libcamera: camera: Provide a list of ControlInfo

Extend the Camera class to expose the controls it supports. Each
pipeline should generate a list of controls supported by each camera it
creates. These are represented by a ControlInfoMap, and an associated
ControlList of default values.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

include/libcamera/camera.h

@@ -12,6 +12,7 @@
 #include <set>
 #include <string>
 
+#include <libcamera/controls.h>
 #include <libcamera/request.h>
 #include <libcamera/signal.h>
 #include <libcamera/stream.h>
@@ -83,6 +84,8 @@ public:
 	int acquire();
 	int release();
 
+	const ControlInfoMap &controls();
+
 	const std::set<Stream *> &streams() const;
 	std::unique_ptr<CameraConfiguration> generateConfiguration(const StreamRoles &roles);
 	int configure(CameraConfiguration *config);

include/libcamera/controls.h

@@ -99,6 +99,8 @@ static inline bool operator!=(const ControlInfo &lhs, const ControlId &rhs)
 	return !(lhs == rhs);
 }
 
+using ControlInfoMap = std::unordered_map<ControlId, ControlInfo>;
+
 class ControlList
 {
 private: