diff --git a/audio/2.0/IStreamIn.hal b/audio/2.0/IStreamIn.hal
index 9a96f71..e34c95f 100644
--- a/audio/2.0/IStreamIn.hal
+++ b/audio/2.0/IStreamIn.hal
@@ -41,6 +41,26 @@
     setGain(float gain) generates (Result retval);
 
     /*
+     * Commands that can be executed on the driver reader thread.
+     */
+    enum ReadCommand : int32_t {
+        READ,
+        GET_CAPTURE_POSITION
+    };
+
+    /*
+     * Data structure passed to the driver for executing commands
+     * on the driver reader thread.
+     */
+    struct ReadParameters {
+        ReadCommand command;  // discriminator
+        union Params {
+            uint64_t read;    // READ command, amount of bytes to read, >= 0.
+            // No parameters for GET_CAPTURE_POSITION.
+        } params;
+    };
+
+    /*
      * Data structure passed back to the client via status message queue
      * of 'read' operation.
      *
@@ -51,24 +71,36 @@
      */
     struct ReadStatus {
         Result retval;
-        uint64_t read;
+        ReadCommand replyTo;  // discriminator
+        union Reply {
+            uint64_t read;    // READ command, amount of bytes read, >= 0.
+            struct CapturePosition { // same as generated by getCapturePosition.
+                uint64_t frames;
+                uint64_t time;
+            } capturePosition;
+        } reply;
     };
 
     /*
      * Set up required transports for receiving audio buffers from the driver.
      *
-     * The transport consists of two message queues: one is used for passing
-     * audio data from the driver to the client, another is used for reporting
-     * read operation status (amount of bytes actually read or error code),
-     * see ReadStatus structure definition.
+     * The transport consists of three message queues:
+     *  -- command queue is used to instruct the reader thread what operation
+     *     to perform;
+     *  -- data queue is used for passing audio data from the driver
+     *     to the client;
+     *  -- status queue is used for reporting operation status
+     *     (e.g. amount of bytes actually read or error code).
+     * The driver operates on a dedicated thread.
      *
      * @param frameSize the size of a single frame, in bytes.
      * @param framesCount the number of frames in a buffer.
-     * @param threadPriority priority of the thread that performs reads.
+     * @param threadPriority priority of the driver thread.
      * @return retval OK if both message queues were created successfully.
      *                INVALID_STATE if the method was already called.
      *                INVALID_ARGUMENTS if there was a problem setting up
      *                                  the queues.
+     * @return commandMQ a message queue used for passing commands.
      * @return dataMQ a message queue used for passing audio data in the format
      *                specified at the stream opening.
      * @return statusMQ a message queue used for passing status from the driver
@@ -79,7 +111,9 @@
             ThreadPriority threadPriority)
     generates (
             Result retval,
-            fmq_sync<uint8_t> dataMQ, fmq_sync<ReadStatus> statusMQ);
+            fmq_sync<ReadParameters> commandMQ,
+            fmq_sync<uint8_t> dataMQ,
+            fmq_sync<ReadStatus> statusMQ);
 
     /*
      * Return the amount of input frames lost in the audio driver since the last