drivers/char/watchdog/pcwd.c

   1 /*
   2  * PC Watchdog Driver
   3  * by Ken Hollis (khollis@bitgate.com)
   4  *
   5  * Permission granted from Simon Machell (73244.1270@compuserve.com)
   6  * Written for the Linux Kernel, and GPLed by Ken Hollis
   7  *
   8  * 960107       Added request_region routines, modulized the whole thing.
   9  * 960108       Fixed end-of-file pointer (Thanks to Dan Hollis), added
  10  *              WD_TIMEOUT define.
  11  * 960216       Added eof marker on the file, and changed verbose messages.
  12  * 960716       Made functional and cosmetic changes to the source for
  13  *              inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
  14  * 960717       Removed read/seek routines, replaced with ioctl.  Also, added
  15  *              check_region command due to Alan's suggestion.
  16  * 960821       Made changes to compile in newer 2.0.x kernels.  Added
  17  *              "cold reboot sense" entry.
  18  * 960825       Made a few changes to code, deleted some defines and made
  19  *              typedefs to replace them.  Made heartbeat reset only available
  20  *              via ioctl, and removed the write routine.
  21  * 960828       Added new items for PC Watchdog Rev.C card.
  22  * 960829       Changed around all of the IOCTLs, added new features,
  23  *              added watchdog disable/re-enable routines.  Added firmware
  24  *              version reporting.  Added read routine for temperature.
  25  *              Removed some extra defines, added an autodetect Revision
  26  *              routine.
  27  * 961006       Revised some documentation, fixed some cosmetic bugs.  Made
  28  *              drivers to panic the system if it's overheating at bootup.
  29  * 961118       Changed some verbiage on some of the output, tidied up
  30  *              code bits, and added compatibility to 2.1.x.
  31  * 970912       Enabled board on open and disable on close.
  32  * 971107       Took account of recent VFS changes (broke read).
  33  * 971210       Disable board on initialisation in case board already ticking.
  34  * 971222       Changed open/close for temperature handling
  35  *              Michael Meskes <meskes@debian.org>.
  36  * 980112       Used minor numbers from include/linux/miscdevice.h
  37  * 990403       Clear reset status after reading control status register in
  38  *              pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
  39  * 990605       Made changes to code to support Firmware 1.22a, added
  40  *              fairly useless proc entry.
  41  * 990610       removed said useless proc code for the merge <alan>
  42  * 000403       Removed last traces of proc code. <davej>
  43  * 011214       Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT <Matt_Domsch@dell.com>
  44  *              Added timeout module option to override default
  45  */
  46
  47 /*
  48  *      A bells and whistles driver is available from http://www.pcwd.de/
  49  *      More info available at http://www.berkprod.com/ or http://www.pcwatchdog.com/
  50  */
  51
  52 #include <linux/config.h>       /* For CONFIG_WATCHDOG_NOWAYOUT/... */
  53 #include <linux/module.h>       /* For module specific items */
  54 #include <linux/moduleparam.h>  /* For new moduleparam's */
  55 #include <linux/types.h>        /* For standard types (like size_t) */
  56 #include <linux/errno.h>        /* For the -ENODEV/... values */
  57 #include <linux/kernel.h>       /* For printk/panic/... */
  58 #include <linux/delay.h>        /* For mdelay function */
  59 #include <linux/timer.h>        /* For timer related operations */
  60 #include <linux/jiffies.h>      /* For jiffies stuff */
  61 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  62 #include <linux/watchdog.h>     /* For the watchdog specific items */
  63 #include <linux/notifier.h>     /* For notifier support */
  64 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  65 #include <linux/init.h>         /* For __init/__exit/... */
  66 #include <linux/fs.h>           /* For file operations */
  67 #include <linux/ioport.h>       /* For io-port access */
  68 #include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  69 #include <linux/sched.h>        /* TASK_INTERRUPTIBLE, set_current_state() and friends */
  70 #include <linux/slab.h>         /* For kmalloc */
  71
  72 #include <asm/uaccess.h>        /* For copy_to_user/put_user/... */
  73 #include <asm/io.h>             /* For inb/outb/... */
  74
  75 /* Module and version information */
  76 #define WATCHDOG_VERSION "1.17"
  77 #define WATCHDOG_DATE "12 Feb 2006"
  78 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
  79 #define WATCHDOG_NAME "pcwd"
  80 #define PFX WATCHDOG_NAME ": "
  81 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION " (" WATCHDOG_DATE ")\n"
  82 #define WD_VER WATCHDOG_VERSION " (" WATCHDOG_DATE ")"
  83
  84 /*
  85  * It should be noted that PCWD_REVISION_B was removed because A and B
  86  * are essentially the same types of card, with the exception that B
  87  * has temperature reporting.  Since I didn't receive a Rev.B card,
  88  * the Rev.B card is not supported.  (It's a good thing too, as they
  89  * are no longer in production.)
