[net-next-2.6.git] / drivers / rtc / rtc-dev.c

/*
 * RTC subsystem, dev interface
 *
 * 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/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;

	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_update_irq(rtc, num, RTC_UF | RTC_IRQF);
}
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;

	/* try the driver's ioctl interface */
	if (ops->ioctl) {
		err = ops->ioctl(rtc->dev.parent, cmd, arg);
		if (err != -ENOIOCTLCMD) {
			mutex_unlock(&rtc->ops_lock);
			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.
	 *
	 * 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:
		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 <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/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	28
b1c3c898 DB	29	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
b1c3c898 DB	30	return -EBUSY;
e824290e	31
ab6a2d70	32	file->private_data = rtc;
e824290e	33
cd966209	34	err = ops->open ? ops->open(rtc->dev.parent) : 0;
e824290e AZ	35	if (err == 0) {
	36	spin_lock_irq(&rtc->irq_lock);
	37	rtc->irq_data = 0;
	38	spin_unlock_irq(&rtc->irq_lock);
	39
b1c3c898	40	return 0;
e824290e AZ	41	}
e824290e AZ	42
8853c202	43	/* something has gone wrong */
372a302e	44	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
e824290e AZ	45	return err;
	46	}
	47
655066c3 AN	48	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	49	/*
	50	* Routine to poll RTC seconds field for change as often as possible,
	51	* after first RTC_UIE use timer to reduce polling
	52	*/
c4028958	53	static void rtc_uie_task(struct work_struct *work)
655066c3	54	{
c4028958 DH	55	struct rtc_device *rtc =
c4028958 DH	56	container_of(work, struct rtc_device, uie_task);
655066c3 AN	57	struct rtc_time tm;
	58	int num = 0;
	59	int err;
	60
ab6a2d70	61	err = rtc_read_time(rtc, &tm);
d728b1e6	62
e6229bec	63	spin_lock_irq(&rtc->irq_lock);
655066c3 AN	64	if (rtc->stop_uie_polling \|\| err) {
	65	rtc->uie_task_active = 0;
	66	} else if (rtc->oldsecs != tm.tm_sec) {
	67	num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
	68	rtc->oldsecs = tm.tm_sec;
	69	rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
	70	rtc->uie_timer_active = 1;
	71	rtc->uie_task_active = 0;
	72	add_timer(&rtc->uie_timer);
	73	} else if (schedule_work(&rtc->uie_task) == 0) {
	74	rtc->uie_task_active = 0;
	75	}
e6229bec	76	spin_unlock_irq(&rtc->irq_lock);
655066c3	77	if (num)
ab6a2d70	78	rtc_update_irq(rtc, num, RTC_UF \| RTC_IRQF);
655066c3	79	}
655066c3 AN	80	static void rtc_uie_timer(unsigned long data)
	81	{
	82	struct rtc_device rtc = (struct rtc_device )data;
	83	unsigned long flags;
	84
	85	spin_lock_irqsave(&rtc->irq_lock, flags);
	86	rtc->uie_timer_active = 0;
	87	rtc->uie_task_active = 1;
	88	if ((schedule_work(&rtc->uie_task) == 0))
	89	rtc->uie_task_active = 0;
	90	spin_unlock_irqrestore(&rtc->irq_lock, flags);
	91	}
	92
099e6576	93	static int clear_uie(struct rtc_device *rtc)
655066c3 AN	94	{
655066c3 AN	95	spin_lock_irq(&rtc->irq_lock);
099e6576	96	if (rtc->uie_irq_active) {
655066c3 AN	97	rtc->stop_uie_polling = 1;
	98	if (rtc->uie_timer_active) {
	99	spin_unlock_irq(&rtc->irq_lock);
	100	del_timer_sync(&rtc->uie_timer);
	101	spin_lock_irq(&rtc->irq_lock);
	102	rtc->uie_timer_active = 0;
	103	}
	104	if (rtc->uie_task_active) {
	105	spin_unlock_irq(&rtc->irq_lock);
	106	flush_scheduled_work();
	107	spin_lock_irq(&rtc->irq_lock);
	108	}
099e6576	109	rtc->uie_irq_active = 0;
