drivers/watchdog/pcwd.c

   1 /*
   2  * PC Watchdog Driver
   3  * by Ken Hollis (khollis@bitgate.com)
   4  *
   5  * Permission granted from Simon Machell (smachell@berkprod.com)
   6  * Written for the Linux Kernel, and GPLed by Ken Hollis
   7  *
   8  * 960107       Added request_region routines, modulized the whole thing.
   9  * 960108       Fixed end-of-file pointer (Thanks to Dan Hollis), added
  10  *              WD_TIMEOUT define.
  11  * 960216       Added eof marker on the file, and changed verbose messages.
  12  * 960716       Made functional and cosmetic changes to the source for
  13  *              inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
  14  * 960717       Removed read/seek routines, replaced with ioctl.  Also, added
  15  *              check_region command due to Alan's suggestion.
  16  * 960821       Made changes to compile in newer 2.0.x kernels.  Added
  17  *              "cold reboot sense" entry.
  18  * 960825       Made a few changes to code, deleted some defines and made
  19  *              typedefs to replace them.  Made heartbeat reset only available
  20  *              via ioctl, and removed the write routine.
  21  * 960828       Added new items for PC Watchdog Rev.C card.
  22  * 960829       Changed around all of the IOCTLs, added new features,
  23  *              added watchdog disable/re-enable routines.  Added firmware
  24  *              version reporting.  Added read routine for temperature.
  25  *              Removed some extra defines, added an autodetect Revision
  26  *              routine.
  27  * 961006       Revised some documentation, fixed some cosmetic bugs.  Made
  28  *              drivers to panic the system if it's overheating at bootup.
  29  * 961118       Changed some verbiage on some of the output, tidied up
  30  *              code bits, and added compatibility to 2.1.x.
  31  * 970912       Enabled board on open and disable on close.
  32  * 971107       Took account of recent VFS changes (broke read).
  33  * 971210       Disable board on initialisation in case board already ticking.
  34  * 971222       Changed open/close for temperature handling
  35  *              Michael Meskes <meskes@debian.org>.
  36  * 980112       Used minor numbers from include/linux/miscdevice.h
  37  * 990403       Clear reset status after reading control status register in
  38  *              pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
  39  * 990605       Made changes to code to support Firmware 1.22a, added
  40  *              fairly useless proc entry.
  41  * 990610       removed said useless proc code for the merge <alan>
  42  * 000403       Removed last traces of proc code. <davej>
  43  * 011214       Added nowayout module option to override
  44  *              CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
  45  *              Added timeout module option to override default
  46  */
  47
  48 /*
  49  *      A bells and whistles driver is available from http://www.pcwd.de/
  50  *      More info available at http://www.berkprod.com/ or
  51  *      http://www.pcwatchdog.com/
  52  */
  53
  54 #include <linux/module.h>       /* For module specific items */
  55 #include <linux/moduleparam.h>  /* For new moduleparam's */
  56 #include <linux/types.h>        /* For standard types (like size_t) */
  57 #include <linux/errno.h>        /* For the -ENODEV/... values */
  58 #include <linux/kernel.h>       /* For printk/panic/... */
  59 #include <linux/delay.h>        /* For mdelay function */
  60 #include <linux/timer.h>        /* For timer related operations */
  61 #include <linux/jiffies.h>      /* For jiffies stuff */
  62 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  63 #include <linux/watchdog.h>     /* For the watchdog specific items */
  64 #include <linux/reboot.h>       /* For kernel_power_off() */
  65 #include <linux/init.h>         /* For __init/__exit/... */
  66 #include <linux/fs.h>           /* For file operations */
  67 #include <linux/isa.h>          /* For isa devices */
  68 #include <linux/ioport.h>       /* For io-port access */
  69 #include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  70 #include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  71 #include <linux/io.h>           /* For inb/outb/... */
  72
  73 /* Module and version information */
  74 #define WATCHDOG_VERSION "1.20"
  75 #define WATCHDOG_DATE "18 Feb 2007"
  76 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
  77 #define WATCHDOG_NAME "pcwd"
  78 #define PFX WATCHDOG_NAME ": "
