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_F81866_REG_PORT_SEL	0x27	/* F81866 Multi-Function Register */
49 #define SIO_REG_MFUNCT1		0x29	/* Multi function select 1 */
50 #define SIO_REG_MFUNCT2		0x2a	/* Multi function select 2 */
51 #define SIO_REG_MFUNCT3		0x2b	/* Multi function select 3 */
52 #define SIO_F81866_REG_GPIO1	0x2c	/* F81866 GPIO1 Enable Register */
53 #define SIO_REG_ENABLE		0x30	/* Logical device enable */
54 #define SIO_REG_ADDR		0x60	/* Logical device address (2 bytes) */
55 
56 #define SIO_FINTEK_ID		0x1934	/* Manufacturers ID */
57 #define SIO_F71808_ID		0x0901	/* Chipset ID */
58 #define SIO_F71858_ID		0x0507	/* Chipset ID */
59 #define SIO_F71862_ID		0x0601	/* Chipset ID */
60 #define SIO_F71868_ID		0x1106	/* Chipset ID */
61 #define SIO_F71869_ID		0x0814	/* Chipset ID */
62 #define SIO_F71869A_ID		0x1007	/* Chipset ID */
63 #define SIO_F71882_ID		0x0541	/* Chipset ID */
64 #define SIO_F71889_ID		0x0723	/* Chipset ID */
65 #define SIO_F81865_ID		0x0704	/* Chipset ID */
66 #define SIO_F81866_ID		0x1010	/* Chipset ID */
67 
68 #define F71808FG_REG_WDO_CONF		0xf0
69 #define F71808FG_REG_WDT_CONF		0xf5
70 #define F71808FG_REG_WD_TIME		0xf6
71 
72 #define F71808FG_FLAG_WDOUT_EN		7
73 
74 #define F71808FG_FLAG_WDTMOUT_STS	6
75 #define F71808FG_FLAG_WD_EN		5
76 #define F71808FG_FLAG_WD_PULSE		4
77 #define F71808FG_FLAG_WD_UNIT		3
78 
79 #define F81865_REG_WDO_CONF		0xfa
80 #define F81865_FLAG_WDOUT_EN		0
81 
82 /* Default values */
83 #define WATCHDOG_TIMEOUT	60	/* 1 minute default timeout */
84 #define WATCHDOG_MAX_TIMEOUT	(60 * 255)
85 #define WATCHDOG_PULSE_WIDTH	125	/* 125 ms, default pulse width for
86 					   watchdog signal */
87 #define WATCHDOG_F71862FG_PIN	63	/* default watchdog reset output
88 					   pin number 63 */
89 
90 static unsigned short force_id;
91 module_param(force_id, ushort, 0);
92 MODULE_PARM_DESC(force_id, "Override the detected device ID");
93 
94 static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
95 static int timeout = WATCHDOG_TIMEOUT;	/* default timeout in seconds */
96 module_param(timeout, int, 0);
97 MODULE_PARM_DESC(timeout,
98 	"Watchdog timeout in seconds. 1<= timeout <="
99 			__MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
100 			__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
101 
102 static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
103 module_param(pulse_width, uint, 0);
104 MODULE_PARM_DESC(pulse_width,
105 	"Watchdog signal pulse width. 0(=level), 1, 25, 30, 125, 150, 5000 or 6000 ms"
106 			" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");
107 
108 static unsigned int f71862fg_pin = WATCHDOG_F71862FG_PIN;
109 module_param(f71862fg_pin, uint, 0);
110 MODULE_PARM_DESC(f71862fg_pin,
111 	"Watchdog f71862fg reset output pin configuration. Choose pin 56 or 63"
112 			" (default=" __MODULE_STRING(WATCHDOG_F71862FG_PIN)")");
113 
114 static bool nowayout = WATCHDOG_NOWAYOUT;
115 module_param(nowayout, bool, 0444);
116 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
117 
118 static unsigned int start_withtimeout;
119 module_param(start_withtimeout, uint, 0);
120 MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
121 	" given initial timeout. Zero (default) disables this feature.");
122 
123 enum chips { f71808fg, f71858fg, f71862fg, f71868, f71869, f71882fg, f71889fg,
124 	     f81865, f81866};
125 
126 static const char *f71808e_names[] = {
127 	"f71808fg",
128 	"f71858fg",
129 	"f71862fg",
130 	"f71868",
