STM3210C_EVAL BSP User Manual: stm3210c_eval_audio.c Source File

STM3210C EVAL BSP Drivers

stm3210c_eval_audio.c
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00001 /**
00002   ******************************************************************************
00003   * @file    stm3210c_eval_audio.c
00004   * @author  MCD Application Team
00005   * @version V6.0.1
00006   * @date    18-December-2015
00007   * @brief   This file provides the Audio driver for the STM3210C-Eval 
00008   *          board.  
00009   @verbatim
00010   ==============================================================================
00011                      ##### How to use this driver #####
00012   ==============================================================================  
00013    [..] 
00014   (#) This driver supports STM32F107xC devices on STM3210C-Eval Kit:
00015        (++) to play an audio file (all functions names start by BSP_AUDIO_OUT_xxx)
00016 
00017   [..] 
00018    (#) PLAY A FILE:
00019        (++) Call the function BSP_AUDIO_OUT_Init(
00020               OutputDevice: physical output mode (OUTPUT_DEVICE_SPEAKER, 
00021                            OUTPUT_DEVICE_HEADPHONE, OUTPUT_DEVICE_AUTO or 
00022                            OUTPUT_DEVICE_BOTH)
00023               Volume: initial volume to be set (0 is min (mute), 100 is max (100%)
00024               AudioFreq: Audio frequency in Hz (8000, 16000, 22500, 32000 ...)
00025               this parameter is relative to the audio file/stream type.
00026                )
00027            This function configures all the hardware required for the audio application 
00028            (codec, I2C, I2S, GPIOs, DMA and interrupt if needed). This function returns 0
00029            if configuration is OK.
00030            If the returned value is different from 0 or the function is stuck then the 
00031            communication with the codec (try to un-plug the power or reset device in this case).
00032               (+++) OUTPUT_DEVICE_SPEAKER: only speaker will be set as output for the 
00033                     audio stream.
00034               (+++) OUTPUT_DEVICE_HEADPHONE: only headphones will be set as output for 
00035                     the audio stream.
00036               (+++) OUTPUT_DEVICE_AUTO: Selection of output device is made through external 
00037                     switch (implemented into the audio jack on the evaluation board). 
00038                     When the Headphone is connected it is used as output. 
00039                     When the headphone is disconnected from the audio jack, the output is
00040                     automatically switched to Speaker.
00041               (+++) OUTPUT_DEVICE_BOTH: both Speaker and Headphone are used as outputs 
00042                     for the audio stream at the same time.
00043        (++) Call the function BSP_AUDIO_OUT_Play(
00044                 pBuffer: pointer to the audio data file address
00045                 Size: size of the buffer to be sent in Bytes
00046                )
00047               to start playing (for the first time) from the audio file/stream.
00048        (++) Call the function BSP_AUDIO_OUT_Pause() to pause playing 
00049        (++) Call the function BSP_AUDIO_OUT_Resume() to resume playing.
00050             Note. After calling BSP_AUDIO_OUT_Pause() function for pause, 
00051             only BSP_AUDIO_OUT_Resume() should be called for resume 
00052             (it is not allowed to call BSP_AUDIO_OUT_Play() in this case).
00053             Note. This function should be called only when the audio file is played 
00054             or paused (not stopped).
00055        (++) For each mode, you may need to implement the relative callback functions 
00056             into your code.
00057             The Callback functions are named BSP_AUDIO_OUT_XXXCallBack() and only 
00058             their prototypes are declared in the stm3210c_eval_audio.h file. 
00059             (refer to the example for more details on the callbacks implementations)
00060        (++) To Stop playing, to modify the volume level, the frequency or to mute, 
00061             use the functions BSP_AUDIO_OUT_Stop(), BSP_AUDIO_OUT_SetVolume(), 
00062             AUDIO_OUT_SetFrequency() BSP_AUDIO_OUT_SetOutputMode and BSP_AUDIO_OUT_SetMute().
00063        (++) The driver API and the callback functions are at the end of the 
00064             stm3210c_eval_audio.h file.
