drivers/char/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 Netwinders only
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/config.h>
  28 #include <linux/types.h>
  29 #include <linux/kernel.h>
  30 #include <linux/fs.h>
  31 #include <linux/miscdevice.h>
  32 #include <linux/init.h>
  33 #include <linux/ioport.h>
  34 #include <linux/watchdog.h>
  35 #include <linux/notifier.h>
  36 #include <linux/reboot.h>
  37
  38 #include <asm/io.h>
  39 #include <asm/system.h>
  40 #include <asm/mach-types.h>
  41 #include <asm/uaccess.h>
  42
  43 #define WATCHDOG_VERSION  "0.04"
  44 #define WATCHDOG_NAME     "Wdt977"
  45 #define PFX WATCHDOG_NAME ": "
  46 #define DRIVER_VERSION    WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
  47
  48 #define IO_INDEX_PORT   0x370           /* on some systems it can be 0x3F0 */
  49 #define IO_DATA_PORT    (IO_INDEX_PORT+1)
  50
  51 #define UNLOCK_DATA     0x87
  52 #define LOCK_DATA       0xAA
  53 #define DEVICE_REGISTER 0x07
  54
  55
  56 #define DEFAULT_TIMEOUT 60                      /* default timeout in seconds */
  57
  58 static  int timeout = DEFAULT_TIMEOUT;
  59 static  int timeoutM;                           /* timeout in minutes */
  60 static  unsigned long timer_alive;
  61 static  int testmode;
  62 static  char expect_close;
  63 static  spinlock_t spinlock;
  64
  65 module_param(timeout, int, 0);
  66 MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (60..15300), default=" __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 int nowayout = WATCHDOG_NOWAYOUT;
  71 module_param(nowayout, int, 0);
  72 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
  73
  74 /*
  75  * Start the watchdog
  76  */
  77
  78 static int wdt977_start(void)
  79 {
  80         unsigned long flags;
  81
  82         spin_lock_irqsave(&spinlock, flags);
  83
  84         /* unlock the SuperIO chip */
  85         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
  86         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
  87
  88         /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
  89          * F2 has the timeout in minutes
  90          * F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
  91          *   at timeout, and to reset timer on kbd/mouse activity (not impl.)
  92          * F4 is used to just clear the TIMEOUT'ed state (bit 0)
  93          */
  94         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
  95         outb_p(0x08, IO_DATA_PORT);
  96         outb_p(0xF2, IO_INDEX_PORT);
  97         outb_p(timeoutM, IO_DATA_PORT);
  98         outb_p(0xF3, IO_INDEX_PORT);
  99         outb_p(0x00, IO_DATA_PORT);     /* another setting is 0E for kbd/mouse/LED */
 100         outb_p(0xF4, IO_INDEX_PORT);
 101         outb_p(0x00, IO_DATA_PORT);
 102
 103         /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */
 104         /* in test mode watch the bit 1 on F4 to indicate "triggered" */
 105         if (!testmode)
 106         {
 107                 outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 108                 outb_p(0x07, IO_DATA_PORT);
 109                 outb_p(0xE6, IO_INDEX_PORT);
 110                 outb_p(0x08, IO_DATA_PORT);
 111         }
 112
 113         /* lock the SuperIO chip */
 114         outb_p(LOCK_DATA, IO_INDEX_PORT);
 115
 116         spin_unlock_irqrestore(&spinlock, flags);
 117         printk(KERN_INFO PFX "activated.\n");
 118
 119         return 0;
 120 }
 121
 122 /*
 123  * Stop the watchdog
 124  */
 125
 126 static int wdt977_stop(void)
 127 {
 128         unsigned long flags;
 129         spin_lock_irqsave(&spinlock, flags);
 130
 131         /* unlock the SuperIO chip */
 132         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 133         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 134
 135         /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
 136         * F3 is reset to its default state
 137         * F4 can clear the TIMEOUT'ed state (bit 0) - back to default
 138         * We can not use GP17 as a PowerLed, as we use its usage as a RedLed
 139         */
 140         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 141         outb_p(0x08, IO_DATA_PORT);
