1 /* 2 * Industrial Computer Source PCI-WDT500/501 driver 3 * 4 * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>, 5 * All Rights Reserved. 6 * 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. 11 * 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. 15 * 16 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> 17 * 18 * Release 0.10. 19 * 20 * Fixes 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 24 * Matt Crocker). 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 33 * failures 34 * Joel Becker : Added WDIOC_GET/SETTIMEOUT 35 * Zwane Mwaikambo : Magic char closing, locking changes, 36 * cleanups 37 * Matt Domsch : nowayout module option 38 */ 39 40 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 41 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/fs.h> 53 #include <linux/pci.h> 54 #include <linux/io.h> 55 #include <linux/uaccess.h> 56 57 58 #define WDT_IS_PCI 59 #include "wd501p.h" 60 61 /* We can only use 1 card due to the /dev/watchdog restriction */ 62 static int dev_count; 63 64 static unsigned long open_lock; 65 static DEFINE_SPINLOCK(wdtpci_lock); 66 static char expect_close; 67 68 static resource_size_t io; 69 static int irq; 70 71 /* Default timeout */ 72 #define WD_TIMO 60 /* Default heartbeat = 60 seconds */ 73 74 static int heartbeat = WD_TIMO; 75 static int wd_heartbeat; 76 module_param(heartbeat, int, 0); 77 MODULE_PARM_DESC(heartbeat, 78 "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" 79 __MODULE_STRING(WD_TIMO) ")"); 80 81 static bool nowayout = WATCHDOG_NOWAYOUT; 82 module_param(nowayout, bool, 0); 83 MODULE_PARM_DESC(nowayout, 84 "Watchdog cannot be stopped once started (default=" 85 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 86 87 /* Support for the Fan Tachometer on the PCI-WDT501 */ 88 static int tachometer; 89 module_param(tachometer, int, 0); 90 MODULE_PARM_DESC(tachometer, 91 "PCI-WDT501 Fan Tachometer support (0=disable, default=0)"); 92 93 static int type = 500; 94 module_param(type, int, 0); 95 MODULE_PARM_DESC(type, 96 "PCI-WDT501 Card type (500 or 501 , default=500)"); 97 98 /* 99 * Programming support 100 */ 101 102 static void wdtpci_ctr_mode(int ctr, int mode) 103 { 104 ctr <<= 6; 105 ctr |= 0x30; 106 ctr |= (mode << 1); 107 outb(ctr, WDT_CR); 108 udelay(8); 109 } 110 111 static void wdtpci_ctr_load(int ctr, int val) 112 { 113 outb(val & 0xFF, WDT_COUNT0 + ctr); 114 udelay(8); 115 outb(val >> 8, WDT_COUNT0 + ctr); 116 udelay(8); 117 } 118 119 /** 120 * wdtpci_start: 121 * 122 * Start the watchdog driver. 123 */ 124 125 static int wdtpci_start(void) 126 { 127 unsigned long flags; 128 129 spin_lock_irqsave(&wdtpci_lock, flags); 130 131 /* 132 * "pet" the watchdog, as Access says. 133 * This resets the clock outputs. 134 */ 135 inb(WDT_DC); /* Disable watchdog */ 136 udelay(8); 137 wdtpci_ctr_mode(2, 0); /* Program CTR2 for Mode 0: 138 Pulse on Terminal Count */ 139 outb(0, WDT_DC); /* Enable watchdog */ 140 udelay(8); 141 inb(WDT_DC); /* Disable watchdog */ 142 udelay(8); 143 outb(0, WDT_CLOCK); /* 2.0833MHz clock */ 144 udelay(8); 145 inb(WDT_BUZZER); /* disable */ 146 udelay(8); 147 inb(WDT_OPTONOTRST); /* disable */ 148 udelay(8); 149 inb(WDT_OPTORST); /* disable */ 150 udelay(8); 151 inb(WDT_PROGOUT); /* disable */ 152 udelay(8); 153 wdtpci_ctr_mode(0, 3); /* Program CTR0 for Mode 3: 154 Square Wave Generator */ 155 wdtpci_ctr_mode(1, 2); /* Program CTR1 for Mode 2: 156 Rate Generator */ 157 wdtpci_ctr_mode(2, 1); /* Program CTR2 for Mode 1: 158 Retriggerable One-Shot */ 159 wdtpci_ctr_load(0, 20833); /* count at 100Hz */ 160 wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */ 161 /* DO NOT LOAD CTR2 on PCI card! -- JPN */ 162 outb(0, WDT_DC); /* Enable watchdog */ 163 udelay(8); 164 165 spin_unlock_irqrestore(&wdtpci_lock, flags); 166 return 0; 167 } 168 169 /** 170 * wdtpci_stop: 171 * 172 * Stop the watchdog driver. 