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, IT8726
  16  *      and IT8728.
  17  *
  18  *      This program is free software; you can redistribute it and/or
  19  *      modify it under the terms of the GNU General Public License
  20  *      as published by the Free Software Foundation; either version
  21  *      2 of the License, or (at your option) any later version.
  22  *
  23  *      This program is distributed in the hope that it will be useful,
  24  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  25  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  26  *      GNU General Public License for more details.
  27  *
  28  *      You should have received a copy of the GNU General Public License
  29  *      along with this program; if not, write to the Free Software
  30  *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  31  */
  32
  33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  34
  35 #include <linux/module.h>
  36 #include <linux/moduleparam.h>
  37 #include <linux/types.h>
  38 #include <linux/kernel.h>
  39 #include <linux/fs.h>
  40 #include <linux/miscdevice.h>
  41 #include <linux/init.h>
  42 #include <linux/ioport.h>
  43 #include <linux/watchdog.h>
  44 #include <linux/notifier.h>
  45 #include <linux/reboot.h>
  46 #include <linux/uaccess.h>
  47 #include <linux/io.h>
  48
  49
  50 #define WATCHDOG_VERSION        "1.14"
  51 #define WATCHDOG_NAME           "IT87 WDT"
  52 #define DRIVER_VERSION          WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
  53 #define WD_MAGIC                'V'
  54
  55 /* Defaults for Module Parameter */
  56 #define DEFAULT_NOGAMEPORT      0
  57 #define DEFAULT_EXCLUSIVE       1
  58 #define DEFAULT_TIMEOUT         60
  59 #define DEFAULT_TESTMODE        0
  60 #define DEFAULT_NOWAYOUT        WATCHDOG_NOWAYOUT
  61
  62 /* IO Ports */
  63 #define REG             0x2e
  64 #define VAL             0x2f
  65
  66 /* Logical device Numbers LDN */
  67 #define GPIO            0x07
  68 #define GAMEPORT        0x09
  69 #define CIR             0x0a
  70
  71 /* Configuration Registers and Functions */
  72 #define LDNREG          0x07
  73 #define CHIPID          0x20
  74 #define CHIPREV         0x22
  75 #define ACTREG          0x30
  76 #define BASEREG         0x60
  77
  78 /* Chip Id numbers */
  79 #define NO_DEV_ID       0xffff
  80 #define IT8702_ID       0x8702
  81 #define IT8705_ID       0x8705
  82 #define IT8712_ID       0x8712
  83 #define IT8716_ID       0x8716
  84 #define IT8718_ID       0x8718
  85 #define IT8720_ID       0x8720
  86 #define IT8721_ID       0x8721
  87 #define IT8726_ID       0x8726  /* the data sheet suggest wrongly 0x8716 */
  88 #define IT8728_ID       0x8728
  89
  90 /* GPIO Configuration Registers LDN=0x07 */
  91 #define WDTCTRL         0x71
  92 #define WDTCFG          0x72
