1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /***************************************************************************
3  *   Copyright (C) 2006 by Hans Edgington <hans@edgington.nl>              *
4  *   Copyright (C) 2007-2009 Hans de Goede <hdegoede@redhat.com>           *
5  *   Copyright (C) 2010 Giel van Schijndel <me@mortis.eu>                  *
6  *                                                                         *
7  ***************************************************************************/
8 
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 
11 #include <linux/err.h>
12 #include <linux/fs.h>
13 #include <linux/init.h>
14 #include <linux/io.h>
15 #include <linux/ioport.h>
16 #include <linux/miscdevice.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/notifier.h>
20 #include <linux/reboot.h>
21 #include <linux/uaccess.h>
22 #include <linux/watchdog.h>
23 
24 #define DRVNAME "f71808e_wdt"
25 
26 #define SIO_F71808FG_LD_WDT	0x07	/* Watchdog timer logical device */
27 #define SIO_UNLOCK_KEY		0x87	/* Key to enable Super-I/O */
28 #define SIO_LOCK_KEY		0xAA	/* Key to disable Super-I/O */
29 
30 #define SIO_REG_LDSEL		0x07	/* Logical device select */
31 #define SIO_REG_DEVID		0x20	/* Device ID (2 bytes) */
32 #define SIO_REG_DEVREV		0x22	/* Device revision */
33 #define SIO_REG_MANID		0x23	/* Fintek ID (2 bytes) */
34 #define SIO_REG_CLOCK_SEL	0x26	/* Clock select */
35 #define SIO_REG_ROM_ADDR_SEL	0x27	/* ROM address select */
36 #define SIO_F81866_REG_PORT_SEL	0x27	/* F81866 Multi-Function Register */
37 #define SIO_REG_TSI_LEVEL_SEL	0x28	/* TSI Level select */
38 #define SIO_REG_MFUNCT1		0x29	/* Multi function select 1 */
39 #define SIO_REG_MFUNCT2		0x2a	/* Multi function select 2 */
40 #define SIO_REG_MFUNCT3		0x2b	/* Multi function select 3 */
41 #define SIO_F81866_REG_GPIO1	0x2c	/* F81866 GPIO1 Enable Register */
42 #define SIO_REG_ENABLE		0x30	/* Logical device enable */
43 #define SIO_REG_ADDR		0x60	/* Logical device address (2 bytes) */
44 
45 #define SIO_FINTEK_ID		0x1934	/* Manufacturers ID */
46 #define SIO_F71808_ID		0x0901	/* Chipset ID */
47 #define SIO_F71858_ID		0x0507	/* Chipset ID */
48 #define SIO_F71862_ID		0x0601	/* Chipset ID */
49 #define SIO_F71868_ID		0x1106	/* Chipset ID */
50 #define SIO_F71869_ID		0x0814	/* Chipset ID */
51 #define SIO_F71869A_ID		0x1007	/* Chipset ID */
52 #define SIO_F71882_ID		0x0541	/* Chipset ID */
53 #define SIO_F71889_ID		0x0723	/* Chipset ID */
54 #define SIO_F81803_ID		0x1210	/* Chipset ID */
55 #define SIO_F81865_ID		0x0704	/* Chipset ID */
56 #define SIO_F81866_ID		0x1010	/* Chipset ID */
57 
58 #define F71808FG_REG_WDO_CONF		0xf0
59 #define F71808FG_REG_WDT_CONF		0xf5
60 #define F71808FG_REG_WD_TIME		0xf6
61 
62 #define F71808FG_FLAG_WDOUT_EN		7
63 
64 #define F71808FG_FLAG_WDTMOUT_STS	6
65 #define F71808FG_FLAG_WD_EN		5
66 #define F71808FG_FLAG_WD_PULSE		4
67 #define F71808FG_FLAG_WD_UNIT		3
68 
69 #define F81865_REG_WDO_CONF		0xfa
70 #define F81865_FLAG_WDOUT_EN		0
71 
72 /* Default values */
73 #define WATCHDOG_TIMEOUT	60	/* 1 minute default timeout */
74 #define WATCHDOG_MAX_TIMEOUT	(60 * 255)
75 #define WATCHDOG_PULSE_WIDTH	125	/* 125 ms, default pulse width for
76 					   watchdog signal */
77 #define WATCHDOG_F71862FG_PIN	63	/* default watchdog reset output
78 					   pin number 63 */
79 
80 static unsigned short force_id;
81 module_param(force_id, ushort, 0);
82 MODULE_PARM_DESC(force_id, "Override the detected device ID");
83 
84 static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
