drivers/watchdog/w83977f_wdt.c

   1 /*
   2  *      W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip
   3  *
   4  *      (c) Copyright 2005  Jose Goncalves <jose.goncalves@inov.pt>
   5  *
   6  *      Based on w83877f_wdt.c by Scott Jennings,
   7  *           and wdt977.c by Woody Suwalski
   8  *
   9  *                      -----------------------
  10  *
  11  *      This program is free software; you can redistribute it and/or
  12  *      modify it under the terms of the GNU General Public License
  13  *      as published by the Free Software Foundation; either version
  14  *      2 of the License, or (at your option) any later version.
  15  *
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/types.h>
  21 #include <linux/kernel.h>
  22 #include <linux/fs.h>
  23 #include <linux/miscdevice.h>
  24 #include <linux/init.h>
  25 #include <linux/ioport.h>
  26 #include <linux/watchdog.h>
  27 #include <linux/notifier.h>
  28 #include <linux/reboot.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/io.h>
  31
  32 #include <asm/system.h>
  33
  34 #define WATCHDOG_VERSION  "1.00"
  35 #define WATCHDOG_NAME     "W83977F WDT"
  36 #define PFX WATCHDOG_NAME ": "
  37 #define DRIVER_VERSION    WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
  38
  39 #define IO_INDEX_PORT     0x3F0
  40 #define IO_DATA_PORT      (IO_INDEX_PORT+1)
  41
  42 #define UNLOCK_DATA       0x87
  43 #define LOCK_DATA         0xAA
  44 #define DEVICE_REGISTER   0x07
  45
  46 #define DEFAULT_TIMEOUT   45            /* default timeout in seconds */
  47
  48 static  int timeout = DEFAULT_TIMEOUT;
  49 static  int timeoutW;                   /* timeout in watchdog counter units */
  50 static  unsigned long timer_alive;
  51 static  int testmode;
  52 static  char expect_close;
  53 static  DEFINE_SPINLOCK(spinlock);
  54
  55 module_param(timeout, int, 0);
  56 MODULE_PARM_DESC(timeout,
  57                 "Watchdog timeout in seconds (15..7635), default="
  58                                 __MODULE_STRING(DEFAULT_TIMEOUT) ")");
  59 module_param(testmode, int, 0);
  60 MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0");
  61
  62 static int nowayout = WATCHDOG_NOWAYOUT;
  63 module_param(nowayout, int, 0);
  64 MODULE_PARM_DESC(nowayout,
  65                 "Watchdog cannot be stopped once started (default="
  66                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  67
  68 /*
  69  * Start the watchdog
  70  */
  71
  72 static int wdt_start(void)
  73 {
  74         unsigned long flags;
  75
  76         spin_lock_irqsave(&spinlock, flags);
  77
  78         /* Unlock the SuperIO chip */
  79         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
  80         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
  81
  82         /*
  83          * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
  84          * F2 has the timeout in watchdog counter units.
  85          * F3 is set to enable watchdog LED blink at timeout.
  86          * F4 is used to just clear the TIMEOUT'ed state (bit 0).
  87          */
  88         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
  89         outb_p(0x08, IO_DATA_PORT);
  90         outb_p(0xF2, IO_INDEX_PORT);
  91         outb_p(timeoutW, IO_DATA_PORT);
  92         outb_p(0xF3, IO_INDEX_PORT);
  93         outb_p(0x08, IO_DATA_PORT);
  94         outb_p(0xF4, IO_INDEX_PORT);
  95         outb_p(0x00, IO_DATA_PORT);
  96
  97         /* Set device Aux2 active */
  98         outb_p(0x30, IO_INDEX_PORT);
  99         outb_p(0x01, IO_DATA_PORT);
 100
 101         /*
 102          * Select device Aux1 (dev=7) to set GP16 as the watchdog output
 103          * (in reg E6) and GP13 as the watchdog LED output (in reg E3).
 104          * Map GP16 at pin 119.
 105          * In test mode watch the bit 0 on F4 to indicate "triggered" or
 106          * check watchdog LED on SBC.
