xref: /openbmc/linux/drivers/watchdog/it87_wdt.c (revision 1c2dd16a)
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  *	IT8620, 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 IT8620_ID	0x8620
82 #define IT8702_ID	0x8702
83 #define IT8705_ID	0x8705
84 #define IT8712_ID	0x8712
85 #define IT8716_ID	0x8716
86 #define IT8718_ID	0x8718
87 #define IT8720_ID	0x8720
88 #define IT8721_ID	0x8721
89 #define IT8726_ID	0x8726	/* the data sheet suggest wrongly 0x8716 */
90 #define IT8728_ID	0x8728
91 #define IT8783_ID	0x8783
92 
93 /* GPIO Configuration Registers LDN=0x07 */
94 #define WDTCTRL		0x71
95 #define WDTCFG		0x72
96 #define WDTVALLSB	0x73
97 #define WDTVALMSB	0x74
98 
99 /* GPIO Bits WDTCTRL */
100 #define WDT_CIRINT	0x80
101 #define WDT_MOUSEINT	0x40
102 #define WDT_KYBINT	0x20
103 #define WDT_GAMEPORT	0x10 /* not in it8718, it8720, it8721, it8728 */
104 #define WDT_FORCE	0x02
105 #define WDT_ZERO	0x01
106 
107 /* GPIO Bits WDTCFG */
108 #define WDT_TOV1	0x80
109 #define WDT_KRST	0x40
110 #define WDT_TOVE	0x20
111 #define WDT_PWROK	0x10 /* not in it8721 */
112 #define WDT_INT_MASK	0x0f
113 
114 /* CIR Configuration Register LDN=0x0a */
115 #define CIR_ILS		0x70
116 
117 /* The default Base address is not always available, we use this */
118 #define CIR_BASE	0x0208
119 
120 /* CIR Controller */
121 #define CIR_DR(b)	(b)
122 #define CIR_IER(b)	(b + 1)
123 #define CIR_RCR(b)	(b + 2)
124 #define CIR_TCR1(b)	(b + 3)
125 #define CIR_TCR2(b)	(b + 4)
126 #define CIR_TSR(b)	(b + 5)
127 #define CIR_RSR(b)	(b + 6)
128 #define CIR_BDLR(b)	(b + 5)
129 #define CIR_BDHR(b)	(b + 6)
130 #define CIR_IIR(b)	(b + 7)
131 
132 /* Default Base address of Game port */
133 #define GP_BASE_DEFAULT	0x0201
134 
135 /* wdt_status */
136 #define WDTS_TIMER_RUN	0
137 #define WDTS_DEV_OPEN	1
138 #define WDTS_KEEPALIVE	2
139 #define WDTS_LOCKED	3
140 #define WDTS_USE_GP	4
141 #define WDTS_EXPECTED	5
142 #define WDTS_USE_CIR	6
143 
144 static	unsigned int base, gpact, ciract, max_units, chip_type;
145 static	unsigned long wdt_status;
146 
147 static	int nogameport = DEFAULT_NOGAMEPORT;
148 static int nocir      = DEFAULT_NOCIR;
149 static	int exclusive  = DEFAULT_EXCLUSIVE;
150 static	int timeout    = DEFAULT_TIMEOUT;
151 static	int testmode   = DEFAULT_TESTMODE;
152 static	bool nowayout   = DEFAULT_NOWAYOUT;
153 
154 module_param(nogameport, int, 0);
155 MODULE_PARM_DESC(nogameport, "Forbid the activation of game port, default="
156 		__MODULE_STRING(DEFAULT_NOGAMEPORT));
157 module_param(nocir, int, 0);
158 MODULE_PARM_DESC(nocir, "Forbid the use of Consumer IR interrupts to reset timer, default="
159 		__MODULE_STRING(DEFAULT_NOCIR));
160 module_param(exclusive, int, 0);
161 MODULE_PARM_DESC(exclusive, "Watchdog exclusive device open, default="
162 		__MODULE_STRING(DEFAULT_EXCLUSIVE));
163 module_param(timeout, int, 0);
164 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default="
165 		__MODULE_STRING(DEFAULT_TIMEOUT));
166 module_param(testmode, int, 0);
167 MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default="
168 		__MODULE_STRING(DEFAULT_TESTMODE));
169 module_param(nowayout, bool, 0);
170 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default="
171 		__MODULE_STRING(WATCHDOG_NOWAYOUT));
172 
173 /* Superio Chip */
174 
175 static inline int superio_enter(void)
176 {
177 	/*
178 	 * Try to reserve REG and REG + 1 for exclusive access.
