1 /* 2 * w83627hf/thf WDT driver 3 * 4 * (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com> 5 * added support for W83627THF. 6 * 7 * (c) Copyright 2003,2007 Pádraig Brady <P@draigBrady.com> 8 * 9 * Based on advantechwdt.c which is based on wdt.c. 10 * Original copyright messages: 11 * 12 * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl> 13 * 14 * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>, 15 * All Rights Reserved. 16 * 17 * This program is free software; you can redistribute it and/or 18 * modify it under the terms of the GNU General Public License 19 * as published by the Free Software Foundation; either version 20 * 2 of the License, or (at your option) any later version. 21 * 22 * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide 23 * warranty for any of this software. This material is provided 24 * "AS-IS" and at no charge. 25 * 26 * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> 27 */ 28 29 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 30 31 #include <linux/module.h> 32 #include <linux/moduleparam.h> 33 #include <linux/types.h> 34 #include <linux/miscdevice.h> 35 #include <linux/watchdog.h> 36 #include <linux/fs.h> 37 #include <linux/ioport.h> 38 #include <linux/notifier.h> 39 #include <linux/reboot.h> 40 #include <linux/init.h> 41 #include <linux/spinlock.h> 42 #include <linux/io.h> 43 #include <linux/uaccess.h> 44 45 46 #define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT" 47 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ 48 49 static unsigned long wdt_is_open; 50 static char expect_close; 51 static DEFINE_SPINLOCK(io_lock); 52 53 /* You must set this - there is no sane way to probe for this board. */ 54 static int wdt_io = 0x2E; 55 module_param(wdt_io, int, 0); 56 MODULE_PARM_DESC(wdt_io, "w83627hf/thf WDT io port (default 0x2E)"); 57 58 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ 59 module_param(timeout, int, 0); 60 MODULE_PARM_DESC(timeout, 61 "Watchdog timeout in seconds. 1 <= timeout <= 255, default=" 62 __MODULE_STRING(WATCHDOG_TIMEOUT) "."); 63 64 static bool nowayout = WATCHDOG_NOWAYOUT; 65 module_param(nowayout, bool, 0); 66 MODULE_PARM_DESC(nowayout, 67 "Watchdog cannot be stopped once started (default=" 68 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 69 70 /* 71 * Kernel methods. 72 */ 73 74 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */ 75 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register 76 (same as EFER) */ 77 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */ 78 79 static void w83627hf_select_wd_register(void) 80 { 81 unsigned char c; 82 outb_p(0x87, WDT_EFER); /* Enter extended function mode */ 83 outb_p(0x87, WDT_EFER); /* Again according to manual */ 84 85 outb(0x20, WDT_EFER); /* check chip version */ 86 c = inb(WDT_EFDR); 87 if (c == 0x82) { /* W83627THF */ 88 outb_p(0x2b, WDT_EFER); /* select GPIO3 */ 89 c = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */ 90 outb_p(0x2b, WDT_EFER); 91 outb_p(c, WDT_EFDR); /* set GPIO3 to WDT0 */ 92 } else if (c == 0x88 || c == 0xa0) { /* W83627EHF / W83627DHG */ 93 outb_p(0x2d, WDT_EFER); /* select GPIO5 */ 94 c = inb_p(WDT_EFDR) & ~0x01; /* PIN77 -> WDT0# */ 95 outb_p(0x2d, WDT_EFER); 96 outb_p(c, WDT_EFDR); /* set GPIO5 to WDT0 */ 97 } 98 99 outb_p(0x07, WDT_EFER); /* point to logical device number reg */ 100 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */ 101 outb_p(0x30, WDT_EFER); /* select CR30 */ 102 outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */ 103 } 104 105 static void w83627hf_unselect_wd_register(void) 106 { 107 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */ 108 } 109 110 /* tyan motherboards seem to set F5 to 0x4C ? 