1 /* 2 * Industrial Computer Source WDT500/501 driver 3 * 4 * (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved. 5 * http://www.redhat.com 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 Alan Cox nor CymruNet Ltd. 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 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> 17 * 18 * Release 0.10. 19 * 20 * Fixes 21 * Dave Gregorich : Modularisation and minor bugs 22 * Alan Cox : Added the watchdog ioctl() stuff 23 * Alan Cox : Fixed the reboot problem (as noted by 24 * Matt Crocker). 25 * Alan Cox : Added wdt= boot option 26 * Alan Cox : Cleaned up copy/user stuff 27 * Tim Hockin : Added insmod parameters, comment cleanup 28 * Parameterized timeout 29 * Tigran Aivazian : Restructured wdt_init() to handle failures 30 * Joel Becker : Added WDIOC_GET/SETTIMEOUT 31 * Matt Domsch : Added nowayout module option 32 */ 33 34 #include <linux/interrupt.h> 35 #include <linux/module.h> 36 #include <linux/moduleparam.h> 37 #include <linux/types.h> 38 #include <linux/miscdevice.h> 39 #include <linux/watchdog.h> 40 #include <linux/fs.h> 41 #include <linux/ioport.h> 42 #include <linux/notifier.h> 43 #include <linux/reboot.h> 44 #include <linux/init.h> 45 46 #include <asm/io.h> 47 #include <asm/uaccess.h> 48 #include <asm/system.h> 49 #include "wd501p.h" 50 51 static unsigned long wdt_is_open; 52 static char expect_close; 53 54 /* 55 * Module parameters 56 */ 57 58 #define WD_TIMO 60 /* Default heartbeat = 60 seconds */ 59 60 static int heartbeat = WD_TIMO; 61 static int wd_heartbeat; 62 module_param(heartbeat, int, 0); 63 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (0<heartbeat<65536, default=" __MODULE_STRING(WD_TIMO) ")"); 64 65 static int nowayout = WATCHDOG_NOWAYOUT; 66 module_param(nowayout, int, 0); 67 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 68 69 /* You must set these - there is no sane way to probe for this board. */ 70 static int io=0x240; 71 static int irq=11; 72 73 static DEFINE_SPINLOCK(wdt_lock); 74 75 module_param(io, int, 0); 76 MODULE_PARM_DESC(io, "WDT io port (default=0x240)"); 77 module_param(irq, int, 0); 78 MODULE_PARM_DESC(irq, "WDT irq (default=11)"); 79 80 #ifdef CONFIG_WDT_501 81 /* Support for the Fan Tachometer on the WDT501-P */ 82 static int tachometer; 83 84 module_param(tachometer, int, 0); 85 MODULE_PARM_DESC(tachometer, "WDT501-P Fan Tachometer support (0=disable, default=0)"); 86 #endif /* CONFIG_WDT_501 */ 87 88 /* 89 * Programming support 90 */ 91 92 static void wdt_ctr_mode(int ctr, int mode) 93 { 94 ctr<<=6; 95 ctr|=0x30; 96 ctr|=(mode<<1); 97 outb_p(ctr, WDT_CR); 98 } 99 100 static void wdt_ctr_load(int ctr, int val) 101 { 102 outb_p(val&0xFF, WDT_COUNT0+ctr); 103 outb_p(val>>8, WDT_COUNT0+ctr); 104 } 105 106 /** 107 * wdt_start: 108 * 109 * Start the watchdog driver. 110 */ 111 112 static int wdt_start(void) 113 { 114 unsigned long flags; 115 spin_lock_irqsave(&wdt_lock, flags); 116 inb_p(WDT_DC); /* Disable watchdog */ 117 wdt_ctr_mode(0,3); /* Program CTR0 for Mode 3: Square Wave Generator */ 118 wdt_ctr_mode(1,2); /* Program CTR1 for Mode 2: Rate Generator */ 119 wdt_ctr_mode(2,0); /* Program CTR2 for Mode 0: Pulse on Terminal Count */ 120 wdt_ctr_load(0, 8948); /* Count at 100Hz */ 121 wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */ 122 wdt_ctr_load(2,65535); /* Length of reset pulse */ 123 outb_p(0, WDT_DC); /* Enable watchdog */ 124 spin_unlock_irqrestore(&wdt_lock, flags); 125 return 0; 126 } 127 128 /** 129 * wdt_stop: 130 * 131 * Stop the watchdog driver. 