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 module_param(io, int, 0); 74 MODULE_PARM_DESC(io, "WDT io port (default=0x240)"); 75 module_param(irq, int, 0); 76 MODULE_PARM_DESC(irq, "WDT irq (default=11)"); 77 78 #ifdef CONFIG_WDT_501 79 /* Support for the Fan Tachometer on the WDT501-P */ 80 static int tachometer; 81 82 module_param(tachometer, int, 0); 83 MODULE_PARM_DESC(tachometer, "WDT501-P Fan Tachometer support (0=disable, default=0)"); 84 #endif /* CONFIG_WDT_501 */ 85 86 /* 87 * Programming support 88 */ 89 90 static void wdt_ctr_mode(int ctr, int mode) 91 { 92 ctr<<=6; 93 ctr|=0x30; 94 ctr|=(mode<<1); 95 outb_p(ctr, WDT_CR); 96 } 97 98 static void wdt_ctr_load(int ctr, int val) 99 { 100 outb_p(val&0xFF, WDT_COUNT0+ctr); 101 outb_p(val>>8, WDT_COUNT0+ctr); 102 } 103 104 /** 105 * wdt_start: 106 * 107 * Start the watchdog driver. 108 */ 109 110 static int wdt_start(void) 111 { 112 inb_p(WDT_DC); /* Disable watchdog */ 113 wdt_ctr_mode(0,3); /* Program CTR0 for Mode 3: Square Wave Generator */ 114 wdt_ctr_mode(1,2); /* Program CTR1 for Mode 2: Rate Generator */ 115 wdt_ctr_mode(2,0); /* Program CTR2 for Mode 0: Pulse on Terminal Count */ 116 wdt_ctr_load(0, 8948); /* Count at 100Hz */ 117 wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */ 118 wdt_ctr_load(2,65535); /* Length of reset pulse */ 119 outb_p(0, WDT_DC); /* Enable watchdog */ 120 return 0; 121 } 122 123 /** 124 * wdt_stop: 125 * 126 * Stop the watchdog driver. 127 */ 128 129 static int wdt_stop (void) 130 { 131 /* Turn the card off */ 132 inb_p(WDT_DC); /* Disable watchdog */ 133 wdt_ctr_load(2,0); /* 0 length reset pulses now */ 134 return 0; 135 } 136 137 /** 138 * wdt_ping: 139 * 140 * Reload counter one with the watchdog heartbeat. We don't bother reloading 141 * the cascade counter. 142 */ 143 144 static int wdt_ping(void) 145 { 146 /* Write a watchdog value */ 147 inb_p(WDT_DC); /* Disable watchdog */ 148 wdt_ctr_mode(1,2); /* Re-Program CTR1 for Mode 2: Rate Generator */ 149 wdt_ctr_load(1,wd_heartbeat); /* Heartbeat */ 150 outb_p(0, WDT_DC); /* Enable watchdog */ 151 return 0; 152 } 153 154 /** 155 * wdt_set_heartbeat: 156 * @t: the new heartbeat value that needs to be set. 157 * 158 * Set a new heartbeat value for the watchdog device. If the heartbeat value is 159 * incorrect we keep the old value and return -EINVAL. If successfull we 160 * return 0. 161 */ 162 static int wdt_set_heartbeat(int t) 163 { 164 if ((t < 1) || (t > 65535)) 165 return -EINVAL; 166 167 heartbeat = t; 168 wd_heartbeat = t * 100; 169 return 0; 170 } 171 172 /** 173 * wdt_get_status: 174 * @status: the new status. 175 * 176 * Extract the status information from a WDT watchdog device. There are 177 * several board variants so we have to know which bits are valid. Some 178 * bits default to one and some to zero in order to be maximally painful. 179 * 180 * we then map the bits onto the status ioctl flags. 181 */ 182 183 static int wdt_get_status(int *status) 184 { 185 unsigned char new_status=inb_p(WDT_SR); 186 187 *status=0; 188 if (new_status & WDC_SR_ISOI0) 189 *status |= WDIOF_EXTERN1; 190 if (new_status & WDC_SR_ISII1) 191 *status |= WDIOF_EXTERN2; 192 #ifdef CONFIG_WDT_501 193 if (!(new_status & WDC_SR_TGOOD)) 194 *status |= WDIOF_OVERHEAT; 195 if (!(new_status & WDC_SR_PSUOVER)) 196 *status |= WDIOF_POWEROVER; 197 if (!(new_status & WDC_SR_PSUUNDR)) 198 *status |= WDIOF_POWERUNDER; 199 if (tachometer) { 200 if (!(new_status & WDC_SR_FANGOOD)) 201 *status |= WDIOF_FANFAULT; 202 } 203 #endif /* CONFIG_WDT_501 */ 204 return 0; 205 } 206 207 #ifdef CONFIG_WDT_501 208 /** 209 * wdt_get_temperature: 210 * 211 * Reports the temperature in degrees Fahrenheit. The API is in 212 * farenheit. It was designed by an imperial measurement luddite. 