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#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 "\n"
  80
  81/*
  82 * It should be noted that PCWD_REVISION_B was removed because A and B
  83 * are essentially the same types of card, with the exception that B
  84 * has temperature reporting.  Since I didn't receive a Rev.B card,
  85 * the Rev.B card is not supported.  (It's a good thing too, as they
  86 * are no longer in production.)
  87 */
  88#define PCWD_REVISION_A         1
  89#define PCWD_REVISION_C         2
  90
  91/*
  92 * These are the auto-probe addresses available.
  93 *
  94 * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
  95 * Revision A has an address range of 2 addresses, while Revision C has 4.
  96 */
  97#define PCWD_ISA_NR_CARDS       3
  98static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
  99
 100/*
 101 * These are the defines that describe the control status bits for the
 102 * PCI-PC Watchdog card.
 103*/
 104/* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
 105#define WD_WDRST                0x01    /* Previously reset state */
 106#define WD_T110                 0x02    /* Temperature overheat sense */
 107#define WD_HRTBT                0x04    /* Heartbeat sense */
 108#define WD_RLY2                 0x08    /* External relay triggered */
 109#define WD_SRLY2                0x80    /* Software external relay triggered */
 110/* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 111#define WD_REVC_WTRP            0x01    /* Watchdog Trip status */
 112#define WD_REVC_HRBT            0x02    /* Watchdog Heartbeat */
 113#define WD_REVC_TTRP            0x04    /* Temperature Trip status */
 114#define WD_REVC_RL2A            0x08    /* Relay 2 activated by
 115                                                        on-board processor */
 116#define WD_REVC_RL1A            0x10    /* Relay 1 active */
 117#define WD_REVC_R2DS            0x40    /* Relay 2 disable */
 118#define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
 119/* Port 2 : Control Status #2 */
 120#define WD_WDIS                 0x10    /* Watchdog Disabled */
 121#define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 122#define WD_SSEL                 0x40    /* Watchdog Switch Select
 123                                                        (1:SW1 <-> 0:SW2) */
 124#define WD_WCMD                 0x80    /* Watchdog Command Mode */
 125
 126/* max. time we give an ISA watchdog card to process a command */
 127/* 500ms for each 4 bit response (according to spec.) */
 128#define ISA_COMMAND_TIMEOUT     1000
 129
 130/* Watchdog's internal commands */
 131#define CMD_ISA_IDLE                    0x00
 132#define CMD_ISA_VERSION_INTEGER         0x01
 133#define CMD_ISA_VERSION_TENTH           0x02
 134#define CMD_ISA_VERSION_HUNDRETH        0x03
 135#define CMD_ISA_VERSION_MINOR           0x04
 136#define CMD_ISA_SWITCH_SETTINGS         0x05
 137#define CMD_ISA_RESET_PC                0x06
 138#define CMD_ISA_ARM_0                   0x07
 139#define CMD_ISA_ARM_30                  0x08
 140#define CMD_ISA_ARM_60                  0x09
 141#define CMD_ISA_DELAY_TIME_2SECS        0x0A
 142#define CMD_ISA_DELAY_TIME_4SECS        0x0B
 143#define CMD_ISA_DELAY_TIME_8SECS        0x0C
 144#define CMD_ISA_RESET_RELAYS            0x0D
 145
 146/* Watchdog's Dip Switch heartbeat values */
 147static const int heartbeat_tbl[] = {
 148        20,     /* OFF-OFF-OFF  = 20 Sec  */
 149        40,     /* OFF-OFF-ON   = 40 Sec  */
 150        60,     /* OFF-ON-OFF   =  1 Min  */
 151        300,    /* OFF-ON-ON    =  5 Min  */
 152        600,    /* ON-OFF-OFF   = 10 Min  */
 153        1800,   /* ON-OFF-ON    = 30 Min  */
 154        3600,   /* ON-ON-OFF    =  1 Hour */
 155        7200,   /* ON-ON-ON     =  2 hour */
 156};
 157
 158/*
 159 * We are using an kernel timer to do the pinging of the watchdog
 160 * every ~500ms. We try to set the internal heartbeat of the
 161 * watchdog to 2 ms.
