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1/*
2 * Industrial Computer Source WDT501 driver
3 *
4 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
5 * All Rights Reserved.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
13 * warranty for any of this software. This material is provided
14 * "AS-IS" and at no charge.
15 *
16 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
17 *
18 * Release 0.10.
19 *
20 * Fixes
21 * Dave Gregorich : Modularisation and minor bugs
22 * Alan Cox : Added the watchdog ioctl() stuff
23 * Alan Cox : Fixed the reboot problem (as noted by
24 * Matt Crocker).
25 * Alan Cox : Added wdt= boot option
26 * Alan Cox : Cleaned up copy/user stuff
27 * Tim Hockin : Added insmod parameters, comment
28 * cleanup, parameterized timeout
29 * Tigran Aivazian : Restructured wdt_init() to handle
30 * failures
31 * Joel Becker : Added WDIOC_GET/SETTIMEOUT
32 * Matt Domsch : Added nowayout module option
33 */
34
35#include <linux/interrupt.h>
36#include <linux/module.h>
37#include <linux/moduleparam.h>
38#include <linux/types.h>
39#include <linux/miscdevice.h>
40#include <linux/watchdog.h>
41#include <linux/fs.h>
42#include <linux/ioport.h>
43#include <linux/notifier.h>
44#include <linux/reboot.h>
45#include <linux/init.h>
46#include <linux/io.h>
47#include <linux/uaccess.h>
48
49#include <asm/system.h>
50#include "wd501p.h"
51
52static unsigned long wdt_is_open;
53static char expect_close;
54
55/*
56 * Module parameters
57 */
58
59#define WD_TIMO 60 /* Default heartbeat = 60 seconds */
60
61static int heartbeat = WD_TIMO;
62static int wd_heartbeat;
63module_param(heartbeat, int, 0);
64MODULE_PARM_DESC(heartbeat,
65 "Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
66 __MODULE_STRING(WD_TIMO) ")");
67
68static int nowayout = WATCHDOG_NOWAYOUT;
69module_param(nowayout, int, 0);
70MODULE_PARM_DESC(nowayout,
71 "Watchdog cannot be stopped once started (default="
72 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
73
74/* You must set these - there is no sane way to probe for this board. */
75static int io = 0x240;
76static int irq = 11;
77
78static DEFINE_SPINLOCK(wdt_lock);
79
80module_param(io, int, 0);
81MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
82module_param(irq, int, 0);
83MODULE_PARM_DESC(irq, "WDT irq (default=11)");
84
85/* Support for the Fan Tachometer on the WDT501-P */
86static int tachometer;
87module_param(tachometer, int, 0);
88MODULE_PARM_DESC(tachometer,
89 "WDT501-P Fan Tachometer support (0=disable, default=0)");
90
91static int type = 500;
92module_param(type, int, 0);
93MODULE_PARM_DESC(type,
94 "WDT501-P Card type (500 or 501, default=500)");
95
96/*
97 * Programming support
98 */
99
100static void wdt_ctr_mode(int ctr, int mode)
101{
102 ctr <<= 6;
103 ctr |= 0x30;
104 ctr |= (mode << 1);
105 outb_p(ctr, WDT_CR);
106}
107
108static void wdt_ctr_load(int ctr, int val)
109{
110 outb_p(val&0xFF, WDT_COUNT0+ctr);
111 outb_p(val>>8, WDT_COUNT0+ctr);
112}
113
114/**
115 * wdt_start:
116 *
117 * Start the watchdog driver.
118 */
119
120static int wdt_start(void)
121{
122 unsigned long flags;
123 spin_lock_irqsave(&wdt_lock, flags);
124 inb_p(WDT_DC); /* Disable watchdog */
125 wdt_ctr_mode(0, 3); /* Program CTR0 for Mode 3:
126 Square Wave Generator */
127 wdt_ctr_mode(1, 2); /* Program CTR1 for Mode 2:
128 Rate Generator */
129 wdt_ctr_mode(2, 0); /* Program CTR2 for Mode 0:
130 Pulse on Terminal Count */
131 wdt_ctr_load(0, 8948); /* Count at 100Hz */
132 wdt_ctr_load(1, wd_heartbeat); /* Heartbeat */
133 wdt_ctr_load(2, 65535); /* Length of reset pulse */
134 outb_p(0, WDT_DC); /* Enable watchdog */
135 spin_unlock_irqrestore(&wdt_lock, flags);
136 return 0;
137}
138
139/**
140 * wdt_stop:
141 *
142 * Stop the watchdog driver.
143 */
144
145static int wdt_stop(void)
146{
147 unsigned long flags;
148 spin_lock_irqsave(&wdt_lock, flags);
149 /* Turn the card off */
150 inb_p(WDT_DC); /* Disable watchdog */
151 wdt_ctr_load(2, 0); /* 0 length reset pulses now */
152 spin_unlock_irqrestore(&wdt_lock, flags);
153 return 0;
154}
155
156/**
157 * wdt_ping:
158 *
159 * Reload counter one with the watchdog heartbeat. We don't bother
160 * reloading the cascade counter.
