linux/drivers/watchdog/pcwd.c
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   1/*
   2 * PC Watchdog Driver
   3 * by Ken Hollis (khollis@bitgate.com)
   4 *
   5 * Permission granted from Simon Machell (smachell@berkprod.com)
   6 * Written for the Linux Kernel, and GPLed by Ken Hollis
   7 *
   8 * 960107       Added request_region routines, modulized the whole thing.
   9 * 960108       Fixed end-of-file pointer (Thanks to Dan Hollis), added
  10 *              WD_TIMEOUT define.
  11 * 960216       Added eof marker on the file, and changed verbose messages.
  12 * 960716       Made functional and cosmetic changes to the source for
  13 *              inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
  14 * 960717       Removed read/seek routines, replaced with ioctl.  Also, added
  15 *              check_region command due to Alan's suggestion.
  16 * 960821       Made changes to compile in newer 2.0.x kernels.  Added
  17 *              "cold reboot sense" entry.
  18 * 960825       Made a few changes to code, deleted some defines and made
  19 *              typedefs to replace them.  Made heartbeat reset only available
  20 *              via ioctl, and removed the write routine.
  21 * 960828       Added new items for PC Watchdog Rev.C card.
  22 * 960829       Changed around all of the IOCTLs, added new features,
  23 *              added watchdog disable/re-enable routines.  Added firmware
  24 *              version reporting.  Added read routine for temperature.
  25 *              Removed some extra defines, added an autodetect Revision
  26 *              routine.
  27 * 961006       Revised some documentation, fixed some cosmetic bugs.  Made
  28 *              drivers to panic the system if it's overheating at bootup.
  29 * 961118       Changed some verbiage on some of the output, tidied up
  30 *              code bits, and added compatibility to 2.1.x.
  31 * 970912       Enabled board on open and disable on close.
  32 * 971107       Took account of recent VFS changes (broke read).
  33 * 971210       Disable board on initialisation in case board already ticking.
  34 * 971222       Changed open/close for temperature handling
  35 *              Michael Meskes <meskes@debian.org>.
  36 * 980112       Used minor numbers from include/linux/miscdevice.h
  37 * 990403       Clear reset status after reading control status register in
  38 *              pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
  39 * 990605       Made changes to code to support Firmware 1.22a, added
  40 *              fairly useless proc entry.
  41 * 990610       removed said useless proc code for the merge <alan>
  42 * 000403       Removed last traces of proc code. <davej>
  43 * 011214       Added nowayout module option to override
  44 *              CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
  45 *              Added timeout module option to override default
  46 */
  47
  48/*
  49 *      A bells and whistles driver is available from http://www.pcwd.de/
  50 *      More info available at http://www.berkprod.com/ or
  51 *      http://www.pcwatchdog.com/
  52 */
  53
  54#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  55
  56#include <linux/module.h>       /* For module specific items */
  57#include <linux/moduleparam.h>  /* For new moduleparam's */
  58#include <linux/types.h>        /* For standard types (like size_t) */
  59#include <linux/errno.h>        /* For the -ENODEV/... values */
  60#include <linux/kernel.h>       /* For printk/panic/... */
  61#include <linux/delay.h>        /* For mdelay function */
  62#include <linux/timer.h>        /* For timer related operations */
  63#include <linux/jiffies.h>      /* For jiffies stuff */
  64#include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  65#include <linux/watchdog.h>     /* For the watchdog specific items */
  66#include <linux/reboot.h>       /* For kernel_power_off() */
  67#include <linux/init.h>         /* For __init/__exit/... */
  68#include <linux/fs.h>           /* For file operations */
  69#include <linux/isa.h>          /* For isa devices */
  70#include <linux/ioport.h>       /* For io-port access */
  71#include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  72#include <linux/uaccess.h>      /* For copy_to_user/put_user/... */
  73#include <linux/io.h>           /* For inb/outb/... */
  74
  75/* Module and version information */
  76#define WATCHDOG_VERSION "1.20"
  77#define WATCHDOG_DATE "18 Feb 2007"
  78#define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
  79#define WATCHDOG_NAME "pcwd"
  80#define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION "\n"
  81
  82/*
  83 * It should be noted that PCWD_REVISION_B was removed because A and B
  84 * are essentially the same types of card, with the exception that B
  85 * has temperature reporting.  Since I didn't receive a Rev.B card,
  86 * the Rev.B card is not supported.  (It's a good thing too, as they
  87 * are no longer in production.)
