LXR linux/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 Netwinders only
  23 */
  24
  25#include <linux/module.h>
  26#include <linux/moduleparam.h>
  27#include <linux/types.h>
  28#include <linux/kernel.h>
  29#include <linux/fs.h>
  30#include <linux/miscdevice.h>
  31#include <linux/init.h>
  32#include <linux/ioport.h>
  33#include <linux/watchdog.h>
  34#include <linux/notifier.h>
  35#include <linux/reboot.h>
  36
  37#include <asm/io.h>
  38#include <asm/system.h>
  39#include <asm/mach-types.h>
  40#include <asm/uaccess.h>
  41
  42#define WATCHDOG_VERSION  "0.04"
  43#define WATCHDOG_NAME     "Wdt977"
  44#define PFX WATCHDOG_NAME ": "
  45#define DRIVER_VERSION    WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n"
  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
  57static  int timeout = DEFAULT_TIMEOUT;
  58static  int timeoutM;                           /* timeout in minutes */
  59static  unsigned long timer_alive;
  60static  int testmode;
  61static  char expect_close;
  62static  DEFINE_SPINLOCK(spinlock);
  63
  64module_param(timeout, int, 0);
  65MODULE_PARM_DESC(timeout,"Watchdog timeout in seconds (60..15300), default=" __MODULE_STRING(DEFAULT_TIMEOUT) ")");
  66module_param(testmode, int, 0);
  67MODULE_PARM_DESC(testmode,"Watchdog testmode (1 = no reboot), default=0");
  68
  69static int nowayout = WATCHDOG_NOWAYOUT;
  70module_param(nowayout, int, 0);
  71MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  72
  73/*
  74 * Start the watchdog
  75 */
  76
  77static int wdt977_start(void)
  78{
  79        unsigned long flags;
  80
  81        spin_lock_irqsave(&spinlock, flags);
  82
  83        /* unlock the SuperIO chip */
  84        outb_p(UNLOCK_DATA, IO_INDEX_PORT);
  85        outb_p(UNLOCK_DATA, IO_INDEX_PORT);
  86
  87        /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4
  88         * F2 has the timeout in minutes
  89         * F3 could be set to the POWER LED blink (with GP17 set to PowerLed)
  90         *   at timeout, and to reset timer on kbd/mouse activity (not impl.)
  91         * F4 is used to just clear the TIMEOUT'ed state (bit 0)
  92         */
  93        outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
  94        outb_p(0x08, IO_DATA_PORT);
  95        outb_p(0xF2, IO_INDEX_PORT);
  96        outb_p(timeoutM, IO_DATA_PORT);
  97        outb_p(0xF3, IO_INDEX_PORT);
  98        outb_p(0x00, IO_DATA_PORT);     /* another setting is 0E for kbd/mouse/LED */
  99        outb_p(0xF4, IO_INDEX_PORT);
 100        outb_p(0x00, IO_DATA_PORT);
 101
 102        /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */
 103        /* in test mode watch the bit 1 on F4 to indicate "triggered" */
 104        if (!testmode)
 105        {
 106                outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 107                outb_p(0x07, IO_DATA_PORT);
 108                outb_p(0xE6, IO_INDEX_PORT);
 109                outb_p(0x08, IO_DATA_PORT);
 110        }
 111
 112        /* lock the SuperIO chip */
 113        outb_p(LOCK_DATA, IO_INDEX_PORT);
 114
 115        spin_unlock_irqrestore(&spinlock, flags);
 116        printk(KERN_INFO PFX "activated.\n");
 117
 118        return 0;
 119}
 120
 121/*
 122 * Stop the watchdog
 123 */
 124
 125static int wdt977_stop(void)
 126{
 127        unsigned long flags;
 128        spin_lock_irqsave(&spinlock, flags);
 129
 130        /* unlock the SuperIO chip */
 131        outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 132        outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 133
 134        /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4
 135        * F3 is reset to its default state
 136        * F4 can clear the TIMEOUT'ed state (bit 0) - back to default
 137        * We can not use GP17 as a PowerLed, as we use its usage as a RedLed
 138        */
 139        outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 140        outb_p(0x08, IO_DATA_PORT);
 141        outb_p(0xF2, IO_INDEX_PORT);
 142        outb_p(0xFF, IO_DATA_PORT);
 143        outb_p(0xF3, IO_INDEX_PORT);
 144        outb_p(0x00, IO_DATA_PORT);
 145        outb_p(0xF4, IO_INDEX_PORT);
 146        outb_p(0x00, IO_DATA_PORT);
 147        outb_p(0xF2, IO_INDEX_PORT);
 148        outb_p(0x00, IO_DATA_PORT);
 149
 150        /* at last select device Aux1 (dev=7) and set GP16 as a watchdog output */
 151        outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 152        outb_p(0x07, IO_DATA_PORT);
 153        outb_p(0xE6, IO_INDEX_PORT);
 154        outb_p(0x08, IO_DATA_PORT);
 155
 156        /* lock the SuperIO chip */
 157        outb_p(LOCK_DATA, IO_INDEX_PORT);
 158
 159        spin_unlock_irqrestore(&spinlock, flags);
 160        printk(KERN_INFO PFX "shutdown.\n");
 161
 162        return 0;
 163}
 164
 165/*
 166 * Send a keepalive ping to the watchdog
 167 * This is done by simply re-writing the timeout to reg. 0xF2
 168 */
 169
 170static int wdt977_keepalive(void)
 171{
 172        unsigned long flags;
 173        spin_lock_irqsave(&spinlock, flags);
 174
 175        /* unlock the SuperIO chip */
