Kontron KTAM3874-pITX - Manual (Page 73)

KTD-S0057-I Page 69 Linux® Programming Examples (DebianTM)
KTAM3874/pITX Software Guide
10.7 Watchdog Example
The watchdog option represents a nice feature for industrial applications. You can also download a watch-
dog daemon with 'sudo apt-get install watchdog' for additional features.
Further information about watchdog programming is available on
https://www.kernel.org/doc/Documen-
tation/watchdog/watchdog-api.txt . The demonstration program needs root rights (compiled on Ubuntu TM
distribution).
/* Watchdog test program
* Copyright (c) 2013 Kontron Technology A/S
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License.
*/
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <asm/types.h>
#include <linux/watchdog.h>
#define WDT_TIMEOUT 20 /* Seconds */
#define WDT_TRIG_TIME 3
#define WDT_DELAY 10 /* Seconds */
#define WDT_MARKUP ((WDT_TIMEOUT - WDT_DELAY) + 10)
static const char *device = "/dev/watchdog";
int main (void)
{
int fd, i;
/*int bootstat;*/
int wdt_time = WDT_TIMEOUT;
fd = open (device, O_WRONLY);
if (fd < 0)
{
printf ("\nWatchdog init error !\n\n");
return -1;
}
/* Check if last boot is caused by watchdog - NOT WORKING PROPERLY */
/*if (ioctl (fd, WDIOC_GETBOOTSTATUS, &bootstat))
printf ("\nCannot read watchdog status !\n");
else
printf ("\nLast boot is caused by : %s\n", (bootstat != 0) ? "Watchdog" : "Power-On-Reset"); */
if (ioctl (fd, WDIOC_SETTIMEOUT, &wdt_time))
printf ("\nSetting of watchdog timeout fails !\n");
else
printf ("\nNew timeout value is : %d seconds\n", wdt_time);