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 disclaims 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                                 .DataOUTEndpoint          =
  50                                         {
  51                                                 .Address          = AUDIO_STREAM_EPADDR,
  52                                                 .Size             = AUDIO_STREAM_EPSIZE,
  53                                                 .Banks            = 2,
  54                                         },
  55                         },
  56         };
  57
  58 /** Current audio sampling frequency of the streaming audio endpoint. */
  59 static uint32_t CurrentAudioSampleFrequency = 48000;
  60
  61
  62 /** Main program entry point. This routine contains the overall program flow, including initial
  63  *  setup of all components and the main program loop.
  64  */
  65 int main(void)
  66 {
  67         SetupHardware();
  68
  69         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
  70         GlobalInterruptEnable();
  71
  72         for (;;)
  73         {
  74                 Audio_Device_USBTask(&Speaker_Audio_Interface);
  75                 USB_USBTask();
  76         }
  77 }
  78
  79 /** Configures the board hardware and chip peripherals for the demo's functionality. */
  80 void SetupHardware(void)
  81 {
  82         /* Disable watchdog if enabled by bootloader/fuses */
  83         MCUSR &= ~(1 << WDRF);
  84         wdt_disable();
  85
  86         /* Disable clock division */
  87         clock_prescale_set(clock_div_1);
  88
  89         /* Hardware Initialization */
  90         LEDs_Init();
  91         USB_Init();
  92 }
  93
  94 /** ISR to handle the reloading of the PWM timer with the next sample. */
  95 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
  96 {
  97         uint8_t PrevEndpoint = Endpoint_GetCurrentEndpoint();
  98
  99         /* Check that the USB bus is ready for the next sample to read */
 100         if (Audio_Device_IsSampleReceived(&Speaker_Audio_Interface))
 101         {
 102                 /* Retrieve the signed 16-bit left and right audio samples, convert to 8-bit */
 103                 int8_t LeftSample_8Bit  = (Audio_Device_ReadSample16(&Speaker_Audio_Interface) >> 8);
 104                 int8_t RightSample_8Bit = (Audio_Device_ReadSample16(&Speaker_Audio_Interface) >> 8);
 105
 106                 /* Mix the two channels together to produce a mono, 8-bit sample */
 107                 int8_t MixedSample_8Bit = (((int16_t)LeftSample_8Bit + (int16_t)RightSample_8Bit) >> 1);
 108
 109                 #if defined(AUDIO_OUT_MONO)
 110                 /* Load the sample into the PWM timer channel */
 111                 OCR3A = (MixedSample_8Bit ^ (1 << 7));
 112                 #elif defined(AUDIO_OUT_STEREO)
 113                 /* Load the dual 8-bit samples into the PWM timer channels */
 114                 OCR3A = (LeftSample_8Bit  ^ (1 << 7));
 115                 OCR3B = (RightSample_8Bit ^ (1 << 7));
 116                 #elif defined(AUDIO_OUT_PORTC)
 117                 /* Load the 8-bit mixed sample into PORTC */
 118                 PORTC = MixedSample_8Bit;
 119                 #endif
 120
 121                 uint8_t LEDMask = LEDS_NO_LEDS;
 122
 123                 /* Turn on LEDs as the sample amplitude increases */
 124                 if (MixedSample_8Bit > 16)
 125                   LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3 | LEDS_LED4);
 126                 else if (MixedSample_8Bit > 8)
 127                   LEDMask = (LEDS_LED1 | LEDS_LED2 | LEDS_LED3);
 128                 else if (MixedSample_8Bit > 4)
 129                   LEDMask = (LEDS_LED1 | LEDS_LED2);
 130                 else if (MixedSample_8Bit > 2)
 131                   LEDMask = (LEDS_LED1);
 132
 133                 LEDs_SetAllLEDs(LEDMask);
 134         }
 135
 136         Endpoint_SelectEndpoint(PrevEndpoint);
 137 }
 138
