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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  55
  56 #include <linux/module.h>       /* For module specific items */
  57 #include <linux/moduleparam.h>  /* For new moduleparam's */
  58 #include <linux/types.h>        /* For standard types (like size_t) */
  59 #include <linux/errno.h>        /* For the -ENODEV/... values */
  60 #include <linux/kernel.h>       /* For printk/panic/... */
  61 #include <linux/delay.h>        /* For mdelay function */
  62 #include <linux/timer.h>        /* For timer related operations */
  63 #include <linux/jiffies.h>      /* For jiffies stuff */
  64 #include <linux/miscdevice.h>   /* For struct miscdevice */
  65 #include <linux/watchdog.h>     /* For the watchdog specific items */
  66 #include <linux/reboot.h>       /* For kernel_power_off() */
  67 #include <linux/init.h>         /* For __init/__exit/... */
  68 #include <linux/fs.h>           /* For file operations */
  69 #include <linux/isa.h>          /* For isa devices */
  70 #include <linux/ioport.h>       /* For io-port access */
  71 #include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  72 #include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  73 #include <linux/io.h>           /* For inb/outb/... */
  74
  75 /* Module and version information */
  76 #define WATCHDOG_VERSION "1.20"
  77 #define WATCHDOG_DATE "18 Feb 2007"
  78 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
  79 #define WATCHDOG_NAME "pcwd"
  80 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION "\n"
  81
  82 /*
  83  * It should be noted that PCWD_REVISION_B was removed because A and B
  84  * are essentially the same types of card, with the exception that B
  85  * has temperature reporting.  Since I didn't receive a Rev.B card,
  86  * the Rev.B card is not supported.  (It's a good thing too, as they
  87  * are no longer in production.)
  88  */
  89 #define PCWD_REVISION_A         1
  90 #define PCWD_REVISION_C         2
  91
  92 /*
  93  * These are the auto-probe addresses available.
  94  *
  95  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
  96  * Revision A has an address range of 2 addresses, while Revision C has 4.
  97  */
  98 #define PCWD_ISA_NR_CARDS       3
  99 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
 100
 101 /*
 102  * These are the defines that describe the control status bits for the
 103  * PCI-PC Watchdog card.
 104 */
 105 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
 106 #define WD_WDRST                0x01    /* Previously reset state */
 107 #define WD_T110                 0x02    /* Temperature overheat sense */
 108 #define WD_HRTBT                0x04    /* Heartbeat sense */
 109 #define WD_RLY2                 0x08    /* External relay triggered */
 110 #define WD_SRLY2                0x80    /* Software external relay triggered */
 111 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 112 #define WD_REVC_WTRP            0x01    /* Watchdog Trip status */
 113 #define WD_REVC_HRBT            0x02    /* Watchdog Heartbeat */
 114 #define WD_REVC_TTRP            0x04    /* Temperature Trip status */
 115 #define WD_REVC_RL2A            0x08    /* Relay 2 activated by
 116                                                         on-board processor */
 117 #define WD_REVC_RL1A            0x10    /* Relay 1 active */
 118 #define WD_REVC_R2DS            0x40    /* Relay 2 disable */
 119 #define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
 120 /* Port 2 : Control Status #2 */
 121 #define WD_WDIS                 0x10    /* Watchdog Disabled */
 122 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 123 #define WD_SSEL                 0x40    /* Watchdog Switch Select
 124                                                         (1:SW1 <-> 0:SW2) */
 125 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
 126
 127 /* max. time we give an ISA watchdog card to process a command */
 128 /* 500ms for each 4 bit response (according to spec.) */
 129 #define ISA_COMMAND_TIMEOUT     1000
 130
 131 /* Watchdog's internal commands */
 132 #define CMD_ISA_IDLE                    0x00
 133 #define CMD_ISA_VERSION_INTEGER         0x01
 134 #define CMD_ISA_VERSION_TENTH           0x02
 135 #define CMD_ISA_VERSION_HUNDRETH        0x03
 136 #define CMD_ISA_VERSION_MINOR           0x04
 137 #define CMD_ISA_SWITCH_SETTINGS         0x05
 138 #define CMD_ISA_RESET_PC                0x06
