2 * Industrial Computer Source PCI-WDT500/501 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 cleanup
28 * Parameterized timeout
29 * JP Nollmann : Added support for PCI wdt501p
30 * Alan Cox : Split ISA and PCI cards into two drivers
31 * Jeff Garzik : PCI cleanups
32 * Tigran Aivazian : Restructured wdtpci_init_one() to handle
34 * Joel Becker : Added WDIOC_GET/SETTIMEOUT
35 * Zwane Mwaikambo : Magic char closing, locking changes,
37 * Matt Domsch : nowayout module option
40 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
42 #include <linux/interrupt.h>
43 #include <linux/module.h>
44 #include <linux/moduleparam.h>
45 #include <linux/types.h>
46 #include <linux/miscdevice.h>
47 #include <linux/watchdog.h>
48 #include <linux/ioport.h>
49 #include <linux/delay.h>
50 #include <linux/notifier.h>
51 #include <linux/reboot.h>
52 #include <linux/init.h>
54 #include <linux/pci.h>
56 #include <linux/uaccess.h>
62 /* We can only use 1 card due to the /dev/watchdog restriction */
65 static unsigned long open_lock;
66 static DEFINE_SPINLOCK(wdtpci_lock);
67 static char expect_close;
69 static resource_size_t io;
73 #define WD_TIMO 60 /* Default heartbeat = 60 seconds */
75 static int heartbeat = WD_TIMO;
76 static int wd_heartbeat;
77 module_param(heartbeat, int, 0);
78 MODULE_PARM_DESC(heartbeat,
79 "Watchdog heartbeat in seconds. (0<heartbeat<65536, default="
80 __MODULE_STRING(WD_TIMO) ")");
82 static bool nowayout = WATCHDOG_NOWAYOUT;
83 module_param(nowayout, bool, 0);
84 MODULE_PARM_DESC(nowayout,
85 "Watchdog cannot be stopped once started (default="
86 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
88 /* Support for the Fan Tachometer on the PCI-WDT501 */
89 static int tachometer;
90 module_param(tachometer, int, 0);
91 MODULE_PARM_DESC(tachometer,
92 "PCI-WDT501 Fan Tachometer support (0=disable, default=0)");
94 static int type = 500;
95 module_param(type, int, 0);
96 MODULE_PARM_DESC(type,
97 "PCI-WDT501 Card type (500 or 501 , default=500)");
100 * Programming support
103 static void wdtpci_ctr_mode(int ctr, int mode)
112 static void wdtpci_ctr_load(int ctr, int val)
114 outb(val & 0xFF, WDT_COUNT0 + ctr);
116 outb(val >> 8, WDT_COUNT0 + ctr);
123 * Start the watchdog driver.
126 static int wdtpci_start(void)
130 spin_lock_irqsave(&wdtpci_lock, flags);
133 * "pet" the watchdog, as Access says.
134 * This resets the clock outputs.
136 inb(WDT_DC); /* Disable watchdog */
138 wdtpci_ctr_mode(2, 0); /* Program CTR2 for Mode 0:
139 Pulse on Terminal Count */
140 outb(0, WDT_DC); /* Enable watchdog */
142 inb(WDT_DC); /* Disable watchdog */
144 outb(0, WDT_CLOCK); /* 2.0833MHz clock */
146 inb(WDT_BUZZER); /* disable */
148 inb(WDT_OPTONOTRST); /* disable */
150 inb(WDT_OPTORST); /* disable */
152 inb(WDT_PROGOUT); /* disable */
154 wdtpci_ctr_mode(0, 3); /* Program CTR0 for Mode 3:
155 Square Wave Generator */
156 wdtpci_ctr_mode(1, 2); /* Program CTR1 for Mode 2:
158 wdtpci_ctr_mode(2, 1); /* Program CTR2 for Mode 1:
159 Retriggerable One-Shot */
160 wdtpci_ctr_load(0, 20833); /* count at 100Hz */
161 wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
162 /* DO NOT LOAD CTR2 on PCI card! -- JPN */
163 outb(0, WDT_DC); /* Enable watchdog */
166 spin_unlock_irqrestore(&wdtpci_lock, flags);
173 * Stop the watchdog driver.
