1 /* 2 * IT8712F "Smart Guardian" Watchdog support 3 * 4 * Copyright (c) 2006-2007 Jorge Boncompte - DTI2 <jorge@dti2.net> 5 * 6 * Based on info and code taken from: 7 * 8 * drivers/char/watchdog/scx200_wdt.c 9 * drivers/hwmon/it87.c 10 * IT8712F EC-LPC I/O Preliminary Specification 0.8.2 11 * IT8712F EC-LPC I/O Preliminary Specification 0.9.3 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License as 15 * published by the Free Software Foundation; either version 2 of the 16 * License, or (at your option) any later version. 17 * 18 * The author(s) of this software shall not be held liable for damages 19 * of any nature resulting due to the use of this software. This 20 * software is provided AS-IS with no warranties. 21 */ 22 23 #include <linux/module.h> 24 #include <linux/moduleparam.h> 25 #include <linux/init.h> 26 #include <linux/miscdevice.h> 27 #include <linux/watchdog.h> 28 #include <linux/notifier.h> 29 #include <linux/reboot.h> 30 #include <linux/fs.h> 31 #include <linux/pci.h> 32 #include <linux/spinlock.h> 33 #include <linux/uaccess.h> 34 #include <linux/io.h> 35 36 #define NAME "it8712f_wdt" 37 38 MODULE_AUTHOR("Jorge Boncompte - DTI2 <jorge@dti2.net>"); 39 MODULE_DESCRIPTION("IT8712F Watchdog Driver"); 40 MODULE_LICENSE("GPL"); 41 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 42 43 static int max_units = 255; 44 static int margin = 60; /* in seconds */ 45 module_param(margin, int, 0); 46 MODULE_PARM_DESC(margin, "Watchdog margin in seconds"); 47 48 static int nowayout = WATCHDOG_NOWAYOUT; 49 module_param(nowayout, int, 0); 50 MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close"); 51 52 static unsigned long wdt_open; 53 static unsigned expect_close; 54 static spinlock_t io_lock; 55 static unsigned char revision; 56 57 /* Dog Food address - We use the game port address */ 58 static unsigned short address; 59 60 #define REG 0x2e /* The register to read/write */ 61 #define VAL 0x2f /* The value to read/write */ 62 63 #define LDN 0x07 /* Register: Logical device select */ 64 #define DEVID 0x20 /* Register: Device ID */ 65 #define DEVREV 0x22 /* Register: Device Revision */ 66 #define ACT_REG 0x30 /* LDN Register: Activation */ 67 #define BASE_REG 0x60 /* LDN Register: Base address */ 68 69 #define IT8712F_DEVID 0x8712 70 71 #define LDN_GPIO 0x07 /* GPIO and Watch Dog Timer */ 72 #define LDN_GAME 0x09 /* Game Port */ 73 74 #define WDT_CONTROL 0x71 /* WDT Register: Control */ 75 #define WDT_CONFIG 0x72 /* WDT Register: Configuration */ 76 #define WDT_TIMEOUT 0x73 /* WDT Register: Timeout Value */ 77 78 #define WDT_RESET_GAME 0x10 /* Reset timer on read or write to game port */ 79 #define WDT_RESET_KBD 0x20 /* Reset timer on keyboard interrupt */ 80 #define WDT_RESET_MOUSE 0x40 /* Reset timer on mouse interrupt */ 81 #define WDT_RESET_CIR 0x80 /* Reset timer on consumer IR interrupt */ 82 83 #define WDT_UNIT_SEC 0x80 /* If 0 in MINUTES */ 84 85 #define WDT_OUT_PWROK 0x10 /* Pulse PWROK on timeout */ 86 #define WDT_OUT_KRST 0x40 /* Pulse reset on timeout */ 87 88 static int wdt_control_reg = WDT_RESET_GAME; 89 module_param(wdt_control_reg, int, 0); 90 MODULE_PARM_DESC(wdt_control_reg, "Value to write to watchdog control " 91 "register. The default WDT_RESET_GAME resets the timer on " 92 "game port reads that this driver generates. You can also " 93 "use KBD, MOUSE or CIR if you have some external way to " 94 "generate those interrupts."); 95 96 static int superio_inb(int reg) 97 { 98 outb(reg, REG); 99 return inb(VAL); 100 } 101 102 static void superio_outb(int val, int reg) 103 { 104 outb(reg, REG); 105 outb(val, VAL); 106 } 107 108 static int superio_inw(int reg) 109 { 110 int val; 111 