drivers/watchdog/pcwd.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * PC Watchdog Driver
   4  * by Ken Hollis (khollis@bitgate.com)
   5  *
   6  * Permission granted from Simon Machell (smachell@berkprod.com)
   7  * Written for the Linux Kernel, and GPLed by Ken Hollis
   8  *
   9  * 960107       Added request_region routines, modulized the whole thing.
  10  * 960108       Fixed end-of-file pointer (Thanks to Dan Hollis), added
  11  *              WD_TIMEOUT define.
  12  * 960216       Added eof marker on the file, and changed verbose messages.
  13  * 960716       Made functional and cosmetic changes to the source for
  14  *              inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
  15  * 960717       Removed read/seek routines, replaced with ioctl.  Also, added
  16  *              check_region command due to Alan's suggestion.
  17  * 960821       Made changes to compile in newer 2.0.x kernels.  Added
  18  *              "cold reboot sense" entry.
  19  * 960825       Made a few changes to code, deleted some defines and made
  20  *              typedefs to replace them.  Made heartbeat reset only available
  21  *              via ioctl, and removed the write routine.
  22  * 960828       Added new items for PC Watchdog Rev.C card.
  23  * 960829       Changed around all of the IOCTLs, added new features,
  24  *              added watchdog disable/re-enable routines.  Added firmware
  25  *              version reporting.  Added read routine for temperature.
  26  *              Removed some extra defines, added an autodetect Revision
  27  *              routine.
  28  * 961006       Revised some documentation, fixed some cosmetic bugs.  Made
  29  *              drivers to panic the system if it's overheating at bootup.
  30  * 961118       Changed some verbiage on some of the output, tidied up
  31  *              code bits, and added compatibility to 2.1.x.
  32  * 970912       Enabled board on open and disable on close.
  33  * 971107       Took account of recent VFS changes (broke read).
  34  * 971210       Disable board on initialisation in case board already ticking.
  35  * 971222       Changed open/close for temperature handling
  36  *              Michael Meskes <meskes@debian.org>.
  37  * 980112       Used minor numbers from include/linux/miscdevice.h
  38  * 990403       Clear reset status after reading control status register in
  39  *              pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
  40  * 990605       Made changes to code to support Firmware 1.22a, added
  41  *              fairly useless proc entry.
  42  * 990610       removed said useless proc code for the merge <alan>
  43  * 000403       Removed last traces of proc code. <davej>
  44  * 011214       Added nowayout module option to override
  45  *              CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
  46  *              Added timeout module option to override default
  47  */
  48
  49 /*
  50  *      A bells and whistles driver is available from http://www.pcwd.de/
  51  *      More info available at http://www.berkprod.com/ or
  52  *      http://www.pcwatchdog.com/
  53  */
  54
  55 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  56
  57 #include <linux/module.h>       /* For module specific items */
  58 #include <linux/moduleparam.h>  /* For new moduleparam's */
  59 #include <linux/types.h>        /* For standard types (like size_t) */
  60 #include <linux/errno.h>        /* For the -ENODEV/... values */
  61 #include <linux/kernel.h>       /* For printk/panic/... */
  62 #include <linux/delay.h>        /* For mdelay function */
  63 #include <linux/timer.h>        /* For timer related operations */
  64 #include <linux/jiffies.h>      /* For jiffies stuff */
  65 #include <linux/miscdevice.h>   /* For struct miscdevice */
  66 #include <linux/watchdog.h>     /* For the watchdog specific items */
  67 #include <linux/reboot.h>       /* For kernel_power_off() */
  68 #include <linux/init.h>         /* For __init/__exit/... */
  69 #include <linux/fs.h>           /* For file operations */
  70 #include <linux/isa.h>          /* For isa devices */
  71 #include <linux/ioport.h>       /* For io-port access */
  72 #include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  73 #include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  74 #include <linux/io.h>           /* For inb/outb/... */
  75
  76 /* Module and version information */
  77 #define WATCHDOG_VERSION "1.20"
  78 #define WATCHDOG_DATE "18 Feb 2007"
  79 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
  80 #define WATCHDOG_NAME "pcwd"
  81 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION "\n"
  82
  83 /*
  84  * It should be noted that PCWD_REVISION_B was removed because A and B
  85  * are essentially the same types of card, with the exception that B
  86  * has temperature reporting.  Since I didn't receive a Rev.B card,
  87  * the Rev.B card is not supported.  (It's a good thing too, as they
  88  * are no longer in production.)
