[linux-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/compat.h>
#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;
}

#ifdef CONFIG_COMPAT
#define RTC_IRQP_SET32		_IOW('p', 0x0c, __u32)
#define RTC_IRQP_READ32		_IOR('p', 0x0b, __u32)
#define RTC_EPOCH_SET32		_IOW('p', 0x0e, __u32)

static long rtc_dev_compat_ioctl(struct file *file,
				 unsigned int cmd, unsigned long arg)
{
	struct rtc_device *rtc = file->private_data;
	void __user *uarg = compat_ptr(arg);

	switch (cmd) {
	case RTC_IRQP_READ32:
		return put_user(rtc->irq_freq, (__u32 __user *)uarg);

	case RTC_IRQP_SET32:
		/* arg is a plain integer, not pointer */
		return rtc_dev_ioctl(file, RTC_IRQP_SET, arg);

	case RTC_EPOCH_SET32:
		/* arg is a plain integer, not pointer */
		return rtc_dev_ioctl(file, RTC_EPOCH_SET, arg);
	}

	return rtc_dev_ioctl(file, cmd, (unsigned long)uarg);
}
#endif

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,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= rtc_dev_compat_ioctl,
#endif
	.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
076ff658	13	#include <linux/compat.h>
e824290e AZ	14	#include <linux/module.h>
e824290e AZ	15	#include <linux/rtc.h>
174cd4b1	16	#include <linux/sched/signal.h>
5726fb20	17	#include "rtc-core.h"
e824290e	18
e824290e AZ	19	static dev_t rtc_devt;
	20
	21	#define RTC_DEV_MAX 16 /* 16 RTCs should be enough for everyone... */
	22
	23	static int rtc_dev_open(struct inode inode, struct file file)
	24	{
e824290e AZ	25	struct rtc_device *rtc = container_of(inode->i_cdev,
e824290e AZ	26	struct rtc_device, char_dev);
e824290e	27
b1c3c898 DB	28	if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
b1c3c898 DB	29	return -EBUSY;
e824290e	30
ab6a2d70	31	file->private_data = rtc;
e824290e	32
ea369ea6 AB	33	spin_lock_irq(&rtc->irq_lock);
	34	rtc->irq_data = 0;
	35	spin_unlock_irq(&rtc->irq_lock);
e824290e	36
ea369ea6	37	return 0;
e824290e AZ	38	}
e824290e AZ	39
6e57b1d6 JS	40	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
	41	/*
	42	* Routine to poll RTC seconds field for change as often as possible,
	43	* after first RTC_UIE use timer to reduce polling
	44	*/
	45	static void rtc_uie_task(struct work_struct *work)
	46	{
	47	struct rtc_device *rtc =
	48	container_of(work, struct rtc_device, uie_task);
	49	struct rtc_time tm;
	50	int num = 0;
	51	int err;
	52
	53	err = rtc_read_time(rtc, &tm);
	54
	55	spin_lock_irq(&rtc->irq_lock);
	56	if (rtc->stop_uie_polling \|\| err) {
	57	rtc->uie_task_active = 0;
	58	} else if (rtc->oldsecs != tm.tm_sec) {
	59	num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
	60	rtc->oldsecs = tm.tm_sec;
606cc43c	61	rtc->uie_timer.expires = jiffies + HZ - (HZ / 10);
6e57b1d6 JS	62	rtc->uie_timer_active = 1;
	63	rtc->uie_task_active = 0;
	64	add_timer(&rtc->uie_timer);
	65	} else if (schedule_work(&rtc->uie_task) == 0) {
	66	rtc->uie_task_active = 0;
	67	}
	68	spin_unlock_irq(&rtc->irq_lock);
	69	if (num)
456d66ec	70	rtc_handle_legacy_irq(rtc, num, RTC_UF);
6e57b1d6	71	}
606cc43c	72
e99e88a9	73	static void rtc_uie_timer(struct timer_list *t)
6e57b1d6	74	{
e99e88a9	75	struct rtc_device *rtc = from_timer(rtc, t, uie_timer);
6e57b1d6 JS	76	unsigned long flags;
	77
	78	spin_lock_irqsave(&rtc->irq_lock, flags);
	79	rtc->uie_timer_active = 0;
	80	rtc->uie_task_active = 1;
	81	if ((schedule_work(&rtc->uie_task) == 0))
	82	rtc->uie_task_active = 0;
	83	spin_unlock_irqrestore(&rtc->irq_lock, flags);
	84	}
	85
	86	static int clear_uie(struct rtc_device *rtc)
	87	{
	88	spin_lock_irq(&rtc->irq_lock);
	89	if (rtc->uie_irq_active) {
	90	rtc->stop_uie_polling = 1;
	91	if (rtc->uie_timer_active) {
	92	spin_unlock_irq(&rtc->irq_lock);
	93	del_timer_sync(&rtc->uie_timer);
	94	spin_lock_irq(&rtc->irq_lock);
	95	rtc->uie_timer_active = 0;
	96	}
	97	if (rtc->uie_task_active) {
	98	spin_unlock_irq(&rtc->irq_lock);
	99	flush_scheduled_work();
	100	spin_lock_irq(&rtc->irq_lock);
	101	}
	102	rtc->uie_irq_active = 0;
	103	}
	104	spin_unlock_irq(&rtc->irq_lock);
	105	return 0;
	106	}
	107
	108	static int set_uie(struct rtc_device *rtc)
	109	{
	110	struct rtc_time tm;
	111	int err;
	112
	113	err = rtc_read_time(rtc, &tm);
	114	if (err)
	115	return err;
	116	spin_lock_irq(&rtc->irq_lock);
	117	if (!rtc->uie_irq_active) {
	118	rtc->uie_irq_active = 1;
	119	rtc->stop_uie_polling = 0;
	120	rtc->oldsecs = tm.tm_sec;
	121	rtc->uie_task_active = 1;
	122	if (schedule_work(&rtc->uie_task) == 0)
	123	rtc->uie_task_active = 0;
	124	}
	125	rtc->irq_data = 0;
	126	spin_unlock_irq(&rtc->irq_lock);
	127	return 0;
	128	}
	129
	130	int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc, unsigned int enabled)
	131	{
	132	if (enabled)
	133	return set_uie(rtc);
	134	else
	135	return clear_uie(rtc);
	136	}
	137	EXPORT_SYMBOL(rtc_dev_update_irq_enable_emul);
	138
	139	#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */
e824290e AZ	140
	141	static ssize_t
	142	rtc_dev_read(struct file file, char __user buf, size_t count, loff_t *ppos)
	143	{
88efe137	144	struct rtc_device *rtc = file->private_data;
e824290e AZ	145
	146	DECLARE_WAITQUEUE(wait, current);
	147	unsigned long data;
	148	ssize_t ret;
	149
3418ff76	150	if (count != sizeof(unsigned int) && count < sizeof(unsigned long))
e824290e AZ	151	return -EINVAL;
	152
	153	add_wait_queue(&rtc->irq_queue, &wait);
	154	do {
	155	__set_current_state(TASK_INTERRUPTIBLE);
	156
	157	spin_lock_irq(&rtc->irq_lock);
	158	data = rtc->irq_data;
	159	rtc->irq_data = 0;
	160	spin_unlock_irq(&rtc->irq_lock);
	161
	162	if (data != 0) {
	163	ret = 0;
	164	break;
	165	}
	166	if (file->f_flags & O_NONBLOCK) {
	167	ret = -EAGAIN;
	168	break;
	169	}
	170	if (signal_pending(current)) {
	171	ret = -ERESTARTSYS;
	172	break;
	173	}
	174	schedule();
	175	} while (1);
	176	set_current_state(TASK_RUNNING);
	177	remove_wait_queue(&rtc->irq_queue, &wait);
	178
	179	if (ret == 0) {
3418ff76 AN	180	if (sizeof(int) != sizeof(long) &&
	181	count == sizeof(unsigned int))
	182	ret = put_user(data, (unsigned int __user *)buf) ?:
	183	sizeof(unsigned int);
	184	else
	185	ret = put_user(data, (unsigned long __user *)buf) ?:
	186	sizeof(unsigned long);
e824290e AZ	187	}
	188	return ret;
	189	}
	190
afc9a42b	191	static __poll_t rtc_dev_poll(struct file file, poll_table wait)
e824290e	192	{
88efe137	193	struct rtc_device *rtc = file->private_data;
e824290e AZ	194	unsigned long data;
	195
