[linux.git] / drivers / rtc / rtc-dev.c

/*
 * RTC subsystem, dev interface
 *
 * Copyright (C) 2005 Tower Technologies
 * Author: Alessandro Zummo <[email protected]>
 *
 * 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/module.h>
#include <linux/rtc.h>
#include "rtc-core.h"

static dev_t rtc_devt;

#define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */

static int rtc_dev_open(struct inode *inode, struct file *file)
{
	int err;
	struct rtc_device *rtc = container_of(inode->i_cdev,
					struct rtc_device, char_dev);
	const struct rtc_class_ops *ops = rtc->ops;

	/* We keep the lock as long as the device is in use
	 * and return immediately if busy
	 */
	if (!(mutex_trylock(&rtc->char_lock)))
		return -EBUSY;

	file->private_data = rtc;

	err = ops->open ? ops->open(rtc->dev.parent) : 0;
	if (err == 0) {
		spin_lock_irq(&rtc->irq_lock);
		rtc->irq_data = 0;
		spin_unlock_irq(&rtc->irq_lock);

		return 0;
	}

	/* something has gone wrong, release the lock */
	mutex_unlock(&rtc->char_lock);
	return err;
}

#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
/*
 * Routine to poll RTC seconds field for change as often as possible,
 * after first RTC_UIE use timer to reduce polling
 */
static void rtc_uie_task(struct work_struct *work)
{
	struct rtc_device *rtc =
		container_of(work, struct rtc_device, uie_task);
	struct rtc_time tm;
	int num = 0;
	int err;

	err = rtc_read_time(rtc, &tm);

	local_irq_disable();
	spin_lock(&rtc->irq_lock);
	if (rtc->stop_uie_polling || err) {
		rtc->uie_task_active = 0;
	} else if (rtc->oldsecs != tm.tm_sec) {
		num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
		rtc->oldsecs = tm.tm_sec;
		rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
		rtc->uie_timer_active = 1;
		rtc->uie_task_active = 0;
		add_timer(&rtc->uie_timer);
	} else if (schedule_work(&rtc->uie_task) == 0) {
		rtc->uie_task_active = 0;
	}
	spin_unlock(&rtc->irq_lock);
	if (num)
		rtc_update_irq(rtc, num, RTC_UF | RTC_IRQF);
	local_irq_enable();
}
static void rtc_uie_timer(unsigned long data)
{
	struct rtc_device *rtc = (struct rtc_device *)data;
	unsigned long flags;

	spin_lock_irqsave(&rtc->irq_lock, flags);
	rtc->uie_timer_active = 0;
	rtc->uie_task_active = 1;
	if ((schedule_work(&rtc->uie_task) == 0))
		rtc->uie_task_active = 0;
	spin_unlock_irqrestore(&rtc->irq_lock, flags);
}

static void clear_uie(struct rtc_device *rtc)
{
	spin_lock_irq(&rtc->irq_lock);
	if (rtc->irq_active) {
		rtc->stop_uie_polling = 1;
		if (rtc->uie_timer_active) {
			spin_unlock_irq(&rtc->irq_lock);
			del_timer_sync(&rtc->uie_timer);
			spin_lock_irq(&rtc->irq_lock);
			rtc->uie_timer_active = 0;
		}
		if (rtc->uie_task_active) {
			spin_unlock_irq(&rtc->irq_lock);
			flush_scheduled_work();
			spin_lock_irq(&rtc->irq_lock);
		}
		rtc->irq_active = 0;
	}
	spin_unlock_irq(&rtc->irq_lock);
}

static int set_uie(struct rtc_device *rtc)
{
	struct rtc_time tm;
	int err;

	err = rtc_read_time(rtc, &tm);
	if (err)
		return err;
	spin_lock_irq(&rtc->irq_lock);
	if (!rtc->irq_active) {
		rtc->irq_active = 1;
		rtc->stop_uie_polling = 0;
		rtc->oldsecs = tm.tm_sec;
		rtc->uie_task_active = 1;
		if (schedule_work(&rtc->uie_task) == 0)
			rtc->uie_task_active = 0;
	}
	rtc->irq_data = 0;
	spin_unlock_irq(&rtc->irq_lock);
	return 0;
}
#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */

static ssize_t
rtc_dev_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
	struct rtc_device *rtc = to_rtc_device(file->private_data);

