drivers/char/watchdog/pcwd.c

   1 /*
   2  * PC Watchdog Driver
   3  * by Ken Hollis (khollis@bitgate.com)
   4  *
   5  * Permission granted from Simon Machell (smachell@berkprod.com)
   6  * Written for the Linux Kernel, and GPLed by Ken Hollis
   7  *
   8  * 960107       Added request_region routines, modulized the whole thing.
   9  * 960108       Fixed end-of-file pointer (Thanks to Dan Hollis), added
  10  *              WD_TIMEOUT define.
  11  * 960216       Added eof marker on the file, and changed verbose messages.
  12  * 960716       Made functional and cosmetic changes to the source for
  13  *              inclusion in Linux 2.0.x kernels, thanks to Alan Cox.
  14  * 960717       Removed read/seek routines, replaced with ioctl.  Also, added
  15  *              check_region command due to Alan's suggestion.
  16  * 960821       Made changes to compile in newer 2.0.x kernels.  Added
  17  *              "cold reboot sense" entry.
  18  * 960825       Made a few changes to code, deleted some defines and made
  19  *              typedefs to replace them.  Made heartbeat reset only available
  20  *              via ioctl, and removed the write routine.
  21  * 960828       Added new items for PC Watchdog Rev.C card.
  22  * 960829       Changed around all of the IOCTLs, added new features,
  23  *              added watchdog disable/re-enable routines.  Added firmware
  24  *              version reporting.  Added read routine for temperature.
  25  *              Removed some extra defines, added an autodetect Revision
  26  *              routine.
  27  * 961006       Revised some documentation, fixed some cosmetic bugs.  Made
  28  *              drivers to panic the system if it's overheating at bootup.
  29  * 961118       Changed some verbiage on some of the output, tidied up
  30  *              code bits, and added compatibility to 2.1.x.
  31  * 970912       Enabled board on open and disable on close.
  32  * 971107       Took account of recent VFS changes (broke read).
  33  * 971210       Disable board on initialisation in case board already ticking.
  34  * 971222       Changed open/close for temperature handling
  35  *              Michael Meskes <meskes@debian.org>.
  36  * 980112       Used minor numbers from include/linux/miscdevice.h
  37  * 990403       Clear reset status after reading control status register in
  38  *              pcwd_showprevstate(). [Marc Boucher <marc@mbsi.ca>]
  39  * 990605       Made changes to code to support Firmware 1.22a, added
  40  *              fairly useless proc entry.
  41  * 990610       removed said useless proc code for the merge <alan>
  42  * 000403       Removed last traces of proc code. <davej>
  43  * 011214       Added nowayout module option to override 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/module.h>       /* For module specific items */
  53 #include <linux/moduleparam.h>  /* For new moduleparam's */
  54 #include <linux/types.h>        /* For standard types (like size_t) */
  55 #include <linux/errno.h>        /* For the -ENODEV/... values */
  56 #include <linux/kernel.h>       /* For printk/panic/... */
  57 #include <linux/delay.h>        /* For mdelay function */
  58 #include <linux/timer.h>        /* For timer related operations */
  59 #include <linux/jiffies.h>      /* For jiffies stuff */
  60 #include <linux/miscdevice.h>   /* For MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR) */
  61 #include <linux/watchdog.h>     /* For the watchdog specific items */
  62 #include <linux/notifier.h>     /* For notifier support */
  63 #include <linux/reboot.h>       /* For reboot_notifier stuff */
  64 #include <linux/init.h>         /* For __init/__exit/... */
  65 #include <linux/fs.h>           /* For file operations */
  66 #include <linux/ioport.h>       /* For io-port access */
  67 #include <linux/spinlock.h>     /* For spin_lock/spin_unlock/... */
  68
  69 #include <asm/uaccess.h>        /* For copy_to_user/put_user/... */
  70 #include <asm/io.h>             /* For inb/outb/... */
  71
  72 /* Module and version information */
  73 #define WATCHDOG_VERSION "1.18"
  74 #define WATCHDOG_DATE "06 Jan 2007"
  75 #define WATCHDOG_DRIVER_NAME "ISA-PC Watchdog"
  76 #define WATCHDOG_NAME "pcwd"
  77 #define PFX WATCHDOG_NAME ": "
  78 #define DRIVER_VERSION WATCHDOG_DRIVER_NAME " driver, v" WATCHDOG_VERSION " (" WATCHDOG_DATE ")\n"
  79 #define WD_VER WATCHDOG_VERSION " (" WATCHDOG_DATE ")"
  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 defines that describe the control status bits for the
  93  * PCI-PC Watchdog card.
