[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 <linux/sched.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;

	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
		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 */
	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
	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);

	spin_lock_irq(&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_irq(&rtc->irq_lock);
	if (num)
		rtc_handle_legacy_irq(rtc, num, RTC_UF);
}
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 int clear_uie(struct rtc_device *rtc)
{
	spin_lock_irq(&rtc->irq_lock);
	if (rtc->uie_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->uie_irq_active = 0;
	}
	spin_unlock_irq(&rtc->irq_lock);
	return 0;
}

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->uie_irq_active) {
		rtc->uie_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;
}

int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
{
	if (enabled)
		return set_uie(rtc);
	else
		return clear_uie(rtc);
}
EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);

#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 = 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 = file->private_data;
	unsigned long data;

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

	data = rtc->irq_data;

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

static long rtc_dev_ioctl(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;

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

	/* 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))
			err = -EACCES;
		break;

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

	case RTC_PIE_ON:
		if (rtc->irq_freq > rtc->max_user_freq &&
				!capable(CAP_SYS_RESOURCE))
			err = -EACCES;
		break;
	}

	if (err)
		goto done;

	/*
	 * Drivers *SHOULD NOT* provide ioctl implementations
	 * for these requests.  Instead, provide methods to
	 * support the following code, so that the RTC's main
	 * features are accessible without using ioctls.
	 *
	 * RTC and alarm times will be in UTC, by preference,
	 * but dual-booting with MS-Windows implies RTCs must
	 * use the local wall clock time.
	 */

	switch (cmd) {
	case RTC_ALM_READ:
		mutex_unlock(&rtc->ops_lock);

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

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

	case RTC_ALM_SET:
		mutex_unlock(&rtc->ops_lock);

		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;
			}
		}

		return rtc_set_alarm(rtc, &alarm);

	case RTC_RD_TIME:
		mutex_unlock(&rtc->ops_lock);

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

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

	case RTC_SET_TIME:
		mutex_unlock(&rtc->ops_lock);

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

		return rtc_set_time(rtc, &tm);

	case RTC_PIE_ON:
		err = rtc_irq_set_state(rtc, NULL, 1);
		break;

	case RTC_PIE_OFF:
		err = rtc_irq_set_state(rtc, NULL, 0);
		break;

	case RTC_AIE_ON:
		mutex_unlock(&rtc->ops_lock);
		return rtc_alarm_irq_enable(rtc, 1);

	case RTC_AIE_OFF:
		mutex_unlock(&rtc->ops_lock);
		return rtc_alarm_irq_enable(rtc, 0);

	case RTC_UIE_ON:
		mutex_unlock(&rtc->ops_lock);
		return rtc_update_irq_enable(rtc, 1);

	case RTC_UIE_OFF:
		mutex_unlock(&rtc->ops_lock);
		return rtc_update_irq_enable(rtc, 0);

	case RTC_IRQP_SET:
		err = rtc_irq_set_freq(rtc, NULL, arg);
		break;

	case RTC_IRQP_READ:
		err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
		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:
		mutex_unlock(&rtc->ops_lock);
		if (copy_from_user(&alarm, uarg, sizeof(alarm)))
			return -EFAULT;

		return rtc_set_alarm(rtc, &alarm);

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

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

	default:
		/* Finally try the driver's ioctl interface */
		if (ops->ioctl) {
			err = ops->ioctl(rtc->dev.parent, cmd, arg);
			if (err == -ENOIOCTLCMD)
				err = -ENOTTY;
		} else
			err = -ENOTTY;
		break;
	}

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

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

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

	/* We shut down the repeating IRQs that userspace enabled,
	 * since nothing is listening to them.
	 *  - Update (UIE) ... currently only managed through ioctls
	 *  - Periodic (PIE) ... also used through rtc_*() interface calls
	 *
	 * Leave the alarm alone; it may be set to trigger a system wakeup
	 * later, or be used by kernel code, and is a one-shot event anyway.
	 */

	/* Keep ioctl until all drivers are converted */
	rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
	rtc_update_irq_enable(rtc, 0);
	rtc_irq_set_state(rtc, NULL, 0);

	if (rtc->ops->release)
		rtc->ops->release(rtc->dev.parent);

