drivers/watchdog/pcwd.c

   1 /*
   2  * PC Watchdog Driver
   3  * by Ken Hollis (khollis@bitgate.com)
   4  *
   5  * Permission granted from Simon Machell (smachell@berkprod.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
  44  *              CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
  45  *              Added timeout module option to override default
  46  */
  47
  48 /*
  49  *      A bells and whistles driver is available from http://www.pcwd.de/
  50  *      More info available at http://www.berkprod.com/ or
  51  *      http://www.pcwatchdog.com/
  52  */
  53
  54 #include <linux/module.h>       /* For module specific items */
  55 #include <linux/moduleparam.h>  /* For new moduleparam's */
  56 #include <linux/types.h>        /* For standard types (like size_t) */
  57 #include <linux/errno.h>        /* For the -ENODEV/... values */
  58 #include <linux/kernel.h>       /* For printk/panic/... */
  59 #include <linux/delay.h>        /* For mdelay function */
  60 #include <linux/timer.h>        /* For timer related operations */
  61 #include <linux/jiffies.h>      /* For jiffies stuff */
  62 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  63 #include <linux/watchdog.h>     /* For the watchdog specific items */
  64 #include <linux/reboot.h>       /* For kernel_power_off() */
  65 #include <linux/init.h>         /* For __init/__exit/... */
  66 #include <linux/fs.h>           /* For file operations */
  67 #include <linux/isa.h>          /* For isa devices */
  68 #include <linux/ioport.h>       /* For io-port access */
  69 #include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  70 #include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  71 #include <linux/io.h>           /* For inb/outb/... */
  72
  73 /* Module and version information */
  74 #define WATCHDOG_VERSION "1.20"
  75 #define WATCHDOG_DATE "18 Feb 2007"
  76 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
  77 #define WATCHDOG_NAME "pcwd"
  78 #define PFX WATCHDOG_NAME ": "
  79 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION "\n"
  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 auto-probe addresses available.
  93  *
  94  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
  95  * Revision A has an address range of 2 addresses, while Revision C has 4.
  96  */
  97 #define PCWD_ISA_NR_CARDS       3
  98 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
  99
 100 /*
 101  * These are the defines that describe the control status bits for the
 102  * PCI-PC Watchdog card.
 103 */
 104 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
 105 #define WD_WDRST                0x01    /* Previously reset state */
 106 #define WD_T110                 0x02    /* Temperature overheat sense */
 107 #define WD_HRTBT                0x04    /* Heartbeat sense */
 108 #define WD_RLY2                 0x08    /* External relay triggered */
 109 #define WD_SRLY2                0x80    /* Software external relay triggered */
 110 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 111 #define WD_REVC_WTRP            0x01    /* Watchdog Trip status */
 112 #define WD_REVC_HRBT            0x02    /* Watchdog Heartbeat */
 113 #define WD_REVC_TTRP            0x04    /* Temperature Trip status */
 114 #define WD_REVC_RL2A            0x08    /* Relay 2 activated by
 115                                                         on-board processor */
 116 #define WD_REVC_RL1A            0x10    /* Relay 1 active */
 117 #define WD_REVC_R2DS            0x40    /* Relay 2 disable */
 118 #define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
 119 /* Port 2 : Control Status #2 */
 120 #define WD_WDIS                 0x10    /* Watchdog Disabled */
 121 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 122 #define WD_SSEL                 0x40    /* Watchdog Switch Select
 123                                                         (1:SW1 <-> 0:SW2) */
 124 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
 125
 126 /* max. time we give an ISA watchdog card to process a command */
 127 /* 500ms for each 4 bit response (according to spec.) */
 128 #define ISA_COMMAND_TIMEOUT     1000
 129
 130 /* Watchdog's internal commands */
 131 #define CMD_ISA_IDLE                    0x00
 132 #define CMD_ISA_VERSION_INTEGER         0x01
 133 #define CMD_ISA_VERSION_TENTH           0x02
 134 #define CMD_ISA_VERSION_HUNDRETH        0x03
 135 #define CMD_ISA_VERSION_MINOR           0x04
 136 #define CMD_ISA_SWITCH_SETTINGS         0x05
 137 #define CMD_ISA_RESET_PC                0x06
 138 #define CMD_ISA_ARM_0                   0x07
 139 #define CMD_ISA_ARM_30                  0x08
 140 #define CMD_ISA_ARM_60                  0x09
 141 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 142 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 143 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 144 #define CMD_ISA_RESET_RELAYS            0x0D
 145
 146 /* Watchdog's Dip Switch heartbeat values */
 147 static const int heartbeat_tbl[] = {
 148         20,     /* OFF-OFF-OFF  = 20 Sec  */
 149         40,     /* OFF-OFF-ON   = 40 Sec  */
 150         60,     /* OFF-ON-OFF   =  1 Min  */
 151         300,    /* OFF-ON-ON    =  5 Min  */
 152         600,    /* ON-OFF-OFF   = 10 Min  */
 153         1800,   /* ON-OFF-ON    = 30 Min  */
 154         3600,   /* ON-ON-OFF    =  1 Hour */
 155         7200,   /* ON-ON-ON     =  2 hour */
 156 };
 157
 158 /*
 159  * We are using an kernel timer to do the pinging of the watchdog
 160  * every ~500ms. We try to set the internal heartbeat of the
 161  * watchdog to 2 ms.
