1 /***************************************************************************
2  *   Copyright (C) 2006 by Hans Edgington <hans@edgington.nl>              *
3  *   Copyright (C) 2007-2009 Hans de Goede <hdegoede@redhat.com>           *
4  *   Copyright (C) 2010 Giel van Schijndel <me@mortis.eu>                  *
5  *                                                                         *
6  *   This program is free software; you can redistribute it and/or modify  *
7  *   it under the terms of the GNU General Public License as published by  *
8  *   the Free Software Foundation; either version 2 of the License, or     *
9  *   (at your option) any later version.                                   *
10  *                                                                         *
11  *   This program is distributed in the hope that it will be useful,       *
12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
14  *   GNU General Public License for more details.                          *
15  *                                                                         *
16  *   You should have received a copy of the GNU General Public License     *
17  *   along with this program; if not, write to the                         *
18  *   Free Software Foundation, Inc.,                                       *
19  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
20  ***************************************************************************/
21 
22 #include <linux/err.h>
23 #include <linux/fs.h>
24 #include <linux/init.h>
25 #include <linux/io.h>
26 #include <linux/ioport.h>
27 #include <linux/miscdevice.h>
28 #include <linux/module.h>
29 #include <linux/mutex.h>
30 #include <linux/notifier.h>
31 #include <linux/reboot.h>
32 #include <linux/uaccess.h>
33 #include <linux/watchdog.h>
34 
35 #define DRVNAME "f71808e_wdt"
36 
37 #define SIO_F71808FG_LD_WDT	0x07	/* Watchdog timer logical device */
38 #define SIO_UNLOCK_KEY		0x87	/* Key to enable Super-I/O */
39 #define SIO_LOCK_KEY		0xAA	/* Key to diasble Super-I/O */
40 
41 #define SIO_REG_LDSEL		0x07	/* Logical device select */
42 #define SIO_REG_DEVID		0x20	/* Device ID (2 bytes) */
43 #define SIO_REG_DEVREV		0x22	/* Device revision */
44 #define SIO_REG_MANID		0x23	/* Fintek ID (2 bytes) */
45 #define SIO_REG_ROM_ADDR_SEL	0x27	/* ROM address select */
46 #define SIO_REG_MFUNCT1		0x29	/* Multi function select 1 */
47 #define SIO_REG_MFUNCT2		0x2a	/* Multi function select 2 */
48 #define SIO_REG_MFUNCT3		0x2b	/* Multi function select 3 */
49 #define SIO_REG_ENABLE		0x30	/* Logical device enable */
50 #define SIO_REG_ADDR		0x60	/* Logical device address (2 bytes) */
51 
52 #define SIO_FINTEK_ID		0x1934	/* Manufacturers ID */
53 #define SIO_F71808_ID		0x0901	/* Chipset ID */
54 #define SIO_F71858_ID		0x0507	/* Chipset ID */
55 #define SIO_F71862_ID		0x0601	/* Chipset ID */
56 #define SIO_F71869_ID		0x0814	/* Chipset ID */
57 #define SIO_F71882_ID		0x0541	/* Chipset ID */
58 #define SIO_F71889_ID		0x0723	/* Chipset ID */
59 
60 #define F71808FG_REG_WDO_CONF		0xf0
61 #define F71808FG_REG_WDT_CONF		0xf5
62 #define F71808FG_REG_WD_TIME		0xf6
63 
64 #define F71808FG_FLAG_WDOUT_EN		7
65 
66 #define F71808FG_FLAG_WDTMOUT_STS	5
67 #define F71808FG_FLAG_WD_EN		5
68 #define F71808FG_FLAG_WD_PULSE		4
69 #define F71808FG_FLAG_WD_UNIT		3
70 
71 /* Default values */
