Doc updates

module_usb_audio/mixer/mixer.h

@@ -0,0 +1,32 @@
+#ifndef __mixer_h__
+#define __mixer_h__
+
+enum mix_ctl_cmd {
+  SET_SAMPLES_TO_HOST_MAP,
+  SET_SAMPLES_TO_DEVICE_MAP,
+  SET_MIX_MULT,
+  SET_MIX_MAP,
+  SET_MIX_IN_VOL,
+  SET_MIX_OUT_VOL,
+  GET_INPUT_LEVELS,
+  GET_STREAM_LEVELS,
+  GET_OUTPUT_LEVELS
+};
+
+
+/** Digital sample mixer.
+ *
+ *  This thread mixes audio streams between the decouple() thread and
+ *  the audio() thread.
+ * 
+ *  \param c_to_host a chanend connected to the decouple() thread for
+ *                   receiving/transmitting samples
+ *  \param c_to_audio a chanend connected to the audio() thread for
+ *                    receiving/transmitting samples
+ *  \param c_mix_ctl a chanend connected to the Endpoint0() thread for
+ *                   receiving control commands 
+ * 
+ */
+void mixer(chanend c_to_host, chanend c_to_audio, chanend c_mix_ctl);
+
+#endif