	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
	return 0;
}

static const struct file_operations rtc_dev_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= rtc_dev_read,
	.poll		= rtc_dev_poll,
	.unlocked_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);

#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>
d43c36dc	16	#include <linux/sched.h>
5726fb20	17	#include "rtc-core.h"
e824290e	18
e824290e AZ	19	static dev_t rtc_devt;
	20
	21	#define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */
	22
	23	static int rtc_dev_open(struct inode inode, struct file file)
	24	{
	25	int err;
	26	struct rtc_device *rtc = container_of(inode->i_cdev,
	27	struct rtc_device, char_dev);
ff8371ac	28	const struct rtc_class_ops *ops = rtc->ops;
e824290e	29
b1c3c898 DB	30	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
b1c3c898 DB	31	return -EBUSY;
e824290e	32
ab6a2d70	33	file->private_data = rtc;
e824290e	34
cd966209	35	err = ops->open ? ops->open(rtc->dev.parent) : 0;
e824290e AZ	36	if (err == 0) {
	37	spin_lock_irq(&rtc->irq_lock);
	38	rtc->irq_data = 0;
	39	spin_unlock_irq(&rtc->irq_lock);
	40
b1c3c898	41	return 0;
e824290e AZ	42	}
e824290e AZ	43
8853c202	44	/* something has gone wrong */
372a302e	45	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
e824290e AZ	46	return err;
	47	}
	48
6e57b1d6 JS	49	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	50	/*
	51	* Routine to poll RTC seconds field for change as often as possible,
	52	* after first RTC_UIE use timer to reduce polling
	53	*/
	54	static void rtc_uie_task(struct work_struct *work)
	55	{
	56	struct rtc_device *rtc =
	57	container_of(work, struct rtc_device, uie_task);
	58	struct rtc_time tm;
	59	int num = 0;
	60	int err;
	61
	62	err = rtc_read_time(rtc, &tm);
	63
	64	spin_lock_irq(&rtc->irq_lock);
	65	if (rtc->stop_uie_polling \|\| err) {
	66	rtc->uie_task_active = 0;
	67	} else if (rtc->oldsecs != tm.tm_sec) {
	68	num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
	69	rtc->oldsecs = tm.tm_sec;
	70	rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
	71	rtc->uie_timer_active = 1;
	72	rtc->uie_task_active = 0;
	73	add_timer(&rtc->uie_timer);
	74	} else if (schedule_work(&rtc->uie_task) == 0) {
	75	rtc->uie_task_active = 0;
	76	}
	77	spin_unlock_irq(&rtc->irq_lock);
	78	if (num)
456d66ec	79	rtc_handle_legacy_irq(rtc, num, RTC_UF);
6e57b1d6 JS	80	}
	81	static void rtc_uie_timer(unsigned long data)
	82	{
	83	struct rtc_device rtc = (struct rtc_device )data;
	84	unsigned long flags;
	85
	86	spin_lock_irqsave(&rtc->irq_lock, flags);
	87	rtc->uie_timer_active = 0;
	88	rtc->uie_task_active = 1;
	89	if ((schedule_work(&rtc->uie_task) == 0))
	90	rtc->uie_task_active = 0;
	91	spin_unlock_irqrestore(&rtc->irq_lock, flags);
	92	}
	93
	94	static int clear_uie(struct rtc_device *rtc)
	95	{
	96	spin_lock_irq(&rtc->irq_lock);
	97	if (rtc->uie_irq_active) {
	98	rtc->stop_uie_polling = 1;
	99	if (rtc->uie_timer_active) {
	100	spin_unlock_irq(&rtc->irq_lock);
	101	del_timer_sync(&rtc->uie_timer);
	102	spin_lock_irq(&rtc->irq_lock);
	103	rtc->uie_timer_active = 0;
	104	}
	105	if (rtc->uie_task_active) {
	106	spin_unlock_irq(&rtc->irq_lock);