213 */ 214 215 static int wdt_get_temperature(int *temperature) 216 { 217 unsigned short c=inb_p(WDT_RT); 218 219 *temperature = (c * 11 / 15) + 7; 220 return 0; 221 } 222 #endif /* CONFIG_WDT_501 */ 223 224 /** 225 * wdt_interrupt: 226 * @irq: Interrupt number 227 * @dev_id: Unused as we don't allow multiple devices. 228 * 229 * Handle an interrupt from the board. These are raised when the status 230 * map changes in what the board considers an interesting way. That means 231 * a failure condition occurring. 232 */ 233 234 static irqreturn_t wdt_interrupt(int irq, void *dev_id) 235 { 236 /* 237 * Read the status register see what is up and 238 * then printk it. 239 */ 240 unsigned char status=inb_p(WDT_SR); 241 242 printk(KERN_CRIT "WDT status %d\n", status); 243 244 #ifdef CONFIG_WDT_501 245 if (!(status & WDC_SR_TGOOD)) 246 printk(KERN_CRIT "Overheat alarm.(%d)\n",inb_p(WDT_RT)); 247 if (!(status & WDC_SR_PSUOVER)) 248 printk(KERN_CRIT "PSU over voltage.\n"); 249 if (!(status & WDC_SR_PSUUNDR)) 250 printk(KERN_CRIT "PSU under voltage.\n"); 251 if (tachometer) { 252 if (!(status & WDC_SR_FANGOOD)) 253 printk(KERN_CRIT "Possible fan fault.\n"); 254 } 255 #endif /* CONFIG_WDT_501 */ 256 if (!(status & WDC_SR_WCCR)) 257 #ifdef SOFTWARE_REBOOT 258 #ifdef ONLY_TESTING 259 printk(KERN_CRIT "Would Reboot.\n"); 260 #else 261 printk(KERN_CRIT "Initiating system reboot.\n"); 262 emergency_restart(); 263 #endif 264 #else 265 printk(KERN_CRIT "Reset in 5ms.\n"); 266 #endif 267 return IRQ_HANDLED; 268 } 269 270 271 /** 272 * wdt_write: 273 * @file: file handle to the watchdog 274 * @buf: buffer to write (unused as data does not matter here 275 * @count: count of bytes 276 * @ppos: pointer to the position to write. No seeks allowed 277 * 278 * A write to a watchdog device is defined as a keepalive signal. Any 279 * write of data will do, as we we don't define content meaning. 280 */ 281 282 static ssize_t wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) 283 { 284 if(count) { 285 if (!nowayout) { 286 size_t i; 287 288 /* In case it was set long ago */ 289 expect_close = 0; 290 291 for (i = 0; i != count; i++) { 292 char c; 293 if (get_user(c, buf + i)) 294 return -EFAULT; 295 if (c == 'V') 296 expect_close = 42; 297 } 298 } 299 wdt_ping(); 300 } 301 return count; 302 } 303 304 /** 305 * wdt_ioctl: 306 * @inode: inode of the device 307 * @file: file handle to the device 308 * @cmd: watchdog command 309 * @arg: argument pointer 310 * 311 * The watchdog API defines a common set of functions for all watchdogs 312 * according to their available features. We only actually usefully support 313 * querying capabilities and current status. 314 */ 315 316 static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 317 unsigned long arg) 318 { 319 void __user *argp = (void __user *)arg; 320 int __user *p = argp; 321 int new_heartbeat; 322 int status; 323 324 static struct watchdog_info ident = { 325 .options = WDIOF_SETTIMEOUT| 326 WDIOF_MAGICCLOSE| 327 WDIOF_KEEPALIVEPING, 328 .firmware_version = 1, 329 .identity = "WDT500/501", 330 }; 331 332 /* Add options according to the card we have */ 333 ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2); 334 #ifdef CONFIG_WDT_501 335 ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER); 336 if (tachometer) 337 ident.options |= WDIOF_FANFAULT; 338 #endif /* CONFIG_WDT_501 */ 339 340 switch(cmd) 341 { 342 default: 343 return -ENOTTY; 344 case WDIOC_GETSUPPORT: 345 return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0; 346 347 case WDIOC_GETSTATUS: 348 wdt_get_status(&status); 349 return put_user(status, p); 350 case WDIOC_GETBOOTSTATUS: 351 return put_user(0, p); 352 case WDIOC_KEEPALIVE: 353 wdt_ping(); 354 return 0; 355 case WDIOC_SETTIMEOUT: 