  79 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION " (" 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 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. (2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 204
 205 static int nowayout = WATCHDOG_NOWAYOUT;
 206 module_param(nowayout, int, 0);
 207 MODULE_PARM_DESC(nowayout,
 208                 "Watchdog cannot be stopped once started (default="
 209                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 210
 211 /*
 212  *      Internal functions
 213  */
 214
 215 static int send_isa_command(int cmd)
 216 {
 217         int i;
 218         int control_status;
 219         int port0, last_port0;  /* Double read for stabilising */
 220
 221         if (debug >= DEBUG)
 222                 printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
 223                         cmd);
 224
 225         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 226         control_status = (cmd & 0x0F) | WD_WCMD;
 227         outb_p(control_status, pcwd_private.io_addr + 2);
 228         udelay(ISA_COMMAND_TIMEOUT);
 229
 230         port0 = inb_p(pcwd_private.io_addr);
 231         for (i = 0; i < 25; ++i) {
 232                 last_port0 = port0;
 233                 port0 = inb_p(pcwd_private.io_addr);
 234
 235                 if (port0 == last_port0)
 236                         break;  /* Data is stable */
 237
 238                 udelay(250);
 239         }
 240
 241         if (debug >= DEBUG)
 242                 printk(KERN_DEBUG PFX "received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 243                         cmd, port0, last_port0);
 244
 245         return port0;
 246 }
 247
 248 static int set_command_mode(void)
 249 {
 250         int i, found = 0, count = 0;
 251
 252         /* Set the card into command mode */
 253         spin_lock(&pcwd_private.io_lock);
 254         while ((!found) && (count < 3)) {
 255                 i = send_isa_command(CMD_ISA_IDLE);
 256
 257                 if (i == 0x00)
 258                         found = 1;
 259                 else if (i == 0xF3) {
 260                         /* Card does not like what we've done to it */
 261                         outb_p(0x00, pcwd_private.io_addr + 2);
 262                         udelay(1200);   /* Spec says wait 1ms */
 263                         outb_p(0x00, pcwd_private.io_addr + 2);
 264                         udelay(ISA_COMMAND_TIMEOUT);
 265                 }
 266                 count++;
 267         }
 268         spin_unlock(&pcwd_private.io_lock);
 269         pcwd_private.command_mode = found;
 270
 271         if (debug >= DEBUG)
 272                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 273                                 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                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 290                                 pcwd_private.command_mode);
 291 }
 292
 293 static inline void pcwd_check_temperature_support(void)
 294 {
 295         if (inb(pcwd_private.io_addr) != 0xF0)
 296                 pcwd_private.supports_temp = 1;
 297 }
 298
 299 static inline void pcwd_get_firmware(void)
 300 {
 301         int one, ten, hund, minor;
 302
 303         strcpy(pcwd_private.fw_ver_str, "ERROR");
 304
 305         if (set_command_mode()) {
 306                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 307                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 308                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 309                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 310                 sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
 311                                         one, ten, hund, minor);
 312         }
 313         unset_command_mode();
 314
 315         return;
 316 }
 317
 318 static inline int pcwd_get_option_switches(void)
 319 {
 320         int option_switches = 0;
 321
 322         if (set_command_mode()) {
 323                 /* Get switch settings */
 324                 option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 325         }
 326
 327         unset_command_mode();
 328         return option_switches;
 329 }
 330
 331 static void pcwd_show_card_info(void)
 332 {
 333         int option_switches;
 334
 335         /* Get some extra info from the hardware (in command/debug/diag mode) */
 336         if (pcwd_private.revision == PCWD_REVISION_A)
 337                 printk(KERN_INFO PFX
 338                         "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
 339                                                         pcwd_private.io_addr);
 340         else if (pcwd_private.revision == PCWD_REVISION_C) {
 341                 pcwd_get_firmware();
