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/init.h> 53 #include <linux/fs.h> 54 #include <linux/pci.h> 55 #include <linux/io.h> 56 #include <linux/uaccess.h> 57 58 59 #define WDT_IS_PCI 60 #include "wd501p.h" 61 62 /* We can only use 1 card due to the /dev/watchdog restriction */ 63 static int dev_count; 64 65 static unsigned long open_lock; 66 static DEFINE_SPINLOCK(wdtpci_lock); 67 static char expect_close; 68 69 static resource_size_t io; 70 static int irq; 71 72 /* Default timeout */ 73 #define WD_TIMO 60 /* Default heartbeat = 60 seconds */ 74 75 static int heartbeat = WD_TIMO; 76 static int wd_heartbeat; 77 module_param(heartbeat, int, 0); 78 MODULE_PARM_DESC(heartbeat, 79 "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" 80 __MODULE_STRING(WD_TIMO) ")"); 81 82 static bool nowayout = WATCHDOG_NOWAYOUT; 83 module_param(nowayout, bool, 0); 84 MODULE_PARM_DESC(nowayout, 85 "Watchdog cannot be stopped once started (default=" 86 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 87 88 /* Support for the Fan Tachometer on the PCI-WDT501 */ 89 static int tachometer; 90 module_param(tachometer, int, 0); 91 MODULE_PARM_DESC(tachometer, 92 "PCI-WDT501 Fan Tachometer support (0=disable, default=0)"); 93 94 static int type = 500; 95 module_param(type, int, 0); 96 MODULE_PARM_DESC(type, 97 "PCI-WDT501 Card type (500 or 501 , default=500)"); 98 99 /* 100 * Programming support 101 */ 102 103 static void wdtpci_ctr_mode(int ctr, int mode) 104 { 105 ctr <<= 6; 106 ctr |= 0x30; 107 ctr |= (mode << 1); 108 outb(ctr, WDT_CR); 109 udelay(8); 110 } 111 112 static void wdtpci_ctr_load(int ctr, int val) 113 { 114 outb(val & 0xFF, WDT_COUNT0 + ctr); 115 udelay(8); 116 outb(val >> 8, WDT_COUNT0 + ctr); 117 udelay(8); 118 } 119 120 /** 121 * wdtpci_start: 122 * 123 * Start the watchdog driver. 124 */ 125 126 static int wdtpci_start(void) 127 { 128 unsigned long flags; 129 130 spin_lock_irqsave(&wdtpci_lock, flags); 131 132 /* 133 * "pet" the watchdog, as Access says. 134 * This resets the clock outputs. 135 */ 136 inb(WDT_DC); /* Disable watchdog */ 137 udelay(8); 138 wdtpci_ctr_mode(2, 0); /* Program CTR2 for Mode 0: 139 Pulse on Terminal Count */ 140 outb(0, WDT_DC); /* Enable watchdog */ 141 udelay(8); 142 inb(WDT_DC); /* Disable watchdog */ 143 udelay(8); 144 outb(0, WDT_CLOCK); /* 2.0833MHz clock */ 145 udelay(8); 146 inb(WDT_BUZZER); /* disable */ 147 udelay(8); 148 inb(WDT_OPTONOTRST); /* disable */ 149 udelay(8); 150 inb(WDT_OPTORST); /* disable */ 151 udelay(8); 152 inb(WDT_PROGOUT); /* disable */ 153 udelay(8); 154 wdtpci_ctr_mode(0, 3); /* Program CTR0 for Mode 3: 155 Square Wave Generator */ 156 wdtpci_ctr_mode(1, 2); /* Program CTR1 for Mode 2: 157 Rate Generator */ 158 wdtpci_ctr_mode(2, 1); /* Program CTR2 for Mode 1: 159 Retriggerable One-Shot */ 160 wdtpci_ctr_load(0, 20833); /* count at 100Hz */ 161 wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */ 162 /* DO NOT LOAD CTR2 on PCI card! -- JPN */ 163 outb(0, WDT_DC); /* Enable watchdog */ 164 udelay(8); 165 166 spin_unlock_irqrestore(&wdtpci_lock, flags); 167 return 0; 168 } 169 170 /** 171 * wdtpci_stop: 172 * 173 * Stop the watchdog driver. 174 */ 175 176 static int wdtpci_stop(void) 177 { 178 unsigned long flags; 179 180 /* Turn the card off */ 181 spin_lock_irqsave(&wdtpci_lock, flags); 182 inb(WDT_DC); /* Disable watchdog */ 183 udelay(8); 184 wdtpci_ctr_load(2, 0); /* 0 length reset pulses now */ 185 spin_unlock_irqrestore(&wdtpci_lock, flags); 186 return 0; 187 } 188 189 /** 190 * wdtpci_ping: 191 * 192 * Reload counter one with the watchdog heartbeat. We don't bother 193 * reloading the cascade counter. 