356 if (get_user(new_heartbeat, p)) 357 return -EFAULT; 358 359 if (wdt_set_heartbeat(new_heartbeat)) 360 return -EINVAL; 361 362 wdt_ping(); 363 /* Fall */ 364 case WDIOC_GETTIMEOUT: 365 return put_user(heartbeat, p); 366 } 367 } 368 369 /** 370 * wdt_open: 371 * @inode: inode of device 372 * @file: file handle to device 373 * 374 * The watchdog device has been opened. The watchdog device is single 375 * open and on opening we load the counters. Counter zero is a 100Hz 376 * cascade, into counter 1 which downcounts to reboot. When the counter 377 * triggers counter 2 downcounts the length of the reset pulse which 378 * set set to be as long as possible. 379 */ 380 381 static int wdt_open(struct inode *inode, struct file *file) 382 { 383 if(test_and_set_bit(0, &wdt_is_open)) 384 return -EBUSY; 385 /* 386 * Activate 387 */ 388 wdt_start(); 389 return nonseekable_open(inode, file); 390 } 391 392 /** 393 * wdt_release: 394 * @inode: inode to board 395 * @file: file handle to board 396 * 397 * The watchdog has a configurable API. There is a religious dispute 398 * between people who want their watchdog to be able to shut down and 399 * those who want to be sure if the watchdog manager dies the machine 400 * reboots. In the former case we disable the counters, in the latter 401 * case you have to open it again very soon. 402 */ 403 404 static int wdt_release(struct inode *inode, struct file *file) 405 { 406 if (expect_close == 42) { 407 wdt_stop(); 408 clear_bit(0, &wdt_is_open); 409 } else { 410 printk(KERN_CRIT "wdt: WDT device closed unexpectedly. WDT will not stop!\n"); 411 wdt_ping(); 412 } 413 expect_close = 0; 414 return 0; 415 } 416 417 #ifdef CONFIG_WDT_501 418 /** 419 * wdt_temp_read: 420 * @file: file handle to the watchdog board 421 * @buf: buffer to write 1 byte into 422 * @count: length of buffer 423 * @ptr: offset (no seek allowed) 424 * 425 * Temp_read reports the temperature in degrees Fahrenheit. The API is in 426 * farenheit. It was designed by an imperial measurement luddite. 427 */ 428 429 static ssize_t wdt_temp_read(struct file *file, char __user *buf, size_t count, loff_t *ptr) 430 { 431 int temperature; 432 433 if (wdt_get_temperature(&temperature)) 434 return -EFAULT; 435 436 if (copy_to_user (buf, &temperature, 1)) 437 return -EFAULT; 438 439 return 1; 440 } 441 442 /** 443 * wdt_temp_open: 444 * @inode: inode of device 445 * @file: file handle to device 446 * 447 * The temperature device has been opened. 448 */ 449 450 static int wdt_temp_open(struct inode *inode, struct file *file) 451 { 452 return nonseekable_open(inode, file); 453 } 454 455 /** 456 * wdt_temp_release: 457 * @inode: inode to board 458 * @file: file handle to board 459 * 460 * The temperature device has been closed. 461 */ 462 463 static int wdt_temp_release(struct inode *inode, struct file *file) 464 { 465 return 0; 466 } 467 #endif /* CONFIG_WDT_501 */ 468 469 /** 470 * notify_sys: 471 * @this: our notifier block 472 * @code: the event being reported 473 * @unused: unused 474 * 475 * Our notifier is called on system shutdowns. We want to turn the card 476 * off at reboot otherwise the machine will reboot again during memory 477 * test or worse yet during the following fsck. This would suck, in fact 478 * trust me - if it happens it does suck. 479 */ 480 481 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 482 void *unused) 483 { 484 if(code==SYS_DOWN || code==SYS_HALT) { 485 /* Turn the card off */ 486 wdt_stop(); 487 } 488 return NOTIFY_DONE; 489 } 490 491 /* 492 * Kernel Interfaces 493 */ 494 495 496 static const struct file_operations wdt_fops = { 497 .owner = THIS_MODULE, 498 .llseek = no_llseek, 499 .write = wdt_write, 500 .ioctl = wdt_ioctl, 501 .open = wdt_open, 502 .release = wdt_release, 