[media] rcar-vin: refactor pad lookup code

The pad lookup code can be broken out to increase readability and to
reduce code duplication.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/rcar-vin/rcar-v4l2.c

@@ -870,11 +870,25 @@ static void rvin_notify(struct v4l2_subdev *sd,
 	}
 }
 
+static int rvin_find_pad(struct v4l2_subdev *sd, int direction)
+{
+	unsigned int pad;
+
+	if (sd->entity.num_pads <= 1)
+		return 0;
+
+	for (pad = 0; pad < sd->entity.num_pads; pad++)
+		if (sd->entity.pads[pad].flags & direction)
+			return pad;
+
+	return -EINVAL;
+}
+
 int rvin_v4l2_probe(struct rvin_dev *vin)
 {
 	struct video_device *vdev = &vin->vdev;
 	struct v4l2_subdev *sd = vin_to_source(vin);
-	int pad_idx, ret;
+	int ret;
 
 	v4l2_set_subdev_hostdata(sd, vin);
 
@@ -920,21 +934,13 @@ int rvin_v4l2_probe(struct rvin_dev *vin)
 	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
 		V4L2_CAP_READWRITE;
 
-	vin->digital.source_pad = 0;
-	for (pad_idx = 0; pad_idx < sd->entity.num_pads; pad_idx++)
-		if (sd->entity.pads[pad_idx].flags == MEDIA_PAD_FL_SOURCE)
-			break;
-	if (pad_idx >= sd->entity.num_pads)
-		return -EINVAL;
-
-	vin->digital.source_pad = pad_idx;
+	ret = rvin_find_pad(sd, MEDIA_PAD_FL_SOURCE);
+	if (ret < 0)
+		return ret;
+	vin->digital.source_pad = ret;
 
-	vin->digital.sink_pad = 0;
-	for (pad_idx = 0; pad_idx < sd->entity.num_pads; pad_idx++)
-		if (sd->entity.pads[pad_idx].flags == MEDIA_PAD_FL_SINK) {
-			vin->digital.sink_pad = pad_idx;
-			break;
-		}
+	ret = rvin_find_pad(sd, MEDIA_PAD_FL_SINK);
+	vin->digital.sink_pad = ret < 0 ? 0 : ret;
 
 	vin->format.pixelformat	= RVIN_DEFAULT_FORMAT;
 	rvin_reset_format(vin);