85 static int timeout = WATCHDOG_TIMEOUT;	/* default timeout in seconds */
86 module_param(timeout, int, 0);
87 MODULE_PARM_DESC(timeout,
88 	"Watchdog timeout in seconds. 1<= timeout <="
89 			__MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
90 			__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
91 
92 static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
93 module_param(pulse_width, uint, 0);
94 MODULE_PARM_DESC(pulse_width,
95 	"Watchdog signal pulse width. 0(=level), 1, 25, 30, 125, 150, 5000 or 6000 ms"
96 			" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");
97 
98 static unsigned int f71862fg_pin = WATCHDOG_F71862FG_PIN;
99 module_param(f71862fg_pin, uint, 0);
100 MODULE_PARM_DESC(f71862fg_pin,
101 	"Watchdog f71862fg reset output pin configuration. Choose pin 56 or 63"
102 			" (default=" __MODULE_STRING(WATCHDOG_F71862FG_PIN)")");
103 
104 static bool nowayout = WATCHDOG_NOWAYOUT;
105 module_param(nowayout, bool, 0444);
106 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
107 
108 static unsigned int start_withtimeout;
109 module_param(start_withtimeout, uint, 0);
110 MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
111 	" given initial timeout. Zero (default) disables this feature.");
112 
113 enum chips { f71808fg, f71858fg, f71862fg, f71868, f71869, f71882fg, f71889fg,
114 	     f81803, f81865, f81866};
115 
116 static const char *f71808e_names[] = {
117 	"f71808fg",
118 	"f71858fg",
119 	"f71862fg",
120 	"f71868",
121 	"f71869",
122 	"f71882fg",
123 	"f71889fg",
124 	"f81803",
125 	"f81865",
126 	"f81866",
127 };
128 
129 /* Super-I/O Function prototypes */
130 static inline int superio_inb(int base, int reg);
131 static inline int superio_inw(int base, int reg);
132 static inline void superio_outb(int base, int reg, u8 val);
133 static inline void superio_set_bit(int base, int reg, int bit);
134 static inline void superio_clear_bit(int base, int reg, int bit);
135 static inline int superio_enter(int base);
136 static inline void superio_select(int base, int ld);
137 static inline void superio_exit(int base);
138 
139 struct watchdog_data {
140 	unsigned short	sioaddr;
141 	enum chips	type;
142 	unsigned long	opened;
143 	struct mutex	lock;
144 	char		expect_close;
145 	struct watchdog_info ident;
146 
147 	unsigned short	timeout;
148 	u8		timer_val;	/* content for the wd_time register */
149 	char		minutes_mode;
150 	u8		pulse_val;	/* pulse width flag */
151 	char		pulse_mode;	/* enable pulse output mode? */
152 	char		caused_reboot;	/* last reboot was by the watchdog */
153 };
154 
155 static struct watchdog_data watchdog = {
156 	.lock = __MUTEX_INITIALIZER(watchdog.lock),
157 };
158 
159 /* Super I/O functions */
160 static inline int superio_inb(int base, int reg)
161 {
162 	outb(reg, base);
163 	return inb(base + 1);
164 }
165 
166 static int superio_inw(int base, int reg)
167 {
168 	int val;
169 	val  = superio_inb(base, reg) << 8;
170 	val |= superio_inb(base, reg + 1);
171 	return val;
172 }
173 
174 static inline void superio_outb(int base, int reg, u8 val)
175 {
176 	outb(reg, base);
177 	outb(val, base + 1);
178 }
179 
180 static inline void superio_set_bit(int base, int reg, int bit)
181 {
182 	unsigned long val = superio_inb(base, reg);
183 	__set_bit(bit, &val);
184 	superio_outb(base, reg, val);
185 }
186 
187 static inline void superio_clear_bit(int base, int reg, int bit)
188 {
189 	unsigned long val = superio_inb(base, reg);
190 	__clear_bit(bit, &val);
191 	superio_outb(base, reg, val);
192 }
193 
194 static inline int superio_enter(int base)
195 {
