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@lxorguk.ukuu.org.uk>,
  15  *                                              All Rights Reserved.
  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@lxorguk.ukuu.org.uk>
  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 #include <linux/io.h>
  41 #include <linux/uaccess.h>
  42
  43
  44 #define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
  45 #define PFX WATCHDOG_NAME ": "
  46 #define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
  47
  48 static unsigned long wdt_is_open;
  49 static char expect_close;
  50 static DEFINE_SPINLOCK(io_lock);
  51
  52 /* You must set this - there is no sane way to probe for this board. */
  53 static int wdt_io = 0x2E;
  54 module_param(wdt_io, int, 0);
  55 MODULE_PARM_DESC(wdt_io, "w83627hf/thf WDT io port (default 0x2E)");
  56
  57 static int timeout = WATCHDOG_TIMEOUT;  /* in seconds */
  58 module_param(timeout, int, 0);
  59 MODULE_PARM_DESC(timeout,
  60                 "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
  61                                 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
  62
  63 static int nowayout = WATCHDOG_NOWAYOUT;
  64 module_param(nowayout, int, 0);
  65 MODULE_PARM_DESC(nowayout,
  66                 "Watchdog cannot be stopped once started (default="
  67                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  68
  69 /*
  70  *      Kernel methods.
  71  */
  72
  73 #define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
  74 #define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register
  75                                                         (same as EFER) */
  76 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
  77
  78 static void w83627hf_select_wd_register(void)
  79 {
  80         unsigned char c;
  81         outb_p(0x87, WDT_EFER); /* Enter extended function mode */
  82         outb_p(0x87, WDT_EFER); /* Again according to manual */
  83
  84         outb(0x20, WDT_EFER);   /* check chip version   */
  85         c = inb(WDT_EFDR);
  86         if (c == 0x82) {        /* W83627THF            */
  87                 outb_p(0x2b, WDT_EFER); /* select GPIO3 */
  88                 c = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */
  89                 outb_p(0x2b, WDT_EFER);
  90                 outb_p(c, WDT_EFDR);    /* set GPIO3 to WDT0 */
  91         } else if (c == 0x88 || c == 0xa0) {    /* W83627EHF / W83627DHG */
  92                 outb_p(0x2d, WDT_EFER); /* select GPIO5 */
  93                 c = inb_p(WDT_EFDR) & ~0x01; /* PIN77 -> WDT0# */
  94                 outb_p(0x2d, WDT_EFER);
  95                 outb_p(c, WDT_EFDR); /* set GPIO5 to WDT0 */
  96         }
  97
  98         outb_p(0x07, WDT_EFER); /* point to logical device number reg */
  99         outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
 100         outb_p(0x30, WDT_EFER); /* select CR30 */
 101         outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
 102 }
 103
 104 static void w83627hf_unselect_wd_register(void)
 105 {
 106         outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
 107 }
 108
 109 /* tyan motherboards seem to set F5 to 0x4C ?