	DECLARE_WAITQUEUE(wait, current);
	unsigned long data;
	ssize_t ret;

	if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
		return -EINVAL;

	add_wait_queue(&rtc->irq_queue, &wait);
	do {
		__set_current_state(TASK_INTERRUPTIBLE);

		spin_lock_irq(&rtc->irq_lock);
		data = rtc->irq_data;
		rtc->irq_data = 0;
		spin_unlock_irq(&rtc->irq_lock);

		if (data != 0) {
			ret = 0;
			break;
		}
		if (file->f_flags & O_NONBLOCK) {
			ret = -EAGAIN;
			break;
		}
		if (signal_pending(current)) {
			ret = -ERESTARTSYS;
			break;
		}
		schedule();
	} while (1);
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&rtc->irq_queue, &wait);

	if (ret == 0) {
		/* Check for any data updates */
		if (rtc->ops->read_callback)
			data = rtc->ops->read_callback(rtc->dev.parent,
						       data);

		if (sizeof(int) != sizeof(long) &&
		    count == sizeof(unsigned int))
			ret = put_user(data, (unsigned int __user *)buf) ?:
				sizeof(unsigned int);
		else
			ret = put_user(data, (unsigned long __user *)buf) ?:
				sizeof(unsigned long);
	}
	return ret;
}

static unsigned int rtc_dev_poll(struct file *file, poll_table *wait)
{
	struct rtc_device *rtc = to_rtc_device(file->private_data);
	unsigned long data;

	poll_wait(file, &rtc->irq_queue, wait);

	data = rtc->irq_data;

	return (data != 0) ? (POLLIN | POLLRDNORM) : 0;
}

static int rtc_dev_ioctl(struct inode *inode, struct file *file,
		unsigned int cmd, unsigned long arg)
{
	int err = 0;
	struct rtc_device *rtc = file->private_data;
	const struct rtc_class_ops *ops = rtc->ops;
	struct rtc_time tm;
	struct rtc_wkalrm alarm;
	void __user *uarg = (void __user *) arg;

	/* check that the calling task has appropriate permissions
	 * for certain ioctls. doing this check here is useful
	 * to avoid duplicate code in each driver.
	 */
	switch (cmd) {
	case RTC_EPOCH_SET:
	case RTC_SET_TIME:
		if (!capable(CAP_SYS_TIME))
			return -EACCES;
		break;

	case RTC_IRQP_SET:
		if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
			return -EACCES;
		break;

	case RTC_PIE_ON:
		if (!capable(CAP_SYS_RESOURCE))
			return -EACCES;
		break;
	}

	/* avoid conflicting IRQ users */
	if (cmd == RTC_PIE_ON || cmd == RTC_PIE_OFF || cmd == RTC_IRQP_SET) {
		spin_lock_irq(&rtc->irq_task_lock);
		if (rtc->irq_task)
			err = -EBUSY;
		spin_unlock_irq(&rtc->irq_task_lock);

		if (err < 0)
			return err;
	}

	/* try the driver's ioctl interface */
	if (ops->ioctl) {
		err = ops->ioctl(rtc->dev.parent, cmd, arg);
		if (err != -ENOIOCTLCMD)
			return err;
	}

	/* if the driver does not provide the ioctl interface
	 * or if that particular ioctl was not implemented
	 * (-ENOIOCTLCMD), we will try to emulate here.
	 */

	switch (cmd) {
	case RTC_ALM_READ:
		err = rtc_read_alarm(rtc, &alarm);
		if (err < 0)
			return err;

		if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
			return -EFAULT;
		break;

	case RTC_ALM_SET:
		if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
			return -EFAULT;

		alarm.enabled = 0;
		alarm.pending = 0;
		alarm.time.tm_wday = -1;
		alarm.time.tm_yday = -1;
		alarm.time.tm_isdst = -1;