196 	/* Don't step on other drivers' I/O space by accident */
197 	if (!request_muxed_region(base, 2, DRVNAME)) {
198 		pr_err("I/O address 0x%04x already in use\n", (int)base);
199 		return -EBUSY;
200 	}
201 
202 	/* according to the datasheet the key must be sent twice! */
203 	outb(SIO_UNLOCK_KEY, base);
204 	outb(SIO_UNLOCK_KEY, base);
205 
206 	return 0;
207 }
208 
209 static inline void superio_select(int base, int ld)
210 {
211 	outb(SIO_REG_LDSEL, base);
212 	outb(ld, base + 1);
213 }
214 
215 static inline void superio_exit(int base)
216 {
217 	outb(SIO_LOCK_KEY, base);
218 	release_region(base, 2);
219 }
220 
221 static int watchdog_set_timeout(int timeout)
222 {
223 	if (timeout <= 0
224 	 || timeout >  max_timeout) {
225 		pr_err("watchdog timeout out of range\n");
226 		return -EINVAL;
227 	}
228 
229 	mutex_lock(&watchdog.lock);
230 
231 	watchdog.timeout = timeout;
232 	if (timeout > 0xff) {
233 		watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
234 		watchdog.minutes_mode = true;
235 	} else {
236 		watchdog.timer_val = timeout;
237 		watchdog.minutes_mode = false;
238 	}
239 
240 	mutex_unlock(&watchdog.lock);
241 
242 	return 0;
243 }
244 
245 static int watchdog_set_pulse_width(unsigned int pw)
246 {
247 	int err = 0;
248 	unsigned int t1 = 25, t2 = 125, t3 = 5000;
249 
250 	if (watchdog.type == f71868) {
251 		t1 = 30;
252 		t2 = 150;
253 		t3 = 6000;
254 	}
255 
256 	mutex_lock(&watchdog.lock);
257 
258 	if        (pw <=  1) {
259 		watchdog.pulse_val = 0;
260 	} else if (pw <= t1) {
261 		watchdog.pulse_val = 1;
262 	} else if (pw <= t2) {
263 		watchdog.pulse_val = 2;
264 	} else if (pw <= t3) {
265 		watchdog.pulse_val = 3;
266 	} else {
267 		pr_err("pulse width out of range\n");
268 		err = -EINVAL;
269 		goto exit_unlock;
270 	}
271 
272 	watchdog.pulse_mode = pw;
273 
274 exit_unlock:
275 	mutex_unlock(&watchdog.lock);
276 	return err;
277 }
278 
279 static int watchdog_keepalive(void)
280 {
281 	int err = 0;
282 
283 	mutex_lock(&watchdog.lock);
284 	err = superio_enter(watchdog.sioaddr);
285 	if (err)
286 		goto exit_unlock;
287 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
288 
289 	if (watchdog.minutes_mode)
290 		/* select minutes for timer units */
291 		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
292 				F71808FG_FLAG_WD_UNIT);
293 	else
294 		/* select seconds for timer units */
295 		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
296 				F71808FG_FLAG_WD_UNIT);
297 
298 	/* Set timer value */
299 	superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
300 			   watchdog.timer_val);
301 
302 	superio_exit(watchdog.sioaddr);
303 
304 exit_unlock:
305 	mutex_unlock(&watchdog.lock);
306 	return err;
307 }
308 
309 static int f71862fg_pin_configure(unsigned short ioaddr)
310 {
311 	/* When ioaddr is non-zero the calling function has to take care of
312 	   mutex handling and superio preparation! */
313 
314 	if (f71862fg_pin == 63) {
315 		if (ioaddr) {
316 			/* SPI must be disabled first to use this pin! */
317 			superio_clear_bit(ioaddr, SIO_REG_ROM_ADDR_SEL, 6);
318 			superio_set_bit(ioaddr, SIO_REG_MFUNCT3, 4);
319 		}
320 	} else if (f71862fg_pin == 56) {
321 		if (ioaddr)
322 			superio_set_bit(ioaddr, SIO_REG_MFUNCT1, 1);
323 	} else {
324 		pr_err("Invalid argument f71862fg_pin=%d\n", f71862fg_pin);
325 		return -EINVAL;
326 	}
327 	return 0;
328 }
329 
330 static int watchdog_start(void)
331 {
332 	int err;
333 	u8 tmp;
334 
335 	/* Make sure we don't die as soon as the watchdog is enabled below */
336 	err = watchdog_keepalive();
337 	if (err)
