drivers/char/watchdog/w83697hf_wdt.c

   1 /*
   2  *      w83697hf WDT driver
   3  *
   4  *      (c) Copyright 2006 Marcus Junker <junker@anduras.de>
   5  *
   6  *      Based on w83627hf_wdt.c advantechwdt.c which is based on wdt.c.
   7  *      Original copyright messages:
   8  *
   9  *     (c) Copyright 2003 Pádraig Brady <P@draigBrady.com>
  10  *
  11  *      (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
  12  *
  13  *      (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
  14  *                              http://www.redhat.com
  15  *
  16  *      This program is free software; you can redistribute it and/or
  17  *      modify it under the terms of the GNU General Public License
  18  *      as published by the Free Software Foundation; either version
  19  *      2 of the License, or (at your option) any later version.
  20  *
  21  *      Neither Marcus Junker nor ANDURAS AG admit liability nor provide
  22  *      warranty for any of this software. This material is provided
  23  *      "AS-IS" and at no charge.
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/types.h>
  29 #include <linux/miscdevice.h>
  30 #include <linux/watchdog.h>
  31 #include <linux/fs.h>
  32 #include <linux/ioport.h>
  33 #include <linux/notifier.h>
  34 #include <linux/reboot.h>
  35 #include <linux/init.h>
  36 #include <linux/spinlock.h>
  37
  38 #include <asm/io.h>
  39 #include <asm/uaccess.h>
  40 #include <asm/system.h>
  41
  42 #define WATCHDOG_NAME "w83697hf WDT"
  43 #define PFX WATCHDOG_NAME ": "
  44 #define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
  45
  46 static unsigned long wdt_is_open;
  47 static char expect_close;
  48 static spinlock_t io_lock;
  49
  50 /* You must set this - there is no sane way to probe for this board. */
  51 static int wdt_io = 0x2E;
  52 module_param(wdt_io, int, 0);
  53 MODULE_PARM_DESC(wdt_io, "w83697hf WDT io port (default 0x2E)");
  54
  55 static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
  56 module_param(timeout, int, 0);
  57 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. 1<= timeout <=63, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
  58
  59 static int nowayout = WATCHDOG_NOWAYOUT;
  60 module_param(nowayout, int, 0);
  61 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
  62
  63 /*
  64  *      Kernel methods.
  65  */
  66
  67 #define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
  68 #define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register (same as EFER) */
  69 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
  70
  71 static void
  72 w83697hf_select_wd_register(void)
  73 {
  74         outb_p(0x87, WDT_EFER); /* Enter extended function mode */
  75         outb_p(0x87, WDT_EFER); /* Again according to manual */
  76
  77         outb_p(0x29, WDT_EFER); /* select CR29 */
  78         outb_p(0x20, WDT_EFDR); /* select WDTO */
  79
  80         outb_p(0x07, WDT_EFER); /* point to logical device number reg */
  81         outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
  82         outb_p(0x30, WDT_EFER); /* select CR30 */
  83         outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
  84 }
  85
  86 static void
  87 w83697hf_unselect_wd_register(void)
  88 {
  89         outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
  90 }
  91
  92 /* tyan motherboards seem to set F5 to 0x4C ?
  93  * So explicitly init to appropriate value. */
  94 static void
  95 w83697hf_init(void)
  96 {
  97         unsigned char t;
  98
  99         w83697hf_select_wd_register();
 100
 101         outb_p(0xF3, WDT_EFER); /* Select CRF3 */
 102
 103         t=inb_p(WDT_EFDR);      /* read CRF6 */
 104         if (t != 0) {
 105                 printk (KERN_INFO PFX "Watchdog already running. Resetting timeout to %d sec\n", timeout);
 106                 outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
 107         }
 108         outb_p(0xF4, WDT_EFER); /* Select CRF4 */
 109         t=inb_p(WDT_EFDR);      /* read CRF4 */
 110         t&=~0x0C;               /* set second mode & disable keyboard turning off watchdog */
 111         outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
 112
 113         w83697hf_unselect_wd_register();
 114 }
 115
 116 static void
 117 wdt_ctrl(int timeout)
 118 {
 119         spin_lock(&io_lock);
 120
 121         w83697hf_select_wd_register();
 122
 123         outb_p(0xF4, WDT_EFER);    /* Select CRF4 */
 124         outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF4 */
 125
 126         w83697hf_unselect_wd_register();
 127
 128         spin_unlock(&io_lock);
 129 }
 130
 131 static int
 132 wdt_ping(void)
 133 {
 134         wdt_ctrl(timeout);
 135         return 0;
 136 }
 137
 138 static int
 139 wdt_disable(void)
 140 {
 141         wdt_ctrl(0);
 142         return 0;
 143 }
 144
 145 static int
 146 wdt_set_heartbeat(int t)
 147 {
 148         if ((t < 1) || (t > 63))
 149                 return -EINVAL;
 150
 151         timeout = t;
 152         return 0;
 153 }
 154
 155 static ssize_t
 156 wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
 157 {
 158         if (count) {
 159                 if (!nowayout) {
 160                         size_t i;
 161
 162                         expect_close = 0;
 163
 164                         for (i = 0; i != count; i++) {
 165                                 char c;
 166                                 if (get_user(c, buf+i))
 167                                         return -EFAULT;
 168                                 if (c == 'V')
 169                                         expect_close = 42;
 170                         }
 171                 }
 172                 wdt_ping();
 173         }
 174         return count;
 175 }
 176
 177 static int
