drivers/char/watchdog/i8xx_tco.c

   1 /*
   2  *      i8xx_tco:       TCO timer driver for i8xx chipsets
   3  *
   4  *      (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights Reserved.
   5  *                              http://www.kernelconcepts.de
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  *
  12  *      Neither kernel concepts nor Nils Faerber admit liability nor provide
  13  *      warranty for any of this software. This material is provided
  14  *      "AS-IS" and at no charge.
  15  *
  16  *      (c) Copyright 2000      kernel concepts <nils@kernelconcepts.de>
  17  *                              developed for
  18  *                              Jentro AG, Haar/Munich (Germany)
  19  *
  20  *      TCO timer driver for i8xx chipsets
  21  *      based on softdog.c by Alan Cox <alan@redhat.com>
  22  *
  23  *      The TCO timer is implemented in the following I/O controller hubs:
  24  *      (See the intel documentation on http://developer.intel.com.)
  25  *      82801AA  (ICH)    : document number 290655-003, 290677-014,
  26  *      82801AB  (ICHO)   : document number 290655-003, 290677-014,
  27  *      82801BA  (ICH2)   : document number 290687-002, 298242-027,
  28  *      82801BAM (ICH2-M) : document number 290687-002, 298242-027,
  29  *      82801CA  (ICH3-S) : document number 290733-003, 290739-013,
  30  *      82801CAM (ICH3-M) : document number 290716-001, 290718-007,
  31  *      82801DB  (ICH4)   : document number 290744-001, 290745-020,
  32  *      82801DBM (ICH4-M) : document number 252337-001, 252663-005,
  33  *      82801E   (C-ICH)  : document number 273599-001, 273645-002,
  34  *      82801EB  (ICH5)   : document number 252516-001, 252517-003,
  35  *      82801ER  (ICH5R)  : document number 252516-001, 252517-003,
  36  *      82801FB  (ICH6)   : document number 301473-002, 301474-007,
  37  *      82801FR  (ICH6R)  : document number 301473-002, 301474-007,
  38  *      82801FBM (ICH6-M) : document number 301473-002, 301474-007,
  39  *      82801FW  (ICH6W)  : document number 301473-001, 301474-007,
  40  *      82801FRW (ICH6RW) : document number 301473-001, 301474-007
  41  *
  42  *  20000710 Nils Faerber
  43  *      Initial Version 0.01
  44  *  20000728 Nils Faerber
  45  *      0.02 Fix for SMI_EN->TCO_EN bit, some cleanups
  46  *  20011214 Matt Domsch <Matt_Domsch@dell.com>
  47  *      0.03 Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
  48  *           Didn't add timeout option as i810_margin already exists.
  49  *  20020224 Joel Becker, Wim Van Sebroeck
  50  *      0.04 Support for 82801CA(M) chipset, timer margin needs to be > 3,
  51  *           add support for WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT.
  52  *  20020412 Rob Radez <rob@osinvestor.com>, Wim Van Sebroeck
  53  *      0.05 Fix possible timer_alive race, add expect close support,
  54  *           clean up ioctls (WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS and
  55  *           WDIOC_SETOPTIONS), made i810tco_getdevice __init,
  56  *           removed boot_status, removed tco_timer_read,
  57  *           added support for 82801DB and 82801E chipset,
  58  *           added support for 82801EB and 8280ER chipset,
  59  *           general cleanup.
  60  *  20030921 Wim Van Sebroeck <wim@iguana.be>
  61  *      0.06 change i810_margin to heartbeat, use module_param,
  62  *           added notify system support, renamed module to i8xx_tco.
  63  *  20050128 Wim Van Sebroeck <wim@iguana.be>
  64  *      0.07 Added support for the ICH4-M, ICH6, ICH6R, ICH6-M, ICH6W and ICH6RW
  65  *           chipsets. Also added support for the "undocumented" ICH7 chipset.
  66  *  20050807 Wim Van Sebroeck <wim@iguana.be>
  67  *      0.08 Make sure that the watchdog is only "armed" when started.
  68  *           (Kernel Bug 4251)
  69  */
  70
  71 /*
  72  *      Includes, defines, variables, module parameters, ...