 139 #define CMD_ISA_ARM_0                   0x07
 140 #define CMD_ISA_ARM_30                  0x08
 141 #define CMD_ISA_ARM_60                  0x09
 142 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 143 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 144 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 145 #define CMD_ISA_RESET_RELAYS            0x0D
 146
 147 /* Watchdog's Dip Switch heartbeat values */
 148 static const int heartbeat_tbl[] = {
 149         20,     /* OFF-OFF-OFF  = 20 Sec  */
 150         40,     /* OFF-OFF-ON   = 40 Sec  */
 151         60,     /* OFF-ON-OFF   =  1 Min  */
 152         300,    /* OFF-ON-ON    =  5 Min  */
 153         600,    /* ON-OFF-OFF   = 10 Min  */
 154         1800,   /* ON-OFF-ON    = 30 Min  */
 155         3600,   /* ON-ON-OFF    =  1 Hour */
 156         7200,   /* ON-ON-ON     =  2 hour */
 157 };
 158
 159 /*
 160  * We are using an kernel timer to do the pinging of the watchdog
 161  * every ~500ms. We try to set the internal heartbeat of the
 162  * watchdog to 2 ms.
 163  */
 164
 165 #define WDT_INTERVAL (HZ/2+1)
 166
 167 /* We can only use 1 card due to the /dev/watchdog restriction */
 168 static int cards_found;
 169
 170 /* internal variables */
 171 static unsigned long open_allowed;
 172 static char expect_close;
 173 static int temp_panic;
 174
 175 /* this is private data for each ISA-PC watchdog card */
 176 static struct {
 177         char fw_ver_str[6];             /* The cards firmware version */
 178         int revision;                   /* The card's revision */
 179         int supports_temp;              /* Whether or not the card has
 180                                                 a temperature device */
 181         int command_mode;               /* Whether or not the card is in
 182                                                 command mode */
 183         int boot_status;                /* The card's boot status */
 184         int io_addr;                    /* The cards I/O address */
 185         spinlock_t io_lock;             /* the lock for io operations */
 186         struct timer_list timer;        /* The timer that pings the watchdog */
 187         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 188 } pcwd_private;
 189
 190 /* module parameters */
 191 #define QUIET   0       /* Default */
 192 #define VERBOSE 1       /* Verbose */
 193 #define DEBUG   2       /* print fancy stuff too */
 194 static int debug = QUIET;
 195 module_param(debug, int, 0);
 196 MODULE_PARM_DESC(debug,
 197                 "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
 198
 199 /* default heartbeat = delay-time from dip-switches */
 200 #define WATCHDOG_HEARTBEAT 0
 201 static int heartbeat = WATCHDOG_HEARTBEAT;
 202 module_param(heartbeat, int, 0);
 203 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
 204         "(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
 205                                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 206
 207 static bool nowayout = WATCHDOG_NOWAYOUT;
 208 module_param(nowayout, bool, 0);
 209 MODULE_PARM_DESC(nowayout,
 210                 "Watchdog cannot be stopped once started (default="
 211                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 212
 213 /*
 214  *      Internal functions
 215  */
 216
 217 static int send_isa_command(int cmd)
 218 {
 219         int i;
 220         int control_status;
 221         int port0, last_port0;  /* Double read for stabilising */
 222
 223         if (debug >= DEBUG)
 224                 pr_debug("sending following data cmd=0x%02x\n", 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                 pr_debug("received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 244                          cmd, port0, last_port0);
 245
 246         return port0;
 247 }
 248
 249 static int set_command_mode(void)
 250 {
 251         int i, found = 0, count = 0;
 252
 253         /* Set the card into command mode */
 254         spin_lock(&pcwd_private.io_lock);
 255         while ((!found) && (count < 3)) {
 256                 i = send_isa_command(CMD_ISA_IDLE);
 257
 258                 if (i == 0x00)
 259                         found = 1;
 260                 else if (i == 0xF3) {
 261                         /* Card does not like what we've done to it */
 262                         outb_p(0x00, pcwd_private.io_addr + 2);
 263                         udelay(1200);   /* Spec says wait 1ms */