72 #define WATCHDOG_TIMEOUT	60	/* 1 minute default timeout */
73 #define WATCHDOG_MAX_TIMEOUT	(60 * 255)
74 #define WATCHDOG_PULSE_WIDTH	125	/* 125 ms, default pulse width for
75 					   watchdog signal */
76 #define WATCHDOG_F71862FG_PIN	63	/* default watchdog reset output
77 					   pin number 63 */
78 
79 static unsigned short force_id;
80 module_param(force_id, ushort, 0);
81 MODULE_PARM_DESC(force_id, "Override the detected device ID");
82 
83 static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
84 static int timeout = WATCHDOG_TIMEOUT;	/* default timeout in seconds */
85 module_param(timeout, int, 0);
86 MODULE_PARM_DESC(timeout,
87 	"Watchdog timeout in seconds. 1<= timeout <="
88 			__MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
89 			__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
90 
91 static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
92 module_param(pulse_width, uint, 0);
93 MODULE_PARM_DESC(pulse_width,
94 	"Watchdog signal pulse width. 0(=level), 1 ms, 25 ms, 125 ms or 5000 ms"
95 			" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");
96 
97 static unsigned int f71862fg_pin = WATCHDOG_F71862FG_PIN;
98 module_param(f71862fg_pin, uint, 0);
99 MODULE_PARM_DESC(f71862fg_pin,
100 	"Watchdog f71862fg reset output pin configuration. Choose pin 56 or 63"
101 			" (default=" __MODULE_STRING(WATCHDOG_F71862FG_PIN)")");
102 
103 static int nowayout = WATCHDOG_NOWAYOUT;
104 module_param(nowayout, bool, 0444);
105 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
106 
107 static unsigned int start_withtimeout;
108 module_param(start_withtimeout, uint, 0);
109 MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
110 	" given initial timeout. Zero (default) disables this feature.");
111 
112 enum chips { f71808fg, f71858fg, f71862fg, f71869, f71882fg, f71889fg };
113 
114 static const char *f71808e_names[] = {
115 	"f71808fg",
116 	"f71858fg",
117 	"f71862fg",
118 	"f71869",
119 	"f71882fg",
120 	"f71889fg",
121 };
122 
123 /* Super-I/O Function prototypes */
124 static inline int superio_inb(int base, int reg);
125 static inline int superio_inw(int base, int reg);
126 static inline void superio_outb(int base, int reg, u8 val);
127 static inline void superio_set_bit(int base, int reg, int bit);
128 static inline void superio_clear_bit(int base, int reg, int bit);
129 static inline int superio_enter(int base);
130 static inline void superio_select(int base, int ld);
131 static inline void superio_exit(int base);
132 
133 struct watchdog_data {
134 	unsigned short	sioaddr;
135 	enum chips	type;
136 	unsigned long	opened;
137 	struct mutex	lock;
138 	char		expect_close;
139 	struct watchdog_info ident;
140 
141 	unsigned short	timeout;
142 	u8		timer_val;	/* content for the wd_time register */
143 	char		minutes_mode;
144 	u8		pulse_val;	/* pulse width flag */
145 	char		pulse_mode;	/* enable pulse output mode? */
146 	char		caused_reboot;	/* last reboot was by the watchdog */
147 };
148 
149 static struct watchdog_data watchdog = {
150 	.lock = __MUTEX_INITIALIZER(watchdog.lock),
151 };
152 
153 /* Super I/O functions */
154 static inline int superio_inb(int base, int reg)
155 {
156 	outb(reg, base);
157 	return inb(base + 1);
158 }
159 
160 static int superio_inw(int base, int reg)
161 {
162 	int val;
163 	val  = superio_inb(base, reg) << 8;
164 	val |= superio_inb(base, reg + 1);
165 	return val;