  94 */
  95 /* Port 1 : Control Status #1 for the PC Watchdog card, revision A. */
  96 #define WD_WDRST                0x01    /* Previously reset state */
  97 #define WD_T110                 0x02    /* Temperature overheat sense */
  98 #define WD_HRTBT                0x04    /* Heartbeat sense */
  99 #define WD_RLY2                 0x08    /* External relay triggered */
 100 #define WD_SRLY2                0x80    /* Software external relay triggered */
 101 /* Port 1 : Control Status #1 for the PC Watchdog card, revision C. */
 102 #define WD_REVC_WTRP            0x01    /* Watchdog Trip status */
 103 #define WD_REVC_HRBT            0x02    /* Watchdog Heartbeat */
 104 #define WD_REVC_TTRP            0x04    /* Temperature Trip status */
 105 #define WD_REVC_RL2A            0x08    /* Relay 2 activated by on-board processor */
 106 #define WD_REVC_RL1A            0x10    /* Relay 1 active */
 107 #define WD_REVC_R2DS            0x40    /* Relay 2 disable */
 108 #define WD_REVC_RLY2            0x80    /* Relay 2 activated? */
 109 /* Port 2 : Control Status #2 */
 110 #define WD_WDIS                 0x10    /* Watchdog Disabled */
 111 #define WD_ENTP                 0x20    /* Watchdog Enable Temperature Trip */
 112 #define WD_SSEL                 0x40    /* Watchdog Switch Select (1:SW1 <-> 0:SW2) */
 113 #define WD_WCMD                 0x80    /* Watchdog Command Mode */
 114
 115 /* max. time we give an ISA watchdog card to process a command */
 116 /* 500ms for each 4 bit response (according to spec.) */
 117 #define ISA_COMMAND_TIMEOUT     1000
 118
 119 /* Watchdog's internal commands */
 120 #define CMD_ISA_IDLE                    0x00
 121 #define CMD_ISA_VERSION_INTEGER         0x01
 122 #define CMD_ISA_VERSION_TENTH           0x02
 123 #define CMD_ISA_VERSION_HUNDRETH        0x03
 124 #define CMD_ISA_VERSION_MINOR           0x04
 125 #define CMD_ISA_SWITCH_SETTINGS         0x05
 126 #define CMD_ISA_RESET_PC                0x06
 127 #define CMD_ISA_ARM_0                   0x07
 128 #define CMD_ISA_ARM_30                  0x08
 129 #define CMD_ISA_ARM_60                  0x09
 130 #define CMD_ISA_DELAY_TIME_2SECS        0x0A
 131 #define CMD_ISA_DELAY_TIME_4SECS        0x0B
 132 #define CMD_ISA_DELAY_TIME_8SECS        0x0C
 133 #define CMD_ISA_RESET_RELAYS            0x0D
 134
 135 /* Watchdog's Dip Switch heartbeat values */
 136 static const int heartbeat_tbl [] = {
 137         20,     /* OFF-OFF-OFF  = 20 Sec  */
 138         40,     /* OFF-OFF-ON   = 40 Sec  */
 139         60,     /* OFF-ON-OFF   =  1 Min  */
 140         300,    /* OFF-ON-ON    =  5 Min  */
 141         600,    /* ON-OFF-OFF   = 10 Min  */
 142         1800,   /* ON-OFF-ON    = 30 Min  */
 143         3600,   /* ON-ON-OFF    =  1 Hour */
 144         7200,   /* ON-ON-ON     =  2 hour */
 145 };
 146
 147 /*
 148  * We are using an kernel timer to do the pinging of the watchdog
 149  * every ~500ms. We try to set the internal heartbeat of the
 150  * watchdog to 2 ms.
 151  */
 152
 153 #define WDT_INTERVAL (HZ/2+1)
 154
 155 /* We can only use 1 card due to the /dev/watchdog restriction */
 156 static int cards_found;
 157
 158 /* internal variables */
 159 static atomic_t open_allowed = ATOMIC_INIT(1);
 160 static char expect_close;
 161 static int temp_panic;
 162 static struct {                         /* this is private data for each ISA-PC watchdog card */
 163         char fw_ver_str[6];             /* The cards firmware version */
 164         int revision;                   /* The card's revision */
 165         int supports_temp;              /* Wether or not the card has a temperature device */
 166         int command_mode;               /* Wether or not the card is in command mode */
 167         int boot_status;                /* The card's boot status */
 168         int io_addr;                    /* The cards I/O address */
 169         spinlock_t io_lock;             /* the lock for io operations */
 170         struct timer_list timer;        /* The timer that pings the watchdog */
 171         unsigned long next_heartbeat;   /* the next_heartbeat for the timer */
 172 } pcwd_private;
 173
 174 /* module parameters */
 175 #define QUIET   0       /* Default */
 176 #define VERBOSE 1       /* Verbose */
 177 #define DEBUG   2       /* print fancy stuff too */
 178 static int debug = QUIET;
 179 module_param(debug, int, 0);
 180 MODULE_PARM_DESC(debug, "Debug level: 0=Quiet, 1=Verbose, 2=Debug (default=0)");
 181
 182 #define WATCHDOG_HEARTBEAT 0            /* default heartbeat = delay-time from dip-switches */
 183 static int heartbeat = WATCHDOG_HEARTBEAT;
 184 module_param(heartbeat, int, 0);
