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/config.h>       /* For CONFIG_WATCHDOG_NOWAYOUT/... */
  53 #include <linux/module.h>       /* For module specific items */
  54 #include <linux/moduleparam.h>  /* For new moduleparam's */
  55 #include <linux/types.h>        /* For standard types (like size_t) */
  56 #include <linux/errno.h>        /* For the -ENODEV/... values */
  57 #include <linux/kernel.h>       /* For printk/panic/... */
  58 #include <linux/delay.h>        /* For mdelay function */
  59 #include <linux/timer.h>        /* For timer related operations */
  60 #include <linux/jiffies.h>      /* For jiffies stuff */
  61 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  62 #include <linux/watchdog.h>     /* For the watchdog specific items */
  63 #include <linux/notifier.h>     /* For notifier support */
  64 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  65 #include <linux/init.h>         /* For __init/__exit/... */
  66 #include <linux/fs.h>           /* For file operations */
  67 #include <linux/ioport.h>       /* For io-port access */
  68 #include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  69 #include <linux/sched.h>        /* TASK_INTERRUPTIBLE, set_current_state() and friends */
  70 #include <linux/slab.h>         /* For kmalloc */
  71
  72 #include <asm/uaccess.h>        /* For copy_to_user/put_user/... */
  73 #include <asm/io.h>             /* For inb/outb/... */
  74
  75 /* Module and version information */
  76 #define WD_VER                  "1.16 (03/01/2006)"
  77 #define PFX                     "pcwd: "
  78
  79 /*
  80  * It should be noted that PCWD_REVISION_B was removed because A and B
  81  * are essentially the same types of card, with the exception that B
  82  * has temperature reporting.  Since I didn't receive a Rev.B card,
  83  * the Rev.B card is not supported.  (It's a good thing too, as they
  84  * are no longer in production.)
  85  */
  86 #define PCWD_REVISION_A         1
  87 #define PCWD_REVISION_C         2
  88
  89 /*
  90  * These are the defines that describe the control status bits for the
  91  * PCI-PC Watchdog card.
  92 */
  93 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
  94 #define WD_WDRST                0x01    /* Previously reset state */
  95 #define WD_T110                 0x02    /* Temperature overheat sense */
  96 #define WD_HRTBT                0x04    /* Heartbeat sense */
  97 #define WD_RLY2                 0x08    /* External relay triggered */
  98 #define WD_SRLY2                0x80    /* Software external relay triggered */
  99 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 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 /* Port 2 : Control Status #2 */
 104 #define WD_WDIS                 0x10    /* Watchdog Disabled */
 105 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 106 #define WD_SSEL                 0x40    /* Watchdog Switch Select (1:SW1 <-> 0:SW2) */
 107 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
 108
 109 /* max. time we give an ISA watchdog card to process a command */
 110 /* 500ms for each 4 bit response (according to spec.) */
 111 #define ISA_COMMAND_TIMEOUT     1000
 112
 113 /* Watchdog's internal commands */
 114 #define CMD_ISA_IDLE                    0x00
 115 #define CMD_ISA_VERSION_INTEGER         0x01
 116 #define CMD_ISA_VERSION_TENTH           0x02
 117 #define CMD_ISA_VERSION_HUNDRETH        0x03
 118 #define CMD_ISA_VERSION_MINOR           0x04
 119 #define CMD_ISA_SWITCH_SETTINGS         0x05
 120 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 121 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 122 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 123
 124 /*
 125  * We are using an kernel timer to do the pinging of the watchdog
 126  * every ~500ms. We try to set the internal heartbeat of the
 127  * watchdog to 2 ms.
