[mirror_ubuntu-bionic-kernel.git] / drivers / watchdog / w83697ug_wdt.c

/*
 *	w83697ug/uf WDT driver
 *
 *	(c) Copyright 2008 Flemming Fransen <ff@nrvissing.net>
 *		reused original code to support w83697ug/uf.
 *
 *	Based on w83627hf_wdt.c which is based on advantechwdt.c
 *	which is based on wdt.c.
 *	Original copyright messages:
 *
 *	(c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
 *		added support for W83627THF.
 *
 *	(c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
 *
 *	(c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
 *
 *	(c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
 *				http://www.redhat.com
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
 *	warranty for any of this software. This material is provided
 *	"AS-IS" and at no charge.
 *
 *	(c) Copyright 1995    Alan Cox <alan@redhat.com>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/uaccess.h>

#include <asm/system.h>

#define WATCHDOG_NAME "w83697ug/uf WDT"
#define PFX WATCHDOG_NAME ": "
#define WATCHDOG_TIMEOUT 60		/* 60 sec default timeout */

static unsigned long wdt_is_open;
static char expect_close;
static DEFINE_SPINLOCK(io_lock);

static int wdt_io = 0x2e;
module_param(wdt_io, int, 0);
MODULE_PARM_DESC(wdt_io, "w83697ug/uf WDT io port (default 0x2e)");

static int timeout = WATCHDOG_TIMEOUT;	/* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
	"Watchdog timeout in seconds. 1<= timeout <=255 (default="
				__MODULE_STRING(WATCHDOG_TIMEOUT) ")");

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
	"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

/*
 *	Kernel methods.
 */

#define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
#define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register
							(same as EFER) */
#define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */

static int w83697ug_select_wd_register(void)
{
	unsigned char c;
	unsigned char version;

	outb_p(0x87, WDT_EFER); /* Enter extended function mode */
	outb_p(0x87, WDT_EFER); /* Again according to manual */

	outb(0x20, WDT_EFER); 	/* check chip version	*/
	version = inb(WDT_EFDR);

	if (version == 0x68) {	/* W83697UG 		*/
		printk(KERN_INFO PFX "Watchdog chip version 0x%02x = "
			"W83697UG/UF found at 0x%04x\n", version, wdt_io);

		outb_p(0x2b, WDT_EFER);
		c = inb_p(WDT_EFDR);    /* select WDT0 */
		c &= ~0x04;
		outb_p(0x2b, WDT_EFER);
		outb_p(c, WDT_EFDR);	/* set pin118 to WDT0 */

	} else {
		printk(KERN_ERR PFX "No W83697UG/UF could be found\n");
		return -ENODEV;
	}

	outb_p(0x07, WDT_EFER); /* point to logical device number reg */
	outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
	outb_p(0x30, WDT_EFER); /* select CR30 */
	c = inb_p(WDT_EFDR);
	outb_p(c || 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */

	return 0;
}

static void w83697ug_unselect_wd_register(void)
{
	outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
}

static int w83697ug_init(void)
{
	int ret;
	unsigned char t;

	ret = w83697ug_select_wd_register();
	if (ret != 0)
		return ret;

	outb_p(0xF6, WDT_EFER); /* Select CRF6 */
	t = inb_p(WDT_EFDR);    /* read CRF6 */
	if (t != 0) {
		printk(KERN_INFO PFX "Watchdog already running."
			" Resetting timeout to %d sec\n", timeout);
		outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
	}
	outb_p(0xF5, WDT_EFER); /* Select CRF5 */
	t = inb_p(WDT_EFDR);    /* read CRF5 */
	t &= ~0x0C;             /* set second mode &
					disable keyboard turning off watchdog */
	outb_p(t, WDT_EFDR);    /* Write back to CRF5 */

	w83697ug_unselect_wd_register();
	return 0;
}

static void wdt_ctrl(int timeout)
{
	spin_lock(&io_lock);

	if (w83697ug_select_wd_register() < 0)
		return;

	outb_p(0xF4, WDT_EFER);    /* Select CRF4 */
	outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */

	w83697ug_unselect_wd_register();

	spin_unlock(&io_lock);
}

static int wdt_ping(void)
{
	wdt_ctrl(timeout);
	return 0;
}

static int wdt_disable(void)
{
	wdt_ctrl(0);
	return 0;
}

static int wdt_set_heartbeat(int t)
{
	if (t < 1 || t > 255)
		return -EINVAL;

