git.oblomov.eu Git - linux-2.6/blob - 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 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/reboot.h>       /* For kernel_power_off() */
  63 #include <linux/init.h>         /* For __init/__exit/... */
  64 #include <linux/fs.h>           /* For file operations */
  65 #include <linux/isa.h>          /* For isa devices */
  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 "1.20"
  74 #define WATCHDOG_DATE "18 Feb 2007"
  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 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 on-board processor */
 115 #define WD_REVC_RL1A            0x10    /* Relay 1 active */
 116 #define WD_REVC_R2DS            0x40    /* Relay 2 disable */
 117 #define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
 118 /* Port 2 : Control Status #2 */
 119 #define WD_WDIS                 0x10    /* Watchdog Disabled */
 120 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 121 #define WD_SSEL                 0x40    /* Watchdog Switch Select (1:SW1 <-> 0:SW2) */
 122 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
 123
 124 /* max. time we give an ISA watchdog card to process a command */
 125 /* 500ms for each 4 bit response (according to spec.) */
 126 #define ISA_COMMAND_TIMEOUT     1000
 127
 128 /* Watchdog's internal commands */
 129 #define CMD_ISA_IDLE                    0x00
 130 #define CMD_ISA_VERSION_INTEGER         0x01
 131 #define CMD_ISA_VERSION_TENTH           0x02
 132 #define CMD_ISA_VERSION_HUNDRETH        0x03
 133 #define CMD_ISA_VERSION_MINOR           0x04
 134 #define CMD_ISA_SWITCH_SETTINGS         0x05
 135 #define CMD_ISA_RESET_PC                0x06
 136 #define CMD_ISA_ARM_0                   0x07
 137 #define CMD_ISA_ARM_30                  0x08
 138 #define CMD_ISA_ARM_60                  0x09
 139 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 140 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 141 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 142 #define CMD_ISA_RESET_RELAYS            0x0D
 143
 144 /* Watchdog's Dip Switch heartbeat values */
 145 static const int heartbeat_tbl [] = {
 146         20,     /* OFF-OFF-OFF  = 20 Sec  */
 147         40,     /* OFF-OFF-ON   = 40 Sec  */
 148         60,     /* OFF-ON-OFF   =  1 Min  */
 149         300,    /* OFF-ON-ON    =  5 Min  */
 150         600,    /* ON-OFF-OFF   = 10 Min  */
 151         1800,   /* ON-OFF-ON    = 30 Min  */
 152         3600,   /* ON-ON-OFF    =  1 Hour */
 153         7200,   /* ON-ON-ON     =  2 hour */
 154 };
 155
 156 /*
 157  * We are using an kernel timer to do the pinging of the watchdog
 158  * every ~500ms. We try to set the internal heartbeat of the
 159  * watchdog to 2 ms.
 160  */
 161
 162 #define WDT_INTERVAL (HZ/2+1)
 163
 164 /* We can only use 1 card due to the /dev/watchdog restriction */
 165 static int cards_found;
 166
 167 /* internal variables */
 168 static atomic_t open_allowed = ATOMIC_INIT(1);
 169 static char expect_close;
 170 static int temp_panic;
 171 static struct {                         /* this is private data for each ISA-PC watchdog card */
 172         char fw_ver_str[6];             /* The cards firmware version */
 173         int revision;                   /* The card's revision */
 174         int supports_temp;              /* Wether or not the card has a temperature device */
 175         int command_mode;               /* Wether or not the card is in command mode */
 176         int boot_status;                /* The card's boot status */
 177         int io_addr;                    /* The cards I/O address */
 178         spinlock_t io_lock;             /* the lock for io operations */
 179         struct timer_list timer;        /* The timer that pings the watchdog */
 180         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 181 } pcwd_private;
 182
 183 /* module parameters */
 184 #define QUIET   0       /* Default */
 185 #define VERBOSE 1       /* Verbose */
 186 #define DEBUG   2       /* print fancy stuff too */
 187 static int debug = QUIET;
 188 module_param(debug, int, 0);
 189 MODULE_PARM_DESC(debug, "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
 190
 191 #define WATCHDOG_HEARTBEAT 0            /* default heartbeat = delay-time from dip-switches */
 192 static int heartbeat = WATCHDOG_HEARTBEAT;
 193 module_param(heartbeat, int, 0);
 194 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200 or 0=delay-time from dip-switches, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 195
 196 static int nowayout = WATCHDOG_NOWAYOUT;
