1 // SPDX-License-Identifier: GPL-2.0+
3 * Industrial Computer Source PCI-WDT500/501 driver
5 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
8 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
9 * warranty for any of this software. This material is provided
10 * "AS-IS" and at no charge.
12 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
17 * Dave Gregorich : Modularisation and minor bugs
18 * Alan Cox : Added the watchdog ioctl() stuff
19 * Alan Cox : Fixed the reboot problem (as noted by
21 * Alan Cox : Added wdt= boot option
22 * Alan Cox : Cleaned up copy/user stuff
23 * Tim Hockin : Added insmod parameters, comment cleanup
24 * Parameterized timeout
25 * JP Nollmann : Added support for PCI wdt501p
26 * Alan Cox : Split ISA and PCI cards into two drivers
27 * Jeff Garzik : PCI cleanups
28 * Tigran Aivazian : Restructured wdtpci_init_one() to handle
30 * Joel Becker : Added WDIOC_GET/SETTIMEOUT
31 * Zwane Mwaikambo : Magic char closing, locking changes,
33 * Matt Domsch : nowayout module option
36 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38 #include <linux/interrupt.h>
39 #include <linux/module.h>
40 #include <linux/moduleparam.h>
41 #include <linux/types.h>
42 #include <linux/miscdevice.h>
43 #include <linux/watchdog.h>
44 #include <linux/ioport.h>
45 #include <linux/delay.h>
46 #include <linux/notifier.h>
47 #include <linux/reboot.h>
49 #include <linux/pci.h>
51 #include <linux/uaccess.h>
57 /* We can only use 1 card due to the /dev/watchdog restriction */
60 static unsigned long open_lock;
61 static DEFINE_SPINLOCK(wdtpci_lock);
62 static char expect_close;
64 static resource_size_t io;
68 #define WD_TIMO 60 /* Default heartbeat = 60 seconds */
70 static int heartbeat = WD_TIMO;
71 static int wd_heartbeat;
72 module_param(heartbeat, int, 0);
73 MODULE_PARM_DESC(heartbeat,
74 "Watchdog heartbeat in seconds. (0<heartbeat<65536, default="
75 __MODULE_STRING(WD_TIMO) ")");
77 static bool nowayout = WATCHDOG_NOWAYOUT;
78 module_param(nowayout, bool, 0);
79 MODULE_PARM_DESC(nowayout,
80 "Watchdog cannot be stopped once started (default="
81 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
83 /* Support for the Fan Tachometer on the PCI-WDT501 */
84 static int tachometer;
85 module_param(tachometer, int, 0);
86 MODULE_PARM_DESC(tachometer,
87 "PCI-WDT501 Fan Tachometer support (0=disable, default=0)");
89 static int type = 500;
90 module_param(type, int, 0);
91 MODULE_PARM_DESC(type,
92 "PCI-WDT501 Card type (500 or 501 , default=500)");
98 static void wdtpci_ctr_mode(int ctr, int mode)
107 static void wdtpci_ctr_load(int ctr, int val)
109 outb(val & 0xFF, WDT_COUNT0 + ctr);
111 outb(val >> 8, WDT_COUNT0 + ctr);
118 * Start the watchdog driver.
121 static int wdtpci_start(void)
125 spin_lock_irqsave(&wdtpci_lock, flags);
128 * "pet" the watchdog, as Access says.
129 * This resets the clock outputs.
131 inb(WDT_DC); /* Disable watchdog */
133 wdtpci_ctr_mode(2, 0); /* Program CTR2 for Mode 0:
134 Pulse on Terminal Count */
135 outb(0, WDT_DC); /* Enable watchdog */
137 inb(WDT_DC); /* Disable watchdog */
139 outb(0, WDT_CLOCK); /* 2.0833MHz clock */
141 inb(WDT_BUZZER); /* disable */
143 inb(WDT_OPTONOTRST); /* disable */
145 inb(WDT_OPTORST); /* disable */
147 inb(WDT_PROGOUT); /* disable */
149 wdtpci_ctr_mode(0, 3); /* Program CTR0 for Mode 3:
150 Square Wave Generator */
151 wdtpci_ctr_mode(1, 2); /* Program CTR1 for Mode 2:
153 wdtpci_ctr_mode(2, 1); /* Program CTR2 for Mode 1:
154 Retriggerable One-Shot */
155 wdtpci_ctr_load(0, 20833); /* count at 100Hz */
156 wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
157 /* DO NOT LOAD CTR2 on PCI card! -- JPN */
158 outb(0, WDT_DC); /* Enable watchdog */
161 spin_unlock_irqrestore(&wdtpci_lock, flags);
168 * Stop the watchdog driver.