	timeout = t;
	return 0;
}

static ssize_t wdt_write(struct file *file, const char __user *buf,
						size_t count, loff_t *ppos)
{
	if (count) {
		if (!nowayout) {
			size_t i;

			expect_close = 0;

			for (i = 0; i != count; i++) {
				char c;
				if (get_user(c, buf + i))
					return -EFAULT;
				if (c == 'V')
					expect_close = 42;
			}
		}
		wdt_ping();
	}
	return count;
}

static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	void __user *argp = (void __user *)arg;
	int __user *p = argp;
	int new_timeout;
	static const struct watchdog_info ident = {
		.options =		WDIOF_KEEPALIVEPING |
					WDIOF_SETTIMEOUT |
					WDIOF_MAGICCLOSE,
		.firmware_version =	1,
		.identity =		"W83697UG WDT",
	};

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		if (copy_to_user(argp, &ident, sizeof(ident)))
			return -EFAULT;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		return put_user(0, p);

	case WDIOC_SETOPTIONS:
	{
		int options, retval = -EINVAL;

		if (get_user(options, p))
			return -EFAULT;

		if (options & WDIOS_DISABLECARD) {
			wdt_disable();
			retval = 0;
		}

		if (options & WDIOS_ENABLECARD) {
			wdt_ping();
			retval = 0;
		}

		return retval;
	}

	case WDIOC_KEEPALIVE:
		wdt_ping();
		break;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, p))
			return -EFAULT;
		if (wdt_set_heartbeat(new_timeout))
			return -EINVAL;
		wdt_ping();
		/* Fall */

	case WDIOC_GETTIMEOUT:
		return put_user(timeout, p);

	default:
		return -ENOTTY;
	}
	return 0;
}

static int wdt_open(struct inode *inode, struct file *file)
{
	if (test_and_set_bit(0, &wdt_is_open))
		return -EBUSY;
	/*
	 *	Activate
	 */

	wdt_ping();
	return nonseekable_open(inode, file);
}

static int wdt_close(struct inode *inode, struct file *file)
{
	if (expect_close == 42)
		wdt_disable();
	else {
		printk(KERN_CRIT PFX
			"Unexpected close, not stopping watchdog!\n");
		wdt_ping();
	}
	expect_close = 0;
	clear_bit(0, &wdt_is_open);
	return 0;
}

/*
 *	Notifier for system down
 */

static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		wdt_disable();	/* Turn the WDT off */

	return NOTIFY_DONE;
}

/*
 *	Kernel Interfaces
 */

static const struct file_operations wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= wdt_write,
	.unlocked_ioctl	= wdt_ioctl,
	.open		= wdt_open,
	.release	= wdt_close,
};

static struct miscdevice wdt_miscdev = {
	.minor = WATCHDOG_MINOR,
	.name = "watchdog",
	.fops = &wdt_fops,
};

/*
 *	The WDT needs to learn about soft shutdowns in order to
 *	turn the timebomb registers off.
 */

static struct notifier_block wdt_notifier = {
	.notifier_call = wdt_notify_sys,
};

static int __init wdt_init(void)
{
	int ret;

	printk(KERN_INFO "WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising.\n");

	if (wdt_set_heartbeat(timeout)) {
		wdt_set_heartbeat(WATCHDOG_TIMEOUT);
		printk(KERN_INFO PFX
			"timeout value must be 1<=timeout<=255, using %d\n",
			WATCHDOG_TIMEOUT);
	}

	if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
		printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
			wdt_io);
		ret = -EIO;
		goto out;
	}

	ret = w83697ug_init();
	if (ret != 0)
		goto unreg_regions;

	ret = register_reboot_notifier(&wdt_notifier);
	if (ret != 0) {
		printk(KERN_ERR PFX
			"cannot register reboot notifier (err=%d)\n", ret);
		goto unreg_regions;
	}

	ret = misc_register(&wdt_miscdev);
	if (ret != 0) {
		printk(KERN_ERR PFX
			"cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		goto unreg_reboot;
	}

	printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
		timeout, nowayout);

out:
	return ret;
unreg_reboot:
	unregister_reboot_notifier(&wdt_notifier);
unreg_regions:
	release_region(wdt_io, 1);
	goto out;
}