	107	flush_scheduled_work();
	108	spin_lock_irq(&rtc->irq_lock);
	109	}
	110	rtc->uie_irq_active = 0;
	111	}
	112	spin_unlock_irq(&rtc->irq_lock);
	113	return 0;
	114	}
	115
	116	static int set_uie(struct rtc_device *rtc)
	117	{
	118	struct rtc_time tm;
	119	int err;
	120
	121	err = rtc_read_time(rtc, &tm);
	122	if (err)
	123	return err;
	124	spin_lock_irq(&rtc->irq_lock);
	125	if (!rtc->uie_irq_active) {
	126	rtc->uie_irq_active = 1;
	127	rtc->stop_uie_polling = 0;
	128	rtc->oldsecs = tm.tm_sec;
	129	rtc->uie_task_active = 1;
	130	if (schedule_work(&rtc->uie_task) == 0)
	131	rtc->uie_task_active = 0;
	132	}
	133	rtc->irq_data = 0;
	134	spin_unlock_irq(&rtc->irq_lock);
	135	return 0;
	136	}
	137
	138	int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
	139	{
	140	if (enabled)
	141	return set_uie(rtc);
	142	else
	143	return clear_uie(rtc);
144	}
145	EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);
146
147	#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
e824290e AZ	148
	149	static ssize_t
	150	rtc_dev_read(struct file file, char __user buf, size_t count, loff_t *ppos)
	151	{
88efe137	152	struct rtc_device *rtc = file->private_data;
e824290e AZ	153
	154	DECLARE_WAITQUEUE(wait, current);
	155	unsigned long data;
	156	ssize_t ret;
	157
3418ff76	158	if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
e824290e AZ	159	return -EINVAL;
	160
	161	add_wait_queue(&rtc->irq_queue, &wait);
	162	do {
	163	__set_current_state(TASK_INTERRUPTIBLE);
	164
	165	spin_lock_irq(&rtc->irq_lock);
	166	data = rtc->irq_data;
	167	rtc->irq_data = 0;
	168	spin_unlock_irq(&rtc->irq_lock);
	169
	170	if (data != 0) {
	171	ret = 0;
	172	break;
	173	}
	174	if (file->f_flags & O_NONBLOCK) {
	175	ret = -EAGAIN;
	176	break;
	177	}
	178	if (signal_pending(current)) {
	179	ret = -ERESTARTSYS;
	180	break;
	181	}
	182	schedule();
	183	} while (1);
	184	set_current_state(TASK_RUNNING);
	185	remove_wait_queue(&rtc->irq_queue, &wait);
	186
	187	if (ret == 0) {
	188	/* Check for any data updates */
	189	if (rtc->ops->read_callback)
cd966209	190	data = rtc->ops->read_callback(rtc->dev.parent,
3418ff76 AN	191	data);
	192
	193	if (sizeof(int) != sizeof(long) &&
	194	count == sizeof(unsigned int))
	195	ret = put_user(data, (unsigned int __user *)buf) ?:
	196	sizeof(unsigned int);
	197	else
	198	ret = put_user(data, (unsigned long __user *)buf) ?:
	199	sizeof(unsigned long);
e824290e AZ	200	}
	201	return ret;
	202	}
	203
	204	static unsigned int rtc_dev_poll(struct file file, poll_table wait)
	205	{
88efe137	206	struct rtc_device *rtc = file->private_data;
e824290e AZ	207	unsigned long data;
	208
	209	poll_wait(file, &rtc->irq_queue, wait);
	210
	211	data = rtc->irq_data;
	212
	213	return (data != 0) ? (POLLIN \| POLLRDNORM) : 0;
	214	}
	215
5ad31a57	216	static long rtc_dev_ioctl(struct file *file,
e824290e AZ	217	unsigned int cmd, unsigned long arg)
	218	{
	219	int err = 0;
ab6a2d70	220	struct rtc_device *rtc = file->private_data;
ff8371ac	221	const struct rtc_class_ops *ops = rtc->ops;
e824290e AZ	222	struct rtc_time tm;
	223	struct rtc_wkalrm alarm;
	224	void __user uarg = (void __user ) arg;
	225