179 	 */
180 	if (!request_muxed_region(REG, 2, WATCHDOG_NAME))
181 		return -EBUSY;
182 
183 	outb(0x87, REG);
184 	outb(0x01, REG);
185 	outb(0x55, REG);
186 	outb(0x55, REG);
187 	return 0;
188 }
189 
190 static inline void superio_exit(void)
191 {
192 	outb(0x02, REG);
193 	outb(0x02, VAL);
194 	release_region(REG, 2);
195 }
196 
197 static inline void superio_select(int ldn)
198 {
199 	outb(LDNREG, REG);
200 	outb(ldn, VAL);
201 }
202 
203 static inline int superio_inb(int reg)
204 {
205 	outb(reg, REG);
206 	return inb(VAL);
207 }
208 
209 static inline void superio_outb(int val, int reg)
210 {
211 	outb(reg, REG);
212 	outb(val, VAL);
213 }
214 
215 static inline int superio_inw(int reg)
216 {
217 	int val;
218 	outb(reg++, REG);
219 	val = inb(VAL) << 8;
220 	outb(reg, REG);
221 	val |= inb(VAL);
222 	return val;
223 }
224 
225 static inline void superio_outw(int val, int reg)
226 {
227 	outb(reg++, REG);
228 	outb(val >> 8, VAL);
229 	outb(reg, REG);
230 	outb(val, VAL);
231 }
232 
233 /* Internal function, should be called after superio_select(GPIO) */
234 static void wdt_update_timeout(void)
235 {
236 	unsigned char cfg = WDT_KRST;
237 	int tm = timeout;
238 
239 	if (testmode)
240 		cfg = 0;
241 
242 	if (tm <= max_units)
243 		cfg |= WDT_TOV1;
244 	else
245 		tm /= 60;
246 
247 	if (chip_type != IT8721_ID)
248 		cfg |= WDT_PWROK;
249 
250 	superio_outb(cfg, WDTCFG);
251 	superio_outb(tm, WDTVALLSB);
252 	if (max_units > 255)
253 		superio_outb(tm>>8, WDTVALMSB);
254 }
255 
256 static int wdt_round_time(int t)
257 {
258 	t += 59;
259 	t -= t % 60;
260 	return t;
261 }
262 
263 /* watchdog timer handling */
264 
265 static void wdt_keepalive(void)
266 {
267 	if (test_bit(WDTS_USE_GP, &wdt_status))
268 		inb(base);
269 	else if (test_bit(WDTS_USE_CIR, &wdt_status))
270 		/* The timer reloads with around 5 msec delay */
271 		outb(0x55, CIR_DR(base));
272 	else {
273 		if (superio_enter())
274 			return;
275 
276 		superio_select(GPIO);
277 		wdt_update_timeout();
278 		superio_exit();
279 	}
280 	set_bit(WDTS_KEEPALIVE, &wdt_status);
281 }
282 
283 static int wdt_start(void)
284 {
285 	int ret = superio_enter();
286 	if (ret)
287 		return ret;
288 
289 	superio_select(GPIO);
290 	if (test_bit(WDTS_USE_GP, &wdt_status))
291 		superio_outb(WDT_GAMEPORT, WDTCTRL);
292 	else if (test_bit(WDTS_USE_CIR, &wdt_status))
293 		superio_outb(WDT_CIRINT, WDTCTRL);
294 	wdt_update_timeout();
295 
296 	superio_exit();
297 
298 	return 0;
299 }
300 
301 static int wdt_stop(void)
302 {
303 	int ret = superio_enter();
304 	if (ret)
305 		return ret;
306 
307 	superio_select(GPIO);
308 	superio_outb(0x00, WDTCTRL);
309 	superio_outb(WDT_TOV1, WDTCFG);
310 	superio_outb(0x00, WDTVALLSB);
311 	if (max_units > 255)
312 		superio_outb(0x00, WDTVALMSB);
313 
314 	superio_exit();
315 	return 0;
316 }
317 
318 /**
319  *	wdt_set_timeout - set a new timeout value with watchdog ioctl
320  *	@t: timeout value in seconds
321  *
322  *	The hardware device has a 8 or 16 bit watchdog timer (depends on
323  *	chip version) that can be configured to count seconds or minutes.
