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