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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Industrial Computer Source WDT500/501 driver
3 *
4 * (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
5 * http://www.redhat.com
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 cleanup
28 * Parameterized timeout
29 * Tigran Aivazian : Restructured wdt_init() to handle failures
30 * Joel Becker : Added WDIOC_GET/SETTIMEOUT
31 * Matt Domsch : Added nowayout module option
32 */
33
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/interrupt.h>
35#include <linux/module.h>
36#include <linux/moduleparam.h>
37#include <linux/types.h>
38#include <linux/miscdevice.h>
39#include <linux/watchdog.h>
40#include <linux/fs.h>
41#include <linux/ioport.h>
42#include <linux/notifier.h>
43#include <linux/reboot.h>
44#include <linux/init.h>
45
46#include <asm/io.h>
47#include <asm/uaccess.h>
48#include <asm/system.h>
49#include "wd501p.h"
50
51static unsigned long wdt_is_open;
52static char expect_close;
53
54/*
55 * Module parameters
56 */
57
58#define WD_TIMO 60 /* Default heartbeat = 60 seconds */
59
60static int heartbeat = WD_TIMO;
61static int wd_heartbeat;
62module_param(heartbeat, int, 0);
63MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WD_TIMO) ")");
64
Andrey Panin4bfdf372005-07-27 11:43:58 -070065static int nowayout = WATCHDOG_NOWAYOUT;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066module_param(nowayout, int, 0);
67MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
68
69/* You must set these - there is no sane way to probe for this board. */
70static int io=0x240;
71static int irq=11;
72
73module_param(io, int, 0);
74MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
75module_param(irq, int, 0);
76MODULE_PARM_DESC(irq, "WDT irq (default=11)");
77
78#ifdef CONFIG_WDT_501
79/* Support for the Fan Tachometer on the WDT501-P */
80static int tachometer;
81
82module_param(tachometer, int, 0);
83MODULE_PARM_DESC(tachometer, "WDT501-P Fan Tachometer support (0=disable, default=0)");
84#endif /* CONFIG_WDT_501 */
85
86/*
87 * Programming support
88 */
89
90static void wdt_ctr_mode(int ctr, int mode)
91{
92 ctr<<=6;
93 ctr|=0x30;
94 ctr|=(mode<<1);
95 outb_p(ctr, WDT_CR);
96}
97
98static void wdt_ctr_load(int ctr, int val)
99{
100 outb_p(val&0xFF, WDT_COUNT0+ctr);
101 outb_p(val>>8, WDT_COUNT0+ctr);
102}
103
104/**
105 * wdt_start:
106 *
107 * Start the watchdog driver.
108 */
109
110static int wdt_start(void)
111{
112 inb_p(WDT_DC); /* Disable watchdog */
113 wdt_ctr_mode(0,3); /* Program CTR0 for Mode 3: Square Wave Generator */
114 wdt_ctr_mode(1,2); /* Program CTR1 for Mode 2: Rate Generator */
115 wdt_ctr_mode(2,0); /* Program CTR2 for Mode 0: Pulse on Terminal Count */
116 wdt_ctr_load(0, 8948); /* Count at 100Hz */
117 wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */
118 wdt_ctr_load(2,65535); /* Length of reset pulse */
119 outb_p(0, WDT_DC); /* Enable watchdog */
120 return 0;
121}
122
123/**
124 * wdt_stop:
125 *
126 * Stop the watchdog driver.
127 */
128
129static int wdt_stop (void)
130{
131 /* Turn the card off */
132 inb_p(WDT_DC); /* Disable watchdog */
133 wdt_ctr_load(2,0); /* 0 length reset pulses now */
134 return 0;
135}
136
137/**
138 * wdt_ping:
139 *
140 * Reload counter one with the watchdog heartbeat. We don't bother reloading
141 * the cascade counter.
