git.oblomov.eu Git - linux-2.6/blob - 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>       /* For module specific items */
  53 #include <linux/moduleparam.h>  /* For new moduleparam's */
  54 #include <linux/types.h>        /* For standard types (like size_t) */
  55 #include <linux/errno.h>        /* For the -ENODEV/... values */
  56 #include <linux/kernel.h>       /* For printk/panic/... */
  57 #include <linux/delay.h>        /* For mdelay function */
  58 #include <linux/timer.h>        /* For timer related operations */
  59 #include <linux/jiffies.h>      /* For jiffies stuff */
  60 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  61 #include <linux/watchdog.h>     /* For the watchdog specific items */
  62 #include <linux/notifier.h>     /* For notifier support */
  63 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  64 #include <linux/init.h>         /* For __init/__exit/... */
  65 #include <linux/fs.h>           /* For file operations */
  66 #include <linux/ioport.h>       /* For io-port access */
  67 #include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  68
  69 #include <asm/uaccess.h>        /* For copy_to_user/put_user/... */
  70 #include <asm/io.h>             /* For inb/outb/... */
  71
  72 /* Module and version information */
  73 #define WATCHDOG_VERSION "1.17"
  74 #define WATCHDOG_DATE "12 Feb 2006"
  75 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
  76 #define WATCHDOG_NAME "pcwd"
  77 #define PFX WATCHDOG_NAME ": "
  78 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION " (" WATCHDOG_DATE ")\n"
  79 #define WD_VER WATCHDOG_VERSION " (" WATCHDOG_DATE ")"
  80
  81 /*
  82  * It should be noted that PCWD_REVISION_B was removed because A and B
  83  * are essentially the same types of card, with the exception that B
  84  * has temperature reporting.  Since I didn't receive a Rev.B card,
  85  * the Rev.B card is not supported.  (It's a good thing too, as they
  86  * are no longer in production.)
  87  */
  88 #define PCWD_REVISION_A         1
  89 #define PCWD_REVISION_C         2
  90
  91 /*
  92  * These are the defines that describe the control status bits for the
  93  * PCI-PC Watchdog card.
  94 */
  95 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
  96 #define WD_WDRST                0x01    /* Previously reset state */
  97 #define WD_T110                 0x02    /* Temperature overheat sense */
  98 #define WD_HRTBT                0x04    /* Heartbeat sense */
  99 #define WD_RLY2                 0x08    /* External relay triggered */
 100 #define WD_SRLY2                0x80    /* Software external relay triggered */
 101 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 102 #define WD_REVC_WTRP            0x01    /* Watchdog Trip status */
 103 #define WD_REVC_HRBT            0x02    /* Watchdog Heartbeat */
 104 #define WD_REVC_TTRP            0x04    /* Temperature Trip status */
 105 #define WD_REVC_RL2A            0x08    /* Relay 2 activated by on-board processor */
 106 #define WD_REVC_RL1A            0x10    /* Relay 1 active */
 107 #define WD_REVC_R2DS            0x40    /* Relay 2 disable */
 108 #define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
 109 /* Port 2 : Control Status #2 */
 110 #define WD_WDIS                 0x10    /* Watchdog Disabled */
 111 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 112 #define WD_SSEL                 0x40    /* Watchdog Switch Select (1:SW1 <-> 0:SW2) */
 113 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
 114
 115 /* max. time we give an ISA watchdog card to process a command */
 116 /* 500ms for each 4 bit response (according to spec.) */
 117 #define ISA_COMMAND_TIMEOUT     1000
 118
 119 /* Watchdog's internal commands */
 120 #define CMD_ISA_IDLE                    0x00
 121 #define CMD_ISA_VERSION_INTEGER         0x01
 122 #define CMD_ISA_VERSION_TENTH           0x02
 123 #define CMD_ISA_VERSION_HUNDRETH        0x03
 124 #define CMD_ISA_VERSION_MINOR           0x04
 125 #define CMD_ISA_SWITCH_SETTINGS         0x05
 126 #define CMD_ISA_RESET_PC                0x06
 127 #define CMD_ISA_ARM_0                   0x07
 128 #define CMD_ISA_ARM_30                  0x08
 129 #define CMD_ISA_ARM_60                  0x09
 130 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 131 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 132 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 133 #define CMD_ISA_RESET_RELAYS            0x0D
 134
 135 /*
 136  * We are using an kernel timer to do the pinging of the watchdog
 137  * every ~500ms. We try to set the internal heartbeat of the
 138  * watchdog to 2 ms.
