parent);
			schedule_work(&rtc->irqwork);
		} else if (err) {
			timerqueue_del(&rtc->timerqueue, &timer->node);
			timer->enabled = 0;
			return err;
		}
	}
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
105
54.12%
2
28.57%
Colin Ian King
60
30.93%
1
14.29%
Dave Young
15
7.73%
1
14.29%
Zoran Markovic
11
5.67%
1
14.29%
Kay Sievers
2
1.03%
1
14.29%
Thomas Gleixner
1
0.52%
1
14.29%
Total
194
100.00%
7
100.00%



static void rtc_alarm_disable(struct rtc_device *rtc)
{
	if (!rtc->ops || !rtc->ops->alarm_irq_enable)
		return;

	rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Rabin Vincent
41
100.00%
1
100.00%
Total
41
100.00%
1
100.00%

/**
 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
 * @rtc rtc device
 * @timer timer being removed.
 *
 * Removes a timer onto the rtc devices timerqueue and sets
 * the next alarm event appropriately.
 *
 * Clears the enabled bit on the removed timer.
 *
 * Must hold ops_lock for proper serialization of timerqueue
 */


static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
{
	struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
	timerqueue_del(&rtc->timerqueue, &timer->node);
	timer->enabled = 0;
	if (next == &timer->node) {
		struct rtc_wkalrm alarm;
		int err;
		next = timerqueue_getnext(&rtc->timerqueue);
		if (!next) {
			rtc_alarm_disable(rtc);
			return;
		}
		alarm.time = rtc_ktime_to_tm(next->expires);
		alarm.enabled = 1;
		err = __rtc_set_alarm(rtc, &alarm);
		if (err == -ETIME) {
			pm_stay_awake(rtc->dev.parent);
			schedule_work(&rtc->irqwork);
		}
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
89
62.68%
2
25.00%
Alessandro Zummo
19
13.38%
1
12.50%
David Brownell
15
10.56%
2
25.00%
Zoran Markovic
11
7.75%
1
12.50%
Rabin Vincent
7
4.93%
1
12.50%
Thomas Gleixner
1
0.70%
1
12.50%
Total
142
100.00%
8
100.00%

/**
 * rtc_timer_do_work - Expires rtc timers
 * @rtc rtc device
 * @timer timer being removed.
 *
 * Expires rtc timers. Reprograms next alarm event if needed.
 * Called via worktask.
 *
 * Serializes access to timerqueue via ops_lock mutex
 */


void rtc_timer_do_work(struct work_struct *work)
{
	struct rtc_timer *timer;
	struct timerqueue_node *next;
	ktime_t now;
	struct rtc_time tm;

	struct rtc_device *rtc =
		container_of(work, struct rtc_device, irqwork);

	mutex_lock(&rtc->ops_lock);
again:
	__rtc_read_time(rtc, &tm);
	now = rtc_tm_to_ktime(tm);
	while ((next = timerqueue_getnext(&rtc->timerqueue))) {
		if (next->expires > now)
			break;

		/* expire timer */
		timer = container_of(next, struct rtc_timer, node);
		timerqueue_del(&rtc->timerqueue, &timer->node);
		timer->enabled = 0;
		if (timer->task.func)
			timer->task.func(timer->task.private_data);

		/* Re-add/fwd periodic timers */
		if (ktime_to_ns(timer->period)) {
			timer->node.expires = ktime_add(timer->node.expires,
							timer->period);
			timer->enabled = 1;
			timerqueue_add(&rtc->timerqueue, &timer->node);
		}
	}

	/* Set next alarm */
	if (next) {
		struct rtc_wkalrm alarm;
		int err;
		int retry = 3;

		alarm.time = rtc_ktime_to_tm(next->expires);
		alarm.enabled = 1;
reprogram:
		err = __rtc_set_alarm(rtc, &alarm);
		if (err == -ETIME)
			goto again;
		else if (err) {
			if (retry-- > 0)
				goto reprogram;

			timer = container_of(next, struct rtc_timer, node);
			timerqueue_del(&rtc->timerqueue, &timer->node);
			timer->enabled = 0;
			dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err);
			goto again;
		}
	} else
		rtc_alarm_disable(rtc);

	pm_relax(rtc->dev.parent);
	mutex_unlock(&rtc->ops_lock);
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
194
57.23%
1
10.00%
Xunlei Pang
70
20.65%
1
10.00%
Alessandro Zummo
51
15.04%
2
20.00%
Zoran Markovic
9
2.65%
1
10.00%
David Brownell
6
1.77%
2
20.00%
Rabin Vincent
6
1.77%
1
10.00%
Jiri Kosina
2
0.59%
1
10.00%
Thomas Gleixner
1
0.29%
1
10.00%
Total
339
100.00%
10
100.00%

/* rtc_timer_init - Initializes an rtc_timer
 * @timer: timer to be intiialized
 * @f: function pointer to be called when timer fires
 * @data: private data passed to function pointer
 *
 * Kernel interface to initializing an rtc_timer.
 */


void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
{
	timerqueue_init(&timer->node);
	timer->enabled = 0;
	timer->task.func = f;
	timer->task.private_data = data;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
34
61.82%
1
33.33%
Alessandro Zummo
20
36.36%
1
33.33%
Thomas Gleixner
1
1.82%
1
33.33%
Total
55
100.00%
3
100.00%