  89  */
  90 #define PCWD_REVISION_A         1
  91 #define PCWD_REVISION_C         2
  92
  93 /*
  94  * These are the auto-probe addresses available.
  95  *
  96  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
  97  * Revision A has an address range of 2 addresses, while Revision C has 4.
  98  */
  99 #define PCWD_ISA_NR_CARDS       3
 100 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
 101
 102 /*
 103  * These are the defines that describe the control status bits for the
 104  * PCI-PC Watchdog card.
 105 */
 106 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
 107 #define WD_WDRST                0x01    /* Previously reset state */
 108 #define WD_T110                 0x02    /* Temperature overheat sense */
 109 #define WD_HRTBT                0x04    /* Heartbeat sense */
 110 #define WD_RLY2                 0x08    /* External relay triggered */
 111 #define WD_SRLY2                0x80    /* Software external relay triggered */
 112 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 113 #define WD_REVC_WTRP            0x01    /* Watchdog Trip status */
 114 #define WD_REVC_HRBT            0x02    /* Watchdog Heartbeat */
 115 #define WD_REVC_TTRP            0x04    /* Temperature Trip status */
 116 #define WD_REVC_RL2A            0x08    /* Relay 2 activated by
 117                                                         on-board processor */
 118 #define WD_REVC_RL1A            0x10    /* Relay 1 active */
 119 #define WD_REVC_R2DS            0x40    /* Relay 2 disable */
 120 #define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
 121 /* Port 2 : Control Status #2 */
 122 #define WD_WDIS                 0x10    /* Watchdog Disabled */
 123 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 124 #define WD_SSEL                 0x40    /* Watchdog Switch Select
 125                                                         (1:SW1 <-> 0:SW2) */
 126 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
 127
 128 /* max. time we give an ISA watchdog card to process a command */
 129 /* 500ms for each 4 bit response (according to spec.) */
 130 #define ISA_COMMAND_TIMEOUT     1000
 131
 132 /* Watchdog's internal commands */
 133 #define CMD_ISA_IDLE                    0x00
 134 #define CMD_ISA_VERSION_INTEGER         0x01
 135 #define CMD_ISA_VERSION_TENTH           0x02
 136 #define CMD_ISA_VERSION_HUNDRETH        0x03
 137 #define CMD_ISA_VERSION_MINOR           0x04
 138 #define CMD_ISA_SWITCH_SETTINGS         0x05
 139 #define CMD_ISA_RESET_PC                0x06
 140 #define CMD_ISA_ARM_0                   0x07
 141 #define CMD_ISA_ARM_30                  0x08
 142 #define CMD_ISA_ARM_60                  0x09
 143 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 144 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 145 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 146 #define CMD_ISA_RESET_RELAYS            0x0D
 147
 148 /* Watchdog's Dip Switch heartbeat values */
 149 static const int heartbeat_tbl[] = {
 150         20,     /* OFF-OFF-OFF  = 20 Sec  */
 151         40,     /* OFF-OFF-ON   = 40 Sec  */
 152         60,     /* OFF-ON-OFF   =  1 Min  */
 153         300,    /* OFF-ON-ON    =  5 Min  */
 154         600,    /* ON-OFF-OFF   = 10 Min  */
 155         1800,   /* ON-OFF-ON    = 30 Min  */
 156         3600,   /* ON-ON-OFF    =  1 Hour */
 157         7200,   /* ON-ON-ON     =  2 hour */
 158 };
 159
 160 /*
 161  * We are using an kernel timer to do the pinging of the watchdog
 162  * every ~500ms. We try to set the internal heartbeat of the
 163  * watchdog to 2 ms.
