1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Wdt977 0.04: A Watchdog Device for Netwinder W83977AF chip 4 * 5 * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>) 6 * 7 * ----------------------- 8 * 9 * ----------------------- 10 * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> 11 * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT 12 * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface 13 * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts 14 * from minutes to seconds. 15 * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in 16 * nwwatchdog_init. 17 * 25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks 18 * remove limitiation to be used on 19 * Netwinders only 20 */ 21 22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 23 24 #include <linux/module.h> 25 #include <linux/moduleparam.h> 26 #include <linux/types.h> 27 #include <linux/kernel.h> 28 #include <linux/fs.h> 29 #include <linux/miscdevice.h> 30 #include <linux/init.h> 31 #include <linux/ioport.h> 32 #include <linux/watchdog.h> 33 #include <linux/notifier.h> 34 #include <linux/reboot.h> 35 #include <linux/io.h> 36 #include <linux/uaccess.h> 37 38 #include <asm/mach-types.h> 39 40 #define WATCHDOG_VERSION "0.04" 41 #define WATCHDOG_NAME "Wdt977" 42 43 #define IO_INDEX_PORT 0x370 /* on some systems it can be 0x3F0 */ 44 #define IO_DATA_PORT (IO_INDEX_PORT + 1) 45 46 #define UNLOCK_DATA 0x87 47 #define LOCK_DATA 0xAA 48 #define DEVICE_REGISTER 0x07 49 50 51 #define DEFAULT_TIMEOUT 60 /* default timeout in seconds */ 52 53 static int timeout = DEFAULT_TIMEOUT; 54 static int timeoutM; /* timeout in minutes */ 55 static unsigned long timer_alive; 56 static int testmode; 57 static char expect_close; 58 static DEFINE_SPINLOCK(spinlock); 59 60 module_param(timeout, int, 0); 61 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default=" 62 __MODULE_STRING(DEFAULT_TIMEOUT) ")"); 63 module_param(testmode, int, 0); 64 MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0"); 65 66 static bool nowayout = WATCHDOG_NOWAYOUT; 67 module_param(nowayout, bool, 0); 68 MODULE_PARM_DESC(nowayout, 69 "Watchdog cannot be stopped once started (default=" 70 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 71 72 /* 73 * Start the watchdog 74 */ 75 76 static int wdt977_start(void) 77 { 78 unsigned long flags; 79 80 spin_lock_irqsave(&spinlock, flags); 81 82 /* unlock the SuperIO chip */ 83 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 84 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 85 86 /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4 87 * F2 has the timeout in minutes 88 * F3 could be set to the POWER LED blink (with GP17 set to PowerLed) 89 * at timeout, and to reset timer on kbd/mouse activity (not impl.) 90 * F4 is used to just clear the TIMEOUT'ed state (bit 0) 91 */ 92 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 93 outb_p(0x08, IO_DATA_PORT); 94 outb_p(0xF2, IO_INDEX_PORT); 95 outb_p(timeoutM, IO_DATA_PORT); 96 outb_p(0xF3, IO_INDEX_PORT); 97 outb_p(0x00, IO_DATA_PORT); /* another setting is 0E for 98 kbd/mouse/LED */ 99 outb_p(0xF4, IO_INDEX_PORT); 100 outb_p(0x00, IO_DATA_PORT); 101 102 /* At last select device Aux1 (dev=7) and set GP16 as a 103 * watchdog output. In test mode watch the bit 1 on F4 to 