 128  */
 129
 130 #define WDT_INTERVAL (HZ/2+1)
 131
 132 /* We can only use 1 card due to the /dev/watchdog restriction */
 133 static int cards_found;
 134
 135 /* internal variables */
 136 static atomic_t open_allowed = ATOMIC_INIT(1);
 137 static char expect_close;
 138 static int temp_panic;
 139 static struct {                         /* this is private data for each ISA-PC watchdog card */
 140         int revision;                   /* The card's revision */
 141         int supports_temp;              /* Wether or not the card has a temperature device */
 142         int command_mode;               /* Wether or not the card is in command mode */
 143         int boot_status;                /* The card's boot status */
 144         int io_addr;                    /* The cards I/O address */
 145         spinlock_t io_lock;             /* the lock for io operations */
 146         struct timer_list timer;        /* The timer that pings the watchdog */
 147         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 148 } pcwd_private;
 149
 150 /* module parameters */
 151 #define WATCHDOG_HEARTBEAT 60           /* 60 sec default heartbeat */
 152 static int heartbeat = WATCHDOG_HEARTBEAT;
 153 module_param(heartbeat, int, 0);
 154 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 155
 156 static int nowayout = WATCHDOG_NOWAYOUT;
 157 module_param(nowayout, int, 0);
 158 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 159
 160 /*
 161  *      Internal functions
 162  */
 163
 164 static int send_isa_command(int cmd)
 165 {
 166         int i;
 167         int control_status;
 168         int port0, last_port0;  /* Double read for stabilising */
 169
 170         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 171         control_status = (cmd & 0x0F) | WD_WCMD;
 172         outb_p(control_status, pcwd_private.io_addr + 2);
 173         udelay(ISA_COMMAND_TIMEOUT);
 174
 175         port0 = inb_p(pcwd_private.io_addr);
 176         for (i = 0; i < 25; ++i) {
 177                 last_port0 = port0;
 178                 port0 = inb_p(pcwd_private.io_addr);
 179
 180                 if (port0 == last_port0)
 181                         break;  /* Data is stable */
 182
 183                 udelay (250);
 184         }
 185
 186         return port0;
 187 }
 188
 189 static int set_command_mode(void)
 190 {
 191         int i, found=0, count=0;
 192
 193         /* Set the card into command mode */
 194         spin_lock(&pcwd_private.io_lock);
 195         while ((!found) && (count < 3)) {
 196                 i = send_isa_command(CMD_ISA_IDLE);
 197
 198                 if (i == 0x00)
 199                         found = 1;
 200                 else if (i == 0xF3) {
 201                         /* Card does not like what we've done to it */
 202                         outb_p(0x00, pcwd_private.io_addr + 2);
 203                         udelay(1200);   /* Spec says wait 1ms */
 204                         outb_p(0x00, pcwd_private.io_addr + 2);
 205                         udelay(ISA_COMMAND_TIMEOUT);
 206                 }
 207                 count++;
 208         }
 209         spin_unlock(&pcwd_private.io_lock);
 210         pcwd_private.command_mode = found;
 211
 212         return(found);
 213 }
 214
 215 static void unset_command_mode(void)
 216 {
 217         /* Set the card into normal mode */
 218         spin_lock(&pcwd_private.io_lock);
 219         outb_p(0x00, pcwd_private.io_addr + 2);
 220         udelay(ISA_COMMAND_TIMEOUT);
 221         spin_unlock(&pcwd_private.io_lock);
 222
 223         pcwd_private.command_mode = 0;
 224 }
 225
 226 static void pcwd_timer_ping(unsigned long data)
 227 {
 228         int wdrst_stat;
 229
 230         /* If we got a heartbeat pulse within the WDT_INTERVAL
 231          * we agree to ping the WDT */
 232         if(time_before(jiffies, pcwd_private.next_heartbeat)) {
 233                 /* Ping the watchdog */
 234                 spin_lock(&pcwd_private.io_lock);
 235                 if (pcwd_private.revision == PCWD_REVISION_A) {
 236                         /*  Rev A cards are reset by setting the WD_WDRST bit in register 1 */
 237                         wdrst_stat = inb_p(pcwd_private.io_addr);
 238                         wdrst_stat &= 0x0F;
 239                         wdrst_stat |= WD_WDRST;
 240
 241                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 242                 } else {
 243                         /* Re-trigger watchdog by writing to port 0 */
 244                         outb_p(0x00, pcwd_private.io_addr);
 245                 }
 246
 247                 /* Re-set the timer interval */
 248                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 249
 250                 spin_unlock(&pcwd_private.io_lock);
 251         } else {
 252                 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
 253         }
 254 }
 255
 256 static int pcwd_start(void)