131 	"f71869",
132 	"f71882fg",
133 	"f71889fg",
134 	"f81865",
135 	"f81866",
136 };
137 
138 /* Super-I/O Function prototypes */
139 static inline int superio_inb(int base, int reg);
140 static inline int superio_inw(int base, int reg);
141 static inline void superio_outb(int base, int reg, u8 val);
142 static inline void superio_set_bit(int base, int reg, int bit);
143 static inline void superio_clear_bit(int base, int reg, int bit);
144 static inline int superio_enter(int base);
145 static inline void superio_select(int base, int ld);
146 static inline void superio_exit(int base);
147 
148 struct watchdog_data {
149 	unsigned short	sioaddr;
150 	enum chips	type;
151 	unsigned long	opened;
152 	struct mutex	lock;
153 	char		expect_close;
154 	struct watchdog_info ident;
155 
156 	unsigned short	timeout;
157 	u8		timer_val;	/* content for the wd_time register */
158 	char		minutes_mode;
159 	u8		pulse_val;	/* pulse width flag */
160 	char		pulse_mode;	/* enable pulse output mode? */
161 	char		caused_reboot;	/* last reboot was by the watchdog */
162 };
163 
164 static struct watchdog_data watchdog = {
165 	.lock = __MUTEX_INITIALIZER(watchdog.lock),
166 };
167 
168 /* Super I/O functions */
169 static inline int superio_inb(int base, int reg)
170 {
171 	outb(reg, base);
172 	return inb(base + 1);
173 }
174 
175 static int superio_inw(int base, int reg)
176 {
177 	int val;
178 	val  = superio_inb(base, reg) << 8;
179 	val |= superio_inb(base, reg + 1);
180 	return val;
181 }
182 
183 static inline void superio_outb(int base, int reg, u8 val)
184 {
185 	outb(reg, base);
186 	outb(val, base + 1);
187 }
188 
189 static inline void superio_set_bit(int base, int reg, int bit)
190 {
191 	unsigned long val = superio_inb(base, reg);
192 	__set_bit(bit, &val);
193 	superio_outb(base, reg, val);
194 }
195 
196 static inline void superio_clear_bit(int base, int reg, int bit)
197 {
198 	unsigned long val = superio_inb(base, reg);
199 	__clear_bit(bit, &val);
200 	superio_outb(base, reg, val);
201 }
202 
203 static inline int superio_enter(int base)
204 {
205 	/* Don't step on other drivers' I/O space by accident */
206 	if (!request_muxed_region(base, 2, DRVNAME)) {
207 		pr_err("I/O address 0x%04x already in use\n", (int)base);
208 		return -EBUSY;
209 	}
210 
211 	/* according to the datasheet the key must be sent twice! */
212 	outb(SIO_UNLOCK_KEY, base);
213 	outb(SIO_UNLOCK_KEY, base);
214 
215 	return 0;
216 }
217 
218 static inline void superio_select(int base, int ld)
219 {
220 	outb(SIO_REG_LDSEL, base);
221 	outb(ld, base + 1);
222 }
223 
224 static inline void superio_exit(int base)
225 {
226 	outb(SIO_LOCK_KEY, base);
227 	release_region(base, 2);
228 }
229 
230 static int watchdog_set_timeout(int timeout)
231 {
232 	if (timeout <= 0
233 	 || timeout >  max_timeout) {
234 		pr_err("watchdog timeout out of range\n");
235 		return -EINVAL;
236 	}
237 
238 	mutex_lock(&watchdog.lock);
239 
240 	watchdog.timeout = timeout;
241 	if (timeout > 0xff) {
242 		watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
243 		watchdog.minutes_mode = true;
244 	} else {
245 		watchdog.timer_val = timeout;
246 		watchdog.minutes_mode = false;
247 	}
248 
249 	mutex_unlock(&watchdog.lock);
250 
251 	return 0;
252 }
253 
254 static int watchdog_set_pulse_width(unsigned int pw)
255 {
256 	int err = 0;
257 	unsigned int t1 = 25, t2 = 125, t3 = 5000;
258 
259 	if (watchdog.type == f71868) {
260 		t1 = 30;
261 		t2 = 150;
262 		t3 = 6000;
263 	}
264 
