Pileus Git - ~andy/linux/blob - drivers/watchdog/w83697ug_wdt.c

   1 /*
   2  *      w83697ug/uf WDT driver
   3  *
   4  *      (c) Copyright 2008 Flemming Fransen <ff@nrvissing.net>
   5  *              reused original code to support w83697ug/uf.
   6  *
   7  *      Based on w83627hf_wdt.c which is based on advantechwdt.c
   8  *      which is based on wdt.c.
   9  *      Original copyright messages:
  10  *
  11  *      (c) Copyright 2007 Vlad Drukker <vlad@storewiz.com>
  12  *              added support for W83627THF.
  13  *
  14  *      (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
  15  *
  16  *      (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
  17  *
  18  *      (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
  19  *                              http://www.redhat.com
  20  *
  21  *      This program is free software; you can redistribute it and/or
  22  *      modify it under the terms of the GNU General Public License
  23  *      as published by the Free Software Foundation; either version
  24  *      2 of the License, or (at your option) any later version.
  25  *
  26  *      Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
  27  *      warranty for any of this software. This material is provided
  28  *      "AS-IS" and at no charge.
  29  *
  30  *      (c) Copyright 1995    Alan Cox <alan@redhat.com>
  31  */
  32
  33 #include <linux/module.h>
  34 #include <linux/moduleparam.h>
  35 #include <linux/types.h>
  36 #include <linux/miscdevice.h>
  37 #include <linux/watchdog.h>
  38 #include <linux/fs.h>
  39 #include <linux/ioport.h>
  40 #include <linux/notifier.h>
  41 #include <linux/reboot.h>
  42 #include <linux/init.h>
  43 #include <linux/spinlock.h>
  44 #include <linux/io.h>
  45 #include <linux/uaccess.h>
  46
  47
  48 #define WATCHDOG_NAME "w83697ug/uf WDT"
  49 #define PFX WATCHDOG_NAME ": "
  50 #define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
  51
  52 static unsigned long wdt_is_open;
  53 static char expect_close;
  54 static DEFINE_SPINLOCK(io_lock);
  55
  56 static int wdt_io = 0x2e;
  57 module_param(wdt_io, int, 0);
  58 MODULE_PARM_DESC(wdt_io, "w83697ug/uf WDT io port (default 0x2e)");
  59
  60 static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
  61 module_param(timeout, int, 0);
  62 MODULE_PARM_DESC(timeout,
  63         "Watchdog timeout in seconds. 1<= timeout <=255 (default="
  64                                 __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
  65
  66 static int nowayout = WATCHDOG_NOWAYOUT;
  67 module_param(nowayout, int, 0);
  68 MODULE_PARM_DESC(nowayout,
  69         "Watchdog cannot be stopped once started (default="
  70                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  71
  72 /*
  73  *      Kernel methods.
  74  */
  75
  76 #define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
  77 #define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register
  78                                                         (same as EFER) */
  79 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
  80
  81 static int w83697ug_select_wd_register(void)
  82 {
  83         unsigned char c;
  84         unsigned char version;
  85
  86         outb_p(0x87, WDT_EFER); /* Enter extended function mode */
  87         outb_p(0x87, WDT_EFER); /* Again according to manual */
  88
  89         outb(0x20, WDT_EFER);   /* check chip version   */
  90         version = inb(WDT_EFDR);
  91
  92         if (version == 0x68) {  /* W83697UG             */
  93                 printk(KERN_INFO PFX "Watchdog chip version 0x%02x = "
  94                         "W83697UG/UF found at 0x%04x\n", version, wdt_io);
  95
  96                 outb_p(0x2b, WDT_EFER);
  97                 c = inb_p(WDT_EFDR);    /* select WDT0 */
  98                 c &= ~0x04;
  99                 outb_p(0x2b, WDT_EFER);
 100                 outb_p(c, WDT_EFDR);    /* set pin118 to WDT0 */
 101
 102         } else {
 103                 printk(KERN_ERR PFX "No W83697UG/UF could be found\n");
 104                 return -ENODEV;
 105         }
 106
 107         outb_p(0x07, WDT_EFER); /* point to logical device number reg */
 108         outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
 109         outb_p(0x30, WDT_EFER); /* select CR30 */
 110         c = inb_p(WDT_EFDR);
 111         outb_p(c | 0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
 112
 113         return 0;
 114 }
 115
 116 static void w83697ug_unselect_wd_register(void)
 117 {
 118         outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
 119 }
 120
 121 static int w83697ug_init(void)
 122 {
 123         int ret;
 124         unsigned char t;
 125
 126         ret = w83697ug_select_wd_register();
 127         if (ret != 0)
 128                 return ret;
 129
 130         outb_p(0xF6, WDT_EFER); /* Select CRF6 */
 131         t = inb_p(WDT_EFDR);    /* read CRF6 */
 132         if (t != 0) {
 133                 printk(KERN_INFO PFX "Watchdog already running."