 110  * So explicitly init to appropriate value. */
 111
 112 static void w83627hf_init(void)
 113 {
 114         unsigned char t;
 115
 116         w83627hf_select_wd_register();
 117
 118         outb_p(0xF6, WDT_EFER); /* Select CRF6 */
 119         t = inb_p(WDT_EFDR);      /* read CRF6 */
 120         if (t != 0) {
 121                 printk(KERN_INFO PFX
 122                      "Watchdog already running. Resetting timeout to %d sec\n",
 123                                                                 timeout);
 124                 outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
 125         }
 126
 127         outb_p(0xF5, WDT_EFER); /* Select CRF5 */
 128         t = inb_p(WDT_EFDR);      /* read CRF5 */
 129         t &= ~0x0C;               /* set second mode & disable keyboard
 130                                     turning off watchdog */
 131         t |= 0x02;                /* enable the WDTO# output low pulse
 132                                     to the KBRST# pin (PIN60) */
 133         outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
 134
 135         outb_p(0xF7, WDT_EFER); /* Select CRF7 */
 136         t = inb_p(WDT_EFDR);      /* read CRF7 */
 137         t &= ~0xC0;               /* disable keyboard & mouse turning off
 138                                     watchdog */
 139         outb_p(t, WDT_EFDR);    /* Write back to CRF7 */
 140
 141         w83627hf_unselect_wd_register();
 142 }
 143
 144 static void wdt_set_time(int timeout)
 145 {
 146         spin_lock(&io_lock);
 147
 148         w83627hf_select_wd_register();
 149
 150         outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
 151         outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
 152
 153         w83627hf_unselect_wd_register();
 154
 155         spin_unlock(&io_lock);
 156 }
 157
 158 static int wdt_ping(void)
 159 {
 160         wdt_set_time(timeout);
 161         return 0;
 162 }
 163
 164 static int wdt_disable(void)
 165 {
 166         wdt_set_time(0);
 167         return 0;
 168 }
 169
 170 static int wdt_set_heartbeat(int t)
 171 {
 172         if (t < 1 || t > 255)
 173                 return -EINVAL;
 174         timeout = t;
 175         return 0;
 176 }
 177
 178 static int wdt_get_time(void)
 179 {
 180         int timeleft;
 181
 182         spin_lock(&io_lock);
 183
 184         w83627hf_select_wd_register();
 185
 186         outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
 187         timeleft = inb_p(WDT_EFDR); /* Read Timeout counter to CRF6 */
 188
 189         w83627hf_unselect_wd_register();
 190
 191         spin_unlock(&io_lock);
 192
 193         return timeleft;
 194 }
 195
 196 static ssize_t wdt_write(struct file *file, const char __user *buf,
 197                                                 size_t count, loff_t *ppos)
 198 {
 199         if (count) {
 200                 if (!nowayout) {
 201                         size_t i;
 202
 203                         expect_close = 0;
 204
 205                         for (i = 0; i != count; i++) {
 206                                 char c;
 207                                 if (get_user(c, buf + i))
 208                                         return -EFAULT;
 209                                 if (c == 'V')
 210                                         expect_close = 42;
 211                         }
 212                 }
 213                 wdt_ping();
 214         }
 215         return count;
 216 }
 217
 218 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 219 {
 220         void __user *argp = (void __user *)arg;
 221         int __user *p = argp;
 222         int timeval;
 223         static const struct watchdog_info ident = {
 224                 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
 225                                                         WDIOF_MAGICCLOSE,
 226                 .firmware_version = 1,
 227                 .identity = "W83627HF WDT",
 228         };
 229
 230         switch (cmd) {
 231         case WDIOC_GETSUPPORT:
 232                 if (copy_to_user(argp, &ident, sizeof(ident)))
 233                         return -EFAULT;
 234                 break;
 235         case WDIOC_GETSTATUS:
 236         case WDIOC_GETBOOTSTATUS:
 237                 return put_user(0, p);
 238         case WDIOC_SETOPTIONS:
 239         {
 240                 int options, retval = -EINVAL;
 241
 242                 if (get_user(options, p))
 243                         return -EFAULT;
 244                 if (options & WDIOS_DISABLECARD) {
 245                         wdt_disable();
 246                         retval = 0;
 247                 }
 248                 if (options & WDIOS_ENABLECARD) {
 249                         wdt_ping();
 250                         retval = 0;
 251                 }
 252                 return retval;