132 */ 133 134 static int wdt_stop (void) 135 { 136 unsigned long flags; 137 spin_lock_irqsave(&wdt_lock, flags); 138 /* Turn the card off */ 139 inb_p(WDT_DC); /* Disable watchdog */ 140 wdt_ctr_load(2,0); /* 0 length reset pulses now */ 141 spin_unlock_irqrestore(&wdt_lock, flags); 142 return 0; 143 } 144 145 /** 146 * wdt_ping: 147 * 148 * Reload counter one with the watchdog heartbeat. We don't bother reloading 149 * the cascade counter. 150 */ 151 152 static int wdt_ping(void) 153 { 154 unsigned long flags; 155 spin_lock_irqsave(&wdt_lock, flags); 156 /* Write a watchdog value */ 157 inb_p(WDT_DC); /* Disable watchdog */ 158 wdt_ctr_mode(1,2); /* Re-Program CTR1 for Mode 2: Rate Generator */ 159 wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */ 160 outb_p(0, WDT_DC); /* Enable watchdog */ 161 spin_unlock_irqrestore(&wdt_lock, flags); 162 return 0; 163 } 164 165 /** 166 * wdt_set_heartbeat: 167 * @t: the new heartbeat value that needs to be set. 168 * 169 * Set a new heartbeat value for the watchdog device. If the heartbeat value is 170 * incorrect we keep the old value and return -EINVAL. If successfull we 171 * return 0. 172 */ 173 static int wdt_set_heartbeat(int t) 174 { 175 if ((t < 1) || (t > 65535)) 176 return -EINVAL; 177 178 heartbeat = t; 179 wd_heartbeat = t * 100; 180 return 0; 181 } 182 183 /** 184 * wdt_get_status: 185 * @status: the new status. 186 * 187 * Extract the status information from a WDT watchdog device. There are 188 * several board variants so we have to know which bits are valid. Some 189 * bits default to one and some to zero in order to be maximally painful. 190 * 191 * we then map the bits onto the status ioctl flags. 192 */ 193 194 static int wdt_get_status(int *status) 195 { 196 unsigned char new_status; 197 unsigned long flags; 198 199 spin_lock_irqsave(&wdt_lock, flags); 200 new_status = inb_p(WDT_SR); 201 spin_unlock_irqrestore(&wdt_lock, flags); 202 203 *status=0; 204 if (new_status & WDC_SR_ISOI0) 205 *status |= WDIOF_EXTERN1; 206 if (new_status & WDC_SR_ISII1) 207 *status |= WDIOF_EXTERN2; 208 #ifdef CONFIG_WDT_501 209 if (!(new_status & WDC_SR_TGOOD)) 210 *status |= WDIOF_OVERHEAT; 211 if (!(new_status & WDC_SR_PSUOVER)) 212 *status |= WDIOF_POWEROVER; 213 if (!(new_status & WDC_SR_PSUUNDR)) 214 *status |= WDIOF_POWERUNDER; 215 if (tachometer) { 216 if (!(new_status & WDC_SR_FANGOOD)) 217 *status |= WDIOF_FANFAULT; 218 } 219 #endif /* CONFIG_WDT_501 */ 220 return 0; 221 } 222 223 #ifdef CONFIG_WDT_501 224 /** 225 * wdt_get_temperature: 226 * 227 * Reports the temperature in degrees Fahrenheit. The API is in 228 * farenheit. It was designed by an imperial measurement luddite. 229 */ 230 231 static int wdt_get_temperature(int *temperature) 232 { 233 unsigned short c; 234 unsigned long flags; 235 236 spin_lock_irqsave(&wdt_lock, flags); 237 c = inb_p(WDT_RT); 238 spin_unlock_irqrestore(&wdt_lock, flags); 239 *temperature = (c * 11 / 15) + 7; 240 return 0; 241 } 242 #endif /* CONFIG_WDT_501 */ 243 244 /** 245 * wdt_interrupt: 246 * @irq: Interrupt number 247 * @dev_id: Unused as we don't allow multiple devices. 248 * 249 * Handle an interrupt from the board. These are raised when the status 250 * map changes in what the board considers an interesting way. That means 251 * a failure condition occurring. 