324  *
325  *	Used within WDIOC_SETTIMEOUT watchdog device ioctl.
326  */
327 
328 static int wdt_set_timeout(int t)
329 {
330 	if (t < 1 || t > max_units * 60)
331 		return -EINVAL;
332 
333 	if (t > max_units)
334 		timeout = wdt_round_time(t);
335 	else
336 		timeout = t;
337 
338 	if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
339 		int ret = superio_enter();
340 		if (ret)
341 			return ret;
342 
343 		superio_select(GPIO);
344 		wdt_update_timeout();
345 		superio_exit();
346 	}
347 	return 0;
348 }
349 
350 /**
351  *	wdt_get_status - determines the status supported by watchdog ioctl
352  *	@status: status returned to user space
353  *
354  *	The status bit of the device does not allow to distinguish
355  *	between a regular system reset and a watchdog forced reset.
356  *	But, in test mode it is useful, so it is supported through
357  *	WDIOC_GETSTATUS watchdog ioctl. Additionally the driver
358  *	reports the keepalive signal and the acception of the magic.
359  *
360  *	Used within WDIOC_GETSTATUS watchdog device ioctl.
361  */
362 
363 static int wdt_get_status(int *status)
364 {
365 	*status = 0;
366 	if (testmode) {
367 		int ret = superio_enter();
368 		if (ret)
369 			return ret;
370 
371 		superio_select(GPIO);
372 		if (superio_inb(WDTCTRL) & WDT_ZERO) {
373 			superio_outb(0x00, WDTCTRL);
374 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
375 			*status |= WDIOF_CARDRESET;
376 		}
377 
378 		superio_exit();
379 	}
380 	if (test_and_clear_bit(WDTS_KEEPALIVE, &wdt_status))
381 		*status |= WDIOF_KEEPALIVEPING;
382 	if (test_bit(WDTS_EXPECTED, &wdt_status))
383 		*status |= WDIOF_MAGICCLOSE;
384 	return 0;
385 }
386 
387 /* /dev/watchdog handling */
388 
389 /**
390  *	wdt_open - watchdog file_operations .open
391  *	@inode: inode of the device
392  *	@file: file handle to the device
393  *
394  *	The watchdog timer starts by opening the device.
395  *
396  *	Used within the file operation of the watchdog device.
397  */
398 
399 static int wdt_open(struct inode *inode, struct file *file)
400 {
401 	if (exclusive && test_and_set_bit(WDTS_DEV_OPEN, &wdt_status))
402 		return -EBUSY;
403 	if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
404 		int ret;
405 		if (nowayout && !test_and_set_bit(WDTS_LOCKED, &wdt_status))
406 			__module_get(THIS_MODULE);
407 
408 		ret = wdt_start();
409 		if (ret) {
410 			clear_bit(WDTS_LOCKED, &wdt_status);
411 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
412 			clear_bit(WDTS_DEV_OPEN, &wdt_status);
413 			return ret;
414 		}
415 	}
416 	return nonseekable_open(inode, file);
417 }
418 
419 /**
420  *	wdt_release - watchdog file_operations .release
421  *	@inode: inode of the device
422  *	@file: file handle to the device
423  *
424  *	Closing the watchdog device either stops the watchdog timer
425  *	or in the case, that nowayout is set or the magic character
426  *	wasn't written, a critical warning about an running watchdog
427  *	timer is given.
428  *
429  *	Used within the file operation of the watchdog device.