338 		return err;
339 
340 	mutex_lock(&watchdog.lock);
341 	err = superio_enter(watchdog.sioaddr);
342 	if (err)
343 		goto exit_unlock;
344 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
345 
346 	/* Watchdog pin configuration */
347 	switch (watchdog.type) {
348 	case f71808fg:
349 		/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
350 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT2, 3);
351 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 3);
352 		break;
353 
354 	case f71862fg:
355 		err = f71862fg_pin_configure(watchdog.sioaddr);
356 		if (err)
357 			goto exit_superio;
358 		break;
359 
360 	case f71868:
361 	case f71869:
362 		/* GPIO14 --> WDTRST# */
363 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 4);
364 		break;
365 
366 	case f71882fg:
367 		/* Set pin 56 to WDTRST# */
368 		superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
369 		break;
370 
371 	case f71889fg:
372 		/* set pin 40 to WDTRST# */
373 		superio_outb(watchdog.sioaddr, SIO_REG_MFUNCT3,
374 			superio_inb(watchdog.sioaddr, SIO_REG_MFUNCT3) & 0xcf);
375 		break;
376 
377 	case f81803:
378 		/* Enable TSI Level register bank */
379 		superio_clear_bit(watchdog.sioaddr, SIO_REG_CLOCK_SEL, 3);
380 		/* Set pin 27 to WDTRST# */
381 		superio_outb(watchdog.sioaddr, SIO_REG_TSI_LEVEL_SEL, 0x5f &
382 			superio_inb(watchdog.sioaddr, SIO_REG_TSI_LEVEL_SEL));
383 		break;
384 
385 	case f81865:
386 		/* Set pin 70 to WDTRST# */
387 		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 5);
388 		break;
389 
390 	case f81866:
391 		/*
392 		 * GPIO1 Control Register when 27h BIT3:2 = 01 & BIT0 = 0.
393 		 * The PIN 70(GPIO15/WDTRST) is controlled by 2Ch:
394 		 *     BIT5: 0 -> WDTRST#
395 		 *           1 -> GPIO15
396 		 */
397 		tmp = superio_inb(watchdog.sioaddr, SIO_F81866_REG_PORT_SEL);
398 		tmp &= ~(BIT(3) | BIT(0));
399 		tmp |= BIT(2);
400 		superio_outb(watchdog.sioaddr, SIO_F81866_REG_PORT_SEL, tmp);
401 
402 		superio_clear_bit(watchdog.sioaddr, SIO_F81866_REG_GPIO1, 5);
403 		break;
404 
405 	default:
406 		/*
407 		 * 'default' label to shut up the compiler and catch
408 		 * programmer errors
409 		 */
410 		err = -ENODEV;
411 		goto exit_superio;
412 	}
413 
414 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
415 	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
416 
417 	if (watchdog.type == f81865 || watchdog.type == f81866)
418 		superio_set_bit(watchdog.sioaddr, F81865_REG_WDO_CONF,
419 				F81865_FLAG_WDOUT_EN);
420 	else
421 		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
422 				F71808FG_FLAG_WDOUT_EN);
423 
424 	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
425 			F71808FG_FLAG_WD_EN);
426 
427 	if (watchdog.pulse_mode) {
428 		/* Select "pulse" output mode with given duration */
429 		u8 wdt_conf = superio_inb(watchdog.sioaddr,
430 				F71808FG_REG_WDT_CONF);
431 
432 		/* Set WD_PSWIDTH bits (1:0) */
433 		wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
434 		/* Set WD_PULSE to "pulse" mode */
435 		wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);
436 
437 		superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
438 				wdt_conf);
439 	} else {
440 		/* Select "level" output mode */
441 		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
442 				F71808FG_FLAG_WD_PULSE);
443 	}
444 
445 exit_superio:
446 	superio_exit(watchdog.sioaddr);
447 exit_unlock:
448 	mutex_unlock(&watchdog.lock);
449 
450 	return err;
451 }
452 
453 static int watchdog_stop(void)
454 {
455 	int err = 0;
456 
457 	mutex_lock(&watchdog.lock);