 197 module_param(nowayout, int, 0);
 198 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 199
 200 /*
 201  *      Internal functions
 202  */
 203
 204 static int send_isa_command(int cmd)
 205 {
 206         int i;
 207         int control_status;
 208         int port0, last_port0;  /* Double read for stabilising */
 209
 210         if (debug >= DEBUG)
 211                 printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
 212                         cmd);
 213
 214         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 215         control_status = (cmd & 0x0F) | WD_WCMD;
 216         outb_p(control_status, pcwd_private.io_addr + 2);
 217         udelay(ISA_COMMAND_TIMEOUT);
 218
 219         port0 = inb_p(pcwd_private.io_addr);
 220         for (i = 0; i < 25; ++i) {
 221                 last_port0 = port0;
 222                 port0 = inb_p(pcwd_private.io_addr);
 223
 224                 if (port0 == last_port0)
 225                         break;  /* Data is stable */
 226
 227                 udelay (250);
 228         }
 229
 230         if (debug >= DEBUG)
 231                 printk(KERN_DEBUG PFX "received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 232                         cmd, port0, last_port0);
 233
 234         return port0;
 235 }
 236
 237 static int set_command_mode(void)
 238 {
 239         int i, found=0, count=0;
 240
 241         /* Set the card into command mode */
 242         spin_lock(&pcwd_private.io_lock);
 243         while ((!found) && (count < 3)) {
 244                 i = send_isa_command(CMD_ISA_IDLE);
 245
 246                 if (i == 0x00)
 247                         found = 1;
 248                 else if (i == 0xF3) {
 249                         /* Card does not like what we've done to it */
 250                         outb_p(0x00, pcwd_private.io_addr + 2);
 251                         udelay(1200);   /* Spec says wait 1ms */
 252                         outb_p(0x00, pcwd_private.io_addr + 2);
 253                         udelay(ISA_COMMAND_TIMEOUT);
 254                 }
 255                 count++;
 256         }
 257         spin_unlock(&pcwd_private.io_lock);
 258         pcwd_private.command_mode = found;
 259
 260         if (debug >= DEBUG)
 261                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 262                                 pcwd_private.command_mode);
 263
 264         return(found);
 265 }
 266
 267 static void unset_command_mode(void)
 268 {
 269         /* Set the card into normal mode */
 270         spin_lock(&pcwd_private.io_lock);
 271         outb_p(0x00, pcwd_private.io_addr + 2);
 272         udelay(ISA_COMMAND_TIMEOUT);
 273         spin_unlock(&pcwd_private.io_lock);
 274
 275         pcwd_private.command_mode = 0;
 276
 277         if (debug >= DEBUG)
 278                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 279                                 pcwd_private.command_mode);
 280 }
 281
 282 static inline void pcwd_check_temperature_support(void)
 283 {
 284         if (inb(pcwd_private.io_addr) != 0xF0)
 285                 pcwd_private.supports_temp = 1;
 286 }
 287
 288 static inline void pcwd_get_firmware(void)
 289 {
 290         int one, ten, hund, minor;
 291
 292         strcpy(pcwd_private.fw_ver_str, "ERROR");
 293
 294         if (set_command_mode()) {
 295                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 296                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 297                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 298                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 299                 sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c", one, ten, hund, minor);
 300         }
 301         unset_command_mode();
 302
 303         return;
 304 }
 305
 306 static inline int pcwd_get_option_switches(void)
 307 {
 308         int option_switches=0;
 309
 310         if (set_command_mode()) {
 311                 /* Get switch settings */
 312                 option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 313         }
 314
 315         unset_command_mode();
 316         return(option_switches);
 317 }
 318
 319 static void pcwd_show_card_info(void)
 320 {
 321         int option_switches;
 322
 323         /* Get some extra info from the hardware (in command/debug/diag mode) */
 324         if (pcwd_private.revision == PCWD_REVISION_A)
 325                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", pcwd_private.io_addr);
 326         else if (pcwd_private.revision == PCWD_REVISION_C) {
