drivers/watchdog/it87_wdt.c

   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  *      IT8702, IT8712, IT8716, IT8718, IT8720, IT8721 and IT8726.
  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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  33
  34 #include <linux/module.h>
  35 #include <linux/moduleparam.h>
  36 #include <linux/types.h>
  37 #include <linux/kernel.h>
  38 #include <linux/fs.h>
  39 #include <linux/miscdevice.h>
  40 #include <linux/init.h>
  41 #include <linux/ioport.h>
  42 #include <linux/watchdog.h>
  43 #include <linux/notifier.h>
  44 #include <linux/reboot.h>
  45 #include <linux/uaccess.h>
  46 #include <linux/io.h>
  47
  48
  49 #define WATCHDOG_VERSION        "1.14"
  50 #define WATCHDOG_NAME           "IT87 WDT"
  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 IT8702_ID       0x8702
  80 #define IT8705_ID       0x8705
  81 #define IT8712_ID       0x8712
  82 #define IT8716_ID       0x8716
  83 #define IT8718_ID       0x8718
  84 #define IT8720_ID       0x8720
  85 #define IT8721_ID       0x8721
  86 #define IT8726_ID       0x8726  /* the data sheet suggest wrongly 0x8716 */
  87
  88 /* GPIO Configuration Registers LDN=0x07 */
  89 #define WDTCTRL         0x71
  90 #define WDTCFG          0x72
  91 #define WDTVALLSB       0x73
  92 #define WDTVALMSB       0x74
  93
  94 /* GPIO Bits WDTCTRL */
  95 #define WDT_CIRINT      0x80
  96 #define WDT_MOUSEINT    0x40
  97 #define WDT_KYBINT      0x20
  98 #define WDT_GAMEPORT    0x10 /* not in it8718, it8720, it8721 */
  99 #define WDT_FORCE       0x02
 100 #define WDT_ZERO        0x01
 101
 102 /* GPIO Bits WDTCFG */
 103 #define WDT_TOV1        0x80
 104 #define WDT_KRST        0x40
 105 #define WDT_TOVE        0x20
 106 #define WDT_PWROK       0x10 /* not in it8721 */
 107 #define WDT_INT_MASK    0x0f
 108
 109 /* CIR Configuration Register LDN=0x0a */
 110 #define CIR_ILS         0x70
 111
 112 /* The default Base address is not always available, we use this */
 113 #define CIR_BASE        0x0208
 114
 115 /* CIR Controller */
 116 #define CIR_DR(b)       (b)
 117 #define CIR_IER(b)      (b + 1)
 118 #define CIR_RCR(b)      (b + 2)
 119 #define CIR_TCR1(b)     (b + 3)
 120 #define CIR_TCR2(b)     (b + 4)
 121 #define CIR_TSR(b)      (b + 5)
 122 #define CIR_RSR(b)      (b + 6)
 123 #define CIR_BDLR(b)     (b + 5)
 124 #define CIR_BDHR(b)     (b + 6)
 125 #define CIR_IIR(b)      (b + 7)
 126
 127 /* Default Base address of Game port */
 128 #define GP_BASE_DEFAULT 0x0201
 129
 130 /* wdt_status */
 131 #define WDTS_TIMER_RUN  0
 132 #define WDTS_DEV_OPEN   1
 133 #define WDTS_KEEPALIVE  2
 134 #define WDTS_LOCKED     3
 135 #define WDTS_USE_GP     4
 136 #define WDTS_EXPECTED   5
 137
 138 static  unsigned int base, gpact, ciract, max_units, chip_type;
 139 static  unsigned long wdt_status;
 140
 141 static  int nogameport = DEFAULT_NOGAMEPORT;
 142 static  int exclusive  = DEFAULT_EXCLUSIVE;
 143 static  int timeout    = DEFAULT_TIMEOUT;
 144 static  int testmode   = DEFAULT_TESTMODE;
 145 static  bool nowayout   = DEFAULT_NOWAYOUT;
 146
 147 module_param(nogameport, int, 0);
 148 MODULE_PARM_DESC(nogameport, "Forbid the activation of game port, default="
 149                 __MODULE_STRING(DEFAULT_NOGAMEPORT));
 150 module_param(exclusive, int, 0);
 151 MODULE_PARM_DESC(exclusive, "Watchdog exclusive device open, default="
 152                 __MODULE_STRING(DEFAULT_EXCLUSIVE));
 153 module_param(timeout, int, 0);
 154 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default="
 155                 __MODULE_STRING(DEFAULT_TIMEOUT));
 156 module_param(testmode, int, 0);
 157 MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default="
 158                 __MODULE_STRING(DEFAULT_TESTMODE));
 159 module_param(nowayout, bool, 0);
 160 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default="
 161                 __MODULE_STRING(WATCHDOG_NOWAYOUT));
 162
 163 /* Superio Chip */
 164
 165 static inline int superio_enter(void)
 166 {
 167         /*
 168          * Try to reserve REG and REG + 1 for exclusive access.