 162 */
 163
 164#define WDT_INTERVAL (HZ/2+1)
 165
 166/* We can only use 1 card due to the /dev/watchdog restriction */
 167static int cards_found;
 168
 169/* internal variables */
 170static unsigned long open_allowed;
 171static char expect_close;
 172static int temp_panic;
 173
 174/* this is private data for each ISA-PC watchdog card */
 175static struct {
 176        char fw_ver_str[6];             /* The cards firmware version */
 177        int revision;                   /* The card's revision */
 178        int supports_temp;              /* Whether or not the card has
 179                                                a temperature device */
 180        int command_mode;               /* Whether or not the card is in
 181                                                command mode */
 182        int boot_status;                /* The card's boot status */
 183        int io_addr;                    /* The cards I/O address */
 184        spinlock_t io_lock;             /* the lock for io operations */
 185        struct timer_list timer;        /* The timer that pings the watchdog */
 186        unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 187} pcwd_private;
 188
 189/* module parameters */
 190#define QUIET   0       /* Default */
 191#define VERBOSE 1       /* Verbose */
 192#define DEBUG   2       /* print fancy stuff too */
 193static int debug = QUIET;
 194module_param(debug, int, 0);
 195MODULE_PARM_DESC(debug,
 196                "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
 197
 198/* default heartbeat = delay-time from dip-switches */
 199#define WATCHDOG_HEARTBEAT 0
 200static int heartbeat = WATCHDOG_HEARTBEAT;
 201module_param(heartbeat, int, 0);
 202MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. "
 203        "(2 <= heartbeat <= 7200 or 0=delay-time from dip-switches, default="
 204                                __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 205
 206static int nowayout = WATCHDOG_NOWAYOUT;
 207module_param(nowayout, int, 0);
 208MODULE_PARM_DESC(nowayout,
 209                "Watchdog cannot be stopped once started (default="
 210                                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 211
 212/*
 213 *      Internal functions
 214 */
 215
 216static int send_isa_command(int cmd)
 217{
 218        int i;
 219        int control_status;
 220        int port0, last_port0;  /* Double read for stabilising */
 221
 222        if (debug >= DEBUG)
 223                printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
 224                        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                printk(KERN_DEBUG PFX "received following data for "
 244                        "cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 245                        cmd, port0, last_port0);
 246
 247        return port0;
 248}
 249
 250static 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                printk(KERN_DEBUG PFX "command_mode=%d\n",
 275                                pcwd_private.command_mode);
 276
 277        return found;
 278}
 279
 280static void unset_command_mode(void)
 281{
 282        /* Set the card into normal mode */
 283        spin_lock(&pcwd_private.io_lock);
 284        outb_p(0x00, pcwd_private.io_addr + 2);
 285        udelay(ISA_COMMAND_TIMEOUT);
 286        spin_unlock(&pcwd_private.io_lock);
 287
 288        pcwd_private.command_mode = 0;
 289
 290        if (debug >= DEBUG)
 291                printk(KERN_DEBUG PFX "command_mode=%d\n",
 292                                pcwd_private.command_mode);
 293}
 294
 295static inline void pcwd_check_temperature_support(void)
 296{
 297        if (inb(pcwd_private.io_addr) != 0xF0)
 298                pcwd_private.supports_temp = 1;
 299}
 300
 301static inline void pcwd_get_firmware(void)
 302{
 303        int one, ten, hund, minor;
 304
 305        strcpy(pcwd_private.fw_ver_str, "ERROR");
 306
 307        if (set_command_mode()) {
 308                one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 309                ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 310                hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 311                minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 312                sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c",
 313                                        one, ten, hund, minor);
 314        }