171 static int wdtpci_stop(void)
175 /* Turn the card off */
176 spin_lock_irqsave(&wdtpci_lock, flags);
177 inb(WDT_DC); /* Disable watchdog */
179 wdtpci_ctr_load(2, 0); /* 0 length reset pulses now */
180 spin_unlock_irqrestore(&wdtpci_lock, flags);
187 * Reload counter one with the watchdog heartbeat. We don't bother
188 * reloading the cascade counter.
191 static int wdtpci_ping(void)
195 spin_lock_irqsave(&wdtpci_lock, flags);
196 /* Write a watchdog value */
197 inb(WDT_DC); /* Disable watchdog */
199 wdtpci_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2:
201 wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
202 outb(0, WDT_DC); /* Enable watchdog */
204 spin_unlock_irqrestore(&wdtpci_lock, flags);
209 * wdtpci_set_heartbeat:
210 * @t: the new heartbeat value that needs to be set.
212 * Set a new heartbeat value for the watchdog device. If the heartbeat
213 * value is incorrect we keep the old value and return -EINVAL.
214 * If successful we return 0.
216 static int wdtpci_set_heartbeat(int t)
218 /* Arbitrary, can't find the card's limits */
219 if (t < 1 || t > 65535)
223 wd_heartbeat = t * 100;
229 * @status: the new status.
231 * Extract the status information from a WDT watchdog device. There are
232 * several board variants so we have to know which bits are valid. Some
233 * bits default to one and some to zero in order to be maximally painful.
235 * we then map the bits onto the status ioctl flags.
238 static int wdtpci_get_status(int *status)
240 unsigned char new_status;
243 spin_lock_irqsave(&wdtpci_lock, flags);
244 new_status = inb(WDT_SR);
245 spin_unlock_irqrestore(&wdtpci_lock, flags);
248 if (new_status & WDC_SR_ISOI0)
249 *status |= WDIOF_EXTERN1;
250 if (new_status & WDC_SR_ISII1)
251 *status |= WDIOF_EXTERN2;
253 if (!(new_status & WDC_SR_TGOOD))
254 *status |= WDIOF_OVERHEAT;
255 if (!(new_status & WDC_SR_PSUOVER))
256 *status |= WDIOF_POWEROVER;
257 if (!(new_status & WDC_SR_PSUUNDR))
258 *status |= WDIOF_POWERUNDER;
260 if (!(new_status & WDC_SR_FANGOOD))
261 *status |= WDIOF_FANFAULT;
268 * wdtpci_get_temperature:
270 * Reports the temperature in degrees Fahrenheit. The API is in
271 * farenheit. It was designed by an imperial measurement luddite.
274 static int wdtpci_get_temperature(int *temperature)
278 spin_lock_irqsave(&wdtpci_lock, flags);
281 spin_unlock_irqrestore(&wdtpci_lock, flags);
282 *temperature = (c * 11 / 15) + 7;
288 * @irq: Interrupt number
289 * @dev_id: Unused as we don't allow multiple devices.
291 * Handle an interrupt from the board. These are raised when the status
292 * map changes in what the board considers an interesting way. That means
293 * a failure condition occurring.
296 static irqreturn_t wdtpci_interrupt(int irq, void *dev_id)
299 * Read the status register see what is up and
302 unsigned char status;
304 spin_lock(&wdtpci_lock);
306 status = inb(WDT_SR);
309 pr_crit("status %d\n", status);
312 if (!(status & WDC_SR_TGOOD)) {
313 pr_crit("Overheat alarm (%d)\n", inb(WDT_RT));
316 if (!(status & WDC_SR_PSUOVER))
317 pr_crit("PSU over voltage\n");
318 if (!(status & WDC_SR_PSUUNDR))
319 pr_crit("PSU under voltage\n");
321 if (!(status & WDC_SR_FANGOOD))
322 pr_crit("Possible fan fault\n");
325 if (!(status & WDC_SR_WCCR)) {
326 #ifdef SOFTWARE_REBOOT
328 pr_crit("Would Reboot\n");
330 pr_crit("Initiating system reboot\n");
334 pr_crit("Reset in 5ms\n");
337 spin_unlock(&wdtpci_lock);
344 * @file: file handle to the watchdog
345 * @buf: buffer to write (unused as data does not matter here
346 * @count: count of bytes
347 * @ppos: pointer to the position to write. No seeks allowed
349 * A write to a watchdog device is defined as a keepalive signal. Any
350 * write of data will do, as we we don't define content meaning.
