Linux Audio

Check our new training course

Loading...
v3.1
 
  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#include <linux/err.h>
 23#include <linux/fs.h>
 24#include <linux/init.h>
 25#include <linux/io.h>
 26#include <linux/ioport.h>
 27#include <linux/miscdevice.h>
 28#include <linux/module.h>
 29#include <linux/mutex.h>
 30#include <linux/notifier.h>
 31#include <linux/reboot.h>
 32#include <linux/uaccess.h>
 33#include <linux/watchdog.h>
 34
 35#define DRVNAME "f71808e_wdt"
 36
 37#define SIO_F71808FG_LD_WDT	0x07	/* Watchdog timer logical device */
 38#define SIO_UNLOCK_KEY		0x87	/* Key to enable Super-I/O */
 39#define SIO_LOCK_KEY		0xAA	/* Key to diasble Super-I/O */
 40
 41#define SIO_REG_LDSEL		0x07	/* Logical device select */
 42#define SIO_REG_DEVID		0x20	/* Device ID (2 bytes) */
 43#define SIO_REG_DEVREV		0x22	/* Device revision */
 44#define SIO_REG_MANID		0x23	/* Fintek ID (2 bytes) */
 
 45#define SIO_REG_ROM_ADDR_SEL	0x27	/* ROM address select */
 
 
 46#define SIO_REG_MFUNCT1		0x29	/* Multi function select 1 */
 47#define SIO_REG_MFUNCT2		0x2a	/* Multi function select 2 */
 48#define SIO_REG_MFUNCT3		0x2b	/* Multi function select 3 */
 
 49#define SIO_REG_ENABLE		0x30	/* Logical device enable */
 50#define SIO_REG_ADDR		0x60	/* Logical device address (2 bytes) */
 51
 52#define SIO_FINTEK_ID		0x1934	/* Manufacturers ID */
 53#define SIO_F71808_ID		0x0901	/* Chipset ID */
 54#define SIO_F71858_ID		0x0507	/* Chipset ID */
 55#define SIO_F71862_ID		0x0601	/* Chipset ID */
 
 56#define SIO_F71869_ID		0x0814	/* Chipset ID */
 
 57#define SIO_F71882_ID		0x0541	/* Chipset ID */
 58#define SIO_F71889_ID		0x0723	/* Chipset ID */
 
 
 
 59
 60#define F71808FG_REG_WDO_CONF		0xf0
 61#define F71808FG_REG_WDT_CONF		0xf5
 62#define F71808FG_REG_WD_TIME		0xf6
 63
 64#define F71808FG_FLAG_WDOUT_EN		7
 65
 66#define F71808FG_FLAG_WDTMOUT_STS	5
 67#define F71808FG_FLAG_WD_EN		5
 68#define F71808FG_FLAG_WD_PULSE		4
 69#define F71808FG_FLAG_WD_UNIT		3
 70
 
 
 
 71/* Default values */
 72#define WATCHDOG_TIMEOUT	60	/* 1 minute default timeout */
 73#define WATCHDOG_MAX_TIMEOUT	(60 * 255)
 74#define WATCHDOG_PULSE_WIDTH	125	/* 125 ms, default pulse width for
 75					   watchdog signal */
 76#define WATCHDOG_F71862FG_PIN	63	/* default watchdog reset output
 77					   pin number 63 */
 78
 79static unsigned short force_id;
 80module_param(force_id, ushort, 0);
 81MODULE_PARM_DESC(force_id, "Override the detected device ID");
 82
 83static const int max_timeout = WATCHDOG_MAX_TIMEOUT;
 84static int timeout = WATCHDOG_TIMEOUT;	/* default timeout in seconds */
 85module_param(timeout, int, 0);
 86MODULE_PARM_DESC(timeout,
 87	"Watchdog timeout in seconds. 1<= timeout <="
 88			__MODULE_STRING(WATCHDOG_MAX_TIMEOUT) " (default="
 89			__MODULE_STRING(WATCHDOG_TIMEOUT) ")");
 90
 91static unsigned int pulse_width = WATCHDOG_PULSE_WIDTH;
 92module_param(pulse_width, uint, 0);
 93MODULE_PARM_DESC(pulse_width,
 94	"Watchdog signal pulse width. 0(=level), 1 ms, 25 ms, 125 ms or 5000 ms"
 95			" (default=" __MODULE_STRING(WATCHDOG_PULSE_WIDTH) ")");
 96
 97static unsigned int f71862fg_pin = WATCHDOG_F71862FG_PIN;
 98module_param(f71862fg_pin, uint, 0);
 99MODULE_PARM_DESC(f71862fg_pin,
100	"Watchdog f71862fg reset output pin configuration. Choose pin 56 or 63"
101			" (default=" __MODULE_STRING(WATCHDOG_F71862FG_PIN)")");
102
103static int nowayout = WATCHDOG_NOWAYOUT;
104module_param(nowayout, bool, 0444);
105MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
106
107static unsigned int start_withtimeout;
108module_param(start_withtimeout, uint, 0);
109MODULE_PARM_DESC(start_withtimeout, "Start watchdog timer on module load with"
110	" given initial timeout. Zero (default) disables this feature.");
111
112enum chips { f71808fg, f71858fg, f71862fg, f71869, f71882fg, f71889fg };
 
113
114static const char *f71808e_names[] = {
115	"f71808fg",
116	"f71858fg",
117	"f71862fg",
 