 315        unset_command_mode();
 316
 317        return;
 318}
 319
 320static inline int pcwd_get_option_switches(void)
 321{
 322        int option_switches = 0;
 323
 324        if (set_command_mode()) {
 325                /* Get switch settings */
 326                option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 327        }
 328
 329        unset_command_mode();
 330        return option_switches;
 331}
 332
 333static void pcwd_show_card_info(void)
 334{
 335        int option_switches;
 336
 337        /* Get some extra info from the hardware (in command/debug/diag mode) */
 338        if (pcwd_private.revision == PCWD_REVISION_A)
 339                printk(KERN_INFO PFX
 340                        "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n",
 341                                                        pcwd_private.io_addr);
 342        else if (pcwd_private.revision == PCWD_REVISION_C) {
 343                pcwd_get_firmware();
 344                printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port "
 345                        "0x%04x (Firmware version: %s)\n",
 346                        pcwd_private.io_addr, pcwd_private.fw_ver_str);
 347                option_switches = pcwd_get_option_switches();
 348                printk(KERN_INFO PFX "Option switches (0x%02x): "
 349                        "Temperature Reset Enable=%s, Power On Delay=%s\n",
 350                        option_switches,
 351                        ((option_switches & 0x10) ? "ON" : "OFF"),
 352                        ((option_switches & 0x08) ? "ON" : "OFF"));
 353
 354                /* Reprogram internal heartbeat to 2 seconds */
 355                if (set_command_mode()) {
 356                        send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 357                        unset_command_mode();
 358                }
 359        }
 360
 361        if (pcwd_private.supports_temp)
 362                printk(KERN_INFO PFX "Temperature Option Detected\n");
 363
 364        if (pcwd_private.boot_status & WDIOF_CARDRESET)
 365                printk(KERN_INFO PFX
 366                        "Previous reboot was caused by the card\n");
 367
 368        if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 369                printk(KERN_EMERG PFX
 370                        "Card senses a CPU Overheat. Panicking!\n");
 371                printk(KERN_EMERG PFX
 372                        "CPU Overheat\n");
 373        }
 374
 375        if (pcwd_private.boot_status == 0)
 376                printk(KERN_INFO PFX
 377                        "No previous trip detected - Cold boot or reset\n");
 378}
 379
 380static void pcwd_timer_ping(unsigned long data)
 381{
 382        int wdrst_stat;
 383
 384        /* If we got a heartbeat pulse within the WDT_INTERVAL
 385         * we agree to ping the WDT */
 386        if (time_before(jiffies, pcwd_private.next_heartbeat)) {
 387                /* Ping the watchdog */
 388                spin_lock(&pcwd_private.io_lock);
 389                if (pcwd_private.revision == PCWD_REVISION_A) {
 390                        /*  Rev A cards are reset by setting the
 391                            WD_WDRST bit in register 1 */
 392                        wdrst_stat = inb_p(pcwd_private.io_addr);
 393                        wdrst_stat &= 0x0F;
 394                        wdrst_stat |= WD_WDRST;
 395
 396                        outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 397                } else {
 398                        /* Re-trigger watchdog by writing to port 0 */
 399                        outb_p(0x00, pcwd_private.io_addr);
 400                }
 401
 402                /* Re-set the timer interval */
 403                mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 404
 405                spin_unlock(&pcwd_private.io_lock);
 406        } else {
 407                printk(KERN_WARNING PFX
 408                        "Heartbeat lost! Will not ping the watchdog\n");
 409        }
 410}
 411
 412static int pcwd_start(void)
 413{
 414        int stat_reg;
 415
 416        pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 417
 418        /* Start the timer */
 419        mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 420
 421        /* Enable the port */
 422        if (pcwd_private.revision == PCWD_REVISION_C) {
 423                spin_lock(&pcwd_private.io_lock);
