aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/f71808e_wdt.c
blob: 7e5c266cda4804b39e0acef3338ab0c67ba37c63 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
/***************************************************************************
 *   Copyright (C) 2006 by Hans Edgington <hans@edgington.nl>              *
 *   Copyright (C) 2007-2009 Hans de Goede <hdegoede@redhat.com>           *
 *   Copyright (C) 2010 Giel van Schijndel <me@mortis.eu>                  *
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

#include <linux/err.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/uaccess.h>
#include <linux/watchdog.h>

#define DRVNAME "f71808e_wdt"

#define SIO_F71808FG_LD_WDT	0x07	/* Watchdog timer logical device */
#define SIO_UNLOCK_KEY		0x87	/* Key to enable Super-I/O */
#define SIO_LOCK_KEY		0xAA	/* Key to diasble Super-I/O */

#define SIO_REG_LDSEL		0x07	/* Logical device select */
#define SIO_REG_DEVID		0x20	/* Device ID (2 bytes) */
#define SIO_REG_DEVREV		0x22	/* Device revision */
#define SIO_REG_MANID		0x23	/* Fintek ID (2 bytes) */
#define SIO_REG_ENABLE		0x30	/* Logical device enable */
#define SIO_REG_ADDR		0x60	/* Logical device address (2 bytes) */

#define SIO_FINTEK_ID		0x1934	/* Manufacturers ID */
#define SIO_F71808_ID		0x0901  /* Chipset ID */
#define SIO_F71858_ID		0x0507  /* Chipset ID */
#define SIO_F71862_ID		0x0601	/* Chipset ID */
#define SIO_F71882_ID		0x0541	/* Chipset ID */
#define SIO_F71889_ID		0x0723	/* Chipset ID */

#define	F71882FG_REG_START		0x01

#define F71808FG_REG_WDO_CONF		0xf0
#define F71808FG_REG_WDT_CONF		0xf5
#define F71808FG_REG_WD_TIME		0xf6

#define F71808FG_FLAG_WDOUT_EN		7

#define F71808FG_FLAG_WDTMOUT_STS	5
#define F71808FG_FLAG_WD_EN		5
#define F71808FG_FLAG_WD_PULSE		4
#define F71808FG_FLAG_WD_UNIT		3

/* Default values */
#define WATCHDOG_TIMEOUT	60	/* 1 minute default timeout */
#define WATCHDOG_MAX_TIMEOUT	(60 * 255)
#define WATCHDOG_PULSE_WIDTH	125	/* 125 ms, default pulse width for
					   watchdog signal */

static unsigned short force_id;
module_param(force_id, ushort, 0);
MODULE_PARM_DESC(force_id, "Override the detected device ID");

static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
static int timeout = 60;	/* default timeout in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
	"Watchdog timeout in seconds. 1<= timeout <="
			__MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
			__MODULE_STRING(WATCHDOG_TIMEOUT) ")");

static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
module_param(pulse_width, uint, 0);
MODULE_PARM_DESC(pulse_width,
	"Watchdog signal pulse width. 0(=level), 1 ms, 25 ms, 125 ms or 5000 ms"
			" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");

static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0444);
MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");

static unsigned int start_withtimeout;
module_param(start_withtimeout, uint, 0);
MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
	" given initial timeout. Zero (default) disables this feature.");

enum chips { f71808fg, f71858fg, f71862fg, f71882fg, f71889fg };

static const char *f71808e_names[] = {
	"f71808fg",
	"f71858fg",
	"f71862fg",
	"f71882fg",
	"f71889fg",
};

/* Super-I/O Function prototypes */
static inline int superio_inb(int base, int reg);
static inline int superio_inw(int base, int reg);
static inline void superio_outb(int base, int reg, u8 val);
static inline void superio_set_bit(int base, int reg, int bit);
static inline void superio_clear_bit(int base, int reg, int bit);
static inline int superio_enter(int base);
static inline void superio_select(int base, int ld);
static inline void superio_exit(int base);

struct watchdog_data {
	unsigned short	sioaddr;
	enum chips	type;
	unsigned long	opened;
	struct mutex	lock;
	char		expect_close;
	struct watchdog_info ident;

	unsigned short	timeout;
	u8		timer_val;	/* content for the wd_time register */
	char		minutes_mode;
	u8		pulse_val;	/* pulse width flag */
	char		pulse_mode;	/* enable pulse output mode? */
	char		caused_reboot;	/* last reboot was by the watchdog */
};

static struct watchdog_data watchdog = {
	.lock = __MUTEX_INITIALIZER(watchdog.lock),
};

