[deliverable/linux.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->class_dev.dev, 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->class_dev.dev, 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->class_dev.dev, secs);
	else if (rtc->ops->read_time && rtc->ops->set_time) {
		struct rtc_time new, old;

		err = rtc->ops->read_time(rtc->class_dev.dev, &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->class_dev.dev,
						&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->class_dev.dev, 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 = 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->class_dev.dev, 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 class_device *class_dev_tmp;
	struct rtc_device *rtc = NULL;

	down(&rtc_class->sem);
	list_for_each_entry(class_dev_tmp, &rtc_class->children, node) {
		if (strncmp(class_dev_tmp->class_id, name, BUS_ID_SIZE) == 0) {
			class_dev_tmp = class_device_get(class_dev_tmp);
			if (class_dev_tmp)
				rtc = to_rtc_device(class_dev_tmp);
			break;
		}
	}

	if (rtc) {
		if (!try_module_get(rtc->owner)) {
			class_device_put(class_dev_tmp);
			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);
	class_device_put(&rtc->class_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;

	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);

	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 != task)
		err = -ENXIO;
	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);

	if (err == 0)
		err = rtc->ops->irq_set_state(rtc->class_dev.dev, 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 != task)
		err = -ENXIO;
	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);

	if (err == 0) {
		err = rtc->ops->irq_set_freq(rtc->class_dev.dev, 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));
ab6a2d70	30	err = rtc->ops->read_time(rtc->class_dev.dev, 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
ab6a2d70	55	err = rtc->ops->set_time(rtc->class_dev.dev, 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)
ab6a2d70	73	err = rtc->ops->set_mmss(rtc->class_dev.dev, secs);
0c86edc0 AZ	74	else if (rtc->ops->read_time && rtc->ops->set_time) {
	75	struct rtc_time new, old;
	76
ab6a2d70	77	err = rtc->ops->read_time(rtc->class_dev.dev, &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)))
ab6a2d70 DB	89	err = rtc->ops->set_time(rtc->class_dev.dev,
ab6a2d70 DB	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));
ab6a2d70	116	err = rtc->ops->read_alarm(rtc->class_dev.dev, 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 AZ	127
	128	err = mutex_lock_interruptible(&rtc->ops_lock);
	129	if (err)
	130	return -EBUSY;
	131
	132	if (!rtc->ops)
	133	err = -ENODEV;
	134	else if (!rtc->ops->set_alarm)
	135	err = -EINVAL;
	136	else
ab6a2d70	137	err = rtc->ops->set_alarm(rtc->class_dev.dev, alarm);
0c86edc0 AZ	138
	139	mutex_unlock(&rtc->ops_lock);
	140	return err;
	141	}
	142	EXPORT_SYMBOL_GPL(rtc_set_alarm);
	143
d728b1e6 DB	144	/**
d728b1e6 DB	145	* rtc_update_irq - report RTC periodic, alarm, and/or update irqs
ab6a2d70	146	* @rtc: the rtc device
d728b1e6 DB	147	* @num: how many irqs are being reported (usually one)
	148	* @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
	149	* Context: in_interrupt(), irqs blocked
	150	*/
ab6a2d70	151	void rtc_update_irq(struct rtc_device *rtc,
0c86edc0 AZ	152	unsigned long num, unsigned long events)
0c86edc0 AZ	153	{
0c86edc0 AZ	154	spin_lock(&rtc->irq_lock);
	155	rtc->irq_data = (rtc->irq_data + (num << 8)) \| events;