 139  */
 140
 141 #define WDT_INTERVAL (HZ/2+1)
 142
 143 /* We can only use 1 card due to the /dev/watchdog restriction */
 144 static int cards_found;
 145
 146 /* internal variables */
 147 static atomic_t open_allowed = ATOMIC_INIT(1);
 148 static char expect_close;
 149 static int temp_panic;
 150 static struct {                         /* this is private data for each ISA-PC watchdog card */
 151         char fw_ver_str[6];             /* The cards firmware version */
 152         int revision;                   /* The card's revision */
 153         int supports_temp;              /* Wether or not the card has a temperature device */
 154         int command_mode;               /* Wether or not the card is in command mode */
 155         int boot_status;                /* The card's boot status */
 156         int io_addr;                    /* The cards I/O address */
 157         spinlock_t io_lock;             /* the lock for io operations */
 158         struct timer_list timer;        /* The timer that pings the watchdog */
 159         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 160 } pcwd_private;
 161
 162 /* module parameters */
 163 #define QUIET   0       /* Default */
 164 #define VERBOSE 1       /* Verbose */
 165 #define DEBUG   2       /* print fancy stuff too */
 166 static int debug = QUIET;
 167 module_param(debug, int, 0);
 168 MODULE_PARM_DESC(debug, "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
 169
 170 #define WATCHDOG_HEARTBEAT 60           /* 60 sec default heartbeat */
 171 static int heartbeat = WATCHDOG_HEARTBEAT;
 172 module_param(heartbeat, int, 0);
 173 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 174
 175 static int nowayout = WATCHDOG_NOWAYOUT;
 176 module_param(nowayout, int, 0);
 177 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 178
 179 /*
 180  *      Internal functions
 181  */
 182
 183 static int send_isa_command(int cmd)
 184 {
 185         int i;
 186         int control_status;
 187         int port0, last_port0;  /* Double read for stabilising */
 188
 189         if (debug >= DEBUG)
 190                 printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
 191                         cmd);
 192
 193         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 194         control_status = (cmd & 0x0F) | WD_WCMD;
 195         outb_p(control_status, pcwd_private.io_addr + 2);
 196         udelay(ISA_COMMAND_TIMEOUT);
 197
 198         port0 = inb_p(pcwd_private.io_addr);
 199         for (i = 0; i < 25; ++i) {
 200                 last_port0 = port0;
 201                 port0 = inb_p(pcwd_private.io_addr);
 202
 203                 if (port0 == last_port0)
 204                         break;  /* Data is stable */
 205
 206                 udelay (250);
 207         }
 208
 209         if (debug >= DEBUG)
 210                 printk(KERN_DEBUG PFX "received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 211                         cmd, port0, last_port0);
 212
 213         return port0;
 214 }
 215
 216 static int set_command_mode(void)
 217 {
 218         int i, found=0, count=0;
 219
 220         /* Set the card into command mode */
 221         spin_lock(&pcwd_private.io_lock);
 222         while ((!found) && (count < 3)) {
 223                 i = send_isa_command(CMD_ISA_IDLE);
 224
 225                 if (i == 0x00)
 226                         found = 1;
 227                 else if (i == 0xF3) {
 228                         /* Card does not like what we've done to it */
 229                         outb_p(0x00, pcwd_private.io_addr + 2);
 230                         udelay(1200);   /* Spec says wait 1ms */
 231                         outb_p(0x00, pcwd_private.io_addr + 2);
 232                         udelay(ISA_COMMAND_TIMEOUT);
 233                 }
 234                 count++;
 235         }
 236         spin_unlock(&pcwd_private.io_lock);
 237         pcwd_private.command_mode = found;
 238
 239         if (debug >= DEBUG)
 240                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 241                                 pcwd_private.command_mode);
 242
 243         return(found);
 244 }
 245
 246 static void unset_command_mode(void)
 247 {
 248         /* Set the card into normal mode */
 249         spin_lock(&pcwd_private.io_lock);
 250         outb_p(0x00, pcwd_private.io_addr + 2);
 251         udelay(ISA_COMMAND_TIMEOUT);
 252         spin_unlock(&pcwd_private.io_lock);
 253
 254         pcwd_private.command_mode = 0;
 255
 256         if (debug >= DEBUG)
 257                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 258                                 pcwd_private.command_mode);
 259 }
 260
 261 static inline void pcwd_check_temperature_support(void)
 262 {
 263         if (inb(pcwd_private.io_addr) != 0xF0)
 264                 pcwd_private.supports_temp = 1;
 265 }
 266
 267 static inline void pcwd_get_firmware(void)
 268 {
 269         int one, ten, hund, minor;
 270
 271         strcpy(pcwd_private.fw_ver_str, "ERROR");
 272
 273         if (set_command_mode()) {
 274                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 275                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 276                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 277                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 278                 sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c", one, ten, hund, minor);
 279         }
 280         unset_command_mode();
 281
 282         return;
 283 }
 284
 285 static inline int pcwd_get_option_switches(void)
 286 {
 287         int option_switches=0;
 288
 289         if (set_command_mode()) {
 290                 /* Get switch settings */
 291                 option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 292         }
 293
 294         unset_command_mode();
 295         return(option_switches);
 296 }
 297
 298 static void pcwd_show_card_info(void)
 299 {
 300         int option_switches;
 301
 302         /* Get some extra info from the hardware (in command/debug/diag mode) */
 303         if (pcwd_private.revision == PCWD_REVISION_A)
 304                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", pcwd_private.io_addr);
 305         else if (pcwd_private.revision == PCWD_REVISION_C) {
 306                 pcwd_get_firmware();
 307                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 308                         pcwd_private.io_addr, pcwd_private.fw_ver_str);
 309                 option_switches = pcwd_get_option_switches();
 310                 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 311                         option_switches,
 312                         ((option_switches & 0x10) ? "ON" : "OFF"),
 313                         ((option_switches & 0x08) ? "ON" : "OFF"));
 314
 315                 /* Reprogram internal heartbeat to 2 seconds */
 316                 if (set_command_mode()) {
 317                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 318                         unset_command_mode();
 319                 }
 320         }
 321
 322         if (pcwd_private.supports_temp)
 323                 printk(KERN_INFO PFX "Temperature Option Detected\n");
 324
 325         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 326                 printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
 327
 328         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 329                 printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
 330                 printk(KERN_EMERG PFX "CPU Overheat\n");
 331         }
 332
 333         if (pcwd_private.boot_status == 0)
 334                 printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");
 335 }
 336
 337 static void pcwd_timer_ping(unsigned long data)
 338 {
 339         int wdrst_stat;
 340
 341         /* If we got a heartbeat pulse within the WDT_INTERVAL
 342          * we agree to ping the WDT */
 343         if(time_before(jiffies, pcwd_private.next_heartbeat)) {
 344                 /* Ping the watchdog */
 345                 spin_lock(&pcwd_private.io_lock);
 346                 if (pcwd_private.revision == PCWD_REVISION_A) {
 347                         /*  Rev A cards are reset by setting the WD_WDRST bit in register 1 */
 348                         wdrst_stat = inb_p(pcwd_private.io_addr);
 349                         wdrst_stat &= 0x0F;
 350                         wdrst_stat |= WD_WDRST;
 351
 352                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 353                 } else {
 354                         /* Re-trigger watchdog by writing to port 0 */
 355                         outb_p(0x00, pcwd_private.io_addr);
 356                 }
 357
 358                 /* Re-set the timer interval */
 359                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 360