173 */ 174 175 static int wdtpci_stop(void) 176 { 177 unsigned long flags; 178 179 /* Turn the card off */ 180 spin_lock_irqsave(&wdtpci_lock, flags); 181 inb(WDT_DC); /* Disable watchdog */ 182 udelay(8); 183 wdtpci_ctr_load(2, 0); /* 0 length reset pulses now */ 184 spin_unlock_irqrestore(&wdtpci_lock, flags); 185 return 0; 186 } 187 188 /** 189 * wdtpci_ping: 190 * 191 * Reload counter one with the watchdog heartbeat. We don't bother 192 * reloading the cascade counter. 193 */ 194 195 static int wdtpci_ping(void) 196 { 197 unsigned long flags; 198 199 spin_lock_irqsave(&wdtpci_lock, flags); 200 /* Write a watchdog value */ 201 inb(WDT_DC); /* Disable watchdog */ 202 udelay(8); 203 wdtpci_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2: 204 Rate Generator */ 205 wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */ 206 outb(0, WDT_DC); /* Enable watchdog */ 207 udelay(8); 208 spin_unlock_irqrestore(&wdtpci_lock, flags); 209 return 0; 210 } 211 212 /** 213 * wdtpci_set_heartbeat: 214 * @t: the new heartbeat value that needs to be set. 215 * 216 * Set a new heartbeat value for the watchdog device. If the heartbeat 217 * value is incorrect we keep the old value and return -EINVAL. 218 * If successful we return 0. 219 */ 220 static int wdtpci_set_heartbeat(int t) 221 { 222 /* Arbitrary, can't find the card's limits */ 223 if (t < 1 || t > 65535) 224 return -EINVAL; 225 226 heartbeat = t; 227 wd_heartbeat = t * 100; 228 return 0; 229 } 230 231 /** 232 * wdtpci_get_status: 233 * @status: the new status. 234 * 235 * Extract the status information from a WDT watchdog device. There are 236 * several board variants so we have to know which bits are valid. Some 237 * bits default to one and some to zero in order to be maximally painful. 238 * 239 * we then map the bits onto the status ioctl flags. 240 */ 241 242 static int wdtpci_get_status(int *status) 243 { 244 unsigned char new_status; 245 unsigned long flags; 246 247 spin_lock_irqsave(&wdtpci_lock, flags); 248 new_status = inb(WDT_SR); 249 spin_unlock_irqrestore(&wdtpci_lock, flags); 250 251 *status = 0; 252 if (new_status & WDC_SR_ISOI0) 253 *status |= WDIOF_EXTERN1; 254 if (new_status & WDC_SR_ISII1) 255 *status |= WDIOF_EXTERN2; 256 if (type == 501) { 257 if (!(new_status & WDC_SR_TGOOD)) 258 *status |= WDIOF_OVERHEAT; 259 if (!(new_status & WDC_SR_PSUOVER)) 260 *status |= WDIOF_POWEROVER; 261 if (!(new_status & WDC_SR_PSUUNDR)) 262 *status |= WDIOF_POWERUNDER; 263 if (tachometer) { 264 if (!(new_status & WDC_SR_FANGOOD)) 265 *status |= WDIOF_FANFAULT; 266 } 267 } 268 return 0; 269 } 270 271 /** 272 * wdtpci_get_temperature: 273 * 274 * Reports the temperature in degrees Fahrenheit. The API is in 275 * farenheit. It was designed by an imperial measurement luddite. 276 */ 277 278 static int wdtpci_get_temperature(int *temperature) 279 { 280 unsigned short c; 281 unsigned long flags; 282 spin_lock_irqsave(&wdtpci_lock, flags); 283 c = inb(WDT_RT); 284 udelay(8); 285 spin_unlock_irqrestore(&wdtpci_lock, flags); 286 *temperature = (c * 11 / 15) + 7; 287 return 0; 288 } 289 290 /** 291 * wdtpci_interrupt: 292 * @irq: Interrupt number 293 * @dev_id: Unused as we don't allow multiple devices. 294 * 295 * Handle an interrupt from the board. These are raised when the status 296 * map changes in what the board considers an interesting way. That means 297 * a failure condition occurring. 