drivers/char/watchdog/pcwd.c

   1 /*
   2  * PC Watchdog Driver
   3  * by Ken Hollis (khollis@bitgate.com)
   4  *
   5  * Permission granted from Simon Machell (73244.1270@compuserve.com)
   6  * Written for the Linux Kernel, and GPLed by Ken Hollis
   7  *
   8  * 960107       Added request_region routines, modulized the whole thing.
   9  * 960108       Fixed end-of-file pointer (Thanks to Dan Hollis), added
  10  *              WD_TIMEOUT define.
  11  * 960216       Added eof marker on the file, and changed verbose messages.
  12  * 960716       Made functional and cosmetic changes to the source for
  13  *              inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
  14  * 960717       Removed read/seek routines, replaced with ioctl.  Also, added
  15  *              check_region command due to Alan's suggestion.
  16  * 960821       Made changes to compile in newer 2.0.x kernels.  Added
  17  *              "cold reboot sense" entry.
  18  * 960825       Made a few changes to code, deleted some defines and made
  19  *              typedefs to replace them.  Made heartbeat reset only available
  20  *              via ioctl, and removed the write routine.
  21  * 960828       Added new items for PC Watchdog Rev.C card.
  22  * 960829       Changed around all of the IOCTLs, added new features,
  23  *              added watchdog disable/re-enable routines.  Added firmware
  24  *              version reporting.  Added read routine for temperature.
  25  *              Removed some extra defines, added an autodetect Revision
  26  *              routine.
  27  * 961006       Revised some documentation, fixed some cosmetic bugs.  Made
  28  *              drivers to panic the system if it's overheating at bootup.
  29  * 961118       Changed some verbiage on some of the output, tidied up
  30  *              code bits, and added compatibility to 2.1.x.
  31  * 970912       Enabled board on open and disable on close.
  32  * 971107       Took account of recent VFS changes (broke read).
  33  * 971210       Disable board on initialisation in case board already ticking.
  34  * 971222       Changed open/close for temperature handling
  35  *              Michael Meskes <meskes@debian.org>.
  36  * 980112       Used minor numbers from include/linux/miscdevice.h
  37  * 990403       Clear reset status after reading control status register in
  38  *              pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
  39  * 990605       Made changes to code to support Firmware 1.22a, added
  40  *              fairly useless proc entry.
  41  * 990610       removed said useless proc code for the merge <alan>
  42  * 000403       Removed last traces of proc code. <davej>
  43  * 011214       Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
  44  *              Added timeout module option to override default
  45  */
  46
  47 /*
  48  *      A bells and whistles driver is available from http://www.pcwd.de/
  49  *      More info available at http://www.berkprod.com/ or http://www.pcwatchdog.com/
  50  */
  51
  52 #include <linux/config.h>       /* For CONFIG_WATCHDOG_NOWAYOUT/... */
  53 #include <linux/module.h>       /* For module specific items */
  54 #include <linux/moduleparam.h>  /* For new moduleparam's */
  55 #include <linux/types.h>        /* For standard types (like size_t) */
  56 #include <linux/errno.h>        /* For the -ENODEV/... values */
  57 #include <linux/kernel.h>       /* For printk/panic/... */
  58 #include <linux/delay.h>        /* For mdelay function */
  59 #include <linux/timer.h>        /* For timer related operations */
  60 #include <linux/jiffies.h>      /* For jiffies stuff */
  61 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  62 #include <linux/watchdog.h>     /* For the watchdog specific items */
  63 #include <linux/notifier.h>     /* For notifier support */
  64 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  65 #include <linux/init.h>         /* For __init/__exit/... */
  66 #include <linux/fs.h>           /* For file operations */
  67 #include <linux/ioport.h>       /* For io-port access */
  68 #include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  69
  70 #include <asm/uaccess.h>        /* For copy_to_user/put_user/... */
  71 #include <asm/io.h>             /* For inb/outb/... */
  72
  73 /* Module and version information */
  74 #define WATCHDOG_VERSION "1.17"
  75 #define WATCHDOG_DATE "12 Feb 2006"
  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 " (" WATCHDOG_DATE ")\n"
  80 #define WD_VER WATCHDOG_VERSION " (" WATCHDOG_DATE ")"
  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 defines that describe the control status bits for the
  94  * PCI-PC Watchdog card.
  95 */
  96 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
  97 #define WD_WDRST                0x01    /* Previously reset state */
  98 #define WD_T110                 0x02    /* Temperature overheat sense */
  99 #define WD_HRTBT                0x04    /* Heartbeat sense */
 100 #define WD_RLY2                 0x08    /* External relay triggered */
 101 #define WD_SRLY2                0x80    /* Software external relay triggered */
 102 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 103 #define WD_REVC_WTRP            0x01    /* Watchdog Trip status */
 104 #define WD_REVC_HRBT            0x02    /* Watchdog Heartbeat */
 105 #define WD_REVC_TTRP            0x04    /* Temperature Trip status */
 106 #define WD_REVC_RL2A            0x08    /* Relay 2 activated by on-board processor */
 107 #define WD_REVC_RL1A            0x10    /* Relay 1 active */
 108 #define WD_REVC_R2DS            0x40    /* Relay 2 disable */
 109 #define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
 110 /* Port 2 : Control Status #2 */
 111 #define WD_WDIS                 0x10    /* Watchdog Disabled */
 112 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 113 #define WD_SSEL                 0x40    /* Watchdog Switch Select (1:SW1 <-> 0:SW2) */
 114 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
 115
 116 /* max. time we give an ISA watchdog card to process a command */
 117 /* 500ms for each 4 bit response (according to spec.) */
 118 #define ISA_COMMAND_TIMEOUT     1000
 119
 120 /* Watchdog's internal commands */
 121 #define CMD_ISA_IDLE                    0x00
 122 #define CMD_ISA_VERSION_INTEGER         0x01
 123 #define CMD_ISA_VERSION_TENTH           0x02
 124 #define CMD_ISA_VERSION_HUNDRETH        0x03
 125 #define CMD_ISA_VERSION_MINOR           0x04
 126 #define CMD_ISA_SWITCH_SETTINGS         0x05
 127 #define CMD_ISA_RESET_PC                0x06
 128 #define CMD_ISA_ARM_0                   0x07
 129 #define CMD_ISA_ARM_30                  0x08
 130 #define CMD_ISA_ARM_60                  0x09
 131 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 132 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 133 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 134 #define CMD_ISA_RESET_RELAYS            0x0D
 135
 136 /*
 137  * We are using an kernel timer to do the pinging of the watchdog
 138  * every ~500ms. We try to set the internal heartbeat of the
 139  * watchdog to 2 ms.
 140  */
 141
 142 #define WDT_INTERVAL (HZ/2+1)
 143
 144 /* We can only use 1 card due to the /dev/watchdog restriction */
 145 static int cards_found;
 146
 147 /* internal variables */
 148 static atomic_t open_allowed = ATOMIC_INIT(1);
 149 static char expect_close;
 150 static int temp_panic;
 151 static struct {                         /* this is private data for each ISA-PC watchdog card */
 152         char fw_ver_str[6];             /* The cards firmware version */
 153         int revision;                   /* The card's revision */
 154         int supports_temp;              /* Wether or not the card has a temperature device */
 155         int command_mode;               /* Wether or not the card is in command mode */
 156         int boot_status;                /* The card's boot status */
 157         int io_addr;                    /* The cards I/O address */
 158         spinlock_t io_lock;             /* the lock for io operations */
 159         struct timer_list timer;        /* The timer that pings the watchdog */
 160         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 161 } pcwd_private;
 162
 163 /* module parameters */
 164 #define QUIET   0       /* Default */
 165 #define VERBOSE 1       /* Verbose */
 166 #define DEBUG   2       /* print fancy stuff too */
 167 static int debug = QUIET;
 168 module_param(debug, int, 0);
 169 MODULE_PARM_DESC(debug, "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
 170
 171 #define WATCHDOG_HEARTBEAT 60           /* 60 sec default heartbeat */
 172 static int heartbeat = WATCHDOG_HEARTBEAT;
 173 module_param(heartbeat, int, 0);
 174 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 175
 176 static int nowayout = WATCHDOG_NOWAYOUT;
 177 module_param(nowayout, int, 0);
 178 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 179
 180 /*
 181  *      Internal functions
 182  */
 183
 184 static int send_isa_command(int cmd)
 185 {
 186         int i;
 187         int control_status;
 188         int port0, last_port0;  /* Double read for stabilising */