 342                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 343                         pcwd_private.io_addr, pcwd_private.fw_ver_str);
 344                 option_switches = pcwd_get_option_switches();
 345                 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 346                         option_switches,
 347                         ((option_switches & 0x10) ? "ON" : "OFF"),
 348                         ((option_switches & 0x08) ? "ON" : "OFF"));
 349
 350                 /* Reprogram internal heartbeat to 2 seconds */
 351                 if (set_command_mode()) {
 352                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 353                         unset_command_mode();
 354                 }
 355         }
 356
 357         if (pcwd_private.supports_temp)
 358                 printk(KERN_INFO PFX "Temperature Option Detected\n");
 359
 360         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 361                 printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
 362
 363         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 364                 printk(KERN_EMERG PFX
 365                         "Card senses a CPU Overheat. Panicking!\n");
 366                 printk(KERN_EMERG PFX
 367                         "CPU Overheat\n");
 368         }
 369
 370         if (pcwd_private.boot_status == 0)
 371                 printk(KERN_INFO PFX
 372                         "No previous trip detected - Cold boot or reset\n");
 373 }
 374
 375 static void pcwd_timer_ping(unsigned long data)
 376 {
 377         int wdrst_stat;
 378
 379         /* If we got a heartbeat pulse within the WDT_INTERVAL
 380          * we agree to ping the WDT */
 381         if (time_before(jiffies, pcwd_private.next_heartbeat)) {
 382                 /* Ping the watchdog */
 383                 spin_lock(&pcwd_private.io_lock);
 384                 if (pcwd_private.revision == PCWD_REVISION_A) {
 385                         /*  Rev A cards are reset by setting the
 386                             WD_WDRST bit in register 1 */
 387                         wdrst_stat = inb_p(pcwd_private.io_addr);
 388                         wdrst_stat &= 0x0F;
 389                         wdrst_stat |= WD_WDRST;
 390
 391                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 392                 } else {
 393                         /* Re-trigger watchdog by writing to port 0 */
 394                         outb_p(0x00, pcwd_private.io_addr);
 395                 }
 396
 397                 /* Re-set the timer interval */
 398                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 399
 400                 spin_unlock(&pcwd_private.io_lock);
 401         } else {
 402                 printk(KERN_WARNING PFX
 403                         "Heartbeat lost! Will not ping the watchdog\n");
 404         }
 405 }
 406
 407 static int pcwd_start(void)
 408 {
 409         int stat_reg;
 410
 411         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 412
 413         /* Start the timer */
 414         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 415
 416         /* Enable the port */
 417         if (pcwd_private.revision == PCWD_REVISION_C) {
 418                 spin_lock(&pcwd_private.io_lock);
 419                 outb_p(0x00, pcwd_private.io_addr + 3);
 420                 udelay(ISA_COMMAND_TIMEOUT);
 421                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 422                 spin_unlock(&pcwd_private.io_lock);
 423                 if (stat_reg & WD_WDIS) {
 424                         printk(KERN_INFO PFX "Could not start watchdog\n");
 425                         return -EIO;
 426                 }
 427         }
 428
 429         if (debug >= VERBOSE)
 430                 printk(KERN_DEBUG PFX "Watchdog started\n");
 431
 432         return 0;
 433 }
 434
 435 static int pcwd_stop(void)
 436 {
 437         int stat_reg;
 438
 439         /* Stop the timer */
 440         del_timer(&pcwd_private.timer);
 441
 442         /*  Disable the board  */
 443         if (pcwd_private.revision == PCWD_REVISION_C) {
 444                 spin_lock(&pcwd_private.io_lock);
 445                 outb_p(0xA5, pcwd_private.io_addr + 3);
 446                 udelay(ISA_COMMAND_TIMEOUT);
 447                 outb_p(0xA5, pcwd_private.io_addr + 3);
 448                 udelay(ISA_COMMAND_TIMEOUT);
 449                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 450                 spin_unlock(&pcwd_private.io_lock);
 451                 if ((stat_reg & WD_WDIS) == 0) {
 452                         printk(KERN_INFO PFX "Could not stop watchdog\n");
