libcamera: media_device: Use Loggable interface

Extend MediaDevice to inherit from the Loggable interface to support a
logPrefix which presents the device node path, and the driver name.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/include/media_device.h

@@ -16,11 +16,12 @@
 
 #include <libcamera/signal.h>
 
+#include "log.h"
 #include "media_object.h"
 
 namespace libcamera {
 
-class MediaDevice
+class MediaDevice : protected Loggable
 {
 public:
 	MediaDevice(const std::string &deviceNode);
@@ -52,6 +53,9 @@ public:
 
 	Signal<MediaDevice *> disconnected;
 
+protected:
+	std::string logPrefix() const;
+
 private:
 	std::string driver_;
 	std::string deviceNode_;

src/libcamera/media_device.cpp

@@ -75,6 +75,11 @@ MediaDevice::~MediaDevice()
 	clear();
 }
 
+std::string MediaDevice::logPrefix() const
+{
+	return deviceNode() + "[" + driver() + "]";
+}
+
 /**
  * \brief Claim a device for exclusive use
  *