/* Super I/O functions */
static inline int superio_inb(int base, int reg)
{
	outb(reg, base);
	return inb(base + 1);
}

static int superio_inw(int base, int reg)
{
	int val;
	val  = superio_inb(base, reg) << 8;
	val |= superio_inb(base, reg + 1);
	return val;
}

static inline void superio_outb(int base, int reg, u8 val)
{
	outb(reg, base);
	outb(val, base + 1);
}

static inline void superio_set_bit(int base, int reg, int bit)
{
	unsigned long val = superio_inb(base, reg);
	__set_bit(bit, &val);
	superio_outb(base, reg, val);
}

static inline void superio_clear_bit(int base, int reg, int bit)
{
	unsigned long val = superio_inb(base, reg);
	__clear_bit(bit, &val);
	superio_outb(base, reg, val);
}

static inline int superio_enter(int base)
{
	/* Don't step on other drivers' I/O space by accident */
	if (!request_muxed_region(base, 2, DRVNAME)) {
		printk(KERN_ERR DRVNAME ": I/O address 0x%04x already in use\n",
				(int)base);
		return -EBUSY;
	}

	/* according to the datasheet the key must be send twice! */
	outb(SIO_UNLOCK_KEY, base);
	outb(SIO_UNLOCK_KEY, base);

	return 0;
}

static inline void superio_select(int base, int ld)
{
	outb(SIO_REG_LDSEL, base);
	outb(ld, base + 1);
}

static inline void superio_exit(int base)
{
	outb(SIO_LOCK_KEY, base);
	release_region(base, 2);
}

static int watchdog_set_timeout(int timeout)
{
	if (timeout <= 0
	 || timeout >  max_timeout) {
		printk(KERN_ERR DRVNAME ": watchdog timeout out of range\n");
		return -EINVAL;
	}

	mutex_lock(&watchdog.lock);

	watchdog.timeout = timeout;
	if (timeout > 0xff) {
		watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
		watchdog.minutes_mode = true;
	} else {
		watchdog.timer_val = timeout;
		watchdog.minutes_mode = false;
	}

	mutex_unlock(&watchdog.lock);

	return 0;
}

static int watchdog_set_pulse_width(unsigned int pw)
{
	int err = 0;

	mutex_lock(&watchdog.lock);

	if        (pw <=    1) {
		watchdog.pulse_val = 0;
	} else if (pw <=   25) {
		watchdog.pulse_val = 1;
	} else if (pw <=  125) {
		watchdog.pulse_val = 2;
	} else if (pw <= 5000) {
		watchdog.pulse_val = 3;
	} else {
		printk(KERN_ERR DRVNAME ": pulse width out of range\n");
		err = -EINVAL;
		goto exit_unlock;
	}

	watchdog.pulse_mode = pw;

exit_unlock:
	mutex_unlock(&watchdog.lock);
	return err;
}

static int watchdog_keepalive(void)
{
	int err = 0;

	mutex_lock(&watchdog.lock);
	err = superio_enter(watchdog.sioaddr);
	if (err)
		goto exit_unlock;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	if (watchdog.minutes_mode)
		/* select minutes for timer units */
		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_UNIT);
	else
		/* select seconds for timer units */
		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_UNIT);

	/* Set timer value */
	superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
			   watchdog.timer_val);

	superio_exit(watchdog.sioaddr);

exit_unlock:
	mutex_unlock(&watchdog.lock);
	return err;
}

static int watchdog_start(void)
{
	/* Make sure we don't die as soon as the watchdog is enabled below */
	int err = watchdog_keepalive();
	if (err)
		return err;

	mutex_lock(&watchdog.lock);
	err = superio_enter(watchdog.sioaddr);
	if (err)
		goto exit_unlock;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	/* Watchdog pin configuration */
	switch (watchdog.type) {
	case f71808fg:
		/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
		superio_clear_bit(watchdog.sioaddr, 0x2a, 3);
		superio_clear_bit(watchdog.sioaddr, 0x2b, 3);
		break;

	case f71882fg:
		/* Set pin 56 to WDTRST# */
		superio_set_bit(watchdog.sioaddr, 0x29, 1);
		break;

	default:
		/*
		 * 'default' label to shut up the compiler and catch
		 * programmer errors
		 */
		err = -ENODEV;
		goto exit_superio;
	}

	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
			F71808FG_FLAG_WDOUT_EN);

	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
			F71808FG_FLAG_WD_EN);

	if (watchdog.pulse_mode) {
		/* Select "pulse" output mode with given duration */
		u8 wdt_conf = superio_inb(watchdog.sioaddr,
				F71808FG_REG_WDT_CONF);