  90  */
  91 #define PCWD_REVISION_A         1
  92 #define PCWD_REVISION_C         2
  93
  94 /*
  95  * These are the defines that describe the control status bits for the
  96  * PCI-PC Watchdog card.
  97 */
  98 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
  99 #define WD_WDRST                0x01    /* Previously reset state */
 100 #define WD_T110                 0x02    /* Temperature overheat sense */
 101 #define WD_HRTBT                0x04    /* Heartbeat sense */
 102 #define WD_RLY2                 0x08    /* External relay triggered */
 103 #define WD_SRLY2                0x80    /* Software external relay triggered */
 104 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 105 #define WD_REVC_WTRP            0x01    /* Watchdog Trip status */
 106 #define WD_REVC_HRBT            0x02    /* Watchdog Heartbeat */
 107 #define WD_REVC_TTRP            0x04    /* Temperature Trip status */
 108 #define WD_REVC_RL2A            0x08    /* Relay 2 activated by on-board processor */
 109 #define WD_REVC_RL1A            0x10    /* Relay 1 active */
 110 #define WD_REVC_R2DS            0x40    /* Relay 2 disable */
 111 #define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
 112 /* Port 2 : Control Status #2 */
 113 #define WD_WDIS                 0x10    /* Watchdog Disabled */
 114 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 115 #define WD_SSEL                 0x40    /* Watchdog Switch Select (1:SW1 <-> 0:SW2) */
 116 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
 117
 118 /* max. time we give an ISA watchdog card to process a command */
 119 /* 500ms for each 4 bit response (according to spec.) */
 120 #define ISA_COMMAND_TIMEOUT     1000
 121
 122 /* Watchdog's internal commands */
 123 #define CMD_ISA_IDLE                    0x00
 124 #define CMD_ISA_VERSION_INTEGER         0x01
 125 #define CMD_ISA_VERSION_TENTH           0x02
 126 #define CMD_ISA_VERSION_HUNDRETH        0x03
 127 #define CMD_ISA_VERSION_MINOR           0x04
 128 #define CMD_ISA_SWITCH_SETTINGS         0x05
 129 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 130 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 131 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 132
 133 /*
 134  * We are using an kernel timer to do the pinging of the watchdog
 135  * every ~500ms. We try to set the internal heartbeat of the
 136  * watchdog to 2 ms.
