1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Industrial Computer Source PCI-WDT500/501 driver 4 * 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 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 <alan@lxorguk.ukuu.org.uk> 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 */ 58 static int dev_count; 59 60 static unsigned long open_lock; 61 static DEFINE_SPINLOCK(wdtpci_lock); 62 static char expect_close; 63 64 static resource_size_t io; 65 static int irq; 66 67 /* Default timeout */ 68 #define WD_TIMO 60 /* Default heartbeat = 60 seconds */ 69 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) ")"); 76 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) ")"); 82 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)"); 88 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)"); 93 94 /* 95 * Programming support 96 */ 97 98 static 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 } 106 107 static 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 */ 120 121 static 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 */ 170 171 static 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 */ 190 191 static 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 */ 216 static 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 */ 237 238 static 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 */ 273 274 static 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 */ 295 296 static 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 */ 352 353 static 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 */ 386 387 static 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 /* fall through */ 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 */ 448 449 static 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 */ 474 475 static 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 */ 498 499 static 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 */ 520 521 static 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 */ 533 534 static int wdtpci_temp_release(struct inode *inode, struct file *file) 535 { 536 return 0; 537 } 538 539 /** 540 * 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 */ 550 551 static 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 */ 562 563 564 static const struct file_operations wdtpci_fops = { 565 .owner = THIS_MODULE, 566 .llseek = no_llseek, 567 .write = wdtpci_write, 568 .unlocked_ioctl = wdtpci_ioctl, 569 .compat_ioctl = compat_ptr_ioctl, 570 .open = wdtpci_open, 571 .release = wdtpci_release, 572 }; 573 574 static struct miscdevice wdtpci_miscdev = { 575 .minor = WATCHDOG_MINOR, 576 .name = "watchdog", 577 .fops = &wdtpci_fops, 578 }; 579 580 static const struct file_operations wdtpci_temp_fops = { 581 .owner = THIS_MODULE, 582 .llseek = no_llseek, 583 .read = wdtpci_temp_read, 584 .open = wdtpci_temp_open, 585 .release = wdtpci_temp_release, 586 }; 587 588 static struct miscdevice temp_miscdev = { 589 .minor = TEMP_MINOR, 590 .name = "temperature", 591 .fops = &wdtpci_temp_fops, 592 }; 593 594 /* 595 * The WDT card needs to learn about soft shutdowns in order to 596 * turn the timebomb registers off. 597 */ 598 599 static struct notifier_block wdtpci_notifier = { 600 .notifier_call = wdtpci_notify_sys, 601 }; 602 603 604 static int wdtpci_init_one(struct pci_dev *dev, 605 const struct pci_device_id *ent) 606 { 607 int ret = -EIO; 608 609 dev_count++; 610 if (dev_count > 1) { 611 pr_err("This driver only supports one device\n"); 612 return -ENODEV; 613 } 614 615 if (type != 500 && type != 501) { 616 pr_err("unknown card type '%d'\n", type); 617 return -ENODEV; 618 } 619 620 if (pci_enable_device(dev)) { 621 pr_err("Not possible to enable PCI Device\n"); 622 return -ENODEV; 623 } 624 625 if (pci_resource_start(dev, 2) == 0x0000) { 626 pr_err("No I/O-Address for card detected\n"); 627 ret = -ENODEV; 628 goto out_pci; 629 } 630 631 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)); 634 goto out_pci; 635 } 636 637 irq = dev->irq; 638 io = pci_resource_start(dev, 2); 639 640 if (request_irq(irq, wdtpci_interrupt, IRQF_SHARED, 641 "wdt_pci", &wdtpci_miscdev)) { 642 pr_err("IRQ %d is not free\n", irq); 643 goto out_reg; 644 } 645 646 pr_info("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%llx (Interrupt %d)\n", 647 (unsigned long long)io, irq); 648 649 /* 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", 654 WD_TIMO); 655 } 656 657 ret = register_reboot_notifier(&wdtpci_notifier); 658 if (ret) { 659 pr_err("cannot register reboot notifier (err=%d)\n", ret); 660 goto out_irq; 661 } 662 663 if (type == 501) { 664 ret = misc_register(&temp_miscdev); 665 if (ret) { 666 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 667 TEMP_MINOR, ret); 668 goto out_rbt; 669 } 670 } 671 672 ret = misc_register(&wdtpci_miscdev); 673 if (ret) { 674 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 675 WATCHDOG_MINOR, ret); 676 goto out_misc; 677 } 678 679 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n", 680 heartbeat, nowayout); 681 if (type == 501) 682 pr_info("Fan Tachometer is %s\n", 683 tachometer ? "Enabled" : "Disabled"); 684 685 ret = 0; 686 out: 687 return ret; 688 689 out_misc: 690 if (type == 501) 691 misc_deregister(&temp_miscdev); 692 out_rbt: 693 unregister_reboot_notifier(&wdtpci_notifier); 694 out_irq: 695 free_irq(irq, &wdtpci_miscdev); 696 out_reg: 697 pci_release_region(dev, 2); 698 out_pci: 699 pci_disable_device(dev); 700 goto out; 701 } 702 703 704 static void wdtpci_remove_one(struct pci_dev *pdev) 705 { 706 /* here we assume only one device will ever have 707 * been picked up and registered by probe function */ 708 misc_deregister(&wdtpci_miscdev); 709 if (type == 501) 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); 715 dev_count--; 716 } 717 718 719 static const struct pci_device_id wdtpci_pci_tbl[] = { 720 { 721 .vendor = PCI_VENDOR_ID_ACCESSIO, 722 .device = PCI_DEVICE_ID_ACCESSIO_WDG_CSM, 723 .subvendor = PCI_ANY_ID, 724 .subdevice = PCI_ANY_ID, 725 }, 726 { 0, }, /* terminate list */ 727 }; 728 MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl); 729 730 731 static struct pci_driver wdtpci_driver = { 732 .name = "wdt_pci", 733 .id_table = wdtpci_pci_tbl, 734 .probe = wdtpci_init_one, 735 .remove = wdtpci_remove_one, 736 }; 737 738 module_pci_driver(wdtpci_driver); 739 740 MODULE_AUTHOR("JP Nollmann, Alan Cox"); 741 MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards"); 742 MODULE_LICENSE("GPL"); 743