xref: /openbmc/linux/drivers/watchdog/it87_wdt.c (revision 615c36f5)
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 and IT8726.
16  *
17  *	This program is free software; you can redistribute it and/or
18  *	modify it under the terms of the GNU General Public License
19  *	as published by the Free Software Foundation; either version
20  *	2 of the License, or (at your option) any later version.
21  *
22  *	This program is distributed in the hope that it will be useful,
23  *	but WITHOUT ANY WARRANTY; without even the implied warranty of
24  *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
25  *	GNU General Public License for more details.
26  *
27  *	You should have received a copy of the GNU General Public License
28  *	along with this program; if not, write to the Free Software
29  *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
30  */
31 
32 #include <linux/module.h>
33 #include <linux/moduleparam.h>
34 #include <linux/types.h>
35 #include <linux/kernel.h>
36 #include <linux/fs.h>
37 #include <linux/miscdevice.h>
38 #include <linux/init.h>
39 #include <linux/ioport.h>
40 #include <linux/watchdog.h>
41 #include <linux/notifier.h>
42 #include <linux/reboot.h>
43 #include <linux/uaccess.h>
44 #include <linux/io.h>
45 
46 #include <asm/system.h>
47 
48 #define WATCHDOG_VERSION	"1.14"
49 #define WATCHDOG_NAME		"IT87 WDT"
50 #define PFX			WATCHDOG_NAME ": "
51 #define DRIVER_VERSION		WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
52 #define WD_MAGIC		'V'
53 
54 /* Defaults for Module Parameter */
55 #define DEFAULT_NOGAMEPORT	0
56 #define DEFAULT_EXCLUSIVE	1
57 #define DEFAULT_TIMEOUT		60
58 #define DEFAULT_TESTMODE	0
59 #define DEFAULT_NOWAYOUT	WATCHDOG_NOWAYOUT
60 
61 /* IO Ports */
62 #define REG		0x2e
63 #define VAL		0x2f
64 
65 /* Logical device Numbers LDN */
66 #define GPIO		0x07
67 #define GAMEPORT	0x09
68 #define CIR		0x0a
69 
70 /* Configuration Registers and Functions */
71 #define LDNREG		0x07
72 #define CHIPID		0x20
73 #define CHIPREV		0x22
74 #define ACTREG		0x30
75 #define BASEREG		0x60
76 
77 /* Chip Id numbers */
78 #define NO_DEV_ID	0xffff
79 #define IT8702_ID	0x8702
80 #define IT8705_ID	0x8705
81 #define IT8712_ID	0x8712
82 #define IT8716_ID	0x8716
83 #define IT8718_ID	0x8718
84 #define IT8720_ID	0x8720
85 #define IT8721_ID	0x8721
86 #define IT8726_ID	0x8726	/* the data sheet suggest wrongly 0x8716 */
87 
88 /* GPIO Configuration Registers LDN=0x07 */
89 #define WDTCTRL		0x71
90 #define WDTCFG		0x72
91 #define WDTVALLSB	0x73
92 #define WDTVALMSB	0x74
93 
94 /* GPIO Bits WDTCTRL */
95 #define WDT_CIRINT	0x80
96 #define WDT_MOUSEINT	0x40
97 #define WDT_KYBINT	0x20
98 #define WDT_GAMEPORT	0x10 /* not in it8718, it8720, it8721 */
99 #define WDT_FORCE	0x02
100 #define WDT_ZERO	0x01
101 
102 /* GPIO Bits WDTCFG */
103 #define WDT_TOV1	0x80
104 #define WDT_KRST	0x40
105 #define WDT_TOVE	0x20
106 #define WDT_PWROK	0x10 /* not in it8721 */
107 #define WDT_INT_MASK	0x0f
108 
109 /* CIR Configuration Register LDN=0x0a */
110 #define CIR_ILS		0x70
111 
112 /* The default Base address is not always available, we use this */
113 #define CIR_BASE	0x0208
114 
115 /* CIR Controller */
116 #define CIR_DR(b)	(b)
117 #define CIR_IER(b)	(b + 1)
118 #define CIR_RCR(b)	(b + 2)
119 #define CIR_TCR1(b)	(b + 3)