161 */
162
163static void wdt_ping(void)
164{
165 unsigned long flags;
166 spin_lock_irqsave(&wdt_lock, flags);
167 /* Write a watchdog value */
168 inb_p(WDT_DC); /* Disable watchdog */
169 wdt_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2:
170 Rate Generator */
171 wdt_ctr_load(1, wd_heartbeat); /* Heartbeat */
172 outb_p(0, WDT_DC); /* Enable watchdog */
173 spin_unlock_irqrestore(&wdt_lock, flags);
174}
175
176/**
177 * wdt_set_heartbeat:
178 * @t: the new heartbeat value that needs to be set.
179 *
180 * Set a new heartbeat value for the watchdog device. If the heartbeat
181 * value is incorrect we keep the old value and return -EINVAL. If
182 * successful we return 0.
183 */
184
185static int wdt_set_heartbeat(int t)
186{
187 if (t < 1 || t > 65535)
188 return -EINVAL;
189
190 heartbeat = t;
191 wd_heartbeat = t * 100;
192 return 0;
193}
194
195/**
196 * wdt_get_status:
197 *
198 * Extract the status information from a WDT watchdog device. There are
199 * several board variants so we have to know which bits are valid. Some
200 * bits default to one and some to zero in order to be maximally painful.
201 *
202 * we then map the bits onto the status ioctl flags.
203 */
204
205static int wdt_get_status(void)
206{
207 unsigned char new_status;
208 int status = 0;
209 unsigned long flags;
210
211 spin_lock_irqsave(&wdt_lock, flags);
212 new_status = inb_p(WDT_SR);
213 spin_unlock_irqrestore(&wdt_lock, flags);
214
215 if (new_status & WDC_SR_ISOI0)
216 status |= WDIOF_EXTERN1;
217 if (new_status & WDC_SR_ISII1)
218 status |= WDIOF_EXTERN2;
219 if (type == 501) {
220 if (!(new_status & WDC_SR_TGOOD))
221 status |= WDIOF_OVERHEAT;
222 if (!(new_status & WDC_SR_PSUOVER))
223 status |= WDIOF_POWEROVER;
224 if (!(new_status & WDC_SR_PSUUNDR))
225 status |= WDIOF_POWERUNDER;
226 if (tachometer) {
227 if (!(new_status & WDC_SR_FANGOOD))
228 status |= WDIOF_FANFAULT;
229 }
230 }
231 return status;
232}
233
234/**
235 * wdt_get_temperature:
236 *
237 * Reports the temperature in degrees Fahrenheit. The API is in
238 * farenheit. It was designed by an imperial measurement luddite.
239 */
240
241static int wdt_get_temperature(void)
242{
243 unsigned short c;
244 unsigned long flags;
245
246 spin_lock_irqsave(&wdt_lock, flags);
247 c = inb_p(WDT_RT);
248 spin_unlock_irqrestore(&wdt_lock, flags);
249 return (c * 11 / 15) + 7;
250}
251
252static void wdt_decode_501(int status)
253{
254 if (!(status & WDC_SR_TGOOD))
255 printk(KERN_CRIT "Overheat alarm.(%d)\n", inb_p(WDT_RT));
256 if (!(status & WDC_SR_PSUOVER))
257 printk(KERN_CRIT "PSU over voltage.\n");
258 if (!(status & WDC_SR_PSUUNDR))
259 printk(KERN_CRIT "PSU under voltage.\n");
260}
261
262/**
263 * wdt_interrupt:
264 * @irq: Interrupt number
265 * @dev_id: Unused as we don't allow multiple devices.
266 *
267 * Handle an interrupt from the board. These are raised when the status
268 * map changes in what the board considers an interesting way. That means
269 * a failure condition occurring.
270 */
271
272static irqreturn_t wdt_interrupt(int irq, void *dev_id)
273{
274 /*
275 * Read the status register see what is up and
276 * then printk it.
277 */
278 unsigned char status;
279
280 spin_lock(&wdt_lock);
281 status = inb_p(WDT_SR);
282
283 printk(KERN_CRIT "WDT status %d\n", status);
284
285 if (type == 501) {
286 wdt_decode_501(status);
287 if (tachometer) {
288 if (!(status & WDC_SR_FANGOOD))
289 printk(KERN_CRIT "Possible fan fault.\n");
290 }
291 }
292 if (!(status & WDC_SR_WCCR)) {
293#ifdef SOFTWARE_REBOOT
294#ifdef ONLY_TESTING
295 printk(KERN_CRIT "Would Reboot.\n");
296#else
297 printk(KERN_CRIT "Initiating system reboot.\n");
298 emergency_restart();
299#endif
300#else
301 printk(KERN_CRIT "Reset in 5ms.\n");
302#endif
303 }
304 spin_unlock(&wdt_lock);
305 return IRQ_HANDLED;
306}
307
308
309/**
310 * wdt_write:
311 * @file: file handle to the watchdog
312 * @buf: buffer to write (unused as data does not matter here
313 * @count: count of bytes
314 * @ppos: pointer to the position to write. No seeks allowed
315 *
316 * A write to a watchdog device is defined as a keepalive signal. Any
317 * write of data will do, as we we don't define content meaning.
