linux_kernel/tools/testing/selftests/watchdog/watchdog-test.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Watchdog Driver Test Program
 */

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

#define DEFAULT_PING_RATE	1

int fd;
const char v = 'V';
static const char sopts[] = "bdehp:t:";
static const struct option lopts[] = {
	{"bootstatus",          no_argument, NULL, 'b'},
	{"disable",             no_argument, NULL, 'd'},
	{"enable",              no_argument, NULL, 'e'},
	{"help",                no_argument, NULL, 'h'},
	{"pingrate",      required_argument, NULL, 'p'},
	{"timeout",       required_argument, NULL, 't'},
	{NULL,                  no_argument, NULL, 0x0}
};

/*
 * 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;
	int ret;

	ret = ioctl(fd, WDIOC_KEEPALIVE, &dummy);
	if (!ret)
		printf(".");
}

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

static void term(int sig)
{
	int ret = write(fd, &v, 1);

	close(fd);
	if (ret < 0)
		printf("\nStopping watchdog ticks failed (%d)...\n", errno);
	else
		printf("\nStopping watchdog ticks...\n");
	exit(0);
}

static void usage(char *progname)
{
	printf("Usage: %s [options]\n", progname);
	printf(" -b, --bootstatus    Get last boot status (Watchdog/POR)\n");
	printf(" -d, --disable       Turn off the watchdog timer\n");
	printf(" -e, --enable        Turn on the watchdog timer\n");
	printf(" -h, --help          Print the help message\n");
	printf(" -p, --pingrate=P    Set ping rate to P seconds (default %d)\n", DEFAULT_PING_RATE);
	printf(" -t, --timeout=T     Set timeout to T seconds\n");
	printf("\n");
	printf("Parameters are parsed left-to-right in real-time.\n");
	printf("Example: %s -d -t 10 -p 5 -e\n", progname);
}

int main(int argc, char *argv[])
{
	int flags;
	unsigned int ping_rate = DEFAULT_PING_RATE;
	int ret;
	int c;
	int oneshot = 0;

	setbuf(stdout, NULL);

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

	if (fd == -1) {
		printf("Watchdog device not enabled.\n");
		exit(-1);
	}

	while ((c = getopt_long(argc, argv, sopts, lopts, NULL)) != -1) {
		switch (c) {
		case 'b':
			flags = 0;
			oneshot = 1;
			ret = ioctl(fd, WDIOC_GETBOOTSTATUS, &flags);
			if (!ret)
				printf("Last boot is caused by: %s.\n", (flags != 0) ?
					"Watchdog" : "Power-On-Reset");
			else
				printf("WDIOC_GETBOOTSTATUS errno '%s'\n", strerror(errno));
			break;
		case 'd':
			flags = WDIOS_DISABLECARD;
			ret = ioctl(fd, WDIOC_SETOPTIONS, &flags);
			if (!ret)
				printf("Watchdog card disabled.\n");
			else
				printf("WDIOS_DISABLECARD errno '%s'\n", strerror(errno));
			break;
		case 'e':
			flags = WDIOS_ENABLECARD;
			ret = ioctl(fd, WDIOC_SETOPTIONS, &flags);
			if (!ret)
				printf("Watchdog card enabled.\n");
			else
				printf("WDIOS_ENABLECARD errno '%s'\n", strerror(errno));
			break;
		case 'p':
			ping_rate = strtoul(optarg, NULL, 0);
			if (!ping_rate)
				ping_rate = DEFAULT_PING_RATE;
			printf("Watchdog ping rate set to %u seconds.\n", ping_rate);
			break;
		case 't':
			flags = strtoul(optarg, NULL, 0);
			ret = ioctl(fd, WDIOC_SETTIMEOUT, &flags);
			if (!ret)
				printf("Watchdog timeout set to %u seconds.\n", flags);
			else
				printf("WDIOC_SETTIMEOUT errno '%s'\n", strerror(errno));
			break;
		default:
			usage(argv[0]);
			goto end;
		}
	}

	if (oneshot)
		goto end;

	printf("Watchdog Ticking Away!\n");

	signal(SIGINT, term);

	while (1) {
		keep_alive();
		sleep(ping_rate);
	}
end:
	ret = write(fd, &v, 1);
	if (ret < 0)
		printf("Stopping watchdog ticks failed (%d)...\n", errno);
	close(fd);
	return 0;
}