1/* 2 * w83697hf/hg WDT driver 3 * 4 * (c) Copyright 2006 Samuel Tardieu <sam@rfc1149.net> 5 * (c) Copyright 2006 Marcus Junker <junker@anduras.de> 6 * 7 * Based on w83627hf_wdt.c which is based on advantechwdt.c 8 * which is based on wdt.c. 9 * Original copyright messages: 10 * 11 * (c) Copyright 2003 P��draig Brady <P@draigBrady.com> 12 * 13 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> 14 * 15 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>, 16 * All Rights Reserved. 17 * 18 * This program is free software; you can redistribute it and/or 19 * modify it under the terms of the GNU General Public License 20 * as published by the Free Software Foundation; either version 21 * 2 of the License, or (at your option) any later version. 22 * 23 * Neither Marcus Junker nor ANDURAS AG admit liability nor provide 24 * warranty for any of this software. This material is provided 25 * "AS-IS" and at no charge. 26 */ 27 28#include <linux/module.h> 29#include <linux/moduleparam.h> 30#include <linux/types.h> 31#include <linux/miscdevice.h> 32#include <linux/watchdog.h> 33#include <linux/fs.h> 34#include <linux/ioport.h> 35#include <linux/notifier.h> 36#include <linux/reboot.h> 37#include <linux/init.h> 38#include <linux/spinlock.h> 39#include <linux/io.h> 40#include <linux/uaccess.h> 41 42#include <asm/system.h> 43 44#define WATCHDOG_NAME "w83697hf/hg WDT" 45#define PFX WATCHDOG_NAME ": " 46#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ 47#define WATCHDOG_EARLY_DISABLE 1 /* Disable until userland kicks in */ 48 49static unsigned long wdt_is_open; 50static char expect_close; 51static DEFINE_SPINLOCK(io_lock); 52 53/* You must set this - there is no sane way to probe for this board. */ 54static int wdt_io = 0x2e; 55module_param(wdt_io, int, 0); 56MODULE_PARM_DESC(wdt_io, 57 "w83697hf/hg WDT io port (default 0x2e, 0 = autodetect)"); 58 59static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ 60module_param(timeout, int, 0); 61MODULE_PARM_DESC(timeout, 62 "Watchdog timeout in seconds. 1<= timeout <=255 (default=" 63 __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); 64 65static int nowayout = WATCHDOG_NOWAYOUT; 66module_param(nowayout, int, 0); 67MODULE_PARM_DESC(nowayout, 68 "Watchdog cannot be stopped once started (default=" 69 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 70 71static int early_disable = WATCHDOG_EARLY_DISABLE; 72module_param(early_disable, int, 0); 73MODULE_PARM_DESC(early_disable, 74 "Watchdog gets disabled at boot time (default=" 75 __MODULE_STRING(WATCHDOG_EARLY_DISABLE) ")"); 76 77/* 78 * Kernel methods. 79 */ 80 81#define W83697HF_EFER (wdt_io + 0) /* Extended Function Enable Register */ 82#define W83697HF_EFIR (wdt_io + 0) /* Extended Function Index Register 83 (same as EFER) */ 84#define W83697HF_EFDR (wdt_io + 1) /* Extended Function Data Register */ 85 86static inline void w83697hf_unlock(void) 87{ 88 outb_p(0x87, W83697HF_EFER); /* Enter extended function mode */ 89 outb_p(0x87, W83697HF_EFER); /* Again according to manual */ 90} 91 92static inline void w83697hf_lock(void) 93{ 94 outb_p(0xAA, W83697HF_EFER); /* Leave extended function mode */ 95} 96 97/* 98 * The three functions w83697hf_get_reg(), w83697hf_set_reg() and 99 * w83697hf_write_timeout() must be called with the device unlocked. 