xref: /linux/drivers/watchdog/it87_wdt.c (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 /*
2  *	Watchdog Timer Driver
3  *	   for ITE IT87xx Environment Control - Low Pin Count Input / Output
4  *
5  *	(c) Copyright 2007  Oliver Schuster <olivers137@aol.com>
6  *
7  *	Based on softdog.c	by Alan Cox,
8  *		 83977f_wdt.c	by Jose Goncalves,
9  *		 it87.c		by Chris Gauthron, Jean Delvare
10  *
11  *	Data-sheets: Publicly available at the ITE website
12  *		    http://www.ite.com.tw/
13  *
14  *	Support of the watchdog timers, which are available on
15  *	IT8702, IT8712, IT8716, IT8718, IT8720, IT8721, IT8726,
16  *	IT8728 and IT8783.
17  *
18  *	This program is free software; you can redistribute it and/or
19  *	modify it under the terms of the GNU General Public License
20  *	as published by the Free Software Foundation; either version
21  *	2 of the License, or (at your option) any later version.
22  *
23  *	This program is distributed in the hope that it will be useful,
24  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
25  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
26  *	GNU General Public License for more details.
27  *
28  *	You should have received a copy of the GNU General Public License
29  *	along with this program; if not, write to the Free Software
30  *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
31  */
32 
33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34 
35 #include <linux/module.h>
36 #include <linux/moduleparam.h>
37 #include <linux/types.h>
38 #include <linux/kernel.h>
39 #include <linux/fs.h>
40 #include <linux/miscdevice.h>
41 #include <linux/init.h>
42 #include <linux/ioport.h>
43 #include <linux/watchdog.h>
44 #include <linux/notifier.h>
45 #include <linux/reboot.h>
46 #include <linux/uaccess.h>
47 #include <linux/io.h>
48 
49 
50 #define WATCHDOG_VERSION	"1.14"
51 #define WATCHDOG_NAME		"IT87 WDT"
52 #define DRIVER_VERSION		WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
53 #define WD_MAGIC		'V'
54 
55 /* Defaults for Module Parameter */
56 #define DEFAULT_NOGAMEPORT	0
57 #define DEFAULT_NOCIR		0
58 #define DEFAULT_EXCLUSIVE	1
59 #define DEFAULT_TIMEOUT		60
60 #define DEFAULT_TESTMODE	0
61 #define DEFAULT_NOWAYOUT	WATCHDOG_NOWAYOUT
62 
63 /* IO Ports */
64 #define REG		0x2e
65 #define VAL		0x2f
66 
67 /* Logical device Numbers LDN */
68 #define GPIO		0x07
69 #define GAMEPORT	0x09
70 #define CIR		0x0a
71 
72 /* Configuration Registers and Functions */
73 #define LDNREG		0x07
74 #define CHIPID		0x20
75 #define CHIPREV		0x22
76 #define ACTREG		0x30
77 #define BASEREG		0x60
78 
79 /* Chip Id numbers */
80 #define NO_DEV_ID	0xffff
81 #define IT8702_ID	0x8702
82 #define IT8705_ID	0x8705
83 #define IT8712_ID	0x8712
84 #define IT8716_ID	0x8716
85 #define IT8718_ID	0x8718
86 #define IT8720_ID	0x8720
87 #define IT8721_ID	0x8721
88 #define IT8726_ID	0x8726	/* the data sheet suggest wrongly 0x8716 */