00065    
00066        (++) This driver provide the High Audio Layer: consists of the function API 
00067             exported in the stm3210c_eval_audio.h file (BSP_AUDIO_OUT_Init(), 
00068             BSP_AUDIO_OUT_Play() ...)
00069        (++) This driver provide also the Media Access Layer (MAL): which consists 
00070             of functions allowing to access the media containing/providing the 
00071             audio file/stream. These functions are also included as local functions into
00072             the stm3210c_eval_audio.c file (I2SOUT_Init()...)
00073        
00074   [..] 
00075                      ##### Known Limitations #####
00076   ==============================================================================  
00077    (#) When using the Speaker, if the audio file quality is not high enough, the 
00078        speaker output may produce high and uncomfortable noise level. To avoid 
00079        this issue, to use speaker output properly, try to increase audio file 
00080        sampling rate (typically higher than 48KHz).
00081        This operation will lead to larger file size.
00082        
00083    (#) Communication with the audio codec (through I2C) may be corrupted if it 
00084        is interrupted by some user interrupt routines (in this case, interrupts 
00085        could be disabled just before the start of communication then re-enabled 
00086        when it is over). Note that this communication is only done at the 
00087        configuration phase (BSP_AUDIO_OUT_Init() or BSP_AUDIO_OUT_Stop()) 
00088        and when Volume control modification is performed (BSP_AUDIO_OUT_SetVolume() 
00089        or BSP_AUDIO_OUT_SetMute()or BSP_AUDIO_OUT_SetOutputMode()). 
00090        When the audio data is played, no communication is required with the audio codec.
00091        
00092    (#) Parsing of audio file is not implemented (in order to determine audio file
00093        properties: Mono/Stereo, Data size, File size, Audio Frequency, Audio Data 
00094        header size ...). The configuration is fixed for the given audio file.
00095        
00096    (#) Mono audio streaming is not supported (in order to play mono audio streams, 
00097        each data should be sent twice on the I2S or should be duplicated on the 
00098        source buffer. Or convert the stream in stereo before playing).
00099        
00100    (#) Supports only 16-bit audio data size.
00101 
00102   @endverbatim
00103   ******************************************************************************
00104   * @attention
00105   *
00106   * <h2><center>&copy; COPYRIGHT(c) 2015 STMicroelectronics</center></h2>
00107   *
00108   * Redistribution and use in source and binary forms, with or without modification,
00109   * are permitted provided that the following conditions are met:
00110   *   1. Redistributions of source code must retain the above copyright notice,
00111   *      this list of conditions and the following disclaimer.
00112   *   2. Redistributions in binary form must reproduce the above copyright notice,
00113   *      this list of conditions and the following disclaimer in the documentation
00114   *      and/or other materials provided with the distribution.
00115   *   3. Neither the name of STMicroelectronics nor the names of its contributors
00116   *      may be used to endorse or promote products derived from this software
00117   *      without specific prior written permission.
00118   *
00119   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
00120   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00121   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
00122   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
00123   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00124   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
00125   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
00126   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00127   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
00128   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00129   *
00130   ******************************************************************************
00131   */ 
00132 
00133 /* Includes ------------------------------------------------------------------*/
00134 #include "stm3210c_eval_audio.h"
00135 
00136 /** @addtogroup BSP
00137   * @{
00138   */
00139   
00140 /** @addtogroup STM3210C_EVAL
00141   * @{
00142   */
00143 
00144 /** @addtogroup STM3210C_EVAL_AUDIO
00145   * @brief This file includes the low layer audio driver available on STM3210C-Eval
00146   * eval board.
