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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/char/watchdog/wdt.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/char/watchdog/wdt.c')
-rw-r--r--drivers/char/watchdog/wdt.c647
1 files changed, 647 insertions, 0 deletions
diff --git a/drivers/char/watchdog/wdt.c b/drivers/char/watchdog/wdt.c
new file mode 100644
index 000000000000..5684aa379886
--- /dev/null
+++ b/drivers/char/watchdog/wdt.c
@@ -0,0 +1,647 @@
1/*
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
34#include <linux/config.h>
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
47#include <asm/io.h>
48#include <asm/uaccess.h>
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, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WD_TIMO) ")");
65
66#ifdef CONFIG_WATCHDOG_NOWAYOUT
67static int nowayout = 1;
68#else
69static int nowayout = 0;
70#endif
71
72module_param(nowayout, int, 0);
73MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_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
79module_param(io, int, 0);
80MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
81module_param(irq, int, 0);
82MODULE_PARM_DESC(irq, "WDT irq (default=11)");
83
84#ifdef CONFIG_WDT_501
85/* Support for the Fan Tachometer on the WDT501-P */
86static int tachometer;
87
88module_param(tachometer, int, 0);
89MODULE_PARM_DESC(tachometer, "WDT501-P Fan Tachometer support (0=disable, default=0)");
90#endif /* CONFIG_WDT_501 */
91
92/*
93 * Programming support
94 */
95
96static void wdt_ctr_mode(int ctr, int mode)
97{
98 ctr<<=6;
99 ctr|=0x30;
100 ctr|=(mode<<1);
101 outb_p(ctr, WDT_CR);
102}
103
104static void wdt_ctr_load(int ctr, int val)
105{
106 outb_p(val&0xFF, WDT_COUNT0+ctr);
107 outb_p(val>>8, WDT_COUNT0+ctr);
108}
109
110/**
111 * wdt_start:
112 *
113 * Start the watchdog driver.
114 */
115
116static int wdt_start(void)
117{
118 inb_p(WDT_DC); /* Disable watchdog */
119 wdt_ctr_mode(0,3); /* Program CTR0 for Mode 3: Square Wave Generator */
120 wdt_ctr_mode(1,2); /* Program CTR1 for Mode 2: Rate Generator */
121 wdt_ctr_mode(2,0); /* Program CTR2 for Mode 0: Pulse on Terminal Count */
122 wdt_ctr_load(0, 8948); /* Count at 100Hz */
123 wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */
124 wdt_ctr_load(2,65535); /* Length of reset pulse */
125 outb_p(0, WDT_DC); /* Enable watchdog */
126 return 0;
127}
128
129/**
130 * wdt_stop:
131 *
132 * Stop the watchdog driver.
133 */
134
135static int wdt_stop (void)
136{
137 /* Turn the card off */
138 inb_p(WDT_DC); /* Disable watchdog */
139 wdt_ctr_load(2,0); /* 0 length reset pulses now */
140 return 0;
141}
142
143/**
144 * wdt_ping:
145 *
146 * Reload counter one with the watchdog heartbeat. We don't bother reloading
147 * the cascade counter.
148 */
149
150static int wdt_ping(void)
151{
152 /* Write a watchdog value */
153 inb_p(WDT_DC); /* Disable watchdog */
154 wdt_ctr_mode(1,2); /* Re-Program CTR1 for Mode 2: Rate Generator */
155 wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */
156 outb_p(0, WDT_DC); /* Enable watchdog */
157 return 0;
158}
159
160/**
161 * wdt_set_heartbeat:
162 * @t: the new heartbeat value that needs to be set.
163 *
164 * Set a new heartbeat value for the watchdog device. If the heartbeat value is
165 * incorrect we keep the old value and return -EINVAL. If successfull we
166 * return 0.
167 */
168static int wdt_set_heartbeat(int t)
169{
170 if ((t < 1) || (t > 65535))
171 return -EINVAL;
172
173 heartbeat = t;
174 wd_heartbeat = t * 100;
175 return 0;
176}
177
178/**
179 * wdt_get_status:
180 * @status: the new status.
181 *
182 * Extract the status information from a WDT watchdog device. There are
183 * several board variants so we have to know which bits are valid. Some
184 * bits default to one and some to zero in order to be maximally painful.
185 *
186 * we then map the bits onto the status ioctl flags.
187 */
188
189static int wdt_get_status(int *status)
190{
191 unsigned char new_status=inb_p(WDT_SR);
192
193 *status=0;
194 if (new_status & WDC_SR_ISOI0)
195 *status |= WDIOF_EXTERN1;
196 if (new_status & WDC_SR_ISII1)
197 *status |= WDIOF_EXTERN2;
198#ifdef CONFIG_WDT_501
199 if (!(new_status & WDC_SR_TGOOD))
200 *status |= WDIOF_OVERHEAT;
201 if (!(new_status & WDC_SR_PSUOVER))
202 *status |= WDIOF_POWEROVER;
203 if (!(new_status & WDC_SR_PSUUNDR))
204 *status |= WDIOF_POWERUNDER;
205 if (tachometer) {
206 if (!(new_status & WDC_SR_FANGOOD))
207 *status |= WDIOF_FANFAULT;
208 }
209#endif /* CONFIG_WDT_501 */
210 return 0;
211}
212
213#ifdef CONFIG_WDT_501
214/**
215 * wdt_get_temperature:
216 *
217 * Reports the temperature in degrees Fahrenheit. The API is in
218 * farenheit. It was designed by an imperial measurement luddite.
219 */
220
221static int wdt_get_temperature(int *temperature)
222{
223 unsigned short c=inb_p(WDT_RT);
224
225 *temperature = (c * 11 / 15) + 7;
226 return 0;
227}
228#endif /* CONFIG_WDT_501 */
229
230/**
231 * wdt_interrupt:
232 * @irq: Interrupt number
233 * @dev_id: Unused as we don't allow multiple devices.
234 * @regs: Unused.
235 *
236 * Handle an interrupt from the board. These are raised when the status
237 * map changes in what the board considers an interesting way. That means
238 * a failure condition occurring.
239 */
240
241static irqreturn_t wdt_interrupt(int irq, void *dev_id, struct pt_regs *regs)
242{
243 /*
244 * Read the status register see what is up and
245 * then printk it.
246 */
247 unsigned char status=inb_p(WDT_SR);
248
249 printk(KERN_CRIT "WDT status %d\n", status);
250
251#ifdef CONFIG_WDT_501
252 if (!(status & WDC_SR_TGOOD))
253 printk(KERN_CRIT "Overheat alarm.(%d)\n",inb_p(WDT_RT));
254 if (!(status & WDC_SR_PSUOVER))
255 printk(KERN_CRIT "PSU over voltage.\n");
256 if (!(status & WDC_SR_PSUUNDR))
257 printk(KERN_CRIT "PSU under voltage.\n");
258 if (tachometer) {
259 if (!(status & WDC_SR_FANGOOD))
260 printk(KERN_CRIT "Possible fan fault.\n");
261 }
262#endif /* CONFIG_WDT_501 */
263 if (!(status & WDC_SR_WCCR))
264#ifdef SOFTWARE_REBOOT
265#ifdef ONLY_TESTING
266 printk(KERN_CRIT "Would Reboot.\n");
267#else
268 printk(KERN_CRIT "Initiating system reboot.\n");
269 machine_restart(NULL);
270#endif
271#else
272 printk(KERN_CRIT "Reset in 5ms.\n");
273#endif
274 return IRQ_HANDLED;
275}
276
277
278/**
279 * wdt_write:
280 * @file: file handle to the watchdog
281 * @buf: buffer to write (unused as data does not matter here
282 * @count: count of bytes
283 * @ppos: pointer to the position to write. No seeks allowed
284 *
285 * A write to a watchdog device is defined as a keepalive signal. Any
286 * write of data will do, as we we don't define content meaning.
287 */
288
289static ssize_t wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
290{
291 if(count) {
292 if (!nowayout) {
293 size_t i;
294
295 /* In case it was set long ago */
296 expect_close = 0;
297
298 for (i = 0; i != count; i++) {
299 char c;
300 if (get_user(c, buf + i))
301 return -EFAULT;
302 if (c == 'V')
303 expect_close = 42;
304 }
305 }
306 wdt_ping();
307 }
308 return count;
309}
310
311/**
312 * wdt_ioctl:
313 * @inode: inode of the device
314 * @file: file handle to the device
315 * @cmd: watchdog command
316 * @arg: argument pointer
317 *
318 * The watchdog API defines a common set of functions for all watchdogs
319 * according to their available features. We only actually usefully support
320 * querying capabilities and current status.