194 */ 195 196 static int wdtpci_ping(void) 197 { 198 unsigned long flags; 199 200 spin_lock_irqsave(&wdtpci_lock, flags); 201 /* Write a watchdog value */ 202 inb(WDT_DC); /* Disable watchdog */ 203 udelay(8); 204 wdtpci_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2: 205 Rate Generator */ 206 wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */ 207 outb(0, WDT_DC); /* Enable watchdog */ 208 udelay(8); 209 spin_unlock_irqrestore(&wdtpci_lock, flags); 210 return 0; 211 } 212 213 /** 214 * wdtpci_set_heartbeat: 215 * @t: the new heartbeat value that needs to be set. 216 * 217 * Set a new heartbeat value for the watchdog device. If the heartbeat 218 * value is incorrect we keep the old value and return -EINVAL. 219 * If successful we return 0. 220 */ 221 static int wdtpci_set_heartbeat(int t) 222 { 223 /* Arbitrary, can't find the card's limits */ 224 if (t < 1 || t > 65535) 225 return -EINVAL; 226 227 heartbeat = t; 228 wd_heartbeat = t * 100; 229 return 0; 230 } 231 232 /** 233 * wdtpci_get_status: 234 * @status: the new status. 235 * 236 * Extract the status information from a WDT watchdog device. There are 237 * several board variants so we have to know which bits are valid. Some 238 * bits default to one and some to zero in order to be maximally painful. 239 * 240 * we then map the bits onto the status ioctl flags. 241 */ 242 243 static int wdtpci_get_status(int *status) 244 { 245 unsigned char new_status; 246 unsigned long flags; 247 248 spin_lock_irqsave(&wdtpci_lock, flags); 249 new_status = inb(WDT_SR); 250 spin_unlock_irqrestore(&wdtpci_lock, flags); 251 252 *status = 0; 253 if (new_status & WDC_SR_ISOI0) 254 *status |= WDIOF_EXTERN1; 255 if (new_status & WDC_SR_ISII1) 256 *status |= WDIOF_EXTERN2; 257 if (type == 501) { 258 if (!(new_status & WDC_SR_TGOOD)) 259 *status |= WDIOF_OVERHEAT; 260 if (!(new_status & WDC_SR_PSUOVER)) 261 *status |= WDIOF_POWEROVER; 262 if (!(new_status & WDC_SR_PSUUNDR)) 263 *status |= WDIOF_POWERUNDER; 264 if (tachometer) { 265 if (!(new_status & WDC_SR_FANGOOD)) 266 *status |= WDIOF_FANFAULT; 267 } 268 } 269 return 0; 270 } 271 272 /** 273 * wdtpci_get_temperature: 274 * 275 * Reports the temperature in degrees Fahrenheit. The API is in 276 * farenheit. It was designed by an imperial measurement luddite. 277 */ 278 279 static int wdtpci_get_temperature(int *temperature) 280 { 281 unsigned short c; 282 unsigned long flags; 283 spin_lock_irqsave(&wdtpci_lock, flags); 284 c = inb(WDT_RT); 285 udelay(8); 286 spin_unlock_irqrestore(&wdtpci_lock, flags); 287 *temperature = (c * 11 / 15) + 7; 288 return 0; 289 } 290 291 /** 292 * wdtpci_interrupt: 293 * @irq: Interrupt number 294 * @dev_id: Unused as we don't allow multiple devices. 295 * 296 * Handle an interrupt from the board. These are raised when the status 297 * map changes in what the board considers an interesting way. That means 298 * a failure condition occurring. 299 */ 300 301 static irqreturn_t wdtpci_interrupt(int irq, void *dev_id) 302 { 303 /* 304 * Read the status register see what is up and 305 * then printk it. 306 */ 307 unsigned char status; 308 309 spin_lock(&wdtpci_lock); 310 311 status = inb(WDT_SR); 312 udelay(8); 313 314 pr_crit("status %d\n", status); 315 316 if (type == 501) { 317 if (!(status & WDC_SR_TGOOD)) { 318 pr_crit("Overheat alarm (%d)\n", inb(WDT_RT)); 319 udelay(8); 320 } 321 if (!(status & WDC_SR_PSUOVER)) 322 pr_crit("PSU over voltage\n"); 323 if (!(status & WDC_SR_PSUUNDR)) 324 pr_crit("PSU under voltage\n"); 325 if (tachometer) { 326 if (!