 142         outb_p(0xF2, IO_INDEX_PORT);
 143         outb_p(0xFF, IO_DATA_PORT);
 144         outb_p(0xF3, IO_INDEX_PORT);
 145         outb_p(0x00, IO_DATA_PORT);
 146         outb_p(0xF4, IO_INDEX_PORT);
 147         outb_p(0x00, IO_DATA_PORT);
 148         outb_p(0xF2, IO_INDEX_PORT);
 149         outb_p(0x00, IO_DATA_PORT);
 150
 151         /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */
 152         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 153         outb_p(0x07, IO_DATA_PORT);
 154         outb_p(0xE6, IO_INDEX_PORT);
 155         outb_p(0x08, IO_DATA_PORT);
 156
 157         /* lock the SuperIO chip */
 158         outb_p(LOCK_DATA, IO_INDEX_PORT);
 159
 160         spin_unlock_irqrestore(&spinlock, flags);
 161         printk(KERN_INFO PFX "shutdown.\n");
 162
 163         return 0;
 164 }
 165
 166 /*
 167  * Send a keepalive ping to the watchdog
 168  * This is done by simply re-writing the timeout to reg. 0xF2
 169  */
 170
 171 static int wdt977_keepalive(void)
 172 {
 173         unsigned long flags;
 174         spin_lock_irqsave(&spinlock, flags);
 175
 176         /* unlock the SuperIO chip */
 177         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 178         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 179
 180         /* select device Aux2 (device=8) and kicks watchdog reg F2 */
 181         /* F2 has the timeout in minutes */
 182         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 183         outb_p(0x08, IO_DATA_PORT);
 184         outb_p(0xF2, IO_INDEX_PORT);
 185         outb_p(timeoutM, IO_DATA_PORT);
 186
 187         /* lock the SuperIO chip */
 188         outb_p(LOCK_DATA, IO_INDEX_PORT);
 189         spin_unlock_irqrestore(&spinlock, flags);
 190
 191         return 0;
 192 }
 193
 194 /*
 195  * Set the watchdog timeout value
 196  */
 197
 198 static int wdt977_set_timeout(int t)
 199 {
 200         int tmrval;
 201
 202         /* convert seconds to minutes, rounding up */
 203         tmrval = (t + 59) / 60;
 204
 205         if (machine_is_netwinder()) {
 206                 /* we have a hw bug somewhere, so each 977 minute is actually only 30sec
 207                  *  this limits the max timeout to half of device max of 255 minutes...
 208                  */
 209                 tmrval += tmrval;
 210         }
 211
 212         if ((tmrval < 1) || (tmrval > 255))
 213                 return -EINVAL;
 214
 215         /* timeout is the timeout in seconds, timeoutM is the timeout in minutes) */
 216         timeout = t;
 217         timeoutM = tmrval;
 218         return 0;
 219 }
 220
 221 /*
 222  * Get the watchdog status
 223  */
 224
 225 static int wdt977_get_status(int *status)
 226 {
 227         int new_status;
 228         unsigned long flags;
 229
 230         spin_lock_irqsave(&spinlock, flags);
 231
 232         /* unlock the SuperIO chip */
 233         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 234         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 235
 236         /* select device Aux2 (device=8) and read watchdog reg F4 */
 237         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 238         outb_p(0x08, IO_DATA_PORT);
 239         outb_p(0xF4, IO_INDEX_PORT);
 240         new_status = inb_p(IO_DATA_PORT);
 241
 242         /* lock the SuperIO chip */
 243         outb_p(LOCK_DATA, IO_INDEX_PORT);
 244
 245         spin_unlock_irqrestore(&spinlock, flags);
 246
 247         *status=0;
 248         if (new_status & 1)
 249                 *status |= WDIOF_CARDRESET;
 250
 251         return 0;
 252 }
 253
 254
 255 /*
 256  *      /dev/watchdog handling
 257  */
 258
 259 static int wdt977_open(struct inode *inode, struct file *file)
 260 {
 261         /* If the watchdog is alive we don't need to start it again */
 262         if( test_and_set_bit(0,&timer_alive) )
 263                 return -EBUSY;
 264
 265         if (nowayout)
 266                 __module_get(THIS_MODULE);
 267
 268         wdt977_start();
 269         return nonseekable_open(inode, file);
 270 }
 271
 272 static int wdt977_release(struct inode *inode, struct file *file)
 273 {
 274         /*
 275          *      Shut off the timer.
