UNICAM_SD_PAD_SINK
.sink_pad = UNICAM_SD_PAD_SINK,
unicam->subdev.pads[UNICAM_SD_PAD_SINK].flags = MEDIA_PAD_FL_SINK;
struct media_pad *sink = &unicam->subdev.pads[UNICAM_SD_PAD_SINK];
return pad != UNICAM_SD_PAD_SINK;