353 static ssize_t wdtpci_write(struct file *file, const char __user *buf,
354 size_t count, loff_t *ppos)
360 /* In case it was set long ago */
363 for (i = 0; i != count; i++) {
365 if (get_user(c, buf + i))
378 * @file: file handle to the device
379 * @cmd: watchdog command
380 * @arg: argument pointer
382 * The watchdog API defines a common set of functions for all watchdogs
383 * according to their available features. We only actually usefully support
384 * querying capabilities and current status.
387 static long wdtpci_ioctl(struct file *file, unsigned int cmd,
390 void __user *argp = (void __user *)arg;
391 int __user *p = argp;
395 struct watchdog_info ident = {
396 .options = WDIOF_SETTIMEOUT|
399 .firmware_version = 1,
400 .identity = "PCI-WDT500/501",
403 /* Add options according to the card we have */
404 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
406 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
409 ident.options |= WDIOF_FANFAULT;
413 case WDIOC_GETSUPPORT:
414 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
415 case WDIOC_GETSTATUS:
416 wdtpci_get_status(&status);
417 return put_user(status, p);
418 case WDIOC_GETBOOTSTATUS:
419 return put_user(0, p);
420 case WDIOC_KEEPALIVE:
423 case WDIOC_SETTIMEOUT:
424 if (get_user(new_heartbeat, p))
426 if (wdtpci_set_heartbeat(new_heartbeat))
430 case WDIOC_GETTIMEOUT:
431 return put_user(heartbeat, p);
439 * @inode: inode of device
440 * @file: file handle to device
442 * The watchdog device has been opened. The watchdog device is single
443 * open and on opening we load the counters. Counter zero is a 100Hz
444 * cascade, into counter 1 which downcounts to reboot. When the counter
445 * triggers counter 2 downcounts the length of the reset pulse which
446 * set set to be as long as possible.
449 static int wdtpci_open(struct inode *inode, struct file *file)
451 if (test_and_set_bit(0, &open_lock))
455 __module_get(THIS_MODULE);
460 return stream_open(inode, file);
465 * @inode: inode to board
466 * @file: file handle to board
468 * The watchdog has a configurable API. There is a religious dispute
469 * between people who want their watchdog to be able to shut down and
470 * those who want to be sure if the watchdog manager dies the machine
471 * reboots. In the former case we disable the counters, in the latter
472 * case you have to open it again very soon.
475 static int wdtpci_release(struct inode *inode, struct file *file)
477 if (expect_close == 42) {
480 pr_crit("Unexpected close, not stopping timer!\n");
484 clear_bit(0, &open_lock);
490 * @file: file handle to the watchdog board
491 * @buf: buffer to write 1 byte into
492 * @count: length of buffer
493 * @ptr: offset (no seek allowed)
495 * Read reports the temperature in degrees Fahrenheit. The API is in
496 * fahrenheit. It was designed by an imperial measurement luddite.
499 static ssize_t wdtpci_temp_read(struct file *file, char __user *buf,
500 size_t count, loff_t *ptr)
504 if (wdtpci_get_temperature(&temperature))
507 if (copy_to_user(buf, &temperature, 1))
515 * @inode: inode of device
516 * @file: file handle to device
518 * The temperature device has been opened.
521 static int wdtpci_temp_open(struct inode *inode, struct file *file)
523 return stream_open(inode, file);
527 * wdtpci_temp_release:
528 * @inode: inode to board
529 * @file: file handle to board
531 * The temperature device has been closed.
534 static int wdtpci_temp_release(struct inode *inode, struct file *file)
541 * @this: our notifier block
542 * @code: the event being reported
545 * Our notifier is called on system shutdowns. We want to turn the card
546 * off at reboot otherwise the machine will reboot again during memory
547 * test or worse yet during the following fsck. This would suck, in fact
548 * trust me - if it happens it does suck.