 424                outb_p(0x00, pcwd_private.io_addr + 3);
 425                udelay(ISA_COMMAND_TIMEOUT);
 426                stat_reg = inb_p(pcwd_private.io_addr + 2);
 427                spin_unlock(&pcwd_private.io_lock);
 428                if (stat_reg & WD_WDIS) {
 429                        printk(KERN_INFO PFX "Could not start watchdog\n");
 430                        return -EIO;
 431                }
 432        }
 433
 434        if (debug >= VERBOSE)
 435                printk(KERN_DEBUG PFX "Watchdog started\n");
 436
 437        return 0;
 438}
 439
 440static int pcwd_stop(void)
 441{
 442        int stat_reg;
 443
 444        /* Stop the timer */
 445        del_timer(&pcwd_private.timer);
 446
 447        /*  Disable the board  */
 448        if (pcwd_private.revision == PCWD_REVISION_C) {
 449                spin_lock(&pcwd_private.io_lock);
 450                outb_p(0xA5, pcwd_private.io_addr + 3);
 451                udelay(ISA_COMMAND_TIMEOUT);
 452                outb_p(0xA5, pcwd_private.io_addr + 3);
 453                udelay(ISA_COMMAND_TIMEOUT);
 454                stat_reg = inb_p(pcwd_private.io_addr + 2);
 455                spin_unlock(&pcwd_private.io_lock);
 456                if ((stat_reg & WD_WDIS) == 0) {
 457                        printk(KERN_INFO PFX "Could not stop watchdog\n");
 458                        return -EIO;
 459                }
 460        }
 461
 462        if (debug >= VERBOSE)
 463                printk(KERN_DEBUG PFX "Watchdog stopped\n");
 464
 465        return 0;
 466}
 467
 468static int pcwd_keepalive(void)
 469{
 470        /* user land ping */
 471        pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 472
 473        if (debug >= DEBUG)
 474                printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
 475
 476        return 0;
 477}
 478
 479static int pcwd_set_heartbeat(int t)
 480{
 481        if (t < 2 || t > 7200) /* arbitrary upper limit */
 482                return -EINVAL;
 483
 484        heartbeat = t;
 485
 486        if (debug >= VERBOSE)
 487                printk(KERN_DEBUG PFX "New heartbeat: %d\n",
 488                       heartbeat);
 489
 490        return 0;
 491}
 492
 493static int pcwd_get_status(int *status)
 494{
 495        int control_status;
 496
 497        *status = 0;
 498        spin_lock(&pcwd_private.io_lock);
 499        if (pcwd_private.revision == PCWD_REVISION_A)
 500                /* Rev A cards return status information from
 501                 * the base register, which is used for the
 502                 * temperature in other cards. */
 503                control_status = inb(pcwd_private.io_addr);
 504        else {
 505                /* Rev C cards return card status in the base
 506                 * address + 1 register. And use different bits
 507                 * to indicate a card initiated reset, and an
 508                 * over-temperature condition. And the reboot
 509                 * status can be reset. */
 510                control_status = inb(pcwd_private.io_addr + 1);
 511        }
 512        spin_unlock(&pcwd_private.io_lock);
 513
 514        if (pcwd_private.revision == PCWD_REVISION_A) {
 515                if (control_status & WD_WDRST)
 516                        *status |= WDIOF_CARDRESET;
 517
 518                if (control_status & WD_T110) {
 519                        *status |= WDIOF_OVERHEAT;
 520                        if (temp_panic) {
 521                                printk(KERN_INFO PFX
 522                                        "Temperature overheat trip!\n");
 523                                kernel_power_off();
 524                        }
 525                }
 526        } else {
 527                if (control_status & WD_REVC_WTRP)
 528                        *status |= WDIOF_CARDRESET;
 529
 530                if (control_status & WD_REVC_TTRP) {
 531                        *status |= WDIOF_OVERHEAT;
 532                        if (temp_panic) {
 533                                printk(KERN_INFO PFX
 534                                        "Temperature overheat trip!\n");
 535                                kernel_power_off();
 536                        }
 537                }
 538        }
 539
 540        return 0;
 541}
 542
 543static int pcwd_clear_status(void)
 544{
 545        int control_status;
 546
 547        if (pcwd_private.revision == PCWD_REVISION_C) {
 548                spin_lock(&pcwd_private.io_lock);