318 */
319
320static ssize_t wdt_write(struct file *file, const char __user *buf,
321 size_t count, loff_t *ppos)
322{
323 if (count) {
324 if (!nowayout) {
325 size_t i;
326
327 /* In case it was set long ago */
328 expect_close = 0;
329
330 for (i = 0; i != count; i++) {
331 char c;
332 if (get_user(c, buf + i))
333 return -EFAULT;
334 if (c == 'V')
335 expect_close = 42;
336 }
337 }
338 wdt_ping();
339 }
340 return count;
341}
342
343/**
344 * wdt_ioctl:
345 * @file: file handle to the device
346 * @cmd: watchdog command
347 * @arg: argument pointer
348 *
349 * The watchdog API defines a common set of functions for all watchdogs
350 * according to their available features. We only actually usefully support
351 * querying capabilities and current status.
352 */
353
354static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
355{
356 void __user *argp = (void __user *)arg;
357 int __user *p = argp;
358 int new_heartbeat;
359 int status;
360
361 struct watchdog_info ident = {
362 .options = WDIOF_SETTIMEOUT|
363 WDIOF_MAGICCLOSE|
364 WDIOF_KEEPALIVEPING,
365 .firmware_version = 1,
366 .identity = "WDT500/501",
367 };
368
369 /* Add options according to the card we have */
370 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
371 if (type == 501) {
372 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
373 WDIOF_POWEROVER);
374 if (tachometer)
375 ident.options |= WDIOF_FANFAULT;
376 }
377
378 switch (cmd) {
379 case WDIOC_GETSUPPORT:
380 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
381 case WDIOC_GETSTATUS:
382 status = wdt_get_status();
383 return put_user(status, p);
384 case WDIOC_GETBOOTSTATUS:
385 return put_user(0, p);
386 case WDIOC_KEEPALIVE:
387 wdt_ping();
388 return 0;
389 case WDIOC_SETTIMEOUT:
390 if (get_user(new_heartbeat, p))
391 return -EFAULT;
392 if (wdt_set_heartbeat(new_heartbeat))
393 return -EINVAL;
394 wdt_ping();
395 /* Fall */
396 case WDIOC_GETTIMEOUT:
397 return put_user(heartbeat, p);
398 default:
399 return -ENOTTY;
400 }
401}
402
403/**
404 * wdt_open:
405 * @inode: inode of device
406 * @file: file handle to device
407 *
408 * The watchdog device has been opened. The watchdog device is single
409 * open and on opening we load the counters. Counter zero is a 100Hz
410 * cascade, into counter 1 which downcounts to reboot. When the counter
411 * triggers counter 2 downcounts the length of the reset pulse which
412 * set set to be as long as possible.
413 */
414
415static int wdt_open(struct inode *inode, struct file *file)
416{
417 if (test_and_set_bit(0, &wdt_is_open))
418 return -EBUSY;
419 /*
420 * Activate
421 */
422 wdt_start();
423 return nonseekable_open(inode, file);
424}
425
426/**
427 * wdt_release:
428 * @inode: inode to board
429 * @file: file handle to board
430 *
431 * The watchdog has a configurable API. There is a religious dispute
432 * between people who want their watchdog to be able to shut down and
433 * those who want to be sure if the watchdog manager dies the machine
434 * reboots. In the former case we disable the counters, in the latter
435 * case you have to open it again very soon.
436 */
437
438static int wdt_release(struct inode *inode, struct file *file)
439{
440 if (expect_close == 42) {
441 wdt_stop();
442 clear_bit(0, &wdt_is_open);
443 } else {
444 printk(KERN_CRIT
445 "wdt: WDT device closed unexpectedly. WDT will not stop!\n");
446 wdt_ping();
447 }
448 expect_close = 0;
449 return 0;
450}
451
452/**
453 * wdt_temp_read:
454 * @file: file handle to the watchdog board
455 * @buf: buffer to write 1 byte into
456 * @count: length of buffer
457 * @ptr: offset (no seek allowed)
458 *
459 * Temp_read reports the temperature in degrees Fahrenheit. The API is in
460 * farenheit. It was designed by an imperial measurement luddite.
461 */
462
463static ssize_t wdt_temp_read(struct file *file, char __user *buf,
464 size_t count, loff_t *ptr)
465{
466 int temperature = wdt_get_temperature();
467
468 if (copy_to_user(buf, &temperature, 1))
469 return -EFAULT;
470
471 return 1;
472}
473
474/**
475 * wdt_temp_open:
476 * @inode: inode of device
477 * @file: file handle to device
478 *
479 * The temperature device has been opened.
480 */
481
482static int wdt_temp_open(struct inode *inode, struct file *file)
483{
484 return nonseekable_open(inode, file);
485}
486
487/**
488 * wdt_temp_release:
489 * @inode: inode to board
490 * @file: file handle to board
491 *
492 * The temperature device has been closed.
