drivers/watchdog/wdt977.c

   1 /*
   2  *      Wdt977  0.04:   A Watchdog Device for Netwinder W83977AF chip
   3  *
   4  *      (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>)
   5  *
   6  *                      -----------------------
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  *
  13  *                      -----------------------
  14  *      14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
  15  *           Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
  16  *      19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface
  17  *      06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts
  18  *                                  from minutes to seconds.
  19  *      07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in
  20  *                                    nwwatchdog_init.
  21  *      25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks
  22  *                                  remove limitiation to be used on
  23  *                                  Netwinders only
  24  */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/moduleparam.h>
  30 #include <linux/types.h>
  31 #include <linux/kernel.h>
  32 #include <linux/fs.h>
  33 #include <linux/miscdevice.h>
  34 #include <linux/init.h>
  35 #include <linux/ioport.h>
  36 #include <linux/watchdog.h>
  37 #include <linux/notifier.h>
  38 #include <linux/reboot.h>
  39 #include <linux/io.h>
  40 #include <linux/uaccess.h>
  41
  42 #include <asm/mach-types.h>
  43
  44 #define WATCHDOG_VERSION  "0.04"
  45 #define WATCHDOG_NAME     "Wdt977"
  46
  47 #define IO_INDEX_PORT   0x370           /* on some systems it can be 0x3F0 */
  48 #define IO_DATA_PORT    (IO_INDEX_PORT + 1)
  49
  50 #define UNLOCK_DATA     0x87
  51 #define LOCK_DATA       0xAA
  52 #define DEVICE_REGISTER 0x07
  53
  54
  55 #define DEFAULT_TIMEOUT 60                      /* default timeout in seconds */
  56
  57 static  int timeout = DEFAULT_TIMEOUT;
  58 static  int timeoutM;                           /* timeout in minutes */
  59 static  unsigned long timer_alive;
  60 static  int testmode;
  61 static  char expect_close;
  62 static  DEFINE_SPINLOCK(spinlock);
  63
  64 module_param(timeout, int, 0);
  65 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default="
  66                                 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
  67 module_param(testmode, int, 0);
  68 MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
  69
  70 static bool nowayout = WATCHDOG_NOWAYOUT;
  71 module_param(nowayout, bool, 0);
  72 MODULE_PARM_DESC(nowayout,
  73                 "Watchdog cannot be stopped once started (default="
  74                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  75
  76 /*
  77  * Start the watchdog
  78  */
  79
  80 static int wdt977_start(void)
  81 {
  82         unsigned long flags;
  83
  84         spin_lock_irqsave(&spinlock, flags);
  85
  86         /* unlock the SuperIO chip */
  87         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
  88         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
  89
  90         /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
  91          * F2 has the timeout in minutes
  92          * F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
  93          *   at timeout, and to reset timer on kbd/mouse activity (not impl.)
  94          * F4 is used to just clear the TIMEOUT'ed state (bit 0)
  95          */
  96         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
  97         outb_p(0x08, IO_DATA_PORT);
  98         outb_p(0xF2, IO_INDEX_PORT);
  99         outb_p(timeoutM, IO_DATA_PORT);
 100         outb_p(0xF3, IO_INDEX_PORT);
 101         outb_p(0x00, IO_DATA_PORT);     /* another setting is 0E for
 102                                            kbd/mouse/LED */
 103         outb_p(0xF4, IO_INDEX_PORT);
 104         outb_p(0x00, IO_DATA_PORT);
 105
 106         /* At last select device Aux1 (dev=7) and set GP16 as a
 107          * watchdog output. In test mode watch the bit 1 on F4 to
 108          * indicate "triggered"
 109          */
 110         if (!testmode) {
 111                 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 112                 outb_p(0x07, IO_DATA_PORT);
 113                 outb_p(0xE6, IO_INDEX_PORT);
 114                 outb_p(0x08, IO_DATA_PORT);
 115         }
 116
 117         /* lock the SuperIO chip */
 118         outb_p(LOCK_DATA, IO_INDEX_PORT);
 119
 120         spin_unlock_irqrestore(&spinlock, flags);
 121         pr_info("activated\n");
 122
 123         return 0;
 124 }
 125
 126 /*
 127  * Stop the watchdog
 128  */
 129
 130 static int wdt977_stop(void)
 131 {
 132         unsigned long flags;
 133         spin_lock_irqsave(&spinlock, flags);
 134
 135         /* unlock the SuperIO chip */
