drivers/char/softdog.c

/* */
This source file includes following definitions.
watchdog_fire
softdog_open
softdog_release
softdog_write
watchdog_init
   1 /*
   2  *      SoftDog 0.02:   A Software Watchdog Device
   3  *
   4  *      (c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
   5  *
   6  *      Email us for quotes on Linux software and driver development. 
   7  *
   8  *                      -----------------------
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  *
  15  *                      -----------------------
  16  *
  17  *      Software only watchdog driver. Unlike its big brother the WDT501P
  18  *      driver this won't always recover a failed machine.
  19  */
  20  
  21 #include <linux/config.h>
  22 #include <linux/types.h>
  23 #include <linux/kernel.h>
  24 #include <linux/fs.h>
  25 #include <linux/mm.h>
  26 #include <linux/miscdevice.h>
  27 
  28 #define WATCHDOG_MINOR  130
  29 #define TIMER_MARGIN    (60*HZ)         /* Allow 1 minute */
  30 
  31 /*
  32  *      Our timer
  33  */
  34  
  35 struct timer_list watchdog_ticktock;
  36 static int timer_alive = 0;
  37 
  38 
  39 /*
  40  *      If the timer expires..
  41  */
  42  
  43 static void watchdog_fire(unsigned long data)
     /*  */
  44 {
  45         extern void hard_reset_now(void);
  46         hard_reset_now();
  47         printk("WATCHDOG: Reboot didn't ?????\n");
  48 }
  49 
  50 /*
  51  *      Allow only one person to hold it open
  52  */
  53  
  54 static int softdog_open(struct inode *inode, struct file *file)
     /*  */
  55 {
  56         if(timer_alive)
  57                 return -EBUSY;
  58         /*
  59          *      Activate timer
  60          */
  61         watchdog_ticktock.expires=jiffies+TIMER_MARGIN;
  62         add_timer(&watchdog_ticktock);
  63         timer_alive++;
  64         return 0;
  65 }
  66 
  67 static void softdog_release(struct inode *inode, struct file *file)
     /*  */
  68 {
  69         /*
  70          *      Shut off the timer.
  71          */
  72 #ifndef CONFIG_WATCHDOG_NOWAYOUT         
  73         del_timer(&watchdog_ticktock);
  74 #endif  
  75         timer_alive=0;
  76 }
  77 
  78 static int softdog_write(struct inode *inode, struct file *file, const char *data, int len)
     /*  */
  79 {
  80         /*
  81          *      Refresh the timer.
  82          */
  83         del_timer(&watchdog_ticktock);
  84         watchdog_ticktock.expires=jiffies+TIMER_MARGIN;
  85         add_timer(&watchdog_ticktock);
  86         return 1;
  87 }
  88 
  89 /*
  90  *      The mouse stuff ought to be renamed misc_register etc before 1.4...
  91  */
  92  
  93 void watchdog_init(void)
     /*  */
  94 {
  95         static struct file_operations softdog_fops=
  96         {
  97                 NULL,           /* Seek */
  98                 NULL,           /* Read */
  99                 softdog_write,  /* Write */
 100                 NULL,           /* Readdir */
 101                 NULL,           /* Select */
 102                 NULL,           /* Ioctl */
 103                 NULL,           /* MMap */
 104                 softdog_open,
 105                 softdog_release,
 106                 NULL,           
 107                 NULL            /* Fasync */
 108         };
 109         static struct miscdevice softdog_mouse={
 110                 WATCHDOG_MINOR,
 111                 "softdog",
 112                 &softdog_fops
 113         };
 114 
 115         misc_register(&softdog_mouse);
 116         init_timer(&watchdog_ticktock);
 117         watchdog_ticktock.function=watchdog_fire;
 118         printk("Software Watchdog Timer: 0.03\n");
 119 }
/* */
root/drivers/char/softdog.c

DEFINITIONS