 361                 spin_unlock(&pcwd_private.io_lock);
 362         } else {
 363                 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
 364         }
 365 }
 366
 367 static int pcwd_start(void)
 368 {
 369         int stat_reg;
 370
 371         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 372
 373         /* Start the timer */
 374         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 375
 376         /* Enable the port */
 377         if (pcwd_private.revision == PCWD_REVISION_C) {
 378                 spin_lock(&pcwd_private.io_lock);
 379                 outb_p(0x00, pcwd_private.io_addr + 3);
 380                 udelay(ISA_COMMAND_TIMEOUT);
 381                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 382                 spin_unlock(&pcwd_private.io_lock);
 383                 if (stat_reg & WD_WDIS) {
 384                         printk(KERN_INFO PFX "Could not start watchdog\n");
 385                         return -EIO;
 386                 }
 387         }
 388
 389         if (debug >= VERBOSE)
 390                 printk(KERN_DEBUG PFX "Watchdog started\n");
 391
 392         return 0;
 393 }
 394
 395 static int pcwd_stop(void)
 396 {
 397         int stat_reg;
 398
 399         /* Stop the timer */
 400         del_timer(&pcwd_private.timer);
 401
 402         /*  Disable the board  */
 403         if (pcwd_private.revision == PCWD_REVISION_C) {
 404                 spin_lock(&pcwd_private.io_lock);
 405                 outb_p(0xA5, pcwd_private.io_addr + 3);
 406                 udelay(ISA_COMMAND_TIMEOUT);
 407                 outb_p(0xA5, pcwd_private.io_addr + 3);
 408                 udelay(ISA_COMMAND_TIMEOUT);
 409                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 410                 spin_unlock(&pcwd_private.io_lock);
 411                 if ((stat_reg & WD_WDIS) == 0) {
 412                         printk(KERN_INFO PFX "Could not stop watchdog\n");
 413                         return -EIO;
 414                 }
 415         }
 416
 417         if (debug >= VERBOSE)
 418                 printk(KERN_DEBUG PFX "Watchdog stopped\n");
 419
 420         return 0;
 421 }
 422
 423 static int pcwd_keepalive(void)
 424 {
 425         /* user land ping */
 426         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 427
 428         if (debug >= DEBUG)
 429                 printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
 430
 431         return 0;
 432 }
 433
 434 static int pcwd_set_heartbeat(int t)
 435 {
 436         if ((t < 2) || (t > 7200)) /* arbitrary upper limit */
 437                 return -EINVAL;
 438
 439         heartbeat = t;
 440
 441         if (debug >= VERBOSE)
 442                 printk(KERN_DEBUG PFX "New heartbeat: %d\n",
 443                        heartbeat);
 444
 445         return 0;
 446 }
 447
 448 static int pcwd_get_status(int *status)
 449 {
 450         int control_status;
 451
 452         *status=0;
 453         spin_lock(&pcwd_private.io_lock);
 454         if (pcwd_private.revision == PCWD_REVISION_A)
 455                 /* Rev A cards return status information from
 456                  * the base register, which is used for the
 457                  * temperature in other cards. */
 458                 control_status = inb(pcwd_private.io_addr);
 459         else {
 460                 /* Rev C cards return card status in the base
 461                  * address + 1 register. And use different bits
 462                  * to indicate a card initiated reset, and an
 463                  * over-temperature condition. And the reboot
 464                  * status can be reset. */
 465                 control_status = inb(pcwd_private.io_addr + 1);
 466         }
 467         spin_unlock(&pcwd_private.io_lock);
 468
 469         if (pcwd_private.revision == PCWD_REVISION_A) {
 470                 if (control_status & WD_WDRST)
 471                         *status |= WDIOF_CARDRESET;
 472
 473                 if (control_status & WD_T110) {
 474                         *status |= WDIOF_OVERHEAT;
 475                         if (temp_panic) {
 476                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 477                                 kernel_power_off();
 478                                 /* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
 479                         }
 480                 }
 481         } else {