458 	err = superio_enter(watchdog.sioaddr);
459 	if (err)
460 		goto exit_unlock;
461 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
462 
463 	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
464 			F71808FG_FLAG_WD_EN);
465 
466 	superio_exit(watchdog.sioaddr);
467 
468 exit_unlock:
469 	mutex_unlock(&watchdog.lock);
470 
471 	return err;
472 }
473 
474 static int watchdog_get_status(void)
475 {
476 	int status = 0;
477 
478 	mutex_lock(&watchdog.lock);
479 	status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
480 	mutex_unlock(&watchdog.lock);
481 
482 	return status;
483 }
484 
485 static bool watchdog_is_running(void)
486 {
487 	/*
488 	 * if we fail to determine the watchdog's status assume it to be
489 	 * running to be on the safe side
490 	 */
491 	bool is_running = true;
492 
493 	mutex_lock(&watchdog.lock);
494 	if (superio_enter(watchdog.sioaddr))
495 		goto exit_unlock;
496 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
497 
498 	is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
499 		&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
500 			& BIT(F71808FG_FLAG_WD_EN));
501 
502 	superio_exit(watchdog.sioaddr);
503 
504 exit_unlock:
505 	mutex_unlock(&watchdog.lock);
506 	return is_running;
507 }
508 
509 /* /dev/watchdog api */
510 
511 static int watchdog_open(struct inode *inode, struct file *file)
512 {
513 	int err;
514 
515 	/* If the watchdog is alive we don't need to start it again */
516 	if (test_and_set_bit(0, &watchdog.opened))
517 		return -EBUSY;
518 
519 	err = watchdog_start();
520 	if (err) {
521 		clear_bit(0, &watchdog.opened);
522 		return err;
523 	}
524 
525 	if (nowayout)
526 		__module_get(THIS_MODULE);
527 
528 	watchdog.expect_close = 0;
529 	return stream_open(inode, file);
530 }
531 
532 static int watchdog_release(struct inode *inode, struct file *file)
533 {
534 	clear_bit(0, &watchdog.opened);
535 
536 	if (!watchdog.expect_close) {
537 		watchdog_keepalive();
538 		pr_crit("Unexpected close, not stopping watchdog!\n");
539 	} else if (!nowayout) {
540 		watchdog_stop();
541 	}
542 	return 0;
543 }
544 
545 /*
546  *      watchdog_write:
547  *      @file: file handle to the watchdog
548  *      @buf: buffer to write
549  *      @count: count of bytes
550  *      @ppos: pointer to the position to write. No seeks allowed
551  *
552  *      A write to a watchdog device is defined as a keepalive signal. Any
553  *      write of data will do, as we we don't define content meaning.
554  */
555 
556 static ssize_t watchdog_write(struct file *file, const char __user *buf,
557 			    size_t count, loff_t *ppos)
558 {
559 	if (count) {
560 		if (!nowayout) {
561 			size_t i;
562 
563 			/* In case it was set long ago */
564 			bool expect_close = false;
565 
566 			for (i = 0; i != count; i++) {
567 				char c;
568 				if (get_user(c, buf + i))
569 					return -EFAULT;
570 				if (c == 'V')
571 					expect_close = true;
572 			}
573 
574 			/* Properly order writes across fork()ed processes */
575 			mutex_lock(&watchdog.lock);
576 			watchdog.expect_close = expect_close;
577 			mutex_unlock(&watchdog.lock);
578 		}
579 
580 		/* someone wrote to us, we should restart timer */
581 		watchdog_keepalive();
582 	}
583 	return count;
584 }
585 
586 /*
587  *      watchdog_ioctl:
588  *      @inode: inode of the device
589  *      @file: file handle to the device
590  *      @cmd: watchdog command
591  *      @arg: argument pointer
592  *
593  *      The watchdog API defines a common set of functions for all watchdogs
594  *      according to their available features.
