[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 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 = 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 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 (rtc->irq_freq > rtc->max_user_freq &&
				!capable(CAP_SYS_RESOURCE))
			return -EACCES;
		break;
	}

	/* 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.
	 *
	 * 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:
		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_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_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:
		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 = file->private_data;

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

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

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 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);

#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
372a302e	29	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
e824290e AZ	30	return -EBUSY;
e824290e AZ	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
	40	return 0;
	41	}
	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
	95	static void clear_uie(struct rtc_device *rtc)
	96	{
	97	spin_lock_irq(&rtc->irq_lock);
	98	if (rtc->irq_active) {
	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	}
	111	rtc->irq_active = 0;
	112	}
	113	spin_unlock_irq(&rtc->irq_lock);
	114	}
	115
	116	static int set_uie(struct rtc_device *rtc)
	117	{
	118	struct rtc_time tm;
	119	int err;
	120
ab6a2d70	121	err = rtc_read_time(rtc, &tm);
655066c3 AN	122	if (err)
	123	return err;
	124	spin_lock_irq(&rtc->irq_lock);
	125	if (!rtc->irq_active) {
	126	rtc->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	#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
e824290e AZ	138
	139	static ssize_t
	140	rtc_dev_read(struct file file, char __user buf, size_t count, loff_t *ppos)
	141	{
88efe137	142	struct rtc_device *rtc = file->private_data;
e824290e AZ	143
	144	DECLARE_WAITQUEUE(wait, current);
	145	unsigned long data;
	146	ssize_t ret;
	147
3418ff76	148	if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
e824290e AZ	149	return -EINVAL;
	150
	151	add_wait_queue(&rtc->irq_queue, &wait);
	152	do {
	153	__set_current_state(TASK_INTERRUPTIBLE);
	154
	155	spin_lock_irq(&rtc->irq_lock);
	156	data = rtc->irq_data;
	157	rtc->irq_data = 0;
	158	spin_unlock_irq(&rtc->irq_lock);
	159
	160	if (data != 0) {
	161	ret = 0;
	162	break;
	163	}
	164	if (file->f_flags & O_NONBLOCK) {
	165	ret = -EAGAIN;
	166	break;
	167	}
	168	if (signal_pending(current)) {
	169	ret = -ERESTARTSYS;
	170	break;
	171	}
	172	schedule();
	173	} while (1);
	174	set_current_state(TASK_RUNNING);
	175	remove_wait_queue(&rtc->irq_queue, &wait);
	176
	177	if (ret == 0) {
	178	/* Check for any data updates */
	179	if (rtc->ops->read_callback)
cd966209	180	data = rtc->ops->read_callback(rtc->dev.parent,
3418ff76 AN	181	data);
	182
	183	if (sizeof(int) != sizeof(long) &&
	184	count == sizeof(unsigned int))
	185	ret = put_user(data, (unsigned int __user *)buf) ?:
	186	sizeof(unsigned int);
	187	else
	188	ret = put_user(data, (unsigned long __user *)buf) ?:
	189	sizeof(unsigned long);
e824290e AZ	190	}
	191	return ret;
	192	}
	193
	194	static unsigned int rtc_dev_poll(struct file file, poll_table wait)
	195	{
88efe137	196	struct rtc_device *rtc = file->private_data;
e824290e AZ	197	unsigned long data;
	198
	199	poll_wait(file, &rtc->irq_queue, wait);
	200
	201	data = rtc->irq_data;
	202
	203	return (data != 0) ? (POLLIN \| POLLRDNORM) : 0;
	204	}
	205
	206	static int rtc_dev_ioctl(struct inode inode, struct file file,
	207	unsigned int cmd, unsigned long arg)
	208	{
	209	int err = 0;
ab6a2d70	210	struct rtc_device *rtc = file->private_data;
ff8371ac	211	const struct rtc_class_ops *ops = rtc->ops;
e824290e AZ	212	struct rtc_time tm;
	213	struct rtc_wkalrm alarm;
	214	void __user uarg = (void __user ) arg;
	215