 164  */
 165
 166 #define WDT_INTERVAL (HZ/2+1)
 167
 168 /* We can only use 1 card due to the /dev/watchdog restriction */
 169 static int cards_found;
 170
 171 /* internal variables */
 172 static unsigned long open_allowed;
 173 static char expect_close;
 174 static int temp_panic;
 175
 176 /* this is private data for each ISA-PC watchdog card */
 177 static struct {
 178         char fw_ver_str[6];             /* The cards firmware version */
 179         int revision;                   /* The card's revision */
 180         int supports_temp;              /* Whether or not the card has
 181                                                 a temperature device */
 182         int command_mode;               /* Whether or not the card is in
 183                                                 command mode */
 184         int boot_status;                /* The card's boot status */
 185         int io_addr;                    /* The cards I/O address */
 186         spinlock_t io_lock;             /* the lock for io operations */
 187         struct timer_list timer;        /* The timer that pings the watchdog */
 188         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 189 } pcwd_private;
 190
 191 /* module parameters */
 192 #define QUIET   0       /* Default */
 193 #define VERBOSE 1       /* Verbose */
 194 #define DEBUG   2       /* print fancy stuff too */
 195 static int debug = QUIET;
 196 module_param(debug, int, 0);
 197 MODULE_PARM_DESC(debug,
 198                 "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
 199
 200 /* default heartbeat = delay-time from dip-switches */
 201 #define WATCHDOG_HEARTBEAT 0
 202 static int heartbeat = WATCHDOG_HEARTBEAT;
 203 module_param(heartbeat, int, 0);
 204 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
 205         "(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
 206                                 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 207
 208 static bool nowayout = WATCHDOG_NOWAYOUT;
 209 module_param(nowayout, bool, 0);
 210 MODULE_PARM_DESC(nowayout,
 211                 "Watchdog cannot be stopped once started (default="
 212                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 213
 214 /*
 215  *      Internal functions
 216  */
 217
 218 static int send_isa_command(int cmd)
 219 {
 220         int i;
 221         int control_status;
 222         int port0, last_port0;  /* Double read for stabilising */
 223
 224         if (debug >= DEBUG)
 225                 pr_debug("sending following data cmd=0x%02x\n", cmd);
 226
 227         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 228         control_status = (cmd & 0x0F) | WD_WCMD;
 229         outb_p(control_status, pcwd_private.io_addr + 2);
 230         udelay(ISA_COMMAND_TIMEOUT);
 231
 232         port0 = inb_p(pcwd_private.io_addr);
 233         for (i = 0; i < 25; ++i) {
 234                 last_port0 = port0;
 235                 port0 = inb_p(pcwd_private.io_addr);
 236
 237                 if (port0 == last_port0)
 238                         break;  /* Data is stable */
 239
 240                 udelay(250);
 241         }
 242
 243         if (debug >= DEBUG)
 244                 pr_debug("received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 245                          cmd, port0, last_port0);
 246
 247         return port0;
 248 }
 249
 250 static int set_command_mode(void)
 251 {
 252         int i, found = 0, count = 0;
 253
 254         /* Set the card into command mode */
 255         spin_lock(&pcwd_private.io_lock);
 256         while ((!found) && (count < 3)) {
 257                 i = send_isa_command(CMD_ISA_IDLE);
 258
 259                 if (i == 0x00)
 260                         found = 1;
 261                 else if (i == 0xF3) {
 262                         /* Card does not like what we've done to it */
 263                         outb_p(0x00, pcwd_private.io_addr + 2);
 264                         udelay(1200);   /* Spec says wait 1ms */
 265                         outb_p(0x00, pcwd_private.io_addr + 2);
 266                         udelay(ISA_COMMAND_TIMEOUT);
 267                 }
 268                 count++;
 269         }
 270         spin_unlock(&pcwd_private.io_lock);
 271         pcwd_private.command_mode = found;
 272
 273         if (debug >= DEBUG)
 274                 pr_debug("command_mode=%d\n", pcwd_private.command_mode);
 275
 276         return found;
 277 }
 278
 279 static void unset_command_mode(void)
 280 {
 281         /* Set the card into normal mode */
 282         spin_lock(&pcwd_private.io_lock);
 283         outb_p(0x00, pcwd_private.io_addr + 2);