252 */ 253 254 static irqreturn_t wdt_interrupt(int irq, void *dev_id) 255 { 256 /* 257 * Read the status register see what is up and 258 * then printk it. 259 */ 260 unsigned char status; 261 262 spin_lock(&wdt_lock); 263 status = inb_p(WDT_SR); 264 265 printk(KERN_CRIT "WDT status %d\n", status); 266 267 #ifdef CONFIG_WDT_501 268 if (!(status & WDC_SR_TGOOD)) 269 printk(KERN_CRIT "Overheat alarm.(%d)\n",inb_p(WDT_RT)); 270 if (!(status & WDC_SR_PSUOVER)) 271 printk(KERN_CRIT "PSU over voltage.\n"); 272 if (!(status & WDC_SR_PSUUNDR)) 273 printk(KERN_CRIT "PSU under voltage.\n"); 274 if (tachometer) { 275 if (!(status & WDC_SR_FANGOOD)) 276 printk(KERN_CRIT "Possible fan fault.\n"); 277 } 278 #endif /* CONFIG_WDT_501 */ 279 if (!(status & WDC_SR_WCCR)) { 280 #ifdef SOFTWARE_REBOOT 281 #ifdef ONLY_TESTING 282 printk(KERN_CRIT "Would Reboot.\n"); 283 #else 284 printk(KERN_CRIT "Initiating system reboot.\n"); 285 emergency_restart(); 286 #endif 287 #else 288 printk(KERN_CRIT "Reset in 5ms.\n"); 289 #endif 290 } 291 spin_unlock(&wdt_lock); 292 return IRQ_HANDLED; 293 } 294 295 296 /** 297 * wdt_write: 298 * @file: file handle to the watchdog 299 * @buf: buffer to write (unused as data does not matter here 300 * @count: count of bytes 301 * @ppos: pointer to the position to write. No seeks allowed 302 * 303 * A write to a watchdog device is defined as a keepalive signal. Any 304 * write of data will do, as we we don't define content meaning. 305 */ 306 307 static ssize_t wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) 308 { 309 if(count) { 310 if (!nowayout) { 311 size_t i; 312 313 /* In case it was set long ago */ 314 expect_close = 0; 315 316 for (i = 0; i != count; i++) { 317 char c; 318 if (get_user(c, buf + i)) 319 return -EFAULT; 320 if (c == 'V') 321 expect_close = 42; 322 } 323 } 324 wdt_ping(); 325 } 326 return count; 327 } 328 329 /** 330 * wdt_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. We only actually usefully support 338 * querying capabilities and current status. 339 */ 340 341 static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 342 unsigned long arg) 343 { 344 void __user *argp = (void __user *)arg; 345 int __user *p = argp; 346 int new_heartbeat; 347 int status; 348 349 static struct watchdog_info ident = { 350 .options = WDIOF_SETTIMEOUT| 351 WDIOF_MAGICCLOSE| 352 WDIOF_KEEPALIVEPING, 353 .firmware_version = 1, 354 .identity = "WDT500/501", 355 }; 356 357 /* Add options according to the card we have */ 358 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2); 359 #ifdef CONFIG_WDT_501 360 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER); 361 if (tachometer) 362 ident.options |= WDIOF_FANFAULT; 363 #endif /* CONFIG_WDT_501 */ 364 365 switch(cmd) 366 { 367 default: 368 return -ENOTTY; 369 case WDIOC_GETSUPPORT: 370 return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0; 371 372 case WDIOC_GETSTATUS: 373 wdt_get_status(&status); 374 return put_user(status, p); 375 case WDIOC_GETBOOTSTATUS: 376 return put_user(0, p); 377 case WDIOC_KEEPALIVE: 378 wdt_ping(); 379 return 0; 380 case WDIOC_SETTIMEOUT: 381 if (get_user(new_heartbeat, p)) 382 return -EFAULT; 383 384 if (wdt_set_heartbeat(new_heartbeat)) 385 return -EINVAL; 386 387 wdt_ping(); 388 /* Fall */ 389 case WDIOC_GETTIMEOUT: 390 return put_user(heartbeat, p); 391 } 392 } 393 394 /** 395 * wdt_open: 396 * @inode: inode of device 397 * @file: file handle to device 398 * 399 * The watchdog device has been opened. The watchdog device is single 400 * open and on opening we load the counters. Counter zero is a 100Hz 401 * cascade, into counter 1 which downcounts to reboot. When the counter 402 * triggers counter 2 downcounts the length of the reset pulse which 403 * set set to be as long as possible. 