static void __exit wdt_exit(void)
{
	misc_deregister(&wdt_miscdev);
	unregister_reboot_notifier(&wdt_notifier);
	release_region(wdt_io, 1);
}

module_init(wdt_init);
module_exit(wdt_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
MODULE_DESCRIPTION("w83697ug/uf WDT driver");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
7d8b0906 FF	1	/*
	2	* w83697ug/uf WDT driver
	3	*
	4	* (c) Copyright 2008 Flemming Fransen <ff@nrvissing.net>
143a2e54	5	* reused original code to support w83697ug/uf.
7d8b0906 FF	6	*
	7	* Based on w83627hf_wdt.c which is based on advantechwdt.c
	8	* which is based on wdt.c.
	9	* Original copyright messages:
	10	*
	11	* (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
	12	* added support for W83627THF.
	13	*
	14	* (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
	15	*
	16	* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
	17	*
	18	* (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
	19	* http://www.redhat.com
	20	*
	21	* This program is free software; you can redistribute it and/or
	22	* modify it under the terms of the GNU General Public License
	23	* as published by the Free Software Foundation; either version
	24	* 2 of the License, or (at your option) any later version.
	25	*
	26	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	27	* warranty for any of this software. This material is provided
	28	* "AS-IS" and at no charge.
	29	*
	30	* (c) Copyright 1995 Alan Cox <alan@redhat.com>
	31	*/
	32
	33	#include <linux/module.h>
	34	#include <linux/moduleparam.h>
	35	#include <linux/types.h>
	36	#include <linux/miscdevice.h>
	37	#include <linux/watchdog.h>
	38	#include <linux/fs.h>
	39	#include <linux/ioport.h>
	40	#include <linux/notifier.h>
	41	#include <linux/reboot.h>
	42	#include <linux/init.h>
	43	#include <linux/spinlock.h>
	44	#include <linux/io.h>
	45	#include <linux/uaccess.h>
	46
	47	#include <asm/system.h>
	48
	49	#define WATCHDOG_NAME "w83697ug/uf WDT"
	50	#define PFX WATCHDOG_NAME ": "
	51	#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
	52
	53	static unsigned long wdt_is_open;
	54	static char expect_close;
	55	static DEFINE_SPINLOCK(io_lock);
	56
	57	static int wdt_io = 0x2e;
	58	module_param(wdt_io, int, 0);
	59	MODULE_PARM_DESC(wdt_io, "w83697ug/uf WDT io port (default 0x2e)");
	60
	61	static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
	62	module_param(timeout, int, 0);
	63	MODULE_PARM_DESC(timeout,
	64	"Watchdog timeout in seconds. 1<= timeout <=255 (default="
	65	__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
	66
	67	static int nowayout = WATCHDOG_NOWAYOUT;
	68	module_param(nowayout, int, 0);
	69	MODULE_PARM_DESC(nowayout,
70	"Watchdog cannot be stopped once started (default="
71	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
72
73	/*
74	* Kernel methods.
75	*/
76
77	#define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */
78	#define WDT_EFIR (wdt_io+0) /* Extended Function Index Register
79	(same as EFER) */
80	#define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
81
63bad145	82	static int w83697ug_select_wd_register(void)
7d8b0906 FF	83	{
	84	unsigned char c;
	85	unsigned char version;
	86
	87	outb_p(0x87, WDT_EFER); /* Enter extended function mode */
	88	outb_p(0x87, WDT_EFER); /* Again according to manual */
	89
	90	outb(0x20, WDT_EFER); /* check chip version */
	91	version = inb(WDT_EFDR);
	92
	93	if (version == 0x68) { /* W83697UG */
	94	printk(KERN_INFO PFX "Watchdog chip version 0x%02x = "
	95	"W83697UG/UF found at 0x%04x\n", version, wdt_io);
	96