321 */
322
323static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
324 unsigned long arg)
325{
326 void __user *argp = (void __user *)arg;
327 int __user *p = argp;
328 int new_heartbeat;
329 int status;
330
331 static struct watchdog_info ident = {
332 .options = WDIOF_SETTIMEOUT|
333 WDIOF_MAGICCLOSE|
334 WDIOF_KEEPALIVEPING,
335 .firmware_version = 1,
336 .identity = "WDT500/501",
337 };
338
339 /* Add options according to the card we have */
340 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
341#ifdef CONFIG_WDT_501
342 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER);
343 if (tachometer)
344 ident.options |= WDIOF_FANFAULT;
345#endif /* CONFIG_WDT_501 */
346
347 switch(cmd)
348 {
349 default:
350 return -ENOIOCTLCMD;
351 case WDIOC_GETSUPPORT:
352 return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0;
353
354 case WDIOC_GETSTATUS:
355 wdt_get_status(&status);
356 return put_user(status, p);
357 case WDIOC_GETBOOTSTATUS:
358 return put_user(0, p);
359 case WDIOC_KEEPALIVE:
360 wdt_ping();
361 return 0;
362 case WDIOC_SETTIMEOUT:
363 if (get_user(new_heartbeat, p))
364 return -EFAULT;
365
366 if (wdt_set_heartbeat(new_heartbeat))
367 return -EINVAL;
368
369 wdt_ping();
370 /* Fall */
371 case WDIOC_GETTIMEOUT:
372 return put_user(heartbeat, p);
373 }
374}
375
376/**
377 * wdt_open:
378 * @inode: inode of device
379 * @file: file handle to device
380 *
381 * The watchdog device has been opened. The watchdog device is single
382 * open and on opening we load the counters. Counter zero is a 100Hz
383 * cascade, into counter 1 which downcounts to reboot. When the counter
384 * triggers counter 2 downcounts the length of the reset pulse which
385 * set set to be as long as possible.
386 */
387
388static int wdt_open(struct inode *inode, struct file *file)
389{
390 if(test_and_set_bit(0, &wdt_is_open))
391 return -EBUSY;
392 /*
393 * Activate
394 */
395 wdt_start();
396 return nonseekable_open(inode, file);
397}
398
399/**
400 * wdt_release:
401 * @inode: inode to board
402 * @file: file handle to board
403 *
404 * The watchdog has a configurable API. There is a religious dispute
405 * between people who want their watchdog to be able to shut down and
406 * those who want to be sure if the watchdog manager dies the machine
407 * reboots. In the former case we disable the counters, in the latter
408 * case you have to open it again very soon.
409 */
410
411static int wdt_release(struct inode *inode, struct file *file)
412{
413 if (expect_close == 42) {
414 wdt_stop();
415 clear_bit(0, &wdt_is_open);
416 } else {
417 printk(KERN_CRIT "wdt: WDT device closed unexpectedly. WDT will not stop!\n");
418 wdt_ping();
419 }
420 expect_close = 0;
421 return 0;
422}
423
424#ifdef CONFIG_WDT_501
425/**
426 * wdt_temp_read:
427 * @file: file handle to the watchdog board
428 * @buf: buffer to write 1 byte into
429 * @count: length of buffer
430 * @ptr: offset (no seek allowed)
431 *
432 * Temp_read reports the temperature in degrees Fahrenheit. The API is in
433 * farenheit. It was designed by an imperial measurement luddite.
434 */
435
436static ssize_t wdt_temp_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
437{
438 int temperature;
439
440 if (wdt_get_temperature(&temperature))
441 return -EFAULT;
442
443 if (copy_to_user (buf, &temperature, 1))
444 return -EFAULT;
445
446 return 1;
447}
448
449/**
450 * wdt_temp_open:
451 * @inode: inode of device
452 * @file: file handle to device
453 *
454 * The temperature device has been opened.
455 */
456
457static int wdt_temp_open(struct inode *inode, struct file *file)
458{
459 return nonseekable_open(inode, file);
460}
461
462/**
463 * wdt_temp_release:
464 * @inode: inode to board
465 * @file: file handle to board
466 *
467 * The temperature device has been closed.
468 */
469
470static int wdt_temp_release(struct inode *inode, struct file *file)
471{
472 return 0;
473}
474#endif /* CONFIG_WDT_501 */
475
476/**
477 * notify_sys:
478 * @this: our notifier block
479 * @code: the event being reported
480 * @unused: unused
481 *
482 * Our notifier is called on system shutdowns. We want to turn the card
483 * off at reboot otherwise the machine will reboot again during memory
484 * test or worse yet during the following fsck. This would suck, in fact
485 * trust me - if it happens it does suck.
