xref: /linux/drivers/watchdog/f71808e_wdt.c (revision 0883c2c06fb5bcf5b9e008270827e63c09a88c1e)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 
24 #include <linux/err.h>
25 #include <linux/fs.h>
26 #include <linux/init.h>
27 #include <linux/io.h>
28 #include <linux/ioport.h>
29 #include <linux/miscdevice.h>
30 #include <linux/module.h>
31 #include <linux/mutex.h>
32 #include <linux/notifier.h>
33 #include <linux/reboot.h>
34 #include <linux/uaccess.h>
35 #include <linux/watchdog.h>
36 
37 #define DRVNAME "f71808e_wdt"
38 
39 #define SIO_F71808FG_LD_WDT	0x07	/* Watchdog timer logical device */
40 #define SIO_UNLOCK_KEY		0x87	/* Key to enable Super-I/O */
41 #define SIO_LOCK_KEY		0xAA	/* Key to disable Super-I/O */
42 
43 #define SIO_REG_LDSEL		0x07	/* Logical device select */
44 #define SIO_REG_DEVID		0x20	/* Device ID (2 bytes) */
45 #define SIO_REG_DEVREV		0x22	/* Device revision */
46 #define SIO_REG_MANID		0x23	/* Fintek ID (2 bytes) */
47 #define SIO_REG_ROM_ADDR_SEL	0x27	/* ROM address select */
48 #define SIO_REG_MFUNCT1		0x29	/* Multi function select 1 */
49 #define SIO_REG_MFUNCT2		0x2a	/* Multi function select 2 */
50 #define SIO_REG_MFUNCT3		0x2b	/* Multi function select 3 */
51 #define SIO_REG_ENABLE		0x30	/* Logical device enable */
52 #define SIO_REG_ADDR		0x60	/* Logical device address (2 bytes) */
53 
54 #define SIO_FINTEK_ID		0x1934	/* Manufacturers ID */
55 #define SIO_F71808_ID		0x0901	/* Chipset ID */
56 #define SIO_F71858_ID		0x0507	/* Chipset ID */
57 #define SIO_F71862_ID		0x0601	/* Chipset ID */
58 #define SIO_F71869_ID		0x0814	/* Chipset ID */
59 #define SIO_F71869A_ID		0x1007	/* Chipset ID */
60 #define SIO_F71882_ID		0x0541	/* Chipset ID */
61 #define SIO_F71889_ID		0x0723	/* Chipset ID */
62 #define SIO_F81865_ID		0x0704	/* Chipset ID */
63 
64 #define F71808FG_REG_WDO_CONF		0xf0
65 #define F71808FG_REG_WDT_CONF		0xf5
66 #define F71808FG_REG_WD_TIME		0xf6
67 
68 #define F71808FG_FLAG_WDOUT_EN		7
69 
70 #define F71808FG_FLAG_WDTMOUT_STS	6
71 #define F71808FG_FLAG_WD_EN		5
72 #define F71808FG_FLAG_WD_PULSE		4
73 #define F71808FG_FLAG_WD_UNIT		3
74 
75 #define F81865_REG_WDO_CONF		0xfa
76 #define F81865_FLAG_WDOUT_EN		0
77 
78 /* Default values */
79 #define WATCHDOG_TIMEOUT	60	/* 1 minute default timeout */
80 #define WATCHDOG_MAX_TIMEOUT	(60 * 255)
81 #define WATCHDOG_PULSE_WIDTH	125	/* 125 ms, default pulse width for
82 					   watchdog signal */
83 #define WATCHDOG_F71862FG_PIN	63	/* default watchdog reset output
84 					   pin number 63 */
85 
86 static unsigned short force_id;
87 module_param(force_id, ushort, 0);
88 MODULE_PARM_DESC(force_id, "Override the detected device ID");
89 
90 static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
91 static int timeout = WATCHDOG_TIMEOUT;	/* default timeout in seconds */
92 module_param(timeout, int, 0);
93 MODULE_PARM_DESC(timeout,
94 	"Watchdog timeout in seconds. 1<= timeout <="
95 			__MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
96 			__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
97 
98 static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
99 module_param(pulse_width, uint, 0);
100 MODULE_PARM_DESC(pulse_width,