00147   * @{
00148   */ 
00149 
00150 /** @defgroup STM3210C_EVAL_AUDIO_Private_Types AUDIO_Private_Types
00151   * @{
00152   */ 
00153 /**
00154   * @}
00155   */ 
00156   
00157 /** @defgroup STM3210C_EVAL_AUDIO_Private_Defines AUDIO_Private_Defines
00158   * @{
00159   */ 
00160 
00161 /**
00162   * @}
00163   */ 
00164 
00165 /** @defgroup STM3210C_EVAL_AUDIO_Private_Macros AUDIO Private_Macros
00166   * @{
00167   */
00168 /**
00169   * @}
00170   */ 
00171   
00172 /** @defgroup STM3210C_EVAL_AUDIO_Private_Variables AUDIO_Private_Variables
00173   * @{
00174   */
00175 /*### PLAY ###*/
00176 static AUDIO_DrvTypeDef         *pAudioDrv;
00177 I2S_HandleTypeDef               hAudioOutI2s;
00178 
00179 /**
00180   * @}
00181   */ 
00182 
00183 /** @defgroup STM3210C_EVAL_AUDIO_Private_Function_Prototypes AUDIO_Private_Function_Prototypes
00184   * @{
00185   */ 
00186 static void  I2SOUT_MspInit(void);
00187 static void  I2SOUT_Init(uint32_t AudioFreq);
00188 
00189 /**
00190   * @}
00191   */ 
00192 
00193 /** @defgroup STM3210C_EVAL_AUDIO_OUT_Exported_Functions AUDIO_OUT_Exported_Functions
00194   * @{
00195   */ 
00196 
00197 /**
00198   * @brief  Configure the audio peripherals.
00199   * @param  OutputDevice: OUTPUT_DEVICE_SPEAKER, OUTPUT_DEVICE_HEADPHONE,
00200   *                       OUTPUT_DEVICE_BOTH or OUTPUT_DEVICE_AUTO .
00201   * @param  Volume: Initial volume level (from 0 (Mute) to 100 (Max))
00202   * @param  AudioFreq: Audio frequency used to play the audio stream.
00203   * @retval 0 if correct communication, else wrong communication
00204   */
00205 uint8_t BSP_AUDIO_OUT_Init(uint16_t OutputDevice, uint8_t Volume, uint32_t AudioFreq)
00206 {
00207   uint8_t ret = AUDIO_ERROR;
00208   uint32_t deviceid = 0x00;
00209 
00210   deviceid = cs43l22_drv.ReadID(AUDIO_I2C_ADDRESS);
00211 
00212   if((deviceid & CS43L22_ID_MASK) == CS43L22_ID)
00213   {  
00214     /* Initialize the audio driver structure */
00215     pAudioDrv = &cs43l22_drv; 
00216     ret = AUDIO_OK;
00217   }
00218   else
00219   {
00220     ret = AUDIO_ERROR;
00221   }
00222   
00223   if(ret == AUDIO_OK)
00224   {
00225     pAudioDrv->Init(AUDIO_I2C_ADDRESS, OutputDevice, Volume, AudioFreq);
00226     /* I2S data transfer preparation:
00227     Prepare the Media to be used for the audio transfer from memory to I2S peripheral */
00228     /* Configure the I2S peripheral */
00229     I2SOUT_Init(AudioFreq);
00230   }
00231   
00232   return ret;
00233 }
00234 
00235 /**
00236   * @brief  Starts playing audio stream from a data buffer for a determined size. 
00237   * @param  pBuffer: Pointer to the buffer 
00238   * @param  Size: Number of audio data BYTES.
