[media] ivtv: don't allow g/s_frequency for output device nodes

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/pci/ivtv/ivtv-ioctl.c b/drivers/media/pci/ivtv/ivtv-ioctl.c
index e5ce970..5537c88 100644
--- a/drivers/media/pci/ivtv/ivtv-ioctl.c
+++ b/drivers/media/pci/ivtv/ivtv-ioctl.c
@@ -1064,7 +1064,10 @@
 static int ivtv_g_frequency(struct file *file, void *fh, struct v4l2_frequency *vf)
 {
 	struct ivtv *itv = fh2id(fh)->itv;
+	struct ivtv_stream *s = &itv->streams[fh2id(fh)->type];
 
+	if (s->vdev->vfl_dir)
+		return -ENOTTY;
 	if (vf->tuner != 0)
 		return -EINVAL;
 
@@ -1075,7 +1078,10 @@
 int ivtv_s_frequency(struct file *file, void *fh, struct v4l2_frequency *vf)
 {
 	struct ivtv *itv = fh2id(fh)->itv;
+	struct ivtv_stream *s = &itv->streams[fh2id(fh)->type];
 
+	if (s->vdev->vfl_dir)
+		return -ENOTTY;
 	if (vf->tuner != 0)
 		return -EINVAL;