v4l2_pipeline_inherit_controls() will add the v4l2 controls from
all subdev entities in a pipeline to a given video device.
Signed-off-by: Steve Longerbeam <steve_longerbeam@xxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-mc.c | 50 +++++++++++++++++++++++++++++++++++++++
include/media/v4l2-mc.h | 31 ++++++++++++++++++++++++
2 files changed, 81 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
index 303980b..fda580e 100644
--- a/drivers/media/v4l2-core/v4l2-mc.c
+++ b/drivers/media/v4l2-core/v4l2-mc.c
@@ -22,6 +22,7 @@
#include <linux/usb.h>
#include <media/media-device.h>
#include <media/media-entity.h>
+#include <media/v4l2-ctrls.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-mc.h>
#include <media/v4l2-subdev.h>
@@ -238,6 +239,55 @@ int v4l_vb2q_enable_media_source(struct vb2_queue *q)
}
EXPORT_SYMBOL_GPL(v4l_vb2q_enable_media_source);
+int __v4l2_pipeline_inherit_controls(struct video_device *vfd,
+ struct media_entity *start_entity)
+{
+ struct media_device *mdev = start_entity->graph_obj.mdev;
+ struct media_entity *entity;
+ struct media_graph graph;
+ struct v4l2_subdev *sd;
+ int ret;
+
+ lockdep_assert_held(&mdev->graph_mutex);
+
+ ret = media_graph_walk_init(&graph, mdev);
+ if (ret)
+ return ret;
+
+ media_graph_walk_start(&graph, start_entity);
+
+ while ((entity = media_graph_walk_next(&graph))) {
+ if (!is_media_entity_v4l2_subdev(entity))
+ continue;
+
+ sd = media_entity_to_v4l2_subdev(entity);
+
+ ret = v4l2_ctrl_add_handler(vfd->ctrl_handler,
+ sd->ctrl_handler,
+ NULL);
+ if (ret)
+ break;
+ }
+
+ media_graph_walk_cleanup(&graph);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__v4l2_pipeline_inherit_controls);
+
+int v4l2_pipeline_inherit_controls(struct video_device *vfd,
+ struct media_entity *start_entity)
+{
+ struct media_device *mdev = start_entity->graph_obj.mdev;
+ int ret;
+
+ mutex_lock(&mdev->graph_mutex);
+ ret = __v4l2_pipeline_inherit_controls(vfd, start_entity);
+ mutex_unlock(&mdev->graph_mutex);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_pipeline_inherit_controls);
+
/* -----------------------------------------------------------------------------
* Pipeline power management
*
diff --git a/include/media/v4l2-mc.h b/include/media/v4l2-mc.h
index 2634d9d..299d75d 100644
--- a/include/media/v4l2-mc.h
+++ b/include/media/v4l2-mc.h
@@ -171,6 +171,23 @@ void v4l_disable_media_source(struct video_device *vdev);
*/
int v4l_vb2q_enable_media_source(struct vb2_queue *q);
+/**
+ * v4l2_pipeline_inherit_controls - Add the v4l2 controls from all
+ * subdev entities in a pipeline to
+ * the given video device.
+ * @vfd: the video device
+ * @start_entity: Starting entity
+ *
+ * This function is intended to be called from the link_notify callback,
+ * which holds the media graph mutex lock. __v4l2_pipeline_inherit_controls
+ * is provided (which does not acquire the lock) for this purpose.
+ * v4l2_pipeline_inherit_controls is also provided for use in other
+ * locations where the graph mutex is not held.
+ */
+int __v4l2_pipeline_inherit_controls(struct video_device *vfd,
+ struct media_entity *start_entity);
+int v4l2_pipeline_inherit_controls(struct video_device *vfd,
+ struct media_entity *start_entity);
/**
* v4l2_pipeline_pm_use - Update the use count of an entity
@@ -231,6 +248,20 @@ static inline int v4l_vb2q_enable_media_source(struct vb2_queue *q)
return 0;
}
+static inline int __v4l2_pipeline_inherit_controls(
+ struct video_device *vfd,
+ struct media_entity *start_entity)
+{
+ return 0;
+}
+
+static inline int v4l2_pipeline_inherit_controls(
+ struct video_device *vfd,
+ struct media_entity *start_entity)
+{
+ return 0;
+}
+
static inline int v4l2_pipeline_pm_use(struct media_entity *entity, int use)
{
return 0;
--
2.7.4
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