265 	mutex_lock(&watchdog.lock);
266 
267 	if        (pw <=  1) {
268 		watchdog.pulse_val = 0;
269 	} else if (pw <= t1) {
270 		watchdog.pulse_val = 1;
271 	} else if (pw <= t2) {
272 		watchdog.pulse_val = 2;
273 	} else if (pw <= t3) {
274 		watchdog.pulse_val = 3;
275 	} else {
276 		pr_err("pulse width out of range\n");
277 		err = -EINVAL;
278 		goto exit_unlock;
279 	}
280 
281 	watchdog.pulse_mode = pw;
282 
283 exit_unlock:
284 	mutex_unlock(&watchdog.lock);
285 	return err;
286 }
287 
288 static int watchdog_keepalive(void)
289 {
290 	int err = 0;
291 
292 	mutex_lock(&watchdog.lock);
293 	err = superio_enter(watchdog.sioaddr);
294 	if (err)
295 		goto exit_unlock;
296 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
297 
298 	if (watchdog.minutes_mode)
299 		/* select minutes for timer units */
300 		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
301 				F71808FG_FLAG_WD_UNIT);
302 	else
303 		/* select seconds for timer units */
304 		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
305 				F71808FG_FLAG_WD_UNIT);
306 
307 	/* Set timer value */
308 	superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
309 			   watchdog.timer_val);
310 
311 	superio_exit(watchdog.sioaddr);
312 
313 exit_unlock:
314 	mutex_unlock(&watchdog.lock);
315 	return err;
316 }
317 
318 static int f71862fg_pin_configure(unsigned short ioaddr)
319 {
320 	/* When ioaddr is non-zero the calling function has to take care of
321 	   mutex handling and superio preparation! */
322 
323 	if (f71862fg_pin == 63) {
324 		if (ioaddr) {
325 			/* SPI must be disabled first to use this pin! */
326 			superio_clear_bit(ioaddr, SIO_REG_ROM_ADDR_SEL, 6);
327 			superio_set_bit(ioaddr, SIO_REG_MFUNCT3, 4);
328 		}
329 	} else if (f71862fg_pin == 56) {
330 		if (ioaddr)
331 			superio_set_bit(ioaddr, SIO_REG_MFUNCT1, 1);
332 	} else {
333 		pr_err("Invalid argument f71862fg_pin=%d\n", f71862fg_pin);
334 		return -EINVAL;
335 	}
336 	return 0;
337 }
338 
339 static int watchdog_start(void)
340 {
341 	int err;
342 	u8 tmp;
343 
344 	/* Make sure we don't die as soon as the watchdog is enabled below */
345 	err = watchdog_keepalive();
346 	if (err)
347 		return err;
348 
349 	mutex_lock(&watchdog.lock);
350 	err = superio_enter(watchdog.sioaddr);
351 	if (err)
352 		goto exit_unlock;
353 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
354 
355 	/* Watchdog pin configuration */
356 	switch (watchdog.type) {
357 	case f71808fg:
358 		/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
359 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT2, 3);
360 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 3);
361 		break;
362 
363 	case f71862fg:
364 		err = f71862fg_pin_configure(watchdog.sioaddr);
365 		if (err)
366 			goto exit_superio;
367 		break;
368 
369 	case f71868:
370 	case f71869:
371 		/* GPIO14 --> WDTRST# */
372 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 4);
373 		break;
374 
375 	case f71882fg:
376 		/* Set pin 56 to WDTRST# */
377 		superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
378 		break;
379 
380 	case f71889fg:
381 		/* set pin 40 to WDTRST# */
382 		superio_outb(watchdog.sioaddr, SIO_REG_MFUNCT3,
383 			superio_inb(watchdog.sioaddr, SIO_REG_MFUNCT3) & 0xcf);
384 		break;
385 
386 	case f81865:
387 		/* Set pin 70 to WDTRST# */
388 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 5);
389 		break;
390 
391 	case f81866:
392 		/*
393 		 * GPIO1 Control Register when 27h BIT3:2 = 01 & BIT0 = 0.