118	"f71869",
119	"f71882fg",
120	"f71889fg",
 
 
 
121};
122
123/* Super-I/O Function prototypes */
124static inline int superio_inb(int base, int reg);
125static inline int superio_inw(int base, int reg);
126static inline void superio_outb(int base, int reg, u8 val);
127static inline void superio_set_bit(int base, int reg, int bit);
128static inline void superio_clear_bit(int base, int reg, int bit);
129static inline int superio_enter(int base);
130static inline void superio_select(int base, int ld);
131static inline void superio_exit(int base);
132
133struct watchdog_data {
134	unsigned short	sioaddr;
135	enum chips	type;
136	unsigned long	opened;
137	struct mutex	lock;
138	char		expect_close;
139	struct watchdog_info ident;
140
141	unsigned short	timeout;
142	u8		timer_val;	/* content for the wd_time register */
143	char		minutes_mode;
144	u8		pulse_val;	/* pulse width flag */
145	char		pulse_mode;	/* enable pulse output mode? */
146	char		caused_reboot;	/* last reboot was by the watchdog */
147};
148
149static struct watchdog_data watchdog = {
150	.lock = __MUTEX_INITIALIZER(watchdog.lock),
151};
152
153/* Super I/O functions */
154static inline int superio_inb(int base, int reg)
155{
156	outb(reg, base);
157	return inb(base + 1);
158}
159
160static int superio_inw(int base, int reg)
161{
162	int val;
163	val  = superio_inb(base, reg) << 8;
164	val |= superio_inb(base, reg + 1);
165	return val;
166}
167
168static inline void superio_outb(int base, int reg, u8 val)
169{
170	outb(reg, base);
171	outb(val, base + 1);
172}
173
174static inline void superio_set_bit(int base, int reg, int bit)
175{
176	unsigned long val = superio_inb(base, reg);
177	__set_bit(bit, &val);
178	superio_outb(base, reg, val);
179}
180
181static inline void superio_clear_bit(int base, int reg, int bit)
182{
183	unsigned long val = superio_inb(base, reg);
184	__clear_bit(bit, &val);
185	superio_outb(base, reg, val);
186}
187
188static inline int superio_enter(int base)
189{
190	/* Don't step on other drivers' I/O space by accident */
191	if (!request_muxed_region(base, 2, DRVNAME)) {
192		printk(KERN_ERR DRVNAME ": I/O address 0x%04x already in use\n",
193				(int)base);
194		return -EBUSY;
195	}
196
197	/* according to the datasheet the key must be send twice! */
198	outb(SIO_UNLOCK_KEY, base);
199	outb(SIO_UNLOCK_KEY, base);
200
201	return 0;
202}
203
204static inline void superio_select(int base, int ld)
205{
206	outb(SIO_REG_LDSEL, base);
207	outb(ld, base + 1);
208}
209
210static inline void superio_exit(int base)
211{
212	outb(SIO_LOCK_KEY, base);
213	release_region(base, 2);
214}
215
216static int watchdog_set_timeout(int timeout)
217{
218	if (timeout <= 0
219	 || timeout >  max_timeout) {
220		printk(KERN_ERR DRVNAME ": watchdog timeout out of range\n");
221		return -EINVAL;
222	}
223
224	mutex_lock(&watchdog.lock);
225
226	watchdog.timeout = timeout;
227	if (timeout > 0xff) {
228		watchdog.timer_val = DIV_ROUND_UP(timeout, 60);
229		watchdog.minutes_mode = true;
230	} else {
231		watchdog.timer_val = timeout;
232		watchdog.minutes_mode = false;
233	}
234
235	mutex_unlock(&watchdog.lock);
236
237	return 0;
238}
239
240static int watchdog_set_pulse_width(unsigned int pw)
241{
242	int err = 0;
 
 
 
 
 
 
 
243
244	mutex_lock(&watchdog.lock);
245
246	if        (pw <=    1) {
247		watchdog.pulse_val = 0;
248	} else if (pw <=   25) {
249		watchdog.pulse_val = 1;
250	} else if (pw <=  125) {
251		watchdog.pulse_val = 2;
252	} else if (pw <= 5000) {
253		watchdog.pulse_val = 3;
254	} else {
255		printk(KERN_ERR DRVNAME ": pulse width out of range\n");
256		err = -EINVAL;
257		goto exit_unlock;
258	}
259
260	watchdog.pulse_mode = pw;
261
262exit_unlock:
263	mutex_unlock(&watchdog.lock);
264	return err;
265}
266
267static int watchdog_keepalive(void)
268{
269	int err = 0;
270
271	mutex_lock(&watchdog.lock);
272	err = superio_enter(watchdog.sioaddr);
273	if (err)
274		goto exit_unlock;
275	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
276
277	if (watchdog.minutes_mode)
278		/* select minutes for timer units */
279		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
280				F71808FG_FLAG_WD_UNIT);
281	else
282		/* select seconds for timer units */
283		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
284				F71808FG_FLAG_WD_UNIT);
285
286	/* Set timer value */
287	superio_outb(watchdog.sioaddr, F71808FG_REG_WD_TIME,
288			   watchdog.timer_val);
289
290	superio_exit(watchdog.sioaddr);
291
292exit_unlock:
293	mutex_unlock(&watchdog.lock);
294	return err;
295}
296
297static int f71862fg_pin_configure(unsigned short ioaddr)
298{
299	/* When ioaddr is non-zero the calling function has to take care of
300	   mutex handling and superio preparation! */
301
302	if (f71862fg_pin == 63) {
303		if (ioaddr) {
304			/* SPI must be disabled first to use this pin! */
305			superio_clear_bit(ioaddr, SIO_REG_ROM_ADDR_SEL, 6);
306			superio_set_bit(ioaddr, SIO_REG_MFUNCT3, 4);
307		}
308	} else if (f71862fg_pin == 56) {
309		if (ioaddr)
310			superio_set_bit(ioaddr, SIO_REG_MFUNCT1, 1);
311	} else {
312		printk(KERN_ERR DRVNAME ": Invalid argument f71862fg_pin=%d\n",
313				f71862fg_pin);
314		return -EINVAL;
315	}
316	return 0;
317}
318
319static int watchdog_start(void)
320{
 
