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 struct pci_device_id 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 __init 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 tco_timer_stop(); 462 } 463 464 static struct platform_driver nv_tco_driver = { 465 .probe = nv_tco_init, 466 .remove = __devexit_p(nv_tco_remove), 467 .shutdown = nv_tco_shutdown, 468 .driver = { 469 .owner = THIS_MODULE, 470 .name = TCO_MODULE_NAME, 471 }, 472 }; 473 474 static int __init nv_tco_init_module(void) 475 { 476 int err; 477 478 printk(KERN_INFO PFX "NV TCO WatchDog Timer Driver v%s\n", 479 TCO_VERSION); 480 481 err = platform_driver_register(&nv_tco_driver); 482 if (err) 483 return err; 484 485 nv_tco_platform_device = platform_device_register_simple( 486 TCO_MODULE_NAME, -1, NULL, 0); 487 if (IS_ERR(nv_tco_platform_device)) { 488 err = PTR_ERR(nv_tco_platform_device); 489 goto unreg_platform_driver; 490 } 491 492 return 0; 493 494 unreg_platform_driver: 495 platform_driver_unregister(&nv_tco_driver); 496 return err; 497 } 498 499 static void __exit nv_tco_cleanup_module(void) 500 { 501 platform_device_unregister(nv_tco_platform_device); 502 platform_driver_unregister(&nv_tco_driver); 503 printk(KERN_INFO PFX "NV TCO Watchdog Module Unloaded.\n"); 504 } 505 506 module_init(nv_tco_init_module); 507 module_exit(nv_tco_cleanup_module); 508 509 MODULE_AUTHOR("Mike Waychison"); 510 MODULE_DESCRIPTION("TCO timer driver for NV chipsets"); 511 MODULE_LICENSE("GPL"); 512 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 513