00239   * @retval AUDIO_OK if correct communication, else wrong communication
00240   */
00241 uint8_t BSP_AUDIO_OUT_Play(uint16_t* pBuffer, uint32_t Size)
00242 {
00243   /* Call the audio Codec Play function */
00244   if(pAudioDrv->Play(AUDIO_I2C_ADDRESS, pBuffer, Size) != 0)
00245   {
00246     return AUDIO_ERROR;
00247   }
00248   else 
00249   {
00250     /* Update the Media layer and enable it for play */  
00251     HAL_I2S_Transmit_DMA(&hAudioOutI2s, pBuffer, DMA_MAX(Size)); 
00252     
00253     return AUDIO_OK;
00254   }
00255 }
00256 
00257 /**
00258   * @brief Sends n-Bytes on the I2S interface.
00259   * @param pData: pointer on data address 
00260   * @param Size: number of data to be written
00261   * @retval None
00262   */
00263 void BSP_AUDIO_OUT_ChangeBuffer(uint16_t *pData, uint16_t Size)
00264 {
00265   HAL_I2S_Transmit_DMA(&hAudioOutI2s, pData, Size); 
00266 }
00267 
00268 /**
00269   * @brief  This function Pauses the audio file stream. In case
00270   *         of using DMA, the DMA Pause feature is used.
00271   * @note When calling BSP_AUDIO_OUT_Pause() function for pause, only
00272   *          BSP_AUDIO_OUT_Resume() function should be called for resume (use of BSP_AUDIO_OUT_Play() 
00273   *          function for resume could lead to unexpected behavior).
00274   * @retval AUDIO_OK if correct communication, else wrong communication
00275   */
00276 uint8_t BSP_AUDIO_OUT_Pause(void)
00277 {    
00278   /* Call the Audio Codec Pause/Resume function */
00279   if(pAudioDrv->Pause(AUDIO_I2C_ADDRESS) != 0)
00280   {
00281     return AUDIO_ERROR;
00282   }
00283   else
00284   {
00285     /* Call the Media layer pause function */
00286     HAL_I2S_DMAPause(&hAudioOutI2s);
00287     
00288     /* Return AUDIO_OK if all operations are OK */
00289     return AUDIO_OK;
00290   }
00291 }
00292 
00293 /**
00294   * @brief  This function  Resumes the audio file stream.  
00295   * @note When calling BSP_AUDIO_OUT_Pause() function for pause, only
00296   *          BSP_AUDIO_OUT_Resume() function should be called for resume (use of BSP_AUDIO_OUT_Play() 
00297   *          function for resume could lead to unexpected behavior).
00298   * @retval AUDIO_OK if correct communication, else wrong communication
00299   */
00300 uint8_t BSP_AUDIO_OUT_Resume(void)
00301 {    
00302   /* Call the Audio Codec Pause/Resume function */
00303   if(pAudioDrv->Resume(AUDIO_I2C_ADDRESS) != 0)
00304   {
00305     return AUDIO_ERROR;
00306   }
00307   else
00308   {
00309     /* Call the Media layer resume function */
00310     HAL_I2S_DMAResume(&hAudioOutI2s);
00311     /* Return AUDIO_OK if all operations are OK */
00312     return AUDIO_OK;
00313   }
00314 }
00315 
00316 /**
00317   * @brief  Stops audio playing and Power down the Audio Codec. 
00318   * @param  Option: could be one of the following parameters 
00319   *           - CODEC_PDWN_HW: completely shut down the codec (physically). 
00320   *                            Then need to reconfigure the Codec after power on.  
00321   * @retval AUDIO_OK if correct communication, else wrong communication
00322   */
00323 uint8_t BSP_AUDIO_OUT_Stop(uint32_t Option)
00324 {
00325   /* Call DMA Stop to disable DMA stream before stopping codec */
00326   HAL_I2S_DMAStop(&hAudioOutI2s);
00327   
00328   /* Call Audio Codec Stop function */
00329   if(pAudioDrv->Stop(AUDIO_I2C_ADDRESS, Option) != 0)
00330   {
00331     return AUDIO_ERROR;
00332   }
00333   else
00334   {
00335     if(Option == CODEC_PDWN_HW)
00336     { 
00337       /* Wait at least 100us */
00338       HAL_Delay(1);
00339   
00340       /* Power Down the codec */
00341       BSP_IO_WritePin(AUDIO_RESET_PIN, GPIO_PIN_RESET);
00342   
00343     }
00344     /* Return AUDIO_OK when all operations are correctly done */
00345     return AUDIO_OK;
00346   }
00347 }
00348 
00349 /**
00350   * @brief  Controls the current audio volume level. 