 264                         outb_p(0x00, pcwd_private.io_addr + 2);
 265                         udelay(ISA_COMMAND_TIMEOUT);
 266                 }
 267                 count++;
 268         }
 269         spin_unlock(&pcwd_private.io_lock);
 270         pcwd_private.command_mode = found;
 271
 272         if (debug >= DEBUG)
 273                 pr_debug("command_mode=%d\n", pcwd_private.command_mode);
 274
 275         return found;
 276 }
 277
 278 static void unset_command_mode(void)
 279 {
 280         /* Set the card into normal mode */
 281         spin_lock(&pcwd_private.io_lock);
 282         outb_p(0x00, pcwd_private.io_addr + 2);
 283         udelay(ISA_COMMAND_TIMEOUT);
 284         spin_unlock(&pcwd_private.io_lock);
 285
 286         pcwd_private.command_mode = 0;
 287
 288         if (debug >= DEBUG)
 289                 pr_debug("command_mode=%d\n", pcwd_private.command_mode);
 290 }
 291
 292 static inline void pcwd_check_temperature_support(void)
 293 {
 294         if (inb(pcwd_private.io_addr) != 0xF0)
 295                 pcwd_private.supports_temp = 1;
 296 }
 297
 298 static inline void pcwd_get_firmware(void)
 299 {
 300         int one, ten, hund, minor;
 301
 302         strcpy(pcwd_private.fw_ver_str, "ERROR");
 303
 304         if (set_command_mode()) {
 305                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 306                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 307                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 308                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 309                 sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
 310                                         one, ten, hund, minor);
 311         }
 312         unset_command_mode();
 313
 314         return;
 315 }
 316
 317 static inline int pcwd_get_option_switches(void)
 318 {
 319         int option_switches = 0;
 320
 321         if (set_command_mode()) {
 322                 /* Get switch settings */
 323                 option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 324         }
 325
 326         unset_command_mode();
 327         return option_switches;
 328 }
 329
 330 static void pcwd_show_card_info(void)
 331 {
 332         int option_switches;
 333
 334         /* Get some extra info from the hardware (in command/debug/diag mode) */
 335         if (pcwd_private.revision == PCWD_REVISION_A)
 336                 pr_info("ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
 337                         pcwd_private.io_addr);
 338         else if (pcwd_private.revision == PCWD_REVISION_C) {
 339                 pcwd_get_firmware();
 340                 pr_info("ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 341                         pcwd_private.io_addr, pcwd_private.fw_ver_str);
 342                 option_switches = pcwd_get_option_switches();
 343                 pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 344                         option_switches,
 345                         ((option_switches & 0x10) ? "ON" : "OFF"),
 346                         ((option_switches & 0x08) ? "ON" : "OFF"));
 347
 348                 /* Reprogram internal heartbeat to 2 seconds */
 349                 if (set_command_mode()) {
 350                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 351                         unset_command_mode();
 352                 }
 353         }
 354
 355         if (pcwd_private.supports_temp)
 356                 pr_info("Temperature Option Detected\n");
 357
 358         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 359                 pr_info("Previous reboot was caused by the card\n");
 360
 361         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 362                 pr_emerg("Card senses a CPU Overheat. Panicking!\n");
 363                 pr_emerg("CPU Overheat\n");
 364         }
 365
 366         if (pcwd_private.boot_status == 0)
 367                 pr_info("No previous trip detected - Cold boot or reset\n");
 368 }
 369
 370 static void pcwd_timer_ping(unsigned long data)
 371 {
 372         int wdrst_stat;
 373
 374         /* If we got a heartbeat pulse within the WDT_INTERVAL
 375          * we agree to ping the WDT */
 376         if (time_before(jiffies, pcwd_private.next_heartbeat)) {
 377                 /* Ping the watchdog */
 378                 spin_lock(&pcwd_private.io_lock);
