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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  30
  31 #include <linux/module.h>
  32 #include <linux/moduleparam.h>
  33 #include <linux/types.h>
  34 #include <linux/miscdevice.h>
  35 #include <linux/watchdog.h>
  36 #include <linux/fs.h>
  37 #include <linux/ioport.h>
  38 #include <linux/notifier.h>
  39 #include <linux/reboot.h>
  40 #include <linux/init.h>
  41 #include <linux/spinlock.h>
  42 #include <linux/io.h>
  43 #include <linux/uaccess.h>
  44
  45
  46 #define WATCHDOG_NAME "w83627hf/thf/hg/dhg WDT"
  47 #define WATCHDOG_TIMEOUT 60             /* 60 sec default timeout */
  48
  49 static unsigned long wdt_is_open;
  50 static char expect_close;
  51 static DEFINE_SPINLOCK(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,
  61                 "Watchdog timeout in seconds. 1 <= timeout <= 255, default="
  62                                 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
  63
  64 static bool nowayout = WATCHDOG_NOWAYOUT;
  65 module_param(nowayout, bool, 0);
  66 MODULE_PARM_DESC(nowayout,
  67                 "Watchdog cannot be stopped once started (default="
  68                                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  69
  70 /*
  71  *      Kernel methods.
  72  */
  73
  74 #define WDT_EFER (wdt_io+0)   /* Extended Function Enable Registers */
  75 #define WDT_EFIR (wdt_io+0)   /* Extended Function Index Register
  76                                                         (same as EFER) */
  77 #define WDT_EFDR (WDT_EFIR+1) /* Extended Function Data Register */
  78
  79 static void w83627hf_select_wd_register(void)
  80 {
  81         unsigned char c;
  82         outb_p(0x87, WDT_EFER); /* Enter extended function mode */
  83         outb_p(0x87, WDT_EFER); /* Again according to manual */
  84
  85         outb(0x20, WDT_EFER);   /* check chip version   */
  86         c = inb(WDT_EFDR);
  87         if (c == 0x82) {        /* W83627THF            */
  88                 outb_p(0x2b, WDT_EFER); /* select GPIO3 */
  89                 c = ((inb_p(WDT_EFDR) & 0xf7) | 0x04); /* select WDT0 */
  90                 outb_p(0x2b, WDT_EFER);
  91                 outb_p(c, WDT_EFDR);    /* set GPIO3 to WDT0 */
  92         } else if (c == 0x88 || c == 0xa0) {    /* W83627EHF / W83627DHG */
  93                 outb_p(0x2d, WDT_EFER); /* select GPIO5 */
  94                 c = inb_p(WDT_EFDR) & ~0x01; /* PIN77 -> WDT0# */
  95                 outb_p(0x2d, WDT_EFER);
  96                 outb_p(c, WDT_EFDR); /* set GPIO5 to WDT0 */
  97         }
  98
  99         outb_p(0x07, WDT_EFER); /* point to logical device number reg */
 100         outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
 101         outb_p(0x30, WDT_EFER); /* select CR30 */
 102         outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
 103 }
 104
 105 static void w83627hf_unselect_wd_register(void)
 106 {
 107         outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
 108 }
 109
 110 /* tyan motherboards seem to set F5 to 0x4C ?
 111  * So explicitly init to appropriate value. */
 112
 113 static void w83627hf_init(void)
 114 {
 115         unsigned char t;
 116
 117         w83627hf_select_wd_register();
 118
 119         outb_p(0xF6, WDT_EFER); /* Select CRF6 */
 120         t = inb_p(WDT_EFDR);      /* read CRF6 */
 121         if (t != 0) {
 122                 pr_info("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                 pr_crit("Unexpected close, not stopping watchdog!\n");
 293                 wdt_ping();
 294         }
 295         expect_close = 0;
 296         clear_bit(0, &wdt_is_open);
 297         return 0;
 298 }
 299
 300 /*
 301  *      Notifier for system down
 302  */
 303
 304 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
 305         void *unused)
 306 {
 307         if (code == SYS_DOWN || code == SYS_HALT)
 308                 wdt_disable();  /* Turn the WDT off */
 309
 310         return NOTIFY_DONE;
 311 }
 312
 313 /*
 314  *      Kernel Interfaces
 315  */
 316
 317 static const struct file_operations wdt_fops = {
 318         .owner          = THIS_MODULE,
 319         .llseek         = no_llseek,
 320         .write          = wdt_write,
 321         .unlocked_ioctl = wdt_ioctl,
 322         .open           = wdt_open,
 323         .release        = wdt_close,
 324 };
 325
 326 static struct miscdevice wdt_miscdev = {
 327         .minor = WATCHDOG_MINOR,
 328         .name = "watchdog",
 329         .fops = &wdt_fops,
 330 };
 331
 332 /*
 333  *      The WDT needs to learn about soft shutdowns in order to
 334  *      turn the timebomb registers off.
 335  */
 336
 337 static struct notifier_block wdt_notifier = {
 338         .notifier_call = wdt_notify_sys,
 339 };
 340
 341 static int __init wdt_init(void)
 342 {
 343         int ret;
 344
 345         pr_info("WDT driver for the Winbond(TM) W83627HF/THF/HG/DHG Super I/O chip initialising\n");
 346
 347         if (wdt_set_heartbeat(timeout)) {
 348                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 349                 pr_info("timeout value must be 1 <= timeout <= 255, using %d\n",
 350                         WATCHDOG_TIMEOUT);
 351         }
 352
 353         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
 354                 pr_err("I/O address 0x%04x already in use\n", wdt_io);
 355                 ret = -EIO;
 356                 goto out;
 357         }
 358
 359         w83627hf_init();
 360
 361         ret = register_reboot_notifier(&wdt_notifier);
 362         if (ret != 0) {
 363                 pr_err("cannot register reboot notifier (err=%d)\n", ret);
 364                 goto unreg_regions;
 365         }
 366
 367         ret = misc_register(&wdt_miscdev);
 368         if (ret != 0) {
 369                 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
 370                        WATCHDOG_MINOR, ret);
 371                 goto unreg_reboot;
 372         }
 373
 374         pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
 375                 timeout, nowayout);
 376
 377 out:
 378         return ret;
 379 unreg_reboot:
 380         unregister_reboot_notifier(&wdt_notifier);
 381 unreg_regions:
 382         release_region(wdt_io, 1);
 383         goto out;
 384 }
 385
 386 static void __exit wdt_exit(void)
 387 {
 388         misc_deregister(&wdt_miscdev);
 389         unregister_reboot_notifier(&wdt_notifier);
 390         release_region(wdt_io, 1);
 391 }
 392
 393 module_init(wdt_init);
 394 module_exit(wdt_exit);
 395
 396 MODULE_LICENSE("GPL");
 397 MODULE_AUTHOR("Pádraig  Brady <P@draigBrady.com>");
 398 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
 399 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);