I2S.h

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/*!*****************************************************************************
 *  @file       I2S.h
 *
 *  @brief      I2S driver interface
 *
 *  The I2S header file should be included in an application as follows:
 *  @code
 *  #include <ti/drivers/I2S.h>
 *  @endcode
 *
 *  # Overview #
 *  The I2S driver facilitates the use of Inter-IC Sound (I2S), which is
 *  used to connect digital audio devices so that audio signals can be
 *  communicated between devices. The I2S driver simplifies reading and
 *  writing to any of the Multichannel Audio Serial Port (McASP) peripherals
 *  on the board with Receive and Transmit support. These include blocking,
 *  non-blocking, read and write characters on the McASP peripheral.
 *
 *  The APIs in this driver serve as an interface to a typical RTOS
 *  application.  Its purpose is to redirect the I2S APIs to specific
 *  driver implementations which are specified using a pointer to an
 *  #I2S_FxnTable.
 *  The specific peripheral implementations are responsible
 *  for creating all the RTOS specific primitives to allow for thread-safe
 *  operation.
 *
 *  # Usage #
 *
 *  To use the I2S driver for reaading and writing data to the I2S peripheral,
 *  the application calls the following APIs:
 *    - I2S_init(): Initialize the I2S driver.
 *    - I2S_Params_init():  Initialize a #I2S_Params structure with default
 *      vaules.  Then change the parameters from non-default values as
 *      needed.
 *    - I2S_open():  Open an instance of the I2S driver, passing the
 *      initialized parameters, or NULL, and an index (described later).
 *    - If using callback mode, I2S_read() and I2S_write().
 *    - If using issue/reclaim mode, I2S_readIssue(), I2S_readReclaim(),
 *      I2S_writeIssue() and I2S_writeReclaim().
 *    - I2S_close():  De-initialize the I2S instance.
 *
 *  ### I2S Driver Configuration #
 *
 *  In order to use the I2S APIs, the application is required
 *  to provide device-specific I2S configuration in the Board.c file.
 *  The I2S driver interface defines a configuration data structure:
 *
 *  @code
 *  typedef struct I2S_Config_ {
 *      // Pointer to driver-specific implementation of I2S functions
 *      I2S_FxnTable const *fxnTablePtr;
 *      void               *object;   // Driver specific data object
 *      void         const *hwAttrs;  // Driver specific hardware attributes
 *  } I2S_Config;
 *  @endcode
 *
 *  The application must declare an array of I2S_Config elements, named
 *  I2S_config[].  Each element of I2S_config[] must be populated with
 *  pointers to a device specific I2S driver implementation's function
 *  table, driver object, and hardware attributes.  The hardware attributes
 *  define properties such as the I2S peripheral's base address and pins.
 *  Each element in I2S_config[] corresponds to an I2S instance, and
 *  and none of the elements should have NULL pointers.
 *  There is no correlation between the index and the peripheral
 *  designation (such as I2S0 or I2S1).  For example, it is possible
 *  to use I2S_config[0] for I2S1.
 *
 *  Because I2S configuration is very device dependent, you will need to
 *  check the doxygen for the device specific I2S implementation.  There you
 *  will find a description of the I2S hardware attributes.  Please also
 *  refer to the board.c file of any of your examples to see the I2S
 *  configuration.
 *
 *  ### Initializing the I2S Driver #
 *
 *  I2S_init() must be called before any other I2S APIs.  This function
 *  iterates through the elements of the I2S_config[] array, calling
 *  the element's device implementation I2S initialization function.
 *
 *  ### I2S Parameters
 *
 *  The #I2S_Params structure is passed to the I2S_open() call.  If NULL
 *  is passed for the parameters, I2S_open() uses default parameters.
 *  An #I2S_Params structure is initialized with default values by passing
 *  it to I2S_Params_init().
 *  Some of the I2S parameters are described below.  To see brief descriptions
 *  of all the parameters, see #I2S_Params.
 *
 *  #### I2S Operation Mode
 *  The I2S operation mode determines whether transmit and/or receive modes
 *  are enabled. The mode is specified with one of the following constants:
 *  - #I2S_OPMODE_TX_ONLY: Enable transmit only.