  93 #define WDTVALLSB       0x73
  94 #define WDTVALMSB       0x74
  95
  96 /* GPIO Bits WDTCTRL */
  97 #define WDT_CIRINT      0x80
  98 #define WDT_MOUSEINT    0x40
  99 #define WDT_KYBINT      0x20
 100 #define WDT_GAMEPORT    0x10 /* not in it8718, it8720, it8721, it8728 */
 101 #define WDT_FORCE       0x02
 102 #define WDT_ZERO        0x01
 103
 104 /* GPIO Bits WDTCFG */
 105 #define WDT_TOV1        0x80
 106 #define WDT_KRST        0x40
 107 #define WDT_TOVE        0x20
 108 #define WDT_PWROK       0x10 /* not in it8721 */
 109 #define WDT_INT_MASK    0x0f
 110
 111 /* CIR Configuration Register LDN=0x0a */
 112 #define CIR_ILS         0x70
 113
 114 /* The default Base address is not always available, we use this */
 115 #define CIR_BASE        0x0208
 116
 117 /* CIR Controller */
 118 #define CIR_DR(b)       (b)
 119 #define CIR_IER(b)      (b + 1)
 120 #define CIR_RCR(b)      (b + 2)
 121 #define CIR_TCR1(b)     (b + 3)
 122 #define CIR_TCR2(b)     (b + 4)
 123 #define CIR_TSR(b)      (b + 5)
 124 #define CIR_RSR(b)      (b + 6)
 125 #define CIR_BDLR(b)     (b + 5)
 126 #define CIR_BDHR(b)     (b + 6)
 127 #define CIR_IIR(b)      (b + 7)
 128
 129 /* Default Base address of Game port */
 130 #define GP_BASE_DEFAULT 0x0201
 131
 132 /* wdt_status */
 133 #define WDTS_TIMER_RUN  0
 134 #define WDTS_DEV_OPEN   1
 135 #define WDTS_KEEPALIVE  2
 136 #define WDTS_LOCKED     3
 137 #define WDTS_USE_GP     4
 138 #define WDTS_EXPECTED   5
 139
 140 static  unsigned int base, gpact, ciract, max_units, chip_type;
 141 static  unsigned long wdt_status;
 142
 143 static  int nogameport = DEFAULT_NOGAMEPORT;
 144 static  int exclusive  = DEFAULT_EXCLUSIVE;
 145 static  int timeout    = DEFAULT_TIMEOUT;
 146 static  int testmode   = DEFAULT_TESTMODE;
 147 static  bool nowayout   = DEFAULT_NOWAYOUT;
 148
 149 module_param(nogameport, int, 0);
 150 MODULE_PARM_DESC(nogameport, "Forbid the activation of game port, default="
 151                 __MODULE_STRING(DEFAULT_NOGAMEPORT));
 152 module_param(exclusive, int, 0);
 153 MODULE_PARM_DESC(exclusive, "Watchdog exclusive device open, default="
 154                 __MODULE_STRING(DEFAULT_EXCLUSIVE));
 155 module_param(timeout, int, 0);
 156 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds, default="
 157                 __MODULE_STRING(DEFAULT_TIMEOUT));
 158 module_param(testmode, int, 0);
 159 MODULE_PARM_DESC(testmode, "Watchdog test mode (1 = no reboot), default="
 160                 __MODULE_STRING(DEFAULT_TESTMODE));
 161 module_param(nowayout, bool, 0);
 162 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started, default="
 163                 __MODULE_STRING(WATCHDOG_NOWAYOUT));
 164
 165 /* Superio Chip */
 166
 167 static inline int superio_enter(void)
 168 {
 169         /*
 170          * Try to reserve REG and REG + 1 for exclusive access.
