On 03/02/2017 03:48 PM, Steve Longerbeam wrote:

On 03/02/2017 08:02 AM, Sakari Ailus wrote:

quoted

Hi Steve,

On Wed, Feb 15, 2017 at 06:19:16PM -0800, Steve Longerbeam wrote:

quoted

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 <redacted>
---
 drivers/media/v4l2-core/v4l2-mc.c | 48
+++++++++++++++++++++++++++++++++++++++
 include/media/v4l2-mc.h           | 25 ++++++++++++++++++++
 2 files changed, 73 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-mc.c

b/drivers/media/v4l2-core/v4l2-mc.c
index 303980b..09d4d97 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 +239,53 @@ 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)

I have a few concerns / questions:

- What's the purpose of this patch? Why not to access the sub-device node
  directly?

I don't really understand what you are trying to say.<snip>

Actually I think I understand what you mean now. Yes, the user can
always access a subdev's control directly from its /dev/v4l-subdevXX.
I'm only providing this feature as a convenience to the user, so that
all controls in a pipeline can be accessed from one place, i.e. the
main capture device node.

Steve