[deliverable/linux.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);

	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 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 DB	62
	63	local_irq_disable();
	64	spin_lock(&rtc->irq_lock);
655066c3 AN	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	}
d728b1e6	77	spin_unlock(&rtc->irq_lock);
655066c3	78	if (num)
ab6a2d70	79	rtc_update_irq(rtc, num, RTC_UF \| RTC_IRQF);
d728b1e6	80	local_irq_enable();
655066c3	81	}
655066c3 AN	82	static void rtc_uie_timer(unsigned long data)
	83	{
	84	struct rtc_device rtc = (struct rtc_device )data;
	85	unsigned long flags;
	86
	87	spin_lock_irqsave(&rtc->irq_lock, flags);
	88	rtc->uie_timer_active = 0;
	89	rtc->uie_task_active = 1;
	90	if ((schedule_work(&rtc->uie_task) == 0))
	91	rtc->uie_task_active = 0;
	92	spin_unlock_irqrestore(&rtc->irq_lock, flags);
	93	}
	94
099e6576	95	static int clear_uie(struct rtc_device *rtc)
655066c3 AN	96	{
655066c3 AN	97	spin_lock_irq(&rtc->irq_lock);
099e6576	98	if (rtc->uie_irq_active) {
655066c3 AN	99	rtc->stop_uie_polling = 1;
	100	if (rtc->uie_timer_active) {
	101	spin_unlock_irq(&rtc->irq_lock);
	102	del_timer_sync(&rtc->uie_timer);
	103	spin_lock_irq(&rtc->irq_lock);
	104	rtc->uie_timer_active = 0;
	105	}
	106	if (rtc->uie_task_active) {
	107	spin_unlock_irq(&rtc->irq_lock);
	108	flush_scheduled_work();
	109	spin_lock_irq(&rtc->irq_lock);
	110	}
099e6576	111	rtc->uie_irq_active = 0;
655066c3 AN	112	}
655066c3 AN	113	spin_unlock_irq(&rtc->irq_lock);
099e6576	114	return 0;
655066c3 AN	115	}
	116
	117	static int set_uie(struct rtc_device *rtc)
	118	{
	119	struct rtc_time tm;
	120	int err;
	121
ab6a2d70	122	err = rtc_read_time(rtc, &tm);
655066c3 AN	123	if (err)
	124	return err;
	125	spin_lock_irq(&rtc->irq_lock);
099e6576 AZ	126	if (!rtc->uie_irq_active) {
099e6576 AZ	127	rtc->uie_irq_active = 1;
655066c3 AN	128	rtc->stop_uie_polling = 0;
	129	rtc->oldsecs = tm.tm_sec;
	130	rtc->uie_task_active = 1;
	131	if (schedule_work(&rtc->uie_task) == 0)
	132	rtc->uie_task_active = 0;
	133	}
	134	rtc->irq_data = 0;
	135	spin_unlock_irq(&rtc->irq_lock);
	136	return 0;
	137	}
099e6576 AZ	138
	139	int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
	140	{
	141	if (enabled)
	142	return set_uie(rtc);
	143	else
	144	return clear_uie(rtc);
	145	}
	146	EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);
	147
655066c3	148	#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
e824290e AZ	149
	150	static ssize_t
	151	rtc_dev_read(struct file file, char __user buf, size_t count, loff_t *ppos)
	152	{
88efe137	153	struct rtc_device *rtc = file->private_data;
e824290e AZ	154
	155	DECLARE_WAITQUEUE(wait, current);
	156	unsigned long data;
	157	ssize_t ret;
	158
3418ff76	159	if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
e824290e AZ	160	return -EINVAL;
	161
	162	add_wait_queue(&rtc->irq_queue, &wait);
	163	do {
	164	__set_current_state(TASK_INTERRUPTIBLE);
	165
	166	spin_lock_irq(&rtc->irq_lock);
	167	data = rtc->irq_data;
	168	rtc->irq_data = 0;
	169	spin_unlock_irq(&rtc->irq_lock);
	170
	171	if (data != 0) {
	172	ret = 0;
	173	break;
	174	}
	175	if (file->f_flags & O_NONBLOCK) {
	176	ret = -EAGAIN;
	177	break;
	178	}
	179	if (signal_pending(current)) {
	180	ret = -ERESTARTSYS;
	181	break;
	182	}
	183	schedule();
	184	} while (1);
	185	set_current_state(TASK_RUNNING);
	186	remove_wait_queue(&rtc->irq_queue, &wait);
	187
	188	if (ret == 0) {
	189	/* Check for any data updates */
	190	if (rtc->ops->read_callback)
cd966209	191	data = rtc->ops->read_callback(rtc->dev.parent,
3418ff76 AN	192	data);
	193
	194	if (sizeof(int) != sizeof(long) &&
	195	count == sizeof(unsigned int))