00351   * @param  Volume: Volume level to be set in percentage from 0% to 100% (0 for 
00352   *         Mute and 100 for Max volume level).
00353   * @retval AUDIO_OK if correct communication, else wrong communication
00354   */
00355 uint8_t BSP_AUDIO_OUT_SetVolume(uint8_t Volume)
00356 {
00357   /* Call the codec volume control function with converted volume value */
00358   if(pAudioDrv->SetVolume(AUDIO_I2C_ADDRESS, Volume) != 0)
00359   {
00360     return AUDIO_ERROR;
00361   }
00362   else
00363   {
00364     /* Return AUDIO_OK when all operations are correctly done */
00365     return AUDIO_OK;
00366   }
00367 }
00368 
00369 /**
00370   * @brief  Enables or disables the MUTE mode by software 
00371   * @param  Cmd: could be AUDIO_MUTE_ON to mute sound or AUDIO_MUTE_OFF to 
00372   *         unmute the codec and restore previous volume level.
00373   * @retval AUDIO_OK if correct communication, else wrong communication
00374   */
00375 uint8_t BSP_AUDIO_OUT_SetMute(uint32_t Cmd)
00376 { 
00377   /* Call the Codec Mute function */
00378   if(pAudioDrv->SetMute(AUDIO_I2C_ADDRESS, Cmd) != 0)
00379   {
00380     return AUDIO_ERROR;
00381   }
00382   else
00383   {
00384     /* Return AUDIO_OK when all operations are correctly done */
00385     return AUDIO_OK;
00386   }
00387 }
00388 
00389 /**
00390   * @brief  Switch dynamically (while audio file is played) the output target 
00391   *         (speaker or headphone).
00392   * @note   This function modifies a global variable of the audio codec driver: OutputDev.
00393   * @param  Output: specifies the audio output target: OUTPUT_DEVICE_SPEAKER,
00394   *         OUTPUT_DEVICE_HEADPHONE, OUTPUT_DEVICE_BOTH or OUTPUT_DEVICE_AUTO 
00395   * @retval AUDIO_OK if correct communication, else wrong communication
00396   */
00397 uint8_t BSP_AUDIO_OUT_SetOutputMode(uint8_t Output)
00398 {
00399   /* Call the Codec output Device function */
00400   if(pAudioDrv->SetOutputMode(AUDIO_I2C_ADDRESS, Output) != 0)
00401   {
00402     return AUDIO_ERROR;
00403   }
00404   else
00405   {
00406     /* Return AUDIO_OK when all operations are correctly done */
00407     return AUDIO_OK;
00408   }
00409 }
00410 
00411 /**
00412   * @brief  Update the audio frequency.
00413   * @param  AudioFreq: Audio frequency used to play the audio stream.
00414   * @retval None
00415   * @note This API should be called after the BSP_AUDIO_OUT_Init() to adjust the
00416   * audio frequency. 