404 */ 405 406 static int wdt_open(struct inode *inode, struct file *file) 407 { 408 if(test_and_set_bit(0, &wdt_is_open)) 409 return -EBUSY; 410 /* 411 * Activate 412 */ 413 wdt_start(); 414 return nonseekable_open(inode, file); 415 } 416 417 /** 418 * wdt_release: 419 * @inode: inode to board 420 * @file: file handle to board 421 * 422 * The watchdog has a configurable API. There is a religious dispute 423 * between people who want their watchdog to be able to shut down and 424 * those who want to be sure if the watchdog manager dies the machine 425 * reboots. In the former case we disable the counters, in the latter 426 * case you have to open it again very soon. 427 */ 428 429 static int wdt_release(struct inode *inode, struct file *file) 430 { 431 if (expect_close == 42) { 432 wdt_stop(); 433 clear_bit(0, &wdt_is_open); 434 } else { 435 printk(KERN_CRIT "wdt: WDT device closed unexpectedly. WDT will not stop!\n"); 436 wdt_ping(); 437 } 438 expect_close = 0; 439 return 0; 440 } 441 442 #ifdef CONFIG_WDT_501 443 /** 444 * wdt_temp_read: 445 * @file: file handle to the watchdog board 446 * @buf: buffer to write 1 byte into 447 * @count: length of buffer 448 * @ptr: offset (no seek allowed) 449 * 450 * Temp_read reports the temperature in degrees Fahrenheit. The API is in 451 * farenheit. It was designed by an imperial measurement luddite. 452 */ 453 454 static ssize_t wdt_temp_read(struct file *file, char __user *buf, size_t count, loff_t *ptr) 455 { 456 int temperature; 457 458 if (wdt_get_temperature(&temperature)) 459 return -EFAULT; 460 461 if (copy_to_user (buf, &temperature, 1)) 462 return -EFAULT; 463 464 return 1; 465 } 466 467 /** 468 * wdt_temp_open: 469 * @inode: inode of device 470 * @file: file handle to device 471 * 472 * The temperature device has been opened. 473 */ 474 475 static int wdt_temp_open(struct inode *inode, struct file *file) 476 { 477 return nonseekable_open(inode, file); 478 } 479 480 /** 481 * wdt_temp_release: 482 * @inode: inode to board 483 * @file: file handle to board 484 * 485 * The temperature device has been closed. 486 */ 487 488 static int wdt_temp_release(struct inode *inode, struct file *file) 489 { 490 return 0; 491 } 492 #endif /* CONFIG_WDT_501 */ 493 494 /** 495 * notify_sys: 496 * @this: our notifier block 497 * @code: the event being reported 498 * @unused: unused 499 * 500 * Our notifier is called on system shutdowns. We want to turn the card 501 * off at reboot otherwise the machine will reboot again during memory 502 * test or worse yet during the following fsck. This would suck, in fact 503 * trust me - if it happens it does suck. 504 */ 505 506 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 507 void *unused) 508 { 509 if(code==SYS_DOWN || code==SYS_HALT) { 510 /* Turn the card off */ 511 wdt_stop(); 512 } 513 return NOTIFY_DONE; 514 } 515 516 /* 517 * Kernel Interfaces 518 */ 519 520 521 static const struct file_operations wdt_fops = { 522 .owner = THIS_MODULE, 523 .llseek = no_llseek, 524 .write = wdt_write, 525 .ioctl = wdt_ioctl, 526 .open = wdt_open, 527 .release = wdt_release, 528 }; 529 530 static struct miscdevice wdt_miscdev = { 531 .minor = WATCHDOG_MINOR, 532 .name = "watchdog", 533 .fops = &wdt_fops, 534 }; 535 536 #ifdef CONFIG_WDT_501 537 static const struct file_operations wdt_temp_fops = { 538 .owner = THIS_MODULE, 