2601a464	216	/* check that the calling task has appropriate permissions
110d693d AZ	217	* for certain ioctls. doing this check here is useful
	218	* to avoid duplicate code in each driver.
	219	*/
	220	switch (cmd) {
	221	case RTC_EPOCH_SET:
	222	case RTC_SET_TIME:
	223	if (!capable(CAP_SYS_TIME))
	224	return -EACCES;
	225	break;
	226
	227	case RTC_IRQP_SET:
	228	if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
	229	return -EACCES;
	230	break;
	231
	232	case RTC_PIE_ON:
9d013d3b BK	233	if (rtc->irq_freq > rtc->max_user_freq &&
9d013d3b BK	234	!capable(CAP_SYS_RESOURCE))
110d693d AZ	235	return -EACCES;
	236	break;
	237	}
	238
e824290e AZ	239	/* try the driver's ioctl interface */
e824290e AZ	240	if (ops->ioctl) {
cd966209	241	err = ops->ioctl(rtc->dev.parent, cmd, arg);
b3969e58	242	if (err != -ENOIOCTLCMD)
e824290e AZ	243	return err;
	244	}
	245
	246	/* if the driver does not provide the ioctl interface
	247	* or if that particular ioctl was not implemented
b3969e58	248	* (-ENOIOCTLCMD), we will try to emulate here.
8a0bdfd7 DB	249	*
	250	* Drivers SHOULD NOT provide ioctl implementations
	251	* for these requests. Instead, provide methods to
	252	* support the following code, so that the RTC's main
	253	* features are accessible without using ioctls.
	254	*
	255	* RTC and alarm times will be in UTC, by preference,
	256	* but dual-booting with MS-Windows implies RTCs must
	257	* use the local wall clock time.
e824290e AZ	258	*/
	259
	260	switch (cmd) {
	261	case RTC_ALM_READ:
ab6a2d70	262	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	263	if (err < 0)
	264	return err;
	265
	266	if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
	267	return -EFAULT;
	268	break;
	269
	270	case RTC_ALM_SET:
	271	if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
	272	return -EFAULT;
	273
	274	alarm.enabled = 0;
	275	alarm.pending = 0;
e824290e AZ	276	alarm.time.tm_wday = -1;
	277	alarm.time.tm_yday = -1;
	278	alarm.time.tm_isdst = -1;
f8245c26 DB	279
	280	/* RTC_ALM_SET alarms may be up to 24 hours in the future.
	281	* Rather than expecting every RTC to implement "don't care"
	282	* for day/month/year fields, just force the alarm to have
	283	* the right values for those fields.
	284	*
	285	* RTC_WKALM_SET should be used instead. Not only does it
	286	* eliminate the need for a separate RTC_AIE_ON call, it
	287	* doesn't have the "alarm 23:59:59 in the future" race.
	288	*
	289	* NOTE: some legacy code may have used invalid fields as
	290	* wildcards, exposing hardware "periodic alarm" capabilities.
	291	* Not supported here.
	292	*/
	293	{
	294	unsigned long now, then;
	295
	296	err = rtc_read_time(rtc, &tm);
	297	if (err < 0)
	298	return err;
	299	rtc_tm_to_time(&tm, &now);
	300
	301	alarm.time.tm_mday = tm.tm_mday;
	302	alarm.time.tm_mon = tm.tm_mon;
	303	alarm.time.tm_year = tm.tm_year;
	304	err = rtc_valid_tm(&alarm.time);
	305	if (err < 0)
	306	return err;
	307	rtc_tm_to_time(&alarm.time, &then);
	308
	309	/* alarm may need to wrap into tomorrow */
	310	if (then < now) {
	311	rtc_time_to_tm(now + 24 * 60 * 60, &tm);
	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	}
	316	}
	317
ab6a2d70	318	err = rtc_set_alarm(rtc, &alarm);
e824290e AZ	319	break;
	320
	321	case RTC_RD_TIME:
ab6a2d70	322	err = rtc_read_time(rtc, &tm);
e824290e AZ	323	if (err < 0)
	324	return err;
	325
	326	if (copy_to_user(uarg, &tm, sizeof(tm)))
	327	return -EFAULT;
	328	break;
	329
	330	case RTC_SET_TIME:
e824290e AZ	331	if (copy_from_user(&tm, uarg, sizeof(tm)))
	332	return -EFAULT;
	333
ab6a2d70	334	err = rtc_set_time(rtc, &tm);
e824290e	335	break;
2601a464	336
d691eb90 AZ	337	case RTC_PIE_ON:
	338	err = rtc_irq_set_state(rtc, NULL, 1);
	339	break;
	340
	341	case RTC_PIE_OFF:
	342	err = rtc_irq_set_state(rtc, NULL, 0);
2601a464 DB	343	break;
	344
	345	case RTC_IRQP_SET:
d691eb90 AZ	346	err = rtc_irq_set_freq(rtc, NULL, arg);
	347	break;
	348
	349	case RTC_IRQP_READ:
	350	err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