176 static int wdtpci_stop(void)
180 /* Turn the card off */
181 spin_lock_irqsave(&wdtpci_lock, flags);
182 inb(WDT_DC); /* Disable watchdog */
184 wdtpci_ctr_load(2, 0); /* 0 length reset pulses now */
185 spin_unlock_irqrestore(&wdtpci_lock, flags);
192 * Reload counter one with the watchdog heartbeat. We don't bother
193 * reloading the cascade counter.
196 static int wdtpci_ping(void)
200 spin_lock_irqsave(&wdtpci_lock, flags);
201 /* Write a watchdog value */
202 inb(WDT_DC); /* Disable watchdog */
204 wdtpci_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2:
206 wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
207 outb(0, WDT_DC); /* Enable watchdog */
209 spin_unlock_irqrestore(&wdtpci_lock, flags);
214 * wdtpci_set_heartbeat:
215 * @t: the new heartbeat value that needs to be set.
217 * Set a new heartbeat value for the watchdog device. If the heartbeat
218 * value is incorrect we keep the old value and return -EINVAL.
219 * If successful we return 0.
221 static int wdtpci_set_heartbeat(int t)
223 /* Arbitrary, can't find the card's limits */
224 if (t < 1 || t > 65535)
228 wd_heartbeat = t * 100;
234 * @status: the new status.
236 * Extract the status information from a WDT watchdog device. There are
237 * several board variants so we have to know which bits are valid. Some
238 * bits default to one and some to zero in order to be maximally painful.
240 * we then map the bits onto the status ioctl flags.
243 static int wdtpci_get_status(int *status)
245 unsigned char new_status;
248 spin_lock_irqsave(&wdtpci_lock, flags);
249 new_status = inb(WDT_SR);
250 spin_unlock_irqrestore(&wdtpci_lock, flags);
253 if (new_status & WDC_SR_ISOI0)
254 *status |= WDIOF_EXTERN1;
255 if (new_status & WDC_SR_ISII1)
256 *status |= WDIOF_EXTERN2;
258 if (!(new_status & WDC_SR_TGOOD))
259 *status |= WDIOF_OVERHEAT;
260 if (!(new_status & WDC_SR_PSUOVER))
261 *status |= WDIOF_POWEROVER;
262 if (!(new_status & WDC_SR_PSUUNDR))
263 *status |= WDIOF_POWERUNDER;
265 if (!(new_status & WDC_SR_FANGOOD))
266 *status |= WDIOF_FANFAULT;
273 * wdtpci_get_temperature:
275 * Reports the temperature in degrees Fahrenheit. The API is in
276 * farenheit. It was designed by an imperial measurement luddite.
279 static int wdtpci_get_temperature(int *temperature)
283 spin_lock_irqsave(&wdtpci_lock, flags);
286 spin_unlock_irqrestore(&wdtpci_lock, flags);
287 *temperature = (c * 11 / 15) + 7;
293 * @irq: Interrupt number
294 * @dev_id: Unused as we don't allow multiple devices.
296 * Handle an interrupt from the board. These are raised when the status
297 * map changes in what the board considers an interesting way. That means
298 * a failure condition occurring.
301 static irqreturn_t wdtpci_interrupt(int irq, void *dev_id)
304 * Read the status register see what is up and
307 unsigned char status;
309 spin_lock(&wdtpci_lock);
311 status = inb(WDT_SR);
314 pr_crit("status %d\n", status);
317 if (!(status & WDC_SR_TGOOD)) {
318 pr_crit("Overheat alarm (%d)\n", inb(WDT_RT));
321 if (!(status & WDC_SR_PSUOVER))
322 pr_crit("PSU over voltage\n");
323 if (!(status & WDC_SR_PSUUNDR))
324 pr_crit("PSU under voltage\n");
326 if (!(status & WDC_SR_FANGOOD))
327 pr_crit("Possible fan fault\n");
330 if (!(status & WDC_SR_WCCR)) {
331 #ifdef SOFTWARE_REBOOT
333 pr_crit("Would Reboot\n");
335 pr_crit("Initiating system reboot\n");
336 emergency_restart(NULL);
339 pr_crit("Reset in 5ms\n");
342 spin_unlock(&wdtpci_lock);
349 * @file: file handle to the watchdog
350 * @buf: buffer to write (unused as data does not matter here
351 * @count: count of bytes
352 * @ppos: pointer to the position to write. No seeks allowed
354 * A write to a watchdog device is defined as a keepalive signal. Any
355 * write of data will do, as we we don't define content meaning.