142 */
143
144static int wdt_ping(void)
145{
146 /* Write a watchdog value */
147 inb_p(WDT_DC); /* Disable watchdog */
148 wdt_ctr_mode(1,2); /* Re-Program CTR1 for Mode 2: Rate Generator */
149 wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */
150 outb_p(0, WDT_DC); /* Enable watchdog */
151 return 0;
152}
153
154/**
155 * wdt_set_heartbeat:
156 * @t: the new heartbeat value that needs to be set.
157 *
158 * Set a new heartbeat value for the watchdog device. If the heartbeat value is
159 * incorrect we keep the old value and return -EINVAL. If successfull we
160 * return 0.
161 */
162static int wdt_set_heartbeat(int t)
163{
164 if ((t < 1) || (t > 65535))
165 return -EINVAL;
166
167 heartbeat = t;
168 wd_heartbeat = t * 100;
169 return 0;
170}
171
172/**
173 * wdt_get_status:
174 * @status: the new status.
175 *
176 * Extract the status information from a WDT watchdog device. There are
177 * several board variants so we have to know which bits are valid. Some
178 * bits default to one and some to zero in order to be maximally painful.
179 *
180 * we then map the bits onto the status ioctl flags.
181 */
182
183static int wdt_get_status(int *status)
184{
185 unsigned char new_status=inb_p(WDT_SR);
186
187 *status=0;
188 if (new_status & WDC_SR_ISOI0)
189 *status |= WDIOF_EXTERN1;
190 if (new_status & WDC_SR_ISII1)
191 *status |= WDIOF_EXTERN2;
192#ifdef CONFIG_WDT_501
193 if (!(new_status & WDC_SR_TGOOD))
194 *status |= WDIOF_OVERHEAT;
195 if (!(new_status & WDC_SR_PSUOVER))
196 *status |= WDIOF_POWEROVER;
197 if (!(new_status & WDC_SR_PSUUNDR))
198 *status |= WDIOF_POWERUNDER;
199 if (tachometer) {
200 if (!(new_status & WDC_SR_FANGOOD))
201 *status |= WDIOF_FANFAULT;
202 }
203#endif /* CONFIG_WDT_501 */
204 return 0;
205}
206
207#ifdef CONFIG_WDT_501
208/**
209 * wdt_get_temperature:
210 *
211 * Reports the temperature in degrees Fahrenheit. The API is in
212 * farenheit. It was designed by an imperial measurement luddite.
213 */
214
215static int wdt_get_temperature(int *temperature)
216{
217 unsigned short c=inb_p(WDT_RT);
218
219 *temperature = (c * 11 / 15) + 7;
220 return 0;
221}
222#endif /* CONFIG_WDT_501 */
223
224/**
225 * wdt_interrupt:
226 * @irq: Interrupt number
227 * @dev_id: Unused as we don't allow multiple devices.
228 * @regs: Unused.
229 *
230 * Handle an interrupt from the board. These are raised when the status
231 * map changes in what the board considers an interesting way. That means
232 * a failure condition occurring.
233 */
234
235static irqreturn_t wdt_interrupt(int irq, void *dev_id, struct pt_regs *regs)
236{
237 /*
238 * Read the status register see what is up and
239 * then printk it.
