diff --git a/include/media/AudioIoDescriptor.h b/include/media/AudioIoDescriptor.h
index 2437901..c94b738 100644
--- a/include/media/AudioIoDescriptor.h
+++ b/include/media/AudioIoDescriptor.h
@@ -33,12 +33,31 @@
 class AudioIoDescriptor : public RefBase {
 public:
     AudioIoDescriptor() :
+        mIoHandle(AUDIO_IO_HANDLE_NONE),
         mSamplingRate(0), mFormat(AUDIO_FORMAT_DEFAULT), mChannelMask(AUDIO_CHANNEL_NONE),
-        mFrameCount(0), mLatency(0) {}
+        mFrameCount(0), mLatency(0)
+    {
+        memset(&mPatch, 0, sizeof(struct audio_patch));
+    }
 
     virtual ~AudioIoDescriptor() {}
 
+    audio_port_handle_t getDeviceId() {
+        if (mPatch.num_sources != 0 && mPatch.num_sinks != 0) {
+            if (mPatch.sources[0].type == AUDIO_PORT_TYPE_MIX) {
+                // this is an output mix
+                // FIXME: the API only returns the first device in case of multiple device selection
+                return mPatch.sinks[0].id;
+            } else {
+                // this is an input mix
+                return mPatch.sources[0].id;
+            }
+        }
+        return AUDIO_PORT_HANDLE_NONE;
+    }
+
     audio_io_handle_t mIoHandle;
+    struct audio_patch mPatch;
     uint32_t mSamplingRate;
     audio_format_t mFormat;
     audio_channel_mask_t mChannelMask;
diff --git a/include/media/AudioRecord.h b/include/media/AudioRecord.h
index b743c11..0403e1a 100644
--- a/include/media/AudioRecord.h
+++ b/include/media/AudioRecord.h
@@ -390,6 +390,39 @@
      * TODO Document this method.
      */
             audio_port_handle_t getInputDevice();
+
+     /* Returns the ID of the audio device actually used by the input to which this AudioRecord
+      * is attached.
+      * A value of AUDIO_PORT_HANDLE_NONE indicates the AudioRecord is not attached to any input.
+      *
+      * Parameters:
+      *  none.
+      */
+     audio_port_handle_t getRoutedDeviceId();
+
+    /* Add an AudioDeviceCallback. The caller will be notified when the audio device
+     * to which this AudioRecord is routed is updated.
+     * Replaces any previously installed callback.
+     * Parameters:
+     *  callback:  The callback interface
+     * Returns NO_ERROR if successful.
+     *         INVALID_OPERATION if the same callback is already installed.
+     *         NO_INIT or PREMISSION_DENIED if AudioFlinger service is not reachable
+     *         BAD_VALUE if the callback is NULL
+     */
+            status_t addAudioDeviceCallback(
+                    const sp<AudioSystem::AudioDeviceCallback>& callback);
+
+    /* remove an AudioDeviceCallback.
+     * Parameters:
+     *  callback:  The callback interface
+     * Returns NO_ERROR if successful.
+     *         INVALID_OPERATION if the callback is not installed
+     *         BAD_VALUE if the callback is NULL
+     */
+            status_t removeAudioDeviceCallback(
+                    const sp<AudioSystem::AudioDeviceCallback>& callback);
+
 private:
     /* If nonContig is non-NULL, it is an output parameter that will be set to the number of
      * additional non-contiguous frames that are predicted to be available immediately,
@@ -582,6 +615,7 @@
     // For Device Selection API
     //  a value of AUDIO_PORT_HANDLE_NONE indicated default (AudioPolicyManager) routing.
     audio_port_handle_t    mSelectedDeviceId;
+    sp<AudioSystem::AudioDeviceCallback> mDeviceCallback;
 };
 
 }; // namespace android
diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index 0cbcdb1..3241e9c 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -332,8 +332,26 @@
 
     };
 
-    static status_t addAudioPortCallback(const sp<AudioPortCallback>& callBack);
-    static status_t removeAudioPortCallback(const sp<AudioPortCallback>& callBack);
+    static status_t addAudioPortCallback(const sp<AudioPortCallback>& callback);
+    static status_t removeAudioPortCallback(const sp<AudioPortCallback>& callback);
+
+    class AudioDeviceCallback : public RefBase
+    {
+    public:
+
+                AudioDeviceCallback() {}
+        virtual ~AudioDeviceCallback() {}
+
+        virtual void onAudioDeviceUpdate(audio_io_handle_t audioIo,
+                                         audio_port_handle_t deviceId) = 0;
+    };
+
+    static status_t addAudioDeviceCallback(const sp<AudioDeviceCallback>& callback,
+                                           audio_io_handle_t audioIo);
+    static status_t removeAudioDeviceCallback(const sp<AudioDeviceCallback>& callback,
+                                              audio_io_handle_t audioIo);
+
+    static audio_port_handle_t getDeviceIdForIo(audio_io_handle_t audioIo);
 
 private:
 