298 */ 299 300 static irqreturn_t wdtpci_interrupt(int irq, void *dev_id) 301 { 302 /* 303 * Read the status register see what is up and 304 * then printk it. 305 */ 306 unsigned char status; 307 308 spin_lock(&wdtpci_lock); 309 310 status = inb(WDT_SR); 311 udelay(8); 312 313 pr_crit("status %d\n", status); 314 315 if (type == 501) { 316 if (!(status & WDC_SR_TGOOD)) { 317 pr_crit("Overheat alarm (%d)\n", inb(WDT_RT)); 318 udelay(8); 319 } 320 if (!(status & WDC_SR_PSUOVER)) 321 pr_crit("PSU over voltage\n"); 322 if (!(status & WDC_SR_PSUUNDR)) 323 pr_crit("PSU under voltage\n"); 324 if (tachometer) { 325 if (!(status & WDC_SR_FANGOOD)) 326 pr_crit("Possible fan fault\n"); 327 } 328 } 329 if (!(status & WDC_SR_WCCR)) { 330 #ifdef SOFTWARE_REBOOT 331 #ifdef ONLY_TESTING 332 pr_crit("Would Reboot\n"); 333 #else 334 pr_crit("Initiating system reboot\n"); 335 emergency_restart(); 336 #endif 337 #else 338 pr_crit("Reset in 5ms\n"); 339 #endif 340 } 341 spin_unlock(&wdtpci_lock); 342 return IRQ_HANDLED; 343 } 344 345 346 /** 347 * wdtpci_write: 348 * @file: file handle to the watchdog 349 * @buf: buffer to write (unused as data does not matter here 350 * @count: count of bytes 351 * @ppos: pointer to the position to write. No seeks allowed 352 * 353 * A write to a watchdog device is defined as a keepalive signal. Any 354 * write of data will do, as we we don't define content meaning. 355 */ 356 357 static ssize_t wdtpci_write(struct file *file, const char __user *buf, 358 size_t count, loff_t *ppos) 359 { 360 if (count) { 361 if (!nowayout) { 362 size_t i; 363 364 /* In case it was set long ago */ 365 expect_close = 0; 366 367 for (i = 0; i != count; i++) { 368 char c; 369 if (get_user(c, buf + i)) 370 return -EFAULT; 371 if (c == 'V') 372 expect_close = 42; 373 } 374 } 375 wdtpci_ping(); 376 } 377 return count; 378 } 379 380 /** 381 * wdtpci_ioctl: 382 * @file: file handle to the device 383 * @cmd: watchdog command 384 * @arg: argument pointer 385 * 386 * The watchdog API defines a common set of functions for all watchdogs 387 * according to their available features. We only actually usefully support 388 * querying capabilities and current status. 389 */ 390 391 static long wdtpci_ioctl(struct file *file, unsigned int cmd, 392 unsigned long arg) 393 { 394 void __user *argp = (void __user *)arg; 395 int __user *p = argp; 396 int new_heartbeat; 397 int status; 398 399 struct watchdog_info ident = { 400 .options = WDIOF_SETTIMEOUT| 401 WDIOF_MAGICCLOSE| 402 WDIOF_KEEPALIVEPING, 403 .firmware_version = 1, 404 .identity = "PCI-WDT500/501", 405 }; 406 407 /* Add options according to the card we have */ 408 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2); 409 if (type == 501) { 410 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER| 411 WDIOF_POWEROVER); 412 if (tachometer) 413 ident.options |= WDIOF_FANFAULT; 414 } 415 416 switch (cmd) { 417 case WDIOC_GETSUPPORT: 418 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; 419 case WDIOC_GETSTATUS: 420 wdtpci_get_status(&status); 421 return put_user(status, p); 422 case WDIOC_GETBOOTSTATUS: 423 return put_user(0, p); 424 case WDIOC_KEEPALIVE: 425 wdtpci_ping(); 426 return 0; 427 case WDIOC_SETTIMEOUT: 428 if (get_user(new_heartbeat, p)) 429 return -EFAULT; 430 if (wdtpci_set_heartbeat(new_heartbeat)) 431 return -EINVAL; 432 wdtpci_ping(); 433 /* fall through */ 434 case WDIOC_GETTIMEOUT: 435 return put_user(heartbeat, p); 436 default: 437 return -ENOTTY; 438 } 439 } 440 441 /** 442 * wdtpci_open: 443 * @inode: inode of device 444 * @file: file handle to device 445 * 446 * The watchdog device has been opened. The watchdog device is single 447 * open and on opening we load the counters. Counter zero is a 100Hz 448 * cascade, into counter 1 which downcounts to reboot. When the counter 449 * triggers counter 2 downcounts the length of the reset pulse which 450 * set set to be as long as possible. 