 162  */
 163
 164 #define WDT_INTERVAL (HZ/2+1)
 165
 166 /* We can only use 1 card due to the /dev/watchdog restriction */
 167 static int cards_found;
 168
 169 /* internal variables */
 170 static unsigned long open_allowed;
 171 static char expect_close;
 172 static int temp_panic;
 173
 174 /* this is private data for each ISA-PC watchdog card */
 175 static struct {
 176         char fw_ver_str[6];             /* The cards firmware version */
 177         int revision;                   /* The card's revision */
 178         int supports_temp;              /* Whether or not the card has
 179                                                 a temperature device */
 180         int command_mode;               /* Whether or not the card is in
 181                                                 command mode */
 182         int boot_status;                /* The card's boot status */
 183         int io_addr;                    /* The cards I/O address */
 184         spinlock_t io_lock;             /* the lock for io operations */
 185         struct timer_list timer;        /* The timer that pings the watchdog */
 186         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 187 } pcwd_private;
 188
 189 /* module parameters */
 190 #define QUIET   0       /* Default */
 191 #define VERBOSE 1       /* Verbose */
 192 #define DEBUG   2       /* print fancy stuff too */
 193 static int debug = QUIET;
 194 module_param(debug, int, 0);
 195 MODULE_PARM_DESC(debug,
 196                 "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
 197
 198 /* default heartbeat = delay-time from dip-switches */
 199 #define WATCHDOG_HEARTBEAT 0
 200 static int heartbeat = WATCHDOG_HEARTBEAT;
 201 module_param(heartbeat, int, 0);
 202 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
 203         "(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
 204                                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 205
 206 static int nowayout = WATCHDOG_NOWAYOUT;
 207 module_param(nowayout, int, 0);
 208 MODULE_PARM_DESC(nowayout,
 209                 "Watchdog cannot be stopped once started (default="
 210                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 211
 212 /*
 213  *      Internal functions
 214  */
 215
 216 static int send_isa_command(int cmd)
 217 {
 218         int i;
 219         int control_status;
 220         int port0, last_port0;  /* Double read for stabilising */
 221
 222         if (debug >= DEBUG)
 223                 printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
 224                         cmd);
 225
 226         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 227         control_status = (cmd & 0x0F) | WD_WCMD;
 228         outb_p(control_status, pcwd_private.io_addr + 2);
 229         udelay(ISA_COMMAND_TIMEOUT);
 230
 231         port0 = inb_p(pcwd_private.io_addr);
 232         for (i = 0; i < 25; ++i) {
 233                 last_port0 = port0;
 234                 port0 = inb_p(pcwd_private.io_addr);
 235
 236                 if (port0 == last_port0)
 237                         break;  /* Data is stable */
 238
 239                 udelay(250);
 240         }
 241
 242         if (debug >= DEBUG)
 243                 printk(KERN_DEBUG PFX "received following data for "
 244                         "cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 245                         cmd, port0, last_port0);
 246
 247         return port0;
 248 }
 249
 250 static int set_command_mode(void)
 251 {
 252         int i, found = 0, count = 0;
 253
 254         /* Set the card into command mode */
 255         spin_lock(&pcwd_private.io_lock);
 256         while ((!found) && (count < 3)) {
 257                 i = send_isa_command(CMD_ISA_IDLE);
 258
 259                 if (i == 0x00)
 260                         found = 1;
 261                 else if (i == 0xF3) {
 262                         /* Card does not like what we've done to it */
 263                         outb_p(0x00, pcwd_private.io_addr + 2);
 264                         udelay(1200);   /* Spec says wait 1ms */
 265                         outb_p(0x00, pcwd_private.io_addr + 2);
 266                         udelay(ISA_COMMAND_TIMEOUT);
 267                 }
 268                 count++;
 269         }
 270         spin_unlock(&pcwd_private.io_lock);
 271         pcwd_private.command_mode = found;
 272
 273         if (debug >= DEBUG)
 274                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 275                                 pcwd_private.command_mode);
 276
 277         return found;