166 }
167 
168 static inline void superio_outb(int base, int reg, u8 val)
169 {
170 	outb(reg, base);
171 	outb(val, base + 1);
172 }
173 
174 static inline void superio_set_bit(int base, int reg, int bit)
175 {
176 	unsigned long val = superio_inb(base, reg);
177 	__set_bit(bit, &val);
178 	superio_outb(base, reg, val);
179 }
180 
181 static inline void superio_clear_bit(int base, int reg, int bit)
182 {
183 	unsigned long val = superio_inb(base, reg);
184 	__clear_bit(bit, &val);
185 	superio_outb(base, reg, val);
186 }
187 
188 static inline int superio_enter(int base)
189 {
190 	/* Don't step on other drivers' I/O space by accident */
191 	if (!request_muxed_region(base, 2, DRVNAME)) {
192 		printk(KERN_ERR DRVNAME ": I/O address 0x%04x already in use\n",
193 				(int)base);
194 		return -EBUSY;
195 	}
196 
197 	/* according to the datasheet the key must be send twice! */
198 	outb(SIO_UNLOCK_KEY, base);
199 	outb(SIO_UNLOCK_KEY, base);
200 
201 	return 0;
202 }
203 
204 static inline void superio_select(int base, int ld)
205 {
206 	outb(SIO_REG_LDSEL, base);
207 	outb(ld, base + 1);
208 }
209 
210 static inline void superio_exit(int base)
211 {
212 	outb(SIO_LOCK_KEY, base);
213 	release_region(base, 2);
214 }
215 
216 static int watchdog_set_timeout(int timeout)
217 {
218 	if (timeout <= 0
219 	 || timeout >  max_timeout) {
220 		printk(KERN_ERR DRVNAME ": watchdog timeout out of range\n");
221 		return -EINVAL;
222 	}
223 
224 	mutex_lock(&watchdog.lock);
225 
226 	watchdog.timeout = timeout;
227 	if (timeout > 0xff) {
228 		watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
229 		watchdog.minutes_mode = true;
230 	} else {
231 		watchdog.timer_val = timeout;
232 		watchdog.minutes_mode = false;
233 	}
234 
235 	mutex_unlock(&watchdog.lock);
236 
237 	return 0;
238 }
239 
240 static int watchdog_set_pulse_width(unsigned int pw)
241 {
242 	int err = 0;
243 
244 	mutex_lock(&watchdog.lock);
245 
246 	if        (pw <=    1) {
247 		watchdog.pulse_val = 0;
248 	} else if (pw <=   25) {
249 		watchdog.pulse_val = 1;
250 	} else if (pw <=  125) {
251 		watchdog.pulse_val = 2;
252 	} else if (pw <= 5000) {
253 		watchdog.pulse_val = 3;
254 	} else {
255 		printk(KERN_ERR DRVNAME ": pulse width out of range\n");
256 		err = -EINVAL;
257 		goto exit_unlock;
258 	}
259 
260 	watchdog.pulse_mode = pw;
261 
262 exit_unlock:
263 	mutex_unlock(&watchdog.lock);
264 	return err;
265 }
266 
267 static int watchdog_keepalive(void)
268 {
269 	int err = 0;
270 
271 	mutex_lock(&watchdog.lock);
272 	err = superio_enter(watchdog.sioaddr);
273 	if (err)
274 		goto exit_unlock;
275 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
276 
277 	if (watchdog.minutes_mode)
278 		/* select minutes for timer units */
279 		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
280 				F71808FG_FLAG_WD_UNIT);
281 	else
282 		/* select seconds for timer units */
283 		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
284 				F71808FG_FLAG_WD_UNIT);
285 
286 	/* Set timer value */
287 	superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
288 			   watchdog.timer_val);
289 
290 	superio_exit(watchdog.sioaddr);
291 
292 exit_unlock:
293 	mutex_unlock(&watchdog.lock);
294 	return err;
295 }
296 
297 static int f71862fg_pin_configure(unsigned short ioaddr)
298 {
299 	/* When ioaddr is non-zero the calling function has to take care of