 284         udelay(ISA_COMMAND_TIMEOUT);
 285         spin_unlock(&pcwd_private.io_lock);
 286
 287         pcwd_private.command_mode = 0;
 288
 289         if (debug >= DEBUG)
 290                 pr_debug("command_mode=%d\n", 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                 pr_info("ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
 338                         pcwd_private.io_addr);
 339         else if (pcwd_private.revision == PCWD_REVISION_C) {
 340                 pcwd_get_firmware();
 341                 pr_info("ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 342                         pcwd_private.io_addr, pcwd_private.fw_ver_str);
 343                 option_switches = pcwd_get_option_switches();
 344                 pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 345                         option_switches,
 346                         ((option_switches & 0x10) ? "ON" : "OFF"),
 347                         ((option_switches & 0x08) ? "ON" : "OFF"));
 348
 349                 /* Reprogram internal heartbeat to 2 seconds */
 350                 if (set_command_mode()) {
 351                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 352                         unset_command_mode();
 353                 }
 354         }
 355
 356         if (pcwd_private.supports_temp)
 357                 pr_info("Temperature Option Detected\n");
 358
 359         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 360                 pr_info("Previous reboot was caused by the card\n");
 361
 362         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 363                 pr_emerg("Card senses a CPU Overheat. Panicking!\n");
 364                 pr_emerg("CPU Overheat\n");
 365         }
 366
 367         if (pcwd_private.boot_status == 0)
 368                 pr_info("No previous trip detected - Cold boot or reset\n");
 369 }
 370
 371 static void pcwd_timer_ping(struct timer_list *unused)
 372 {
 373         int wdrst_stat;
 374
 375         /* If we got a heartbeat pulse within the WDT_INTERVAL
 376          * we agree to ping the WDT */
 377         if (time_before(jiffies, pcwd_private.next_heartbeat)) {
 378                 /* Ping the watchdog */
 379                 spin_lock(&pcwd_private.io_lock);
 380                 if (pcwd_private.revision == PCWD_REVISION_A) {
 381                         /*  Rev A cards are reset by setting the
 382                             WD_WDRST bit in register 1 */
 383                         wdrst_stat = inb_p(pcwd_private.io_addr);
 384                         wdrst_stat &= 0x0F;
 385                         wdrst_stat |= WD_WDRST;
 386
 387                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 388                 } else {
 389                         /* Re-trigger watchdog by writing to port 0 */
 390                         outb_p(0x00, pcwd_private.io_addr);
 391                 }
 392
 393                 /* Re-set the timer interval */
 394                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 395
 396                 spin_unlock(&pcwd_private.io_lock);
 397         } else {
 398                 pr_warn("Heartbeat lost! Will not ping the watchdog\n");
 399         }
 400 }
 401
 402 static int pcwd_start(void)
 403 {
 404         int stat_reg;
 405
 406         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 407
 408         /* Start the timer */
 409         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 410
 411         /* Enable the port */
 412         if (pcwd_private.revision == PCWD_REVISION_C) {
 413                 spin_lock(&pcwd_private.io_lock);
 414                 outb_p(0x00, pcwd_private.io_addr + 3);
 415                 udelay(ISA_COMMAND_TIMEOUT);
 416                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 417                 spin_unlock(&pcwd_private.io_lock);
 418                 if (stat_reg & WD_WDIS) {
 419                         pr_info("Could not start watchdog\n");
 420                         return -EIO;
 421                 }
 422         }
 423
 424         if (debug >= VERBOSE)
 425                 pr_debug("Watchdog started\n");
 426
 427         return 0;
 428 }
 429
 430 static int pcwd_stop(void)
 431 {
 432         int stat_reg;
 433
 434         /* Stop the timer */
 435         del_timer(&pcwd_private.timer);
 436
 437         /*  Disable the board  */
 438         if (pcwd_private.revision == PCWD_REVISION_C) {
 439                 spin_lock(&pcwd_private.io_lock);
 440                 outb_p(0xA5, pcwd_private.io_addr + 3);
 441                 udelay(ISA_COMMAND_TIMEOUT);
