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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Industrial Computer Source PCI-WDT500/501 driver
4 *
5 * (c) Copyright 1996-1997 Alan Cox <[email protected]>,
6 * All Rights Reserved.
7 *
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.
11 *
12 * (c) Copyright 1995 Alan Cox <[email protected]>
13 *
14 * Release 0.10.
15 *
16 * Fixes
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
20 * Matt Crocker).
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
29 * failures
30 * Joel Becker : Added WDIOC_GET/SETTIMEOUT
31 * Zwane Mwaikambo : Magic char closing, locking changes,
32 * cleanups
33 * Matt Domsch : nowayout module option
34 */
35
36#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
37
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>
48#include <linux/fs.h>
49#include <linux/pci.h>
50#include <linux/io.h>
51#include <linux/uaccess.h>
52
53
54#define WDT_IS_PCI
55#include "wd501p.h"
56
57/* We can only use 1 card due to the /dev/watchdog restriction */
58static int dev_count;
59
60static unsigned long open_lock;
61static DEFINE_SPINLOCK(wdtpci_lock);
62static char expect_close;
63
64static resource_size_t io;
65static int irq;
66
67/* Default timeout */
68#define WD_TIMO 60 /* Default heartbeat = 60 seconds */
69
70static int heartbeat = WD_TIMO;
71static int wd_heartbeat;
72module_param(heartbeat, int, 0);
73MODULE_PARM_DESC(heartbeat,
74 "Watchdog heartbeat in seconds. (0<heartbeat<65536, default="
75 __MODULE_STRING(WD_TIMO) ")");
76
77static bool nowayout = WATCHDOG_NOWAYOUT;
78module_param(nowayout, bool, 0);
79MODULE_PARM_DESC(nowayout,
80 "Watchdog cannot be stopped once started (default="
81 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
82
83/* Support for the Fan Tachometer on the PCI-WDT501 */
84static int tachometer;
85module_param(tachometer, int, 0);
86MODULE_PARM_DESC(tachometer,
87 "PCI-WDT501 Fan Tachometer support (0=disable, default=0)");
88
89static int type = 500;
90module_param(type, int, 0);
91MODULE_PARM_DESC(type,
92 "PCI-WDT501 Card type (500 or 501 , default=500)");
93
94/*
95 * Programming support
96 */
97
98static void wdtpci_ctr_mode(int ctr, int mode)
99{
100 ctr <<= 6;
101 ctr |= 0x30;
102 ctr |= (mode << 1);
103 outb(ctr, WDT_CR);
104 udelay(8);
105}
106
107static void wdtpci_ctr_load(int ctr, int val)
108{
109 outb(val & 0xFF, WDT_COUNT0 + ctr);
110 udelay(8);
111 outb(val >> 8, WDT_COUNT0 + ctr);
112 udelay(8);
113}
114
115/**
116 * wdtpci_start:
117 *
118 * Start the watchdog driver.
119 */
120
121static int wdtpci_start(void)
122{
123 unsigned long flags;
124
125 spin_lock_irqsave(&wdtpci_lock, flags);
126
127 /*
128 * "pet" the watchdog, as Access says.
129 * This resets the clock outputs.
130 */
131 inb(WDT_DC); /* Disable watchdog */
132 udelay(8);
133 wdtpci_ctr_mode(2, 0); /* Program CTR2 for Mode 0:
134 Pulse on Terminal Count */
135 outb(0, WDT_DC); /* Enable watchdog */
136 udelay(8);
137 inb(WDT_DC); /* Disable watchdog */
138 udelay(8);
139 outb(0, WDT_CLOCK); /* 2.0833MHz clock */
140 udelay(8);
141 inb(WDT_BUZZER); /* disable */
142 udelay(8);
143 inb(WDT_OPTONOTRST); /* disable */
144 udelay(8);
145 inb(WDT_OPTORST); /* disable */
146 udelay(8);
147 inb(WDT_PROGOUT); /* disable */
148 udelay(8);
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:
152 Rate Generator */
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 */
159 udelay(8);
160
161 spin_unlock_irqrestore(&wdtpci_lock, flags);
162 return 0;
163}
164
165/**
166 * wdtpci_stop:
167 *
168 * Stop the watchdog driver.
169 */
170
171static int wdtpci_stop(void)
172{
173 unsigned long flags;
174
175 /* Turn the card off */
176 spin_lock_irqsave(&wdtpci_lock, flags);
177 inb(WDT_DC); /* Disable watchdog */
178 udelay(8);
179 wdtpci_ctr_load(2, 0); /* 0 length reset pulses now */
180 spin_unlock_irqrestore(&wdtpci_lock, flags);
181 return 0;
182}
183
184/**
185 * wdtpci_ping:
186 *
187 * Reload counter one with the watchdog heartbeat. We don't bother
188 * reloading the cascade counter.
