1/* 2 * W83977F Watchdog Timer Driver for Winbond W83977F I/O Chip 3 * 4 * (c) Copyright 2005 Jose Goncalves <jose.goncalves@inov.pt> 5 * 6 * Based on w83877f_wdt.c by Scott Jennings, 7 * and wdt977.c by Woody Suwalski 8 * 9 * ----------------------- 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 */ 17 18#include <linux/module.h> 19#include <linux/moduleparam.h> 20#include <linux/types.h> 21#include <linux/kernel.h> 22#include <linux/fs.h> 23#include <linux/miscdevice.h> 24#include <linux/init.h> 25#include <linux/ioport.h> 26#include <linux/watchdog.h> 27#include <linux/notifier.h> 28#include <linux/reboot.h> 29#include <linux/uaccess.h> 30#include <linux/io.h> 31 32#include <asm/system.h> 33 34#define WATCHDOG_VERSION "1.00" 35#define WATCHDOG_NAME "W83977F WDT" 36#define PFX WATCHDOG_NAME ": " 37#define DRIVER_VERSION WATCHDOG_NAME " driver, v" WATCHDOG_VERSION "\n" 38 39#define IO_INDEX_PORT 0x3F0 40#define IO_DATA_PORT (IO_INDEX_PORT+1) 41 42#define UNLOCK_DATA 0x87 43#define LOCK_DATA 0xAA 44#define DEVICE_REGISTER 0x07 45 46#define DEFAULT_TIMEOUT 45 /* default timeout in seconds */ 47 48static int timeout = DEFAULT_TIMEOUT; 49static int timeoutW; /* timeout in watchdog counter units */ 50static unsigned long timer_alive; 51static int testmode; 52static char expect_close; 53static DEFINE_SPINLOCK(spinlock); 54 55module_param(timeout, int, 0); 56MODULE_PARM_DESC(timeout, 57 "Watchdog timeout in seconds (15..7635), default=" 58 __MODULE_STRING(DEFAULT_TIMEOUT) ")"); 59module_param(testmode, int, 0); 60MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0"); 61 62static int nowayout = WATCHDOG_NOWAYOUT; 63module_param(nowayout, int, 0); 64MODULE_PARM_DESC(nowayout, 65 "Watchdog cannot be stopped once started (default=" 66 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 67 68/* 69 * Start the watchdog 70 */ 71 72static int wdt_start(void) 73{ 74 unsigned long flags; 75 76 spin_lock_irqsave(&spinlock, flags); 77 78 /* Unlock the SuperIO chip */ 79 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 80 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 81 82 /* 83 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. 84 * F2 has the timeout in watchdog counter units. 85 * F3 is set to enable watchdog LED blink at timeout. 86 * F4 is used to just clear the TIMEOUT'ed state (bit 0). 87 */ 88 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 89 outb_p(0x08, IO_DATA_PORT); 90 outb_p(0xF2, IO_INDEX_PORT); 91 outb_p(timeoutW, IO_DATA_PORT); 92 outb_p(0xF3, IO_INDEX_PORT); 93 outb_p(0x08, IO_DATA_PORT); 94 outb_p(0xF4, IO_INDEX_PORT); 95 outb_p(0x00, IO_DATA_PORT); 96 97 /* Set device Aux2 active */ 98 outb_p(0x30, IO_INDEX_PORT); 99 outb_p(0x01, IO_DATA_PORT); 100 101 /* 102 * Select device Aux1 (dev=7) to set GP16 as the watchdog output 103 * (in reg E6) and GP13 as the watchdog LED output (in reg E3). 104 * Map GP16 at pin 119. 105 * In test mode watch the bit 0 on F4 to indicate "triggered" or 106 * check watchdog LED on SBC. 107 */ 108 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 109 outb_p(0x07, IO_DATA_PORT); 110 if (!testmode) { 111 unsigned pin_map; 112 113 outb_p(0xE6, IO_INDEX_PORT); 114 outb_p(0x0A, IO_DATA_PORT); 115 outb_p(0x2C, IO_INDEX_PORT); 116 pin_map = inb_p(IO_DATA_PORT); 117 pin_map |= 0x10; 118 pin_map &= ~(0x20); 119 outb_p(0x2C, IO_INDEX_PORT); 120 outb_p(pin_map, IO_DATA_PORT); 121 } 122 outb_p(0xE3, IO_INDEX_PORT); 123 outb_p(0x08, IO_DATA_PORT); 124 125 /* Set device Aux1 active */ 126 outb_p(0x30, IO_INDEX_PORT); 127 outb_p(0x01, IO_DATA_PORT); 128 129 /* Lock the SuperIO chip */ 130 outb_p(LOCK_DATA, IO_INDEX_PORT); 131 132 spin_unlock_irqrestore(&spinlock, flags); 133 134 printk(KERN_INFO PFX "activated.