 278 }
 279
 280 static void unset_command_mode(void)
 281 {
 282         /* Set the card into normal mode */
 283         spin_lock(&pcwd_private.io_lock);
 284         outb_p(0x00, pcwd_private.io_addr + 2);
 285         udelay(ISA_COMMAND_TIMEOUT);
 286         spin_unlock(&pcwd_private.io_lock);
 287
 288         pcwd_private.command_mode = 0;
 289
 290         if (debug >= DEBUG)
 291                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 292                                 pcwd_private.command_mode);
 293 }
 294
 295 static inline void pcwd_check_temperature_support(void)
 296 {
 297         if (inb(pcwd_private.io_addr) != 0xF0)
 298                 pcwd_private.supports_temp = 1;
 299 }
 300
 301 static inline void pcwd_get_firmware(void)
 302 {
 303         int one, ten, hund, minor;
 304
 305         strcpy(pcwd_private.fw_ver_str, "ERROR");
 306
 307         if (set_command_mode()) {
 308                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 309                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 310                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 311                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 312                 sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
 313                                         one, ten, hund, minor);
 314         }
 315         unset_command_mode();
 316
 317         return;
 318 }
 319
 320 static inline int pcwd_get_option_switches(void)
 321 {
 322         int option_switches = 0;
 323
 324         if (set_command_mode()) {
 325                 /* Get switch settings */
 326                 option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 327         }
 328
 329         unset_command_mode();
 330         return option_switches;
 331 }
 332
 333 static void pcwd_show_card_info(void)
 334 {
 335         int option_switches;
 336
 337         /* Get some extra info from the hardware (in command/debug/diag mode) */
 338         if (pcwd_private.revision == PCWD_REVISION_A)
 339                 printk(KERN_INFO PFX
 340                         "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
 341                                                         pcwd_private.io_addr);
 342         else if (pcwd_private.revision == PCWD_REVISION_C) {
 343                 pcwd_get_firmware();
 344                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port "
 345                         "0x%04x (Firmware version: %s)\n",
 346                         pcwd_private.io_addr, pcwd_private.fw_ver_str);
 347                 option_switches = pcwd_get_option_switches();
 348                 printk(KERN_INFO PFX "Option switches (0x%02x): "
 349                         "Temperature Reset Enable=%s, Power On Delay=%s\n",
 350                         option_switches,
 351                         ((option_switches & 0x10) ? "ON" : "OFF"),
 352                         ((option_switches & 0x08) ? "ON" : "OFF"));
 353
 354                 /* Reprogram internal heartbeat to 2 seconds */
 355                 if (set_command_mode()) {
 356                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 357                         unset_command_mode();
 358                 }
 359         }
 360
 361         if (pcwd_private.supports_temp)
 362                 printk(KERN_INFO PFX "Temperature Option Detected\n");
 363
 364         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 365                 printk(KERN_INFO PFX
 366                         "Previous reboot was caused by the card\n");
 367
 368         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 369                 printk(KERN_EMERG PFX
 370                         "Card senses a CPU Overheat. Panicking!\n");
 371                 printk(KERN_EMERG PFX
 372                         "CPU Overheat\n");
 373         }
 374
 375         if (pcwd_private.boot_status == 0)
 376                 printk(KERN_INFO PFX
 377                         "No previous trip detected - Cold boot or reset\n");
 378 }
 379
 380 static void pcwd_timer_ping(unsigned long data)
 381 {
 382         int wdrst_stat;
 383
 384         /* If we got a heartbeat pulse within the WDT_INTERVAL
 385          * we agree to ping the WDT */
 386         if (time_before(jiffies, pcwd_private.next_heartbeat)) {
 387                 /* Ping the watchdog */
 388                 spin_lock(&pcwd_private.io_lock);
 389                 if (pcwd_private.revision == PCWD_REVISION_A) {
 390                         /*  Rev A cards are reset by setting the
