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#include <linux/module.h> 30#include <linux/moduleparam.h> 31#include <linux/types.h> 32#include <linux/miscdevice.h> 33#include <linux/watchdog.h> 34#include <linux/fs.h> 35#include <linux/ioport.h> 36#include <linux/notifier.h> 37#include <linux/reboot.h> 38#include <linux/init.h> 39#include <linux/spinlock.h> 40#include <linux/io.h> 41#include <linux/uaccess.h> 42 43#include <asm/system.h> 44 45#define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT" 46#define PFX WATCHDOG_NAME ": " 47#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */ 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, "w83627hf/thf WDT io port (default 0x2E)"); 57 58static int timeout = WATCHDOG_TIMEOUT; /* in seconds */ 59module_param(timeout, int, 0); 60MODULE_PARM_DESC(timeout, 61 "Watchdog timeout in seconds. 1 <= timeout <= 255, default=" 62 __MODULE_STRING(WATCHDOG_TIMEOUT) "."); 63 64static int nowayout = WATCHDOG_NOWAYOUT; 65module_param(nowayout, int, 0); 66MODULE_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 79static 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 105static 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 113static 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 printk(KERN_INFO PFX 123 "Watchdog already running. Resetting timeout to %d sec\n", 124 timeout); 125 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */ 126 } 127 128 outb_p(0xF5, WDT_EFER); /* Select CRF5 */ 129 t = inb_p(WDT_EFDR); /* read CRF5 */ 130 t &= ~0x0C; /* set second mode & disable keyboard 131 turning off watchdog */ 132 t |= 0x02; /* enable the WDTO# output low pulse 133 to the KBRST# pin (PIN60) */ 134 outb_p(t, WDT_EFDR); /* Write back to CRF5 */ 135 136 outb_p(0xF7, WDT_EFER); /* Select CRF7 */ 137 t = inb_p(WDT_EFDR); /* read CRF7 */ 138 t &= ~0xC0; /* disable keyboard & mouse turning off 139 watchdog */ 140 outb_p(t, WDT_EFDR); /* Write back to CRF7 */ 141 142 w83627hf_unselect_wd_register(); 143} 144 145static void wdt_set_time(int timeout) 146{ 147 spin_lock(&io_lock); 148 149 w83627hf_select_wd_register(); 150 151 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 152 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */ 153 154 w83627hf_unselect_wd_register(); 155 156 spin_unlock(&io_lock); 157} 158 159static int wdt_ping(void) 160{ 161 wdt_set_time(timeout); 162 return 0; 163} 164 165static int wdt_disable(void) 166{ 167 wdt_set_time(0); 168 return 0; 169} 170 171static int wdt_set_heartbeat(int t) 172{ 173 if (t < 1 || t > 255) 174 return -EINVAL; 175 timeout = t; 176 return 0; 177} 178 179static int wdt_get_time(void) 180{ 181 int timeleft; 182 183 spin_lock(&io_lock); 184 185 w83627hf_select_wd_register(); 186 187 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 188 timeleft = inb_p(WDT_EFDR); /* Read Timeout counter to CRF6 */ 189 190 w83627hf_unselect_wd_register(); 191 192 spin_unlock(&io_lock); 193 194 return timeleft; 195} 196 197static ssize_t wdt_write(struct file *file, const char __user *buf, 198 size_t count, loff_t *ppos) 199{ 200 if (count) { 201 if (!nowayout) { 202 size_t i; 203 204 expect_close = 0; 205 206 for (i = 0; i != count; i++) { 207 char c; 208 if (get_user(c, buf + i)) 209 return -EFAULT; 210 if (c == 'V') 211 expect_close = 42; 212 } 213 } 214 wdt_ping(); 215 } 216 return count; 217} 218 219static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 220{ 221 void __user *argp = (void __user *)arg; 222 int __user *p = argp; 223 int timeval; 224 static const struct watchdog_info ident = { 225 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | 226 WDIOF_MAGICCLOSE, 227 .firmware_version = 1, 228 .identity = "W83627HF WDT", 229 }; 230 231 switch (cmd) { 232 case WDIOC_GETSUPPORT: 233 if (copy_to_user(argp, &ident, sizeof(ident))) 234 return -EFAULT; 235 