	196	poll_wait(file, &rtc->irq_queue, wait);
	197
	198	data = rtc->irq_data;
	199
a9a08845	200	return (data != 0) ? (EPOLLIN \| EPOLLRDNORM) : 0;
e824290e AZ	201	}
e824290e AZ	202
5ad31a57	203	static long rtc_dev_ioctl(struct file *file,
606cc43c	204	unsigned int cmd, unsigned long arg)
e824290e AZ	205	{
e824290e AZ	206	int err = 0;
ab6a2d70	207	struct rtc_device *rtc = file->private_data;
ff8371ac	208	const struct rtc_class_ops *ops = rtc->ops;
e824290e AZ	209	struct rtc_time tm;
e824290e AZ	210	struct rtc_wkalrm alarm;
606cc43c	211	void __user uarg = (void __user )arg;
e824290e	212
5ad31a57 DB	213	err = mutex_lock_interruptible(&rtc->ops_lock);
5ad31a57 DB	214	if (err)
b68bb263	215	return err;
5ad31a57	216
2601a464	217	/* check that the calling task has appropriate permissions
110d693d AZ	218	* for certain ioctls. doing this check here is useful
	219	* to avoid duplicate code in each driver.
	220	*/
	221	switch (cmd) {
	222	case RTC_EPOCH_SET:
	223	case RTC_SET_TIME:
	224	if (!capable(CAP_SYS_TIME))
5ad31a57	225	err = -EACCES;
110d693d AZ	226	break;
	227
	228	case RTC_IRQP_SET:
	229	if (arg > rtc->max_user_freq && !capable(CAP_SYS_RESOURCE))
5ad31a57	230	err = -EACCES;
110d693d AZ	231	break;
	232
	233	case RTC_PIE_ON:
9d013d3b	234	if (rtc->irq_freq > rtc->max_user_freq &&
606cc43c	235	!capable(CAP_SYS_RESOURCE))
5ad31a57	236	err = -EACCES;
110d693d AZ	237	break;
	238	}
	239
5ad31a57 DB	240	if (err)
	241	goto done;
	242
ac54cd2b	243	/*
8a0bdfd7 DB	244	* Drivers SHOULD NOT provide ioctl implementations
	245	* for these requests. Instead, provide methods to
	246	* support the following code, so that the RTC's main
	247	* features are accessible without using ioctls.
	248	*
	249	* RTC and alarm times will be in UTC, by preference,
	250	* but dual-booting with MS-Windows implies RTCs must
	251	* use the local wall clock time.
e824290e AZ	252	*/
	253
	254	switch (cmd) {
	255	case RTC_ALM_READ:
5ad31a57 DB	256	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	257
ab6a2d70	258	err = rtc_read_alarm(rtc, &alarm);
e824290e AZ	259	if (err < 0)
	260	return err;
	261
	262	if (copy_to_user(uarg, &alarm.time, sizeof(tm)))
5ad31a57 DB	263	err = -EFAULT;
5ad31a57 DB	264	return err;
e824290e AZ	265
e824290e AZ	266	case RTC_ALM_SET:
5ad31a57 DB	267	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	268
e824290e AZ	269	if (copy_from_user(&alarm.time, uarg, sizeof(tm)))
	270	return -EFAULT;
	271
	272	alarm.enabled = 0;
	273	alarm.pending = 0;
e824290e AZ	274	alarm.time.tm_wday = -1;
	275	alarm.time.tm_yday = -1;
	276	alarm.time.tm_isdst = -1;
f8245c26 DB	277
	278	/* RTC_ALM_SET alarms may be up to 24 hours in the future.
	279	* Rather than expecting every RTC to implement "don't care"
	280	* for day/month/year fields, just force the alarm to have
	281	* the right values for those fields.
	282	*
	283	* RTC_WKALM_SET should be used instead. Not only does it
	284	* eliminate the need for a separate RTC_AIE_ON call, it
	285	* doesn't have the "alarm 23:59:59 in the future" race.
	286	*
	287	* NOTE: some legacy code may have used invalid fields as
	288	* wildcards, exposing hardware "periodic alarm" capabilities.
	289	* Not supported here.
