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 P�draig 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 WDT" 46 #define PFX WATCHDOG_NAME ": " 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 int nowayout = WATCHDOG_NOWAYOUT; 65 module_param(nowayout, int, 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 } 93 94 outb_p(0x07, WDT_EFER); /* point to logical device number reg */ 95 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */ 96 outb_p(0x30, WDT_EFER); /* select CR30 */ 97 outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */ 98 } 99 100 static void w83627hf_unselect_wd_register(void) 101 { 102 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */ 103 } 104 105 /* tyan motherboards seem to set F5 to 0x4C ? 106 * So explicitly init to appropriate value. */ 107 108 static void w83627hf_init(void) 109 { 110 unsigned char t; 111 112 w83627hf_select_wd_register(); 113 114 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 115 t = inb_p(WDT_EFDR); /* read CRF6 */ 116 if (t != 0) { 117 printk(KERN_INFO PFX 118 "Watchdog already running. Resetting timeout to %d sec\n", 119 timeout); 120 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */ 121 } 122 123 outb_p(0xF5, WDT_EFER); /* Select CRF5 */ 124 t = inb_p(WDT_EFDR); /* read CRF5 */ 125 t &= ~0x0C; /* set second mode & disable keyboard 126 turning off watchdog */ 127 outb_p(t, WDT_EFDR); /* Write back to CRF5 */ 128 129 outb_p(0xF7, WDT_EFER); /* Select CRF7 */ 130 t = inb_p(WDT_EFDR); /* read CRF7 */ 131 t &= ~0xC0; /* disable keyboard & mouse turning off 132 watchdog */ 133 outb_p(t, WDT_EFDR); /* Write back to CRF7 */ 134 135 w83627hf_unselect_wd_register(); 136 } 137 138 static void wdt_ctrl(int timeout) 139 { 140 spin_lock(&io_lock); 141 142 w83627hf_select_wd_register(); 143 144 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 145 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */ 146 147 w83627hf_unselect_wd_register(); 148 149 spin_unlock(&io_lock); 150 } 151 152 static int wdt_ping(void) 153 { 154 wdt_ctrl(timeout); 155 return 0; 156 } 157 158 static int wdt_disable(void) 159 { 160 wdt_ctrl(0); 161 return 0; 162 } 163 164 static int wdt_set_heartbeat(int t) 165 { 166 if (t < 1 || t > 255) 167 return -EINVAL; 168 timeout = t; 169 return 0; 170 } 171 172 static ssize_t wdt_write(struct file *file, const char __user *buf, 173 size_t count, loff_t *ppos) 174 { 175 if (count) { 176 if (!nowayout) { 177 size_t i; 178 179 expect_close = 0; 180 181 for (i = 0; i != count; i++) { 182 char c; 183 if (get_user(c, buf + i)) 184 return -EFAULT; 185 if (c == 'V') 186 expect_close = 42; 187 } 188 } 189 wdt_ping(); 190 } 191 return count; 192 } 193 194 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 195 { 196 void __user *argp = (void __user *)arg; 197 int __user *p = argp; 198 int new_timeout; 199 static struct watchdog_info ident = { 200 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | 201 WDIOF_MAGICCLOSE, 202 .firmware_version = 1, 203 .identity = "W83627HF WDT", 204 }; 205 206 switch (cmd) { 207 case WDIOC_GETSUPPORT: 208 if (copy_to_user(argp, &ident, sizeof(ident))) 209 return -EFAULT; 210 break; 211 case WDIOC_GETSTATUS: 212 case WDIOC_GETBOOTSTATUS: 213 return put_user(0, p); 214 case WDIOC_SETOPTIONS: 215 { 216 int options, retval = -EINVAL; 217 218 if (get_user(options, p)) 219 return -EFAULT; 220 if (options & WDIOS_DISABLECARD) { 221 wdt_disable(); 222 retval = 0; 223 } 