 178 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 179           unsigned long arg)
 180 {
 181         void __user *argp = (void __user *)arg;
 182         int __user *p = argp;
 183         int new_timeout;
 184         static struct watchdog_info ident = {
 185                 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
 186                 .firmware_version = 1,
 187                 .identity = "W83697HF WDT",
 188         };
 189
 190         switch (cmd) {
 191         case WDIOC_GETSUPPORT:
 192           if (copy_to_user(argp, &ident, sizeof(ident)))
 193             return -EFAULT;
 194           break;
 195
 196         case WDIOC_GETSTATUS:
 197         case WDIOC_GETBOOTSTATUS:
 198           return put_user(0, p);
 199
 200         case WDIOC_KEEPALIVE:
 201           wdt_ping();
 202           break;
 203
 204         case WDIOC_SETTIMEOUT:
 205           if (get_user(new_timeout, p))
 206                   return -EFAULT;
 207           if (wdt_set_heartbeat(new_timeout))
 208                   return -EINVAL;
 209           wdt_ping();
 210           /* Fall */
 211
 212         case WDIOC_GETTIMEOUT:
 213           return put_user(timeout, p);
 214
 215         case WDIOC_SETOPTIONS:
 216         {
 217           int options, retval = -EINVAL;
 218
 219           if (get_user(options, p))
 220             return -EFAULT;
 221
 222           if (options & WDIOS_DISABLECARD) {
 223             wdt_disable();
 224             retval = 0;
 225           }
 226
 227           if (options & WDIOS_ENABLECARD) {
 228             wdt_ping();
 229             retval = 0;
 230           }
 231
 232           return retval;
 233         }
 234
 235         default:
 236           return -ENOIOCTLCMD;
 237         }
 238         return 0;
 239 }
 240
 241 static int
 242 wdt_open(struct inode *inode, struct file *file)
 243 {
 244         if (test_and_set_bit(0, &wdt_is_open))
 245                 return -EBUSY;
 246         /*
 247          *      Activate
 248          */
 249
 250         wdt_ping();
 251         return nonseekable_open(inode, file);
 252 }
 253
 254 static int
 255 wdt_close(struct inode *inode, struct file *file)
 256 {
 257         if (expect_close == 42) {
 258                 wdt_disable();
 259         } else {
 260                 printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
 261                 wdt_ping();
 262         }
 263         expect_close = 0;
 264         clear_bit(0, &wdt_is_open);
 265         return 0;
 266 }
 267
 268 /*
 269  *      Notifier for system down
 270  */
 271
 272 static int
 273 wdt_notify_sys(struct notifier_block *this, unsigned long code,
 274         void *unused)
 275 {
 276         if (code == SYS_DOWN || code == SYS_HALT) {
 277                 /* Turn the WDT off */
 278                 wdt_disable();
 279         }
 280         return NOTIFY_DONE;
 281 }
 282
 283 /*
 284  *      Kernel Interfaces
 285  */
 286
 287 static struct file_operations wdt_fops = {
 288         .owner          = THIS_MODULE,
 289         .llseek         = no_llseek,
 290         .write          = wdt_write,
 291         .ioctl          = wdt_ioctl,
 292         .open           = wdt_open,
 293         .release        = wdt_close,
 294 };
 295
 296 static struct miscdevice wdt_miscdev = {
 297         .minor = WATCHDOG_MINOR,
 298         .name = "watchdog",
 299         .fops = &wdt_fops,
 300 };
 301
 302 /*
 303  *      The WDT needs to learn about soft shutdowns in order to
 304  *      turn the timebomb registers off.
 305  */
 306
 307 static struct notifier_block wdt_notifier = {
 308         .notifier_call = wdt_notify_sys,
 309 };
 310
 311 static int __init
 312 wdt_init(void)
 313 {
 314         int ret;
 315
 316         spin_lock_init(&io_lock);
 317
 318         printk(KERN_INFO "WDT driver for the Winbond(TM) W83697HF Super I/O chip initialising.\n");
 319
 320         if (wdt_set_heartbeat(timeout)) {
 321                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 322                 printk (KERN_INFO PFX "timeout value must be 1<=timeout<=63, using %d\n",
 323                         WATCHDOG_TIMEOUT);
 324         }
 325
 326         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
 327                 printk (KERN_ERR PFX "I/O address 0x%04x already in use\n",
 328                         wdt_io);
 329                 ret = -EIO;
 330                 goto out;
 331         }
 332
 333         w83697hf_init();
 334
 335         ret = register_reboot_notifier(&wdt_notifier);
 336         if (ret != 0) {
 337                 printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
 338                         ret);
 339                 goto unreg_regions;
 340         }
 341
 342         ret = misc_register(&wdt_miscdev);
 343         if (ret != 0) {
 344                 printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
 345                         WATCHDOG_MINOR, ret);
 346                 goto unreg_reboot;
 347         }
 348
 349         printk (KERN_INFO PFX "initialized. timeout=%d sec (nowayout=%d)\n",
 350                 timeout, nowayout);
 351
 352 out:
 353         return ret;
 354 unreg_reboot:
 355         unregister_reboot_notifier(&wdt_notifier);
 356 unreg_regions:
 357         release_region(wdt_io, 1);
 358         goto out;
 359 }
 360
 361 static void __exit
 362 wdt_exit(void)
 363 {
 364         misc_deregister(&wdt_miscdev);
 365         unregister_reboot_notifier(&wdt_notifier);
 366         release_region(wdt_io,1);
 367 }
 368
 369 module_init(wdt_init);
 370 module_exit(wdt_exit);
 371
 372 MODULE_LICENSE("GPL");
 373 MODULE_AUTHOR("Marcus Junker <junker@anduras.de>");
 374 MODULE_DESCRIPTION("w83697hf WDT driver");
 375 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);