 107          */
 108         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 109         outb_p(0x07, IO_DATA_PORT);
 110         if (!testmode) {
 111                 unsigned pin_map;
 112
 113                 outb_p(0xE6, IO_INDEX_PORT);
 114                 outb_p(0x0A, IO_DATA_PORT);
 115                 outb_p(0x2C, IO_INDEX_PORT);
 116                 pin_map = inb_p(IO_DATA_PORT);
 117                 pin_map |= 0x10;
 118                 pin_map &= ~(0x20);
 119                 outb_p(0x2C, IO_INDEX_PORT);
 120                 outb_p(pin_map, IO_DATA_PORT);
 121         }
 122         outb_p(0xE3, IO_INDEX_PORT);
 123         outb_p(0x08, IO_DATA_PORT);
 124
 125         /* Set device Aux1 active */
 126         outb_p(0x30, IO_INDEX_PORT);
 127         outb_p(0x01, IO_DATA_PORT);
 128
 129         /* Lock the SuperIO chip */
 130         outb_p(LOCK_DATA, IO_INDEX_PORT);
 131
 132         spin_unlock_irqrestore(&spinlock, flags);
 133
 134         printk(KERN_INFO PFX "activated.\n");
 135
 136         return 0;
 137 }
 138
 139 /*
 140  * Stop the watchdog
 141  */
 142
 143 static int wdt_stop(void)
 144 {
 145         unsigned long flags;
 146
 147         spin_lock_irqsave(&spinlock, flags);
 148
 149         /* Unlock the SuperIO chip */
 150         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 151         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 152
 153         /*
 154          * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4.
 155          * F2 is reset to its default value (watchdog timer disabled).
 156          * F3 is reset to its default state.
 157          * F4 clears the TIMEOUT'ed state (bit 0) - back to default.
 158          */
 159         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 160         outb_p(0x08, IO_DATA_PORT);
 161         outb_p(0xF2, IO_INDEX_PORT);
 162         outb_p(0xFF, IO_DATA_PORT);
 163         outb_p(0xF3, IO_INDEX_PORT);
 164         outb_p(0x00, IO_DATA_PORT);
 165         outb_p(0xF4, IO_INDEX_PORT);
 166         outb_p(0x00, IO_DATA_PORT);
 167         outb_p(0xF2, IO_INDEX_PORT);
 168         outb_p(0x00, IO_DATA_PORT);
 169
 170         /*
 171          * Select device Aux1 (dev=7) to set GP16 (in reg E6) and
 172          * Gp13 (in reg E3) as inputs.
 173          */
 174         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 175         outb_p(0x07, IO_DATA_PORT);
 176         if (!testmode) {
 177                 outb_p(0xE6, IO_INDEX_PORT);
 178                 outb_p(0x01, IO_DATA_PORT);
 179         }
 180         outb_p(0xE3, IO_INDEX_PORT);
 181         outb_p(0x01, IO_DATA_PORT);
 182
 183         /* Lock the SuperIO chip */
 184         outb_p(LOCK_DATA, IO_INDEX_PORT);
 185
 186         spin_unlock_irqrestore(&spinlock, flags);
 187
 188         printk(KERN_INFO PFX "shutdown.\n");
 189
 190         return 0;
 191 }
 192
 193 /*
 194  * Send a keepalive ping to the watchdog
 195  * This is done by simply re-writing the timeout to reg. 0xF2
 196  */
 197
 198 static int wdt_keepalive(void)
 199 {
 200         unsigned long flags;
 201
 202         spin_lock_irqsave(&spinlock, flags);
 203
 204         /* Unlock the SuperIO chip */
 205         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 206         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 207
 208         /* Select device Aux2 (device=8) to kick watchdog reg F2 */
 209         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 210         outb_p(0x08, IO_DATA_PORT);
 211         outb_p(0xF2, IO_INDEX_PORT);
 212         outb_p(timeoutW, IO_DATA_PORT);
 213
 214         /* Lock the SuperIO chip */
 215         outb_p(LOCK_DATA, IO_INDEX_PORT);
 216
 217         spin_unlock_irqrestore(&spinlock, flags);
 218
 219         return 0;
 220 }
 221
 222 /*
 223  * Set the watchdog timeout value
 224  */
 225
 226 static int wdt_set_timeout(int t)
 227 {
 228         int tmrval;
 229
 230         /*
 231          * Convert seconds to watchdog counter time units, rounding up.
 232          * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup
 233          * value. This information is supplied in the PCM-5335 manual and was
 234          * checked by me on a real board. This is a bit strange because W83977f
 235          * datasheet says counter unit is in minutes!
 236          */
 237         if (t < 15)
 238                 return -EINVAL;
 239
 240         tmrval = ((t + 15) + 29) / 30;
 241
 242         if (tmrval > 255)
 243                 return -EINVAL;
 244
 245         /*
 246          * timeout is the timeout in seconds,
 247          * timeoutW is the timeout in watchdog counter units.