		/* RTC_ALM_SET alarms may be up to 24 hours in the future.
		 * Rather than expecting every RTC to implement "don't care"
		 * for day/month/year fields, just force the alarm to have
		 * the right values for those fields.
		 *
		 * RTC_WKALM_SET should be used instead.  Not only does it
		 * eliminate the need for a separate RTC_AIE_ON call, it
		 * doesn't have the "alarm 23:59:59 in the future" race.
		 *
		 * NOTE:  some legacy code may have used invalid fields as
		 * wildcards, exposing hardware "periodic alarm" capabilities.
		 * Not supported here.
		 */
		{
			unsigned long now, then;

			err = rtc_read_time(rtc, &tm);
			if (err < 0)
				return err;
			rtc_tm_to_time(&tm, &now);

			alarm.time.tm_mday = tm.tm_mday;
			alarm.time.tm_mon = tm.tm_mon;
			alarm.time.tm_year = tm.tm_year;
			err  = rtc_valid_tm(&alarm.time);
			if (err < 0)
				return err;
			rtc_tm_to_time(&alarm.time, &then);

			/* alarm may need to wrap into tomorrow */
			if (then < now) {
				rtc_time_to_tm(now + 24 * 60 * 60, &tm);
				alarm.time.tm_mday = tm.tm_mday;
				alarm.time.tm_mon = tm.tm_mon;
				alarm.time.tm_year = tm.tm_year;
			}
		}

		err = rtc_set_alarm(rtc, &alarm);
		break;

	case RTC_RD_TIME:
		err = rtc_read_time(rtc, &tm);
		if (err < 0)
			return err;

		if (copy_to_user(uarg, &tm, sizeof(tm)))
			return -EFAULT;
		break;

	case RTC_SET_TIME:
		if (copy_from_user(&tm, uarg, sizeof(tm)))
			return -EFAULT;

		err = rtc_set_time(rtc, &tm);
		break;

	case RTC_IRQP_READ:
		if (ops->irq_set_freq)
			err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
		break;

	case RTC_IRQP_SET:
		if (ops->irq_set_freq)
			err = rtc_irq_set_freq(rtc, rtc->irq_task, arg);
		break;

#if 0
	case RTC_EPOCH_SET:
#ifndef rtc_epoch
		/*
		 * There were no RTC clocks before 1900.
		 */
		if (arg < 1900) {
			err = -EINVAL;
			break;
		}
		rtc_epoch = arg;
		err = 0;
#endif
		break;

	case RTC_EPOCH_READ:
		err = put_user(rtc_epoch, (unsigned long __user *)uarg);
		break;
#endif
	case RTC_WKALM_SET:
		if (copy_from_user(&alarm, uarg, sizeof(alarm)))
			return -EFAULT;

		err = rtc_set_alarm(rtc, &alarm);
		break;

	case RTC_WKALM_RD:
		err = rtc_read_alarm(rtc, &alarm);
		if (err < 0)
			return err;

		if (copy_to_user(uarg, &alarm, sizeof(alarm)))
			return -EFAULT;
		break;

#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	case RTC_UIE_OFF:
		clear_uie(rtc);
		return 0;

	case RTC_UIE_ON:
		return set_uie(rtc);
#endif
	default:
		err = -ENOTTY;
		break;
	}

	return err;
}

static int rtc_dev_release(struct inode *inode, struct file *file)
{
	struct rtc_device *rtc = to_rtc_device(file->private_data);

#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	clear_uie(rtc);
#endif
	if (rtc->ops->release)
		rtc->ops->release(rtc->dev.parent);

	mutex_unlock(&rtc->char_lock);
	return 0;
}

static int rtc_dev_fasync(int fd, struct file *file, int on)
{
	struct rtc_device *rtc = to_rtc_device(file->private_data);
	return fasync_helper(fd, file, on, &rtc->async_queue);
}

static const struct file_operations rtc_dev_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= rtc_dev_read,
	.poll		= rtc_dev_poll,
	.ioctl		= rtc_dev_ioctl,
	.open		= rtc_dev_open,
	.release	= rtc_dev_release,
	.fasync		= rtc_dev_fasync,
};