 327                 pcwd_get_firmware();
 328                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 329                         pcwd_private.io_addr, pcwd_private.fw_ver_str);
 330                 option_switches = pcwd_get_option_switches();
 331                 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 332                         option_switches,
 333                         ((option_switches & 0x10) ? "ON" : "OFF"),
 334                         ((option_switches & 0x08) ? "ON" : "OFF"));
 335
 336                 /* Reprogram internal heartbeat to 2 seconds */
 337                 if (set_command_mode()) {
 338                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 339                         unset_command_mode();
 340                 }
 341         }
 342
 343         if (pcwd_private.supports_temp)
 344                 printk(KERN_INFO PFX "Temperature Option Detected\n");
 345
 346         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 347                 printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
 348
 349         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 350                 printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
 351                 printk(KERN_EMERG PFX "CPU Overheat\n");
 352         }
 353
 354         if (pcwd_private.boot_status == 0)
 355                 printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");
 356 }
 357
 358 static void pcwd_timer_ping(unsigned long data)
 359 {
 360         int wdrst_stat;
 361
 362         /* If we got a heartbeat pulse within the WDT_INTERVAL
 363          * we agree to ping the WDT */
 364         if(time_before(jiffies, pcwd_private.next_heartbeat)) {
 365                 /* Ping the watchdog */
 366                 spin_lock(&pcwd_private.io_lock);
 367                 if (pcwd_private.revision == PCWD_REVISION_A) {
 368                         /*  Rev A cards are reset by setting the WD_WDRST bit in register 1 */
 369                         wdrst_stat = inb_p(pcwd_private.io_addr);
 370                         wdrst_stat &= 0x0F;
 371                         wdrst_stat |= WD_WDRST;
 372
 373                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 374                 } else {
 375                         /* Re-trigger watchdog by writing to port 0 */
 376                         outb_p(0x00, pcwd_private.io_addr);
 377                 }
 378
 379                 /* Re-set the timer interval */
 380                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 381
 382                 spin_unlock(&pcwd_private.io_lock);
 383         } else {
 384                 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
 385         }
 386 }
 387
 388 static int pcwd_start(void)
 389 {
 390         int stat_reg;
 391
 392         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 393
 394         /* Start the timer */
 395         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 396
 397         /* Enable the port */
 398         if (pcwd_private.revision == PCWD_REVISION_C) {
 399                 spin_lock(&pcwd_private.io_lock);
 400                 outb_p(0x00, pcwd_private.io_addr + 3);
 401                 udelay(ISA_COMMAND_TIMEOUT);
 402                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 403                 spin_unlock(&pcwd_private.io_lock);
 404                 if (stat_reg & WD_WDIS) {
 405                         printk(KERN_INFO PFX "Could not start watchdog\n");
 406                         return -EIO;
 407                 }
 408         }
 409
 410         if (debug >= VERBOSE)
 411                 printk(KERN_DEBUG PFX "Watchdog started\n");
 412
 413         return 0;
 414 }
 415
 416 static int pcwd_stop(void)
 417 {
 418         int stat_reg;
 419
 420         /* Stop the timer */
 421         del_timer(&pcwd_private.timer);
 422
 423         /*  Disable the board  */
 424         if (pcwd_private.revision == PCWD_REVISION_C) {
 425                 spin_lock(&pcwd_private.io_lock);
 426                 outb_p(0xA5, pcwd_private.io_addr + 3);
 427                 udelay(ISA_COMMAND_TIMEOUT);
 428                 outb_p(0xA5, pcwd_private.io_addr + 3);
 429                 udelay(ISA_COMMAND_TIMEOUT);
 430                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 431                 spin_unlock(&pcwd_private.io_lock);
 432                 if ((stat_reg & WD_WDIS) == 0) {
 433                         printk(KERN_INFO PFX "Could not stop watchdog\n");