 253         }
 254         case WDIOC_KEEPALIVE:
 255                 wdt_ping();
 256                 break;
 257         case WDIOC_SETTIMEOUT:
 258                 if (get_user(timeval, p))
 259                         return -EFAULT;
 260                 if (wdt_set_heartbeat(timeval))
 261                         return -EINVAL;
 262                 wdt_ping();
 263                 /* Fall */
 264         case WDIOC_GETTIMEOUT:
 265                 return put_user(timeout, p);
 266         case WDIOC_GETTIMELEFT:
 267                 timeval = wdt_get_time();
 268                 return put_user(timeval, p);
 269         default:
 270                 return -ENOTTY;
 271         }
 272         return 0;
 273 }
 274
 275 static int wdt_open(struct inode *inode, struct file *file)
 276 {
 277         if (test_and_set_bit(0, &wdt_is_open))
 278                 return -EBUSY;
 279         /*
 280          *      Activate
 281          */
 282
 283         wdt_ping();
 284         return nonseekable_open(inode, file);
 285 }
 286
 287 static int wdt_close(struct inode *inode, struct file *file)
 288 {
 289         if (expect_close == 42)
 290                 wdt_disable();
 291         else {
 292                 printk(KERN_CRIT PFX
 293                         "Unexpected close, not stopping watchdog!\n");
 294                 wdt_ping();
 295         }
 296         expect_close = 0;
 297         clear_bit(0, &wdt_is_open);
 298         return 0;
 299 }
 300
 301 /*
 302  *      Notifier for system down
 303  */
 304
 305 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
 306         void *unused)
 307 {
 308         if (code == SYS_DOWN || code == SYS_HALT)
 309                 wdt_disable();  /* Turn the WDT off */
 310
 311         return NOTIFY_DONE;
 312 }
 313
 314 /*
 315  *      Kernel Interfaces
 316  */
 317
 318 static const struct file_operations wdt_fops = {
 319         .owner          = THIS_MODULE,
 320         .llseek         = no_llseek,
 321         .write          = wdt_write,
 322         .unlocked_ioctl = wdt_ioctl,
 323         .open           = wdt_open,
 324         .release        = wdt_close,
 325 };
 326
 327 static struct miscdevice wdt_miscdev = {
 328         .minor = WATCHDOG_MINOR,
 329         .name = "watchdog",
 330         .fops = &wdt_fops,
 331 };
 332
 333 /*
 334  *      The WDT needs to learn about soft shutdowns in order to
 335  *      turn the timebomb registers off.
 336  */
 337
 338 static struct notifier_block wdt_notifier = {
 339         .notifier_call = wdt_notify_sys,
 340 };
 341
 342 static int __init wdt_init(void)
 343 {
 344         int ret;
 345
 346         printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG/DHG Super I/O chip initialising.\n");
 347
 348         if (wdt_set_heartbeat(timeout)) {
 349                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 350                 printk(KERN_INFO PFX
 351                      "timeout value must be 1 <= timeout <= 255, using %d\n",
 352                                 WATCHDOG_TIMEOUT);
 353         }
 354
 355         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
 356                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 357                         wdt_io);
 358                 ret = -EIO;
 359                 goto out;
 360         }
 361
 362         w83627hf_init();
 363
 364         ret = register_reboot_notifier(&wdt_notifier);
 365         if (ret != 0) {
 366                 printk(KERN_ERR PFX
 367                         "cannot register reboot notifier (err=%d)\n", ret);
 368                 goto unreg_regions;
 369         }
 370
 371         ret = misc_register(&wdt_miscdev);
 372         if (ret != 0) {
 373                 printk(KERN_ERR PFX
 374                         "cannot register miscdev on minor=%d (err=%d)\n",
 375                                                         WATCHDOG_MINOR, ret);
 376                 goto unreg_reboot;
 377         }
 378
 379         printk(KERN_INFO PFX
 380                         "initialized. timeout=%d sec (nowayout=%d)\n",
 381                                                         timeout, nowayout);
 382
 383 out:
 384         return ret;
 385 unreg_reboot:
 386         unregister_reboot_notifier(&wdt_notifier);
 387 unreg_regions:
 388         release_region(wdt_io, 1);
 389         goto out;
 390 }
 391
 392 static void __exit wdt_exit(void)
 393 {
 394         misc_deregister(&wdt_miscdev);
 395         unregister_reboot_notifier(&wdt_notifier);
 396         release_region(wdt_io, 1);
 397 }
 398
 399 module_init(wdt_init);
 400 module_exit(wdt_exit);
 401
 402 MODULE_LICENSE("GPL");
 403 MODULE_AUTHOR("Pádraig  Brady <P@draigBrady.com>");
 404 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
 405 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);