	97	outb_p(0x2b, WDT_EFER);
	98	c = inb_p(WDT_EFDR); /* select WDT0 */
	99	c &= ~0x04;
	100	outb_p(0x2b, WDT_EFER);
	101	outb_p(c, WDT_EFDR); /* set pin118 to WDT0 */
	102
	103	} else {
	104	printk(KERN_ERR PFX "No W83697UG/UF could be found\n");
63bad145	105	return -ENODEV;
7d8b0906 FF	106	}
	107
	108	outb_p(0x07, WDT_EFER); /* point to logical device number reg */
	109	outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
	110	outb_p(0x30, WDT_EFER); /* select CR30 */
	111	c = inb_p(WDT_EFDR);
	112	outb_p(c \|\| 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
63bad145 EL	113
63bad145 EL	114	return 0;
7d8b0906 FF	115	}
	116
	117	static void w83697ug_unselect_wd_register(void)
	118	{
	119	outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
	120	}
	121
63bad145	122	static int w83697ug_init(void)
7d8b0906	123	{
63bad145	124	int ret;
7d8b0906 FF	125	unsigned char t;
7d8b0906 FF	126
63bad145 EL	127	ret = w83697ug_select_wd_register();
	128	if (ret != 0)
	129	return ret;
7d8b0906 FF	130
	131	outb_p(0xF6, WDT_EFER); /* Select CRF6 */
	132	t = inb_p(WDT_EFDR); /* read CRF6 */
	133	if (t != 0) {
	134	printk(KERN_INFO PFX "Watchdog already running."
	135	" Resetting timeout to %d sec\n", timeout);
	136	outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */
	137	}
	138	outb_p(0xF5, WDT_EFER); /* Select CRF5 */
	139	t = inb_p(WDT_EFDR); /* read CRF5 */
	140	t &= ~0x0C; /* set second mode &
	141	disable keyboard turning off watchdog */
	142	outb_p(t, WDT_EFDR); /* Write back to CRF5 */
	143
	144	w83697ug_unselect_wd_register();
63bad145	145	return 0;
7d8b0906 FF	146	}
	147
	148	static void wdt_ctrl(int timeout)
	149	{
	150	spin_lock(&io_lock);
	151
63bad145 EL	152	if (w83697ug_select_wd_register() < 0)
63bad145 EL	153	return;
7d8b0906 FF	154
	155	outb_p(0xF4, WDT_EFER); /* Select CRF4 */
	156	outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
	157
	158	w83697ug_unselect_wd_register();
	159
	160	spin_unlock(&io_lock);
	161	}
	162
	163	static int wdt_ping(void)
	164	{
	165	wdt_ctrl(timeout);
	166	return 0;
	167	}
	168
	169	static int wdt_disable(void)
	170	{
	171	wdt_ctrl(0);
	172	return 0;
	173	}
	174
	175	static int wdt_set_heartbeat(int t)
	176	{
	177	if (t < 1 \|\| t > 255)
	178	return -EINVAL;
	179
	180	timeout = t;
	181	return 0;
	182	}
	183
	184	static ssize_t wdt_write(struct file file, const char __user buf,
	185	size_t count, loff_t *ppos)
	186	{
	187	if (count) {
	188	if (!nowayout) {
	189	size_t i;
	190
	191	expect_close = 0;
	192
	193	for (i = 0; i != count; i++) {
	194	char c;
	195	if (get_user(c, buf + i))
	196	return -EFAULT;
	197	if (c == 'V')
	198	expect_close = 42;
	199	}
	200	}
	201	wdt_ping();
	202	}
	203	return count;
	204	}
	205
	206	static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	207	{
	208	void __user argp = (void __user )arg;
	209	int __user *p = argp;
	210	int new_timeout;
	211	static const struct watchdog_info ident = {
	212	.options = WDIOF_KEEPALIVEPING \|
	213	WDIOF_SETTIMEOUT \|
	214	WDIOF_MAGICCLOSE,
	215	.firmware_version = 1,
	216	.identity = "W83697UG WDT",
	217	};
218
219	switch (cmd) {
220	case WDIOC_GETSUPPORT:
221	if (copy_to_user(argp, &ident, sizeof(ident)))
222	return -EFAULT;
223	break;
224
225	case WDIOC_GETSTATUS:
226	case WDIOC_GETBOOTSTATUS:
227	return put_user(0, p);
228
229	case WDIOC_SETOPTIONS:
230	{
231	int options, retval = -EINVAL;
232
233	if (get_user(options, p))
234	return -EFAULT;
235
236	if (options & WDIOS_DISABLECARD) {
237	wdt_disable();
238	retval = 0;
239	}
240
241	if (options & WDIOS_ENABLECARD) {
242	wdt_ping();