 139 /** Event handler for the library USB Connection event. */
 140 void EVENT_USB_Device_Connect(void)
 141 {
 142         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 143
 144         /* Sample reload timer initialization */
 145         TIMSK0  = (1 << OCIE0A);
 146         OCR0A   = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 147         TCCR0A  = (1 << WGM01);  // CTC mode
 148         TCCR0B  = (1 << CS01);   // Fcpu/8 speed
 149
 150         #if defined(AUDIO_OUT_MONO)
 151         /* Set speaker as output */
 152         DDRC   |= (1 << 6);
 153         #elif defined(AUDIO_OUT_STEREO)
 154         /* Set speakers as outputs */
 155         DDRC   |= ((1 << 6) | (1 << 5));
 156         #elif defined(AUDIO_OUT_PORTC)
 157         /* Set PORTC as outputs */
 158         DDRC   |= 0xFF;
 159         #endif
 160
 161         #if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
 162         /* PWM speaker timer initialization */
 163         TCCR3A  = ((1 << WGM30) | (1 << COM3A1) | (1 << COM3A0)
 164                 | (1 << COM3B1) | (1 << COM3B0)); // Set on match, clear on TOP
 165         TCCR3B  = ((1 << WGM32) | (1 << CS30));  // Fast 8-Bit PWM, F_CPU speed
 166         #endif
 167 }
 168
 169 /** Event handler for the library USB Disconnection event. */
 170 void EVENT_USB_Device_Disconnect(void)
 171 {
 172         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
 173
 174         /* Stop the sample reload timer */
 175         TCCR0B = 0;
 176
 177         #if (defined(AUDIO_OUT_MONO) || defined(AUDIO_OUT_STEREO))
 178         /* Stop the PWM generation timer */
 179         TCCR3B = 0;
 180         #endif
 181
 182         #if defined(AUDIO_OUT_MONO)
 183         /* Set speaker as input to reduce current draw */
 184         DDRC  &= ~(1 << 6);
 185         #elif defined(AUDIO_OUT_STEREO)
 186         /* Set speakers as inputs to reduce current draw */
 187         DDRC  &= ~((1 << 6) | (1 << 5));
 188         #elif defined(AUDIO_OUT_PORTC)
 189         /* Set PORTC low */
 190         PORTC = 0x00;
 191         #endif
 192 }
 193
 194 /** Event handler for the library USB Configuration Changed event. */
 195 void EVENT_USB_Device_ConfigurationChanged(void)
 196 {
 197         bool ConfigSuccess = true;
 198
 199         ConfigSuccess &= Audio_Device_ConfigureEndpoints(&Speaker_Audio_Interface);
 200
 201         LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 202 }
 203
 204 /** Event handler for the library USB Control Request reception event. */
 205 void EVENT_USB_Device_ControlRequest(void)
 206 {
 207         Audio_Device_ProcessControlRequest(&Speaker_Audio_Interface);
 208 }
 209
 210 /** Audio class driver callback for the setting and retrieval of streaming endpoint properties. This callback must be implemented
 211  *  in the user application to handle property manipulations on streaming audio endpoints.
 212  *
 213  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 214  *  the given endpoint index, and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 215  *  to indicate the size of the retrieved data.
 216  *
 217  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 218  *        of the \c DataLength parameter.
 219  *
 220  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 221  *  \param[in]     EndpointProperty    Property of the endpoint to get or set, a value from Audio_ClassRequests_t.
 222  *  \param[in]     EndpointAddress     Address of the streaming endpoint whose property is being referenced.
 223  *  \param[in]     EndpointControl     Parameter of the endpoint to get or set, a value from Audio_EndpointControls_t.
 224  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 225  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 226  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 227  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 228  *                                     the retrieved data is to be stored for GET operations.