595  */
596 static long watchdog_ioctl(struct file *file, unsigned int cmd,
597 	unsigned long arg)
598 {
599 	int status;
600 	int new_options;
601 	int new_timeout;
602 	union {
603 		struct watchdog_info __user *ident;
604 		int __user *i;
605 	} uarg;
606 
607 	uarg.i = (int __user *)arg;
608 
609 	switch (cmd) {
610 	case WDIOC_GETSUPPORT:
611 		return copy_to_user(uarg.ident, &watchdog.ident,
612 			sizeof(watchdog.ident)) ? -EFAULT : 0;
613 
614 	case WDIOC_GETSTATUS:
615 		status = watchdog_get_status();
616 		if (status < 0)
617 			return status;
618 		return put_user(status, uarg.i);
619 
620 	case WDIOC_GETBOOTSTATUS:
621 		return put_user(0, uarg.i);
622 
623 	case WDIOC_SETOPTIONS:
624 		if (get_user(new_options, uarg.i))
625 			return -EFAULT;
626 
627 		if (new_options & WDIOS_DISABLECARD)
628 			watchdog_stop();
629 
630 		if (new_options & WDIOS_ENABLECARD)
631 			return watchdog_start();
632 		/* fall through */
633 
634 	case WDIOC_KEEPALIVE:
635 		watchdog_keepalive();
636 		return 0;
637 
638 	case WDIOC_SETTIMEOUT:
639 		if (get_user(new_timeout, uarg.i))
640 			return -EFAULT;
641 
642 		if (watchdog_set_timeout(new_timeout))
643 			return -EINVAL;
644 
645 		watchdog_keepalive();
646 		/* fall through */
647 
648 	case WDIOC_GETTIMEOUT:
649 		return put_user(watchdog.timeout, uarg.i);
650 
651 	default:
652 		return -ENOTTY;
653 
654 	}
655 }
656 
657 static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
658 	void *unused)
659 {
660 	if (code == SYS_DOWN || code == SYS_HALT)
661 		watchdog_stop();
662 	return NOTIFY_DONE;
663 }
664 
665 static const struct file_operations watchdog_fops = {
666 	.owner		= THIS_MODULE,
667 	.llseek		= no_llseek,
668 	.open		= watchdog_open,
669 	.release	= watchdog_release,
670 	.write		= watchdog_write,
671 	.unlocked_ioctl	= watchdog_ioctl,
672 };
673 
674 static struct miscdevice watchdog_miscdev = {
675 	.minor		= WATCHDOG_MINOR,
676 	.name		= "watchdog",
677 	.fops		= &watchdog_fops,
678 };
679 
680 static struct notifier_block watchdog_notifier = {
681 	.notifier_call = watchdog_notify_sys,
682 };
683 
684 static int __init watchdog_init(int sioaddr)
685 {
686 	int wdt_conf, err = 0;
687 
688 	/* No need to lock watchdog.lock here because no entry points
689 	 * into the module have been registered yet.
690 	 */
691 	watchdog.sioaddr = sioaddr;
692 	watchdog.ident.options = WDIOC_SETTIMEOUT
693 				| WDIOF_MAGICCLOSE
694 				| WDIOF_KEEPALIVEPING;
695 
696 	snprintf(watchdog.ident.identity,
697 		sizeof(watchdog.ident.identity), "%s watchdog",
698 		f71808e_names[watchdog.type]);
699 
700 	err = superio_enter(sioaddr);
701 	if (err)
702 		return err;
703 	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
704 
705 	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
706 	watchdog.caused_reboot = wdt_conf & BIT(F71808FG_FLAG_WDTMOUT_STS);
707 
708 	superio_exit(sioaddr);
709 
710 	err = watchdog_set_timeout(timeout);
711 	if (err)
712 		return err;
713 	err = watchdog_set_pulse_width(pulse_width);
714 	if (err)
715 		return err;
716 
717 	err = register_reboot_notifier(&watchdog_notifier);
718 	if (err)
719 		return err;
720 
721 	err = misc_register(&watchdog_miscdev);
722 	if (err) {
723 		pr_err("cannot register miscdev on minor=%d\n",
724 		       watchdog_miscdev.minor);
725 		goto exit_reboot;
726 	}
727 
728 	if (start_withtimeout) {
729 		if (start_withtimeout <= 0
730 		 || start_withtimeout >  max_timeout) {
731 			pr_err("starting timeout out of range\n");
732 			err = -EINVAL;
733 			goto exit_miscdev;
734 		}
735 
736 		err = watchdog_start();
737 		if (err) {
738 			pr_err("cannot start watchdog timer\n");
739 			goto exit_miscdev;
