X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/0ce2950d811b8dc11e46602e7490d795d8ddfb5d..d4b45e8502a27c0f5ad3e26eabd2b30e84c20bac:/Demos/Device/LowLevel/AudioOutput/AudioOutput.c diff --git a/Demos/Device/LowLevel/AudioOutput/AudioOutput.c b/Demos/Device/LowLevel/AudioOutput/AudioOutput.c index 178fd5bb3..813108a71 100644 --- a/Demos/Device/LowLevel/AudioOutput/AudioOutput.c +++ b/Demos/Device/LowLevel/AudioOutput/AudioOutput.c @@ -1,13 +1,13 @@ /* LUFA Library - Copyright (C) Dean Camera, 2010. + Copyright (C) Dean Camera, 2012. dean [at] fourwalledcubicle [dot] com www.lufa-lib.org */ /* - Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com) + Copyright 2012 Dean Camera (dean [at] fourwalledcubicle [dot] com) Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted @@ -37,7 +37,11 @@ #include "AudioOutput.h" /** Flag to indicate if the streaming audio alternative interface has been selected by the host. */ -bool StreamingAudioInterfaceSelected = false; +static bool StreamingAudioInterfaceSelected = false; + +/** 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. @@ -80,7 +84,7 @@ 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 @@ -168,6 +172,66 @@ void EVENT_USB_Device_ControlRequest(void) } break; + 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_DIR_OUT | AUDIO_STREAM_EPNUM)) && (EndpointControl == AUDIO_EPCONTROL_SamplingFreq)) + { + uint8_t SampleRate[3]; + + Endpoint_ClearSETUP(); + Endpoint_Read_Control_Stream_LE(SampleRate, sizeof(SampleRate)); + Endpoint_ClearOUT(); + + /* 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_HOSTTODEVICE | 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_DIR_OUT | 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; } } @@ -183,8 +247,8 @@ ISR(TIMER0_COMPA_vect, ISR_BLOCK) if (Endpoint_IsOUTReceived() && StreamingAudioInterfaceSelected) { /* Retrieve the signed 16-bit left and right audio samples, convert to 8-bit */ - int8_t LeftSample_8Bit = ((int16_t)Endpoint_Read_Word_LE() >> 8); - int8_t RightSample_8Bit = ((int16_t)Endpoint_Read_Word_LE() >> 8); + int8_t LeftSample_8Bit = ((int16_t)Endpoint_Read_16_LE() >> 8); + int8_t RightSample_8Bit = ((int16_t)Endpoint_Read_16_LE() >> 8); /* Mix the two channels together to produce a mono, 8-bit sample */ int8_t MixedSample_8Bit = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1); @@ -222,7 +286,7 @@ ISR(TIMER0_COMPA_vect, ISR_BLOCK) LEDs_SetAllLEDs(LEDMask); } - + Endpoint_SelectEndpoint(PrevEndpoint); }