sys/dev/watchdog/watchdog.c

   1 /*-
   2  * Copyright (c) 2004 Poul-Henning Kamp
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer
  10  *    in this position and unchanged.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  */
  27
  28 #include <sys/cdefs.h>
  29 __FBSDID("$FreeBSD$");
  30
  31 #include <sys/param.h>
  32 #include <sys/systm.h>
  33 #include <sys/conf.h>
  34 #include <sys/uio.h>
  35 #include <sys/kernel.h>
  36 #include <sys/malloc.h>
  37 #include <sys/module.h>
  38 #include <sys/watchdog.h>
  39 #include <sys/bus.h>
  40 #include <machine/bus.h>
  41
  42 static struct cdev *wd_dev;
  43
  44 static int
  45 wd_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data,
  46     int flags __unused, struct thread *td)
  47 {
  48         int error;
  49         u_int u;
  50
  51         if (cmd != WDIOCPATPAT)
  52                 return (ENOIOCTL);
  53         u = *(u_int *)data;
  54         if (u & ~(WD_ACTIVE | WD_PASSIVE | WD_INTERVAL))
  55                 return (EINVAL);
  56         if ((u & (WD_ACTIVE | WD_PASSIVE)) == (WD_ACTIVE | WD_PASSIVE))
  57                 return (EINVAL);
  58         if ((u & (WD_ACTIVE | WD_PASSIVE)) == 0 && (u & WD_INTERVAL) > 0)
  59                 return (EINVAL);
  60         if (u & WD_PASSIVE)
  61                 return (ENOSYS);        /* XXX Not implemented yet */
  62         if ((u & WD_INTERVAL) == WD_TO_NEVER) {
  63                 u = 0;
  64                 /* Assume all is well; watchdog signals failure. */
  65                 error = 0;
  66         } else {
  67                 /* Assume no watchdog available; watchdog flags success */
  68                 error = EOPNOTSUPP;
  69         }
  70         EVENTHANDLER_INVOKE(watchdog_list, u, &error);
  71         return (error);
  72 }
  73
  74 static struct cdevsw wd_cdevsw = {
  75         .d_version =    D_VERSION,
  76         .d_ioctl =      wd_ioctl,
  77         .d_name =       "watchdog",
  78 };
  79
  80 static int
  81 watchdog_modevent(module_t mod __unused, int type, void *data __unused)
  82 {
  83         switch(type) {
  84         case MOD_LOAD:
  85                 wd_dev = make_dev(&wd_cdevsw, 0,
  86                     UID_ROOT, GID_WHEEL, 0600, _PATH_WATCHDOG);
  87                 return 0;
  88         case MOD_UNLOAD:
  89                 destroy_dev(wd_dev);
  90                 return 0;
  91         case MOD_SHUTDOWN:
  92                 return 0;
  93         default:
  94                 return EOPNOTSUPP;
  95         }
  96 }
  97
  98 DEV_MODULE(watchdog, watchdog_modevent, NULL);