 
 
321	/* Make sure we don't die as soon as the watchdog is enabled below */
322	int err = watchdog_keepalive();
323	if (err)
324		return err;
325
326	mutex_lock(&watchdog.lock);
327	err = superio_enter(watchdog.sioaddr);
328	if (err)
329		goto exit_unlock;
330	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
331
332	/* Watchdog pin configuration */
333	switch (watchdog.type) {
334	case f71808fg:
335		/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
336		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT2, 3);
337		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 3);
338		break;
339
340	case f71862fg:
341		err = f71862fg_pin_configure(watchdog.sioaddr);
342		if (err)
343			goto exit_superio;
 
 
 
 
344		break;
345
 
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	default:
363		/*
364		 * 'default' label to shut up the compiler and catch
365		 * programmer errors
366		 */
367		err = -ENODEV;
368		goto exit_superio;
369	}
370
371	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
372	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
373	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
374			F71808FG_FLAG_WDOUT_EN);
 
 
 
 
 
375
376	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
377			F71808FG_FLAG_WD_EN);
378
379	if (watchdog.pulse_mode) {
380		/* Select "pulse" output mode with given duration */
381		u8 wdt_conf = superio_inb(watchdog.sioaddr,
382				F71808FG_REG_WDT_CONF);
383
384		/* Set WD_PSWIDTH bits (1:0) */
385		wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
386		/* Set WD_PULSE to "pulse" mode */
387		wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);
388
389		superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
390				wdt_conf);
391	} else {
392		/* Select "level" output mode */
393		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
394				F71808FG_FLAG_WD_PULSE);
395	}
396
397exit_superio:
398	superio_exit(watchdog.sioaddr);
399exit_unlock:
400	mutex_unlock(&watchdog.lock);
401
402	return err;
403}
404
405static int watchdog_stop(void)
406{
407	int err = 0;
408
409	mutex_lock(&watchdog.lock);
410	err = superio_enter(watchdog.sioaddr);
411	if (err)
412		goto exit_unlock;
413	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
414
415	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
416			F71808FG_FLAG_WD_EN);
417
418	superio_exit(watchdog.sioaddr);
419
420exit_unlock:
421	mutex_unlock(&watchdog.lock);
422
423	return err;
424}
425
426static int watchdog_get_status(void)
427{
428	int status = 0;
429
430	mutex_lock(&watchdog.lock);
431	status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
432	mutex_unlock(&watchdog.lock);
433
434	return status;
435}
436
437static bool watchdog_is_running(void)
438{
439	/*
440	 * if we fail to determine the watchdog's status assume it to be
441	 * running to be on the safe side
442	 */
443	bool is_running = true;
444
445	mutex_lock(&watchdog.lock);
446	if (superio_enter(watchdog.sioaddr))
447		goto exit_unlock;
448	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
449
450	is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
451		&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
452			& F71808FG_FLAG_WD_EN);
453
454	superio_exit(watchdog.sioaddr);
455
456exit_unlock:
457	mutex_unlock(&watchdog.lock);
458	return is_running;
459}
460
461/* /dev/watchdog api */
462
463static int watchdog_open(struct inode *inode, struct file *file)
464{
465	int err;
466
467	/* If the watchdog is alive we don't need to start it again */
468	if (test_and_set_bit(0, &watchdog.opened))
469		return -EBUSY;
470
471	err = watchdog_start();
472	if (err) {
473		clear_bit(0, &watchdog.opened);
474		return err;
475	}
476
477	if (nowayout)
478		__module_get(THIS_MODULE);
479
480	watchdog.expect_close = 0;
481	return nonseekable_open(inode, file);
482}
483
484static int watchdog_release(struct inode *inode, struct file *file)
485{
486	clear_bit(0, &watchdog.opened);
487
488	if (!watchdog.expect_close) {
489		watchdog_keepalive();
490		printk(KERN_CRIT DRVNAME
491			": Unexpected close, not stopping watchdog!\n");
492	} else if (!nowayout) {
493		watchdog_stop();
494	}
495	return 0;
496}
497
498/*
499 *      watchdog_write:
500 *      @file: file handle to the watchdog
501 *      @buf: buffer to write
502 *      @count: count of bytes
503 *      @ppos: pointer to the position to write. No seeks allowed
504 *
505 *      A write to a watchdog device is defined as a keepalive signal. Any
506 *      write of data will do, as we we don't define content meaning.
507 */
508
509static ssize_t watchdog_write(struct file *file, const char __user *buf,
510			    size_t count, loff_t *ppos)
511{
512	if (count) {
513		if (!nowayout) {
514			size_t i;
515
516			/* In case it was set long ago */
517			bool expect_close = false;
518
519			for (i = 0; i != count; i++) {
520				char c;
521				if (get_user(c, buf + i))
522					return -EFAULT;
523				expect_close = (c == 'V');
 