 137  */
 138
 139 #define WDT_INTERVAL (HZ/2+1)
 140
 141 /* We can only use 1 card due to the /dev/watchdog restriction */
 142 static int cards_found;
 143
 144 /* internal variables */
 145 static atomic_t open_allowed = ATOMIC_INIT(1);
 146 static char expect_close;
 147 static int temp_panic;
 148 static struct {                         /* this is private data for each ISA-PC watchdog card */
 149         int revision;                   /* The card's revision */
 150         int supports_temp;              /* Wether or not the card has a temperature device */
 151         int command_mode;               /* Wether or not the card is in command mode */
 152         int boot_status;                /* The card's boot status */
 153         int io_addr;                    /* The cards I/O address */
 154         spinlock_t io_lock;             /* the lock for io operations */
 155         struct timer_list timer;        /* The timer that pings the watchdog */
 156         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 157 } pcwd_private;
 158
 159 /* module parameters */
 160 #define WATCHDOG_HEARTBEAT 60           /* 60 sec default heartbeat */
 161 static int heartbeat = WATCHDOG_HEARTBEAT;
 162 module_param(heartbeat, int, 0);
 163 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 164
 165 static int nowayout = WATCHDOG_NOWAYOUT;
 166 module_param(nowayout, int, 0);
 167 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 168
 169 /*
 170  *      Internal functions
 171  */
 172
 173 static int send_isa_command(int cmd)
 174 {
 175         int i;
 176         int control_status;
 177         int port0, last_port0;  /* Double read for stabilising */
 178
 179         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 180         control_status = (cmd & 0x0F) | WD_WCMD;
 181         outb_p(control_status, pcwd_private.io_addr + 2);
 182         udelay(ISA_COMMAND_TIMEOUT);
 183
 184         port0 = inb_p(pcwd_private.io_addr);
 185         for (i = 0; i < 25; ++i) {
 186                 last_port0 = port0;
 187                 port0 = inb_p(pcwd_private.io_addr);
 188
 189                 if (port0 == last_port0)
 190                         break;  /* Data is stable */
 191
 192                 udelay (250);
 193         }
 194
 195         return port0;
 196 }
 197
 198 static int set_command_mode(void)
 199 {
 200         int i, found=0, count=0;
 201
 202         /* Set the card into command mode */
 203         spin_lock(&pcwd_private.io_lock);
 204         while ((!found) && (count < 3)) {
 205                 i = send_isa_command(CMD_ISA_IDLE);
 206
 207                 if (i == 0x00)
 208                         found = 1;
 209                 else if (i == 0xF3) {
 210                         /* Card does not like what we've done to it */
 211                         outb_p(0x00, pcwd_private.io_addr + 2);
 212                         udelay(1200);   /* Spec says wait 1ms */
 213                         outb_p(0x00, pcwd_private.io_addr + 2);
 214                         udelay(ISA_COMMAND_TIMEOUT);
 215                 }
 216                 count++;
 217         }
 218         spin_unlock(&pcwd_private.io_lock);
 219         pcwd_private.command_mode = found;
 220
 221         return(found);
 222 }
 223
 224 static void unset_command_mode(void)
 225 {
 226         /* Set the card into normal mode */
 227         spin_lock(&pcwd_private.io_lock);
 228         outb_p(0x00, pcwd_private.io_addr + 2);
 229         udelay(ISA_COMMAND_TIMEOUT);
 230         spin_unlock(&pcwd_private.io_lock);
 231
 232         pcwd_private.command_mode = 0;
 233 }
 234
 235 static inline void pcwd_check_temperature_support(void)
 236 {
 237         if (inb(pcwd_private.io_addr) != 0xF0)
 238                 pcwd_private.supports_temp = 1;
 239 }
 240
 241 static inline char *get_firmware(void)
 242 {
 243         int one, ten, hund, minor;
 244         char *ret;
 245
 246         ret = kmalloc(6, GFP_KERNEL);
 247         if(ret == NULL)
 248                 return NULL;
 249
 250         if (set_command_mode()) {
 251                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 252                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 253                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 254                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 255                 sprintf(ret, "%c.%c%c%c", one, ten, hund, minor);
 256         }
 257         else
 258                 sprintf(ret, "ERROR");
 259
 260         unset_command_mode();
 261         return(ret);
 262 }
 263
 264 static inline int pcwd_get_option_switches(void)
 265 {
 266         int option_switches=0;
 267
 268         if (set_command_mode()) {
 269                 /* Get switch settings */