 136         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 137         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 138
 139         /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
 140         * F3 is reset to its default state
 141         * F4 can clear the TIMEOUT'ed state (bit 0) - back to default
 142         * We can not use GP17 as a PowerLed, as we use its usage as a RedLed
 143         */
 144         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 145         outb_p(0x08, IO_DATA_PORT);
 146         outb_p(0xF2, IO_INDEX_PORT);
 147         outb_p(0xFF, IO_DATA_PORT);
 148         outb_p(0xF3, IO_INDEX_PORT);
 149         outb_p(0x00, IO_DATA_PORT);
 150         outb_p(0xF4, IO_INDEX_PORT);
 151         outb_p(0x00, IO_DATA_PORT);
 152         outb_p(0xF2, IO_INDEX_PORT);
 153         outb_p(0x00, IO_DATA_PORT);
 154
 155         /* at last select device Aux1 (dev=7) and set
 156            GP16 as a watchdog output */
 157         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 158         outb_p(0x07, IO_DATA_PORT);
 159         outb_p(0xE6, IO_INDEX_PORT);
 160         outb_p(0x08, IO_DATA_PORT);
 161
 162         /* lock the SuperIO chip */
 163         outb_p(LOCK_DATA, IO_INDEX_PORT);
 164
 165         spin_unlock_irqrestore(&spinlock, flags);
 166         pr_info("shutdown\n");
 167
 168         return 0;
 169 }
 170
 171 /*
 172  * Send a keepalive ping to the watchdog
 173  * This is done by simply re-writing the timeout to reg. 0xF2
 174  */
 175
 176 static int wdt977_keepalive(void)
 177 {
 178         unsigned long flags;
 179         spin_lock_irqsave(&spinlock, flags);
 180
 181         /* unlock the SuperIO chip */
 182         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 183         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 184
 185         /* select device Aux2 (device=8) and kicks watchdog reg F2 */
 186         /* F2 has the timeout in minutes */
 187         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 188         outb_p(0x08, IO_DATA_PORT);
 189         outb_p(0xF2, IO_INDEX_PORT);
 190         outb_p(timeoutM, IO_DATA_PORT);
 191
 192         /* lock the SuperIO chip */
 193         outb_p(LOCK_DATA, IO_INDEX_PORT);
 194         spin_unlock_irqrestore(&spinlock, flags);
 195
 196         return 0;
 197 }
 198
 199 /*
 200  * Set the watchdog timeout value
 201  */
 202
 203 static int wdt977_set_timeout(int t)
 204 {
 205         int tmrval;
 206
 207         /* convert seconds to minutes, rounding up */
 208         tmrval = (t + 59) / 60;
 209
 210         if (machine_is_netwinder()) {
 211                 /* we have a hw bug somewhere, so each 977 minute is actually
 212                  * only 30sec. This limits the max timeout to half of device
 213                  * max of 255 minutes...
 214                  */
 215                 tmrval += tmrval;
 216         }
 217
 218         if (tmrval < 1 || tmrval > 255)
 219                 return -EINVAL;
 220
 221         /* timeout is the timeout in seconds, timeoutM is
 222            the timeout in minutes) */
 223         timeout = t;
 224         timeoutM = tmrval;
 225         return 0;
 226 }
 227
 228 /*
 229  * Get the watchdog status
 230  */
 231
 232 static int wdt977_get_status(int *status)
 233 {
 234         int new_status;
 235         unsigned long flags;
 236
 237         spin_lock_irqsave(&spinlock, flags);
 238
 239         /* unlock the SuperIO chip */
 240         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 241         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 242
 243         /* select device Aux2 (device=8) and read watchdog reg F4 */
 244         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 245         outb_p(0x08, IO_DATA_PORT);
 246         outb_p(0xF4, IO_INDEX_PORT);
 247         new_status = inb_p(IO_DATA_PORT);
 248
 249         /* lock the SuperIO chip */
 250         outb_p(LOCK_DATA, IO_INDEX_PORT);
 251
 252         spin_unlock_irqrestore(&spinlock, flags);
 253
 254         *status = 0;
 255         if (new_status & 1)
 256                 *status |= WDIOF_CARDRESET;
 257
 258         return 0;
 259 }
 260
 261
 262 /*
 263  *      /dev/watchdog handling
 264  */
 265
 266 static int wdt977_open(struct inode *inode, struct file *file)
 267 {
 268         /* If the watchdog is alive we don't need to start it again */
 269         if (test_and_set_bit(0, &timer_alive))
 270                 return -EBUSY;
 271
 272         if (nowayout)
 273                 __module_get(THIS_MODULE);
 274
 275         wdt977_start();
 276         return nonseekable_open(inode, file);
 277 }
 278
 279 static int wdt977_release(struct inode *inode, struct file *file)
 280 {
 281         /*
 282          *      Shut off the timer.