outb(reg++, REG); 112 val = inb(VAL) << 8; 113 outb(reg, REG); 114 val |= inb(VAL); 115 return val; 116 } 117 118 static inline void superio_select(int ldn) 119 { 120 outb(LDN, REG); 121 outb(ldn, VAL); 122 } 123 124 static inline void superio_enter(void) 125 { 126 spin_lock(&io_lock); 127 outb(0x87, REG); 128 outb(0x01, REG); 129 outb(0x55, REG); 130 outb(0x55, REG); 131 } 132 133 static inline void superio_exit(void) 134 { 135 outb(0x02, REG); 136 outb(0x02, VAL); 137 spin_unlock(&io_lock); 138 } 139 140 static inline void it8712f_wdt_ping(void) 141 { 142 if (wdt_control_reg & WDT_RESET_GAME) 143 inb(address); 144 } 145 146 static void it8712f_wdt_update_margin(void) 147 { 148 int config = WDT_OUT_KRST | WDT_OUT_PWROK; 149 int units = margin; 150 151 /* Switch to minutes precision if the configured margin 152 * value does not fit within the register width. 153 */ 154 if (units <= max_units) { 155 config |= WDT_UNIT_SEC; /* else UNIT is MINUTES */ 156 printk(KERN_INFO NAME ": timer margin %d seconds\n", units); 157 } else { 158 units /= 60; 159 printk(KERN_INFO NAME ": timer margin %d minutes\n", units); 160 } 161 superio_outb(config, WDT_CONFIG); 162 163 if (revision >= 0x08) 164 superio_outb(units >> 8, WDT_TIMEOUT + 1); 165 superio_outb(units, WDT_TIMEOUT); 166 } 167 168 static int it8712f_wdt_get_status(void) 169 { 170 if (superio_inb(WDT_CONTROL) & 0x01) 171 return WDIOF_CARDRESET; 172 else 173 return 0; 174 } 175 176 static void it8712f_wdt_enable(void) 177 { 178 printk(KERN_DEBUG NAME ": enabling watchdog timer\n"); 179 superio_enter(); 180 superio_select(LDN_GPIO); 181 182 superio_outb(wdt_control_reg, WDT_CONTROL); 183 184 it8712f_wdt_update_margin(); 185 186 superio_exit(); 187 188 it8712f_wdt_ping(); 189 } 190 191 static void it8712f_wdt_disable(void) 192 { 193 printk(KERN_DEBUG NAME ": disabling watchdog timer\n"); 194 195 superio_enter(); 196 superio_select(LDN_GPIO); 197 198 superio_outb(0, WDT_CONFIG); 199 superio_outb(0, WDT_CONTROL); 200 if (revision >= 0x08) 201 superio_outb(0, WDT_TIMEOUT + 1); 202 superio_outb(0, WDT_TIMEOUT); 203 204 superio_exit(); 205 } 206 207 static int it8712f_wdt_notify(struct notifier_block *this, 208 unsigned long code, void *unused) 209 { 210 if (code == SYS_HALT || code == SYS_POWER_OFF) 211 if (!nowayout) 212 it8712f_wdt_disable(); 213 214 return NOTIFY_DONE; 215 } 216 217 static struct notifier_block it8712f_wdt_notifier = { 218 .notifier_call = it8712f_wdt_notify, 219 }; 220 221 static ssize_t it8712f_wdt_write(struct file *file, const char __user *data, 222 size_t len, loff_t *ppos) 223 { 224 /* check for a magic close character */ 225 if (len) { 226 size_t i; 227 228 it8712f_wdt_ping(); 229 230 expect_close = 0; 231 for (i = 0; i < len; ++i) { 232 char c; 233 if (get_user(c, data + i)) 234 return -EFAULT; 235 if (c == 'V') 236 expect_close = 42; 237 } 238 } 239 240 return len; 241 } 242 243 static long it8712f_wdt_ioctl(struct file *file, unsigned int cmd, 244 unsigned long arg) 245 { 246 void __user *argp = (void __user *)arg; 247 int __user *p = argp; 248 static const struct watchdog_info ident = { 249 .identity = "IT8712F Watchdog", 250 .firmware_version = 1, 251 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | 252 WDIOF_MAGICCLOSE, 253 }; 254 int value; 255 256 switch (cmd) { 257 case WDIOC_GETSUPPORT: 258 if (copy_to_user(argp, &ident, sizeof(ident))) 259 return -EFAULT; 260 return 0; 261 case WDIOC_GETSTATUS: 262 superio_enter(); 263 superio_select(LDN_GPIO); 264 265 value = it8712f_wdt_get_status(); 266 267 superio_exit(); 268 269 return put_user(value, p); 270 case WDIOC_GETBOOTSTATUS: 271 return put_user(0, p); 272 case WDIOC_KEEPALIVE: 273 it8712f_wdt_ping(); 