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@redhat.com>, All Rights Reserved. 15 * http://www.redhat.com 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@redhat.com> 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 41 #include <asm/io.h> 42 #include <asm/uaccess.h> 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, "Watchdog timeout in seconds. 1<= timeout <=255, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) "."); 61 62 static int nowayout = WATCHDOG_NOWAYOUT; 63 module_param(nowayout, int, 0); 64 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 65 66 /* 67 * Kernel methods. 68 */ 69 70 #define WDT_EFER (wdt_io+0) /* Extended Function Enable Registers */ 71 #define WDT_EFIR (wdt_io+0) /* Extended Function Index Register (same as EFER) */ 72 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */ 73 74 static void 75 w83627hf_select_wd_register(void) 76 { 77 unsigned char c; 78 outb_p(0x87, WDT_EFER); /* Enter extended function mode */ 79 outb_p(0x87, WDT_EFER); /* Again according to manual */ 80 81 outb(0x20, WDT_EFER); /* check chip version */ 82 c = inb(WDT_EFDR); 83 if (c == 0x82) { /* W83627THF */ 84 outb_p(0x2b, WDT_EFER); /* select GPIO3 */ 85 c = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */ 86 outb_p(0x2b, WDT_EFER); 87 outb_p(c, WDT_EFDR); /* set GPIO3 to WDT0 */ 88 } 89 90 outb_p(0x07, WDT_EFER); /* point to logical device number reg */ 91 outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */ 92 outb_p(0x30, WDT_EFER); /* select CR30 */ 93 outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */ 94 } 95 96 static void 97 w83627hf_unselect_wd_register(void) 98 { 99 outb_p(0xAA, WDT_EFER); /* Leave extended function mode */ 100 } 101 102 /* tyan motherboards seem to set F5 to 0x4C ? 103 * So explicitly init to appropriate value. */ 104 static void 105 w83627hf_init(void) 106 { 107 unsigned char t; 108 109 w83627hf_select_wd_register(); 110 111 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 112 t=inb_p(WDT_EFDR); /* read CRF6 */ 113 if (t != 0) { 114 printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout); 115 outb_p(timeout, WDT_EFDR); /* Write back to CRF6 */ 116 } 117 118 outb_p(0xF5, WDT_EFER); /* Select CRF5 */ 119 t=inb_p(WDT_EFDR); /* read CRF5 */ 120 t&=~0x0C; /* set second mode & disable keyboard turning off watchdog */ 121 outb_p(t, WDT_EFDR); /* Write back to CRF5 */ 122 123 outb_p(0xF7, WDT_EFER); /* Select CRF7 */ 124 t=inb_p(WDT_EFDR); /* read CRF7 */ 125 t&=~0xC0; /* disable keyboard & mouse turning off watchdog */ 126 outb_p(t, WDT_EFDR); /* Write back to CRF7 */ 127 128 w83627hf_unselect_wd_register(); 129 } 130 131 static void 132 wdt_ctrl(int timeout) 133 { 134 spin_lock(&io_lock); 135 136 w83627hf_select_wd_register(); 137 138 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 139 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */ 140 141 w83627hf_unselect_wd_register(); 142 143 spin_unlock(&io_lock); 144 } 145 146 static int 147 wdt_ping(void) 148 { 149 wdt_ctrl(timeout); 150 return 0; 151 } 152 153 static int 154 wdt_disable(void) 155 { 156 wdt_ctrl(0); 157 return 0; 158 } 159 160 static int 161 wdt_set_heartbeat(int t) 162 { 163 if ((t < 1) || (t > 255)) 164 return -EINVAL; 165 166 timeout = t; 167 return 0; 168 } 169 170 static ssize_t 171 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) 172 { 173 if (count) { 174 if (!nowayout) { 175 size_t i; 176 177 expect_close = 0; 178 179 for (i = 0; i != count; i++) { 180 char c; 181 if (get_user(c, buf+i)) 182 return -EFAULT; 183 if (c == 'V') 184 expect_close = 42; 185 } 186 } 187 wdt_ping(); 188 } 189 return count; 190 } 191 192 static int 193 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 194 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 | WDIOF_MAGICCLOSE, 201 .firmware_version = 1, 202 .identity = "W83627HF WDT", 203 }; 204 205 