2 * Industrial Computer Source WDT501 driver
4 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
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.
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.
16 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
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
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
31 * Joel Becker : Added WDIOC_GET/SETTIMEOUT
32 * Matt Domsch : Added nowayout module option
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>
42 #include <linux/ioport.h>
43 #include <linux/notifier.h>
44 #include <linux/reboot.h>
45 #include <linux/init.h>
47 #include <linux/uaccess.h>
51 static unsigned long wdt_is_open
;
52 static char expect_close
;
58 #define WD_TIMO 60 /* Default heartbeat = 60 seconds */
60 static int heartbeat
= WD_TIMO
;
61 static int wd_heartbeat
;
62 module_param(heartbeat
, int, 0);
63 MODULE_PARM_DESC(heartbeat
,
64 "Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
65 __MODULE_STRING(WD_TIMO
) ")");
67 static int nowayout
= WATCHDOG_NOWAYOUT
;
68 module_param(nowayout
, int, 0);
69 MODULE_PARM_DESC(nowayout
,
70 "Watchdog cannot be stopped once started (default="
71 __MODULE_STRING(WATCHDOG_NOWAYOUT
) ")");
73 /* You must set these - there is no sane way to probe for this board. */
74 static int io
= 0x240;
77 static DEFINE_SPINLOCK(wdt_lock
);
79 module_param(io
, int, 0);
80 MODULE_PARM_DESC(io
, "WDT io port (default=0x240)");
81 module_param(irq
, int, 0);
82 MODULE_PARM_DESC(irq
, "WDT irq (default=11)");
84 /* Support for the Fan Tachometer on the WDT501-P */
85 static int tachometer
;
86 module_param(tachometer
, int, 0);
87 MODULE_PARM_DESC(tachometer
,
88 "WDT501-P Fan Tachometer support (0=disable, default=0)");
90 static int type
= 500;
91 module_param(type
, int, 0);
92 MODULE_PARM_DESC(type
,
93 "WDT501-P Card type (500 or 501, default=500)");
99 static void wdt_ctr_mode(int ctr
, int mode
)
107 static void wdt_ctr_load(int ctr
, int val
)
109 outb_p(val
&0xFF, WDT_COUNT0
+ctr
);
110 outb_p(val
>>8, WDT_COUNT0
+ctr
);
116 * Start the watchdog driver.
119 static int wdt_start(void)
122 spin_lock_irqsave(&wdt_lock
, flags
);
123 inb_p(WDT_DC
); /* Disable watchdog */
124 wdt_ctr_mode(0, 3); /* Program CTR0 for Mode 3:
125 Square Wave Generator */
126 wdt_ctr_mode(1, 2); /* Program CTR1 for Mode 2:
128 wdt_ctr_mode(2, 0); /* Program CTR2 for Mode 0:
129 Pulse on Terminal Count */
130 wdt_ctr_load(0, 8948); /* Count at 100Hz */
131 wdt_ctr_load(1, wd_heartbeat
); /* Heartbeat */
132 wdt_ctr_load(2, 65535); /* Length of reset pulse */
133 outb_p(0, WDT_DC
); /* Enable watchdog */
134 spin_unlock_irqrestore(&wdt_lock
, flags
);
141 * Stop the watchdog driver.
144 static int wdt_stop(void)
147 spin_lock_irqsave(&wdt_lock
, flags
);
148 /* Turn the card off */
149 inb_p(WDT_DC
); /* Disable watchdog */
150 wdt_ctr_load(2, 0); /* 0 length reset pulses now */
151 spin_unlock_irqrestore(&wdt_lock
, flags
);
158 * Reload counter one with the watchdog heartbeat. We don't bother
159 * reloading the cascade counter.
162 static void wdt_ping(void)
165 spin_lock_irqsave(&wdt_lock
, flags
);
166 /* Write a watchdog value */
167 inb_p(WDT_DC
); /* Disable watchdog */
168 wdt_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2:
170 wdt_ctr_load(1, wd_heartbeat
); /* Heartbeat */
171 outb_p(0, WDT_DC
); /* Enable watchdog */
172 spin_unlock_irqrestore(&wdt_lock
, flags
);
177 * @t: the new heartbeat value that needs to be set.