524			}
525
526			/* Properly order writes across fork()ed processes */
527			mutex_lock(&watchdog.lock);
528			watchdog.expect_close = expect_close;
529			mutex_unlock(&watchdog.lock);
530		}
531
532		/* someone wrote to us, we should restart timer */
533		watchdog_keepalive();
534	}
535	return count;
536}
537
538/*
539 *      watchdog_ioctl:
540 *      @inode: inode of the device
541 *      @file: file handle to the device
542 *      @cmd: watchdog command
543 *      @arg: argument pointer
544 *
545 *      The watchdog API defines a common set of functions for all watchdogs
546 *      according to their available features.
547 */
548static long watchdog_ioctl(struct file *file, unsigned int cmd,
549	unsigned long arg)
550{
551	int status;
552	int new_options;
553	int new_timeout;
554	union {
555		struct watchdog_info __user *ident;
556		int __user *i;
557	} uarg;
558
559	uarg.i = (int __user *)arg;
560
561	switch (cmd) {
562	case WDIOC_GETSUPPORT:
563		return copy_to_user(uarg.ident, &watchdog.ident,
564			sizeof(watchdog.ident)) ? -EFAULT : 0;
565
566	case WDIOC_GETSTATUS:
567		status = watchdog_get_status();
568		if (status < 0)
569			return status;
570		return put_user(status, uarg.i);
571
572	case WDIOC_GETBOOTSTATUS:
573		return put_user(0, uarg.i);
574
575	case WDIOC_SETOPTIONS:
576		if (get_user(new_options, uarg.i))
577			return -EFAULT;
578
579		if (new_options & WDIOS_DISABLECARD)
580			watchdog_stop();
581
582		if (new_options & WDIOS_ENABLECARD)
583			return watchdog_start();
584
585
586	case WDIOC_KEEPALIVE:
587		watchdog_keepalive();
588		return 0;
589
590	case WDIOC_SETTIMEOUT:
591		if (get_user(new_timeout, uarg.i))
592			return -EFAULT;
593
594		if (watchdog_set_timeout(new_timeout))
595			return -EINVAL;
596
597		watchdog_keepalive();
598		/* Fall */
599
600	case WDIOC_GETTIMEOUT:
601		return put_user(watchdog.timeout, uarg.i);
602
603	default:
604		return -ENOTTY;
605
606	}
607}
608
609static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
610	void *unused)
611{
612	if (code == SYS_DOWN || code == SYS_HALT)
613		watchdog_stop();
614	return NOTIFY_DONE;
615}
616
617static const struct file_operations watchdog_fops = {
618	.owner		= THIS_MODULE,
619	.llseek		= no_llseek,
620	.open		= watchdog_open,
621	.release	= watchdog_release,
622	.write		= watchdog_write,
623	.unlocked_ioctl	= watchdog_ioctl,
 
624};
625
626static struct miscdevice watchdog_miscdev = {
627	.minor		= WATCHDOG_MINOR,
628	.name		= "watchdog",
629	.fops		= &watchdog_fops,
630};
631
632static struct notifier_block watchdog_notifier = {
633	.notifier_call = watchdog_notify_sys,
634};
635
636static int __init watchdog_init(int sioaddr)
637{
638	int wdt_conf, err = 0;
639
640	/* No need to lock watchdog.lock here because no entry points
641	 * into the module have been registered yet.
642	 */
643	watchdog.sioaddr = sioaddr;
644	watchdog.ident.options = WDIOC_SETTIMEOUT
645				| WDIOF_MAGICCLOSE
646				| WDIOF_KEEPALIVEPING;
647
648	snprintf(watchdog.ident.identity,
649		sizeof(watchdog.ident.identity), "%s watchdog",
650		f71808e_names[watchdog.type]);
651
652	err = superio_enter(sioaddr);
653	if (err)
654		return err;
655	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
656
657	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
658	watchdog.caused_reboot = wdt_conf & F71808FG_FLAG_WDTMOUT_STS;
 
 
 
 
 
 
 