300 	   mutex handling and superio preparation! */
301 
302 	if (f71862fg_pin == 63) {
303 		if (ioaddr) {
304 			/* SPI must be disabled first to use this pin! */
305 			superio_clear_bit(ioaddr, SIO_REG_ROM_ADDR_SEL, 6);
306 			superio_set_bit(ioaddr, SIO_REG_MFUNCT3, 4);
307 		}
308 	} else if (f71862fg_pin == 56) {
309 		if (ioaddr)
310 			superio_set_bit(ioaddr, SIO_REG_MFUNCT1, 1);
311 	} else {
312 		printk(KERN_ERR DRVNAME ": Invalid argument f71862fg_pin=%d\n",
313 				f71862fg_pin);
314 		return -EINVAL;
315 	}
316 	return 0;
317 }
318 
319 static int watchdog_start(void)
320 {
321 	/* Make sure we don't die as soon as the watchdog is enabled below */
322 	int err = watchdog_keepalive();
323 	if (err)
324 		return err;
325 
326 	mutex_lock(&watchdog.lock);
327 	err = superio_enter(watchdog.sioaddr);
328 	if (err)
329 		goto exit_unlock;
330 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
331 
332 	/* Watchdog pin configuration */
333 	switch (watchdog.type) {
334 	case f71808fg:
335 		/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
336 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT2, 3);
337 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 3);
338 		break;
339 
340 	case f71862fg:
341 		err = f71862fg_pin_configure(watchdog.sioaddr);
342 		if (err)
343 			goto exit_superio;
344 		break;
345 
346 	case f71869:
347 		/* GPIO14 --> WDTRST# */
348 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 4);
349 		break;
350 
351 	case f71882fg:
352 		/* Set pin 56 to WDTRST# */
353 		superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
354 		break;
355 
356 	case f71889fg:
357 		/* set pin 40 to WDTRST# */
358 		superio_outb(watchdog.sioaddr, SIO_REG_MFUNCT3,
359 			superio_inb(watchdog.sioaddr, SIO_REG_MFUNCT3) & 0xcf);
360 		break;
361 
362 	default:
363 		/*
364 		 * 'default' label to shut up the compiler and catch
365 		 * programmer errors
366 		 */
367 		err = -ENODEV;
368 		goto exit_superio;
369 	}
370 
371 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
372 	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
373 	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
374 			F71808FG_FLAG_WDOUT_EN);
375 
376 	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
377 			F71808FG_FLAG_WD_EN);
378 
379 	if (watchdog.pulse_mode) {
380 		/* Select "pulse" output mode with given duration */
381 		u8 wdt_conf = superio_inb(watchdog.sioaddr,
382 				F71808FG_REG_WDT_CONF);
383 
384 		/* Set WD_PSWIDTH bits (1:0) */
385 		wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
386 		/* Set WD_PULSE to "pulse" mode */
387 		wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);
388 
389 		superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
390 				wdt_conf);
391 	} else {
392 		/* Select "level" output mode */
393 		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
394 				F71808FG_FLAG_WD_PULSE);
395 	}
396 
397 exit_superio:
398 	superio_exit(watchdog.sioaddr);
399 exit_unlock:
400 	mutex_unlock(&watchdog.lock);
401 
402 	return err;
403 }
404 
405 static int watchdog_stop(void)
406 {
407 	int err = 0;
408 
409 	mutex_lock(&watchdog.lock);
410 	err = superio_enter(watchdog.sioaddr);
411 	if (err)
412 		goto exit_unlock;
413 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
414 
415 	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
416 			F71808FG_FLAG_WD_EN);