 379                 if (pcwd_private.revision == PCWD_REVISION_A) {
 380                         /*  Rev A cards are reset by setting the
 381                             WD_WDRST bit in register 1 */
 382                         wdrst_stat = inb_p(pcwd_private.io_addr);
 383                         wdrst_stat &= 0x0F;
 384                         wdrst_stat |= WD_WDRST;
 385
 386                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 387                 } else {
 388                         /* Re-trigger watchdog by writing to port 0 */
 389                         outb_p(0x00, pcwd_private.io_addr);
 390                 }
 391
 392                 /* Re-set the timer interval */
 393                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 394
 395                 spin_unlock(&pcwd_private.io_lock);
 396         } else {
 397                 pr_warn("Heartbeat lost! Will not ping the watchdog\n");
 398         }
 399 }
 400
 401 static int pcwd_start(void)
 402 {
 403         int stat_reg;
 404
 405         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 406
 407         /* Start the timer */
 408         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 409
 410         /* Enable the port */
 411         if (pcwd_private.revision == PCWD_REVISION_C) {
 412                 spin_lock(&pcwd_private.io_lock);
 413                 outb_p(0x00, pcwd_private.io_addr + 3);
 414                 udelay(ISA_COMMAND_TIMEOUT);
 415                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 416                 spin_unlock(&pcwd_private.io_lock);
 417                 if (stat_reg & WD_WDIS) {
 418                         pr_info("Could not start watchdog\n");
 419                         return -EIO;
 420                 }
 421         }
 422
 423         if (debug >= VERBOSE)
 424                 pr_debug("Watchdog started\n");
 425
 426         return 0;
 427 }
 428
 429 static int pcwd_stop(void)
 430 {
 431         int stat_reg;
 432
 433         /* Stop the timer */
 434         del_timer(&pcwd_private.timer);
 435
 436         /*  Disable the board  */
 437         if (pcwd_private.revision == PCWD_REVISION_C) {
 438                 spin_lock(&pcwd_private.io_lock);
 439                 outb_p(0xA5, pcwd_private.io_addr + 3);
 440                 udelay(ISA_COMMAND_TIMEOUT);
 441                 outb_p(0xA5, pcwd_private.io_addr + 3);
 442                 udelay(ISA_COMMAND_TIMEOUT);
 443                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 444                 spin_unlock(&pcwd_private.io_lock);
 445                 if ((stat_reg & WD_WDIS) == 0) {
 446                         pr_info("Could not stop watchdog\n");
 447                         return -EIO;
 448                 }
 449         }
 450
 451         if (debug >= VERBOSE)
 452                 pr_debug("Watchdog stopped\n");
 453
 454         return 0;
 455 }
 456
 457 static int pcwd_keepalive(void)
 458 {
 459         /* user land ping */
 460         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 461
 462         if (debug >= DEBUG)
 463                 pr_debug("Watchdog keepalive signal send\n");
 464
 465         return 0;
 466 }
 467
 468 static int pcwd_set_heartbeat(int t)
 469 {
 470         if (t < 2 || t > 7200) /* arbitrary upper limit */
 471                 return -EINVAL;
 472
 473         heartbeat = t;
 474
 475         if (debug >= VERBOSE)
 476                 pr_debug("New heartbeat: %d\n", heartbeat);
 477
 478         return 0;
 479 }
 480
 481 static int pcwd_get_status(int *status)
 482 {
 483         int control_status;
 484
 485         *status = 0;
 486         spin_lock(&pcwd_private.io_lock);
 487         if (pcwd_private.revision == PCWD_REVISION_A)
 488                 /* Rev A cards return status information from
 489                  * the base register, which is used for the
 490                  * temperature in other cards. */
 491                 control_status = inb(pcwd_private.io_addr);
 492         else {
 493                 /* Rev C cards return card status in the base
 494                  * address + 1 register. And use different bits
 495                  * to indicate a card initiated reset, and an
 496                  * over-temperature condition. And the reboot
 497                  * status can be reset. */
 498                 control_status = inb(pcwd_private.io_addr + 1);
 499         }
 500         spin_unlock(&pcwd_private.io_lock);