  88 */
  89#define PCWD_REVISION_A         1
  90#define PCWD_REVISION_C         2
  91
  92/*
  93 * These are the auto-probe addresses available.
  94 *
  95 * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
  96 * Revision A has an address range of 2 addresses, while Revision C has 4.
  97 */
  98#define PCWD_ISA_NR_CARDS       3
  99static 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 */
 148static 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 */
 168static int cards_found;
 169
 170/* internal variables */
 171static unsigned long open_allowed;
 172static char expect_close;
 173static int temp_panic;
 174
 175/* this is private data for each ISA-PC watchdog card */
 176static 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 */
 194static int debug = QUIET;
 195module_param(debug, int, 0);
 196MODULE_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
 201static int heartbeat = WATCHDOG_HEARTBEAT;
 202module_param(heartbeat, int, 0);
 203MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
 204        "(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
 205                                __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 206
 207static bool nowayout = WATCHDOG_NOWAYOUT;
 208module_param(nowayout, bool, 0);
 209MODULE_PARM_DESC(nowayout,
 210                "Watchdog cannot be stopped once started (default="
 211                                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 212
 213/*
 214 *      Internal functions
 215 */
 216
 217static int send_isa_command(int cmd)
 218{
 219        int i;
 220        int control_status;
 221        int port0, last_port0;  /* Double read for stabilising */
 222
 223        if (debug >= DEBUG)
 224                pr_debug("sending following data cmd=0x%02x\n", cmd);
 225
 226        /* The WCMD bit must be 1 and the command is only 4 bits in size */
 227        control_status = (cmd & 0x0F) | WD_WCMD;
 228        outb_p(control_status, pcwd_private.io_addr + 2);
 229        udelay(ISA_COMMAND_TIMEOUT);
 230
 231        port0 = inb_p(pcwd_private.io_addr);
 232        for (i = 0; i < 25; ++i) {
 233                last_port0 = port0;
 234                port0 = inb_p(pcwd_private.io_addr);
 235
 236                if (port0 == last_port0)
 237                        break;  /* Data is stable */
 238
 239                udelay(250);
 240        }
 241
 242        if (debug >= DEBUG)
 243                pr_debug("received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 244                         cmd, port0, last_port0);
 245
 246        return port0;
 247}
 248
 249static int set_command_mode(void)
 250{
 251        int i, found = 0, count = 0;
 252
 253        /* Set the card into command mode */
 254        spin_lock(&pcwd_private.io_lock);
 255        while ((!found) && (count < 3)) {
 256                i = send_isa_command(CMD_ISA_IDLE);
 257
 258                if (i == 0x00)
 259                        found = 1;
 260                else if (i == 0xF3) {
 261                        /* Card does not like what we've done to it */
 262                        outb_p(0x00, pcwd_private.io_addr + 2);
 263                        udelay(1200);   /* Spec says wait 1ms */
 264                        outb_p(0x00, pcwd_private.io_addr + 2);
 265                        udelay(ISA_COMMAND_TIMEOUT);
 266                }
 267                count++;
 268        }
 269        spin_unlock(&pcwd_private.io_lock);
 270        pcwd_private.command_mode = found;
 271
 272        if (debug >= DEBUG)
 273                pr_debug("command_mode=%d\n", pcwd_private.command_mode);
 274
 275        return found;
 276}
 277
 278static void unset_command_mode(void)
 279{
 280        /* Set the card into normal mode */
 281        spin_lock(&pcwd_private.io_lock);
 282        outb_p(0x00, pcwd_private.io_addr + 2);
 283        udelay(ISA_COMMAND_TIMEOUT);
 284        spin_unlock(&pcwd_private.io_lock);
 285
 286        pcwd_private.command_mode = 0;
 287
 288        if (debug >= DEBUG)
 289                pr_debug("command_mode=%d\n", pcwd_private.command_mode);
 290}
 291
 292static inline void pcwd_check_temperature_support(void)
 293{
 294        if (inb(pcwd_private.io_addr) != 0xF0)
 295                pcwd_private.supports_temp = 1;
 296}
 297
 298static inline void pcwd_get_firmware(void)
 299{
