[mirror_ubuntu-bionic-kernel.git] / 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>

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

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

	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);
	}

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

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

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

int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
{
	int err;

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

	if (!rtc->ops)
		err = -ENODEV;
	else if (rtc->ops->set_mmss)
		err = rtc->ops->set_mmss(rtc->dev.parent, secs);
	else if (rtc->ops->read_time && rtc->ops->set_time) {
		struct rtc_time new, old;

		err = rtc->ops->read_time(rtc->dev.parent, &old);
		if (err == 0) {
			rtc_time_to_tm(secs, &new);

			/*
			 * avoid writing when we're going to change the day of
			 * the month. We will retry in the next minute. This
			 * basically means that if the RTC must not drift
			 * by more than 1 minute in 11 minutes.
			 */
			if (!((old.tm_hour == 23 && old.tm_min == 59) ||
				(new.tm_hour == 23 && new.tm_min == 59)))
				err = rtc->ops->set_time(rtc->dev.parent,
						&new);
		}
	}
	else
		err = -EINVAL;

	mutex_unlock(&rtc->ops_lock);

	return err;
}
EXPORT_SYMBOL_GPL(rtc_set_mmss);

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

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

	if (rtc->ops == NULL)
		err = -ENODEV;
	else if (!rtc->ops->read_alarm)
		err = -EINVAL;
	else {
		memset(alarm, 0, sizeof(struct rtc_wkalrm));
		err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
	}

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

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 -EBUSY;

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

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

/**
 * rtc_update_irq - report RTC periodic, alarm, and/or update irqs
 * @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: in_interrupt(), irqs blocked
 */
void rtc_update_irq(struct rtc_device *rtc,
		unsigned long num, unsigned long events)
{
	spin_lock(&rtc->irq_lock);
	rtc->irq_data = (rtc->irq_data + (num << 8)) | events;
	spin_unlock(&rtc->irq_lock);

	spin_lock(&rtc->irq_task_lock);
	if (rtc->irq_task)
		rtc->irq_task->func(rtc->irq_task->private_data);
	spin_unlock(&rtc->irq_task_lock);

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

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

	down(&rtc_class->sem);
	list_for_each_entry(dev, &rtc_class->devices, node) {
		if (strncmp(dev->bus_id, name, BUS_ID_SIZE) == 0) {
			dev = get_device(dev);
			if (dev)
				rtc = to_rtc_device(dev);
			break;
		}
	}

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

	return rtc;
}
EXPORT_SYMBOL_GPL(rtc_class_open);

void rtc_class_close(struct rtc_device *rtc)
{
	module_put(rtc->owner);
	put_device(&rtc->dev);
}
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 (!(mutex_trylock(&rtc->char_lock)))
		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);

	mutex_unlock(&rtc->char_lock);

	return retval;
}
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);
}
EXPORT_SYMBOL_GPL(rtc_irq_unregister);

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

	if (rtc->ops->irq_set_state == NULL)
		return -ENXIO;

	spin_lock_irqsave(&rtc->irq_task_lock, flags);
	if (rtc->irq_task != NULL && task == NULL)
		err = -EBUSY;
	if (rtc->irq_task != task)
		err = -EACCES;
	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);

	if (err == 0)
		err = rtc->ops->irq_set_state(rtc->dev.parent, enabled);

	return err;
}
EXPORT_SYMBOL_GPL(rtc_irq_set_state);

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

	if (rtc->ops->irq_set_freq == NULL)
		return -ENXIO;

	spin_lock_irqsave(&rtc->irq_task_lock, flags);
	if (rtc->irq_task != NULL && task == NULL)
		err = -EBUSY;
	if (rtc->irq_task != task)
		err = -EACCES;
	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);