	290	*/
	291	{
4ec2364f	292	time64_t now, then;
f8245c26 DB	293
	294	err = rtc_read_time(rtc, &tm);
	295	if (err < 0)
	296	return err;
4ec2364f	297	now = rtc_tm_to_time64(&tm);
f8245c26 DB	298
	299	alarm.time.tm_mday = tm.tm_mday;
	300	alarm.time.tm_mon = tm.tm_mon;
	301	alarm.time.tm_year = tm.tm_year;
	302	err = rtc_valid_tm(&alarm.time);
	303	if (err < 0)
	304	return err;
4ec2364f	305	then = rtc_tm_to_time64(&alarm.time);
f8245c26 DB	306
	307	/* alarm may need to wrap into tomorrow */
	308	if (then < now) {
4ec2364f	309	rtc_time64_to_tm(now + 24 * 60 * 60, &tm);
f8245c26 DB	310	alarm.time.tm_mday = tm.tm_mday;
	311	alarm.time.tm_mon = tm.tm_mon;
	312	alarm.time.tm_year = tm.tm_year;
	313	}
	314	}
	315
5ad31a57	316	return rtc_set_alarm(rtc, &alarm);
e824290e AZ	317
e824290e AZ	318	case RTC_RD_TIME:
5ad31a57 DB	319	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	320
ab6a2d70	321	err = rtc_read_time(rtc, &tm);
e824290e AZ	322	if (err < 0)
	323	return err;
	324
	325	if (copy_to_user(uarg, &tm, sizeof(tm)))
5ad31a57 DB	326	err = -EFAULT;
5ad31a57 DB	327	return err;
e824290e AZ	328
e824290e AZ	329	case RTC_SET_TIME:
5ad31a57 DB	330	mutex_unlock(&rtc->ops_lock);
5ad31a57 DB	331
e824290e AZ	332	if (copy_from_user(&tm, uarg, sizeof(tm)))
	333	return -EFAULT;
	334
5ad31a57	335	return rtc_set_time(rtc, &tm);
2601a464	336
d691eb90	337	case RTC_PIE_ON:
8719d3c9	338	err = rtc_irq_set_state(rtc, 1);
d691eb90 AZ	339	break;
	340
	341	case RTC_PIE_OFF:
8719d3c9	342	err = rtc_irq_set_state(rtc, 0);
2601a464 DB	343	break;
2601a464 DB	344
099e6576 AZ	345	case RTC_AIE_ON:
	346	mutex_unlock(&rtc->ops_lock);
	347	return rtc_alarm_irq_enable(rtc, 1);
	348
	349	case RTC_AIE_OFF:
	350	mutex_unlock(&rtc->ops_lock);
	351	return rtc_alarm_irq_enable(rtc, 0);
	352
	353	case RTC_UIE_ON:
	354	mutex_unlock(&rtc->ops_lock);
	355	return rtc_update_irq_enable(rtc, 1);
	356
	357	case RTC_UIE_OFF:
	358	mutex_unlock(&rtc->ops_lock);
	359	return rtc_update_irq_enable(rtc, 0);
	360
2601a464	361	case RTC_IRQP_SET:
8719d3c9	362	err = rtc_irq_set_freq(rtc, arg);
d691eb90	363	break;
d691eb90 AZ	364	case RTC_IRQP_READ:
d691eb90 AZ	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
076ff658 AB	402	#ifdef CONFIG_COMPAT
	403	#define RTC_IRQP_SET32 _IOW('p', 0x0c, __u32)
	404	#define RTC_IRQP_READ32 _IOR('p', 0x0b, __u32)
	405	#define RTC_EPOCH_SET32 _IOW('p', 0x0e, __u32)
	406
	407	static long rtc_dev_compat_ioctl(struct file *file,
	408	unsigned int cmd, unsigned long arg)
	409	{
	410	struct rtc_device *rtc = file->private_data;
	411	void __user *uarg = compat_ptr(arg);
	412
	413	switch (cmd) {
	414	case RTC_IRQP_READ32:
	415	return put_user(rtc->irq_freq, (__u32 __user *)uarg);
	416
	417	case RTC_IRQP_SET32:
	418	/* arg is a plain integer, not pointer */
	419	return rtc_dev_ioctl(file, RTC_IRQP_SET, arg);
	420
	421	case RTC_EPOCH_SET32:
	422	/* arg is a plain integer, not pointer */
	423	return rtc_dev_ioctl(file, RTC_EPOCH_SET, arg);
	424	}
	425
	426	return rtc_dev_ioctl(file, cmd, (unsigned long)uarg);
	427	}
	428	#endif
	429
2e4a75cd MS	430	static int rtc_dev_fasync(int fd, struct file *file, int on)
	431	{
	432	struct rtc_device *rtc = file->private_data;
606cc43c	433
2e4a75cd MS	434	return fasync_helper(fd, file, on, &rtc->async_queue);
	435	}
	436
e824290e AZ	437	static int rtc_dev_release(struct inode inode, struct file file)
e824290e AZ	438	{
88efe137	439	struct rtc_device *rtc = file->private_data;
e824290e	440
743e6a50 DB	441	/* We shut down the repeating IRQs that userspace enabled,
	442	* since nothing is listening to them.
