libcamera: camera_lens: Add function to fetch subdev controls

Add a function to the CameraLens class to fetch the V4L2 controls
for its V4L2 subdev

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
diff --git a/include/libcamera/internal/camera_lens.h b/include/libcamera/internal/camera_lens.h
index ff4d066..277417d 100644
--- a/include/libcamera/internal/camera_lens.h
+++ b/include/libcamera/internal/camera_lens.h
@@ -12,6 +12,8 @@
 #include <libcamera/base/class.h>
 #include <libcamera/base/log.h>
 
+#include <libcamera/controls.h>
+
 namespace libcamera {
 
 class MediaEntity;
@@ -28,6 +30,8 @@
 
 	const std::string &model() const { return model_; }
 
+	const ControlInfoMap &controls() const;
+
 protected:
 	std::string logPrefix() const override;
 
diff --git a/src/libcamera/camera_lens.cpp b/src/libcamera/camera_lens.cpp
index 810fcff..b3d4819 100644
--- a/src/libcamera/camera_lens.cpp
+++ b/src/libcamera/camera_lens.cpp
@@ -139,4 +139,15 @@
 	return "'" + entity_->name() + "'";
 }
 
+/**
+ * \fn CameraLens::controls()
+ * \brief Retrieve the V4L2 controls of the lens' subdev
+ *
+ * \return A map of the V4L2 controls supported by the lens' driver
+ */
+const ControlInfoMap &CameraLens::controls() const
+{
+	return subdev_->controls();
+}
+
 } /* namespace libcamera */