89 #define IT8728_ID	0x8728
90 #define IT8783_ID	0x8783
91 
92 /* GPIO Configuration Registers LDN=0x07 */
93 #define WDTCTRL		0x71
94 #define WDTCFG		0x72
95 #define WDTVALLSB	0x73
96 #define WDTVALMSB	0x74
97 
98 /* GPIO Bits WDTCTRL */
99 #define WDT_CIRINT	0x80
100 #define WDT_MOUSEINT	0x40
101 #define WDT_KYBINT	0x20
102 #define WDT_GAMEPORT	0x10 /* not in it8718, it8720, it8721, it8728 */
103 #define WDT_FORCE	0x02
104 #define WDT_ZERO	0x01
105 
106 /* GPIO Bits WDTCFG */
107 #define WDT_TOV1	0x80
108 #define WDT_KRST	0x40
109 #define WDT_TOVE	0x20
110 #define WDT_PWROK	0x10 /* not in it8721 */
111 #define WDT_INT_MASK	0x0f
112 
113 /* CIR Configuration Register LDN=0x0a */
114 #define CIR_ILS		0x70
115 
116 /* The default Base address is not always available, we use this */
117 #define CIR_BASE	0x0208
118 
119 /* CIR Controller */
120 #define CIR_DR(b)	(b)
121 #define CIR_IER(b)	(b + 1)
122 #define CIR_RCR(b)	(b + 2)
123 #define CIR_TCR1(b)	(b + 3)
124 #define CIR_TCR2(b)	(b + 4)
125 #define CIR_TSR(b)	(b + 5)
126 #define CIR_RSR(b)	(b + 6)
127 #define CIR_BDLR(b)	(b + 5)
128 #define CIR_BDHR(b)	(b + 6)
129 #define CIR_IIR(b)	(b + 7)
130 
131 /* Default Base address of Game port */
132 #define GP_BASE_DEFAULT	0x0201
133 
134 /* wdt_status */
135 #define WDTS_TIMER_RUN	0
136 #define WDTS_DEV_OPEN	1
137 #define WDTS_KEEPALIVE	2
138 #define WDTS_LOCKED	3
139 #define WDTS_USE_GP	4
140 #define WDTS_EXPECTED	5
141 #define WDTS_USE_CIR	6
142 
143 static	unsigned int base, gpact, ciract, max_units, chip_type;
144 static	unsigned long wdt_status;
145 
146 static	int nogameport = DEFAULT_NOGAMEPORT;
147 static int nocir      = DEFAULT_NOCIR;
148 static	int exclusive  = DEFAULT_EXCLUSIVE;
149 static	int timeout    = DEFAULT_TIMEOUT;
150 static	int testmode   = DEFAULT_TESTMODE;
151 static	bool nowayout   = DEFAULT_NOWAYOUT;
152 
153 module_param(nogameport, int, 0);
154 MODULE_PARM_DESC(nogameport, "Forbid the activation of game port, default="
155 		__MODULE_STRING(DEFAULT_NOGAMEPORT));
156 module_param(nocir, int, 0);
157 MODULE_PARM_DESC(nocir, "Forbid the use of Consumer IR interrupts to reset timer, default="
158 		__MODULE_STRING(DEFAULT_NOCIR));
159 module_param(exclusive, int, 0);
160 MODULE_PARM_DESC(exclusive, "Watchdog exclusive device open, default="
161 		__MODULE_STRING(DEFAULT_EXCLUSIVE));
162 module_param(timeout, int, 0);
163 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default="
164 		__MODULE_STRING(DEFAULT_TIMEOUT));
165 module_param(testmode, int, 0);
166 MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default="
167 		__MODULE_STRING(DEFAULT_TESTMODE));
168 module_param(nowayout, bool, 0);
169 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default="
170 		__MODULE_STRING(WATCHDOG_NOWAYOUT));
171 
172 /* Superio Chip */
173 
174 static inline int superio_enter(void)
175 {
176 	/*
177 	 * Try to reserve REG and REG + 1 for exclusive access.