 169          */
 170         if (!request_muxed_region(REG, 2, WATCHDOG_NAME))
 171                 return -EBUSY;
 172
 173         outb(0x87, REG);
 174         outb(0x01, REG);
 175         outb(0x55, REG);
 176         outb(0x55, REG);
 177         return 0;
 178 }
 179
 180 static inline void superio_exit(void)
 181 {
 182         outb(0x02, REG);
 183         outb(0x02, VAL);
 184         release_region(REG, 2);
 185 }
 186
 187 static inline void superio_select(int ldn)
 188 {
 189         outb(LDNREG, REG);
 190         outb(ldn, VAL);
 191 }
 192
 193 static inline int superio_inb(int reg)
 194 {
 195         outb(reg, REG);
 196         return inb(VAL);
 197 }
 198
 199 static inline void superio_outb(int val, int reg)
 200 {
 201         outb(reg, REG);
 202         outb(val, VAL);
 203 }
 204
 205 static inline int superio_inw(int reg)
 206 {
 207         int val;
 208         outb(reg++, REG);
 209         val = inb(VAL) << 8;
 210         outb(reg, REG);
 211         val |= inb(VAL);
 212         return val;
 213 }
 214
 215 static inline void superio_outw(int val, int reg)
 216 {
 217         outb(reg++, REG);
 218         outb(val >> 8, VAL);
 219         outb(reg, REG);
 220         outb(val, VAL);
 221 }
 222
 223 /* Internal function, should be called after superio_select(GPIO) */
 224 static void wdt_update_timeout(void)
 225 {
 226         unsigned char cfg = WDT_KRST;
 227         int tm = timeout;
 228
 229         if (testmode)
 230                 cfg = 0;
 231
 232         if (tm <= max_units)
 233                 cfg |= WDT_TOV1;
 234         else
 235                 tm /= 60;
 236
 237         if (chip_type != IT8721_ID)
 238                 cfg |= WDT_PWROK;
 239
 240         superio_outb(cfg, WDTCFG);
 241         superio_outb(tm, WDTVALLSB);
 242         if (max_units > 255)
 243                 superio_outb(tm>>8, WDTVALMSB);
 244 }
 245
 246 static int wdt_round_time(int t)
 247 {
 248         t += 59;
 249         t -= t % 60;
 250         return t;
 251 }
 252
 253 /* watchdog timer handling */
 254
 255 static void wdt_keepalive(void)
 256 {
 257         if (test_bit(WDTS_USE_GP, &wdt_status))
 258                 inb(base);
 259         else
 260                 /* The timer reloads with around 5 msec delay */
 261                 outb(0x55, CIR_DR(base));
 262         set_bit(WDTS_KEEPALIVE, &wdt_status);
 263 }
 264
 265 static int wdt_start(void)
 266 {
 267         int ret = superio_enter();
 268         if (ret)
 269                 return ret;
 270
 271         superio_select(GPIO);
 272         if (test_bit(WDTS_USE_GP, &wdt_status))
 273                 superio_outb(WDT_GAMEPORT, WDTCTRL);
 274         else
 275                 superio_outb(WDT_CIRINT, WDTCTRL);
 276         wdt_update_timeout();
 277
 278         superio_exit();
 279
 280         return 0;
 281 }
 282
 283 static int wdt_stop(void)
 284 {
 285         int ret = superio_enter();
 286         if (ret)
 287                 return ret;
 288
 289         superio_select(GPIO);
 290         superio_outb(0x00, WDTCTRL);
 291         superio_outb(WDT_TOV1, WDTCFG);
 292         superio_outb(0x00, WDTVALLSB);
 293         if (max_units > 255)
 294                 superio_outb(0x00, WDTVALMSB);
 295
 296         superio_exit();
 297         return 0;
 298 }
 299
 300 /**
 301  *      wdt_set_timeout - set a new timeout value with watchdog ioctl
 302  *      @t: timeout value in seconds
 303  *
 304  *      The hardware device has a 8 or 16 bit watchdog timer (depends on
 305  *      chip version) that can be configured to count seconds or minutes.