111 * So explicitly init to appropriate value. */ 112 113 static void w83627hf_init(void) 114 { 115 unsigned char t; 116 117 w83627hf_select_wd_register(); 118 119 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 120 t = inb_p(WDT_EFDR); /* read CRF6 */ 121 if (t != 0) { 122 pr_info("Watchdog already running. Resetting timeout to %d sec\n", 123 timeout); 124 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */ 125 } 126 127 outb_p(0xF5, WDT_EFER); /* Select CRF5 */ 128 t = inb_p(WDT_EFDR); /* read CRF5 */ 129 t &= ~0x0C; /* set second mode & disable keyboard 130 turning off watchdog */ 131 t |= 0x02; /* enable the WDTO# output low pulse 132 to the KBRST# pin (PIN60) */ 133 outb_p(t, WDT_EFDR); /* Write back to CRF5 */ 134 135 outb_p(0xF7, WDT_EFER); /* Select CRF7 */ 136 t = inb_p(WDT_EFDR); /* read CRF7 */ 137 t &= ~0xC0; /* disable keyboard & mouse turning off 138 watchdog */ 139 outb_p(t, WDT_EFDR); /* Write back to CRF7 */ 140 141 w83627hf_unselect_wd_register(); 142 } 143 144 static void wdt_set_time(int timeout) 145 { 146 spin_lock(&io_lock); 147 148 w83627hf_select_wd_register(); 149 150 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 151 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */ 152 153 w83627hf_unselect_wd_register(); 154 155 spin_unlock(&io_lock); 156 } 157 158 static int wdt_ping(void) 159 { 160 wdt_set_time(timeout); 161 return 0; 162 } 163 164 static int wdt_disable(void) 165 { 166 wdt_set_time(0); 167 return 0; 168 } 169 170 static int wdt_set_heartbeat(int t) 171 { 172 if (t < 1 || t > 255) 173 return -EINVAL; 174 timeout = t; 175 return 0; 176 } 177 178 static int wdt_get_time(void) 179 { 180 int timeleft; 181 182 spin_lock(&io_lock); 183 184 w83627hf_select_wd_register(); 185 186 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 187 timeleft = inb_p(WDT_EFDR); /* Read Timeout counter to CRF6 */ 188 189 w83627hf_unselect_wd_register(); 190 191 spin_unlock(&io_lock); 192 193 return timeleft; 194 } 195 196 static ssize_t wdt_write(struct file *file, const char __user *buf, 197 size_t count, loff_t *ppos) 198 { 199 if (count) { 200 if (!nowayout) { 201 size_t i; 202 203 expect_close = 0; 204 205 for (i = 0; i != count; i++) { 206 char c; 207 if (get_user(c, buf + i)) 208 return -EFAULT; 209 if (c == 'V') 210 expect_close = 42; 211 } 212 } 213 wdt_ping(); 214 } 215 return count; 216 } 217 218 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 219 { 220 void __user *argp = (void __user *)arg; 221 int __user *p = argp; 222 int timeval; 223 static const struct watchdog_info ident = { 224 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | 225 WDIOF_MAGICCLOSE, 226 .firmware_version = 1, 227 .identity = "W83627HF WDT", 228 }; 229 230 switch (cmd) { 231 case WDIOC_GETSUPPORT: 232 if (copy_to_user(argp, &ident, sizeof(ident))) 233 return -EFAULT; 234 break; 235 case WDIOC_GETSTATUS: 236 case WDIOC_GETBOOTSTATUS: 237 return put_user(0, p); 238 case WDIOC_SETOPTIONS: 239 { 240 int options, retval = -EINVAL; 241 242 if (get_user(options, p)) 243 return -EFAULT; 244 if (options & WDIOS_DISABLECARD) { 245 wdt_disable(); 246 retval = 0; 247 } 248 if (options & WDIOS_ENABLECARD) { 