V4L/DVB: v4l2: hook up the new control framework into the core framework

Add the calls needed to automatically merge subdev controls into a bridge
control handler.

Hook up the control framework in __video_ioctl2 and video_register_device.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c
index 5a7dc4a..0b08f96 100644
--- a/drivers/media/video/v4l2-device.c
+++ b/drivers/media/video/v4l2-device.c
@@ -26,6 +26,7 @@
 #endif
 #include <linux/videodev2.h>
 #include <media/v4l2-device.h>
+#include <media/v4l2-ctrls.h>
 
 int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev)
 {
@@ -115,6 +116,8 @@
 int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
 						struct v4l2_subdev *sd)
 {
+	int err;
+
 	/* Check for valid input */
 	if (v4l2_dev == NULL || sd == NULL || !sd->name[0])
 		return -EINVAL;
@@ -122,6 +125,10 @@
 	WARN_ON(sd->v4l2_dev != NULL);
 	if (!try_module_get(sd->owner))
 		return -ENODEV;
+	/* This just returns 0 if either of the two args is NULL */
+	err = v4l2_ctrl_add_handler(v4l2_dev->ctrl_handler, sd->ctrl_handler);
+	if (err)
+		return err;
 	sd->v4l2_dev = v4l2_dev;
 	spin_lock(&v4l2_dev->lock);
 	list_add_tail(&sd->list, &v4l2_dev->subdevs);