451 */ 452 453 static int wdtpci_open(struct inode *inode, struct file *file) 454 { 455 if (test_and_set_bit(0, &open_lock)) 456 return -EBUSY; 457 458 if (nowayout) 459 __module_get(THIS_MODULE); 460 /* 461 * Activate 462 */ 463 wdtpci_start(); 464 return stream_open(inode, file); 465 } 466 467 /** 468 * wdtpci_release: 469 * @inode: inode to board 470 * @file: file handle to board 471 * 472 * The watchdog has a configurable API. There is a religious dispute 473 * between people who want their watchdog to be able to shut down and 474 * those who want to be sure if the watchdog manager dies the machine 475 * reboots. In the former case we disable the counters, in the latter 476 * case you have to open it again very soon. 477 */ 478 479 static int wdtpci_release(struct inode *inode, struct file *file) 480 { 481 if (expect_close == 42) { 482 wdtpci_stop(); 483 } else { 484 pr_crit("Unexpected close, not stopping timer!\n"); 485 wdtpci_ping(); 486 } 487 expect_close = 0; 488 clear_bit(0, &open_lock); 489 return 0; 490 } 491 492 /** 493 * wdtpci_temp_read: 494 * @file: file handle to the watchdog board 495 * @buf: buffer to write 1 byte into 496 * @count: length of buffer 497 * @ptr: offset (no seek allowed) 498 * 499 * Read reports the temperature in degrees Fahrenheit. The API is in 500 * fahrenheit. It was designed by an imperial measurement luddite. 501 */ 502 503 static ssize_t wdtpci_temp_read(struct file *file, char __user *buf, 504 size_t count, loff_t *ptr) 505 { 506 int temperature; 507 508 if (wdtpci_get_temperature(&temperature)) 509 return -EFAULT; 510 511 if (copy_to_user(buf, &temperature, 1)) 512 return -EFAULT; 513 514 return 1; 515 } 516 517 /** 518 * wdtpci_temp_open: 519 * @inode: inode of device 520 * @file: file handle to device 521 * 522 * The temperature device has been opened. 523 */ 524 525 static int wdtpci_temp_open(struct inode *inode, struct file *file) 526 { 527 return stream_open(inode, file); 528 } 529 530 /** 531 * wdtpci_temp_release: 532 * @inode: inode to board 533 * @file: file handle to board 534 * 535 * The temperature device has been closed. 536 */ 537 538 static int wdtpci_temp_release(struct inode *inode, struct file *file) 539 { 540 return 0; 541 } 542 543 /** 544 * notify_sys: 545 * @this: our notifier block 546 * @code: the event being reported 547 * @unused: unused 548 * 549 * Our notifier is called on system shutdowns. We want to turn the card 550 * off at reboot otherwise the machine will reboot again during memory 551 * test or worse yet during the following fsck. This would suck, in fact 552 * trust me - if it happens it does suck. 553 */ 554 555 static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code, 556 void *unused) 557 { 558 if (code == SYS_DOWN || code == SYS_HALT) 559 wdtpci_stop(); 560 return NOTIFY_DONE; 561 } 562 563 /* 564 * Kernel Interfaces 565 */ 566 567 568 static const struct file_operations wdtpci_fops = { 569 .owner = THIS_MODULE, 570 .llseek = no_llseek, 571 .write = wdtpci_write, 572 .unlocked_ioctl = wdtpci_ioctl, 573 .open = wdtpci_open, 574 .release = wdtpci_release, 575 }; 576 577 static struct miscdevice wdtpci_miscdev = { 578 .minor = WATCHDOG_MINOR, 579 .name = "watchdog", 580 .fops = &wdtpci_fops, 581 }; 582 583 static const struct file_operations wdtpci_temp_fops = { 584 .owner = THIS_MODULE, 585 .llseek = no_llseek, 586 .read = wdtpci_temp_read, 587 .open = wdtpci_temp_open, 588 .release = wdtpci_temp_release, 589 }; 590 591 static struct miscdevice temp_miscdev = { 592 .minor = TEMP_MINOR, 593 .name = "temperature", 594 .fops = &wdtpci_temp_fops, 595 }; 596 597 /* 598 * The WDT card needs to learn about soft shutdowns in order to 599 * turn the timebomb