430  */
431 
432 static int wdt_release(struct inode *inode, struct file *file)
433 {
434 	if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
435 		if (test_and_clear_bit(WDTS_EXPECTED, &wdt_status)) {
436 			int ret = wdt_stop();
437 			if (ret) {
438 				/*
439 				 * Stop failed. Just keep the watchdog alive
440 				 * and hope nothing bad happens.
441 				 */
442 				set_bit(WDTS_EXPECTED, &wdt_status);
443 				wdt_keepalive();
444 				return ret;
445 			}
446 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
447 		} else {
448 			wdt_keepalive();
449 			pr_crit("unexpected close, not stopping watchdog!\n");
450 		}
451 	}
452 	clear_bit(WDTS_DEV_OPEN, &wdt_status);
453 	return 0;
454 }
455 
456 /**
457  *	wdt_write - watchdog file_operations .write
458  *	@file: file handle to the watchdog
459  *	@buf: buffer to write
460  *	@count: count of bytes
461  *	@ppos: pointer to the position to write. No seeks allowed
462  *
463  *	A write to a watchdog device is defined as a keepalive signal. Any
464  *	write of data will do, as we don't define content meaning.
465  *
466  *	Used within the file operation of the watchdog device.
467  */
468 
469 static ssize_t wdt_write(struct file *file, const char __user *buf,
470 			    size_t count, loff_t *ppos)
471 {
472 	if (count) {
473 		clear_bit(WDTS_EXPECTED, &wdt_status);
474 		wdt_keepalive();
475 	}
476 	if (!nowayout) {
477 		size_t ofs;
478 
479 	/* note: just in case someone wrote the magic character long ago */
480 		for (ofs = 0; ofs != count; ofs++) {
481 			char c;
482 			if (get_user(c, buf + ofs))
483 				return -EFAULT;
484 			if (c == WD_MAGIC)
485 				set_bit(WDTS_EXPECTED, &wdt_status);
486 		}
487 	}
488 	return count;
489 }
490 
491 static const struct watchdog_info ident = {
492 	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
493 	.firmware_version =	1,
494 	.identity = WATCHDOG_NAME,
495 };
496 
497 /**
498  *	wdt_ioctl - watchdog file_operations .unlocked_ioctl
499  *	@file: file handle to the device
500  *	@cmd: watchdog command
501  *	@arg: argument pointer
502  *
503  *	The watchdog API defines a common set of functions for all watchdogs
504  *	according to their available features.
505  *
506  *	Used within the file operation of the watchdog device.
507  */
508 
509 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
510 {
511 	int rc = 0, status, new_options, new_timeout;
512 	union {
513 		struct watchdog_info __user *ident;
514 		int __user *i;
515 	} uarg;
516 
517 	uarg.i = (int __user *)arg;
518 
519 	switch (cmd) {
520 	case WDIOC_GETSUPPORT:
521 		return copy_to_user(uarg.ident,
522 				    &ident, sizeof(ident)) ? -EFAULT : 0;
523 
524 	case WDIOC_GETSTATUS:
525 		rc = wdt_get_status(&status);
526 		if (rc)
527 			return rc;
528 		return put_user(status, uarg.i);
529 
530 	case WDIOC_GETBOOTSTATUS:
531 		return put_user(0, uarg.i);
532 
533 	case WDIOC_KEEPALIVE:
534 		wdt_keepalive();
535 		return 0;
536 
537 	case WDIOC_SETOPTIONS:
538 		if (get_user(new_options, uarg.i))
539 			return -EFAULT;
540 
541 		switch (new_options) {
542 		case WDIOS_DISABLECARD:
543 			if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
544 				rc = wdt_stop();
545 				if (rc)
546 					return rc;
547 			}
548 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