  73  */
  74
  75 #include <linux/module.h>
  76 #include <linux/moduleparam.h>
  77 #include <linux/types.h>
  78 #include <linux/miscdevice.h>
  79 #include <linux/watchdog.h>
  80 #include <linux/notifier.h>
  81 #include <linux/reboot.h>
  82 #include <linux/init.h>
  83 #include <linux/fs.h>
  84 #include <linux/pci.h>
  85 #include <linux/ioport.h>
  86
  87 #include <asm/uaccess.h>
  88 #include <asm/io.h>
  89
  90 #include "i8xx_tco.h"
  91
  92 /* Module and version information */
  93 #define TCO_VERSION "0.08"
  94 #define TCO_MODULE_NAME "i8xx TCO timer"
  95 #define TCO_DRIVER_NAME   TCO_MODULE_NAME ", v" TCO_VERSION
  96 #define PFX TCO_MODULE_NAME ": "
  97
  98 /* internal variables */
  99 static unsigned int ACPIBASE;
 100 static spinlock_t tco_lock;     /* Guards the hardware */
 101 static unsigned long timer_alive;
 102 static char tco_expect_close;
 103 static struct pci_dev *i8xx_tco_pci;
 104
 105 /* module parameters */
 106 #define WATCHDOG_HEARTBEAT 30   /* 30 sec default heartbeat (2<heartbeat<39) */
 107 static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
 108 module_param(heartbeat, int, 0);
 109 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<heartbeat<39, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 110
 111 static int nowayout = WATCHDOG_NOWAYOUT;
 112 module_param(nowayout, int, 0);
 113 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 114
 115 /*
 116  * Some TCO specific functions
 117  */
 118
 119 static inline unsigned char seconds_to_ticks(int seconds)
 120 {
 121         /* the internal timer is stored as ticks which decrement
 122          * every 0.6 seconds */
 123         return (seconds * 10) / 6;
 124 }
 125
 126 static int tco_timer_start (void)
 127 {
 128         unsigned char val;
 129
 130         spin_lock(&tco_lock);
 131
 132         /* disable chipset's NO_REBOOT bit */
 133         pci_read_config_byte (i8xx_tco_pci, 0xd4, &val);
 134         val &= 0xfd;
 135         pci_write_config_byte (i8xx_tco_pci, 0xd4, val);
 136
 137         /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
 138         val = inb (TCO1_CNT + 1);
 139         val &= 0xf7;
 140         outb (val, TCO1_CNT + 1);
 141         val = inb (TCO1_CNT + 1);
 142
 143         spin_unlock(&tco_lock);
 144
 145         if (val & 0x08)
 146                 return -1;
 147         return 0;
 148 }
 149
 150 static int tco_timer_stop (void)
 151 {
 152         unsigned char val, val1;
 153
 154         spin_lock(&tco_lock);
 155         /* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
 156         val = inb (TCO1_CNT + 1);
 157         val |= 0x08;
 158         outb (val, TCO1_CNT + 1);
 159         val = inb (TCO1_CNT + 1);
 160
 161         /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
 162         pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
 163         val1 |= 0x02;
 164         pci_write_config_byte (i8xx_tco_pci, 0xd4, val1);
 165
 166         spin_unlock(&tco_lock);
 167
 168         if ((val & 0x08) == 0)
 169                 return -1;
 170         return 0;
 171 }
 172
 173 static int tco_timer_keepalive (void)
 174 {
 175         spin_lock(&tco_lock);
 176         /* Reload the timer by writing to the TCO Timer Reload register */
 177         outb (0x01, TCO1_RLD);
 178         spin_unlock(&tco_lock);
 179         return 0;
 180 }
 181
 182 static int tco_timer_set_heartbeat (int t)
 183 {
 184         unsigned char val;
 185         unsigned char tmrval;
 186
 187         tmrval = seconds_to_ticks(t);
 188         /* from the specs: */
 189         /* "Values of 0h-3h are ignored and should not be attempted" */
 190         if (tmrval > 0x3f || tmrval < 0x04)
 191                 return -EINVAL;
 192
 193         /* Write new heartbeat to watchdog */
 194         spin_lock(&tco_lock);
 195         val = inb (TCO1_TMR);
 196         val &= 0xc0;
 197         val |= tmrval;
 198         outb (val, TCO1_TMR);
 199         val = inb (TCO1_TMR);
 200         spin_unlock(&tco_lock);
 201
 202         if ((val & 0x3f) != tmrval)
 203                 return -EINVAL;
 204
 205         heartbeat = t;
 206         return 0;
 207 }
 208
 209 /*
 210  *      /dev/watchdog handling
 211  */
 212
 213 static int i8xx_tco_open (struct inode *inode, struct file *file)
 214 {
 215         /* /dev/watchdog can only be opened once */
 216         if (test_and_set_bit(0, &timer_alive))
 217                 return -EBUSY;
 218
 219         /*
 220          *      Reload and activate timer
 221          */
 222         tco_timer_keepalive ();
 223         tco_timer_start ();
 224         return nonseekable_open(inode, file);
 225 }
 226
 227 static int i8xx_tco_release (struct inode *inode, struct file *file)
 228 {
 229         /*
 230          *      Shut off the timer.