 453                         return -EIO;
 454                 }
 455         }
 456
 457         if (debug >= VERBOSE)
 458                 printk(KERN_DEBUG PFX "Watchdog stopped\n");
 459
 460         return 0;
 461 }
 462
 463 static int pcwd_keepalive(void)
 464 {
 465         /* user land ping */
 466         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 467
 468         if (debug >= DEBUG)
 469                 printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
 470
 471         return 0;
 472 }
 473
 474 static int pcwd_set_heartbeat(int t)
 475 {
 476         if (t < 2 || t > 7200) /* arbitrary upper limit */
 477                 return -EINVAL;
 478
 479         heartbeat = t;
 480
 481         if (debug >= VERBOSE)
 482                 printk(KERN_DEBUG PFX "New heartbeat: %d\n",
 483                        heartbeat);
 484
 485         return 0;
 486 }
 487
 488 static int pcwd_get_status(int *status)
 489 {
 490         int control_status;
 491
 492         *status = 0;
 493         spin_lock(&pcwd_private.io_lock);
 494         if (pcwd_private.revision == PCWD_REVISION_A)
 495                 /* Rev A cards return status information from
 496                  * the base register, which is used for the
 497                  * temperature in other cards. */
 498                 control_status = inb(pcwd_private.io_addr);
 499         else {
 500                 /* Rev C cards return card status in the base
 501                  * address + 1 register. And use different bits
 502                  * to indicate a card initiated reset, and an
 503                  * over-temperature condition. And the reboot
 504                  * status can be reset. */
 505                 control_status = inb(pcwd_private.io_addr + 1);
 506         }
 507         spin_unlock(&pcwd_private.io_lock);
 508
 509         if (pcwd_private.revision == PCWD_REVISION_A) {
 510                 if (control_status & WD_WDRST)
 511                         *status |= WDIOF_CARDRESET;
 512
 513                 if (control_status & WD_T110) {
 514                         *status |= WDIOF_OVERHEAT;
 515                         if (temp_panic) {
 516                                 printk(KERN_INFO PFX
 517                                         "Temperature overheat trip!\n");
 518                                 kernel_power_off();
 519                         }
 520                 }
 521         } else {
 522                 if (control_status & WD_REVC_WTRP)
 523                         *status |= WDIOF_CARDRESET;
 524
 525                 if (control_status & WD_REVC_TTRP) {
 526                         *status |= WDIOF_OVERHEAT;
 527                         if (temp_panic) {
 528                                 printk(KERN_INFO PFX
 529                                         "Temperature overheat trip!\n");
 530                                 kernel_power_off();
 531                         }
 532                 }
 533         }
 534
 535         return 0;
 536 }
 537
 538 static int pcwd_clear_status(void)
 539 {
 540         int control_status;
 541
 542         if (pcwd_private.revision == PCWD_REVISION_C) {
 543                 spin_lock(&pcwd_private.io_lock);
 544
 545                 if (debug >= VERBOSE)
 546                         printk(KERN_INFO PFX
 547                                         "clearing watchdog trip status\n");
 548
 549                 control_status = inb_p(pcwd_private.io_addr + 1);
 550
 551                 if (debug >= DEBUG) {
 552                         printk(KERN_DEBUG PFX "status was: 0x%02x\n",
 553                                 control_status);
 554                         printk(KERN_DEBUG PFX "sending: 0x%02x\n",
 555                                 (control_status & WD_REVC_R2DS));
 556                 }
 557
 558                 /* clear reset status & Keep Relay 2 disable state as it is */
 559                 outb_p((control_status & WD_REVC_R2DS),
 560                                                 pcwd_private.io_addr + 1);
 561
 562                 spin_unlock(&pcwd_private.io_lock);
 563         }
 564         return 0;
 565 }
 566
 567 static int pcwd_get_temperature(int *temperature)
 568 {
 569         /* check that port 0 gives temperature info and no command results */
 570         if (pcwd_private.command_mode)
 571                 return -1;
 572
 573         *temperature = 0;
 574         if (!pcwd_private.supports_temp)
 575                 return -ENODEV;
 576
 577         /*
 578          * Convert celsius to fahrenheit, since this was
 579          * the decided 'standard' for this return value.