00417   */
00418 void BSP_AUDIO_OUT_SetFrequency(uint32_t AudioFreq)
00419 { 
00420   /* Update the I2S audio frequency configuration */
00421   I2SOUT_Init(AudioFreq);
00422 }
00423 
00424 /**
00425   * @brief Tx Transfer completed callbacks
00426   * @param hi2s: I2S handle
00427   * @retval None
00428   */
00429 void HAL_I2S_TxCpltCallback(I2S_HandleTypeDef *hi2s)
00430 {
00431   if(hi2s->Instance == I2SOUT)
00432   {
00433     /* Call the user function which will manage directly transfer complete*/  
00434     BSP_AUDIO_OUT_TransferComplete_CallBack();       
00435   }
00436 }
00437 
00438 /**
00439   * @brief Tx Transfer Half completed callbacks
00440   * @param hi2s: I2S handle
00441   * @retval None
00442   */
00443 void HAL_I2S_TxHalfCpltCallback(I2S_HandleTypeDef *hi2s)
00444 {
00445   if(hi2s->Instance == I2SOUT)
00446   {
00447     /* Manage the remaining file size and new address offset: This function 
00448     should be coded by user (its prototype is already declared in stm3210c_eval_audio.h) */  
00449     BSP_AUDIO_OUT_HalfTransfer_CallBack();
00450   }
00451 }
00452 
00453 /**
00454   * @brief I2S error callbacks
00455   * @param hi2s: I2S handle
00456   * @retval None
00457   */
00458 void HAL_I2S_ErrorCallback(I2S_HandleTypeDef *hi2s)
00459 {
00460   /* Manage the error generated on DMA FIFO: This function 
00461      should be coded by user (its prototype is already declared in stm3210c_eval_audio.h) */  
00462   if(hi2s->Instance == I2SOUT)
00463   {
00464     BSP_AUDIO_OUT_Error_CallBack();
00465   }
00466 }
00467 
00468 /**
00469   * @brief  Manages the DMA full Transfer complete event.
00470   * @retval None
00471   */
00472 __weak void BSP_AUDIO_OUT_TransferComplete_CallBack(void)
00473 {
00474 }
00475 
00476 /**
00477   * @brief  Manages the DMA Half Transfer complete event.
00478   * @retval None
00479   */
00480 __weak void BSP_AUDIO_OUT_HalfTransfer_CallBack(void)
00481 {
00482 }
00483 
00484 /**
00485   * @brief  Manages the DMA FIFO error event.
00486   * @retval None
00487   */
00488 __weak void BSP_AUDIO_OUT_Error_CallBack(void)
00489 {
00490 }
00491 
00492 /******************************************************************************
00493                             Static Function
00494 *******************************************************************************/
00495 
00496 /**
00497   * @brief AUDIO OUT I2S MSP Init
00498   * @retval None
00499   */
00500 static void I2SOUT_MspInit(void)
00501 {
00502   static DMA_HandleTypeDef  hdma_i2stx;
00503   GPIO_InitTypeDef          gpioinitstruct = {0};
00504   I2S_HandleTypeDef         *hi2s = &hAudioOutI2s;
00505 
00506   /* Enable I2SOUT clock */
00507   I2SOUT_CLK_ENABLE();
00508 
00509   /*** Configure the GPIOs ***/  
00510   /* Enable I2S GPIO clocks */
00511   I2SOUT_SCK_SD_CLK_ENABLE();
00512   I2SOUT_WS_CLK_ENABLE();
00513 
00514   /* I2SOUT pins configuration: WS, SCK and SD pins -----------------------------*/
00515   gpioinitstruct.Pin         = I2SOUT_SCK_PIN | I2SOUT_SD_PIN; 
00516   gpioinitstruct.Mode        = GPIO_MODE_AF_PP;
00517   gpioinitstruct.Pull        = GPIO_NOPULL;