/* insertion/removal hooks */

void rtc_dev_prepare(struct rtc_device *rtc)
{
	if (!rtc_devt)
		return;

	if (rtc->id >= RTC_DEV_MAX) {
		pr_debug("%s: too many RTC devices\n", rtc->name);
		return;
	}

	rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);

	mutex_init(&rtc->char_lock);
	spin_lock_init(&rtc->irq_lock);
	init_waitqueue_head(&rtc->irq_queue);
#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	INIT_WORK(&rtc->uie_task, rtc_uie_task);
	setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
#endif

	cdev_init(&rtc->char_dev, &rtc_dev_fops);
	rtc->char_dev.owner = rtc->owner;
}

void rtc_dev_add_device(struct rtc_device *rtc)
{
	if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
		printk(KERN_WARNING "%s: failed to add char device %d:%d\n",
			rtc->name, MAJOR(rtc_devt), rtc->id);
	else
		pr_debug("%s: dev (%d:%d)\n", rtc->name,
			MAJOR(rtc_devt), rtc->id);
}

void rtc_dev_del_device(struct rtc_device *rtc)
{
	if (rtc->dev.devt)
		cdev_del(&rtc->char_dev);
}

void __init rtc_dev_init(void)
{
	int err;

	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
	if (err < 0)
		printk(KERN_ERR "%s: failed to allocate char dev region\n",
			__FILE__);
}