178 	 */
179 	if (!request_muxed_region(REG, 2, WATCHDOG_NAME))
180 		return -EBUSY;
181 
182 	outb(0x87, REG);
183 	outb(0x01, REG);
184 	outb(0x55, REG);
185 	outb(0x55, REG);
186 	return 0;
187 }
188 
189 static inline void superio_exit(void)
190 {
191 	outb(0x02, REG);
192 	outb(0x02, VAL);
193 	release_region(REG, 2);
194 }
195 
196 static inline void superio_select(int ldn)
197 {
198 	outb(LDNREG, REG);
199 	outb(ldn, VAL);
200 }
201 
202 static inline int superio_inb(int reg)
203 {
204 	outb(reg, REG);
205 	return inb(VAL);
206 }
207 
208 static inline void superio_outb(int val, int reg)
209 {
210 	outb(reg, REG);
211 	outb(val, VAL);
212 }
213 
214 static inline int superio_inw(int reg)
215 {
216 	int val;
217 	outb(reg++, REG);
218 	val = inb(VAL) << 8;
219 	outb(reg, REG);
220 	val |= inb(VAL);
221 	return val;
222 }
223 
224 static inline void superio_outw(int val, int reg)
225 {
226 	outb(reg++, REG);
227 	outb(val >> 8, VAL);
228 	outb(reg, REG);
229 	outb(val, VAL);
230 }
231 
232 /* Internal function, should be called after superio_select(GPIO) */
233 static void wdt_update_timeout(void)
234 {
235 	unsigned char cfg = WDT_KRST;
236 	int tm = timeout;
237 
238 	if (testmode)
239 		cfg = 0;
240 
241 	if (tm <= max_units)
242 		cfg |= WDT_TOV1;
243 	else
244 		tm /= 60;
245 
246 	if (chip_type != IT8721_ID)
247 		cfg |= WDT_PWROK;
248 
249 	superio_outb(cfg, WDTCFG);
250 	superio_outb(tm, WDTVALLSB);
251 	if (max_units > 255)
252 		superio_outb(tm>>8, WDTVALMSB);
253 }
254 
255 static int wdt_round_time(int t)
256 {
257 	t += 59;
258 	t -= t % 60;
259 	return t;
260 }
261 
262 /* watchdog timer handling */
263 
264 static void wdt_keepalive(void)
265 {
266 	if (test_bit(WDTS_USE_GP, &wdt_status))
267 		inb(base);
268 	else if (test_bit(WDTS_USE_CIR, &wdt_status))
269 		/* The timer reloads with around 5 msec delay */
270 		outb(0x55, CIR_DR(base));
271 	else {
272 		if (superio_enter())
273 			return;
274 
275 		superio_select(GPIO);
276 		wdt_update_timeout();
277 		superio_exit();
278 	}
279 	set_bit(WDTS_KEEPALIVE, &wdt_status);
280 }
281 
282 static int wdt_start(void)
283 {
284 	int ret = superio_enter();
285 	if (ret)
286 		return ret;
287 
288 	superio_select(GPIO);
289 	if (test_bit(WDTS_USE_GP, &wdt_status))
290 		superio_outb(WDT_GAMEPORT, WDTCTRL);
291 	else if (test_bit(WDTS_USE_CIR, &wdt_status))
292 		superio_outb(WDT_CIRINT, WDTCTRL);
293 	wdt_update_timeout();
294 
295 	superio_exit();
296 
297 	return 0;
298 }
299 
300 static int wdt_stop(void)
301 {
302 	int ret = superio_enter();
303 	if (ret)
304 		return ret;
305 
306 	superio_select(GPIO);
307 	superio_outb(0x00, WDTCTRL);
308 	superio_outb(WDT_TOV1, WDTCFG);
309 	superio_outb(0x00, WDTVALLSB);
310 	if (max_units > 255)
311 		superio_outb(0x00, WDTVALMSB);
312 
313 	superio_exit();
314 	return 0;
315 }
316 
317 /**
318  *	wdt_set_timeout - set a new timeout value with watchdog ioctl
319  *	@t: timeout value in seconds
320  *
321  *	The hardware device has a 8 or 16 bit watchdog timer (depends on
322  *	chip version) that can be configured to count seconds or minutes.
323  *
324  *	Used within WDIOC_SETTIMEOUT watchdog device ioctl.
325  */
326 
327 static int wdt_set_timeout(int t)
328 {
329 	if (t < 1 || t > max_units * 60)
330 		return -EINVAL;
331 
332 	if (t > max_units)
333 		timeout = wdt_round_time(t);
334 	else
335 		timeout = t;
336 
337 	if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
338 		int ret = superio_enter();
339 		if (ret)
340 			return ret;
341 
342 		superio_select(GPIO);
343 		wdt_update_timeout();
344 		superio_exit();
345 	}
346 	return 0;
347 }
348 
349 /**
350  *	wdt_get_status - determines the status supported by watchdog ioctl
351  *	@status: status returned to user space
352  *
353  *	The status bit of the device does not allow to distinguish
354  *	between a regular system reset and a watchdog forced reset.
355  *	But, in test mode it is useful, so it is supported through
356  *	WDIOC_GETSTATUS watchdog ioctl. Additionally the driver
357  *	reports the keepalive signal and the acception of the magic.
358  *
359  *	Used within WDIOC_GETSTATUS watchdog device ioctl.
360  */
361 
362 static int wdt_get_status(int *status)
363 {
364 	*status = 0;
365 	if (testmode) {
366 		int ret = superio_enter();
367 		if (ret)
368 			return ret;
369 
370 		superio_select(GPIO);
371 		if (superio_inb(WDTCTRL) & WDT_ZERO) {
372 			superio_outb(0x00, WDTCTRL);
373 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
374 			*status |= WDIOF_CARDRESET;
375 		}
376 
377 		superio_exit();
378 	}
379 	if (test_and_clear_bit(WDTS_KEEPALIVE, &wdt_status))
380 		*status |= WDIOF_KEEPALIVEPING;
381 	if (test_bit(WDTS_EXPECTED, &wdt_status))
382 		*status |= WDIOF_MAGICCLOSE;
383 	return 0;
384 }
385 
386 /* /dev/watchdog handling */
387 
388 /**
389  *	wdt_open - watchdog file_operations .open
390  *	@inode: inode of the device
391  *	@file: file handle to the device
392  *
393  *	The watchdog timer starts by opening the device.
394  *
395  *	Used within the file operation of the watchdog device.
396  */
397 
398 static int wdt_open(struct inode *inode, struct file *file)
399 {
400 	if (exclusive && test_and_set_bit(WDTS_DEV_OPEN, &wdt_status))
401 		return -EBUSY;
402 	if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
403 		int ret;
404 		if (nowayout && !test_and_set_bit(WDTS_LOCKED, &wdt_status))
405 			__module_get(THIS_MODULE);
406 
407 		ret = wdt_start();
408 		if (ret) {
409 			clear_bit(WDTS_LOCKED, &wdt_status);
410 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
411 			clear_bit(WDTS_DEV_OPEN, &wdt_status);
412 			return ret;
413 		}
414 	}
415 	return nonseekable_open(inode, file);
416 }
417 
418 /**
419  *	wdt_release - watchdog file_operations .release
420  *	@inode: inode of the device
421  *	@file: file handle to the device
422  *
423  *	Closing the watchdog device either stops the watchdog timer
424  *	or in the case, that nowayout is set or the magic character
425  *	wasn't written, a critical warning about an running watchdog
426  *	timer is given.
427  *
428  *	Used within the file operation of the watchdog device.
429  */
430 
431 static int wdt_release(struct inode *inode, struct file *file)
432 {
433 	if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
434 		if (test_and_clear_bit(WDTS_EXPECTED, &wdt_status)) {
435 			int ret = wdt_stop();
436 			if (ret) {
437 				/*
438 				 * Stop failed. Just keep the watchdog alive
439 				 * and hope nothing bad happens.
