drivers/watchdog/nv_tco.c

   1 /*
   2  *      nv_tco 0.01:    TCO timer driver for NV chipsets
   3  *
   4  *      (c) Copyright 2005 Google Inc., All Rights Reserved.
   5  *
   6  *      Based off i8xx_tco.c:
   7  *      (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
   8  *      Reserved.
   9  *                              http://www.kernelconcepts.de
  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  *      TCO timer driver for NV chipsets
  17  *      based on softdog.c by Alan Cox <alan@redhat.com>
  18  */
  19
  20 /*
  21  *      Includes, defines, variables, module parameters, ...
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/moduleparam.h>
  26 #include <linux/types.h>
  27 #include <linux/miscdevice.h>
  28 #include <linux/watchdog.h>
  29 #include <linux/init.h>
  30 #include <linux/fs.h>
  31 #include <linux/pci.h>
  32 #include <linux/ioport.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/platform_device.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/io.h>
  37
  38 #include "nv_tco.h"
  39
  40 /* Module and version information */
  41 #define TCO_VERSION "0.01"
  42 #define TCO_MODULE_NAME "NV_TCO"
  43 #define TCO_DRIVER_NAME   TCO_MODULE_NAME ", v" TCO_VERSION
  44 #define PFX TCO_MODULE_NAME ": "
  45
  46 /* internal variables */
  47 static unsigned int tcobase;
  48 static DEFINE_SPINLOCK(tco_lock);       /* Guards the hardware */
  49 static unsigned long timer_alive;
  50 static char tco_expect_close;
  51 static struct pci_dev *tco_pci;
  52
  53 /* the watchdog platform device */
  54 static struct platform_device *nv_tco_platform_device;
  55
  56 /* module parameters */
  57 #define WATCHDOG_HEARTBEAT 30   /* 30 sec default heartbeat (2<heartbeat<39) */
  58 static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
  59 module_param(heartbeat, int, 0);
  60 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (2<heartbeat<39, "
  61                             "default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
  62
  63 static int nowayout = WATCHDOG_NOWAYOUT;
  64 module_param(nowayout, int, 0);
  65 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"
  66                 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  67
  68 /*
  69  * Some TCO specific functions
  70  */
  71 static inline unsigned char seconds_to_ticks(int seconds)
  72 {
  73         /* the internal timer is stored as ticks which decrement
  74          * every 0.6 seconds */
  75         return (seconds * 10) / 6;
  76 }
  77
  78 static void tco_timer_start(void)
  79 {
  80         u32 val;
  81         unsigned long flags;
  82
  83         spin_lock_irqsave(&tco_lock, flags);
  84         val = inl(TCO_CNT(tcobase));
  85         val &= ~TCO_CNT_TCOHALT;
  86         outl(val, TCO_CNT(tcobase));
  87         spin_unlock_irqrestore(&tco_lock, flags);
  88 }
  89
  90 static void tco_timer_stop(void)
  91 {
  92         u32 val;
  93         unsigned long flags;
  94
  95         spin_lock_irqsave(&tco_lock, flags);
  96         val = inl(TCO_CNT(tcobase));
  97         val |= TCO_CNT_TCOHALT;
  98         outl(val, TCO_CNT(tcobase));
  99         spin_unlock_irqrestore(&tco_lock, flags);
 100 }
 101
 102 static void tco_timer_keepalive(void)
 103 {
 104         unsigned long flags;
 105
 106         spin_lock_irqsave(&tco_lock, flags);
 107         outb(0x01, TCO_RLD(tcobase));
 108         spin_unlock_irqrestore(&tco_lock, flags);
 109 }
 110
 111 static int tco_timer_set_heartbeat(int t)
 112 {
 113         int ret = 0;
 114         unsigned char tmrval;
 115         unsigned long flags;
 116         u8 val;
 117
 118         /*
 119          * note seconds_to_ticks(t) > t, so if t > 0x3f, so is
 120          * tmrval=seconds_to_ticks(t).  Check that the count in seconds isn't
 121          * out of range on it's own (to avoid overflow in tmrval).