 270                 option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 271         }
 272
 273         unset_command_mode();
 274         return(option_switches);
 275 }
 276
 277 static void pcwd_show_card_info(void)
 278 {
 279         char *firmware;
 280         int option_switches;
 281
 282         /* Get some extra info from the hardware (in command/debug/diag mode) */
 283         if (pcwd_private.revision == PCWD_REVISION_A)
 284                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", pcwd_private.io_addr);
 285         else if (pcwd_private.revision == PCWD_REVISION_C) {
 286                 firmware = get_firmware();
 287                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 288                         pcwd_private.io_addr, firmware);
 289                 kfree(firmware);
 290                 option_switches = pcwd_get_option_switches();
 291                 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 292                         option_switches,
 293                         ((option_switches & 0x10) ? "ON" : "OFF"),
 294                         ((option_switches & 0x08) ? "ON" : "OFF"));
 295
 296                 /* Reprogram internal heartbeat to 2 seconds */
 297                 if (set_command_mode()) {
 298                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 299                         unset_command_mode();
 300                 }
 301         }
 302
 303         if (pcwd_private.supports_temp)
 304                 printk(KERN_INFO PFX "Temperature Option Detected\n");
 305
 306         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 307                 printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
 308
 309         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 310                 printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
 311                 printk(KERN_EMERG PFX "CPU Overheat\n");
 312         }
 313
 314         if (pcwd_private.boot_status == 0)
 315                 printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");
 316 }
 317
 318 static void pcwd_timer_ping(unsigned long data)
 319 {
 320         int wdrst_stat;
 321
 322         /* If we got a heartbeat pulse within the WDT_INTERVAL
 323          * we agree to ping the WDT */
 324         if(time_before(jiffies, pcwd_private.next_heartbeat)) {
 325                 /* Ping the watchdog */
 326                 spin_lock(&pcwd_private.io_lock);
 327                 if (pcwd_private.revision == PCWD_REVISION_A) {
 328                         /*  Rev A cards are reset by setting the WD_WDRST bit in register 1 */
 329                         wdrst_stat = inb_p(pcwd_private.io_addr);
 330                         wdrst_stat &= 0x0F;
 331                         wdrst_stat |= WD_WDRST;
 332
 333                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 334                 } else {
 335                         /* Re-trigger watchdog by writing to port 0 */
 336                         outb_p(0x00, pcwd_private.io_addr);
 337                 }
 338
 339                 /* Re-set the timer interval */
 340                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 341
 342                 spin_unlock(&pcwd_private.io_lock);
 343         } else {
 344                 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
 345         }
 346 }
 347
 348 static int pcwd_start(void)
 349 {
 350         int stat_reg;
 351
 352         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 353
 354         /* Start the timer */
 355         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 356
 357         /* Enable the port */
 358         if (pcwd_private.revision == PCWD_REVISION_C) {
 359                 spin_lock(&pcwd_private.io_lock);
 360                 outb_p(0x00, pcwd_private.io_addr + 3);
 361                 udelay(ISA_COMMAND_TIMEOUT);
 362                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 363                 spin_unlock(&pcwd_private.io_lock);
 364                 if (stat_reg & WD_WDIS) {
 365                         printk(KERN_INFO PFX "Could not start watchdog\n");
 366                         return -EIO;
 367                 }
 368         }
 369         return 0;
 370 }
 371
 372 static int pcwd_stop(void)
 373 {
 374         int stat_reg;
 375
 376         /* Stop the timer */
 377         del_timer(&pcwd_private.timer);
 378
 379         /*  Disable the board  */
 380         if (pcwd_private.revision == PCWD_REVISION_C) {
 381                 spin_lock(&pcwd_private.io_lock);
 382                 outb_p(0xA5, pcwd_private.io_addr + 3);
 383                 udelay(ISA_COMMAND_TIMEOUT);
 384                 outb_p(0xA5, pcwd_private.io_addr + 3);
 385                 udelay(ISA_COMMAND_TIMEOUT);