655066c3 AN	110	}
655066c3 AN	111	spin_unlock_irq(&rtc->irq_lock);
099e6576	112	return 0;
655066c3 AN	113	}
	114
	115	static int set_uie(struct rtc_device *rtc)
	116	{
	117	struct rtc_time tm;
	118	int err;
	119
ab6a2d70	120	err = rtc_read_time(rtc, &tm);
655066c3 AN	121	if (err)
	122	return err;
	123	spin_lock_irq(&rtc->irq_lock);
099e6576 AZ	124	if (!rtc->uie_irq_active) {
099e6576 AZ	125	rtc->uie_irq_active = 1;
655066c3 AN	126	rtc->stop_uie_polling = 0;
	127	rtc->oldsecs = tm.tm_sec;
	128	rtc->uie_task_active = 1;
	129	if (schedule_work(&rtc->uie_task) == 0)
	130	rtc->uie_task_active = 0;
	131	}
	132	rtc->irq_data = 0;
	133	spin_unlock_irq(&rtc->irq_lock);
	134	return 0;
	135	}
099e6576 AZ	136
	137	int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
	138	{
	139	if (enabled)
	140	return set_uie(rtc);
	141	else
	142	return clear_uie(rtc);
	143	}
	144	EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);
	145
655066c3	146	#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
e824290e AZ	147
	148	static ssize_t
	149	rtc_dev_read(struct file file, char __user buf, size_t count, loff_t *ppos)
	150	{
88efe137	151	struct rtc_device *rtc = file->private_data;
e824290e AZ	152
	153	DECLARE_WAITQUEUE(wait, current);
	154	unsigned long data;
	155	ssize_t ret;
	156
3418ff76	157	if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
e824290e AZ	158	return -EINVAL;
	159
	160	add_wait_queue(&rtc->irq_queue, &wait);
	161	do {
	162	__set_current_state(TASK_INTERRUPTIBLE);
	163
	164	spin_lock_irq(&rtc->irq_lock);
	165	data = rtc->irq_data;
	166	rtc->irq_data = 0;
	167	spin_unlock_irq(&rtc->irq_lock);
	168
	169	if (data != 0) {
	170	ret = 0;
	171	break;
	172	}
	173	if (file->f_flags & O_NONBLOCK) {
	174	ret = -EAGAIN;
	175	break;
	176	}
	177	if (signal_pending(current)) {
	178	ret = -ERESTARTSYS;
	179	break;
	180	}
	181	schedule();
	182	} while (1);
	183	set_current_state(TASK_RUNNING);
	184	remove_wait_queue(&rtc->irq_queue, &wait);
	185
	186	if (ret == 0) {
	187	/* Check for any data updates */
	188	if (rtc->ops->read_callback)
cd966209	189	data = rtc->ops->read_callback(rtc->dev.parent,
3418ff76 AN	190	data);
	191
	192	if (sizeof(int) != sizeof(long) &&
	193	count == sizeof(unsigned int))
	194	ret = put_user(data, (unsigned int __user *)buf) ?:
	195	sizeof(unsigned int);
	196	else
	197	ret = put_user(data, (unsigned long __user *)buf) ?:
	198	sizeof(unsigned long);
e824290e AZ	199	}
	200	return ret;
	201	}
	202
	203	static unsigned int rtc_dev_poll(struct file file, poll_table wait)
	204	{
88efe137	205	struct rtc_device *rtc = file->private_data;
e824290e AZ	206	unsigned long data;
	207
	208	poll_wait(file, &rtc->irq_queue, wait);
	209
	210	data = rtc->irq_data;
	211
	212	return (data != 0) ? (POLLIN \| POLLRDNORM) : 0;
	213	}
	214
5ad31a57	215	static long rtc_dev_ioctl(struct file *file,
e824290e AZ	216	unsigned int cmd, unsigned long arg)
	217	{
	218	int err = 0;
ab6a2d70	219	struct rtc_device *rtc = file->private_data;
ff8371ac	220	const struct rtc_class_ops *ops = rtc->ops;
e824290e AZ	221	struct rtc_time tm;
	222	struct rtc_wkalrm alarm;
	223	void __user uarg = (void __user ) arg;
	224
5ad31a57 DB	225	err = mutex_lock_interruptible(&rtc->ops_lock);
5ad31a57 DB	226	if (err)
b68bb263	227	return err;
5ad31a57	228
2601a464	229	/* check that the calling task has appropriate permissions
110d693d AZ	230	* for certain ioctls. doing this check here is useful
	231	* to avoid duplicate code in each driver.