240 */
241 unsigned char status=inb_p(WDT_SR);
242
243 printk(KERN_CRIT "WDT status %d\n", status);
244
245#ifdef CONFIG_WDT_501
246 if (!(status & WDC_SR_TGOOD))
247 printk(KERN_CRIT "Overheat alarm.(%d)\n",inb_p(WDT_RT));
248 if (!(status & WDC_SR_PSUOVER))
249 printk(KERN_CRIT "PSU over voltage.\n");
250 if (!(status & WDC_SR_PSUUNDR))
251 printk(KERN_CRIT "PSU under voltage.\n");
252 if (tachometer) {
253 if (!(status & WDC_SR_FANGOOD))
254 printk(KERN_CRIT "Possible fan fault.\n");
255 }
256#endif /* CONFIG_WDT_501 */
257 if (!(status & WDC_SR_WCCR))
258#ifdef SOFTWARE_REBOOT
259#ifdef ONLY_TESTING
260 printk(KERN_CRIT "Would Reboot.\n");
261#else
262 printk(KERN_CRIT "Initiating system reboot.\n");
Eric W. Biedermanf82567e2005-07-26 11:53:19 -0600263 emergency_restart();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264#endif
265#else
266 printk(KERN_CRIT "Reset in 5ms.\n");
267#endif
268 return IRQ_HANDLED;
269}
270
271
272/**
273 * wdt_write:
274 * @file: file handle to the watchdog
275 * @buf: buffer to write (unused as data does not matter here
276 * @count: count of bytes
277 * @ppos: pointer to the position to write. No seeks allowed
278 *
279 * A write to a watchdog device is defined as a keepalive signal. Any
280 * write of data will do, as we we don't define content meaning.
281 */
282
283static ssize_t wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
284{
285 if(count) {
286 if (!nowayout) {
287 size_t i;
288
289 /* In case it was set long ago */
290 expect_close = 0;
291
292 for (i = 0; i != count; i++) {
293 char c;
294 if (get_user(c, buf + i))
295 return -EFAULT;
296 if (c == 'V')
297 expect_close = 42;
298 }
299 }
300 wdt_ping();
301 }
302 return count;
303}
304
305/**
306 * wdt_ioctl:
307 * @inode: inode of the device
308 * @file: file handle to the device
309 * @cmd: watchdog command
310 * @arg: argument pointer
311 *
312 * The watchdog API defines a common set of functions for all watchdogs
313 * according to their available features. We only actually usefully support
314 * querying capabilities and current status.
315 */
316
317static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
318 unsigned long arg)
319{
320 void __user *argp = (void __user *)arg;
321 int __user *p = argp;
322 int new_heartbeat;
323 int status;
324
325 static struct watchdog_info ident = {
326 .options = WDIOF_SETTIMEOUT|
327 WDIOF_MAGICCLOSE|
328 WDIOF_KEEPALIVEPING,
329 .firmware_version = 1,
330 .identity = "WDT500/501",
331 };
332
333 /* Add options according to the card we have */
334 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
335#ifdef CONFIG_WDT_501
336 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER);
337 if (tachometer)
338 ident.options |= WDIOF_FANFAULT;
339#endif /* CONFIG_WDT_501 */
340
341 switch(cmd)
342 {
343 default:
344 return -ENOIOCTLCMD;
345 case WDIOC_GETSUPPORT:
346 return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0;
347
348 case WDIOC_GETSTATUS:
349 wdt_get_status(&status);
350 return put_user(status, p);
351 case WDIOC_GETBOOTSTATUS:
352 return put_user(0, p);
353 case WDIOC_KEEPALIVE:
354 wdt_ping();
355 return 0;
356 case WDIOC_SETTIMEOUT:
357 if (get_user(new_heartbeat, p))
358 return -EFAULT;
359
360 if (wdt_set_heartbeat(new_heartbeat))
361 return -EINVAL;
362
363 wdt_ping();
364 /* Fall */
365 case WDIOC_GETTIMEOUT:
366 return put_user(heartbeat, p);
367 }
368}
369
370/**
371 * wdt_open:
372 * @inode: inode of device
373 * @file: file handle to device
374 *
375 * The watchdog device has been opened. The watchdog device is single
376 * open and on opening we load the counters. Counter zero is a 100Hz
377 * cascade, into counter 1 which downcounts to reboot. When the counter
378 * triggers counter 2 downcounts the length of the reset pulse which
379 * set set to be as long as possible.