249 wdt_ping(); 250 retval = 0; 251 } 252 return retval; 253 } 254 case WDIOC_KEEPALIVE: 255 wdt_ping(); 256 break; 257 case WDIOC_SETTIMEOUT: 258 if (get_user(timeval, p)) 259 return -EFAULT; 260 if (wdt_set_heartbeat(timeval)) 261 return -EINVAL; 262 wdt_ping(); 263 /* Fall */ 264 case WDIOC_GETTIMEOUT: 265 return put_user(timeout, p); 266 case WDIOC_GETTIMELEFT: 267 timeval = wdt_get_time(); 268 return put_user(timeval, p); 269 default: 270 return -ENOTTY; 271 } 272 return 0; 273 } 274 275 static int wdt_open(struct inode *inode, struct file *file) 276 { 277 if (test_and_set_bit(0, &wdt_is_open)) 278 return -EBUSY; 279 /* 280 * Activate 281 */ 282 283 wdt_ping(); 284 return nonseekable_open(inode, file); 285 } 286 287 static int wdt_close(struct inode *inode, struct file *file) 288 { 289 if (expect_close == 42) 290 wdt_disable(); 291 else { 292 pr_crit("Unexpected close, not stopping watchdog!\n"); 293 wdt_ping(); 294 } 295 expect_close = 0; 296 clear_bit(0, &wdt_is_open); 297 return 0; 298 } 299 300 /* 301 * Notifier for system down 302 */ 303 304 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 305 void *unused) 306 { 307 if (code == SYS_DOWN || code == SYS_HALT) 308 wdt_disable(); /* Turn the WDT off */ 309 310 return NOTIFY_DONE; 311 } 312 313 /* 314 * Kernel Interfaces 315 */ 316 317 static const struct file_operations wdt_fops = { 318 .owner = THIS_MODULE, 319 .llseek = no_llseek, 320 .write = wdt_write, 321 .unlocked_ioctl = wdt_ioctl, 322 .open = wdt_open, 323 .release = wdt_close, 324 }; 325 326 static struct miscdevice wdt_miscdev = { 327 .minor = WATCHDOG_MINOR, 328 .name = "watchdog", 329 .fops = &wdt_fops, 330 }; 331 332 /* 333 * The WDT needs to learn about soft shutdowns in order to 334 * turn the timebomb registers off. 335 */ 336 337 static struct notifier_block wdt_notifier = { 338 .notifier_call = wdt_notify_sys, 339 }; 340 341 static int __init wdt_init(void) 342 { 343 int ret; 344 345 pr_info("WDT driver for the Winbond(TM) W83627HF/THF/HG/DHG Super I/O chip initialising\n"); 346 347 if (wdt_set_heartbeat(timeout)) { 348 wdt_set_heartbeat(WATCHDOG_TIMEOUT); 349 pr_info("timeout value must be 1 <= timeout <= 255, using %d\n", 350 WATCHDOG_TIMEOUT); 351 } 352 353 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) { 354 pr_err("I/O address 0x%04x already in use\n", wdt_io); 355 ret = -EIO; 356 goto out; 357 } 358 359 w83627hf_init(); 360 361 ret = register_reboot_notifier(&wdt_notifier); 362 if (ret != 0) { 363 pr_err("cannot register reboot notifier (err=%d)\n", ret); 364 goto unreg_regions; 365 } 366 367 ret = misc_register(&wdt_miscdev); 368 if (ret != 0) { 369 pr_err("cannot register miscdev on minor=%d (err=%d)\n", 370 WATCHDOG_MINOR, ret); 371 goto unreg_reboot; 372 } 373 374 pr_info("initialized. timeout=%d sec (nowayout=%d)\n", 375 timeout, nowayout); 376 377 out: 378 return ret; 379 unreg_reboot: 380 unregister_reboot_notifier(&wdt_notifier); 381 unreg_regions: 382 release_region(wdt_io, 1); 383 goto out; 384 } 385 386 static void __exit wdt_exit(void) 387 { 388 misc_deregister(&wdt_miscdev); 389 unregister_reboot_notifier(&wdt_notifier); 390 release_region(wdt_io, 1); 391 } 392 393 module_init(wdt_init); 394 module_exit(wdt_exit); 395 396 MODULE_LICENSE("GPL"); 397 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>"); 398 MODULE_DESCRIPTION("w83627hf/thf WDT driver"); 399 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 400