101 	"Watchdog signal pulse width. 0(=level), 1 ms, 25 ms, 125 ms or 5000 ms"
102 			" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");
103 
104 static unsigned int f71862fg_pin = WATCHDOG_F71862FG_PIN;
105 module_param(f71862fg_pin, uint, 0);
106 MODULE_PARM_DESC(f71862fg_pin,
107 	"Watchdog f71862fg reset output pin configuration. Choose pin 56 or 63"
108 			" (default=" __MODULE_STRING(WATCHDOG_F71862FG_PIN)")");
109 
110 static bool nowayout = WATCHDOG_NOWAYOUT;
111 module_param(nowayout, bool, 0444);
112 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
113 
114 static unsigned int start_withtimeout;
115 module_param(start_withtimeout, uint, 0);
116 MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
117 	" given initial timeout. Zero (default) disables this feature.");
118 
119 enum chips { f71808fg, f71858fg, f71862fg, f71869, f71882fg, f71889fg, f81865 };
120 
121 static const char *f71808e_names[] = {
122 	"f71808fg",
123 	"f71858fg",
124 	"f71862fg",
125 	"f71869",
126 	"f71882fg",
127 	"f71889fg",
128 	"f81865",
129 };
130 
131 /* Super-I/O Function prototypes */
132 static inline int superio_inb(int base, int reg);
133 static inline int superio_inw(int base, int reg);
134 static inline void superio_outb(int base, int reg, u8 val);
135 static inline void superio_set_bit(int base, int reg, int bit);
136 static inline void superio_clear_bit(int base, int reg, int bit);
137 static inline int superio_enter(int base);
138 static inline void superio_select(int base, int ld);
139 static inline void superio_exit(int base);
140 
141 struct watchdog_data {
142 	unsigned short	sioaddr;
143 	enum chips	type;
144 	unsigned long	opened;
145 	struct mutex	lock;
146 	char		expect_close;
147 	struct watchdog_info ident;
148 
149 	unsigned short	timeout;
150 	u8		timer_val;	/* content for the wd_time register */
151 	char		minutes_mode;
152 	u8		pulse_val;	/* pulse width flag */
153 	char		pulse_mode;	/* enable pulse output mode? */
154 	char		caused_reboot;	/* last reboot was by the watchdog */
155 };
156 
157 static struct watchdog_data watchdog = {
158 	.lock = __MUTEX_INITIALIZER(watchdog.lock),
159 };
160 
161 /* Super I/O functions */
162 static inline int superio_inb(int base, int reg)
163 {
164 	outb(reg, base);
165 	return inb(base + 1);
166 }
167 
168 static int superio_inw(int base, int reg)
169 {
170 	int val;
171 	val  = superio_inb(base, reg) << 8;
172 	val |= superio_inb(base, reg + 1);
173 	return val;
174 }
175 
176 static inline void superio_outb(int base, int reg, u8 val)
177 {
178 	outb(reg, base);
179 	outb(val, base + 1);
180 }
181 
182 static inline void superio_set_bit(int base, int reg, int bit)
183 {
184 	unsigned long val = superio_inb(base, reg);
185 	__set_bit(bit, &val);
186 	superio_outb(base, reg, val);
187 }
188 
189 static inline void superio_clear_bit(int base, int reg, int bit)
190 {
191 	unsigned long val = superio_inb(base, reg);
192 	__clear_bit(bit, &val);
193 	superio_outb(base, reg, val);
194 }
195 
196 static inline int superio_enter(int base)
197 {
198 	/* Don't step on other drivers' I/O space by accident */
199 	if (!request_muxed_region(base, 2, DRVNAME)) {