 386                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 387                 spin_unlock(&pcwd_private.io_lock);
 388                 if ((stat_reg & WD_WDIS) == 0) {
 389                         printk(KERN_INFO PFX "Could not stop watchdog\n");
 390                         return -EIO;
 391                 }
 392         }
 393         return 0;
 394 }
 395
 396 static int pcwd_keepalive(void)
 397 {
 398         /* user land ping */
 399         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 400         return 0;
 401 }
 402
 403 static int pcwd_set_heartbeat(int t)
 404 {
 405         if ((t < 2) || (t > 7200)) /* arbitrary upper limit */
 406                 return -EINVAL;
 407
 408         heartbeat = t;
 409         return 0;
 410 }
 411
 412 static int pcwd_get_status(int *status)
 413 {
 414         int control_status;
 415
 416         *status=0;
 417         spin_lock(&pcwd_private.io_lock);
 418         if (pcwd_private.revision == PCWD_REVISION_A)
 419                 /* Rev A cards return status information from
 420                  * the base register, which is used for the
 421                  * temperature in other cards. */
 422                 control_status = inb(pcwd_private.io_addr);
 423         else {
 424                 /* Rev C cards return card status in the base
 425                  * address + 1 register. And use different bits
 426                  * to indicate a card initiated reset, and an
 427                  * over-temperature condition. And the reboot
 428                  * status can be reset. */
 429                 control_status = inb(pcwd_private.io_addr + 1);
 430         }
 431         spin_unlock(&pcwd_private.io_lock);
 432
 433         if (pcwd_private.revision == PCWD_REVISION_A) {
 434                 if (control_status & WD_WDRST)
 435                         *status |= WDIOF_CARDRESET;
 436
 437                 if (control_status & WD_T110) {
 438                         *status |= WDIOF_OVERHEAT;
 439                         if (temp_panic) {
 440                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 441                                 kernel_power_off();
 442                         }
 443                 }
 444         } else {
 445                 if (control_status & WD_REVC_WTRP)
 446                         *status |= WDIOF_CARDRESET;
 447
 448                 if (control_status & WD_REVC_TTRP) {
 449                         *status |= WDIOF_OVERHEAT;
 450                         if (temp_panic) {
 451                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 452                                 kernel_power_off();
 453                         }
 454                 }
 455         }
 456
 457         return 0;
 458 }
 459
 460 static int pcwd_clear_status(void)
 461 {
 462         int control_status;
 463
 464         if (pcwd_private.revision == PCWD_REVISION_C) {
 465                 spin_lock(&pcwd_private.io_lock);
 466
 467                 control_status = inb_p(pcwd_private.io_addr + 1);
 468
 469                 /* clear reset status & Keep Relay 2 disable state as it is */
 470                 outb_p((control_status & WD_REVC_R2DS), pcwd_private.io_addr + 1);
 471
 472                 spin_unlock(&pcwd_private.io_lock);
 473         }
 474         return 0;
 475 }
 476
 477 static int pcwd_get_temperature(int *temperature)
 478 {
 479         /* check that port 0 gives temperature info and no command results */
 480         if (pcwd_private.command_mode)
 481                 return -1;
 482
 483         *temperature = 0;
 484         if (!pcwd_private.supports_temp)
 485                 return -ENODEV;
 486
 487         /*
 488          * Convert celsius to fahrenheit, since this was
 489          * the decided 'standard' for this return value.
 490          */
 491         spin_lock(&pcwd_private.io_lock);
 492         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 493         spin_unlock(&pcwd_private.io_lock);
 494
 495         return 0;
 496 }
 497
 498 /*
 499  *      /dev/watchdog handling
 500  */
 501
 502 static int pcwd_ioctl(struct inode *inode, struct file *file,
 503                       unsigned int cmd, unsigned long arg)
 504 {
 505         int rv;
 506         int status;
 507         int temperature;
 508         int new_heartbeat;
 509         int __user *argp = (int __user *)arg;
 510         static struct watchdog_info ident = {
 511                 .options =              WDIOF_OVERHEAT |
 512                                         WDIOF_CARDRESET |
 513                                         WDIOF_KEEPALIVEPING |
 514                                         WDIOF_SETTIMEOUT |
 515                                         WDIOF_MAGICCLOSE,
 516                 .firmware_version =     1,
