1 /* 2 * Watchdog Timer Driver 3 * for ITE IT87xx Environment Control - Low Pin Count Input / Output 4 * 5 * (c) Copyright 2007 Oliver Schuster <olivers137@aol.com> 6 * 7 * Based on softdog.c by Alan Cox, 8 * 83977f_wdt.c by Jose Goncalves, 9 * it87.c by Chris Gauthron, Jean Delvare 10 * 11 * Data-sheets: Publicly available at the ITE website 12 * http://www.ite.com.tw/ 13 * 14 * Support of the watchdog timers, which are available on 15 * IT8716, IT8718, IT8726 and IT8712 (J,K version). 16 * 17 * This program is free software; you can redistribute it and/or 18 * modify it under the terms of the GNU General Public License 19 * as published by the Free Software Foundation; either version 20 * 2 of the License, or (at your option) any later version. 21 * 22 * This program is distributed in the hope that it will be useful, 23 * but WITHOUT ANY WARRANTY; without even the implied warranty of 24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 25 * GNU General Public License for more details. 26 * 27 * You should have received a copy of the GNU General Public License 28 * along with this program; if not, write to the Free Software 29 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 30 */ 31 32 #include <linux/module.h> 33 #include <linux/moduleparam.h> 34 #include <linux/types.h> 35 #include <linux/kernel.h> 36 #include <linux/fs.h> 37 #include <linux/miscdevice.h> 38 #include <linux/init.h> 39 #include <linux/ioport.h> 40 #include <linux/watchdog.h> 41 #include <linux/notifier.h> 42 #include <linux/reboot.h> 43 #include <linux/uaccess.h> 44 #include <linux/io.h> 45 46 #include <asm/system.h> 47 48 #define WATCHDOG_VERSION "1.12" 49 #define WATCHDOG_NAME "IT87 WDT" 50 #define PFX WATCHDOG_NAME ": " 51 #define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n" 52 #define WD_MAGIC 'V' 53 54 /* Defaults for Module Parameter */ 55 #define DEFAULT_NOGAMEPORT 0 56 #define DEFAULT_EXCLUSIVE 1 57 #define DEFAULT_TIMEOUT 60 58 #define DEFAULT_TESTMODE 0 59 #define DEFAULT_NOWAYOUT WATCHDOG_NOWAYOUT 60 61 /* IO Ports */ 62 #define REG 0x2e 63 #define VAL 0x2f 64 65 /* Logical device Numbers LDN */ 66 #define GPIO 0x07 67 #define GAMEPORT 0x09 68 #define CIR 0x0a 69 70 /* Configuration Registers and Functions */ 71 #define LDNREG 0x07 72 #define CHIPID 0x20 73 #define CHIPREV 0x22 74 #define ACTREG 0x30 75 #define BASEREG 0x60 76 77 /* Chip Id numbers */ 78 #define NO_DEV_ID 0xffff 79 #define IT8705_ID 0x8705 80 #define IT8712_ID 0x8712 81 #define IT8716_ID 0x8716 82 #define IT8718_ID 0x8718 83 #define IT8726_ID 0x8726 /* the data sheet suggest wrongly 0x8716 */ 84 85 /* GPIO Configuration Registers LDN=0x07 */ 86 #define WDTCTRL 0x71 87 #define WDTCFG 0x72 88 #define WDTVALLSB 0x73 89 #define WDTVALMSB 0x74 90 91 /* GPIO Bits WDTCTRL */ 92 #define WDT_CIRINT 0x80 93 #define WDT_MOUSEINT 0x40 94 #define WDT_KYBINT 0x20 95 #define WDT_GAMEPORT 0x10 /* not it8718 */ 96 #define WDT_FORCE 0x02 97 #define WDT_ZERO 0x01 98 99 /* GPIO Bits WDTCFG */ 100 #define WDT_TOV1 0x80 101 #define WDT_KRST 0x40 102 #define WDT_TOVE 0x20 103 #define WDT_PWROK 0x10 104 #define WDT_INT_MASK 0x0f 105 106 /* CIR Configuration Register LDN=0x0a */ 107 #define CIR_ILS 0x70 108 109 /* The default Base