 501
 502         if (pcwd_private.revision == PCWD_REVISION_A) {
 503                 if (control_status & WD_WDRST)
 504                         *status |= WDIOF_CARDRESET;
 505
 506                 if (control_status & WD_T110) {
 507                         *status |= WDIOF_OVERHEAT;
 508                         if (temp_panic) {
 509                                 pr_info("Temperature overheat trip!\n");
 510                                 kernel_power_off();
 511                         }
 512                 }
 513         } else {
 514                 if (control_status & WD_REVC_WTRP)
 515                         *status |= WDIOF_CARDRESET;
 516
 517                 if (control_status & WD_REVC_TTRP) {
 518                         *status |= WDIOF_OVERHEAT;
 519                         if (temp_panic) {
 520                                 pr_info("Temperature overheat trip!\n");
 521                                 kernel_power_off();
 522                         }
 523                 }
 524         }
 525
 526         return 0;
 527 }
 528
 529 static int pcwd_clear_status(void)
 530 {
 531         int control_status;
 532
 533         if (pcwd_private.revision == PCWD_REVISION_C) {
 534                 spin_lock(&pcwd_private.io_lock);
 535
 536                 if (debug >= VERBOSE)
 537                         pr_info("clearing watchdog trip status\n");
 538
 539                 control_status = inb_p(pcwd_private.io_addr + 1);
 540
 541                 if (debug >= DEBUG) {
 542                         pr_debug("status was: 0x%02x\n", control_status);
 543                         pr_debug("sending: 0x%02x\n",
 544                                  (control_status & WD_REVC_R2DS));
 545                 }
 546
 547                 /* clear reset status & Keep Relay 2 disable state as it is */
 548                 outb_p((control_status & WD_REVC_R2DS),
 549                                                 pcwd_private.io_addr + 1);
 550
 551                 spin_unlock(&pcwd_private.io_lock);
 552         }
 553         return 0;
 554 }
 555
 556 static int pcwd_get_temperature(int *temperature)
 557 {
 558         /* check that port 0 gives temperature info and no command results */
 559         if (pcwd_private.command_mode)
 560                 return -1;
 561
 562         *temperature = 0;
 563         if (!pcwd_private.supports_temp)
 564                 return -ENODEV;
 565
 566         /*
 567          * Convert celsius to fahrenheit, since this was
 568          * the decided 'standard' for this return value.
 569          */
 570         spin_lock(&pcwd_private.io_lock);
 571         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 572         spin_unlock(&pcwd_private.io_lock);
 573
 574         if (debug >= DEBUG) {
 575                 pr_debug("temperature is: %d F\n", *temperature);
 576         }
 577
 578         return 0;
 579 }
 580
 581 /*
 582  *      /dev/watchdog handling
 583  */
 584
 585 static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 586 {
 587         int rv;
 588         int status;
 589         int temperature;
 590         int new_heartbeat;
 591         int __user *argp = (int __user *)arg;
 592         static const struct watchdog_info ident = {
 593                 .options =              WDIOF_OVERHEAT |
 594                                         WDIOF_CARDRESET |
 595                                         WDIOF_KEEPALIVEPING |
 596                                         WDIOF_SETTIMEOUT |
 597                                         WDIOF_MAGICCLOSE,
 598                 .firmware_version =     1,
 599                 .identity =             "PCWD",
 600         };
 601
 602         switch (cmd) {
 603         case WDIOC_GETSUPPORT:
 604                 if (copy_to_user(argp, &ident, sizeof(ident)))
 605                         return -EFAULT;
 606                 return 0;
 607
 608         case WDIOC_GETSTATUS:
 609                 pcwd_get_status(&status);
 610                 return put_user(status, argp);
 611
 612         case WDIOC_GETBOOTSTATUS:
 613                 return put_user(pcwd_private.boot_status, argp);
 614
 615         case WDIOC_GETTEMP:
 616                 if (pcwd_get_temperature(&temperature))
 617                         return -EFAULT;
 618
 619                 return put_user(temperature, argp);
 620
 621         case WDIOC_SETOPTIONS:
 622                 if (pcwd_private.revision == PCWD_REVISION_C) {