486 */
487
488static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
489 void *unused)
490{
491 if(code==SYS_DOWN || code==SYS_HALT) {
492 /* Turn the card off */
493 wdt_stop();
494 }
495 return NOTIFY_DONE;
496}
497
498/*
499 * Kernel Interfaces
500 */
501
502
503static struct file_operations wdt_fops = {
504 .owner = THIS_MODULE,
505 .llseek = no_llseek,
506 .write = wdt_write,
507 .ioctl = wdt_ioctl,
508 .open = wdt_open,
509 .release = wdt_release,
510};
511
512static struct miscdevice wdt_miscdev = {
513 .minor = WATCHDOG_MINOR,
514 .name = "watchdog",
515 .fops = &wdt_fops,
516};
517
518#ifdef CONFIG_WDT_501
519static struct file_operations wdt_temp_fops = {
520 .owner = THIS_MODULE,
521 .llseek = no_llseek,
522 .read = wdt_temp_read,
523 .open = wdt_temp_open,
524 .release = wdt_temp_release,
525};
526
527static struct miscdevice temp_miscdev = {
528 .minor = TEMP_MINOR,
529 .name = "temperature",
530 .fops = &wdt_temp_fops,
531};
532#endif /* CONFIG_WDT_501 */
533
534/*
535 * The WDT card needs to learn about soft shutdowns in order to
536 * turn the timebomb registers off.
537 */
538
539static struct notifier_block wdt_notifier = {
540 .notifier_call = wdt_notify_sys,
541};
542
543/**
544 * cleanup_module:
545 *
546 * Unload the watchdog. You cannot do this with any file handles open.
547 * If your watchdog is set to continue ticking on close and you unload
548 * it, well it keeps ticking. We won't get the interrupt but the board
549 * will not touch PC memory so all is fine. You just have to load a new
550 * module in 60 seconds or reboot.
551 */
552
553static void __exit wdt_exit(void)
554{
555 misc_deregister(&wdt_miscdev);
556#ifdef CONFIG_WDT_501
557 misc_deregister(&temp_miscdev);
558#endif /* CONFIG_WDT_501 */
559 unregister_reboot_notifier(&wdt_notifier);
560 free_irq(irq, NULL);
561 release_region(io,8);
562}
563
564/**
565 * wdt_init:
566 *
567 * Set up the WDT watchdog board. All we have to do is grab the
568 * resources we require and bitch if anyone beat us to them.
569 * The open() function will actually kick the board off.
570 */
571
572static int __init wdt_init(void)
573{
574 int ret;
575
576 /* Check that the heartbeat value is within it's range ; if not reset to the default */
577 if (wdt_set_heartbeat(heartbeat)) {
578 wdt_set_heartbeat(WD_TIMO);
579 printk(KERN_INFO "wdt: heartbeat value must be 0<heartbeat<65536, using %d\n",
580 WD_TIMO);
581 }
582
583 if (!request_region(io, 8, "wdt501p")) {
584 printk(KERN_ERR "wdt: I/O address 0x%04x already in use\n", io);
585 ret = -EBUSY;
586 goto out;
587 }
588
589 ret = request_irq(irq, wdt_interrupt, SA_INTERRUPT, "wdt501p", NULL);
590 if(ret) {
591 printk(KERN_ERR "wdt: IRQ %d is not free.\n", irq);
592 goto outreg;
593 }
594
595 ret = register_reboot_notifier(&wdt_notifier);
596 if(ret) {
597 printk(KERN_ERR "wdt: cannot register reboot notifier (err=%d)\n", ret);
598 goto outirq;
599 }
600
601#ifdef CONFIG_WDT_501
602 ret = misc_register(&temp_miscdev);
603 if (ret) {
604 printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n",
605 TEMP_MINOR, ret);
606 goto outrbt;
607 }
608#endif /* CONFIG_WDT_501 */
609
610 ret = misc_register(&wdt_miscdev);
611 if (ret) {
612 printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n",
613 WATCHDOG_MINOR, ret);
614 goto outmisc;
615 }
616
617 ret = 0;
618 printk(KERN_INFO "WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
619 io, irq, heartbeat, nowayout);
620#ifdef CONFIG_WDT_501
621 printk(KERN_INFO "wdt: Fan Tachometer is %s\n", (tachometer ? "Enabled" : "Disabled"));
622#endif /* CONFIG_WDT_501 */
623
624out:
625 return ret;
626
627outmisc:
628#ifdef CONFIG_WDT_501
629 misc_deregister(&temp_miscdev);
630outrbt:
631#endif /* CONFIG_WDT_501 */
632 unregister_reboot_notifier(&wdt_notifier);
633outirq:
634 free_irq(irq, NULL);
635outreg:
636 release_region(io,8);
637 goto out;
638}
639
640module_init(wdt_init);
641module_exit(wdt_exit);
642
643MODULE_AUTHOR("Alan Cox");
644MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
645MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
646MODULE_ALIAS_MISCDEV(TEMP_MINOR);
647MODULE_LICENSE("GPL");