120 #define CIR_TCR2(b)	(b + 4)
121 #define CIR_TSR(b)	(b + 5)
122 #define CIR_RSR(b)	(b + 6)
123 #define CIR_BDLR(b)	(b + 5)
124 #define CIR_BDHR(b)	(b + 6)
125 #define CIR_IIR(b)	(b + 7)
126 
127 /* Default Base address of Game port */
128 #define GP_BASE_DEFAULT	0x0201
129 
130 /* wdt_status */
131 #define WDTS_TIMER_RUN	0
132 #define WDTS_DEV_OPEN	1
133 #define WDTS_KEEPALIVE	2
134 #define WDTS_LOCKED	3
135 #define WDTS_USE_GP	4
136 #define WDTS_EXPECTED	5
137 
138 static	unsigned int base, gpact, ciract, max_units, chip_type;
139 static	unsigned long wdt_status;
140 
141 static	int nogameport = DEFAULT_NOGAMEPORT;
142 static	int exclusive  = DEFAULT_EXCLUSIVE;
143 static	int timeout    = DEFAULT_TIMEOUT;
144 static	int testmode   = DEFAULT_TESTMODE;
145 static	int nowayout   = DEFAULT_NOWAYOUT;
146 
147 module_param(nogameport, int, 0);
148 MODULE_PARM_DESC(nogameport, "Forbid the activation of game port, default="
149 		__MODULE_STRING(DEFAULT_NOGAMEPORT));
150 module_param(exclusive, int, 0);
151 MODULE_PARM_DESC(exclusive, "Watchdog exclusive device open, default="
152 		__MODULE_STRING(DEFAULT_EXCLUSIVE));
153 module_param(timeout, int, 0);
154 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default="
155 		__MODULE_STRING(DEFAULT_TIMEOUT));
156 module_param(testmode, int, 0);
157 MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default="
158 		__MODULE_STRING(DEFAULT_TESTMODE));
159 module_param(nowayout, int, 0);
160 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default="
161 		__MODULE_STRING(WATCHDOG_NOWAYOUT));
162 
163 /* Superio Chip */
164 
165 static inline int superio_enter(void)
166 {
167 	/*
168 	 * Try to reserve REG and REG + 1 for exclusive access.
169 	 */
170 	if (!request_muxed_region(REG, 2, WATCHDOG_NAME))
171 		return -EBUSY;
172 
173 	outb(0x87, REG);
174 	outb(0x01, REG);
175 	outb(0x55, REG);
176 	outb(0x55, REG);
177 	return 0;
178 }
179 
180 static inline void superio_exit(void)
181 {
182 	outb(0x02, REG);
183 	outb(0x02, VAL);
184 	release_region(REG, 2);
185 }
186 
187 static inline void superio_select(int ldn)
188 {
189 	outb(LDNREG, REG);
190 	outb(ldn, VAL);
191 }
192 
193 static inline int superio_inb(int reg)
194 {
195 	outb(reg, REG);
196 	return inb(VAL);
197 }
198 
199 static inline void superio_outb(int val, int reg)
200 {
201 	outb(reg, REG);
202 	outb(val, VAL);
203 }
204 
205 static inline int superio_inw(int reg)
206 {
207 	int val;
208 	outb(reg++, REG);
209 	val = inb(VAL) << 8;
210 	outb(reg, REG);
211 	val |= inb(VAL);
212 	return val;
213 }
214 
215 static inline void superio_outw(int val, int reg)
216 {
217 	outb(reg++, REG);
218 	outb(val >> 8, VAL);
219 	outb(reg, REG);
220 	outb(val, VAL);
221 }
222 
223 /* Internal function, should be called after superio_select(GPIO) */
224 static void wdt_update_timeout(void)
225 {
226 	unsigned char cfg = WDT_KRST;
227 	int tm = timeout;
228 
229 	if (testmode)
230 		cfg = 0;
231 
232 	if (tm <= max_units)
233 		cfg |= WDT_TOV1;
234 	else
235 		tm /= 60;
236 
237 	if (chip_type != IT8721_ID)
238 		cfg |= WDT_PWROK;
239 
240 	superio_outb(cfg, WDTCFG);
241 	superio_outb(tm, WDTVALLSB);
242 	if (max_units > 255)
243 		superio_outb(tm>>8, WDTVALMSB);
244 }
245 
246 static int wdt_round_time(int t)
247 {
248 	t += 59;
