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 #include <asm/system.h>
  44
  45 #define WATCHDOG_NAME "w83627hf/thf/hg WDT"
  46 #define PFX WATCHDOG_NAME ": "
  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 int nowayout = WATCHDOG_NOWAYOUT;
  65 module_param(nowayout, int, 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         }
  93
  94         outb_p(0x07, WDT_EFER); /* point to logical device number reg */
  95         outb_p(0x08, WDT_EFDR); /* select logical device 8 (GPIO2) */
  96         outb_p(0x30, WDT_EFER); /* select CR30 */
  97         outb_p(0x01, WDT_EFDR); /* set bit 0 to activate GPIO2 */
  98 }
  99
 100 static void w83627hf_unselect_wd_register(void)
 101 {
 102         outb_p(0xAA, WDT_EFER); /* Leave extended function mode */
 103 }
 104
 105 /* tyan motherboards seem to set F5 to 0x4C ?
 106  * So explicitly init to appropriate value. */
 107
 108 static void w83627hf_init(void)
 109 {
 110         unsigned char t;
 111
 112         w83627hf_select_wd_register();
 113
 114         outb_p(0xF6, WDT_EFER); /* Select CRF6 */
 115         t = inb_p(WDT_EFDR);      /* read CRF6 */
 116         if (t != 0) {
 117                 printk(KERN_INFO PFX
 118                      "Watchdog already running. Resetting timeout to %d sec\n",
 119                                                                 timeout);
 120                 outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
 121         }
 122
 123         outb_p(0xF5, WDT_EFER); /* Select CRF5 */
 124         t = inb_p(WDT_EFDR);      /* read CRF5 */
 125         t &= ~0x0C;               /* set second mode & disable keyboard
 126                                     turning off watchdog */
 127         outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
 128
 129         outb_p(0xF7, WDT_EFER); /* Select CRF7 */
 130         t = inb_p(WDT_EFDR);      /* read CRF7 */
 131         t &= ~0xC0;               /* disable keyboard & mouse turning off
 132                                     watchdog */
 133         outb_p(t, WDT_EFDR);    /* Write back to CRF7 */
 134
 135         w83627hf_unselect_wd_register();
 136 }
 137
 138 static void wdt_ctrl(int timeout)
 139 {
 140         spin_lock(&io_lock);
 141
 142         w83627hf_select_wd_register();
 143
 144         outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
 145         outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
 146
 147         w83627hf_unselect_wd_register();
 148
 149         spin_unlock(&io_lock);
 150 }
 151
 152 static int wdt_ping(void)
 153 {
 154         wdt_ctrl(timeout);
 155         return 0;
 156 }
 157
 158 static int wdt_disable(void)
 159 {
 160         wdt_ctrl(0);
 161         return 0;
 162 }
 163
 164 static int wdt_set_heartbeat(int t)
 165 {
 166         if (t < 1 || t > 255)
 167                 return -EINVAL;
 168         timeout = t;
 169         return 0;
 170 }
 171
 172 static ssize_t wdt_write(struct file *file, const char __user *buf,
 173                                                 size_t count, loff_t *ppos)
 174 {
 175         if (count) {
 176                 if (!nowayout) {
 177                         size_t i;
 178
 179                         expect_close = 0;
 180
 181                         for (i = 0; i != count; i++) {
 182                                 char c;
 183                                 if (get_user(c, buf + i))
 184                                         return -EFAULT;
 185                                 if (c == 'V')
 186                                         expect_close = 42;
 187                         }
 188                 }
 189                 wdt_ping();
 190         }
 191         return count;
 192 }
 193
 194 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 195 {
 196         void __user *argp = (void __user *)arg;
 197         int __user *p = argp;
 198         int new_timeout;
 199         static struct watchdog_info ident = {
 200                 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
 201                                                         WDIOF_MAGICCLOSE,
 202                 .firmware_version = 1,
 203                 .identity = "W83627HF WDT",
 204         };
 205
 206         switch (cmd) {
 207         case WDIOC_GETSUPPORT:
 208                 if (copy_to_user(argp, &ident, sizeof(ident)))
 209                         return -EFAULT;
 210                 break;
 211         case WDIOC_GETSTATUS:
 212         case WDIOC_GETBOOTSTATUS:
 213                 return put_user(0, p);
 214         case WDIOC_SETOPTIONS:
 215         {
 216                 int options, retval = -EINVAL;
 217
 218                 if (get_user(options, p))
 219                         return -EFAULT;
 220                 if (options & WDIOS_DISABLECARD) {
 221                         wdt_disable();
 222                         retval = 0;
 223                 }