 171          */
 172         if (!request_muxed_region(REG, 2, WATCHDOG_NAME))
 173                 return -EBUSY;
 174
 175         outb(0x87, REG);
 176         outb(0x01, REG);
 177         outb(0x55, REG);
 178         outb(0x55, REG);
 179         return 0;
 180 }
 181
 182 static inline void superio_exit(void)
 183 {
 184         outb(0x02, REG);
 185         outb(0x02, VAL);
 186         release_region(REG, 2);
 187 }
 188
 189 static inline void superio_select(int ldn)
 190 {
 191         outb(LDNREG, REG);
 192         outb(ldn, VAL);
 193 }
 194
 195 static inline int superio_inb(int reg)
 196 {
 197         outb(reg, REG);
 198         return inb(VAL);
 199 }
 200
 201 static inline void superio_outb(int val, int reg)
 202 {
 203         outb(reg, REG);
 204         outb(val, VAL);
 205 }
 206
 207 static inline int superio_inw(int reg)
 208 {
 209         int val;
 210         outb(reg++, REG);
 211         val = inb(VAL) << 8;
 212         outb(reg, REG);
 213         val |= inb(VAL);
 214         return val;
 215 }
 216
 217 static inline void superio_outw(int val, int reg)
 218 {
 219         outb(reg++, REG);
 220         outb(val >> 8, VAL);
 221         outb(reg, REG);
 222         outb(val, VAL);
 223 }
 224
 225 /* Internal function, should be called after superio_select(GPIO) */
 226 static void wdt_update_timeout(void)
 227 {
 228         unsigned char cfg = WDT_KRST;
 229         int tm = timeout;
 230
 231         if (testmode)
 232                 cfg = 0;
 233
 234         if (tm <= max_units)
 235                 cfg |= WDT_TOV1;
 236         else
 237                 tm /= 60;
 238
 239         if (chip_type != IT8721_ID)
 240                 cfg |= WDT_PWROK;
 241
 242         superio_outb(cfg, WDTCFG);
 243         superio_outb(tm, WDTVALLSB);
 244         if (max_units > 255)
 245                 superio_outb(tm>>8, WDTVALMSB);
 246 }
 247
 248 static int wdt_round_time(int t)
 249 {
 250         t += 59;
 251         t -= t % 60;
 252         return t;
 253 }
 254
 255 /* watchdog timer handling */
 256
 257 static void wdt_keepalive(void)
 258 {
 259         if (test_bit(WDTS_USE_GP, &wdt_status))
 260                 inb(base);
 261         else
 262                 /* The timer reloads with around 5 msec delay */
 263                 outb(0x55, CIR_DR(base));
 264         set_bit(WDTS_KEEPALIVE, &wdt_status);
 265 }
 266
 267 static int wdt_start(void)
 268 {
 269         int ret = superio_enter();
 270         if (ret)
 271                 return ret;
 272
 273         superio_select(GPIO);
 274         if (test_bit(WDTS_USE_GP, &wdt_status))
 275                 superio_outb(WDT_GAMEPORT, WDTCTRL);
 276         else
 277                 superio_outb(WDT_CIRINT, WDTCTRL);
 278         wdt_update_timeout();
 279
 280         superio_exit();
 281
 282         return 0;
 283 }
 284
 285 static int wdt_stop(void)
 286 {
 287         int ret = superio_enter();
 288         if (ret)
 289                 return ret;
 290
 291         superio_select(GPIO);
 292         superio_outb(0x00, WDTCTRL);
 293         superio_outb(WDT_TOV1, WDTCFG);
 294         superio_outb(0x00, WDTVALLSB);
 295         if (max_units > 255)
 296                 superio_outb(0x00, WDTVALMSB);
 297
 298         superio_exit();
 299         return 0;
 300 }
 301
 302 /**
 303  *      wdt_set_timeout - set a new timeout value with watchdog ioctl
 304  *      @t: timeout value in seconds
 305  *
 306  *      The hardware device has a 8 or 16 bit watchdog timer (depends on
 307  *      chip version) that can be configured to count seconds or minutes.
 308  *
 309  *      Used within WDIOC_SETTIMEOUT watchdog device ioctl.
 310  */
 311
 312 static int wdt_set_timeout(int t)
 313 {
 314         if (t < 1 || t > max_units * 60)
 315                 return -EINVAL;
 316
 317         if (t > max_units)
 318                 timeout = wdt_round_time(t);
 319         else
 320                 timeout = t;
 321
 322         if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
 323                 int ret = superio_enter();
 324                 if (ret)
 325                         return ret;
 326
 327                 superio_select(GPIO);
 328                 wdt_update_timeout();
 329                 superio_exit();
 330         }
 331         return 0;
 332 }
 333
 334 /**
 335  *      wdt_get_status - determines the status supported by watchdog ioctl
 336  *      @status: status returned to user space
 337  *
 338  *      The status bit of the device does not allow to distinguish
 339  *      between a regular system reset and a watchdog forced reset.