@@ -359,10 +377,20 @@
         // values for output/input parameters up-to-date in client process
         virtual void ioConfigChanged(audio_io_config_event event,
                                      const sp<AudioIoDescriptor>& ioDesc);
+
+
+        status_t addAudioDeviceCallback(const sp<AudioDeviceCallback>& callback,
+                                               audio_io_handle_t audioIo);
+        status_t removeAudioDeviceCallback(const sp<AudioDeviceCallback>& callback,
+                                           audio_io_handle_t audioIo);
+
+        audio_port_handle_t getDeviceIdForIo(audio_io_handle_t audioIo);
+
     private:
         Mutex                               mLock;
-        DefaultKeyedVector<audio_io_handle_t, sp<AudioIoDescriptor> > mIoDescriptors;
-
+        DefaultKeyedVector<audio_io_handle_t, sp<AudioIoDescriptor> >   mIoDescriptors;
+        DefaultKeyedVector<audio_io_handle_t, Vector < sp<AudioDeviceCallback> > >
+                                                                        mAudioDeviceCallbacks;
         // cached values for recording getInputBufferSize() queries
         size_t                              mInBuffSize;    // zero indicates cache is invalid
         uint32_t                            mInSamplingRate;
@@ -377,8 +405,8 @@
         AudioPolicyServiceClient() {
         }
 
-        status_t addAudioPortCallback(const sp<AudioPortCallback>& callBack);
-        status_t removeAudioPortCallback(const sp<AudioPortCallback>& callBack);
+        status_t addAudioPortCallback(const sp<AudioPortCallback>& callback);
+        status_t removeAudioPortCallback(const sp<AudioPortCallback>& callback);
 
         // DeathRecipient
         virtual void binderDied(const wp<IBinder>& who);
@@ -393,6 +421,9 @@
         Vector <sp <AudioPortCallback> >    mAudioPortCallbacks;
     };
 
+    static const sp<AudioFlingerClient> getAudioFlingerClient();
+    static sp<AudioIoDescriptor> getIoDescriptor(audio_io_handle_t ioHandle);
+
     static sp<AudioFlingerClient> gAudioFlingerClient;
     static sp<AudioPolicyServiceClient> gAudioPolicyServiceClient;
     friend class AudioFlingerClient;
diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
index 0ccd19e..458f4b4 100644
--- a/include/media/AudioTrack.h
+++ b/include/media/AudioTrack.h
@@ -510,7 +510,7 @@
      */
             status_t    setOutputDevice(audio_port_handle_t deviceId);
 
-    /* Returns the ID of the audio device used for output of this AudioTrack.
+    /* Returns the ID of the audio device selected for this AudioTrack.
      * A value of AUDIO_PORT_HANDLE_NONE indicates default (AudioPolicyManager) routing.
      *
      * Parameters:
@@ -518,6 +518,15 @@
      */
      audio_port_handle_t getOutputDevice();
 
+     /* Returns the ID of the audio device actually used by the output to which this AudioTrack is
+      * attached.
+      * A value of AUDIO_PORT_HANDLE_NONE indicates the audio track is not attached to any output.
+      *
+      * Parameters:
+      *  none.
+      */
+     audio_port_handle_t getRoutedDeviceId();
+
     /* Returns the unique session ID associated with this track.
      *
      * Parameters:
@@ -664,6 +673,28 @@
      */
             status_t    getTimestamp(AudioTimestamp& timestamp);
 
+    /* Add an AudioDeviceCallback. The caller will be notified when the audio device to which this
+     * AudioTrack is routed is updated.
+     * Replaces any previously installed callback.
+     * Parameters:
+     *  callback:  The callback interface
+     * Returns NO_ERROR if successful.
+     *         INVALID_OPERATION if the same callback is already installed.
+     *         NO_INIT or PREMISSION_DENIED if AudioFlinger service is not reachable
+     *         BAD_VALUE if the callback is NULL
+     */
+            status_t addAudioDeviceCallback(const sp<AudioSystem::AudioDeviceCallback>& callback);
+
+    /* remove an AudioDeviceCallback.
+     * Parameters:
+     *  callback:  The callback interface
+     * Returns NO_ERROR if successful.
+     *         INVALID_OPERATION if the callback is not installed
+     *         BAD_VALUE if the callback is NULL
+     */
+            status_t removeAudioDeviceCallback(
+                    const sp<AudioSystem::AudioDeviceCallback>& callback);
+
 protected:
     /* copying audio tracks is not allowed */
                         AudioTrack(const AudioTrack& other);
@@ -885,6 +916,8 @@
     uint32_t                mSequence;              // incremented for each new IAudioTrack attempt
     int                     mClientUid;
     pid_t                   mClientPid;
+
+    sp<AudioSystem::AudioDeviceCallback> mDeviceCallback;
 };
 
 class TimedAudioTrack : public AudioTrack