address is not always available, we use this */ 110 #define CIR_BASE 0x0208 111 112 /* CIR Controller */ 113 #define CIR_DR(b) (b) 114 #define CIR_IER(b) (b + 1) 115 #define CIR_RCR(b) (b + 2) 116 #define CIR_TCR1(b) (b + 3) 117 #define CIR_TCR2(b) (b + 4) 118 #define CIR_TSR(b) (b + 5) 119 #define CIR_RSR(b) (b + 6) 120 #define CIR_BDLR(b) (b + 5) 121 #define CIR_BDHR(b) (b + 6) 122 #define CIR_IIR(b) (b + 7) 123 124 /* Default Base address of Game port */ 125 #define GP_BASE_DEFAULT 0x0201 126 127 /* wdt_status */ 128 #define WDTS_TIMER_RUN 0 129 #define WDTS_DEV_OPEN 1 130 #define WDTS_KEEPALIVE 2 131 #define WDTS_LOCKED 3 132 #define WDTS_USE_GP 4 133 #define WDTS_EXPECTED 5 134 135 static unsigned int base, gpact, ciract; 136 static unsigned long wdt_status; 137 static DEFINE_SPINLOCK(spinlock); 138 139 static int nogameport = DEFAULT_NOGAMEPORT; 140 static int exclusive = DEFAULT_EXCLUSIVE; 141 static int timeout = DEFAULT_TIMEOUT; 142 static int testmode = DEFAULT_TESTMODE; 143 static int nowayout = DEFAULT_NOWAYOUT; 144 145 module_param(nogameport, int, 0); 146 MODULE_PARM_DESC(nogameport, "Forbid the activation of game port, default=" 147 __MODULE_STRING(DEFAULT_NOGAMEPORT)); 148 module_param(exclusive, int, 0); 149 MODULE_PARM_DESC(exclusive, "Watchdog exclusive device open, default=" 150 __MODULE_STRING(DEFAULT_EXCLUSIVE)); 151 module_param(timeout, int, 0); 152 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default=" 153 __MODULE_STRING(DEFAULT_TIMEOUT)); 154 module_param(testmode, int, 0); 155 MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default=" 156 __MODULE_STRING(DEFAULT_TESTMODE)); 157 module_param(nowayout, int, 0); 158 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default=" 159 __MODULE_STRING(WATCHDOG_NOWAYOUT)); 160 161 /* Superio Chip */ 162 163 static inline void superio_enter(void) 164 { 165 outb(0x87, REG); 166 outb(0x01, REG); 167 outb(0x55, REG); 168 outb(0x55, REG); 169 } 170 171 static inline void superio_exit(void) 172 { 173 outb(0x02, REG); 174 outb(0x02, VAL); 175 } 176 177 static inline void superio_select(int ldn) 178 { 179 outb(LDNREG, REG); 180 outb(ldn, VAL); 181 } 182 183 static inline int superio_inb(int reg) 184 { 185 outb(reg, REG); 186 return inb(VAL); 187 } 188 189 static inline void superio_outb(int val, int reg) 190 { 191 outb(reg, REG); 192 outb(val, VAL); 193 } 194 195 static inline int superio_inw(int reg) 196 { 197 int val; 198 outb(reg++, REG); 199 val = inb(VAL) << 8; 200 outb(reg, REG); 201 val |= inb(VAL); 202 return val; 203 } 204 205 static inline void superio_outw(int val, int reg) 206 { 207 outb(reg++, REG); 208 outb(val >> 8, VAL); 209 outb(reg, REG); 210 outb(val, VAL); 211 } 212 213 /* watchdog timer handling */ 214 215 static void wdt_keepalive(void) 216 { 217 if (test_bit(WDTS_USE_GP, &wdt_status)) 218 inb(base); 219 else 220 /* The timer reloads with around 5 msec delay */ 221 outb(0x55, CIR_DR(base)); 222 set_bit(WDTS_KEEPALIVE, &wdt_status); 223 } 224 225 static void wdt_start(void) 226 { 227 unsigned long flags; 228 229 spin_lock_irqsave(&spinlock, flags); 230 superio_enter(); 231 232 superio_select(GPIO); 233 if (test_bit(WDTS_USE_GP, &wdt_status)) 234 superio_outb(WDT_GAMEPORT, WDTCTRL); 