417 
418 	superio_exit(watchdog.sioaddr);
419 
420 exit_unlock:
421 	mutex_unlock(&watchdog.lock);
422 
423 	return err;
424 }
425 
426 static int watchdog_get_status(void)
427 {
428 	int status = 0;
429 
430 	mutex_lock(&watchdog.lock);
431 	status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
432 	mutex_unlock(&watchdog.lock);
433 
434 	return status;
435 }
436 
437 static bool watchdog_is_running(void)
438 {
439 	/*
440 	 * if we fail to determine the watchdog's status assume it to be
441 	 * running to be on the safe side
442 	 */
443 	bool is_running = true;
444 
445 	mutex_lock(&watchdog.lock);
446 	if (superio_enter(watchdog.sioaddr))
447 		goto exit_unlock;
448 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
449 
450 	is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
451 		&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
452 			& F71808FG_FLAG_WD_EN);
453 
454 	superio_exit(watchdog.sioaddr);
455 
456 exit_unlock:
457 	mutex_unlock(&watchdog.lock);
458 	return is_running;
459 }
460 
461 /* /dev/watchdog api */
462 
463 static int watchdog_open(struct inode *inode, struct file *file)
464 {
465 	int err;
466 
467 	/* If the watchdog is alive we don't need to start it again */
468 	if (test_and_set_bit(0, &watchdog.opened))
469 		return -EBUSY;
470 
471 	err = watchdog_start();
472 	if (err) {
473 		clear_bit(0, &watchdog.opened);
474 		return err;
475 	}
476 
477 	if (nowayout)
478 		__module_get(THIS_MODULE);
479 
480 	watchdog.expect_close = 0;
481 	return nonseekable_open(inode, file);
482 }
483 
484 static int watchdog_release(struct inode *inode, struct file *file)
485 {
486 	clear_bit(0, &watchdog.opened);
487 
488 	if (!watchdog.expect_close) {
489 		watchdog_keepalive();
490 		printk(KERN_CRIT DRVNAME
491 			": Unexpected close, not stopping watchdog!\n");
492 	} else if (!nowayout) {
493 		watchdog_stop();
494 	}
495 	return 0;
496 }
497 
498 /*
499  *      watchdog_write:
500  *      @file: file handle to the watchdog
501  *      @buf: buffer to write
502  *      @count: count of bytes
503  *      @ppos: pointer to the position to write. No seeks allowed
504  *
505  *      A write to a watchdog device is defined as a keepalive signal. Any
506  *      write of data will do, as we we don't define content meaning.
507  */
508 
509 static ssize_t watchdog_write(struct file *file, const char __user *buf,
510 			    size_t count, loff_t *ppos)
511 {
512 	if (count) {
513 		if (!nowayout) {
514 			size_t i;
515 
516 			/* In case it was set long ago */
517 			bool expect_close = false;
518 
519 			for (i = 0; i != count; i++) {
520 				char c;
521 				if (get_user(c, buf + i))
522 					return -EFAULT;
523 				expect_close = (c == 'V');
524 			}
525 
526 			/* Properly order writes across fork()ed processes */
527 			mutex_lock(&watchdog.lock);
528 			watchdog.expect_close = expect_close;
529 			mutex_unlock(&watchdog.lock);
530 		}
531 
532 		/* someone wrote to us, we should restart timer */
533 		watchdog_keepalive();
534 	}
535 	return count;
536 }
537 
538 /*
539  *      watchdog_ioctl:
540  *      @inode: inode of the device
541  *      @file: file handle to the device
542  *      @cmd: watchdog command
543  *      @arg: argument pointer
544  *
545  *      The watchdog API defines a common set of functions for all watchdogs
546  *      according to their available features.