493 */
494
495static int wdt_temp_release(struct inode *inode, struct file *file)
496{
497 return 0;
498}
499
500/**
501 * notify_sys:
502 * @this: our notifier block
503 * @code: the event being reported
504 * @unused: unused
505 *
506 * Our notifier is called on system shutdowns. We want to turn the card
507 * off at reboot otherwise the machine will reboot again during memory
508 * test or worse yet during the following fsck. This would suck, in fact
509 * trust me - if it happens it does suck.
510 */
511
512static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
513 void *unused)
514{
515 if (code == SYS_DOWN || code == SYS_HALT)
516 wdt_stop();
517 return NOTIFY_DONE;
518}
519
520/*
521 * Kernel Interfaces
522 */
523
524
525static const struct file_operations wdt_fops = {
526 .owner = THIS_MODULE,
527 .llseek = no_llseek,
528 .write = wdt_write,
529 .unlocked_ioctl = wdt_ioctl,
530 .open = wdt_open,
531 .release = wdt_release,
532};
533
534static struct miscdevice wdt_miscdev = {
535 .minor = WATCHDOG_MINOR,
536 .name = "watchdog",
537 .fops = &wdt_fops,
538};
539
540static const struct file_operations wdt_temp_fops = {
541 .owner = THIS_MODULE,
542 .llseek = no_llseek,
543 .read = wdt_temp_read,
544 .open = wdt_temp_open,
545 .release = wdt_temp_release,
546};
547
548static struct miscdevice temp_miscdev = {
549 .minor = TEMP_MINOR,
550 .name = "temperature",
551 .fops = &wdt_temp_fops,
552};
553
554/*
555 * The WDT card needs to learn about soft shutdowns in order to
556 * turn the timebomb registers off.
557 */
558
559static struct notifier_block wdt_notifier = {
560 .notifier_call = wdt_notify_sys,
561};
562
563/**
564 * cleanup_module:
565 *
566 * Unload the watchdog. You cannot do this with any file handles open.
567 * If your watchdog is set to continue ticking on close and you unload
568 * it, well it keeps ticking. We won't get the interrupt but the board
569 * will not touch PC memory so all is fine. You just have to load a new
570 * module in 60 seconds or reboot.
571 */
572
573static void __exit wdt_exit(void)
574{
575 misc_deregister(&wdt_miscdev);
576 if (type == 501)
577 misc_deregister(&temp_miscdev);
578 unregister_reboot_notifier(&wdt_notifier);
579 free_irq(irq, NULL);
580 release_region(io, 8);
581}
582
583/**
584 * wdt_init:
585 *
586 * Set up the WDT watchdog board. All we have to do is grab the
587 * resources we require and bitch if anyone beat us to them.
588 * The open() function will actually kick the board off.
589 */
590
591static int __init wdt_init(void)
592{
593 int ret;
594
595 if (type != 500 && type != 501) {
596 printk(KERN_ERR "wdt: unknown card type '%d'.\n", type);
597 return -ENODEV;
598 }
599
600 /* Check that the heartbeat value is within it's range;
601 if not reset to the default */
602 if (wdt_set_heartbeat(heartbeat)) {
603 wdt_set_heartbeat(WD_TIMO);
604 printk(KERN_INFO "wdt: heartbeat value must be "
605 "0 < heartbeat < 65536, using %d\n", WD_TIMO);
606 }
607
608 if (!request_region(io, 8, "wdt501p")) {
609 printk(KERN_ERR
610 "wdt: I/O address 0x%04x already in use\n", io);
611 ret = -EBUSY;
612 goto out;
613 }
614
615 ret = request_irq(irq, wdt_interrupt, IRQF_DISABLED, "wdt501p", NULL);
616 if (ret) {
617 printk(KERN_ERR "wdt: IRQ %d is not free.\n", irq);
618 goto outreg;
619 }
620
621 ret = register_reboot_notifier(&wdt_notifier);
622 if (ret) {
623 printk(KERN_ERR
624 "wdt: cannot register reboot notifier (err=%d)\n", ret);
625 goto outirq;
626 }
627
628 if (type == 501) {
629 ret = misc_register(&temp_miscdev);
630 if (ret) {
631 printk(KERN_ERR "wdt: cannot register miscdev "
632 "on minor=%d (err=%d)\n", TEMP_MINOR, ret);
633 goto outrbt;
634 }
635 }
636
637 ret = misc_register(&wdt_miscdev);
638 if (ret) {
639 printk(KERN_ERR
640 "wdt: cannot register miscdev on minor=%d (err=%d)\n",
641 WATCHDOG_MINOR, ret);
642 goto outmisc;
643 }
644
645 printk(KERN_INFO "WDT500/501-P driver 0.10 "
646 "at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
647 io, irq, heartbeat, nowayout);
648 if (type == 501)
649 printk(KERN_INFO "wdt: Fan Tachometer is %s\n",
650 (tachometer ? "Enabled" : "Disabled"));
651 return 0;
652
653outmisc:
654 if (type == 501)
655 misc_deregister(&temp_miscdev);
656outrbt:
657 unregister_reboot_notifier(&wdt_notifier);
658outirq:
659 free_irq(irq, NULL);
660outreg:
661 release_region(io, 8);
662out:
663 return ret;
664}
665
666module_init(wdt_init);
667module_exit(wdt_exit);
668
669MODULE_AUTHOR("Alan Cox");
670MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
671MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
672MODULE_ALIAS_MISCDEV(TEMP_MINOR);
673MODULE_LICENSE("GPL");
1/*
2 * Industrial Computer Source WDT501 driver
3 *
4 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
5 * All Rights Reserved.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
13 * warranty for any of this software. This material is provided
14 * "AS-IS" and at no charge.