 391                             WD_WDRST bit in register 1 */
 392                         wdrst_stat = inb_p(pcwd_private.io_addr);
 393                         wdrst_stat &= 0x0F;
 394                         wdrst_stat |= WD_WDRST;
 395
 396                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 397                 } else {
 398                         /* Re-trigger watchdog by writing to port 0 */
 399                         outb_p(0x00, pcwd_private.io_addr);
 400                 }
 401
 402                 /* Re-set the timer interval */
 403                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 404
 405                 spin_unlock(&pcwd_private.io_lock);
 406         } else {
 407                 printk(KERN_WARNING PFX
 408                         "Heartbeat lost! Will not ping the watchdog\n");
 409         }
 410 }
 411
 412 static int pcwd_start(void)
 413 {
 414         int stat_reg;
 415
 416         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 417
 418         /* Start the timer */
 419         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 420
 421         /* Enable the port */
 422         if (pcwd_private.revision == PCWD_REVISION_C) {
 423                 spin_lock(&pcwd_private.io_lock);
 424                 outb_p(0x00, pcwd_private.io_addr + 3);
 425                 udelay(ISA_COMMAND_TIMEOUT);
 426                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 427                 spin_unlock(&pcwd_private.io_lock);
 428                 if (stat_reg & WD_WDIS) {
 429                         printk(KERN_INFO PFX "Could not start watchdog\n");
 430                         return -EIO;
 431                 }
 432         }
 433
 434         if (debug >= VERBOSE)
 435                 printk(KERN_DEBUG PFX "Watchdog started\n");
 436
 437         return 0;
 438 }
 439
 440 static int pcwd_stop(void)
 441 {
 442         int stat_reg;
 443
 444         /* Stop the timer */
 445         del_timer(&pcwd_private.timer);
 446
 447         /*  Disable the board  */
 448         if (pcwd_private.revision == PCWD_REVISION_C) {
 449                 spin_lock(&pcwd_private.io_lock);
 450                 outb_p(0xA5, pcwd_private.io_addr + 3);
 451                 udelay(ISA_COMMAND_TIMEOUT);
 452                 outb_p(0xA5, pcwd_private.io_addr + 3);
 453                 udelay(ISA_COMMAND_TIMEOUT);
 454                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 455                 spin_unlock(&pcwd_private.io_lock);
 456                 if ((stat_reg & WD_WDIS) == 0) {
 457                         printk(KERN_INFO PFX "Could not stop watchdog\n");
 458                         return -EIO;
 459                 }
 460         }
 461
 462         if (debug >= VERBOSE)
 463                 printk(KERN_DEBUG PFX "Watchdog stopped\n");
 464
 465         return 0;
 466 }
 467
 468 static int pcwd_keepalive(void)
 469 {
 470         /* user land ping */
 471         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 472
 473         if (debug >= DEBUG)
 474                 printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
 475
 476         return 0;
 477 }
 478
 479 static int pcwd_set_heartbeat(int t)
 480 {
 481         if (t < 2 || t > 7200) /* arbitrary upper limit */
 482                 return -EINVAL;
 483
 484         heartbeat = t;
 485
 486         if (debug >= VERBOSE)
 487                 printk(KERN_DEBUG PFX "New heartbeat: %d\n",
 488                        heartbeat);
 489
 490         return 0;
 491 }
 492
 493 static int pcwd_get_status(int *status)
 494 {
 495         int control_status;
 496
 497         *status = 0;
 498         spin_lock(&pcwd_private.io_lock);
 499         if (pcwd_private.revision == PCWD_REVISION_A)
 500                 /* Rev A cards return status information from
 501                  * the base register, which is used for the
 502                  * temperature in other cards. */
 503                 control_status = inb(pcwd_private.io_addr);
 504         else {
 505                 /* Rev C cards return card status in the base
 506                  * address + 1 register. And use different bits
 507                  * to indicate a card initiated reset, and an
 508                  * over-temperature condition. And the reboot
 509                  * status can be reset. */
 510                 control_status = inb(pcwd_private.io_addr + 1);
 511         }
 512         spin_unlock(&pcwd_private.io_lock);
 513
 514         if (pcwd_private.revision == PCWD_REVISION_A) {
 515                 if (control_status & WD_WDRST)
 516                         *status |= WDIOF_CARDRESET;
