[linux-2.6-block.git] / drivers / rtc / dev.c

// SPDX-License-Identifier: GPL-2.0
/*
 * RTC subsystem, dev interface
 *
 * Copyright (C) 2005 Tower Technologies
 * Author: Alessandro Zummo <a.zummo@towertech.it>
 *
 * based on arch/arm/common/rtctime.c
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/sched/signal.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)
{
	struct rtc_device *rtc = container_of(inode->i_cdev,
					struct rtc_device, char_dev);

	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
		return -EBUSY;

	file->private_data = rtc;

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

	return 0;
}

#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(struct timer_list *t)
{
	struct rtc_device *rtc = from_timer(rtc, t, uie_timer);
	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) {
		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 __poll_t 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) ? (EPOLLIN | EPOLLRDNORM) : 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.
		 */
		{
			time64_t now, then;

			err = rtc_read_time(rtc, &tm);
			if (err < 0)
				return err;
			now = rtc_tm_to_time64(&tm);

			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;
			then = rtc_tm_to_time64(&alarm.time);

			/* alarm may need to wrap into tomorrow */
			if (then < now) {
				rtc_time64_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, 1);
		break;

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

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

	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, 0);

	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) {
		dev_dbg(&rtc->dev, "too many RTC devices\n");
		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);
	timer_setup(&rtc->uie_timer, rtc_uie_timer, 0);
#endif

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

void __init rtc_dev_init(void)
{
	int err;

	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
	if (err < 0)
		pr_err("failed to allocate char dev region\n");
}