 482                 if (control_status & WD_REVC_WTRP)
 483                         *status |= WDIOF_CARDRESET;
 484
 485                 if (control_status & WD_REVC_TTRP) {
 486                         *status |= WDIOF_OVERHEAT;
 487                         if (temp_panic) {
 488                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 489                                 kernel_power_off();
 490                                 /* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
 491                         }
 492                 }
 493         }
 494
 495         return 0;
 496 }
 497
 498 static int pcwd_clear_status(void)
 499 {
 500         int control_status;
 501
 502         if (pcwd_private.revision == PCWD_REVISION_C) {
 503                 spin_lock(&pcwd_private.io_lock);
 504
 505                 if (debug >= VERBOSE)
 506                         printk(KERN_INFO PFX "clearing watchdog trip status\n");
 507
 508                 control_status = inb_p(pcwd_private.io_addr + 1);
 509
 510                 if (debug >= DEBUG) {
 511                         printk(KERN_DEBUG PFX "status was: 0x%02x\n", control_status);
 512                         printk(KERN_DEBUG PFX "sending: 0x%02x\n",
 513                                 (control_status & WD_REVC_R2DS));
 514                 }
 515
 516                 /* clear reset status & Keep Relay 2 disable state as it is */
 517                 outb_p((control_status & WD_REVC_R2DS), pcwd_private.io_addr + 1);
 518
 519                 spin_unlock(&pcwd_private.io_lock);
 520         }
 521         return 0;
 522 }
 523
 524 static int pcwd_get_temperature(int *temperature)
 525 {
 526         /* check that port 0 gives temperature info and no command results */
 527         if (pcwd_private.command_mode)
 528                 return -1;
 529
 530         *temperature = 0;
 531         if (!pcwd_private.supports_temp)
 532                 return -ENODEV;
 533
 534         /*
 535          * Convert celsius to fahrenheit, since this was
 536          * the decided 'standard' for this return value.
 537          */
 538         spin_lock(&pcwd_private.io_lock);
 539         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 540         spin_unlock(&pcwd_private.io_lock);
 541
 542         if (debug >= DEBUG) {
 543                 printk(KERN_DEBUG PFX "temperature is: %d F\n",
 544                         *temperature);
 545         }
 546
 547         return 0;
 548 }
 549
 550 /*
 551  *      /dev/watchdog handling
 552  */
 553
 554 static int pcwd_ioctl(struct inode *inode, struct file *file,
 555                       unsigned int cmd, unsigned long arg)
 556 {
 557         int rv;
 558         int status;
 559         int temperature;
 560         int new_heartbeat;
 561         int __user *argp = (int __user *)arg;
 562         static struct watchdog_info ident = {
 563                 .options =              WDIOF_OVERHEAT |
 564                                         WDIOF_CARDRESET |
 565                                         WDIOF_KEEPALIVEPING |
 566                                         WDIOF_SETTIMEOUT |
 567                                         WDIOF_MAGICCLOSE,
 568                 .firmware_version =     1,
 569                 .identity =             "PCWD",
 570         };
 571
 572         switch(cmd) {
 573         default:
 574                 return -ENOTTY;
 575
 576         case WDIOC_GETSUPPORT:
 577                 if(copy_to_user(argp, &ident, sizeof(ident)))
 578                         return -EFAULT;
 579                 return 0;
 580
 581         case WDIOC_GETSTATUS:
 582                 pcwd_get_status(&status);
 583                 return put_user(status, argp);
 584
 585         case WDIOC_GETBOOTSTATUS:
 586                 return put_user(pcwd_private.boot_status, argp);
 587
 588         case WDIOC_GETTEMP:
 589                 if (pcwd_get_temperature(&temperature))
 590                         return -EFAULT;
 591
 592                 return put_user(temperature, argp);
 593
 594         case WDIOC_SETOPTIONS:
 595                 if (pcwd_private.revision == PCWD_REVISION_C)
 596                 {
 597                         if(copy_from_user(&rv, argp, sizeof(int)))
 598                                 return -EFAULT;
 599
 600                         if (rv & WDIOS_DISABLECARD)
 601                         {
 602                                 return pcwd_stop();