	232	*/
	233	switch (cmd) {
	234	case RTC_EPOCH_SET:
	235	case RTC_SET_TIME:
	236	if (!capable(CAP_SYS_TIME))
5ad31a57	237	err = -EACCES;
110d693d AZ	238	break;
	239
	240	case RTC_IRQP_SET:
	241	if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
5ad31a57	242	err = -EACCES;
110d693d AZ	243	break;
	244
	245	case RTC_PIE_ON:
9d013d3b BK	246	if (rtc->irq_freq > rtc->max_user_freq &&
9d013d3b BK	247	!capable(CAP_SYS_RESOURCE))
5ad31a57	248	err = -EACCES;
110d693d AZ	249	break;
	250	}
	251
5ad31a57 DB	252	if (err)
	253	goto done;
	254
e824290e AZ	255	/* try the driver's ioctl interface */
e824290e AZ	256	if (ops->ioctl) {
cd966209	257	err = ops->ioctl(rtc->dev.parent, cmd, arg);
5ad31a57 DB	258	if (err != -ENOIOCTLCMD) {
5ad31a57 DB	259	mutex_unlock(&rtc->ops_lock);
e824290e	260	return err;
5ad31a57	261	}
e824290e AZ	262	}
	263
	264	/* if the driver does not provide the ioctl interface
	265	* or if that particular ioctl was not implemented
b3969e58	266	* (-ENOIOCTLCMD), we will try to emulate here.
8a0bdfd7 DB	267	*
	268	* Drivers SHOULD NOT provide ioctl implementations
	269	* for these requests. Instead, provide methods to
	270	* support the following code, so that the RTC's main
	271	* features are accessible without using ioctls.
	272	*
	273	* RTC and alarm times will be in UTC, by preference,
	274	* but dual-booting with MS-Windows implies RTCs must
	275	* use the local wall clock time.
e824290e AZ	276	*/
	277
	278	switch (cmd) {
	279	case RTC_ALM_READ:
5ad31a57 DB	280	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	281
ab6a2d70	282	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	283	if (err < 0)
	284	return err;
	285
	286	if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
5ad31a57 DB	287	err = -EFAULT;
5ad31a57 DB	288	return err;
e824290e AZ	289
e824290e AZ	290	case RTC_ALM_SET:
5ad31a57 DB	291	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	292
e824290e AZ	293	if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
	294	return -EFAULT;
	295
	296	alarm.enabled = 0;
	297	alarm.pending = 0;
e824290e AZ	298	alarm.time.tm_wday = -1;
	299	alarm.time.tm_yday = -1;
	300	alarm.time.tm_isdst = -1;
f8245c26 DB	301
	302	/* RTC_ALM_SET alarms may be up to 24 hours in the future.
	303	* Rather than expecting every RTC to implement "don't care"
	304	* for day/month/year fields, just force the alarm to have
	305	* the right values for those fields.
	306	*
	307	* RTC_WKALM_SET should be used instead. Not only does it
	308	* eliminate the need for a separate RTC_AIE_ON call, it
	309	* doesn't have the "alarm 23:59:59 in the future" race.
	310	*
	311	* NOTE: some legacy code may have used invalid fields as
	312	* wildcards, exposing hardware "periodic alarm" capabilities.
	313	* Not supported here.
