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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
44 #include <linux/ioport.h>
45 #include <linux/notifier.h>
46 #include <linux/reboot.h>
47 #include <linux/init.h>
49 #include <linux/uaccess.h>
53 static unsigned long wdt_is_open
;
54 static char expect_close
;
60 #define WD_TIMO 60 /* Default heartbeat = 60 seconds */
62 static int heartbeat
= WD_TIMO
;
63 static int wd_heartbeat
;
64 module_param(heartbeat
, int, 0);
65 MODULE_PARM_DESC(heartbeat
,
66 "Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default="
67 __MODULE_STRING(WD_TIMO
) ")");
69 static bool nowayout
= WATCHDOG_NOWAYOUT
;
70 module_param(nowayout
, bool, 0);
71 MODULE_PARM_DESC(nowayout
,
72 "Watchdog cannot be stopped once started (default="
73 __MODULE_STRING(WATCHDOG_NOWAYOUT
) ")");
75 /* You must set these - there is no sane way to probe for this board. */
76 static int io
= 0x240;
79 static DEFINE_SPINLOCK(wdt_lock
);
81 module_param(io
, int, 0);
82 MODULE_PARM_DESC(io
, "WDT io port (default=0x240)");
83 module_param(irq
, int, 0);
84 MODULE_PARM_DESC(irq
, "WDT irq (default=11)");
86 /* Support for the Fan Tachometer on the WDT501-P */
87 static int tachometer
;
88 module_param(tachometer
, int, 0);
89 MODULE_PARM_DESC(tachometer
,
90 "WDT501-P Fan Tachometer support (0=disable, default=0)");
92 static int type
= 500;
93 module_param(type
, int, 0);
94 MODULE_PARM_DESC(type
,
95 "WDT501-P Card type (500 or 501, default=500)");
101 static void wdt_ctr_mode(int ctr
, int mode
)
109 static void wdt_ctr_load(int ctr
, int val
)
111 outb_p(val
&0xFF, WDT_COUNT0
+ctr
);
112 outb_p(val
>>8, WDT_COUNT0
+ctr
);
118 * Start the watchdog driver.
121 static int wdt_start(void)
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:
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
);
143 * Stop the watchdog driver.
146 static int wdt_stop(void)
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
);
160 * Reload counter one with the watchdog heartbeat. We don't bother
161 * reloading the cascade counter.
164 static void wdt_ping(void)
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:
172 wdt_ctr_load(1, wd_heartbeat
); /* Heartbeat */
173 outb_p(0, WDT_DC
); /* Enable watchdog */
174 spin_unlock_irqrestore(&wdt_lock
, flags
);
179 * @t: the new heartbeat value that needs to be set.
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.
186 static int wdt_set_heartbeat(int t
)
188 if (t
< 1 || t
> 65535)
192 wd_heartbeat
= t
* 100;
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.
203 * we then map the bits onto the status ioctl flags.
206 static int wdt_get_status(void)
208 unsigned char new_status
;
212 spin_lock_irqsave(&wdt_lock
, flags
);
213 new_status
= inb_p(WDT_SR
);
214 spin_unlock_irqrestore(&wdt_lock
, flags
);
216 if (new_status
& WDC_SR_ISOI0
)
217 status
|= WDIOF_EXTERN1
;
218 if (new_status
& WDC_SR_ISII1
)
219 status
|= WDIOF_EXTERN2
;
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
;
228 if (!(new_status
& WDC_SR_FANGOOD
))
229 status
|= WDIOF_FANFAULT
;
236 * wdt_get_temperature:
238 * Reports the temperature in degrees Fahrenheit. The API is in
239 * farenheit. It was designed by an imperial measurement luddite.
242 static int wdt_get_temperature(void)
247 spin_lock_irqsave(&wdt_lock
, flags
);
249 spin_unlock_irqrestore(&wdt_lock
, flags
);
250 return (c
* 11 / 15) + 7;
253 static void wdt_decode_501(int status
)
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");
265 * @irq: Interrupt number
266 * @dev_id: Unused as we don't allow multiple devices.
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.
273 static irqreturn_t
wdt_interrupt(int irq
, void *dev_id
)
276 * Read the status register see what is up and
279 unsigned char status
;
281 spin_lock(&wdt_lock
);
282 status
= inb_p(WDT_SR
);
284 pr_crit("WDT status %d\n", status
);
287 wdt_decode_501(status
);
289 if (!(status
& WDC_SR_FANGOOD
))
290 pr_crit("Possible fan fault\n");
293 if (!(status
& WDC_SR_WCCR
)) {
294 #ifdef SOFTWARE_REBOOT
296 pr_crit("Would Reboot\n");
298 pr_crit("Initiating system reboot\n");
302 pr_crit("Reset in 5ms\n");
305 spin_unlock(&wdt_lock
);
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
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.