15 *
16 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
17 *
18 * Release 0.10.
19 *
20 * Fixes
21 * Dave Gregorich : Modularisation and minor bugs
22 * Alan Cox : Added the watchdog ioctl() stuff
23 * Alan Cox : Fixed the reboot problem (as noted by
24 * Matt Crocker).
25 * Alan Cox : Added wdt= boot option
26 * Alan Cox : Cleaned up copy/user stuff
27 * Tim Hockin : Added insmod parameters, comment
28 * cleanup, parameterized timeout
29 * Tigran Aivazian : Restructured wdt_init() to handle
30 * failures
31 * Joel Becker : Added WDIOC_GET/SETTIMEOUT
32 * Matt Domsch : Added nowayout module option
33 */
34
35#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
36
37#include <linux/interrupt.h>
38#include <linux/module.h>
39#include <linux/moduleparam.h>
40#include <linux/types.h>
41#include <linux/miscdevice.h>
42#include <linux/watchdog.h>
43#include <linux/fs.h>
44#include <linux/ioport.h>
45#include <linux/notifier.h>
46#include <linux/reboot.h>
47#include <linux/init.h>
48#include <linux/io.h>
49#include <linux/uaccess.h>
50
51#include "wd501p.h"
52
53static unsigned long wdt_is_open;
54static char expect_close;
55
56/*
57 * Module parameters
58 */
59
60#define WD_TIMO 60 /* Default heartbeat = 60 seconds */
61
62static int heartbeat = WD_TIMO;
63static int wd_heartbeat;
64module_param(heartbeat, int, 0);
65MODULE_PARM_DESC(heartbeat,
66 "Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
67 __MODULE_STRING(WD_TIMO) ")");
68
69static bool nowayout = WATCHDOG_NOWAYOUT;
70module_param(nowayout, bool, 0);
71MODULE_PARM_DESC(nowayout,
72 "Watchdog cannot be stopped once started (default="
73 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
74
75/* You must set these - there is no sane way to probe for this board. */
76static int io = 0x240;
77static int irq = 11;
78
79static DEFINE_SPINLOCK(wdt_lock);
80
81module_param(io, int, 0);
82MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
83module_param(irq, int, 0);
84MODULE_PARM_DESC(irq, "WDT irq (default=11)");
85
86/* Support for the Fan Tachometer on the WDT501-P */
87static int tachometer;
88module_param(tachometer, int, 0);
89MODULE_PARM_DESC(tachometer,
90 "WDT501-P Fan Tachometer support (0=disable, default=0)");
91
92static int type = 500;
93module_param(type, int, 0);
94MODULE_PARM_DESC(type,
95 "WDT501-P Card type (500 or 501, default=500)");
96
97/*
98 * Programming support
99 */
100
101static void wdt_ctr_mode(int ctr, int mode)
102{
103 ctr <<= 6;
104 ctr |= 0x30;
105 ctr |= (mode << 1);
106 outb_p(ctr, WDT_CR);
107}
108
109static void wdt_ctr_load(int ctr, int val)
110{
111 outb_p(val&0xFF, WDT_COUNT0+ctr);
112 outb_p(val>>8, WDT_COUNT0+ctr);
113}
114
115/**
116 * wdt_start:
117 *
118 * Start the watchdog driver.
119 */
120
121static int wdt_start(void)
122{
123 unsigned long flags;
124 spin_lock_irqsave(&wdt_lock, flags);
125 inb_p(WDT_DC); /* Disable watchdog */
126 wdt_ctr_mode(0, 3); /* Program CTR0 for Mode 3:
127 Square Wave Generator */
128 wdt_ctr_mode(1, 2); /* Program CTR1 for Mode 2:
129 Rate Generator */
130 wdt_ctr_mode(2, 0); /* Program CTR2 for Mode 0:
131 Pulse on Terminal Count */
132 wdt_ctr_load(0, 8948); /* Count at 100Hz */
133 wdt_ctr_load(1, wd_heartbeat); /* Heartbeat */
134 wdt_ctr_load(2, 65535); /* Length of reset pulse */
135 outb_p(0, WDT_DC); /* Enable watchdog */
136 spin_unlock_irqrestore(&wdt_lock, flags);
137 return 0;
138}
139
140/**
141 * wdt_stop:
142 *
143 * Stop the watchdog driver.