 300        int one, ten, hund, minor;
 301
 302        strcpy(pcwd_private.fw_ver_str, "ERROR");
 303
 304        if (set_command_mode()) {
 305                one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 306                ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 307                hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 308                minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 309                sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
 310                                        one, ten, hund, minor);
 311        }
 312        unset_command_mode();
 313
 314        return;
 315}
 316
 317static inline int pcwd_get_option_switches(void)
 318{
 319        int option_switches = 0;
 320
 321        if (set_command_mode()) {
 322                /* Get switch settings */
 323                option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 324        }
 325
 326        unset_command_mode();
 327        return option_switches;
 328}
 329
 330static void pcwd_show_card_info(void)
 331{
 332        int option_switches;
 333
 334        /* Get some extra info from the hardware (in command/debug/diag mode) */
 335        if (pcwd_private.revision == PCWD_REVISION_A)
 336                pr_info("ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
 337                        pcwd_private.io_addr);
 338        else if (pcwd_private.revision == PCWD_REVISION_C) {
 339                pcwd_get_firmware();
 340                pr_info("ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 341                        pcwd_private.io_addr, pcwd_private.fw_ver_str);
 342                option_switches = pcwd_get_option_switches();
 343                pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 344                        option_switches,
 345                        ((option_switches & 0x10) ? "ON" : "OFF"),
 346                        ((option_switches & 0x08) ? "ON" : "OFF"));
 347
 348                /* Reprogram internal heartbeat to 2 seconds */
 349                if (set_command_mode()) {
 350                        send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 351                        unset_command_mode();
 352                }
 353        }
 354
 355        if (pcwd_private.supports_temp)
 356                pr_info("Temperature Option Detected\n");
 357
 358        if (pcwd_private.boot_status & WDIOF_CARDRESET)
 359                pr_info("Previous reboot was caused by the card\n");
 360
 361        if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 362                pr_emerg("Card senses a CPU Overheat. Panicking!\n");
 363                pr_emerg("CPU Overheat\n");
 364        }
 365
 366        if (pcwd_private.boot_status == 0)
 367                pr_info("No previous trip detected - Cold boot or reset\n");
 368}
 369
 370static void pcwd_timer_ping(unsigned long data)
 371{
 372        int wdrst_stat;
 373
 374        /* If we got a heartbeat pulse within the WDT_INTERVAL
 375         * we agree to ping the WDT */
 376        if (time_before(jiffies, pcwd_private.next_heartbeat)) {
 377                /* Ping the watchdog */
 378                spin_lock(&pcwd_private.io_lock);
 379                if (pcwd_private.revision == PCWD_REVISION_A) {
 380                        /*  Rev A cards are reset by setting the
 381                            WD_WDRST bit in register 1 */
 382                        wdrst_stat = inb_p(pcwd_private.io_addr);
 383                        wdrst_stat &= 0x0F;
 384                        wdrst_stat |= WD_WDRST;
 385
 386                        outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 387                } else {
 388                        /* Re-trigger watchdog by writing to port 0 */
 389                        outb_p(0x00, pcwd_private.io_addr);
 390                }
 391
 392                /* Re-set the timer interval */
 393                mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 394
 395                spin_unlock(&pcwd_private.io_lock);
 396        } else {
 397                pr_warn("Heartbeat lost! Will not ping the watchdog\n");
 398        }
 399}
 400
 401static int pcwd_start(void)
 402{
 403        int stat_reg;
 404
 405        pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 406
 407        /* Start the timer */