249 	t -= t % 60;
250 	return t;
251 }
252 
253 /* watchdog timer handling */
254 
255 static void wdt_keepalive(void)
256 {
257 	if (test_bit(WDTS_USE_GP, &wdt_status))
258 		inb(base);
259 	else
260 		/* The timer reloads with around 5 msec delay */
261 		outb(0x55, CIR_DR(base));
262 	set_bit(WDTS_KEEPALIVE, &wdt_status);
263 }
264 
265 static int wdt_start(void)
266 {
267 	int ret = superio_enter();
268 	if (ret)
269 		return ret;
270 
271 	superio_select(GPIO);
272 	if (test_bit(WDTS_USE_GP, &wdt_status))
273 		superio_outb(WDT_GAMEPORT, WDTCTRL);
274 	else
275 		superio_outb(WDT_CIRINT, WDTCTRL);
276 	wdt_update_timeout();
277 
278 	superio_exit();
279 
280 	return 0;
281 }
282 
283 static int wdt_stop(void)
284 {
285 	int ret = superio_enter();
286 	if (ret)
287 		return ret;
288 
289 	superio_select(GPIO);
290 	superio_outb(0x00, WDTCTRL);
291 	superio_outb(WDT_TOV1, WDTCFG);
292 	superio_outb(0x00, WDTVALLSB);
293 	if (max_units > 255)
294 		superio_outb(0x00, WDTVALMSB);
295 
296 	superio_exit();
297 	return 0;
298 }
299 
300 /**
301  *	wdt_set_timeout - set a new timeout value with watchdog ioctl
302  *	@t: timeout value in seconds
303  *
304  *	The hardware device has a 8 or 16 bit watchdog timer (depends on
305  *	chip version) that can be configured to count seconds or minutes.
306  *
307  *	Used within WDIOC_SETTIMEOUT watchdog device ioctl.
308  */
309 
310 static int wdt_set_timeout(int t)
311 {
312 	if (t < 1 || t > max_units * 60)
313 		return -EINVAL;
314 
315 	if (t > max_units)
316 		timeout = wdt_round_time(t);
317 	else
318 		timeout = t;
319 
320 	if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
321 		int ret = superio_enter();
322 		if (ret)
323 			return ret;
324 
325 		superio_select(GPIO);
326 		wdt_update_timeout();
327 		superio_exit();
328 	}
329 	return 0;
330 }
331 
332 /**
333  *	wdt_get_status - determines the status supported by watchdog ioctl
334  *	@status: status returned to user space
335  *
336  *	The status bit of the device does not allow to distinguish
337  *	between a regular system reset and a watchdog forced reset.
338  *	But, in test mode it is useful, so it is supported through
339  *	WDIOC_GETSTATUS watchdog ioctl. Additionally the driver
340  *	reports the keepalive signal and the acception of the magic.
341  *
342  *	Used within WDIOC_GETSTATUS watchdog device ioctl.
343  */
344 
345 static int wdt_get_status(int *status)
346 {
347 	*status = 0;
348 	if (testmode) {
349 		int ret = superio_enter();
350 		if (ret)
351 			return ret;
352 
353 		superio_select(GPIO);
354 		if (superio_inb(WDTCTRL) & WDT_ZERO) {
355 			superio_outb(0x00, WDTCTRL);
356 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
357 			*status |= WDIOF_CARDRESET;
358 		}
359 
360 		superio_exit();
361 	}
362 	if (test_and_clear_bit(WDTS_KEEPALIVE, &wdt_status))
363 		*status |= WDIOF_KEEPALIVEPING;
364 	if (test_bit(WDTS_EXPECTED, &wdt_status))
365 		*status |= WDIOF_MAGICCLOSE;
366 	return 0;
367 }
368 
369 /* /dev/watchdog handling */
370 
371 /**
372  *	wdt_open - watchdog file_operations .open
373  *	@inode: inode of the device
374  *	@file: file handle to the device
375  *
376  *	The watchdog timer starts by opening the device.
377  *
378  *	Used within the file operation of the watchdog device.