\n"); 135 136 return 0; 137} 138 139/* 140 * Stop the watchdog 141 */ 142 143static int wdt_stop(void) 144{ 145 unsigned long flags; 146 147 spin_lock_irqsave(&spinlock, flags); 148 149 /* Unlock the SuperIO chip */ 150 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 151 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 152 153 /* 154 * Select device Aux2 (device=8) to set watchdog regs F2, F3 and F4. 155 * F2 is reset to its default value (watchdog timer disabled). 156 * F3 is reset to its default state. 157 * F4 clears the TIMEOUT'ed state (bit 0) - back to default. 158 */ 159 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 160 outb_p(0x08, IO_DATA_PORT); 161 outb_p(0xF2, IO_INDEX_PORT); 162 outb_p(0xFF, IO_DATA_PORT); 163 outb_p(0xF3, IO_INDEX_PORT); 164 outb_p(0x00, IO_DATA_PORT); 165 outb_p(0xF4, IO_INDEX_PORT); 166 outb_p(0x00, IO_DATA_PORT); 167 outb_p(0xF2, IO_INDEX_PORT); 168 outb_p(0x00, IO_DATA_PORT); 169 170 /* 171 * Select device Aux1 (dev=7) to set GP16 (in reg E6) and 172 * Gp13 (in reg E3) as inputs. 173 */ 174 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 175 outb_p(0x07, IO_DATA_PORT); 176 if (!testmode) { 177 outb_p(0xE6, IO_INDEX_PORT); 178 outb_p(0x01, IO_DATA_PORT); 179 } 180 outb_p(0xE3, IO_INDEX_PORT); 181 outb_p(0x01, IO_DATA_PORT); 182 183 /* Lock the SuperIO chip */ 184 outb_p(LOCK_DATA, IO_INDEX_PORT); 185 186 spin_unlock_irqrestore(&spinlock, flags); 187 188 printk(KERN_INFO PFX "shutdown.\n"); 189 190 return 0; 191} 192 193/* 194 * Send a keepalive ping to the watchdog 195 * This is done by simply re-writing the timeout to reg. 0xF2 196 */ 197 198static int wdt_keepalive(void) 199{ 200 unsigned long flags; 201 202 spin_lock_irqsave(&spinlock, flags); 203 204 /* Unlock the SuperIO chip */ 205 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 206 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 207 208 /* Select device Aux2 (device=8) to kick watchdog reg F2 */ 209 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 210 outb_p(0x08, IO_DATA_PORT); 211 outb_p(0xF2, IO_INDEX_PORT); 212 outb_p(timeoutW, IO_DATA_PORT); 213 214 /* Lock the SuperIO chip */ 215 outb_p(LOCK_DATA, IO_INDEX_PORT); 216 217 spin_unlock_irqrestore(&spinlock, flags); 218 219 return 0; 220} 221 222/* 223 * Set the watchdog timeout value 224 */ 225 226static int wdt_set_timeout(int t) 227{ 228 int tmrval; 229 230 /* 231 * Convert seconds to watchdog counter time units, rounding up. 232 * On PCM-5335 watchdog units are 30 seconds/step with 15 sec startup 233 * value. This information is supplied in the PCM-5335 manual and was 234 * checked by me on a real board. This is a bit strange because W83977f 235 * datasheet says counter unit is in minutes! 236 */ 237 if (t < 15) 238 return -EINVAL; 239 240 tmrval = ((t + 15) + 29) / 30; 241 242 if (tmrval > 255) 243 return -EINVAL; 244 245 /* 246 * timeout is the timeout in seconds, 247 * timeoutW is the timeout in watchdog counter units. 