	if (err == 0) {
		err = rtc->ops->irq_set_freq(rtc->dev.parent, freq);
		if (err == 0)
			rtc->irq_freq = freq;
	}
	return err;
}
EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
Commit	Line	Data
0c86edc0 AZ	1	/*
	2	* RTC subsystem, interface functions
	3	*
	4	* Copyright (C) 2005 Tower Technologies
	5	* Author: Alessandro Zummo <a.zummo@towertech.it>
	6	*
	7	* based on arch/arm/common/rtctime.c
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/rtc.h>
	15
ab6a2d70	16	int rtc_read_time(struct rtc_device rtc, struct rtc_time tm)
0c86edc0 AZ	17	{
0c86edc0 AZ	18	int err;
0c86edc0 AZ	19
	20	err = mutex_lock_interruptible(&rtc->ops_lock);
	21	if (err)
	22	return -EBUSY;
	23
	24	if (!rtc->ops)
	25	err = -ENODEV;
	26	else if (!rtc->ops->read_time)
	27	err = -EINVAL;
	28	else {
	29	memset(tm, 0, sizeof(struct rtc_time));
cd966209	30	err = rtc->ops->read_time(rtc->dev.parent, tm);
0c86edc0 AZ	31	}
	32
	33	mutex_unlock(&rtc->ops_lock);
	34	return err;
	35	}
	36	EXPORT_SYMBOL_GPL(rtc_read_time);
	37
ab6a2d70	38	int rtc_set_time(struct rtc_device rtc, struct rtc_time tm)
0c86edc0 AZ	39	{
0c86edc0 AZ	40	int err;
0c86edc0 AZ	41
	42	err = rtc_valid_tm(tm);
	43	if (err != 0)
	44	return err;
	45
	46	err = mutex_lock_interruptible(&rtc->ops_lock);
	47	if (err)
	48	return -EBUSY;
	49
	50	if (!rtc->ops)
	51	err = -ENODEV;
	52	else if (!rtc->ops->set_time)
	53	err = -EINVAL;
	54	else
cd966209	55	err = rtc->ops->set_time(rtc->dev.parent, tm);
0c86edc0 AZ	56
	57	mutex_unlock(&rtc->ops_lock);
	58	return err;
	59	}
	60	EXPORT_SYMBOL_GPL(rtc_set_time);
	61
ab6a2d70	62	int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
0c86edc0 AZ	63	{
0c86edc0 AZ	64	int err;
0c86edc0 AZ	65
	66	err = mutex_lock_interruptible(&rtc->ops_lock);
	67	if (err)
	68	return -EBUSY;
	69
	70	if (!rtc->ops)
	71	err = -ENODEV;
	72	else if (rtc->ops->set_mmss)
cd966209	73	err = rtc->ops->set_mmss(rtc->dev.parent, secs);
0c86edc0 AZ	74	else if (rtc->ops->read_time && rtc->ops->set_time) {
	75	struct rtc_time new, old;
	76
cd966209	77	err = rtc->ops->read_time(rtc->dev.parent, &old);
0c86edc0 AZ	78	if (err == 0) {
	79	rtc_time_to_tm(secs, &new);
	80
	81	/*
	82	* avoid writing when we're going to change the day of
	83	* the month. We will retry in the next minute. This
	84	* basically means that if the RTC must not drift
	85	* by more than 1 minute in 11 minutes.
	86	*/
	87	if (!((old.tm_hour == 23 && old.tm_min == 59) \|\|
	88	(new.tm_hour == 23 && new.tm_min == 59)))
cd966209	89	err = rtc->ops->set_time(rtc->dev.parent,
ab6a2d70	90	&new);
0c86edc0 AZ	91	}
	92	}
	93	else
	94	err = -EINVAL;
	95
	96	mutex_unlock(&rtc->ops_lock);
	97
	98	return err;
	99	}
	100	EXPORT_SYMBOL_GPL(rtc_set_mmss);
	101
ab6a2d70	102	int rtc_read_alarm(struct rtc_device rtc, struct rtc_wkalrm alarm)