 434                         return -EIO;
 435                 }
 436         }
 437
 438         if (debug >= VERBOSE)
 439                 printk(KERN_DEBUG PFX "Watchdog stopped\n");
 440
 441         return 0;
 442 }
 443
 444 static int pcwd_keepalive(void)
 445 {
 446         /* user land ping */
 447         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 448
 449         if (debug >= DEBUG)
 450                 printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
 451
 452         return 0;
 453 }
 454
 455 static int pcwd_set_heartbeat(int t)
 456 {
 457         if ((t < 2) || (t > 7200)) /* arbitrary upper limit */
 458                 return -EINVAL;
 459
 460         heartbeat = t;
 461
 462         if (debug >= VERBOSE)
 463                 printk(KERN_DEBUG PFX "New heartbeat: %d\n",
 464                        heartbeat);
 465
 466         return 0;
 467 }
 468
 469 static int pcwd_get_status(int *status)
 470 {
 471         int control_status;
 472
 473         *status=0;
 474         spin_lock(&pcwd_private.io_lock);
 475         if (pcwd_private.revision == PCWD_REVISION_A)
 476                 /* Rev A cards return status information from
 477                  * the base register, which is used for the
 478                  * temperature in other cards. */
 479                 control_status = inb(pcwd_private.io_addr);
 480         else {
 481                 /* Rev C cards return card status in the base
 482                  * address + 1 register. And use different bits
 483                  * to indicate a card initiated reset, and an
 484                  * over-temperature condition. And the reboot
 485                  * status can be reset. */
 486                 control_status = inb(pcwd_private.io_addr + 1);
 487         }
 488         spin_unlock(&pcwd_private.io_lock);
 489
 490         if (pcwd_private.revision == PCWD_REVISION_A) {
 491                 if (control_status & WD_WDRST)
 492                         *status |= WDIOF_CARDRESET;
 493
 494                 if (control_status & WD_T110) {
 495                         *status |= WDIOF_OVERHEAT;
 496                         if (temp_panic) {
 497                                 printk(KERN_INFO PFX "Temperature overheat trip!\n");
 498                                 kernel_power_off();
 499                                 /* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
 500                         }
 501                 }
 502         } else {
 503                 if (control_status & WD_REVC_WTRP)
 504                         *status |= WDIOF_CARDRESET;
 505
 506                 if (control_status & WD_REVC_TTRP) {
 507                         *status |= WDIOF_OVERHEAT;
 508                         if (temp_panic) {
 509                                 printk(KERN_INFO PFX "Temperature overheat trip!\n");
 510                                 kernel_power_off();
 511                                 /* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
 512                         }
 513                 }
 514         }
 515
 516         return 0;
 517 }
 518
 519 static int pcwd_clear_status(void)
 520 {
 521         int control_status;
 522
 523         if (pcwd_private.revision == PCWD_REVISION_C) {
 524                 spin_lock(&pcwd_private.io_lock);
 525
 526                 if (debug >= VERBOSE)
 527                         printk(KERN_INFO PFX "clearing watchdog trip status\n");
 528
 529                 control_status = inb_p(pcwd_private.io_addr + 1);
 530
 531                 if (debug >= DEBUG) {
 532                         printk(KERN_DEBUG PFX "status was: 0x%02x\n", control_status);
 533                         printk(KERN_DEBUG PFX "sending: 0x%02x\n",
 534                                 (control_status & WD_REVC_R2DS));
 535                 }
 536
 537                 /* clear reset status & Keep Relay 2 disable state as it is */
 538                 outb_p((control_status & WD_REVC_R2DS), pcwd_private.io_addr + 1);
 539
 540                 spin_unlock(&pcwd_private.io_lock);
 541         }
 542         return 0;
 543 }
 544
 545 static int pcwd_get_temperature(int *temperature)
 546 {
 547         /* check that port 0 gives temperature info and no command results */
 548         if (pcwd_private.command_mode)
 549                 return -1;
 550
 551         *temperature = 0;
 552         if (!pcwd_private.supports_temp)
 553                 return -ENODEV;
 554
 555         /*
 556          * Convert celsius to fahrenheit, since this was
 557          * the decided 'standard' for this return value.