 603                         }
 604
 605                         if (rv & WDIOS_ENABLECARD)
 606                         {
 607                                 return pcwd_start();
 608                         }
 609
 610                         if (rv & WDIOS_TEMPPANIC)
 611                         {
 612                                 temp_panic = 1;
 613                         }
 614                 }
 615                 return -EINVAL;
 616
 617         case WDIOC_KEEPALIVE:
 618                 pcwd_keepalive();
 619                 return 0;
 620
 621         case WDIOC_SETTIMEOUT:
 622                 if (get_user(new_heartbeat, argp))
 623                         return -EFAULT;
 624
 625                 if (pcwd_set_heartbeat(new_heartbeat))
 626                         return -EINVAL;
 627
 628                 pcwd_keepalive();
 629                 /* Fall */
 630
 631         case WDIOC_GETTIMEOUT:
 632                 return put_user(heartbeat, argp);
 633         }
 634
 635         return 0;
 636 }
 637
 638 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 639                           loff_t *ppos)
 640 {
 641         if (len) {
 642                 if (!nowayout) {
 643                         size_t i;
 644
 645                         /* In case it was set long ago */
 646                         expect_close = 0;
 647
 648                         for (i = 0; i != len; i++) {
 649                                 char c;
 650
 651                                 if (get_user(c, buf + i))
 652                                         return -EFAULT;
 653                                 if (c == 'V')
 654                                         expect_close = 42;
 655                         }
 656                 }
 657                 pcwd_keepalive();
 658         }
 659         return len;
 660 }
 661
 662 static int pcwd_open(struct inode *inode, struct file *file)
 663 {
 664         if (!atomic_dec_and_test(&open_allowed) ) {
 665                 if (debug >= VERBOSE)
 666                         printk(KERN_ERR PFX "Attempt to open already opened device.\n");
 667                 atomic_inc( &open_allowed );
 668                 return -EBUSY;
 669         }
 670
 671         if (nowayout)
 672                 __module_get(THIS_MODULE);
 673
 674         /* Activate */
 675         pcwd_start();
 676         pcwd_keepalive();
 677         return nonseekable_open(inode, file);
 678 }
 679
 680 static int pcwd_close(struct inode *inode, struct file *file)
 681 {
 682         if (expect_close == 42) {
 683                 pcwd_stop();
 684         } else {
 685                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 686                 pcwd_keepalive();
 687         }
 688         expect_close = 0;
 689         atomic_inc( &open_allowed );
 690         return 0;
 691 }
 692
 693 /*
 694  *      /dev/temperature handling
 695  */
 696
 697 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 698                          loff_t *ppos)
 699 {
 700         int temperature;
 701
 702         if (pcwd_get_temperature(&temperature))
 703                 return -EFAULT;
 704
 705         if (copy_to_user(buf, &temperature, 1))
 706                 return -EFAULT;
 707
 708         return 1;
 709 }
 710
 711 static int pcwd_temp_open(struct inode *inode, struct file *file)
 712 {
 713         if (!pcwd_private.supports_temp)
 714                 return -ENODEV;
 715
 716         return nonseekable_open(inode, file);
 717 }
 718
 719 static int pcwd_temp_close(struct inode *inode, struct file *file)
 720 {
 721         return 0;
 722 }
 723
 724 /*
 725  *      Notify system
 726  */
 727
 728 static int pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 729 {
 730         if (code==SYS_DOWN || code==SYS_HALT) {
 731                 /* Turn the WDT off */
 732                 pcwd_stop();
 733         }
 734
 735         return NOTIFY_DONE;
 736 }
 737
 738 /*
 739  *      Kernel Interfaces
 740  */
 741
 742 static const struct file_operations pcwd_fops = {
 743         .owner          = THIS_MODULE,
 744         .llseek         = no_llseek,
 745         .write          = pcwd_write,
 746         .ioctl          = pcwd_ioctl,
 747         .open           = pcwd_open,
 748         .release        = pcwd_close,
 749 };
 750
 751 static struct miscdevice pcwd_miscdev = {
 752         .minor =        WATCHDOG_MINOR,
 753         .name =         "watchdog",
