[media] ivtv: add IVTV_IOC_PASSTHROUGH_MODE

With this private ioctl it is possible to use the ivtv decoder without
requiring the dvb/video.h and dvb/audio.h headers.

Eventually support for those DVB APIs will be dropped from ivtv.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/linux/ivtv.h b/include/linux/ivtv.h
index 062d20f..42bf725 100644
--- a/include/linux/ivtv.h
+++ b/include/linux/ivtv.h
@@ -58,7 +58,11 @@
 	__u32 src_height;
 };
 
-#define IVTV_IOC_DMA_FRAME  _IOW ('V', BASE_VIDIOC_PRIVATE+0, struct ivtv_dma_frame)
+#define IVTV_IOC_DMA_FRAME		_IOW ('V', BASE_VIDIOC_PRIVATE+0, struct ivtv_dma_frame)
+
+/* Select the passthrough mode (if the argument is non-zero). In the passthrough
+   mode the output of the encoder is passed immediately into the decoder. */
+#define IVTV_IOC_PASSTHROUGH_MODE	_IOW ('V', BASE_VIDIOC_PRIVATE+1, int)
 
 /* Deprecated defines: applications should use the defines from videodev2.h */
 #define IVTV_SLICED_TYPE_TELETEXT_B     V4L2_MPEG_VBI_IVTV_TELETEXT_B