 276          *      Lock it in if it's a module and we set nowayout
 277          */
 278         if (expect_close == 42)
 279         {
 280                 wdt977_stop();
 281                 clear_bit(0,&timer_alive);
 282         } else {
 283                 wdt977_keepalive();
 284                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 285         }
 286         expect_close = 0;
 287         return 0;
 288 }
 289
 290
 291 /*
 292  *      wdt977_write:
 293  *      @file: file handle to the watchdog
 294  *      @buf: buffer to write (unused as data does not matter here
 295  *      @count: count of bytes
 296  *      @ppos: pointer to the position to write. No seeks allowed
 297  *
 298  *      A write to a watchdog device is defined as a keepalive signal. Any
 299  *      write of data will do, as we we don't define content meaning.
 300  */
 301
 302 static ssize_t wdt977_write(struct file *file, const char __user *buf,
 303                             size_t count, loff_t *ppos)
 304 {
 305         if (count)
 306         {
 307                 if (!nowayout)
 308                 {
 309                         size_t i;
 310
 311                         /* In case it was set long ago */
 312                         expect_close = 0;
 313
 314                         for (i = 0; i != count; i++)
 315                         {
 316                                 char c;
 317                                 if (get_user(c, buf + i))
 318                                         return -EFAULT;
 319                                 if (c == 'V')
 320                                         expect_close = 42;
 321                         }
 322                 }
 323
 324                 /* someone wrote to us, we should restart timer */
 325                 wdt977_keepalive();
 326         }
 327         return count;
 328 }
 329
 330 /*
 331  *      wdt977_ioctl:
 332  *      @inode: inode of the device
 333  *      @file: file handle to the device
 334  *      @cmd: watchdog command
 335  *      @arg: argument pointer
 336  *
 337  *      The watchdog API defines a common set of functions for all watchdogs
 338  *      according to their available features.
 339  */
 340
 341 static struct watchdog_info ident = {
 342         .options =              WDIOF_SETTIMEOUT |
 343                                 WDIOF_MAGICCLOSE |
 344                                 WDIOF_KEEPALIVEPING,
 345         .firmware_version =     1,
 346         .identity =             WATCHDOG_NAME,
 347 };
 348
 349 static int wdt977_ioctl(struct inode *inode, struct file *file,
 350         unsigned int cmd, unsigned long arg)
 351 {
 352         int status;
 353         int new_options, retval = -EINVAL;
 354         int new_timeout;
 355         union {
 356                 struct watchdog_info __user *ident;
 357                 int __user *i;
 358         } uarg;
 359
 360         uarg.i = (int __user *)arg;
 361
 362         switch(cmd)
 363         {
 364         default:
 365                 return -ENOIOCTLCMD;
 366
 367         case WDIOC_GETSUPPORT:
 368                 return copy_to_user(uarg.ident, &ident,
 369                         sizeof(ident)) ? -EFAULT : 0;
 370
 371         case WDIOC_GETSTATUS:
 372                 wdt977_get_status(&status);
 373                 return put_user(status, uarg.i);
 374
 375         case WDIOC_GETBOOTSTATUS:
 376                 return put_user(0, uarg.i);
 377
 378         case WDIOC_KEEPALIVE:
 379                 wdt977_keepalive();
 380                 return 0;
 381
 382         case WDIOC_SETOPTIONS:
 383                 if (get_user (new_options, uarg.i))
 384                         return -EFAULT;
 385
 386                 if (new_options & WDIOS_DISABLECARD) {
 387                         wdt977_stop();
 388                         retval = 0;
 389                 }
 390