179 * Set a new heartbeat value for the watchdog device. If the heartbeat
180 * value is incorrect we keep the old value and return -EINVAL. If
181 * successful we return 0.
184 static int wdt_set_heartbeat(int t
)
186 if (t
< 1 || t
> 65535)
190 wd_heartbeat
= t
* 100;
197 * Extract the status information from a WDT watchdog device. There are
198 * several board variants so we have to know which bits are valid. Some
199 * bits default to one and some to zero in order to be maximally painful.
201 * we then map the bits onto the status ioctl flags.
204 static int wdt_get_status(void)
206 unsigned char new_status
;
210 spin_lock_irqsave(&wdt_lock
, flags
);
211 new_status
= inb_p(WDT_SR
);
212 spin_unlock_irqrestore(&wdt_lock
, flags
);
214 if (new_status
& WDC_SR_ISOI0
)
215 status
|= WDIOF_EXTERN1
;
216 if (new_status
& WDC_SR_ISII1
)
217 status
|= WDIOF_EXTERN2
;
219 if (!(new_status
& WDC_SR_TGOOD
))
220 status
|= WDIOF_OVERHEAT
;
221 if (!(new_status
& WDC_SR_PSUOVER
))
222 status
|= WDIOF_POWEROVER
;
223 if (!(new_status
& WDC_SR_PSUUNDR
))
224 status
|= WDIOF_POWERUNDER
;
226 if (!(new_status
& WDC_SR_FANGOOD
))
227 status
|= WDIOF_FANFAULT
;
234 * wdt_get_temperature:
236 * Reports the temperature in degrees Fahrenheit. The API is in
237 * farenheit. It was designed by an imperial measurement luddite.
240 static int wdt_get_temperature(void)
245 spin_lock_irqsave(&wdt_lock
, flags
);
247 spin_unlock_irqrestore(&wdt_lock
, flags
);
248 return (c
* 11 / 15) + 7;
251 static void wdt_decode_501(int status
)
253 if (!(status
& WDC_SR_TGOOD
))
254 printk(KERN_CRIT
"Overheat alarm.(%d)\n", inb_p(WDT_RT
));
255 if (!(status
& WDC_SR_PSUOVER
))
256 printk(KERN_CRIT
"PSU over voltage.\n");
257 if (!(status
& WDC_SR_PSUUNDR
))
258 printk(KERN_CRIT
"PSU under voltage.\n");
263 * @irq: Interrupt number
264 * @dev_id: Unused as we don't allow multiple devices.
266 * Handle an interrupt from the board. These are raised when the status
267 * map changes in what the board considers an interesting way. That means
268 * a failure condition occurring.
271 static irqreturn_t
wdt_interrupt(int irq
, void *dev_id
)
274 * Read the status register see what is up and
277 unsigned char status
;
279 spin_lock(&wdt_lock
);
280 status
= inb_p(WDT_SR
);
282 printk(KERN_CRIT
"WDT status %d\n", status
);
285 wdt_decode_501(status
);
287 if (!(status
& WDC_SR_FANGOOD
))
288 printk(KERN_CRIT
"Possible fan fault.\n");
291 if (!(status
& WDC_SR_WCCR
)) {
292 #ifdef SOFTWARE_REBOOT
294 printk(KERN_CRIT
"Would Reboot.\n");
296 printk(KERN_CRIT
"Initiating system reboot.\n");
300 printk(KERN_CRIT
"Reset in 5ms.\n");
303 spin_unlock(&wdt_lock
);
310 * @file: file handle to the watchdog
311 * @buf: buffer to write (unused as data does not matter here
312 * @count: count of bytes
313 * @ppos: pointer to the position to write. No seeks allowed
315 * A write to a watchdog device is defined as a keepalive signal. Any
316 * write of data will do, as we we don't define content meaning.