321 static ssize_t
wdt_write(struct file
*file
, const char __user
*buf
,
322 size_t count
, loff_t
*ppos
)
328 /* In case it was set long ago */
331 for (i
= 0; i
!= count
; i
++) {
333 if (get_user(c
, buf
+ i
))
346 * @file: file handle to the device
347 * @cmd: watchdog command
348 * @arg: argument pointer
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.
355 static long wdt_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
357 void __user
*argp
= (void __user
*)arg
;
358 int __user
*p
= argp
;
362 struct watchdog_info ident
= {
363 .options
= WDIOF_SETTIMEOUT
|
366 .firmware_version
= 1,
367 .identity
= "WDT500/501",
370 /* Add options according to the card we have */
371 ident
.options
|= (WDIOF_EXTERN1
|WDIOF_EXTERN2
);
373 ident
.options
|= (WDIOF_OVERHEAT
|WDIOF_POWERUNDER
|
376 ident
.options
|= WDIOF_FANFAULT
;
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
:
390 case WDIOC_SETTIMEOUT
:
391 if (get_user(new_heartbeat
, p
))
393 if (wdt_set_heartbeat(new_heartbeat
))
397 case WDIOC_GETTIMEOUT
:
398 return put_user(heartbeat
, p
);
406 * @inode: inode of device
407 * @file: file handle to device
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.
416 static int wdt_open(struct inode
*inode
, struct file
*file
)
418 if (test_and_set_bit(0, &wdt_is_open
))
424 return nonseekable_open(inode
, file
);
429 * @inode: inode to board
430 * @file: file handle to board
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.
439 static int wdt_release(struct inode
*inode
, struct file
*file
)
441 if (expect_close
== 42) {
443 clear_bit(0, &wdt_is_open
);
445 pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
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)
459 * Temp_read reports the temperature in degrees Fahrenheit. The API is in
460 * farenheit. It was designed by an imperial measurement luddite.
463 static ssize_t
wdt_temp_read(struct file
*file
, char __user
*buf
,
464 size_t count
, loff_t
*ptr
)
466 int temperature
= wdt_get_temperature();
468 if (copy_to_user(buf
, &temperature
, 1))
476 * @inode: inode of device
477 * @file: file handle to device
479 * The temperature device has been opened.
482 static int wdt_temp_open(struct inode
*inode
, struct file
*file
)
484 return nonseekable_open(inode
, file
);
489 * @inode: inode to board
490 * @file: file handle to board
492 * The temperature device has been closed.
495 static int wdt_temp_release(struct inode
*inode
, struct file
*file
)
502 * @this: our notifier block
503 * @code: the event being reported
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.
512 static int wdt_notify_sys(struct notifier_block
*this, unsigned long code
,
515 if (code
== SYS_DOWN
|| code
== SYS_HALT
)
525 static const struct file_operations wdt_fops
= {
526 .owner
= THIS_MODULE
,
529 .unlocked_ioctl
= wdt_ioctl
,
531 .release
= wdt_release
,
534 static struct miscdevice wdt_miscdev
= {
535 .minor
= WATCHDOG_MINOR
,
540 static const struct file_operations wdt_temp_fops
= {
541 .owner
= THIS_MODULE
,
543 .read
= wdt_temp_read
,
544 .open
= wdt_temp_open
,
545 .release
= wdt_temp_release
,
548 static struct miscdevice temp_miscdev
= {
550 .name
= "temperature",
551 .fops
= &wdt_temp_fops
,
555 * The WDT card needs to learn about soft shutdowns in order to
556 * turn the timebomb registers off.
559 static struct notifier_block wdt_notifier
= {
560 .notifier_call
= wdt_notify_sys
,
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.
573 static void __exit
wdt_exit(void)
575 misc_deregister(&wdt_miscdev
);
577 misc_deregister(&temp_miscdev
);
578 unregister_reboot_notifier(&wdt_notifier
);
580 release_region(io
, 8);
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.
591 static int __init
wdt_init(void)
595 if (type
!= 500 && type
!= 501) {
596 pr_err("unknown card type '%d'\n", type
);
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",
608 if (!request_region(io
, 8, "wdt501p")) {
609 pr_err("I/O address 0x%04x already in use\n", io
);
614 ret
= request_irq(irq
, wdt_interrupt
, 0, "wdt501p", NULL
);
616 pr_err("IRQ %d is not free\n", irq
);
620 ret
= register_reboot_notifier(&wdt_notifier
);
622 pr_err("cannot register reboot notifier (err=%d)\n", ret
);
627 ret
= misc_register(&temp_miscdev
);
629 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
635 ret
= misc_register(&wdt_miscdev
);
637 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
638 WATCHDOG_MINOR
, ret
);
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
);
645 pr_info("Fan Tachometer is %s\n",
646 tachometer
? "Enabled" : "Disabled");
651 misc_deregister(&temp_miscdev
);
653 unregister_reboot_notifier(&wdt_notifier
);
657 release_region(io
, 8);
662 module_init(wdt_init
);
663 module_exit(wdt_exit
);
665 MODULE_AUTHOR("Alan Cox");
666 MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
667 MODULE_LICENSE("GPL");