5ad31a57 DB	226	err = mutex_lock_interruptible(&rtc->ops_lock);
5ad31a57 DB	227	if (err)
b68bb263	228	return err;
5ad31a57	229
2601a464	230	/* check that the calling task has appropriate permissions
110d693d AZ	231	* for certain ioctls. doing this check here is useful
	232	* to avoid duplicate code in each driver.
	233	*/
	234	switch (cmd) {
	235	case RTC_EPOCH_SET:
	236	case RTC_SET_TIME:
	237	if (!capable(CAP_SYS_TIME))
5ad31a57	238	err = -EACCES;
110d693d AZ	239	break;
	240
	241	case RTC_IRQP_SET:
	242	if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
5ad31a57	243	err = -EACCES;
110d693d AZ	244	break;
	245
	246	case RTC_PIE_ON:
9d013d3b BK	247	if (rtc->irq_freq > rtc->max_user_freq &&
9d013d3b BK	248	!capable(CAP_SYS_RESOURCE))
5ad31a57	249	err = -EACCES;
110d693d AZ	250	break;
	251	}
	252
5ad31a57 DB	253	if (err)
	254	goto done;
	255
ac54cd2b	256	/*
8a0bdfd7 DB	257	* Drivers SHOULD NOT provide ioctl implementations
	258	* for these requests. Instead, provide methods to
	259	* support the following code, so that the RTC's main
	260	* features are accessible without using ioctls.
	261	*
	262	* RTC and alarm times will be in UTC, by preference,
	263	* but dual-booting with MS-Windows implies RTCs must
	264	* use the local wall clock time.
e824290e AZ	265	*/
	266
	267	switch (cmd) {
	268	case RTC_ALM_READ:
5ad31a57 DB	269	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	270
ab6a2d70	271	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	272	if (err < 0)
	273	return err;
	274
	275	if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
5ad31a57 DB	276	err = -EFAULT;
5ad31a57 DB	277	return err;
e824290e AZ	278
e824290e AZ	279	case RTC_ALM_SET:
5ad31a57 DB	280	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	281
e824290e AZ	282	if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
	283	return -EFAULT;
	284
	285	alarm.enabled = 0;
	286	alarm.pending = 0;
e824290e AZ	287	alarm.time.tm_wday = -1;
	288	alarm.time.tm_yday = -1;
	289	alarm.time.tm_isdst = -1;
f8245c26 DB	290
	291	/* RTC_ALM_SET alarms may be up to 24 hours in the future.
	292	* Rather than expecting every RTC to implement "don't care"
	293	* for day/month/year fields, just force the alarm to have
	294	* the right values for those fields.
	295	*
	296	* RTC_WKALM_SET should be used instead. Not only does it
	297	* eliminate the need for a separate RTC_AIE_ON call, it
	298	* doesn't have the "alarm 23:59:59 in the future" race.
	299	*
	300	* NOTE: some legacy code may have used invalid fields as
	301	* wildcards, exposing hardware "periodic alarm" capabilities.
	302	* Not supported here.
	303	*/
	304	{
	305	unsigned long now, then;
	306
	307	err = rtc_read_time(rtc, &tm);
	308	if (err < 0)
	309	return err;
	310	rtc_tm_to_time(&tm, &now);
	311
	312	alarm.time.tm_mday = tm.tm_mday;
	313	alarm.time.tm_mon = tm.tm_mon;
	314	alarm.time.tm_year = tm.tm_year;
	315	err = rtc_valid_tm(&alarm.time);
	316	if (err < 0)
	317	return err;
	318	rtc_tm_to_time(&alarm.time, &then);
	319
	320	/* alarm may need to wrap into tomorrow */
	321	if (then < now) {
	322	rtc_time_to_tm(now + 24 * 60 * 60, &tm);
	323	alarm.time.tm_mday = tm.tm_mday;
	324	alarm.time.tm_mon = tm.tm_mon;