144 */
145
146static int wdt_stop(void)
147{
148 unsigned long flags;
149 spin_lock_irqsave(&wdt_lock, flags);
150 /* Turn the card off */
151 inb_p(WDT_DC); /* Disable watchdog */
152 wdt_ctr_load(2, 0); /* 0 length reset pulses now */
153 spin_unlock_irqrestore(&wdt_lock, flags);
154 return 0;
155}
156
157/**
158 * wdt_ping:
159 *
160 * Reload counter one with the watchdog heartbeat. We don't bother
161 * reloading the cascade counter.
162 */
163
164static void wdt_ping(void)
165{
166 unsigned long flags;
167 spin_lock_irqsave(&wdt_lock, flags);
168 /* Write a watchdog value */
169 inb_p(WDT_DC); /* Disable watchdog */
170 wdt_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2:
171 Rate Generator */
172 wdt_ctr_load(1, wd_heartbeat); /* Heartbeat */
173 outb_p(0, WDT_DC); /* Enable watchdog */
174 spin_unlock_irqrestore(&wdt_lock, flags);
175}
176
177/**
178 * wdt_set_heartbeat:
179 * @t: the new heartbeat value that needs to be set.
180 *
181 * Set a new heartbeat value for the watchdog device. If the heartbeat
182 * value is incorrect we keep the old value and return -EINVAL. If
183 * successful we return 0.
184 */
185
186static int wdt_set_heartbeat(int t)
187{
188 if (t < 1 || t > 65535)
189 return -EINVAL;
190
191 heartbeat = t;
192 wd_heartbeat = t * 100;
193 return 0;
194}
195
196/**
197 * wdt_get_status:
198 *
199 * Extract the status information from a WDT watchdog device. There are
200 * several board variants so we have to know which bits are valid. Some
201 * bits default to one and some to zero in order to be maximally painful.
202 *
203 * we then map the bits onto the status ioctl flags.
204 */
205
206static int wdt_get_status(void)
207{
208 unsigned char new_status;
209 int status = 0;
210 unsigned long flags;
211
212 spin_lock_irqsave(&wdt_lock, flags);
213 new_status = inb_p(WDT_SR);
214 spin_unlock_irqrestore(&wdt_lock, flags);
215
216 if (new_status & WDC_SR_ISOI0)
217 status |= WDIOF_EXTERN1;
218 if (new_status & WDC_SR_ISII1)
219 status |= WDIOF_EXTERN2;
220 if (type == 501) {
221 if (!(new_status & WDC_SR_TGOOD))
222 status |= WDIOF_OVERHEAT;
223 if (!(new_status & WDC_SR_PSUOVER))
224 status |= WDIOF_POWEROVER;
225 if (!(new_status & WDC_SR_PSUUNDR))
226 status |= WDIOF_POWERUNDER;
227 if (tachometer) {
228 if (!(new_status & WDC_SR_FANGOOD))
229 status |= WDIOF_FANFAULT;
230 }
231 }
232 return status;
233}
234
235/**
236 * wdt_get_temperature:
237 *
238 * Reports the temperature in degrees Fahrenheit. The API is in
239 * farenheit. It was designed by an imperial measurement luddite.
240 */
241
242static int wdt_get_temperature(void)
243{
244 unsigned short c;
245 unsigned long flags;
246
247 spin_lock_irqsave(&wdt_lock, flags);
248 c = inb_p(WDT_RT);
249 spin_unlock_irqrestore(&wdt_lock, flags);
250 return (c * 11 / 15) + 7;
251}
252
253static void wdt_decode_501(int status)
254{
255 if (!(status & WDC_SR_TGOOD))
256 pr_crit("Overheat alarm (%d)\n", inb_p(WDT_RT));
257 if (!(status & WDC_SR_PSUOVER))
258 pr_crit("PSU over voltage\n");
259 if (!(status & WDC_SR_PSUUNDR))
260 pr_crit("PSU under voltage\n");
261}
262
263/**
264 * wdt_interrupt:
265 * @irq: Interrupt number
266 * @dev_id: Unused as we don't allow multiple devices.
267 *
268 * Handle an interrupt from the board. These are raised when the status
269 * map changes in what the board considers an interesting way. That means
270 * a failure condition occurring.
271 */
272
273static irqreturn_t wdt_interrupt(int irq, void *dev_id)
274{
275 /*
276 * Read the status register see what is up and
277 * then printk it.
278 */
279 unsigned char status;
280
281 spin_lock(&wdt_lock);
282 status = inb_p(WDT_SR);
283
284 pr_crit("WDT status %d\n", status);
285
286 if (type == 501) {
287 wdt_decode_501(status);
288 if (tachometer) {
289 if (!(status & WDC_SR_FANGOOD))
290 pr_crit("Possible fan fault\n");
291 }
292 }
293 if (!(status & WDC_SR_WCCR)) {
294#ifdef SOFTWARE_REBOOT
295#ifdef ONLY_TESTING
296 pr_crit("Would Reboot\n");
297#else
298 pr_crit("Initiating system reboot\n");
299 emergency_restart();
300#endif
301#else
302 pr_crit("Reset in 5ms\n");
303#endif
304 }
305 spin_unlock(&wdt_lock);
306 return IRQ_HANDLED;
307}
308
309
310/**
311 * wdt_write:
312 * @file: file handle to the watchdog
313 * @buf: buffer to write (unused as data does not matter here
314 * @count: count of bytes
315 * @ppos: pointer to the position to write. No seeks allowed
316 *
317 * A write to a watchdog device is defined as a keepalive signal. Any
318 * write of data will do, as we we don't define content meaning.