 442                 outb_p(0xA5, pcwd_private.io_addr + 3);
 443                 udelay(ISA_COMMAND_TIMEOUT);
 444                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 445                 spin_unlock(&pcwd_private.io_lock);
 446                 if ((stat_reg & WD_WDIS) == 0) {
 447                         pr_info("Could not stop watchdog\n");
 448                         return -EIO;
 449                 }
 450         }
 451
 452         if (debug >= VERBOSE)
 453                 pr_debug("Watchdog stopped\n");
 454
 455         return 0;
 456 }
 457
 458 static int pcwd_keepalive(void)
 459 {
 460         /* user land ping */
 461         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 462
 463         if (debug >= DEBUG)
 464                 pr_debug("Watchdog keepalive signal send\n");
 465
 466         return 0;
 467 }
 468
 469 static int pcwd_set_heartbeat(int t)
 470 {
 471         if (t < 2 || t > 7200) /* arbitrary upper limit */
 472                 return -EINVAL;
 473
 474         heartbeat = t;
 475
 476         if (debug >= VERBOSE)
 477                 pr_debug("New heartbeat: %d\n", heartbeat);
 478
 479         return 0;
 480 }
 481
 482 static int pcwd_get_status(int *status)
 483 {
 484         int control_status;
 485
 486         *status = 0;
 487         spin_lock(&pcwd_private.io_lock);
 488         if (pcwd_private.revision == PCWD_REVISION_A)
 489                 /* Rev A cards return status information from
 490                  * the base register, which is used for the
 491                  * temperature in other cards. */
 492                 control_status = inb(pcwd_private.io_addr);
 493         else {
 494                 /* Rev C cards return card status in the base
 495                  * address + 1 register. And use different bits
 496                  * to indicate a card initiated reset, and an
 497                  * over-temperature condition. And the reboot
 498                  * status can be reset. */
 499                 control_status = inb(pcwd_private.io_addr + 1);
 500         }
 501         spin_unlock(&pcwd_private.io_lock);
 502
 503         if (pcwd_private.revision == PCWD_REVISION_A) {
 504                 if (control_status & WD_WDRST)
 505                         *status |= WDIOF_CARDRESET;
 506
 507                 if (control_status & WD_T110) {
 508                         *status |= WDIOF_OVERHEAT;
 509                         if (temp_panic) {
 510                                 pr_info("Temperature overheat trip!\n");
 511                                 kernel_power_off();
 512                         }
 513                 }
 514         } else {
 515                 if (control_status & WD_REVC_WTRP)
 516                         *status |= WDIOF_CARDRESET;
 517
 518                 if (control_status & WD_REVC_TTRP) {
 519                         *status |= WDIOF_OVERHEAT;
 520                         if (temp_panic) {
 521                                 pr_info("Temperature overheat trip!\n");
 522                                 kernel_power_off();
 523                         }
 524                 }
 525         }
 526
 527         return 0;
 528 }
 529
 530 static int pcwd_clear_status(void)
 531 {
 532         int control_status;
 533
 534         if (pcwd_private.revision == PCWD_REVISION_C) {
 535                 spin_lock(&pcwd_private.io_lock);
 536
 537                 if (debug >= VERBOSE)
 538                         pr_info("clearing watchdog trip status\n");
 539
 540                 control_status = inb_p(pcwd_private.io_addr + 1);
 541
 542                 if (debug >= DEBUG) {
 543                         pr_debug("status was: 0x%02x\n", control_status);
 544                         pr_debug("sending: 0x%02x\n",
 545                                  (control_status & WD_REVC_R2DS));
 546                 }
 547
 548                 /* clear reset status & Keep Relay 2 disable state as it is */
 549                 outb_p((control_status & WD_REVC_R2DS),
 550                                                 pcwd_private.io_addr + 1);
 551
 552                 spin_unlock(&pcwd_private.io_lock);
 553         }
 554         return 0;
 555 }
 556
 557 static int pcwd_get_temperature(int *temperature)
 558 {
 559         /* check that port 0 gives temperature info and no command results */
 560         if (pcwd_private.command_mode)
 561                 return -1;
 562
 563         *temperature = 0;
 564         if (!pcwd_private.supports_temp)
 565                 return -ENODEV;
 566
 567         /*
 568          * Convert celsius to fahrenheit, since this was
 569          * the decided 'standard' for this return value.