 122          */
 123         if (t < 0 || t > 0x3f)
 124                 return -EINVAL;
 125         tmrval = seconds_to_ticks(t);
 126
 127         /* "Values of 0h-3h are ignored and should not be attempted" */
 128         if (tmrval > 0x3f || tmrval < 0x04)
 129                 return -EINVAL;
 130
 131         /* Write new heartbeat to watchdog */
 132         spin_lock_irqsave(&tco_lock, flags);
 133         val = inb(TCO_TMR(tcobase));
 134         val &= 0xc0;
 135         val |= tmrval;
 136         outb(val, TCO_TMR(tcobase));
 137         val = inb(TCO_TMR(tcobase));
 138
 139         if ((val & 0x3f) != tmrval)
 140                 ret = -EINVAL;
 141         spin_unlock_irqrestore(&tco_lock, flags);
 142
 143         if (ret)
 144                 return ret;
 145
 146         heartbeat = t;
 147         return 0;
 148 }
 149
 150 /*
 151  *      /dev/watchdog handling
 152  */
 153
 154 static int nv_tco_open(struct inode *inode, struct file *file)
 155 {
 156         /* /dev/watchdog can only be opened once */
 157         if (test_and_set_bit(0, &timer_alive))
 158                 return -EBUSY;
 159
 160         /* Reload and activate timer */
 161         tco_timer_keepalive();
 162         tco_timer_start();
 163         return nonseekable_open(inode, file);
 164 }
 165
 166 static int nv_tco_release(struct inode *inode, struct file *file)
 167 {
 168         /* Shut off the timer */
 169         if (tco_expect_close == 42) {
 170                 tco_timer_stop();
 171         } else {
 172                 printk(KERN_CRIT PFX "Unexpected close, not stopping "
 173                        "watchdog!\n");
 174                 tco_timer_keepalive();
 175         }
 176         clear_bit(0, &timer_alive);
 177         tco_expect_close = 0;
 178         return 0;
 179 }
 180
 181 static ssize_t nv_tco_write(struct file *file, const char __user *data,
 182                             size_t len, loff_t *ppos)
 183 {
 184         /* See if we got the magic character 'V' and reload the timer */
 185         if (len) {
 186                 if (!nowayout) {
 187                         size_t i;
 188
 189                         /*
 190                          * note: just in case someone wrote the magic character
 191                          * five months ago...
 192                          */
 193                         tco_expect_close = 0;
 194
 195                         /*
 196                          * scan to see whether or not we got the magic
 197                          * character
 198                          */
 199                         for (i = 0; i != len; i++) {
 200                                 char c;
 201                                 if (get_user(c, data + i))
 202                                         return -EFAULT;
 203                                 if (c == 'V')
 204                                         tco_expect_close = 42;
 205                         }
 206                 }
 207
 208                 /* someone wrote to us, we should reload the timer */
 209                 tco_timer_keepalive();
 210         }
 211         return len;
 212 }
 213
 214 static long nv_tco_ioctl(struct file *file, unsigned int cmd,
 215                          unsigned long arg)
 216 {
 217         int new_options, retval = -EINVAL;
 218         int new_heartbeat;
 219         void __user *argp = (void __user *)arg;
 220         int __user *p = argp;
 221         static const struct watchdog_info ident = {
 222                 .options =              WDIOF_SETTIMEOUT |
 223                                         WDIOF_KEEPALIVEPING |
 224                                         WDIOF_MAGICCLOSE,
 225                 .firmware_version =     0,
 226                 .identity =             TCO_MODULE_NAME,
 227         };
 228
 229         switch (cmd) {
 230         case WDIOC_GETSUPPORT:
 231                 return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
 232         case WDIOC_GETSTATUS:
 233         case WDIOC_GETBOOTSTATUS:
 234                 return put_user(0, p);
 235         case WDIOC_SETOPTIONS:
 236                 if (get_user(new_options, p))
 237                         return -EFAULT;
 238                 if (new_options & WDIOS_DISABLECARD) {
 239                         tco_timer_stop();
 240                         retval = 0;
 241                 }
 242                 if (new_options & WDIOS_ENABLECARD) {
 243                         tco_timer_keepalive();
 244                         tco_timer_start();
 245                         retval = 0;
 246                 }
 247                 return retval;
 248         case WDIOC_KEEPALIVE:
 249                 tco_timer_keepalive();
 250                 return 0;
 251         case WDIOC_SETTIMEOUT:
 252                 if (get_user(new_heartbeat, p))
 253                         return -EFAULT;
 254                 if (tco_timer_set_heartbeat(new_heartbeat))
 255                         return -EINVAL;
 256                 tco_timer_keepalive();
 257                 /* Fall through */
 258         case WDIOC_GETTIMEOUT:
 259                 return put_user(heartbeat, p);
 260         default:
 261                 return -ENOTTY;
 262         }
 263 }
 264
 265 /*
 266  *      Kernel Interfaces
 267  */
 268
 269 static const struct file_operations nv_tco_fops = {
 270         .owner =                THIS_MODULE,
 271         .llseek =               no_llseek,
 272         .write =                nv_tco_write,
 273         .unlocked_ioctl =       nv_tco_ioctl,
 274         .open =                 nv_tco_open,
 275         .release =              nv_tco_release,
 276 };
 277
 278 static struct miscdevice nv_tco_miscdev = {
 279         .minor =        WATCHDOG_MINOR,
 280         .name =         "watchdog",
 281         .fops =         &nv_tco_fops,
 282 };
 283
 284 /*
 285  * Data for PCI driver interface
 286  *
 287  * This data only exists for exporting the supported
 288  * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
 289  * register a pci_driver, because someone else might one day
 290  * want to register another driver on the same PCI id.