	196	ret = put_user(data, (unsigned int __user *)buf) ?:
	197	sizeof(unsigned int);
	198	else
	199	ret = put_user(data, (unsigned long __user *)buf) ?:
	200	sizeof(unsigned long);
e824290e AZ	201	}
	202	return ret;
	203	}
	204
	205	static unsigned int rtc_dev_poll(struct file file, poll_table wait)
	206	{
88efe137	207	struct rtc_device *rtc = file->private_data;
e824290e AZ	208	unsigned long data;
	209
	210	poll_wait(file, &rtc->irq_queue, wait);
	211
	212	data = rtc->irq_data;
	213
	214	return (data != 0) ? (POLLIN \| POLLRDNORM) : 0;
	215	}
	216
5ad31a57	217	static long rtc_dev_ioctl(struct file *file,
e824290e AZ	218	unsigned int cmd, unsigned long arg)
	219	{
	220	int err = 0;
ab6a2d70	221	struct rtc_device *rtc = file->private_data;
ff8371ac	222	const struct rtc_class_ops *ops = rtc->ops;
e824290e AZ	223	struct rtc_time tm;
	224	struct rtc_wkalrm alarm;
	225	void __user uarg = (void __user ) arg;
	226
5ad31a57 DB	227	err = mutex_lock_interruptible(&rtc->ops_lock);
5ad31a57 DB	228	if (err)
b68bb263	229	return err;
5ad31a57	230
2601a464	231	/* check that the calling task has appropriate permissions
110d693d AZ	232	* for certain ioctls. doing this check here is useful
	233	* to avoid duplicate code in each driver.
	234	*/
	235	switch (cmd) {
	236	case RTC_EPOCH_SET:
	237	case RTC_SET_TIME:
	238	if (!capable(CAP_SYS_TIME))
5ad31a57	239	err = -EACCES;
110d693d AZ	240	break;
	241
	242	case RTC_IRQP_SET:
	243	if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
5ad31a57	244	err = -EACCES;
110d693d AZ	245	break;
	246
	247	case RTC_PIE_ON:
9d013d3b BK	248	if (rtc->irq_freq > rtc->max_user_freq &&
9d013d3b BK	249	!capable(CAP_SYS_RESOURCE))
5ad31a57	250	err = -EACCES;
110d693d AZ	251	break;
	252	}
	253
5ad31a57 DB	254	if (err)
	255	goto done;
	256
e824290e AZ	257	/* try the driver's ioctl interface */
e824290e AZ	258	if (ops->ioctl) {
cd966209	259	err = ops->ioctl(rtc->dev.parent, cmd, arg);
5ad31a57 DB	260	if (err != -ENOIOCTLCMD) {
5ad31a57 DB	261	mutex_unlock(&rtc->ops_lock);
e824290e	262	return err;
5ad31a57	263	}
e824290e AZ	264	}
	265
	266	/* if the driver does not provide the ioctl interface
	267	* or if that particular ioctl was not implemented
b3969e58	268	* (-ENOIOCTLCMD), we will try to emulate here.
8a0bdfd7 DB	269	*
	270	* Drivers SHOULD NOT provide ioctl implementations
	271	* for these requests. Instead, provide methods to
	272	* support the following code, so that the RTC's main
	273	* features are accessible without using ioctls.
	274	*
	275	* RTC and alarm times will be in UTC, by preference,
	276	* but dual-booting with MS-Windows implies RTCs must
	277	* use the local wall clock time.
e824290e AZ	278	*/
	279
	280	switch (cmd) {
	281	case RTC_ALM_READ:
5ad31a57 DB	282	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	283
ab6a2d70	284	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	285	if (err < 0)
	286	return err;
	287
	288	if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
5ad31a57 DB	289	err = -EFAULT;
5ad31a57 DB	290	return err;
e824290e AZ	291
e824290e AZ	292	case RTC_ALM_SET:
5ad31a57 DB	293	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	294
e824290e AZ	295	if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
	296	return -EFAULT;
	297
	298	alarm.enabled = 0;
	299	alarm.pending = 0;
e824290e AZ	300	alarm.time.tm_wday = -1;
	301	alarm.time.tm_yday = -1;
	302	alarm.time.tm_isdst = -1;
f8245c26 DB	303
	304	/* RTC_ALM_SET alarms may be up to 24 hours in the future.
	305	* Rather than expecting every RTC to implement "don't care"
	306	* for day/month/year fields, just force the alarm to have
	307	* the right values for those fields.