243	retval = 0;
244	}
245
246	return retval;
247	}
248
249	case WDIOC_KEEPALIVE:
250	wdt_ping();
251	break;
252
253	case WDIOC_SETTIMEOUT:
254	if (get_user(new_timeout, p))
255	return -EFAULT;
256	if (wdt_set_heartbeat(new_timeout))
257	return -EINVAL;
258	wdt_ping();
259	/* Fall */
260
261	case WDIOC_GETTIMEOUT:
262	return put_user(timeout, p);
263
264	default:
265	return -ENOTTY;
266	}
267	return 0;
268	}
269
270	static int wdt_open(struct inode inode, struct file file)
271	{
272	if (test_and_set_bit(0, &wdt_is_open))
273	return -EBUSY;
274	/*
275	* Activate
276	*/
277
278	wdt_ping();
279	return nonseekable_open(inode, file);
280	}
281
282	static int wdt_close(struct inode inode, struct file file)
283	{
284	if (expect_close == 42)
285	wdt_disable();
286	else {
287	printk(KERN_CRIT PFX
288	"Unexpected close, not stopping watchdog!\n");
289	wdt_ping();
290	}
291	expect_close = 0;
292	clear_bit(0, &wdt_is_open);
293	return 0;
294	}
295
296	/*
297	* Notifier for system down
298	*/
299
300	static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
301	void *unused)
302	{
303	if (code == SYS_DOWN \|\| code == SYS_HALT)
304	wdt_disable(); /* Turn the WDT off */
305
306	return NOTIFY_DONE;
307	}
308
309	/*
310	* Kernel Interfaces
311	*/
312
313	static const struct file_operations wdt_fops = {
314	.owner = THIS_MODULE,
315	.llseek = no_llseek,
316	.write = wdt_write,
317	.unlocked_ioctl = wdt_ioctl,
318	.open = wdt_open,
319	.release = wdt_close,
320	};
321
322	static struct miscdevice wdt_miscdev = {
323	.minor = WATCHDOG_MINOR,
324	.name = "watchdog",
325	.fops = &wdt_fops,
326	};
327
328	/*
329	* The WDT needs to learn about soft shutdowns in order to
330	* turn the timebomb registers off.
331	*/
332
333	static struct notifier_block wdt_notifier = {
334	.notifier_call = wdt_notify_sys,
335	};
336
337	static int __init wdt_init(void)
338	{
339	int ret;
340
341	printk(KERN_INFO "WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising.\n");
342
343	if (wdt_set_heartbeat(timeout)) {
344	wdt_set_heartbeat(WATCHDOG_TIMEOUT);
345	printk(KERN_INFO PFX
346	"timeout value must be 1<=timeout<=255, using %d\n",
347	WATCHDOG_TIMEOUT);
348	}
349
350	if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
351	printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
352	wdt_io);
353	ret = -EIO;
354	goto out;
355	}
356
63bad145 EL	357	ret = w83697ug_init();
	358	if (ret != 0)
	359	goto unreg_regions;
7d8b0906 FF	360
	361	ret = register_reboot_notifier(&wdt_notifier);
	362	if (ret != 0) {
	363	printk(KERN_ERR PFX
	364	"cannot register reboot notifier (err=%d)\n", ret);
	365	goto unreg_regions;
	366	}
	367
	368	ret = misc_register(&wdt_miscdev);
	369	if (ret != 0) {
	370	printk(KERN_ERR PFX
	371	"cannot register miscdev on minor=%d (err=%d)\n",
	372	WATCHDOG_MINOR, ret);
	373	goto unreg_reboot;
	374	}
	375
	376	printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
	377	timeout, nowayout);
	378
	379	out:
	380	return ret;
	381	unreg_reboot:
	382	unregister_reboot_notifier(&wdt_notifier);
	383	unreg_regions:
	384	release_region(wdt_io, 1);
	385	goto out;
	386	}
	387
	388	static void __exit wdt_exit(void)
	389	{
	390	misc_deregister(&wdt_miscdev);
	391	unregister_reboot_notifier(&wdt_notifier);
	392	release_region(wdt_io, 1);
	393	}
	394
	395	module_init(wdt_init);
	396	module_exit(wdt_exit);
	397
	398	MODULE_LICENSE("GPL");
	399	MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
	400	MODULE_DESCRIPTION("w83697ug/uf WDT driver");
	401	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);