00518   gpioinitstruct.Speed       = GPIO_SPEED_FREQ_MEDIUM;
00519   HAL_GPIO_Init(I2SOUT_SCK_SD_GPIO_PORT, &gpioinitstruct);
00520   
00521   gpioinitstruct.Pin         = I2SOUT_WS_PIN ;
00522   HAL_GPIO_Init(I2SOUT_WS_GPIO_PORT, &gpioinitstruct); 
00523 
00524   /* I2SOUT pins configuration: MCK pin */
00525   I2SOUT_MCK_CLK_ENABLE();
00526   gpioinitstruct.Pin         = I2SOUT_MCK_PIN; 
00527   HAL_GPIO_Init(I2SOUT_MCK_GPIO_PORT, &gpioinitstruct);   
00528 
00529   /* Enable the I2S DMA clock */
00530   I2SOUT_DMAx_CLK_ENABLE(); 
00531   
00532   if(hi2s->Instance == I2SOUT)
00533   {
00534     /* Configure the hdma_i2stx handle parameters */   
00535     hdma_i2stx.Init.Direction           = DMA_MEMORY_TO_PERIPH;
00536     hdma_i2stx.Init.PeriphInc           = DMA_PINC_DISABLE;
00537     hdma_i2stx.Init.MemInc              = DMA_MINC_ENABLE;
00538     hdma_i2stx.Init.PeriphDataAlignment = I2SOUT_DMAx_PERIPH_DATA_SIZE;
00539     hdma_i2stx.Init.MemDataAlignment    = I2SOUT_DMAx_MEM_DATA_SIZE;
00540     hdma_i2stx.Init.Mode                = DMA_NORMAL;
00541     hdma_i2stx.Init.Priority            = DMA_PRIORITY_HIGH;
00542 
00543     hdma_i2stx.Instance                 = I2SOUT_DMAx_CHANNEL;
00544 
00545     /* Associate the DMA handle */
00546     __HAL_LINKDMA(hi2s, hdmatx, hdma_i2stx);
00547     
00548     /* Deinitialize the Channel for new transfer */
00549     HAL_DMA_DeInit(&hdma_i2stx);
00550     
00551     /* Configure the DMA Channel */
00552     HAL_DMA_Init(&hdma_i2stx);
00553   }
00554   
00555   /* I2S DMA IRQ Channel configuration */
00556   HAL_NVIC_SetPriority(I2SOUT_DMAx_IRQ, AUDIO_OUT_IRQ_PREPRIO, 0);
00557   HAL_NVIC_EnableIRQ(I2SOUT_DMAx_IRQ); 
00558 }
00559 
00560 /**
00561   * @brief  Initializes the Audio Codec audio interface (I2S)
00562   * @param  AudioFreq: Audio frequency to be configured for the I2S peripheral. 
00563   */
00564 static void I2SOUT_Init(uint32_t AudioFreq)
00565 {
00566   /* Initialize the hAudioOutI2s Instance parameter */
00567   hAudioOutI2s.Instance         = I2SOUT;
00568 
00569  /* Disable I2S block */
00570   __HAL_I2S_DISABLE(&hAudioOutI2s);
00571   
00572   /* Perform MSP initialization at first function call */
00573   if(HAL_I2S_GetState(&hAudioOutI2s) == HAL_I2S_STATE_RESET)
00574   { 
00575     I2SOUT_MspInit();
00576   }
00577   
00578   /* I2SOUT peripheral configuration */
00579   hAudioOutI2s.Init.AudioFreq   = AudioFreq;
00580   hAudioOutI2s.Init.CPOL        = I2S_CPOL_LOW;
00581   hAudioOutI2s.Init.DataFormat  = I2S_DATAFORMAT_16B;
00582   hAudioOutI2s.Init.MCLKOutput  = I2S_MCLKOUTPUT_ENABLE;
00583   hAudioOutI2s.Init.Mode        = I2S_MODE_MASTER_TX;
00584   hAudioOutI2s.Init.Standard    = I2S_STANDARD;
00585   
00586   /* Initialize the I2S peripheral with the structure above */
00587   HAL_I2S_Init(&hAudioOutI2s);
00588 }
00589   
00590 /**
00591   * @}
00592   */ 
00593  
00594 /**
00595   * @}
00596   */
00597 
00598 /**
00599   * @}
00600   */
00601 
00602 /**
00603   * @}
00604   */
00605 
00606 /**
00607   * @}
00608   */
00609 
00610 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
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