659
660	superio_exit(sioaddr);
661
662	err = watchdog_set_timeout(timeout);
663	if (err)
664		return err;
665	err = watchdog_set_pulse_width(pulse_width);
666	if (err)
667		return err;
668
669	err = register_reboot_notifier(&watchdog_notifier);
670	if (err)
671		return err;
672
673	err = misc_register(&watchdog_miscdev);
674	if (err) {
675		printk(KERN_ERR DRVNAME
676			": cannot register miscdev on minor=%d\n",
677				watchdog_miscdev.minor);
678		goto exit_reboot;
679	}
680
681	if (start_withtimeout) {
682		if (start_withtimeout <= 0
683		 || start_withtimeout >  max_timeout) {
684			printk(KERN_ERR DRVNAME
685				": starting timeout out of range\n");
686			err = -EINVAL;
687			goto exit_miscdev;
688		}
689
690		err = watchdog_start();
691		if (err) {
692			printk(KERN_ERR DRVNAME
693				": cannot start watchdog timer\n");
694			goto exit_miscdev;
695		}
696
697		mutex_lock(&watchdog.lock);
698		err = superio_enter(sioaddr);
699		if (err)
700			goto exit_unlock;
701		superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
702
703		if (start_withtimeout > 0xff) {
704			/* select minutes for timer units */
705			superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
706				F71808FG_FLAG_WD_UNIT);
707			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
708				DIV_ROUND_UP(start_withtimeout, 60));
709		} else {
710			/* select seconds for timer units */
711			superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
712				F71808FG_FLAG_WD_UNIT);
713			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
714				start_withtimeout);
715		}
716
717		superio_exit(sioaddr);
718		mutex_unlock(&watchdog.lock);
719
720		if (nowayout)
721			__module_get(THIS_MODULE);
722
723		printk(KERN_INFO DRVNAME
724			": watchdog started with initial timeout of %u sec\n",
725			start_withtimeout);
726	}
727
728	return 0;
729
730exit_unlock:
731	mutex_unlock(&watchdog.lock);
732exit_miscdev:
733	misc_deregister(&watchdog_miscdev);
734exit_reboot:
735	unregister_reboot_notifier(&watchdog_notifier);
736
737	return err;
738}
739
740static int __init f71808e_find(int sioaddr)
741{
742	u16 devid;
743	int err = superio_enter(sioaddr);
744	if (err)
745		return err;
746
747	devid = superio_inw(sioaddr, SIO_REG_MANID);
748	if (devid != SIO_FINTEK_ID) {
749		pr_debug(DRVNAME ": Not a Fintek device\n");
750		err = -ENODEV;
751		goto exit;
752	}
753
754	devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
755	switch (devid) {
756	case SIO_F71808_ID:
757		watchdog.type = f71808fg;
758		break;
759	case SIO_F71862_ID:
760		watchdog.type = f71862fg;
761		err = f71862fg_pin_configure(0); /* validate module parameter */
 
 
762		break;
763	case SIO_F71869_ID:
 
764		watchdog.type = f71869;
765		break;
766	case SIO_F71882_ID:
767		watchdog.type = f71882fg;
768		break;
769	case SIO_F71889_ID:
770		watchdog.type = f71889fg;
771		break;
772	case SIO_F71858_ID:
773		/* Confirmed (by datasheet) not to have a watchdog. */
774		err = -ENODEV;
775		goto exit;
 
 
 
 
 
 
 
 
 
776	default:
777		printk(KERN_INFO DRVNAME ": Unrecognized Fintek device: %04x\n",
778		       (unsigned int)devid);
779		err = -ENODEV;
780		goto exit;
781	}
782
783	printk(KERN_INFO DRVNAME ": Found %s watchdog chip, revision %d\n",
784		f71808e_names[watchdog.type],
785		(int)superio_inb(sioaddr, SIO_REG_DEVREV));
786exit:
787	superio_exit(sioaddr);
788	return err;
789}
790
791static int __init f71808e_init(void)
792{
793	static const unsigned short addrs[] = { 0x2e, 0x4e };
794	int err = -ENODEV;
795	int i;
796
 
 
 
 
 