 517                 .identity =             "PCWD",
 518         };
 519
 520         switch(cmd) {
 521         default:
 522                 return -ENOIOCTLCMD;
 523
 524         case WDIOC_GETSUPPORT:
 525                 if(copy_to_user(argp, &ident, sizeof(ident)))
 526                         return -EFAULT;
 527                 return 0;
 528
 529         case WDIOC_GETSTATUS:
 530                 pcwd_get_status(&status);
 531                 return put_user(status, argp);
 532
 533         case WDIOC_GETBOOTSTATUS:
 534                 return put_user(pcwd_private.boot_status, argp);
 535
 536         case WDIOC_GETTEMP:
 537                 if (pcwd_get_temperature(&temperature))
 538                         return -EFAULT;
 539
 540                 return put_user(temperature, argp);
 541
 542         case WDIOC_SETOPTIONS:
 543                 if (pcwd_private.revision == PCWD_REVISION_C)
 544                 {
 545                         if(copy_from_user(&rv, argp, sizeof(int)))
 546                                 return -EFAULT;
 547
 548                         if (rv & WDIOS_DISABLECARD)
 549                         {
 550                                 return pcwd_stop();
 551                         }
 552
 553                         if (rv & WDIOS_ENABLECARD)
 554                         {
 555                                 return pcwd_start();
 556                         }
 557
 558                         if (rv & WDIOS_TEMPPANIC)
 559                         {
 560                                 temp_panic = 1;
 561                         }
 562                 }
 563                 return -EINVAL;
 564
 565         case WDIOC_KEEPALIVE:
 566                 pcwd_keepalive();
 567                 return 0;
 568
 569         case WDIOC_SETTIMEOUT:
 570                 if (get_user(new_heartbeat, argp))
 571                         return -EFAULT;
 572
 573                 if (pcwd_set_heartbeat(new_heartbeat))
 574                         return -EINVAL;
 575
 576                 pcwd_keepalive();
 577                 /* Fall */
 578
 579         case WDIOC_GETTIMEOUT:
 580                 return put_user(heartbeat, argp);
 581         }
 582
 583         return 0;
 584 }
 585
 586 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 587                           loff_t *ppos)
 588 {
 589         if (len) {
 590                 if (!nowayout) {
 591                         size_t i;
 592
 593                         /* In case it was set long ago */
 594                         expect_close = 0;
 595
 596                         for (i = 0; i != len; i++) {
 597                                 char c;
 598
 599                                 if (get_user(c, buf + i))
 600                                         return -EFAULT;
 601                                 if (c == 'V')
 602                                         expect_close = 42;
 603                         }
 604                 }
 605                 pcwd_keepalive();
 606         }
 607         return len;
 608 }
 609
 610 static int pcwd_open(struct inode *inode, struct file *file)
 611 {
 612         if (!atomic_dec_and_test(&open_allowed) ) {
 613                 atomic_inc( &open_allowed );
 614                 return -EBUSY;
 615         }
 616
 617         if (nowayout)
 618                 __module_get(THIS_MODULE);
 619
 620         /* Activate */
 621         pcwd_start();
 622         pcwd_keepalive();
 623         return nonseekable_open(inode, file);
 624 }
 625
 626 static int pcwd_close(struct inode *inode, struct file *file)
 627 {
 628         if (expect_close == 42) {
 629                 pcwd_stop();
 630         } else {
 631                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 632                 pcwd_keepalive();
 633         }
 634         expect_close = 0;
 635         atomic_inc( &open_allowed );
 636         return 0;
 637 }
 638
 639 /*
 640  *      /dev/temperature handling
 641  */
 642
 643 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 644                          loff_t *ppos)
 645 {
 646         int temperature;
 647
 648         if (pcwd_get_temperature(&temperature))
 649                 return -EFAULT;
 650
 651         if (copy_to_user(buf, &temperature, 1))
 652                 return -EFAULT;
 653
 654         return 1;
 655 }
 656
 657 static int pcwd_temp_open(struct inode *inode, struct file *file)
 658 {
 659         if (!pcwd_private.supports_temp)
 660                 return -ENODEV;
 661
 662         return nonseekable_open(inode, file);
 663 }
 664
 665 static int pcwd_temp_close(struct inode *inode, struct file *file)
 666 {
 667         return 0;
 668 }
 669
 670 /*
 671  *      Notify system
 672  */
 673