104 * indicate "triggered" 105 */ 106 if (!testmode) { 107 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 108 outb_p(0x07, IO_DATA_PORT); 109 outb_p(0xE6, IO_INDEX_PORT); 110 outb_p(0x08, IO_DATA_PORT); 111 } 112 113 /* lock the SuperIO chip */ 114 outb_p(LOCK_DATA, IO_INDEX_PORT); 115 116 spin_unlock_irqrestore(&spinlock, flags); 117 pr_info("activated\n"); 118 119 return 0; 120 } 121 122 /* 123 * Stop the watchdog 124 */ 125 126 static int wdt977_stop(void) 127 { 128 unsigned long flags; 129 spin_lock_irqsave(&spinlock, flags); 130 131 /* unlock the SuperIO chip */ 132 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 133 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 134 135 /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4 136 * F3 is reset to its default state 137 * F4 can clear the TIMEOUT'ed state (bit 0) - back to default 138 * We can not use GP17 as a PowerLed, as we use its usage as a RedLed 139 */ 140 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 141 outb_p(0x08, IO_DATA_PORT); 142 outb_p(0xF2, IO_INDEX_PORT); 143 outb_p(0xFF, IO_DATA_PORT); 144 outb_p(0xF3, IO_INDEX_PORT); 145 outb_p(0x00, IO_DATA_PORT); 146 outb_p(0xF4, IO_INDEX_PORT); 147 outb_p(0x00, IO_DATA_PORT); 148 outb_p(0xF2, IO_INDEX_PORT); 149 outb_p(0x00, IO_DATA_PORT); 150 151 /* at last select device Aux1 (dev=7) and set 152 GP16 as a watchdog output */ 153 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 154 outb_p(0x07, IO_DATA_PORT); 155 outb_p(0xE6, IO_INDEX_PORT); 156 outb_p(0x08, IO_DATA_PORT); 157 158 /* lock the SuperIO chip */ 159 outb_p(LOCK_DATA, IO_INDEX_PORT); 160 161 spin_unlock_irqrestore(&spinlock, flags); 162 pr_info("shutdown\n"); 163 164 return 0; 165 } 166 167 /* 168 * Send a keepalive ping to the watchdog 169 * This is done by simply re-writing the timeout to reg. 0xF2 170 */ 171 172 static int wdt977_keepalive(void) 173 { 174 unsigned long flags; 175 spin_lock_irqsave(&spinlock, flags); 176 177 /* unlock the SuperIO chip */ 178 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 179 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 180 181 /* select device Aux2 (device=8) and kicks watchdog reg F2 */ 182 /* F2 has the timeout in minutes */ 183 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 184 outb_p(0x08, IO_DATA_PORT); 185 outb_p(0xF2, IO_INDEX_PORT); 186 outb_p(timeoutM, IO_DATA_PORT); 187 188 /* lock the SuperIO chip */ 189 outb_p(LOCK_DATA, IO_INDEX_PORT); 190 spin_unlock_irqrestore(&spinlock, flags); 191 192 return 0; 193 } 194 195 /* 196 * Set the watchdog timeout value 197 */ 198 199 static int wdt977_set_timeout(int t) 200 { 201 int tmrval; 202 203 /* convert seconds to minutes, rounding up */ 204 tmrval = (t + 59) / 60; 205 206 if (machine_is_netwinder()) { 207 /* we have a hw bug somewhere, so each 977 minute is actually 208 * only 30sec. This limits the max timeout to half of device 209 * max of 255 minutes... 