319 static ssize_t
wdt_write(struct file
*file
, const char __user
*buf
,
320 size_t count
, loff_t
*ppos
)
326 /* In case it was set long ago */
329 for (i
= 0; i
!= count
; i
++) {
331 if (get_user(c
, buf
+ i
))
344 * @file: file handle to the device
345 * @cmd: watchdog command
346 * @arg: argument pointer
348 * The watchdog API defines a common set of functions for all watchdogs
349 * according to their available features. We only actually usefully support
350 * querying capabilities and current status.
353 static long wdt_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
355 void __user
*argp
= (void __user
*)arg
;
356 int __user
*p
= argp
;
360 struct watchdog_info ident
= {
361 .options
= WDIOF_SETTIMEOUT
|
364 .firmware_version
= 1,
365 .identity
= "WDT500/501",
368 /* Add options according to the card we have */
369 ident
.options
|= (WDIOF_EXTERN1
|WDIOF_EXTERN2
);
371 ident
.options
|= (WDIOF_OVERHEAT
|WDIOF_POWERUNDER
|
374 ident
.options
|= WDIOF_FANFAULT
;
378 case WDIOC_GETSUPPORT
:
379 return copy_to_user(argp
, &ident
, sizeof(ident
)) ? -EFAULT
: 0;
380 case WDIOC_GETSTATUS
:
381 status
= wdt_get_status();
382 return put_user(status
, p
);
383 case WDIOC_GETBOOTSTATUS
:
384 return put_user(0, p
);
385 case WDIOC_KEEPALIVE
:
388 case WDIOC_SETTIMEOUT
:
389 if (get_user(new_heartbeat
, p
))
391 if (wdt_set_heartbeat(new_heartbeat
))
395 case WDIOC_GETTIMEOUT
:
396 return put_user(heartbeat
, p
);
404 * @inode: inode of device
405 * @file: file handle to device
407 * The watchdog device has been opened. The watchdog device is single
408 * open and on opening we load the counters. Counter zero is a 100Hz
409 * cascade, into counter 1 which downcounts to reboot. When the counter
410 * triggers counter 2 downcounts the length of the reset pulse which
411 * set set to be as long as possible.
414 static int wdt_open(struct inode
*inode
, struct file
*file
)
416 if (test_and_set_bit(0, &wdt_is_open
))
422 return nonseekable_open(inode
, file
);
427 * @inode: inode to board
428 * @file: file handle to board
430 * The watchdog has a configurable API. There is a religious dispute
431 * between people who want their watchdog to be able to shut down and
432 * those who want to be sure if the watchdog manager dies the machine
433 * reboots. In the former case we disable the counters, in the latter
434 * case you have to open it again very soon.
437 static int wdt_release(struct inode
*inode
, struct file
*file
)
439 if (expect_close
== 42) {
441 clear_bit(0, &wdt_is_open
);
444 "wdt: WDT device closed unexpectedly. WDT will not stop!\n");
453 * @file: file handle to the watchdog board
454 * @buf: buffer to write 1 byte into
455 * @count: length of buffer
456 * @ptr: offset (no seek allowed)
458 * Temp_read reports the temperature in degrees Fahrenheit. The API is in
459 * farenheit. It was designed by an imperial measurement luddite.
462 static ssize_t
wdt_temp_read(struct file
*file
, char __user
*buf
,
463 size_t count
, loff_t
*ptr
)
465 int temperature
= wdt_get_temperature();
467 if (copy_to_user(buf
, &temperature
, 1))
475 * @inode: inode of device
476 * @file: file handle to device
478 * The temperature device has been opened.
481 static int wdt_temp_open(struct inode
*inode
, struct file
*file
)
483 return nonseekable_open(inode
, file
);
488 * @inode: inode to board
489 * @file: file handle to board
491 * The temperature device has been closed.
494 static int wdt_temp_release(struct inode
*inode
, struct file
*file
)
501 * @this: our notifier block
502 * @code: the event being reported
505 * Our notifier is called on system shutdowns. We want to turn the card
506 * off at reboot otherwise the machine will reboot again during memory
507 * test or worse yet during the following fsck. This would suck, in fact
508 * trust me - if it happens it does suck.