358 static ssize_t wdtpci_write(struct file *file, const char __user *buf,
359 size_t count, loff_t *ppos)
365 /* In case it was set long ago */
368 for (i = 0; i != count; i++) {
370 if (get_user(c, buf + i))
383 * @file: file handle to the device
384 * @cmd: watchdog command
385 * @arg: argument pointer
387 * The watchdog API defines a common set of functions for all watchdogs
388 * according to their available features. We only actually usefully support
389 * querying capabilities and current status.
392 static long wdtpci_ioctl(struct file *file, unsigned int cmd,
395 void __user *argp = (void __user *)arg;
396 int __user *p = argp;
400 struct watchdog_info ident = {
401 .options = WDIOF_SETTIMEOUT|
404 .firmware_version = 1,
405 .identity = "PCI-WDT500/501",
408 /* Add options according to the card we have */
409 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
411 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
414 ident.options |= WDIOF_FANFAULT;
418 case WDIOC_GETSUPPORT:
419 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
420 case WDIOC_GETSTATUS:
421 wdtpci_get_status(&status);
422 return put_user(status, p);
423 case WDIOC_GETBOOTSTATUS:
424 return put_user(0, p);
425 case WDIOC_KEEPALIVE:
428 case WDIOC_SETTIMEOUT:
429 if (get_user(new_heartbeat, p))
431 if (wdtpci_set_heartbeat(new_heartbeat))
435 case WDIOC_GETTIMEOUT:
436 return put_user(heartbeat, p);
444 * @inode: inode of device
445 * @file: file handle to device
447 * The watchdog device has been opened. The watchdog device is single
448 * open and on opening we load the counters. Counter zero is a 100Hz
449 * cascade, into counter 1 which downcounts to reboot. When the counter
450 * triggers counter 2 downcounts the length of the reset pulse which
451 * set set to be as long as possible.
454 static int wdtpci_open(struct inode *inode, struct file *file)
456 if (test_and_set_bit(0, &open_lock))
460 __module_get(THIS_MODULE);
465 return nonseekable_open(inode, file);
470 * @inode: inode to board
471 * @file: file handle to board
473 * The watchdog has a configurable API. There is a religious dispute
474 * between people who want their watchdog to be able to shut down and
475 * those who want to be sure if the watchdog manager dies the machine
476 * reboots. In the former case we disable the counters, in the latter
477 * case you have to open it again very soon.
480 static int wdtpci_release(struct inode *inode, struct file *file)
482 if (expect_close == 42) {
485 pr_crit("Unexpected close, not stopping timer!\n");
489 clear_bit(0, &open_lock);
495 * @file: file handle to the watchdog board
496 * @buf: buffer to write 1 byte into
497 * @count: length of buffer
498 * @ptr: offset (no seek allowed)
500 * Read reports the temperature in degrees Fahrenheit. The API is in
501 * fahrenheit. It was designed by an imperial measurement luddite.
504 static ssize_t wdtpci_temp_read(struct file *file, char __user *buf,
505 size_t count, loff_t *ptr)
509 if (wdtpci_get_temperature(&temperature))
512 if (copy_to_user(buf, &temperature, 1))
520 * @inode: inode of device
521 * @file: file handle to device
523 * The temperature device has been opened.
526 static int wdtpci_temp_open(struct inode *inode, struct file *file)
528 return nonseekable_open(inode, file);
532 * wdtpci_temp_release:
533 * @inode: inode to board
534 * @file: file handle to board
536 * The temperature device has been closed.
539 static int wdtpci_temp_release(struct inode *inode, struct file *file)
546 * @this: our notifier block
547 * @code: the event being reported
550 * Our notifier is called on system shutdowns. We want to turn the card
551 * off at reboot otherwise the machine will reboot again during memory
552 * test or worse yet during the following fsck. This would suck, in fact
553 * trust me - if it happens it does suck.