	325	alarm.time.tm_year = tm.tm_year;
	326	}
	327	}
	328
5ad31a57	329	return rtc_set_alarm(rtc, &alarm);
e824290e AZ	330
e824290e AZ	331	case RTC_RD_TIME:
5ad31a57 DB	332	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	333
ab6a2d70	334	err = rtc_read_time(rtc, &tm);
e824290e AZ	335	if (err < 0)
	336	return err;
	337
	338	if (copy_to_user(uarg, &tm, sizeof(tm)))
5ad31a57 DB	339	err = -EFAULT;
5ad31a57 DB	340	return err;
e824290e AZ	341
e824290e AZ	342	case RTC_SET_TIME:
5ad31a57 DB	343	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	344
e824290e AZ	345	if (copy_from_user(&tm, uarg, sizeof(tm)))
	346	return -EFAULT;
	347
5ad31a57	348	return rtc_set_time(rtc, &tm);
2601a464	349
d691eb90 AZ	350	case RTC_PIE_ON:
	351	err = rtc_irq_set_state(rtc, NULL, 1);
	352	break;
	353
	354	case RTC_PIE_OFF:
	355	err = rtc_irq_set_state(rtc, NULL, 0);
2601a464 DB	356	break;
2601a464 DB	357
099e6576 AZ	358	case RTC_AIE_ON:
	359	mutex_unlock(&rtc->ops_lock);
	360	return rtc_alarm_irq_enable(rtc, 1);
	361
	362	case RTC_AIE_OFF:
	363	mutex_unlock(&rtc->ops_lock);
	364	return rtc_alarm_irq_enable(rtc, 0);
	365
	366	case RTC_UIE_ON:
	367	mutex_unlock(&rtc->ops_lock);
	368	return rtc_update_irq_enable(rtc, 1);
	369
	370	case RTC_UIE_OFF:
	371	mutex_unlock(&rtc->ops_lock);
	372	return rtc_update_irq_enable(rtc, 0);
	373
2601a464	374	case RTC_IRQP_SET:
d691eb90 AZ	375	err = rtc_irq_set_freq(rtc, NULL, arg);
	376	break;
	377
	378	case RTC_IRQP_READ:
	379	err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
2601a464 DB	380	break;
2601a464 DB	381
e824290e AZ	382	#if 0
	383	case RTC_EPOCH_SET:
	384	#ifndef rtc_epoch
	385	/*
	386	* There were no RTC clocks before 1900.
	387	*/
	388	if (arg < 1900) {
	389	err = -EINVAL;
	390	break;
	391	}
e824290e AZ	392	rtc_epoch = arg;
	393	err = 0;
	394	#endif
	395	break;
	396
	397	case RTC_EPOCH_READ:
	398	err = put_user(rtc_epoch, (unsigned long __user *)uarg);
	399	break;
	400	#endif
	401	case RTC_WKALM_SET:
5ad31a57	402	mutex_unlock(&rtc->ops_lock);
e824290e AZ	403	if (copy_from_user(&alarm, uarg, sizeof(alarm)))
	404	return -EFAULT;
	405
5ad31a57	406	return rtc_set_alarm(rtc, &alarm);
e824290e AZ	407
e824290e AZ	408	case RTC_WKALM_RD:
5ad31a57	409	mutex_unlock(&rtc->ops_lock);
ab6a2d70	410	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	411	if (err < 0)
	412	return err;
	413
	414	if (copy_to_user(uarg, &alarm, sizeof(alarm)))
5ad31a57 DB	415	err = -EFAULT;
5ad31a57 DB	416	return err;
e824290e AZ	417
e824290e AZ	418	default:
ac54cd2b JS	419	/* Finally try the driver's ioctl interface */
	420	if (ops->ioctl) {
	421	err = ops->ioctl(rtc->dev.parent, cmd, arg);
	422	if (err == -ENOIOCTLCMD)
	423	err = -ENOTTY;
e17fd4ba JS	424	} else
e17fd4ba JS	425	err = -ENOTTY;
e824290e AZ	426	break;
	427	}
	428
5ad31a57 DB	429	done:
5ad31a57 DB	430	mutex_unlock(&rtc->ops_lock);
e824290e AZ	431	return err;
	432	}
	433
2e4a75cd MS	434	static int rtc_dev_fasync(int fd, struct file *file, int on)
	435	{
	436	struct rtc_device *rtc = file->private_data;
	437	return fasync_helper(fd, file, on, &rtc->async_queue);
	438	}
	439
e824290e AZ	440	static int rtc_dev_release(struct inode inode, struct file file)
