Demos/Device/ClassDriver/AudioOutput/AudioOutput.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2012.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2012  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  Main source file for the AudioOutput demo. This file contains the main tasks of
  34  *  the demo and is responsible for the initial application hardware configuration.
  35  */
  36
  37 #include "AudioOutput.h"
  38
  39 /** LUFA Audio Class driver interface configuration and state information. This structure is
  40  *  passed to all Audio Class driver functions, so that multiple instances of the same class
  41  *  within a device can be differentiated from one another.
  42  */
  43 USB_ClassInfo_Audio_Device_t Speaker_Audio_Interface =
  44         {
  45                 .Config =
  46                         {
  47                                 .ControlInterfaceNumber   = 0,
  48                                 .StreamingInterfaceNumber = 1,
  49
  50                                 .DataOUTEndpointNumber    = AUDIO_STREAM_EPNUM,
  51                                 .DataOUTEndpointSize      = AUDIO_STREAM_EPSIZE,
  52                         },
  53         };
  54
  55 /** Current audio sampling frequency of the streaming audio endpoint. */
  56 static uint32_t CurrentAudioSampleFrequency = 48000;
  57
  58
  59 /** Main program entry point. This routine contains the overall program flow, including initial
  60  *  setup of all components and the main program loop.
  61  */
  62 int main(void)
  63 {
  64         SetupHardware();
  65
  66         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
  67         sei();
  68
  69         for (;;)
  70         {
  71                 Audio_Device_USBTask(&Speaker_Audio_Interface);
  72                 USB_USBTask();
  73         }
  74 }
  75
  76 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  77 void SetupHardware(void)
  78 {
  79         /* Disable watchdog if enabled by bootloader/fuses */
  80         MCUSR &= ~(1 << WDRF);
  81         wdt_disable();
  82
  83         /* Disable clock division */
  84         clock_prescale_set(clock_div_1);
  85
  86         /* Hardware Initialization */
  87         LEDs_Init();
  88         USB_Init();
  89 }
  90
  91 /** ISR to handle the reloading of the PWM timer with the next sample. */
  92 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
  93 {
  94         uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
  95
  96         /* Check that the USB bus is ready for the next sample to read */
  97         if (Audio_Device_IsSampleReceived(&Speaker_Audio_Interface))
  98         {
  99                 /* Retrieve the signed 16-bit left and right audio samples, convert to 8-bit */
 100                 int8_t LeftSample_8Bit  = (Audio_Device_ReadSample16(&Speaker_Audio_Interface) >> 8);
 101                 int8_t RightSample_8Bit = (Audio_Device_ReadSample16(&Speaker_Audio_Interface) >> 8);
 102
 103                 /* Mix the two channels together to produce a mono, 8-bit sample */
 104                 int8_t MixedSample_8Bit = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1);
 105
 106                 #if defined(AUDIO_OUT_MONO)
 107                 /* Load the sample into the PWM timer channel */
 108                 OCR3A = (MixedSample_8Bit ^ (1 << 7));
 109                 #elif defined(AUDIO_OUT_STEREO)
 110                 /* Load the dual 8-bit samples into the PWM timer channels */
 111                 OCR3A = (LeftSample_8Bit  ^ (1 << 7));
 112                 OCR3B = (RightSample_8Bit ^ (1 << 7));
 113                 #elif defined(AUDIO_OUT_PORTC)
 114                 /* Load the 8-bit mixed sample into PORTC */
 115                 PORTC = MixedSample_8Bit;
 116                 #endif
 117
 118                 uint8_t LEDMask = LEDS_NO_LEDS;
 119
 120                 /* Turn on LEDs as the sample amplitude increases */
 121                 if (MixedSample_8Bit > 16)
 122                   LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3 | LEDS_LED4);
 123                 else if (MixedSample_8Bit > 8)
 124                   LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3);
 125                 else if (MixedSample_8Bit > 4)
 126                   LEDMask = (LEDS_LED1 | LEDS_LED2);
 127                 else if (MixedSample_8Bit > 2)
 128                   LEDMask = (LEDS_LED1);
 129
 130                 LEDs_SetAllLEDs(LEDMask);
 131         }
 132
 133         Endpoint_SelectEndpoint(PrevEndpoint);
 134 }
 135
 136 /** Event handler for the library USB Connection event. */
 137 void EVENT_USB_Device_Connect(void)
 138 {
 139         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 140
 141         /* Sample reload timer initialization */
 142         TIMSK0  = (1 << OCIE0A);
 143         OCR0A   = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 144         TCCR0A  = (1 << WGM01);  // CTC mode
 145         TCCR0B  = (1 << CS01);   // Fcpu/8 speed
 146
 147         #if defined(AUDIO_OUT_MONO)
 148         /* Set speaker as output */
 149         DDRC   |= (1 << 6);
 150         #elif defined(AUDIO_OUT_STEREO)
 151         /* Set speakers as outputs */
 152         DDRC   |= ((1 << 6) | (1 << 5));
 153         #elif defined(AUDIO_OUT_PORTC)
 154         /* Set PORTC as outputs */
 155         DDRC   |= 0xFF;
 156         #endif
 157
 158         #if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
 159         /* PWM speaker timer initialization */
 160         TCCR3A  = ((1 << WGM30) | (1 << COM3A1) | (1 << COM3A0)
 161                 | (1 << COM3B1) | (1 << COM3B0)); // Set on match, clear on TOP
 162         TCCR3B  = ((1 << WGM32) | (1 << CS30));  // Fast 8-Bit PWM, F_CPU speed
 163         #endif
 164 }
 165
 166 /** Event handler for the library USB Disconnection event. */
 167 void EVENT_USB_Device_Disconnect(void)
 168 {
 169         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
 170
 171         /* Stop the sample reload timer */
 172         TCCR0B = 0;
 173
 174         #if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
 175         /* Stop the PWM generation timer */
 176         TCCR3B = 0;
 177         #endif
 178
 179         #if defined(AUDIO_OUT_MONO)
 180         /* Set speaker as input to reduce current draw */
 181         DDRC  &= ~(1 << 6);
 182         #elif defined(AUDIO_OUT_STEREO)
 183         /* Set speakers as inputs to reduce current draw */
 184         DDRC  &= ~((1 << 6) | (1 << 5));
 185         #elif defined(AUDIO_OUT_PORTC)
 186         /* Set PORTC low */
 187         PORTC = 0x00;
 188         #endif
 189 }
 190
 191 /** Event handler for the library USB Configuration Changed event. */
 192 void EVENT_USB_Device_ConfigurationChanged(void)
 193 {
 194         bool ConfigSuccess = true;
 195
 196         ConfigSuccess &= Audio_Device_ConfigureEndpoints(&Speaker_Audio_Interface);
 197
 198         LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 199 }
 200
 201 /** Event handler for the library USB Control Request reception event. */
 202 void EVENT_USB_Device_ControlRequest(void)
 203 {
 204         Audio_Device_ProcessControlRequest(&Speaker_Audio_Interface);
 205 }
 206
 207 /** Audio class driver callback for the setting and retrieval of streaming endpoint properties. This callback must be implemented
 208  *  in the user application to handle property manipulations on streaming audio endpoints.