 517
 518                 if (control_status & WD_T110) {
 519                         *status |= WDIOF_OVERHEAT;
 520                         if (temp_panic) {
 521                                 printk(KERN_INFO PFX
 522                                         "Temperature overheat trip!\n");
 523                                 kernel_power_off();
 524                         }
 525                 }
 526         } else {
 527                 if (control_status & WD_REVC_WTRP)
 528                         *status |= WDIOF_CARDRESET;
 529
 530                 if (control_status & WD_REVC_TTRP) {
 531                         *status |= WDIOF_OVERHEAT;
 532                         if (temp_panic) {
 533                                 printk(KERN_INFO PFX
 534                                         "Temperature overheat trip!\n");
 535                                 kernel_power_off();
 536                         }
 537                 }
 538         }
 539
 540         return 0;
 541 }
 542
 543 static int pcwd_clear_status(void)
 544 {
 545         int control_status;
 546
 547         if (pcwd_private.revision == PCWD_REVISION_C) {
 548                 spin_lock(&pcwd_private.io_lock);
 549
 550                 if (debug >= VERBOSE)
 551                         printk(KERN_INFO PFX
 552                                         "clearing watchdog trip status\n");
 553
 554                 control_status = inb_p(pcwd_private.io_addr + 1);
 555
 556                 if (debug >= DEBUG) {
 557                         printk(KERN_DEBUG PFX "status was: 0x%02x\n",
 558                                 control_status);
 559                         printk(KERN_DEBUG PFX "sending: 0x%02x\n",
 560                                 (control_status & WD_REVC_R2DS));
 561                 }
 562
 563                 /* clear reset status & Keep Relay 2 disable state as it is */
 564                 outb_p((control_status & WD_REVC_R2DS),
 565                                                 pcwd_private.io_addr + 1);
 566
 567                 spin_unlock(&pcwd_private.io_lock);
 568         }
 569         return 0;
 570 }
 571
 572 static int pcwd_get_temperature(int *temperature)
 573 {
 574         /* check that port 0 gives temperature info and no command results */
 575         if (pcwd_private.command_mode)
 576                 return -1;
 577
 578         *temperature = 0;
 579         if (!pcwd_private.supports_temp)
 580                 return -ENODEV;
 581
 582         /*
 583          * Convert celsius to fahrenheit, since this was
 584          * the decided 'standard' for this return value.
 585          */
 586         spin_lock(&pcwd_private.io_lock);
 587         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 588         spin_unlock(&pcwd_private.io_lock);
 589
 590         if (debug >= DEBUG) {
 591                 printk(KERN_DEBUG PFX "temperature is: %d F\n",
 592                         *temperature);
 593         }
 594
 595         return 0;
 596 }
 597
 598 /*
 599  *      /dev/watchdog handling
 600  */
 601
 602 static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 603 {
 604         int rv;
 605         int status;
 606         int temperature;
 607         int new_heartbeat;
 608         int __user *argp = (int __user *)arg;
 609         static const struct watchdog_info ident = {
 610                 .options =              WDIOF_OVERHEAT |
 611                                         WDIOF_CARDRESET |
 612                                         WDIOF_KEEPALIVEPING |
 613                                         WDIOF_SETTIMEOUT |
 614                                         WDIOF_MAGICCLOSE,
 615                 .firmware_version =     1,
 616                 .identity =             "PCWD",
 617         };
 618
 619         switch (cmd) {
 620         case WDIOC_GETSUPPORT:
 621                 if (copy_to_user(argp, &ident, sizeof(ident)))
 622                         return -EFAULT;
 623                 return 0;
 624
 625         case WDIOC_GETSTATUS:
 626                 pcwd_get_status(&status);
 627                 return put_user(status, argp);
 628
 629         case WDIOC_GETBOOTSTATUS:
 630                 return put_user(pcwd_private.boot_status, argp);
 631
 632         case WDIOC_GETTEMP:
 633                 if (pcwd_get_temperature(&temperature))
 634                         return -EFAULT;
 635
 636                 return put_user(temperature, argp);
 637
 638         case WDIOC_SETOPTIONS:
 639                 if (pcwd_private.revision == PCWD_REVISION_C) {
 640                         if (get_user(rv, argp))