394 		 * The PIN 70(GPIO15/WDTRST) is controlled by 2Ch:
395 		 *     BIT5: 0 -> WDTRST#
396 		 *           1 -> GPIO15
397 		 */
398 		tmp = superio_inb(watchdog.sioaddr, SIO_F81866_REG_PORT_SEL);
399 		tmp &= ~(BIT(3) | BIT(0));
400 		tmp |= BIT(2);
401 		superio_outb(watchdog.sioaddr, SIO_F81866_REG_PORT_SEL, tmp);
402 
403 		superio_clear_bit(watchdog.sioaddr, SIO_F81866_REG_GPIO1, 5);
404 		break;
405 
406 	default:
407 		/*
408 		 * 'default' label to shut up the compiler and catch
409 		 * programmer errors
410 		 */
411 		err = -ENODEV;
412 		goto exit_superio;
413 	}
414 
415 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
416 	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
417 
418 	if (watchdog.type == f81865 || watchdog.type == f81866)
419 		superio_set_bit(watchdog.sioaddr, F81865_REG_WDO_CONF,
420 				F81865_FLAG_WDOUT_EN);
421 	else
422 		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
423 				F71808FG_FLAG_WDOUT_EN);
424 
425 	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
426 			F71808FG_FLAG_WD_EN);
427 
428 	if (watchdog.pulse_mode) {
429 		/* Select "pulse" output mode with given duration */
430 		u8 wdt_conf = superio_inb(watchdog.sioaddr,
431 				F71808FG_REG_WDT_CONF);
432 
433 		/* Set WD_PSWIDTH bits (1:0) */
434 		wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
435 		/* Set WD_PULSE to "pulse" mode */
436 		wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);
437 
438 		superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
439 				wdt_conf);
440 	} else {
441 		/* Select "level" output mode */
442 		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
443 				F71808FG_FLAG_WD_PULSE);
444 	}
445 
446 exit_superio:
447 	superio_exit(watchdog.sioaddr);
448 exit_unlock:
449 	mutex_unlock(&watchdog.lock);
450 
451 	return err;
452 }
453 
454 static int watchdog_stop(void)
455 {
456 	int err = 0;
457 
458 	mutex_lock(&watchdog.lock);
459 	err = superio_enter(watchdog.sioaddr);
460 	if (err)
461 		goto exit_unlock;
462 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
463 
464 	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
465 			F71808FG_FLAG_WD_EN);
466 
467 	superio_exit(watchdog.sioaddr);
468 
469 exit_unlock:
470 	mutex_unlock(&watchdog.lock);
471 
472 	return err;
473 }
474 
475 static int watchdog_get_status(void)
476 {
477 	int status = 0;
478 
479 	mutex_lock(&watchdog.lock);
480 	status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
481 	mutex_unlock(&watchdog.lock);
482 
483 	return status;
484 }
485 
486 static bool watchdog_is_running(void)
487 {
488 	/*
489 	 * if we fail to determine the watchdog's status assume it to be
490 	 * running to be on the safe side
491 	 */
492 	bool is_running = true;
493 
494 	mutex_lock(&watchdog.lock);