 570          */
 571         spin_lock(&pcwd_private.io_lock);
 572         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 573         spin_unlock(&pcwd_private.io_lock);
 574
 575         if (debug >= DEBUG) {
 576                 pr_debug("temperature is: %d F\n", *temperature);
 577         }
 578
 579         return 0;
 580 }
 581
 582 /*
 583  *      /dev/watchdog handling
 584  */
 585
 586 static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 587 {
 588         int rv;
 589         int status;
 590         int temperature;
 591         int new_heartbeat;
 592         int __user *argp = (int __user *)arg;
 593         static const struct watchdog_info ident = {
 594                 .options =              WDIOF_OVERHEAT |
 595                                         WDIOF_CARDRESET |
 596                                         WDIOF_KEEPALIVEPING |
 597                                         WDIOF_SETTIMEOUT |
 598                                         WDIOF_MAGICCLOSE,
 599                 .firmware_version =     1,
 600                 .identity =             "PCWD",
 601         };
 602
 603         switch (cmd) {
 604         case WDIOC_GETSUPPORT:
 605                 if (copy_to_user(argp, &ident, sizeof(ident)))
 606                         return -EFAULT;
 607                 return 0;
 608
 609         case WDIOC_GETSTATUS:
 610                 pcwd_get_status(&status);
 611                 return put_user(status, argp);
 612
 613         case WDIOC_GETBOOTSTATUS:
 614                 return put_user(pcwd_private.boot_status, argp);
 615
 616         case WDIOC_GETTEMP:
 617                 if (pcwd_get_temperature(&temperature))
 618                         return -EFAULT;
 619
 620                 return put_user(temperature, argp);
 621
 622         case WDIOC_SETOPTIONS:
 623                 if (pcwd_private.revision == PCWD_REVISION_C) {
 624                         if (get_user(rv, argp))
 625                                 return -EFAULT;
 626
 627                         if (rv & WDIOS_DISABLECARD) {
 628                                 status = pcwd_stop();
 629                                 if (status < 0)
 630                                         return status;
 631                         }
 632                         if (rv & WDIOS_ENABLECARD) {
 633                                 status = pcwd_start();
 634                                 if (status < 0)
 635                                         return status;
 636                         }
 637                         if (rv & WDIOS_TEMPPANIC)
 638                                 temp_panic = 1;
 639                 }
 640                 return -EINVAL;
 641
 642         case WDIOC_KEEPALIVE:
 643                 pcwd_keepalive();
 644                 return 0;
 645
 646         case WDIOC_SETTIMEOUT:
 647                 if (get_user(new_heartbeat, argp))
 648                         return -EFAULT;
 649
 650                 if (pcwd_set_heartbeat(new_heartbeat))
 651                         return -EINVAL;
 652
 653                 pcwd_keepalive();
 654                 fallthrough;
 655
 656         case WDIOC_GETTIMEOUT:
 657                 return put_user(heartbeat, argp);
 658
 659         default:
 660                 return -ENOTTY;
 661         }
 662
 663         return 0;
 664 }
 665
 666 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 667                           loff_t *ppos)
 668 {
 669         if (len) {
 670                 if (!nowayout) {
 671                         size_t i;
 672
 673                         /* In case it was set long ago */
 674                         expect_close = 0;
 675
 676                         for (i = 0; i != len; i++) {
 677                                 char c;
 678
 679                                 if (get_user(c, buf + i))
 680                                         return -EFAULT;
 681                                 if (c == 'V')
 682                                         expect_close = 42;
 683                         }
 684                 }
 685                 pcwd_keepalive();
 686         }
 687         return len;
 688 }
 689
 690 static int pcwd_open(struct inode *inode, struct file *file)
 691 {
 692         if (test_and_set_bit(0, &open_allowed))
 693                 return -EBUSY;
 694         if (nowayout)
 695                 __module_get(THIS_MODULE);
 696         /* Activate */
 697         pcwd_start();
 698         pcwd_keepalive();
 699         return stream_open(inode, file);
 700 }
 701
 702 static int pcwd_close(struct inode *inode, struct file *file)
 703 {
 704         if (expect_close == 42)
 705                 pcwd_stop();
 706         else {
 707                 pr_crit("Unexpected close, not stopping watchdog!\n");
 708                 pcwd_keepalive();
 709         }
 710         expect_close = 0;
 711         clear_bit(0, &open_allowed);
 712         return 0;
 713 }
 714
 715 /*