 185 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<=heartbeat<=7200 or 0=delay-time from dip-switches, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 186
 187 static int nowayout = WATCHDOG_NOWAYOUT;
 188 module_param(nowayout, int, 0);
 189 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 190
 191 /*
 192  *      Internal functions
 193  */
 194
 195 static int send_isa_command(int cmd)
 196 {
 197         int i;
 198         int control_status;
 199         int port0, last_port0;  /* Double read for stabilising */
 200
 201         if (debug >= DEBUG)
 202                 printk(KERN_DEBUG PFX "sending following data cmd=0x%02x\n",
 203                         cmd);
 204
 205         /* The WCMD bit must be 1 and the command is only 4 bits in size */
 206         control_status = (cmd & 0x0F) | WD_WCMD;
 207         outb_p(control_status, pcwd_private.io_addr + 2);
 208         udelay(ISA_COMMAND_TIMEOUT);
 209
 210         port0 = inb_p(pcwd_private.io_addr);
 211         for (i = 0; i < 25; ++i) {
 212                 last_port0 = port0;
 213                 port0 = inb_p(pcwd_private.io_addr);
 214
 215                 if (port0 == last_port0)
 216                         break;  /* Data is stable */
 217
 218                 udelay (250);
 219         }
 220
 221         if (debug >= DEBUG)
 222                 printk(KERN_DEBUG PFX "received following data for cmd=0x%02x: port0=0x%02x last_port0=0x%02x\n",
 223                         cmd, port0, last_port0);
 224
 225         return port0;
 226 }
 227
 228 static int set_command_mode(void)
 229 {
 230         int i, found=0, count=0;
 231
 232         /* Set the card into command mode */
 233         spin_lock(&pcwd_private.io_lock);
 234         while ((!found) && (count < 3)) {
 235                 i = send_isa_command(CMD_ISA_IDLE);
 236
 237                 if (i == 0x00)
 238                         found = 1;
 239                 else if (i == 0xF3) {
 240                         /* Card does not like what we've done to it */
 241                         outb_p(0x00, pcwd_private.io_addr + 2);
 242                         udelay(1200);   /* Spec says wait 1ms */
 243                         outb_p(0x00, pcwd_private.io_addr + 2);
 244                         udelay(ISA_COMMAND_TIMEOUT);
 245                 }
 246                 count++;
 247         }
 248         spin_unlock(&pcwd_private.io_lock);
 249         pcwd_private.command_mode = found;
 250
 251         if (debug >= DEBUG)
 252                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 253                                 pcwd_private.command_mode);
 254
 255         return(found);
 256 }
 257
 258 static void unset_command_mode(void)
 259 {
 260         /* Set the card into normal mode */
 261         spin_lock(&pcwd_private.io_lock);
 262         outb_p(0x00, pcwd_private.io_addr + 2);
 263         udelay(ISA_COMMAND_TIMEOUT);
 264         spin_unlock(&pcwd_private.io_lock);
 265
 266         pcwd_private.command_mode = 0;
 267
 268         if (debug >= DEBUG)
 269                 printk(KERN_DEBUG PFX "command_mode=%d\n",
 270                                 pcwd_private.command_mode);
 271 }
 272
 273 static inline void pcwd_check_temperature_support(void)
 274 {
 275         if (inb(pcwd_private.io_addr) != 0xF0)
 276                 pcwd_private.supports_temp = 1;
 277 }
 278
 279 static inline void pcwd_get_firmware(void)
 280 {
 281         int one, ten, hund, minor;
 282
 283         strcpy(pcwd_private.fw_ver_str, "ERROR");
 284
 285         if (set_command_mode()) {
 286                 one = send_isa_command(CMD_ISA_VERSION_INTEGER);
 287                 ten = send_isa_command(CMD_ISA_VERSION_TENTH);
 288                 hund = send_isa_command(CMD_ISA_VERSION_HUNDRETH);
 289                 minor = send_isa_command(CMD_ISA_VERSION_MINOR);
 290                 sprintf(pcwd_private.fw_ver_str, "%c.%c%c%c", one, ten, hund, minor);
 291         }
 292         unset_command_mode();
 293
 294         return;
 295 }
 296
 297 static inline int pcwd_get_option_switches(void)
 298 {
 299         int option_switches=0;
 300
 301         if (set_command_mode()) {
 302                 /* Get switch settings */
 303                 option_switches = send_isa_command(CMD_ISA_SWITCH_SETTINGS);
 304         }
 305
 306         unset_command_mode();
 307         return(option_switches);
 308 }
 309
 310 static void pcwd_show_card_info(void)
 311 {
 312         int option_switches;
 313
 314         /* Get some extra info from the hardware (in command/debug/diag mode) */
 315         if (pcwd_private.revision == PCWD_REVISION_A)