 229  *
 230  *  \return Boolean true if the property get/set was successful, false otherwise
 231  */
 232 bool CALLBACK_Audio_Device_GetSetEndpointProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 233                                                   const uint8_t EndpointProperty,
 234                                                   const uint8_t EndpointAddress,
 235                                                   const uint8_t EndpointControl,
 236                                                   uint16_t* const DataLength,
 237                                                   uint8_t* Data)
 238 {
 239         /* Check the requested endpoint to see if a supported endpoint is being manipulated */
 240         if (EndpointAddress == Speaker_Audio_Interface.Config.DataOUTEndpoint.Address)
 241         {
 242                 /* Check the requested control to see if a supported control is being manipulated */
 243                 if (EndpointControl == AUDIO_EPCONTROL_SamplingFreq)
 244                 {
 245                         switch (EndpointProperty)
 246                         {
 247                                 case AUDIO_REQ_SetCurrent:
 248                                         /* Check if we are just testing for a valid property, or actually adjusting it */
 249                                         if (DataLength != NULL)
 250                                         {
 251                                                 /* Set the new sampling frequency to the value given by the host */
 252                                                 CurrentAudioSampleFrequency = (((uint32_t)Data[2] << 16) | ((uint32_t)Data[1] << 8) | (uint32_t)Data[0]);
 253
 254                                                 /* Adjust sample reload timer to the new frequency */
 255                                                 OCR0A = ((F_CPU / 8 / CurrentAudioSampleFrequency) - 1);
 256                                         }
 257
 258                                         return true;
 259                                 case AUDIO_REQ_GetCurrent:
 260                                         /* Check if we are just testing for a valid property, or actually reading it */
 261                                         if (DataLength != NULL)
 262                                         {
 263                                                 *DataLength = 3;
 264
 265                                                 Data[2] = (CurrentAudioSampleFrequency >> 16);
 266                                                 Data[1] = (CurrentAudioSampleFrequency >> 8);
 267                                                 Data[0] = (CurrentAudioSampleFrequency &  0xFF);
 268                                         }
 269
 270                                         return true;
 271                         }
 272                 }
 273         }
 274
 275         return false;
 276 }
 277
 278 /** Audio class driver callback for the setting and retrieval of streaming interface properties. This callback must be implemented
 279  *  in the user application to handle property manipulations on streaming audio interfaces.
 280  *
 281  *  When the DataLength parameter is NULL, this callback should only indicate whether the specified operation is valid for
 282  *  the given entity and should return as fast as possible. When non-NULL, this value may be altered for GET operations
 283  *  to indicate the size of the retrieved data.
 284  *
 285  *  \note The length of the retrieved data stored into the Data buffer on GET operations should not exceed the initial value
 286  *        of the \c DataLength parameter.
 287  *
 288  *  \param[in,out] AudioInterfaceInfo  Pointer to a structure containing an Audio Class configuration and state.
 289  *  \param[in]     Property            Property of the interface to get or set, a value from Audio_ClassRequests_t.
 290  *  \param[in]     EntityAddress       Address of the audio entity whose property is being referenced.
 291  *  \param[in]     Parameter           Parameter of the entity to get or set, specific to each type of entity (see USB Audio specification).
 292  *  \param[in,out] DataLength          For SET operations, the length of the parameter data to set. For GET operations, the maximum
 293  *                                     length of the retrieved data. When NULL, the function should return whether the given property
 294  *                                     and parameter is valid for the requested endpoint without reading or modifying the Data buffer.
 295  *  \param[in,out] Data                Pointer to a location where the parameter data is stored for SET operations, or where
 296  *                                     the retrieved data is to be stored for GET operations.
 297  *
 298  *  \return Boolean \c true if the property GET/SET was successful, \c false otherwise
 299  */
 300 bool CALLBACK_Audio_Device_GetSetInterfaceProperty(USB_ClassInfo_Audio_Device_t* const AudioInterfaceInfo,
 301                                                    const uint8_t Property,
 302                                                    const uint8_t EntityAddress,
 303                                                    const uint16_t Parameter,
 304                                                    uint16_t* const DataLength,
 305                                                    uint8_t* Data)
 306 {
 307         /* No audio interface entities in the device descriptor, thus no properties to get or set. */
 308         return false;
 309 }