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  *
  37  *  20000710 Nils Faerber
  38  *      Initial Version 0.01
  39  *  20000728 Nils Faerber
  40  *      0.02 Fix for SMI_EN->TCO_EN bit, some cleanups
  41  *  20011214 Matt Domsch <Matt_Domsch@dell.com>
  42  *      0.03 Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
  43  *           Didn't add timeout option as i810_margin already exists.
  44  *  20020224 Joel Becker, Wim Van Sebroeck
  45  *      0.04 Support for 82801CA(M) chipset, timer margin needs to be > 3,
  46  *           add support for WDIOC_SETTIMEOUT and WDIOC_GETTIMEOUT.
  47  *  20020412 Rob Radez <rob@osinvestor.com>, Wim Van Sebroeck
  48  *      0.05 Fix possible timer_alive race, add expect close support,
  49  *           clean up ioctls (WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS and
  50  *           WDIOC_SETOPTIONS), made i810tco_getdevice __init,
  51  *           removed boot_status, removed tco_timer_read,
  52  *           added support for 82801DB and 82801E chipset,
  53  *           added support for 82801EB and 8280ER chipset,
  54  *           general cleanup.
  55  *  20030921 Wim Van Sebroeck <wim@iguana.be>
  56  *      0.06 change i810_margin to heartbeat, use module_param,
  57  *           added notify system support, renamed module to i8xx_tco.
  58  *  20050128 Wim Van Sebroeck <wim@iguana.be>
  59  *      0.07 Added support for the ICH4-M, ICH6, ICH6R, ICH6-M, ICH6W and ICH6RW
  60  *           chipsets. Also added support for the "undocumented" ICH7 chipset.
  61  *  20050807 Wim Van Sebroeck <wim@iguana.be>
  62  *      0.08 Make sure that the watchdog is only "armed" when started.
  63  *           (Kernel Bug 4251)
  64  *  20060416 Wim Van Sebroeck <wim@iguana.be>
  65  *      0.09 Remove support for the ICH6, ICH6R, ICH6-M, ICH6W and ICH6RW and
  66  *           ICH7 chipsets. (See Kernel Bug 6031 - other code will support these
  67  *           chipsets)
  68  */
  69
  70 /*
  71  *      Includes, defines, variables, module parameters, ...
  72  */
  73
  74 #include <linux/module.h>
  75 #include <linux/moduleparam.h>
  76 #include <linux/types.h>
  77 #include <linux/miscdevice.h>
  78 #include <linux/watchdog.h>
  79 #include <linux/notifier.h>
  80 #include <linux/reboot.h>
  81 #include <linux/init.h>
  82 #include <linux/fs.h>
  83 #include <linux/pci.h>
  84 #include <linux/ioport.h>
  85
  86 #include <asm/uaccess.h>
  87 #include <asm/io.h>
  88
  89 #include "i8xx_tco.h"
  90
  91 /* Module and version information */
  92 #define TCO_VERSION "0.09"
  93 #define TCO_MODULE_NAME "i8xx TCO timer"
  94 #define TCO_DRIVER_NAME   TCO_MODULE_NAME ", v" TCO_VERSION
  95 #define PFX TCO_MODULE_NAME ": "
  96
  97 /* internal variables */
  98 static unsigned int ACPIBASE;
  99 static spinlock_t tco_lock;     /* Guards the hardware */
 100 static unsigned long timer_alive;
 101 static char tco_expect_close;
 102 static struct pci_dev *i8xx_tco_pci;
 103
 104 /* module parameters */
 105 #define WATCHDOG_HEARTBEAT 30   /* 30 sec default heartbeat (2<heartbeat<39) */
 106 static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
 107 module_param(heartbeat, int, 0);
 108 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<heartbeat<39, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
 109
 110 static int nowayout = WATCHDOG_NOWAYOUT;
 111 module_param(nowayout, int, 0);
 112 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
 113
 114 /*
 115  * Some TCO specific functions
 116  */
 117
 118 static inline unsigned char seconds_to_ticks(int seconds)
 119 {
 120         /* the internal timer is stored as ticks which decrement
 121          * every 0.6 seconds */
 122         return (seconds * 10) / 6;
 123 }
 124
 125 static int tco_timer_start (void)
 126 {
 127         unsigned char val;
 128
 129         spin_lock(&tco_lock);
 130
 131         /* disable chipset's NO_REBOOT bit */
 132         pci_read_config_byte (i8xx_tco_pci, 0xd4, &val);
 133         val &= 0xfd;
 134         pci_write_config_byte (i8xx_tco_pci, 0xd4, val);
 135
 136         /* Bit 11: TCO Timer Halt -> 0 = The TCO timer is enabled to count */
 137         val = inb (TCO1_CNT + 1);
 138         val &= 0xf7;
 139         outb (val, TCO1_CNT + 1);
 140         val = inb (TCO1_CNT + 1);
 141
 142         spin_unlock(&tco_lock);
 143
 144         if (val & 0x08)
 145                 return -1;
 146         return 0;
 147 }
 148
 149 static int tco_timer_stop (void)
 150 {
 151         unsigned char val, val1;
 152
 153         spin_lock(&tco_lock);
 154         /* Bit 11: TCO Timer Halt -> 1 = The TCO timer is disabled */
 155         val = inb (TCO1_CNT + 1);
 156         val |= 0x08;
 157         outb (val, TCO1_CNT + 1);
 158         val = inb (TCO1_CNT + 1);
 159