 316                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.A) detected at port 0x%04x\n", pcwd_private.io_addr);
 317         else if (pcwd_private.revision == PCWD_REVISION_C) {
 318                 pcwd_get_firmware();
 319                 printk(KERN_INFO PFX "ISA-PC Watchdog (REV.C) detected at port 0x%04x (Firmware version: %s)\n",
 320                         pcwd_private.io_addr, pcwd_private.fw_ver_str);
 321                 option_switches = pcwd_get_option_switches();
 322                 printk(KERN_INFO PFX "Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n",
 323                         option_switches,
 324                         ((option_switches & 0x10) ? "ON" : "OFF"),
 325                         ((option_switches & 0x08) ? "ON" : "OFF"));
 326
 327                 /* Reprogram internal heartbeat to 2 seconds */
 328                 if (set_command_mode()) {
 329                         send_isa_command(CMD_ISA_DELAY_TIME_2SECS);
 330                         unset_command_mode();
 331                 }
 332         }
 333
 334         if (pcwd_private.supports_temp)
 335                 printk(KERN_INFO PFX "Temperature Option Detected\n");
 336
 337         if (pcwd_private.boot_status & WDIOF_CARDRESET)
 338                 printk(KERN_INFO PFX "Previous reboot was caused by the card\n");
 339
 340         if (pcwd_private.boot_status & WDIOF_OVERHEAT) {
 341                 printk(KERN_EMERG PFX "Card senses a CPU Overheat. Panicking!\n");
 342                 printk(KERN_EMERG PFX "CPU Overheat\n");
 343         }
 344
 345         if (pcwd_private.boot_status == 0)
 346                 printk(KERN_INFO PFX "No previous trip detected - Cold boot or reset\n");
 347 }
 348
 349 static void pcwd_timer_ping(unsigned long data)
 350 {
 351         int wdrst_stat;
 352
 353         /* If we got a heartbeat pulse within the WDT_INTERVAL
 354          * we agree to ping the WDT */
 355         if(time_before(jiffies, pcwd_private.next_heartbeat)) {
 356                 /* Ping the watchdog */
 357                 spin_lock(&pcwd_private.io_lock);
 358                 if (pcwd_private.revision == PCWD_REVISION_A) {
 359                         /*  Rev A cards are reset by setting the WD_WDRST bit in register 1 */
 360                         wdrst_stat = inb_p(pcwd_private.io_addr);
 361                         wdrst_stat &= 0x0F;
 362                         wdrst_stat |= WD_WDRST;
 363
 364                         outb_p(wdrst_stat, pcwd_private.io_addr + 1);
 365                 } else {
 366                         /* Re-trigger watchdog by writing to port 0 */
 367                         outb_p(0x00, pcwd_private.io_addr);
 368                 }
 369
 370                 /* Re-set the timer interval */
 371                 mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 372
 373                 spin_unlock(&pcwd_private.io_lock);
 374         } else {
 375                 printk(KERN_WARNING PFX "Heartbeat lost! Will not ping the watchdog\n");
 376         }
 377 }
 378
 379 static int pcwd_start(void)
 380 {
 381         int stat_reg;
 382
 383         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 384
 385         /* Start the timer */
 386         mod_timer(&pcwd_private.timer, jiffies + WDT_INTERVAL);
 387
 388         /* Enable the port */
 389         if (pcwd_private.revision == PCWD_REVISION_C) {
 390                 spin_lock(&pcwd_private.io_lock);
 391                 outb_p(0x00, pcwd_private.io_addr + 3);
 392                 udelay(ISA_COMMAND_TIMEOUT);
 393                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 394                 spin_unlock(&pcwd_private.io_lock);
 395                 if (stat_reg & WD_WDIS) {
 396                         printk(KERN_INFO PFX "Could not start watchdog\n");
 397                         return -EIO;
 398                 }
 399         }
 400
 401         if (debug >= VERBOSE)
 402                 printk(KERN_DEBUG PFX "Watchdog started\n");
 403
 404         return 0;
 405 }
 406
 407 static int pcwd_stop(void)
 408 {
 409         int stat_reg;
 410
 411         /* Stop the timer */
 412         del_timer(&pcwd_private.timer);
 413
 414         /*  Disable the board  */
 415         if (pcwd_private.revision == PCWD_REVISION_C) {
 416                 spin_lock(&pcwd_private.io_lock);
 417                 outb_p(0xA5, pcwd_private.io_addr + 3);
 418                 udelay(ISA_COMMAND_TIMEOUT);
 419                 outb_p(0xA5, pcwd_private.io_addr + 3);
 420                 udelay(ISA_COMMAND_TIMEOUT);
 421                 stat_reg = inb_p(pcwd_private.io_addr + 2);
 422                 spin_unlock(&pcwd_private.io_lock);
 423                 if ((stat_reg & WD_WDIS) == 0) {
 424                         printk(KERN_INFO PFX "Could not stop watchdog\n");
 425                         return -EIO;
 426                 }
 427         }
 428
 429         if (debug >= VERBOSE)
 430                 printk(KERN_DEBUG PFX "Watchdog stopped\n");
 431
 432         return 0;
 433 }
 434
 435 static int pcwd_keepalive(void)
 436 {
 437         /* user land ping */
 438         pcwd_private.next_heartbeat = jiffies + (heartbeat * HZ);
 439
 440         if (debug >= DEBUG)
 441                 printk(KERN_DEBUG PFX "Watchdog keepalive signal send\n");
 442
 443         return 0;
 444 }
 445
 446 static int pcwd_set_heartbeat(int t)
 447 {
 448         if ((t < 2) || (t > 7200)) /* arbitrary upper limit */
 449                 return -EINVAL;
 450
 451         heartbeat = t;
 452
 453         if (debug >= VERBOSE)
 454                 printk(KERN_DEBUG PFX "New heartbeat: %d\n",
 455                        heartbeat);
 456
 457         return 0;
 458 }
 459
 460 static int pcwd_get_status(int *status)
 461 {
 462         int control_status;
 463
 464         *status=0;
 465         spin_lock(&pcwd_private.io_lock);
 466         if (pcwd_private.revision == PCWD_REVISION_A)
 467                 /* Rev A cards return status information from
 468                  * the base register, which is used for the
 469                  * temperature in other cards. */
 470                 control_status = inb(pcwd_private.io_addr);
 471         else {
 472                 /* Rev C cards return card status in the base
 473                  * address + 1 register. And use different bits
 474                  * to indicate a card initiated reset, and an
 475                  * over-temperature condition. And the reboot
 476                  * status can be reset. */
 477                 control_status = inb(pcwd_private.io_addr + 1);
 478         }
 479         spin_unlock(&pcwd_private.io_lock);
 480
 481         if (pcwd_private.revision == PCWD_REVISION_A) {
 482                 if (control_status & WD_WDRST)
 483                         *status |= WDIOF_CARDRESET;
 484
 485                 if (control_status & WD_T110) {
 486                         *status |= WDIOF_OVERHEAT;
 487                         if (temp_panic) {
 488                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 489                                 kernel_power_off();
 490                                 /* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
 491                         }
 492                 }
 493         } else {
 494                 if (control_status & WD_REVC_WTRP)
 495                         *status |= WDIOF_CARDRESET;
 496
 497                 if (control_status & WD_REVC_TTRP) {
 498                         *status |= WDIOF_OVERHEAT;
 499                         if (temp_panic) {
 500                                 printk (KERN_INFO PFX "Temperature overheat trip!\n");
 501                                 kernel_power_off();
 502                                 /* or should we just do a: panic(PFX "Temperature overheat trip!\n"); */
 503                         }
 504                 }
 505         }
 506
 507         return 0;
 508 }
 509
 510 static int pcwd_clear_status(void)
 511 {
 512         int control_status;
 513
 514         if (pcwd_private.revision == PCWD_REVISION_C) {
 515                 spin_lock(&pcwd_private.io_lock);
 516
 517                 if (debug >= VERBOSE)
 518                         printk(KERN_INFO PFX "clearing watchdog trip status\n");
 519
 520                 control_status = inb_p(pcwd_private.io_addr + 1);
 521
 522                 if (debug >= DEBUG) {
 523                         printk(KERN_DEBUG PFX "status was: 0x%02x\n", control_status);
 524                         printk(KERN_DEBUG PFX "sending: 0x%02x\n",
 525                                 (control_status & WD_REVC_R2DS));
 526                 }
 527
 528                 /* clear reset status & Keep Relay 2 disable state as it is */
 529                 outb_p((control_status & WD_REVC_R2DS), pcwd_private.io_addr + 1);
 530
 531                 spin_unlock(&pcwd_private.io_lock);
 532         }
 533         return 0;
 534 }
 535
 536 static int pcwd_get_temperature(int *temperature)
 537 {
 538         /* check that port 0 gives temperature info and no command results */
 539         if (pcwd_private.command_mode)
 540                 return -1;
 541
 542         *temperature = 0;
 543         if (!pcwd_private.supports_temp)
 544                 return -ENODEV;
 545
 546         /*
 547          * Convert celsius to fahrenheit, since this was
 548          * the decided 'standard' for this return value.