 641                                 return -EFAULT;
 642
 643                         if (rv & WDIOS_DISABLECARD) {
 644                                 status = pcwd_stop();
 645                                 if (status < 0)
 646                                         return status;
 647                         }
 648                         if (rv & WDIOS_ENABLECARD) {
 649                                 status = pcwd_start();
 650                                 if (status < 0)
 651                                         return status;
 652                         }
 653                         if (rv & WDIOS_TEMPPANIC)
 654                                 temp_panic = 1;
 655                 }
 656                 return -EINVAL;
 657
 658         case WDIOC_KEEPALIVE:
 659                 pcwd_keepalive();
 660                 return 0;
 661
 662         case WDIOC_SETTIMEOUT:
 663                 if (get_user(new_heartbeat, argp))
 664                         return -EFAULT;
 665
 666                 if (pcwd_set_heartbeat(new_heartbeat))
 667                         return -EINVAL;
 668
 669                 pcwd_keepalive();
 670                 /* Fall */
 671
 672         case WDIOC_GETTIMEOUT:
 673                 return put_user(heartbeat, argp);
 674
 675         default:
 676                 return -ENOTTY;
 677         }
 678
 679         return 0;
 680 }
 681
 682 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 683                           loff_t *ppos)
 684 {
 685         if (len) {
 686                 if (!nowayout) {
 687                         size_t i;
 688
 689                         /* In case it was set long ago */
 690                         expect_close = 0;
 691
 692                         for (i = 0; i != len; i++) {
 693                                 char c;
 694
 695                                 if (get_user(c, buf + i))
 696                                         return -EFAULT;
 697                                 if (c == 'V')
 698                                         expect_close = 42;
 699                         }
 700                 }
 701                 pcwd_keepalive();
 702         }
 703         return len;
 704 }
 705
 706 static int pcwd_open(struct inode *inode, struct file *file)
 707 {
 708         if (test_and_set_bit(0, &open_allowed))
 709                 return -EBUSY;
 710         if (nowayout)
 711                 __module_get(THIS_MODULE);
 712         /* Activate */
 713         pcwd_start();
 714         pcwd_keepalive();
 715         return nonseekable_open(inode, file);
 716 }
 717
 718 static int pcwd_close(struct inode *inode, struct file *file)
 719 {
 720         if (expect_close == 42)
 721                 pcwd_stop();
 722         else {
 723                 printk(KERN_CRIT PFX
 724                         "Unexpected close, not stopping watchdog!\n");
 725                 pcwd_keepalive();
 726         }
 727         expect_close = 0;
 728         clear_bit(0, &open_allowed);
 729         return 0;
 730 }
 731
 732 /*
 733  *      /dev/temperature handling
 734  */
 735
 736 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 737                          loff_t *ppos)
 738 {
 739         int temperature;
 740
 741         if (pcwd_get_temperature(&temperature))
 742                 return -EFAULT;
 743
 744         if (copy_to_user(buf, &temperature, 1))
 745                 return -EFAULT;
 746
 747         return 1;
 748 }
 749
 750 static int pcwd_temp_open(struct inode *inode, struct file *file)
 751 {
 752         if (!pcwd_private.supports_temp)
 753                 return -ENODEV;
 754
 755         return nonseekable_open(inode, file);
 756 }
 757
 758 static int pcwd_temp_close(struct inode *inode, struct file *file)
 759 {
 760         return 0;
 761 }
 762
 763 /*
 764  *      Kernel Interfaces
 765  */
 766
 767 static const struct file_operations pcwd_fops = {
 768         .owner          = THIS_MODULE,
 769         .llseek         = no_llseek,
 770         .write          = pcwd_write,
 771         .unlocked_ioctl = pcwd_ioctl,
 772         .open           = pcwd_open,
 773         .release        = pcwd_close,
 774 };
 775
 776 static struct miscdevice pcwd_miscdev = {
 777         .minor =        WATCHDOG_MINOR,
 778         .name =         "watchdog",
 779         .fops =         &pcwd_fops,
 780 };
 781
 782 static const struct file_operations pcwd_temp_fops = {
 783         .owner          = THIS_MODULE,
 784         .llseek         = no_llseek,
 785         .read           = pcwd_temp_read,