 549
 550                if (debug >= VERBOSE)
 551                        printk(KERN_INFO PFX
 552                                        "clearing watchdog trip status\n");
 553
 554                control_status = inb_p(pcwd_private.io_addr + 1);
 555
 556                if (debug >= DEBUG) {
 557                        printk(KERN_DEBUG PFX "status was: 0x%02x\n",
 558                                control_status);
 559                        printk(KERN_DEBUG PFX "sending: 0x%02x\n",
 560                                (control_status & WD_REVC_R2DS));
 561                }
 562
 563                /* clear reset status & Keep Relay 2 disable state as it is */
 564                outb_p((control_status & WD_REVC_R2DS),
 565                                                pcwd_private.io_addr + 1);
 566
 567                spin_unlock(&pcwd_private.io_lock);
 568        }
 569        return 0;
 570}
 571
 572static int pcwd_get_temperature(int *temperature)
 573{
 574        /* check that port 0 gives temperature info and no command results */
 575        if (pcwd_private.command_mode)
 576                return -1;
 577
 578        *temperature = 0;
 579        if (!pcwd_private.supports_temp)
 580                return -ENODEV;
 581
 582        /*
 583         * Convert celsius to fahrenheit, since this was
 584         * the decided 'standard' for this return value.
 585         */
 586        spin_lock(&pcwd_private.io_lock);
 587        *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 588        spin_unlock(&pcwd_private.io_lock);
 589
 590        if (debug >= DEBUG) {
 591                printk(KERN_DEBUG PFX "temperature is: %d F\n",
 592                        *temperature);
 593        }
 594
 595        return 0;
 596}
 597
 598/*
 599 *      /dev/watchdog handling
 600 */
 601
 602static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 603{
 604        int rv;
 605        int status;
 606        int temperature;
 607        int new_heartbeat;
 608        int __user *argp = (int __user *)arg;
 609        static const struct watchdog_info ident = {
 610                .options =              WDIOF_OVERHEAT |
 611                                        WDIOF_CARDRESET |
 612                                        WDIOF_KEEPALIVEPING |
 613                                        WDIOF_SETTIMEOUT |
 614                                        WDIOF_MAGICCLOSE,
 615                .firmware_version =     1,
 616                .identity =             "PCWD",
 617        };
 618
 619        switch (cmd) {
 620        case WDIOC_GETSUPPORT:
 621                if (copy_to_user(argp, &ident, sizeof(ident)))
 622                        return -EFAULT;
 623                return 0;
 624
 625        case WDIOC_GETSTATUS:
 626                pcwd_get_status(&status);
 627                return put_user(status, argp);
 628
 629        case WDIOC_GETBOOTSTATUS:
 630                return put_user(pcwd_private.boot_status, argp);
 631
 632        case WDIOC_GETTEMP:
 633                if (pcwd_get_temperature(&temperature))
 634                        return -EFAULT;
 635
 636                return put_user(temperature, argp);
 637
 638        case WDIOC_SETOPTIONS:
 639                if (pcwd_private.revision == PCWD_REVISION_C) {
 640                        if (get_user(rv, argp))
 641                                return -EFAULT;
 642
 643                        if (rv & WDIOS_DISABLECARD) {
 644                                status = pcwd_stop();
 645                                if (status < 0)
 646                                        return status;
 647                        }
 648                        if (rv & WDIOS_ENABLECARD) {
 649                                status = pcwd_start();
 650                                if (status < 0)
 651                                        return status;
 652                        }
 653                        if (rv & WDIOS_TEMPPANIC)
 654                                temp_panic = 1;
 655                }
 656                return -EINVAL;
 657
 658        case WDIOC_KEEPALIVE:
 659                pcwd_keepalive();
 660                return 0;
 661
 662        case WDIOC_SETTIMEOUT:
 663                if (get_user(new_heartbeat, argp))
 664                        return -EFAULT;
 665
 666                if (pcwd_set_heartbeat(new_heartbeat))
 667                        return -EINVAL;