0c86edc0 AZ	103	{
0c86edc0 AZ	104	int err;
0c86edc0 AZ	105
	106	err = mutex_lock_interruptible(&rtc->ops_lock);
	107	if (err)
	108	return -EBUSY;
	109
	110	if (rtc->ops == NULL)
	111	err = -ENODEV;
	112	else if (!rtc->ops->read_alarm)
	113	err = -EINVAL;
	114	else {
	115	memset(alarm, 0, sizeof(struct rtc_wkalrm));
cd966209	116	err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
0c86edc0 AZ	117	}
	118
	119	mutex_unlock(&rtc->ops_lock);
	120	return err;
	121	}
	122	EXPORT_SYMBOL_GPL(rtc_read_alarm);
	123
ab6a2d70	124	int rtc_set_alarm(struct rtc_device rtc, struct rtc_wkalrm alarm)
0c86edc0 AZ	125	{
0c86edc0 AZ	126	int err;
0c86edc0	127
f8245c26 DB	128	err = rtc_valid_tm(&alarm->time);
	129	if (err != 0)
	130	return err;
	131
0c86edc0 AZ	132	err = mutex_lock_interruptible(&rtc->ops_lock);
	133	if (err)
	134	return -EBUSY;
	135
	136	if (!rtc->ops)
	137	err = -ENODEV;
	138	else if (!rtc->ops->set_alarm)
	139	err = -EINVAL;
	140	else
cd966209	141	err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
0c86edc0 AZ	142
	143	mutex_unlock(&rtc->ops_lock);
	144	return err;
	145	}
	146	EXPORT_SYMBOL_GPL(rtc_set_alarm);
	147
d728b1e6 DB	148	/**
d728b1e6 DB	149	* rtc_update_irq - report RTC periodic, alarm, and/or update irqs
ab6a2d70	150	* @rtc: the rtc device
d728b1e6 DB	151	* @num: how many irqs are being reported (usually one)
	152	* @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
	153	* Context: in_interrupt(), irqs blocked
	154	*/
ab6a2d70	155	void rtc_update_irq(struct rtc_device *rtc,
0c86edc0 AZ	156	unsigned long num, unsigned long events)
0c86edc0 AZ	157	{
0c86edc0 AZ	158	spin_lock(&rtc->irq_lock);
	159	rtc->irq_data = (rtc->irq_data + (num << 8)) \| events;
	160	spin_unlock(&rtc->irq_lock);
	161
	162	spin_lock(&rtc->irq_task_lock);
	163	if (rtc->irq_task)
	164	rtc->irq_task->func(rtc->irq_task->private_data);
	165	spin_unlock(&rtc->irq_task_lock);
	166
	167	wake_up_interruptible(&rtc->irq_queue);
	168	kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
	169	}
	170	EXPORT_SYMBOL_GPL(rtc_update_irq);
	171
ab6a2d70	172	struct rtc_device rtc_class_open(char name)
0c86edc0	173	{
cd966209	174	struct device *dev;
ab6a2d70	175	struct rtc_device *rtc = NULL;
0c86edc0 AZ	176
0c86edc0 AZ	177	down(&rtc_class->sem);
cd966209 DB	178	list_for_each_entry(dev, &rtc_class->devices, node) {
	179	if (strncmp(dev->bus_id, name, BUS_ID_SIZE) == 0) {
	180	dev = get_device(dev);
	181	if (dev)
	182	rtc = to_rtc_device(dev);
0c86edc0 AZ	183	break;
	184	}
	185	}
	186
ab6a2d70 DB	187	if (rtc) {
ab6a2d70 DB	188	if (!try_module_get(rtc->owner)) {
cd966209	189	put_device(dev);
ab6a2d70 DB	190	rtc = NULL;
ab6a2d70 DB	191	}
0c86edc0 AZ	192	}
	193	up(&rtc_class->sem);
	194
ab6a2d70	195	return rtc;
0c86edc0 AZ	196	}
	197	EXPORT_SYMBOL_GPL(rtc_class_open);