495 	if (superio_enter(watchdog.sioaddr))
496 		goto exit_unlock;
497 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
498 
499 	is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
500 		&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
501 			& BIT(F71808FG_FLAG_WD_EN));
502 
503 	superio_exit(watchdog.sioaddr);
504 
505 exit_unlock:
506 	mutex_unlock(&watchdog.lock);
507 	return is_running;
508 }
509 
510 /* /dev/watchdog api */
511 
512 static int watchdog_open(struct inode *inode, struct file *file)
513 {
514 	int err;
515 
516 	/* If the watchdog is alive we don't need to start it again */
517 	if (test_and_set_bit(0, &watchdog.opened))
518 		return -EBUSY;
519 
520 	err = watchdog_start();
521 	if (err) {
522 		clear_bit(0, &watchdog.opened);
523 		return err;
524 	}
525 
526 	if (nowayout)
527 		__module_get(THIS_MODULE);
528 
529 	watchdog.expect_close = 0;
530 	return stream_open(inode, file);
531 }
532 
533 static int watchdog_release(struct inode *inode, struct file *file)
534 {
535 	clear_bit(0, &watchdog.opened);
536 
537 	if (!watchdog.expect_close) {
538 		watchdog_keepalive();
539 		pr_crit("Unexpected close, not stopping watchdog!\n");
540 	} else if (!nowayout) {
541 		watchdog_stop();
542 	}
543 	return 0;
544 }
545 
546 /*
547  *      watchdog_write:
548  *      @file: file handle to the watchdog
549  *      @buf: buffer to write
550  *      @count: count of bytes
551  *      @ppos: pointer to the position to write. No seeks allowed
552  *
553  *      A write to a watchdog device is defined as a keepalive signal. Any
554  *      write of data will do, as we we don't define content meaning.
555  */
556 
557 static ssize_t watchdog_write(struct file *file, const char __user *buf,
558 			    size_t count, loff_t *ppos)
559 {
560 	if (count) {
561 		if (!nowayout) {
562 			size_t i;
563 
564 			/* In case it was set long ago */
565 			bool expect_close = false;
566 
567 			for (i = 0; i != count; i++) {
568 				char c;
569 				if (get_user(c, buf + i))
570 					return -EFAULT;
571 				if (c == 'V')
572 					expect_close = true;
573 			}
574 
575 			/* Properly order writes across fork()ed processes */
576 			mutex_lock(&watchdog.lock);
577 			watchdog.expect_close = expect_close;
578 			mutex_unlock(&watchdog.lock);
579 		}
580 
581 		/* someone wrote to us, we should restart timer */
582 		watchdog_keepalive();
583 	}
584 	return count;
585 }
586 
587 /*
588  *      watchdog_ioctl:
589  *      @inode: inode of the device
590  *      @file: file handle to the device
591  *      @cmd: watchdog command
592  *      @arg: argument pointer
593  *
594  *      The watchdog API defines a common set of functions for all watchdogs
595  *      according to their available features.