 716  *      /dev/temperature handling
 717  */
 718
 719 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 720                          loff_t *ppos)
 721 {
 722         int temperature;
 723
 724         if (pcwd_get_temperature(&temperature))
 725                 return -EFAULT;
 726
 727         if (copy_to_user(buf, &temperature, 1))
 728                 return -EFAULT;
 729
 730         return 1;
 731 }
 732
 733 static int pcwd_temp_open(struct inode *inode, struct file *file)
 734 {
 735         if (!pcwd_private.supports_temp)
 736                 return -ENODEV;
 737
 738         return stream_open(inode, file);
 739 }
 740
 741 static int pcwd_temp_close(struct inode *inode, struct file *file)
 742 {
 743         return 0;
 744 }
 745
 746 /*
 747  *      Kernel Interfaces
 748  */
 749
 750 static const struct file_operations pcwd_fops = {
 751         .owner          = THIS_MODULE,
 752         .llseek         = no_llseek,
 753         .write          = pcwd_write,
 754         .unlocked_ioctl = pcwd_ioctl,
 755         .compat_ioctl   = compat_ptr_ioctl,
 756         .open           = pcwd_open,
 757         .release        = pcwd_close,
 758 };
 759
 760 static struct miscdevice pcwd_miscdev = {
 761         .minor =        WATCHDOG_MINOR,
 762         .name =         "watchdog",
 763         .fops =         &pcwd_fops,
 764 };
 765
 766 static const struct file_operations pcwd_temp_fops = {
 767         .owner          = THIS_MODULE,
 768         .llseek         = no_llseek,
 769         .read           = pcwd_temp_read,
 770         .open           = pcwd_temp_open,
 771         .release        = pcwd_temp_close,
 772 };
 773
 774 static struct miscdevice temp_miscdev = {
 775         .minor =        TEMP_MINOR,
 776         .name =         "temperature",
 777         .fops =         &pcwd_temp_fops,
 778 };
 779
 780 /*
 781  *      Init & exit routines
 782  */
 783
 784 static inline int get_revision(void)
 785 {
 786         int r = PCWD_REVISION_C;
 787
 788         spin_lock(&pcwd_private.io_lock);
 789         /* REV A cards use only 2 io ports; test
 790          * presumes a floating bus reads as 0xff. */
 791         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 792             (inb(pcwd_private.io_addr + 3) == 0xFF))
 793                 r = PCWD_REVISION_A;
 794         spin_unlock(&pcwd_private.io_lock);
 795
 796         return r;
 797 }
 798
 799 /*
 800  *  The ISA cards have a heartbeat bit in one of the registers, which
 801  *  register is card dependent.  The heartbeat bit is monitored, and if
 802  *  found, is considered proof that a Berkshire card has been found.
 803  *  The initial rate is once per second at board start up, then twice
 804  *  per second for normal operation.
 805  */
 806 static int pcwd_isa_match(struct device *dev, unsigned int id)
 807 {
 808         int base_addr = pcwd_ioports[id];
 809         int port0, last_port0;  /* Reg 0, in case it's REV A */
 810         int port1, last_port1;  /* Register 1 for REV C cards */
 811         int i;
 812         int retval;
 813
 814         if (debug >= DEBUG)
 815                 pr_debug("pcwd_isa_match id=%d\n", id);
 816
 817         if (!request_region(base_addr, 4, "PCWD")) {
 818                 pr_info("Port 0x%04x unavailable\n", base_addr);
 819                 return 0;
 820         }
 821
 822         retval = 0;
 823
 824         port0 = inb_p(base_addr);       /* For REV A boards */
 825         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 826         if (port0 != 0xff || port1 != 0xff) {
 827                 /* Not an 'ff' from a floating bus, so must be a card! */
 828                 for (i = 0; i < 4; ++i) {
 829
 830                         msleep(500);
 831
 832                         last_port0 = port0;
 833                         last_port1 = port1;
 834
 835                         port0 = inb_p(base_addr);
 836                         port1 = inb_p(base_addr + 1);
 837
 838                         /* Has either hearbeat bit changed?  */
 839                         if ((port0 ^ last_port0) & WD_HRTBT ||
 840                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 841                                 retval = 1;
 842                                 break;
 843                         }
 844                 }
 845         }
 846         release_region(base_addr, 4);
 847
 848         return retval;
 849 }
 850
 851 static int pcwd_isa_probe(struct device *dev, unsigned int id)
 852 {
 853         int ret;
 854
 855         if (debug >= DEBUG)
 856                 pr_debug("pcwd_isa_probe id=%d\n", id);
 857
 858         cards_found++;
 859         if (cards_found == 1)
 860                 pr_info("v%s Ken Hollis (kenji@bitgate.com)\n",
 861                                                         WATCHDOG_VERSION);
 862
 863         if (cards_found > 1) {
 864                 pr_err("This driver only supports 1 device\n");