		/* Set WD_PSWIDTH bits (1:0) */
		wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
		/* Set WD_PULSE to "pulse" mode */
		wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);

		superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
				wdt_conf);
	} else {
		/* Select "level" output mode */
		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_PULSE);
	}

exit_superio:
	superio_exit(watchdog.sioaddr);
exit_unlock:
	mutex_unlock(&watchdog.lock);

	return err;
}

static int watchdog_stop(void)
{
	int err = 0;

	mutex_lock(&watchdog.lock);
	err = superio_enter(watchdog.sioaddr);
	if (err)
		goto exit_unlock;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
			F71808FG_FLAG_WD_EN);

	superio_exit(watchdog.sioaddr);

exit_unlock:
	mutex_unlock(&watchdog.lock);

	return err;
}

static int watchdog_get_status(void)
{
	int status = 0;

	mutex_lock(&watchdog.lock);
	status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
	mutex_unlock(&watchdog.lock);

	return status;
}

static bool watchdog_is_running(void)
{
	/*
	 * if we fail to determine the watchdog's status assume it to be
	 * running to be on the safe side
	 */
	bool is_running = true;

	mutex_lock(&watchdog.lock);
	if (superio_enter(watchdog.sioaddr))
		goto exit_unlock;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
		&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
			& F71808FG_FLAG_WD_EN);

	superio_exit(watchdog.sioaddr);

exit_unlock:
	mutex_unlock(&watchdog.lock);
	return is_running;
}

/* /dev/watchdog api */

static int watchdog_open(struct inode *inode, struct file *file)
{
	int err;

	/* If the watchdog is alive we don't need to start it again */
	if (test_and_set_bit(0, &watchdog.opened))
		return -EBUSY;

	err = watchdog_start();
	if (err) {
		clear_bit(0, &watchdog.opened);
		return err;
	}

	if (nowayout)
		__module_get(THIS_MODULE);

	watchdog.expect_close = 0;
	return nonseekable_open(inode, file);
}

static int watchdog_release(struct inode *inode, struct file *file)
{
	clear_bit(0, &watchdog.opened);

	if (!watchdog.expect_close) {
		watchdog_keepalive();
		printk(KERN_CRIT DRVNAME
			": Unexpected close, not stopping watchdog!\n");
	} else if (!nowayout) {
		watchdog_stop();
	}
	return 0;
}

/*
 *      watchdog_write:
 *      @file: file handle to the watchdog
 *      @buf: buffer to write
 *      @count: count of bytes
 *      @ppos: pointer to the position to write. No seeks allowed
 *
 *      A write to a watchdog device is defined as a keepalive signal. Any
 *      write of data will do, as we we don't define content meaning.
 */

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

			/* In case it was set long ago */
			bool expect_close = false;

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

			/* Properly order writes across fork()ed processes */
			mutex_lock(&watchdog.lock);
			watchdog.expect_close = expect_close;
			mutex_unlock(&watchdog.lock);
		}

		/* someone wrote to us, we should restart timer */
		watchdog_keepalive();
	}
	return count;
}

/*
 *      watchdog_ioctl:
 *      @inode: inode of the device
 *      @file: file handle to the device
 *      @cmd: watchdog command
 *      @arg: argument pointer
 *
 *      The watchdog API defines a common set of functions for all watchdogs
 *      according to their available features.
 */
static long watchdog_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
{
	int status;
	int new_options;
	int new_timeout;
	union {
		struct watchdog_info __user *ident;
		int __user *i;
	} uarg;

	uarg.i = (int __user *)arg;

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		return copy_to_user(uarg.ident, &watchdog.ident,
			sizeof(watchdog.ident)) ? -EFAULT : 0;

	case WDIOC_GETSTATUS:
		status = watchdog_get_status();
		if (status < 0)
			return status;
		return put_user(status, uarg.i);

	case WDIOC_GETBOOTSTATUS:
		return put_user(0, uarg.i);

	case WDIOC_SETOPTIONS:
		if (get_user(new_options, uarg.i))
			return -EFAULT;

		if (new_options & WDIOS_DISABLECARD)
			watchdog_stop();

		if (new_options & WDIOS_ENABLECARD)
			return watchdog_start();


	case WDIOC_KEEPALIVE:
		watchdog_keepalive();
		return 0;

	case WDIOC_SETTIMEOUT:
		if (get_user(new_timeout, uarg.i))
			return -EFAULT;

		if (watchdog_set_timeout(new_timeout))
			return -EINVAL;

		watchdog_keepalive();
		/* Fall */

	case WDIOC_GETTIMEOUT:
		return put_user(watchdog.timeout, uarg.i);

	default:
		return -ENOTTY;

	}
}

static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
	void *unused)
{
	if (code == SYS_DOWN || code == SYS_HALT)
		watchdog_stop();
	return NOTIFY_DONE;
}

static const struct file_operations watchdog_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.open		= watchdog_open,
	.release	= watchdog_release,
	.write		= watchdog_write,
	.unlocked_ioctl	= watchdog_ioctl,
};

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

static struct notifier_block watchdog_notifier = {
	.notifier_call = watchdog_notify_sys,
};

static int __init watchdog_init(int sioaddr)
{
	int wdt_conf, err = 0;