100 */ 101 102static unsigned char w83697hf_get_reg(unsigned char reg) 103{ 104 outb_p(reg, W83697HF_EFIR); 105 return inb_p(W83697HF_EFDR); 106} 107 108static void w83697hf_set_reg(unsigned char reg, unsigned char data) 109{ 110 outb_p(reg, W83697HF_EFIR); 111 outb_p(data, W83697HF_EFDR); 112} 113 114static void w83697hf_write_timeout(int timeout) 115{ 116 /* Write Timeout counter to CRF4 */ 117 w83697hf_set_reg(0xF4, timeout); 118} 119 120static void w83697hf_select_wdt(void) 121{ 122 w83697hf_unlock(); 123 w83697hf_set_reg(0x07, 0x08); /* Switch to logic device 8 (GPIO2) */ 124} 125 126static inline void w83697hf_deselect_wdt(void) 127{ 128 w83697hf_lock(); 129} 130 131static void w83697hf_init(void) 132{ 133 unsigned char bbuf; 134 135 w83697hf_select_wdt(); 136 137 bbuf = w83697hf_get_reg(0x29); 138 bbuf &= ~0x60; 139 bbuf |= 0x20; 140 141 /* Set pin 119 to WDTO# mode (= CR29, WDT0) */ 142 w83697hf_set_reg(0x29, bbuf); 143 144 bbuf = w83697hf_get_reg(0xF3); 145 bbuf &= ~0x04; 146 w83697hf_set_reg(0xF3, bbuf); /* Count mode is seconds */ 147 148 w83697hf_deselect_wdt(); 149} 150 151static void wdt_ping(void) 152{ 153 spin_lock(&io_lock); 154 w83697hf_select_wdt(); 155 156 w83697hf_write_timeout(timeout); 157 158 w83697hf_deselect_wdt(); 159 spin_unlock(&io_lock); 160} 161 162static void wdt_enable(void) 163{ 164 spin_lock(&io_lock); 165 w83697hf_select_wdt(); 166 167 w83697hf_write_timeout(timeout); 168 w83697hf_set_reg(0x30, 1); /* Enable timer */ 169 170 w83697hf_deselect_wdt(); 171 spin_unlock(&io_lock); 172} 173 174static void wdt_disable(void) 175{ 176 spin_lock(&io_lock); 177 w83697hf_select_wdt(); 178 179 w83697hf_set_reg(0x30, 0); /* Disable timer */ 180 w83697hf_write_timeout(0); 181 182 w83697hf_deselect_wdt(); 183 spin_unlock(&io_lock); 184} 185 186static unsigned char wdt_running(void) 187{ 188 unsigned char t; 189 190 spin_lock(&io_lock); 191 w83697hf_select_wdt(); 192 193 t = w83697hf_get_reg(0xF4); /* Read timer */ 194 195 w83697hf_deselect_wdt(); 196 spin_unlock(&io_lock); 197 198 return t; 199} 200 201static int wdt_set_heartbeat(int t) 202{ 203 if (t < 1 || t > 255) 204 return -EINVAL; 205 206 timeout = t; 207 return 0; 208} 209 210static ssize_t wdt_write(struct file *file, const char __user *buf, 211 size_t count, loff_t *ppos) 212{ 213 if (count) { 214 if (!nowayout) { 215 size_t i; 216 217 expect_close = 0; 218 219 for (i = 0; i != count; i++) { 220 char c; 221 if (get_user(c, buf + i)) 222 return -EFAULT; 223 if (c == 'V') 224 expect_close = 42; 225 } 226 } 227 wdt_ping(); 228 } 229 return count; 230} 231 232static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 233{ 234 void __user *argp = (void __user *)arg; 235 int __user *p = argp; 236 int new_timeout; 237 static const struct watchdog_info ident = { 238 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT 239 | WDIOF_MAGICCLOSE, 240 .firmware_version = 1, 241 .identity = "W83697HF WDT", 242 }; 243 244 switch (cmd) { 245 case WDIOC_GETSUPPORT: 246 if (copy_to_user(argp, &ident, sizeof(ident))) 247 return -EFAULT; 248 break; 249 250 case WDIOC_GETSTATUS: 251 case WDIOC_GETBOOTSTATUS: 252 return put_user(0, p); 253 254 case WDIOC_SETOPTIONS: 255 { 256 int options, retval = -EINVAL; 257 258 if (get_user(options, p)) 259 return -EFAULT; 260 261 if (options & WDIOS_DISABLECARD) { 262 wdt_disable(); 263 retval = 0; 264 } 265 266 if (options & WDIOS_ENABLECARD) { 267 wdt_enable(); 268 retval = 0; 269 } 270 271 return retval; 272 } 273 274 case WDIOC_KEEPALIVE: 275 wdt_ping(); 276 break; 277 278 case WDIOC_SETTIMEOUT: 279 if (get_user(new_timeout, p)) 280 return -EFAULT; 281 if (wdt_set_heartbeat(new_timeout)) 282 return -EINVAL; 283 wdt_ping(); 284 /* Fall */ 285 286 case WDIOC_GETTIMEOUT: 287 return put_user(timeout, p); 288 289 default: 290 return -ENOTTY; 291 } 292 return 0; 293} 294 295static int wdt_open(struct inode *inode, struct file *file) 296{ 297 if (test_and_set_bit(0, &wdt_is_open)) 298 return -EBUSY; 299 /* 300 * Activate 301 */ 302 303 wdt_enable(); 304 return nonseekable_open(inode, file); 305} 306 307static int wdt_close(struct inode *inode, struct file *file) 308{ 309 if (expect_close == 42) 310 wdt_disable(); 311 else { 312 printk(KERN_CRIT PFX 313 "Unexpected close, not stopping watchdog!