 248          */
 249         timeoutW = tmrval;
 250         timeout = (timeoutW * 30) - 15;
 251         return 0;
 252 }
 253
 254 /*
 255  * Get the watchdog status
 256  */
 257
 258 static int wdt_get_status(int *status)
 259 {
 260         int new_status;
 261         unsigned long flags;
 262
 263         spin_lock_irqsave(&spinlock, flags);
 264
 265         /* Unlock the SuperIO chip */
 266         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 267         outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 268
 269         /* Select device Aux2 (device=8) to read watchdog reg F4 */
 270         outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 271         outb_p(0x08, IO_DATA_PORT);
 272         outb_p(0xF4, IO_INDEX_PORT);
 273         new_status = inb_p(IO_DATA_PORT);
 274
 275         /* Lock the SuperIO chip */
 276         outb_p(LOCK_DATA, IO_INDEX_PORT);
 277
 278         spin_unlock_irqrestore(&spinlock, flags);
 279
 280         *status = 0;
 281         if (new_status & 1)
 282                 *status |= WDIOF_CARDRESET;
 283
 284         return 0;
 285 }
 286
 287
 288 /*
 289  *      /dev/watchdog handling
 290  */
 291
 292 static int wdt_open(struct inode *inode, struct file *file)
 293 {
 294         /* If the watchdog is alive we don't need to start it again */
 295         if (test_and_set_bit(0, &timer_alive))
 296                 return -EBUSY;
 297
 298         if (nowayout)
 299                 __module_get(THIS_MODULE);
 300
 301         wdt_start();
 302         return nonseekable_open(inode, file);
 303 }
 304
 305 static int wdt_release(struct inode *inode, struct file *file)
 306 {
 307         /*
 308          * Shut off the timer.
 309          * Lock it in if it's a module and we set nowayout
 310          */
 311         if (expect_close == 42) {
 312                 wdt_stop();
 313                 clear_bit(0, &timer_alive);
 314         } else {
 315                 wdt_keepalive();
 316                 printk(KERN_CRIT PFX
 317                         "unexpected close, not stopping watchdog!\n");
 318         }
 319         expect_close = 0;
 320         return 0;
 321 }
 322
 323 /*
 324  *      wdt_write:
 325  *      @file: file handle to the watchdog
 326  *      @buf: buffer to write (unused as data does not matter here
 327  *      @count: count of bytes
 328  *      @ppos: pointer to the position to write. No seeks allowed
 329  *
 330  *      A write to a watchdog device is defined as a keepalive signal. Any
 331  *      write of data will do, as we we don't define content meaning.
 332  */
 333
 334 static ssize_t wdt_write(struct file *file, const char __user *buf,
 335                             size_t count, loff_t *ppos)
 336 {
 337         /* See if we got the magic character 'V' and reload the timer */
 338         if (count) {
 339                 if (!nowayout) {
 340                         size_t ofs;
 341
 342                         /* note: just in case someone wrote the
 343                            magic character long ago */
 344                         expect_close = 0;
 345
 346                         /* scan to see whether or not we got the
 347                            magic character */
 348                         for (ofs = 0; ofs != count; ofs++) {
 349                                 char c;
 350                                 if (get_user(c, buf + ofs))
 351                                         return -EFAULT;
 352                                 if (c == 'V')
 353                                         expect_close = 42;
 354                         }
 355                 }
 356
 357                 /* someone wrote to us, we should restart timer */
 358                 wdt_keepalive();
 359         }
 360         return count;
 361 }
 362
 363 /*
 364  *      wdt_ioctl:
 365  *      @inode: inode of the device
 366  *      @file: file handle to the device
 367  *      @cmd: watchdog command
 368  *      @arg: argument pointer
 369  *
 370  *      The watchdog API defines a common set of functions for all watchdogs
 371  *      according to their available features.