 283          *      Lock it in if it's a module and we set nowayout
 284          */
 285         if (expect_close == 42) {
 286                 wdt977_stop();
 287                 clear_bit(0, &timer_alive);
 288         } else {
 289                 wdt977_keepalive();
 290                 pr_crit("Unexpected close, not stopping watchdog!\n");
 291         }
 292         expect_close = 0;
 293         return 0;
 294 }
 295
 296
 297 /*
 298  *      wdt977_write:
 299  *      @file: file handle to the watchdog
 300  *      @buf: buffer to write (unused as data does not matter here
 301  *      @count: count of bytes
 302  *      @ppos: pointer to the position to write. No seeks allowed
 303  *
 304  *      A write to a watchdog device is defined as a keepalive signal. Any
 305  *      write of data will do, as we we don't define content meaning.
 306  */
 307
 308 static ssize_t wdt977_write(struct file *file, const char __user *buf,
 309                             size_t count, loff_t *ppos)
 310 {
 311         if (count) {
 312                 if (!nowayout) {
 313                         size_t i;
 314
 315                         /* In case it was set long ago */
 316                         expect_close = 0;
 317
 318                         for (i = 0; i != count; i++) {
 319                                 char c;
 320                                 if (get_user(c, buf + i))
 321                                         return -EFAULT;
 322                                 if (c == 'V')
 323                                         expect_close = 42;
 324                         }
 325                 }
 326
 327                 /* someone wrote to us, we should restart timer */
 328                 wdt977_keepalive();
 329         }
 330         return count;
 331 }
 332
 333 static const struct watchdog_info ident = {
 334         .options =              WDIOF_SETTIMEOUT |
 335                                 WDIOF_MAGICCLOSE |
 336                                 WDIOF_KEEPALIVEPING,
 337         .firmware_version =     1,
 338         .identity =             WATCHDOG_NAME,
 339 };
 340
 341 /*
 342  *      wdt977_ioctl:
 343  *      @inode: inode of the device
 344  *      @file: file handle to the device
 345  *      @cmd: watchdog command
 346  *      @arg: argument pointer
 347  *
 348  *      The watchdog API defines a common set of functions for all watchdogs
 349  *      according to their available features.