 754         .fops =         &pcwd_fops,
 755 };
 756
 757 static const struct file_operations pcwd_temp_fops = {
 758         .owner          = THIS_MODULE,
 759         .llseek         = no_llseek,
 760         .read           = pcwd_temp_read,
 761         .open           = pcwd_temp_open,
 762         .release        = pcwd_temp_close,
 763 };
 764
 765 static struct miscdevice temp_miscdev = {
 766         .minor =        TEMP_MINOR,
 767         .name =         "temperature",
 768         .fops =         &pcwd_temp_fops,
 769 };
 770
 771 static struct notifier_block pcwd_notifier = {
 772         .notifier_call =        pcwd_notify_sys,
 773 };
 774
 775 /*
 776  *      Init & exit routines
 777  */
 778
 779 static inline int get_revision(void)
 780 {
 781         int r = PCWD_REVISION_C;
 782
 783         spin_lock(&pcwd_private.io_lock);
 784         /* REV A cards use only 2 io ports; test
 785          * presumes a floating bus reads as 0xff. */
 786         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 787             (inb(pcwd_private.io_addr + 3) == 0xFF))
 788                 r=PCWD_REVISION_A;
 789         spin_unlock(&pcwd_private.io_lock);
 790
 791         return r;
 792 }
 793
 794 static int __devinit pcwatchdog_init(int base_addr)
 795 {
 796         int ret;
 797
 798         cards_found++;
 799         if (cards_found == 1)
 800                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER);
 801
 802         if (cards_found > 1) {
 803                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 804                 return -ENODEV;
 805         }
 806
 807         if (base_addr == 0x0000) {
 808                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 809                 return -ENODEV;
 810         }
 811         pcwd_private.io_addr = base_addr;
 812
 813         /* Check card's revision */
 814         pcwd_private.revision = get_revision();
 815
 816         if (!request_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 817                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 818                         pcwd_private.io_addr);
 819                 pcwd_private.io_addr = 0x0000;
 820                 return -EIO;
 821         }
 822
 823         /* Initial variables */
 824         pcwd_private.supports_temp = 0;
 825         temp_panic = 0;
 826         pcwd_private.boot_status = 0x0000;
 827
 828         /* get the boot_status */
 829         pcwd_get_status(&pcwd_private.boot_status);
 830
 831         /* clear the "card caused reboot" flag */
 832         pcwd_clear_status();
 833
 834         init_timer(&pcwd_private.timer);
 835         pcwd_private.timer.function = pcwd_timer_ping;
 836         pcwd_private.timer.data = 0;
 837
 838         /*  Disable the board  */
 839         pcwd_stop();
 840
 841         /*  Check whether or not the card supports the temperature device */
 842         pcwd_check_temperature_support();
 843
 844         /* Show info about the card itself */
 845         pcwd_show_card_info();
 846
 847         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 848         if (pcwd_set_heartbeat(heartbeat)) {
 849                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 850                 printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
 851                         WATCHDOG_HEARTBEAT);
 852         }
 853
 854         ret = register_reboot_notifier(&pcwd_notifier);
 855         if (ret) {
 856                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 857                         ret);
 858                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 859                 pcwd_private.io_addr = 0x0000;
 860                 return ret;
 861         }
 862
 863         if (pcwd_private.supports_temp) {
 864                 ret = misc_register(&temp_miscdev);
 865                 if (ret) {
 866                         printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 867                                 TEMP_MINOR, ret);
 868                         unregister_reboot_notifier(&pcwd_notifier);
 869                         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 870                         pcwd_private.io_addr = 0x0000;
 871                         return ret;
 872                 }
 873         }
 874
 875         ret = misc_register(&pcwd_miscdev);
 876         if (ret) {