	308	*
	309	* RTC_WKALM_SET should be used instead. Not only does it
	310	* eliminate the need for a separate RTC_AIE_ON call, it
	311	* doesn't have the "alarm 23:59:59 in the future" race.
	312	*
	313	* NOTE: some legacy code may have used invalid fields as
	314	* wildcards, exposing hardware "periodic alarm" capabilities.
	315	* Not supported here.
	316	*/
	317	{
	318	unsigned long now, then;
	319
	320	err = rtc_read_time(rtc, &tm);
	321	if (err < 0)
	322	return err;
	323	rtc_tm_to_time(&tm, &now);
	324
	325	alarm.time.tm_mday = tm.tm_mday;
	326	alarm.time.tm_mon = tm.tm_mon;
	327	alarm.time.tm_year = tm.tm_year;
	328	err = rtc_valid_tm(&alarm.time);
	329	if (err < 0)
	330	return err;
	331	rtc_tm_to_time(&alarm.time, &then);
	332
	333	/* alarm may need to wrap into tomorrow */
	334	if (then < now) {
	335	rtc_time_to_tm(now + 24 * 60 * 60, &tm);
	336	alarm.time.tm_mday = tm.tm_mday;
	337	alarm.time.tm_mon = tm.tm_mon;
	338	alarm.time.tm_year = tm.tm_year;
	339	}
	340	}
	341
5ad31a57	342	return rtc_set_alarm(rtc, &alarm);
e824290e AZ	343
e824290e AZ	344	case RTC_RD_TIME:
5ad31a57 DB	345	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	346
ab6a2d70	347	err = rtc_read_time(rtc, &tm);
e824290e AZ	348	if (err < 0)
	349	return err;
	350
	351	if (copy_to_user(uarg, &tm, sizeof(tm)))
5ad31a57 DB	352	err = -EFAULT;
5ad31a57 DB	353	return err;
e824290e AZ	354
e824290e AZ	355	case RTC_SET_TIME:
5ad31a57 DB	356	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	357
e824290e AZ	358	if (copy_from_user(&tm, uarg, sizeof(tm)))
	359	return -EFAULT;
	360
5ad31a57	361	return rtc_set_time(rtc, &tm);
2601a464	362
d691eb90 AZ	363	case RTC_PIE_ON:
	364	err = rtc_irq_set_state(rtc, NULL, 1);
	365	break;
	366
	367	case RTC_PIE_OFF:
	368	err = rtc_irq_set_state(rtc, NULL, 0);
2601a464 DB	369	break;
2601a464 DB	370
099e6576 AZ	371	case RTC_AIE_ON:
	372	mutex_unlock(&rtc->ops_lock);
	373	return rtc_alarm_irq_enable(rtc, 1);
	374
	375	case RTC_AIE_OFF:
	376	mutex_unlock(&rtc->ops_lock);
	377	return rtc_alarm_irq_enable(rtc, 0);
	378
	379	case RTC_UIE_ON:
	380	mutex_unlock(&rtc->ops_lock);
	381	return rtc_update_irq_enable(rtc, 1);
	382
	383	case RTC_UIE_OFF:
	384	mutex_unlock(&rtc->ops_lock);
	385	return rtc_update_irq_enable(rtc, 0);
	386
2601a464	387	case RTC_IRQP_SET:
d691eb90 AZ	388	err = rtc_irq_set_freq(rtc, NULL, arg);
	389	break;
	390
	391	case RTC_IRQP_READ:
	392	err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
2601a464 DB	393	break;
2601a464 DB	394
e824290e AZ	395	#if 0
	396	case RTC_EPOCH_SET:
	397	#ifndef rtc_epoch
	398	/*
	399	* There were no RTC clocks before 1900.
	400	*/
	401	if (arg < 1900) {
	402	err = -EINVAL;
	403	break;
	404	}
e824290e AZ	405	rtc_epoch = arg;
	406	err = 0;
	407	#endif
	408	break;
	409
	410	case RTC_EPOCH_READ:
	411	err = put_user(rtc_epoch, (unsigned long __user *)uarg);
	412	break;
	413	#endif
	414	case RTC_WKALM_SET:
5ad31a57	415	mutex_unlock(&rtc->ops_lock);
e824290e AZ	416	if (copy_from_user(&alarm, uarg, sizeof(alarm)))
	417	return -EFAULT;
	418
5ad31a57	419	return rtc_set_alarm(rtc, &alarm);
e824290e AZ	420
e824290e AZ	421	case RTC_WKALM_RD:
5ad31a57	422	mutex_unlock(&rtc->ops_lock);
ab6a2d70	423	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	424	if (err < 0)
	425	return err;
	426
	427	if (copy_to_user(uarg, &alarm, sizeof(alarm)))
5ad31a57 DB	428	err = -EFAULT;
5ad31a57 DB	429	return err;
e824290e AZ	430
e824290e AZ	431	default:
b3969e58	432	err = -ENOTTY;
e824290e AZ	433	break;
	434	}
	435
5ad31a57 DB	436	done:
5ad31a57 DB	437	mutex_unlock(&rtc->ops_lock);
e824290e AZ	438	return err;
	439	}
	440
2e4a75cd MS	441	static int rtc_dev_fasync(int fd, struct file *file, int on)
	442	{
	443	struct rtc_device *rtc = file->private_data;
	444	return fasync_helper(fd, file, on, &rtc->async_queue);
	445	}
	446
e824290e AZ	447	static int rtc_dev_release(struct inode inode, struct file file)
e824290e AZ	448	{
88efe137	449	struct rtc_device *rtc = file->private_data;
e824290e	450
743e6a50 DB	451	/* We shut down the repeating IRQs that userspace enabled,
	452	* since nothing is listening to them.