void __exit rtc_dev_exit(void)
{
	if (rtc_devt)
		unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
}
Commit	Line	Data
e824290e AZ	1	/*
	2	* RTC subsystem, dev interface
	3	*
	4	* Copyright (C) 2005 Tower Technologies
	5	* Author: Alessandro Zummo <[email protected]>
	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/module.h>
	15	#include <linux/rtc.h>
5726fb20	16	#include "rtc-core.h"
e824290e	17
e824290e AZ	18	static dev_t rtc_devt;
	19
	20	#define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */
	21
	22	static int rtc_dev_open(struct inode inode, struct file file)
	23	{
	24	int err;
	25	struct rtc_device *rtc = container_of(inode->i_cdev,
	26	struct rtc_device, char_dev);
ff8371ac	27	const struct rtc_class_ops *ops = rtc->ops;
e824290e AZ	28
	29	/* We keep the lock as long as the device is in use
	30	* and return immediately if busy
	31	*/
	32	if (!(mutex_trylock(&rtc->char_lock)))
	33	return -EBUSY;
	34
ab6a2d70	35	file->private_data = rtc;
e824290e	36
cd966209	37	err = ops->open ? ops->open(rtc->dev.parent) : 0;
e824290e AZ	38	if (err == 0) {
	39	spin_lock_irq(&rtc->irq_lock);
	40	rtc->irq_data = 0;
	41	spin_unlock_irq(&rtc->irq_lock);
	42
	43	return 0;
	44	}
	45
	46	/* something has gone wrong, release the lock */
	47	mutex_unlock(&rtc->char_lock);
	48	return err;
	49	}
	50
655066c3 AN	51	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	52	/*
	53	* Routine to poll RTC seconds field for change as often as possible,
	54	* after first RTC_UIE use timer to reduce polling
	55	*/
c4028958	56	static void rtc_uie_task(struct work_struct *work)
655066c3	57	{
c4028958 DH	58	struct rtc_device *rtc =
c4028958 DH	59	container_of(work, struct rtc_device, uie_task);
655066c3 AN	60	struct rtc_time tm;
	61	int num = 0;
	62	int err;
	63
ab6a2d70	64	err = rtc_read_time(rtc, &tm);
d728b1e6 DB	65
	66	local_irq_disable();
	67	spin_lock(&rtc->irq_lock);
655066c3 AN	68	if (rtc->stop_uie_polling \|\| err) {
	69	rtc->uie_task_active = 0;
	70	} else if (rtc->oldsecs != tm.tm_sec) {
	71	num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
	72	rtc->oldsecs = tm.tm_sec;
	73	rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
	74	rtc->uie_timer_active = 1;
	75	rtc->uie_task_active = 0;
	76	add_timer(&rtc->uie_timer);
	77	} else if (schedule_work(&rtc->uie_task) == 0) {
	78	rtc->uie_task_active = 0;
	79	}
d728b1e6	80	spin_unlock(&rtc->irq_lock);
655066c3	81	if (num)
ab6a2d70	82	rtc_update_irq(rtc, num, RTC_UF \| RTC_IRQF);
d728b1e6	83	local_irq_enable();
655066c3	84	}
655066c3 AN	85	static void rtc_uie_timer(unsigned long data)
	86	{
	87	struct rtc_device rtc = (struct rtc_device )data;
	88	unsigned long flags;
	89
	90	spin_lock_irqsave(&rtc->irq_lock, flags);
	91	rtc->uie_timer_active = 0;
	92	rtc->uie_task_active = 1;
	93	if ((schedule_work(&rtc->uie_task) == 0))
	94	rtc->uie_task_active = 0;
	95	spin_unlock_irqrestore(&rtc->irq_lock, flags);
	96	}
	97
	98	static void clear_uie(struct rtc_device *rtc)
	99	{
	100	spin_lock_irq(&rtc->irq_lock);
	101	if (rtc->irq_active) {
	102	rtc->stop_uie_polling = 1;
	103	if (rtc->uie_timer_active) {
	104	spin_unlock_irq(&rtc->irq_lock);
	105	del_timer_sync(&rtc->uie_timer);
	106	spin_lock_irq(&rtc->irq_lock);
	107	rtc->uie_timer_active = 0;
	108	}
	109	if (rtc->uie_task_active) {
	110	spin_unlock_irq(&rtc->irq_lock);
	111	flush_scheduled_work();
	112	spin_lock_irq(&rtc->irq_lock);
	113	}
	114	rtc->irq_active = 0;
	115	}
	116	spin_unlock_irq(&rtc->irq_lock);
	117	}
	118
	119	static int set_uie(struct rtc_device *rtc)