 623                         if (get_user(rv, argp))
 624                                 return -EFAULT;
 625
 626                         if (rv & WDIOS_DISABLECARD) {
 627                                 status = pcwd_stop();
 628                                 if (status < 0)
 629                                         return status;
 630                         }
 631                         if (rv & WDIOS_ENABLECARD) {
 632                                 status = pcwd_start();
 633                                 if (status < 0)
 634                                         return status;
 635                         }
 636                         if (rv & WDIOS_TEMPPANIC)
 637                                 temp_panic = 1;
 638                 }
 639                 return -EINVAL;
 640
 641         case WDIOC_KEEPALIVE:
 642                 pcwd_keepalive();
 643                 return 0;
 644
 645         case WDIOC_SETTIMEOUT:
 646                 if (get_user(new_heartbeat, argp))
 647                         return -EFAULT;
 648
 649                 if (pcwd_set_heartbeat(new_heartbeat))
 650                         return -EINVAL;
 651
 652                 pcwd_keepalive();
 653                 /* Fall */
 654
 655         case WDIOC_GETTIMEOUT:
 656                 return put_user(heartbeat, argp);
 657
 658         default:
 659                 return -ENOTTY;
 660         }
 661
 662         return 0;
 663 }
 664
 665 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 666                           loff_t *ppos)
 667 {
 668         if (len) {
 669                 if (!nowayout) {
 670                         size_t i;
 671
 672                         /* In case it was set long ago */
 673                         expect_close = 0;
 674
 675                         for (i = 0; i != len; i++) {
 676                                 char c;
 677
 678                                 if (get_user(c, buf + i))
 679                                         return -EFAULT;
 680                                 if (c == 'V')
 681                                         expect_close = 42;
 682                         }
 683                 }
 684                 pcwd_keepalive();
 685         }
 686         return len;
 687 }
 688
 689 static int pcwd_open(struct inode *inode, struct file *file)
 690 {
 691         if (test_and_set_bit(0, &open_allowed))
 692                 return -EBUSY;
 693         if (nowayout)
 694                 __module_get(THIS_MODULE);
 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                 pr_crit("Unexpected close, not stopping watchdog!\n");
 707                 pcwd_keepalive();
 708         }
 709         expect_close = 0;
 710         clear_bit(0, &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         .unlocked_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 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                 pr_debug("pcwd_isa_match id=%d\n", id);
 814
 815         if (!request_region(base_addr, 4, "PCWD")) {
 816                 pr_info("Port 0x%04x unavailable\n", base_addr);
 817                 return 0;
 818         }
 819
 820         retval = 0;
 821
 822         port0 = inb_p(base_addr);       /* For REV A boards */
 823         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 824         if (port0 != 0xff || port1 != 0xff) {
 825                 /* Not an 'ff' from a floating bus, so must be a card! */
 826                 for (i = 0; i < 4; ++i) {
 827
 828                         msleep(500);
 829
 830                         last_port0 = port0;
 831                         last_port1 = port1;
 832
 833                         port0 = inb_p(base_addr);
 834                         port1 = inb_p(base_addr + 1);
 835
 836                         /* Has either hearbeat bit changed?  */
 837                         if ((port0 ^ last_port0) & WD_HRTBT ||
 838                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 839                                 retval = 1;
 840                                 break;
 841                         }
 842                 }
 843         }
 844         release_region(base_addr, 4);
 845
 846         return retval;
 847 }
 848
 849 static int pcwd_isa_probe(struct device *dev, unsigned int id)
 850 {
 851         int ret;
 852
 853         if (debug >= DEBUG)
 854                 pr_debug("pcwd_isa_probe id=%d\n", id);
 855
 856         cards_found++;
