+ case AUDIO_REQ_GetStatus:
+ /* Get Status request can be directed at either the interface or endpoint, neither is currently used
+ * according to the latest USB Audio 1.0 standard, but must be ACKed with no data when requested */
+ if ((USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_INTERFACE)) ||
+ (USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_ENDPOINT)))
+ {
+ Endpoint_ClearSETUP();
+ Endpoint_ClearStatusStage();
+ }
+
+ break;
+ case AUDIO_REQ_SetCurrent:
+ if (USB_ControlRequest.bmRequestType == (REQDIR_HOSTTODEVICE | REQTYPE_CLASS | REQREC_ENDPOINT))
+ {
+ /* Extract out the relevant request information to get the target Endpoint address and control being set */
+ uint8_t EndpointAddress = (uint8_t)USB_ControlRequest.wIndex;
+ uint8_t EndpointControl = (USB_ControlRequest.wValue >> 8);
+
+ /* Only handle SET CURRENT requests to the audio endpoint's sample frequency property */
+ if ((EndpointAddress == (ENDPOINT_DESCRIPTOR_DIR_IN | AUDIO_STREAM_EPNUM)) && (EndpointControl == AUDIO_EPCONTROL_SamplingFreq))
+ {
+ uint8_t SampleRate[3];
+
+ Endpoint_ClearSETUP();
+ Endpoint_Read_Control_Stream_LE(SampleRate, sizeof(SampleRate));
+ Endpoint_ClearIN();
+
+ /* Set the new sampling frequency to the value given by the host */
+ CurrentAudioSampleFrequency = (((uint32_t)SampleRate[2] << 16) | ((uint32_t)SampleRate[1] << 8) | (uint32_t)SampleRate[0]);
+
+ /* Adjust sample reload timer to the new frequency */
+ OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
+ }
+ }
+
+ break;
+ case AUDIO_REQ_GetCurrent:
+ if (USB_ControlRequest.bmRequestType == (REQDIR_DEVICETOHOST | REQTYPE_CLASS | REQREC_ENDPOINT))
+ {
+ /* Extract out the relevant request information to get the target Endpoint address and control being retrieved */
+ uint8_t EndpointAddress = (uint8_t)USB_ControlRequest.wIndex;
+ uint8_t EndpointControl = (USB_ControlRequest.wValue >> 8);
+
+ /* Only handle GET CURRENT requests to the audio endpoint's sample frequency property */
+ if ((EndpointAddress == (ENDPOINT_DESCRIPTOR_DIR_IN | AUDIO_STREAM_EPNUM)) && (EndpointControl == AUDIO_EPCONTROL_SamplingFreq))
+ {
+ uint8_t SampleRate[3];
+
+ /* Convert the sampling rate value into the 24-bit format the host expects for the property */
+ SampleRate[2] = (CurrentAudioSampleFrequency >> 16);
+ SampleRate[1] = (CurrentAudioSampleFrequency >> 8);
+ SampleRate[0] = (CurrentAudioSampleFrequency & 0xFF);
+
+ Endpoint_ClearSETUP();
+ Endpoint_Write_Control_Stream_LE(SampleRate, sizeof(SampleRate));
+ Endpoint_ClearOUT();
+ }
+ }
+
+ break;