503 }; 504 505 static struct miscdevice wdt_miscdev = { 506 .minor = WATCHDOG_MINOR, 507 .name = "watchdog", 508 .fops = &wdt_fops, 509 }; 510 511 #ifdef CONFIG_WDT_501 512 static const struct file_operations wdt_temp_fops = { 513 .owner = THIS_MODULE, 514 .llseek = no_llseek, 515 .read = wdt_temp_read, 516 .open = wdt_temp_open, 517 .release = wdt_temp_release, 518 }; 519 520 static struct miscdevice temp_miscdev = { 521 .minor = TEMP_MINOR, 522 .name = "temperature", 523 .fops = &wdt_temp_fops, 524 }; 525 #endif /* CONFIG_WDT_501 */ 526 527 /* 528 * The WDT card needs to learn about soft shutdowns in order to 529 * turn the timebomb registers off. 530 */ 531 532 static struct notifier_block wdt_notifier = { 533 .notifier_call = wdt_notify_sys, 534 }; 535 536 /** 537 * cleanup_module: 538 * 539 * Unload the watchdog. You cannot do this with any file handles open. 540 * If your watchdog is set to continue ticking on close and you unload 541 * it, well it keeps ticking. We won't get the interrupt but the board 542 * will not touch PC memory so all is fine. You just have to load a new 543 * module in 60 seconds or reboot. 544 */ 545 546 static void __exit wdt_exit(void) 547 { 548 misc_deregister(&wdt_miscdev); 549 #ifdef CONFIG_WDT_501 550 misc_deregister(&temp_miscdev); 551 #endif /* CONFIG_WDT_501 */ 552 unregister_reboot_notifier(&wdt_notifier); 553 free_irq(irq, NULL); 554 release_region(io,8); 555 } 556 557 /** 558 * wdt_init: 559 * 560 * Set up the WDT watchdog board. All we have to do is grab the 561 * resources we require and bitch if anyone beat us to them. 562 * The open() function will actually kick the board off. 563 */ 564 565 static int __init wdt_init(void) 566 { 567 int ret; 568 569 /* Check that the heartbeat value is within it's range ; if not reset to the default */ 570 if (wdt_set_heartbeat(heartbeat)) { 571 wdt_set_heartbeat(WD_TIMO); 572 printk(KERN_INFO "wdt: heartbeat value must be 0<heartbeat<65536, using %d\n", 573 WD_TIMO); 574 } 575 576 if (!request_region(io, 8, "wdt501p")) { 577 printk(KERN_ERR "wdt: I/O address 0x%04x already in use\n", io); 578 ret = -EBUSY; 579 goto out; 580 } 581 582 ret = request_irq(irq, wdt_interrupt, IRQF_DISABLED, "wdt501p", NULL); 583 if(ret) { 584 printk(KERN_ERR "wdt: IRQ %d is not free.\n", irq); 585 goto outreg; 586 } 587 588 ret = register_reboot_notifier(&wdt_notifier); 589 if(ret) { 590 printk(KERN_ERR "wdt: cannot register reboot notifier (err=%d)\n", ret); 591 goto outirq; 592 } 593 594 #ifdef CONFIG_WDT_501 595 ret = misc_register(&temp_miscdev); 596 if (ret) { 597 printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n", 598 TEMP_MINOR, ret); 599 goto outrbt; 600 } 601 #endif /* CONFIG_WDT_501 */ 602 603 ret = misc_register(&wdt_miscdev); 604 if (ret) { 605 printk(KERN_ERR "wdt: cannot register miscdev on minor=%d (err=%d)\n", 606 WATCHDOG_MINOR, ret); 607 goto outmisc; 608 } 609 610 ret = 0; 611 printk(KERN_INFO "WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n", 612 io, irq, heartbeat, nowayout); 613 #ifdef CONFIG_WDT_501 614 printk(KERN_INFO "wdt: Fan Tachometer is %s\n", (tachometer ? "Enabled" : "Disabled")); 615 #endif /* CONFIG_WDT_501 */ 616 617 out: 618 return ret; 619 620 outmisc: 621 #ifdef CONFIG_WDT_501 622 misc_deregister(&temp_miscdev); 623 outrbt: 624 #endif /* CONFIG_WDT_501 */ 625 unregister_reboot_notifier(&wdt_notifier); 626 outirq: 627 free_irq(irq, NULL); 628 outreg: 629 release_region(io,8); 630 goto out; 631 } 632 633 module_init(wdt_init); 634 module_exit(wdt_exit); 635 636 MODULE_AUTHOR("Alan Cox"); 637 MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)"); 638 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 639 MODULE_ALIAS_MISCDEV(TEMP_MINOR); 640 MODULE_LICENSE("GPL"); 641