	453	* - Update (UIE) ... currently only managed through ioctls
	454	* - Periodic (PIE) ... also used through rtc_*() interface calls
	455	*
	456	* Leave the alarm alone; it may be set to trigger a system wakeup
	457	* later, or be used by kernel code, and is a one-shot event anyway.
	458	*/
099e6576 AZ	459
099e6576 AZ	460	/* Keep ioctl until all drivers are converted */
743e6a50	461	rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
099e6576	462	rtc_update_irq_enable(rtc, 0);
5cdc98b8 TJ	463	rtc_irq_set_state(rtc, NULL, 0);
5cdc98b8 TJ	464
e824290e	465	if (rtc->ops->release)
cd966209	466	rtc->ops->release(rtc->dev.parent);
e824290e	467
372a302e	468	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
e824290e AZ	469	return 0;
	470	}
	471
d54b1fdb	472	static const struct file_operations rtc_dev_fops = {
e824290e AZ	473	.owner = THIS_MODULE,
	474	.llseek = no_llseek,
	475	.read = rtc_dev_read,
	476	.poll = rtc_dev_poll,
5ad31a57	477	.unlocked_ioctl = rtc_dev_ioctl,
e824290e AZ	478	.open = rtc_dev_open,
	479	.release = rtc_dev_release,
	480	.fasync = rtc_dev_fasync,
	481	};
	482
	483	/* insertion/removal hooks */
	484
cb3a58d2	485	void rtc_dev_prepare(struct rtc_device *rtc)
e824290e	486	{
5726fb20 DB	487	if (!rtc_devt)
5726fb20 DB	488	return;
e824290e AZ	489
e824290e AZ	490	if (rtc->id >= RTC_DEV_MAX) {
5726fb20 DB	491	pr_debug("%s: too many RTC devices\n", rtc->name);
5726fb20 DB	492	return;
e824290e AZ	493	}
e824290e AZ	494
cd966209	495	rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
5726fb20	496
655066c3	497	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
c4028958	498	INIT_WORK(&rtc->uie_task, rtc_uie_task);
655066c3 AN	499	setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
655066c3 AN	500	#endif
e824290e AZ	501
	502	cdev_init(&rtc->char_dev, &rtc_dev_fops);
	503	rtc->char_dev.owner = rtc->owner;
cb3a58d2	504	}
e824290e	505
cb3a58d2 DB	506	void rtc_dev_add_device(struct rtc_device *rtc)
cb3a58d2 DB	507	{
cd966209	508	if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
5726fb20 DB	509	printk(KERN_WARNING "%s: failed to add char device %d:%d\n",
	510	rtc->name, MAJOR(rtc_devt), rtc->id);
	511	else
	512	pr_debug("%s: dev (%d:%d)\n", rtc->name,
e824290e	513	MAJOR(rtc_devt), rtc->id);
e824290e AZ	514	}
e824290e AZ	515
5726fb20	516	void rtc_dev_del_device(struct rtc_device *rtc)
e824290e	517	{
cd966209	518	if (rtc->dev.devt)
e824290e	519	cdev_del(&rtc->char_dev);
e824290e AZ	520	}
e824290e AZ	521
5726fb20	522	void __init rtc_dev_init(void)
e824290e AZ	523	{
	524	int err;
	525
e824290e	526	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
5726fb20	527	if (err < 0)
e824290e AZ	528	printk(KERN_ERR "%s: failed to allocate char dev region\n",
e824290e AZ	529	__FILE__);
e824290e AZ	530	}
e824290e AZ	531
5726fb20	532	void __exit rtc_dev_exit(void)
e824290e	533	{
5726fb20 DB	534	if (rtc_devt)
5726fb20 DB	535	unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
e824290e	536	}