Add LUFA-111009-BETA tag.

[pub/USBasp.git] / Demos / Device / ClassDriver / AudioInput / AudioInput.c

diff --git a/Demos/Device/ClassDriver/AudioInput/AudioInput.c b/Demos/Device/ClassDriver/AudioInput/AudioInput.c
index b197588..31e8d96 100644 (file)
--- a/Demos/Device/ClassDriver/AudioInput/AudioInput.c
+++ b/Demos/Device/ClassDriver/AudioInput/AudioInput.c
@@ -51,6 +51,9 @@ USB_ClassInfo_Audio_Device_t Microphone_Audio_Interface =
                        },
        };
 
+/** Current audio sampling frequency of the streaming audio endpoint. */
+static uint32_t CurrentAudioSampleFrequency = 48000;
+
 
 /** Main program entry point. This routine contains the overall program flow, including initial
  *  setup of all components and the main program loop.
@@ -95,7 +98,7 @@ ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 {
        uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
 
-       /* Check if the sample reload timer period has elapsed, and that the USB bus is ready for a new sample */
+       /* Check that the USB bus is ready for the next sample to write */
        if (Audio_Device_IsReadyForNextSample(&Microphone_Audio_Interface))
        {
                int16_t AudioSample;
@@ -133,7 +136,7 @@ void EVENT_USB_Device_Connect(void)
 
        /* Sample reload timer initialization */
        TIMSK0  = (1 << OCIE0A);
-       OCR0A   = ((F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1);
+       OCR0A   = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
        TCCR0A  = (1 << WGM01);  // CTC mode
        TCCR0B  = (1 << CS01);   // Fcpu/8 speed
 }
@@ -163,3 +166,70 @@ void EVENT_USB_Device_ControlRequest(void)
        Audio_Device_ProcessControlRequest(&Microphone_Audio_Interface);
 }
 
+/** Audio class driver callback for the setting and retrieval of streaming endpoint properties. This callback must be implemented
+ *  in the user application to handle property manipulations on streaming audio endpoints.
+ *
+ *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
+ *  the given endpoint index, and should return as fast as possible. When non-NULL, this value may be altered for GET operations
+ *  to indicate the size of the retreived data.
+ *
+ *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
+ *        of the \c DataLength parameter.
+ *
+ *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
+ *  \param[in]     EndpointProperty    Property of the endpoint to get or set, a value from Audio_ClassRequests_t.
+ *  \param[in]     EndpointAddress     Address of the streaming endpoint whose property is being referenced.
+ *  \param[in]     EndpointControl     Parameter of the endpoint to get or set, a value from Audio_EndpointControls_t.
+ *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
+ *                                     length of the retrieved data. When NULL, the function should return whether the given property
+ *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
+ *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
+ *                                     the retrieved data is to be stored for GET operations.
+ *
+ *  \return Boolean true if the property get/set was successful, false otherwise
+ */
+bool CALLBACK_Audio_Device_GetSetEndpointProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
+                                                  const uint8_t EndpointProperty,
+                                                  const uint8_t EndpointAddress,
+                                                  const uint8_t EndpointControl,
+                                                  uint16_t* const DataLength,
+                                                  uint8_t* Data)
+{
+       /* Check the requested endpoint to see if a supported endpoint is being manipulated */
+       if (EndpointAddress == (ENDPOINT_DIR_IN | Microphone_Audio_Interface.Config.DataINEndpointNumber))
+       {
+               /* Check the requested control to see if a supported control is being manipulated */
+               if (EndpointControl == AUDIO_EPCONTROL_SamplingFreq)
+               {
+                       switch (EndpointProperty)
+                       {
+                               case AUDIO_REQ_SetCurrent:
+                                       /* Check if we are just testing for a valid property, or actually adjusting it */
+                                       if (DataLength != NULL)
+                                       {
+                                               /* Set the new sampling frequency to the value given by the host */
+                                               CurrentAudioSampleFrequency = (((uint32_t)Data[2] << 16) | ((uint32_t)Data[1] << 8) | (uint32_t)Data[0]);
+
+                                               /* Adjust sample reload timer to the new frequency */
+                                               OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);                                
+                                       }
+                                       
+                                       return true;                            
+                               case AUDIO_REQ_GetCurrent:
+                                       /* Check if we are just testing for a valid property, or actually reading it */
+                                       if (DataLength != NULL)
+                                       {
+                                               *DataLength = 3;
+
+                                               Data[2] = (CurrentAudioSampleFrequency >> 16);
+                                               Data[1] = (CurrentAudioSampleFrequency >> 8);
+                                               Data[0] = (CurrentAudioSampleFrequency &  0xFF);                                        
+                                       }
+                                       
+                                       return true;
+                       }
+               }
+       }
+       
+       return false;
+}