319 */
320
321static ssize_t wdt_write(struct file *file, const char __user *buf,
322 size_t count, loff_t *ppos)
323{
324 if (count) {
325 if (!nowayout) {
326 size_t i;
327
328 /* In case it was set long ago */
329 expect_close = 0;
330
331 for (i = 0; i != count; i++) {
332 char c;
333 if (get_user(c, buf + i))
334 return -EFAULT;
335 if (c == 'V')
336 expect_close = 42;
337 }
338 }
339 wdt_ping();
340 }
341 return count;
342}
343
344/**
345 * wdt_ioctl:
346 * @file: file handle to the device
347 * @cmd: watchdog command
348 * @arg: argument pointer
349 *
350 * The watchdog API defines a common set of functions for all watchdogs
351 * according to their available features. We only actually usefully support
352 * querying capabilities and current status.
353 */
354
355static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
356{
357 void __user *argp = (void __user *)arg;
358 int __user *p = argp;
359 int new_heartbeat;
360 int status;
361
362 struct watchdog_info ident = {
363 .options = WDIOF_SETTIMEOUT|
364 WDIOF_MAGICCLOSE|
365 WDIOF_KEEPALIVEPING,
366 .firmware_version = 1,
367 .identity = "WDT500/501",
368 };
369
370 /* Add options according to the card we have */
371 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
372 if (type == 501) {
373 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
374 WDIOF_POWEROVER);
375 if (tachometer)
376 ident.options |= WDIOF_FANFAULT;
377 }
378
379 switch (cmd) {
380 case WDIOC_GETSUPPORT:
381 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
382 case WDIOC_GETSTATUS:
383 status = wdt_get_status();
384 return put_user(status, p);
385 case WDIOC_GETBOOTSTATUS:
386 return put_user(0, p);
387 case WDIOC_KEEPALIVE:
388 wdt_ping();
389 return 0;
390 case WDIOC_SETTIMEOUT:
391 if (get_user(new_heartbeat, p))
392 return -EFAULT;
393 if (wdt_set_heartbeat(new_heartbeat))
394 return -EINVAL;
395 wdt_ping();
396 /* Fall */
397 case WDIOC_GETTIMEOUT:
398 return put_user(heartbeat, p);
399 default:
400 return -ENOTTY;
401 }
402}
403
404/**
405 * wdt_open:
406 * @inode: inode of device
407 * @file: file handle to device
408 *
409 * The watchdog device has been opened. The watchdog device is single
410 * open and on opening we load the counters. Counter zero is a 100Hz
411 * cascade, into counter 1 which downcounts to reboot. When the counter
412 * triggers counter 2 downcounts the length of the reset pulse which
413 * set set to be as long as possible.
414 */
415
416static int wdt_open(struct inode *inode, struct file *file)
417{
418 if (test_and_set_bit(0, &wdt_is_open))
419 return -EBUSY;
420 /*
421 * Activate
422 */
423 wdt_start();
424 return nonseekable_open(inode, file);
425}
426
427/**
428 * wdt_release:
429 * @inode: inode to board
430 * @file: file handle to board
431 *
432 * The watchdog has a configurable API. There is a religious dispute
433 * between people who want their watchdog to be able to shut down and
434 * those who want to be sure if the watchdog manager dies the machine
435 * reboots. In the former case we disable the counters, in the latter
436 * case you have to open it again very soon.
437 */
438
439static int wdt_release(struct inode *inode, struct file *file)
440{
441 if (expect_close == 42) {
442 wdt_stop();
443 clear_bit(0, &wdt_is_open);
444 } else {
445 pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
446 wdt_ping();
447 }
448 expect_close = 0;
449 return 0;
450}
451
452/**
453 * wdt_temp_read:
454 * @file: file handle to the watchdog board
455 * @buf: buffer to write 1 byte into
456 * @count: length of buffer
457 * @ptr: offset (no seek allowed)
458 *
459 * Temp_read reports the temperature in degrees Fahrenheit. The API is in
460 * farenheit. It was designed by an imperial measurement luddite.
461 */
462
463static ssize_t wdt_temp_read(struct file *file, char __user *buf,
464 size_t count, loff_t *ptr)
465{
466 int temperature = wdt_get_temperature();
467
468 if (copy_to_user(buf, &temperature, 1))
469 return -EFAULT;
470
471 return 1;
472}
473
474/**
475 * wdt_temp_open:
476 * @inode: inode of device
477 * @file: file handle to device
478 *
479 * The temperature device has been opened.
480 */
481
482static int wdt_temp_open(struct inode *inode, struct file *file)
483{
484 return nonseekable_open(inode, file);
485}
486
487/**
488 * wdt_temp_release:
489 * @inode: inode to board
490 * @file: file handle to board
491 *
492 * The temperature device has been closed.
