[PATCH v2 2/4] media: v4l2-mc add v4l_change_media_source() to invoke change_source

[Shuah Khan]

Add a common routine to invoke media device change_source handler.

Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
---

Changes since v1:
- Fixed !CONFIG_MEDIA_CONTROLLER compile error for v4l_change_media_source()

 drivers/media/v4l2-core/v4l2-mc.c | 14 ++++++++++++++
 include/media/v4l2-mc.h           | 25 ++++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index ae661ac..478b2768 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -217,6 +217,20 @@ void v4l_disable_media_source(struct video_device *vdev)
 }
 EXPORT_SYMBOL_GPL(v4l_disable_media_source);
 
+int v4l_change_media_source(struct video_device *vdev)
+{
+	struct media_device *mdev = vdev->entity.graph_obj.mdev;
+	int ret;
+
+	if (!mdev || !mdev->change_source)
+		return 0;
+	ret = mdev->change_source(&vdev->entity, &vdev->pipe);
+	if (ret)
+		return -EBUSY;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(v4l_change_media_source);
+
 int v4l_vb2q_enable_media_source(struct vb2_queue *q)
 {
 	struct v4l2_fh *fh = q->owner;
diff --git a/include/media/v4l2-mc.h b/include/media/v4l2-mc.h
index 98a938a..50b9348 100644
--- a/include/media/v4l2-mc.h
+++ b/include/media/v4l2-mc.h
@@ -154,8 +154,26 @@ int v4l_enable_media_source(struct video_device *vdev);
  */
 void v4l_disable_media_source(struct video_device *vdev);
 
+/**
+ * v4l_change_media_source() -	Hold media source for exclusive use
+ *				if free
+ *
+ * @vdev:	pointer to struct video_device
+ *
+ * This interface calls change_source handler to change
+ * the current source it is holding. The change_source
+ * disables the current source and starts pipeline to
+ * the new source. This interface should be used when
+ * user changes source using s_input handler to keep
+ * the previously granted permission for exclusive use
+ * with a new input source.
+ *
+ * Return: returns zero on success or a negative error code.
+ */
+int v4l_change_media_source(struct video_device *vdev);
+
 /*
- * v4l_vb2q_enable_media_tuner -  Hold media source for exclusive use
+ * v4l_vb2q_enable_media_source - Hold media source for exclusive use
  *				  if free.
  * @q - pointer to struct vb2_queue
  *
@@ -219,6 +237,11 @@ static inline int v4l_enable_media_source(struct video_device *vdev)
 	return 0;
 }
 
+static inline int v4l_change_media_source(struct video_device *vdev)
+{
+	return 0;
+}
+
 static inline void v4l_disable_media_source(struct video_device *vdev)
 {
 }
-- 
2.5.0