 *  - #I2S_OPMODE_RX_ONLY: Enable receive only.
 *  - #I2S_OPMODE_TX_RX_SYNC: Enable both receive and transmit.
 *
 *  #### I2S Data Mode
 *  A separate data mode may be specified for read calls and write calls.
 *  The available modes are:
 *  - #I2S_MODE_CALLBACK: This mode is non-blocking. Calls to I2S_read() or
 *    I2S_write() return immediately. When the transfer is finished, the
 *    user configured callback function is called.
 *  - #I2S_MODE_ISSUERECLAIM: Call I2S_readIssue() and I2S_writeIssue() to
 *    queue buffers to the I2S.  I2S_readReclaim() blocks until a buffer
 *    of data is available. I2S_writeReclaim() blocks until a buffer of
 *    data has been issued and the descriptor can be returned back to the
 *    caller.
 *
 *  ### Opening the I2S Driver #
 *  After initializing the I2S driver by calling I2S_init(), the application
 *  can open an I2S instance by calling I2S_open().  This function
 *  takes an index into the I2S_config[] array, and an I2S parameters data
 *  structure.   The I2S instance is specified by the index of the I2S in
 *  I2S_config[].  Only one I2S index can be used at a time;
 *  calling I2S_open() a second time with the same index previosly
 *  passed to I2S_open() will result in an error.  You can,
 *  though, re-use the index if the instance is closed via I2S_close().
 *
 *  If NULL is passed for the I2S_Params structure to I2S_open(), default values
 *  are used. If the open call is successful, it returns a non-NULL value.
 *
 *  Example opening an I2S driver instance:
 *  @code
 *  I2S_Handle      handle;
 *  I2S_Params      params;
 *
 *  I2S_Params_init(&params);
 *  params.operationMode = I2S_MODE_TX_RX_SYNC;
 *  < Change other params as required >
 *
 *  handle = I2S_open(Board_I2S0, &params);
 *  if (!handle) {
 *      // Error opening I2S, handle accordingly
 *  }
 *  @endcode
 *
 *  ### Writing Data #
 *  The following example calls I2S_writeIssue() to write to an I2S driver
 *  instance that has been opened. It first queues up two buffers of text.
 *  Within an infinite loop, it calls I2S_writeReclaim() to retrieve a
 *  buffer and then re-queues the buffer.
 *
 *  @code
 *  const unsigned char hello[] = "Hello World\n";
 *  const unsigned char hello1[] = "Hello World1\n";
 *  I2S_BufDesc writeBuffer1;
 *  I2S_BufDesc writeBuffer2;
 *  I2S_BufDesc *pDesc = NULL;
 *
 *  writeBuffer1.bufPtr  = &hello;
 *  writeBuffer1.bufSize = sizeof(hello);
 *  writeBuffer2.bufPtr  = &hello1;
 *  writeBuffer2.bufSize = sizeof(hello1);
 *
 *  ret = I2S_writeIssue(handle, &writeBuffer1);
 *  ret = I2S_writeIssue(handle, &writeBuffer2);
 *
 *  while(1) {
 *      ret = I2S_writeReclaim(handle, &pDesc);
 *      pDesc->bufPtr  = &hello;;
 *      pDesc->bufSize = sizeof(hello);
 *      ret = I2S_writeIssue(handle, pDesc);
 *  }
 *
 *  @endcode
 *
 *  ### Reading Data #
 *  The following example calls I2S_readIssue() to queue a buffer for
 *  reading from an I2S driver instance. It first queues up two buffers of
 *  text. Within an infinite loop, it then calls I2S_readReclaim() to retrieve
 *  a full buffer of data.
 *
 *  @code
 *  unsigned char rxBuffer[20];
 *  unsigned char rxBuffer1[20];
 *  I2S_BufDesc readBuffer1;
 *  I2S_BufDesc readBuffer2;
 *  I2S_BufDesc *pDesc = NULL;
 *
 *  readBuffer1.bufPtr = &rxBuffer;
 *  readBuffer1.bufSize = 20;
 *  readBuffer2.bufPtr = &rxBuffer1;
 *  readBuffer2.bufSize = 20;
 *
 *  ret = I2S_readIssue(handle, &readBuffer1);
 *  ret = I2S_readIssue(handle, &readBuffer2);
 *
 *  while(1)
 *  {
 *      ret = I2S_readReclaim(handle, &pDesc);
 *      pDesc->bufPtr = &rxBuffer;
 *      pDesc->bufSize = 20;
 *      ret = I2S_readIssue(handle, pDesc);
 *  }
 *  @endcode
 *
 *  # Implementation #
 *
 *  The I2S driver interface module is joined (at link time) to an
 *  array of I2S_Config data structures named *I2S_config*.
 *  *I2S_config* is implemented in the application with each entry being an
 *  instance of a I2S peripheral. Each entry in *I2S_config* contains a:
 *  - (I2S_FxnTable *) to a set of functions that implement a I2S peripheral
 *  - (void *) data object that is associated with the I2S_FxnTable
 *  - (void *) hardware attributes that are associated to the I2S_FxnTable
 *
 *******************************************************************************
 */

