/* * 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; 	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->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 != task)		err = -ENXIO;	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);