797	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
798		err = f71808e_find(addrs[i]);
799		if (err == 0)
800			break;
801	}
802	if (i == ARRAY_SIZE(addrs))
803		return err;
804
805	return watchdog_init(addrs[i]);
806}
807
808static void __exit f71808e_exit(void)
809{
810	if (watchdog_is_running()) {
811		printk(KERN_WARNING DRVNAME
812			": Watchdog timer still running, stopping it\n");
813		watchdog_stop();
814	}
815	misc_deregister(&watchdog_miscdev);
816	unregister_reboot_notifier(&watchdog_notifier);
817}
818
819MODULE_DESCRIPTION("F71808E Watchdog Driver");
820MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
821MODULE_LICENSE("GPL");
822
823module_init(f71808e_init);
824module_exit(f71808e_exit);
v5.14.15
  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	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
245static 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
274exit_unlock:
275	mutex_unlock(&watchdog.lock);
276	return err;
277}
278
279static 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
304exit_unlock:
305	mutex_unlock(&watchdog.lock);
306	return err;
307}
308
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
309static int watchdog_start(void)
310{
311	int err;
312	u8 tmp;
313
314	/* Make sure we don't die as soon as the watchdog is enabled below */
315	err = watchdog_keepalive();
316	if (err)
317		return err;
318
319	mutex_lock(&watchdog.lock);
320	err = superio_enter(watchdog.sioaddr);
321	if (err)
322		goto exit_unlock;
323	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
324
325	/* Watchdog pin configuration */
326	switch (watchdog.type) {
327	case f71808fg:
328		/* Set pin 21 to GPIO23/WDTRST#, then to WDTRST# */
329		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT2, 3);
330		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 3);
331		break;
332
333	case f71862fg:
334		if (f71862fg_pin == 63) {
335			/* SPI must be disabled first to use this pin! */
336			superio_clear_bit(watchdog.sioaddr, SIO_REG_ROM_ADDR_SEL, 6);
337			superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT3, 4);
338		} else if (f71862fg_pin == 56) {
339			superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
340		}
341		break;
342
343	case f71868:
344	case f71869:
345		/* GPIO14 --> WDTRST# */
346		superio_clear_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 4);
347		break;
348
349	case f71882fg:
350		/* Set pin 56 to WDTRST# */
351		superio_set_bit(watchdog.sioaddr, SIO_REG_MFUNCT1, 1);
352		break;
353
354	case f71889fg:
355		/* set pin 40 to WDTRST# */
356		superio_outb(watchdog.sioaddr, SIO_REG_MFUNCT3,
357			superio_inb(watchdog.sioaddr, SIO_REG_MFUNCT3) & 0xcf);
358		break;
359
360	case f81803:
361		/* Enable TSI Level register bank */
362		superio_clear_bit(watchdog.sioaddr, SIO_REG_CLOCK_SEL, 3);
363		/* Set pin 27 to WDTRST# */
364		superio_outb(watchdog.sioaddr, SIO_REG_TSI_LEVEL_SEL, 0x5f &
365			superio_inb(watchdog.sioaddr, SIO_REG_TSI_LEVEL_SEL));
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	case f81866:
374		/*
375		 * GPIO1 Control Register when 27h BIT3:2 = 01 & BIT0 = 0.
376		 * The PIN 70(GPIO15/WDTRST) is controlled by 2Ch:
377		 *     BIT5: 0 -> WDTRST#
378		 *           1 -> GPIO15
379		 */
380		tmp = superio_inb(watchdog.sioaddr, SIO_F81866_REG_PORT_SEL);
381		tmp &= ~(BIT(3) | BIT(0));
382		tmp |= BIT(2);
383		superio_outb(watchdog.sioaddr, SIO_F81866_REG_PORT_SEL, tmp);
384
385		superio_clear_bit(watchdog.sioaddr, SIO_F81866_REG_GPIO1, 5);
386		break;
387
388	default:
389		/*
390		 * 'default' label to shut up the compiler and catch
391		 * programmer errors
392		 */
393		err = -ENODEV;
394		goto exit_superio;
395	}
396
397	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
398	superio_set_bit(watchdog.sioaddr, SIO_REG_ENABLE, 0);
399
400	if (watchdog.type == f81865 || watchdog.type == f81866)
401		superio_set_bit(watchdog.sioaddr, F81865_REG_WDO_CONF,
402				F81865_FLAG_WDOUT_EN);
403	else
404		superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDO_CONF,
405				F71808FG_FLAG_WDOUT_EN);
406
407	superio_set_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
408			F71808FG_FLAG_WD_EN);
409
410	if (watchdog.pulse_mode) {
411		/* Select "pulse" output mode with given duration */
412		u8 wdt_conf = superio_inb(watchdog.sioaddr,
413				F71808FG_REG_WDT_CONF);
414
415		/* Set WD_PSWIDTH bits (1:0) */
416		wdt_conf = (wdt_conf & 0xfc) | (watchdog.pulse_val & 0x03);
417		/* Set WD_PULSE to "pulse" mode */
418		wdt_conf |= BIT(F71808FG_FLAG_WD_PULSE);
419
420		superio_outb(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
421				wdt_conf);
422	} else {
423		/* Select "level" output mode */
424		superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
425				F71808FG_FLAG_WD_PULSE);
426	}
427
428exit_superio:
429	superio_exit(watchdog.sioaddr);
430exit_unlock:
431	mutex_unlock(&watchdog.lock);
432
433	return err;
434}
435
436static int watchdog_stop(void)
437{
438	int err = 0;
439
440	mutex_lock(&watchdog.lock);
441	err = superio_enter(watchdog.sioaddr);
442	if (err)
443		goto exit_unlock;
444	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
445
446	superio_clear_bit(watchdog.sioaddr, F71808FG_REG_WDT_CONF,
447			F71808FG_FLAG_WD_EN);
448
449	superio_exit(watchdog.sioaddr);
450
451exit_unlock:
452	mutex_unlock(&watchdog.lock);
453
454	return err;
455}
456
457static int watchdog_get_status(void)
458{
459	int status = 0;
460
461	mutex_lock(&watchdog.lock);
462	status = (watchdog.caused_reboot) ? WDIOF_CARDRESET : 0;
463	mutex_unlock(&watchdog.lock);
464
465	return status;
466}
467
468static bool watchdog_is_running(void)
469{
470	/*
471	 * if we fail to determine the watchdog's status assume it to be
472	 * running to be on the safe side
473	 */
474	bool is_running = true;
475
476	mutex_lock(&watchdog.lock);
477	if (superio_enter(watchdog.sioaddr))
478		goto exit_unlock;
479	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
480
481	is_running = (superio_inb(watchdog.sioaddr, SIO_REG_ENABLE) & BIT(0))
482		&& (superio_inb(watchdog.sioaddr, F71808FG_REG_WDT_CONF)
483			& BIT(F71808FG_FLAG_WD_EN));
484
485	superio_exit(watchdog.sioaddr);
486
487exit_unlock:
488	mutex_unlock(&watchdog.lock);
489	return is_running;
490}
491
492/* /dev/watchdog api */
493
494static int watchdog_open(struct inode *inode, struct file *file)
495{
496	int err;
497
498	/* If the watchdog is alive we don't need to start it again */
499	if (test_and_set_bit(0, &watchdog.opened))
500		return -EBUSY;
501
502	err = watchdog_start();
503	if (err) {
504		clear_bit(0, &watchdog.opened);
505		return err;
506	}
507
508	if (nowayout)
509		__module_get(THIS_MODULE);
510
511	watchdog.expect_close = 0;
512	return stream_open(inode, file);
513}
514
515static int watchdog_release(struct inode *inode, struct file *file)
516{
517	clear_bit(0, &watchdog.opened);
518
519	if (!watchdog.expect_close) {
520		watchdog_keepalive();
521		pr_crit("Unexpected close, not stopping watchdog!\n");
 
