/*
 * udi_audio.c
*/

//===================== DAC/Speaker Interface =====================


	UDC_DESC_STORAGE udi_api_t udi_api_audio_out_stream = 
	{
		.enable =		udi_audio_stream_out_enable,
		.disable =		udi_audio_stream_out_disable,
		.setup =		udi_audio_stream_out_setup,
		.getsetting =	udi_audio_stream_out_getsetting,
		.sof_notify =	udi_audio_stream_out_SOF_routine,
	};
	
	//SOF routine provides Feedback data to IN endpoint
	static void udi_audio_stream_out_SOF_routine(void){
		
		#if (SPEAKER_FB_EP_ENABLED)
			
			if (udi_audio_out_alt_setting)
			{	
				if (FB_EP_start_counter)
				{					
					//read current timer value
					FB_EP_tc_last_val = tc_get_count_value(&tc_instance);
					
					//reset flag
					FB_EP_start_counter = false;
					
					return;
				} 
				
				//4 ms refresh cycle
				if (++FB_EP_SOF_count == UDI_AUDIO_OUT_FB_EP_IN_POLL_RATE_MS)		
				{	
					//read current timer value
					FB_EP_tc_cur_val = tc_get_count_value(&tc_instance);
					
					//check for buffer overflow
					if (FB_EP_tc_cur_val > FB_EP_tc_last_val)
					{
						//buffer has not overflowed
						FB_EP_tmp = FB_EP_tc_cur_val - FB_EP_tc_last_val;
					}
					else
					{	//buffer has overflowed
						FB_EP_tmp = FB_EP_tc_cur_val - FB_EP_tc_last_val + 65536;
					}
					
					FB_EP_tmp /=  1024;		//49152 / 1024 = 48
					
					//convert new fb value and store to array
					FB_EP_val_1014 = ConvFloatTo1014(FB_EP_tmp);
					PutBytesToBuf(FB_EP_IN_BUF, FB_EP_val_1014);
					
					//reset counter for averaging
					FB_EP_SOF_count = 0;

					//read current timer value
					FB_EP_tc_last_val = tc_get_count_value(&tc_instance);
					
					return;
				}
			}
		#endif
	}
	
	static bool udi_audio_stream_out_enable(void)
	{
		udi_audio_out_alt_setting = udc_get_interface_desc()->bAlternateSetting;
	
		if (udi_audio_out_alt_setting)	// Alternate Setting 1 (streaming on)
		{
				// start streaming
				startOutStreaming = 1;
				speaker_fifo.buf_write_block_index = 0;
				speaker_fifo.buf_write_sample_index = 0;
				
				#if (SPEAKER_TMP_BUFFERS_ENABLE)
					tx_tmp_buffer_index = 0;	
				#endif
				
				#if (SPEAKER_FB_EP_ENABLED)
					//get first timer value
					FB_EP_start_counter = true;
					
					udd_ep_run(UDI_AUDIO_OUT_FB_EP_IN, true, (uint8_t*) &FB_EP_IN_BUF, 
							   UDI_AUDIO_OUT_FB_EP_IN_PACKETSIZE, NULL);
				#endif
				
				if(!udi_audio_stream_out_start()) return false;
				startOutStreaming = 1;
		}
		else							// Alternate Setting 0 (streaming off)
		{
			// stop streaming
			startOutStreaming = 0;
			udi_audio_stream_out_stop();
		}
		return true;
	}


#endif