More documentation changes (rawmidi, timer)

src/control/hcontrol.c

@@ -7,6 +7,7 @@
  *
  * HCTL interface is designed to access preloaded and sorted primitive controls.
  * Callbacks may be used for event handling.
+ * See \ref hcontrol page for more details.
  */
 /*
  *  Control Interface - highlevel API
@@ -30,6 +31,17 @@
  *
  */
 
+/*! \page hcontrol High level control interface
+
+<P> High level control interface is designed to access preloaded and sorted primitive controls.
+
+\section hcontrol_general_overview General overview
+
+<P> High level control interface caches the accesses to primitive controls
+to reduce overhead accessing the real controls in kernel drivers.
+
+*/
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>