511 static int wdt_notify_sys(struct notifier_block
*this, unsigned long code
,
514 if (code
== SYS_DOWN
|| code
== SYS_HALT
)
524 static const struct file_operations wdt_fops
= {
525 .owner
= THIS_MODULE
,
528 .unlocked_ioctl
= wdt_ioctl
,
530 .release
= wdt_release
,
533 static struct miscdevice wdt_miscdev
= {
534 .minor
= WATCHDOG_MINOR
,
539 static const struct file_operations wdt_temp_fops
= {
540 .owner
= THIS_MODULE
,
542 .read
= wdt_temp_read
,
543 .open
= wdt_temp_open
,
544 .release
= wdt_temp_release
,
547 static struct miscdevice temp_miscdev
= {
549 .name
= "temperature",
550 .fops
= &wdt_temp_fops
,
554 * The WDT card needs to learn about soft shutdowns in order to
555 * turn the timebomb registers off.
558 static struct notifier_block wdt_notifier
= {
559 .notifier_call
= wdt_notify_sys
,
565 * Unload the watchdog. You cannot do this with any file handles open.
566 * If your watchdog is set to continue ticking on close and you unload
567 * it, well it keeps ticking. We won't get the interrupt but the board
568 * will not touch PC memory so all is fine. You just have to load a new
569 * module in 60 seconds or reboot.
572 static void __exit
wdt_exit(void)
574 misc_deregister(&wdt_miscdev
);
576 misc_deregister(&temp_miscdev
);
577 unregister_reboot_notifier(&wdt_notifier
);
579 release_region(io
, 8);
585 * Set up the WDT watchdog board. All we have to do is grab the
586 * resources we require and bitch if anyone beat us to them.
587 * The open() function will actually kick the board off.
590 static int __init
wdt_init(void)
594 if (type
!= 500 && type
!= 501) {
595 printk(KERN_ERR
"wdt: unknown card type '%d'.\n", type
);
599 /* Check that the heartbeat value is within it's range;
600 if not reset to the default */
601 if (wdt_set_heartbeat(heartbeat
)) {
602 wdt_set_heartbeat(WD_TIMO
);
603 printk(KERN_INFO
"wdt: heartbeat value must be "
604 "0 < heartbeat < 65536, using %d\n", WD_TIMO
);
607 if (!request_region(io
, 8, "wdt501p")) {
609 "wdt: I/O address 0x%04x already in use\n", io
);
614 ret
= request_irq(irq
, wdt_interrupt
, 0, "wdt501p", NULL
);
616 printk(KERN_ERR
"wdt: IRQ %d is not free.\n", irq
);
620 ret
= register_reboot_notifier(&wdt_notifier
);
623 "wdt: cannot register reboot notifier (err=%d)\n", ret
);
628 ret
= misc_register(&temp_miscdev
);
630 printk(KERN_ERR
"wdt: cannot register miscdev "
631 "on minor=%d (err=%d)\n", TEMP_MINOR
, ret
);
636 ret
= misc_register(&wdt_miscdev
);
639 "wdt: cannot register miscdev on minor=%d (err=%d)\n",
640 WATCHDOG_MINOR
, ret
);
644 printk(KERN_INFO
"WDT500/501-P driver 0.10 "
645 "at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n",
646 io
, irq
, heartbeat
, nowayout
);
648 printk(KERN_INFO
"wdt: Fan Tachometer is %s\n",
649 (tachometer
? "Enabled" : "Disabled"));
654 misc_deregister(&temp_miscdev
);
656 unregister_reboot_notifier(&wdt_notifier
);
660 release_region(io
, 8);
665 module_init(wdt_init
);
666 module_exit(wdt_exit
);
668 MODULE_AUTHOR("Alan Cox");
669 MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
670 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);
671 MODULE_ALIAS_MISCDEV(TEMP_MINOR
);
672 MODULE_LICENSE("GPL");