 786         .open           = pcwd_temp_open,
 787         .release        = pcwd_temp_close,
 788 };
 789
 790 static struct miscdevice temp_miscdev = {
 791         .minor =        TEMP_MINOR,
 792         .name =         "temperature",
 793         .fops =         &pcwd_temp_fops,
 794 };
 795
 796 /*
 797  *      Init & exit routines
 798  */
 799
 800 static inline int get_revision(void)
 801 {
 802         int r = PCWD_REVISION_C;
 803
 804         spin_lock(&pcwd_private.io_lock);
 805         /* REV A cards use only 2 io ports; test
 806          * presumes a floating bus reads as 0xff. */
 807         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 808             (inb(pcwd_private.io_addr + 3) == 0xFF))
 809                 r = PCWD_REVISION_A;
 810         spin_unlock(&pcwd_private.io_lock);
 811
 812         return r;
 813 }
 814
 815 /*
 816  *  The ISA cards have a heartbeat bit in one of the registers, which
 817  *  register is card dependent.  The heartbeat bit is monitored, and if
 818  *  found, is considered proof that a Berkshire card has been found.
 819  *  The initial rate is once per second at board start up, then twice
 820  *  per second for normal operation.
 821  */
 822 static int __devinit pcwd_isa_match(struct device *dev, unsigned int id)
 823 {
 824         int base_addr = pcwd_ioports[id];
 825         int port0, last_port0;  /* Reg 0, in case it's REV A */
 826         int port1, last_port1;  /* Register 1 for REV C cards */
 827         int i;
 828         int retval;
 829
 830         if (debug >= DEBUG)
 831                 printk(KERN_DEBUG PFX "pcwd_isa_match id=%d\n",
 832                         id);
 833
 834         if (!request_region(base_addr, 4, "PCWD")) {
 835                 printk(KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 836                 return 0;
 837         }
 838
 839         retval = 0;
 840
 841         port0 = inb_p(base_addr);       /* For REV A boards */
 842         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 843         if (port0 != 0xff || port1 != 0xff) {
 844                 /* Not an 'ff' from a floating bus, so must be a card! */
 845                 for (i = 0; i < 4; ++i) {
 846
 847                         msleep(500);
 848
 849                         last_port0 = port0;
 850                         last_port1 = port1;
 851
 852                         port0 = inb_p(base_addr);
 853                         port1 = inb_p(base_addr + 1);
 854
 855                         /* Has either hearbeat bit changed?  */
 856                         if ((port0 ^ last_port0) & WD_HRTBT ||
 857                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 858                                 retval = 1;
 859                                 break;
 860                         }
 861                 }
 862         }
 863         release_region(base_addr, 4);
 864
 865         return retval;
 866 }
 867
 868 static int __devinit pcwd_isa_probe(struct device *dev, unsigned int id)
 869 {
 870         int ret;
 871
 872         if (debug >= DEBUG)
 873                 printk(KERN_DEBUG PFX "pcwd_isa_probe id=%d\n",
 874                         id);
 875
 876         cards_found++;
 877         if (cards_found == 1)
 878                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n",
 879                                                         WATCHDOG_VERSION);
 880
 881         if (cards_found > 1) {
 882                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 883                 return -ENODEV;
 884         }
 885
 886         if (pcwd_ioports[id] == 0x0000) {
 887                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 888                 return -ENODEV;
 889         }
 890         pcwd_private.io_addr = pcwd_ioports[id];
 891
 892         spin_lock_init(&pcwd_private.io_lock);
 893
 894         /* Check card's revision */
 895         pcwd_private.revision = get_revision();
 896
 897         if (!request_region(pcwd_private.io_addr,
 898                 (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 899                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 900                         pcwd_private.io_addr);
 901                 ret = -EIO;
 902                 goto error_request_region;
 903         }
 904
 905         /* Initial variables */
 906         pcwd_private.supports_temp = 0;
 907         temp_panic = 0;
 908         pcwd_private.boot_status = 0x0000;
 909
 910         /* get the boot_status */
 911         pcwd_get_status(&pcwd_private.boot_status);
 912
 913         /* clear the "card caused reboot" flag */
