VIDIOC_SUBDEV_ENUM_MBUS_CODE — Enumerate media bus formats
| int fsfuncioctl( | int fd, | 
| int request, | |
| struct v4l2_subdev_mbus_code_enum *
	argp ); | 
This is an experimental interface and may change in the future.
To enumerate media bus formats available at a given sub-device pad
    applications initialize the pad and
    index fields of struct v4l2_subdev_mbus_code_enum and
    call the VIDIOC_SUBDEV_ENUM_MBUS_CODE ioctl with a
    pointer to this structure. Drivers fill the rest of the structure or return
    an EINVAL error code if either the pad or
    index are invalid. All media bus formats are
    enumerable by beginning at index zero and incrementing by one until
    EINVAL is returned.
Available media bus formats may depend on the current 'try' formats
    at other pads of the sub-device, as well as on the current active links. See
    VIDIOC_SUBDEV_G_FMT for more information about the try formats.
Table A.90. struct v4l2_subdev_mbus_code_enum
| __u32 | pad | Pad number as reported by the media controller API. | 
| __u32 | index | Number of the format in the enumeration, set by the application. | 
| __u32 | code | The media bus format code, as defined in the section called “Media Bus Formats”. | 
| __u32 | reserved[9] | Reserved for future extensions. Applications and drivers must set the array to zero. | 
On success 0 is returned, on error -1 and the errno variable is set appropriately. The generic error codes are described at the Generic Error Codes chapter.
The struct v4l2_subdev_mbus_code_enum pad
	  references a non-existing pad, or the index
	  field is out of bounds.