linux/tools/testing/selftests/media_tests/media_device_open.c

// SPDX-License-Identifier: GPL-2.0

/*
 * media_device_open.c - Media Controller Device Open Test
 *
 * Copyright (c) 2016 Shuah Khan <shuahkh@osg.samsung.com>
 * Copyright (c) 2016 Samsung Electronics Co., Ltd.
 *
 */

/*
 * This file adds a test for Media Controller API.
 * This test should be run as root and should not be
 * included in the Kselftest run. This test should be
 * run when hardware and driver that makes use Media
 * Controller API are present in the system.
 *
 * This test opens user specified Media Device and calls
 * MEDIA_IOC_DEVICE_INFO ioctl, closes the file, and exits.
 *
 * Usage:
 *	sudo ./media_device_open -d /dev/mediaX
 *
 *	Run this test is a loop and run bind/unbind on the driver.
*/

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <linux/media.h>

int main(int argc, char **argv)
{
	int opt;
	char media_device[256];
	int count = 0;
	struct media_device_info mdi;
	int ret;
	int fd;

	if (argc < 2) {
		printf("Usage: %s [-d </dev/mediaX>]\n", argv[0]);
		exit(-1);
	}

	/* Process arguments */
	while ((opt = getopt(argc, argv, "d:")) != -1) {
		switch (opt) {
		case 'd':
			strncpy(media_device, optarg, sizeof(media_device) - 1);
			media_device[sizeof(media_device)-1] = '\0';
			break;
		default:
			printf("Usage: %s [-d </dev/mediaX>]\n", argv[0]);
			exit(-1);
		}
	}

	if (getuid() != 0) {
		printf("Please run the test as root - Exiting.\n");
		exit(-1);
	}

	/* Open Media device and keep it open */
	fd = open(media_device, O_RDWR);
	if (fd == -1) {
		printf("Media Device open errno %s\n", strerror(errno));
		exit(-1);
	}

	ret = ioctl(fd, MEDIA_IOC_DEVICE_INFO, &mdi);
	if (ret < 0)
		printf("Media Device Info errno %s\n", strerror(errno));
	else
		printf("Media device model %s driver %s\n",
			mdi.model, mdi.driver);
}