	198
ab6a2d70	199	void rtc_class_close(struct rtc_device *rtc)
0c86edc0	200	{
ab6a2d70	201	module_put(rtc->owner);
cd966209	202	put_device(&rtc->dev);
0c86edc0 AZ	203	}
	204	EXPORT_SYMBOL_GPL(rtc_class_close);
	205
ab6a2d70	206	int rtc_irq_register(struct rtc_device rtc, struct rtc_task task)
0c86edc0 AZ	207	{
0c86edc0 AZ	208	int retval = -EBUSY;
0c86edc0 AZ	209
	210	if (task == NULL \|\| task->func == NULL)
	211	return -EINVAL;
	212
d691eb90 AZ	213	/* Cannot register while the char dev is in use */
	214	if (!(mutex_trylock(&rtc->char_lock)))
	215	return -EBUSY;
	216
d728b1e6	217	spin_lock_irq(&rtc->irq_task_lock);
0c86edc0 AZ	218	if (rtc->irq_task == NULL) {
	219	rtc->irq_task = task;
	220	retval = 0;
	221	}
d728b1e6	222	spin_unlock_irq(&rtc->irq_task_lock);
0c86edc0	223
d691eb90 AZ	224	mutex_unlock(&rtc->char_lock);
d691eb90 AZ	225
0c86edc0 AZ	226	return retval;
	227	}
	228	EXPORT_SYMBOL_GPL(rtc_irq_register);
	229
ab6a2d70	230	void rtc_irq_unregister(struct rtc_device rtc, struct rtc_task task)
0c86edc0	231	{
d728b1e6	232	spin_lock_irq(&rtc->irq_task_lock);
0c86edc0 AZ	233	if (rtc->irq_task == task)
0c86edc0 AZ	234	rtc->irq_task = NULL;
d728b1e6	235	spin_unlock_irq(&rtc->irq_task_lock);
0c86edc0 AZ	236	}
	237	EXPORT_SYMBOL_GPL(rtc_irq_unregister);
	238
ab6a2d70	239	int rtc_irq_set_state(struct rtc_device rtc, struct rtc_task task, int enabled)
0c86edc0 AZ	240	{
	241	int err = 0;
	242	unsigned long flags;
0c86edc0	243
56f10c63 AZ	244	if (rtc->ops->irq_set_state == NULL)
	245	return -ENXIO;
	246
0c86edc0	247	spin_lock_irqsave(&rtc->irq_task_lock, flags);
d691eb90 AZ	248	if (rtc->irq_task != NULL && task == NULL)
d691eb90 AZ	249	err = -EBUSY;
0c86edc0	250	if (rtc->irq_task != task)
d691eb90	251	err = -EACCES;
0c86edc0 AZ	252	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
	253
	254	if (err == 0)
cd966209	255	err = rtc->ops->irq_set_state(rtc->dev.parent, enabled);
0c86edc0 AZ	256
	257	return err;
	258	}
	259	EXPORT_SYMBOL_GPL(rtc_irq_set_state);
	260
ab6a2d70	261	int rtc_irq_set_freq(struct rtc_device rtc, struct rtc_task task, int freq)
0c86edc0	262	{
56f10c63	263	int err = 0;
0c86edc0	264	unsigned long flags;
0c86edc0	265
56f10c63 AZ	266	if (rtc->ops->irq_set_freq == NULL)
56f10c63 AZ	267	return -ENXIO;
0c86edc0 AZ	268
0c86edc0 AZ	269	spin_lock_irqsave(&rtc->irq_task_lock, flags);
d691eb90 AZ	270	if (rtc->irq_task != NULL && task == NULL)
d691eb90 AZ	271	err = -EBUSY;
0c86edc0	272	if (rtc->irq_task != task)
d691eb90	273	err = -EACCES;
0c86edc0 AZ	274	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
	275
	276	if (err == 0) {
cd966209	277	err = rtc->ops->irq_set_freq(rtc->dev.parent, freq);
0c86edc0 AZ	278	if (err == 0)
	279	rtc->irq_freq = freq;
	280	}
	281	return err;
	282	}
2601a464	283	EXPORT_SYMBOL_GPL(rtc_irq_set_freq);