 340  *      But, in test mode it is useful, so it is supported through
 341  *      WDIOC_GETSTATUS watchdog ioctl. Additionally the driver
 342  *      reports the keepalive signal and the acception of the magic.
 343  *
 344  *      Used within WDIOC_GETSTATUS watchdog device ioctl.
 345  */
 346
 347 static int wdt_get_status(int *status)
 348 {
 349         *status = 0;
 350         if (testmode) {
 351                 int ret = superio_enter();
 352                 if (ret)
 353                         return ret;
 354
 355                 superio_select(GPIO);
 356                 if (superio_inb(WDTCTRL) & WDT_ZERO) {
 357                         superio_outb(0x00, WDTCTRL);
 358                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 359                         *status |= WDIOF_CARDRESET;
 360                 }
 361
 362                 superio_exit();
 363         }
 364         if (test_and_clear_bit(WDTS_KEEPALIVE, &wdt_status))
 365                 *status |= WDIOF_KEEPALIVEPING;
 366         if (test_bit(WDTS_EXPECTED, &wdt_status))
 367                 *status |= WDIOF_MAGICCLOSE;
 368         return 0;
 369 }
 370
 371 /* /dev/watchdog handling */
 372
 373 /**
 374  *      wdt_open - watchdog file_operations .open
 375  *      @inode: inode of the device
 376  *      @file: file handle to the device
 377  *
 378  *      The watchdog timer starts by opening the device.
 379  *
 380  *      Used within the file operation of the watchdog device.
 381  */
 382
 383 static int wdt_open(struct inode *inode, struct file *file)
 384 {
 385         if (exclusive && test_and_set_bit(WDTS_DEV_OPEN, &wdt_status))
 386                 return -EBUSY;
 387         if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
 388                 int ret;
 389                 if (nowayout && !test_and_set_bit(WDTS_LOCKED, &wdt_status))
 390                         __module_get(THIS_MODULE);
 391
 392                 ret = wdt_start();
 393                 if (ret) {
 394                         clear_bit(WDTS_LOCKED, &wdt_status);
 395                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 396                         clear_bit(WDTS_DEV_OPEN, &wdt_status);
 397                         return ret;
 398                 }
 399         }
 400         return nonseekable_open(inode, file);
 401 }
 402
 403 /**
 404  *      wdt_release - watchdog file_operations .release
 405  *      @inode: inode of the device
 406  *      @file: file handle to the device
 407  *
 408  *      Closing the watchdog device either stops the watchdog timer
 409  *      or in the case, that nowayout is set or the magic character
 410  *      wasn't written, a critical warning about an running watchdog
 411  *      timer is given.
 412  *
 413  *      Used within the file operation of the watchdog device.
 414  */
 415
 416 static int wdt_release(struct inode *inode, struct file *file)
 417 {
 418         if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
 419                 if (test_and_clear_bit(WDTS_EXPECTED, &wdt_status)) {
 420                         int ret = wdt_stop();
 421                         if (ret) {
 422                                 /*
 423                                  * Stop failed. Just keep the watchdog alive
 424                                  * and hope nothing bad happens.
 425                                  */
 426                                 set_bit(WDTS_EXPECTED, &wdt_status);
 427                                 wdt_keepalive();
 428                                 return ret;
 429                         }
 430                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 431                 } else {
 432                         wdt_keepalive();
 433                         pr_crit("unexpected close, not stopping watchdog!\n");
 434                 }
 435         }
 436         clear_bit(WDTS_DEV_OPEN, &wdt_status);
 437         return 0;
 438 }
 439
 440 /**
 441  *      wdt_write - watchdog file_operations .write
 442  *      @file: file handle to the watchdog
 443  *      @buf: buffer to write
 444  *      @count: count of bytes
 445  *      @ppos: pointer to the position to write. No seeks allowed
 446  *
 447  *      A write to a watchdog device is defined as a keepalive signal. Any
 448  *      write of data will do, as we don't define content meaning.
 449  *
 450  *      Used within the file operation of the watchdog device.