 224                 if (options & WDIOS_ENABLECARD) {
 225                         wdt_ping();
 226                         retval = 0;
 227                 }
 228                 return retval;
 229         }
 230         case WDIOC_KEEPALIVE:
 231                 wdt_ping();
 232                 break;
 233         case WDIOC_SETTIMEOUT:
 234                 if (get_user(new_timeout, p))
 235                         return -EFAULT;
 236                 if (wdt_set_heartbeat(new_timeout))
 237                         return -EINVAL;
 238                 wdt_ping();
 239                 /* Fall */
 240         case WDIOC_GETTIMEOUT:
 241                 return put_user(timeout, p);
 242         default:
 243                 return -ENOTTY;
 244         }
 245         return 0;
 246 }
 247
 248 static int wdt_open(struct inode *inode, struct file *file)
 249 {
 250         if (test_and_set_bit(0, &wdt_is_open))
 251                 return -EBUSY;
 252         /*
 253          *      Activate
 254          */
 255
 256         wdt_ping();
 257         return nonseekable_open(inode, file);
 258 }
 259
 260 static int wdt_close(struct inode *inode, struct file *file)
 261 {
 262         if (expect_close == 42)
 263                 wdt_disable();
 264         else {
 265                 printk(KERN_CRIT PFX
 266                         "Unexpected close, not stopping watchdog!\n");
 267                 wdt_ping();
 268         }
 269         expect_close = 0;
 270         clear_bit(0, &wdt_is_open);
 271         return 0;
 272 }
 273
 274 /*
 275  *      Notifier for system down
 276  */
 277
 278 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
 279         void *unused)
 280 {
 281         if (code == SYS_DOWN || code == SYS_HALT)
 282                 wdt_disable();  /* Turn the WDT off */
 283
 284         return NOTIFY_DONE;
 285 }
 286
 287 /*
 288  *      Kernel Interfaces
 289  */
 290
 291 static const struct file_operations wdt_fops = {
 292         .owner          = THIS_MODULE,
 293         .llseek         = no_llseek,
 294         .write          = wdt_write,
 295         .unlocked_ioctl = wdt_ioctl,
 296         .open           = wdt_open,
 297         .release        = wdt_close,
 298 };
 299
 300 static struct miscdevice wdt_miscdev = {
 301         .minor = WATCHDOG_MINOR,
 302         .name = "watchdog",
 303         .fops = &wdt_fops,
 304 };
 305
 306 /*
 307  *      The WDT needs to learn about soft shutdowns in order to
 308  *      turn the timebomb registers off.
 309  */
 310
 311 static struct notifier_block wdt_notifier = {
 312         .notifier_call = wdt_notify_sys,
 313 };
 314
 315 static int __init wdt_init(void)
 316 {
 317         int ret;
 318
 319         printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n");
 320
 321         if (wdt_set_heartbeat(timeout)) {
 322                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 323                 printk(KERN_INFO PFX
 324                      "timeout value must be 1 <= timeout <= 255, using %d\n",
 325                                 WATCHDOG_TIMEOUT);
 326         }
 327
 328         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
 329                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 330                         wdt_io);
 331                 ret = -EIO;
 332                 goto out;
 333         }
 334
 335         w83627hf_init();
 336
 337         ret = register_reboot_notifier(&wdt_notifier);
 338         if (ret != 0) {
 339                 printk(KERN_ERR PFX
 340                         "cannot register reboot notifier (err=%d)\n", ret);
 341                 goto unreg_regions;
 342         }
 343
 344         ret = misc_register(&wdt_miscdev);
 345         if (ret != 0) {
 346                 printk(KERN_ERR PFX
 347                         "cannot register miscdev on minor=%d (err=%d)\n",
 348                                                         WATCHDOG_MINOR, ret);
 349                 goto unreg_reboot;
 350         }
 351
 352         printk(KERN_INFO PFX
 353                         "initialized. timeout=%d sec (nowayout=%d)\n",
 354                                                         timeout, nowayout);
 355
 356 out:
 357         return ret;
 358 unreg_reboot:
 359         unregister_reboot_notifier(&wdt_notifier);
 360 unreg_regions:
 361         release_region(wdt_io, 1);
 362         goto out;
 363 }
 364
 365 static void __exit wdt_exit(void)
 366 {
 367         misc_deregister(&wdt_miscdev);
 368         unregister_reboot_notifier(&wdt_notifier);
 369         release_region(wdt_io, 1);
 370 }
 371
 372 module_init(wdt_init);
 373 module_exit(wdt_exit);
 374
 375 MODULE_LICENSE("GPL");
 376 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
 377 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
 378 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);