 558          */
 559         spin_lock(&pcwd_private.io_lock);
 560         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 561         spin_unlock(&pcwd_private.io_lock);
 562
 563         if (debug >= DEBUG) {
 564                 printk(KERN_DEBUG PFX "temperature is: %d F\n",
 565                         *temperature);
 566         }
 567
 568         return 0;
 569 }
 570
 571 /*
 572  *      /dev/watchdog handling
 573  */
 574
 575 static int pcwd_ioctl(struct inode *inode, struct file *file,
 576                       unsigned int cmd, unsigned long arg)
 577 {
 578         int rv;
 579         int status;
 580         int temperature;
 581         int new_heartbeat;
 582         int __user *argp = (int __user *)arg;
 583         static struct watchdog_info ident = {
 584                 .options =              WDIOF_OVERHEAT |
 585                                         WDIOF_CARDRESET |
 586                                         WDIOF_KEEPALIVEPING |
 587                                         WDIOF_SETTIMEOUT |
 588                                         WDIOF_MAGICCLOSE,
 589                 .firmware_version =     1,
 590                 .identity =             "PCWD",
 591         };
 592
 593         switch(cmd) {
 594         default:
 595                 return -ENOTTY;
 596
 597         case WDIOC_GETSUPPORT:
 598                 if(copy_to_user(argp, &ident, sizeof(ident)))
 599                         return -EFAULT;
 600                 return 0;
 601
 602         case WDIOC_GETSTATUS:
 603                 pcwd_get_status(&status);
 604                 return put_user(status, argp);
 605
 606         case WDIOC_GETBOOTSTATUS:
 607                 return put_user(pcwd_private.boot_status, argp);
 608
 609         case WDIOC_GETTEMP:
 610                 if (pcwd_get_temperature(&temperature))
 611                         return -EFAULT;
 612
 613                 return put_user(temperature, argp);
 614
 615         case WDIOC_SETOPTIONS:
 616                 if (pcwd_private.revision == PCWD_REVISION_C)
 617                 {
 618                         if(copy_from_user(&rv, argp, sizeof(int)))
 619                                 return -EFAULT;
 620
 621                         if (rv & WDIOS_DISABLECARD)
 622                         {
 623                                 return pcwd_stop();
 624                         }
 625
 626                         if (rv & WDIOS_ENABLECARD)
 627                         {
 628                                 return pcwd_start();
 629                         }
 630
 631                         if (rv & WDIOS_TEMPPANIC)
 632                         {
 633                                 temp_panic = 1;
 634                         }
 635                 }
 636                 return -EINVAL;
 637
 638         case WDIOC_KEEPALIVE:
 639                 pcwd_keepalive();
 640                 return 0;
 641
 642         case WDIOC_SETTIMEOUT:
 643                 if (get_user(new_heartbeat, argp))
 644                         return -EFAULT;
 645
 646                 if (pcwd_set_heartbeat(new_heartbeat))
 647                         return -EINVAL;
 648
 649                 pcwd_keepalive();
 650                 /* Fall */
 651
 652         case WDIOC_GETTIMEOUT:
 653                 return put_user(heartbeat, argp);
 654         }
 655
 656         return 0;
 657 }
 658
 659 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 660                           loff_t *ppos)
 661 {
 662         if (len) {
 663                 if (!nowayout) {
 664                         size_t i;
 665
 666                         /* In case it was set long ago */
 667                         expect_close = 0;
 668
 669                         for (i = 0; i != len; i++) {
 670                                 char c;
 671
 672                                 if (get_user(c, buf + i))
 673                                         return -EFAULT;
 674                                 if (c == 'V')
 675                                         expect_close = 42;
 676                         }
 677                 }
 678                 pcwd_keepalive();
 679         }
 680         return len;
 681 }
 682
 683 static int pcwd_open(struct inode *inode, struct file *file)
 684 {
 685         if (!atomic_dec_and_test(&open_allowed) ) {
 686                 if (debug >= VERBOSE)
 687                         printk(KERN_ERR PFX "Attempt to open already opened device.\n");
 688                 atomic_inc( &open_allowed );
 689                 return -EBUSY;
 690         }
 691
 692         if (nowayout)
 693                 __module_get(THIS_MODULE);
 694
 695         /* Activate */
 696         pcwd_start();
 697         pcwd_keepalive();
 698         return nonseekable_open(inode, file);
 699 }
 700
 701 static int pcwd_close(struct inode *inode, struct file *file)
 702 {
 703         if (expect_close == 42) {
 704                 pcwd_stop();
 705         } else {
 706                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 707                 pcwd_keepalive();
 708         }
 709         expect_close = 0;
