drivers/char/watchdog/pcwd.c

   1 /*
   2  * PC Watchdog Driver
   3  * by Ken Hollis (khollis@bitgate.com)
   4  *
   5  * Permission granted from Simon Machell (73244.1270@compuserve.com)
   6  * Written for the Linux Kernel, and GPLed by Ken Hollis
   7  *
   8  * 960107       Added request_region routines, modulized the whole thing.
   9  * 960108       Fixed end-of-file pointer (Thanks to Dan Hollis), added
  10  *              WD_TIMEOUT define.
  11  * 960216       Added eof marker on the file, and changed verbose messages.
  12  * 960716       Made functional and cosmetic changes to the source for
  13  *              inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
  14  * 960717       Removed read/seek routines, replaced with ioctl.  Also, added
  15  *              check_region command due to Alan's suggestion.
  16  * 960821       Made changes to compile in newer 2.0.x kernels.  Added
  17  *              "cold reboot sense" entry.
  18  * 960825       Made a few changes to code, deleted some defines and made
  19  *              typedefs to replace them.  Made heartbeat reset only available
  20  *              via ioctl, and removed the write routine.
  21  * 960828       Added new items for PC Watchdog Rev.C card.
  22  * 960829       Changed around all of the IOCTLs, added new features,
  23  *              added watchdog disable/re-enable routines.  Added firmware
  24  *              version reporting.  Added read routine for temperature.
  25  *              Removed some extra defines, added an autodetect Revision
  26  *              routine.
  27  * 961006       Revised some documentation, fixed some cosmetic bugs.  Made
  28  *              drivers to panic the system if it's overheating at bootup.
  29  * 961118       Changed some verbiage on some of the output, tidied up
  30  *              code bits, and added compatibility to 2.1.x.
  31  * 970912       Enabled board on open and disable on close.
  32  * 971107       Took account of recent VFS changes (broke read).
  33  * 971210       Disable board on initialisation in case board already ticking.
  34  * 971222       Changed open/close for temperature handling
  35  *              Michael Meskes <meskes@debian.org>.
  36  * 980112       Used minor numbers from include/linux/miscdevice.h
  37  * 990403       Clear reset status after reading control status register in
  38  *              pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
  39  * 990605       Made changes to code to support Firmware 1.22a, added
  40  *              fairly useless proc entry.
  41  * 990610       removed said useless proc code for the merge <alan>
  42  * 000403       Removed last traces of proc code. <davej>
  43  * 011214       Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
  44  *              Added timeout module option to override default
  45  */
  46
  47 /*
  48  *      A bells and whistles driver is available from http://www.pcwd.de/
  49  *      More info available at http://www.berkprod.com/ or http://www.pcwatchdog.com/
  50  */
  51
  52 #include <linux/module.h>
  53 #include <linux/moduleparam.h>
  54 #include <linux/types.h>
  55 #include <linux/timer.h>
  56 #include <linux/jiffies.h>
  57 #include <linux/config.h>
  58 #include <linux/wait.h>
  59 #include <linux/slab.h>
  60 #include <linux/ioport.h>
  61 #include <linux/delay.h>
  62 #include <linux/fs.h>
  63 #include <linux/miscdevice.h>
  64 #include <linux/watchdog.h>
  65 #include <linux/notifier.h>
  66 #include <linux/init.h>
  67 #include <linux/spinlock.h>
  68 #include <linux/reboot.h>
  69
  70 #include <asm/uaccess.h>
  71 #include <asm/io.h>
  72
  73 #define WD_VER                  "1.16 (06/12/2004)"
  74 #define PFX                     "pcwd: "
  75
  76 /*
  77  * It should be noted that PCWD_REVISION_B was removed because A and B
  78  * are essentially the same types of card, with the exception that B
  79  * has temperature reporting.  Since I didn't receive a Rev.B card,
  80  * the Rev.B card is not supported.  (It's a good thing too, as they
  81  * are no longer in production.)
  82  */
  83 #define PCWD_REVISION_A         1
  84 #define PCWD_REVISION_C         2
  85
  86 /*
  87  * These are the defines that describe the control status bits for the
  88  * PC Watchdog card, revision A.