210 */ 211 tmrval += tmrval; 212 } 213 214 if (tmrval < 1 || tmrval > 255) 215 return -EINVAL; 216 217 /* timeout is the timeout in seconds, timeoutM is 218 the timeout in minutes) */ 219 timeout = t; 220 timeoutM = tmrval; 221 return 0; 222 } 223 224 /* 225 * Get the watchdog status 226 */ 227 228 static int wdt977_get_status(int *status) 229 { 230 int new_status; 231 unsigned long flags; 232 233 spin_lock_irqsave(&spinlock, flags); 234 235 /* unlock the SuperIO chip */ 236 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 237 outb_p(UNLOCK_DATA, IO_INDEX_PORT); 238 239 /* select device Aux2 (device=8) and read watchdog reg F4 */ 240 outb_p(DEVICE_REGISTER, IO_INDEX_PORT); 241 outb_p(0x08, IO_DATA_PORT); 242 outb_p(0xF4, IO_INDEX_PORT); 243 new_status = inb_p(IO_DATA_PORT); 244 245 /* lock the SuperIO chip */ 246 outb_p(LOCK_DATA, IO_INDEX_PORT); 247 248 spin_unlock_irqrestore(&spinlock, flags); 249 250 *status = 0; 251 if (new_status & 1) 252 *status |= WDIOF_CARDRESET; 253 254 return 0; 255 } 256 257 258 /* 259 * /dev/watchdog handling 260 */ 261 262 static int wdt977_open(struct inode *inode, struct file *file) 263 { 264 /* If the watchdog is alive we don't need to start it again */ 265 if (test_and_set_bit(0, &timer_alive)) 266 return -EBUSY; 267 268 if (nowayout) 269 __module_get(THIS_MODULE); 270 271 wdt977_start(); 272 return stream_open(inode, file); 273 } 274 275 static int wdt977_release(struct inode *inode, struct file *file) 276 { 277 /* 278 * Shut off the timer. 279 * Lock it in if it's a module and we set nowayout 280 */ 281 if (expect_close == 42) { 282 wdt977_stop(); 283 clear_bit(0, &timer_alive); 284 } else { 285 wdt977_keepalive(); 286 pr_crit("Unexpected close, not stopping watchdog!\n"); 287 } 288 expect_close = 0; 289 return 0; 290 } 291 292 293 /* 294 * wdt977_write: 295 * @file: file handle to the watchdog 296 * @buf: buffer to write (unused as data does not matter here 297 * @count: count of bytes 298 * @ppos: pointer to the position to write. No seeks allowed 299 * 300 * A write to a watchdog device is defined as a keepalive signal. Any 301 * write of data will do, as we we don't define content meaning. 302 */ 303 304 static ssize_t wdt977_write(struct file *file, const char __user *buf, 305 size_t count, loff_t *ppos) 306 { 307 if (count) { 308 if (!nowayout) { 309 size_t i; 310 311 /* In case it was set long ago */ 312 expect_close = 0; 313 314 for (i = 0; i != count; i++) { 315 char c; 316 if (get_user(c, buf + i)) 317 return -EFAULT; 318 if (c == 'V') 319 expect_close = 42; 320 } 321 } 322 323 /* someone wrote to us, we should restart timer */ 324 wdt977_keepalive(); 325 } 326 return count; 327 } 328 329 static const struct watchdog_info ident = { 330 .options = WDIOF_SETTIMEOUT | 331 WDIOF_MAGICCLOSE | 332 WDIOF_KEEPALIVEPING, 333 .firmware_version = 1, 334 .identity = WATCHDOG_NAME, 335 }; 336 337 /* 338 * wdt977_ioctl: 339 * @inode: inode of the device 340 * @file: file handle to the device 341 * @cmd: watchdog command 342 * @arg: argument pointer 343 * 344 * The watchdog API defines a common set of functions for all watchdogs 345 * according to their available features. 