 668
 669                pcwd_keepalive();
 670                /* Fall */
 671
 672        case WDIOC_GETTIMEOUT:
 673                return put_user(heartbeat, argp);
 674
 675        default:
 676                return -ENOTTY;
 677        }
 678
 679        return 0;
 680}
 681
 682static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 683                          loff_t *ppos)
 684{
 685        if (len) {
 686                if (!nowayout) {
 687                        size_t i;
 688
 689                        /* In case it was set long ago */
 690                        expect_close = 0;
 691
 692                        for (i = 0; i != len; i++) {
 693                                char c;
 694
 695                                if (get_user(c, buf + i))
 696                                        return -EFAULT;
 697                                if (c == 'V')
 698                                        expect_close = 42;
 699                        }
 700                }
 701                pcwd_keepalive();
 702        }
 703        return len;
 704}
 705
 706static int pcwd_open(struct inode *inode, struct file *file)
 707{
 708        if (test_and_set_bit(0, &open_allowed))
 709                return -EBUSY;
 710        if (nowayout)
 711                __module_get(THIS_MODULE);
 712        /* Activate */
 713        pcwd_start();
 714        pcwd_keepalive();
 715        return nonseekable_open(inode, file);
 716}
 717
 718static int pcwd_close(struct inode *inode, struct file *file)
 719{
 720        if (expect_close == 42)
 721                pcwd_stop();
 722        else {
 723                printk(KERN_CRIT PFX
 724                        "Unexpected close, not stopping watchdog!\n");
 725                pcwd_keepalive();
 726        }
 727        expect_close = 0;
 728        clear_bit(0, &open_allowed);
 729        return 0;
 730}
 731
 732/*
 733 *      /dev/temperature handling
 734 */
 735
 736static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 737                         loff_t *ppos)
 738{
 739        int temperature;
 740
 741        if (pcwd_get_temperature(&temperature))
 742                return -EFAULT;
 743
 744        if (copy_to_user(buf, &temperature, 1))
 745                return -EFAULT;
 746
 747        return 1;
 748}
 749
 750static int pcwd_temp_open(struct inode *inode, struct file *file)
 751{
 752        if (!pcwd_private.supports_temp)
 753                return -ENODEV;
 754
 755        return nonseekable_open(inode, file);
 756}
 757
 758static int pcwd_temp_close(struct inode *inode, struct file *file)
 759{
 760        return 0;
 761}
 762
 763/*
 764 *      Kernel Interfaces
 765 */
 766
 767static const struct file_operations pcwd_fops = {
 768        .owner          = THIS_MODULE,
 769        .llseek         = no_llseek,
 770        .write          = pcwd_write,
 771        .unlocked_ioctl = pcwd_ioctl,
 772        .open           = pcwd_open,
 773        .release        = pcwd_close,
 774};
 775
 776static struct miscdevice pcwd_miscdev = {
 777        .minor =        WATCHDOG_MINOR,
 778        .name =         "watchdog",
 779        .fops =         &pcwd_fops,
 780};
 781
 782static const struct file_operations pcwd_temp_fops = {
 783        .owner          = THIS_MODULE,
 784        .llseek         = no_llseek,
 785        .read           = pcwd_temp_read,
 786        .open           = pcwd_temp_open,
 787        .release        = pcwd_temp_close,
 788};
 789
 790static struct miscdevice temp_miscdev = {
 791        .minor =        TEMP_MINOR,
 792        .name =         "temperature",
 793        .fops =         &pcwd_temp_fops,
 794};
 795
 796/*
 797 *      Init & exit routines
 798 */
 799
 800static inline int get_revision(void)
 801{
 802        int r = PCWD_REVISION_C;
 803
 804        spin_lock(&pcwd_private.io_lock);
 805        /* REV A cards use only 2 io ports; test
 806         * presumes a floating bus reads as 0xff. */
 807        if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 808            (inb(pcwd_private.io_addr + 3) == 0xFF))
 809                r = PCWD_REVISION_A;
 810        spin_unlock(&pcwd_private.io_lock);
 811
 812        return r;
 813}
 814
 815/*
 816 *  The ISA cards have a heartbeat bit in one of the registers, which
 817 *  register is card dependent.  The heartbeat bit is monitored, and if
 818 *  found, is considered proof that a Berkshire card has been found.