549 			return 0;
550 
551 		case WDIOS_ENABLECARD:
552 			if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
553 				rc = wdt_start();
554 				if (rc) {
555 					clear_bit(WDTS_TIMER_RUN, &wdt_status);
556 					return rc;
557 				}
558 			}
559 			return 0;
560 
561 		default:
562 			return -EFAULT;
563 		}
564 
565 	case WDIOC_SETTIMEOUT:
566 		if (get_user(new_timeout, uarg.i))
567 			return -EFAULT;
568 		rc = wdt_set_timeout(new_timeout);
569 	case WDIOC_GETTIMEOUT:
570 		if (put_user(timeout, uarg.i))
571 			return -EFAULT;
572 		return rc;
573 
574 	default:
575 		return -ENOTTY;
576 	}
577 }
578 
579 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
580 	void *unused)
581 {
582 	if (code == SYS_DOWN || code == SYS_HALT)
583 		wdt_stop();
584 	return NOTIFY_DONE;
585 }
586 
587 static const struct file_operations wdt_fops = {
588 	.owner		= THIS_MODULE,
589 	.llseek		= no_llseek,
590 	.write		= wdt_write,
591 	.unlocked_ioctl	= wdt_ioctl,
592 	.open		= wdt_open,
593 	.release	= wdt_release,
594 };
595 
596 static struct miscdevice wdt_miscdev = {
597 	.minor		= WATCHDOG_MINOR,
598 	.name		= "watchdog",
599 	.fops		= &wdt_fops,
600 };
601 
602 static struct notifier_block wdt_notifier = {
603 	.notifier_call = wdt_notify_sys,
604 };
605 
606 static int __init it87_wdt_init(void)
607 {
608 	int rc = 0;
609 	int try_gameport = !nogameport;
610 	u8  chip_rev;
611 	int gp_rreq_fail = 0;
612 
613 	wdt_status = 0;
614 
615 	rc = superio_enter();
616 	if (rc)
617 		return rc;
618 
619 	chip_type = superio_inw(CHIPID);
620 	chip_rev  = superio_inb(CHIPREV) & 0x0f;
621 	superio_exit();
622 
623 	switch (chip_type) {
624 	case IT8702_ID:
625 		max_units = 255;
626 		break;
627 	case IT8712_ID:
628 		max_units = (chip_rev < 8) ? 255 : 65535;
629 		break;
630 	case IT8716_ID:
631 	case IT8726_ID:
632 		max_units = 65535;
633 		break;
634 	case IT8620_ID:
635 	case IT8718_ID:
636 	case IT8720_ID:
637 	case IT8721_ID:
638 	case IT8728_ID:
639 	case IT8783_ID:
640 		max_units = 65535;
641 		try_gameport = 0;
642 		break;
643 	case IT8705_ID:
644 		pr_err("Unsupported Chip found, Chip %04x Revision %02x\n",
645 		       chip_type, chip_rev);
646 		return -ENODEV;
647 	case NO_DEV_ID:
648 		pr_err("no device\n");
649 		return -ENODEV;
650 	default:
651 		pr_err("Unknown Chip found, Chip %04x Revision %04x\n",
652 		       chip_type, chip_rev);
653 		return -ENODEV;
654 	}
655 
656 	rc = superio_enter();
657 	if (rc)
658 		return rc;
659 
660 	superio_select(GPIO);
661 	superio_outb(WDT_TOV1, WDTCFG);
662 	superio_outb(0x00, WDTCTRL);
663 
664 	/* First try to get Gameport support */
665 	if (try_gameport) {
666 		superio_select(GAMEPORT);
667 		base = superio_inw(BASEREG);
668 		if (!base) {
669 			base = GP_BASE_DEFAULT;
670 			superio_outw(base, BASEREG);
671 		}
672 		gpact = superio_inb(ACTREG);
673 		superio_outb(0x01, ACTREG);
674 		if (request_region(base, 1, WATCHDOG_NAME))
675 			set_bit(WDTS_USE_GP, &wdt_status);
676 		else
677 			gp_rreq_fail = 1;
678 	}
679 
680 	/* If we haven't Gameport support, try to get CIR support */
681 	if (!nocir && !test_bit(WDTS_USE_GP, &wdt_status)) {
682 		if (!request_region(CIR_BASE, 8, WATCHDOG_NAME)) {
683 			if (gp_rreq_fail)