 580          */
 581         spin_lock(&pcwd_private.io_lock);
 582         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 583         spin_unlock(&pcwd_private.io_lock);
 584
 585         if (debug >= DEBUG) {
 586                 printk(KERN_DEBUG PFX "temperature is: %d F\n",
 587                         *temperature);
 588         }
 589
 590         return 0;
 591 }
 592
 593 /*
 594  *      /dev/watchdog handling
 595  */
 596
 597 static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 598 {
 599         int rv;
 600         int status;
 601         int temperature;
 602         int new_heartbeat;
 603         int __user *argp = (int __user *)arg;
 604         static struct watchdog_info ident = {
 605                 .options =              WDIOF_OVERHEAT |
 606                                         WDIOF_CARDRESET |
 607                                         WDIOF_KEEPALIVEPING |
 608                                         WDIOF_SETTIMEOUT |
 609                                         WDIOF_MAGICCLOSE,
 610                 .firmware_version =     1,
 611                 .identity =             "PCWD",
 612         };
 613
 614         switch (cmd) {
 615         case WDIOC_GETSUPPORT:
 616                 if (copy_to_user(argp, &ident, sizeof(ident)))
 617                         return -EFAULT;
 618                 return 0;
 619
 620         case WDIOC_GETSTATUS:
 621                 pcwd_get_status(&status);
 622                 return put_user(status, argp);
 623
 624         case WDIOC_GETBOOTSTATUS:
 625                 return put_user(pcwd_private.boot_status, argp);
 626
 627         case WDIOC_GETTEMP:
 628                 if (pcwd_get_temperature(&temperature))
 629                         return -EFAULT;
 630
 631                 return put_user(temperature, argp);
 632
 633         case WDIOC_SETOPTIONS:
 634                 if (pcwd_private.revision == PCWD_REVISION_C) {
 635                         if (get_user(rv, argp))
 636                                 return -EFAULT;
 637
 638                         if (rv & WDIOS_DISABLECARD) {
 639                                 status = pcwd_stop();
 640                                 if (status < 0)
 641                                         return status;
 642                         }
 643                         if (rv & WDIOS_ENABLECARD) {
 644                                 status = pcwd_start();
 645                                 if (status < 0)
 646                                         return status;
 647                         }
 648                         if (rv & WDIOS_TEMPPANIC)
 649                                 temp_panic = 1;
 650                 }
 651                 return -EINVAL;
 652
 653         case WDIOC_KEEPALIVE:
 654                 pcwd_keepalive();
 655                 return 0;
 656
 657         case WDIOC_SETTIMEOUT:
 658                 if (get_user(new_heartbeat, argp))
 659                         return -EFAULT;
 660
 661                 if (pcwd_set_heartbeat(new_heartbeat))
 662                         return -EINVAL;
 663
 664                 pcwd_keepalive();
 665                 /* Fall */
 666
 667         case WDIOC_GETTIMEOUT:
 668                 return put_user(heartbeat, argp);
 669
 670         default:
 671                 return -ENOTTY;
 672         }
 673
 674         return 0;
 675 }
 676
 677 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 678                           loff_t *ppos)
 679 {
 680         if (len) {
 681                 if (!nowayout) {
 682                         size_t i;
 683
 684                         /* In case it was set long ago */
 685                         expect_close = 0;
 686
 687                         for (i = 0; i != len; i++) {
 688                                 char c;
 689
 690                                 if (get_user(c, buf + i))
 691                                         return -EFAULT;
 692                                 if (c == 'V')
 693                                         expect_close = 42;
 694                         }
 695                 }
 696                 pcwd_keepalive();
 697         }
 698         return len;
 699 }
 700
 701 static int pcwd_open(struct inode *inode, struct file *file)
 702 {
 703         if (test_and_set_bit(0, &open_allowed))
 704                 return -EBUSY;
 705         if (nowayout)
 706                 __module_get(THIS_MODULE);
 707         /* Activate */
 708         pcwd_start();
 709         pcwd_keepalive();
 710         return nonseekable_open(inode, file);
 711 }
 712
 713 static int pcwd_close(struct inode *inode, struct file *file)
 714 {
 715         if (expect_close == 42)
 716                 pcwd_stop();
 717         else {
 718                 printk(KERN_CRIT PFX
 719                         "Unexpected close, not stopping watchdog!\n");
 720                 pcwd_keepalive();
 721         }
 722         expect_close = 0;
 723         clear_bit(0, &open_allowed);
 724         return 0;
 725 }
 726
 727 /*
 728  *      /dev/temperature handling
 729  */
 730
 731 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 732                          loff_t *ppos)
 733 {
 734         int temperature;
 735