 710         atomic_inc( &open_allowed );
 711         return 0;
 712 }
 713
 714 /*
 715  *      /dev/temperature handling
 716  */
 717
 718 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 719                          loff_t *ppos)
 720 {
 721         int temperature;
 722
 723         if (pcwd_get_temperature(&temperature))
 724                 return -EFAULT;
 725
 726         if (copy_to_user(buf, &temperature, 1))
 727                 return -EFAULT;
 728
 729         return 1;
 730 }
 731
 732 static int pcwd_temp_open(struct inode *inode, struct file *file)
 733 {
 734         if (!pcwd_private.supports_temp)
 735                 return -ENODEV;
 736
 737         return nonseekable_open(inode, file);
 738 }
 739
 740 static int pcwd_temp_close(struct inode *inode, struct file *file)
 741 {
 742         return 0;
 743 }
 744
 745 /*
 746  *      Kernel Interfaces
 747  */
 748
 749 static const struct file_operations pcwd_fops = {
 750         .owner          = THIS_MODULE,
 751         .llseek         = no_llseek,
 752         .write          = pcwd_write,
 753         .ioctl          = pcwd_ioctl,
 754         .open           = pcwd_open,
 755         .release        = pcwd_close,
 756 };
 757
 758 static struct miscdevice pcwd_miscdev = {
 759         .minor =        WATCHDOG_MINOR,
 760         .name =         "watchdog",
 761         .fops =         &pcwd_fops,
 762 };
 763
 764 static const struct file_operations pcwd_temp_fops = {
 765         .owner          = THIS_MODULE,
 766         .llseek         = no_llseek,
 767         .read           = pcwd_temp_read,
 768         .open           = pcwd_temp_open,
 769         .release        = pcwd_temp_close,
 770 };
 771
 772 static struct miscdevice temp_miscdev = {
 773         .minor =        TEMP_MINOR,
 774         .name =         "temperature",
 775         .fops =         &pcwd_temp_fops,
 776 };
 777
 778 /*
 779  *      Init & exit routines
 780  */
 781
 782 static inline int get_revision(void)
 783 {
 784         int r = PCWD_REVISION_C;
 785
 786         spin_lock(&pcwd_private.io_lock);
 787         /* REV A cards use only 2 io ports; test
 788          * presumes a floating bus reads as 0xff. */
 789         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 790             (inb(pcwd_private.io_addr + 3) == 0xFF))
 791                 r=PCWD_REVISION_A;
 792         spin_unlock(&pcwd_private.io_lock);
 793
 794         return r;
 795 }
 796
 797 /*
 798  *  The ISA cards have a heartbeat bit in one of the registers, which
 799  *  register is card dependent.  The heartbeat bit is monitored, and if
 800  *  found, is considered proof that a Berkshire card has been found.
 801  *  The initial rate is once per second at board start up, then twice
 802  *  per second for normal operation.
 803  */
 804 static int __devinit pcwd_isa_match(struct device *dev, unsigned int id)
 805 {
 806         int base_addr=pcwd_ioports[id];
 807         int port0, last_port0;  /* Reg 0, in case it's REV A */
 808         int port1, last_port1;  /* Register 1 for REV C cards */
 809         int i;
 810         int retval;
 811
 812         if (debug >= DEBUG)
 813                 printk(KERN_DEBUG PFX "pcwd_isa_match id=%d\n",
 814                         id);
 815
 816         if (!request_region (base_addr, 4, "PCWD")) {
 817                 printk(KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 818                 return 0;
 819         }
 820
 821         retval = 0;
 822
 823         port0 = inb_p(base_addr);       /* For REV A boards */
 824         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 825         if (port0 != 0xff || port1 != 0xff) {
 826                 /* Not an 'ff' from a floating bus, so must be a card! */
 827                 for (i = 0; i < 4; ++i) {
 828
 829                         msleep(500);
 830
 831                         last_port0 = port0;
 832                         last_port1 = port1;
 833
 834                         port0 = inb_p(base_addr);
 835                         port1 = inb_p(base_addr + 1);
 836
 837                         /* Has either hearbeat bit changed?  */
 838                         if ((port0 ^ last_port0) & WD_HRTBT ||
 839                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 840                                 retval = 1;
 841                                 break;
 842                         }
 843                 }
 844         }
 845         release_region (base_addr, 4);
 846
 847         return retval;
 848 }
 849
 850 static int __devinit pcwd_isa_probe(struct device *dev, unsigned int id)
 851 {
 852         int ret;
 853
 854         if (debug >= DEBUG)
 855                 printk(KERN_DEBUG PFX "pcwd_isa_probe id=%d\n",
 856                         id);
 857
 858         cards_found++;
 859         if (cards_found == 1)
 860                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER);
 861
 862         if (cards_found > 1) {
 863                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 864                 return -ENODEV;
 865         }
 866
 867         if (pcwd_ioports[id] == 0x0000) {