380 */
381
382static int wdt_open(struct inode *inode, struct file *file)
383{
384 if(test_and_set_bit(0, &wdt_is_open))
385 return -EBUSY;
386 /*
387 * Activate
388 */
389 wdt_start();
390 return nonseekable_open(inode, file);
391}
392
393/**
394 * wdt_release:
395 * @inode: inode to board
396 * @file: file handle to board
397 *
398 * The watchdog has a configurable API. There is a religious dispute
399 * between people who want their watchdog to be able to shut down and
400 * those who want to be sure if the watchdog manager dies the machine
401 * reboots. In the former case we disable the counters, in the latter
402 * case you have to open it again very soon.
403 */
404
405static int wdt_release(struct inode *inode, struct file *file)
406{
407 if (expect_close == 42) {
408 wdt_stop();
409 clear_bit(0, &wdt_is_open);
410 } else {
411 printk(KERN_CRIT "wdt: WDT device closed unexpectedly. WDT will not stop!\n");
412 wdt_ping();
413 }
414 expect_close = 0;
415 return 0;
416}
417
418#ifdef CONFIG_WDT_501
419/**
420 * wdt_temp_read:
421 * @file: file handle to the watchdog board
422 * @buf: buffer to write 1 byte into
423 * @count: length of buffer
424 * @ptr: offset (no seek allowed)
425 *
426 * Temp_read reports the temperature in degrees Fahrenheit. The API is in
427 * farenheit. It was designed by an imperial measurement luddite.
428 */
429
430static ssize_t wdt_temp_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
431{
432 int temperature;
433
434 if (wdt_get_temperature(&temperature))
435 return -EFAULT;
436
437 if (copy_to_user (buf, &temperature, 1))
438 return -EFAULT;
439
440 return 1;
441}
442
443/**
444 * wdt_temp_open:
445 * @inode: inode of device
446 * @file: file handle to device
447 *
448 * The temperature device has been opened.
449 */
450
451static int wdt_temp_open(struct inode *inode, struct file *file)
452{
453 return nonseekable_open(inode, file);
454}
455
456/**
457 * wdt_temp_release:
458 * @inode: inode to board
459 * @file: file handle to board
460 *
461 * The temperature device has been closed.
462 */
463
464static int wdt_temp_release(struct inode *inode, struct file *file)
465{
466 return 0;
467}
468#endif /* CONFIG_WDT_501 */
469
470/**
471 * notify_sys:
472 * @this: our notifier block
473 * @code: the event being reported
474 * @unused: unused
475 *
476 * Our notifier is called on system shutdowns. We want to turn the card
477 * off at reboot otherwise the machine will reboot again during memory
478 * test or worse yet during the following fsck. This would suck, in fact
479 * trust me - if it happens it does suck.
480 */
481
482static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
483 void *unused)
484{
485 if(code==SYS_DOWN || code==SYS_HALT) {
486 /* Turn the card off */
487 wdt_stop();
488 }
489 return NOTIFY_DONE;
490}
491
492/*
493 * Kernel Interfaces
494 */
495
496
497static struct file_operations wdt_fops = {
498 .owner = THIS_MODULE,
499 .llseek = no_llseek,
500 .write = wdt_write,
501 .ioctl = wdt_ioctl,
502 .open = wdt_open,
503 .release = wdt_release,
504};
505
506static struct miscdevice wdt_miscdev = {
507 .minor = WATCHDOG_MINOR,
508 .name = "watchdog",
509 .fops = &wdt_fops,
510};
511
512#ifdef CONFIG_WDT_501
513static struct file_operations wdt_temp_fops = {
514 .owner = THIS_MODULE,
515 .llseek = no_llseek,
516 .read = wdt_temp_read,
517 .open = wdt_temp_open,
518 .release = wdt_temp_release,
519};
520
521static struct miscdevice temp_miscdev = {
522 .minor = TEMP_MINOR,
523 .name = "temperature",
524 .fops = &wdt_temp_fops,
525};
526#endif /* CONFIG_WDT_501 */
527
528/*
529 * The WDT card needs to learn about soft shutdowns in order to
530 * turn the timebomb registers off.