 549          */
 550         spin_lock(&pcwd_private.io_lock);
 551         *temperature = ((inb(pcwd_private.io_addr)) * 9 / 5) + 32;
 552         spin_unlock(&pcwd_private.io_lock);
 553
 554         if (debug >= DEBUG) {
 555                 printk(KERN_DEBUG PFX "temperature is: %d F\n",
 556                         *temperature);
 557         }
 558
 559         return 0;
 560 }
 561
 562 /*
 563  *      /dev/watchdog handling
 564  */
 565
 566 static int pcwd_ioctl(struct inode *inode, struct file *file,
 567                       unsigned int cmd, unsigned long arg)
 568 {
 569         int rv;
 570         int status;
 571         int temperature;
 572         int new_heartbeat;
 573         int __user *argp = (int __user *)arg;
 574         static struct watchdog_info ident = {
 575                 .options =              WDIOF_OVERHEAT |
 576                                         WDIOF_CARDRESET |
 577                                         WDIOF_KEEPALIVEPING |
 578                                         WDIOF_SETTIMEOUT |
 579                                         WDIOF_MAGICCLOSE,
 580                 .firmware_version =     1,
 581                 .identity =             "PCWD",
 582         };
 583
 584         switch(cmd) {
 585         default:
 586                 return -ENOTTY;
 587
 588         case WDIOC_GETSUPPORT:
 589                 if(copy_to_user(argp, &ident, sizeof(ident)))
 590                         return -EFAULT;
 591                 return 0;
 592
 593         case WDIOC_GETSTATUS:
 594                 pcwd_get_status(&status);
 595                 return put_user(status, argp);
 596
 597         case WDIOC_GETBOOTSTATUS:
 598                 return put_user(pcwd_private.boot_status, argp);
 599
 600         case WDIOC_GETTEMP:
 601                 if (pcwd_get_temperature(&temperature))
 602                         return -EFAULT;
 603
 604                 return put_user(temperature, argp);
 605
 606         case WDIOC_SETOPTIONS:
 607                 if (pcwd_private.revision == PCWD_REVISION_C)
 608                 {
 609                         if(copy_from_user(&rv, argp, sizeof(int)))
 610                                 return -EFAULT;
 611
 612                         if (rv & WDIOS_DISABLECARD)
 613                         {
 614                                 return pcwd_stop();
 615                         }
 616
 617                         if (rv & WDIOS_ENABLECARD)
 618                         {
 619                                 return pcwd_start();
 620                         }
 621
 622                         if (rv & WDIOS_TEMPPANIC)
 623                         {
 624                                 temp_panic = 1;
 625                         }
 626                 }
 627                 return -EINVAL;
 628
 629         case WDIOC_KEEPALIVE:
 630                 pcwd_keepalive();
 631                 return 0;
 632
 633         case WDIOC_SETTIMEOUT:
 634                 if (get_user(new_heartbeat, argp))
 635                         return -EFAULT;
 636
 637                 if (pcwd_set_heartbeat(new_heartbeat))
 638                         return -EINVAL;
 639
 640                 pcwd_keepalive();
 641                 /* Fall */
 642
 643         case WDIOC_GETTIMEOUT:
 644                 return put_user(heartbeat, argp);
 645         }
 646
 647         return 0;
 648 }
 649
 650 static ssize_t pcwd_write(struct file *file, const char __user *buf, size_t len,
 651                           loff_t *ppos)
 652 {
 653         if (len) {
 654                 if (!nowayout) {
 655                         size_t i;
 656
 657                         /* In case it was set long ago */
 658                         expect_close = 0;
 659
 660                         for (i = 0; i != len; i++) {
 661                                 char c;
 662
 663                                 if (get_user(c, buf + i))
 664                                         return -EFAULT;
 665                                 if (c == 'V')
 666                                         expect_close = 42;
 667                         }
 668                 }
 669                 pcwd_keepalive();
 670         }
 671         return len;
 672 }
 673
 674 static int pcwd_open(struct inode *inode, struct file *file)
 675 {
 676         if (!atomic_dec_and_test(&open_allowed) ) {
 677                 if (debug >= VERBOSE)
 678                         printk(KERN_ERR PFX "Attempt to open already opened device.\n");
 679                 atomic_inc( &open_allowed );
 680                 return -EBUSY;
 681         }
 682
 683         if (nowayout)
 684                 __module_get(THIS_MODULE);
 685
 686         /* Activate */
 687         pcwd_start();
 688         pcwd_keepalive();
 689         return nonseekable_open(inode, file);
 690 }
 691
 692 static int pcwd_close(struct inode *inode, struct file *file)
 693 {
 694         if (expect_close == 42) {
 695                 pcwd_stop();
 696         } else {
 697                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 698                 pcwd_keepalive();
 699         }
 700         expect_close = 0;
 701         atomic_inc( &open_allowed );
 702         return 0;
 703 }
 704
 705 /*
 706  *      /dev/temperature handling
 707  */
 708
 709 static ssize_t pcwd_temp_read(struct file *file, char __user *buf, size_t count,