 372  */
 373
 374 static const struct watchdog_info ident = {
 375         .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
 376         .firmware_version =     1,
 377         .identity = WATCHDOG_NAME,
 378 };
 379
 380 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 381 {
 382         int status;
 383         int new_options, retval = -EINVAL;
 384         int new_timeout;
 385         union {
 386                 struct watchdog_info __user *ident;
 387                 int __user *i;
 388         } uarg;
 389
 390         uarg.i = (int __user *)arg;
 391
 392         switch (cmd) {
 393         case WDIOC_GETSUPPORT:
 394                 return copy_to_user(uarg.ident, &ident,
 395                                                 sizeof(ident)) ? -EFAULT : 0;
 396
 397         case WDIOC_GETSTATUS:
 398                 wdt_get_status(&status);
 399                 return put_user(status, uarg.i);
 400
 401         case WDIOC_GETBOOTSTATUS:
 402                 return put_user(0, uarg.i);
 403
 404         case WDIOC_SETOPTIONS:
 405                 if (get_user(new_options, uarg.i))
 406                         return -EFAULT;
 407
 408                 if (new_options & WDIOS_DISABLECARD) {
 409                         wdt_stop();
 410                         retval = 0;
 411                 }
 412
 413                 if (new_options & WDIOS_ENABLECARD) {
 414                         wdt_start();
 415                         retval = 0;
 416                 }
 417
 418                 return retval;
 419
 420         case WDIOC_KEEPALIVE:
 421                 wdt_keepalive();
 422                 return 0;
 423
 424         case WDIOC_SETTIMEOUT:
 425                 if (get_user(new_timeout, uarg.i))
 426                         return -EFAULT;
 427
 428                 if (wdt_set_timeout(new_timeout))
 429                         return -EINVAL;
 430
 431                 wdt_keepalive();
 432                 /* Fall */
 433
 434         case WDIOC_GETTIMEOUT:
 435                 return put_user(timeout, uarg.i);
 436
 437         default:
 438                 return -ENOTTY;
 439
 440         }
 441 }
 442
 443 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
 444         void *unused)
 445 {
 446         if (code == SYS_DOWN || code == SYS_HALT)
 447                 wdt_stop();
 448         return NOTIFY_DONE;
 449 }
 450
 451 static const struct file_operations wdt_fops = {
 452         .owner          = THIS_MODULE,
 453         .llseek         = no_llseek,
 454         .write          = wdt_write,
 455         .unlocked_ioctl = wdt_ioctl,
 456         .open           = wdt_open,
 457         .release        = wdt_release,
 458 };
 459
 460 static struct miscdevice wdt_miscdev = {
 461         .minor          = WATCHDOG_MINOR,
 462         .name           = "watchdog",
 463         .fops           = &wdt_fops,
 464 };
 465
 466 static struct notifier_block wdt_notifier = {
 467         .notifier_call = wdt_notify_sys,
 468 };
 469
 470 static int __init w83977f_wdt_init(void)
 471 {
 472         int rc;
 473
 474         printk(KERN_INFO PFX DRIVER_VERSION);
 475
 476         /*
 477          * Check that the timeout value is within it's range;
 478          * if not reset to the default
 479          */
 480         if (wdt_set_timeout(timeout)) {
 481                 wdt_set_timeout(DEFAULT_TIMEOUT);
 482                 printk(KERN_INFO PFX
 483                     "timeout value must be 15 <= timeout <= 7635, using %d\n",
 484                                                         DEFAULT_TIMEOUT);
 485         }
 486
 487         if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) {
 488                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 489                         IO_INDEX_PORT);
 490                 rc = -EIO;
 491                 goto err_out;
 492         }
 493
 494         rc = register_reboot_notifier(&wdt_notifier);
 495         if (rc) {
 496                 printk(KERN_ERR PFX
 497                         "cannot register reboot notifier (err=%d)\n", rc);
 498                 goto err_out_region;
 499         }
 500
 501         rc = misc_register(&wdt_miscdev);
 502         if (rc) {
 503                 printk(KERN_ERR PFX
 504                         "cannot register miscdev on minor=%d (err=%d)\n",
 505                                                 wdt_miscdev.minor, rc);
 506                 goto err_out_reboot;
 507         }
 508
 509         printk(KERN_INFO PFX
 510                 "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n",
 511                                         timeout, nowayout, testmode);
 512
 513         return 0;
 514
 515 err_out_reboot:
 516         unregister_reboot_notifier(&wdt_notifier);
 517 err_out_region:
 518         release_region(IO_INDEX_PORT, 2);
 519 err_out:
 520         return rc;
 521 }
 522
 523 static void __exit w83977f_wdt_exit(void)
 524 {
 525         wdt_stop();
 526         misc_deregister(&wdt_miscdev);
 527         unregister_reboot_notifier(&wdt_notifier);
 528         release_region(IO_INDEX_PORT, 2);
 529 }
 530
 531 module_init(w83977f_wdt_init);
 532 module_exit(w83977f_wdt_exit);
 533
 534 MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>");
 535 MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip");
 536 MODULE_LICENSE("GPL");
 537 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);