522	} else if (!nowayout) {
523		watchdog_stop();
524	}
525	return 0;
526}
527
528/*
529 *      watchdog_write:
530 *      @file: file handle to the watchdog
531 *      @buf: buffer to write
532 *      @count: count of bytes
533 *      @ppos: pointer to the position to write. No seeks allowed
534 *
535 *      A write to a watchdog device is defined as a keepalive signal. Any
536 *      write of data will do, as we we don't define content meaning.
537 */
538
539static ssize_t watchdog_write(struct file *file, const char __user *buf,
540			    size_t count, loff_t *ppos)
541{
542	if (count) {
543		if (!nowayout) {
544			size_t i;
545
546			/* In case it was set long ago */
547			bool expect_close = false;
548
549			for (i = 0; i != count; i++) {
550				char c;
551				if (get_user(c, buf + i))
552					return -EFAULT;
553				if (c == 'V')
554					expect_close = true;
555			}
556
557			/* Properly order writes across fork()ed processes */
558			mutex_lock(&watchdog.lock);
559			watchdog.expect_close = expect_close;
560			mutex_unlock(&watchdog.lock);
561		}
562
563		/* someone wrote to us, we should restart timer */
564		watchdog_keepalive();
565	}
566	return count;
567}
568
569/*
570 *      watchdog_ioctl:
571 *      @inode: inode of the device
572 *      @file: file handle to the device
573 *      @cmd: watchdog command
574 *      @arg: argument pointer
575 *
576 *      The watchdog API defines a common set of functions for all watchdogs
577 *      according to their available features.
578 */
579static long watchdog_ioctl(struct file *file, unsigned int cmd,
580	unsigned long arg)
581{
582	int status;
583	int new_options;
584	int new_timeout;
585	union {
586		struct watchdog_info __user *ident;
587		int __user *i;
588	} uarg;
589
590	uarg.i = (int __user *)arg;
591
592	switch (cmd) {
593	case WDIOC_GETSUPPORT:
594		return copy_to_user(uarg.ident, &watchdog.ident,
595			sizeof(watchdog.ident)) ? -EFAULT : 0;
596
597	case WDIOC_GETSTATUS:
598		status = watchdog_get_status();
599		if (status < 0)
600			return status;
601		return put_user(status, uarg.i);
602
603	case WDIOC_GETBOOTSTATUS:
604		return put_user(0, uarg.i);
605
606	case WDIOC_SETOPTIONS:
607		if (get_user(new_options, uarg.i))
608			return -EFAULT;
609
610		if (new_options & WDIOS_DISABLECARD)
611			watchdog_stop();
612
613		if (new_options & WDIOS_ENABLECARD)
614			return watchdog_start();
615		fallthrough;
616
617	case WDIOC_KEEPALIVE:
618		watchdog_keepalive();
619		return 0;
620
621	case WDIOC_SETTIMEOUT:
622		if (get_user(new_timeout, uarg.i))
623			return -EFAULT;
624
625		if (watchdog_set_timeout(new_timeout))
626			return -EINVAL;
627
628		watchdog_keepalive();
629		fallthrough;
630
631	case WDIOC_GETTIMEOUT:
632		return put_user(watchdog.timeout, uarg.i);
633
634	default:
635		return -ENOTTY;
636
637	}
638}
639
640static int watchdog_notify_sys(struct notifier_block *this, unsigned long code,
641	void *unused)
642{
643	if (code == SYS_DOWN || code == SYS_HALT)
644		watchdog_stop();
645	return NOTIFY_DONE;
646}
647
648static const struct file_operations watchdog_fops = {
649	.owner		= THIS_MODULE,
650	.llseek		= no_llseek,
651	.open		= watchdog_open,
652	.release	= watchdog_release,
653	.write		= watchdog_write,
654	.unlocked_ioctl	= watchdog_ioctl,
655	.compat_ioctl	= compat_ptr_ioctl,
656};
657
658static struct miscdevice watchdog_miscdev = {
659	.minor		= WATCHDOG_MINOR,
660	.name		= "watchdog",
661	.fops		= &watchdog_fops,
662};
663
664static struct notifier_block watchdog_notifier = {
665	.notifier_call = watchdog_notify_sys,
666};
667
668static int __init watchdog_init(int sioaddr)
669{
670	int wdt_conf, err = 0;
671
672	/* No need to lock watchdog.lock here because no entry points
673	 * into the module have been registered yet.
674	 */
675	watchdog.sioaddr = sioaddr;
676	watchdog.ident.options = WDIOF_MAGICCLOSE
677				| WDIOF_KEEPALIVEPING
678				| WDIOF_CARDRESET;
679
680	snprintf(watchdog.ident.identity,
681		sizeof(watchdog.ident.identity), "%s watchdog",
682		f71808e_names[watchdog.type]);
683
684	err = superio_enter(sioaddr);
685	if (err)
686		return err;
687	superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
688
689	wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF);
690	watchdog.caused_reboot = wdt_conf & BIT(F71808FG_FLAG_WDTMOUT_STS);
691
692	/*
693	 * We don't want WDTMOUT_STS to stick around till regular reboot.
694	 * Write 1 to the bit to clear it to zero.
695	 */
696	superio_outb(sioaddr, F71808FG_REG_WDT_CONF,
697		     wdt_conf | BIT(F71808FG_FLAG_WDTMOUT_STS));
698
699	superio_exit(sioaddr);
700
701	err = watchdog_set_timeout(timeout);
702	if (err)
703		return err;
704	err = watchdog_set_pulse_width(pulse_width);
705	if (err)
706		return err;
707
708	err = register_reboot_notifier(&watchdog_notifier);
709	if (err)
710		return err;
711
712	err = misc_register(&watchdog_miscdev);
713	if (err) {
714		pr_err("cannot register miscdev on minor=%d\n",
715		       watchdog_miscdev.minor);
 