248 */ 249 timeoutW = tmrval; 250 timeout = (timeoutW * 30) - 15; 251 return 0; 252} 253 254/* 255 * Get the watchdog status 256 */ 257 258static int wdt_get_status(int *status) 259{ 260 int new_status; 261 unsigned long flags; 262 263 spin_lock_irqsave(&spinlock, flags); 264 265 /* Unlock the SuperIO chip */ 266 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 267 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 268 269 /* Select device Aux2 (device=8) to read watchdog reg F4 */ 270 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 271 outb_p(0x08, IO_DATA_PORT); 272 outb_p(0xF4, IO_INDEX_PORT); 273 new_status = inb_p(IO_DATA_PORT); 274 275 /* Lock the SuperIO chip */ 276 outb_p(LOCK_DATA, IO_INDEX_PORT); 277 278 spin_unlock_irqrestore(&spinlock, flags); 279 280 *status = 0; 281 if (new_status & 1) 282 *status |= WDIOF_CARDRESET; 283 284 return 0; 285} 286 287 288/* 289 * /dev/watchdog handling 290 */ 291 292static int wdt_open(struct inode *inode, struct file *file) 293{ 294 /* If the watchdog is alive we don't need to start it again */ 295 if (test_and_set_bit(0, &timer_alive)) 296 return -EBUSY; 297 298 if (nowayout) 299 __module_get(THIS_MODULE); 300 301 wdt_start(); 302 return nonseekable_open(inode, file); 303} 304 305static int wdt_release(struct inode *inode, struct file *file) 306{ 307 /* 308 * Shut off the timer. 309 * Lock it in if it's a module and we set nowayout 310 */ 311 if (expect_close == 42) { 312 wdt_stop(); 313 clear_bit(0, &timer_alive); 314 } else { 315 wdt_keepalive(); 316 printk(KERN_CRIT PFX 317 "unexpected close, not stopping watchdog!\n"); 318 } 319 expect_close = 0; 320 return 0; 321} 322 323/* 324 * wdt_write: 325 * @file: file handle to the watchdog 326 * @buf: buffer to write (unused as data does not matter here 327 * @count: count of bytes 328 * @ppos: pointer to the position to write. No seeks allowed 329 * 330 * A write to a watchdog device is defined as a keepalive signal. Any 331 * write of data will do, as we we don't define content meaning. 332 */ 333 334static ssize_t wdt_write(struct file *file, const char __user *buf, 335 size_t count, loff_t *ppos) 336{ 337 /* See if we got the magic character 'V' and reload the timer */ 338 if (count) { 339 if (!nowayout) { 340 size_t ofs; 341 342 /* note: just in case someone wrote the 343 magic character long ago */ 344 expect_close = 0; 345 346 /* scan to see whether or not we got the 347 magic character */ 348 for (ofs = 0; ofs != count; ofs++) { 349 char c; 350 if (get_user(c, buf + ofs)) 351 return -EFAULT; 352 if (c == 'V') 353 expect_close = 42; 354 } 355 } 356 357 /* someone wrote to us, we should restart timer */ 358 wdt_keepalive(); 359 } 360 return count; 361} 362 363/* 364 * wdt_ioctl: 365 * @inode: inode of the device 366 * @file: file handle to the device 367 * @cmd: watchdog command 368 * @arg: argument pointer 369 * 370 * The watchdog API defines a common set of functions for all watchdogs 371 * according to their available features. 