596  */
597 static long watchdog_ioctl(struct file *file, unsigned int cmd,
598 	unsigned long arg)
599 {
600 	int status;
601 	int new_options;
602 	int new_timeout;
603 	union {
604 		struct watchdog_info __user *ident;
605 		int __user *i;
606 	} uarg;
607 
608 	uarg.i = (int __user *)arg;
609 
610 	switch (cmd) {
611 	case WDIOC_GETSUPPORT:
612 		return copy_to_user(uarg.ident, &watchdog.ident,
613 			sizeof(watchdog.ident)) ? -EFAULT : 0;
614 
615 	case WDIOC_GETSTATUS:
616 		status = watchdog_get_status();
617 		if (status < 0)
618 			return status;
619 		return put_user(status, uarg.i);
620 
621 	case WDIOC_GETBOOTSTATUS:
622 		return put_user(0, uarg.i);
623 
624 	case WDIOC_SETOPTIONS:
625 		if (get_user(new_options, uarg.i))
626 			return -EFAULT;
627 
628 		if (new_options & WDIOS_DISABLECARD)
629 			watchdog_stop();
630 
631 		if (new_options & WDIOS_ENABLECARD)
632 			return watchdog_start();
633 		/* fall through */
634 
635 	case WDIOC_KEEPALIVE:
636 		watchdog_keepalive();
637 		return 0;
638 
639 	case WDIOC_SETTIMEOUT:
640 		if (get_user(new_timeout, uarg.i))
641 			return -EFAULT;
642 
643 		if (watchdog_set_timeout(new_timeout))
644 			return -EINVAL;
645 
646 		watchdog_keepalive();
647 		/* fall through */
648 
649 	case WDIOC_GETTIMEOUT:
650 		return put_user(watchdog.timeout, uarg.i);
651 
652 	default:
653 		return -ENOTTY;
654 
655 	}
656 }
657 
658 static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
659 	void *unused)
660 {
661 	if (code == SYS_DOWN || code == SYS_HALT)
662 		watchdog_stop();
663 	return NOTIFY_DONE;
664 }
665 
666 static const struct file_operations watchdog_fops = {
667 	.owner		= THIS_MODULE,
668 	.llseek		= no_llseek,
669 	.open		= watchdog_open,
670 	.release	= watchdog_release,
671 	.write		= watchdog_write,
672 	.unlocked_ioctl	= watchdog_ioctl,
673 };
674 
675 static struct miscdevice watchdog_miscdev = {
676 	.minor		= WATCHDOG_MINOR,
677 	.name		= "watchdog",
678 	.fops		= &watchdog_fops,
679 };
680 
681 static struct notifier_block watchdog_notifier = {
682 	.notifier_call = watchdog_notify_sys,
683 };
684 
685 static int __init watchdog_init(int sioaddr)
686 {
687 	int wdt_conf, err = 0;
688 
689 	/* No need to lock watchdog.lock here because no entry points
690 	 * into the module have been registered yet.
691 	 */
692 	watchdog.sioaddr = sioaddr;
693 	watchdog.ident.options = WDIOC_SETTIMEOUT
694 				| WDIOF_MAGICCLOSE
695 				| WDIOF_KEEPALIVEPING;
696 
697 	snprintf(watchdog.ident.identity,
698 		sizeof(watchdog.ident.identity), "%s watchdog",
699 		f71808e_names[watchdog.type]);
700 
701 	err = superio_enter(sioaddr);
702 	if (err)
703 		return err;
704 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
705 
706 	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
707 	watchdog.caused_reboot = wdt_conf & BIT(F71808FG_FLAG_WDTMOUT_STS);
708 
709 	superio_exit(sioaddr);
710 
711 	err = watchdog_set_timeout(timeout);
712 	if (err)
713 		return err;
714 	err = watchdog_set_pulse_width(pulse_width);
715 	if (err)
716 		return err;
717 
718 	err = register_reboot_notifier(&watchdog_notifier);
719 	if (err)
720 		return err;
721 
722 	err = misc_register(&watchdog_miscdev);
723 	if (err) {
724 		pr_err("cannot register miscdev on minor=%d\n",
725 		       watchdog_miscdev.minor);
726 		goto exit_reboot;
727 	}
728 
729 	if (start_withtimeout) {
730 		if (start_withtimeout <= 0
731 		 || start_withtimeout >  max_timeout) {
732 			pr_err("starting timeout out of range\n");
733 			err = -EINVAL;
734 			goto exit_miscdev;
735 		}
736 
737 		err = watchdog_start();
738 		if (err) {
739 			pr_err("cannot start watchdog timer\n");