(status & WDC_SR_FANGOOD)) 327 pr_crit("Possible fan fault\n"); 328 } 329 } 330 if (!(status & WDC_SR_WCCR)) { 331 #ifdef SOFTWARE_REBOOT 332 #ifdef ONLY_TESTING 333 pr_crit("Would Reboot\n"); 334 #else 335 pr_crit("Initiating system reboot\n"); 336 emergency_restart(NULL); 337 #endif 338 #else 339 pr_crit("Reset in 5ms\n"); 340 #endif 341 } 342 spin_unlock(&wdtpci_lock); 343 return IRQ_HANDLED; 344 } 345 346 347 /** 348 * wdtpci_write: 349 * @file: file handle to the watchdog 350 * @buf: buffer to write (unused as data does not matter here 351 * @count: count of bytes 352 * @ppos: pointer to the position to write. No seeks allowed 353 * 354 * A write to a watchdog device is defined as a keepalive signal. Any 355 * write of data will do, as we we don't define content meaning. 356 */ 357 358 static ssize_t wdtpci_write(struct file *file, const char __user *buf, 359 size_t count, loff_t *ppos) 360 { 361 if (count) { 362 if (!nowayout) { 363 size_t i; 364 365 /* In case it was set long ago */ 366 expect_close = 0; 367 368 for (i = 0; i != count; i++) { 369 char c; 370 if (get_user(c, buf + i)) 371 return -EFAULT; 372 if (c == 'V') 373 expect_close = 42; 374 } 375 } 376 wdtpci_ping(); 377 } 378 return count; 379 } 380 381 /** 382 * wdtpci_ioctl: 383 * @file: file handle to the device 384 * @cmd: watchdog command 385 * @arg: argument pointer 386 * 387 * The watchdog API defines a common set of functions for all watchdogs 388 * according to their available features. We only actually usefully support 389 * querying capabilities and current status. 390 */ 391 392 static long wdtpci_ioctl(struct file *file, unsigned int cmd, 393 unsigned long arg) 394 { 395 void __user *argp = (void __user *)arg; 396 int __user *p = argp; 397 int new_heartbeat; 398 int status; 399 400 struct watchdog_info ident = { 401 .options = WDIOF_SETTIMEOUT| 402 WDIOF_MAGICCLOSE| 403 WDIOF_KEEPALIVEPING, 404 .firmware_version = 1, 405 .identity = "PCI-WDT500/501", 406 }; 407 408 /* Add options according to the card we have */ 409 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2); 410 if (type == 501) { 411 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER| 412 WDIOF_POWEROVER); 413 if (tachometer) 414 ident.options |= WDIOF_FANFAULT; 415 } 416 417 switch (cmd) { 418 case WDIOC_GETSUPPORT: 419 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; 420 case WDIOC_GETSTATUS: 421 wdtpci_get_status(&status); 422 return put_user(status, p); 423 case WDIOC_GETBOOTSTATUS: 424 return put_user(0, p); 425 case WDIOC_KEEPALIVE: 426 wdtpci_ping(); 427 return 0; 428 case WDIOC_SETTIMEOUT: 429 if (get_user(new_heartbeat, p)) 430 return -EFAULT; 431 if (wdtpci_set_heartbeat(new_heartbeat)) 432 return -EINVAL; 433 wdtpci_ping(); 434 /* Fall */ 435 case WDIOC_GETTIMEOUT: 436 return put_user(heartbeat, p); 437 default: 438 return -ENOTTY; 439 } 440 } 441 442 /** 443 * wdtpci_open: 444 * @inode: inode of device 445 * @file: file handle to device 446 * 447 * The watchdog device has been opened. The watchdog device is single 448 * open and on opening we load the counters. Counter zero is a 100Hz 449 * cascade, into counter 1 which downcounts to reboot. When the counter 450 * triggers counter 2 downcounts the length of the reset pulse which 451 * set set to be as long as possible. 