	/* No need to lock watchdog.lock here because no entry points
	 * into the module have been registered yet.
	 */
	watchdog.sioaddr = sioaddr;
	watchdog.ident.options = WDIOC_SETTIMEOUT
				| WDIOF_MAGICCLOSE
				| WDIOF_KEEPALIVEPING;

	snprintf(watchdog.ident.identity,
		sizeof(watchdog.ident.identity), "%s watchdog",
		f71808e_names[watchdog.type]);

	err = superio_enter(sioaddr);
	if (err)
		return err;
	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
	watchdog.caused_reboot = wdt_conf & F71808FG_FLAG_WDTMOUT_STS;

	superio_exit(sioaddr);

	err = watchdog_set_timeout(timeout);
	if (err)
		return err;
	err = watchdog_set_pulse_width(pulse_width);
	if (err)
		return err;

	err = register_reboot_notifier(&watchdog_notifier);
	if (err)
		return err;

	err = misc_register(&watchdog_miscdev);
	if (err) {
		printk(KERN_ERR DRVNAME
			": cannot register miscdev on minor=%d\n",
				watchdog_miscdev.minor);
		goto exit_reboot;
	}

	if (start_withtimeout) {
		if (start_withtimeout <= 0
		 || start_withtimeout >  max_timeout) {
			printk(KERN_ERR DRVNAME
				": starting timeout out of range\n");
			err = -EINVAL;
			goto exit_miscdev;
		}

		err = watchdog_start();
		if (err) {
			printk(KERN_ERR DRVNAME
				": cannot start watchdog timer\n");
			goto exit_miscdev;
		}

		mutex_lock(&watchdog.lock);
		err = superio_enter(sioaddr);
		if (err)
			goto exit_unlock;
		superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);

		if (start_withtimeout > 0xff) {
			/* select minutes for timer units */
			superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_UNIT);
			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
				DIV_ROUND_UP(start_withtimeout, 60));
		} else {
			/* select seconds for timer units */
			superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
				F71808FG_FLAG_WD_UNIT);
			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
				start_withtimeout);
		}

		superio_exit(sioaddr);
		mutex_unlock(&watchdog.lock);

		if (nowayout)
			__module_get(THIS_MODULE);

		printk(KERN_INFO DRVNAME
			": watchdog started with initial timeout of %u sec\n",
			start_withtimeout);
	}

	return 0;

exit_unlock:
	mutex_unlock(&watchdog.lock);
exit_miscdev:
	misc_deregister(&watchdog_miscdev);
exit_reboot:
	unregister_reboot_notifier(&watchdog_notifier);

	return err;
}

static int __init f71808e_find(int sioaddr)
{
	u16 devid;
	int err = superio_enter(sioaddr);
	if (err)
		return err;

	devid = superio_inw(sioaddr, SIO_REG_MANID);
	if (devid != SIO_FINTEK_ID) {
		pr_debug(DRVNAME ": Not a Fintek device\n");
		err = -ENODEV;
		goto exit;
	}

	devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
	switch (devid) {
	case SIO_F71808_ID:
		watchdog.type = f71808fg;
		break;
	case SIO_F71882_ID:
		watchdog.type = f71882fg;
		break;
	case SIO_F71862_ID:
	case SIO_F71889_ID:
		/* These have a watchdog, though it isn't implemented (yet). */
		err = -ENOSYS;
		goto exit;
	case SIO_F71858_ID:
		/* Confirmed (by datasheet) not to have a watchdog. */
		err = -ENODEV;
		goto exit;
	default:
		printk(KERN_INFO DRVNAME ": Unrecognized Fintek device: %04x\n",
		       (unsigned int)devid);
		err = -ENODEV;
		goto exit;
	}

	printk(KERN_INFO DRVNAME ": Found %s watchdog chip, revision %d\n",
		f71808e_names[watchdog.type],
		(int)superio_inb(sioaddr, SIO_REG_DEVREV));
exit:
	superio_exit(sioaddr);
	return err;
}

static int __init f71808e_init(void)
{
	static const unsigned short addrs[] = { 0x2e, 0x4e };
	int err = -ENODEV;
	int i;

	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
		err = f71808e_find(addrs[i]);
		if (err == 0)
			break;
	}
	if (i == ARRAY_SIZE(addrs))
		return err;

	return watchdog_init(addrs[i]);
}

static void __exit f71808e_exit(void)
{
	if (watchdog_is_running()) {
		printk(KERN_WARNING DRVNAME
			": Watchdog timer still running, stopping it\n");
		watchdog_stop();
	}
	misc_deregister(&watchdog_miscdev);
	unregister_reboot_notifier(&watchdog_notifier);
}

MODULE_DESCRIPTION("F71808E Watchdog Driver");
MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
MODULE_LICENSE("GPL");

module_init(f71808e_init);
module_exit(f71808e_exit);