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