 189
 190         if (debug >= DEBUG)
 191                 printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
 192                         cmd);
 193
 194         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 195         control_status = (cmd & 0x0F) | WD_WCMD;
 196         outb_p(control_status, pcwd_private.io_addr + 2);
 197         udelay(ISA_COMMAND_TIMEOUT);
 198
 199         port0 = inb_p(pcwd_private.io_addr);
 200         for (i = 0; i < 25; ++i) {
 201                 last_port0 = port0;
 202                 port0 = inb_p(pcwd_private.io_addr);
 203
 204                 if (port0 == last_port0)
 205                         break;  /* Data is stable */
 206
 207                 udelay (250);
 208         }
 209
 210         if (debug >= DEBUG)
 211                 printk(KERN_DEBUG PFX "received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 212                         cmd, port0, last_port0);
 213
 214         return port0;
 215 }
 216
 217 static int set_command_mode(void)
 218 {
 219         int i, found=0, count=0;
 220
 221         /* Set the card into command mode */
 222         spin_lock(&pcwd_private.io_lock);
 223         while ((!found) && (count < 3)) {
 224                 i = send_isa_command(CMD_ISA_IDLE);
 225
 226                 if (i == 0x00)
 227                         found = 1;
 228                 else if (i == 0xF3) {
 229                         /* Card does not like what we've done to it */
 230                         outb_p(0x00, pcwd_private.io_addr + 2);
 231                         udelay(1200);   /* Spec says wait 1ms */
 232                         outb_p(0x00, pcwd_private.io_addr + 2);
 233                         udelay(ISA_COMMAND_TIMEOUT);
 234                 }
 235                 count++;
 236         }
 237         spin_unlock(&pcwd_private.io_lock);
 238         pcwd_private.command_mode = found;
 239
 240         if (debug >= DEBUG)
 241                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 242                                 pcwd_private.command_mode);
 243
 244         return(found);
 245 }
 246
 247 static void unset_command_mode(void)
 248 {
 249         /* Set the card into normal mode */
 250         spin_lock(&pcwd_private.io_lock);
 251         outb_p(0x00, pcwd_private.io_addr + 2);
 252         udelay(ISA_COMMAND_TIMEOUT);
 253         spin_unlock(&pcwd_private.io_lock);
 254
 255         pcwd_private.command_mode = 0;
 256
 257         if (debug >= DEBUG)
 258                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 259                                 pcwd_private.command_mode);
 260 }
 261
 262 static inline void pcwd_check_temperature_support(void)
 263 {
 264         if (inb(pcwd_private.io_addr) != 0xF0)
 265                 pcwd_private.supports_temp = 1;
 266 }
 267
 268 static inline void pcwd_get_firmware(void)
 269 {
 270         int one, ten, hund, minor;
 271
 272         strcpy(pcwd_private.fw_ver_str, "ERROR");
 273
 274         if (set_command_mode()) {
 275                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 276                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 277                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 278                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 279                 sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c", one, ten, hund, minor);
 280         }
 281         unset_command_mode();
 282
 283         return;
 284 }
 285
 286 static inline int pcwd_get_option_switches(void)
 287 {
 288         int option_switches=0;
 289
 290         if (set_command_mode()) {
 291                 /* Get switch settings */
 292                 option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 293         }
 294
 295         unset_command_mode();
 296         return(option_switches);
 297 }
 298
 299 static void pcwd_show_card_info(void)
 300 {
 301         int option_switches;
 302
 303         /* Get some extra info from the hardware (in command/debug/diag mode) */
 304         if (pcwd_private.revision == PCWD_REVISION_A)
 305                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", pcwd_private.io_addr);
 306         else if (pcwd_private.revision == PCWD_REVISION_C) {
 307                 pcwd_get_firmware();
 308                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 309                         pcwd_private.io_addr, pcwd_private.fw_ver_str);