e824290e AZ	441	{
88efe137	442	struct rtc_device *rtc = file->private_data;
e824290e	443
743e6a50 DB	444	/* We shut down the repeating IRQs that userspace enabled,
	445	* since nothing is listening to them.
	446	* - Update (UIE) ... currently only managed through ioctls
	447	* - Periodic (PIE) ... also used through rtc_*() interface calls
	448	*
	449	* Leave the alarm alone; it may be set to trigger a system wakeup
	450	* later, or be used by kernel code, and is a one-shot event anyway.
	451	*/
099e6576 AZ	452
099e6576 AZ	453	/* Keep ioctl until all drivers are converted */
743e6a50	454	rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
099e6576	455	rtc_update_irq_enable(rtc, 0);
5cdc98b8 TJ	456	rtc_irq_set_state(rtc, NULL, 0);
5cdc98b8 TJ	457
e824290e	458	if (rtc->ops->release)
cd966209	459	rtc->ops->release(rtc->dev.parent);
e824290e	460
372a302e	461	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
e824290e AZ	462	return 0;
	463	}
	464
d54b1fdb	465	static const struct file_operations rtc_dev_fops = {
e824290e AZ	466	.owner = THIS_MODULE,
	467	.llseek = no_llseek,
	468	.read = rtc_dev_read,
	469	.poll = rtc_dev_poll,
5ad31a57	470	.unlocked_ioctl = rtc_dev_ioctl,
e824290e AZ	471	.open = rtc_dev_open,
	472	.release = rtc_dev_release,
	473	.fasync = rtc_dev_fasync,
	474	};
	475
	476	/* insertion/removal hooks */
	477
cb3a58d2	478	void rtc_dev_prepare(struct rtc_device *rtc)
e824290e	479	{
5726fb20 DB	480	if (!rtc_devt)
5726fb20 DB	481	return;
e824290e AZ	482
e824290e AZ	483	if (rtc->id >= RTC_DEV_MAX) {
5726fb20 DB	484	pr_debug("%s: too many RTC devices\n", rtc->name);
5726fb20 DB	485	return;
e824290e AZ	486	}
e824290e AZ	487
cd966209	488	rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
5726fb20	489
6e57b1d6 JS	490	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	491	INIT_WORK(&rtc->uie_task, rtc_uie_task);
	492	setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
	493	#endif
	494
e824290e AZ	495	cdev_init(&rtc->char_dev, &rtc_dev_fops);
e824290e AZ	496	rtc->char_dev.owner = rtc->owner;
cb3a58d2	497	}
e824290e	498
cb3a58d2 DB	499	void rtc_dev_add_device(struct rtc_device *rtc)
cb3a58d2 DB	500	{
cd966209	501	if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
5726fb20 DB	502	printk(KERN_WARNING "%s: failed to add char device %d:%d\n",
	503	rtc->name, MAJOR(rtc_devt), rtc->id);
	504	else
	505	pr_debug("%s: dev (%d:%d)\n", rtc->name,
e824290e	506	MAJOR(rtc_devt), rtc->id);
e824290e AZ	507	}
e824290e AZ	508
5726fb20	509	void rtc_dev_del_device(struct rtc_device *rtc)
e824290e	510	{
cd966209	511	if (rtc->dev.devt)
e824290e	512	cdev_del(&rtc->char_dev);
e824290e AZ	513	}
e824290e AZ	514
5726fb20	515	void __init rtc_dev_init(void)
e824290e AZ	516	{
	517	int err;
	518
e824290e	519	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
5726fb20	520	if (err < 0)
e824290e AZ	521	printk(KERN_ERR "%s: failed to allocate char dev region\n",
e824290e AZ	522	__FILE__);
e824290e AZ	523	}
e824290e AZ	524
5726fb20	525	void __exit rtc_dev_exit(void)
e824290e	526	{
5726fb20 DB	527	if (rtc_devt)
5726fb20 DB	528	unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
e824290e	529	}