 176        outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 177        outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 178
 179        /* select device Aux2 (device=8) and kicks watchdog reg F2 */
 180        /* F2 has the timeout in minutes */
 181        outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 182        outb_p(0x08, IO_DATA_PORT);
 183        outb_p(0xF2, IO_INDEX_PORT);
 184        outb_p(timeoutM, IO_DATA_PORT);
 185
 186        /* lock the SuperIO chip */
 187        outb_p(LOCK_DATA, IO_INDEX_PORT);
 188        spin_unlock_irqrestore(&spinlock, flags);
 189
 190        return 0;
 191}
 192
 193/*
 194 * Set the watchdog timeout value
 195 */
 196
 197static int wdt977_set_timeout(int t)
 198{
 199        int tmrval;
 200
 201        /* convert seconds to minutes, rounding up */
 202        tmrval = (t + 59) / 60;
 203
 204        if (machine_is_netwinder()) {
 205                /* we have a hw bug somewhere, so each 977 minute is actually only 30sec
 206                 *  this limits the max timeout to half of device max of 255 minutes...
 207                 */
 208                tmrval += tmrval;
 209        }
 210
 211        if ((tmrval < 1) || (tmrval > 255))
 212                return -EINVAL;
 213
 214        /* timeout is the timeout in seconds, timeoutM is the timeout in minutes) */
 215        timeout = t;
 216        timeoutM = tmrval;
 217        return 0;
 218}
 219
 220/*
 221 * Get the watchdog status
 222 */
 223
 224static int wdt977_get_status(int *status)
 225{
 226        int new_status;
 227        unsigned long flags;
 228
 229        spin_lock_irqsave(&spinlock, flags);
 230
 231        /* unlock the SuperIO chip */
 232        outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 233        outb_p(UNLOCK_DATA, IO_INDEX_PORT);
 234
 235        /* select device Aux2 (device=8) and read watchdog reg F4 */
 236        outb_p(DEVICE_REGISTER, IO_INDEX_PORT);
 237        outb_p(0x08, IO_DATA_PORT);
 238        outb_p(0xF4, IO_INDEX_PORT);
 239        new_status = inb_p(IO_DATA_PORT);
 240
 241        /* lock the SuperIO chip */
 242        outb_p(LOCK_DATA, IO_INDEX_PORT);
 243
 244        spin_unlock_irqrestore(&spinlock, flags);
 245
 246        *status=0;
 247        if (new_status & 1)
 248                *status |= WDIOF_CARDRESET;
 249
 250        return 0;
 251}
 252
 253
 254/*
 255 *      /dev/watchdog handling
 256 */
 257
 258static int wdt977_open(struct inode *inode, struct file *file)
 259{
 260        /* If the watchdog is alive we don't need to start it again */
 261        if( test_and_set_bit(0,&timer_alive) )
 262                return -EBUSY;
 263
 264        if (nowayout)
 265                __module_get(THIS_MODULE);
 266
 267        wdt977_start();
 268        return nonseekable_open(inode, file);
 269}
 270
 271static int wdt977_release(struct inode *inode, struct file *file)
 272{
 273        /*
 274         *      Shut off the timer.
 275         *      Lock it in if it's a module and we set nowayout
 276         */
 277        if (expect_close == 42)
 278        {
 279                wdt977_stop();
 280                clear_bit(0,&timer_alive);
 281        } else {
 282                wdt977_keepalive();
 283                printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 284        }
 285        expect_close = 0;
 286        return 0;
 287}
 288
 289
 290/*
 291 *      wdt977_write:
 292 *      @file: file handle to the watchdog
 293 *      @buf: buffer to write (unused as data does not matter here
 294 *      @count: count of bytes
 295 *      @ppos: pointer to the position to write. No seeks allowed
 296 *
 297 *      A write to a watchdog device is defined as a keepalive signal. Any
 298 *      write of data will do, as we we don't define content meaning.
 299 */
 300
 301static ssize_t wdt977_write(struct file *file, const char __user *buf,
 302                            size_t count, loff_t *ppos)
 303{
 304        if (count)
 305        {
 306                if (!nowayout)
 307                {
 308                        size_t i;
 309
 310                        /* In case it was set long ago */
 311                        expect_close = 0;
 312
 313                        for (i = 0; i != count; i++)
 314                        {
 315                                char c;
 316                                if (get_user(c, buf + i))
 317                                        return -EFAULT;
 318                                if (c == 'V')
 319                                        expect_close = 42;
 320                        }
 321                }
 322
 323                /* someone wrote to us, we should restart timer */
 324                wdt977_keepalive();
 325        }
 326        return count;
 327}
 328
 329/*
 330 *      wdt977_ioctl:
 331 *      @inode: inode of the device
 332 *      @file: file handle to the device
 333 *      @cmd: watchdog command
 334 *      @arg: argument pointer
 335 *
 336 *      The watchdog API defines a common set of functions for all watchdogs
 337 *      according to their available features.