 310                 option_switches = pcwd_get_option_switches();
 311                 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 312                         option_switches,
 313                         ((option_switches & 0x10) ? "ON" : "OFF"),
 314                         ((option_switches & 0x08) ? "ON" : "OFF"));
 315
 316                 /* Reprogram internal heartbeat to 2 seconds */
 317                 if (set_command_mode()) {
 318                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 319                         unset_command_mode();
 320                 }
 321         }
 322
 323         if (pcwd_private.supports_temp)
 324                 printk(KERN_INFO PFX "Temperature Option Detected\n");
 325
 326         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 327                 printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
 328
 329         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 330                 printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
 331                 printk(KERN_EMERG PFX "CPU Overheat\n");
 332         }
 333
 334         if (pcwd_private.boot_status == 0)
 335                 printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");
 336 }
 337
 338 static void pcwd_timer_ping(unsigned long data)
 339 {
 340         int wdrst_stat;
 341
 342         /* If we got a heartbeat pulse within the WDT_INTERVAL
 343          * we agree to ping the WDT */
 344         if(time_before(jiffies, pcwd_private.next_heartbeat)) {
 345                 /* Ping the watchdog */
 346                 spin_lock(&pcwd_private.io_lock);
 347                 if (pcwd_private.revision == PCWD_REVISION_A) {
 348                         /*  Rev A cards are reset by setting the WD_WDRST bit in register 1 */
 349                         wdrst_stat = inb_p(pcwd_private.io_addr);
 350                         wdrst_stat &= 0x0F;
 351                         wdrst_stat |= WD_WDRST;
 352
 353                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 354                 } else {
 355                         /* Re-trigger watchdog by writing to port 0 */
 356                         outb_p(0x00, pcwd_private.io_addr);
 357                 }
 358
 359                 /* Re-set the timer interval */
 360                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 361
 362                 spin_unlock(&pcwd_private.io_lock);
 363         } else {
 364                 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
 365         }
 366 }
 367
 368 static int pcwd_start(void)
 369 {
 370         int stat_reg;
 371
 372         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 373
 374         /* Start the timer */
 375         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 376
 377         /* Enable the port */
 378         if (pcwd_private.revision == PCWD_REVISION_C) {
 379                 spin_lock(&pcwd_private.io_lock);
 380                 outb_p(0x00, pcwd_private.io_addr + 3);
 381                 udelay(ISA_COMMAND_TIMEOUT);
 382                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 383                 spin_unlock(&pcwd_private.io_lock);
 384                 if (stat_reg & WD_WDIS) {
 385                         printk(KERN_INFO PFX "Could not start watchdog\n");
 386                         return -EIO;
 387                 }
 388         }
 389
 390         if (debug >= VERBOSE)
 391                 printk(KERN_DEBUG PFX "Watchdog started\n");
 392
 393         return 0;
 394 }
 395
 396 static int pcwd_stop(void)
 397 {
 398         int stat_reg;
 399
 400         /* Stop the timer */
 401         del_timer(&pcwd_private.timer);
 402
 403         /*  Disable the board  */
 404         if (pcwd_private.revision == PCWD_REVISION_C) {
 405                 spin_lock(&pcwd_private.io_lock);
 406                 outb_p(0xA5, pcwd_private.io_addr + 3);
 407                 udelay(ISA_COMMAND_TIMEOUT);
 408                 outb_p(0xA5, pcwd_private.io_addr + 3);
 409                 udelay(ISA_COMMAND_TIMEOUT);
 410                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 411                 spin_unlock(&pcwd_private.io_lock);
 412                 if ((stat_reg & WD_WDIS) == 0) {
 413                         printk(KERN_INFO PFX "Could not stop watchdog\n");
 414                         return -EIO;
 415                 }
 416         }
 417
