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 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) { /* W83627EHF */ 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 outb_p(t, WDT_EFDR); /* Write back to CRF5 */ 133 134 outb_p(0xF7, WDT_EFER); /* Select CRF7 */ 135 t = inb_p(WDT_EFDR); /* read CRF7 */ 136 t &= ~0xC0; /* disable keyboard & mouse turning off 137 watchdog */ 138 outb_p(t, WDT_EFDR); /* Write back to CRF7 */ 139 140 w83627hf_unselect_wd_register(); 141} 142 143static void wdt_ctrl(int timeout) 144{ 145 spin_lock(&io_lock); 146 147 w83627hf_select_wd_register(); 148 149 outb_p(0xF6, WDT_EFER); /* Select CRF6 */ 150 outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */ 151 152 w83627hf_unselect_wd_register(); 153 154 spin_unlock(&io_lock); 155} 156 157static int wdt_ping(void) 158{ 159 wdt_ctrl(timeout); 160 return 0; 161} 162 163static int wdt_disable(void) 164{ 165 wdt_ctrl(0); 166 return 0; 167} 168 169static int wdt_set_heartbeat(int t) 170{ 171 if (t < 1 || t > 255) 172 return -EINVAL; 173 timeout = t; 174 return 0; 175} 176 177static ssize_t wdt_write(struct file *file, const char __user *buf, 178 size_t count, loff_t *ppos) 179{ 180 if (count) { 181 if (!nowayout) { 182 size_t i; 183 184 expect_close = 0; 185 186 for (i = 0; i != count; i++) { 187 char c; 188 if (get_user(c, buf + i)) 189 return -EFAULT; 190 if (c == 'V') 191 expect_close = 42; 192 } 193 } 194 wdt_ping(); 195 } 196 return count; 197} 198 199static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 200{ 201 void __user *argp = (void __user *)arg; 202 int __user *p = argp; 203 int new_timeout; 204 static const struct watchdog_info ident = { 205 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | 206 WDIOF_MAGICCLOSE, 207 .firmware_version = 1, 208 .identity = "W83627HF WDT", 209 }; 210 211 switch (cmd) { 212 case WDIOC_GETSUPPORT: 213 if (copy_to_user(argp, &ident, sizeof(ident))) 214 return -EFAULT; 215 break; 216 case WDIOC_GETSTATUS: 217 case WDIOC_GETBOOTSTATUS: 218 return put_user(0, p); 219 case WDIOC_SETOPTIONS: 220 { 221 int options, retval = -EINVAL; 222 223 if (get_user(options, p)) 224 return -EFAULT; 225 if (options & WDIOS_DISABLECARD) { 226 wdt_disable(); 227 retval = 0; 228 } 229 if (options & WDIOS_ENABLECARD) { 230 wdt_ping(); 231 retval = 0; 232 } 233 return retval; 234 } 235 case WDIOC_KEEPALIVE: 236 wdt_ping(); 237 break; 238 case WDIOC_SETTIMEOUT: 239 if (get_user(new_timeout, p)) 240 return -EFAULT; 241 if (wdt_set_heartbeat(new_timeout)) 242 return -EINVAL; 243 wdt_ping(); 244 /* Fall */ 245 case WDIOC_GETTIMEOUT: 246 return put_user(timeout, p); 247 default: 248 return -ENOTTY; 249 } 250 return 0; 251} 252 253static int wdt_open(struct inode *inode, struct file *file) 254{ 255 if (test_and_set_bit(0, &wdt_is_open)) 256 return -EBUSY; 257 /* 258 * Activate 259 */ 260 261 wdt_ping(); 262 return nonseekable_open(inode, file); 263} 264 265static int wdt_close(struct inode *inode, struct file *file) 266{ 267 if (expect_close == 42) 268 wdt_disable(); 269 else { 270 printk(KERN_CRIT PFX 271 "Unexpected close, not stopping watchdog!\n"); 272 wdt_ping(); 273 } 274 expect_close = 0; 275 clear_bit(0, &wdt_is_open); 276 return 0; 277} 278 279/* 280 * Notifier for system down 281 */ 282 283static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 284 void *unused) 285{ 286 if (code == SYS_DOWN || code == SYS_HALT) 287 wdt_disable(); /* Turn the WDT off */ 288 289 return NOTIFY_DONE; 290} 291 292/* 293 * Kernel Interfaces 294 */ 295 296static const struct file_operations wdt_fops = { 297 .owner = THIS_MODULE, 298 .llseek = no_llseek, 299 .write = wdt_write, 300 .unlocked_ioctl = wdt_ioctl, 301 .open = wdt_open, 302 .release = wdt_close, 303}; 304 305static struct miscdevice wdt_miscdev = { 306 .minor = WATCHDOG_MINOR, 307 .name = "watchdog", 308 .fops = &wdt_fops, 309}; 310 311/* 312 * The WDT needs to learn about soft shutdowns in order to 313 * turn the timebomb registers off. 314 */ 315 316static struct notifier_block wdt_notifier = { 317 .notifier_call = wdt_notify_sys, 318}; 319 320static int __init wdt_init(void) 321{ 322 int ret; 323 324 printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n"); 325 326 if (wdt_set_heartbeat(timeout)) { 327 wdt_set_heartbeat(WATCHDOG_TIMEOUT); 328 printk(KERN_INFO PFX 329 "timeout value must be 1 <= timeout <= 255, using %d\n", 330 WATCHDOG_TIMEOUT); 331 } 332 333 if (!request_region(wdt_io, 1, WATCHDOG_NAME)) { 334 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", 335 wdt_io); 336 ret = -EIO; 337 goto out; 338 } 339 340 w83627hf_init(); 341 342 ret = register_reboot_notifier(&wdt_notifier); 343 if (ret != 0) { 344 printk(KERN_ERR PFX 345 "cannot register reboot notifier (err=%d)\n", ret); 346 goto unreg_regions; 347 } 348 349 ret = misc_register(&wdt_miscdev); 350 if (ret != 0) { 351 printk(KERN_ERR PFX 352 "cannot register miscdev on minor=%d (err=%d)\n", 353 WATCHDOG_MINOR, ret); 354 goto unreg_reboot; 355 } 356 357 printk(KERN_INFO PFX 358 "initialized. timeout=%d sec (nowayout=%d)\n", 359 timeout, nowayout); 360 361out: 362 return ret; 363unreg_reboot: 364 unregister_reboot_notifier(&wdt_notifier); 365unreg_regions: 366 release_region(wdt_io, 1); 367 goto out; 368} 369 370static void __exit wdt_exit(void) 371{ 372 misc_deregister(&wdt_miscdev); 373 unregister_reboot_notifier(&wdt_notifier); 374 release_region(wdt_io, 1); 375} 376 377module_init(wdt_init); 378module_exit(wdt_exit); 379 380MODULE_LICENSE("GPL"); 381MODULE_AUTHOR("P�draig Brady <P@draigBrady.com>"); 382MODULE_DESCRIPTION("w83627hf/thf WDT driver"); 383MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); 384