Index: uspace/lib/drv/generic/remote_audio_pcm.c
===================================================================
--- uspace/lib/drv/generic/remote_audio_pcm.c	(revision 5b77efc0c3d8840957b1c3898dfb3a262dd34b25)
+++ uspace/lib/drv/generic/remote_audio_pcm.c	(revision eb0ef5148d4b4fe77108a5a24002b26178b294a7)
@@ -36,4 +36,5 @@
 #include <ddf/log.h>
 #include <errno.h>
+#include <macros.h>
 #include <str.h>
 #include <as.h>
@@ -58,4 +59,9 @@
 } audio_pcm_iface_funcs_t;
 
+/**
+ * Get human readable capability name.
+ * @param cap audio capability.
+ * @return Valid string
+ */
 const char *audio_pcm_cap_str(audio_cap_t cap)
 {
@@ -69,5 +75,5 @@
 		[AUDIO_CAP_INTERRUPT_MAX_FRAMES] = "MAXIMUM FRAGMENT SIZE",
 	};
-	if (cap > (sizeof(caps) / sizeof(*caps)))
+	if (cap >= ARRAY_SIZE(caps))
 		return "UNKNOWN CAP";
 	return caps[cap];
@@ -75,4 +81,9 @@
 }
 
+/**
+ * Get human readable event name.
+ * @param event Audio device event
+ * @return Valid string
+ */
 const char *audio_pcm_event_str(pcm_event_t event)
 {
@@ -85,5 +96,5 @@
 		[PCM_EVENT_CAPTURE_TERMINATED] = "CAPTURE TERMINATED",
 	};
-	if (event > (sizeof(events) / sizeof(*events)))
+	if (event >= ARRAY_SIZE(events))
 		return "UNKNOWN EVENT";
 	return events[event];
@@ -123,4 +134,5 @@
 	return session;
 }
+
 /**
  * Open audio session with device identified by location service string.
Index: uspace/lib/drv/include/audio_pcm_iface.h
===================================================================
--- uspace/lib/drv/include/audio_pcm_iface.h	(revision 5b77efc0c3d8840957b1c3898dfb3a262dd34b25)
+++ uspace/lib/drv/include/audio_pcm_iface.h	(revision eb0ef5148d4b4fe77108a5a24002b26178b294a7)
@@ -45,10 +45,17 @@
 
 typedef enum {
+	/** Device is capable of audio capture */
 	AUDIO_CAP_CAPTURE,
+	/** Device is capable of audio playback */
 	AUDIO_CAP_PLAYBACK,
+	/** Maximum size of device buffer */
 	AUDIO_CAP_MAX_BUFFER,
+	/** Device is capable of providing accurate buffer position info */
 	AUDIO_CAP_BUFFER_POS,
+	/** Device is capable of event based playback or capture */
 	AUDIO_CAP_INTERRUPT,
+	/** Minimal size of playback/record fragment */
 	AUDIO_CAP_INTERRUPT_MIN_FRAMES,
+	/** Maximum size of playback/record fragment */
 	AUDIO_CAP_INTERRUPT_MAX_FRAMES,
 } audio_cap_t;