void __exit rtc_dev_exit(void)
{
	if (rtc_devt)
		unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
}
Commit	Line	Data
cdf7545a	1	// SPDX-License-Identifier: GPL-2.0
e824290e AZ	2	/*
	3	* RTC subsystem, dev interface
	4	*
	5	* Copyright (C) 2005 Tower Technologies
	6	* Author: Alessandro Zummo <a.zummo@towertech.it>
	7	*
	8	* based on arch/arm/common/rtctime.c
cdf7545a	9	*/
e824290e	10
c100a5e0 JH	11	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
c100a5e0 JH	12
e824290e AZ	13	#include <linux/module.h>
e824290e AZ	14	#include <linux/rtc.h>
174cd4b1	15	#include <linux/sched/signal.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	{
e824290e AZ	24	struct rtc_device *rtc = container_of(inode->i_cdev,
e824290e AZ	25	struct rtc_device, char_dev);
e824290e	26
b1c3c898 DB	27	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
b1c3c898 DB	28	return -EBUSY;
e824290e	29
ab6a2d70	30	file->private_data = rtc;
e824290e	31
ea369ea6 AB	32	spin_lock_irq(&rtc->irq_lock);
	33	rtc->irq_data = 0;
	34	spin_unlock_irq(&rtc->irq_lock);
e824290e	35
ea369ea6	36	return 0;
e824290e AZ	37	}
e824290e AZ	38
6e57b1d6 JS	39	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	40	/*
	41	* Routine to poll RTC seconds field for change as often as possible,
	42	* after first RTC_UIE use timer to reduce polling
	43	*/
	44	static void rtc_uie_task(struct work_struct *work)
	45	{
	46	struct rtc_device *rtc =
	47	container_of(work, struct rtc_device, uie_task);
	48	struct rtc_time tm;
	49	int num = 0;
	50	int err;
	51
	52	err = rtc_read_time(rtc, &tm);
	53
	54	spin_lock_irq(&rtc->irq_lock);
	55	if (rtc->stop_uie_polling \|\| err) {
	56	rtc->uie_task_active = 0;
	57	} else if (rtc->oldsecs != tm.tm_sec) {
	58	num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
	59	rtc->oldsecs = tm.tm_sec;
606cc43c	60	rtc->uie_timer.expires = jiffies + HZ - (HZ / 10);
6e57b1d6 JS	61	rtc->uie_timer_active = 1;
	62	rtc->uie_task_active = 0;
	63	add_timer(&rtc->uie_timer);
	64	} else if (schedule_work(&rtc->uie_task) == 0) {
	65	rtc->uie_task_active = 0;
	66	}
	67	spin_unlock_irq(&rtc->irq_lock);
	68	if (num)
456d66ec	69	rtc_handle_legacy_irq(rtc, num, RTC_UF);
6e57b1d6	70	}
606cc43c	71
e99e88a9	72	static void rtc_uie_timer(struct timer_list *t)
6e57b1d6	73	{
e99e88a9	74	struct rtc_device *rtc = from_timer(rtc, t, uie_timer);
6e57b1d6 JS	75	unsigned long flags;
	76
	77	spin_lock_irqsave(&rtc->irq_lock, flags);
	78	rtc->uie_timer_active = 0;
	79	rtc->uie_task_active = 1;
	80	if ((schedule_work(&rtc->uie_task) == 0))
	81	rtc->uie_task_active = 0;
	82	spin_unlock_irqrestore(&rtc->irq_lock, flags);
	83	}
	84
	85	static int clear_uie(struct rtc_device *rtc)
	86	{
	87	spin_lock_irq(&rtc->irq_lock);
	88	if (rtc->uie_irq_active) {
	89	rtc->stop_uie_polling = 1;
	90	if (rtc->uie_timer_active) {
	91	spin_unlock_irq(&rtc->irq_lock);
	92	del_timer_sync(&rtc->uie_timer);
	93	spin_lock_irq(&rtc->irq_lock);
	94	rtc->uie_timer_active = 0;
	95	}
	96	if (rtc->uie_task_active) {
	97	spin_unlock_irq(&rtc->irq_lock);
	98	flush_scheduled_work();
	99	spin_lock_irq(&rtc->irq_lock);
	100	}
	101	rtc->uie_irq_active = 0;
	102	}
	103	spin_unlock_irq(&rtc->irq_lock);
	104	return 0;
	105	}
	106
	107	static int set_uie(struct rtc_device *rtc)
	108	{
	109	struct rtc_time tm;
	110	int err;
	111
	112	err = rtc_read_time(rtc, &tm);
	113	if (err)
	114	return err;
	115	spin_lock_irq(&rtc->irq_lock);
	116	if (!rtc->uie_irq_active) {
	117	rtc->uie_irq_active = 1;
	118	rtc->stop_uie_polling = 0;
	119	rtc->oldsecs = tm.tm_sec;
	120	rtc->uie_task_active = 1;
	121	if (schedule_work(&rtc->uie_task) == 0)