200 		pr_err("I/O address 0x%04x already in use\n", (int)base);
201 		return -EBUSY;
202 	}
203 
204 	/* according to the datasheet the key must be sent twice! */
205 	outb(SIO_UNLOCK_KEY, base);
206 	outb(SIO_UNLOCK_KEY, base);
207 
208 	return 0;
209 }
210 
211 static inline void superio_select(int base, int ld)
212 {
213 	outb(SIO_REG_LDSEL, base);
214 	outb(ld, base + 1);
215 }
216 
217 static inline void superio_exit(int base)
218 {
219 	outb(SIO_LOCK_KEY, base);
220 	release_region(base, 2);
221 }
222 
223 static int watchdog_set_timeout(int timeout)
224 {
225 	if (timeout <= 0
226 	 || timeout >  max_timeout) {
227 		pr_err("watchdog timeout out of range\n");
228 		return -EINVAL;
229 	}
230 
231 	mutex_lock(&watchdog.lock);
232 
233 	watchdog.timeout = timeout;
234 	if (timeout > 0xff) {
235 		watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
236 		watchdog.minutes_mode = true;
237 	} else {
238 		watchdog.timer_val = timeout;
239 		watchdog.minutes_mode = false;
240 	}
241 
242 	mutex_unlock(&watchdog.lock);
243 
244 	return 0;
245 }
246 
247 static int watchdog_set_pulse_width(unsigned int pw)
248 {
249 	int err = 0;
250 
251 	mutex_lock(&watchdog.lock);
252 
253 	if        (pw <=    1) {
254 		watchdog.pulse_val = 0;
255 	} else if (pw <=   25) {
256 		watchdog.pulse_val = 1;
257 	} else if (pw <=  125) {
258 		watchdog.pulse_val = 2;
259 	} else if (pw <= 5000) {
260 		watchdog.pulse_val = 3;
261 	} else {
262 		pr_err("pulse width out of range\n");
263 		err = -EINVAL;
264 		goto exit_unlock;
265 	}
266 
267 	watchdog.pulse_mode = pw;
268 
269 exit_unlock:
270 	mutex_unlock(&watchdog.lock);
271 	return err;
272 }
273 
274 static int watchdog_keepalive(void)
275 {
276 	int err = 0;
277 
278 	mutex_lock(&watchdog.lock);
279 	err = superio_enter(watchdog.sioaddr);
280 	if (err)
281 		goto exit_unlock;
282 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
283 
284 	if (watchdog.minutes_mode)
285 		/* select minutes for timer units */
286 		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
287 				F71808FG_FLAG_WD_UNIT);
288 	else
289 		/* select seconds for timer units */
290 		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
291 				F71808FG_FLAG_WD_UNIT);
292 
293 	/* Set timer value */
294 	superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
295 			   watchdog.timer_val);
296 
297 	superio_exit(watchdog.sioaddr);
298 
299 exit_unlock:
300 	mutex_unlock(&watchdog.lock);
301 	return err;
302 }
303 
304 static int f71862fg_pin_configure(unsigned short ioaddr)
305 {
306 	/* When ioaddr is non-zero the calling function has to take care of
307 	   mutex handling and superio preparation! */
308 
309 	if (f71862fg_pin == 63) {
310 		if (ioaddr) {
311 			/* SPI must be disabled first to use this pin! */
312 			superio_clear_bit(ioaddr, SIO_REG_ROM_ADDR_SEL, 6);
313 			superio_set_bit(ioaddr, SIO_REG_MFUNCT3, 4);
314 		}
315 	} else if (f71862fg_pin == 56) {
316 		if (ioaddr)
317 			superio_set_bit(ioaddr, SIO_REG_MFUNCT1, 1);
318 	} else {
319 		pr_err("Invalid argument f71862fg_pin=%d\n", f71862fg_pin);
320 		return -EINVAL;
321 	}
322 	return 0;
323 }
324 
325 static int watchdog_start(void)
326 {