 231          */
 232         if (tco_expect_close == 42) {
 233                 tco_timer_stop ();
 234         } else {
 235                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 236                 tco_timer_keepalive ();
 237         }
 238         clear_bit(0, &timer_alive);
 239         tco_expect_close = 0;
 240         return 0;
 241 }
 242
 243 static ssize_t i8xx_tco_write (struct file *file, const char __user *data,
 244                               size_t len, loff_t * ppos)
 245 {
 246         /* See if we got the magic character 'V' and reload the timer */
 247         if (len) {
 248                 if (!nowayout) {
 249                         size_t i;
 250
 251                         /* note: just in case someone wrote the magic character
 252                          * five months ago... */
 253                         tco_expect_close = 0;
 254
 255                         /* scan to see whether or not we got the magic character */
 256                         for (i = 0; i != len; i++) {
 257                                 char c;
 258                                 if(get_user(c, data+i))
 259                                         return -EFAULT;
 260                                 if (c == 'V')
 261                                         tco_expect_close = 42;
 262                         }
 263                 }
 264
 265                 /* someone wrote to us, we should reload the timer */
 266                 tco_timer_keepalive ();
 267         }
 268         return len;
 269 }
 270
 271 static int i8xx_tco_ioctl (struct inode *inode, struct file *file,
 272                           unsigned int cmd, unsigned long arg)
 273 {
 274         int new_options, retval = -EINVAL;
 275         int new_heartbeat;
 276         void __user *argp = (void __user *)arg;
 277         int __user *p = argp;
 278         static struct watchdog_info ident = {
 279                 .options =              WDIOF_SETTIMEOUT |
 280                                         WDIOF_KEEPALIVEPING |
 281                                         WDIOF_MAGICCLOSE,
 282                 .firmware_version =     0,
 283                 .identity =             TCO_MODULE_NAME,
 284         };
 285
 286         switch (cmd) {
 287                 case WDIOC_GETSUPPORT:
 288                         return copy_to_user(argp, &ident,
 289                                 sizeof (ident)) ? -EFAULT : 0;
 290
 291                 case WDIOC_GETSTATUS:
 292                 case WDIOC_GETBOOTSTATUS:
 293                         return put_user (0, p);
 294
 295                 case WDIOC_KEEPALIVE:
 296                         tco_timer_keepalive ();
 297                         return 0;
 298
 299                 case WDIOC_SETOPTIONS:
 300                 {
 301                         if (get_user (new_options, p))
 302                                 return -EFAULT;
 303
 304                         if (new_options & WDIOS_DISABLECARD) {
 305                                 tco_timer_stop ();
 306                                 retval = 0;
 307                         }
 308
 309                         if (new_options & WDIOS_ENABLECARD) {
 310                                 tco_timer_keepalive ();
 311                                 tco_timer_start ();
 312                                 retval = 0;
 313                         }
 314
 315                         return retval;
 316                 }
 317
 318                 case WDIOC_SETTIMEOUT:
 319                 {
 320                         if (get_user(new_heartbeat, p))
 321                                 return -EFAULT;
 322
 323                         if (tco_timer_set_heartbeat(new_heartbeat))
 324                             return -EINVAL;
 325
 326                         tco_timer_keepalive ();
 327                         /* Fall */
 328                 }
 329
 330                 case WDIOC_GETTIMEOUT:
 331                         return put_user(heartbeat, p);
 332
 333                 default:
 334                         return -ENOIOCTLCMD;
 335         }
 336 }
 337
 338 /*
 339  *      Notify system
 340  */
 341
 342 static int i8xx_tco_notify_sys (struct notifier_block *this, unsigned long code, void *unused)