493 */
494
495static int wdt_temp_release(struct inode *inode, struct file *file)
496{
497 return 0;
498}
499
500/**
501 * notify_sys:
502 * @this: our notifier block
503 * @code: the event being reported
504 * @unused: unused
505 *
506 * Our notifier is called on system shutdowns. We want to turn the card
507 * off at reboot otherwise the machine will reboot again during memory
508 * test or worse yet during the following fsck. This would suck, in fact
509 * trust me - if it happens it does suck.
510 */
511
512static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
513 void *unused)
514{
515 if (code == SYS_DOWN || code == SYS_HALT)
516 wdt_stop();
517 return NOTIFY_DONE;
518}
519
520/*
521 * Kernel Interfaces
522 */
523
524
525static const struct file_operations wdt_fops = {
526 .owner = THIS_MODULE,
527 .llseek = no_llseek,
528 .write = wdt_write,
529 .unlocked_ioctl = wdt_ioctl,
530 .open = wdt_open,
531 .release = wdt_release,
532};
533
534static struct miscdevice wdt_miscdev = {
535 .minor = WATCHDOG_MINOR,
536 .name = "watchdog",
537 .fops = &wdt_fops,
538};
539
540static const struct file_operations wdt_temp_fops = {
541 .owner = THIS_MODULE,
542 .llseek = no_llseek,
543 .read = wdt_temp_read,
544 .open = wdt_temp_open,
545 .release = wdt_temp_release,
546};
547
548static struct miscdevice temp_miscdev = {
549 .minor = TEMP_MINOR,
550 .name = "temperature",
551 .fops = &wdt_temp_fops,
552};
553
554/*
555 * The WDT card needs to learn about soft shutdowns in order to
556 * turn the timebomb registers off.
557 */
558
559static struct notifier_block wdt_notifier = {
560 .notifier_call = wdt_notify_sys,
561};
562
563/**
564 * cleanup_module:
565 *
566 * Unload the watchdog. You cannot do this with any file handles open.
567 * If your watchdog is set to continue ticking on close and you unload
568 * it, well it keeps ticking. We won't get the interrupt but the board
569 * will not touch PC memory so all is fine. You just have to load a new
570 * module in 60 seconds or reboot.
571 */
572
573static void __exit wdt_exit(void)
574{
575 misc_deregister(&wdt_miscdev);
576 if (type == 501)
577 misc_deregister(&temp_miscdev);
578 unregister_reboot_notifier(&wdt_notifier);
579 free_irq(irq, NULL);
580 release_region(io, 8);
581}
582
583/**
584 * wdt_init:
585 *
586 * Set up the WDT watchdog board. All we have to do is grab the
587 * resources we require and bitch if anyone beat us to them.
588 * The open() function will actually kick the board off.
589 */
590
591static int __init wdt_init(void)
592{
593 int ret;
594
595 if (type != 500 && type != 501) {
596 pr_err("unknown card type '%d'\n", type);
597 return -ENODEV;
598 }
599
600 /* Check that the heartbeat value is within it's range;
601 if not reset to the default */
602 if (wdt_set_heartbeat(heartbeat)) {
603 wdt_set_heartbeat(WD_TIMO);
604 pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
605 WD_TIMO);
606 }
607
608 if (!request_region(io, 8, "wdt501p")) {
609 pr_err("I/O address 0x%04x already in use\n", io);
610 ret = -EBUSY;
611 goto out;
612 }
613
614 ret = request_irq(irq, wdt_interrupt, 0, "wdt501p", NULL);
615 if (ret) {
616 pr_err("IRQ %d is not free\n", irq);
617 goto outreg;
618 }
619
620 ret = register_reboot_notifier(&wdt_notifier);
621 if (ret) {
622 pr_err("cannot register reboot notifier (err=%d)\n", ret);
623 goto outirq;
624 }
625
626 if (type == 501) {
627 ret = misc_register(&temp_miscdev);
628 if (ret) {
629 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
630 TEMP_MINOR, ret);
631 goto outrbt;
632 }
633 }
634
635 ret = misc_register(&wdt_miscdev);
636 if (ret) {
637 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
638 WATCHDOG_MINOR, ret);
639 goto outmisc;
640 }
641
642 pr_info("WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
643 io, irq, heartbeat, nowayout);
644 if (type == 501)
645 pr_info("Fan Tachometer is %s\n",
646 tachometer ? "Enabled" : "Disabled");
647 return 0;
648
649outmisc:
650 if (type == 501)
651 misc_deregister(&temp_miscdev);
652outrbt:
653 unregister_reboot_notifier(&wdt_notifier);
654outirq:
655 free_irq(irq, NULL);
656outreg:
657 release_region(io, 8);
658out:
659 return ret;
660}
661
662module_init(wdt_init);
663module_exit(wdt_exit);
664
665MODULE_AUTHOR("Alan Cox");
666MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
667MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
668MODULE_ALIAS_MISCDEV(TEMP_MINOR);
669MODULE_LICENSE("GPL");