 736         if (pcwd_get_temperature(&temperature))
 737                 return -EFAULT;
 738
 739         if (copy_to_user(buf, &temperature, 1))
 740                 return -EFAULT;
 741
 742         return 1;
 743 }
 744
 745 static int pcwd_temp_open(struct inode *inode, struct file *file)
 746 {
 747         if (!pcwd_private.supports_temp)
 748                 return -ENODEV;
 749
 750         return nonseekable_open(inode, file);
 751 }
 752
 753 static int pcwd_temp_close(struct inode *inode, struct file *file)
 754 {
 755         return 0;
 756 }
 757
 758 /*
 759  *      Kernel Interfaces
 760  */
 761
 762 static const struct file_operations pcwd_fops = {
 763         .owner          = THIS_MODULE,
 764         .llseek         = no_llseek,
 765         .write          = pcwd_write,
 766         .unlocked_ioctl = pcwd_ioctl,
 767         .open           = pcwd_open,
 768         .release        = pcwd_close,
 769 };
 770
 771 static struct miscdevice pcwd_miscdev = {
 772         .minor =        WATCHDOG_MINOR,
 773         .name =         "watchdog",
 774         .fops =         &pcwd_fops,
 775 };
 776
 777 static const struct file_operations pcwd_temp_fops = {
 778         .owner          = THIS_MODULE,
 779         .llseek         = no_llseek,
 780         .read           = pcwd_temp_read,
 781         .open           = pcwd_temp_open,
 782         .release        = pcwd_temp_close,
 783 };
 784
 785 static struct miscdevice temp_miscdev = {
 786         .minor =        TEMP_MINOR,
 787         .name =         "temperature",
 788         .fops =         &pcwd_temp_fops,
 789 };
 790
 791 /*
 792  *      Init & exit routines
 793  */
 794
 795 static inline int get_revision(void)
 796 {
 797         int r = PCWD_REVISION_C;
 798
 799         spin_lock(&pcwd_private.io_lock);
 800         /* REV A cards use only 2 io ports; test
 801          * presumes a floating bus reads as 0xff. */
 802         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 803             (inb(pcwd_private.io_addr + 3) == 0xFF))
 804                 r = PCWD_REVISION_A;
 805         spin_unlock(&pcwd_private.io_lock);
 806
 807         return r;
 808 }
 809
 810 /*
 811  *  The ISA cards have a heartbeat bit in one of the registers, which
 812  *  register is card dependent.  The heartbeat bit is monitored, and if
 813  *  found, is considered proof that a Berkshire card has been found.
 814  *  The initial rate is once per second at board start up, then twice
 815  *  per second for normal operation.
 816  */
 817 static int __devinit pcwd_isa_match(struct device *dev, unsigned int id)
 818 {
 819         int base_addr = pcwd_ioports[id];
 820         int port0, last_port0;  /* Reg 0, in case it's REV A */
 821         int port1, last_port1;  /* Register 1 for REV C cards */
 822         int i;
 823         int retval;
 824
 825         if (debug >= DEBUG)
 826                 printk(KERN_DEBUG PFX "pcwd_isa_match id=%d\n",
 827                         id);
 828
 829         if (!request_region(base_addr, 4, "PCWD")) {
 830                 printk(KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 831                 return 0;
 832         }
 833
 834         retval = 0;
 835
 836         port0 = inb_p(base_addr);       /* For REV A boards */
 837         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 838         if (port0 != 0xff || port1 != 0xff) {
 839                 /* Not an 'ff' from a floating bus, so must be a card! */
 840                 for (i = 0; i < 4; ++i) {
 841
 842                         msleep(500);
 843
 844                         last_port0 = port0;
 845                         last_port1 = port1;
 846
 847                         port0 = inb_p(base_addr);
 848                         port1 = inb_p(base_addr + 1);
 849
 850                         /* Has either hearbeat bit changed?  */
 851                         if ((port0 ^ last_port0) & WD_HRTBT ||
 852                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 853                                 retval = 1;
 854                                 break;
 855                         }
 856                 }
 857         }
 858         release_region(base_addr, 4);
 859
 860         return retval;
 861 }
 862
 863 static int __devinit pcwd_isa_probe(struct device *dev, unsigned int id)
 864 {
 865         int ret;
 866
 867         if (debug >= DEBUG)
 868                 printk(KERN_DEBUG PFX "pcwd_isa_probe id=%d\n",
 869                         id);
 870
 871         cards_found++;
 872         if (cards_found == 1)
 873                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n",
 874                                                                 WD_VER);
 875
 876         if (cards_found > 1) {
 877                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 878                 return -ENODEV;
 879         }
 880
 881         if (pcwd_ioports[id] == 0x0000) {
 882                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 883                 return -ENODEV;
 884         }
 885         pcwd_private.io_addr = pcwd_ioports[id];
 886
 887         spin_lock_init(&pcwd_private.io_lock);
 888
 889         /* Check card's revision */
 890         pcwd_private.revision = get_revision();
 891