 306  *
 307  *      Used within WDIOC_SETTIMEOUT watchdog device ioctl.
 308  */
 309
 310 static int wdt_set_timeout(int t)
 311 {
 312         if (t < 1 || t > max_units * 60)
 313                 return -EINVAL;
 314
 315         if (t > max_units)
 316                 timeout = wdt_round_time(t);
 317         else
 318                 timeout = t;
 319
 320         if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
 321                 int ret = superio_enter();
 322                 if (ret)
 323                         return ret;
 324
 325                 superio_select(GPIO);
 326                 wdt_update_timeout();
 327                 superio_exit();
 328         }
 329         return 0;
 330 }
 331
 332 /**
 333  *      wdt_get_status - determines the status supported by watchdog ioctl
 334  *      @status: status returned to user space
 335  *
 336  *      The status bit of the device does not allow to distinguish
 337  *      between a regular system reset and a watchdog forced reset.
 338  *      But, in test mode it is useful, so it is supported through
 339  *      WDIOC_GETSTATUS watchdog ioctl. Additionally the driver
 340  *      reports the keepalive signal and the acception of the magic.
 341  *
 342  *      Used within WDIOC_GETSTATUS watchdog device ioctl.
 343  */
 344
 345 static int wdt_get_status(int *status)
 346 {
 347         *status = 0;
 348         if (testmode) {
 349                 int ret = superio_enter();
 350                 if (ret)
 351                         return ret;
 352
 353                 superio_select(GPIO);
 354                 if (superio_inb(WDTCTRL) & WDT_ZERO) {
 355                         superio_outb(0x00, WDTCTRL);
 356                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 357                         *status |= WDIOF_CARDRESET;
 358                 }
 359
 360                 superio_exit();
 361         }
 362         if (test_and_clear_bit(WDTS_KEEPALIVE, &wdt_status))
 363                 *status |= WDIOF_KEEPALIVEPING;
 364         if (test_bit(WDTS_EXPECTED, &wdt_status))
 365                 *status |= WDIOF_MAGICCLOSE;
 366         return 0;
 367 }
 368
 369 /* /dev/watchdog handling */
 370
 371 /**
 372  *      wdt_open - watchdog file_operations .open
 373  *      @inode: inode of the device
 374  *      @file: file handle to the device
 375  *
 376  *      The watchdog timer starts by opening the device.
 377  *
 378  *      Used within the file operation of the watchdog device.
 379  */
 380
 381 static int wdt_open(struct inode *inode, struct file *file)
 382 {
 383         if (exclusive && test_and_set_bit(WDTS_DEV_OPEN, &wdt_status))
 384                 return -EBUSY;
 385         if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
 386                 int ret;
 387                 if (nowayout && !test_and_set_bit(WDTS_LOCKED, &wdt_status))
 388                         __module_get(THIS_MODULE);
 389
 390                 ret = wdt_start();
 391                 if (ret) {
 392                         clear_bit(WDTS_LOCKED, &wdt_status);
 393                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 394                         clear_bit(WDTS_DEV_OPEN, &wdt_status);
 395                         return ret;
 396                 }
 397         }
 398         return nonseekable_open(inode, file);
 399 }
 400
 401 /**
 402  *      wdt_release - watchdog file_operations .release
 403  *      @inode: inode of the device
 404  *      @file: file handle to the device
 405  *
 406  *      Closing the watchdog device either stops the watchdog timer
 407  *      or in the case, that nowayout is set or the magic character
 408  *      wasn't written, a critical warning about an running watchdog
 409  *      timer is given.