2601a464 DB	351	break;
2601a464 DB	352
e824290e AZ	353	#if 0
	354	case RTC_EPOCH_SET:
	355	#ifndef rtc_epoch
	356	/*
	357	* There were no RTC clocks before 1900.
	358	*/
	359	if (arg < 1900) {
	360	err = -EINVAL;
	361	break;
	362	}
e824290e AZ	363	rtc_epoch = arg;
	364	err = 0;
	365	#endif
	366	break;
	367
	368	case RTC_EPOCH_READ:
	369	err = put_user(rtc_epoch, (unsigned long __user *)uarg);
	370	break;
	371	#endif
	372	case RTC_WKALM_SET:
	373	if (copy_from_user(&alarm, uarg, sizeof(alarm)))
	374	return -EFAULT;
	375
ab6a2d70	376	err = rtc_set_alarm(rtc, &alarm);
e824290e AZ	377	break;
	378
	379	case RTC_WKALM_RD:
ab6a2d70	380	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	381	if (err < 0)
	382	return err;
	383
	384	if (copy_to_user(uarg, &alarm, sizeof(alarm)))
	385	return -EFAULT;
	386	break;
	387
655066c3 AN	388	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	389	case RTC_UIE_OFF:
	390	clear_uie(rtc);
	391	return 0;
	392
	393	case RTC_UIE_ON:
	394	return set_uie(rtc);
	395	#endif
e824290e	396	default:
b3969e58	397	err = -ENOTTY;
e824290e AZ	398	break;
	399	}
	400
	401	return err;
	402	}
	403
	404	static int rtc_dev_release(struct inode inode, struct file file)
	405	{
88efe137	406	struct rtc_device *rtc = file->private_data;
e824290e	407
655066c3 AN	408	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	409	clear_uie(rtc);
	410	#endif
e824290e	411	if (rtc->ops->release)
cd966209	412	rtc->ops->release(rtc->dev.parent);
e824290e	413
372a302e	414	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
e824290e AZ	415	return 0;
	416	}
	417
	418	static int rtc_dev_fasync(int fd, struct file *file, int on)
	419	{
88efe137	420	struct rtc_device *rtc = file->private_data;
e824290e AZ	421	return fasync_helper(fd, file, on, &rtc->async_queue);
	422	}
	423
d54b1fdb	424	static const struct file_operations rtc_dev_fops = {
e824290e AZ	425	.owner = THIS_MODULE,
	426	.llseek = no_llseek,
	427	.read = rtc_dev_read,
	428	.poll = rtc_dev_poll,
	429	.ioctl = rtc_dev_ioctl,
	430	.open = rtc_dev_open,
	431	.release = rtc_dev_release,
	432	.fasync = rtc_dev_fasync,
	433	};
	434
	435	/* insertion/removal hooks */
	436
cb3a58d2	437	void rtc_dev_prepare(struct rtc_device *rtc)
e824290e	438	{
5726fb20 DB	439	if (!rtc_devt)
5726fb20 DB	440	return;
e824290e AZ	441
e824290e AZ	442	if (rtc->id >= RTC_DEV_MAX) {
5726fb20 DB	443	pr_debug("%s: too many RTC devices\n", rtc->name);
5726fb20 DB	444	return;
e824290e AZ	445	}
e824290e AZ	446
cd966209	447	rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
5726fb20	448
655066c3	449	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
c4028958	450	INIT_WORK(&rtc->uie_task, rtc_uie_task);
655066c3 AN	451	setup_timer(&rtc->uie_timer, rtc_uie_timer, (unsigned long)rtc);
655066c3 AN	452	#endif
e824290e AZ	453
	454	cdev_init(&rtc->char_dev, &rtc_dev_fops);
	455	rtc->char_dev.owner = rtc->owner;
cb3a58d2	456	}
e824290e	457
cb3a58d2 DB	458	void rtc_dev_add_device(struct rtc_device *rtc)
cb3a58d2 DB	459	{
cd966209	460	if (cdev_add(&rtc->char_dev, rtc->dev.devt, 1))
5726fb20 DB	461	printk(KERN_WARNING "%s: failed to add char device %d:%d\n",
	462	rtc->name, MAJOR(rtc_devt), rtc->id);
	463	else
	464	pr_debug("%s: dev (%d:%d)\n", rtc->name,
e824290e	465	MAJOR(rtc_devt), rtc->id);
e824290e AZ	466	}
e824290e AZ	467
5726fb20	468	void rtc_dev_del_device(struct rtc_device *rtc)
e824290e	469	{
cd966209	470	if (rtc->dev.devt)
e824290e	471	cdev_del(&rtc->char_dev);
e824290e AZ	472	}
e824290e AZ	473
5726fb20	474	void __init rtc_dev_init(void)
e824290e AZ	475	{
	476	int err;
	477
e824290e	478	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
5726fb20	479	if (err < 0)
e824290e AZ	480	printk(KERN_ERR "%s: failed to allocate char dev region\n",
e824290e AZ	481	__FILE__);
e824290e AZ	482	}
e824290e AZ	483
5726fb20	484	void __exit rtc_dev_exit(void)
e824290e	485	{
5726fb20 DB	486	if (rtc_devt)
5726fb20 DB	487	unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
e824290e	488	}