release/src-rt-6.x/linux/linux-2.6/drivers/char/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 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 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 spinlock_t 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 <=63, 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         outb_p(0xF5, WDT_EFER); /* Select CRF5 */
 118         t=inb_p(WDT_EFDR);      /* read CRF5 */
 119         t&=~0x0C;               /* set second mode & disable keyboard turning off watchdog */
 120         outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
 121
 122         w83627hf_unselect_wd_register();
 123 }
 124
 125 static void
 126 wdt_ctrl(int timeout)
 127 {
 128         spin_lock(&io_lock);
 129
 130         w83627hf_select_wd_register();
 131
 132         outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
 133         outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
 134
 135         w83627hf_unselect_wd_register();
 136
 137         spin_unlock(&io_lock);
 138 }
 139
 140 static int
 141 wdt_ping(void)
 142 {
 143         wdt_ctrl(timeout);
 144         return 0;
 145 }
 146
 147 static int
 148 wdt_disable(void)
 149 {
 150         wdt_ctrl(0);
 151         return 0;
 152 }
 153
 154 static int
 155 wdt_set_heartbeat(int t)
 156 {
 157         if ((t < 1) || (t > 63))
 158                 return -EINVAL;
 159
 160         timeout = t;
 161         return 0;
 162 }
 163
 164 static ssize_t
 165 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
 166 {
 167         if (count) {
 168                 if (!nowayout) {
 169                         size_t i;
 170
 171                         expect_close = 0;
 172
 173                         for (i = 0; i != count; i++) {
 174                                 char c;
 175                                 if (get_user(c, buf+i))
 176                                         return -EFAULT;
 177                                 if (c == 'V')
 178                                         expect_close = 42;
 179                         }
 180                 }
 181                 wdt_ping();
 182         }
 183         return count;
 184 }
 185
 186 static int
 187 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 188           unsigned long arg)
 189 {
 190         void __user *argp = (void __user *)arg;
 191         int __user *p = argp;
 192         int new_timeout;
 193         static struct watchdog_info ident = {
 194                 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 195                 .firmware_version = 1,
 196                 .identity = "W83627HF WDT",
 197         };
 198
 199         switch (cmd) {
 200         case WDIOC_GETSUPPORT:
 201           if (copy_to_user(argp, &ident, sizeof(ident)))
 202             return -EFAULT;
 203           break;
 204
 205         case WDIOC_GETSTATUS:
 206         case WDIOC_GETBOOTSTATUS:
 207           return put_user(0, p);
 208
 209         case WDIOC_KEEPALIVE:
 210           wdt_ping();
 211           break;
 212
 213         case WDIOC_SETTIMEOUT:
 214           if (get_user(new_timeout, p))
 215                   return -EFAULT;
 216           if (wdt_set_heartbeat(new_timeout))
 217                   return -EINVAL;
 218           wdt_ping();
 219           /* Fall */
 220
 221         case WDIOC_GETTIMEOUT:
 222           return put_user(timeout, p);
 223
 224         case WDIOC_SETOPTIONS:
 225         {
 226           int options, retval = -EINVAL;
 227
 228           if (get_user(options, p))
 229             return -EFAULT;
 230
 231           if (options & WDIOS_DISABLECARD) {
 232             wdt_disable();
 233             retval = 0;
 234           }
 235
 236           if (options & WDIOS_ENABLECARD) {
 237             wdt_ping();
 238             retval = 0;
 239           }
 240
 241           return retval;
 242         }
 243
 244         default:
 245           return -ENOTTY;
 246         }
 247         return 0;
 248 }
 249
 250 static int
 251 wdt_open(struct inode *inode, struct file *file)
 252 {
 253         if (test_and_set_bit(0, &wdt_is_open))
 254                 return -EBUSY;
 255         /*
 256          *      Activate
 257          */
 258
 259         wdt_ping();
 260         return nonseekable_open(inode, file);
 261 }
 262
 263 static int
 264 wdt_close(struct inode *inode, struct file *file)
 265 {
 266         if (expect_close == 42) {
 267                 wdt_disable();
 268         } else {
 269                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 270                 wdt_ping();
 271         }
 272         expect_close = 0;
 273         clear_bit(0, &wdt_is_open);
 274         return 0;
 275 }
 276
 277 /*
 278  *      Notifier for system down
 279  */
 280
 281 static int
 282 wdt_notify_sys(struct notifier_block *this, unsigned long code,
 283         void *unused)
 284 {
 285         if (code == SYS_DOWN || code == SYS_HALT) {
 286                 /* Turn the WDT off */
 287                 wdt_disable();
 288         }
 289         return NOTIFY_DONE;
 290 }
 291
 292 /*
 293  *      Kernel Interfaces
 294  */
 295
 296 static const struct file_operations wdt_fops = {
 297         .owner          = THIS_MODULE,
 298         .llseek         = no_llseek,
 299         .write          = wdt_write,
 300         .ioctl          = wdt_ioctl,
 301         .open           = wdt_open,
 302         .release        = wdt_close,
 303 };
 304
 305 static 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
 316 static struct notifier_block wdt_notifier = {
 317         .notifier_call = wdt_notify_sys,
 318 };
 319
 320 static int __init
 321 wdt_init(void)
 322 {
 323         int ret;
 324
 325         spin_lock_init(&io_lock);
 326
 327         printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF Super I/O chip initialising.\n");
 328
 329         if (wdt_set_heartbeat(timeout)) {
 330                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 331                 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=63, using %d\n",
 332                         WATCHDOG_TIMEOUT);
 333         }
 334
 335         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
 336                 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
 337                         wdt_io);
 338                 ret = -EIO;
 339                 goto out;
 340         }
 341
 342         w83627hf_init();
 343
 344         ret = register_reboot_notifier(&wdt_notifier);
 345         if (ret != 0) {
 346                 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 347                         ret);
 348                 goto unreg_regions;
 349         }
 350
 351         ret = misc_register(&wdt_miscdev);
 352         if (ret != 0) {
 353                 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 354                         WATCHDOG_MINOR, ret);
 355                 goto unreg_reboot;
 356         }
 357
 358         printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
 359                 timeout, nowayout);
 360
 361 out:
 362         return ret;
 363 unreg_reboot:
 364         unregister_reboot_notifier(&wdt_notifier);
 365 unreg_regions:
 366         release_region(wdt_io, 1);
 367         goto out;
 368 }
 369
 370 static void __exit
 371 wdt_exit(void)
 372 {
 373         misc_deregister(&wdt_miscdev);
 374         unregister_reboot_notifier(&wdt_notifier);
 375         release_region(wdt_io,1);
 376 }
 377
 378 module_init(wdt_init);
 379 module_exit(wdt_exit);
 380
 381 MODULE_LICENSE("GPL");
 382 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
 383 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
 384 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);