 410  *
 411  *      Used within the file operation of the watchdog device.
 412  */
 413
 414 static int wdt_release(struct inode *inode, struct file *file)
 415 {
 416         if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
 417                 if (test_and_clear_bit(WDTS_EXPECTED, &wdt_status)) {
 418                         int ret = wdt_stop();
 419                         if (ret) {
 420                                 /*
 421                                  * Stop failed. Just keep the watchdog alive
 422                                  * and hope nothing bad happens.
 423                                  */
 424                                 set_bit(WDTS_EXPECTED, &wdt_status);
 425                                 wdt_keepalive();
 426                                 return ret;
 427                         }
 428                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 429                 } else {
 430                         wdt_keepalive();
 431                         pr_crit("unexpected close, not stopping watchdog!\n");
 432                 }
 433         }
 434         clear_bit(WDTS_DEV_OPEN, &wdt_status);
 435         return 0;
 436 }
 437
 438 /**
 439  *      wdt_write - watchdog file_operations .write
 440  *      @file: file handle to the watchdog
 441  *      @buf: buffer to write
 442  *      @count: count of bytes
 443  *      @ppos: pointer to the position to write. No seeks allowed
 444  *
 445  *      A write to a watchdog device is defined as a keepalive signal. Any
 446  *      write of data will do, as we don't define content meaning.
 447  *
 448  *      Used within the file operation of the watchdog device.
 449  */
 450
 451 static ssize_t wdt_write(struct file *file, const char __user *buf,
 452                             size_t count, loff_t *ppos)
 453 {
 454         if (count) {
 455                 clear_bit(WDTS_EXPECTED, &wdt_status);
 456                 wdt_keepalive();
 457         }
 458         if (!nowayout) {
 459                 size_t ofs;
 460
 461         /* note: just in case someone wrote the magic character long ago */
 462                 for (ofs = 0; ofs != count; ofs++) {
 463                         char c;
 464                         if (get_user(c, buf + ofs))
 465                                 return -EFAULT;
 466                         if (c == WD_MAGIC)
 467                                 set_bit(WDTS_EXPECTED, &wdt_status);
 468                 }
 469         }
 470         return count;
 471 }
 472
 473 static const struct watchdog_info ident = {
 474         .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
 475         .firmware_version =     1,
 476         .identity = WATCHDOG_NAME,
 477 };
 478
 479 /**
 480  *      wdt_ioctl - watchdog file_operations .unlocked_ioctl
 481  *      @file: file handle to the device
 482  *      @cmd: watchdog command
 483  *      @arg: argument pointer
 484  *
 485  *      The watchdog API defines a common set of functions for all watchdogs
 486  *      according to their available features.
 487  *
 488  *      Used within the file operation of the watchdog device.
 489  */
 490
 491 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 492 {
 493         int rc = 0, status, new_options, new_timeout;
 494         union {
 495                 struct watchdog_info __user *ident;
 496                 int __user *i;
 497         } uarg;
 498
 499         uarg.i = (int __user *)arg;
 500
 501         switch (cmd) {
 502         case WDIOC_GETSUPPORT:
 503                 return copy_to_user(uarg.ident,
 504                                     &ident, sizeof(ident)) ? -EFAULT : 0;
 505
 506         case WDIOC_GETSTATUS:
 507                 rc = wdt_get_status(&status);
 508                 if (rc)
 509                         return rc;
 510                 return put_user(status, uarg.i);
 511
 512         case WDIOC_GETBOOTSTATUS:
 513                 return put_user(0, uarg.i);
 514
 515         case WDIOC_KEEPALIVE:
 516                 wdt_keepalive();
 517                 return 0;
 518
 519         case WDIOC_SETOPTIONS:
 520                 if (get_user(new_options, uarg.i))
 521                         return -EFAULT;
 522
 523                 switch (new_options) {
 524                 case WDIOS_DISABLECARD:
 525                         if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
 526                                 rc = wdt_stop();
 527                                 if (rc)