 391                 if (new_options & WDIOS_ENABLECARD) {
 392                         wdt977_start();
 393                         retval = 0;
 394                 }
 395
 396                 return retval;
 397
 398         case WDIOC_SETTIMEOUT:
 399                 if (get_user(new_timeout, uarg.i))
 400                         return -EFAULT;
 401
 402                 if (wdt977_set_timeout(new_timeout))
 403                     return -EINVAL;
 404
 405                 wdt977_keepalive();
 406                 /* Fall */
 407
 408         case WDIOC_GETTIMEOUT:
 409                 return put_user(timeout, uarg.i);
 410
 411         }
 412 }
 413
 414 static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
 415         void *unused)
 416 {
 417         if(code==SYS_DOWN || code==SYS_HALT)
 418                 wdt977_stop();
 419         return NOTIFY_DONE;
 420 }
 421
 422 static struct file_operations wdt977_fops=
 423 {
 424         .owner          = THIS_MODULE,
 425         .llseek         = no_llseek,
 426         .write          = wdt977_write,
 427         .ioctl          = wdt977_ioctl,
 428         .open           = wdt977_open,
 429         .release        = wdt977_release,
 430 };
 431
 432 static struct miscdevice wdt977_miscdev=
 433 {
 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         //if (!machine_is_netwinder())
 448         //      return -ENODEV;
 449
 450         printk(KERN_INFO PFX DRIVER_VERSION);
 451
 452         spin_lock_init(&spinlock);
 453
 454         /* Check that the timeout value is within it's range ; if not reset to the default */
 455         if (wdt977_set_timeout(timeout))
 456         {
 457                 wdt977_set_timeout(DEFAULT_TIMEOUT);
 458                 printk(KERN_INFO PFX "timeout value must be 60<timeout<15300, using %d\n",
 459                         DEFAULT_TIMEOUT);
 460         }
 461
 462         /* on Netwinder the IOports are already reserved by
 463          * arch/arm/mach-footbridge/netwinder-hw.c
 464          */
 465         if (!machine_is_netwinder())
 466         {
 467                 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME))
 468                 {
 469                         printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 470                                 IO_INDEX_PORT);
 471                         rc = -EIO;
 472                         goto err_out;
 473                 }
 474         }
 475
 476         rc = misc_register(&wdt977_miscdev);
 477         if (rc)
 478         {
 479                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 480                         wdt977_miscdev.minor, rc);
 481                 goto err_out_region;
 482         }
 483
 484         rc = register_reboot_notifier(&wdt977_notifier);
 485         if (rc)
 486         {
 487                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 488                         rc);
 489                 goto err_out_miscdev;
 490         }
 491
 492         printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
 493                 timeout, nowayout, testmode);
 494
 495         return 0;
 496
 497 err_out_miscdev:
 498         misc_deregister(&wdt977_miscdev);
 499 err_out_region:
 500         if (!machine_is_netwinder())
 501                 release_region(IO_INDEX_PORT,2);
 502 err_out:
 503         return rc;
 504 }
 505
 506 static void __exit wd977_exit(void)
 507 {
 508         wdt977_stop();
 509         misc_deregister(&wdt977_miscdev);
 510         unregister_reboot_notifier(&wdt977_notifier);
 511         release_region(IO_INDEX_PORT,2);
 512 }
 513
 514 module_init(wd977_init);
 515 module_exit(wd977_exit);
 516
 517 MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
 518 MODULE_DESCRIPTION("W83977AF Watchdog driver");
 519 MODULE_LICENSE("GPL");
 520 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);