/* rtc_timer_start - Sets an rtc_timer to fire in the future
 * @ rtc: rtc device to be used
 * @ timer: timer being set
 * @ expires: time at which to expire the timer
 * @ period: period that the timer will recur
 *
 * Kernel interface to set an rtc_timer
 */


int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
			ktime_t expires, ktime_t period)
{
	int ret = 0;
	mutex_lock(&rtc->ops_lock);
	if (timer->enabled)
		rtc_timer_remove(rtc, timer);

	timer->node.expires = expires;
	timer->period = period;

	ret = rtc_timer_enqueue(rtc, timer);

	mutex_unlock(&rtc->ops_lock);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Alessandro Zummo
41
50.62%
2
33.33%
John Stultz
34
41.98%
2
33.33%
David Brownell
3
3.70%
1
16.67%
Thomas Gleixner
3
3.70%
1
16.67%
Total
81
100.00%
6
100.00%

/* rtc_timer_cancel - Stops an rtc_timer
 * @ rtc: rtc device to be used
 * @ timer: timer being set
 *
 * Kernel interface to cancel an rtc_timer
 */


void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
{
	mutex_lock(&rtc->ops_lock);
	if (timer->enabled)
		rtc_timer_remove(rtc, timer);
	mutex_unlock(&rtc->ops_lock);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Alessandro Zummo
28
63.64%
2
33.33%
John Stultz
10
22.73%
1
16.67%
David Brownell
3
6.82%
1
16.67%
Thomas Gleixner
2
4.55%
1
16.67%
Krzysztof Kozlowski
1
2.27%
1
16.67%
Total
44
100.00%
6
100.00%

/**
 * rtc_read_offset - Read the amount of rtc offset in parts per billion
 * @ rtc: rtc device to be used
 * @ offset: the offset in parts per billion
 *
 * see below for details.
 *
 * Kernel interface to read rtc clock offset
 * Returns 0 on success, or a negative number on error.
 * If read_offset() is not implemented for the rtc, return -EINVAL
 */


int rtc_read_offset(struct rtc_device *rtc, long *offset)
{
	int ret;

	if (!rtc->ops)
		return -ENODEV;

	if (!rtc->ops->read_offset)
		return -EINVAL;

	mutex_lock(&rtc->ops_lock);
	ret = rtc->ops->read_offset(rtc->dev.parent, offset);
	mutex_unlock(&rtc->ops_lock);
	return ret;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Joshua Clayton
77
100.00%
1
100.00%
Total
77
100.00%
1
100.00%

/**
 * rtc_set_offset - Adjusts the duration of the average second
 * @ rtc: rtc device to be used
 * @ offset: the offset in parts per billion
 *
 * Some rtc's allow an adjustment to the average duration of a second
 * to compensate for differences in the actual clock rate due to temperature,
 * the crystal, capacitor, etc.
 *
 * Kernel interface to adjust an rtc clock offset.
 * Return 0 on success, or a negative number on error.
 * If the rtc offset is not setable (or not implemented), return -EINVAL
 */


int rtc_set_offset(struct rtc_device *rtc, long offset)
{
	int ret;

	if (!rtc->ops)
		return -ENODEV;

	if (!rtc->ops->set_offset)
		return -EINVAL;

	mutex_lock(&rtc->ops_lock);
	ret = rtc->ops->set_offset(rtc->dev.parent, offset);
	mutex_unlock(&rtc->ops_lock);
	return ret;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Joshua Clayton
76
100.00%
1
100.00%
Total
76
100.00%
1
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
John Stultz
2414
57.48%
8
14.29%
Alessandro Zummo
648
15.43%
5
8.93%
Joshua Clayton
155
3.69%
1
1.79%
Xunlei Pang
127
3.02%
3
5.36%
Thomas Gleixner
123
2.93%
4
7.14%
David Brownell
123
2.93%
7
12.50%
Uwe Kleine-König
94
2.24%
3
5.36%
Mark Lord
84
2.00%
1
1.79%
Ales Novak
79
1.88%
1
1.79%
Colin Ian King
60
1.43%
1
1.79%
Rabin Vincent
54
1.29%
1
1.79%
Hyogi Gim
48
1.14%
2
3.57%
Linus Torvalds
42
1.00%
1
1.79%
Zoran Markovic
40
0.95%
1
1.79%
Vaibhav Jain
20
0.48%
1
1.79%
Neil Brown
18
0.43%
2
3.57%
Dave Young
15
0.36%
1
1.79%
Ben Hutchings
14
0.33%
1
1.79%
Marcelo Roberto Jimenez
10
0.24%
1
1.79%
Atsushi Nemoto
7
0.17%
1
1.79%
Aaro Koskinen
5
0.12%
1
1.79%
Chris Brand
4
0.10%
1
1.79%
Paul Gortmaker
3
0.07%
1
1.79%
Alexey Dobriyan
3
0.07%
1
1.79%
Michał Mirosław
3
0.07%
1
1.79%
Kay Sievers
2
0.05%
1
1.79%
Jiri Kosina
2
0.05%
1
1.79%
Mark Brown
1
0.02%
1
1.79%
Lucas De Marchi
1
0.02%
1
1.79%
Krzysztof Kozlowski
1
0.02%
1
1.79%
Total
4200
100.00%
56
100.00%
Directory: drivers/rtc

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