 710                          loff_t *ppos)
 711 {
 712         int temperature;
 713
 714         if (pcwd_get_temperature(&temperature))
 715                 return -EFAULT;
 716
 717         if (copy_to_user(buf, &temperature, 1))
 718                 return -EFAULT;
 719
 720         return 1;
 721 }
 722
 723 static int pcwd_temp_open(struct inode *inode, struct file *file)
 724 {
 725         if (!pcwd_private.supports_temp)
 726                 return -ENODEV;
 727
 728         return nonseekable_open(inode, file);
 729 }
 730
 731 static int pcwd_temp_close(struct inode *inode, struct file *file)
 732 {
 733         return 0;
 734 }
 735
 736 /*
 737  *      Notify system
 738  */
 739
 740 static int pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
 741 {
 742         if (code==SYS_DOWN || code==SYS_HALT) {
 743                 /* Turn the WDT off */
 744                 pcwd_stop();
 745         }
 746
 747         return NOTIFY_DONE;
 748 }
 749
 750 /*
 751  *      Kernel Interfaces
 752  */
 753
 754 static const struct file_operations pcwd_fops = {
 755         .owner          = THIS_MODULE,
 756         .llseek         = no_llseek,
 757         .write          = pcwd_write,
 758         .ioctl          = pcwd_ioctl,
 759         .open           = pcwd_open,
 760         .release        = pcwd_close,
 761 };
 762
 763 static struct miscdevice pcwd_miscdev = {
 764         .minor =        WATCHDOG_MINOR,
 765         .name =         "watchdog",
 766         .fops =         &pcwd_fops,
 767 };
 768
 769 static const struct file_operations pcwd_temp_fops = {
 770         .owner          = THIS_MODULE,
 771         .llseek         = no_llseek,
 772         .read           = pcwd_temp_read,
 773         .open           = pcwd_temp_open,
 774         .release        = pcwd_temp_close,
 775 };
 776
 777 static struct miscdevice temp_miscdev = {
 778         .minor =        TEMP_MINOR,
 779         .name =         "temperature",
 780         .fops =         &pcwd_temp_fops,
 781 };
 782
 783 static struct notifier_block pcwd_notifier = {
 784         .notifier_call =        pcwd_notify_sys,
 785 };
 786
 787 /*
 788  *      Init & exit routines
 789  */
 790
 791 static inline int get_revision(void)
 792 {
 793         int r = PCWD_REVISION_C;
 794
 795         spin_lock(&pcwd_private.io_lock);
 796         /* REV A cards use only 2 io ports; test
 797          * presumes a floating bus reads as 0xff. */
 798         if ((inb(pcwd_private.io_addr + 2) == 0xFF) ||
 799             (inb(pcwd_private.io_addr + 3) == 0xFF))
 800                 r=PCWD_REVISION_A;
 801         spin_unlock(&pcwd_private.io_lock);
 802
 803         return r;
 804 }
 805
 806 static int __devinit pcwatchdog_init(int base_addr)
 807 {
 808         int ret;
 809
 810         cards_found++;
 811         if (cards_found == 1)
 812                 printk(KERN_INFO PFX "v%s Ken Hollis (kenji@bitgate.com)\n", WD_VER);
 813
 814         if (cards_found > 1) {
 815                 printk(KERN_ERR PFX "This driver only supports 1 device\n");
 816                 return -ENODEV;
 817         }
 818
 819         if (base_addr == 0x0000) {
 820                 printk(KERN_ERR PFX "No I/O-Address for card detected\n");
 821                 return -ENODEV;
 822         }
 823         pcwd_private.io_addr = base_addr;
 824
 825         /* Check card's revision */
 826         pcwd_private.revision = get_revision();
 827
 828         if (!request_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4, "PCWD")) {
 829                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 830                         pcwd_private.io_addr);
 831                 pcwd_private.io_addr = 0x0000;
 832                 return -EIO;
 833         }
 834
 835         /* Initial variables */
 836         pcwd_private.supports_temp = 0;
 837         temp_panic = 0;
 838         pcwd_private.boot_status = 0x0000;
 839
 840         /* get the boot_status */
 841         pcwd_get_status(&pcwd_private.boot_status);
 842
 843         /* clear the "card caused reboot" flag */
 844         pcwd_clear_status();
 845
 846         init_timer(&pcwd_private.timer);
 847         pcwd_private.timer.function = pcwd_timer_ping;
 848         pcwd_private.timer.data = 0;
 849
 850         /*  Disable the board  */
 851         pcwd_stop();
 852
 853         /*  Check whether or not the card supports the temperature device */
 854         pcwd_check_temperature_support();
 855
 856         /* Show info about the card itself */
 857         pcwd_show_card_info();
 858
 859         /* If heartbeat = 0 then we use the heartbeat from the dip-switches */
 860         if (heartbeat == 0)
 861                 heartbeat = heartbeat_tbl[(pcwd_get_option_switches() & 0x07)];
 862
 863         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 864         if (pcwd_set_heartbeat(heartbeat)) {
 865                 pcwd_set_heartbeat(WATCHDOG_HEARTBEAT);
 866                 printk(KERN_INFO PFX "heartbeat value must be 2<=heartbeat<=7200, using %d\n",
 867                         WATCHDOG_HEARTBEAT);
 868         }
 869
 870         ret = register_reboot_notifier(&pcwd_notifier);
 871         if (ret) {
 872                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 873                         ret);