 291  */
 292 static DEFINE_PCI_DEVICE_TABLE(tco_pci_tbl) = {
 293         { PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP51_SMBUS,
 294           PCI_ANY_ID, PCI_ANY_ID, },
 295         { PCI_VENDOR_ID_NVIDIA, PCI_DEVICE_ID_NVIDIA_NFORCE_MCP55_SMBUS,
 296           PCI_ANY_ID, PCI_ANY_ID, },
 297         { 0, },                 /* End of list */
 298 };
 299 MODULE_DEVICE_TABLE(pci, tco_pci_tbl);
 300
 301 /*
 302  *      Init & exit routines
 303  */
 304
 305 static unsigned char __devinit nv_tco_getdevice(void)
 306 {
 307         struct pci_dev *dev = NULL;
 308         u32 val;
 309
 310         /* Find the PCI device */
 311         for_each_pci_dev(dev) {
 312                 if (pci_match_id(tco_pci_tbl, dev) != NULL) {
 313                         tco_pci = dev;
 314                         break;
 315                 }
 316         }
 317
 318         if (!tco_pci)
 319                 return 0;
 320
 321         /* Find the base io port */
 322         pci_read_config_dword(tco_pci, 0x64, &val);
 323         val &= 0xffff;
 324         if (val == 0x0001 || val == 0x0000) {
 325                 /* Something is wrong here, bar isn't setup */
 326                 printk(KERN_ERR PFX "failed to get tcobase address\n");
 327                 return 0;
 328         }
 329         val &= 0xff00;
 330         tcobase = val + 0x40;
 331
 332         if (!request_region(tcobase, 0x10, "NV TCO")) {
 333                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 334                        tcobase);
 335                 return 0;
 336         }
 337
 338         /* Set a reasonable heartbeat before we stop the timer */
 339         tco_timer_set_heartbeat(30);
 340
 341         /*
 342          * Stop the TCO before we change anything so we don't race with
 343          * a zeroed timer.
 344          */
 345         tco_timer_keepalive();
 346         tco_timer_stop();
 347
 348         /* Disable SMI caused by TCO */
 349         if (!request_region(MCP51_SMI_EN(tcobase), 4, "NV TCO")) {
 350                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 351                        MCP51_SMI_EN(tcobase));
 352                 goto out;
 353         }
 354         val = inl(MCP51_SMI_EN(tcobase));
 355         val &= ~MCP51_SMI_EN_TCO;
 356         outl(val, MCP51_SMI_EN(tcobase));
 357         val = inl(MCP51_SMI_EN(tcobase));
 358         release_region(MCP51_SMI_EN(tcobase), 4);
 359         if (val & MCP51_SMI_EN_TCO) {
 360                 printk(KERN_ERR PFX "Could not disable SMI caused by TCO\n");
 361                 goto out;
 362         }
 363
 364         /* Check chipset's NO_REBOOT bit */
 365         pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
 366         val |= MCP51_SMBUS_SETUP_B_TCO_REBOOT;
 367         pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val);
 368         pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
 369         if (!(val & MCP51_SMBUS_SETUP_B_TCO_REBOOT)) {
 370                 printk(KERN_ERR PFX "failed to reset NO_REBOOT flag, reboot "
 371                        "disabled by hardware\n");
 372                 goto out;
 373         }
 374
 375         return 1;
 376 out:
 377         release_region(tcobase, 0x10);
 378         return 0;
 379 }
 380
 381 static int __devinit nv_tco_init(struct platform_device *dev)
 382 {
 383         int ret;
 384
 385         /* Check whether or not the hardware watchdog is there */
 386         if (!nv_tco_getdevice())
 387                 return -ENODEV;
 388
 389         /* Check to see if last reboot was due to watchdog timeout */
 390         printk(KERN_INFO PFX "Watchdog reboot %sdetected.\n",
 391                inl(TCO_STS(tcobase)) & TCO_STS_TCO2TO_STS ? "" : "not ");
 392
 393         /* Clear out the old status */
 394         outl(TCO_STS_RESET, TCO_STS(tcobase));
 395
 396         /*
 397          * Check that the heartbeat value is within it's range.