 528                                         return rc;
 529                         }
 530                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 531                         return 0;
 532
 533                 case WDIOS_ENABLECARD:
 534                         if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
 535                                 rc = wdt_start();
 536                                 if (rc) {
 537                                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 538                                         return rc;
 539                                 }
 540                         }
 541                         return 0;
 542
 543                 default:
 544                         return -EFAULT;
 545                 }
 546
 547         case WDIOC_SETTIMEOUT:
 548                 if (get_user(new_timeout, uarg.i))
 549                         return -EFAULT;
 550                 rc = wdt_set_timeout(new_timeout);
 551         case WDIOC_GETTIMEOUT:
 552                 if (put_user(timeout, uarg.i))
 553                         return -EFAULT;
 554                 return rc;
 555
 556         default:
 557                 return -ENOTTY;
 558         }
 559 }
 560
 561 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
 562         void *unused)
 563 {
 564         if (code == SYS_DOWN || code == SYS_HALT)
 565                 wdt_stop();
 566         return NOTIFY_DONE;
 567 }
 568
 569 static const struct file_operations wdt_fops = {
 570         .owner          = THIS_MODULE,
 571         .llseek         = no_llseek,
 572         .write          = wdt_write,
 573         .unlocked_ioctl = wdt_ioctl,
 574         .open           = wdt_open,
 575         .release        = wdt_release,
 576 };
 577
 578 static struct miscdevice wdt_miscdev = {
 579         .minor          = WATCHDOG_MINOR,
 580         .name           = "watchdog",
 581         .fops           = &wdt_fops,
 582 };
 583
 584 static struct notifier_block wdt_notifier = {
 585         .notifier_call = wdt_notify_sys,
 586 };
 587
 588 static int __init it87_wdt_init(void)
 589 {
 590         int rc = 0;
 591         int try_gameport = !nogameport;
 592         u8  chip_rev;
 593         int gp_rreq_fail = 0;
 594
 595         wdt_status = 0;
 596
 597         rc = superio_enter();
 598         if (rc)
 599                 return rc;
 600
 601         chip_type = superio_inw(CHIPID);
 602         chip_rev  = superio_inb(CHIPREV) & 0x0f;
 603         superio_exit();
 604
 605         switch (chip_type) {
 606         case IT8702_ID:
 607                 max_units = 255;
 608                 break;
 609         case IT8712_ID:
 610                 max_units = (chip_rev < 8) ? 255 : 65535;
 611                 break;
 612         case IT8716_ID:
 613         case IT8726_ID:
 614                 max_units = 65535;
 615                 break;
 616         case IT8718_ID:
 617         case IT8720_ID:
 618         case IT8721_ID:
 619                 max_units = 65535;
 620                 try_gameport = 0;
 621                 break;
 622         case IT8705_ID:
 623                 pr_err("Unsupported Chip found, Chip %04x Revision %02x\n",
 624                        chip_type, chip_rev);
 625                 return -ENODEV;
 626         case NO_DEV_ID:
 627                 pr_err("no device\n");
 628                 return -ENODEV;
 629         default:
 630                 pr_err("Unknown Chip found, Chip %04x Revision %04x\n",
 631                        chip_type, chip_rev);
 632                 return -ENODEV;
 633         }
 634
 635         rc = superio_enter();
 636         if (rc)
 637                 return rc;
 638
 639         superio_select(GPIO);
 640         superio_outb(WDT_TOV1, WDTCFG);
 641         superio_outb(0x00, WDTCTRL);
 642
 643         /* First try to get Gameport support */
 644         if (try_gameport) {
 645                 superio_select(GAMEPORT);
 646                 base = superio_inw(BASEREG);
 647                 if (!base) {
 648                         base = GP_BASE_DEFAULT;
 649                         superio_outw(base, BASEREG);
 650                 }
 651                 gpact = superio_inb(ACTREG);
 652                 superio_outb(0x01, ACTREG);
 653                 if (request_region(base, 1, WATCHDOG_NAME))
 654                         set_bit(WDTS_USE_GP, &wdt_status);
 655                 else
 656                         gp_rreq_fail = 1;
 657         }
 658