 257 {
 258         int stat_reg;
 259
 260         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 261
 262         /* Start the timer */
 263         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 264
 265         /* Enable the port */
 266         if (pcwd_private.revision == PCWD_REVISION_C) {
 267                 spin_lock(&pcwd_private.io_lock);
 268                 outb_p(0x00, pcwd_private.io_addr + 3);
 269                 udelay(ISA_COMMAND_TIMEOUT);
 270                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 271                 spin_unlock(&pcwd_private.io_lock);
 272                 if (stat_reg & WD_WDIS) {
 273                         printk(KERN_INFO PFX "Could not start watchdog\n");
 274                         return -EIO;
 275                 }
 276         }
 277         return 0;
 278 }
 279
 280 static int pcwd_stop(void)
 281 {
 282         int stat_reg;
 283
 284         /* Stop the timer */
 285         del_timer(&pcwd_private.timer);
 286
 287         /*  Disable the board  */
 288         if (pcwd_private.revision == PCWD_REVISION_C) {
 289                 spin_lock(&pcwd_private.io_lock);
 290                 outb_p(0xA5, pcwd_private.io_addr + 3);
 291                 udelay(ISA_COMMAND_TIMEOUT);
 292                 outb_p(0xA5, pcwd_private.io_addr + 3);
 293                 udelay(ISA_COMMAND_TIMEOUT);
 294                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 295                 spin_unlock(&pcwd_private.io_lock);
 296                 if ((stat_reg & WD_WDIS) == 0) {
 297                         printk(KERN_INFO PFX "Could not stop watchdog\n");
 298                         return -EIO;
 299                 }
 300         }
 301         return 0;
 302 }
 303
 304 static int pcwd_keepalive(void)
 305 {
 306         /* user land ping */
 307         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 308         return 0;
 309 }
 310
 311 static int pcwd_set_heartbeat(int t)
 312 {
 313         if ((t < 2) || (t > 7200)) /* arbitrary upper limit */
 314                 return -EINVAL;
 315
 316         heartbeat = t;
 317         return 0;
 318 }
 319
 320 static int pcwd_get_status(int *status)
 321 {
 322         int card_status;
 323
 324         *status=0;
 325         spin_lock(&pcwd_private.io_lock);
 326         if (pcwd_private.revision == PCWD_REVISION_A)
 327                 /* Rev A cards return status information from
 328                  * the base register, which is used for the
 329                  * temperature in other cards. */
 330                 card_status = inb(pcwd_private.io_addr);
 331         else {
 332                 /* Rev C cards return card status in the base
 333                  * address + 1 register. And use different bits
 334                  * to indicate a card initiated reset, and an
 335                  * over-temperature condition. And the reboot
 336                  * status can be reset. */
 337                 card_status = inb(pcwd_private.io_addr + 1);
 338         }
 339         spin_unlock(&pcwd_private.io_lock);
 340
 341         if (pcwd_private.revision == PCWD_REVISION_A) {
 342                 if (card_status & WD_WDRST)
 343                         *status |= WDIOF_CARDRESET;
 344
 345                 if (card_status & WD_T110) {
 346                         *status |= WDIOF_OVERHEAT;
 347                         if (temp_panic) {
 348                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 349                                 kernel_power_off();
 350                         }
 351                 }
 352         } else {
 353                 if (card_status & WD_REVC_WTRP)
 354                         *status |= WDIOF_CARDRESET;
 355
 356                 if (card_status & WD_REVC_TTRP) {
 357                         *status |= WDIOF_OVERHEAT;
 358                         if (temp_panic) {
 359                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 360                                 kernel_power_off();
 361                         }
 362                 }
 363         }
 364
 365         return 0;
 366 }
 367
 368 static int pcwd_clear_status(void)
 369 {
 370         if (pcwd_private.revision == PCWD_REVISION_C) {
 371                 spin_lock(&pcwd_private.io_lock);
 372                 outb_p(0x00, pcwd_private.io_addr + 1); /* clear reset status */
 373                 spin_unlock(&pcwd_private.io_lock);
 374         }
 375         return 0;
 376 }
 377
 378 static int pcwd_get_temperature(int *temperature)
 379 {
 380         /* check that port 0 gives temperature info and no command results */
 381         if (pcwd_private.command_mode)
 382                 return -1;
 383
 384         *temperature = 0;
 385         if (!pcwd_private.supports_temp)
 386                 return -ENODEV;
 387
 388         /*
 389          * Convert celsius to fahrenheit, since this was
 390          * the decided 'standard' for this return value.
 391          */
 392         spin_lock(&pcwd_private.io_lock);
 393         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 394         spin_unlock(&pcwd_private.io_lock);
 395
 396         return 0;
 397 }
 398
 399 /*
 400  *      /dev/watchdog handling
 401  */
 402
 403 static int pcwd_ioctl(struct inode *inode, struct file *file,
 404                       unsigned int cmd, unsigned long arg)
 405 {
 406         int rv;
 407         int status;
 408         int temperature;
 409         int new_heartbeat;
 410         int __user *argp = (int __user *)arg;
 411         static struct watchdog_info ident = {
 412                 .options =              WDIOF_OVERHEAT |
 413                                         WDIOF_CARDRESET |
 414                                         WDIOF_KEEPALIVEPING |
 415                                         WDIOF_SETTIMEOUT |
 416                                         WDIOF_MAGICCLOSE,
 417                 .firmware_version =     1,
 418                 .identity =             "PCWD",
 419         };
 420
 421         switch(cmd) {
 422         default:
 423                 return -ENOIOCTLCMD;
 424
 425         case WDIOC_GETSUPPORT:
 426                 if(copy_to_user(argp, &ident, sizeof(ident)))
 427                         return -EFAULT;
 428                 return 0;
 429
 430         case WDIOC_GETSTATUS:
 431                 pcwd_get_status(&status);
 432                 return put_user(status, argp);
 433
 434         case WDIOC_GETBOOTSTATUS:
 435                 return put_user(pcwd_private.boot_status, argp);
 436
 437         case WDIOC_GETTEMP:
 438                 if (pcwd_get_temperature(&temperature))
 439                         return -EFAULT;
 440
 441                 return put_user(temperature, argp);
 442
 443         case WDIOC_SETOPTIONS:
 444                 if (pcwd_private.revision == PCWD_REVISION_C)
 445                 {
 446                         if(copy_from_user(&rv, argp, sizeof(int)))
 447                                 return -EFAULT;
 448
 449                         if (rv & WDIOS_DISABLECARD)
 450                         {
 451                                 return pcwd_stop();
 452                         }
 453
 454                         if (rv & WDIOS_ENABLECARD)
 455                         {
 456                                 return pcwd_start();
 457                         }
 458
 459                         if (rv & WDIOS_TEMPPANIC)
 460                         {
 461                                 temp_panic = 1;
 462                         }
 463                 }
 464                 return -EINVAL;
 465
 466         case WDIOC_KEEPALIVE:
 467                 pcwd_keepalive();
 468                 return 0;
 469
 470         case WDIOC_SETTIMEOUT:
 471                 if (get_user(new_heartbeat, argp))
 472                         return -EFAULT;
 473
 474                 if (pcwd_set_heartbeat(new_heartbeat))
 475                         return -EINVAL;
 476
 477                 pcwd_keepalive();
 478                 /* Fall */
 479
 480         case WDIOC_GETTIMEOUT:
 481                 return put_user(heartbeat, argp);
 482         }
 483
 484         return 0;
 485 }
 486
 487 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 488                           loff_t *ppos)
 489 {
 490         if (len) {
 491                 if (!nowayout) {
 492                         size_t i;
 493
 494                         /* In case it was set long ago */
 495                         expect_close = 0;
 496
 497                         for (i = 0; i != len; i++) {
 498                                 char c;
 499
 500                                 if (get_user(c, buf + i))
 501                                         return -EFAULT;
 502                                 if (c == 'V')
 503                                         expect_close = 42;
 504                         }
 505                 }
 506                 pcwd_keepalive();
 507         }
 508         return len;
 509 }
 510
 511 static int pcwd_open(struct inode *inode, struct file *file)
 512 {
 513         if (!atomic_dec_and_test(&open_allowed) ) {
 514                 atomic_inc( &open_allowed );
 515                 return -EBUSY;
 516         }
 517
 518         if (nowayout)
 519                 __module_get(THIS_MODULE);
 520
 521         /* Activate */
 522         pcwd_start();
 523         pcwd_keepalive();
 524         return nonseekable_open(inode, file);
 525 }
 526
 527 static int pcwd_close(struct inode *inode, struct file *file)
 528 {
 529         if (expect_close == 42) {
 530                 pcwd_stop();
 531         } else {