  89  */
  90 #define WD_WDRST                0x01    /* Previously reset state */
  91 #define WD_T110                 0x02    /* Temperature overheat sense */
  92 #define WD_HRTBT                0x04    /* Heartbeat sense */
  93 #define WD_RLY2                 0x08    /* External relay triggered */
  94 #define WD_SRLY2                0x80    /* Software external relay triggered */
  95
  96 /*
  97  * These are the defines that describe the control status bits for the
  98  * PC Watchdog card, revision C.
  99  */
 100 #define WD_REVC_WTRP            0x01    /* Watchdog Trip status */
 101 #define WD_REVC_HRBT            0x02    /* Watchdog Heartbeat */
 102 #define WD_REVC_TTRP            0x04    /* Temperature Trip status */
 103
 104 /* max. time we give an ISA watchdog card to process a command */
 105 /* 500ms for each 4 bit response (according to spec.) */
 106 #define ISA_COMMAND_TIMEOUT     1000
 107
 108 /* Watchdog's internal commands */
 109 #define CMD_ISA_IDLE                    0x00
 110 #define CMD_ISA_VERSION_INTEGER         0x01
 111 #define CMD_ISA_VERSION_TENTH           0x02
 112 #define CMD_ISA_VERSION_HUNDRETH        0x03
 113 #define CMD_ISA_VERSION_MINOR           0x04
 114 #define CMD_ISA_SWITCH_SETTINGS         0x05
 115 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 116 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 117 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 118
 119 /*
 120  * We are using an kernel timer to do the pinging of the watchdog
 121  * every ~500ms. We try to set the internal heartbeat of the
 122  * watchdog to 2 ms.
 123  */
 124
 125 #define WDT_INTERVAL (HZ/2+1)
 126
 127 /* We can only use 1 card due to the /dev/watchdog restriction */
 128 static int cards_found;
 129
 130 /* internal variables */
 131 static atomic_t open_allowed = ATOMIC_INIT(1);
 132 static char expect_close;
 133 static struct timer_list timer;
 134 static unsigned long next_heartbeat;
 135 static int temp_panic;
 136 static int revision;                    /* The card's revision */
 137 static int supports_temp;               /* Wether or not the card has a temperature device */
 138 static int command_mode;                /* Wether or not the card is in command mode */
 139 static int initial_status;              /* The card's boot status */
 140 static int current_readport;            /* The cards I/O address */
 141 static spinlock_t io_lock;
 142
 143 /* module parameters */
 144 #define WATCHDOG_HEARTBEAT 60           /* 60 sec default heartbeat */
 145 static int heartbeat = WATCHDOG_HEARTBEAT;
 146 module_param(heartbeat, int, 0);
 147 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 148
 149 #ifdef CONFIG_WATCHDOG_NOWAYOUT
 150 static int nowayout = 1;
 151 #else
 152 static int nowayout = 0;
 153 #endif
 154
 155 module_param(nowayout, int, 0);
 156 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 157
 158 /*
 159  *      Internal functions
 160  */
 161
 162 static int send_isa_command(int cmd)
 163 {
 164         int i;
 165         int control_status;
 166         int port0, last_port0;  /* Double read for stabilising */
 167
 168         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 169         control_status = (cmd & 0x0F) | 0x80;
 170         outb_p(control_status, current_readport + 2);
 171         udelay(ISA_COMMAND_TIMEOUT);
 172
 173         port0 = inb_p(current_readport);
 174         for (i = 0; i < 25; ++i) {
 175                 last_port0 = port0;
 176                 port0 = inb_p(current_readport);
 177
 178                 if (port0 == last_port0)
 179                         break;  /* Data is stable */
 180
 181                 udelay (250);
 182         }
 183
 184         return port0;
 185 }
 186
 187 static int set_command_mode(void)
 188 {
 189         int i, found=0, count=0;
 190
 191         /* Set the card into command mode */
 192         spin_lock(&io_lock);
 193         while ((!found) && (count < 3)) {
 194                 i = send_isa_command(CMD_ISA_IDLE);
 195
 196                 if (i == 0x00)
 197                         found = 1;
 198                 else if (i == 0xF3) {
 199                         /* Card does not like what we've done to it */
 200                         outb_p(0x00, current_readport + 2);
 201                         udelay(1200);   /* Spec says wait 1ms */
 202                         outb_p(0x00, current_readport + 2);
 203                         udelay(ISA_COMMAND_TIMEOUT);
 204                 }
 205                 count++;
 206         }
 207         spin_unlock(&io_lock);
 208         command_mode = found;
 209
 210         return(found);
 211 }
 212
 213 static void unset_command_mode(void)
 214 {
 215         /* Set the card into normal mode */
 216         spin_lock(&io_lock);
 217         outb_p(0x00, current_readport + 2);
 218         udelay(ISA_COMMAND_TIMEOUT);
 219         spin_unlock(&io_lock);
 220
 221         command_mode = 0;
 222 }
 223
 224 static void pcwd_timer_ping(unsigned long data)
 225 {
 226         int wdrst_stat;
 227
 228         /* If we got a heartbeat pulse within the WDT_INTERVAL
 229          * we agree to ping the WDT */
 230         if(time_before(jiffies, next_heartbeat)) {
 231                 /* Ping the watchdog */
 232                 spin_lock(&io_lock);
 233                 if (revision == PCWD_REVISION_A) {
 234                         /*  Rev A cards are reset by setting the WD_WDRST bit in register 1 */
 235                         wdrst_stat = inb_p(current_readport);
 236                         wdrst_stat &= 0x0F;
 237                         wdrst_stat |= WD_WDRST;
 238
 239                         outb_p(wdrst_stat, current_readport + 1);
 240                 } else {
 241                         /* Re-trigger watchdog by writing to port 0 */
 242                         outb_p(0x00, current_readport);
 243                 }
 244
 245                 /* Re-set the timer interval */
 246                 mod_timer(&timer, jiffies + WDT_INTERVAL);
 247
 248                 spin_unlock(&io_lock);
 249         } else {
 250                 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
 251         }
 252 }
 253
 254 static int pcwd_start(void)
 255 {
 256         int stat_reg;
 257
 258         next_heartbeat = jiffies + (heartbeat * HZ);
 259
 260         /* Start the timer */
 261         mod_timer(&timer, jiffies + WDT_INTERVAL);
 262
 263         /* Enable the port */
 264         if (revision == PCWD_REVISION_C) {
 265                 spin_lock(&io_lock);
 266                 outb_p(0x00, current_readport + 3);
 267                 udelay(ISA_COMMAND_TIMEOUT);
 268                 stat_reg = inb_p(current_readport + 2);
 269                 spin_unlock(&io_lock);
 270                 if (stat_reg & 0x10) {
 271                         printk(KERN_INFO PFX "Could not start watchdog\n");
 272                         return -EIO;
 273                 }
 274         }
 275         return 0;
 276 }
 277
 278 static int pcwd_stop(void)
 279 {
 280         int stat_reg;
 281
 282         /* Stop the timer */
 283         del_timer(&timer);
 284
 285         /*  Disable the board  */
 286         if (revision == PCWD_REVISION_C) {
 287                 spin_lock(&io_lock);
 288                 outb_p(0xA5, current_readport + 3);
 289                 udelay(ISA_COMMAND_TIMEOUT);
 290                 outb_p(0xA5, current_readport + 3);
 291                 udelay(ISA_COMMAND_TIMEOUT);
 292                 stat_reg = inb_p(current_readport + 2);
 293                 spin_unlock(&io_lock);
 294                 if ((stat_reg & 0x10) == 0) {
 295                         printk(KERN_INFO PFX "Could not stop watchdog\n");
 296                         return -EIO;
 297                 }
 298         }
 299         return 0;
 300 }
 301
 302 static int pcwd_keepalive(void)
 303 {
 304         /* user land ping */
 305         next_heartbeat = jiffies + (heartbeat * HZ);
 306         return 0;
 307 }
 308
 309 static int pcwd_set_heartbeat(int t)
 310 {
 311         if ((t < 2) || (t > 7200)) /* arbitrary upper limit */
 312                 return -EINVAL;
 313
 314         heartbeat = t;
 315         return 0;
 316 }
 317
 318 static int pcwd_get_status(int *status)
 319 {
 320         int card_status;
 321
 322         *status=0;
 323         spin_lock(&io_lock);
 324         if (revision == PCWD_REVISION_A)
 325                 /* Rev A cards return status information from
 326                  * the base register, which is used for the
 327                  * temperature in other cards. */
 328                 card_status = inb(current_readport);
 329         else {
 330                 /* Rev C cards return card status in the base
 331                  * address + 1 register. And use different bits
 332                  * to indicate a card initiated reset, and an
 333                  * over-temperature condition. And the reboot
 334                  * status can be reset. */
 335                 card_status = inb(current_readport + 1);
 336         }
 337         spin_unlock(&io_lock);
 338
 339         if (revision == PCWD_REVISION_A) {
 340                 if (card_status & WD_WDRST)
 341                         *status |= WDIOF_CARDRESET;
 342
 343                 if (card_status & WD_T110) {
 344                         *status |= WDIOF_OVERHEAT;
 345                         if (temp_panic) {
 346                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 347                                 machine_power_off();
 348                         }
 349                 }
 350         } else {
 351                 if (card_status & WD_REVC_WTRP)
 352                         *status |= WDIOF_CARDRESET;
 353
 354                 if (card_status & WD_REVC_TTRP) {
 355                         *status |= WDIOF_OVERHEAT;
 356                         if (temp_panic) {
 357                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 358                                 machine_power_off();
 359                         }
 360                 }
 361         }
 362
 363         return 0;
 364 }
 365
 366 static int pcwd_clear_status(void)
 367 {
 368         if (revision == PCWD_REVISION_C) {
 369                 spin_lock(&io_lock);
 370                 outb_p(0x00, current_readport + 1); /* clear reset status */
 371                 spin_unlock(&io_lock);
 372         }
 373         return 0;
 374 }
 375
 376 static int pcwd_get_temperature(int *temperature)
 377 {
 378         /* check that port 0 gives temperature info and no command results */
 379         if (command_mode)
 380                 return -1;
 381
 382         *temperature = 0;
 383         if (!supports_temp)
 384                 return -ENODEV;
 385
 386         /*
 387          * Convert celsius to fahrenheit, since this was
 388          * the decided 'standard' for this return value.
 389          */
 390         spin_lock(&io_lock);
 391         *temperature = ((inb(current_readport)) * 9 / 5) + 32;
 392         spin_unlock(&io_lock);
 393
 394         return 0;
 395 }
 396
 397 /*
 398  *      /dev/watchdog handling
 399  */
 400
 401 static int pcwd_ioctl(struct inode *inode, struct file *file,
 402                       unsigned int cmd, unsigned long arg)
 403 {
 404         int rv;
 405         int status;
 406         int temperature;
 407         int new_heartbeat;
 408         int __user *argp = (int __user *)arg;
 409         static struct watchdog_info ident = {
 410                 .options =              WDIOF_OVERHEAT |
 411                                         WDIOF_CARDRESET |
 412                                         WDIOF_KEEPALIVEPING |
 413                                         WDIOF_SETTIMEOUT |
 414                                         WDIOF_MAGICCLOSE,
 415                 .firmware_version =     1,
 416                 .identity =             "PCWD",
 417         };
 418
 419         switch(cmd) {
 420         default:
 421                 return -ENOIOCTLCMD;
 422
 423         case WDIOC_GETSUPPORT:
 424                 if(copy_to_user(argp, &ident, sizeof(ident)))
 425                         return -EFAULT;
 426                 return 0;
 427
 428         case WDIOC_GETSTATUS:
 429                 pcwd_get_status(&status);
 430                 return put_user(status, argp);
 431
 432         case WDIOC_GETBOOTSTATUS:
 433                 return put_user(initial_status, argp);
 434
 435         case WDIOC_GETTEMP:
 436                 if (pcwd_get_temperature(&temperature))
 437                         return -EFAULT;
 438
 439                 return put_user(temperature, argp);
 440
 441         case WDIOC_SETOPTIONS:
 442                 if (revision == PCWD_REVISION_C)
 443                 {
 444                         if(copy_from_user(&rv, argp, sizeof(int)))
 445                                 return -EFAULT;
 446
 447                         if (rv & WDIOS_DISABLECARD)
 448                         {
 449                                 return pcwd_stop();
 450                         }
 451
 452                         if (rv & WDIOS_ENABLECARD)
 453                         {
 454                                 return pcwd_start();
 455                         }
 456
 457                         if (rv & WDIOS_TEMPPANIC)
 458                         {
 459                                 temp_panic = 1;
 460                         }
 461                 }
 462                 return -EINVAL;
 463
 464         case WDIOC_KEEPALIVE:
 465                 pcwd_keepalive();
 466                 return 0;
 467
 468         case WDIOC_SETTIMEOUT:
 469                 if (get_user(new_heartbeat, argp))
 470                         return -EFAULT;
 471
 472                 if (pcwd_set_heartbeat(new_heartbeat))
 473                         return -EINVAL;
 474
 475                 pcwd_keepalive();
 476                 /* Fall */
 477
 478         case WDIOC_GETTIMEOUT:
 479                 return put_user(heartbeat, argp);
 480         }
 481
 482         return 0;
 483 }
 484
 485 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 486                           loff_t *ppos)
 487 {
 488         if (len) {
 489                 if (!nowayout) {
 490                         size_t i;
 491
 492                         /* In case it was set long ago */
 493                         expect_close = 0;
 494
 495                         for (i = 0; i != len; i++) {
 496                                 char c;
 497
 498                                 if (get_user(c, buf + i))
 499                                         return -EFAULT;
 500                                 if (c == 'V')
 501                                         expect_close = 42;
 502                         }
 503                 }
 504                 pcwd_keepalive();
 505         }
 506         return len;
 507 }
 508
 509 static int pcwd_open(struct inode *inode, struct file *file)
 510 {
 511         if (!atomic_dec_and_test(&open_allowed) ) {
 512                 atomic_inc( &open_allowed );
 513                 return -EBUSY;
 514         }
 515
 516         if (nowayout)
 517                 __module_get(THIS_MODULE);
 518
 519         /* Activate */
 520         pcwd_start();
 521         pcwd_keepalive();
 522         return nonseekable_open(inode, file);
 523 }
 524
 525 static int pcwd_close(struct inode *inode, struct file *file)
 526 {
 527         if (expect_close == 42) {
 528                 pcwd_stop();
 529         } else {
 530                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 531                 pcwd_keepalive();
 532         }
 533         expect_close = 0;
 534         atomic_inc( &open_allowed );
 535         return 0;
 536 }
 537
 538 /*
 539  *      /dev/temperature handling
 540  */
 541
 542 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 543                          loff_t *ppos)
 544 {
 545         int temperature;
 546
 547         if (pcwd_get_temperature(&temperature))
 548                 return -EFAULT;
 549
 550         if (copy_to_user(buf, &temperature, 1))
 551                 return -EFAULT;
 552
 553         return 1;
 554 }
 555
 556 static int pcwd_temp_open(struct inode *inode, struct file *file)
 557 {
 558         if (!supports_temp)
 559                 return -ENODEV;
 560
 561         return nonseekable_open(inode, file);
 562 }
 563
 564 static int pcwd_temp_close(struct inode *inode, struct file *file)
 565 {
 566         return 0;
 567 }
 568
 569 /*
 570  *      Notify system
 571  */
 572
 573 static int pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 574 {
 575         if (code==SYS_DOWN || code==SYS_HALT) {
 576                 /* Turn the WDT off */
 577                 pcwd_stop();
 578         }
 579
 580         return NOTIFY_DONE;
 581 }
 582
 583 /*
 584  *      Kernel Interfaces
 585  */
 586
 587 static struct file_operations pcwd_fops = {
 588         .owner          = THIS_MODULE,
 589         .llseek         = no_llseek,
 590         .write          = pcwd_write,
 591         .ioctl          = pcwd_ioctl,
 592         .open           = pcwd_open,
 593         .release        = pcwd_close,
 594 };
 595
 596 static struct miscdevice pcwd_miscdev = {
 597         .minor =        WATCHDOG_MINOR,
 598         .name =         "watchdog",
 599         .fops =         &pcwd_fops,
 600 };
 601
 602 static struct file_operations pcwd_temp_fops = {
 603         .owner          = THIS_MODULE,
 604         .llseek         = no_llseek,
 605         .read           = pcwd_temp_read,
 606         .open           = pcwd_temp_open,
 607         .release        = pcwd_temp_close,
 608 };
 609
 610 static struct miscdevice temp_miscdev = {
 611         .minor =        TEMP_MINOR,
 612         .name =         "temperature",
 613         .fops =         &pcwd_temp_fops,
 614 };
 615
 616 static struct notifier_block pcwd_notifier = {
 617         .notifier_call =        pcwd_notify_sys,
 618 };
 619
 620 /*
 621  *      Init & exit routines
 622  */
 623
 624 static inline void get_support(void)
 625 {
 626         if (inb(current_readport) != 0xF0)
 627                 supports_temp = 1;
 628 }
 629
 630 static inline int get_revision(void)
 631 {
 632         int r = PCWD_REVISION_C;
 633
 634         spin_lock(&io_lock);
 635         /* REV A cards use only 2 io ports; test
 636          * presumes a floating bus reads as 0xff. */
 637         if ((inb(current_readport + 2) == 0xFF) ||
 638             (inb(current_readport + 3) == 0xFF))
 639                 r=PCWD_REVISION_A;
 640         spin_unlock(&io_lock);
 641
 642         return r;
 643 }
 644
 645 static inline char *get_firmware(void)
 646 {
 647         int one, ten, hund, minor;
 648         char *ret;
 649
 650         ret = kmalloc(6, GFP_KERNEL);
 651         if(ret == NULL)
 652                 return NULL;
 653
 654         if (set_command_mode()) {
 655                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 656                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 657                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 658                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 659                 sprintf(ret, "%c.%c%c%c", one, ten, hund, minor);
 660         }
 661         else
 662                 sprintf(ret, "ERROR");
 663
 664         unset_command_mode();
 665         return(ret);
 666 }
 667
 668 static inline int get_option_switches(void)
 669 {
 670         int rv=0;
 671
 672         if (set_command_mode()) {
 673                 /* Get switch settings */
 674                 rv = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 675         }
 676
 677         unset_command_mode();
 678         return(rv);
 679 }
 680
 681 static int __devinit pcwatchdog_init(int base_addr)
 682 {
 683         int ret;
 684         char *firmware;
 685         int option_switches;
 686
 687         cards_found++;
 688         if (cards_found == 1)
 689                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER);
 690
 691         if (cards_found > 1) {
 692                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 693                 return -ENODEV;
 694         }
 695
 696         if (base_addr == 0x0000) {
 697                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 698                 return -ENODEV;
 699         }
 700         current_readport = base_addr;
 701
 702         /* Check card's revision */
 703         revision = get_revision();
 704
 705         if (!request_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 706                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 707                         current_readport);
 708                 current_readport = 0x0000;
 709                 return -EIO;
 710         }
 711
 712         /* Initial variables */
 713         supports_temp = 0;
 714         temp_panic = 0;
 715         initial_status = 0x0000;
 716
 717         /* get the boot_status */
 718         pcwd_get_status(&initial_status);
 719
 720         /* clear the "card caused reboot" flag */
 721         pcwd_clear_status();
 722
 723         init_timer(&timer);
 724         timer.function = pcwd_timer_ping;
 725         timer.data = 0;
 726
 727         /*  Disable the board  */
 728         pcwd_stop();
 729
 730         /*  Check whether or not the card supports the temperature device */
 731         get_support();
 732
 733         /* Get some extra info from the hardware (in command/debug/diag mode) */
 734         if (revision == PCWD_REVISION_A)
 735                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", current_readport);
 736         else if (revision == PCWD_REVISION_C) {
 737                 firmware = get_firmware();
 738                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 739                         current_readport, firmware);
 740                 kfree(firmware);
 741                 option_switches = get_option_switches();
 742                 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 743                         option_switches,
 744                         ((option_switches & 0x10) ? "ON" : "OFF"),
 745                         ((option_switches & 0x08) ? "ON" : "OFF"));
 746
 747                 /* Reprogram internal heartbeat to 2 seconds */
 748                 if (set_command_mode()) {
 749                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 750                         unset_command_mode();
 751                 }
 752         } else {
 753                 /* Should NEVER happen, unless get_revision() fails. */
 754                 printk(KERN_INFO PFX "Unable to get revision\n");
 755                 release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
 756                 current_readport = 0x0000;
 757                 return -1;
 758         }
 759
 760         if (supports_temp)
 761                 printk(KERN_INFO PFX "Temperature Option Detected\n");
 762
 763         if (initial_status & WDIOF_CARDRESET)
 764                 printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
 765
 766         if (initial_status & WDIOF_OVERHEAT) {
 767                 printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
 768                 printk(KERN_EMERG PFX "CPU Overheat\n");
 769         }
 770
 771         if (initial_status == 0)
 772                 printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");
 773
 774         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 775         if (pcwd_set_heartbeat(heartbeat)) {
 776                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 777                 printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
 778                         WATCHDOG_HEARTBEAT);
 779         }
 780
 781         ret = register_reboot_notifier(&pcwd_notifier);
 782         if (ret) {
 783                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 784                         ret);
 785                 release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
 786                 current_readport = 0x0000;
 787                 return ret;
 788         }
 789
 790         if (supports_temp) {
 791                 ret = misc_register(&temp_miscdev);
 792                 if (ret) {
 793                         printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 794                                 TEMP_MINOR, ret);
 795                         unregister_reboot_notifier(&pcwd_notifier);
 796                         release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
 797                         current_readport = 0x0000;
 798                         return ret;
 799                 }
 800         }
 801
 802         ret = misc_register(&pcwd_miscdev);
 803         if (ret) {
 804                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 805                         WATCHDOG_MINOR, ret);
 806                 if (supports_temp)
 807                         misc_deregister(&temp_miscdev);
 808                 unregister_reboot_notifier(&pcwd_notifier);
 809                 release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
 810                 current_readport = 0x0000;
 811                 return ret;
 812         }
 813
 814         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 815                 heartbeat, nowayout);
 816
 817         return 0;
 818 }
 819
 820 static void __devexit pcwatchdog_exit(void)
 821 {
 822         /*  Disable the board  */
 823         if (!nowayout)
 824                 pcwd_stop();
 825
 826         /* Deregister */
 827         misc_deregister(&pcwd_miscdev);
 828         if (supports_temp)
 829                 misc_deregister(&temp_miscdev);
 830         unregister_reboot_notifier(&pcwd_notifier);
 831         release_region(current_readport, (revision == PCWD_REVISION_A) ? 2 : 4);
 832         current_readport = 0x0000;
 833 }
 834
 835 /*
 836  *  The ISA cards have a heartbeat bit in one of the registers, which
 837  *  register is card dependent.  The heartbeat bit is monitored, and if
 838  *  found, is considered proof that a Berkshire card has been found.
 839  *  The initial rate is once per second at board start up, then twice
 840  *  per second for normal operation.
 841  */
 842 static int __init pcwd_checkcard(int base_addr)
 843 {
 844         int port0, last_port0;  /* Reg 0, in case it's REV A */
 845         int port1, last_port1;  /* Register 1 for REV C cards */
 846         int i;
 847         int retval;
 848
 849         if (!request_region (base_addr, 4, "PCWD")) {
 850                 printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 851                 return 0;
 852         }
 853
 854         retval = 0;
 855
 856         port0 = inb_p(base_addr);       /* For REV A boards */
 857         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 858         if (port0 != 0xff || port1 != 0xff) {
 859                 /* Not an 'ff' from a floating bus, so must be a card! */
 860                 for (i = 0; i < 4; ++i) {
 861
 862                         msleep(500);
 863
 864                         last_port0 = port0;
 865                         last_port1 = port1;
 866
 867                         port0 = inb_p(base_addr);
 868                         port1 = inb_p(base_addr + 1);
 869
 870                         /* Has either hearbeat bit changed?  */
 871                         if ((port0 ^ last_port0) & WD_HRTBT ||
 872                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 873                                 retval = 1;
 874                                 break;
 875                         }
 876                 }
 877         }
 878         release_region (base_addr, 4);
 879
 880         return retval;
 881 }
 882
 883 /*
 884  * These are the auto-probe addresses available.
 885  *
 886  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
 887  * Revision A has an address range of 2 addresses, while Revision C has 4.
 888  */
 889 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
 890
 891 static int __init pcwd_init_module(void)
 892 {
 893         int i, found = 0;
 894
 895         spin_lock_init(&io_lock);
 896
 897         for (i = 0; pcwd_ioports[i] != 0; i++) {
 898                 if (pcwd_checkcard(pcwd_ioports[i])) {
 899                         if (!(pcwatchdog_init(pcwd_ioports[i])))
 900                                 found++;
 901                 }
 902         }
 903
 904         if (!found) {
 905                 printk (KERN_INFO PFX "No card detected, or port not available\n");
 906                 return -ENODEV;
 907         }
 908
 909         return 0;
 910 }
 911
 912 static void __exit pcwd_cleanup_module(void)
 913 {
 914         if (current_readport)
 915                 pcwatchdog_exit();
 916         return;
 917 }
 918
 919 module_init(pcwd_init_module);
 920 module_exit(pcwd_cleanup_module);
 921
 922 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>");
 923 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
 924 MODULE_LICENSE("GPL");
 925 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 926 MODULE_ALIAS_MISCDEV(TEMP_MINOR);