 451  */
 452
 453 static ssize_t wdt_write(struct file *file, const char __user *buf,
 454                             size_t count, loff_t *ppos)
 455 {
 456         if (count) {
 457                 clear_bit(WDTS_EXPECTED, &wdt_status);
 458                 wdt_keepalive();
 459         }
 460         if (!nowayout) {
 461                 size_t ofs;
 462
 463         /* note: just in case someone wrote the magic character long ago */
 464                 for (ofs = 0; ofs != count; ofs++) {
 465                         char c;
 466                         if (get_user(c, buf + ofs))
 467                                 return -EFAULT;
 468                         if (c == WD_MAGIC)
 469                                 set_bit(WDTS_EXPECTED, &wdt_status);
 470                 }
 471         }
 472         return count;
 473 }
 474
 475 static const struct watchdog_info ident = {
 476         .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
 477         .firmware_version =     1,
 478         .identity = WATCHDOG_NAME,
 479 };
 480
 481 /**
 482  *      wdt_ioctl - watchdog file_operations .unlocked_ioctl
 483  *      @file: file handle to the device
 484  *      @cmd: watchdog command
 485  *      @arg: argument pointer
 486  *
 487  *      The watchdog API defines a common set of functions for all watchdogs
 488  *      according to their available features.
 489  *
 490  *      Used within the file operation of the watchdog device.
 491  */
 492
 493 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 494 {
 495         int rc = 0, status, new_options, new_timeout;
 496         union {
 497                 struct watchdog_info __user *ident;
 498                 int __user *i;
 499         } uarg;
 500
 501         uarg.i = (int __user *)arg;
 502
 503         switch (cmd) {
 504         case WDIOC_GETSUPPORT:
 505                 return copy_to_user(uarg.ident,
 506                                     &ident, sizeof(ident)) ? -EFAULT : 0;
 507
 508         case WDIOC_GETSTATUS:
 509                 rc = wdt_get_status(&status);
 510                 if (rc)
 511                         return rc;
 512                 return put_user(status, uarg.i);
 513
 514         case WDIOC_GETBOOTSTATUS:
 515                 return put_user(0, uarg.i);
 516
 517         case WDIOC_KEEPALIVE:
 518                 wdt_keepalive();
 519                 return 0;
 520
 521         case WDIOC_SETOPTIONS:
 522                 if (get_user(new_options, uarg.i))
 523                         return -EFAULT;
 524
 525                 switch (new_options) {
 526                 case WDIOS_DISABLECARD:
 527                         if (test_bit(WDTS_TIMER_RUN, &wdt_status)) {
 528                                 rc = wdt_stop();
 529                                 if (rc)
 530                                         return rc;
 531                         }
 532                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 533                         return 0;
 534
 535                 case WDIOS_ENABLECARD:
 536                         if (!test_and_set_bit(WDTS_TIMER_RUN, &wdt_status)) {
 537                                 rc = wdt_start();
 538                                 if (rc) {
 539                                         clear_bit(WDTS_TIMER_RUN, &wdt_status);
 540                                         return rc;
 541                                 }
 542                         }
 543                         return 0;
 544
 545                 default:
 546                         return -EFAULT;
 547                 }
 548
 549         case WDIOC_SETTIMEOUT:
 550                 if (get_user(new_timeout, uarg.i))
 551                         return -EFAULT;
 552                 rc = wdt_set_timeout(new_timeout);
 553         case WDIOC_GETTIMEOUT:
 554                 if (put_user(timeout, uarg.i))
 555                         return -EFAULT;
 556                 return rc;
 557
 558         default:
 559                 return -ENOTTY;
 560         }
 561 }
 562
 563 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
 564         void *unused)
 565 {
 566         if (code == SYS_DOWN || code == SYS_HALT)
 567                 wdt_stop();
 568         return NOTIFY_DONE;
 569 }
 570
 571 static const struct file_operations wdt_fops = {
 572         .owner          = THIS_MODULE,
 573         .llseek         = no_llseek,
 574         .write          = wdt_write,
 575         .unlocked_ioctl = wdt_ioctl,
 576         .open           = wdt_open,
 577         .release        = wdt_release,
 578 };
 579
 580 static struct miscdevice wdt_miscdev = {
 581         .minor          = WATCHDOG_MINOR,
 582         .name           = "watchdog",
 583         .fops           = &wdt_fops,
 584 };
 585
 586 static struct notifier_block wdt_notifier = {
 587         .notifier_call = wdt_notify_sys,
 588 };
 589
 590 static int __init it87_wdt_init(void)
 591 {
 592         int rc = 0;
 593         int try_gameport = !nogameport;
 594         u8  chip_rev;
 595         int gp_rreq_fail = 0;
 596
 597         wdt_status = 0;
 598
 599         rc = superio_enter();
 600         if (rc)
 601                 return rc;
 602
 603         chip_type = superio_inw(CHIPID);
 604         chip_rev  = superio_inb(CHIPREV) & 0x0f;
 605         superio_exit();
 606
 607         switch (chip_type) {
 608         case IT8702_ID:
 609                 max_units = 255;
 610                 break;
 611         case IT8712_ID:
 612                 max_units = (chip_rev < 8) ? 255 : 65535;
 613                 break;
 614         case IT8716_ID:
 615         case IT8726_ID:
 616                 max_units = 65535;
 617                 break;
 618         case IT8718_ID:
 619         case IT8720_ID:
 620         case IT8721_ID:
 621         case IT8728_ID:
 622                 max_units = 65535;
 623                 try_gameport = 0;
 624                 break;
 625         case IT8705_ID:
 626                 pr_err("Unsupported Chip found, Chip %04x Revision %02x\n",
 627                        chip_type, chip_rev);
 628                 return -ENODEV;
 629         case NO_DEV_ID:
 630                 pr_err("no device\n");
 631                 return -ENODEV;
 632         default:
 633                 pr_err("Unknown Chip found, Chip %04x Revision %04x\n",
 634                        chip_type, chip_rev);
 635                 return -ENODEV;
 636         }
 637
 638         rc = superio_enter();
 639         if (rc)
 640                 return rc;
 641
 642         superio_select(GPIO);
 643         superio_outb(WDT_TOV1, WDTCFG);
 644         superio_outb(0x00, WDTCTRL);
 645
 646         /* First try to get Gameport support */
 647         if (try_gameport) {
 648                 superio_select(GAMEPORT);
 649                 base = superio_inw(BASEREG);
 650                 if (!base) {
 651                         base = GP_BASE_DEFAULT;
 652                         superio_outw(base, BASEREG);
 653                 }
 654                 gpact = superio_inb(ACTREG);
 655                 superio_outb(0x01, ACTREG);
 656                 if (request_region(base, 1, WATCHDOG_NAME))
 657                         set_bit(WDTS_USE_GP, &wdt_status);
 658                 else
 659                         gp_rreq_fail = 1;
 660         }
 661
 662         /* If we haven't Gameport support, try to get CIR support */
 663         if (!test_bit(WDTS_USE_GP, &wdt_status)) {
 664                 if (!request_region(CIR_BASE, 8, WATCHDOG_NAME)) {
 665                         if (gp_rreq_fail)
 666                                 pr_err("I/O Address 0x%04x and 0x%04x already in use\n",
 667                                        base, CIR_BASE);
 668                         else
 669                                 pr_err("I/O Address 0x%04x already in use\n",
 670                                        CIR_BASE);
 671                         rc = -EIO;