327 	/* Make sure we don't die as soon as the watchdog is enabled below */
328 	int err = watchdog_keepalive();
329 	if (err)
330 		return err;
331 
332 	mutex_lock(&watchdog.lock);
333 	err = superio_enter(watchdog.sioaddr);
334 	if (err)
335 		goto exit_unlock;
336 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
337 
338 	/* Watchdog pin configuration */
339 	switch (watchdog.type) {
340 	case f71808fg:
341 		/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
342 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT2, 3);
343 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 3);
344 		break;
345 
346 	case f71862fg:
347 		err = f71862fg_pin_configure(watchdog.sioaddr);
348 		if (err)
349 			goto exit_superio;
350 		break;
351 
352 	case f71869:
353 		/* GPIO14 --> WDTRST# */
354 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 4);
355 		break;
356 
357 	case f71882fg:
358 		/* Set pin 56 to WDTRST# */
359 		superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
360 		break;
361 
362 	case f71889fg:
363 		/* set pin 40 to WDTRST# */
364 		superio_outb(watchdog.sioaddr, SIO_REG_MFUNCT3,
365 			superio_inb(watchdog.sioaddr, SIO_REG_MFUNCT3) & 0xcf);
366 		break;
367 
368 	case f81865:
369 		/* Set pin 70 to WDTRST# */
370 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 5);
371 		break;
372 
373 	default:
374 		/*
375 		 * 'default' label to shut up the compiler and catch
376 		 * programmer errors
377 		 */
378 		err = -ENODEV;
379 		goto exit_superio;
380 	}
381 
382 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
383 	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
384 
385 	if (watchdog.type == f81865)
386 		superio_set_bit(watchdog.sioaddr, F81865_REG_WDO_CONF,
387 				F81865_FLAG_WDOUT_EN);
388 	else
389 		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
390 				F71808FG_FLAG_WDOUT_EN);
391 
392 	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
393 			F71808FG_FLAG_WD_EN);
394 
395 	if (watchdog.pulse_mode) {
396 		/* Select "pulse" output mode with given duration */
397 		u8 wdt_conf = superio_inb(watchdog.sioaddr,
398 				F71808FG_REG_WDT_CONF);
399 
400 		/* Set WD_PSWIDTH bits (1:0) */
401 		wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
402 		/* Set WD_PULSE to "pulse" mode */
403 		wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);
404 
405 		superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
406 				wdt_conf);
407 	} else {
408 		/* Select "level" output mode */
409 		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
410 				F71808FG_FLAG_WD_PULSE);
411 	}
412 
413 exit_superio:
414 	superio_exit(watchdog.sioaddr);
415 exit_unlock:
416 	mutex_unlock(&watchdog.lock);
417 
418 	return err;
419 }
420 
421 static int watchdog_stop(void)
422 {
423 	int err = 0;
424 
425 	mutex_lock(&watchdog.lock);
426 	err = superio_enter(watchdog.sioaddr);
427 	if (err)
428 		goto exit_unlock;
429 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
430 
431 	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
432 			F71808FG_FLAG_WD_EN);
433 
434 	superio_exit(watchdog.sioaddr);
435 
436 exit_unlock:
437 	mutex_unlock(&watchdog.lock);
438 
439 	return err;
440 }
441 
442 static int watchdog_get_status(void)