switch (cmd) { 206 case WDIOC_GETSUPPORT: 207 if (copy_to_user(argp, &ident, sizeof(ident))) 208 return -EFAULT; 209 break; 210 211 case WDIOC_GETSTATUS: 212 case WDIOC_GETBOOTSTATUS: 213 return put_user(0, p); 214 215 case WDIOC_KEEPALIVE: 216 wdt_ping(); 217 break; 218 219 case WDIOC_SETTIMEOUT: 220 if (get_user(new_timeout, p)) 221 return -EFAULT; 222 if (wdt_set_heartbeat(new_timeout)) 223 return -EINVAL; 224 wdt_ping(); 225 /* Fall */ 226 227 case WDIOC_GETTIMEOUT: 228 return put_user(timeout, p); 229 230 case WDIOC_SETOPTIONS: 231 { 232 int options, retval = -EINVAL; 233 234 if (get_user(options, p)) 235 return -EFAULT; 236 237 if (options & WDIOS_DISABLECARD) { 238 wdt_disable(); 239 retval = 0; 240 } 241 242 if (options & WDIOS_ENABLECARD) { 243 wdt_ping(); 244 retval = 0; 245 } 246 247 return retval; 248 } 249 250 default: 251 return -ENOTTY; 252 } 253 return 0; 254 } 255 256 static int 257 wdt_open(struct inode *inode, struct file *file) 258 { 259 if (test_and_set_bit(0, &wdt_is_open)) 260 return -EBUSY; 261 /* 262 * Activate 263 */ 264 265 wdt_ping(); 266 return nonseekable_open(inode, file); 267 } 268 269 static int 270 wdt_close(struct inode *inode, struct file *file) 271 { 272 if (expect_close == 42) { 273 wdt_disable(); 274 } else { 275 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); 276 wdt_ping(); 277 } 278 expect_close = 0; 279 clear_bit(0, &wdt_is_open); 280 return 0; 281 } 282 283 /* 284 * Notifier for system down 285 */ 286 287 static int 288 wdt_notify_sys(struct notifier_block *this, unsigned long code, 289 void *unused) 290 { 291 if (code == SYS_DOWN || code == SYS_HALT) { 292 /* Turn the WDT off */ 293 wdt_disable(); 294 } 295 return NOTIFY_DONE; 296 } 297 298 /* 299 * Kernel Interfaces 300 */ 301 302 static const struct file_operations wdt_fops = { 303 .owner = THIS_MODULE, 304 .llseek = no_llseek, 305 .write = wdt_write, 306 .ioctl = wdt_ioctl, 307 .open = wdt_open, 308 .release = wdt_close, 309 }; 310 311 static struct miscdevice wdt_miscdev = { 312 .minor = WATCHDOG_MINOR, 313 .name = "watchdog", 314 .fops = &wdt_fops, 315 }; 316 317 /* 318 * The WDT needs to learn about soft shutdowns in order to 319 * turn the timebomb registers off. 320 */ 321 322 static struct notifier_block wdt_notifier = { 323 .notifier_call = wdt_notify_sys, 324 }; 325 326 static int __init 327 wdt_init(void) 328 { 329 int ret; 330 331 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n"); 332 333 if (wdt_set_heartbeat(timeout)) { 334 wdt_set_heartbeat(WATCHDOG_TIMEOUT); 335 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=255, using %d\n", 336 WATCHDOG_TIMEOUT); 337 } 338 339 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) { 340 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", 341 wdt_io); 342 ret = -EIO; 343 goto out; 344 } 345 346 w83627hf_init(); 347 348 ret = register_reboot_notifier(&wdt_notifier); 349 if (ret != 0) { 350 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", 351 ret); 352 goto unreg_regions; 353 } 354 355 ret = misc_register(&wdt_miscdev); 356 if (ret != 0) { 357 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", 358 WATCHDOG_MINOR, ret); 359 goto unreg_reboot; 360 } 361 362 printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n", 363 timeout, nowayout); 364 365 out: 366 return ret; 367 unreg_reboot: 368 unregister_reboot_notifier(&wdt_notifier); 369 unreg_regions: 370 release_region(wdt_io, 1); 371 goto out; 372 } 373 374 static void __exit 375 wdt_exit(void) 376 { 377 misc_deregister(&wdt_miscdev); 378 unregister_reboot_notifier(&wdt_notifier); 379 release_region(wdt_io,1); 380 } 381 382 module_init(wdt_init); 383 module_exit(wdt_exit); 384 385 MODULE_LICENSE("GPL"); 386 MODULE_AUTHOR("P�draig Brady <P@draigBrady.com>"); 387 MODULE_DESCRIPTION("w83627hf/thf WDT driver"); 388 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 389