 398          * If not, reset to the default.
 399          */
 400         if (tco_timer_set_heartbeat(heartbeat)) {
 401                 heartbeat = WATCHDOG_HEARTBEAT;
 402                 tco_timer_set_heartbeat(heartbeat);
 403                 printk(KERN_INFO PFX "heartbeat value must be 2<heartbeat<39, "
 404                        "using %d\n", heartbeat);
 405         }
 406
 407         ret = misc_register(&nv_tco_miscdev);
 408         if (ret != 0) {
 409                 printk(KERN_ERR PFX "cannot register miscdev on minor=%d "
 410                        "(err=%d)\n", WATCHDOG_MINOR, ret);
 411                 goto unreg_region;
 412         }
 413
 414         clear_bit(0, &timer_alive);
 415
 416         tco_timer_stop();
 417
 418         printk(KERN_INFO PFX "initialized (0x%04x). heartbeat=%d sec "
 419                "(nowayout=%d)\n", tcobase, heartbeat, nowayout);
 420
 421         return 0;
 422
 423 unreg_region:
 424         release_region(tcobase, 0x10);
 425         return ret;
 426 }
 427
 428 static void __devexit nv_tco_cleanup(void)
 429 {
 430         u32 val;
 431
 432         /* Stop the timer before we leave */
 433         if (!nowayout)
 434                 tco_timer_stop();
 435
 436         /* Set the NO_REBOOT bit to prevent later reboots, just for sure */
 437         pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
 438         val &= ~MCP51_SMBUS_SETUP_B_TCO_REBOOT;
 439         pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val);
 440         pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
 441         if (val & MCP51_SMBUS_SETUP_B_TCO_REBOOT) {
 442                 printk(KERN_CRIT PFX "Couldn't unset REBOOT bit.  Machine may "
 443                        "soon reset\n");
 444         }
 445
 446         /* Deregister */
 447         misc_deregister(&nv_tco_miscdev);
 448         release_region(tcobase, 0x10);
 449 }
 450
 451 static int __devexit nv_tco_remove(struct platform_device *dev)
 452 {
 453         if (tcobase)
 454                 nv_tco_cleanup();
 455
 456         return 0;
 457 }
 458
 459 static void nv_tco_shutdown(struct platform_device *dev)
 460 {
 461         u32 val;
 462
 463         tco_timer_stop();
 464
 465         /* Some BIOSes fail the POST (once) if the NO_REBOOT flag is not
 466          * unset during shutdown. */
 467         pci_read_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, &val);
 468         val &= ~MCP51_SMBUS_SETUP_B_TCO_REBOOT;
 469         pci_write_config_dword(tco_pci, MCP51_SMBUS_SETUP_B, val);
 470 }
 471
 472 static struct platform_driver nv_tco_driver = {
 473         .probe          = nv_tco_init,
 474         .remove         = __devexit_p(nv_tco_remove),
 475         .shutdown       = nv_tco_shutdown,
 476         .driver         = {
 477                 .owner  = THIS_MODULE,
 478                 .name   = TCO_MODULE_NAME,
 479         },
 480 };
 481
 482 static int __init nv_tco_init_module(void)
 483 {
 484         int err;
 485
 486         printk(KERN_INFO PFX "NV TCO WatchDog Timer Driver v%s\n",
 487                TCO_VERSION);
 488
 489         err = platform_driver_register(&nv_tco_driver);
 490         if (err)
 491                 return err;
 492
 493         nv_tco_platform_device = platform_device_register_simple(
 494                                         TCO_MODULE_NAME, -1, NULL, 0);
 495         if (IS_ERR(nv_tco_platform_device)) {
 496                 err = PTR_ERR(nv_tco_platform_device);
 497                 goto unreg_platform_driver;
 498         }
 499
 500         return 0;
 501
 502 unreg_platform_driver:
 503         platform_driver_unregister(&nv_tco_driver);
 504         return err;
 505 }
 506
 507 static void __exit nv_tco_cleanup_module(void)
 508 {
 509         platform_device_unregister(nv_tco_platform_device);
 510         platform_driver_unregister(&nv_tco_driver);
 511         printk(KERN_INFO PFX "NV TCO Watchdog Module Unloaded.\n");
 512 }
 513
 514 module_init(nv_tco_init_module);
 515 module_exit(nv_tco_cleanup_module);
 516
 517 MODULE_AUTHOR("Mike Waychison");
 518 MODULE_DESCRIPTION("TCO timer driver for NV chipsets");
 519 MODULE_LICENSE("GPL");
 520 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);