libcamera: camera: Add disconnection notification

As camera object have the potential to outlive the hardware they
represent, there is a need to inform the camera that the underlying
device has been disconnected, and in turn to notify applications.

Implement a disconnection notification mechanism that can be used by
pipeline handlers to notify the camera of disconnection. The camera then
block all new API calls and emit the disconnected signal.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
index efafb9e2..a2ded62d 100644
--- a/include/libcamera/camera.h
+++ b/include/libcamera/camera.h
@@ -10,6 +10,8 @@
 #include <memory>
 #include <string>
 
+#include <libcamera/signal.h>
+
 namespace libcamera {
 
 class PipelineHandler;
@@ -25,10 +27,15 @@ public:
 
 	const std::string &name() const;
 
+	Signal<Camera *> disconnected;
+
 private:
 	Camera(PipelineHandler *pipe, const std::string &name);
 	~Camera();
 
+	friend class PipelineHandler;
+	void disconnect();
+
 	std::shared_ptr<PipelineHandler> pipe_;
 	std::string name_;
 };