 877                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 878                         WATCHDOG_MINOR, ret);
 879                 if (pcwd_private.supports_temp)
 880                         misc_deregister(&temp_miscdev);
 881                 unregister_reboot_notifier(&pcwd_notifier);
 882                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 883                 pcwd_private.io_addr = 0x0000;
 884                 return ret;
 885         }
 886
 887         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 888                 heartbeat, nowayout);
 889
 890         return 0;
 891 }
 892
 893 static void __devexit pcwatchdog_exit(void)
 894 {
 895         /*  Disable the board  */
 896         if (!nowayout)
 897                 pcwd_stop();
 898
 899         /* Deregister */
 900         misc_deregister(&pcwd_miscdev);
 901         if (pcwd_private.supports_temp)
 902                 misc_deregister(&temp_miscdev);
 903         unregister_reboot_notifier(&pcwd_notifier);
 904         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 905         pcwd_private.io_addr = 0x0000;
 906         cards_found--;
 907 }
 908
 909 /*
 910  *  The ISA cards have a heartbeat bit in one of the registers, which
 911  *  register is card dependent.  The heartbeat bit is monitored, and if
 912  *  found, is considered proof that a Berkshire card has been found.
 913  *  The initial rate is once per second at board start up, then twice
 914  *  per second for normal operation.
 915  */
 916 static int __init pcwd_checkcard(int base_addr)
 917 {
 918         int port0, last_port0;  /* Reg 0, in case it's REV A */
 919         int port1, last_port1;  /* Register 1 for REV C cards */
 920         int i;
 921         int retval;
 922
 923         if (!request_region (base_addr, 4, "PCWD")) {
 924                 printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 925                 return 0;
 926         }
 927
 928         retval = 0;
 929
 930         port0 = inb_p(base_addr);       /* For REV A boards */
 931         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 932         if (port0 != 0xff || port1 != 0xff) {
 933                 /* Not an 'ff' from a floating bus, so must be a card! */
 934                 for (i = 0; i < 4; ++i) {
 935
 936                         msleep(500);
 937
 938                         last_port0 = port0;
 939                         last_port1 = port1;
 940
 941                         port0 = inb_p(base_addr);
 942                         port1 = inb_p(base_addr + 1);
 943
 944                         /* Has either hearbeat bit changed?  */
 945                         if ((port0 ^ last_port0) & WD_HRTBT ||
 946                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 947                                 retval = 1;
 948                                 break;
 949                         }
 950                 }
 951         }
 952         release_region (base_addr, 4);
 953
 954         return retval;
 955 }
 956
 957 /*
 958  * These are the auto-probe addresses available.
 959  *
 960  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
 961  * Revision A has an address range of 2 addresses, while Revision C has 4.
 962  */
 963 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
 964
 965 static int __init pcwd_init_module(void)
 966 {
 967         int i, found = 0;
 968
 969         spin_lock_init(&pcwd_private.io_lock);
 970
 971         for (i = 0; pcwd_ioports[i] != 0; i++) {
 972                 if (pcwd_checkcard(pcwd_ioports[i])) {
 973                         if (!(pcwatchdog_init(pcwd_ioports[i])))
 974                                 found++;
 975                 }
 976         }
 977
 978         if (!found) {
 979                 printk (KERN_INFO PFX "No card detected, or port not available\n");
 980                 return -ENODEV;
 981         }
 982
 983         return 0;
 984 }
 985
 986 static void __exit pcwd_cleanup_module(void)
 987 {
 988         if (pcwd_private.io_addr)
 989                 pcwatchdog_exit();
 990
 991         printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
 992 }
 993
 994 module_init(pcwd_init_module);
 995 module_exit(pcwd_cleanup_module);
 996
 997 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>");
 998 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
 999 MODULE_LICENSE("GPL");
1000 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1001 MODULE_ALIAS_MISCDEV(TEMP_MINOR);