	314	*/
	315	{
	316	unsigned long now, then;
	317
	318	err = rtc_read_time(rtc, &tm);
	319	if (err < 0)
	320	return err;
	321	rtc_tm_to_time(&tm, &now);
	322
	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	err = rtc_valid_tm(&alarm.time);
	327	if (err < 0)
	328	return err;
	329	rtc_tm_to_time(&alarm.time, &then);
	330
	331	/* alarm may need to wrap into tomorrow */
	332	if (then < now) {
	333	rtc_time_to_tm(now + 24 * 60 * 60, &tm);
	334	alarm.time.tm_mday = tm.tm_mday;
	335	alarm.time.tm_mon = tm.tm_mon;
	336	alarm.time.tm_year = tm.tm_year;
	337	}
	338	}
	339
5ad31a57	340	return rtc_set_alarm(rtc, &alarm);
e824290e AZ	341
e824290e AZ	342	case RTC_RD_TIME:
5ad31a57 DB	343	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	344
ab6a2d70	345	err = rtc_read_time(rtc, &tm);
e824290e AZ	346	if (err < 0)
	347	return err;
	348
	349	if (copy_to_user(uarg, &tm, sizeof(tm)))
5ad31a57 DB	350	err = -EFAULT;
5ad31a57 DB	351	return err;
e824290e AZ	352
e824290e AZ	353	case RTC_SET_TIME:
5ad31a57 DB	354	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	355
e824290e AZ	356	if (copy_from_user(&tm, uarg, sizeof(tm)))
	357	return -EFAULT;
	358
5ad31a57	359	return rtc_set_time(rtc, &tm);
2601a464	360
d691eb90 AZ	361	case RTC_PIE_ON:
	362	err = rtc_irq_set_state(rtc, NULL, 1);
	363	break;
	364
	365	case RTC_PIE_OFF:
	366	err = rtc_irq_set_state(rtc, NULL, 0);
2601a464 DB	367	break;
2601a464 DB	368
099e6576 AZ	369	case RTC_AIE_ON:
	370	mutex_unlock(&rtc->ops_lock);
	371	return rtc_alarm_irq_enable(rtc, 1);
	372
	373	case RTC_AIE_OFF:
	374	mutex_unlock(&rtc->ops_lock);
	375	return rtc_alarm_irq_enable(rtc, 0);
	376
	377	case RTC_UIE_ON:
	378	mutex_unlock(&rtc->ops_lock);
	379	return rtc_update_irq_enable(rtc, 1);
	380
	381	case RTC_UIE_OFF:
	382	mutex_unlock(&rtc->ops_lock);
	383	return rtc_update_irq_enable(rtc, 0);
	384
2601a464	385	case RTC_IRQP_SET:
d691eb90 AZ	386	err = rtc_irq_set_freq(rtc, NULL, arg);
	387	break;
	388
	389	case RTC_IRQP_READ:
	390	err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
2601a464 DB	391	break;
2601a464 DB	392
e824290e AZ	393	#if 0
	394	case RTC_EPOCH_SET:
	395	#ifndef rtc_epoch
	396	/*
	397	* There were no RTC clocks before 1900.
	398	*/
	399	if (arg < 1900) {
	400	err = -EINVAL;
	401	break;
	402	}
e824290e AZ	403	rtc_epoch = arg;
	404	err = 0;
	405	#endif
	406	break;
	407
	408	case RTC_EPOCH_READ:
	409	err = put_user(rtc_epoch, (unsigned long __user *)uarg);
	410	break;
	411	#endif
	412	case RTC_WKALM_SET:
5ad31a57	413	mutex_unlock(&rtc->ops_lock);
e824290e AZ	414	if (copy_from_user(&alarm, uarg, sizeof(alarm)))
	415	return -EFAULT;
	416
5ad31a57	417	return rtc_set_alarm(rtc, &alarm);
e824290e AZ	418
e824290e AZ	419	case RTC_WKALM_RD:
5ad31a57	420	mutex_unlock(&rtc->ops_lock);
ab6a2d70	421	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	422	if (err < 0)
	423	return err;
	424
	425	if (copy_to_user(uarg, &alarm, sizeof(alarm)))
5ad31a57 DB	426	err = -EFAULT;
5ad31a57 DB	427	return err;
e824290e AZ	428
e824290e AZ	429	default:
b3969e58	430	err = -ENOTTY;
e824290e AZ	431	break;
	432	}
	433
5ad31a57 DB	434	done:
5ad31a57 DB	435	mutex_unlock(&rtc->ops_lock);
e824290e AZ	436	return err;
	437	}
	438
2e4a75cd MS	439	static int rtc_dev_fasync(int fd, struct file *file, int on)
	440	{
	441	struct rtc_device *rtc = file->private_data;
	442	return fasync_helper(fd, file, on, &rtc->async_queue);
	443	}
	444
e824290e AZ	445	static int rtc_dev_release(struct inode inode, struct file file)
e824290e AZ	446	{
88efe137	447	struct rtc_device *rtc = file->private_data;
e824290e	448
743e6a50 DB	449	/* We shut down the repeating IRQs that userspace enabled,
	450	* since nothing is listening to them.