684 				pr_err("I/O Address 0x%04x and 0x%04x already in use\n",
685 				       base, CIR_BASE);
686 			else
687 				pr_err("I/O Address 0x%04x already in use\n",
688 				       CIR_BASE);
689 			rc = -EIO;
690 			goto err_out;
691 		}
692 		base = CIR_BASE;
693 
694 		superio_select(CIR);
695 		superio_outw(base, BASEREG);
696 		superio_outb(0x00, CIR_ILS);
697 		ciract = superio_inb(ACTREG);
698 		superio_outb(0x01, ACTREG);
699 		if (gp_rreq_fail) {
700 			superio_select(GAMEPORT);
701 			superio_outb(gpact, ACTREG);
702 		}
703 		set_bit(WDTS_USE_CIR, &wdt_status);
704 	}
705 
706 	if (timeout < 1 || timeout > max_units * 60) {
707 		timeout = DEFAULT_TIMEOUT;
708 		pr_warn("Timeout value out of range, use default %d sec\n",
709 			DEFAULT_TIMEOUT);
710 	}
711 
712 	if (timeout > max_units)
713 		timeout = wdt_round_time(timeout);
714 
715 	rc = register_reboot_notifier(&wdt_notifier);
716 	if (rc) {
717 		pr_err("Cannot register reboot notifier (err=%d)\n", rc);
718 		goto err_out_region;
719 	}
720 
721 	rc = misc_register(&wdt_miscdev);
722 	if (rc) {
723 		pr_err("Cannot register miscdev on minor=%d (err=%d)\n",
724 		       wdt_miscdev.minor, rc);
725 		goto err_out_reboot;
726 	}
727 
728 	/* Initialize CIR to use it as keepalive source */
729 	if (test_bit(WDTS_USE_CIR, &wdt_status)) {
730 		outb(0x00, CIR_RCR(base));
731 		outb(0xc0, CIR_TCR1(base));
732 		outb(0x5c, CIR_TCR2(base));
733 		outb(0x10, CIR_IER(base));
734 		outb(0x00, CIR_BDHR(base));
735 		outb(0x01, CIR_BDLR(base));
736 		outb(0x09, CIR_IER(base));
737 	}
738 
739 	pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d exclusive=%d nogameport=%d nocir=%d)\n",
740 		chip_type, chip_rev, timeout,
741 		nowayout, testmode, exclusive, nogameport, nocir);
742 
743 	superio_exit();
744 	return 0;
745 
746 err_out_reboot:
747 	unregister_reboot_notifier(&wdt_notifier);
748 err_out_region:
749 	if (test_bit(WDTS_USE_GP, &wdt_status))
750 		release_region(base, 1);
751 	else if (test_bit(WDTS_USE_CIR, &wdt_status)) {
752 		release_region(base, 8);
753 		superio_select(CIR);
754 		superio_outb(ciract, ACTREG);
755 	}
756 err_out:
757 	if (try_gameport) {
758 		superio_select(GAMEPORT);
759 		superio_outb(gpact, ACTREG);
760 	}
761 
762 	superio_exit();
763 	return rc;
764 }
765 
766 static void __exit it87_wdt_exit(void)
767 {
768 	if (superio_enter() == 0) {
769 		superio_select(GPIO);
770 		superio_outb(0x00, WDTCTRL);
771 		superio_outb(0x00, WDTCFG);
772 		superio_outb(0x00, WDTVALLSB);
773 		if (max_units > 255)
774 			superio_outb(0x00, WDTVALMSB);
775 		if (test_bit(WDTS_USE_GP, &wdt_status)) {
776 			superio_select(GAMEPORT);
777 			superio_outb(gpact, ACTREG);
778 		} else if (test_bit(WDTS_USE_CIR, &wdt_status)) {
779 			superio_select(CIR);
780 			superio_outb(ciract, ACTREG);
781 		}
782 		superio_exit();
783 	}
784 
785 	misc_deregister(&wdt_miscdev);
786 	unregister_reboot_notifier(&wdt_notifier);
787 
788 	if (test_bit(WDTS_USE_GP, &wdt_status))
789 		release_region(base, 1);
790 	else if (test_bit(WDTS_USE_CIR, &wdt_status))
791 		release_region(base, 8);
792 }
793 
794 module_init(it87_wdt_init);
795 module_exit(it87_wdt_exit);
796 
797 MODULE_AUTHOR("Oliver Schuster");
798 MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O");
799 MODULE_LICENSE("GPL");
800