 418         if (debug >= VERBOSE)
 419                 printk(KERN_DEBUG PFX "Watchdog stopped\n");
 420
 421         return 0;
 422 }
 423
 424 static int pcwd_keepalive(void)
 425 {
 426         /* user land ping */
 427         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 428
 429         if (debug >= DEBUG)
 430                 printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
 431
 432         return 0;
 433 }
 434
 435 static int pcwd_set_heartbeat(int t)
 436 {
 437         if ((t < 2) || (t > 7200)) /* arbitrary upper limit */
 438                 return -EINVAL;
 439
 440         heartbeat = t;
 441
 442         if (debug >= VERBOSE)
 443                 printk(KERN_DEBUG PFX "New heartbeat: %d\n",
 444                        heartbeat);
 445
 446         return 0;
 447 }
 448
 449 static int pcwd_get_status(int *status)
 450 {
 451         int control_status;
 452
 453         *status=0;
 454         spin_lock(&pcwd_private.io_lock);
 455         if (pcwd_private.revision == PCWD_REVISION_A)
 456                 /* Rev A cards return status information from
 457                  * the base register, which is used for the
 458                  * temperature in other cards. */
 459                 control_status = inb(pcwd_private.io_addr);
 460         else {
 461                 /* Rev C cards return card status in the base
 462                  * address + 1 register. And use different bits
 463                  * to indicate a card initiated reset, and an
 464                  * over-temperature condition. And the reboot
 465                  * status can be reset. */
 466                 control_status = inb(pcwd_private.io_addr + 1);
 467         }
 468         spin_unlock(&pcwd_private.io_lock);
 469
 470         if (pcwd_private.revision == PCWD_REVISION_A) {
 471                 if (control_status & WD_WDRST)
 472                         *status |= WDIOF_CARDRESET;
 473
 474                 if (control_status & WD_T110) {
 475                         *status |= WDIOF_OVERHEAT;
 476                         if (temp_panic) {
 477                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 478                                 kernel_power_off();
 479                                 /* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
 480                         }
 481                 }
 482         } else {
 483                 if (control_status & WD_REVC_WTRP)
 484                         *status |= WDIOF_CARDRESET;
 485
 486                 if (control_status & WD_REVC_TTRP) {
 487                         *status |= WDIOF_OVERHEAT;
 488                         if (temp_panic) {
 489                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 490                                 kernel_power_off();
 491                                 /* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
 492                         }
 493                 }
 494         }
 495
 496         return 0;
 497 }
 498
 499 static int pcwd_clear_status(void)
 500 {
 501         int control_status;
 502
 503         if (pcwd_private.revision == PCWD_REVISION_C) {
 504                 spin_lock(&pcwd_private.io_lock);
 505
 506                 if (debug >= VERBOSE)
 507                         printk(KERN_INFO PFX "clearing watchdog trip status\n");
 508
 509                 control_status = inb_p(pcwd_private.io_addr + 1);
 510
 511                 if (debug >= DEBUG) {
 512                         printk(KERN_DEBUG PFX "status was: 0x%02x\n", control_status);
 513                         printk(KERN_DEBUG PFX "sending: 0x%02x\n",
 514                                 (control_status & WD_REVC_R2DS));
 515                 }
 516
 517                 /* clear reset status & Keep Relay 2 disable state as it is */
 518                 outb_p((control_status & WD_REVC_R2DS), pcwd_private.io_addr + 1);
 519
 520                 spin_unlock(&pcwd_private.io_lock);
 521         }
 522         return 0;
 523 }
 524
 525 static int pcwd_get_temperature(int *temperature)
 526 {
 527         /* check that port 0 gives temperature info and no command results */
 528         if (pcwd_private.command_mode)
 529                 return -1;
 530
 531         *temperature = 0;
 532         if (!pcwd_private.supports_temp)
 533                 return -ENODEV;
 534
 535         /*
 536          * Convert celsius to fahrenheit, since this was
 537          * the decided 'standard' for this return value.