	120	{
	121	struct rtc_time tm;
	122	int err;
	123
ab6a2d70	124	err = rtc_read_time(rtc, &tm);
655066c3 AN	125	if (err)
	126	return err;
	127	spin_lock_irq(&rtc->irq_lock);
	128	if (!rtc->irq_active) {
	129	rtc->irq_active = 1;
	130	rtc->stop_uie_polling = 0;
	131	rtc->oldsecs = tm.tm_sec;
	132	rtc->uie_task_active = 1;
	133	if (schedule_work(&rtc->uie_task) == 0)
	134	rtc->uie_task_active = 0;
	135	}
	136	rtc->irq_data = 0;
	137	spin_unlock_irq(&rtc->irq_lock);
	138	return 0;
	139	}
	140	#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
e824290e AZ	141
	142	static ssize_t
	143	rtc_dev_read(struct file file, char __user buf, size_t count, loff_t *ppos)
	144	{
	145	struct rtc_device *rtc = to_rtc_device(file->private_data);
	146
	147	DECLARE_WAITQUEUE(wait, current);
	148	unsigned long data;
	149	ssize_t ret;
	150
3418ff76	151	if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
e824290e AZ	152	return -EINVAL;
	153
	154	add_wait_queue(&rtc->irq_queue, &wait);
	155	do {
	156	__set_current_state(TASK_INTERRUPTIBLE);
	157
	158	spin_lock_irq(&rtc->irq_lock);
	159	data = rtc->irq_data;
	160	rtc->irq_data = 0;
	161	spin_unlock_irq(&rtc->irq_lock);
	162
	163	if (data != 0) {
	164	ret = 0;
	165	break;
	166	}
	167	if (file->f_flags & O_NONBLOCK) {
	168	ret = -EAGAIN;
	169	break;
	170	}
	171	if (signal_pending(current)) {
	172	ret = -ERESTARTSYS;
	173	break;
	174	}
	175	schedule();
	176	} while (1);
	177	set_current_state(TASK_RUNNING);
	178	remove_wait_queue(&rtc->irq_queue, &wait);
	179
	180	if (ret == 0) {
	181	/* Check for any data updates */
	182	if (rtc->ops->read_callback)
cd966209	183	data = rtc->ops->read_callback(rtc->dev.parent,
3418ff76 AN	184	data);
	185
	186	if (sizeof(int) != sizeof(long) &&
	187	count == sizeof(unsigned int))
	188	ret = put_user(data, (unsigned int __user *)buf) ?:
	189	sizeof(unsigned int);
	190	else
	191	ret = put_user(data, (unsigned long __user *)buf) ?:
	192	sizeof(unsigned long);
e824290e AZ	193	}
	194	return ret;
	195	}
	196
	197	static unsigned int rtc_dev_poll(struct file file, poll_table wait)
	198	{
	199	struct rtc_device *rtc = to_rtc_device(file->private_data);
	200	unsigned long data;
	201
	202	poll_wait(file, &rtc->irq_queue, wait);
	203
	204	data = rtc->irq_data;
	205
	206	return (data != 0) ? (POLLIN \| POLLRDNORM) : 0;
	207	}
	208
	209	static int rtc_dev_ioctl(struct inode inode, struct file file,
	210	unsigned int cmd, unsigned long arg)
	211	{
	212	int err = 0;
ab6a2d70	213	struct rtc_device *rtc = file->private_data;
ff8371ac	214	const struct rtc_class_ops *ops = rtc->ops;
e824290e AZ	215	struct rtc_time tm;
	216	struct rtc_wkalrm alarm;
	217	void __user uarg = (void __user ) arg;
	218
2601a464	219	/* check that the calling task has appropriate permissions
110d693d AZ	220	* for certain ioctls. doing this check here is useful
	221	* to avoid duplicate code in each driver.
	222	*/
	223	switch (cmd) {
	224	case RTC_EPOCH_SET:
	225	case RTC_SET_TIME:
	226	if (!capable(CAP_SYS_TIME))
	227	return -EACCES;
	228	break;
	229
	230	case RTC_IRQP_SET:
	231	if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
	232	return -EACCES;
	233	break;
	234
	235	case RTC_PIE_ON:
	236	if (!capable(CAP_SYS_RESOURCE))
	237	return -EACCES;
	238	break;
	239	}
	240
e824290e AZ	241	/* avoid conflicting IRQ users */
e824290e AZ	242	if (cmd == RTC_PIE_ON \|\| cmd == RTC_PIE_OFF \|\| cmd == RTC_IRQP_SET) {
d728b1e6	243	spin_lock_irq(&rtc->irq_task_lock);
e824290e AZ	244	if (rtc->irq_task)
e824290e AZ	245	err = -EBUSY;