547  */
548 static long watchdog_ioctl(struct file *file, unsigned int cmd,
549 	unsigned long arg)
550 {
551 	int status;
552 	int new_options;
553 	int new_timeout;
554 	union {
555 		struct watchdog_info __user *ident;
556 		int __user *i;
557 	} uarg;
558 
559 	uarg.i = (int __user *)arg;
560 
561 	switch (cmd) {
562 	case WDIOC_GETSUPPORT:
563 		return copy_to_user(uarg.ident, &watchdog.ident,
564 			sizeof(watchdog.ident)) ? -EFAULT : 0;
565 
566 	case WDIOC_GETSTATUS:
567 		status = watchdog_get_status();
568 		if (status < 0)
569 			return status;
570 		return put_user(status, uarg.i);
571 
572 	case WDIOC_GETBOOTSTATUS:
573 		return put_user(0, uarg.i);
574 
575 	case WDIOC_SETOPTIONS:
576 		if (get_user(new_options, uarg.i))
577 			return -EFAULT;
578 
579 		if (new_options & WDIOS_DISABLECARD)
580 			watchdog_stop();
581 
582 		if (new_options & WDIOS_ENABLECARD)
583 			return watchdog_start();
584 
585 
586 	case WDIOC_KEEPALIVE:
587 		watchdog_keepalive();
588 		return 0;
589 
590 	case WDIOC_SETTIMEOUT:
591 		if (get_user(new_timeout, uarg.i))
592 			return -EFAULT;
593 
594 		if (watchdog_set_timeout(new_timeout))
595 			return -EINVAL;
596 
597 		watchdog_keepalive();
598 		/* Fall */
599 
600 	case WDIOC_GETTIMEOUT:
601 		return put_user(watchdog.timeout, uarg.i);
602 
603 	default:
604 		return -ENOTTY;
605 
606 	}
607 }
608 
609 static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
610 	void *unused)
611 {
612 	if (code == SYS_DOWN || code == SYS_HALT)
613 		watchdog_stop();
614 	return NOTIFY_DONE;
615 }
616 
617 static const struct file_operations watchdog_fops = {
618 	.owner		= THIS_MODULE,
619 	.llseek		= no_llseek,
620 	.open		= watchdog_open,
621 	.release	= watchdog_release,
622 	.write		= watchdog_write,
623 	.unlocked_ioctl	= watchdog_ioctl,
624 };
625 
626 static struct miscdevice watchdog_miscdev = {
627 	.minor		= WATCHDOG_MINOR,
628 	.name		= "watchdog",
629 	.fops		= &watchdog_fops,
630 };
631 
632 static struct notifier_block watchdog_notifier = {
633 	.notifier_call = watchdog_notify_sys,
634 };
635 
636 static int __init watchdog_init(int sioaddr)
637 {
638 	int wdt_conf, err = 0;
639 
640 	/* No need to lock watchdog.lock here because no entry points
641 	 * into the module have been registered yet.
642 	 */
643 	watchdog.sioaddr = sioaddr;
644 	watchdog.ident.options = WDIOC_SETTIMEOUT
645 				| WDIOF_MAGICCLOSE
646 				| WDIOF_KEEPALIVEPING;
647 
648 	snprintf(watchdog.ident.identity,
649 		sizeof(watchdog.ident.identity), "%s watchdog",
650 		f71808e_names[watchdog.type]);
651 
652 	err = superio_enter(sioaddr);
653 	if (err)
654 		return err;
655 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
656 
657 	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
658 	watchdog.caused_reboot = wdt_conf & F71808FG_FLAG_WDTMOUT_STS;
659 
660 	superio_exit(sioaddr);
661 
662 	err = watchdog_set_timeout(timeout);
663 	if (err)
664 		return err;
665 	err = watchdog_set_pulse_width(pulse_width);
666 	if (err)
667 		return err;
668 
669 	err = register_reboot_notifier(&watchdog_notifier);
670 	if (err)
671 		return err;
672 
673 	err = misc_register(&watchdog_miscdev);
674 	if (err) {
675 		printk(KERN_ERR DRVNAME
676 			": cannot register miscdev on minor=%d\n",
677 				watchdog_miscdev.minor);
678 		goto exit_reboot;
679 	}
680 
681 	if (start_withtimeout) {
682 		if (start_withtimeout <= 0
683 		 || start_withtimeout >  max_timeout) {
684 			printk(KERN_ERR DRVNAME
685 				": starting timeout out of range\n");
686 			err = -EINVAL;
687 			goto exit_miscdev;
688 		}
689 
690 		err = watchdog_start();