 674 static int pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 675 {
 676         if (code==SYS_DOWN || code==SYS_HALT) {
 677                 /* Turn the WDT off */
 678                 pcwd_stop();
 679         }
 680
 681         return NOTIFY_DONE;
 682 }
 683
 684 /*
 685  *      Kernel Interfaces
 686  */
 687
 688 static struct file_operations pcwd_fops = {
 689         .owner          = THIS_MODULE,
 690         .llseek         = no_llseek,
 691         .write          = pcwd_write,
 692         .ioctl          = pcwd_ioctl,
 693         .open           = pcwd_open,
 694         .release        = pcwd_close,
 695 };
 696
 697 static struct miscdevice pcwd_miscdev = {
 698         .minor =        WATCHDOG_MINOR,
 699         .name =         "watchdog",
 700         .fops =         &pcwd_fops,
 701 };
 702
 703 static struct file_operations pcwd_temp_fops = {
 704         .owner          = THIS_MODULE,
 705         .llseek         = no_llseek,
 706         .read           = pcwd_temp_read,
 707         .open           = pcwd_temp_open,
 708         .release        = pcwd_temp_close,
 709 };
 710
 711 static struct miscdevice temp_miscdev = {
 712         .minor =        TEMP_MINOR,
 713         .name =         "temperature",
 714         .fops =         &pcwd_temp_fops,
 715 };
 716
 717 static struct notifier_block pcwd_notifier = {
 718         .notifier_call =        pcwd_notify_sys,
 719 };
 720
 721 /*
 722  *      Init & exit routines
 723  */
 724
 725 static inline int get_revision(void)
 726 {
 727         int r = PCWD_REVISION_C;
 728
 729         spin_lock(&pcwd_private.io_lock);
 730         /* REV A cards use only 2 io ports; test
 731          * presumes a floating bus reads as 0xff. */
 732         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 733             (inb(pcwd_private.io_addr + 3) == 0xFF))
 734                 r=PCWD_REVISION_A;
 735         spin_unlock(&pcwd_private.io_lock);
 736
 737         return r;
 738 }
 739
 740 static int __devinit pcwatchdog_init(int base_addr)
 741 {
 742         int ret;
 743
 744         cards_found++;
 745         if (cards_found == 1)
 746                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER);
 747
 748         if (cards_found > 1) {
 749                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 750                 return -ENODEV;
 751         }
 752
 753         if (base_addr == 0x0000) {
 754                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 755                 return -ENODEV;
 756         }
 757         pcwd_private.io_addr = base_addr;
 758
 759         /* Check card's revision */
 760         pcwd_private.revision = get_revision();
 761
 762         if (!request_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 763                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 764                         pcwd_private.io_addr);
 765                 pcwd_private.io_addr = 0x0000;
 766                 return -EIO;
 767         }
 768
 769         /* Initial variables */
 770         pcwd_private.supports_temp = 0;
 771         temp_panic = 0;
 772         pcwd_private.boot_status = 0x0000;
 773
 774         /* get the boot_status */
 775         pcwd_get_status(&pcwd_private.boot_status);
 776
 777         /* clear the "card caused reboot" flag */
 778         pcwd_clear_status();
 779
 780         init_timer(&pcwd_private.timer);
 781         pcwd_private.timer.function = pcwd_timer_ping;
 782         pcwd_private.timer.data = 0;
 783
 784         /*  Disable the board  */
 785         pcwd_stop();
 786
 787         /*  Check whether or not the card supports the temperature device */
 788         pcwd_check_temperature_support();
 789
 790         /* Show info about the card itself */
 791         pcwd_show_card_info();
 792
 793         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 794         if (pcwd_set_heartbeat(heartbeat)) {
 795                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 796                 printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
 797                         WATCHDOG_HEARTBEAT);
 798         }
 799
 800         ret = register_reboot_notifier(&pcwd_notifier);
 801         if (ret) {
 802                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 803                         ret);
 804                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 805                 pcwd_private.io_addr = 0x0000;
 806                 return ret;
 807         }
 808
 809         if (pcwd_private.supports_temp) {
 810                 ret = misc_register(&temp_miscdev);
 811                 if (ret) {
 812                         printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 813                                 TEMP_MINOR, ret);