 819 *  The initial rate is once per second at board start up, then twice
 820 *  per second for normal operation.
 821 */
 822static int __devinit pcwd_isa_match(struct device *dev, unsigned int id)
 823{
 824        int base_addr = pcwd_ioports[id];
 825        int port0, last_port0;  /* Reg 0, in case it's REV A */
 826        int port1, last_port1;  /* Register 1 for REV C cards */
 827        int i;
 828        int retval;
 829
 830        if (debug >= DEBUG)
 831                printk(KERN_DEBUG PFX "pcwd_isa_match id=%d\n",
 832                        id);
 833
 834        if (!request_region(base_addr, 4, "PCWD")) {
 835                printk(KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 836                return 0;
 837        }
 838
 839        retval = 0;
 840
 841        port0 = inb_p(base_addr);       /* For REV A boards */
 842        port1 = inb_p(base_addr + 1);   /* For REV C boards */
 843        if (port0 != 0xff || port1 != 0xff) {
 844                /* Not an 'ff' from a floating bus, so must be a card! */
 845                for (i = 0; i < 4; ++i) {
 846
 847                        msleep(500);
 848
 849                        last_port0 = port0;
 850                        last_port1 = port1;
 851
 852                        port0 = inb_p(base_addr);
 853                        port1 = inb_p(base_addr + 1);
 854
 855                        /* Has either hearbeat bit changed?  */
 856                        if ((port0 ^ last_port0) & WD_HRTBT ||
 857                            (port1 ^ last_port1) & WD_REVC_HRBT) {
 858                                retval = 1;
 859                                break;
 860                        }
 861                }
 862        }
 863        release_region(base_addr, 4);
 864
 865        return retval;
 866}
 867
 868static int __devinit pcwd_isa_probe(struct device *dev, unsigned int id)
 869{
 870        int ret;
 871
 872        if (debug >= DEBUG)
 873                printk(KERN_DEBUG PFX "pcwd_isa_probe id=%d\n",
 874                        id);
 875
 876        cards_found++;
 877        if (cards_found == 1)
 878                printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n",
 879                                                        WATCHDOG_VERSION);
 880
 881        if (cards_found > 1) {
 882                printk(KERN_ERR PFX "This driver only supports 1 device\n");
 883                return -ENODEV;
 884        }
 885
 886        if (pcwd_ioports[id] == 0x0000) {
 887                printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 888                return -ENODEV;
 889        }
 890        pcwd_private.io_addr = pcwd_ioports[id];
 891
 892        spin_lock_init(&pcwd_private.io_lock);
 893
 894        /* Check card's revision */
 895        pcwd_private.revision = get_revision();
 896
 897        if (!request_region(pcwd_private.io_addr,
 898                (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 899                printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 900                        pcwd_private.io_addr);
 901                ret = -EIO;
 902                goto error_request_region;
 903        }
 904
 905        /* Initial variables */
 906        pcwd_private.supports_temp = 0;
 907        temp_panic = 0;
 908        pcwd_private.boot_status = 0x0000;
 909
 910        /* get the boot_status */
 911        pcwd_get_status(&pcwd_private.boot_status);
 912
 913        /* clear the "card caused reboot" flag */
 914        pcwd_clear_status();
 915
 916        setup_timer(&pcwd_private.timer, pcwd_timer_ping, 0);
 917
 918        /*  Disable the board  */
 919        pcwd_stop();
 920
 921        /*  Check whether or not the card supports the temperature device */
 922        pcwd_check_temperature_support();
 923
 924        /* Show info about the card itself */
 925        pcwd_show_card_info();
 926
 927        /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 928        if (heartbeat == 0)
