1 /* 2 * Wdt977 0.04: A Watchdog Device for Netwinder W83977AF chip 3 * 4 * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>) 5 * 6 * ----------------------- 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 * 13 * ----------------------- 14 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> 15 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT 16 * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface 17 * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts 18 * from minutes to seconds. 19 * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in 20 * nwwatchdog_init. 21 * 25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks 22 * remove limitiation to be used on 23 * Netwinders only 24 */ 25 26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 27 28 #include <linux/module.h> 29 #include <linux/moduleparam.h> 30 #include <linux/types.h> 31 #include <linux/kernel.h> 32 #include <linux/fs.h> 33 #include <linux/miscdevice.h> 34 #include <linux/init.h> 35 #include <linux/ioport.h> 36 #include <linux/watchdog.h> 37 #include <linux/notifier.h> 38 #include <linux/reboot.h> 39 #include <linux/io.h> 40 #include <linux/uaccess.h> 41 42 #include <asm/mach-types.h> 43 44 #define WATCHDOG_VERSION "0.04" 45 #define WATCHDOG_NAME "Wdt977" 46 47 #define IO_INDEX_PORT 0x370 /* on some systems it can be 0x3F0 */ 48 #define IO_DATA_PORT (IO_INDEX_PORT + 1) 49 50 #define UNLOCK_DATA 0x87 51 #define LOCK_DATA 0xAA 52 #define DEVICE_REGISTER 0x07 53 54 55 #define DEFAULT_TIMEOUT 60 /* default timeout in seconds */ 56 57 static int timeout = DEFAULT_TIMEOUT; 58 static int timeoutM; /* timeout in minutes */ 59 static unsigned long timer_alive; 60 static int testmode; 61 static char expect_close; 62 static DEFINE_SPINLOCK(spinlock); 63 64 module_param(timeout, int, 0); 65 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default=" 66 __MODULE_STRING(DEFAULT_TIMEOUT) ")"); 67 module_param(testmode, int, 0); 68 MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0"); 69 70 static bool nowayout = WATCHDOG_NOWAYOUT; 71 module_param(nowayout, bool, 0); 72 MODULE_PARM_DESC(nowayout, 73 "Watchdog cannot be stopped once started (default=" 74 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 75 76 /* 77 * Start the watchdog 78 */ 79 80 static int wdt977_start(void) 81 { 82 unsigned long flags; 83 84 spin_lock_irqsave(&spinlock, flags); 85 86 /* unlock the SuperIO chip */ 87 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 88 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 89 90 /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4 91 * F2 has the timeout in minutes 92 * F3 could be set to the POWER LED blink (with GP17 set to PowerLed) 93 * at timeout, and to reset timer on kbd/mouse activity (not impl.) 94 * F4 is used to just clear the TIMEOUT'ed state (bit 0) 95 */ 96 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 97 outb_p(0x08, IO_DATA_PORT); 98 outb_p(0xF2, IO_INDEX_PORT); 99 outb_p(timeoutM, IO_DATA_PORT); 100 outb_p(0xF3, IO_INDEX_PORT); 101 outb_p(0x00, IO_DATA_PORT); /* another setting is 0E for 102 kbd/mouse/LED */ 103 outb_p(0xF4, IO_INDEX_PORT); 104 outb_p(0x00, IO_DATA_PORT); 105 106 /* At last select device Aux1 (dev=7) and set GP16 as a 107 * watchdog output. In test mode watch the bit 1 on F4 to 108 * indicate "triggered" 109 */ 110 if (!testmode) { 111 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 112 outb_p(0x07, IO_DATA_PORT); 113 outb_p(0xE6, IO_INDEX_PORT); 114 outb_p(0x08, IO_DATA_PORT); 115 } 116 117 /* lock the SuperIO chip */ 118 outb_p(LOCK_DATA, IO_INDEX_PORT); 119 120 spin_unlock_irqrestore(&spinlock, flags); 121 pr_info("activated\n"); 122 123 return 0; 124 } 125 126 /* 127 * Stop the watchdog 128 */ 129 130 static int wdt977_stop(void) 131 { 132 unsigned long flags; 133 spin_lock_irqsave(&spinlock, flags); 134 135 /* unlock the SuperIO chip */ 136 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 137 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 138 139 /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4 140 * F3 is reset to its default state 141 * F4 can clear the TIMEOUT'ed state (bit 0) - back to default 142 * We can not use GP17 as a PowerLed, as we use its usage as a RedLed 143 */ 144 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 145 outb_p(0x08, IO_DATA_PORT); 146 outb_p(0xF2, IO_INDEX_PORT); 147 outb_p(0xFF, IO_DATA_PORT); 