189 */
190
191static int wdtpci_ping(void)
192{
193 unsigned long flags;
194
195 spin_lock_irqsave(&wdtpci_lock, flags);
196 /* Write a watchdog value */
197 inb(WDT_DC); /* Disable watchdog */
198 udelay(8);
199 wdtpci_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2:
200 Rate Generator */
201 wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
202 outb(0, WDT_DC); /* Enable watchdog */
203 udelay(8);
204 spin_unlock_irqrestore(&wdtpci_lock, flags);
205 return 0;
206}
207
208/**
209 * wdtpci_set_heartbeat:
210 * @t: the new heartbeat value that needs to be set.
211 *
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.
215 */
216static int wdtpci_set_heartbeat(int t)
217{
218 /* Arbitrary, can't find the card's limits */
219 if (t < 1 || t > 65535)
220 return -EINVAL;
221
222 heartbeat = t;
223 wd_heartbeat = t * 100;
224 return 0;
225}
226
227/**
228 * wdtpci_get_status:
229 * @status: the new status.
230 *
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.
234 *
235 * we then map the bits onto the status ioctl flags.
236 */
237
238static int wdtpci_get_status(int *status)
239{
240 unsigned char new_status;
241 unsigned long flags;
242
243 spin_lock_irqsave(&wdtpci_lock, flags);
244 new_status = inb(WDT_SR);
245 spin_unlock_irqrestore(&wdtpci_lock, flags);
246
247 *status = 0;
248 if (new_status & WDC_SR_ISOI0)
249 *status |= WDIOF_EXTERN1;
250 if (new_status & WDC_SR_ISII1)
251 *status |= WDIOF_EXTERN2;
252 if (type == 501) {
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;
259 if (tachometer) {
260 if (!(new_status & WDC_SR_FANGOOD))
261 *status |= WDIOF_FANFAULT;
262 }
263 }
264 return 0;
265}
266
267/*
268 * wdtpci_get_temperature:
269 *
270 * Reports the temperature in degrees Fahrenheit. The API is in
271 * farenheit. It was designed by an imperial measurement luddite.
272 */
273
274static int wdtpci_get_temperature(int *temperature)
275{
276 unsigned short c;
277 unsigned long flags;
278 spin_lock_irqsave(&wdtpci_lock, flags);
279 c = inb(WDT_RT);
280 udelay(8);
281 spin_unlock_irqrestore(&wdtpci_lock, flags);
282 *temperature = (c * 11 / 15) + 7;
283 return 0;
284}
285
286/**
287 * wdtpci_interrupt:
288 * @irq: Interrupt number
289 * @dev_id: Unused as we don't allow multiple devices.
290 *
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.
294 */
295
296static irqreturn_t wdtpci_interrupt(int irq, void *dev_id)
297{
298 /*
299 * Read the status register see what is up and
300 * then printk it.
301 */
302 unsigned char status;
303
304 spin_lock(&wdtpci_lock);
305
306 status = inb(WDT_SR);
307 udelay(8);
308
309 pr_crit("status %d\n", status);
310
311 if (type == 501) {
312 if (!(status & WDC_SR_TGOOD)) {
313 pr_crit("Overheat alarm (%d)\n", inb(WDT_RT));
314 udelay(8);
315 }
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");
320 if (tachometer) {
321 if (!(status & WDC_SR_FANGOOD))
322 pr_crit("Possible fan fault\n");
323 }
324 }
325 if (!(status & WDC_SR_WCCR)) {
326#ifdef SOFTWARE_REBOOT
327#ifdef ONLY_TESTING
328 pr_crit("Would Reboot\n");
329#else
330 pr_crit("Initiating system reboot\n");
331 emergency_restart();
332#endif
333#else
334 pr_crit("Reset in 5ms\n");
335#endif
336 }
337 spin_unlock(&wdtpci_lock);
338 return IRQ_HANDLED;
339}
340
341
342/**
343 * wdtpci_write:
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
348 *
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.
351 */
352
353static ssize_t wdtpci_write(struct file *file, const char __user *buf,
354 size_t count, loff_t *ppos)
355{
356 if (count) {
357 if (!nowayout) {
358 size_t i;
359
360 /* In case it was set long ago */
361 expect_close = 0;
362
363 for (i = 0; i != count; i++) {
364 char c;
365 if (get_user(c, buf + i))
366 return -EFAULT;
367 if (c == 'V')
368 expect_close = 42;
369 }
370 }
371 wdtpci_ping();
372 }
373 return count;
374}
375
376/**
377 * wdtpci_ioctl:
378 * @file: file handle to the device
379 * @cmd: watchdog command
380 * @arg: argument pointer
381 *
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.