 134                         " Resetting timeout to %d sec\n", timeout);
 135                 outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
 136         }
 137         outb_p(0xF5, WDT_EFER); /* Select CRF5 */
 138         t = inb_p(WDT_EFDR);    /* read CRF5 */
 139         t &= ~0x0C;             /* set second mode &
 140                                         disable keyboard turning off watchdog */
 141         outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
 142
 143         w83697ug_unselect_wd_register();
 144         return 0;
 145 }
 146
 147 static void wdt_ctrl(int timeout)
 148 {
 149         spin_lock(&io_lock);
 150
 151         if (w83697ug_select_wd_register() < 0) {
 152                 spin_unlock(&io_lock);
 153                 return;
 154         }
 155
 156         outb_p(0xF4, WDT_EFER);    /* Select CRF4 */
 157         outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
 158
 159         w83697ug_unselect_wd_register();
 160
 161         spin_unlock(&io_lock);
 162 }
 163
 164 static int wdt_ping(void)
 165 {
 166         wdt_ctrl(timeout);
 167         return 0;
 168 }
 169
 170 static int wdt_disable(void)
 171 {
 172         wdt_ctrl(0);
 173         return 0;
 174 }
 175
 176 static int wdt_set_heartbeat(int t)
 177 {
 178         if (t < 1 || t > 255)
 179                 return -EINVAL;
 180
 181         timeout = t;
 182         return 0;
 183 }
 184
 185 static ssize_t wdt_write(struct file *file, const char __user *buf,
 186                                                 size_t count, loff_t *ppos)
 187 {
 188         if (count) {
 189                 if (!nowayout) {
 190                         size_t i;
 191
 192                         expect_close = 0;
 193
 194                         for (i = 0; i != count; i++) {
 195                                 char c;
 196                                 if (get_user(c, buf + i))
 197                                         return -EFAULT;
 198                                 if (c == 'V')
 199                                         expect_close = 42;
 200                         }
 201                 }
 202                 wdt_ping();
 203         }
 204         return count;
 205 }
 206
 207 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 208 {
 209         void __user *argp = (void __user *)arg;
 210         int __user *p = argp;
 211         int new_timeout;
 212         static const struct watchdog_info ident = {
 213                 .options =              WDIOF_KEEPALIVEPING |
 214                                         WDIOF_SETTIMEOUT |
 215                                         WDIOF_MAGICCLOSE,
 216                 .firmware_version =     1,
 217                 .identity =             "W83697UG WDT",
 218         };
 219
 220         switch (cmd) {
 221         case WDIOC_GETSUPPORT:
 222                 if (copy_to_user(argp, &ident, sizeof(ident)))
 223                         return -EFAULT;
 224                 break;
 225
 226         case WDIOC_GETSTATUS:
 227         case WDIOC_GETBOOTSTATUS:
 228                 return put_user(0, 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         case WDIOC_KEEPALIVE:
 251                 wdt_ping();
 252                 break;
 253
 254         case WDIOC_SETTIMEOUT:
 255                 if (get_user(new_timeout, p))
 256                         return -EFAULT;
 257                 if (wdt_set_heartbeat(new_timeout))
 258                         return -EINVAL;
 259                 wdt_ping();
 260                 /* Fall */
 261
 262         case WDIOC_GETTIMEOUT:
 263                 return put_user(timeout, p);
 264
 265         default:
 266                 return -ENOTTY;
 267         }
 268         return 0;
 269 }
 270
 271 static int wdt_open(struct inode *inode, struct file *file)
 272 {
 273         if (test_and_set_bit(0, &wdt_is_open))
 274                 return -EBUSY;