531 */
532
533static struct notifier_block wdt_notifier = {
534 .notifier_call = wdt_notify_sys,
535};
536
537/**
538 * cleanup_module:
539 *
540 * Unload the watchdog. You cannot do this with any file handles open.
541 * If your watchdog is set to continue ticking on close and you unload
542 * it, well it keeps ticking. We won't get the interrupt but the board
543 * will not touch PC memory so all is fine. You just have to load a new
544 * module in 60 seconds or reboot.
545 */
546
547static void __exit wdt_exit(void)
548{
549 misc_deregister(&wdt_miscdev);
550#ifdef CONFIG_WDT_501
551 misc_deregister(&temp_miscdev);
552#endif /* CONFIG_WDT_501 */
553 unregister_reboot_notifier(&wdt_notifier);
554 free_irq(irq, NULL);
555 release_region(io,8);
556}
557
558/**
559 * wdt_init:
560 *
561 * Set up the WDT watchdog board. All we have to do is grab the
562 * resources we require and bitch if anyone beat us to them.
563 * The open() function will actually kick the board off.
564 */
565
566static int __init wdt_init(void)
567{
568 int ret;
569
570 /* Check that the heartbeat value is within it's range ; if not reset to the default */
571 if (wdt_set_heartbeat(heartbeat)) {
572 wdt_set_heartbeat(WD_TIMO);
573 printk(KERN_INFO "wdt: heartbeat value must be 0<heartbeat<65536, using %d\n",
574 WD_TIMO);
575 }
576
577 if (!request_region(io, 8, "wdt501p")) {
578 printk(KERN_ERR "wdt: I/O address 0x%04x already in use\n", io);
579 ret = -EBUSY;
580 goto out;
581 }
582
Thomas Gleixner0f2ed4c2006-07-01 19:29:33 -0700583 ret = request_irq(irq, wdt_interrupt, IRQF_DISABLED, "wdt501p", NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 if(ret) {
585 printk(KERN_ERR "wdt: IRQ %d is not free.\n", irq);
586 goto outreg;
587 }
588
589 ret = register_reboot_notifier(&wdt_notifier);
590 if(ret) {
591 printk(KERN_ERR "wdt: cannot register reboot notifier (err=%d)\n", ret);
592 goto outirq;
593 }
594
595#ifdef CONFIG_WDT_501
596 ret = misc_register(&temp_miscdev);
597 if (ret) {
598 printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n",
599 TEMP_MINOR, ret);
600 goto outrbt;
601 }
602#endif /* CONFIG_WDT_501 */
603
604 ret = misc_register(&wdt_miscdev);
605 if (ret) {
606 printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n",
607 WATCHDOG_MINOR, ret);
608 goto outmisc;
609 }
610
611 ret = 0;
612 printk(KERN_INFO "WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
613 io, irq, heartbeat, nowayout);
614#ifdef CONFIG_WDT_501
615 printk(KERN_INFO "wdt: Fan Tachometer is %s\n", (tachometer ? "Enabled" : "Disabled"));
616#endif /* CONFIG_WDT_501 */
617
618out:
619 return ret;
620
621outmisc:
622#ifdef CONFIG_WDT_501
623 misc_deregister(&temp_miscdev);
624outrbt:
625#endif /* CONFIG_WDT_501 */
626 unregister_reboot_notifier(&wdt_notifier);
627outirq:
628 free_irq(irq, NULL);
629outreg:
630 release_region(io,8);
631 goto out;
632}
633
634module_init(wdt_init);
635module_exit(wdt_exit);
636
637MODULE_AUTHOR("Alan Cox");
638MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
639MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
640MODULE_ALIAS_MISCDEV(TEMP_MINOR);
641MODULE_LICENSE("GPL");