 343 {
 344         if (code==SYS_DOWN || code==SYS_HALT) {
 345                 /* Turn the WDT off */
 346                 tco_timer_stop ();
 347         }
 348
 349         return NOTIFY_DONE;
 350 }
 351
 352 /*
 353  *      Kernel Interfaces
 354  */
 355
 356 static struct file_operations i8xx_tco_fops = {
 357         .owner =        THIS_MODULE,
 358         .llseek =       no_llseek,
 359         .write =        i8xx_tco_write,
 360         .ioctl =        i8xx_tco_ioctl,
 361         .open =         i8xx_tco_open,
 362         .release =      i8xx_tco_release,
 363 };
 364
 365 static struct miscdevice i8xx_tco_miscdev = {
 366         .minor =        WATCHDOG_MINOR,
 367         .name =         "watchdog",
 368         .fops =         &i8xx_tco_fops,
 369 };
 370
 371 static struct notifier_block i8xx_tco_notifier = {
 372         .notifier_call =        i8xx_tco_notify_sys,
 373 };
 374
 375 /*
 376  * Data for PCI driver interface
 377  *
 378  * This data only exists for exporting the supported
 379  * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
 380  * register a pci_driver, because someone else might one day
 381  * want to register another driver on the same PCI id.
 382  */
 383 static struct pci_device_id i8xx_tco_pci_tbl[] = {
 384         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AA_0,   PCI_ANY_ID, PCI_ANY_ID, },
 385         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AB_0,   PCI_ANY_ID, PCI_ANY_ID, },
 386         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,   PCI_ANY_ID, PCI_ANY_ID, },
 387         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_10,  PCI_ANY_ID, PCI_ANY_ID, },
 388         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,   PCI_ANY_ID, PCI_ANY_ID, },
 389         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_12,  PCI_ANY_ID, PCI_ANY_ID, },
 390         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,   PCI_ANY_ID, PCI_ANY_ID, },
 391         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_12,  PCI_ANY_ID, PCI_ANY_ID, },
 392         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801E_0,    PCI_ANY_ID, PCI_ANY_ID, },
 393         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,   PCI_ANY_ID, PCI_ANY_ID, },
 394         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_0,      PCI_ANY_ID, PCI_ANY_ID, },
 395         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_1,      PCI_ANY_ID, PCI_ANY_ID, },
 396         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_2,      PCI_ANY_ID, PCI_ANY_ID, },
 397         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_0,      PCI_ANY_ID, PCI_ANY_ID, },
 398         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH7_1,      PCI_ANY_ID, PCI_ANY_ID, },
 399         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_1,       PCI_ANY_ID, PCI_ANY_ID, },
 400         { 0, },                 /* End of list */
 401 };
 402 MODULE_DEVICE_TABLE (pci, i8xx_tco_pci_tbl);
 403
 404 /*
 405  *      Init & exit routines
 406  */
 407
 408 static unsigned char __init i8xx_tco_getdevice (void)
 409 {
 410         struct pci_dev *dev = NULL;
 411         u8 val1, val2;
 412         u16 badr;
 413         /*
 414          *      Find the PCI device
 415          */
 416
 417         while ((dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
 418                 if (pci_match_id(i8xx_tco_pci_tbl, dev)) {
 419                         i8xx_tco_pci = dev;
 420                         break;
 421                 }
 422         }
 423
 424         if (i8xx_tco_pci) {
 425                 /*
 426                  *      Find the ACPI base I/O address which is the base
 427                  *      for the TCO registers (TCOBASE=ACPIBASE + 0x60)
 428                  *      ACPIBASE is bits [15:7] from 0x40-0x43
 429                  */
 430                 pci_read_config_byte (i8xx_tco_pci, 0x40, &val1);
 431                 pci_read_config_byte (i8xx_tco_pci, 0x41, &val2);
 432                 badr = ((val2 << 1) | (val1 >> 7)) << 7;
 433                 ACPIBASE = badr;
 434                 /* Something's wrong here, ACPIBASE has to be set */
 435                 if (badr == 0x0001 || badr == 0x0000) {
