src/udev/v4l_id/v4l_id.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * Copyright (c) 2009 Filippo Argiolas <filippo.argiolas@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation; either version 2 of the
   8  * License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details:
  14  */
  15
  16 #include <ctype.h>
  17 #include <errno.h>
  18 #include <fcntl.h>
  19 #include <getopt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/ioctl.h>
  24 #include <sys/time.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27 #include <linux/videodev2.h>
  28
  29 #include "fd-util.h"
  30 #include "util.h"
  31
  32 int main(int argc, char *argv[]) {
  33         static const struct option options[] = {
  34                 { "help", no_argument, NULL, 'h' },
  35                 {}
  36         };
  37         _cleanup_close_ int fd = -1;
  38         char *device;
  39         struct v4l2_capability v2cap;
  40         int c;
  41
  42         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
  43
  44                 switch (c) {
  45                 case 'h':
  46                         printf("%s [-h,--help] <device file>\n\n"
  47                                "Video4Linux device identification.\n\n"
  48                                "  -h  Print this message\n"
  49                                , program_invocation_short_name);
  50                         return 0;
  51                 case '?':
  52                         return -EINVAL;
  53
  54                 default:
  55                         assert_not_reached("Unhandled option");
  56                 }
  57
  58         device = argv[optind];
  59         if (device == NULL)
  60                 return 2;
  61
  62         fd = open(device, O_RDONLY);
  63         if (fd < 0)
  64                 return 3;
  65
  66         if (ioctl(fd, VIDIOC_QUERYCAP, &v2cap) == 0) {
  67                 int capabilities;
  68                 printf("ID_V4L_VERSION=2\n");
  69                 printf("ID_V4L_PRODUCT=%s\n", v2cap.card);
  70                 printf("ID_V4L_CAPABILITIES=:");
  71                 if (v2cap.capabilities & V4L2_CAP_DEVICE_CAPS)
  72                         capabilities = v2cap.device_caps;
  73                 else
  74                         capabilities = v2cap.capabilities;
  75                 if ((capabilities & V4L2_CAP_VIDEO_CAPTURE) > 0 ||
  76                     (capabilities & V4L2_CAP_VIDEO_CAPTURE_MPLANE) > 0)
  77                         printf("capture:");
  78                 if ((capabilities & V4L2_CAP_VIDEO_OUTPUT) > 0 ||
  79                     (capabilities & V4L2_CAP_VIDEO_OUTPUT_MPLANE) > 0)
  80                         printf("video_output:");
  81                 if ((capabilities & V4L2_CAP_VIDEO_OVERLAY) > 0)
  82                         printf("video_overlay:");
  83                 if ((capabilities & V4L2_CAP_AUDIO) > 0)
  84                         printf("audio:");
  85                 if ((capabilities & V4L2_CAP_TUNER) > 0)
  86                         printf("tuner:");
  87                 if ((capabilities & V4L2_CAP_RADIO) > 0)
  88                         printf("radio:");
  89                 printf("\n");
  90         }
  91
  92         return 0;
  93 }