379  */
380 
381 static int wdt_open(struct inode *inode, struct file *file)
382 {
383 	if (exclusive && test_and_set_bit(WDTS_DEV_OPEN, &wdt_status))
384 		return -EBUSY;
385 	if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
386 		int ret;
387 		if (nowayout && !test_and_set_bit(WDTS_LOCKED, &wdt_status))
388 			__module_get(THIS_MODULE);
389 
390 		ret = wdt_start();
391 		if (ret) {
392 			clear_bit(WDTS_LOCKED, &wdt_status);
393 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
394 			clear_bit(WDTS_DEV_OPEN, &wdt_status);
395 			return ret;
396 		}
397 	}
398 	return nonseekable_open(inode, file);
399 }
400 
401 /**
402  *	wdt_release - watchdog file_operations .release
403  *	@inode: inode of the device
404  *	@file: file handle to the device
405  *
406  *	Closing the watchdog device either stops the watchdog timer
407  *	or in the case, that nowayout is set or the magic character
408  *	wasn't written, a critical warning about an running watchdog
409  *	timer is given.
410  *
411  *	Used within the file operation of the watchdog device.
412  */
413 
414 static int wdt_release(struct inode *inode, struct file *file)
415 {
416 	if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
417 		if (test_and_clear_bit(WDTS_EXPECTED, &wdt_status)) {
418 			int ret = wdt_stop();
419 			if (ret) {
420 				/*
421 				 * Stop failed. Just keep the watchdog alive
422 				 * and hope nothing bad happens.
423 				 */
424 				set_bit(WDTS_EXPECTED, &wdt_status);
425 				wdt_keepalive();
426 				return ret;
427 			}
428 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
429 		} else {
430 			wdt_keepalive();
431 			printk(KERN_CRIT PFX
432 			       "unexpected close, not stopping watchdog!\n");
433 		}
434 	}
435 	clear_bit(WDTS_DEV_OPEN, &wdt_status);
436 	return 0;
437 }
438 
439 /**
440  *	wdt_write - watchdog file_operations .write
441  *	@file: file handle to the watchdog
442  *	@buf: buffer to write
443  *	@count: count of bytes
444  *	@ppos: pointer to the position to write. No seeks allowed
445  *
446  *	A write to a watchdog device is defined as a keepalive signal. Any
447  *	write of data will do, as we don't define content meaning.
448  *
449  *	Used within the file operation of the watchdog device.
450  */
451 
452 static ssize_t wdt_write(struct file *file, const char __user *buf,
453 			    size_t count, loff_t *ppos)
454 {
455 	if (count) {
456 		clear_bit(WDTS_EXPECTED, &wdt_status);
457 		wdt_keepalive();
458 	}
459 	if (!nowayout) {
460 		size_t ofs;
461 
462 	/* note: just in case someone wrote the magic character long ago */
463 		for (ofs = 0; ofs != count; ofs++) {
464 			char c;
465 			if (get_user(c, buf + ofs))
466 				return -EFAULT;
467 			if (c == WD_MAGIC)
468 				set_bit(WDTS_EXPECTED, &wdt_status);
469 		}
470 	}
471 	return count;
472 }
473 
474 static const struct watchdog_info ident = {
475 	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
476 	.firmware_version =	1,
477 	.identity = WATCHDOG_NAME,
478 };
479 
480 /**
481  *	wdt_ioctl - watchdog file_operations .unlocked_ioctl
482  *	@file: file handle to the device
483  *	@cmd: watchdog command
484  *	@arg: argument pointer
485  *
486  *	The watchdog API defines a common set of functions for all watchdogs
487  *	according to their available features.
488  *
489  *	Used within the file operation of the watchdog device.