440 				 */
441 				set_bit(WDTS_EXPECTED, &wdt_status);
442 				wdt_keepalive();
443 				return ret;
444 			}
445 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
446 		} else {
447 			wdt_keepalive();
448 			pr_crit("unexpected close, not stopping watchdog!\n");
449 		}
450 	}
451 	clear_bit(WDTS_DEV_OPEN, &wdt_status);
452 	return 0;
453 }
454 
455 /**
456  *	wdt_write - watchdog file_operations .write
457  *	@file: file handle to the watchdog
458  *	@buf: buffer to write
459  *	@count: count of bytes
460  *	@ppos: pointer to the position to write. No seeks allowed
461  *
462  *	A write to a watchdog device is defined as a keepalive signal. Any
463  *	write of data will do, as we don't define content meaning.
464  *
465  *	Used within the file operation of the watchdog device.
466  */
467 
468 static ssize_t wdt_write(struct file *file, const char __user *buf,
469 			    size_t count, loff_t *ppos)
470 {
471 	if (count) {
472 		clear_bit(WDTS_EXPECTED, &wdt_status);
473 		wdt_keepalive();
474 	}
475 	if (!nowayout) {
476 		size_t ofs;
477 
478 	/* note: just in case someone wrote the magic character long ago */
479 		for (ofs = 0; ofs != count; ofs++) {
480 			char c;
481 			if (get_user(c, buf + ofs))
482 				return -EFAULT;
483 			if (c == WD_MAGIC)
484 				set_bit(WDTS_EXPECTED, &wdt_status);
485 		}
486 	}
487 	return count;
488 }
489 
490 static const struct watchdog_info ident = {
491 	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
492 	.firmware_version =	1,
493 	.identity = WATCHDOG_NAME,
494 };
495 
496 /**
497  *	wdt_ioctl - watchdog file_operations .unlocked_ioctl
498  *	@file: file handle to the device
499  *	@cmd: watchdog command
500  *	@arg: argument pointer
501  *
502  *	The watchdog API defines a common set of functions for all watchdogs
503  *	according to their available features.
504  *
505  *	Used within the file operation of the watchdog device.
506  */
507 
508 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
509 {
510 	int rc = 0, status, new_options, new_timeout;
511 	union {
512 		struct watchdog_info __user *ident;
513 		int __user *i;
514 	} uarg;
515 
516 	uarg.i = (int __user *)arg;
517 
518 	switch (cmd) {
519 	case WDIOC_GETSUPPORT:
520 		return copy_to_user(uarg.ident,
521 				    &ident, sizeof(ident)) ? -EFAULT : 0;
522 
523 	case WDIOC_GETSTATUS:
524 		rc = wdt_get_status(&status);
525 		if (rc)
526 			return rc;
527 		return put_user(status, uarg.i);
528 
529 	case WDIOC_GETBOOTSTATUS:
530 		return put_user(0, uarg.i);
531 
532 	case WDIOC_KEEPALIVE:
533 		wdt_keepalive();
534 		return 0;
535 
536 	case WDIOC_SETOPTIONS:
537 		if (get_user(new_options, uarg.i))
538 			return -EFAULT;
539 
540 		switch (new_options) {
541 		case WDIOS_DISABLECARD:
542 			if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
543 				rc = wdt_stop();
544 				if (rc)
545 					return rc;
546 			}
547 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
548 			return 0;
549 
550 		case WDIOS_ENABLECARD:
551 			if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
552 				rc = wdt_start();
553 				if (rc) {
554 					clear_bit(WDTS_TIMER_RUN, &wdt_status);