 857         if (cards_found == 1)
 858                 pr_info("v%s Ken Hollis (kenji@bitgate.com)\n",
 859                                                         WATCHDOG_VERSION);
 860
 861         if (cards_found > 1) {
 862                 pr_err("This driver only supports 1 device\n");
 863                 return -ENODEV;
 864         }
 865
 866         if (pcwd_ioports[id] == 0x0000) {
 867                 pr_err("No I/O-Address for card detected\n");
 868                 return -ENODEV;
 869         }
 870         pcwd_private.io_addr = pcwd_ioports[id];
 871
 872         spin_lock_init(&pcwd_private.io_lock);
 873
 874         /* Check card's revision */
 875         pcwd_private.revision = get_revision();
 876
 877         if (!request_region(pcwd_private.io_addr,
 878                 (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 879                 pr_err("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;
 912            if not reset to the default */
 913         if (pcwd_set_heartbeat(heartbeat)) {
 914                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 915                 pr_info("heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
 916                         WATCHDOG_HEARTBEAT);
 917         }
 918
 919         if (pcwd_private.supports_temp) {
 920                 ret = misc_register(&temp_miscdev);
 921                 if (ret) {
 922                         pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 923                                TEMP_MINOR, ret);
 924                         goto error_misc_register_temp;
 925                 }
 926         }
 927
 928         ret = misc_register(&pcwd_miscdev);
 929         if (ret) {
 930                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 931                        WATCHDOG_MINOR, ret);
 932                 goto error_misc_register_watchdog;
 933         }
 934
 935         pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
 936                 heartbeat, nowayout);
 937
 938         return 0;
 939
 940 error_misc_register_watchdog:
 941         if (pcwd_private.supports_temp)
 942                 misc_deregister(&temp_miscdev);
 943 error_misc_register_temp:
 944         release_region(pcwd_private.io_addr,
 945                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 946 error_request_region:
 947         pcwd_private.io_addr = 0x0000;
 948         cards_found--;
 949         return ret;
 950 }
 951
 952 static int pcwd_isa_remove(struct device *dev, unsigned int id)
 953 {
 954         if (debug >= DEBUG)
 955                 pr_debug("pcwd_isa_remove id=%d\n", id);
 956
 957         if (!pcwd_private.io_addr)
 958                 return 1;
 959
 960         /*  Disable the board  */
 961         if (!nowayout)
 962                 pcwd_stop();
 963
 964         /* Deregister */
 965         misc_deregister(&pcwd_miscdev);
 966         if (pcwd_private.supports_temp)
 967                 misc_deregister(&temp_miscdev);
 968         release_region(pcwd_private.io_addr,
 969                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 970         pcwd_private.io_addr = 0x0000;
 971         cards_found--;
 972
 973         return 0;
 974 }
 975
 976 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
 977 {
 978         if (debug >= DEBUG)
 979                 pr_debug("pcwd_isa_shutdown id=%d\n", id);
 980
 981         pcwd_stop();
 982 }
 983
 984 static struct isa_driver pcwd_isa_driver = {
 985         .match          = pcwd_isa_match,
 986         .probe          = pcwd_isa_probe,
 987         .remove         = pcwd_isa_remove,
 988         .shutdown       = pcwd_isa_shutdown,
 989         .driver         = {
 990                 .owner  = THIS_MODULE,
 991                 .name   = WATCHDOG_NAME,
 992         },
 993 };
 994
 995 static int __init pcwd_init_module(void)
 996 {
 997         return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
 998 }
 999
1000 static void __exit pcwd_cleanup_module(void)
1001 {
1002         isa_unregister_driver(&pcwd_isa_driver);
1003         pr_info("Watchdog Module Unloaded\n");
1004 }
1005
1006 module_init(pcwd_init_module);
1007 module_exit(pcwd_cleanup_module);
1008
1009 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, "
1010                 "Wim Van Sebroeck <wim@iguana.be>");
1011 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1012 MODULE_VERSION(WATCHDOG_VERSION);
1013 MODULE_LICENSE("GPL");