490  */
491 
492 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
493 {
494 	int rc = 0, status, new_options, new_timeout;
495 	union {
496 		struct watchdog_info __user *ident;
497 		int __user *i;
498 	} uarg;
499 
500 	uarg.i = (int __user *)arg;
501 
502 	switch (cmd) {
503 	case WDIOC_GETSUPPORT:
504 		return copy_to_user(uarg.ident,
505 				    &ident, sizeof(ident)) ? -EFAULT : 0;
506 
507 	case WDIOC_GETSTATUS:
508 		rc = wdt_get_status(&status);
509 		if (rc)
510 			return rc;
511 		return put_user(status, uarg.i);
512 
513 	case WDIOC_GETBOOTSTATUS:
514 		return put_user(0, uarg.i);
515 
516 	case WDIOC_KEEPALIVE:
517 		wdt_keepalive();
518 		return 0;
519 
520 	case WDIOC_SETOPTIONS:
521 		if (get_user(new_options, uarg.i))
522 			return -EFAULT;
523 
524 		switch (new_options) {
525 		case WDIOS_DISABLECARD:
526 			if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
527 				rc = wdt_stop();
528 				if (rc)
529 					return rc;
530 			}
531 			clear_bit(WDTS_TIMER_RUN, &wdt_status);
532 			return 0;
533 
534 		case WDIOS_ENABLECARD:
535 			if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
536 				rc = wdt_start();
537 				if (rc) {
538 					clear_bit(WDTS_TIMER_RUN, &wdt_status);
539 					return rc;
540 				}
541 			}
542 			return 0;
543 
544 		default:
545 			return -EFAULT;
546 		}
547 
548 	case WDIOC_SETTIMEOUT:
549 		if (get_user(new_timeout, uarg.i))
550 			return -EFAULT;
551 		rc = wdt_set_timeout(new_timeout);
552 	case WDIOC_GETTIMEOUT:
553 		if (put_user(timeout, uarg.i))
554 			return -EFAULT;
555 		return rc;
556 
557 	default:
558 		return -ENOTTY;
559 	}
560 }
561 
562 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
563 	void *unused)
564 {
565 	if (code == SYS_DOWN || code == SYS_HALT)
566 		wdt_stop();
567 	return NOTIFY_DONE;
568 }
569 
570 static const struct file_operations wdt_fops = {
571 	.owner		= THIS_MODULE,
572 	.llseek		= no_llseek,
573 	.write		= wdt_write,
574 	.unlocked_ioctl	= wdt_ioctl,
575 	.open		= wdt_open,
576 	.release	= wdt_release,
577 };
578 
579 static struct miscdevice wdt_miscdev = {
580 	.minor		= WATCHDOG_MINOR,
581 	.name		= "watchdog",
582 	.fops		= &wdt_fops,
583 };
584 
585 static struct notifier_block wdt_notifier = {
586 	.notifier_call = wdt_notify_sys,
587 };
588 
589 static int __init it87_wdt_init(void)
590 {
591 	int rc = 0;
592 	int try_gameport = !nogameport;
593 	u8  chip_rev;
594 	int gp_rreq_fail = 0;
595 
596 	wdt_status = 0;
597 
598 	rc = superio_enter();
599 	if (rc)
600 		return rc;
601 
602 	chip_type = superio_inw(CHIPID);
603 	chip_rev  = superio_inb(CHIPREV) & 0x0f;
604 	superio_exit();
605 
606 	switch (chip_type) {
607 	case IT8702_ID:
608 		max_units = 255;
609 		break;
610 	case IT8712_ID:
611 		max_units = (chip_rev < 8) ? 255 : 65535;
612 		break;
613 	case IT8716_ID:
614 	case IT8726_ID:
615 		max_units = 65535;
616 		break;
617 	case IT8718_ID:
618 	case IT8720_ID:
619 	case IT8721_ID:
620 		max_units = 65535;
621 		try_gameport = 0;
622 		break;
623 	case IT8705_ID:
624 		printk(KERN_ERR PFX
625 		       "Unsupported Chip found, Chip %04x Revision %02x\n",
626 		       chip_type, chip_rev);
627 		return -ENODEV;
628 	case NO_DEV_ID:
629 		printk(KERN_ERR PFX "no device\n");
630 		return -ENODEV;
631 	default:
632 		printk(KERN_ERR PFX
633 		       "Unknown Chip found, Chip %04x Revision %04x\n",
634 		       chip_type, chip_rev);
635 		return -ENODEV;
636 	}
637 
638 	rc = superio_enter();
639 	if (rc)
640 		return rc;
641 
642 	superio_select(GPIO);
643 	superio_outb(WDT_TOV1, WDTCFG);
644 	superio_outb(0x00, WDTCTRL);
645 
646 	/* First try to get Gameport support */
647 	if (try_gameport) {
648 		superio_select(GAMEPORT);
649 		base = superio_inw(BASEREG);
650 		if (!base) {