 408        mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 409
 410        /* Enable the port */
 411        if (pcwd_private.revision == PCWD_REVISION_C) {
 412                spin_lock(&pcwd_private.io_lock);
 413                outb_p(0x00, pcwd_private.io_addr + 3);
 414                udelay(ISA_COMMAND_TIMEOUT);
 415                stat_reg = inb_p(pcwd_private.io_addr + 2);
 416                spin_unlock(&pcwd_private.io_lock);
 417                if (stat_reg & WD_WDIS) {
 418                        pr_info("Could not start watchdog\n");
 419                        return -EIO;
 420                }
 421        }
 422
 423        if (debug >= VERBOSE)
 424                pr_debug("Watchdog started\n");
 425
 426        return 0;
 427}
 428
 429static int pcwd_stop(void)
 430{
 431        int stat_reg;
 432
 433        /* Stop the timer */
 434        del_timer(&pcwd_private.timer);
 435
 436        /*  Disable the board  */
 437        if (pcwd_private.revision == PCWD_REVISION_C) {
 438                spin_lock(&pcwd_private.io_lock);
 439                outb_p(0xA5, pcwd_private.io_addr + 3);
 440                udelay(ISA_COMMAND_TIMEOUT);
 441                outb_p(0xA5, pcwd_private.io_addr + 3);
 442                udelay(ISA_COMMAND_TIMEOUT);
 443                stat_reg = inb_p(pcwd_private.io_addr + 2);
 444                spin_unlock(&pcwd_private.io_lock);
 445                if ((stat_reg & WD_WDIS) == 0) {
 446                        pr_info("Could not stop watchdog\n");
 447                        return -EIO;
 448                }
 449        }
 450
 451        if (debug >= VERBOSE)
 452                pr_debug("Watchdog stopped\n");
 453
 454        return 0;
 455}
 456
 457static int pcwd_keepalive(void)
 458{
 459        /* user land ping */
 460        pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 461
 462        if (debug >= DEBUG)
 463                pr_debug("Watchdog keepalive signal send\n");
 464
 465        return 0;
 466}
 467
 468static int pcwd_set_heartbeat(int t)
 469{
 470        if (t < 2 || t > 7200) /* arbitrary upper limit */
 471                return -EINVAL;
 472
 473        heartbeat = t;
 474
 475        if (debug >= VERBOSE)
 476                pr_debug("New heartbeat: %d\n", heartbeat);
 477
 478        return 0;
 479}
 480
 481static int pcwd_get_status(int *status)
 482{
 483        int control_status;
 484
 485        *status = 0;
 486        spin_lock(&pcwd_private.io_lock);
 487        if (pcwd_private.revision == PCWD_REVISION_A)
 488                /* Rev A cards return status information from
 489                 * the base register, which is used for the
 490                 * temperature in other cards. */
 491                control_status = inb(pcwd_private.io_addr);
 492        else {
 493                /* Rev C cards return card status in the base
 494                 * address + 1 register. And use different bits
 495                 * to indicate a card initiated reset, and an
 496                 * over-temperature condition. And the reboot
 497                 * status can be reset. */
 498                control_status = inb(pcwd_private.io_addr + 1);
 499        }
 500        spin_unlock(&pcwd_private.io_lock);
 501
 502        if (pcwd_private.revision == PCWD_REVISION_A) {
 503                if (control_status & WD_WDRST)
 504                        *status |= WDIOF_CARDRESET;
 505
 506                if (control_status & WD_T110) {
 507                        *status |= WDIOF_OVERHEAT;
 508                        if (temp_panic) {
 509                                pr_info("Temperature overheat trip!\n");
 510                                kernel_power_off();
 511                        }
 512                }
 513        } else {
 514                if (control_status & WD_REVC_WTRP)
 515                        *status |= WDIOF_CARDRESET;
 516
 517                if (control_status & WD_REVC_TTRP) {
 518                        *status |= WDIOF_OVERHEAT;
 519                        if (temp_panic) {
 520                                pr_info("Temperature overheat trip!\n");
 521                                kernel_power_off();
 522                        }
 523                }
 524        }
 525
 526        return 0;
 527}
 528
 529static int pcwd_clear_status(void)
 530{
 531        int control_status;
 532
 533        if (pcwd_private.revision == PCWD_REVISION_C) {
