GREYBUS_PROTOCOL_LIGHTS         = 0x0f,
        GREYBUS_PROTOCOL_VIBRATOR       = 0x10,
        GREYBUS_PROTOCOL_LOOPBACK       = 0x11,
-       /* 0x12 is unused */
-       /* 0x13 is unused */
+       GREYBUS_PROTOCOL_AUDIO_MGMT     = 0x12,
+       GREYBUS_PROTOCOL_AUDIO_DATA     = 0x13,
        GREYBUS_PROTOCOL_SVC            = 0x14,
        GREYBUS_PROTOCOL_FIRMWARE       = 0x15,
                /* ... */
        GREYBUS_CLASS_LIGHTS            = 0x0f,
        GREYBUS_CLASS_VIBRATOR          = 0x10,
        GREYBUS_CLASS_LOOPBACK          = 0x11,
-       /* 0x12 is unused */
-       /* 0x13 is unused */
+       GREYBUS_CLASS_AUDIO_MGMT        = 0x12,
+       GREYBUS_CLASS_AUDIO_DATA        = 0x13,
        GREYBUS_CLASS_SVC               = 0x14,
        GREYBUS_CLASS_FIRMWARE          = 0x15,
                /* ... */