235 else 236 superio_outb(WDT_CIRINT, WDTCTRL); 237 if (!testmode) 238 superio_outb(WDT_TOV1 | WDT_KRST | WDT_PWROK, WDTCFG); 239 else 240 superio_outb(WDT_TOV1, WDTCFG); 241 superio_outb(timeout>>8, WDTVALMSB); 242 superio_outb(timeout, WDTVALLSB); 243 244 superio_exit(); 245 spin_unlock_irqrestore(&spinlock, flags); 246 } 247 248 static void wdt_stop(void) 249 { 250 unsigned long flags; 251 252 spin_lock_irqsave(&spinlock, flags); 253 superio_enter(); 254 255 superio_select(GPIO); 256 superio_outb(0x00, WDTCTRL); 257 superio_outb(WDT_TOV1, WDTCFG); 258 superio_outb(0x00, WDTVALMSB); 259 superio_outb(0x00, WDTVALLSB); 260 261 superio_exit(); 262 spin_unlock_irqrestore(&spinlock, flags); 263 } 264 265 /** 266 * wdt_set_timeout - set a new timeout value with watchdog ioctl 267 * @t: timeout value in seconds 268 * 269 * The hardware device has a 16 bit watchdog timer, thus the 270 * timeout time ranges between 1 and 65535 seconds. 271 * 272 * Used within WDIOC_SETTIMEOUT watchdog device ioctl. 273 */ 274 275 static int wdt_set_timeout(int t) 276 { 277 unsigned long flags; 278 279 if (t < 1 || t > 65535) 280 return -EINVAL; 281 282 timeout = t; 283 284 spin_lock_irqsave(&spinlock, flags); 285 if (test_bit(WDTS_TIMER_RUN, &wdt_status)) { 286 superio_enter(); 287 288 superio_select(GPIO); 289 superio_outb(t>>8, WDTVALMSB); 290 superio_outb(t, WDTVALLSB); 291 292 superio_exit(); 293 } 294 spin_unlock_irqrestore(&spinlock, flags); 295 return 0; 296 } 297 298 /** 299 * wdt_get_status - determines the status supported by watchdog ioctl 300 * @status: status returned to user space 301 * 302 * The status bit of the device does not allow to distinguish 303 * between a regular system reset and a watchdog forced reset. 304 * But, in test mode it is useful, so it is supported through 305 * WDIOC_GETSTATUS watchdog ioctl. Additionally the driver 306 * reports the keepalive signal and the acception of the magic. 307 * 308 * Used within WDIOC_GETSTATUS watchdog device ioctl. 309 */ 310 311 static int wdt_get_status(int *status) 312 { 313 unsigned long flags; 314 315 *status = 0; 316 if (testmode) { 317 spin_lock_irqsave(&spinlock, flags); 318 superio_enter(); 319 superio_select(GPIO); 320 if (superio_inb(WDTCTRL) & WDT_ZERO) { 321 superio_outb(0x00, WDTCTRL); 322 clear_bit(WDTS_TIMER_RUN, &wdt_status); 323 *status |= WDIOF_CARDRESET; 324 } 325 326 superio_exit(); 327 spin_unlock_irqrestore(&spinlock, flags); 328 } 329 if (test_and_clear_bit(WDTS_KEEPALIVE, &wdt_status)) 330 *status |= WDIOF_KEEPALIVEPING; 331 if (test_bit(WDTS_EXPECTED, &wdt_status)) 332 *status |= WDIOF_MAGICCLOSE; 333 return 0; 334 } 335 336 /* /dev/watchdog handling */ 337 338 /** 339 * wdt_open - watchdog file_operations .open 340 * @inode: inode of the device 341 * @file: file handle to the device 342 * 343 * The watchdog timer starts by opening the device. 344 * 345 * Used within the file operation of the watchdog device. 