651 			base = GP_BASE_DEFAULT;
652 			superio_outw(base, BASEREG);
653 		}
654 		gpact = superio_inb(ACTREG);
655 		superio_outb(0x01, ACTREG);
656 		if (request_region(base, 1, WATCHDOG_NAME))
657 			set_bit(WDTS_USE_GP, &wdt_status);
658 		else
659 			gp_rreq_fail = 1;
660 	}
661 
662 	/* If we haven't Gameport support, try to get CIR support */
663 	if (!test_bit(WDTS_USE_GP, &wdt_status)) {
664 		if (!request_region(CIR_BASE, 8, WATCHDOG_NAME)) {
665 			if (gp_rreq_fail)
666 				printk(KERN_ERR PFX
667 					"I/O Address 0x%04x and 0x%04x"
668 					" already in use\n", base, CIR_BASE);
669 			else
670 				printk(KERN_ERR PFX
671 					"I/O Address 0x%04x already in use\n",
672 					CIR_BASE);
673 			rc = -EIO;
674 			goto err_out;
675 		}
676 		base = CIR_BASE;
677 
678 		superio_select(CIR);
679 		superio_outw(base, BASEREG);
680 		superio_outb(0x00, CIR_ILS);
681 		ciract = superio_inb(ACTREG);
682 		superio_outb(0x01, ACTREG);
683 		if (gp_rreq_fail) {
684 			superio_select(GAMEPORT);
685 			superio_outb(gpact, ACTREG);
686 		}
687 	}
688 
689 	if (timeout < 1 || timeout > max_units * 60) {
690 		timeout = DEFAULT_TIMEOUT;
691 		printk(KERN_WARNING PFX
692 		       "Timeout value out of range, use default %d sec\n",
693 		       DEFAULT_TIMEOUT);
694 	}
695 
696 	if (timeout > max_units)
697 		timeout = wdt_round_time(timeout);
698 
699 	rc = register_reboot_notifier(&wdt_notifier);
700 	if (rc) {
701 		printk(KERN_ERR PFX
702 		       "Cannot register reboot notifier (err=%d)\n", rc);
703 		goto err_out_region;
704 	}
705 
706 	rc = misc_register(&wdt_miscdev);
707 	if (rc) {
708 		printk(KERN_ERR PFX
709 		       "Cannot register miscdev on minor=%d (err=%d)\n",
710 			wdt_miscdev.minor, rc);
711 		goto err_out_reboot;
712 	}
713 
714 	/* Initialize CIR to use it as keepalive source */
715 	if (!test_bit(WDTS_USE_GP, &wdt_status)) {
716 		outb(0x00, CIR_RCR(base));
717 		outb(0xc0, CIR_TCR1(base));
718 		outb(0x5c, CIR_TCR2(base));
719 		outb(0x10, CIR_IER(base));
720 		outb(0x00, CIR_BDHR(base));
721 		outb(0x01, CIR_BDLR(base));
722 		outb(0x09, CIR_IER(base));
723 	}
724 
725 	printk(KERN_INFO PFX "Chip IT%04x revision %d initialized. "
726 		"timeout=%d sec (nowayout=%d testmode=%d exclusive=%d "
727 		"nogameport=%d)\n", chip_type, chip_rev, timeout,
728 		nowayout, testmode, exclusive, nogameport);
729 
730 	superio_exit();
731 	return 0;
732 
733 err_out_reboot:
734 	unregister_reboot_notifier(&wdt_notifier);
735 err_out_region:
736 	release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8);
737 	if (!test_bit(WDTS_USE_GP, &wdt_status)) {
738 		superio_select(CIR);
739 		superio_outb(ciract, ACTREG);
740 	}
741 err_out:
742 	if (try_gameport) {
743 		superio_select(GAMEPORT);
744 		superio_outb(gpact, ACTREG);
745 	}
746 
747 	superio_exit();
748 	return rc;
749 }
750 
751 static void __exit it87_wdt_exit(void)
752 {
753 	if (superio_enter() == 0) {
754 		superio_select(GPIO);
755 		superio_outb(0x00, WDTCTRL);
756 		superio_outb(0x00, WDTCFG);
757 		superio_outb(0x00, WDTVALLSB);
758 		if (max_units > 255)
759 			superio_outb(0x00, WDTVALMSB);
760 		if (test_bit(WDTS_USE_GP, &wdt_status)) {
761 			superio_select(GAMEPORT);
762 			superio_outb(gpact, ACTREG);
763 		} else {
764 			superio_select(CIR);
765 			superio_outb(ciract, ACTREG);
766 		}
767 		superio_exit();
768 	}
769 
770 	misc_deregister(&wdt_miscdev);
771 	unregister_reboot_notifier(&wdt_notifier);
772 	release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8);
773 }
774 
775 module_init(it87_wdt_init);
776 module_exit(it87_wdt_exit);
777 
778 MODULE_AUTHOR("Oliver Schuster");
779 MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O");
780 MODULE_LICENSE("GPL");
781 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
782