 538          */
 539         spin_lock(&pcwd_private.io_lock);
 540         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 541         spin_unlock(&pcwd_private.io_lock);
 542
 543         if (debug >= DEBUG) {
 544                 printk(KERN_DEBUG PFX "temperature is: %d F\n",
 545                         *temperature);
 546         }
 547
 548         return 0;
 549 }
 550
 551 /*
 552  *      /dev/watchdog handling
 553  */
 554
 555 static int pcwd_ioctl(struct inode *inode, struct file *file,
 556                       unsigned int cmd, unsigned long arg)
 557 {
 558         int rv;
 559         int status;
 560         int temperature;
 561         int new_heartbeat;
 562         int __user *argp = (int __user *)arg;
 563         static struct watchdog_info ident = {
 564                 .options =              WDIOF_OVERHEAT |
 565                                         WDIOF_CARDRESET |
 566                                         WDIOF_KEEPALIVEPING |
 567                                         WDIOF_SETTIMEOUT |
 568                                         WDIOF_MAGICCLOSE,
 569                 .firmware_version =     1,
 570                 .identity =             "PCWD",
 571         };
 572
 573         switch(cmd) {
 574         default:
 575                 return -ENOIOCTLCMD;
 576
 577         case WDIOC_GETSUPPORT:
 578                 if(copy_to_user(argp, &ident, sizeof(ident)))
 579                         return -EFAULT;
 580                 return 0;
 581
 582         case WDIOC_GETSTATUS:
 583                 pcwd_get_status(&status);
 584                 return put_user(status, argp);
 585
 586         case WDIOC_GETBOOTSTATUS:
 587                 return put_user(pcwd_private.boot_status, argp);
 588
 589         case WDIOC_GETTEMP:
 590                 if (pcwd_get_temperature(&temperature))
 591                         return -EFAULT;
 592
 593                 return put_user(temperature, argp);
 594
 595         case WDIOC_SETOPTIONS:
 596                 if (pcwd_private.revision == PCWD_REVISION_C)
 597                 {
 598                         if(copy_from_user(&rv, argp, sizeof(int)))
 599                                 return -EFAULT;
 600
 601                         if (rv & WDIOS_DISABLECARD)
 602                         {
 603                                 return pcwd_stop();
 604                         }
 605
 606                         if (rv & WDIOS_ENABLECARD)
 607                         {
 608                                 return pcwd_start();
 609                         }
 610
 611                         if (rv & WDIOS_TEMPPANIC)
 612                         {
 613                                 temp_panic = 1;
 614                         }
 615                 }
 616                 return -EINVAL;
 617
 618         case WDIOC_KEEPALIVE:
 619                 pcwd_keepalive();
 620                 return 0;
 621
 622         case WDIOC_SETTIMEOUT:
 623                 if (get_user(new_heartbeat, argp))
 624                         return -EFAULT;
 625
 626                 if (pcwd_set_heartbeat(new_heartbeat))
 627                         return -EINVAL;
 628
 629                 pcwd_keepalive();
 630                 /* Fall */
 631
 632         case WDIOC_GETTIMEOUT:
 633                 return put_user(heartbeat, argp);
 634         }
 635
 636         return 0;
 637 }
 638
 639 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 640                           loff_t *ppos)
 641 {
 642         if (len) {
 643                 if (!nowayout) {
 644                         size_t i;
 645
 646                         /* In case it was set long ago */
 647                         expect_close = 0;
 648
 649                         for (i = 0; i != len; i++) {
 650                                 char c;
 651
 652                                 if (get_user(c, buf + i))
 653                                         return -EFAULT;
 654                                 if (c == 'V')
 655                                         expect_close = 42;
 656                         }
 657                 }
 658                 pcwd_keepalive();
 659         }
 660         return len;
 661 }
 662
 663 static int pcwd_open(struct inode *inode, struct file *file)
 664 {
 665         if (!atomic_dec_and_test(&open_allowed) ) {
 666                 if (debug >= VERBOSE)
 667                         printk(KERN_ERR PFX "Attempt to open already opened device.\n");
 668                 atomic_inc( &open_allowed );
 669                 return -EBUSY;
 670         }
 671
 672         if (nowayout)
 673                 __module_get(THIS_MODULE);
 674
 675         /* Activate */
 676         pcwd_start();
 677         pcwd_keepalive();
 678         return nonseekable_open(inode, file);
 679 }
 680
 681 static int pcwd_close(struct inode *inode, struct file *file)
 682 {
 683         if (expect_close == 42) {
 684                 pcwd_stop();
 685         } else {
 686                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 687                 pcwd_keepalive();
 688         }
 689         expect_close = 0;
 690         atomic_inc( &open_allowed );
 691         return 0;
 692 }
 693
 694 /*