443 {
444 	int status = 0;
445 
446 	mutex_lock(&watchdog.lock);
447 	status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
448 	mutex_unlock(&watchdog.lock);
449 
450 	return status;
451 }
452 
453 static bool watchdog_is_running(void)
454 {
455 	/*
456 	 * if we fail to determine the watchdog's status assume it to be
457 	 * running to be on the safe side
458 	 */
459 	bool is_running = true;
460 
461 	mutex_lock(&watchdog.lock);
462 	if (superio_enter(watchdog.sioaddr))
463 		goto exit_unlock;
464 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
465 
466 	is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
467 		&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
468 			& F71808FG_FLAG_WD_EN);
469 
470 	superio_exit(watchdog.sioaddr);
471 
472 exit_unlock:
473 	mutex_unlock(&watchdog.lock);
474 	return is_running;
475 }
476 
477 /* /dev/watchdog api */
478 
479 static int watchdog_open(struct inode *inode, struct file *file)
480 {
481 	int err;
482 
483 	/* If the watchdog is alive we don't need to start it again */
484 	if (test_and_set_bit(0, &watchdog.opened))
485 		return -EBUSY;
486 
487 	err = watchdog_start();
488 	if (err) {
489 		clear_bit(0, &watchdog.opened);
490 		return err;
491 	}
492 
493 	if (nowayout)
494 		__module_get(THIS_MODULE);
495 
496 	watchdog.expect_close = 0;
497 	return nonseekable_open(inode, file);
498 }
499 
500 static int watchdog_release(struct inode *inode, struct file *file)
501 {
502 	clear_bit(0, &watchdog.opened);
503 
504 	if (!watchdog.expect_close) {
505 		watchdog_keepalive();
506 		pr_crit("Unexpected close, not stopping watchdog!\n");
507 	} else if (!nowayout) {
508 		watchdog_stop();
509 	}
510 	return 0;
511 }
512 
513 /*
514  *      watchdog_write:
515  *      @file: file handle to the watchdog
516  *      @buf: buffer to write
517  *      @count: count of bytes
518  *      @ppos: pointer to the position to write. No seeks allowed
519  *
520  *      A write to a watchdog device is defined as a keepalive signal. Any
521  *      write of data will do, as we we don't define content meaning.
522  */
523 
524 static ssize_t watchdog_write(struct file *file, const char __user *buf,
525 			    size_t count, loff_t *ppos)
526 {
527 	if (count) {
528 		if (!nowayout) {
529 			size_t i;
530 
531 			/* In case it was set long ago */
532 			bool expect_close = false;
533 
534 			for (i = 0; i != count; i++) {
535 				char c;
536 				if (get_user(c, buf + i))
537 					return -EFAULT;
538 				expect_close = (c == 'V');
539 			}
540 
541 			/* Properly order writes across fork()ed processes */
542 			mutex_lock(&watchdog.lock);
543 			watchdog.expect_close = expect_close;
544 			mutex_unlock(&watchdog.lock);
545 		}
546 
547 		/* someone wrote to us, we should restart timer */
548 		watchdog_keepalive();
549 	}
550 	return count;
551 }
552 
553 /*
554  *      watchdog_ioctl:
555  *      @inode: inode of the device
556  *      @file: file handle to the device
557  *      @cmd: watchdog command
558  *      @arg: argument pointer
559  *
560  *      The watchdog API defines a common set of functions for all watchdogs
561  *      according to their available features.