registers off. 600 */ 601 602 static struct notifier_block wdtpci_notifier = { 603 .notifier_call = wdtpci_notify_sys, 604 }; 605 606 607 static int wdtpci_init_one(struct pci_dev *dev, 608 const struct pci_device_id *ent) 609 { 610 int ret = -EIO; 611 612 dev_count++; 613 if (dev_count > 1) { 614 pr_err("This driver only supports one device\n"); 615 return -ENODEV; 616 } 617 618 if (type != 500 && type != 501) { 619 pr_err("unknown card type '%d'\n", type); 620 return -ENODEV; 621 } 622 623 if (pci_enable_device(dev)) { 624 pr_err("Not possible to enable PCI Device\n"); 625 return -ENODEV; 626 } 627 628 if (pci_resource_start(dev, 2) == 0x0000) { 629 pr_err("No I/O-Address for card detected\n"); 630 ret = -ENODEV; 631 goto out_pci; 632 } 633 634 if (pci_request_region(dev, 2, "wdt_pci")) { 635 pr_err("I/O address 0x%llx already in use\n", 636 (unsigned long long)pci_resource_start(dev, 2)); 637 goto out_pci; 638 } 639 640 irq = dev->irq; 641 io = pci_resource_start(dev, 2); 642 643 if (request_irq(irq, wdtpci_interrupt, IRQF_SHARED, 644 "wdt_pci", &wdtpci_miscdev)) { 645 pr_err("IRQ %d is not free\n", irq); 646 goto out_reg; 647 } 648 649 pr_info("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%llx (Interrupt %d)\n", 650 (unsigned long long)io, irq); 651 652 /* Check that the heartbeat value is within its range; 653 if not reset to the default */ 654 if (wdtpci_set_heartbeat(heartbeat)) { 655 wdtpci_set_heartbeat(WD_TIMO); 656 pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n", 657 WD_TIMO); 658 } 659 660 ret = register_reboot_notifier(&wdtpci_notifier); 661 if (ret) { 662 pr_err("cannot register reboot notifier (err=%d)\n", ret); 663 goto out_irq; 664 } 665 666 if (type == 501) { 667 ret = misc_register(&temp_miscdev); 668 if (ret) { 669 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 670 TEMP_MINOR, ret); 671 goto out_rbt; 672 } 673 } 674 675 ret = misc_register(&wdtpci_miscdev); 676 if (ret) { 677 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 678 WATCHDOG_MINOR, ret); 679 goto out_misc; 680 } 681 682 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n", 683 heartbeat, nowayout); 684 if (type == 501) 685 pr_info("Fan Tachometer is %s\n", 686 tachometer ? "Enabled" : "Disabled"); 687 688 ret = 0; 689 out: 690 return ret; 691 692 out_misc: 693 if (type == 501) 694 misc_deregister(&temp_miscdev); 695 out_rbt: 696 unregister_reboot_notifier(&wdtpci_notifier); 697 out_irq: 698 free_irq(irq, &wdtpci_miscdev); 699 out_reg: 700 pci_release_region(dev, 2); 701 out_pci: 702 pci_disable_device(dev); 703 goto out; 704 } 705 706 707 static void wdtpci_remove_one(struct pci_dev *pdev) 708 { 709 /* here we assume only one device will ever have 710 * been picked up and registered by probe function */ 711 misc_deregister(&wdtpci_miscdev); 712 if (type == 501) 713 misc_deregister(&temp_miscdev); 714 unregister_reboot_notifier(&wdtpci_notifier); 715 free_irq(irq, &wdtpci_miscdev); 716 pci_release_region(pdev, 2); 717 pci_disable_device(pdev); 718 dev_count--; 719 } 720 721 722 static const struct pci_device_id wdtpci_pci_tbl[] = { 723 { 724 .vendor = PCI_VENDOR_ID_ACCESSIO, 725 .device = PCI_DEVICE_ID_ACCESSIO_WDG_CSM, 726 .subvendor = PCI_ANY_ID, 727 .subdevice = PCI_ANY_ID, 728 }, 729 { 0, }, /* terminate list */ 730 }; 731 MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl); 732 733 734 static struct pci_driver wdtpci_driver = { 735 .name = "wdt_pci", 736 .id_table = wdtpci_pci_tbl, 737 .probe = wdtpci_init_one, 738 .remove = wdtpci_remove_one, 739 }; 740 741 module_pci_driver(wdtpci_driver); 742 743 MODULE_AUTHOR("JP Nollmann, Alan Cox"); 744 MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards"); 745 MODULE_LICENSE("GPL"); 746