346 */ 347 348 static int wdt_open(struct inode *inode, struct file *file) 349 { 350 if (exclusive && test_and_set_bit(WDTS_DEV_OPEN, &wdt_status)) 351 return -EBUSY; 352 if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) { 353 if (nowayout && !test_and_set_bit(WDTS_LOCKED, &wdt_status)) 354 __module_get(THIS_MODULE); 355 wdt_start(); 356 } 357 return nonseekable_open(inode, file); 358 } 359 360 /** 361 * wdt_release - watchdog file_operations .release 362 * @inode: inode of the device 363 * @file: file handle to the device 364 * 365 * Closing the watchdog device either stops the watchdog timer 366 * or in the case, that nowayout is set or the magic character 367 * wasn't written, a critical warning about an running watchdog 368 * timer is given. 369 * 370 * Used within the file operation of the watchdog device. 371 */ 372 373 static int wdt_release(struct inode *inode, struct file *file) 374 { 375 if (test_bit(WDTS_TIMER_RUN, &wdt_status)) { 376 if (test_and_clear_bit(WDTS_EXPECTED, &wdt_status)) { 377 wdt_stop(); 378 clear_bit(WDTS_TIMER_RUN, &wdt_status); 379 } else { 380 wdt_keepalive(); 381 printk(KERN_CRIT PFX 382 "unexpected close, not stopping watchdog!\n"); 383 } 384 } 385 clear_bit(WDTS_DEV_OPEN, &wdt_status); 386 return 0; 387 } 388 389 /** 390 * wdt_write - watchdog file_operations .write 391 * @file: file handle to the watchdog 392 * @buf: buffer to write 393 * @count: count of bytes 394 * @ppos: pointer to the position to write. No seeks allowed 395 * 396 * A write to a watchdog device is defined as a keepalive signal. Any 397 * write of data will do, as we don't define content meaning. 398 * 399 * Used within the file operation of the watchdog device. 400 */ 401 402 static ssize_t wdt_write(struct file *file, const char __user *buf, 403 size_t count, loff_t *ppos) 404 { 405 if (count) { 406 clear_bit(WDTS_EXPECTED, &wdt_status); 407 wdt_keepalive(); 408 } 409 if (!nowayout) { 410 size_t ofs; 411 412 /* note: just in case someone wrote the magic character long ago */ 413 for (ofs = 0; ofs != count; ofs++) { 414 char c; 415 if (get_user(c, buf + ofs)) 416 return -EFAULT; 417 if (c == WD_MAGIC) 418 set_bit(WDTS_EXPECTED, &wdt_status); 419 } 420 } 421 return count; 422 } 423 424 static const struct watchdog_info ident = { 425 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, 426 .firmware_version = 1, 427 .identity = WATCHDOG_NAME, 428 }; 429 430 /** 431 * wdt_ioctl - watchdog file_operations .unlocked_ioctl 432 * @file: file handle to the device 433 * @cmd: watchdog command 434 * @arg: argument pointer 435 * 436 * The watchdog API defines a common set of functions for all watchdogs 437 * according to their available features. 438 * 439 * Used within the file operation of the watchdog device. 440 */ 441 442 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 443 { 444 int rc = 0, status, new_options, new_timeout; 445 union { 446 struct watchdog_info __user *ident; 447 int __user *i; 448 } uarg; 449 450 uarg.i = (int __user *)arg; 451 452 switch (cmd) { 453 case WDIOC_GETSUPPORT: 454 return copy_to_user(uarg.ident, 455 &ident, sizeof(ident)) ? -EFAULT : 0; 456 457 case WDIOC_GETSTATUS: 458 wdt_get_status(&status); 459 return put_user(status, uarg.i); 460 461 case WDIOC_GETBOOTSTATUS: 462 return put_user(0, uarg.i); 463 464 case WDIOC_KEEPALIVE: 465 wdt_keepalive(); 466 return 0; 467 468 case WDIOC_SETOPTIONS: 469 if (get_user(new_options, uarg.i)) 470 return -EFAULT; 471 472 switch (new_options) { 473 case WDIOS_DISABLECARD: 474 if (test_bit(WDTS_TIMER_RUN, &wdt_status)) 475 wdt_stop(); 476 clear_bit(WDTS_TIMER_RUN, &wdt_status); 477 return 0; 478 479 case WDIOS_ENABLECARD: 480 if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) 481 wdt_start(); 482 return 0; 483 484 default: 485 return -EFAULT; 486 } 487 488 case WDIOC_SETTIMEOUT: 489 if (get_user(new_timeout, uarg.i)) 490 return -EFAULT; 491 rc = wdt_set_timeout(new_timeout); 492 case WDIOC_GETTIMEOUT: 493 if (put_user(timeout, uarg.i)) 494 return -EFAULT; 495 return rc; 496 497 default: 498 return -ENOTTY; 499 } 500 } 501 502 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 503 void *unused) 504 { 505 if (code == SYS_DOWN || code == SYS_HALT) 506 wdt_stop(); 507 return NOTIFY_DONE; 508 } 509 510 static const struct file_operations wdt_fops = { 511 .owner = THIS_MODULE, 512 .llseek = no_llseek, 513 .write = wdt_write, 514 .unlocked_ioctl = wdt_ioctl, 515 .open = wdt_open, 516 .release = wdt_release, 517 }; 518 519 static struct miscdevice wdt_miscdev = { 520 .minor = WATCHDOG_MINOR, 521 .name = "watchdog", 522 .fops = &wdt_fops, 523 }; 524 525 static struct notifier_block wdt_notifier = { 526 .notifier_call = wdt_notify_sys, 527 }; 528 529 static int __init it87_wdt_init(void) 530 { 531 int rc = 0; 532 u16 chip_type; 533 u8 chip_rev; 534 unsigned long flags; 535 536 spin_lock_irqsave(&spinlock, flags); 537 superio_enter(); 538 chip_type = superio_inw(CHIPID); 539 chip_rev = superio_inb(CHIPREV) & 0x0f; 540 superio_exit(); 541 spin_unlock_irqrestore(&spinlock, flags); 542 543 switch (chip_type) { 544 case IT8716_ID: 545 case IT8718_ID: 546 case IT8726_ID: 547 break; 548 case IT8712_ID: 549 if (chip_rev > 7) 550 break; 551 case IT8705_ID: 552 printk(KERN_ERR PFX 553 "Unsupported Chip found, Chip %04x Revision %02x\n", 554 chip_type, chip_rev); 555 return -ENODEV; 556 case NO_DEV_ID: 557 printk(KERN_ERR PFX "no device\n"); 558 return -ENODEV; 559 default: 560 printk(KERN_ERR PFX 561 "Unknown Chip found, Chip %04x Revision %04x\n", 562 chip_type, chip_rev); 563 return -ENODEV; 564 } 565 566 spin_lock_irqsave(&spinlock, flags); 567 superio_enter(); 568 569 superio_select(GPIO); 570 superio_outb(WDT_TOV1, WDTCFG); 571 superio_outb(0x00, WDTCTRL); 572 573 /* First try to get Gameport support */ 574 if (chip_type != IT8718_ID && !nogameport) { 575 superio_select(GAMEPORT); 576 base = superio_inw(BASEREG); 577 if (!base) { 578 base = GP_BASE_DEFAULT; 579 superio_outw(base, BASEREG); 580 } 581 gpact = superio_inb(ACTREG); 582 superio_outb(0x01, ACTREG); 583 superio_exit(); 584 spin_unlock_irqrestore(&spinlock, flags); 585 if (request_region(base, 1, WATCHDOG_NAME)) 586 set_bit(WDTS_USE_GP, &wdt_status); 587 else 588 rc = -EIO; 589 } else { 590 superio_exit(); 591 spin_unlock_irqrestore(&spinlock, flags); 592 } 593 594 /* If we haven't Gameport support, try to get CIR support */ 595 if (!test_bit(WDTS_USE_GP, &wdt_status)) { 596 if (!request_region(CIR_BASE, 8, WATCHDOG_NAME)) { 597 if (rc == -EIO) 598 printk(KERN_ERR PFX 599 "I/O Address 0x%04x and 0x%04x" 600 " already in use\n", base, CIR_BASE); 601 else 602 printk(KERN_ERR PFX 603 "I/O Address 0x%04x already in use\n", 604 CIR_BASE); 605 rc = -EIO; 606 goto err_out; 607 } 608 base = CIR_BASE; 609 