562  */
563 static long watchdog_ioctl(struct file *file, unsigned int cmd,
564 	unsigned long arg)
565 {
566 	int status;
567 	int new_options;
568 	int new_timeout;
569 	union {
570 		struct watchdog_info __user *ident;
571 		int __user *i;
572 	} uarg;
573 
574 	uarg.i = (int __user *)arg;
575 
576 	switch (cmd) {
577 	case WDIOC_GETSUPPORT:
578 		return copy_to_user(uarg.ident, &watchdog.ident,
579 			sizeof(watchdog.ident)) ? -EFAULT : 0;
580 
581 	case WDIOC_GETSTATUS:
582 		status = watchdog_get_status();
583 		if (status < 0)
584 			return status;
585 		return put_user(status, uarg.i);
586 
587 	case WDIOC_GETBOOTSTATUS:
588 		return put_user(0, uarg.i);
589 
590 	case WDIOC_SETOPTIONS:
591 		if (get_user(new_options, uarg.i))
592 			return -EFAULT;
593 
594 		if (new_options & WDIOS_DISABLECARD)
595 			watchdog_stop();
596 
597 		if (new_options & WDIOS_ENABLECARD)
598 			return watchdog_start();
599 
600 
601 	case WDIOC_KEEPALIVE:
602 		watchdog_keepalive();
603 		return 0;
604 
605 	case WDIOC_SETTIMEOUT:
606 		if (get_user(new_timeout, uarg.i))
607 			return -EFAULT;
608 
609 		if (watchdog_set_timeout(new_timeout))
610 			return -EINVAL;
611 
612 		watchdog_keepalive();
613 		/* Fall */
614 
615 	case WDIOC_GETTIMEOUT:
616 		return put_user(watchdog.timeout, uarg.i);
617 
618 	default:
619 		return -ENOTTY;
620 
621 	}
622 }
623 
624 static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
625 	void *unused)
626 {
627 	if (code == SYS_DOWN || code == SYS_HALT)
628 		watchdog_stop();
629 	return NOTIFY_DONE;
630 }
631 
632 static const struct file_operations watchdog_fops = {
633 	.owner		= THIS_MODULE,
634 	.llseek		= no_llseek,
635 	.open		= watchdog_open,
636 	.release	= watchdog_release,
637 	.write		= watchdog_write,
638 	.unlocked_ioctl	= watchdog_ioctl,
639 };
640 
641 static struct miscdevice watchdog_miscdev = {
642 	.minor		= WATCHDOG_MINOR,
643 	.name		= "watchdog",
644 	.fops		= &watchdog_fops,
645 };
646 
647 static struct notifier_block watchdog_notifier = {
648 	.notifier_call = watchdog_notify_sys,
649 };
650 
651 static int __init watchdog_init(int sioaddr)
652 {
653 	int wdt_conf, err = 0;
654 
655 	/* No need to lock watchdog.lock here because no entry points
656 	 * into the module have been registered yet.
657 	 */
658 	watchdog.sioaddr = sioaddr;
659 	watchdog.ident.options = WDIOC_SETTIMEOUT
660 				| WDIOF_MAGICCLOSE
661 				| WDIOF_KEEPALIVEPING;
662 
663 	snprintf(watchdog.ident.identity,
664 		sizeof(watchdog.ident.identity), "%s watchdog",
665 		f71808e_names[watchdog.type]);
666 
667 	err = superio_enter(sioaddr);
668 	if (err)
669 		return err;
670 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
671 
672 	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
673 	watchdog.caused_reboot = wdt_conf & BIT(F71808FG_FLAG_WDTMOUT_STS);
674 
675 	superio_exit(sioaddr);
676 
677 	err = watchdog_set_timeout(timeout);
678 	if (err)
679 		return err;
680 	err = watchdog_set_pulse_width(pulse_width);
681 	if (err)
682 		return err;
683 
684 	err = register_reboot_notifier(&watchdog_notifier);
685 	if (err)
686 		return err;
687 
688 	err = misc_register(&watchdog_miscdev);
689 	if (err) {
690 		pr_err("cannot register miscdev on minor=%d\n",
691 		       watchdog_miscdev.minor);
692 		goto exit_reboot;
693 	}
694 
695 	if (start_withtimeout) {
696 		if (start_withtimeout <= 0
697 		 || start_withtimeout >  max_timeout) {
698 			pr_err("starting timeout out of range\n");
699 			err = -EINVAL;
700 			goto exit_miscdev;
701 		}
702 
703 		err = watchdog_start();