#ifndef ti_drivers_I2S__include
#define ti_drivers_I2S__include

#ifdef __cplusplus
extern "C" {
#endif

#include <stdint.h>
#include <stddef.h>

#include <ti/drivers/utils/List.h>

#define I2S_CMD_RESERVED            (32)

#define I2S_STATUS_RESERVED        (-32)

#define I2S_STATUS_SUCCESS         (0)

#define I2S_STATUS_ERROR          (-1)

#define I2S_STATUS_UNDEFINEDCMD   (-2)

/* Add I2S_CMD_<commands> here */

#define I2S_ERROR  (I2S_STATUS_ERROR)

#define I2S_WAIT_FOREVER (~(0U))

typedef struct I2S_Config_ *I2S_Handle;

typedef struct I2S_BufDesc_ {

    List_Elem              qElem;

    void                   *bufPtr;

    size_t                 bufSize;

    uintptr_t              descArg;
} I2S_BufDesc;

typedef void (*I2S_Callback)(I2S_Handle handle, I2S_BufDesc *desc);

typedef enum I2S_DataMode_ {
    I2S_MODE_CALLBACK,

    I2S_MODE_ISSUERECLAIM
} I2S_DataMode;

typedef enum I2S_OpMode_ {
    I2S_OPMODE_TX_ONLY,       
    I2S_OPMODE_RX_ONLY,       
    I2S_OPMODE_TX_RX_SYNC     
} I2S_OpMode;

typedef enum I2S_SerInActiveConfig_ {
    I2S_SERCONFIG_INACT_TRI_STATE,  
    I2S_SERCONFIG_INACT_LOW_LEVEL,  
    I2S_SERCONFIG_INACT_HIGH_LEVEL  
} I2S_SerInActiveConfig;

typedef enum I2S_PinMode_ {
    I2S_PINMODE_RX,                 
    I2S_PINMODE_TX,                 
    I2S_PINMODE_INACTIVE            
} I2S_PinMode;

typedef struct I2S_Params_ {
    I2S_OpMode            operationMode;

    uint32_t              samplingFrequency;

    uint8_t               slotLength;

    uint8_t               bitsPerSample;

    uint8_t               numChannels;

    I2S_DataMode          readMode;

    I2S_Callback          readCallback;

    uint32_t              readTimeout;

    I2S_DataMode          writeMode;

    I2S_Callback          writeCallback;

    uint32_t              writeTimeout;

    void                 *customParams;
} I2S_Params;

typedef void (*I2S_CloseFxn) (I2S_Handle handle);

typedef int_fast16_t (*I2S_ControlFxn)(I2S_Handle handle,
                                       uint_fast16_t cmd,
                                       void *arg);

typedef void (*I2S_InitFxn)(I2S_Handle handle);

typedef I2S_Handle (*I2S_OpenFxn)(I2S_Handle handle, I2S_Params *params);

typedef int_fast16_t (*I2S_IssueFxn)(I2S_Handle handle, I2S_BufDesc *desc);

typedef size_t (*I2S_ReclaimFxn)(I2S_Handle handle, I2S_BufDesc **desc);

typedef struct I2S_FxnTable_ {
    I2S_CloseFxn           closeFxn;

    I2S_ControlFxn         controlFxn;

    I2S_InitFxn            initFxn;

    I2S_OpenFxn            openFxn;

    I2S_IssueFxn           readIssueFxn;

    I2S_ReclaimFxn         readReclaimFxn;

    I2S_IssueFxn           writeIssueFxn;

    I2S_ReclaimFxn         writeReclaimFxn;

} I2S_FxnTable;

typedef struct I2S_Config_ {
    I2S_FxnTable const    *fxnTablePtr;

    void                   *object;

    void          const    *hwAttrs;
} I2S_Config;

extern void I2S_close(I2S_Handle handle);

extern int_fast16_t I2S_control(I2S_Handle handle,
                                uint_fast16_t cmd,
                                void *arg);

extern void I2S_init(void);

extern I2S_Handle I2S_open(uint_least8_t index, I2S_Params *params);

extern void I2S_Params_init(I2S_Params *params);

extern int_fast16_t I2S_read(I2S_Handle handle, I2S_BufDesc *desc);

extern int_fast16_t I2S_readIssue(I2S_Handle handle, I2S_BufDesc *desc);

extern size_t I2S_readReclaim(I2S_Handle handle, I2S_BufDesc **pDesc);

extern int_fast16_t I2S_write(I2S_Handle handle, I2S_BufDesc *desc);

extern int_fast16_t I2S_writeIssue(I2S_Handle handle, I2S_BufDesc *desc);

extern size_t I2S_writeReclaim(I2S_Handle handle, I2S_BufDesc **pDesc);

#ifdef __cplusplus
}
#endif

#endif /* ti_drivers_I2S__include */