 534                spin_lock(&pcwd_private.io_lock);
 535
 536                if (debug >= VERBOSE)
 537                        pr_info("clearing watchdog trip status\n");
 538
 539                control_status = inb_p(pcwd_private.io_addr + 1);
 540
 541                if (debug >= DEBUG) {
 542                        pr_debug("status was: 0x%02x\n", control_status);
 543                        pr_debug("sending: 0x%02x\n",
 544                                 (control_status & WD_REVC_R2DS));
 545                }
 546
 547                /* clear reset status & Keep Relay 2 disable state as it is */
 548                outb_p((control_status & WD_REVC_R2DS),
 549                                                pcwd_private.io_addr + 1);
 550
 551                spin_unlock(&pcwd_private.io_lock);
 552        }
 553        return 0;
 554}
 555
 556static int pcwd_get_temperature(int *temperature)
 557{
 558        /* check that port 0 gives temperature info and no command results */
 559        if (pcwd_private.command_mode)
 560                return -1;
 561
 562        *temperature = 0;
 563        if (!pcwd_private.supports_temp)
 564                return -ENODEV;
 565
 566        /*
 567         * Convert celsius to fahrenheit, since this was
 568         * the decided 'standard' for this return value.
 569         */
 570        spin_lock(&pcwd_private.io_lock);
 571        *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 572        spin_unlock(&pcwd_private.io_lock);
 573
 574        if (debug >= DEBUG) {
 575                pr_debug("temperature is: %d F\n", *temperature);
 576        }
 577
 578        return 0;
 579}
 580
 581/*
 582 *      /dev/watchdog handling
 583 */
 584
 585static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 586{
 587        int rv;
 588        int status;
 589        int temperature;
 590        int new_heartbeat;
 591        int __user *argp = (int __user *)arg;
 592        static const struct watchdog_info ident = {
 593                .options =              WDIOF_OVERHEAT |
 594                                        WDIOF_CARDRESET |
 595                                        WDIOF_KEEPALIVEPING |
 596                                        WDIOF_SETTIMEOUT |
 597                                        WDIOF_MAGICCLOSE,
 598                .firmware_version =     1,
 599                .identity =             "PCWD",
 600        };
 601
 602        switch (cmd) {
 603        case WDIOC_GETSUPPORT:
 604                if (copy_to_user(argp, &ident, sizeof(ident)))
 605                        return -EFAULT;
 606                return 0;
 607
 608        case WDIOC_GETSTATUS:
 609                pcwd_get_status(&status);
 610                return put_user(status, argp);
 611
 612        case WDIOC_GETBOOTSTATUS:
 613                return put_user(pcwd_private.boot_status, argp);
 614
 615        case WDIOC_GETTEMP:
 616                if (pcwd_get_temperature(&temperature))
 617                        return -EFAULT;
 618
 619                return put_user(temperature, argp);
 620
 621        case WDIOC_SETOPTIONS:
 622                if (pcwd_private.revision == PCWD_REVISION_C) {
 623                        if (get_user(rv, argp))
 624                                return -EFAULT;
 625
 626                        if (rv & WDIOS_DISABLECARD) {
 627                                status = pcwd_stop();
 628                                if (status < 0)
 629                                        return status;
 630                        }
 631                        if (rv & WDIOS_ENABLECARD) {
 632                                status = pcwd_start();
 633                                if (status < 0)
 634                                        return status;
 635                        }
 636                        if (rv & WDIOS_TEMPPANIC)
 637                                temp_panic = 1;
 638                }
 639                return -EINVAL;
 640
 641        case WDIOC_KEEPALIVE:
 642                pcwd_keepalive();
 643                return 0;
 644
 645        case WDIOC_SETTIMEOUT:
 646                if (get_user(new_heartbeat, argp))
 647                        return -EFAULT;
 648
 649                if (pcwd_set_heartbeat(new_heartbeat))
 650                        return -EINVAL;
 651
 652                pcwd_keepalive();