704 		if (err) {
705 			pr_err("cannot start watchdog timer\n");
706 			goto exit_miscdev;
707 		}
708 
709 		mutex_lock(&watchdog.lock);
710 		err = superio_enter(sioaddr);
711 		if (err)
712 			goto exit_unlock;
713 		superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
714 
715 		if (start_withtimeout > 0xff) {
716 			/* select minutes for timer units */
717 			superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
718 				F71808FG_FLAG_WD_UNIT);
719 			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
720 				DIV_ROUND_UP(start_withtimeout, 60));
721 		} else {
722 			/* select seconds for timer units */
723 			superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
724 				F71808FG_FLAG_WD_UNIT);
725 			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
726 				start_withtimeout);
727 		}
728 
729 		superio_exit(sioaddr);
730 		mutex_unlock(&watchdog.lock);
731 
732 		if (nowayout)
733 			__module_get(THIS_MODULE);
734 
735 		pr_info("watchdog started with initial timeout of %u sec\n",
736 			start_withtimeout);
737 	}
738 
739 	return 0;
740 
741 exit_unlock:
742 	mutex_unlock(&watchdog.lock);
743 exit_miscdev:
744 	misc_deregister(&watchdog_miscdev);
745 exit_reboot:
746 	unregister_reboot_notifier(&watchdog_notifier);
747 
748 	return err;
749 }
750 
751 static int __init f71808e_find(int sioaddr)
752 {
753 	u16 devid;
754 	int err = superio_enter(sioaddr);
755 	if (err)
756 		return err;
757 
758 	devid = superio_inw(sioaddr, SIO_REG_MANID);
759 	if (devid != SIO_FINTEK_ID) {
760 		pr_debug("Not a Fintek device\n");
761 		err = -ENODEV;
762 		goto exit;
763 	}
764 
765 	devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
766 	switch (devid) {
767 	case SIO_F71808_ID:
768 		watchdog.type = f71808fg;
769 		break;
770 	case SIO_F71862_ID:
771 		watchdog.type = f71862fg;
772 		err = f71862fg_pin_configure(0); /* validate module parameter */
773 		break;
774 	case SIO_F71869_ID:
775 	case SIO_F71869A_ID:
776 		watchdog.type = f71869;
777 		break;
778 	case SIO_F71882_ID:
779 		watchdog.type = f71882fg;
780 		break;
781 	case SIO_F71889_ID:
782 		watchdog.type = f71889fg;
783 		break;
784 	case SIO_F71858_ID:
785 		/* Confirmed (by datasheet) not to have a watchdog. */
786 		err = -ENODEV;
787 		goto exit;
788 	case SIO_F81865_ID:
789 		watchdog.type = f81865;
790 		break;
791 	default:
792 		pr_info("Unrecognized Fintek device: %04x\n",
793 			(unsigned int)devid);
794 		err = -ENODEV;
795 		goto exit;
796 	}
797 
798 	pr_info("Found %s watchdog chip, revision %d\n",
799 		f71808e_names[watchdog.type],
800 		(int)superio_inb(sioaddr, SIO_REG_DEVREV));
801 exit:
802 	superio_exit(sioaddr);
803 	return err;
804 }
805 
806 static int __init f71808e_init(void)
807 {
808 	static const unsigned short addrs[] = { 0x2e, 0x4e };
809 	int err = -ENODEV;
810 	int i;
811 
812 	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
813 		err = f71808e_find(addrs[i]);
814 		if (err == 0)
815 			break;
816 	}
817 	if (i == ARRAY_SIZE(addrs))
818 		return err;
819 
820 	return watchdog_init(addrs[i]);
821 }
822 
823 static void __exit f71808e_exit(void)
824 {
825 	if (watchdog_is_running()) {
826 		pr_warn("Watchdog timer still running, stopping it\n");
827 		watchdog_stop();
828 	}
829 	misc_deregister(&watchdog_miscdev);
830 	unregister_reboot_notifier(&watchdog_notifier);
831 }
832 
833 MODULE_DESCRIPTION("F71808E Watchdog Driver");
834 MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
835 MODULE_LICENSE("GPL");
836 
837 module_init(f71808e_init);
838 module_exit(f71808e_exit);
839