 275         /*
 276          *      Activate
 277          */
 278
 279         wdt_ping();
 280         return nonseekable_open(inode, file);
 281 }
 282
 283 static int wdt_close(struct inode *inode, struct file *file)
 284 {
 285         if (expect_close == 42)
 286                 wdt_disable();
 287         else {
 288                 printk(KERN_CRIT PFX
 289                         "Unexpected close, not stopping watchdog!\n");
 290                 wdt_ping();
 291         }
 292         expect_close = 0;
 293         clear_bit(0, &wdt_is_open);
 294         return 0;
 295 }
 296
 297 /*
 298  *      Notifier for system down
 299  */
 300
 301 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
 302         void *unused)
 303 {
 304         if (code == SYS_DOWN || code == SYS_HALT)
 305                 wdt_disable();  /* Turn the WDT off */
 306
 307         return NOTIFY_DONE;
 308 }
 309
 310 /*
 311  *      Kernel Interfaces
 312  */
 313
 314 static const struct file_operations wdt_fops = {
 315         .owner          = THIS_MODULE,
 316         .llseek         = no_llseek,
 317         .write          = wdt_write,
 318         .unlocked_ioctl = wdt_ioctl,
 319         .open           = wdt_open,
 320         .release        = wdt_close,
 321 };
 322
 323 static struct miscdevice wdt_miscdev = {
 324         .minor = WATCHDOG_MINOR,
 325         .name = "watchdog",
 326         .fops = &wdt_fops,
 327 };
 328
 329 /*
 330  *      The WDT needs to learn about soft shutdowns in order to
 331  *      turn the timebomb registers off.
 332  */
 333
 334 static struct notifier_block wdt_notifier = {
 335         .notifier_call = wdt_notify_sys,
 336 };
 337
 338 static int __init wdt_init(void)
 339 {
 340         int ret;
 341
 342         printk(KERN_INFO "WDT driver for the Winbond(TM) W83697UG/UF Super I/O chip initialising.\n");
 343
 344         if (wdt_set_heartbeat(timeout)) {
 345                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 346                 printk(KERN_INFO PFX
 347                         "timeout value must be 1<=timeout<=255, using %d\n",
 348                         WATCHDOG_TIMEOUT);
 349         }
 350
 351         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
 352                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 353                         wdt_io);
 354                 ret = -EIO;
 355                 goto out;
 356         }
 357
 358         ret = w83697ug_init();
 359         if (ret != 0)
 360                 goto unreg_regions;
 361
 362         ret = register_reboot_notifier(&wdt_notifier);
 363         if (ret != 0) {
 364                 printk(KERN_ERR PFX
 365                         "cannot register reboot notifier (err=%d)\n", ret);
 366                 goto unreg_regions;
 367         }
 368
 369         ret = misc_register(&wdt_miscdev);
 370         if (ret != 0) {
 371                 printk(KERN_ERR PFX
 372                         "cannot register miscdev on minor=%d (err=%d)\n",
 373                         WATCHDOG_MINOR, ret);
 374                 goto unreg_reboot;
 375         }
 376
 377         printk(KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
 378                 timeout, nowayout);
 379
 380 out:
 381         return ret;
 382 unreg_reboot:
 383         unregister_reboot_notifier(&wdt_notifier);
 384 unreg_regions:
 385         release_region(wdt_io, 1);
 386         goto out;
 387 }
 388
 389 static void __exit wdt_exit(void)
 390 {
 391         misc_deregister(&wdt_miscdev);
 392         unregister_reboot_notifier(&wdt_notifier);
 393         release_region(wdt_io, 1);
 394 }
 395
 396 module_init(wdt_init);
 397 module_exit(wdt_exit);
 398
 399 MODULE_LICENSE("GPL");
 400 MODULE_AUTHOR("Flemming Frandsen <ff@nrvissing.net>");
 401 MODULE_DESCRIPTION("w83697ug/uf WDT driver");
 402 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);