555 					return rc;
556 				}
557 			}
558 			return 0;
559 
560 		default:
561 			return -EFAULT;
562 		}
563 
564 	case WDIOC_SETTIMEOUT:
565 		if (get_user(new_timeout, uarg.i))
566 			return -EFAULT;
567 		rc = wdt_set_timeout(new_timeout);
568 	case WDIOC_GETTIMEOUT:
569 		if (put_user(timeout, uarg.i))
570 			return -EFAULT;
571 		return rc;
572 
573 	default:
574 		return -ENOTTY;
575 	}
576 }
577 
578 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
579 	void *unused)
580 {
581 	if (code == SYS_DOWN || code == SYS_HALT)
582 		wdt_stop();
583 	return NOTIFY_DONE;
584 }
585 
586 static const struct file_operations wdt_fops = {
587 	.owner		= THIS_MODULE,
588 	.llseek		= no_llseek,
589 	.write		= wdt_write,
590 	.unlocked_ioctl	= wdt_ioctl,
591 	.open		= wdt_open,
592 	.release	= wdt_release,
593 };
594 
595 static struct miscdevice wdt_miscdev = {
596 	.minor		= WATCHDOG_MINOR,
597 	.name		= "watchdog",
598 	.fops		= &wdt_fops,
599 };
600 
601 static struct notifier_block wdt_notifier = {
602 	.notifier_call = wdt_notify_sys,
603 };
604 
605 static int __init it87_wdt_init(void)
606 {
607 	int rc = 0;
608 	int try_gameport = !nogameport;
609 	u8  chip_rev;
610 	int gp_rreq_fail = 0;
611 
612 	wdt_status = 0;
613 
614 	rc = superio_enter();
615 	if (rc)
616 		return rc;
617 
618 	chip_type = superio_inw(CHIPID);
619 	chip_rev  = superio_inb(CHIPREV) & 0x0f;
620 	superio_exit();
621 
622 	switch (chip_type) {
623 	case IT8702_ID:
624 		max_units = 255;
625 		break;
626 	case IT8712_ID:
627 		max_units = (chip_rev < 8) ? 255 : 65535;
628 		break;
629 	case IT8716_ID:
630 	case IT8726_ID:
631 		max_units = 65535;
632 		break;
633 	case IT8718_ID:
634 	case IT8720_ID:
635 	case IT8721_ID:
636 	case IT8728_ID:
637 	case IT8783_ID:
638 		max_units = 65535;
639 		try_gameport = 0;
640 		break;
641 	case IT8705_ID:
642 		pr_err("Unsupported Chip found, Chip %04x Revision %02x\n",
643 		       chip_type, chip_rev);
644 		return -ENODEV;
645 	case NO_DEV_ID:
646 		pr_err("no device\n");
647 		return -ENODEV;
648 	default:
649 		pr_err("Unknown Chip found, Chip %04x Revision %04x\n",
650 		       chip_type, chip_rev);
651 		return -ENODEV;
652 	}
653 
654 	rc = superio_enter();
655 	if (rc)
656 		return rc;
657 
658 	superio_select(GPIO);
659 	superio_outb(WDT_TOV1, WDTCFG);
660 	superio_outb(0x00, WDTCTRL);
661 
662 	/* First try to get Gameport support */
663 	if (try_gameport) {
664 		superio_select(GAMEPORT);
665 		base = superio_inw(BASEREG);
666 		if (!base) {
667 			base = GP_BASE_DEFAULT;
668 			superio_outw(base, BASEREG);
669 		}
670 		gpact = superio_inb(ACTREG);
671 		superio_outb(0x01, ACTREG);
672 		if (request_region(base, 1, WATCHDOG_NAME))
673 			set_bit(WDTS_USE_GP, &wdt_status);
674 		else
675 			gp_rreq_fail = 1;
676 	}
677 
678 	/* If we haven't Gameport support, try to get CIR support */
679 	if (!nocir && !test_bit(WDTS_USE_GP, &wdt_status)) {
680 		if (!request_region(CIR_BASE, 8, WATCHDOG_NAME)) {
681 			if (gp_rreq_fail)
682 				pr_err("I/O Address 0x%04x and 0x%04x already in use\n",
683 				       base, CIR_BASE);
684 			else
685 				pr_err("I/O Address 0x%04x already in use\n",