385 */
386
387static long wdtpci_ioctl(struct file *file, unsigned int cmd,
388 unsigned long arg)
389{
390 void __user *argp = (void __user *)arg;
391 int __user *p = argp;
392 int new_heartbeat;
393 int status;
394
395 struct watchdog_info ident = {
396 .options = WDIOF_SETTIMEOUT|
397 WDIOF_MAGICCLOSE|
398 WDIOF_KEEPALIVEPING,
399 .firmware_version = 1,
400 .identity = "PCI-WDT500/501",
401 };
402
403 /* Add options according to the card we have */
404 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
405 if (type == 501) {
406 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
407 WDIOF_POWEROVER);
408 if (tachometer)
409 ident.options |= WDIOF_FANFAULT;
410 }
411
412 switch (cmd) {
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:
421 wdtpci_ping();
422 return 0;
423 case WDIOC_SETTIMEOUT:
424 if (get_user(new_heartbeat, p))
425 return -EFAULT;
426 if (wdtpci_set_heartbeat(new_heartbeat))
427 return -EINVAL;
428 wdtpci_ping();
429 fallthrough;
430 case WDIOC_GETTIMEOUT:
431 return put_user(heartbeat, p);
432 default:
433 return -ENOTTY;
434 }
435}
436
437/**
438 * wdtpci_open:
439 * @inode: inode of device
440 * @file: file handle to device
441 *
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.
447 */
448
449static int wdtpci_open(struct inode *inode, struct file *file)
450{
451 if (test_and_set_bit(0, &open_lock))
452 return -EBUSY;
453
454 if (nowayout)
455 __module_get(THIS_MODULE);
456 /*
457 * Activate
458 */
459 wdtpci_start();
460 return stream_open(inode, file);
461}
462
463/**
464 * wdtpci_release:
465 * @inode: inode to board
466 * @file: file handle to board
467 *
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.
473 */
474
475static int wdtpci_release(struct inode *inode, struct file *file)
476{
477 if (expect_close == 42) {
478 wdtpci_stop();
479 } else {
480 pr_crit("Unexpected close, not stopping timer!\n");
481 wdtpci_ping();
482 }
483 expect_close = 0;
484 clear_bit(0, &open_lock);
485 return 0;
486}
487
488/**
489 * wdtpci_temp_read:
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)
494 *
495 * Read reports the temperature in degrees Fahrenheit. The API is in
496 * fahrenheit. It was designed by an imperial measurement luddite.
497 */
498
499static ssize_t wdtpci_temp_read(struct file *file, char __user *buf,
500 size_t count, loff_t *ptr)
501{
502 int temperature;
503
504 if (wdtpci_get_temperature(&temperature))
505 return -EFAULT;
506
507 if (copy_to_user(buf, &temperature, 1))
508 return -EFAULT;
509
510 return 1;
511}
512
513/**
514 * wdtpci_temp_open:
515 * @inode: inode of device
516 * @file: file handle to device
517 *
518 * The temperature device has been opened.
519 */
520
521static int wdtpci_temp_open(struct inode *inode, struct file *file)
522{
523 return stream_open(inode, file);
524}
525
526/**
527 * wdtpci_temp_release:
528 * @inode: inode to board
529 * @file: file handle to board
530 *
531 * The temperature device has been closed.
532 */
533
534static int wdtpci_temp_release(struct inode *inode, struct file *file)
535{
536 return 0;
537}
538
539/**
540 * wdtpci_notify_sys:
541 * @this: our notifier block
542 * @code: the event being reported
543 * @unused: unused
544 *
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.
549 */
550
551static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code,
552 void *unused)
553{
554 if (code == SYS_DOWN || code == SYS_HALT)
555 wdtpci_stop();
556 return NOTIFY_DONE;
557}
558
559/*
560 * Kernel Interfaces
561 */
562
563
564static const struct file_operations wdtpci_fops = {
565 .owner = THIS_MODULE,
566 .write = wdtpci_write,
567 .unlocked_ioctl = wdtpci_ioctl,
568 .compat_ioctl = compat_ptr_ioctl,
569 .open = wdtpci_open,
570 .release = wdtpci_release,
571};
572
573static struct miscdevice wdtpci_miscdev = {
574 .minor = WATCHDOG_MINOR,
575 .name = "watchdog",
576 .fops = &wdtpci_fops,
577};
578
579static const struct file_operations wdtpci_temp_fops = {
580 .owner = THIS_MODULE,
581 .read = wdtpci_temp_read,
582 .open = wdtpci_temp_open,
583 .release = wdtpci_temp_release,
584};
585
586static struct miscdevice temp_miscdev = {
587 .minor = TEMP_MINOR,
588 .name = "temperature",
589 .fops = &wdtpci_temp_fops,
590};
591
592/*
593 * The WDT card needs to learn about soft shutdowns in order to
594 * turn the timebomb registers off.