	451	* - Update (UIE) ... currently only managed through ioctls
	452	* - Periodic (PIE) ... also used through rtc_*() interface calls
	453	*
	454	* Leave the alarm alone; it may be set to trigger a system wakeup
	455	* later, or be used by kernel code, and is a one-shot event anyway.
	456	*/
099e6576 AZ	457
099e6576 AZ	458	/* Keep ioctl until all drivers are converted */
743e6a50	459	rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
099e6576	460	rtc_update_irq_enable(rtc, 0);
5cdc98b8 TJ	461	rtc_irq_set_state(rtc, NULL, 0);
5cdc98b8 TJ	462
e824290e	463	if (rtc->ops->release)
cd966209	464	rtc->ops->release(rtc->dev.parent);
e824290e	465
372a302e	466	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
e824290e AZ	467	return 0;
	468	}
	469
d54b1fdb	470	static const struct file_operations rtc_dev_fops = {
e824290e AZ	471	.owner = THIS_MODULE,
	472	.llseek = no_llseek,
	473	.read = rtc_dev_read,
	474	.poll = rtc_dev_poll,
5ad31a57	475	.unlocked_ioctl = rtc_dev_ioctl,
e824290e AZ	476	.open = rtc_dev_open,
	477	.release = rtc_dev_release,
	478	.fasync = rtc_dev_fasync,
	479	};
	480
	481	/* insertion/removal hooks */
	482
cb3a58d2	483	void rtc_dev_prepare(struct rtc_device *rtc)
e824290e	484	{
5726fb20 DB	485	if (!rtc_devt)
5726fb20 DB	486	return;
e824290e AZ	487
e824290e AZ	488	if (rtc->id >= RTC_DEV_MAX) {
5726fb20 DB	489	pr_debug("%s: too many RTC devices\n", rtc->name);
5726fb20 DB	490	return;
e824290e AZ	491	}
e824290e AZ	492
cd966209	493	rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
5726fb20	494
655066c3	495	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
c4028958	496	INIT_WORK(&rtc->uie_task, rtc_uie_task);
655066c3 AN	497	setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
655066c3 AN	498	#endif
e824290e AZ	499
	500	cdev_init(&rtc->char_dev, &rtc_dev_fops);
	501	rtc->char_dev.owner = rtc->owner;
cb3a58d2	502	}
e824290e	503
cb3a58d2 DB	504	void rtc_dev_add_device(struct rtc_device *rtc)
cb3a58d2 DB	505	{
cd966209	506	if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
5726fb20 DB	507	printk(KERN_WARNING "%s: failed to add char device %d:%d\n",
	508	rtc->name, MAJOR(rtc_devt), rtc->id);
	509	else
	510	pr_debug("%s: dev (%d:%d)\n", rtc->name,
e824290e	511	MAJOR(rtc_devt), rtc->id);
e824290e AZ	512	}
e824290e AZ	513
5726fb20	514	void rtc_dev_del_device(struct rtc_device *rtc)
e824290e	515	{
cd966209	516	if (rtc->dev.devt)
e824290e	517	cdev_del(&rtc->char_dev);
e824290e AZ	518	}
e824290e AZ	519
5726fb20	520	void __init rtc_dev_init(void)
e824290e AZ	521	{
	522	int err;
	523
e824290e	524	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
5726fb20	525	if (err < 0)
e824290e AZ	526	printk(KERN_ERR "%s: failed to allocate char dev region\n",
e824290e AZ	527	__FILE__);
e824290e AZ	528	}
e824290e AZ	529
5726fb20	530	void __exit rtc_dev_exit(void)
e824290e	531	{
5726fb20 DB	532	if (rtc_devt)
5726fb20 DB	533	unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
e824290e	534	}