spin_lock_irqsave(&spinlock, flags); 610 superio_enter(); 611 612 superio_select(CIR); 613 superio_outw(base, BASEREG); 614 superio_outb(0x00, CIR_ILS); 615 ciract = superio_inb(ACTREG); 616 superio_outb(0x01, ACTREG); 617 if (rc == -EIO) { 618 superio_select(GAMEPORT); 619 superio_outb(gpact, ACTREG); 620 } 621 622 superio_exit(); 623 spin_unlock_irqrestore(&spinlock, flags); 624 } 625 626 if (timeout < 1 || timeout > 65535) { 627 timeout = DEFAULT_TIMEOUT; 628 printk(KERN_WARNING PFX 629 "Timeout value out of range, use default %d sec\n", 630 DEFAULT_TIMEOUT); 631 } 632 633 rc = register_reboot_notifier(&wdt_notifier); 634 if (rc) { 635 printk(KERN_ERR PFX 636 "Cannot register reboot notifier (err=%d)\n", rc); 637 goto err_out_region; 638 } 639 640 rc = misc_register(&wdt_miscdev); 641 if (rc) { 642 printk(KERN_ERR PFX 643 "Cannot register miscdev on minor=%d (err=%d)\n", 644 wdt_miscdev.minor, rc); 645 goto err_out_reboot; 646 } 647 648 /* Initialize CIR to use it as keepalive source */ 649 if (!test_bit(WDTS_USE_GP, &wdt_status)) { 650 outb(0x00, CIR_RCR(base)); 651 outb(0xc0, CIR_TCR1(base)); 652 outb(0x5c, CIR_TCR2(base)); 653 outb(0x10, CIR_IER(base)); 654 outb(0x00, CIR_BDHR(base)); 655 outb(0x01, CIR_BDLR(base)); 656 outb(0x09, CIR_IER(base)); 657 } 658 659 printk(KERN_INFO PFX "Chip it%04x revision %d initialized. " 660 "timeout=%d sec (nowayout=%d testmode=%d exclusive=%d " 661 "nogameport=%d)\n", chip_type, chip_rev, timeout, 662 nowayout, testmode, exclusive, nogameport); 663 664 return 0; 665 666 err_out_reboot: 667 unregister_reboot_notifier(&wdt_notifier); 668 err_out_region: 669 release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8); 670 if (!test_bit(WDTS_USE_GP, &wdt_status)) { 671 spin_lock_irqsave(&spinlock, flags); 672 superio_enter(); 673 superio_select(CIR); 674 superio_outb(ciract, ACTREG); 675 superio_exit(); 676 spin_unlock_irqrestore(&spinlock, flags); 677 } 678 err_out: 679 if (chip_type != IT8718_ID && !nogameport) { 680 spin_lock_irqsave(&spinlock, flags); 681 superio_enter(); 682 superio_select(GAMEPORT); 683 superio_outb(gpact, ACTREG); 684 superio_exit(); 685 spin_unlock_irqrestore(&spinlock, flags); 686 } 687 688 return rc; 689 } 690 691 static void __exit it87_wdt_exit(void) 692 { 693 unsigned long flags; 694 int nolock; 695 696 nolock = !spin_trylock_irqsave(&spinlock, flags); 697 superio_enter(); 698 superio_select(GPIO); 699 superio_outb(0x00, WDTCTRL); 700 superio_outb(0x00, WDTCFG); 701 superio_outb(0x00, WDTVALMSB); 702 superio_outb(0x00, WDTVALLSB); 703 if (test_bit(WDTS_USE_GP, &wdt_status)) { 704 superio_select(GAMEPORT); 705 superio_outb(gpact, ACTREG); 706 } else { 707 superio_select(CIR); 708 superio_outb(ciract, ACTREG); 709 } 710 superio_exit(); 711 if (!nolock) 712 spin_unlock_irqrestore(&spinlock, flags); 713 714 misc_deregister(&wdt_miscdev); 715 unregister_reboot_notifier(&wdt_notifier); 716 release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8); 717 } 718 719 module_init(it87_wdt_init); 720 module_exit(it87_wdt_exit); 721 722 MODULE_AUTHOR("Oliver Schuster"); 723 MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O"); 724 MODULE_LICENSE("GPL"); 725 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 726