 865                 return -ENODEV;
 866         }
 867
 868         if (pcwd_ioports[id] == 0x0000) {
 869                 pr_err("No I/O-Address for card detected\n");
 870                 return -ENODEV;
 871         }
 872         pcwd_private.io_addr = pcwd_ioports[id];
 873
 874         spin_lock_init(&pcwd_private.io_lock);
 875
 876         /* Check card's revision */
 877         pcwd_private.revision = get_revision();
 878
 879         if (!request_region(pcwd_private.io_addr,
 880                 (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 881                 pr_err("I/O address 0x%04x already in use\n",
 882                        pcwd_private.io_addr);
 883                 ret = -EIO;
 884                 goto error_request_region;
 885         }
 886
 887         /* Initial variables */
 888         pcwd_private.supports_temp = 0;
 889         temp_panic = 0;
 890         pcwd_private.boot_status = 0x0000;
 891
 892         /* get the boot_status */
 893         pcwd_get_status(&pcwd_private.boot_status);
 894
 895         /* clear the "card caused reboot" flag */
 896         pcwd_clear_status();
 897
 898         timer_setup(&pcwd_private.timer, pcwd_timer_ping, 0);
 899
 900         /*  Disable the board  */
 901         pcwd_stop();
 902
 903         /*  Check whether or not the card supports the temperature device */
 904         pcwd_check_temperature_support();
 905
 906         /* Show info about the card itself */
 907         pcwd_show_card_info();
 908
 909         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 910         if (heartbeat == 0)
 911                 heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
 912
 913         /* Check that the heartbeat value is within it's range;
 914            if not reset to the default */
 915         if (pcwd_set_heartbeat(heartbeat)) {
 916                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 917                 pr_info("heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
 918                         WATCHDOG_HEARTBEAT);
 919         }
 920
 921         if (pcwd_private.supports_temp) {
 922                 ret = misc_register(&temp_miscdev);
 923                 if (ret) {
 924                         pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 925                                TEMP_MINOR, ret);
 926                         goto error_misc_register_temp;
 927                 }
 928         }
 929
 930         ret = misc_register(&pcwd_miscdev);
 931         if (ret) {
 932                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 933                        WATCHDOG_MINOR, ret);
 934                 goto error_misc_register_watchdog;
 935         }
 936
 937         pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
 938                 heartbeat, nowayout);
 939
 940         return 0;
 941
 942 error_misc_register_watchdog:
 943         if (pcwd_private.supports_temp)
 944                 misc_deregister(&temp_miscdev);
 945 error_misc_register_temp:
 946         release_region(pcwd_private.io_addr,
 947                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 948 error_request_region:
 949         pcwd_private.io_addr = 0x0000;
 950         cards_found--;
 951         return ret;
 952 }
 953
 954 static int pcwd_isa_remove(struct device *dev, unsigned int id)
 955 {
 956         if (debug >= DEBUG)
 957                 pr_debug("pcwd_isa_remove id=%d\n", id);
 958
 959         if (!pcwd_private.io_addr)
 960                 return 1;
 961
 962         /*  Disable the board  */
 963         if (!nowayout)
 964                 pcwd_stop();
 965
 966         /* Deregister */
 967         misc_deregister(&pcwd_miscdev);
 968         if (pcwd_private.supports_temp)
 969                 misc_deregister(&temp_miscdev);
 970         release_region(pcwd_private.io_addr,
 971                         (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 972         pcwd_private.io_addr = 0x0000;
 973         cards_found--;
 974
 975         return 0;
 976 }
 977
 978 static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
 979 {
 980         if (debug >= DEBUG)
 981                 pr_debug("pcwd_isa_shutdown id=%d\n", id);
 982
 983         pcwd_stop();
 984 }
 985
 986 static struct isa_driver pcwd_isa_driver = {
 987         .match          = pcwd_isa_match,
 988         .probe          = pcwd_isa_probe,
 989         .remove         = pcwd_isa_remove,
 990         .shutdown       = pcwd_isa_shutdown,
 991         .driver         = {
 992                 .owner  = THIS_MODULE,
 993                 .name   = WATCHDOG_NAME,
 994         },
 995 };
 996
 997 module_isa_driver(pcwd_isa_driver, PCWD_ISA_NR_CARDS);
 998
 999 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, "
1000                 "Wim Van Sebroeck <wim@iguana.be>");
1001 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1002 MODULE_VERSION(WATCHDOG_VERSION);
1003 MODULE_LICENSE("GPL");