 695  *      /dev/temperature handling
 696  */
 697
 698 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 699                          loff_t *ppos)
 700 {
 701         int temperature;
 702
 703         if (pcwd_get_temperature(&temperature))
 704                 return -EFAULT;
 705
 706         if (copy_to_user(buf, &temperature, 1))
 707                 return -EFAULT;
 708
 709         return 1;
 710 }
 711
 712 static int pcwd_temp_open(struct inode *inode, struct file *file)
 713 {
 714         if (!pcwd_private.supports_temp)
 715                 return -ENODEV;
 716
 717         return nonseekable_open(inode, file);
 718 }
 719
 720 static int pcwd_temp_close(struct inode *inode, struct file *file)
 721 {
 722         return 0;
 723 }
 724
 725 /*
 726  *      Notify system
 727  */
 728
 729 static int pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 730 {
 731         if (code==SYS_DOWN || code==SYS_HALT) {
 732                 /* Turn the WDT off */
 733                 pcwd_stop();
 734         }
 735
 736         return NOTIFY_DONE;
 737 }
 738
 739 /*
 740  *      Kernel Interfaces
 741  */
 742
 743 static const struct file_operations pcwd_fops = {
 744         .owner          = THIS_MODULE,
 745         .llseek         = no_llseek,
 746         .write          = pcwd_write,
 747         .ioctl          = pcwd_ioctl,
 748         .open           = pcwd_open,
 749         .release        = pcwd_close,
 750 };
 751
 752 static struct miscdevice pcwd_miscdev = {
 753         .minor =        WATCHDOG_MINOR,
 754         .name =         "watchdog",
 755         .fops =         &pcwd_fops,
 756 };
 757
 758 static const struct file_operations pcwd_temp_fops = {
 759         .owner          = THIS_MODULE,
 760         .llseek         = no_llseek,
 761         .read           = pcwd_temp_read,
 762         .open           = pcwd_temp_open,
 763         .release        = pcwd_temp_close,
 764 };
 765
 766 static struct miscdevice temp_miscdev = {
 767         .minor =        TEMP_MINOR,
 768         .name =         "temperature",
 769         .fops =         &pcwd_temp_fops,
 770 };
 771
 772 static struct notifier_block pcwd_notifier = {
 773         .notifier_call =        pcwd_notify_sys,
 774 };
 775
 776 /*
 777  *      Init & exit routines
 778  */
 779
 780 static inline int get_revision(void)
 781 {
 782         int r = PCWD_REVISION_C;
 783
 784         spin_lock(&pcwd_private.io_lock);
 785         /* REV A cards use only 2 io ports; test
 786          * presumes a floating bus reads as 0xff. */
 787         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 788             (inb(pcwd_private.io_addr + 3) == 0xFF))
 789                 r=PCWD_REVISION_A;
 790         spin_unlock(&pcwd_private.io_lock);
 791
 792         return r;
 793 }
 794
 795 static int __devinit pcwatchdog_init(int base_addr)
 796 {
 797         int ret;
 798
 799         cards_found++;
 800         if (cards_found == 1)
 801                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER);
 802
 803         if (cards_found > 1) {
 804                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 805                 return -ENODEV;
 806         }
 807
 808         if (base_addr == 0x0000) {
 809                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 810                 return -ENODEV;
 811         }
 812         pcwd_private.io_addr = base_addr;
 813
 814         /* Check card's revision */
 815         pcwd_private.revision = get_revision();
 816
 817         if (!request_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 818                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 819                         pcwd_private.io_addr);
 820                 pcwd_private.io_addr = 0x0000;
 821                 return -EIO;
 822         }
 823
 824         /* Initial variables */
 825         pcwd_private.supports_temp = 0;
 826         temp_panic = 0;
 827         pcwd_private.boot_status = 0x0000;
 828
 829         /* get the boot_status */
 830         pcwd_get_status(&pcwd_private.boot_status);
 831
 832         /* clear the "card caused reboot" flag */
 833         pcwd_clear_status();
 834
 835         init_timer(&pcwd_private.timer);
 836         pcwd_private.timer.function = pcwd_timer_ping;
 837         pcwd_private.timer.data = 0;
 838
 839         /*  Disable the board  */
 840         pcwd_stop();
 841
 842         /*  Check whether or not the card supports the temperature device */
 843         pcwd_check_temperature_support();
 844
 845         /* Show info about the card itself */
 846         pcwd_show_card_info();
 847
 848         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 849         if (pcwd_set_heartbeat(heartbeat)) {
 850                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 851                 printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
 852                         WATCHDOG_HEARTBEAT);
 853         }
 854
 855         ret = register_reboot_notifier(&pcwd_notifier);
 856         if (ret) {
 857                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 858                         ret);
 859                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 860                 pcwd_private.io_addr = 0x0000;