452 */ 453 454 static int wdtpci_open(struct inode *inode, struct file *file) 455 { 456 if (test_and_set_bit(0, &open_lock)) 457 return -EBUSY; 458 459 if (nowayout) 460 __module_get(THIS_MODULE); 461 /* 462 * Activate 463 */ 464 wdtpci_start(); 465 return nonseekable_open(inode, file); 466 } 467 468 /** 469 * wdtpci_release: 470 * @inode: inode to board 471 * @file: file handle to board 472 * 473 * The watchdog has a configurable API. There is a religious dispute 474 * between people who want their watchdog to be able to shut down and 475 * those who want to be sure if the watchdog manager dies the machine 476 * reboots. In the former case we disable the counters, in the latter 477 * case you have to open it again very soon. 478 */ 479 480 static int wdtpci_release(struct inode *inode, struct file *file) 481 { 482 if (expect_close == 42) { 483 wdtpci_stop(); 484 } else { 485 pr_crit("Unexpected close, not stopping timer!\n"); 486 wdtpci_ping(); 487 } 488 expect_close = 0; 489 clear_bit(0, &open_lock); 490 return 0; 491 } 492 493 /** 494 * wdtpci_temp_read: 495 * @file: file handle to the watchdog board 496 * @buf: buffer to write 1 byte into 497 * @count: length of buffer 498 * @ptr: offset (no seek allowed) 499 * 500 * Read reports the temperature in degrees Fahrenheit. The API is in 501 * fahrenheit. It was designed by an imperial measurement luddite. 502 */ 503 504 static ssize_t wdtpci_temp_read(struct file *file, char __user *buf, 505 size_t count, loff_t *ptr) 506 { 507 int temperature; 508 509 if (wdtpci_get_temperature(&temperature)) 510 return -EFAULT; 511 512 if (copy_to_user(buf, &temperature, 1)) 513 return -EFAULT; 514 515 return 1; 516 } 517 518 /** 519 * wdtpci_temp_open: 520 * @inode: inode of device 521 * @file: file handle to device 522 * 523 * The temperature device has been opened. 524 */ 525 526 static int wdtpci_temp_open(struct inode *inode, struct file *file) 527 { 528 return nonseekable_open(inode, file); 529 } 530 531 /** 532 * wdtpci_temp_release: 533 * @inode: inode to board 534 * @file: file handle to board 535 * 536 * The temperature device has been closed. 537 */ 538 539 static int wdtpci_temp_release(struct inode *inode, struct file *file) 540 { 541 return 0; 542 } 543 544 /** 545 * notify_sys: 546 * @this: our notifier block 547 * @code: the event being reported 548 * @unused: unused 549 * 550 * Our notifier is called on system shutdowns. We want to turn the card 551 * off at reboot otherwise the machine will reboot again during memory 552 * test or worse yet during the following fsck. This would suck, in fact 553 * trust me - if it happens it does suck. 554 */ 555 556 static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code, 557 void *unused) 558 { 559 if (code == SYS_DOWN || code == SYS_HALT) 560 wdtpci_stop(); 561 return NOTIFY_DONE; 562 } 563 564 /* 565 * Kernel Interfaces 566 */ 567 568 569 static const struct file_operations wdtpci_fops = { 570 .owner = THIS_MODULE, 571 .llseek = no_llseek, 572 .write = wdtpci_write, 573 .unlocked_ioctl = wdtpci_ioctl, 574 .open = wdtpci_open, 575 .release = wdtpci_release, 576 }; 577 578 static struct miscdevice wdtpci_miscdev = { 579 .minor = WATCHDOG_MINOR, 580 .name = "watchdog", 581 .fops = &wdtpci_fops, 582 }; 583 584 static const struct file_operations wdtpci_temp_fops = { 585 .owner = THIS_MODULE, 586 .llseek = no_llseek, 587 .read = wdtpci_temp_read, 588 .open = wdtpci_temp_open, 589 .release = wdtpci_temp_release, 590 }; 591 592 static struct miscdevice temp_miscdev = { 593 .minor = TEMP_MINOR, 594 .name = "temperature", 595 .fops = &wdtpci_temp_fops, 596 }; 597 598 /* 599 * The WDT card needs to learn about soft shutdowns in order to 600 * turn the timebomb registers off. 601 */ 602 603 static struct notifier_block wdtpci_notifier = { 604 .notifier_call = wdtpci_notify_sys, 605 }; 606 607 608 