 914         pcwd_clear_status();
 915
 916         setup_timer(&pcwd_private.timer, pcwd_timer_ping, 0);
 917
 918         /*  Disable the board  */
 919         pcwd_stop();
 920
 921         /*  Check whether or not the card supports the temperature device */
 922         pcwd_check_temperature_support();
 923
 924         /* Show info about the card itself */
 925         pcwd_show_card_info();
 926
 927         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 928         if (heartbeat == 0)
 929                 heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
 930
 931         /* Check that the heartbeat value is within it's range;
 932            if not reset to the default */
 933         if (pcwd_set_heartbeat(heartbeat)) {
 934                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 935                 printk(KERN_INFO PFX
 936                   "heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
 937                                                         WATCHDOG_HEARTBEAT);
 938         }
 939
 940         if (pcwd_private.supports_temp) {
 941                 ret = misc_register(&temp_miscdev);
 942                 if (ret) {
 943                         printk(KERN_ERR PFX
 944                             "cannot register miscdev on minor=%d (err=%d)\n",
 945                                                         TEMP_MINOR, ret);
 946                         goto error_misc_register_temp;
 947                 }
 948         }
 949
 950         ret = misc_register(&pcwd_miscdev);
 951         if (ret) {
 952                 printk(KERN_ERR PFX
 953                         "cannot register miscdev on minor=%d (err=%d)\n",
 954                                         WATCHDOG_MINOR, ret);
 955                 goto error_misc_register_watchdog;
 956         }
 957
 958         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 959                 heartbeat, nowayout);
 960
 961         return 0;
 962
 963 error_misc_register_watchdog:
 964         if (pcwd_private.supports_temp)
 965                 misc_deregister(&temp_miscdev);
 966 error_misc_register_temp:
 967         release_region(pcwd_private.io_addr,
 968                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 969 error_request_region:
 970         pcwd_private.io_addr = 0x0000;
 971         cards_found--;
 972         return ret;
 973 }
 974
 975 static int __devexit pcwd_isa_remove(struct device *dev, unsigned int id)
 976 {
 977         if (debug >= DEBUG)
 978                 printk(KERN_DEBUG PFX "pcwd_isa_remove id=%d\n",
 979                         id);
 980
 981         if (!pcwd_private.io_addr)
 982                 return 1;
 983
 984         /*  Disable the board  */
 985         if (!nowayout)
 986                 pcwd_stop();
 987
 988         /* Deregister */
 989         misc_deregister(&pcwd_miscdev);
 990         if (pcwd_private.supports_temp)
 991                 misc_deregister(&temp_miscdev);
 992         release_region(pcwd_private.io_addr,
 993                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 994         pcwd_private.io_addr = 0x0000;
 995         cards_found--;
 996
 997         return 0;
 998 }
 999
1000 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
1001 {
1002         if (debug >= DEBUG)
1003                 printk(KERN_DEBUG PFX "pcwd_isa_shutdown id=%d\n",
1004                         id);
1005
1006         pcwd_stop();
1007 }
1008
1009 static struct isa_driver pcwd_isa_driver = {
1010         .match          = pcwd_isa_match,
1011         .probe          = pcwd_isa_probe,
1012         .remove         = __devexit_p(pcwd_isa_remove),
1013         .shutdown       = pcwd_isa_shutdown,
1014         .driver         = {
1015                 .owner  = THIS_MODULE,
1016                 .name   = WATCHDOG_NAME,
1017         },
1018 };
1019
1020 static int __init pcwd_init_module(void)
1021 {
1022         return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
1023 }
1024
1025 static void __exit pcwd_cleanup_module(void)
1026 {
1027         isa_unregister_driver(&pcwd_isa_driver);
1028         printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1029 }
1030
1031 module_init(pcwd_init_module);
1032 module_exit(pcwd_cleanup_module);
1033
1034 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, "
1035                 "Wim Van Sebroeck <wim@iguana.be>");
1036 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1037 MODULE_VERSION(WATCHDOG_VERSION);
1038 MODULE_LICENSE("GPL");
1039 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1040 MODULE_ALIAS_MISCDEV(TEMP_MINOR);