686 				       CIR_BASE);
687 			rc = -EIO;
688 			goto err_out;
689 		}
690 		base = CIR_BASE;
691 
692 		superio_select(CIR);
693 		superio_outw(base, BASEREG);
694 		superio_outb(0x00, CIR_ILS);
695 		ciract = superio_inb(ACTREG);
696 		superio_outb(0x01, ACTREG);
697 		if (gp_rreq_fail) {
698 			superio_select(GAMEPORT);
699 			superio_outb(gpact, ACTREG);
700 		}
701 		set_bit(WDTS_USE_CIR, &wdt_status);
702 	}
703 
704 	if (timeout < 1 || timeout > max_units * 60) {
705 		timeout = DEFAULT_TIMEOUT;
706 		pr_warn("Timeout value out of range, use default %d sec\n",
707 			DEFAULT_TIMEOUT);
708 	}
709 
710 	if (timeout > max_units)
711 		timeout = wdt_round_time(timeout);
712 
713 	rc = register_reboot_notifier(&wdt_notifier);
714 	if (rc) {
715 		pr_err("Cannot register reboot notifier (err=%d)\n", rc);
716 		goto err_out_region;
717 	}
718 
719 	rc = misc_register(&wdt_miscdev);
720 	if (rc) {
721 		pr_err("Cannot register miscdev on minor=%d (err=%d)\n",
722 		       wdt_miscdev.minor, rc);
723 		goto err_out_reboot;
724 	}
725 
726 	/* Initialize CIR to use it as keepalive source */
727 	if (test_bit(WDTS_USE_CIR, &wdt_status)) {
728 		outb(0x00, CIR_RCR(base));
729 		outb(0xc0, CIR_TCR1(base));
730 		outb(0x5c, CIR_TCR2(base));
731 		outb(0x10, CIR_IER(base));
732 		outb(0x00, CIR_BDHR(base));
733 		outb(0x01, CIR_BDLR(base));
734 		outb(0x09, CIR_IER(base));
735 	}
736 
737 	pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d exclusive=%d nogameport=%d nocir=%d)\n",
738 		chip_type, chip_rev, timeout,
739 		nowayout, testmode, exclusive, nogameport, nocir);
740 
741 	superio_exit();
742 	return 0;
743 
744 err_out_reboot:
745 	unregister_reboot_notifier(&wdt_notifier);
746 err_out_region:
747 	if (test_bit(WDTS_USE_GP, &wdt_status))
748 		release_region(base, 1);
749 	else if (test_bit(WDTS_USE_CIR, &wdt_status)) {
750 		release_region(base, 8);
751 		superio_select(CIR);
752 		superio_outb(ciract, ACTREG);
753 	}
754 err_out:
755 	if (try_gameport) {
756 		superio_select(GAMEPORT);
757 		superio_outb(gpact, ACTREG);
758 	}
759 
760 	superio_exit();
761 	return rc;
762 }
763 
764 static void __exit it87_wdt_exit(void)
765 {
766 	if (superio_enter() == 0) {
767 		superio_select(GPIO);
768 		superio_outb(0x00, WDTCTRL);
769 		superio_outb(0x00, WDTCFG);
770 		superio_outb(0x00, WDTVALLSB);
771 		if (max_units > 255)
772 			superio_outb(0x00, WDTVALMSB);
773 		if (test_bit(WDTS_USE_GP, &wdt_status)) {
774 			superio_select(GAMEPORT);
775 			superio_outb(gpact, ACTREG);
776 		} else if (test_bit(WDTS_USE_CIR, &wdt_status)) {
777 			superio_select(CIR);
778 			superio_outb(ciract, ACTREG);
779 		}
780 		superio_exit();
781 	}
782 
783 	misc_deregister(&wdt_miscdev);
784 	unregister_reboot_notifier(&wdt_notifier);
785 
786 	if (test_bit(WDTS_USE_GP, &wdt_status))
787 		release_region(base, 1);
788 	else if (test_bit(WDTS_USE_CIR, &wdt_status))
789 		release_region(base, 8);
790 }
791 
792 module_init(it87_wdt_init);
793 module_exit(it87_wdt_exit);
794 
795 MODULE_AUTHOR("Oliver Schuster");
796 MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O");
797 MODULE_LICENSE("GPL");
798