	443	* - Update (UIE) ... currently only managed through ioctls
	444	* - Periodic (PIE) ... also used through rtc_*() interface calls
	445	*
	446	* Leave the alarm alone; it may be set to trigger a system wakeup
	447	* later, or be used by kernel code, and is a one-shot event anyway.
	448	*/
099e6576 AZ	449
099e6576 AZ	450	/* Keep ioctl until all drivers are converted */
743e6a50	451	rtc_dev_ioctl(file, RTC_UIE_OFF, 0);
099e6576	452	rtc_update_irq_enable(rtc, 0);
8719d3c9	453	rtc_irq_set_state(rtc, 0);
5cdc98b8	454
372a302e	455	clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
e824290e AZ	456	return 0;
	457	}
	458
d54b1fdb	459	static const struct file_operations rtc_dev_fops = {
e824290e AZ	460	.owner = THIS_MODULE,
	461	.llseek = no_llseek,
	462	.read = rtc_dev_read,
	463	.poll = rtc_dev_poll,
5ad31a57	464	.unlocked_ioctl = rtc_dev_ioctl,
076ff658 AB	465	#ifdef CONFIG_COMPAT
	466	.compat_ioctl = rtc_dev_compat_ioctl,
	467	#endif
e824290e AZ	468	.open = rtc_dev_open,
	469	.release = rtc_dev_release,
	470	.fasync = rtc_dev_fasync,
	471	};
	472
	473	/* insertion/removal hooks */
	474
cb3a58d2	475	void rtc_dev_prepare(struct rtc_device *rtc)
e824290e	476	{
5726fb20 DB	477	if (!rtc_devt)
5726fb20 DB	478	return;
e824290e AZ	479
e824290e AZ	480	if (rtc->id >= RTC_DEV_MAX) {
9f860653	481	dev_dbg(&rtc->dev, "too many RTC devices\n");
5726fb20	482	return;
e824290e AZ	483	}
e824290e AZ	484
cd966209	485	rtc->dev.devt = MKDEV(MAJOR(rtc_devt), rtc->id);
5726fb20	486
6e57b1d6 JS	487	#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
6e57b1d6 JS	488	INIT_WORK(&rtc->uie_task, rtc_uie_task);
e99e88a9	489	timer_setup(&rtc->uie_timer, rtc_uie_timer, 0);
6e57b1d6 JS	490	#endif
6e57b1d6 JS	491
e824290e AZ	492	cdev_init(&rtc->char_dev, &rtc_dev_fops);
e824290e AZ	493	rtc->char_dev.owner = rtc->owner;
e824290e AZ	494	}
e824290e AZ	495
5726fb20	496	void __init rtc_dev_init(void)
e824290e AZ	497	{
	498	int err;
	499
e824290e	500	err = alloc_chrdev_region(&rtc_devt, 0, RTC_DEV_MAX, "rtc");
5726fb20	501	if (err < 0)
c100a5e0	502	pr_err("failed to allocate char dev region\n");
e824290e AZ	503	}
e824290e AZ	504
5726fb20	505	void __exit rtc_dev_exit(void)
e824290e	506	{
5726fb20 DB	507	if (rtc_devt)
5726fb20 DB	508	unregister_chrdev_region(rtc_devt, RTC_DEV_MAX);
e824290e	509	}