 861                 return ret;
 862         }
 863
 864         if (pcwd_private.supports_temp) {
 865                 ret = misc_register(&temp_miscdev);
 866                 if (ret) {
 867                         printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 868                                 TEMP_MINOR, ret);
 869                         unregister_reboot_notifier(&pcwd_notifier);
 870                         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 871                         pcwd_private.io_addr = 0x0000;
 872                         return ret;
 873                 }
 874         }
 875
 876         ret = misc_register(&pcwd_miscdev);
 877         if (ret) {
 878                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 879                         WATCHDOG_MINOR, ret);
 880                 if (pcwd_private.supports_temp)
 881                         misc_deregister(&temp_miscdev);
 882                 unregister_reboot_notifier(&pcwd_notifier);
 883                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 884                 pcwd_private.io_addr = 0x0000;
 885                 return ret;
 886         }
 887
 888         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 889                 heartbeat, nowayout);
 890
 891         return 0;
 892 }
 893
 894 static void __devexit pcwatchdog_exit(void)
 895 {
 896         /*  Disable the board  */
 897         if (!nowayout)
 898                 pcwd_stop();
 899
 900         /* Deregister */
 901         misc_deregister(&pcwd_miscdev);
 902         if (pcwd_private.supports_temp)
 903                 misc_deregister(&temp_miscdev);
 904         unregister_reboot_notifier(&pcwd_notifier);
 905         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 906         pcwd_private.io_addr = 0x0000;
 907         cards_found--;
 908 }
 909
 910 /*
 911  *  The ISA cards have a heartbeat bit in one of the registers, which
 912  *  register is card dependent.  The heartbeat bit is monitored, and if
 913  *  found, is considered proof that a Berkshire card has been found.
 914  *  The initial rate is once per second at board start up, then twice
 915  *  per second for normal operation.
 916  */
 917 static int __init pcwd_checkcard(int base_addr)
 918 {
 919         int port0, last_port0;  /* Reg 0, in case it's REV A */
 920         int port1, last_port1;  /* Register 1 for REV C cards */
 921         int i;
 922         int retval;
 923
 924         if (!request_region (base_addr, 4, "PCWD")) {
 925                 printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 926                 return 0;
 927         }
 928
 929         retval = 0;
 930
 931         port0 = inb_p(base_addr);       /* For REV A boards */
 932         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 933         if (port0 != 0xff || port1 != 0xff) {
 934                 /* Not an 'ff' from a floating bus, so must be a card! */
 935                 for (i = 0; i < 4; ++i) {
 936
 937                         msleep(500);
 938
 939                         last_port0 = port0;
 940                         last_port1 = port1;
 941
 942                         port0 = inb_p(base_addr);
 943                         port1 = inb_p(base_addr + 1);
 944
 945                         /* Has either hearbeat bit changed?  */
 946                         if ((port0 ^ last_port0) & WD_HRTBT ||
 947                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 948                                 retval = 1;
 949                                 break;
 950                         }
 951                 }
 952         }
 953         release_region (base_addr, 4);
 954
 955         return retval;
 956 }
 957
 958 /*
 959  * These are the auto-probe addresses available.
 960  *
 961  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
 962  * Revision A has an address range of 2 addresses, while Revision C has 4.
 963  */
 964 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
 965
 966 static int __init pcwd_init_module(void)
 967 {
 968         int i, found = 0;
 969
 970         spin_lock_init(&pcwd_private.io_lock);
 971
 972         for (i = 0; pcwd_ioports[i] != 0; i++) {
 973                 if (pcwd_checkcard(pcwd_ioports[i])) {
 974                         if (!(pcwatchdog_init(pcwd_ioports[i])))
 975                                 found++;
 976                 }
 977         }
 978
 979         if (!found) {
 980                 printk (KERN_INFO PFX "No card detected, or port not available\n");
 981                 return -ENODEV;
 982         }
 983
 984         return 0;
 985 }
 986
 987 static void __exit pcwd_cleanup_module(void)
 988 {
 989         if (pcwd_private.io_addr)
 990                 pcwatchdog_exit();
 991
 992         printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
 993 }
 994
 995 module_init(pcwd_init_module);
 996 module_exit(pcwd_cleanup_module);
 997
 998 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>");
 999 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1000 MODULE_LICENSE("GPL");
1001 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1002 MODULE_ALIAS_MISCDEV(TEMP_MINOR);