break; 236 case WDIOC_GETSTATUS: 237 case WDIOC_GETBOOTSTATUS: 238 return put_user(0, p); 239 case WDIOC_SETOPTIONS: 240 { 241 int options, retval = -EINVAL; 242 243 if (get_user(options, p)) 244 return -EFAULT; 245 if (options & WDIOS_DISABLECARD) { 246 wdt_disable(); 247 retval = 0; 248 } 249 if (options & WDIOS_ENABLECARD) { 250 wdt_ping(); 251 retval = 0; 252 } 253 return retval; 254 } 255 case WDIOC_KEEPALIVE: 256 wdt_ping(); 257 break; 258 case WDIOC_SETTIMEOUT: 259 if (get_user(timeval, p)) 260 return -EFAULT; 261 if (wdt_set_heartbeat(timeval)) 262 return -EINVAL; 263 wdt_ping(); 264 /* Fall */ 265 case WDIOC_GETTIMEOUT: 266 return put_user(timeout, p); 267 case WDIOC_GETTIMELEFT: 268 timeval = wdt_get_time(); 269 return put_user(timeval, p); 270 default: 271 return -ENOTTY; 272 } 273 return 0; 274} 275 276static int wdt_open(struct inode *inode, struct file *file) 277{ 278 if (test_and_set_bit(0, &wdt_is_open)) 279 return -EBUSY; 280 /* 281 * Activate 282 */ 283 284 wdt_ping(); 285 return nonseekable_open(inode, file); 286} 287 288static int wdt_close(struct inode *inode, struct file *file) 289{ 290 if (expect_close == 42) 291 wdt_disable(); 292 else { 293 printk(KERN_CRIT PFX 294 "Unexpected close, not stopping watchdog!\n"); 295 wdt_ping(); 296 } 297 expect_close = 0; 298 clear_bit(0, &wdt_is_open); 299 return 0; 300} 301 302/* 303 * Notifier for system down 304 */ 305 306static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 307 void *unused) 308{ 309 if (code == SYS_DOWN || code == SYS_HALT) 310 wdt_disable(); /* Turn the WDT off */ 311 312 return NOTIFY_DONE; 313} 314 315/* 316 * Kernel Interfaces 317 */ 318 319static const struct file_operations wdt_fops = { 320 .owner = THIS_MODULE, 321 .llseek = no_llseek, 322 .write = wdt_write, 323 .unlocked_ioctl = wdt_ioctl, 324 .open = wdt_open, 325 .release = wdt_close, 326}; 327 328static struct miscdevice wdt_miscdev = { 329 .minor = WATCHDOG_MINOR, 330 .name = "watchdog", 331 .fops = &wdt_fops, 332}; 333 334/* 335 * The WDT needs to learn about soft shutdowns in order to 336 * turn the timebomb registers off. 337 */ 338 339static struct notifier_block wdt_notifier = { 340 .notifier_call = wdt_notify_sys, 341}; 342 343static int __init wdt_init(void) 344{ 345 int ret; 346 347 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG/DHG Super I/O chip initialising.\n"); 348 349 if (wdt_set_heartbeat(timeout)) { 350 wdt_set_heartbeat(WATCHDOG_TIMEOUT); 351 printk(KERN_INFO PFX 352 "timeout value must be 1 <= timeout <= 255, using %d\n", 353 WATCHDOG_TIMEOUT); 354 } 355 356 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) { 357 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", 358 wdt_io); 359 ret = -EIO; 360 goto out; 361 } 362 363 w83627hf_init(); 364 365 ret = register_reboot_notifier(&wdt_notifier); 366 if (ret != 0) { 367 printk(KERN_ERR PFX 368 "cannot register reboot notifier (err=%d)\n", ret); 369 goto unreg_regions; 370 } 371 372 ret = misc_register(&wdt_miscdev); 373 if (ret != 0) { 374 printk(KERN_ERR PFX 375 "cannot register miscdev on minor=%d (err=%d)\n", 376 WATCHDOG_MINOR, ret); 377 goto unreg_reboot; 378 } 379 380 printk(KERN_INFO PFX 381 "initialized. timeout=%d sec (nowayout=%d)\n", 382 timeout, nowayout); 383 384out: 385 return ret; 386unreg_reboot: 387 unregister_reboot_notifier(&wdt_notifier); 388unreg_regions: 389 release_region(wdt_io, 1); 390 goto out; 391} 392 393static void __exit wdt_exit(void) 394{ 395 misc_deregister(&wdt_miscdev); 396 unregister_reboot_notifier(&wdt_notifier); 397 release_region(wdt_io, 1); 398} 399 400module_init(wdt_init); 401module_exit(wdt_exit); 402 403MODULE_LICENSE("GPL"); 404MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>"); 405MODULE_DESCRIPTION("w83627hf/thf WDT driver"); 406MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 407