 892         if (!request_region(pcwd_private.io_addr,
 893                 (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 894                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 895                         pcwd_private.io_addr);
 896                 ret = -EIO;
 897                 goto error_request_region;
 898         }
 899
 900         /* Initial variables */
 901         pcwd_private.supports_temp = 0;
 902         temp_panic = 0;
 903         pcwd_private.boot_status = 0x0000;
 904
 905         /* get the boot_status */
 906         pcwd_get_status(&pcwd_private.boot_status);
 907
 908         /* clear the "card caused reboot" flag */
 909         pcwd_clear_status();
 910
 911         setup_timer(&pcwd_private.timer, pcwd_timer_ping, 0);
 912
 913         /*  Disable the board  */
 914         pcwd_stop();
 915
 916         /*  Check whether or not the card supports the temperature device */
 917         pcwd_check_temperature_support();
 918
 919         /* Show info about the card itself */
 920         pcwd_show_card_info();
 921
 922         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 923         if (heartbeat == 0)
 924                 heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
 925
 926         /* Check that the heartbeat value is within it's range;
 927            if not reset to the default */
 928         if (pcwd_set_heartbeat(heartbeat)) {
 929                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 930                 printk(KERN_INFO PFX
 931                   "heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
 932                                                         WATCHDOG_HEARTBEAT);
 933         }
 934
 935         if (pcwd_private.supports_temp) {
 936                 ret = misc_register(&temp_miscdev);
 937                 if (ret) {
 938                         printk(KERN_ERR PFX
 939                             "cannot register miscdev on minor=%d (err=%d)\n",
 940                                                         TEMP_MINOR, ret);
 941                         goto error_misc_register_temp;
 942                 }
 943         }
 944
 945         ret = misc_register(&pcwd_miscdev);
 946         if (ret) {
 947                 printk(KERN_ERR PFX
 948                         "cannot register miscdev on minor=%d (err=%d)\n",
 949                                         WATCHDOG_MINOR, ret);
 950                 goto error_misc_register_watchdog;
 951         }
 952
 953         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 954                 heartbeat, nowayout);
 955
 956         return 0;
 957
 958 error_misc_register_watchdog:
 959         if (pcwd_private.supports_temp)
 960                 misc_deregister(&temp_miscdev);
 961 error_misc_register_temp:
 962         release_region(pcwd_private.io_addr,
 963                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 964 error_request_region:
 965         pcwd_private.io_addr = 0x0000;
 966         cards_found--;
 967         return ret;
 968 }
 969
 970 static int __devexit pcwd_isa_remove(struct device *dev, unsigned int id)
 971 {
 972         if (debug >= DEBUG)
 973                 printk(KERN_DEBUG PFX "pcwd_isa_remove id=%d\n",
 974                         id);
 975
 976         if (!pcwd_private.io_addr)
 977                 return 1;
 978
 979         /*  Disable the board  */
 980         if (!nowayout)
 981                 pcwd_stop();
 982
 983         /* Deregister */
 984         misc_deregister(&pcwd_miscdev);
 985         if (pcwd_private.supports_temp)
 986                 misc_deregister(&temp_miscdev);
 987         release_region(pcwd_private.io_addr,
 988                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 989         pcwd_private.io_addr = 0x0000;
 990         cards_found--;
 991
 992         return 0;
 993 }
 994
 995 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
 996 {
 997         if (debug >= DEBUG)
 998                 printk(KERN_DEBUG PFX "pcwd_isa_shutdown id=%d\n",
 999                         id);
1000
1001         pcwd_stop();
1002 }
1003
1004 static struct isa_driver pcwd_isa_driver = {
1005         .match          = pcwd_isa_match,
1006         .probe          = pcwd_isa_probe,
1007         .remove         = __devexit_p(pcwd_isa_remove),
1008         .shutdown       = pcwd_isa_shutdown,
1009         .driver         = {
1010                 .owner  = THIS_MODULE,
1011                 .name   = WATCHDOG_NAME,
1012         },
1013 };
1014
1015 static int __init pcwd_init_module(void)
1016 {
1017         return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
1018 }
1019
1020 static void __exit pcwd_cleanup_module(void)
1021 {
1022         isa_unregister_driver(&pcwd_isa_driver);
1023         printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1024 }
1025
1026 module_init(pcwd_init_module);
1027 module_exit(pcwd_cleanup_module);
1028
1029 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, Wim Van Sebroeck <wim@iguana.be>");
1030 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1031 MODULE_VERSION(WATCHDOG_VERSION);
1032 MODULE_LICENSE("GPL");
1033 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1034 MODULE_ALIAS_MISCDEV(TEMP_MINOR);