 653                /* Fall */
 654
 655        case WDIOC_GETTIMEOUT:
 656                return put_user(heartbeat, argp);
 657
 658        default:
 659                return -ENOTTY;
 660        }
 661
 662        return 0;
 663}
 664
 665static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 666                          loff_t *ppos)
 667{
 668        if (len) {
 669                if (!nowayout) {
 670                        size_t i;
 671
 672                        /* In case it was set long ago */
 673                        expect_close = 0;
 674
 675                        for (i = 0; i != len; i++) {
 676                                char c;
 677
 678                                if (get_user(c, buf + i))
 679                                        return -EFAULT;
 680                                if (c == 'V')
 681                                        expect_close = 42;
 682                        }
 683                }
 684                pcwd_keepalive();
 685        }
 686        return len;
 687}
 688
 689static int pcwd_open(struct inode *inode, struct file *file)
 690{
 691        if (test_and_set_bit(0, &open_allowed))
 692                return -EBUSY;
 693        if (nowayout)
 694                __module_get(THIS_MODULE);
 695        /* Activate */
 696        pcwd_start();
 697        pcwd_keepalive();
 698        return nonseekable_open(inode, file);
 699}
 700
 701static int pcwd_close(struct inode *inode, struct file *file)
 702{
 703        if (expect_close == 42)
 704                pcwd_stop();
 705        else {
 706                pr_crit("Unexpected close, not stopping watchdog!\n");
 707                pcwd_keepalive();
 708        }
 709        expect_close = 0;
 710        clear_bit(0, &open_allowed);
 711        return 0;
 712}
 713
 714/*
 715 *      /dev/temperature handling
 716 */
 717
 718static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 719                         loff_t *ppos)
 720{
 721        int temperature;
 722
 723        if (pcwd_get_temperature(&temperature))
 724                return -EFAULT;
 725
 726        if (copy_to_user(buf, &temperature, 1))
 727                return -EFAULT;
 728
 729        return 1;
 730}
 731
 732static int pcwd_temp_open(struct inode *inode, struct file *file)
 733{
 734        if (!pcwd_private.supports_temp)
 735                return -ENODEV;
 736
 737        return nonseekable_open(inode, file);
 738}
 739
 740static int pcwd_temp_close(struct inode *inode, struct file *file)
 741{
 742        return 0;
 743}
 744
 745/*
 746 *      Kernel Interfaces
 747 */
 748
 749static const struct file_operations pcwd_fops = {
 750        .owner          = THIS_MODULE,
 751        .llseek         = no_llseek,
 752        .write          = pcwd_write,
 753        .unlocked_ioctl = pcwd_ioctl,
 754        .open           = pcwd_open,
 755        .release        = pcwd_close,
 756};
 757
 758static struct miscdevice pcwd_miscdev = {
 759        .minor =        WATCHDOG_MINOR,
 760        .name =         "watchdog",
 761        .fops =         &pcwd_fops,
 762};
 763
 764static const struct file_operations pcwd_temp_fops = {
 765        .owner          = THIS_MODULE,
 766        .llseek         = no_llseek,
 767        .read           = pcwd_temp_read,
 768        .open           = pcwd_temp_open,
 769        .release        = pcwd_temp_close,
 770};
 771
 772static struct miscdevice temp_miscdev = {
 773        .minor =        TEMP_MINOR,
 774        .name =         "temperature",
 775        .fops =         &pcwd_temp_fops,
 776};
 777
 778/*
 779 *      Init & exit routines
 780 */
 781
 782static inline int get_revision(void)
 783{
 784        int r = PCWD_REVISION_C;
 785
 786        spin_lock(&pcwd_private.io_lock);
 787        /* REV A cards use only 2 io ports; test
 788         * presumes a floating bus reads as 0xff. */
 789        if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 790            (inb(pcwd_private.io_addr + 3) == 0xFF))
 791                r = PCWD_REVISION_A;
 792        spin_unlock(&pcwd_private.io_lock);
 793
 794        return r;
 795}
 796
 797/*
 798 *  The ISA cards have a heartbeat bit in one of the registers, which
 799 *  register is card dependent.  The heartbeat bit is monitored, and if
 800 *  found, is considered proof that a Berkshire card has been found.