740 			goto exit_miscdev;
741 		}
742 
743 		mutex_lock(&watchdog.lock);
744 		err = superio_enter(sioaddr);
745 		if (err)
746 			goto exit_unlock;
747 		superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
748 
749 		if (start_withtimeout > 0xff) {
750 			/* select minutes for timer units */
751 			superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
752 				F71808FG_FLAG_WD_UNIT);
753 			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
754 				DIV_ROUND_UP(start_withtimeout, 60));
755 		} else {
756 			/* select seconds for timer units */
757 			superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
758 				F71808FG_FLAG_WD_UNIT);
759 			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
760 				start_withtimeout);
761 		}
762 
763 		superio_exit(sioaddr);
764 		mutex_unlock(&watchdog.lock);
765 
766 		if (nowayout)
767 			__module_get(THIS_MODULE);
768 
769 		pr_info("watchdog started with initial timeout of %u sec\n",
770 			start_withtimeout);
771 	}
772 
773 	return 0;
774 
775 exit_unlock:
776 	mutex_unlock(&watchdog.lock);
777 exit_miscdev:
778 	misc_deregister(&watchdog_miscdev);
779 exit_reboot:
780 	unregister_reboot_notifier(&watchdog_notifier);
781 
782 	return err;
783 }
784 
785 static int __init f71808e_find(int sioaddr)
786 {
787 	u16 devid;
788 	int err = superio_enter(sioaddr);
789 	if (err)
790 		return err;
791 
792 	devid = superio_inw(sioaddr, SIO_REG_MANID);
793 	if (devid != SIO_FINTEK_ID) {
794 		pr_debug("Not a Fintek device\n");
795 		err = -ENODEV;
796 		goto exit;
797 	}
798 
799 	devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
800 	switch (devid) {
801 	case SIO_F71808_ID:
802 		watchdog.type = f71808fg;
803 		break;
804 	case SIO_F71862_ID:
805 		watchdog.type = f71862fg;
806 		err = f71862fg_pin_configure(0); /* validate module parameter */
807 		break;
808 	case SIO_F71868_ID:
809 		watchdog.type = f71868;
810 		break;
811 	case SIO_F71869_ID:
812 	case SIO_F71869A_ID:
813 		watchdog.type = f71869;
814 		break;
815 	case SIO_F71882_ID:
816 		watchdog.type = f71882fg;
817 		break;
818 	case SIO_F71889_ID:
819 		watchdog.type = f71889fg;
820 		break;
821 	case SIO_F71858_ID:
822 		/* Confirmed (by datasheet) not to have a watchdog. */
823 		err = -ENODEV;
824 		goto exit;
825 	case SIO_F81865_ID:
826 		watchdog.type = f81865;
827 		break;
828 	case SIO_F81866_ID:
829 		watchdog.type = f81866;
830 		break;
831 	default:
832 		pr_info("Unrecognized Fintek device: %04x\n",
833 			(unsigned int)devid);
834 		err = -ENODEV;
835 		goto exit;
836 	}
837 
838 	pr_info("Found %s watchdog chip, revision %d\n",
839 		f71808e_names[watchdog.type],
840 		(int)superio_inb(sioaddr, SIO_REG_DEVREV));
841 exit:
842 	superio_exit(sioaddr);
843 	return err;
844 }
845 
846 static int __init f71808e_init(void)
847 {
848 	static const unsigned short addrs[] = { 0x2e, 0x4e };
849 	int err = -ENODEV;
850 	int i;
851 
852 	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
853 		err = f71808e_find(addrs[i]);
854 		if (err == 0)
855 			break;
856 	}
857 	if (i == ARRAY_SIZE(addrs))
858 		return err;
859 
860 	return watchdog_init(addrs[i]);
861 }
862 
863 static void __exit f71808e_exit(void)
864 {
865 	if (watchdog_is_running()) {
866 		pr_warn("Watchdog timer still running, stopping it\n");
867 		watchdog_stop();
868 	}
869 	misc_deregister(&watchdog_miscdev);
870 	unregister_reboot_notifier(&watchdog_notifier);
871 }
872 
873 MODULE_DESCRIPTION("F71808E Watchdog Driver");
874 MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
875 MODULE_LICENSE("GPL");
876 
877 module_init(f71808e_init);
878 module_exit(f71808e_exit);
879