691 		if (err) {
692 			printk(KERN_ERR DRVNAME
693 				": cannot start watchdog timer\n");
694 			goto exit_miscdev;
695 		}
696 
697 		mutex_lock(&watchdog.lock);
698 		err = superio_enter(sioaddr);
699 		if (err)
700 			goto exit_unlock;
701 		superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
702 
703 		if (start_withtimeout > 0xff) {
704 			/* select minutes for timer units */
705 			superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
706 				F71808FG_FLAG_WD_UNIT);
707 			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
708 				DIV_ROUND_UP(start_withtimeout, 60));
709 		} else {
710 			/* select seconds for timer units */
711 			superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
712 				F71808FG_FLAG_WD_UNIT);
713 			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
714 				start_withtimeout);
715 		}
716 
717 		superio_exit(sioaddr);
718 		mutex_unlock(&watchdog.lock);
719 
720 		if (nowayout)
721 			__module_get(THIS_MODULE);
722 
723 		printk(KERN_INFO DRVNAME
724 			": watchdog started with initial timeout of %u sec\n",
725 			start_withtimeout);
726 	}
727 
728 	return 0;
729 
730 exit_unlock:
731 	mutex_unlock(&watchdog.lock);
732 exit_miscdev:
733 	misc_deregister(&watchdog_miscdev);
734 exit_reboot:
735 	unregister_reboot_notifier(&watchdog_notifier);
736 
737 	return err;
738 }
739 
740 static int __init f71808e_find(int sioaddr)
741 {
742 	u16 devid;
743 	int err = superio_enter(sioaddr);
744 	if (err)
745 		return err;
746 
747 	devid = superio_inw(sioaddr, SIO_REG_MANID);
748 	if (devid != SIO_FINTEK_ID) {
749 		pr_debug(DRVNAME ": Not a Fintek device\n");
750 		err = -ENODEV;
751 		goto exit;
752 	}
753 
754 	devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
755 	switch (devid) {
756 	case SIO_F71808_ID:
757 		watchdog.type = f71808fg;
758 		break;
759 	case SIO_F71862_ID:
760 		watchdog.type = f71862fg;
761 		err = f71862fg_pin_configure(0); /* validate module parameter */
762 		break;
763 	case SIO_F71869_ID:
764 		watchdog.type = f71869;
765 		break;
766 	case SIO_F71882_ID:
767 		watchdog.type = f71882fg;
768 		break;
769 	case SIO_F71889_ID:
770 		watchdog.type = f71889fg;
771 		break;
772 	case SIO_F71858_ID:
773 		/* Confirmed (by datasheet) not to have a watchdog. */
774 		err = -ENODEV;
775 		goto exit;
776 	default:
777 		printk(KERN_INFO DRVNAME ": Unrecognized Fintek device: %04x\n",
778 		       (unsigned int)devid);
779 		err = -ENODEV;
780 		goto exit;
781 	}
782 
783 	printk(KERN_INFO DRVNAME ": Found %s watchdog chip, revision %d\n",
784 		f71808e_names[watchdog.type],
785 		(int)superio_inb(sioaddr, SIO_REG_DEVREV));
786 exit:
787 	superio_exit(sioaddr);
788 	return err;
789 }
790 
791 static int __init f71808e_init(void)
792 {
793 	static const unsigned short addrs[] = { 0x2e, 0x4e };
794 	int err = -ENODEV;
795 	int i;
796 
797 	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
798 		err = f71808e_find(addrs[i]);
799 		if (err == 0)
800 			break;
801 	}
802 	if (i == ARRAY_SIZE(addrs))
803 		return err;
804 
805 	return watchdog_init(addrs[i]);
806 }
807 
808 static void __exit f71808e_exit(void)
809 {
810 	if (watchdog_is_running()) {
811 		printk(KERN_WARNING DRVNAME
812 			": Watchdog timer still running, stopping it\n");
813 		watchdog_stop();
814 	}
815 	misc_deregister(&watchdog_miscdev);
816 	unregister_reboot_notifier(&watchdog_notifier);
817 }
818 
819 MODULE_DESCRIPTION("F71808E Watchdog Driver");
820 MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
821 MODULE_LICENSE("GPL");
822 
823 module_init(f71808e_init);
824 module_exit(f71808e_exit);
825