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         } else if (c == 0x88) { /* W83627EHF */
  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                 printk(KERN_INFO PFX
 123                      "Watchdog already running. Resetting timeout to %d sec\n",
 124                                                                 timeout);
 125                 outb_p(timeout, WDT_EFDR);    /* Write back to CRF6 */
 126         }
 127
 128         outb_p(0xF5, WDT_EFER); /* Select CRF5 */
 129         t = inb_p(WDT_EFDR);      /* read CRF5 */
 130         t &= ~0x0C;               /* set second mode & disable keyboard
 131                                     turning off watchdog */
 132         outb_p(t, WDT_EFDR);    /* Write back to CRF5 */
 133
 134         outb_p(0xF7, WDT_EFER); /* Select CRF7 */
 135         t = inb_p(WDT_EFDR);      /* read CRF7 */
 136         t &= ~0xC0;               /* disable keyboard & mouse turning off
 137                                     watchdog */
 138         outb_p(t, WDT_EFDR);    /* Write back to CRF7 */
 139
 140         w83627hf_unselect_wd_register();
 141 }
 142
 143 static void wdt_ctrl(int timeout)
 144 {
 145         spin_lock(&io_lock);
 146
 147         w83627hf_select_wd_register();
 148
 149         outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
 150         outb_p(timeout, WDT_EFDR); /* Write Timeout counter to CRF6 */
 151
 152         w83627hf_unselect_wd_register();
 153
 154         spin_unlock(&io_lock);
 155 }
 156
 157 static int wdt_ping(void)
 158 {
 159         wdt_ctrl(timeout);
 160         return 0;
 161 }
 162
 163 static int wdt_disable(void)
 164 {
 165         wdt_ctrl(0);
 166         return 0;
 167 }
 168
 169 static int wdt_set_heartbeat(int t)
 170 {
 171         if (t < 1 || t > 255)
 172                 return -EINVAL;
 173         timeout = t;
 174         return 0;
 175 }
 176
 177 static ssize_t wdt_write(struct file *file, const char __user *buf,
 178                                                 size_t count, loff_t *ppos)
 179 {
 180         if (count) {
 181                 if (!nowayout) {
 182                         size_t i;
 183
 184                         expect_close = 0;
 185
 186                         for (i = 0; i != count; i++) {
 187                                 char c;
 188                                 if (get_user(c, buf + i))
 189                                         return -EFAULT;
 190                                 if (c == 'V')
 191                                         expect_close = 42;
 192                         }
 193                 }
 194                 wdt_ping();
 195         }
 196         return count;
 197 }
 198
 199 static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 200 {
 201         void __user *argp = (void __user *)arg;
 202         int __user *p = argp;
 203         int new_timeout;
 204         static const struct watchdog_info ident = {
 205                 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
 206                                                         WDIOF_MAGICCLOSE,
 207                 .firmware_version = 1,
 208                 .identity = "W83627HF WDT",
 209         };
 210
 211         switch (cmd) {
 212         case WDIOC_GETSUPPORT:
 213                 if (copy_to_user(argp, &ident, sizeof(ident)))
 214                         return -EFAULT;
 215                 break;
 216         case WDIOC_GETSTATUS:
 217         case WDIOC_GETBOOTSTATUS:
 218                 return put_user(0, p);
 219         case WDIOC_SETOPTIONS:
 220         {
 221                 int options, retval = -EINVAL;
 222
 223                 if (get_user(options, p))
 224                         return -EFAULT;
 225                 if (options & WDIOS_DISABLECARD) {
 226                         wdt_disable();
 227                         retval = 0;
 228                 }
 229                 if (options & WDIOS_ENABLECARD) {
 230                         wdt_ping();
 231                         retval = 0;
 232                 }
 233                 return retval;
 234         }
 235         case WDIOC_KEEPALIVE:
 236                 wdt_ping();
 237                 break;
 238         case WDIOC_SETTIMEOUT:
 239                 if (get_user(new_timeout, p))
 240                         return -EFAULT;
 241                 if (wdt_set_heartbeat(new_timeout))