 659         /* If we haven't Gameport support, try to get CIR support */
 660         if (!test_bit(WDTS_USE_GP, &wdt_status)) {
 661                 if (!request_region(CIR_BASE, 8, WATCHDOG_NAME)) {
 662                         if (gp_rreq_fail)
 663                                 pr_err("I/O Address 0x%04x and 0x%04x already in use\n",
 664                                        base, CIR_BASE);
 665                         else
 666                                 pr_err("I/O Address 0x%04x already in use\n",
 667                                        CIR_BASE);
 668                         rc = -EIO;
 669                         goto err_out;
 670                 }
 671                 base = CIR_BASE;
 672
 673                 superio_select(CIR);
 674                 superio_outw(base, BASEREG);
 675                 superio_outb(0x00, CIR_ILS);
 676                 ciract = superio_inb(ACTREG);
 677                 superio_outb(0x01, ACTREG);
 678                 if (gp_rreq_fail) {
 679                         superio_select(GAMEPORT);
 680                         superio_outb(gpact, ACTREG);
 681                 }
 682         }
 683
 684         if (timeout < 1 || timeout > max_units * 60) {
 685                 timeout = DEFAULT_TIMEOUT;
 686                 pr_warn("Timeout value out of range, use default %d sec\n",
 687                         DEFAULT_TIMEOUT);
 688         }
 689
 690         if (timeout > max_units)
 691                 timeout = wdt_round_time(timeout);
 692
 693         rc = register_reboot_notifier(&wdt_notifier);
 694         if (rc) {
 695                 pr_err("Cannot register reboot notifier (err=%d)\n", rc);
 696                 goto err_out_region;
 697         }
 698
 699         rc = misc_register(&wdt_miscdev);
 700         if (rc) {
 701                 pr_err("Cannot register miscdev on minor=%d (err=%d)\n",
 702                        wdt_miscdev.minor, rc);
 703                 goto err_out_reboot;
 704         }
 705
 706         /* Initialize CIR to use it as keepalive source */
 707         if (!test_bit(WDTS_USE_GP, &wdt_status)) {
 708                 outb(0x00, CIR_RCR(base));
 709                 outb(0xc0, CIR_TCR1(base));
 710                 outb(0x5c, CIR_TCR2(base));
 711                 outb(0x10, CIR_IER(base));
 712                 outb(0x00, CIR_BDHR(base));
 713                 outb(0x01, CIR_BDLR(base));
 714                 outb(0x09, CIR_IER(base));
 715         }
 716
 717         pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d exclusive=%d nogameport=%d)\n",
 718                 chip_type, chip_rev, timeout,
 719                 nowayout, testmode, exclusive, nogameport);
 720
 721         superio_exit();
 722         return 0;
 723
 724 err_out_reboot:
 725         unregister_reboot_notifier(&wdt_notifier);
 726 err_out_region:
 727         release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8);
 728         if (!test_bit(WDTS_USE_GP, &wdt_status)) {
 729                 superio_select(CIR);
 730                 superio_outb(ciract, ACTREG);
 731         }
 732 err_out:
 733         if (try_gameport) {
 734                 superio_select(GAMEPORT);
 735                 superio_outb(gpact, ACTREG);
 736         }
 737
 738         superio_exit();
 739         return rc;
 740 }
 741
 742 static void __exit it87_wdt_exit(void)
 743 {
 744         if (superio_enter() == 0) {
 745                 superio_select(GPIO);
 746                 superio_outb(0x00, WDTCTRL);
 747                 superio_outb(0x00, WDTCFG);
 748                 superio_outb(0x00, WDTVALLSB);
 749                 if (max_units > 255)
 750                         superio_outb(0x00, WDTVALMSB);
 751                 if (test_bit(WDTS_USE_GP, &wdt_status)) {
 752                         superio_select(GAMEPORT);
 753                         superio_outb(gpact, ACTREG);
 754                 } else {
 755                         superio_select(CIR);
 756                         superio_outb(ciract, ACTREG);
 757                 }
 758                 superio_exit();
 759         }
 760
 761         misc_deregister(&wdt_miscdev);
 762         unregister_reboot_notifier(&wdt_notifier);
 763         release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8);
 764 }
 765
 766 module_init(it87_wdt_init);
 767 module_exit(it87_wdt_exit);
 768
 769 MODULE_AUTHOR("Oliver Schuster");
 770 MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O");
 771 MODULE_LICENSE("GPL");
 772 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);