 209  *
 210  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 211  *  the given endpoint index, and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 212  *  to indicate the size of the retreived data.
 213  *
 214  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 215  *        of the \c DataLength parameter.
 216  *
 217  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 218  *  \param[in]     EndpointProperty    Property of the endpoint to get or set, a value from Audio_ClassRequests_t.
 219  *  \param[in]     EndpointAddress     Address of the streaming endpoint whose property is being referenced.
 220  *  \param[in]     EndpointControl     Parameter of the endpoint to get or set, a value from Audio_EndpointControls_t.
 221  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 222  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 223  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 224  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 225  *                                     the retrieved data is to be stored for GET operations.
 226  *
 227  *  \return Boolean true if the property get/set was successful, false otherwise
 228  */
 229 bool CALLBACK_Audio_Device_GetSetEndpointProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 230                                                   const uint8_t EndpointProperty,
 231                                                   const uint8_t EndpointAddress,
 232                                                   const uint8_t EndpointControl,
 233                                                   uint16_t* const DataLength,
 234                                                   uint8_t* Data)
 235 {
 236         /* Check the requested endpoint to see if a supported endpoint is being manipulated */
 237         if (EndpointAddress == (ENDPOINT_DIR_OUT | Speaker_Audio_Interface.Config.DataOUTEndpointNumber))
 238         {
 239                 /* Check the requested control to see if a supported control is being manipulated */
 240                 if (EndpointControl == AUDIO_EPCONTROL_SamplingFreq)
 241                 {
 242                         switch (EndpointProperty)
 243                         {
 244                                 case AUDIO_REQ_SetCurrent:
 245                                         /* Check if we are just testing for a valid property, or actually adjusting it */
 246                                         if (DataLength != NULL)
 247                                         {
 248                                                 /* Set the new sampling frequency to the value given by the host */
 249                                                 CurrentAudioSampleFrequency = (((uint32_t)Data[2] << 16) | ((uint32_t)Data[1] << 8) | (uint32_t)Data[0]);
 250
 251                                                 /* Adjust sample reload timer to the new frequency */
 252                                                 OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 253                                         }
 254
 255                                         return true;
 256                                 case AUDIO_REQ_GetCurrent:
 257                                         /* Check if we are just testing for a valid property, or actually reading it */
 258                                         if (DataLength != NULL)
 259                                         {
 260                                                 *DataLength = 3;
 261
 262                                                 Data[2] = (CurrentAudioSampleFrequency >> 16);
 263                                                 Data[1] = (CurrentAudioSampleFrequency >> 8);
 264                                                 Data[0] = (CurrentAudioSampleFrequency &  0xFF);
 265                                         }
 266
 267                                         return true;
 268                         }
 269                 }
 270         }
 271
 272         return false;
 273 }
 274
 275 /** Audio class driver callback for the setting and retrieval of streaming interface properties. This callback must be implemented
 276  *  in the user application to handle property manipulations on streaming audio interfaces.
 277  *
 278  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 279  *  the given entity and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 280  *  to indicate the size of the retreived data.
 281  *
 282  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 283  *        of the \c DataLength parameter.
 284  *
 285  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 286  *  \param[in]     Property            Property of the interface to get or set, a value from Audio_ClassRequests_t.
 287  *  \param[in]     EntityAddress       Address of the audio entity whose property is being referenced.
 288  *  \param[in]     Parameter           Parameter of the entity to get or set, specific to each type of entity (see USB Audio specification).
 289  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 290  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 291  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 292  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 293  *                                     the retrieved data is to be stored for GET operations.
 294  *
 295  *  \return Boolean \c true if the property GET/SET was successful, \c false otherwise
 296  */
 297 bool CALLBACK_Audio_Device_GetSetInterfaceProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 298                                                    const uint8_t Property,
 299                                                    const uint8_t EntityAddress,
 300                                                    const uint16_t Parameter,
 301                                                    uint16_t* const DataLength,
 302                                                    uint8_t* Data)
 303 {
 304         /* No audio interface entities in the device descriptor, thus no properties to get or set. */
 305         return false;
 306 }