 874                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 875                 pcwd_private.io_addr = 0x0000;
 876                 return ret;
 877         }
 878
 879         if (pcwd_private.supports_temp) {
 880                 ret = misc_register(&temp_miscdev);
 881                 if (ret) {
 882                         printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 883                                 TEMP_MINOR, ret);
 884                         unregister_reboot_notifier(&pcwd_notifier);
 885                         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 886                         pcwd_private.io_addr = 0x0000;
 887                         return ret;
 888                 }
 889         }
 890
 891         ret = misc_register(&pcwd_miscdev);
 892         if (ret) {
 893                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 894                         WATCHDOG_MINOR, ret);
 895                 if (pcwd_private.supports_temp)
 896                         misc_deregister(&temp_miscdev);
 897                 unregister_reboot_notifier(&pcwd_notifier);
 898                 release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 899                 pcwd_private.io_addr = 0x0000;
 900                 return ret;
 901         }
 902
 903         printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
 904                 heartbeat, nowayout);
 905
 906         return 0;
 907 }
 908
 909 static void __devexit pcwatchdog_exit(void)
 910 {
 911         /*  Disable the board  */
 912         if (!nowayout)
 913                 pcwd_stop();
 914
 915         /* Deregister */
 916         misc_deregister(&pcwd_miscdev);
 917         if (pcwd_private.supports_temp)
 918                 misc_deregister(&temp_miscdev);
 919         unregister_reboot_notifier(&pcwd_notifier);
 920         release_region(pcwd_private.io_addr, (pcwd_private.revision == PCWD_REVISION_A) ? 2 : 4);
 921         pcwd_private.io_addr = 0x0000;
 922         cards_found--;
 923 }
 924
 925 /*
 926  *  The ISA cards have a heartbeat bit in one of the registers, which
 927  *  register is card dependent.  The heartbeat bit is monitored, and if
 928  *  found, is considered proof that a Berkshire card has been found.
 929  *  The initial rate is once per second at board start up, then twice
 930  *  per second for normal operation.
 931  */
 932 static int __init pcwd_checkcard(int base_addr)
 933 {
 934         int port0, last_port0;  /* Reg 0, in case it's REV A */
 935         int port1, last_port1;  /* Register 1 for REV C cards */
 936         int i;
 937         int retval;
 938
 939         if (!request_region (base_addr, 4, "PCWD")) {
 940                 printk (KERN_INFO PFX "Port 0x%04x unavailable\n", base_addr);
 941                 return 0;
 942         }
 943
 944         retval = 0;
 945
 946         port0 = inb_p(base_addr);       /* For REV A boards */
 947         port1 = inb_p(base_addr + 1);   /* For REV C boards */
 948         if (port0 != 0xff || port1 != 0xff) {
 949                 /* Not an 'ff' from a floating bus, so must be a card! */
 950                 for (i = 0; i < 4; ++i) {
 951
 952                         msleep(500);
 953
 954                         last_port0 = port0;
 955                         last_port1 = port1;
 956
 957                         port0 = inb_p(base_addr);
 958                         port1 = inb_p(base_addr + 1);
 959
 960                         /* Has either hearbeat bit changed?  */
 961                         if ((port0 ^ last_port0) & WD_HRTBT ||
 962                             (port1 ^ last_port1) & WD_REVC_HRBT) {
 963                                 retval = 1;
 964                                 break;
 965                         }
 966                 }
 967         }
 968         release_region (base_addr, 4);
 969
 970         return retval;
 971 }
 972
 973 /*
 974  * These are the auto-probe addresses available.
 975  *
 976  * Revision A only uses ports 0x270 and 0x370.  Revision C introduced 0x350.
 977  * Revision A has an address range of 2 addresses, while Revision C has 4.
 978  */
 979 static int pcwd_ioports[] = { 0x270, 0x350, 0x370, 0x000 };
 980
 981 static int __init pcwd_init_module(void)
 982 {
 983         int i, found = 0;
 984
 985         spin_lock_init(&pcwd_private.io_lock);
 986
 987         for (i = 0; pcwd_ioports[i] != 0; i++) {
 988                 if (pcwd_checkcard(pcwd_ioports[i])) {
 989                         if (!(pcwatchdog_init(pcwd_ioports[i])))
 990                                 found++;
 991                 }
 992         }
 993
 994         if (!found) {
 995                 printk (KERN_INFO PFX "No card detected, or port not available\n");
 996                 return -ENODEV;
 997         }
 998
 999         return 0;
1000 }
1001
1002 static void __exit pcwd_cleanup_module(void)
1003 {
1004         if (pcwd_private.io_addr)
1005                 pcwatchdog_exit();
1006
1007         printk(KERN_INFO PFX "Watchdog Module Unloaded.\n");
1008 }
1009
1010 module_init(pcwd_init_module);
1011 module_exit(pcwd_cleanup_module);
1012
1013 MODULE_AUTHOR("Ken Hollis <kenji@bitgate.com>");
1014 MODULE_DESCRIPTION("Berkshire ISA-PC Watchdog driver");
1015 MODULE_LICENSE("GPL");
1016 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
1017 MODULE_ALIAS_MISCDEV(TEMP_MINOR);