 160         /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
 161         pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
 162         val1 |= 0x02;
 163         pci_write_config_byte (i8xx_tco_pci, 0xd4, val1);
 164
 165         spin_unlock(&tco_lock);
 166
 167         if ((val & 0x08) == 0)
 168                 return -1;
 169         return 0;
 170 }
 171
 172 static int tco_timer_keepalive (void)
 173 {
 174         spin_lock(&tco_lock);
 175         /* Reload the timer by writing to the TCO Timer Reload register */
 176         outb (0x01, TCO1_RLD);
 177         spin_unlock(&tco_lock);
 178         return 0;
 179 }
 180
 181 static int tco_timer_set_heartbeat (int t)
 182 {
 183         unsigned char val;
 184         unsigned char tmrval;
 185
 186         tmrval = seconds_to_ticks(t);
 187         /* from the specs: */
 188         /* "Values of 0h-3h are ignored and should not be attempted" */
 189         if (tmrval > 0x3f || tmrval < 0x04)
 190                 return -EINVAL;
 191
 192         /* Write new heartbeat to watchdog */
 193         spin_lock(&tco_lock);
 194         val = inb (TCO1_TMR);
 195         val &= 0xc0;
 196         val |= tmrval;
 197         outb (val, TCO1_TMR);
 198         val = inb (TCO1_TMR);
 199         spin_unlock(&tco_lock);
 200
 201         if ((val & 0x3f) != tmrval)
 202                 return -EINVAL;
 203
 204         heartbeat = t;
 205         return 0;
 206 }
 207
 208 /*
 209  *      /dev/watchdog handling
 210  */
 211
 212 static int i8xx_tco_open (struct inode *inode, struct file *file)
 213 {
 214         /* /dev/watchdog can only be opened once */
 215         if (test_and_set_bit(0, &timer_alive))
 216                 return -EBUSY;
 217
 218         /*
 219          *      Reload and activate timer
 220          */
 221         tco_timer_keepalive ();
 222         tco_timer_start ();
 223         return nonseekable_open(inode, file);
 224 }
 225
 226 static int i8xx_tco_release (struct inode *inode, struct file *file)
 227 {
 228         /*
 229          *      Shut off the timer.
 230          */
 231         if (tco_expect_close == 42) {
 232                 tco_timer_stop ();
 233         } else {
 234                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 235                 tco_timer_keepalive ();
 236         }
 237         clear_bit(0, &timer_alive);
 238         tco_expect_close = 0;
 239         return 0;
 240 }
 241
 242 static ssize_t i8xx_tco_write (struct file *file, const char __user *data,
 243                               size_t len, loff_t * ppos)
 244 {
 245         /* See if we got the magic character 'V' and reload the timer */
 246         if (len) {
 247                 if (!nowayout) {
 248                         size_t i;
 249
 250                         /* note: just in case someone wrote the magic character
 251                          * five months ago... */
 252                         tco_expect_close = 0;
 253
 254                         /* scan to see whether or not we got the magic character */
 255                         for (i = 0; i != len; i++) {
 256                                 char c;
 257                                 if(get_user(c, data+i))
 258                                         return -EFAULT;
 259                                 if (c == 'V')
 260                                         tco_expect_close = 42;
 261                         }
 262                 }
 263
 264                 /* someone wrote to us, we should reload the timer */
 265                 tco_timer_keepalive ();
 266         }
 267         return len;
 268 }
 269
 270 static int i8xx_tco_ioctl (struct inode *inode, struct file *file,
 271                           unsigned int cmd, unsigned long arg)
 272 {
 273         int new_options, retval = -EINVAL;
 274         int new_heartbeat;
 275         void __user *argp = (void __user *)arg;
 276         int __user *p = argp;
 277         static struct watchdog_info ident = {
 278                 .options =              WDIOF_SETTIMEOUT |
 279                                         WDIOF_KEEPALIVEPING |
 280                                         WDIOF_MAGICCLOSE,
 281                 .firmware_version =     0,
 282                 .identity =             TCO_MODULE_NAME,
 283         };
 284
 285         switch (cmd) {
 286                 case WDIOC_GETSUPPORT:
 287                         return copy_to_user(argp, &ident,
 288                                 sizeof (ident)) ? -EFAULT : 0;
 289
 290                 case WDIOC_GETSTATUS:
 291                 case WDIOC_GETBOOTSTATUS:
 292                         return put_user (0, p);
 293
 294                 case WDIOC_KEEPALIVE:
 295                         tco_timer_keepalive ();
 296                         return 0;