 868                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 869                 return -ENODEV;
 870         }
 871         pcwd_private.io_addr = pcwd_ioports[id];
 872
 873         spin_lock_init(&pcwd_private.io_lock);
 874
 875         /* Check card's revision */
 876         pcwd_private.revision = get_revision();
 877
 878         if (!request_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 879                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 880                         pcwd_private.io_addr);
 881                 ret=-EIO;
 882                 goto error_request_region;
 883         }
 884
 885         /* Initial variables */
 886         pcwd_private.supports_temp = 0;
 887         temp_panic = 0;
 888         pcwd_private.boot_status = 0x0000;
 889
 890         /* get the boot_status */
 891         pcwd_get_status(&pcwd_private.boot_status);
 892
 893         /* clear the "card caused reboot" flag */
 894         pcwd_clear_status();
 895
 896         setup_timer(&pcwd_private.timer, pcwd_timer_ping, 0);
 897
 898         /*  Disable the board  */
 899         pcwd_stop();
 900
 901         /*  Check whether or not the card supports the temperature device */
 902         pcwd_check_temperature_support();
 903
 904         /* Show info about the card itself */
 905         pcwd_show_card_info();
 906
 907         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 908         if (heartbeat == 0)
 909                 heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
 910
 911         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 912         if (pcwd_set_heartbeat(heartbeat)) {
 913                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 914                 printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
 915                         WATCHDOG_HEARTBEAT);
 916         }
 917
 918         if (pcwd_private.supports_temp) {
 919                 ret = misc_register(&temp_miscdev);
 920                 if (ret) {
 921                         printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 922                                 TEMP_MINOR, ret);
 923                         goto error_misc_register_temp;
 924                 }
 925         }
 926
 927         ret = misc_register(&pcwd_miscdev);
 928         if (ret) {
 929                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 930                         WATCHDOG_MINOR, ret);
 931                 goto error_misc_register_watchdog;
 932         }
 933
 934         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 935                 heartbeat, nowayout);
 936
 937         return 0;
 938
 939 error_misc_register_watchdog:
 940         if (pcwd_private.supports_temp)
 941                 misc_deregister(&temp_miscdev);
 942 error_misc_register_temp:
 943         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 944 error_request_region:
 945         pcwd_private.io_addr = 0x0000;
 946         cards_found--;
 947         return ret;
 948 }
 949
 950 static int __devexit pcwd_isa_remove(struct device *dev, unsigned int id)
 951 {
 952         if (debug >= DEBUG)
 953                 printk(KERN_DEBUG PFX "pcwd_isa_remove id=%d\n",
 954                         id);
 955
 956         if (!pcwd_private.io_addr)
 957                 return 1;
 958
 959         /*  Disable the board  */
 960         if (!nowayout)
 961                 pcwd_stop();
 962
 963         /* Deregister */
 964         misc_deregister(&pcwd_miscdev);
 965         if (pcwd_private.supports_temp)
 966                 misc_deregister(&temp_miscdev);
 967         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 968         pcwd_private.io_addr = 0x0000;
 969         cards_found--;
 970
 971         return 0;
 972 }
 973
 974 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
 975 {
 976         if (debug >= DEBUG)
 977                 printk(KERN_DEBUG PFX "pcwd_isa_shutdown id=%d\n",
 978                         id);
 979
 980         pcwd_stop();
 981 }
 982
 983 static struct isa_driver pcwd_isa_driver = {
 984         .match          = pcwd_isa_match,
 985         .probe          = pcwd_isa_probe,
 986         .remove         = __devexit_p(pcwd_isa_remove),
 987         .shutdown       = pcwd_isa_shutdown,
 988         .driver         = {
 989                 .owner  = THIS_MODULE,
 990                 .name   = WATCHDOG_NAME,
 991         },
 992 };
 993
 994 static int __init pcwd_init_module(void)
 995 {
 996         return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
 997 }
 998
 999 static void __exit pcwd_cleanup_module(void)
1000 {
1001         isa_unregister_driver(&pcwd_isa_driver);
1002         printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1003 }
1004
1005 module_init(pcwd_init_module);
1006 module_exit(pcwd_cleanup_module);
1007
1008 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, Wim Van Sebroeck <wim@iguana.be>");
1009 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1010 MODULE_VERSION(WATCHDOG_VERSION);
1011 MODULE_LICENSE("GPL");
1012 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1013 MODULE_ALIAS_MISCDEV(TEMP_MINOR);