d728b1e6	246	spin_unlock_irq(&rtc->irq_task_lock);
e824290e AZ	247
	248	if (err < 0)
	249	return err;
	250	}
	251
	252	/* try the driver's ioctl interface */
	253	if (ops->ioctl) {
cd966209	254	err = ops->ioctl(rtc->dev.parent, cmd, arg);
b3969e58	255	if (err != -ENOIOCTLCMD)
e824290e AZ	256	return err;
	257	}
	258
	259	/* if the driver does not provide the ioctl interface
	260	* or if that particular ioctl was not implemented
b3969e58	261	* (-ENOIOCTLCMD), we will try to emulate here.
e824290e AZ	262	*/
	263
	264	switch (cmd) {
	265	case RTC_ALM_READ:
ab6a2d70	266	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	267	if (err < 0)
	268	return err;
	269
	270	if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
	271	return -EFAULT;
	272	break;
	273
	274	case RTC_ALM_SET:
	275	if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
	276	return -EFAULT;
	277
	278	alarm.enabled = 0;
	279	alarm.pending = 0;
e824290e AZ	280	alarm.time.tm_wday = -1;
	281	alarm.time.tm_yday = -1;
	282	alarm.time.tm_isdst = -1;
f8245c26 DB	283
	284	/* RTC_ALM_SET alarms may be up to 24 hours in the future.
	285	* Rather than expecting every RTC to implement "don't care"
	286	* for day/month/year fields, just force the alarm to have
	287	* the right values for those fields.
	288	*
	289	* RTC_WKALM_SET should be used instead. Not only does it
	290	* eliminate the need for a separate RTC_AIE_ON call, it
	291	* doesn't have the "alarm 23:59:59 in the future" race.
	292	*
	293	* NOTE: some legacy code may have used invalid fields as
	294	* wildcards, exposing hardware "periodic alarm" capabilities.
	295	* Not supported here.
	296	*/
	297	{
	298	unsigned long now, then;
	299
	300	err = rtc_read_time(rtc, &tm);
	301	if (err < 0)
	302	return err;
	303	rtc_tm_to_time(&tm, &now);
	304
	305	alarm.time.tm_mday = tm.tm_mday;
	306	alarm.time.tm_mon = tm.tm_mon;
	307	alarm.time.tm_year = tm.tm_year;
	308	err = rtc_valid_tm(&alarm.time);
	309	if (err < 0)
	310	return err;
	311	rtc_tm_to_time(&alarm.time, &then);
	312
	313	/* alarm may need to wrap into tomorrow */
	314	if (then < now) {
	315	rtc_time_to_tm(now + 24 * 60 * 60, &tm);
	316	alarm.time.tm_mday = tm.tm_mday;
	317	alarm.time.tm_mon = tm.tm_mon;
	318	alarm.time.tm_year = tm.tm_year;
	319	}
	320	}
	321
ab6a2d70	322	err = rtc_set_alarm(rtc, &alarm);
e824290e AZ	323	break;
	324
	325	case RTC_RD_TIME:
ab6a2d70	326	err = rtc_read_time(rtc, &tm);
e824290e AZ	327	if (err < 0)
	328	return err;
	329
	330	if (copy_to_user(uarg, &tm, sizeof(tm)))
	331	return -EFAULT;
	332	break;
	333
	334	case RTC_SET_TIME:
e824290e AZ	335	if (copy_from_user(&tm, uarg, sizeof(tm)))
	336	return -EFAULT;
	337
ab6a2d70	338	err = rtc_set_time(rtc, &tm);
e824290e	339	break;
2601a464 DB	340
	341	case RTC_IRQP_READ:
	342	if (ops->irq_set_freq)
d76fdf75	343	err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
2601a464 DB	344	break;
	345
	346	case RTC_IRQP_SET:
	347	if (ops->irq_set_freq)
ab6a2d70	348	err = rtc_irq_set_freq(rtc, rtc->irq_task, arg);
2601a464 DB	349	break;
2601a464 DB	350
e824290e AZ	351	#if 0
	352	case RTC_EPOCH_SET:
	353	#ifndef rtc_epoch
	354	/*
	355	* There were no RTC clocks before 1900.
	356	*/
	357	if (arg < 1900) {
	358	err = -EINVAL;
	359	break;
	360	}
e824290e AZ	361	rtc_epoch = arg;
	362	err = 0;
	363	#endif
	364	break;
	365
	366	case RTC_EPOCH_READ:
	367	err = put_user(rtc_epoch, (unsigned long __user *)uarg);
	368	break;
	369	#endif
	370	case RTC_WKALM_SET:
	371	if (copy_from_user(&alarm, uarg, sizeof(alarm)))
	372	return -EFAULT;
	373