716		goto exit_reboot;
717	}
718
719	if (start_withtimeout) {
720		if (start_withtimeout <= 0
721		 || start_withtimeout >  max_timeout) {
722			pr_err("starting timeout out of range\n");
 
723			err = -EINVAL;
724			goto exit_miscdev;
725		}
726
727		err = watchdog_start();
728		if (err) {
729			pr_err("cannot start watchdog timer\n");
 
730			goto exit_miscdev;
731		}
732
733		mutex_lock(&watchdog.lock);
734		err = superio_enter(sioaddr);
735		if (err)
736			goto exit_unlock;
737		superio_select(watchdog.sioaddr, SIO_F71808FG_LD_WDT);
738
739		if (start_withtimeout > 0xff) {
740			/* select minutes for timer units */
741			superio_set_bit(sioaddr, F71808FG_REG_WDT_CONF,
742				F71808FG_FLAG_WD_UNIT);
743			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
744				DIV_ROUND_UP(start_withtimeout, 60));
745		} else {
746			/* select seconds for timer units */
747			superio_clear_bit(sioaddr, F71808FG_REG_WDT_CONF,
748				F71808FG_FLAG_WD_UNIT);
749			superio_outb(sioaddr, F71808FG_REG_WD_TIME,
750				start_withtimeout);
751		}
752
753		superio_exit(sioaddr);
754		mutex_unlock(&watchdog.lock);
755
756		if (nowayout)
757			__module_get(THIS_MODULE);
758
759		pr_info("watchdog started with initial timeout of %u sec\n",
 
760			start_withtimeout);
761	}
762
763	return 0;
764
765exit_unlock:
766	mutex_unlock(&watchdog.lock);
767exit_miscdev:
768	misc_deregister(&watchdog_miscdev);
769exit_reboot:
770	unregister_reboot_notifier(&watchdog_notifier);
771
772	return err;
773}
774
775static int __init f71808e_find(int sioaddr)
776{
777	u16 devid;
778	int err = superio_enter(sioaddr);
779	if (err)
780		return err;
781
782	devid = superio_inw(sioaddr, SIO_REG_MANID);
783	if (devid != SIO_FINTEK_ID) {
784		pr_debug("Not a Fintek device\n");
785		err = -ENODEV;
786		goto exit;
787	}
788
789	devid = force_id ? force_id : superio_inw(sioaddr, SIO_REG_DEVID);
790	switch (devid) {
791	case SIO_F71808_ID:
792		watchdog.type = f71808fg;
793		break;
794	case SIO_F71862_ID:
795		watchdog.type = f71862fg;
796		break;
797	case SIO_F71868_ID:
798		watchdog.type = f71868;
799		break;
800	case SIO_F71869_ID:
801	case SIO_F71869A_ID:
802		watchdog.type = f71869;
803		break;
804	case SIO_F71882_ID:
805		watchdog.type = f71882fg;
806		break;
807	case SIO_F71889_ID:
808		watchdog.type = f71889fg;
809		break;
810	case SIO_F71858_ID:
811		/* Confirmed (by datasheet) not to have a watchdog. */
812		err = -ENODEV;
813		goto exit;
814	case SIO_F81803_ID:
815		watchdog.type = f81803;
816		break;
817	case SIO_F81865_ID:
818		watchdog.type = f81865;
819		break;
820	case SIO_F81866_ID:
821		watchdog.type = f81866;
822		break;
823	default:
824		pr_info("Unrecognized Fintek device: %04x\n",
825			(unsigned int)devid);
826		err = -ENODEV;
827		goto exit;
828	}
829
830	pr_info("Found %s watchdog chip, revision %d\n",
831		f71808e_names[watchdog.type],
832		(int)superio_inb(sioaddr, SIO_REG_DEVREV));
833exit:
834	superio_exit(sioaddr);
835	return err;
836}
837
838static int __init f71808e_init(void)
839{
840	static const unsigned short addrs[] = { 0x2e, 0x4e };
841	int err = -ENODEV;
842	int i;
843
844	if (f71862fg_pin != 63 && f71862fg_pin != 56) {
845		pr_err("Invalid argument f71862fg_pin=%d\n", f71862fg_pin);
846		return -EINVAL;
847	}
848
849	for (i = 0; i < ARRAY_SIZE(addrs); i++) {
850		err = f71808e_find(addrs[i]);
851		if (err == 0)
852			break;
853	}
854	if (i == ARRAY_SIZE(addrs))
855		return err;
856
857	return watchdog_init(addrs[i]);
858}
859
860static void __exit f71808e_exit(void)
861{
862	if (watchdog_is_running()) {
863		pr_warn("Watchdog timer still running, stopping it\n");
 
864		watchdog_stop();
865	}
866	misc_deregister(&watchdog_miscdev);
867	unregister_reboot_notifier(&watchdog_notifier);
868}
869
870MODULE_DESCRIPTION("F71808E Watchdog Driver");
871MODULE_AUTHOR("Giel van Schijndel <me@mortis.eu>");
872MODULE_LICENSE("GPL");
873
874module_init(f71808e_init);
875module_exit(f71808e_exit);