V4L/DVB (13905): cx18: Allow MPEG index streams to be started and stopped internally

This change allows the IDX stream to be started and stopped as any other
stream even though it has no associated device node.  This is needed for
cx18 driver internal use.

Also always tell the CX23418 to generate index entries when an analog capture
starts and the IDX stream has had buffers allocated (i.e. is enabled).
Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx18/cx18-streams.c

@@ -358,7 +358,9 @@ void cx18_streams_cleanup(struct cx18 *cx, int unregister)
 
 static inline bool cx18_stream_enabled(struct cx18_stream *s)
 {
-	return s->video_dev || s->dvb.enabled;
+	return s->video_dev || s->dvb.enabled ||
+	       (s->type == CX18_ENC_STREAM_TYPE_IDX &&
+		s->cx->stream_buffers[CX18_ENC_STREAM_TYPE_IDX] != 0);
 }
 
 static void cx18_vbi_setup(struct cx18_stream *s)
@@ -567,6 +569,7 @@ int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
 	struct cx18 *cx = s->cx;
 	int captype = 0;
 	struct cx18_api_func_private priv;
+	struct cx18_stream *s_idx;
 
 	if (!cx18_stream_enabled(s))
 		return -EINVAL;
@@ -582,6 +585,9 @@ int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
 		cx->search_pack_header = 0;
 		break;
 
+	case CX18_ENC_STREAM_TYPE_IDX:
+		captype = CAPTURE_CHANNEL_TYPE_INDEX;
+		break;
 	case CX18_ENC_STREAM_TYPE_TS:
 		captype = CAPTURE_CHANNEL_TYPE_TS;
 		break;
@@ -656,11 +662,13 @@ int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
 			cx18_vbi_setup(s);
 
 		/*
-		 * assign program index info.
-		 * Mask 7: select I/P/B, Num_req: 400 max
-		 * FIXME - currently we have this hardcoded as disabled
+		 * Select to receive I, P, and B frame index entries, if the
+		 * index stream is enabled.  Otherwise disable index entry
+		 * generation.
 		 */
-		cx18_vapi_result(cx, data, CX18_CPU_SET_INDEXTABLE, 1, 0);
+		s_idx = &cx->streams[CX18_ENC_STREAM_TYPE_IDX];
+		cx18_vapi_result(cx, data, CX18_CPU_SET_INDEXTABLE, 1,
+				 cx18_stream_enabled(s_idx) ? 7 : 0);
 
 		/* Call out to the common CX2341x API setup for user controls */
 		priv.cx = cx;