 929                heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
 930
 931        /* Check that the heartbeat value is within it's range;
 932           if not reset to the default */
 933        if (pcwd_set_heartbeat(heartbeat)) {
 934                pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 935                printk(KERN_INFO PFX
 936                  "heartbeat value must be 2 <= heartbeat <= 7200, using %d\n",
 937                                                        WATCHDOG_HEARTBEAT);
 938        }
 939
 940        if (pcwd_private.supports_temp) {
 941                ret = misc_register(&temp_miscdev);
 942                if (ret) {
 943                        printk(KERN_ERR PFX
 944                            "cannot register miscdev on minor=%d (err=%d)\n",
 945                                                        TEMP_MINOR, ret);
 946                        goto error_misc_register_temp;
 947                }
 948        }
 949
 950        ret = misc_register(&pcwd_miscdev);
 951        if (ret) {
 952                printk(KERN_ERR PFX
 953                        "cannot register miscdev on minor=%d (err=%d)\n",
 954                                        WATCHDOG_MINOR, ret);
 955                goto error_misc_register_watchdog;
 956        }
 957
 958        printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 959                heartbeat, nowayout);
 960
 961        return 0;
 962
 963error_misc_register_watchdog:
 964        if (pcwd_private.supports_temp)
 965                misc_deregister(&temp_miscdev);
 966error_misc_register_temp:
 967        release_region(pcwd_private.io_addr,
 968                        (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 969error_request_region:
 970        pcwd_private.io_addr = 0x0000;
 971        cards_found--;
 972        return ret;
 973}
 974
 975static int __devexit pcwd_isa_remove(struct device *dev, unsigned int id)
 976{
 977        if (debug >= DEBUG)
 978                printk(KERN_DEBUG PFX "pcwd_isa_remove id=%d\n",
 979                        id);
 980
 981        if (!pcwd_private.io_addr)
 982                return 1;
 983
 984        /*  Disable the board  */
 985        if (!nowayout)
 986                pcwd_stop();
 987
 988        /* Deregister */
 989        misc_deregister(&pcwd_miscdev);
 990        if (pcwd_private.supports_temp)
 991                misc_deregister(&temp_miscdev);
 992        release_region(pcwd_private.io_addr,
 993                        (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 994        pcwd_private.io_addr = 0x0000;
 995        cards_found--;
 996
 997        return 0;
 998}
 999
1000static void pcwd_isa_shutdown(struct device *dev, unsigned int id)
1001{
1002        if (debug >= DEBUG)
1003                printk(KERN_DEBUG PFX "pcwd_isa_shutdown id=%d\n",
1004                        id);
1005
1006        pcwd_stop();
1007}
1008
1009static struct isa_driver pcwd_isa_driver = {
1010        .match          = pcwd_isa_match,
1011        .probe          = pcwd_isa_probe,
1012        .remove         = __devexit_p(pcwd_isa_remove),
1013        .shutdown       = pcwd_isa_shutdown,
1014        .driver         = {
1015                .owner  = THIS_MODULE,
1016                .name   = WATCHDOG_NAME,
1017        },
1018};
1019
1020static int __init pcwd_init_module(void)
1021{
1022        return isa_register_driver(&pcwd_isa_driver, PCWD_ISA_NR_CARDS);
1023}
1024
1025static void __exit pcwd_cleanup_module(void)
1026{
1027        isa_unregister_driver(&pcwd_isa_driver);
1028        printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1029}
1030
1031module_init(pcwd_init_module);
1032module_exit(pcwd_cleanup_module);
1033
1034MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>, "
1035                "Wim Van Sebroeck <wim@iguana.be>");
1036MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1037MODULE_VERSION(WATCHDOG_VERSION);
1038MODULE_LICENSE("GPL");
1039MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1040MODULE_ALIAS_MISCDEV(TEMP_MINOR);
1041