	156	spin_unlock(&rtc->irq_lock);
	157
	158	spin_lock(&rtc->irq_task_lock);
	159	if (rtc->irq_task)
	160	rtc->irq_task->func(rtc->irq_task->private_data);
	161	spin_unlock(&rtc->irq_task_lock);
	162
	163	wake_up_interruptible(&rtc->irq_queue);
	164	kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
	165	}
	166	EXPORT_SYMBOL_GPL(rtc_update_irq);
	167
ab6a2d70	168	struct rtc_device rtc_class_open(char name)
0c86edc0	169	{
ab6a2d70 DB	170	struct class_device *class_dev_tmp;
ab6a2d70 DB	171	struct rtc_device *rtc = NULL;
0c86edc0 AZ	172
	173	down(&rtc_class->sem);
	174	list_for_each_entry(class_dev_tmp, &rtc_class->children, node) {
	175	if (strncmp(class_dev_tmp->class_id, name, BUS_ID_SIZE) == 0) {
ab6a2d70 DB	176	class_dev_tmp = class_device_get(class_dev_tmp);
	177	if (class_dev_tmp)
	178	rtc = to_rtc_device(class_dev_tmp);
0c86edc0 AZ	179	break;
	180	}
	181	}
	182
ab6a2d70 DB	183	if (rtc) {
	184	if (!try_module_get(rtc->owner)) {
	185	class_device_put(class_dev_tmp);
	186	rtc = NULL;
	187	}
0c86edc0 AZ	188	}
	189	up(&rtc_class->sem);
	190
ab6a2d70	191	return rtc;
0c86edc0 AZ	192	}
	193	EXPORT_SYMBOL_GPL(rtc_class_open);
	194
ab6a2d70	195	void rtc_class_close(struct rtc_device *rtc)
0c86edc0	196	{
ab6a2d70 DB	197	module_put(rtc->owner);
ab6a2d70 DB	198	class_device_put(&rtc->class_dev);
0c86edc0 AZ	199	}
	200	EXPORT_SYMBOL_GPL(rtc_class_close);
	201
ab6a2d70	202	int rtc_irq_register(struct rtc_device rtc, struct rtc_task task)
0c86edc0 AZ	203	{
0c86edc0 AZ	204	int retval = -EBUSY;
0c86edc0 AZ	205
	206	if (task == NULL \|\| task->func == NULL)
	207	return -EINVAL;
	208
d728b1e6	209	spin_lock_irq(&rtc->irq_task_lock);
0c86edc0 AZ	210	if (rtc->irq_task == NULL) {
	211	rtc->irq_task = task;
	212	retval = 0;
	213	}
d728b1e6	214	spin_unlock_irq(&rtc->irq_task_lock);
0c86edc0 AZ	215
	216	return retval;
	217	}
	218	EXPORT_SYMBOL_GPL(rtc_irq_register);
	219
ab6a2d70	220	void rtc_irq_unregister(struct rtc_device rtc, struct rtc_task task)
0c86edc0	221	{
0c86edc0	222
d728b1e6	223	spin_lock_irq(&rtc->irq_task_lock);
0c86edc0 AZ	224	if (rtc->irq_task == task)
0c86edc0 AZ	225	rtc->irq_task = NULL;
d728b1e6	226	spin_unlock_irq(&rtc->irq_task_lock);
0c86edc0 AZ	227	}
	228	EXPORT_SYMBOL_GPL(rtc_irq_unregister);
	229
ab6a2d70	230	int rtc_irq_set_state(struct rtc_device rtc, struct rtc_task task, int enabled)
0c86edc0 AZ	231	{
	232	int err = 0;
	233	unsigned long flags;
0c86edc0	234
56f10c63 AZ	235	if (rtc->ops->irq_set_state == NULL)
	236	return -ENXIO;
	237
0c86edc0 AZ	238	spin_lock_irqsave(&rtc->irq_task_lock, flags);
	239	if (rtc->irq_task != task)
	240	err = -ENXIO;
	241	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
	242
	243	if (err == 0)
ab6a2d70	244	err = rtc->ops->irq_set_state(rtc->class_dev.dev, enabled);
0c86edc0 AZ	245
	246	return err;
	247	}
	248	EXPORT_SYMBOL_GPL(rtc_irq_set_state);
	249
ab6a2d70	250	int rtc_irq_set_freq(struct rtc_device rtc, struct rtc_task task, int freq)
0c86edc0	251	{
56f10c63	252	int err = 0;
0c86edc0	253	unsigned long flags;
0c86edc0	254
56f10c63 AZ	255	if (rtc->ops->irq_set_freq == NULL)
56f10c63 AZ	256	return -ENXIO;
0c86edc0 AZ	257
	258	spin_lock_irqsave(&rtc->irq_task_lock, flags);
	259	if (rtc->irq_task != task)
	260	err = -ENXIO;
	261	spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
	262
	263	if (err == 0) {
ab6a2d70	264	err = rtc->ops->irq_set_freq(rtc->class_dev.dev, freq);
0c86edc0 AZ	265	if (err == 0)
	266	rtc->irq_freq = freq;
	267	}
	268	return err;
	269	}
2601a464	270	EXPORT_SYMBOL_GPL(rtc_irq_set_freq);