 672                         goto err_out;
 673                 }
 674                 base = CIR_BASE;
 675
 676                 superio_select(CIR);
 677                 superio_outw(base, BASEREG);
 678                 superio_outb(0x00, CIR_ILS);
 679                 ciract = superio_inb(ACTREG);
 680                 superio_outb(0x01, ACTREG);
 681                 if (gp_rreq_fail) {
 682                         superio_select(GAMEPORT);
 683                         superio_outb(gpact, ACTREG);
 684                 }
 685         }
 686
 687         if (timeout < 1 || timeout > max_units * 60) {
 688                 timeout = DEFAULT_TIMEOUT;
 689                 pr_warn("Timeout value out of range, use default %d sec\n",
 690                         DEFAULT_TIMEOUT);
 691         }
 692
 693         if (timeout > max_units)
 694                 timeout = wdt_round_time(timeout);
 695
 696         rc = register_reboot_notifier(&wdt_notifier);
 697         if (rc) {
 698                 pr_err("Cannot register reboot notifier (err=%d)\n", rc);
 699                 goto err_out_region;
 700         }
 701
 702         rc = misc_register(&wdt_miscdev);
 703         if (rc) {
 704                 pr_err("Cannot register miscdev on minor=%d (err=%d)\n",
 705                        wdt_miscdev.minor, rc);
 706                 goto err_out_reboot;
 707         }
 708
 709         /* Initialize CIR to use it as keepalive source */
 710         if (!test_bit(WDTS_USE_GP, &wdt_status)) {
 711                 outb(0x00, CIR_RCR(base));
 712                 outb(0xc0, CIR_TCR1(base));
 713                 outb(0x5c, CIR_TCR2(base));
 714                 outb(0x10, CIR_IER(base));
 715                 outb(0x00, CIR_BDHR(base));
 716                 outb(0x01, CIR_BDLR(base));
 717                 outb(0x09, CIR_IER(base));
 718         }
 719
 720         pr_info("Chip IT%04x revision %d initialized. timeout=%d sec (nowayout=%d testmode=%d exclusive=%d nogameport=%d)\n",
 721                 chip_type, chip_rev, timeout,
 722                 nowayout, testmode, exclusive, nogameport);
 723
 724         superio_exit();
 725         return 0;
 726
 727 err_out_reboot:
 728         unregister_reboot_notifier(&wdt_notifier);
 729 err_out_region:
 730         release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8);
 731         if (!test_bit(WDTS_USE_GP, &wdt_status)) {
 732                 superio_select(CIR);
 733                 superio_outb(ciract, ACTREG);
 734         }
 735 err_out:
 736         if (try_gameport) {
 737                 superio_select(GAMEPORT);
 738                 superio_outb(gpact, ACTREG);
 739         }
 740
 741         superio_exit();
 742         return rc;
 743 }
 744
 745 static void __exit it87_wdt_exit(void)
 746 {
 747         if (superio_enter() == 0) {
 748                 superio_select(GPIO);
 749                 superio_outb(0x00, WDTCTRL);
 750                 superio_outb(0x00, WDTCFG);
 751                 superio_outb(0x00, WDTVALLSB);
 752                 if (max_units > 255)
 753                         superio_outb(0x00, WDTVALMSB);
 754                 if (test_bit(WDTS_USE_GP, &wdt_status)) {
 755                         superio_select(GAMEPORT);
 756                         superio_outb(gpact, ACTREG);
 757                 } else {
 758                         superio_select(CIR);
 759                         superio_outb(ciract, ACTREG);
 760                 }
 761                 superio_exit();
 762         }
 763
 764         misc_deregister(&wdt_miscdev);
 765         unregister_reboot_notifier(&wdt_notifier);
 766         release_region(base, test_bit(WDTS_USE_GP, &wdt_status) ? 1 : 8);
 767 }
 768
 769 module_init(it87_wdt_init);
 770 module_exit(it87_wdt_exit);
 771
 772 MODULE_AUTHOR("Oliver Schuster");
 773 MODULE_DESCRIPTION("Hardware Watchdog Device Driver for IT87xx EC-LPC I/O");
 774 MODULE_LICENSE("GPL");
 775 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);