 532                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 533                 pcwd_keepalive();
 534         }
 535         expect_close = 0;
 536         atomic_inc( &open_allowed );
 537         return 0;
 538 }
 539
 540 /*
 541  *      /dev/temperature handling
 542  */
 543
 544 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 545                          loff_t *ppos)
 546 {
 547         int temperature;
 548
 549         if (pcwd_get_temperature(&temperature))
 550                 return -EFAULT;
 551
 552         if (copy_to_user(buf, &temperature, 1))
 553                 return -EFAULT;
 554
 555         return 1;
 556 }
 557
 558 static int pcwd_temp_open(struct inode *inode, struct file *file)
 559 {
 560         if (!pcwd_private.supports_temp)
 561                 return -ENODEV;
 562
 563         return nonseekable_open(inode, file);
 564 }
 565
 566 static int pcwd_temp_close(struct inode *inode, struct file *file)
 567 {
 568         return 0;
 569 }
 570
 571 /*
 572  *      Notify system
 573  */
 574
 575 static int pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 576 {
 577         if (code==SYS_DOWN || code==SYS_HALT) {
 578                 /* Turn the WDT off */
 579                 pcwd_stop();
 580         }
 581
 582         return NOTIFY_DONE;
 583 }
 584
 585 /*
 586  *      Kernel Interfaces
 587  */
 588
 589 static struct file_operations pcwd_fops = {
 590         .owner          = THIS_MODULE,
 591         .llseek         = no_llseek,
 592         .write          = pcwd_write,
 593         .ioctl          = pcwd_ioctl,
 594         .open           = pcwd_open,
 595         .release        = pcwd_close,
 596 };
 597
 598 static struct miscdevice pcwd_miscdev = {
 599         .minor =        WATCHDOG_MINOR,
 600         .name =         "watchdog",
 601         .fops =         &pcwd_fops,
 602 };
 603
 604 static struct file_operations pcwd_temp_fops = {
 605         .owner          = THIS_MODULE,
 606         .llseek         = no_llseek,
 607         .read           = pcwd_temp_read,
 608         .open           = pcwd_temp_open,
 609         .release        = pcwd_temp_close,
 610 };
 611
 612 static struct miscdevice temp_miscdev = {
 613         .minor =        TEMP_MINOR,
 614         .name =         "temperature",
 615         .fops =         &pcwd_temp_fops,
 616 };
 617
 618 static struct notifier_block pcwd_notifier = {
 619         .notifier_call =        pcwd_notify_sys,
 620 };
 621
 622 /*
 623  *      Init & exit routines
 624  */
 625
 626 static inline void get_support(void)
 627 {
 628         if (inb(pcwd_private.io_addr) != 0xF0)
 629                 pcwd_private.supports_temp = 1;
 630 }
 631
 632 static inline int get_revision(void)
 633 {
 634         int r = PCWD_REVISION_C;
 635
 636         spin_lock(&pcwd_private.io_lock);
 637         /* REV A cards use only 2 io ports; test
 638          * presumes a floating bus reads as 0xff. */
 639         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 640             (inb(pcwd_private.io_addr + 3) == 0xFF))
 641                 r=PCWD_REVISION_A;
 642         spin_unlock(&pcwd_private.io_lock);
 643
 644         return r;
 645 }
 646
 647 static inline char *get_firmware(void)
 648 {
 649         int one, ten, hund, minor;
 650         char *ret;
 651
 652         ret = kmalloc(6, GFP_KERNEL);
 653         if(ret == NULL)
 654                 return NULL;
 655
 656         if (set_command_mode()) {
 657                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 658                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 659                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 660                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 661                 sprintf(ret, "%c.%c%c%c", one, ten, hund, minor);
 662         }
 663         else
 664                 sprintf(ret, "ERROR");
 665
 666         unset_command_mode();
 667         return(ret);
 668 }
 669
 670 static inline int get_option_switches(void)
 671 {
 672         int rv=0;
 673
 674         if (set_command_mode()) {
 675                 /* Get switch settings */
 676                 rv = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 677         }
 678
 679         unset_command_mode();
 680         return(rv);
 681 }
 682
 683 static int __devinit pcwatchdog_init(int base_addr)
 684 {
 685         int ret;
 686         char *firmware;
 687         int option_switches;
 688
 689         cards_found++;
 690         if (cards_found == 1)
 691                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER);
 692
 693         if (cards_found > 1) {
 694                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 695                 return -ENODEV;
 696         }
 697
 698         if (base_addr == 0x0000) {
 699                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 700                 return -ENODEV;
 701         }
 702         pcwd_private.io_addr = base_addr;
 703
 704         /* Check card's revision */
 705         pcwd_private.revision = get_revision();
 706
 707         if (!request_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 708                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 709                         pcwd_private.io_addr);
 710                 pcwd_private.io_addr = 0x0000;
 711                 return -EIO;
 712         }
 713
 714         /* Initial variables */
 715         pcwd_private.supports_temp = 0;
 716         temp_panic = 0;
 717         pcwd_private.boot_status = 0x0000;
 718
 719         /* get the boot_status */
 720         pcwd_get_status(&pcwd_private.boot_status);
 721
 722         /* clear the "card caused reboot" flag */
 723         pcwd_clear_status();
 724
 725         init_timer(&pcwd_private.timer);
 726         pcwd_private.timer.function = pcwd_timer_ping;
 727         pcwd_private.timer.data = 0;
 728
 729         /*  Disable the board  */
 730         pcwd_stop();
 731
 732         /*  Check whether or not the card supports the temperature device */
 733         get_support();
 734
 735         /* Get some extra info from the hardware (in command/debug/diag mode) */
 736         if (pcwd_private.revision == PCWD_REVISION_A)
 737                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", pcwd_private.io_addr);
 738         else if (pcwd_private.revision == PCWD_REVISION_C) {
 739                 firmware = get_firmware();
 740                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 741                         pcwd_private.io_addr, firmware);
 742                 kfree(firmware);
 743                 option_switches = get_option_switches();
 744                 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 745                         option_switches,
 746                         ((option_switches & 0x10) ? "ON" : "OFF"),
 747                         ((option_switches & 0x08) ? "ON" : "OFF"));
 748
 749                 /* Reprogram internal heartbeat to 2 seconds */
 750                 if (set_command_mode()) {
 751                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 752                         unset_command_mode();
 753                 }
 754         } else {
 755                 /* Should NEVER happen, unless get_revision() fails. */
 756                 printk(KERN_INFO PFX "Unable to get revision\n");
 757                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 758                 pcwd_private.io_addr = 0x0000;
 759                 return -1;
 760         }
 761
 762         if (pcwd_private.supports_temp)
 763                 printk(KERN_INFO PFX "Temperature Option Detected\n");
 764
 765         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 766                 printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
 767
 768         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 769                 printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
 770                 printk(KERN_EMERG PFX "CPU Overheat\n");
 771         }
 772
 773         if (pcwd_private.boot_status == 0)
 774                 printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");
 775
 776         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 777         if (pcwd_set_heartbeat(heartbeat)) {
 778                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 779                 printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
 780                         WATCHDOG_HEARTBEAT);
 781         }
 782
 783         ret = register_reboot_notifier(&pcwd_notifier);
 784         if (ret) {
 785                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 786                         ret);
 787                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 788                 pcwd_private.io_addr = 0x0000;
 789                 return ret;
 790         }
 791
 792         if (pcwd_private.supports_temp) {
 793                 ret = misc_register(&temp_miscdev);
 794                 if (ret) {
 795                         printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 796                                 TEMP_MINOR, ret);
 797                         unregister_reboot_notifier(&pcwd_notifier);
 798                         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 799                         pcwd_private.io_addr = 0x0000;
 800                         return ret;
 801                 }
 802         }
 803
 804         ret = misc_register(&pcwd_miscdev);
 805         if (ret) {
 806                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 807                         WATCHDOG_MINOR, ret);
 808                 if (pcwd_private.supports_temp)
 809                         misc_deregister(&temp_miscdev);
 810                 unregister_reboot_notifier(&pcwd_notifier);
 811                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 812                 pcwd_private.io_addr = 0x0000;
 813                 return ret;
 814         }
 815
 816         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 817                 heartbeat, nowayout);
 818
 819         return 0;
 820 }
 821
 822 static void __devexit pcwatchdog_exit(void)
 823 {
 824         /*  Disable the board  */
 825         if (!nowayout)
 826                 pcwd_stop();
 827
 828         /* Deregister */
 829         misc_deregister(&pcwd_miscdev);
 830         if (pcwd_private.supports_temp)
 831                 misc_deregister(&temp_miscdev);
 832         unregister_reboot_notifier(&pcwd_notifier);
 833         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 834         pcwd_private.io_addr = 0x0000;
 835         cards_found--;
 836 }
 837
 838 /*
 839  *  The ISA cards have a heartbeat bit in one of the registers, which
 840  *  register is card dependent.  The heartbeat bit is monitored, and if
 841  *  found, is considered proof that a Berkshire card has been found.
 842  *  The initial rate is once per second at board start up, then twice
 843  *  per second for normal operation.
 844  */
 845 static int __init pcwd_checkcard(int base_addr)
 846 {
 847         int port0, last_port0;  /* Reg 0, in case it's REV A */
 848         int port1, last_port1;  /* Register 1 for REV C cards */
 849         int i;
 850         int retval;
 851
 852         if (!request_region (base_addr, 4, "PCWD")) {
 853                 printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 854                 return 0;
 855         }
 856
 857         retval = 0;
 858
 859         port0 = inb_p(base_addr);       /* For REV A boards */
 860         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 861         if (port0 != 0xff || port1 != 0xff) {
 862                 /* Not an 'ff' from a floating bus, so must be a card! */
 863                 for (i = 0; i < 4; ++i) {
 864
 865                         msleep(500);
 866
 867                         last_port0 = port0;
 868                         last_port1 = port1;
 869
 870                         port0 = inb_p(base_addr);
 871                         port1 = inb_p(base_addr + 1);
 872
 873                         /* Has either hearbeat bit changed?  */
 874                         if ((port0 ^ last_port0) & WD_HRTBT ||
 875                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 876                                 retval = 1;
 877                                 break;
 878                         }
 879                 }
 880         }
 881         release_region (base_addr, 4);
 882
 883         return retval;
 884 }
 885
 886 /*
 887  * These are the auto-probe addresses available.
 888  *
 889  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
 890  * Revision A has an address range of 2 addresses, while Revision C has 4.
 891  */
 892 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
 893
 894 static int __init pcwd_init_module(void)
 895 {
 896         int i, found = 0;
 897
 898         spin_lock_init(&pcwd_private.io_lock);
 899
 900         for (i = 0; pcwd_ioports[i] != 0; i++) {
 901                 if (pcwd_checkcard(pcwd_ioports[i])) {
 902                         if (!(pcwatchdog_init(pcwd_ioports[i])))
 903                                 found++;
 904                 }
 905         }
 906
 907         if (!found) {
 908                 printk (KERN_INFO PFX "No card detected, or port not available\n");
 909                 return -ENODEV;
 910         }
 911
 912         return 0;
 913 }
 914
 915 static void __exit pcwd_cleanup_module(void)
 916 {
 917         if (pcwd_private.io_addr)
 918                 pcwatchdog_exit();
 919         return;
 920 }
 921
 922 module_init(pcwd_init_module);
 923 module_exit(pcwd_cleanup_module);
 924
 925 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>");
 926 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
 927 MODULE_LICENSE("GPL");
 928 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 929 MODULE_ALIAS_MISCDEV(TEMP_MINOR);