539 .llseek = no_llseek, 540 .read = wdt_temp_read, 541 .open = wdt_temp_open, 542 .release = wdt_temp_release, 543 }; 544 545 static struct miscdevice temp_miscdev = { 546 .minor = TEMP_MINOR, 547 .name = "temperature", 548 .fops = &wdt_temp_fops, 549 }; 550 #endif /* CONFIG_WDT_501 */ 551 552 /* 553 * The WDT card needs to learn about soft shutdowns in order to 554 * turn the timebomb registers off. 555 */ 556 557 static struct notifier_block wdt_notifier = { 558 .notifier_call = wdt_notify_sys, 559 }; 560 561 /** 562 * cleanup_module: 563 * 564 * Unload the watchdog. You cannot do this with any file handles open. 565 * If your watchdog is set to continue ticking on close and you unload 566 * it, well it keeps ticking. We won't get the interrupt but the board 567 * will not touch PC memory so all is fine. You just have to load a new 568 * module in 60 seconds or reboot. 569 */ 570 571 static void __exit wdt_exit(void) 572 { 573 misc_deregister(&wdt_miscdev); 574 #ifdef CONFIG_WDT_501 575 misc_deregister(&temp_miscdev); 576 #endif /* CONFIG_WDT_501 */ 577 unregister_reboot_notifier(&wdt_notifier); 578 free_irq(irq, NULL); 579 release_region(io,8); 580 } 581 582 /** 583 * wdt_init: 584 * 585 * Set up the WDT watchdog board. All we have to do is grab the 586 * resources we require and bitch if anyone beat us to them. 587 * The open() function will actually kick the board off. 588 */ 589 590 static int __init wdt_init(void) 591 { 592 int ret; 593 594 /* Check that the heartbeat value is within it's range ; if not reset to the default */ 595 if (wdt_set_heartbeat(heartbeat)) { 596 wdt_set_heartbeat(WD_TIMO); 597 printk(KERN_INFO "wdt: heartbeat value must be 0<heartbeat<65536, using %d\n", 598 WD_TIMO); 599 } 600 601 if (!request_region(io, 8, "wdt501p")) { 602 printk(KERN_ERR "wdt: I/O address 0x%04x already in use\n", io); 603 ret = -EBUSY; 604 goto out; 605 } 606 607 ret = request_irq(irq, wdt_interrupt, IRQF_DISABLED, "wdt501p", NULL); 608 if(ret) { 609 printk(KERN_ERR "wdt: IRQ %d is not free.\n", irq); 610 goto outreg; 611 } 612 613 ret = register_reboot_notifier(&wdt_notifier); 614 if(ret) { 615 printk(KERN_ERR "wdt: cannot register reboot notifier (err=%d)\n", ret); 616 goto outirq; 617 } 618 619 #ifdef CONFIG_WDT_501 620 ret = misc_register(&temp_miscdev); 621 if (ret) { 622 printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n", 623 TEMP_MINOR, ret); 624 goto outrbt; 625 } 626 #endif /* CONFIG_WDT_501 */ 627 628 ret = misc_register(&wdt_miscdev); 629 if (ret) { 630 printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n", 631 WATCHDOG_MINOR, ret); 632 goto outmisc; 633 } 634 635 ret = 0; 636 printk(KERN_INFO "WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n", 637 io, irq, heartbeat, nowayout); 638 #ifdef CONFIG_WDT_501 639 printk(KERN_INFO "wdt: Fan Tachometer is %s\n", (tachometer ? "Enabled" : "Disabled")); 640 #endif /* CONFIG_WDT_501 */ 641 642 out: 643 return ret; 644 645 outmisc: 646 #ifdef CONFIG_WDT_501 647 misc_deregister(&temp_miscdev); 648 outrbt: 649 #endif /* CONFIG_WDT_501 */ 650 unregister_reboot_notifier(&wdt_notifier); 651 outirq: 652 free_irq(irq, NULL); 653 outreg: 654 release_region(io,8); 655 goto out; 656 } 657 658 module_init(wdt_init); 659 module_exit(wdt_exit); 660 661 MODULE_AUTHOR("Alan Cox"); 662 MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)"); 663 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 664 MODULE_ALIAS_MISCDEV(TEMP_MINOR); 665 MODULE_LICENSE("GPL"); 666