Add possibility to return the core device interface pointer from the device source API

sdrbase/device/devicesourceapi.cpp

@@ -70,6 +70,11 @@ void DeviceSourceAPI::setSource(DeviceSampleSource* source)
     m_deviceSourceEngine->setSource(source);
 }
 
+DeviceSampleSource *DeviceSourceAPI::getSource()
+{
+    return m_deviceSourceEngine->getSource();
+}
+
 bool DeviceSourceAPI::initAcquisition()
 {
     return m_deviceSourceEngine->initAcquisition();

sdrbase/device/devicesourceapi.h

@@ -48,7 +48,8 @@ public:
     void removeSink(BasebandSampleSink* sink);    //!< Remove a sample sink from device engine
     void addThreadedSink(ThreadedBasebandSampleSink* sink);     //!< Add a sample sink that will run on its own thread to device engine
     void removeThreadedSink(ThreadedBasebandSampleSink* sink);  //!< Remove a sample sink that runs on its own thread from device engine
-    void setSource(DeviceSampleSource* source); //!< Set device engine sample source type
+    void setSource(DeviceSampleSource* source); //!< Set device sample source
+    DeviceSampleSource *getSource();      //!< Return pointer to the device sample source
     bool initAcquisition();               //!< Initialize device engine acquisition sequence
     bool startAcquisition();              //!< Start device engine acquisition sequence
     void stopAcquisition();               //!< Stop device engine acquisition sequence

sdrbase/dsp/dspdevicesourceengine.h

@@ -61,6 +61,7 @@ public:
 
 	void setSource(DeviceSampleSource* source); //!< Set the sample source type
 	void setSourceSequence(int sequence); //!< Set the sample source sequence in type
+	DeviceSampleSource *getSource() { return m_deviceSampleSource; }
 
 	void addSink(BasebandSampleSink* sink); //!< Add a sample sink
 	void removeSink(BasebandSampleSink* sink); //!< Remove a sample sink