	122	rtc->uie_task_active = 0;
	123	}
	124	rtc->irq_data = 0;
	125	spin_unlock_irq(&rtc->irq_lock);
	126	return 0;
	127	}
	128
	129	int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
	130	{
	131	if (enabled)
	132	return set_uie(rtc);
	133	else
	134	return clear_uie(rtc);
	135	}
	136	EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);
	137
	138	#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
e824290e AZ	139
	140	static ssize_t
	141	rtc_dev_read(struct file file, char __user buf, size_t count, loff_t *ppos)
	142	{
88efe137	143	struct rtc_device *rtc = file->private_data;
e824290e AZ	144
	145	DECLARE_WAITQUEUE(wait, current);
	146	unsigned long data;
	147	ssize_t ret;
	148
3418ff76	149	if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
e824290e AZ	150	return -EINVAL;
	151
	152	add_wait_queue(&rtc->irq_queue, &wait);
	153	do {
	154	__set_current_state(TASK_INTERRUPTIBLE);
	155
	156	spin_lock_irq(&rtc->irq_lock);
	157	data = rtc->irq_data;
	158	rtc->irq_data = 0;
	159	spin_unlock_irq(&rtc->irq_lock);
	160
	161	if (data != 0) {
	162	ret = 0;
	163	break;
	164	}
	165	if (file->f_flags & O_NONBLOCK) {
	166	ret = -EAGAIN;
	167	break;
	168	}
	169	if (signal_pending(current)) {
	170	ret = -ERESTARTSYS;
	171	break;
	172	}
	173	schedule();
	174	} while (1);
	175	set_current_state(TASK_RUNNING);
	176	remove_wait_queue(&rtc->irq_queue, &wait);
	177
	178	if (ret == 0) {
3418ff76 AN	179	if (sizeof(int) != sizeof(long) &&
	180	count == sizeof(unsigned int))
	181	ret = put_user(data, (unsigned int __user *)buf) ?:
	182	sizeof(unsigned int);
	183	else
	184	ret = put_user(data, (unsigned long __user *)buf) ?:
	185	sizeof(unsigned long);
e824290e AZ	186	}
	187	return ret;
	188	}
	189
afc9a42b	190	static __poll_t rtc_dev_poll(struct file file, poll_table wait)
e824290e	191	{
88efe137	192	struct rtc_device *rtc = file->private_data;
e824290e AZ	193	unsigned long data;
	194
	195	poll_wait(file, &rtc->irq_queue, wait);
	196
	197	data = rtc->irq_data;
	198
a9a08845	199	return (data != 0) ? (EPOLLIN \| EPOLLRDNORM) : 0;
e824290e AZ	200	}
e824290e AZ	201
5ad31a57	202	static long rtc_dev_ioctl(struct file *file,
606cc43c	203	unsigned int cmd, unsigned long arg)
e824290e AZ	204	{
e824290e AZ	205	int err = 0;
ab6a2d70	206	struct rtc_device *rtc = file->private_data;
ff8371ac	207	const struct rtc_class_ops *ops = rtc->ops;
e824290e AZ	208	struct rtc_time tm;
e824290e AZ	209	struct rtc_wkalrm alarm;
606cc43c	210	void __user uarg = (void __user )arg;
e824290e	211
5ad31a57 DB	212	err = mutex_lock_interruptible(&rtc->ops_lock);
5ad31a57 DB	213	if (err)
b68bb263	214	return err;
5ad31a57	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))
5ad31a57	224	err = -EACCES;
110d693d AZ	225	break;
	226
	227	case RTC_IRQP_SET:
	228	if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
5ad31a57	229	err = -EACCES;
110d693d AZ	230	break;
	231
	232	case RTC_PIE_ON:
9d013d3b	233	if (rtc->irq_freq > rtc->max_user_freq &&
606cc43c	234	!capable(CAP_SYS_RESOURCE))
5ad31a57	235	err = -EACCES;
110d693d AZ	236	break;
	237	}
	238
5ad31a57 DB	239	if (err)
	240	goto done;
	241
ac54cd2b	242	/*
8a0bdfd7 DB	243	* Drivers SHOULD NOT provide ioctl implementations
	244	* for these requests. Instead, provide methods to
	245	* support the following code, so that the RTC's main
	246	* features are accessible without using ioctls.
	247	*
	248	* RTC and alarm times will be in UTC, by preference,
	249	* but dual-booting with MS-Windows implies RTCs must
	250	* use the local wall clock time.
e824290e AZ	251	*/
	252
	253	switch (cmd) {
	254	case RTC_ALM_READ:
5ad31a57 DB	255	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	256
ab6a2d70	257	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	258	if (err < 0)
	259	return err;
	260
	261	if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
5ad31a57 DB	262	err = -EFAULT;
5ad31a57 DB	263	return err;
e824290e AZ	264
e824290e AZ	265	case RTC_ALM_SET:
5ad31a57 DB	266	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	267
e824290e AZ	268	if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
	269	return -EFAULT;
	270
	271	alarm.enabled = 0;
	272	alarm.pending = 0;
e824290e AZ	273	alarm.time.tm_wday = -1;
	274	alarm.time.tm_yday = -1;
	275	alarm.time.tm_isdst = -1;
f8245c26 DB	276
	277	/* RTC_ALM_SET alarms may be up to 24 hours in the future.
	278	* Rather than expecting every RTC to implement "don't care"
	279	* for day/month/year fields, just force the alarm to have
	280	* the right values for those fields.
	281	*
	282	* RTC_WKALM_SET should be used instead. Not only does it
	283	* eliminate the need for a separate RTC_AIE_ON call, it
	284	* doesn't have the "alarm 23:59:59 in the future" race.
	285	*
	286	* NOTE: some legacy code may have used invalid fields as
	287	* wildcards, exposing hardware "periodic alarm" capabilities.
	288	* Not supported here.
	289	*/
	290	{
4ec2364f	291	time64_t now, then;
f8245c26 DB	292
	293	err = rtc_read_time(rtc, &tm);
	294	if (err < 0)
	295	return err;
4ec2364f	296	now = rtc_tm_to_time64(&tm);
f8245c26 DB	297
	298	alarm.time.tm_mday = tm.tm_mday;
	299	alarm.time.tm_mon = tm.tm_mon;
	300	alarm.time.tm_year = tm.tm_year;
	301	err = rtc_valid_tm(&alarm.time);
	302	if (err < 0)
	303	return err;
4ec2364f	304	then = rtc_tm_to_time64(&alarm.time);
f8245c26 DB	305
	306	/* alarm may need to wrap into tomorrow */
	307	if (then < now) {
4ec2364f	308	rtc_time64_to_tm(now + 24 * 60 * 60, &tm);
f8245c26 DB	309	alarm.time.tm_mday = tm.tm_mday;
	310	alarm.time.tm_mon = tm.tm_mon;
	311	alarm.time.tm_year = tm.tm_year;
	312	}
	313	}
	314
5ad31a57	315	return rtc_set_alarm(rtc, &alarm);
e824290e AZ	316
e824290e AZ	317	case RTC_RD_TIME:
5ad31a57 DB	318	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	319
ab6a2d70	320	err = rtc_read_time(rtc, &tm);
e824290e AZ	321	if (err < 0)
	322	return err;
	323
	324	if (copy_to_user(uarg, &tm, sizeof(tm)))
5ad31a57 DB	325	err = -EFAULT;
5ad31a57 DB	326	return err;
e824290e AZ	327
e824290e AZ	328	case RTC_SET_TIME:
5ad31a57 DB	329	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	330
e824290e AZ	331	if (copy_from_user(&tm, uarg, sizeof(tm)))
	332	return -EFAULT;
	333
5ad31a57	334	return rtc_set_time(rtc, &tm);
2601a464	335
d691eb90	336	case RTC_PIE_ON:
8719d3c9	337	err = rtc_irq_set_state(rtc, 1);
d691eb90 AZ	338	break;
	339
	340	case RTC_PIE_OFF:
8719d3c9	341	err = rtc_irq_set_state(rtc, 0);
2601a464 DB	342	break;
2601a464 DB	343
099e6576 AZ	344	case RTC_AIE_ON:
	345	mutex_unlock(&rtc->ops_lock);
	346	return rtc_alarm_irq_enable(rtc, 1);
	347
	348	case RTC_AIE_OFF:
	349	mutex_unlock(&rtc->ops_lock);
	350	return rtc_alarm_irq_enable(rtc, 0);
	351
	352	case RTC_UIE_ON:
	353	mutex_unlock(&rtc->ops_lock);
	354	return rtc_update_irq_enable(rtc, 1);
	355
	356	case RTC_UIE_OFF:
	357	mutex_unlock(&rtc->ops_lock);
	358	return rtc_update_irq_enable(rtc, 0);
	359
2601a464	360	case RTC_IRQP_SET:
8719d3c9	361	err = rtc_irq_set_freq(rtc, arg);
d691eb90 AZ	362	break;
	363
	364	case RTC_IRQP_READ:
	365	err = put_user(rtc->irq_freq, (unsigned long __user *)uarg);
2601a464 DB	366	break;
2601a464 DB	367
e824290e	368	case RTC_WKALM_SET:
5ad31a57	369	mutex_unlock(&rtc->ops_lock);
e824290e AZ	370	if (copy_from_user(&alarm, uarg, sizeof(alarm)))
	371	return -EFAULT;
	372
5ad31a57	373	return rtc_set_alarm(rtc, &alarm);
e824290e AZ	374
e824290e AZ	375	case RTC_WKALM_RD:
5ad31a57	376	mutex_unlock(&rtc->ops_lock);
ab6a2d70	377	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	378	if (err < 0)
	379	return err;
	380
	381	if (copy_to_user(uarg, &alarm, sizeof(alarm)))
5ad31a57 DB	382	err = -EFAULT;
5ad31a57 DB	383	return err;
e824290e AZ	384
e824290e AZ	385	default:
ac54cd2b JS	386	/* Finally try the driver's ioctl interface */
	387	if (ops->ioctl) {
	388	err = ops->ioctl(rtc->dev.parent, cmd, arg);
	389	if (err == -ENOIOCTLCMD)
	390	err = -ENOTTY;
606cc43c	391	} else {
e17fd4ba	392	err = -ENOTTY;
606cc43c	393	}
e824290e AZ	394	break;
	395	}
	396
5ad31a57 DB	397	done:
5ad31a57 DB	398	mutex_unlock(&rtc->ops_lock);
e824290e AZ	399	return err;
	400	}
	401
2e4a75cd MS	402	static int rtc_dev_fasync(int fd, struct file *file, int on)
	403	{
	404	struct rtc_device *rtc = file->private_data;
606cc43c	405
2e4a75cd MS	406	return fasync_helper(fd, file, on, &rtc->async_queue);
	407	}
	408
e824290e AZ	409	static int rtc_dev_release(struct inode inode, struct file file)
e824290e AZ	410	{
88efe137	411	struct rtc_device *rtc = file->private_data;
e824290e	412
743e6a50 DB	413	/* We shut down the repeating IRQs that userspace enabled,
	414	* since nothing is listening to them.
	415	* - Update (UIE) ... currently only managed through ioctls
	416	* - Periodic (PIE) ... also used through rtc_*() interface calls
	417	*
	418	* Leave the alarm alone; it may be set to trigger a system wakeup
	419	* later, or be used by kernel code, and is a one-shot event anyway.
	420	*/
099e6576 AZ	421
099e6576 AZ	422	/* Keep ioctl until all drivers are converted */
743e6a50	423	rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
099e6576	424	rtc_update_irq_enable(rtc, 0);
8719d3c9	425	rtc_irq_set_state(rtc, 0);
5cdc98b8	426
372a302e	427	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
e824290e AZ	428	return 0;
	429	}
	430
d54b1fdb	431	static const struct file_operations rtc_dev_fops = {
e824290e AZ	432	.owner = THIS_MODULE,
	433	.llseek = no_llseek,
	434	.read = rtc_dev_read,
	435	.poll = rtc_dev_poll,
5ad31a57	436	.unlocked_ioctl = rtc_dev_ioctl,
e824290e AZ	437	.open = rtc_dev_open,
	438	.release = rtc_dev_release,
	439	.fasync = rtc_dev_fasync,
	440	};
	441
	442	/* insertion/removal hooks */
	443
cb3a58d2	444	void rtc_dev_prepare(struct rtc_device *rtc)
e824290e	445	{
5726fb20 DB	446	if (!rtc_devt)
5726fb20 DB	447	return;
e824290e AZ	448
e824290e AZ	449	if (rtc->id >= RTC_DEV_MAX) {
9f860653	450	dev_dbg(&rtc->dev, "too many RTC devices\n");
5726fb20	451	return;
e824290e AZ	452	}
e824290e AZ	453
cd966209	454	rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
5726fb20	455
6e57b1d6 JS	456	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
6e57b1d6 JS	457	INIT_WORK(&rtc->uie_task, rtc_uie_task);
e99e88a9	458	timer_setup(&rtc->uie_timer, rtc_uie_timer, 0);
6e57b1d6 JS	459	#endif
6e57b1d6 JS	460
e824290e AZ	461	cdev_init(&rtc->char_dev, &rtc_dev_fops);
e824290e AZ	462	rtc->char_dev.owner = rtc->owner;
e824290e AZ	463	}
e824290e AZ	464
5726fb20	465	void __init rtc_dev_init(void)
e824290e AZ	466	{
	467	int err;
	468
e824290e	469	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
5726fb20	470	if (err < 0)
c100a5e0	471	pr_err("failed to allocate char dev region\n");
e824290e AZ	472	}
e824290e AZ	473
5726fb20	474	void __exit rtc_dev_exit(void)
e824290e	475	{
5726fb20 DB	476	if (rtc_devt)
5726fb20 DB	477	unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
e824290e	478	}