ab6a2d70	374	err = rtc_set_alarm(rtc, &alarm);
e824290e AZ	375	break;
	376
	377	case RTC_WKALM_RD:
ab6a2d70	378	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	379	if (err < 0)
	380	return err;
	381
	382	if (copy_to_user(uarg, &alarm, sizeof(alarm)))
	383	return -EFAULT;
	384	break;
	385
655066c3 AN	386	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	387	case RTC_UIE_OFF:
	388	clear_uie(rtc);
	389	return 0;
	390
	391	case RTC_UIE_ON:
	392	return set_uie(rtc);
	393	#endif
e824290e	394	default:
b3969e58	395	err = -ENOTTY;
e824290e AZ	396	break;
	397	}
	398
	399	return err;
	400	}
	401
	402	static int rtc_dev_release(struct inode inode, struct file file)
	403	{
	404	struct rtc_device *rtc = to_rtc_device(file->private_data);
	405
655066c3 AN	406	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	407	clear_uie(rtc);
	408	#endif
e824290e	409	if (rtc->ops->release)
cd966209	410	rtc->ops->release(rtc->dev.parent);
e824290e AZ	411
	412	mutex_unlock(&rtc->char_lock);
	413	return 0;
	414	}
	415
	416	static int rtc_dev_fasync(int fd, struct file *file, int on)
	417	{
	418	struct rtc_device *rtc = to_rtc_device(file->private_data);
	419	return fasync_helper(fd, file, on, &rtc->async_queue);
	420	}
	421
d54b1fdb	422	static const struct file_operations rtc_dev_fops = {
e824290e AZ	423	.owner = THIS_MODULE,
	424	.llseek = no_llseek,
	425	.read = rtc_dev_read,
	426	.poll = rtc_dev_poll,
	427	.ioctl = rtc_dev_ioctl,
	428	.open = rtc_dev_open,
	429	.release = rtc_dev_release,
	430	.fasync = rtc_dev_fasync,
	431	};
	432
	433	/* insertion/removal hooks */
	434
cb3a58d2	435	void rtc_dev_prepare(struct rtc_device *rtc)
e824290e	436	{
5726fb20 DB	437	if (!rtc_devt)
5726fb20 DB	438	return;
e824290e AZ	439
e824290e AZ	440	if (rtc->id >= RTC_DEV_MAX) {
5726fb20 DB	441	pr_debug("%s: too many RTC devices\n", rtc->name);
5726fb20 DB	442	return;
e824290e AZ	443	}
e824290e AZ	444
cd966209	445	rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
5726fb20	446
e824290e AZ	447	mutex_init(&rtc->char_lock);
	448	spin_lock_init(&rtc->irq_lock);
	449	init_waitqueue_head(&rtc->irq_queue);
655066c3	450	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
c4028958	451	INIT_WORK(&rtc->uie_task, rtc_uie_task);
655066c3 AN	452	setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
655066c3 AN	453	#endif
e824290e AZ	454
	455	cdev_init(&rtc->char_dev, &rtc_dev_fops);
	456	rtc->char_dev.owner = rtc->owner;
cb3a58d2	457	}
e824290e	458
cb3a58d2 DB	459	void rtc_dev_add_device(struct rtc_device *rtc)
cb3a58d2 DB	460	{
cd966209	461	if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
5726fb20 DB	462	printk(KERN_WARNING "%s: failed to add char device %d:%d\n",
	463	rtc->name, MAJOR(rtc_devt), rtc->id);
	464	else
	465	pr_debug("%s: dev (%d:%d)\n", rtc->name,
e824290e	466	MAJOR(rtc_devt), rtc->id);
e824290e AZ	467	}
e824290e AZ	468
5726fb20	469	void rtc_dev_del_device(struct rtc_device *rtc)
e824290e	470	{
cd966209	471	if (rtc->dev.devt)
e824290e	472	cdev_del(&rtc->char_dev);
e824290e AZ	473	}
e824290e AZ	474
5726fb20	475	void __init rtc_dev_init(void)
e824290e AZ	476	{
	477	int err;
	478
e824290e	479	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
5726fb20	480	if (err < 0)
e824290e AZ	481	printk(KERN_ERR "%s: failed to allocate char dev region\n",
e824290e AZ	482	__FILE__);
e824290e AZ	483	}
e824290e AZ	484
5726fb20	485	void __exit rtc_dev_exit(void)
e824290e	486	{
5726fb20 DB	487	if (rtc_devt)
5726fb20 DB	488	unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
e824290e	489	}