 801 *  The initial rate is once per second at board start up, then twice
 802 *  per second for normal operation.
 803 */
 804static int pcwd_isa_match(struct device *dev, unsigned int id)
 805{
 806        int base_addr = pcwd_ioports[id];
 807        int port0, last_port0;  /* Reg 0, in case it's REV A */
 808        int port1, last_port1;  /* Register 1 for REV C cards */
 809        int i;
 810        int retval;
 811
 812        if (debug >= DEBUG)
 813                pr_debug("pcwd_isa_match id=%d\n", id);
 814
 815        if (!request_region(base_addr, 4, "PCWD")) {
 816                pr_info("Port 0x%04x unavailable\n", base_addr);
 817                return 0;
 818        }
 819
 820        retval = 0;
 821
 822        port0 = inb_p(base_addr);       /* For REV A boards */
 823        port1 = inb_p(base_addr + 1);   /* For REV C boards */
 824        if (port0 != 0xff || port1 != 0xff) {
 825                /* Not an 'ff' from a floating bus, so must be a card! */
 826                for (i = 0; i < 4; ++i) {
 827
 828                        msleep(500);
 829
 830                        last_port0 = port0;
 831                        last_port1 = port1;
 832
 833                        port0 = inb_p(base_addr);
 834                        port1 = inb_p(base_addr + 1);
 835
 836                        /* Has either hearbeat bit changed?  */
 837                        if ((port0 ^ last_port0) & WD_HRTBT ||
 838                            (port1 ^ last_port1) & WD_REVC_HRBT) {
 839                                retval = 1;
 840                                break;
 841                        }
 842                }
 843        }
 844        release_region(base_addr, 4);
 845
 846        return retval;
 847}
 848
 849static int pcwd_isa_probe(struct device *dev, unsigned int id)
 850{
 851        int ret;
 852
 853        if (debug >= DEBUG)
 854                pr_debug("pcwd_isa_probe id=%d\n", id);
 855
 856        cards_found++;
 857        if (cards_found == 1)
 858                pr_info("v%s Ken Hollis (kenji@bitgate.com)\n",
 859                                                        WATCHDOG_VERSION);
 860
 861        if (cards_found > 1) {
 862                pr_err("This driver only supports 1 device\n");
 863                return -ENODEV;
 864        }
 865
 866        if (pcwd_ioports[id] == 0x0000) {
 867                pr_err("No I/O-Address for card detected\n");
 868                return -ENODEV;
 869        }
 870        pcwd_private.io_addr = pcwd_ioports[id];
 871
 872        spin_lock_init(&pcwd_private.io_lock);
 873
 874        /* Check card's revision */
 875        pcwd_private.revision = get_revision();
 876
 877        if (!request_region(pcwd_private.io_addr,
 878                (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 879                pr_err("I/O address 0x%04x already in use\n",
 880                       pcwd_private.io_addr);
 881                ret = -EIO;
 882                goto error_request_region;
 883        }
 884
 885        /* Initial variables */
 886        pcwd_private.supports_temp = 0;
 887        temp_panic = 0;
 888        pcwd_private.boot_status = 0x0000;
 889
 890        /* get the boot_status */
 891        pcwd_get_status(&pcwd_private.boot_status);
 892
 893        /* clear the "card caused reboot" flag */
 894        pcwd_clear_status();
 895
 896        setup_timer(&pcwd_private.timer, pcwd_timer_ping, 0);
 897
 898        /*  Disable the board  */
 899        pcwd_stop();
 900
 901        /*  Check whether or not the card supports the temperature device */
 902        pcwd_check_temperature_support();
 903
 904        /* Show info about the card itself */
 905        pcwd_show_card_info();
 906
 907        /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 908        if (heartbeat == 0)