 338 */
 339
 340static struct watchdog_info ident = {
 341        .options =              WDIOF_SETTIMEOUT |
 342                                WDIOF_MAGICCLOSE |
 343                                WDIOF_KEEPALIVEPING,
 344        .firmware_version =     1,
 345        .identity =             WATCHDOG_NAME,
 346};
 347
 348static int wdt977_ioctl(struct inode *inode, struct file *file,
 349        unsigned int cmd, unsigned long arg)
 350{
 351        int status;
 352        int new_options, retval = -EINVAL;
 353        int new_timeout;
 354        union {
 355                struct watchdog_info __user *ident;
 356                int __user *i;
 357        } uarg;
 358
 359        uarg.i = (int __user *)arg;
 360
 361        switch(cmd)
 362        {
 363        default:
 364                return -ENOTTY;
 365
 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_KEEPALIVE:
 378                wdt977_keepalive();
 379                return 0;
 380
 381        case WDIOC_SETOPTIONS:
 382                if (get_user (new_options, uarg.i))
 383                        return -EFAULT;
 384
 385                if (new_options & WDIOS_DISABLECARD) {
 386                        wdt977_stop();
 387                        retval = 0;
 388                }
 389
 390                if (new_options & WDIOS_ENABLECARD) {
 391                        wdt977_start();
 392                        retval = 0;
 393                }
 394
 395                return retval;
 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        }
 411}
 412
 413static int wdt977_notify_sys(struct notifier_block *this, unsigned long code,
 414        void *unused)
 415{
 416        if(code==SYS_DOWN || code==SYS_HALT)
 417                wdt977_stop();
 418        return NOTIFY_DONE;
 419}
 420
 421static const struct file_operations wdt977_fops=
 422{
 423        .owner          = THIS_MODULE,
 424        .llseek         = no_llseek,
 425        .write          = wdt977_write,
 426        .ioctl          = wdt977_ioctl,
 427        .open           = wdt977_open,
 428        .release        = wdt977_release,
 429};
 430
 431static struct miscdevice wdt977_miscdev=
 432{
 433        .minor          = WATCHDOG_MINOR,
 434        .name           = "watchdog",
 435        .fops           = &wdt977_fops,
 436};
 437
 438static struct notifier_block wdt977_notifier = {
 439        .notifier_call = wdt977_notify_sys,
 440};
 441
 442static int __init wd977_init(void)
 443{
 444        int rc;
 445
 446        //if (!machine_is_netwinder())
 447        //      return -ENODEV;
 448
 449        printk(KERN_INFO PFX DRIVER_VERSION);
 450
 451        /* Check that the timeout value is within it's range ; if not reset to the default */
 452        if (wdt977_set_timeout(timeout))
 453        {
 454                wdt977_set_timeout(DEFAULT_TIMEOUT);
 455                printk(KERN_INFO PFX "timeout value must be 60<timeout<15300, using %d\n",
 456                        DEFAULT_TIMEOUT);
 457        }
 458
 459        /* on Netwinder the IOports are already reserved by
 460         * arch/arm/mach-footbridge/netwinder-hw.c
 461         */
 462        if (!machine_is_netwinder())
 463        {
 464                if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME))
 465                {
 466                        printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 467                                IO_INDEX_PORT);
 468                        rc = -EIO;
 469                        goto err_out;
 470                }
 471        }
 472
 473        rc = misc_register(&wdt977_miscdev);
 474        if (rc)
 475        {
 476                printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 477                        wdt977_miscdev.minor, rc);
 478                goto err_out_region;
 479        }
 480
 481        rc = register_reboot_notifier(&wdt977_notifier);
 482        if (rc)
 483        {
 484                printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 485                        rc);
 486                goto err_out_miscdev;
 487        }
 488
 489        printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n",
 490                timeout, nowayout, testmode);
 491
 492        return 0;
 493
 494err_out_miscdev:
 495        misc_deregister(&wdt977_miscdev);
 496err_out_region:
 497        if (!machine_is_netwinder())
 498                release_region(IO_INDEX_PORT,2);
 499err_out:
 500        return rc;
 501}
 502
 503static void __exit wd977_exit(void)
 504{
 505        wdt977_stop();
 506        misc_deregister(&wdt977_miscdev);
 507        unregister_reboot_notifier(&wdt977_notifier);
 508        release_region(IO_INDEX_PORT,2);
 509}
 510
 511module_init(wd977_init);
 512module_exit(wd977_exit);
 513
 514MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>");
 515MODULE_DESCRIPTION("W83977AF Watchdog driver");
 516MODULE_LICENSE("GPL");
 517MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
 518