224 if (options & WDIOS_ENABLECARD) { 225 wdt_ping(); 226 retval = 0; 227 } 228 return retval; 229 } 230 case WDIOC_KEEPALIVE: 231 wdt_ping(); 232 break; 233 case WDIOC_SETTIMEOUT: 234 if (get_user(new_timeout, p)) 235 return -EFAULT; 236 if (wdt_set_heartbeat(new_timeout)) 237 return -EINVAL; 238 wdt_ping(); 239 /* Fall */ 240 case WDIOC_GETTIMEOUT: 241 return put_user(timeout, p); 242 default: 243 return -ENOTTY; 244 } 245 return 0; 246 } 247 248 static int wdt_open(struct inode *inode, struct file *file) 249 { 250 if (test_and_set_bit(0, &wdt_is_open)) 251 return -EBUSY; 252 /* 253 * Activate 254 */ 255 256 wdt_ping(); 257 return nonseekable_open(inode, file); 258 } 259 260 static int wdt_close(struct inode *inode, struct file *file) 261 { 262 if (expect_close == 42) 263 wdt_disable(); 264 else { 265 printk(KERN_CRIT PFX 266 "Unexpected close, not stopping watchdog!\n"); 267 wdt_ping(); 268 } 269 expect_close = 0; 270 clear_bit(0, &wdt_is_open); 271 return 0; 272 } 273 274 /* 275 * Notifier for system down 276 */ 277 278 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 279 void *unused) 280 { 281 if (code == SYS_DOWN || code == SYS_HALT) 282 wdt_disable(); /* Turn the WDT off */ 283 284 return NOTIFY_DONE; 285 } 286 287 /* 288 * Kernel Interfaces 289 */ 290 291 static const struct file_operations wdt_fops = { 292 .owner = THIS_MODULE, 293 .llseek = no_llseek, 294 .write = wdt_write, 295 .unlocked_ioctl = wdt_ioctl, 296 .open = wdt_open, 297 .release = wdt_close, 298 }; 299 300 static struct miscdevice wdt_miscdev = { 301 .minor = WATCHDOG_MINOR, 302 .name = "watchdog", 303 .fops = &wdt_fops, 304 }; 305 306 /* 307 * The WDT needs to learn about soft shutdowns in order to 308 * turn the timebomb registers off. 309 */ 310 311 static struct notifier_block wdt_notifier = { 312 .notifier_call = wdt_notify_sys, 313 }; 314 315 static int __init wdt_init(void) 316 { 317 int ret; 318 319 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n"); 320 321 if (wdt_set_heartbeat(timeout)) { 322 wdt_set_heartbeat(WATCHDOG_TIMEOUT); 323 printk(KERN_INFO PFX 324 "timeout value must be 1 <= timeout <= 255, using %d\n", 325 WATCHDOG_TIMEOUT); 326 } 327 328 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) { 329 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", 330 wdt_io); 331 ret = -EIO; 332 goto out; 333 } 334 335 w83627hf_init(); 336 337 ret = register_reboot_notifier(&wdt_notifier); 338 if (ret != 0) { 339 printk(KERN_ERR PFX 340 "cannot register reboot notifier (err=%d)\n", ret); 341 goto unreg_regions; 342 } 343 344 ret = misc_register(&wdt_miscdev); 345 if (ret != 0) { 346 printk(KERN_ERR PFX 347 "cannot register miscdev on minor=%d (err=%d)\n", 348 WATCHDOG_MINOR, ret); 349 goto unreg_reboot; 350 } 351 352 printk(KERN_INFO PFX 353 "initialized. timeout=%d sec (nowayout=%d)\n", 354 timeout, nowayout); 355 356 out: 357 return ret; 358 unreg_reboot: 359 unregister_reboot_notifier(&wdt_notifier); 360 unreg_regions: 361 release_region(wdt_io, 1); 362 goto out; 363 } 364 365 static void __exit wdt_exit(void) 366 { 367 misc_deregister(&wdt_miscdev); 368 unregister_reboot_notifier(&wdt_notifier); 369 release_region(wdt_io, 1); 370 } 371 372 module_init(wdt_init); 373 module_exit(wdt_exit); 374 375 MODULE_LICENSE("GPL"); 376 MODULE_AUTHOR("P�draig Brady <P@draigBrady.com>"); 377 MODULE_DESCRIPTION("w83627hf/thf WDT driver"); 378 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 379