 350  */
 351
 352 static long wdt977_ioctl(struct file *file, unsigned int cmd,
 353                                                         unsigned long arg)
 354 {
 355         int status;
 356         int new_options, retval = -EINVAL;
 357         int new_timeout;
 358         union {
 359                 struct watchdog_info __user *ident;
 360                 int __user *i;
 361         } uarg;
 362
 363         uarg.i = (int __user *)arg;
 364
 365         switch (cmd) {
 366         case WDIOC_GETSUPPORT:
 367                 return copy_to_user(uarg.ident, &ident,
 368                         sizeof(ident)) ? -EFAULT : 0;
 369
 370         case WDIOC_GETSTATUS:
 371                 wdt977_get_status(&status);
 372                 return put_user(status, uarg.i);
 373
 374         case WDIOC_GETBOOTSTATUS:
 375                 return put_user(0, uarg.i);
 376
 377         case WDIOC_SETOPTIONS:
 378                 if (get_user(new_options, uarg.i))
 379                         return -EFAULT;
 380
 381                 if (new_options & WDIOS_DISABLECARD) {
 382                         wdt977_stop();
 383                         retval = 0;
 384                 }
 385
 386                 if (new_options & WDIOS_ENABLECARD) {
 387                         wdt977_start();
 388                         retval = 0;
 389                 }
 390
 391                 return retval;
 392
 393         case WDIOC_KEEPALIVE:
 394                 wdt977_keepalive();
 395                 return 0;
 396
 397         case WDIOC_SETTIMEOUT:
 398                 if (get_user(new_timeout, uarg.i))
 399                         return -EFAULT;
 400
 401                 if (wdt977_set_timeout(new_timeout))
 402                         return -EINVAL;
 403
 404                 wdt977_keepalive();
 405                 /* Fall */
 406
 407         case WDIOC_GETTIMEOUT:
 408                 return put_user(timeout, uarg.i);
 409
 410         default:
 411                 return -ENOTTY;
 412
 413         }
 414 }
 415
 416 static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
 417         void *unused)
 418 {
 419         if (code == SYS_DOWN || code == SYS_HALT)
 420                 wdt977_stop();
 421         return NOTIFY_DONE;
 422 }
 423
 424 static const struct file_operations wdt977_fops = {
 425         .owner          = THIS_MODULE,
 426         .llseek         = no_llseek,
 427         .write          = wdt977_write,
 428         .unlocked_ioctl = wdt977_ioctl,
 429         .open           = wdt977_open,
 430         .release        = wdt977_release,
 431 };
 432
 433 static struct miscdevice wdt977_miscdev = {
 434         .minor          = WATCHDOG_MINOR,
 435         .name           = "watchdog",
 436         .fops           = &wdt977_fops,
 437 };
 438
 439 static struct notifier_block wdt977_notifier = {
 440         .notifier_call = wdt977_notify_sys,
 441 };
 442
 443 static int __init wd977_init(void)
 444 {
 445         int rc;
 446
 447         pr_info("driver v%s\n", WATCHDOG_VERSION);
 448
 449         /* Check that the timeout value is within its range;
 450            if not reset to the default */
 451         if (wdt977_set_timeout(timeout)) {
 452                 wdt977_set_timeout(DEFAULT_TIMEOUT);
 453                 pr_info("timeout value must be 60 < timeout < 15300, using %d\n",
 454                         DEFAULT_TIMEOUT);
 455         }
 456
 457         /* on Netwinder the IOports are already reserved by
 458          * arch/arm/mach-footbridge/netwinder-hw.c
 459          */
 460         if (!machine_is_netwinder()) {
 461                 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
 462                         pr_err("I/O address 0x%04x already in use\n",
 463                                IO_INDEX_PORT);
 464                         rc = -EIO;
 465                         goto err_out;
 466                 }
 467         }
 468
 469         rc = register_reboot_notifier(&wdt977_notifier);
 470         if (rc) {
 471                 pr_err("cannot register reboot notifier (err=%d)\n", rc);
 472                 goto err_out_region;
 473         }
 474
 475         rc = misc_register(&wdt977_miscdev);
 476         if (rc) {
 477                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 478                        wdt977_miscdev.minor, rc);
 479                 goto err_out_reboot;
 480         }
 481
 482         pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
 483                 timeout, nowayout, testmode);
 484
 485         return 0;
 486
 487 err_out_reboot:
 488         unregister_reboot_notifier(&wdt977_notifier);
 489 err_out_region:
 490         if (!machine_is_netwinder())
 491                 release_region(IO_INDEX_PORT, 2);
 492 err_out:
 493         return rc;
 494 }
 495
 496 static void __exit wd977_exit(void)
 497 {
 498         wdt977_stop();
 499         misc_deregister(&wdt977_miscdev);
 500         unregister_reboot_notifier(&wdt977_notifier);
 501         release_region(IO_INDEX_PORT, 2);
 502 }
 503
 504 module_init(wd977_init);
 505 module_exit(wd977_exit);
 506
 507 MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
 508 MODULE_DESCRIPTION("W83977AF Watchdog driver");
 509 MODULE_LICENSE("GPL");
 510 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);