 436                         printk (KERN_ERR PFX "failed to get TCOBASE address\n");
 437                         return 0;
 438                 }
 439
 440                 /* Check chipset's NO_REBOOT bit */
 441                 pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
 442                 if (val1 & 0x02) {
 443                         val1 &= 0xfd;
 444                         pci_write_config_byte (i8xx_tco_pci, 0xd4, val1);
 445                         pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
 446                         if (val1 & 0x02) {
 447                                 printk (KERN_ERR PFX "failed to reset NO_REBOOT flag, reboot disabled by hardware\n");
 448                                 return 0;       /* Cannot reset NO_REBOOT bit */
 449                         }
 450                 }
 451                 /* Disable reboots untill the watchdog starts */
 452                 val1 |= 0x02;
 453                 pci_write_config_byte (i8xx_tco_pci, 0xd4, val1);
 454
 455                 /* Set the TCO_EN bit in SMI_EN register */
 456                 if (!request_region (SMI_EN + 1, 1, "i8xx TCO")) {
 457                         printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
 458                                 SMI_EN + 1);
 459                         return 0;
 460                 }
 461                 val1 = inb (SMI_EN + 1);
 462                 val1 &= 0xdf;
 463                 outb (val1, SMI_EN + 1);
 464                 release_region (SMI_EN + 1, 1);
 465                 return 1;
 466         }
 467         return 0;
 468 }
 469
 470 static int __init watchdog_init (void)
 471 {
 472         int ret;
 473
 474         spin_lock_init(&tco_lock);
 475
 476         /* Check whether or not the hardware watchdog is there */
 477         if (!i8xx_tco_getdevice () || i8xx_tco_pci == NULL)
 478                 return -ENODEV;
 479
 480         if (!request_region (TCOBASE, 0x10, "i8xx TCO")) {
 481                 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
 482                         TCOBASE);
 483                 ret = -EIO;
 484                 goto out;
 485         }
 486
 487         /* Clear out the (probably old) status */
 488         outb (0, TCO1_STS);
 489         outb (3, TCO2_STS);
 490
 491         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 492         if (tco_timer_set_heartbeat (heartbeat)) {
 493                 heartbeat = WATCHDOG_HEARTBEAT;
 494                 tco_timer_set_heartbeat (heartbeat);
 495                 printk(KERN_INFO PFX "heartbeat value must be 2<heartbeat<39, using %d\n",
 496                         heartbeat);
 497         }
 498
 499         ret = register_reboot_notifier(&i8xx_tco_notifier);
 500         if (ret != 0) {
 501                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 502                         ret);
 503                 goto unreg_region;
 504         }
 505
 506         ret = misc_register(&i8xx_tco_miscdev);
 507         if (ret != 0) {
 508                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 509                         WATCHDOG_MINOR, ret);
 510                 goto unreg_notifier;
 511         }
 512
 513         tco_timer_stop ();
 514
 515         printk (KERN_INFO PFX "initialized (0x%04x). heartbeat=%d sec (nowayout=%d)\n",
 516                 TCOBASE, heartbeat, nowayout);
 517
 518         return 0;
 519
 520 unreg_notifier:
 521         unregister_reboot_notifier(&i8xx_tco_notifier);
 522 unreg_region:
 523         release_region (TCOBASE, 0x10);
 524 out:
 525         return ret;
 526 }
 527
 528 static void __exit watchdog_cleanup (void)
 529 {
 530         /* Stop the timer before we leave */
 531         if (!nowayout)
 532                 tco_timer_stop ();
 533
 534         /* Deregister */
 535         misc_deregister (&i8xx_tco_miscdev);
 536         unregister_reboot_notifier(&i8xx_tco_notifier);
 537         release_region (TCOBASE, 0x10);
 538 }
 539
 540 module_init(watchdog_init);
 541 module_exit(watchdog_cleanup);
 542
 543 MODULE_AUTHOR("Nils Faerber");
 544 MODULE_DESCRIPTION("TCO timer driver for i8xx chipsets");
 545 MODULE_LICENSE("GPL");
 546 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);