m2_g2_fs/Modules/watchdog/main.c

/*
 * Watchdog Driver Test Program
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/watchdog.h>

int fd;

/*
 * This function simply sends an IOCTL to the driver, which in turn ticks
 * the PC Watchdog card to reset its internal timer so it doesn't trigger
 * a computer reset.
 */
static void keep_alive(void)
{
    int dummy;

    ioctl(fd, WDIOC_KEEPALIVE, &dummy);
}

/*
 * The main program.  Run the program with "-d" to disable the card,
 * or "-e" to enable the card.
 */

static void term(int sig)
{
    close(fd);
    printf("Stopping watchdog ticks...\n");
    exit(0);
}

int main(int argc, char *argv[])
{
    int flags;
    int timeout=6;

    fd = open("/dev/watchdog", O_WRONLY);

    if (fd == -1) {
        fprintf(stderr, "Watchdog device not enabled.\n");
        fflush(stderr);
        exit(-1);
    }
    if (argc > 1) {
        if (!strncasecmp(argv[1], "-d", 2)) {
            flags = WDIOS_DISABLECARD;
            ioctl(fd, WDIOC_SETOPTIONS, &flags);
            fprintf(stderr, "Watchdog card disabled.\n");
            fflush(stderr);
            goto end;
        } else if (!strncasecmp(argv[1], "-e", 2)) {
            flags = WDIOS_ENABLECARD;
            ioctl(fd, WDIOC_SETOPTIONS, &flags);
            fprintf(stderr, "Watchdog card enabled.\n");
            fflush(stderr);
            //goto end;
        } else {
            fprintf(stderr, "-d to disable, -e to enable.\n");
            fprintf(stderr, "run by itself to tick the card.\n");
            fflush(stderr);
            goto end;
        }
    } else {
        fprintf(stderr, "Watchdog Ticking Away!\n");
        fflush(stderr);
    }

    signal(SIGTERM, term);
    ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
    ioctl(fd, WDIOC_GETTIMEOUT, &timeout);

    while(1) {
        keep_alive();
        sleep(4);
    }
end:
    close(fd);
    return 0;
}