 909                heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
 910
 911        /* Check that the heartbeat value is within it's range;
 912           if not reset to the default */
 913        if (pcwd_set_heartbeat(heartbeat)) {
 914                pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 915                pr_info("heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
 916                        WATCHDOG_HEARTBEAT);
 917        }
 918
 919        if (pcwd_private.supports_temp) {
 920                ret = misc_register(&temp_miscdev);
 921                if (ret) {
 922                        pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 923                               TEMP_MINOR, ret);
 924                        goto error_misc_register_temp;
 925                }
 926        }
 927
 928        ret = misc_register(&pcwd_miscdev);
 929        if (ret) {
 930                pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 931                       WATCHDOG_MINOR, ret);
 932                goto error_misc_register_watchdog;
 933        }
 934
 935        pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
 936                heartbeat, nowayout);
 937
 938        return 0;
 939
 940error_misc_register_watchdog:
 941        if (pcwd_private.supports_temp)
 942                misc_deregister(&temp_miscdev);
 943error_misc_register_temp:
 944        release_region(pcwd_private.io_addr,
 945                        (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 946error_request_region:
 947        pcwd_private.io_addr = 0x0000;
 948        cards_found--;
 949        return ret;
 950}
 951
 952static int pcwd_isa_remove(struct device *dev, unsigned int id)
 953{
 954        if (debug >= DEBUG)
 955                pr_debug("pcwd_isa_remove id=%d\n", id);
 956
 957        if (!pcwd_private.io_addr)
 958                return 1;
 959
 960        /*  Disable the board  */
 961        if (!nowayout)
 962                pcwd_stop();
 963
 964        /* Deregister */
 965        misc_deregister(&pcwd_miscdev);
 966        if (pcwd_private.supports_temp)
 967                misc_deregister(&temp_miscdev);
 968        release_region(pcwd_private.io_addr,
 969                        (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 970        pcwd_private.io_addr = 0x0000;
 971        cards_found--;
 972
 973        return 0;
 974}
 975
 976static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
 977{
 978        if (debug >= DEBUG)
 979                pr_debug("pcwd_isa_shutdown id=%d\n", id);
 980
 981        pcwd_stop();
 982}
 983
 984static struct isa_driver pcwd_isa_driver = {
 985        .match          = pcwd_isa_match,
 986        .probe          = pcwd_isa_probe,
 987        .remove         = pcwd_isa_remove,
 988        .shutdown       = pcwd_isa_shutdown,
 989        .driver         = {
 990                .owner  = THIS_MODULE,
 991                .name   = WATCHDOG_NAME,
 992        },
 993};
 994
 995static int __init pcwd_init_module(void)
 996{
 997        return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
 998}
 999
1000static void __exit pcwd_cleanup_module(void)
1001{
1002        isa_unregister_driver(&pcwd_isa_driver);
1003        pr_info("Watchdog Module Unloaded\n");
1004}
1005
1006module_init(pcwd_init_module);
1007module_exit(pcwd_cleanup_module);
1008
1009MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, "
1010                "Wim Van Sebroeck <wim@iguana.be>");
1011MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1012MODULE_VERSION(WATCHDOG_VERSION);
1013MODULE_LICENSE("GPL");
1014MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1015MODULE_ALIAS_MISCDEV(TEMP_MINOR);
1016
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