drivers/watchdog/w83627hf_wdt.c

   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@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("Pádraig Brady <P@draigBrady.com>");
 387 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
 388 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);