 814                         unregister_reboot_notifier(&pcwd_notifier);
 815                         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 816                         pcwd_private.io_addr = 0x0000;
 817                         return ret;
 818                 }
 819         }
 820
 821         ret = misc_register(&pcwd_miscdev);
 822         if (ret) {
 823                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 824                         WATCHDOG_MINOR, ret);
 825                 if (pcwd_private.supports_temp)
 826                         misc_deregister(&temp_miscdev);
 827                 unregister_reboot_notifier(&pcwd_notifier);
 828                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 829                 pcwd_private.io_addr = 0x0000;
 830                 return ret;
 831         }
 832
 833         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 834                 heartbeat, nowayout);
 835
 836         return 0;
 837 }
 838
 839 static void __devexit pcwatchdog_exit(void)
 840 {
 841         /*  Disable the board  */
 842         if (!nowayout)
 843                 pcwd_stop();
 844
 845         /* Deregister */
 846         misc_deregister(&pcwd_miscdev);
 847         if (pcwd_private.supports_temp)
 848                 misc_deregister(&temp_miscdev);
 849         unregister_reboot_notifier(&pcwd_notifier);
 850         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 851         pcwd_private.io_addr = 0x0000;
 852         cards_found--;
 853 }
 854
 855 /*
 856  *  The ISA cards have a heartbeat bit in one of the registers, which
 857  *  register is card dependent.  The heartbeat bit is monitored, and if
 858  *  found, is considered proof that a Berkshire card has been found.
 859  *  The initial rate is once per second at board start up, then twice
 860  *  per second for normal operation.
 861  */
 862 static int __init pcwd_checkcard(int base_addr)
 863 {
 864         int port0, last_port0;  /* Reg 0, in case it's REV A */
 865         int port1, last_port1;  /* Register 1 for REV C cards */
 866         int i;
 867         int retval;
 868
 869         if (!request_region (base_addr, 4, "PCWD")) {
 870                 printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 871                 return 0;
 872         }
 873
 874         retval = 0;
 875
 876         port0 = inb_p(base_addr);       /* For REV A boards */
 877         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 878         if (port0 != 0xff || port1 != 0xff) {
 879                 /* Not an 'ff' from a floating bus, so must be a card! */
 880                 for (i = 0; i < 4; ++i) {
 881
 882                         msleep(500);
 883
 884                         last_port0 = port0;
 885                         last_port1 = port1;
 886
 887                         port0 = inb_p(base_addr);
 888                         port1 = inb_p(base_addr + 1);
 889
 890                         /* Has either hearbeat bit changed?  */
 891                         if ((port0 ^ last_port0) & WD_HRTBT ||
 892                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 893                                 retval = 1;
 894                                 break;
 895                         }
 896                 }
 897         }
 898         release_region (base_addr, 4);
 899
 900         return retval;
 901 }
 902
 903 /*
 904  * These are the auto-probe addresses available.
 905  *
 906  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
 907  * Revision A has an address range of 2 addresses, while Revision C has 4.
 908  */
 909 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
 910
 911 static int __init pcwd_init_module(void)
 912 {
 913         int i, found = 0;
 914
 915         spin_lock_init(&pcwd_private.io_lock);
 916
 917         for (i = 0; pcwd_ioports[i] != 0; i++) {
 918                 if (pcwd_checkcard(pcwd_ioports[i])) {
 919                         if (!(pcwatchdog_init(pcwd_ioports[i])))
 920                                 found++;
 921                 }
 922         }
 923
 924         if (!found) {
 925                 printk (KERN_INFO PFX "No card detected, or port not available\n");
 926                 return -ENODEV;
 927         }
 928
 929         return 0;
 930 }
 931
 932 static void __exit pcwd_cleanup_module(void)
 933 {
 934         if (pcwd_private.io_addr)
 935                 pcwatchdog_exit();
 936         return;
 937 }
 938
 939 module_init(pcwd_init_module);
 940 module_exit(pcwd_cleanup_module);
 941
 942 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>");
 943 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
 944 MODULE_LICENSE("GPL");
 945 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 946 MODULE_ALIAS_MISCDEV(TEMP_MINOR);