 242                         return -EINVAL;
 243                 wdt_ping();
 244                 /* Fall */
 245         case WDIOC_GETTIMEOUT:
 246                 return put_user(timeout, p);
 247         default:
 248                 return -ENOTTY;
 249         }
 250         return 0;
 251 }
 252
 253 static int wdt_open(struct inode *inode, struct file *file)
 254 {
 255         if (test_and_set_bit(0, &wdt_is_open))
 256                 return -EBUSY;
 257         /*
 258          *      Activate
 259          */
 260
 261         wdt_ping();
 262         return nonseekable_open(inode, file);
 263 }
 264
 265 static int wdt_close(struct inode *inode, struct file *file)
 266 {
 267         if (expect_close == 42)
 268                 wdt_disable();
 269         else {
 270                 printk(KERN_CRIT PFX
 271                         "Unexpected close, not stopping watchdog!\n");
 272                 wdt_ping();
 273         }
 274         expect_close = 0;
 275         clear_bit(0, &wdt_is_open);
 276         return 0;
 277 }
 278
 279 /*
 280  *      Notifier for system down
 281  */
 282
 283 static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
 284         void *unused)
 285 {
 286         if (code == SYS_DOWN || code == SYS_HALT)
 287                 wdt_disable();  /* Turn the WDT off */
 288
 289         return NOTIFY_DONE;
 290 }
 291
 292 /*
 293  *      Kernel Interfaces
 294  */
 295
 296 static const struct file_operations wdt_fops = {
 297         .owner          = THIS_MODULE,
 298         .llseek         = no_llseek,
 299         .write          = wdt_write,
 300         .unlocked_ioctl = wdt_ioctl,
 301         .open           = wdt_open,
 302         .release        = wdt_close,
 303 };
 304
 305 static struct miscdevice wdt_miscdev = {
 306         .minor = WATCHDOG_MINOR,
 307         .name = "watchdog",
 308         .fops = &wdt_fops,
 309 };
 310
 311 /*
 312  *      The WDT needs to learn about soft shutdowns in order to
 313  *      turn the timebomb registers off.
 314  */
 315
 316 static struct notifier_block wdt_notifier = {
 317         .notifier_call = wdt_notify_sys,
 318 };
 319
 320 static int __init wdt_init(void)
 321 {
 322         int ret;
 323
 324         printk(KERN_INFO "WDT driver for the Winbond(TM) W83627HF/THF/HG Super I/O chip initialising.\n");
 325
 326         if (wdt_set_heartbeat(timeout)) {
 327                 wdt_set_heartbeat(WATCHDOG_TIMEOUT);
 328                 printk(KERN_INFO PFX
 329                      "timeout value must be 1 <= timeout <= 255, using %d\n",
 330                                 WATCHDOG_TIMEOUT);
 331         }
 332
 333         if (!request_region(wdt_io, 1, WATCHDOG_NAME)) {
 334                 printk(KERN_ERR PFX "I/O address 0x%04x already in use\n",
 335                         wdt_io);
 336                 ret = -EIO;
 337                 goto out;
 338         }
 339
 340         w83627hf_init();
 341
 342         ret = register_reboot_notifier(&wdt_notifier);
 343         if (ret != 0) {
 344                 printk(KERN_ERR PFX
 345                         "cannot register reboot notifier (err=%d)\n", ret);
 346                 goto unreg_regions;
 347         }
 348
 349         ret = misc_register(&wdt_miscdev);
 350         if (ret != 0) {
 351                 printk(KERN_ERR PFX
 352                         "cannot register miscdev on minor=%d (err=%d)\n",
 353                                                         WATCHDOG_MINOR, ret);
 354                 goto unreg_reboot;
 355         }
 356
 357         printk(KERN_INFO PFX
 358                         "initialized. timeout=%d sec (nowayout=%d)\n",
 359                                                         timeout, nowayout);
 360
 361 out:
 362         return ret;
 363 unreg_reboot:
 364         unregister_reboot_notifier(&wdt_notifier);
 365 unreg_regions:
 366         release_region(wdt_io, 1);
 367         goto out;
 368 }
 369
 370 static void __exit wdt_exit(void)
 371 {
 372         misc_deregister(&wdt_miscdev);
 373         unregister_reboot_notifier(&wdt_notifier);
 374         release_region(wdt_io, 1);
 375 }
 376
 377 module_init(wdt_init);
 378 module_exit(wdt_exit);
 379
 380 MODULE_LICENSE("GPL");
 381 MODULE_AUTHOR("Pádraig Brady <P@draigBrady.com>");
 382 MODULE_DESCRIPTION("w83627hf/thf WDT driver");
 383 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);