740 		}
741 
742 		mutex_lock(&watchdog.lock);
743 		err = superio_enter(sioaddr);
744 		if (err)
745 			goto exit_unlock;
746 		superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
747 
748 		if (start_withtimeout > 0xff) {
749 			/* select minutes for timer units */
750 			superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
751 				F71808FG_FLAG_WD_UNIT);
752 			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
753 				DIV_ROUND_UP(start_withtimeout, 60));
754 		} else {
755 			/* select seconds for timer units */
756 			superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
757 				F71808FG_FLAG_WD_UNIT);
758 			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
759 				start_withtimeout);
760 		}
761 
762 		superio_exit(sioaddr);
763 		mutex_unlock(&watchdog.lock);
764 
765 		if (nowayout)
766 			__module_get(THIS_MODULE);
767 
768 		pr_info("watchdog started with initial timeout of %u sec\n",
769 			start_withtimeout);
770 	}
771 
772 	return 0;
773 
774 exit_unlock:
775 	mutex_unlock(&watchdog.lock);
776 exit_miscdev:
777 	misc_deregister(&watchdog_miscdev);
778 exit_reboot:
779 	unregister_reboot_notifier(&watchdog_notifier);
780 
781 	return err;
782 }
783 
784 static int __init f71808e_find(int sioaddr)
785 {
786 	u16 devid;
787 	int err = superio_enter(sioaddr);
788 	if (err)
789 		return err;
790 
791 	devid = superio_inw(sioaddr, SIO_REG_MANID);
792 	if (devid != SIO_FINTEK_ID) {
793 		pr_debug("Not a Fintek device\n");
794 		err = -ENODEV;
795 		goto exit;
796 	}
797 
798 	devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
799 	switch (devid) {
800 	case SIO_F71808_ID:
801 		watchdog.type = f71808fg;
802 		break;
803 	case SIO_F71862_ID:
804 		watchdog.type = f71862fg;
805 		err = f71862fg_pin_configure(0); /* validate module parameter */
806 		break;
807 	case SIO_F71868_ID:
808 		watchdog.type = f71868;
809 		break;
810 	case SIO_F71869_ID:
811 	case SIO_F71869A_ID:
812 		watchdog.type = f71869;
813 		break;
814 	case SIO_F71882_ID:
815 		watchdog.type = f71882fg;
816 		break;
817 	case SIO_F71889_ID:
818 		watchdog.type = f71889fg;
819 		break;
820 	case SIO_F71858_ID:
821 		/* Confirmed (by datasheet) not to have a watchdog. */
822 		err = -ENODEV;
823 		goto exit;
824 	case SIO_F81803_ID:
825 		watchdog.type = f81803;
826 		break;
827 	case SIO_F81865_ID:
828 		watchdog.type = f81865;
829 		break;
830 	case SIO_F81866_ID:
831 		watchdog.type = f81866;
832 		break;
833 	default:
834 		pr_info("Unrecognized Fintek device: %04x\n",
835 			(unsigned int)devid);
836 		err = -ENODEV;
837 		goto exit;
838 	}
839 
840 	pr_info("Found %s watchdog chip, revision %d\n",
841 		f71808e_names[watchdog.type],
842 		(int)superio_inb(sioaddr, SIO_REG_DEVREV));
843 exit:
844 	superio_exit(sioaddr);
845 	return err;
846 }
847 
848 static int __init f71808e_init(void)
849 {
850 	static const unsigned short addrs[] = { 0x2e, 0x4e };
851 	int err = -ENODEV;
852 	int i;
853 
854 	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
855 		err = f71808e_find(addrs[i]);
856 		if (err == 0)
857 			break;
858 	}
859 	if (i == ARRAY_SIZE(addrs))
860 		return err;
861 
862 	return watchdog_init(addrs[i]);
863 }
864 
865 static void __exit f71808e_exit(void)
866 {
867 	if (watchdog_is_running()) {
868 		pr_warn("Watchdog timer still running, stopping it\n");
869 		watchdog_stop();
870 	}
871 	misc_deregister(&watchdog_miscdev);
872 	unregister_reboot_notifier(&watchdog_notifier);
873 }
874 
875 MODULE_DESCRIPTION("F71808E Watchdog Driver");
876 MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
877 MODULE_LICENSE("GPL");
878 
879 module_init(f71808e_init);
880 module_exit(f71808e_exit);
881