595 */
596
597static struct notifier_block wdtpci_notifier = {
598 .notifier_call = wdtpci_notify_sys,
599};
600
601
602static int wdtpci_init_one(struct pci_dev *dev,
603 const struct pci_device_id *ent)
604{
605 int ret = -EIO;
606
607 dev_count++;
608 if (dev_count > 1) {
609 pr_err("This driver only supports one device\n");
610 return -ENODEV;
611 }
612
613 if (type != 500 && type != 501) {
614 pr_err("unknown card type '%d'\n", type);
615 return -ENODEV;
616 }
617
618 if (pci_enable_device(dev)) {
619 pr_err("Not possible to enable PCI Device\n");
620 return -ENODEV;
621 }
622
623 if (pci_resource_start(dev, 2) == 0x0000) {
624 pr_err("No I/O-Address for card detected\n");
625 ret = -ENODEV;
626 goto out_pci;
627 }
628
629 if (pci_request_region(dev, 2, "wdt_pci")) {
630 pr_err("I/O address 0x%llx already in use\n",
631 (unsigned long long)pci_resource_start(dev, 2));
632 goto out_pci;
633 }
634
635 irq = dev->irq;
636 io = pci_resource_start(dev, 2);
637
638 if (request_irq(irq, wdtpci_interrupt, IRQF_SHARED,
639 "wdt_pci", &wdtpci_miscdev)) {
640 pr_err("IRQ %d is not free\n", irq);
641 goto out_reg;
642 }
643
644 pr_info("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%llx (Interrupt %d)\n",
645 (unsigned long long)io, irq);
646
647 /* Check that the heartbeat value is within its range;
648 if not reset to the default */
649 if (wdtpci_set_heartbeat(heartbeat)) {
650 wdtpci_set_heartbeat(WD_TIMO);
651 pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
652 WD_TIMO);
653 }
654
655 ret = register_reboot_notifier(&wdtpci_notifier);
656 if (ret) {
657 pr_err("cannot register reboot notifier (err=%d)\n", ret);
658 goto out_irq;
659 }
660
661 if (type == 501) {
662 ret = misc_register(&temp_miscdev);
663 if (ret) {
664 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
665 TEMP_MINOR, ret);
666 goto out_rbt;
667 }
668 }
669
670 ret = misc_register(&wdtpci_miscdev);
671 if (ret) {
672 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
673 WATCHDOG_MINOR, ret);
674 goto out_misc;
675 }
676
677 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
678 heartbeat, nowayout);
679 if (type == 501)
680 pr_info("Fan Tachometer is %s\n",
681 tachometer ? "Enabled" : "Disabled");
682
683 ret = 0;
684out:
685 return ret;
686
687out_misc:
688 if (type == 501)
689 misc_deregister(&temp_miscdev);
690out_rbt:
691 unregister_reboot_notifier(&wdtpci_notifier);
692out_irq:
693 free_irq(irq, &wdtpci_miscdev);
694out_reg:
695 pci_release_region(dev, 2);
696out_pci:
697 pci_disable_device(dev);
698 goto out;
699}
700
701
702static void wdtpci_remove_one(struct pci_dev *pdev)
703{
704 /* here we assume only one device will ever have
705 * been picked up and registered by probe function */
706 misc_deregister(&wdtpci_miscdev);
707 if (type == 501)
708 misc_deregister(&temp_miscdev);
709 unregister_reboot_notifier(&wdtpci_notifier);
710 free_irq(irq, &wdtpci_miscdev);
711 pci_release_region(pdev, 2);
712 pci_disable_device(pdev);
713 dev_count--;
714}
715
716
717static const struct pci_device_id wdtpci_pci_tbl[] = {
718 {
719 .vendor = PCI_VENDOR_ID_ACCESSIO,
720 .device = PCI_DEVICE_ID_ACCESSIO_WDG_CSM,
721 .subvendor = PCI_ANY_ID,
722 .subdevice = PCI_ANY_ID,
723 },
724 { 0, }, /* terminate list */
725};
726MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl);
727
728
729static struct pci_driver wdtpci_driver = {
730 .name = "wdt_pci",
731 .id_table = wdtpci_pci_tbl,
732 .probe = wdtpci_init_one,
733 .remove = wdtpci_remove_one,
734};
735
736module_pci_driver(wdtpci_driver);
737
738MODULE_AUTHOR("JP Nollmann, Alan Cox");
739MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards");
740MODULE_LICENSE("GPL");