372 */ 373 374static const struct watchdog_info ident = { 375 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, 376 .firmware_version = 1, 377 .identity = WATCHDOG_NAME, 378}; 379 380static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 381{ 382 int status; 383 int new_options, retval = -EINVAL; 384 int new_timeout; 385 union { 386 struct watchdog_info __user *ident; 387 int __user *i; 388 } uarg; 389 390 uarg.i = (int __user *)arg; 391 392 switch (cmd) { 393 case WDIOC_GETSUPPORT: 394 return copy_to_user(uarg.ident, &ident, 395 sizeof(ident)) ? -EFAULT : 0; 396 397 case WDIOC_GETSTATUS: 398 wdt_get_status(&status); 399 return put_user(status, uarg.i); 400 401 case WDIOC_GETBOOTSTATUS: 402 return put_user(0, uarg.i); 403 404 case WDIOC_SETOPTIONS: 405 if (get_user(new_options, uarg.i)) 406 return -EFAULT; 407 408 if (new_options & WDIOS_DISABLECARD) { 409 wdt_stop(); 410 retval = 0; 411 } 412 413 if (new_options & WDIOS_ENABLECARD) { 414 wdt_start(); 415 retval = 0; 416 } 417 418 return retval; 419 420 case WDIOC_KEEPALIVE: 421 wdt_keepalive(); 422 return 0; 423 424 case WDIOC_SETTIMEOUT: 425 if (get_user(new_timeout, uarg.i)) 426 return -EFAULT; 427 428 if (wdt_set_timeout(new_timeout)) 429 return -EINVAL; 430 431 wdt_keepalive(); 432 /* Fall */ 433 434 case WDIOC_GETTIMEOUT: 435 return put_user(timeout, uarg.i); 436 437 default: 438 return -ENOTTY; 439 440 } 441} 442 443static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 444 void *unused) 445{ 446 if (code == SYS_DOWN || code == SYS_HALT) 447 wdt_stop(); 448 return NOTIFY_DONE; 449} 450 451static const struct file_operations wdt_fops = { 452 .owner = THIS_MODULE, 453 .llseek = no_llseek, 454 .write = wdt_write, 455 .unlocked_ioctl = wdt_ioctl, 456 .open = wdt_open, 457 .release = wdt_release, 458}; 459 460static struct miscdevice wdt_miscdev = { 461 .minor = WATCHDOG_MINOR, 462 .name = "watchdog", 463 .fops = &wdt_fops, 464}; 465 466static struct notifier_block wdt_notifier = { 467 .notifier_call = wdt_notify_sys, 468}; 469 470static int __init w83977f_wdt_init(void) 471{ 472 int rc; 473 474 printk(KERN_INFO PFX DRIVER_VERSION); 475 476 /* 477 * Check that the timeout value is within it's range; 478 * if not reset to the default 479 */ 480 if (wdt_set_timeout(timeout)) { 481 wdt_set_timeout(DEFAULT_TIMEOUT); 482 printk(KERN_INFO PFX 483 "timeout value must be 15 <= timeout <= 7635, using %d\n", 484 DEFAULT_TIMEOUT); 485 } 486 487 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) { 488 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", 489 IO_INDEX_PORT); 490 rc = -EIO; 491 goto err_out; 492 } 493 494 rc = register_reboot_notifier(&wdt_notifier); 495 if (rc) { 496 printk(KERN_ERR PFX 497 "cannot register reboot notifier (err=%d)\n", rc); 498 goto err_out_region; 499 } 500 501 rc = misc_register(&wdt_miscdev); 502 if (rc) { 503 printk(KERN_ERR PFX 504 "cannot register miscdev on minor=%d (err=%d)\n", 505 wdt_miscdev.minor, rc); 506 goto err_out_reboot; 507 } 508 509 printk(KERN_INFO PFX 510 "initialized. timeout=%d sec (nowayout=%d testmode=%d)\n", 511 timeout, nowayout, testmode); 512 513 return 0; 514 515err_out_reboot: 516 unregister_reboot_notifier(&wdt_notifier); 517err_out_region: 518 release_region(IO_INDEX_PORT, 2); 519err_out: 520 return rc; 521} 522 523static void __exit w83977f_wdt_exit(void) 524{ 525 wdt_stop(); 526 misc_deregister(&wdt_miscdev); 527 unregister_reboot_notifier(&wdt_notifier); 528 release_region(IO_INDEX_PORT, 2); 529} 530 531module_init(w83977f_wdt_init); 532module_exit(w83977f_wdt_exit); 533 534MODULE_AUTHOR("Jose Goncalves <jose.goncalves@inov.pt>"); 535MODULE_DESCRIPTION("Driver for watchdog timer in W83977F I/O chip"); 536MODULE_LICENSE("GPL"); 537MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 538