static int wdtpci_init_one(struct pci_dev *dev, 609 const struct pci_device_id *ent) 610 { 611 int ret = -EIO; 612 613 dev_count++; 614 if (dev_count > 1) { 615 pr_err("This driver only supports one device\n"); 616 return -ENODEV; 617 } 618 619 if (type != 500 && type != 501) { 620 pr_err("unknown card type '%d'\n", type); 621 return -ENODEV; 622 } 623 624 if (pci_enable_device(dev)) { 625 pr_err("Not possible to enable PCI Device\n"); 626 return -ENODEV; 627 } 628 629 if (pci_resource_start(dev, 2) == 0x0000) { 630 pr_err("No I/O-Address for card detected\n"); 631 ret = -ENODEV; 632 goto out_pci; 633 } 634 635 if (pci_request_region(dev, 2, "wdt_pci")) { 636 pr_err("I/O address 0x%llx already in use\n", 637 (unsigned long long)pci_resource_start(dev, 2)); 638 goto out_pci; 639 } 640 641 irq = dev->irq; 642 io = pci_resource_start(dev, 2); 643 644 if (request_irq(irq, wdtpci_interrupt, IRQF_SHARED, 645 "wdt_pci", &wdtpci_miscdev)) { 646 pr_err("IRQ %d is not free\n", irq); 647 goto out_reg; 648 } 649 650 pr_info("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%llx (Interrupt %d)\n", 651 (unsigned long long)io, irq); 652 653 /* Check that the heartbeat value is within its range; 654 if not reset to the default */ 655 if (wdtpci_set_heartbeat(heartbeat)) { 656 wdtpci_set_heartbeat(WD_TIMO); 657 pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n", 658 WD_TIMO); 659 } 660 661 ret = register_reboot_notifier(&wdtpci_notifier); 662 if (ret) { 663 pr_err("cannot register reboot notifier (err=%d)\n", ret); 664 goto out_irq; 665 } 666 667 if (type == 501) { 668 ret = misc_register(&temp_miscdev); 669 if (ret) { 670 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 671 TEMP_MINOR, ret); 672 goto out_rbt; 673 } 674 } 675 676 ret = misc_register(&wdtpci_miscdev); 677 if (ret) { 678 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 679 WATCHDOG_MINOR, ret); 680 goto out_misc; 681 } 682 683 pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n", 684 heartbeat, nowayout); 685 if (type == 501) 686 pr_info("Fan Tachometer is %s\n", 687 tachometer ? "Enabled" : "Disabled"); 688 689 ret = 0; 690 out: 691 return ret; 692 693 out_misc: 694 if (type == 501) 695 misc_deregister(&temp_miscdev); 696 out_rbt: 697 unregister_reboot_notifier(&wdtpci_notifier); 698 out_irq: 699 free_irq(irq, &wdtpci_miscdev); 700 out_reg: 701 pci_release_region(dev, 2); 702 out_pci: 703 pci_disable_device(dev); 704 goto out; 705 } 706 707 708 static void wdtpci_remove_one(struct pci_dev *pdev) 709 { 710 /* here we assume only one device will ever have 711 * been picked up and registered by probe function */ 712 misc_deregister(&wdtpci_miscdev); 713 if (type == 501) 714 misc_deregister(&temp_miscdev); 715 unregister_reboot_notifier(&wdtpci_notifier); 716 free_irq(irq, &wdtpci_miscdev); 717 pci_release_region(pdev, 2); 718 pci_disable_device(pdev); 719 dev_count--; 720 } 721 722 723 static DEFINE_PCI_DEVICE_TABLE(wdtpci_pci_tbl) = { 724 { 725 .vendor = PCI_VENDOR_ID_ACCESSIO, 726 .device = PCI_DEVICE_ID_ACCESSIO_WDG_CSM, 727 .subvendor = PCI_ANY_ID, 728 .subdevice = PCI_ANY_ID, 729 }, 730 { 0, }, /* terminate list */ 731 }; 732 MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl); 733 734 735 static struct pci_driver wdtpci_driver = { 736 .name = "wdt_pci", 737 .id_table = wdtpci_pci_tbl, 738 .probe = wdtpci_init_one, 739 .remove = wdtpci_remove_one, 740 }; 741 742 module_pci_driver(wdtpci_driver); 743 744 MODULE_AUTHOR("JP Nollmann, Alan Cox"); 745 MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards"); 746 MODULE_LICENSE("GPL"); 747