\n"); 314 wdt_ping(); 315 } 316 expect_close = 0; 317 clear_bit(0, &wdt_is_open); 318 return 0; 319} 320 321/* 322 * Notifier for system down 323 */ 324 325static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 326 void *unused) 327{ 328 if (code == SYS_DOWN || code == SYS_HALT) 329 wdt_disable(); /* Turn the WDT off */ 330 331 return NOTIFY_DONE; 332} 333 334/* 335 * Kernel Interfaces 336 */ 337 338static const struct file_operations wdt_fops = { 339 .owner = THIS_MODULE, 340 .llseek = no_llseek, 341 .write = wdt_write, 342 .unlocked_ioctl = wdt_ioctl, 343 .open = wdt_open, 344 .release = wdt_close, 345}; 346 347static struct miscdevice wdt_miscdev = { 348 .minor = WATCHDOG_MINOR, 349 .name = "watchdog", 350 .fops = &wdt_fops, 351}; 352 353/* 354 * The WDT needs to learn about soft shutdowns in order to 355 * turn the timebomb registers off. 356 */ 357 358static struct notifier_block wdt_notifier = { 359 .notifier_call = wdt_notify_sys, 360}; 361 362static int w83697hf_check_wdt(void) 363{ 364 if (!request_region(wdt_io, 2, WATCHDOG_NAME)) { 365 printk(KERN_ERR PFX 366 "I/O address 0x%x already in use\n", wdt_io); 367 return -EIO; 368 } 369 370 printk(KERN_DEBUG PFX 371 "Looking for watchdog at address 0x%x\n", wdt_io); 372 w83697hf_unlock(); 373 if (w83697hf_get_reg(0x20) == 0x60) { 374 printk(KERN_INFO PFX 375 "watchdog found at address 0x%x\n", wdt_io); 376 w83697hf_lock(); 377 return 0; 378 } 379 /* Reprotect in case it was a compatible device */ 380 w83697hf_lock(); 381 382 printk(KERN_INFO PFX "watchdog not found at address 0x%x\n", wdt_io); 383 release_region(wdt_io, 2); 384 return -EIO; 385} 386 387static int w83697hf_ioports[] = { 0x2e, 0x4e, 0x00 }; 388 389static int __init wdt_init(void) 390{ 391 int ret, i, found = 0; 392 393 printk(KERN_INFO PFX "WDT driver for W83697HF/HG initializing\n"); 394 395 if (wdt_io == 0) { 396 /* we will autodetect the W83697HF/HG watchdog */ 397 for (i = 0; ((!found) && (w83697hf_ioports[i] != 0)); i++) { 398 wdt_io = w83697hf_ioports[i]; 399 if (!w83697hf_check_wdt()) 400 found++; 401 } 402 } else { 403 if (!w83697hf_check_wdt()) 404 found++; 405 } 406 407 if (!found) { 408 printk(KERN_ERR PFX "No W83697HF/HG could be found\n"); 409 ret = -EIO; 410 goto out; 411 } 412 413 w83697hf_init(); 414 if (early_disable) { 415 if (wdt_running()) 416 printk(KERN_WARNING PFX "Stopping previously enabled " 417 "watchdog until userland kicks in\n"); 418 wdt_disable(); 419 } 420 421 if (wdt_set_heartbeat(timeout)) { 422 wdt_set_heartbeat(WATCHDOG_TIMEOUT); 423 printk(KERN_INFO PFX 424 "timeout value must be 1 <= timeout <= 255, using %d\n", 425 WATCHDOG_TIMEOUT); 426 } 427 428 ret = register_reboot_notifier(&wdt_notifier); 429 if (ret != 0) { 430 printk(KERN_ERR PFX 431 "cannot register reboot notifier (err=%d)\n", ret); 432 goto unreg_regions; 433 } 434 435 ret = misc_register(&wdt_miscdev); 436 if (ret != 0) { 437 printk(KERN_ERR PFX 438 "cannot register miscdev on minor=%d (err=%d)\n", 439 WATCHDOG_MINOR, ret); 440 goto unreg_reboot; 441 } 442 443 printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", 444 timeout, nowayout); 445 446out: 447 return ret; 448unreg_reboot: 449 unregister_reboot_notifier(&wdt_notifier); 450unreg_regions: 451 release_region(wdt_io, 2); 452 goto out; 453} 454 455static void __exit wdt_exit(void) 456{ 457 misc_deregister(&wdt_miscdev); 458 unregister_reboot_notifier(&wdt_notifier); 459 release_region(wdt_io, 2); 460} 461 462module_init(wdt_init); 463module_exit(wdt_exit); 464 465MODULE_LICENSE("GPL"); 466MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, " 467 "Samuel Tardieu <sam@rfc1149.net>"); 468MODULE_DESCRIPTION("w83697hf/hg WDT driver"); 469MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 470