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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Industrial Computer Source PCI-WDT500/501 driver4 *5 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,6 * All Rights Reserved.7 *8 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide9 * warranty for any of this software. This material is provided10 * "AS-IS" and at no charge.11 *12 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>13 *14 * Release 0.10.15 *16 * Fixes17 * Dave Gregorich : Modularisation and minor bugs18 * Alan Cox : Added the watchdog ioctl() stuff19 * Alan Cox : Fixed the reboot problem (as noted by20 * Matt Crocker).21 * Alan Cox : Added wdt= boot option22 * Alan Cox : Cleaned up copy/user stuff23 * Tim Hockin : Added insmod parameters, comment cleanup24 * Parameterized timeout25 * JP Nollmann : Added support for PCI wdt501p26 * Alan Cox : Split ISA and PCI cards into two drivers27 * Jeff Garzik : PCI cleanups28 * Tigran Aivazian : Restructured wdtpci_init_one() to handle29 * failures30 * Joel Becker : Added WDIOC_GET/SETTIMEOUT31 * Zwane Mwaikambo : Magic char closing, locking changes,32 * cleanups33 * Matt Domsch : nowayout module option34 */35 36#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt37 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_PCI55#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 support96 */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 bother188 * 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 heartbeat213 * 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 are232 * several board variants so we have to know which bits are valid. Some233 * 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 in271 * 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 number289 * @dev_id: Unused as we don't allow multiple devices.290 *291 * Handle an interrupt from the board. These are raised when the status292 * map changes in what the board considers an interesting way. That means293 * 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 and300 * 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_REBOOT327#ifdef ONLY_TESTING328 pr_crit("Would Reboot\n");329#else330 pr_crit("Initiating system reboot\n");331 emergency_restart();332#endif333#else334 pr_crit("Reset in 5ms\n");335#endif336 }337 spin_unlock(&wdtpci_lock);338 return IRQ_HANDLED;339}340 341 342/**343 * wdtpci_write:344 * @file: file handle to the watchdog345 * @buf: buffer to write (unused as data does not matter here346 * @count: count of bytes347 * @ppos: pointer to the position to write. No seeks allowed348 *349 * A write to a watchdog device is defined as a keepalive signal. Any350 * 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 device379 * @cmd: watchdog command380 * @arg: argument pointer381 *382 * The watchdog API defines a common set of functions for all watchdogs383 * according to their available features. We only actually usefully support384 * 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 device440 * @file: file handle to device441 *442 * The watchdog device has been opened. The watchdog device is single443 * open and on opening we load the counters. Counter zero is a 100Hz444 * cascade, into counter 1 which downcounts to reboot. When the counter445 * triggers counter 2 downcounts the length of the reset pulse which446 * 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 * Activate458 */459 wdtpci_start();460 return stream_open(inode, file);461}462 463/**464 * wdtpci_release:465 * @inode: inode to board466 * @file: file handle to board467 *468 * The watchdog has a configurable API. There is a religious dispute469 * between people who want their watchdog to be able to shut down and470 * those who want to be sure if the watchdog manager dies the machine471 * reboots. In the former case we disable the counters, in the latter472 * 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 board491 * @buf: buffer to write 1 byte into492 * @count: length of buffer493 * @ptr: offset (no seek allowed)494 *495 * Read reports the temperature in degrees Fahrenheit. The API is in496 * 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 device516 * @file: file handle to device517 *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 board529 * @file: file handle to board530 *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 block542 * @code: the event being reported543 * @unused: unused544 *545 * Our notifier is called on system shutdowns. We want to turn the card546 * off at reboot otherwise the machine will reboot again during memory547 * test or worse yet during the following fsck. This would suck, in fact548 * 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 Interfaces561 */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 to594 * 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 have705 * 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");741