 297
 298                 case WDIOC_SETOPTIONS:
 299                 {
 300                         if (get_user (new_options, p))
 301                                 return -EFAULT;
 302
 303                         if (new_options & WDIOS_DISABLECARD) {
 304                                 tco_timer_stop ();
 305                                 retval = 0;
 306                         }
 307
 308                         if (new_options & WDIOS_ENABLECARD) {
 309                                 tco_timer_keepalive ();
 310                                 tco_timer_start ();
 311                                 retval = 0;
 312                         }
 313
 314                         return retval;
 315                 }
 316
 317                 case WDIOC_SETTIMEOUT:
 318                 {
 319                         if (get_user(new_heartbeat, p))
 320                                 return -EFAULT;
 321
 322                         if (tco_timer_set_heartbeat(new_heartbeat))
 323                             return -EINVAL;
 324
 325                         tco_timer_keepalive ();
 326                         /* Fall */
 327                 }
 328
 329                 case WDIOC_GETTIMEOUT:
 330                         return put_user(heartbeat, p);
 331
 332                 default:
 333                         return -ENOIOCTLCMD;
 334         }
 335 }
 336
 337 /*
 338  *      Notify system
 339  */
 340
 341 static int i8xx_tco_notify_sys (struct notifier_block *this, unsigned long code, void *unused)
 342 {
 343         if (code==SYS_DOWN || code==SYS_HALT) {
 344                 /* Turn the WDT off */
 345                 tco_timer_stop ();
 346         }
 347
 348         return NOTIFY_DONE;
 349 }
 350
 351 /*
 352  *      Kernel Interfaces
 353  */
 354
 355 static struct file_operations i8xx_tco_fops = {
 356         .owner =        THIS_MODULE,
 357         .llseek =       no_llseek,
 358         .write =        i8xx_tco_write,
 359         .ioctl =        i8xx_tco_ioctl,
 360         .open =         i8xx_tco_open,
 361         .release =      i8xx_tco_release,
 362 };
 363
 364 static struct miscdevice i8xx_tco_miscdev = {
 365         .minor =        WATCHDOG_MINOR,
 366         .name =         "watchdog",
 367         .fops =         &i8xx_tco_fops,
 368 };
 369
 370 static struct notifier_block i8xx_tco_notifier = {
 371         .notifier_call =        i8xx_tco_notify_sys,
 372 };
 373
 374 /*
 375  * Data for PCI driver interface
 376  *
 377  * This data only exists for exporting the supported
 378  * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
 379  * register a pci_driver, because someone else might one day
 380  * want to register another driver on the same PCI id.
 381  */
 382 static struct pci_device_id i8xx_tco_pci_tbl[] = {
 383         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AA_0,   PCI_ANY_ID, PCI_ANY_ID, },
 384         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801AB_0,   PCI_ANY_ID, PCI_ANY_ID, },
 385         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_0,   PCI_ANY_ID, PCI_ANY_ID, },
 386         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801BA_10,  PCI_ANY_ID, PCI_ANY_ID, },
 387         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_0,   PCI_ANY_ID, PCI_ANY_ID, },
 388         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801CA_12,  PCI_ANY_ID, PCI_ANY_ID, },
 389         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_0,   PCI_ANY_ID, PCI_ANY_ID, },
 390         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801DB_12,  PCI_ANY_ID, PCI_ANY_ID, },
 391         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801E_0,    PCI_ANY_ID, PCI_ANY_ID, },
 392         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82801EB_0,   PCI_ANY_ID, PCI_ANY_ID, },
 393         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB_1,       PCI_ANY_ID, PCI_ANY_ID, },
 394         { 0, },                 /* End of list */
 395 };
 396 MODULE_DEVICE_TABLE (pci, i8xx_tco_pci_tbl);
 397
 398 /*
 399  *      Init & exit routines
 400  */
 401
 402 static unsigned char __init i8xx_tco_getdevice (void)
 403 {
 404         struct pci_dev *dev = NULL;
 405         u8 val1, val2;
 406         u16 badr;
 407         /*
 408          *      Find the PCI device
 409          */
 410
 411         while ((dev = pci_find_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
 412                 if (pci_match_id(i8xx_tco_pci_tbl, dev)) {
 413                         i8xx_tco_pci = dev;
 414                         break;
 415                 }
 416         }
 417
 418         if (i8xx_tco_pci) {
 419                 /*
 420                  *      Find the ACPI base I/O address which is the base
 421                  *      for the TCO registers (TCOBASE=ACPIBASE + 0x60)
 422                  *      ACPIBASE is bits [15:7] from 0x40-0x43
 423                  */
 424                 pci_read_config_byte (i8xx_tco_pci, 0x40, &val1);
 425                 pci_read_config_byte (i8xx_tco_pci, 0x41, &val2);
 426                 badr = ((val2 << 1) | (val1 >> 7)) << 7;
 427                 ACPIBASE = badr;
 428                 /* Something's wrong here, ACPIBASE has to be set */
 429                 if (badr == 0x0001 || badr == 0x0000) {
 430                         printk (KERN_ERR PFX "failed to get TCOBASE address\n");
 431                         return 0;
 432                 }
 433
 434                 /* Check chipset's NO_REBOOT bit */
 435                 pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
 436                 if (val1 & 0x02) {
 437                         val1 &= 0xfd;
 438                         pci_write_config_byte (i8xx_tco_pci, 0xd4, val1);
 439                         pci_read_config_byte (i8xx_tco_pci, 0xd4, &val1);
 440                         if (val1 & 0x02) {
 441                                 printk (KERN_ERR PFX "failed to reset NO_REBOOT flag, reboot disabled by hardware\n");
 442                                 return 0;       /* Cannot reset NO_REBOOT bit */
 443                         }
 444                 }
 445                 /* Disable reboots untill the watchdog starts */
 446                 val1 |= 0x02;
 447                 pci_write_config_byte (i8xx_tco_pci, 0xd4, val1);
 448
 449                 /* Set the TCO_EN bit in SMI_EN register */
 450                 if (!request_region (SMI_EN + 1, 1, "i8xx TCO")) {
 451                         printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
 452                                 SMI_EN + 1);
 453                         return 0;
 454                 }
 455                 val1 = inb (SMI_EN + 1);
 456                 val1 &= 0xdf;
 457                 outb (val1, SMI_EN + 1);
 458                 release_region (SMI_EN + 1, 1);
 459                 return 1;
 460         }
 461         return 0;
 462 }
 463
 464 static int __init watchdog_init (void)
 465 {
 466         int ret;
 467
 468         spin_lock_init(&tco_lock);
 469
 470         /* Check whether or not the hardware watchdog is there */
 471         if (!i8xx_tco_getdevice () || i8xx_tco_pci == NULL)
 472                 return -ENODEV;
 473
 474         if (!request_region (TCOBASE, 0x10, "i8xx TCO")) {
 475                 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
 476                         TCOBASE);
 477                 ret = -EIO;
 478                 goto out;
 479         }
 480
 481         /* Clear out the (probably old) status */
 482         outb (0, TCO1_STS);
 483         outb (3, TCO2_STS);
 484
 485         /* Check that the heartbeat value is within it's range ; if not reset to the default */
 486         if (tco_timer_set_heartbeat (heartbeat)) {
 487                 heartbeat = WATCHDOG_HEARTBEAT;
 488                 tco_timer_set_heartbeat (heartbeat);
 489                 printk(KERN_INFO PFX "heartbeat value must be 2<heartbeat<39, using %d\n",
 490                         heartbeat);
 491         }
 492
 493         ret = register_reboot_notifier(&i8xx_tco_notifier);
 494         if (ret != 0) {
 495                 printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 496                         ret);
 497                 goto unreg_region;
 498         }
 499
 500         ret = misc_register(&i8xx_tco_miscdev);
 501         if (ret != 0) {
 502                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 503                         WATCHDOG_MINOR, ret);
 504                 goto unreg_notifier;
 505         }
 506
 507         tco_timer_stop ();
 508
 509         printk (KERN_INFO PFX "initialized (0x%04x). heartbeat=%d sec (nowayout=%d)\n",
 510                 TCOBASE, heartbeat, nowayout);
 511
 512         return 0;
 513
 514 unreg_notifier:
 515         unregister_reboot_notifier(&i8xx_tco_notifier);
 516 unreg_region:
 517         release_region (TCOBASE, 0x10);
 518 out:
 519         return ret;
 520 }
 521
 522 static void __exit watchdog_cleanup (void)
 523 {
 524         /* Stop the timer before we leave */
 525         if (!nowayout)
 526                 tco_timer_stop ();
 527
 528         /* Deregister */
 529         misc_deregister (&i8xx_tco_miscdev);
 530         unregister_reboot_notifier(&i8xx_tco_notifier);
 531         release_region (TCOBASE, 0x10);
 532 }
 533
 534 module_init(watchdog_init);
 535 module_exit(watchdog_cleanup);
 536
 537 MODULE_AUTHOR("Nils Faerber");
 538 MODULE_DESCRIPTION("TCO timer driver for i8xx chipsets");
 539 MODULE_LICENSE("GPL");
 540 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);