346 */ 347 348 static long wdt977_ioctl(struct file *file, unsigned int cmd, 349 unsigned long arg) 350 { 351 int status; 352 int new_options, retval = -EINVAL; 353 int new_timeout; 354 union { 355 struct watchdog_info __user *ident; 356 int __user *i; 357 } uarg; 358 359 uarg.i = (int __user *)arg; 360 361 switch (cmd) { 362 case WDIOC_GETSUPPORT: 363 return copy_to_user(uarg.ident, &ident, 364 sizeof(ident)) ? -EFAULT : 0; 365 366 case WDIOC_GETSTATUS: 367 wdt977_get_status(&status); 368 return put_user(status, uarg.i); 369 370 case WDIOC_GETBOOTSTATUS: 371 return put_user(0, uarg.i); 372 373 case WDIOC_SETOPTIONS: 374 if (get_user(new_options, uarg.i)) 375 return -EFAULT; 376 377 if (new_options & WDIOS_DISABLECARD) { 378 wdt977_stop(); 379 retval = 0; 380 } 381 382 if (new_options & WDIOS_ENABLECARD) { 383 wdt977_start(); 384 retval = 0; 385 } 386 387 return retval; 388 389 case WDIOC_KEEPALIVE: 390 wdt977_keepalive(); 391 return 0; 392 393 case WDIOC_SETTIMEOUT: 394 if (get_user(new_timeout, uarg.i)) 395 return -EFAULT; 396 397 if (wdt977_set_timeout(new_timeout)) 398 return -EINVAL; 399 400 wdt977_keepalive(); 401 fallthrough; 402 403 case WDIOC_GETTIMEOUT: 404 return put_user(timeout, uarg.i); 405 406 default: 407 return -ENOTTY; 408 409 } 410 } 411 412 static int wdt977_notify_sys(struct notifier_block *this, unsigned long code, 413 void *unused) 414 { 415 if (code == SYS_DOWN || code == SYS_HALT) 416 wdt977_stop(); 417 return NOTIFY_DONE; 418 } 419 420 static const struct file_operations wdt977_fops = { 421 .owner = THIS_MODULE, 422 .llseek = no_llseek, 423 .write = wdt977_write, 424 .unlocked_ioctl = wdt977_ioctl, 425 .compat_ioctl = compat_ptr_ioctl, 426 .open = wdt977_open, 427 .release = wdt977_release, 428 }; 429 430 static struct miscdevice wdt977_miscdev = { 431 .minor = WATCHDOG_MINOR, 432 .name = "watchdog", 433 .fops = &wdt977_fops, 434 }; 435 436 static struct notifier_block wdt977_notifier = { 437 .notifier_call = wdt977_notify_sys, 438 }; 439 440 static int __init wd977_init(void) 441 { 442 int rc; 443 444 pr_info("driver v%s\n", WATCHDOG_VERSION); 445 446 /* Check that the timeout value is within its range; 447 if not reset to the default */ 448 if (wdt977_set_timeout(timeout)) { 449 wdt977_set_timeout(DEFAULT_TIMEOUT); 450 pr_info("timeout value must be 60 < timeout < 15300, using %d\n", 451 DEFAULT_TIMEOUT); 452 } 453 454 /* on Netwinder the IOports are already reserved by 455 * arch/arm/mach-footbridge/netwinder-hw.c 456 */ 457 if (!machine_is_netwinder()) { 458 if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) { 459 pr_err("I/O address 0x%04x already in use\n", 460 IO_INDEX_PORT); 461 rc = -EIO; 462 goto err_out; 463 } 464 } 465 466 rc = register_reboot_notifier(&wdt977_notifier); 467 if (rc) { 468 pr_err("cannot register reboot notifier (err=%d)\n", rc); 469 goto err_out_region; 470 } 471 472 rc = misc_register(&wdt977_miscdev); 473 if (rc) { 474 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 475 wdt977_miscdev.minor, rc); 476 goto err_out_reboot; 477 } 478 479 pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n", 480 timeout, nowayout, testmode); 481 482 return 0; 483 484 err_out_reboot: 485 unregister_reboot_notifier(&wdt977_notifier); 486 err_out_region: 487 if (!machine_is_netwinder()) 488 release_region(IO_INDEX_PORT, 2); 489 err_out: 490 return rc; 491 } 492 493 static void __exit wd977_exit(void) 494 { 495 wdt977_stop(); 496 misc_deregister(&wdt977_miscdev); 497 unregister_reboot_notifier(&wdt977_notifier); 498 release_region(IO_INDEX_PORT, 2); 499 } 500 501 module_init(wd977_init); 502 module_exit(wd977_exit); 503 504 MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>"); 505 MODULE_DESCRIPTION("W83977AF Watchdog driver"); 506 MODULE_LICENSE("GPL"); 507