148 outb_p(0xF3, IO_INDEX_PORT); 149 outb_p(0x00, IO_DATA_PORT); 150 outb_p(0xF4, IO_INDEX_PORT); 151 outb_p(0x00, IO_DATA_PORT); 152 outb_p(0xF2, IO_INDEX_PORT); 153 outb_p(0x00, IO_DATA_PORT); 154 155 /* at last select device Aux1 (dev=7) and set 156 GP16 as a watchdog output */ 157 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 158 outb_p(0x07, IO_DATA_PORT); 159 outb_p(0xE6, IO_INDEX_PORT); 160 outb_p(0x08, IO_DATA_PORT); 161 162 /* lock the SuperIO chip */ 163 outb_p(LOCK_DATA, IO_INDEX_PORT); 164 165 spin_unlock_irqrestore(&spinlock, flags); 166 pr_info("shutdown\n"); 167 168 return 0; 169 } 170 171 /* 172 * Send a keepalive ping to the watchdog 173 * This is done by simply re-writing the timeout to reg. 0xF2 174 */ 175 176 static int wdt977_keepalive(void) 177 { 178 unsigned long flags; 179 spin_lock_irqsave(&spinlock, flags); 180 181 /* unlock the SuperIO chip */ 182 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 183 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 184 185 /* select device Aux2 (device=8) and kicks watchdog reg F2 */ 186 /* F2 has the timeout in minutes */ 187 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 188 outb_p(0x08, IO_DATA_PORT); 189 outb_p(0xF2, IO_INDEX_PORT); 190 outb_p(timeoutM, IO_DATA_PORT); 191 192 /* lock the SuperIO chip */ 193 outb_p(LOCK_DATA, IO_INDEX_PORT); 194 spin_unlock_irqrestore(&spinlock, flags); 195 196 return 0; 197 } 198 199 /* 200 * Set the watchdog timeout value 201 */ 202 203 static int wdt977_set_timeout(int t) 204 { 205 int tmrval; 206 207 /* convert seconds to minutes, rounding up */ 208 tmrval = (t + 59) / 60; 209 210 if (machine_is_netwinder()) { 211 /* we have a hw bug somewhere, so each 977 minute is actually 212 * only 30sec. This limits the max timeout to half of device 213 * max of 255 minutes... 214 */ 215 tmrval += tmrval; 216 } 217 218 if (tmrval < 1 || tmrval > 255) 219 return -EINVAL; 220 221 /* timeout is the timeout in seconds, timeoutM is 222 the timeout in minutes) */ 223 timeout = t; 224 timeoutM = tmrval; 225 return 0; 226 } 227 228 /* 229 * Get the watchdog status 230 */ 231 232 static int wdt977_get_status(int *status) 233 { 234 int new_status; 235 unsigned long flags; 236 237 spin_lock_irqsave(&spinlock, flags); 238 239 /* unlock the SuperIO chip */ 240 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 241 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 242 243 /* select device Aux2 (device=8) and read watchdog reg F4 */ 244 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 245 outb_p(0x08, IO_DATA_PORT); 246 outb_p(0xF4, IO_INDEX_PORT); 247 new_status = inb_p(IO_DATA_PORT); 248 249 /* lock the SuperIO chip */ 250 outb_p(LOCK_DATA, IO_INDEX_PORT); 251 252 spin_unlock_irqrestore(&spinlock, flags); 253 254 *status = 0; 255 if (new_status & 1) 256 *status |= WDIOF_CARDRESET; 257 258 return 0; 259 } 260 261 262 /* 263 * /dev/watchdog handling 264 */ 265 266 static int wdt977_open(struct inode *inode, struct file *file) 267 { 268 /* If the watchdog is alive we don't need to start it again */ 269 if (test_and_set_bit(0, &timer_alive)) 270 return -EBUSY; 271 272 if (nowayout) 273 __module_get(THIS_MODULE); 274 275 wdt977_start(); 276 return nonseekable_open(inode, file); 277 } 278 279 static int wdt977_release(struct inode *inode, struct file *file) 280 { 281 /* 282 * Shut off the timer. 283 * Lock it in if it's a module and we set nowayout 284 */ 285 if (expect_close == 42) { 286 wdt977_stop(); 287 clear_bit(0, &timer_alive); 288 } else { 289 wdt977_keepalive(); 290 pr_crit("Unexpected close, not stopping watchdog!\n"); 291 } 292 expect_close = 0; 293 return 0; 294 } 295 296 297 /* 298 * wdt977_write: 299 * @file: file handle to the watchdog 300 * @buf: buffer to write (unused as data does not matter here 301 * @count: count of bytes 302 * @ppos: pointer to the position to write. No seeks allowed 303 * 304 * A write to a watchdog device is defined as a keepalive signal. Any 305 * write of data will do, as we we don't define content meaning. 