274 return 0; 275 case WDIOC_SETTIMEOUT: 276 if (get_user(value, p)) 277 return -EFAULT; 278 if (value < 1) 279 return -EINVAL; 280 if (value > (max_units * 60)) 281 return -EINVAL; 282 margin = value; 283 superio_enter(); 284 superio_select(LDN_GPIO); 285 286 it8712f_wdt_update_margin(); 287 288 superio_exit(); 289 it8712f_wdt_ping(); 290 /* Fall through */ 291 case WDIOC_GETTIMEOUT: 292 if (put_user(margin, p)) 293 return -EFAULT; 294 return 0; 295 default: 296 return -ENOTTY; 297 } 298 } 299 300 static int it8712f_wdt_open(struct inode *inode, struct file *file) 301 { 302 /* only allow one at a time */ 303 if (test_and_set_bit(0, &wdt_open)) 304 return -EBUSY; 305 it8712f_wdt_enable(); 306 return nonseekable_open(inode, file); 307 } 308 309 static int it8712f_wdt_release(struct inode *inode, struct file *file) 310 { 311 if (expect_close != 42) { 312 printk(KERN_WARNING NAME 313 ": watchdog device closed unexpectedly, will not" 314 " disable the watchdog timer\n"); 315 } else if (!nowayout) { 316 it8712f_wdt_disable(); 317 } 318 expect_close = 0; 319 clear_bit(0, &wdt_open); 320 321 return 0; 322 } 323 324 static const struct file_operations it8712f_wdt_fops = { 325 .owner = THIS_MODULE, 326 .llseek = no_llseek, 327 .write = it8712f_wdt_write, 328 .unlocked_ioctl = it8712f_wdt_ioctl, 329 .open = it8712f_wdt_open, 330 .release = it8712f_wdt_release, 331 }; 332 333 static struct miscdevice it8712f_wdt_miscdev = { 334 .minor = WATCHDOG_MINOR, 335 .name = "watchdog", 336 .fops = &it8712f_wdt_fops, 337 }; 338 339 static int __init it8712f_wdt_find(unsigned short *address) 340 { 341 int err = -ENODEV; 342 int chip_type; 343 344 superio_enter(); 345 chip_type = superio_inw(DEVID); 346 if (chip_type != IT8712F_DEVID) 347 goto exit; 348 349 superio_select(LDN_GAME); 350 superio_outb(1, ACT_REG); 351 if (!(superio_inb(ACT_REG) & 0x01)) { 352 printk(KERN_ERR NAME ": Device not activated, skipping\n"); 353 goto exit; 354 } 355 356 *address = superio_inw(BASE_REG); 357 if (*address == 0) { 358 printk(KERN_ERR NAME ": Base address not set, skipping\n"); 359 goto exit; 360 } 361 362 err = 0; 363 revision = superio_inb(DEVREV) & 0x0f; 364 365 /* Later revisions have 16-bit values per datasheet 0.9.1 */ 366 if (revision >= 0x08) 367 max_units = 65535; 368 369 if (margin > (max_units * 60)) 370 margin = (max_units * 60); 371 372 printk(KERN_INFO NAME ": Found IT%04xF chip revision %d - " 373 "using DogFood address 0x%x\n", 374 chip_type, revision, *address); 375 376 exit: 377 superio_exit(); 378 return err; 379 } 380 381 static int __init it8712f_wdt_init(void) 382 { 383 int err = 0; 384 385 spin_lock_init(&io_lock); 386 387 if (it8712f_wdt_find(&address)) 388 return -ENODEV; 389 390 if (!request_region(address, 1, "IT8712F Watchdog")) { 391 printk(KERN_WARNING NAME ": watchdog I/O region busy\n"); 392 return -EBUSY; 393 } 394 395 it8712f_wdt_disable(); 396 397 err = register_reboot_notifier(&it8712f_wdt_notifier); 398 if (err) { 399 printk(KERN_ERR NAME ": unable to register reboot notifier\n"); 400 goto out; 401 } 402 403 err = misc_register(&it8712f_wdt_miscdev); 404 if (err) { 405 printk(KERN_ERR NAME 406 ": cannot register miscdev on minor=%d (err=%d)\n", 407 WATCHDOG_MINOR, err); 408 goto reboot_out; 409 } 410 411 return 0; 412 413 414 reboot_out: 415 unregister_reboot_notifier(&it8712f_wdt_notifier); 416 out: 417 release_region(address, 1); 418 return err; 419 } 420 421 static void __exit it8712f_wdt_exit(void) 422 { 423 misc_deregister(&it8712f_wdt_miscdev); 424 unregister_reboot_notifier(&it8712f_wdt_notifier); 425 release_region(address, 1); 426 } 427 428 module_init(it8712f_wdt_init); 429 module_exit(it8712f_wdt_exit); 430