551 static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code,
554 if (code == SYS_DOWN || code == SYS_HALT)
564 static const struct file_operations wdtpci_fops = {
565 .owner = THIS_MODULE,
567 .write = wdtpci_write,
568 .unlocked_ioctl = wdtpci_ioctl,
569 .compat_ioctl = compat_ptr_ioctl,
571 .release = wdtpci_release,
574 static struct miscdevice wdtpci_miscdev = {
575 .minor = WATCHDOG_MINOR,
577 .fops = &wdtpci_fops,
580 static const struct file_operations wdtpci_temp_fops = {
581 .owner = THIS_MODULE,
583 .read = wdtpci_temp_read,
584 .open = wdtpci_temp_open,
585 .release = wdtpci_temp_release,
588 static struct miscdevice temp_miscdev = {
590 .name = "temperature",
591 .fops = &wdtpci_temp_fops,
595 * The WDT card needs to learn about soft shutdowns in order to
596 * turn the timebomb registers off.
599 static struct notifier_block wdtpci_notifier = {
600 .notifier_call = wdtpci_notify_sys,
604 static int wdtpci_init_one(struct pci_dev *dev,
605 const struct pci_device_id *ent)
611 pr_err("This driver only supports one device\n");
615 if (type != 500 && type != 501) {
616 pr_err("unknown card type '%d'\n", type);
620 if (pci_enable_device(dev)) {
621 pr_err("Not possible to enable PCI Device\n");
625 if (pci_resource_start(dev, 2) == 0x0000) {
626 pr_err("No I/O-Address for card detected\n");
631 if (pci_request_region(dev, 2, "wdt_pci")) {
632 pr_err("I/O address 0x%llx already in use\n",
633 (unsigned long long)pci_resource_start(dev, 2));
638 io = pci_resource_start(dev, 2);
640 if (request_irq(irq, wdtpci_interrupt, IRQF_SHARED,
641 "wdt_pci", &wdtpci_miscdev)) {
642 pr_err("IRQ %d is not free\n", irq);
646 pr_info("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%llx (Interrupt %d)\n",
647 (unsigned long long)io, irq);
649 /* Check that the heartbeat value is within its range;
650 if not reset to the default */
651 if (wdtpci_set_heartbeat(heartbeat)) {
652 wdtpci_set_heartbeat(WD_TIMO);
653 pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
657 ret = register_reboot_notifier(&wdtpci_notifier);
659 pr_err("cannot register reboot notifier (err=%d)\n", ret);
664 ret = misc_register(&temp_miscdev);
666 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
672 ret = misc_register(&wdtpci_miscdev);
674 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
675 WATCHDOG_MINOR, ret);
679 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
680 heartbeat, nowayout);
682 pr_info("Fan Tachometer is %s\n",
683 tachometer ? "Enabled" : "Disabled");
691 misc_deregister(&temp_miscdev);
693 unregister_reboot_notifier(&wdtpci_notifier);
695 free_irq(irq, &wdtpci_miscdev);
697 pci_release_region(dev, 2);
699 pci_disable_device(dev);
704 static void wdtpci_remove_one(struct pci_dev *pdev)
706 /* here we assume only one device will ever have
707 * been picked up and registered by probe function */
708 misc_deregister(&wdtpci_miscdev);
710 misc_deregister(&temp_miscdev);
711 unregister_reboot_notifier(&wdtpci_notifier);
712 free_irq(irq, &wdtpci_miscdev);
713 pci_release_region(pdev, 2);
714 pci_disable_device(pdev);
719 static const struct pci_device_id wdtpci_pci_tbl[] = {
721 .vendor = PCI_VENDOR_ID_ACCESSIO,
722 .device = PCI_DEVICE_ID_ACCESSIO_WDG_CSM,
723 .subvendor = PCI_ANY_ID,
724 .subdevice = PCI_ANY_ID,
726 { 0, }, /* terminate list */
728 MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl);
731 static struct pci_driver wdtpci_driver = {
733 .id_table = wdtpci_pci_tbl,
734 .probe = wdtpci_init_one,
735 .remove = wdtpci_remove_one,
738 module_pci_driver(wdtpci_driver);
740 MODULE_AUTHOR("JP Nollmann, Alan Cox");
741 MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards");
742 MODULE_LICENSE("GPL");