306 */ 307 308 static ssize_t wdt977_write(struct file *file, const char __user *buf, 309 size_t count, loff_t *ppos) 310 { 311 if (count) { 312 if (!nowayout) { 313 size_t i; 314 315 /* In case it was set long ago */ 316 expect_close = 0; 317 318 for (i = 0; i != count; i++) { 319 char c; 320 if (get_user(c, buf + i)) 321 return -EFAULT; 322 if (c == 'V') 323 expect_close = 42; 324 } 325 } 326 327 /* someone wrote to us, we should restart timer */ 328 wdt977_keepalive(); 329 } 330 return count; 331 } 332 333 static const struct watchdog_info ident = { 334 .options = WDIOF_SETTIMEOUT | 335 WDIOF_MAGICCLOSE | 336 WDIOF_KEEPALIVEPING, 337 .firmware_version = 1, 338 .identity = WATCHDOG_NAME, 339 }; 340 341 /* 342 * wdt977_ioctl: 343 * @inode: inode of the device 344 * @file: file handle to the device 345 * @cmd: watchdog command 346 * @arg: argument pointer 347 * 348 * The watchdog API defines a common set of functions for all watchdogs 349 * according to their available features. 350 */ 351 352 static long wdt977_ioctl(struct file *file, unsigned int cmd, 353 unsigned long arg) 354 { 355 int status; 356 int new_options, retval = -EINVAL; 357 int new_timeout; 358 union { 359 struct watchdog_info __user *ident; 360 int __user *i; 361 } uarg; 362 363 uarg.i = (int __user *)arg; 364 365 switch (cmd) { 366 case WDIOC_GETSUPPORT: 367 return copy_to_user(uarg.ident, &ident, 368 sizeof(ident)) ? -EFAULT : 0; 369 370 case WDIOC_GETSTATUS: 371 wdt977_get_status(&status); 372 return put_user(status, uarg.i); 373 374 case WDIOC_GETBOOTSTATUS: 375 return put_user(0, uarg.i); 376 377 case WDIOC_SETOPTIONS: 378 if (get_user(new_options, uarg.i)) 379 return -EFAULT; 380 381 if (new_options & WDIOS_DISABLECARD) { 382 wdt977_stop(); 383 retval = 0; 384 } 385 386 if (new_options & WDIOS_ENABLECARD) { 387 wdt977_start(); 388 retval = 0; 389 } 390 391 return retval; 392 393 case WDIOC_KEEPALIVE: 394 wdt977_keepalive(); 395 return 0; 396 397 case WDIOC_SETTIMEOUT: 398 if (get_user(new_timeout, uarg.i)) 399 return -EFAULT; 400 401 if (wdt977_set_timeout(new_timeout)) 402 return -EINVAL; 403 404 wdt977_keepalive(); 405 /* Fall */ 406 407 case WDIOC_GETTIMEOUT: 408 return put_user(timeout, uarg.i); 409 410 default: 411 return -ENOTTY; 412 413 } 414 } 415 416 static int wdt977_notify_sys(struct notifier_block *this, unsigned long code, 417 void *unused) 418 { 419 if (code == SYS_DOWN || code == SYS_HALT) 420 wdt977_stop(); 421 return NOTIFY_DONE; 422 } 423 424 static const struct file_operations wdt977_fops = { 425 .owner = THIS_MODULE, 426 .llseek = no_llseek, 427 .write = wdt977_write, 428 .unlocked_ioctl = wdt977_ioctl, 429 .open = wdt977_open, 430 .release = wdt977_release, 431 }; 432 433 static struct miscdevice wdt977_miscdev = { 434 .minor = WATCHDOG_MINOR, 435 .name = "watchdog", 436 .fops = &wdt977_fops, 437 }; 438 439 static struct notifier_block wdt977_notifier = { 440 .notifier_call = wdt977_notify_sys, 441 }; 442 443 static int __init wd977_init(void) 444 { 445 int rc; 446 447 pr_info("driver v%s\n", WATCHDOG_VERSION); 448 449 /* Check that the timeout value is within its range; 450 if not reset to the default */ 451 if (wdt977_set_timeout(timeout)) { 452 wdt977_set_timeout(DEFAULT_TIMEOUT); 453 pr_info("timeout value must be 60 < timeout < 15300, using %d\n", 454 DEFAULT_TIMEOUT); 455 } 456 457 /* on Netwinder the IOports are already reserved by 458 * arch/arm/mach-footbridge/netwinder-hw.c 459 */ 460 if (!machine_is_netwinder()) { 461 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) { 462 pr_err("I/O address 0x%04x already in use\n", 463 IO_INDEX_PORT); 464 rc = -EIO; 465 goto err_out; 466 } 467 } 468 469 rc = register_reboot_notifier(&wdt977_notifier); 470 if (rc) { 471 pr_err("cannot register reboot notifier (err=%d)\n", rc); 472 goto err_out_region; 473 } 474 475 rc = misc_register(&wdt977_miscdev); 476 if (rc) { 477 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 478 wdt977_miscdev.minor, rc); 479 goto err_out_reboot; 480 } 481 482 pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n", 483 timeout, nowayout, testmode); 484 485 return 0; 486 487 err_out_reboot: 488 unregister_reboot_notifier(&wdt977_notifier); 489 err_out_region: 490 if (!machine_is_netwinder()) 491 release_region(IO_INDEX_PORT, 2); 492 err_out: 493 return rc; 494 } 495 496 static void __exit wd977_exit(void) 497 { 498 wdt977_stop(); 499 misc_deregister(&wdt977_miscdev); 500 unregister_reboot_notifier(&wdt977_notifier); 501 release_region(IO_INDEX_PORT, 2); 502 } 503 504 module_init(wd977_init); 505 module_exit(wd977_exit); 506 507 MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>"); 508 MODULE_DESCRIPTION("W83977AF Watchdog driver"); 509 MODULE_LICENSE("GPL"); 510