556 static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code,
559 if (code == SYS_DOWN || code == SYS_HALT)
569 static const struct file_operations wdtpci_fops = {
570 .owner = THIS_MODULE,
572 .write = wdtpci_write,
573 .unlocked_ioctl = wdtpci_ioctl,
575 .release = wdtpci_release,
578 static struct miscdevice wdtpci_miscdev = {
579 .minor = WATCHDOG_MINOR,
581 .fops = &wdtpci_fops,
584 static const struct file_operations wdtpci_temp_fops = {
585 .owner = THIS_MODULE,
587 .read = wdtpci_temp_read,
588 .open = wdtpci_temp_open,
589 .release = wdtpci_temp_release,
592 static struct miscdevice temp_miscdev = {
594 .name = "temperature",
595 .fops = &wdtpci_temp_fops,
599 * The WDT card needs to learn about soft shutdowns in order to
600 * turn the timebomb registers off.
603 static struct notifier_block wdtpci_notifier = {
604 .notifier_call = wdtpci_notify_sys,
608 static int wdtpci_init_one(struct pci_dev *dev,
609 const struct pci_device_id *ent)
615 pr_err("This driver only supports one device\n");
619 if (type != 500 && type != 501) {
620 pr_err("unknown card type '%d'\n", type);
624 if (pci_enable_device(dev)) {
625 pr_err("Not possible to enable PCI Device\n");
629 if (pci_resource_start(dev, 2) == 0x0000) {
630 pr_err("No I/O-Address for card detected\n");
635 if (pci_request_region(dev, 2, "wdt_pci")) {
636 pr_err("I/O address 0x%llx already in use\n",
637 (unsigned long long)pci_resource_start(dev, 2));
642 io = pci_resource_start(dev, 2);
644 if (request_irq(irq, wdtpci_interrupt, IRQF_SHARED,
645 "wdt_pci", &wdtpci_miscdev)) {
646 pr_err("IRQ %d is not free\n", irq);
650 pr_info("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%llx (Interrupt %d)\n",
651 (unsigned long long)io, irq);
653 /* Check that the heartbeat value is within its range;
654 if not reset to the default */
655 if (wdtpci_set_heartbeat(heartbeat)) {
656 wdtpci_set_heartbeat(WD_TIMO);
657 pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
661 ret = register_reboot_notifier(&wdtpci_notifier);
663 pr_err("cannot register reboot notifier (err=%d)\n", ret);
668 ret = misc_register(&temp_miscdev);
670 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
676 ret = misc_register(&wdtpci_miscdev);
678 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
679 WATCHDOG_MINOR, ret);
683 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
684 heartbeat, nowayout);
686 pr_info("Fan Tachometer is %s\n",
687 tachometer ? "Enabled" : "Disabled");
695 misc_deregister(&temp_miscdev);
697 unregister_reboot_notifier(&wdtpci_notifier);
699 free_irq(irq, &wdtpci_miscdev);
701 pci_release_region(dev, 2);
703 pci_disable_device(dev);
708 static void wdtpci_remove_one(struct pci_dev *pdev)
710 /* here we assume only one device will ever have
711 * been picked up and registered by probe function */
712 misc_deregister(&wdtpci_miscdev);
714 misc_deregister(&temp_miscdev);
715 unregister_reboot_notifier(&wdtpci_notifier);
716 free_irq(irq, &wdtpci_miscdev);
717 pci_release_region(pdev, 2);
718 pci_disable_device(pdev);
723 static const struct pci_device_id wdtpci_pci_tbl[] = {
725 .vendor = PCI_VENDOR_ID_ACCESSIO,
726 .device = PCI_DEVICE_ID_ACCESSIO_WDG_CSM,
727 .subvendor = PCI_ANY_ID,
728 .subdevice = PCI_ANY_ID,
730 { 0, }, /* terminate list */
732 MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl);
735 static struct pci_driver wdtpci_driver = {
737 .id_table = wdtpci_pci_tbl,
738 .probe = wdtpci_init_one,
739 .remove = wdtpci_remove_one,
742 module_pci_driver(wdtpci_driver);
744 MODULE_AUTHOR("JP Nollmann, Alan Cox");
745 MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards");
746 MODULE_LICENSE("GPL");