I2C.h

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/*
 * Copyright (c) 2015-2019, Texas Instruments Incorporated
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/*!****************************************************************************
 *  @file       I2C.h
 *  @brief      Inter-Integrated Circuit (I2C) Driver
 *
 *  @anchor ti_drivers_I2C_Overview
 *  # Overview
 *
 *  The I2C driver is designed to operate as an I2C master and will not
 *  function as an I2C slave. Multi-master arbitration is not supported;
 *  therefore, this driver assumes it is the only I2C master on the bus.
 *  This I2C driver's API set provides the ability to transmit and receive
 *  data over an I2C bus between the I2C master and I2C slave(s). The
 *  application is responsible for manipulating and interpreting the data.
 *
 *
 *  <hr>
 *  @anchor ti_drivers_I2C_Usage
 *  # Usage
 *
 *  This section provides a basic @ref ti_drivers_I2C_Synopsis
 *  "usage summary" and a set of @ref ti_drivers_I2C_Examples "examples"
 *  in the form of commented code fragments. Detailed descriptions of the
 *  I2C APIs and their effect are provided in subsequent sections.
 *
 *  @anchor ti_drivers_I2C_Synopsis
 *  ## Synopsis #
 *  @anchor ti_drivers_I2C_Synopsis_Code
 *  @code
 *  // Import I2C Driver definitions
 *  #include <ti/drivers/I2C.h>
 *
 *  // Define name for an index of an I2C bus
 *  #define SENSORS 0
 *
 *  // Define the slave address of device on the SENSORS bus
 *  #define OPT_ADDR 0x47
 *
 *  // One-time init of I2C driver
 *  I2C_init();
 *
 *  // initialize optional I2C bus parameters
 *  I2C_Params params;
 *  I2C_Params_init(&params);
 *  params.bitRate = I2C_400kHz;
 *
 *  // Open I2C bus for usage
 *  I2C_Handle i2cHandle = I2C_open(SENSORS, &params);
 *
 *  // Initialize slave address of transaction
 *  I2C_Transaction transaction = {0};
 *  transaction.slaveAddress = OPT_ADDR;
 *
 *  // Read from I2C slave device
 *  transaction.readBuf = data;
 *  transaction.readCount = sizeof(data);
 *  transaction.writeCount = 0;
 *  I2C_transfer(i2cHandle, &transaction);
 *
 *  // Write to I2C slave device
 *  transaction.writeBuf = command;
 *  transaction.writeCount = sizeof(command);
 *  transaction.readCount = 0;
 *  I2C_transfer(i2cHandle, &transaction);
 *
 *  // Close I2C
 *  I2C_close(i2cHandle);
 *  @endcode
 *
 *  @anchor ti_drivers_I2C_Examples
 *  ## Examples
 *
 *  @li @ref ti_drivers_I2C_Example_open "Getting an I2C bus handle"
 *  @li @ref ti_drivers_I2C_Example_write3bytes "Sending 3 bytes"
 *  @li @ref ti_drivers_I2C_Example_read5bytes "Reading 5 bytes"
 *  @li @ref ti_drivers_I2C_Example_writeread "Writing then reading in a single transaction"
 *  @li @ref ti_drivers_I2C_Example_callback "Using Callback mode"
 *
 *  @anchor ti_drivers_I2C_Example_open
 *  ## Opening the I2C Driver
 *
 *  After calling I2C_init(), the application can open an I2C instance by
 *  calling I2C_open().The following code example opens an I2C instance with
 *  default parameters by passing @p NULL for the #I2C_Params argument.
 *
 *  @code
 *  I2C_Handle i2cHandle;
 *
 *  i2cHandle = I2C_open(0, NULL);
 *
 *  if (i2cHandle == NULL) {
 *      // Error opening I2C
 *      while (1) {}
 *  }
 *  @endcode
 *
 *  @anchor ti_drivers_I2C_Example_write3bytes
 *  ## Sending three bytes of data.
 *
 *  @code
 *  I2C_Transaction i2cTransaction = {0};
 *  uint8_t writeBuffer[3];
 *
 *  writeBuffer[0] = 0xAB;
 *  writeBuffer[1] = 0xCD;
 *  writeBuffer[2] = 0xEF;
 *
 *  i2cTransaction.slaveAddress = 0x50;
 *  i2cTransaction.writeBuf = writeBuffer;
 *  i2cTransaction.writeCount = 3;
 *  i2cTransaction.readBuf = NULL;
 *  i2cTransaction.readCount = 0;
 *
 *  status = I2C_transfer(i2cHandle, &i2cTransaction);
 *
 *  if (status == false) {
 *      // Unsuccessful I2C transfer
 *  }
 *  @endcode
 *
 *  @anchor ti_drivers_I2C_Example_read5bytes
 *  ## Reading five bytes of data.
 *
 *  @code
 *  I2C_Transaction i2cTransaction = {0};
 *  uint8_t readBuffer[5];
 *
 *  i2cTransaction.slaveAddress = 0x50;
 *  i2cTransaction.writeBuf = NULL;
 *  i2cTransaction.writeCount = 0;
 *  i2cTransaction.readBuf = readBuffer;
 *  i2cTransaction.readCount = 5;
 *
 *  status = I2C_transfer(i2cHandle, &i2cTransaction);
 *
 *  if (status == false) {
 *      // Unsuccessful I2C transfer
 *  }
 *  @endcode
 *
 *  @anchor ti_drivers_I2C_Example_writeread
 *  ## Writing two bytes and reading four bytes in a single transaction.
 *
 *  @code
 *  I2C_Transaction i2cTransaction = {0};
 *  uint8_t readBuffer[4];
 *  uint8_t writeBuffer[2];
 *
 *  writeBuffer[0] = 0xAB;
 *  writeBuffer[1] = 0xCD;
 *
 *  i2cTransaction.slaveAddress = 0x50;
 *  i2cTransaction.writeBuf = writeBuffer;
 *  i2cTransaction.writeCount = 2;
 *  i2cTransaction.readBuf = readBuffer;
 *  i2cTransaction.readCount = 4;
 *
 *  status = I2C_transfer(i2cHandle, &i2cTransaction);
 *
 *  if (status == false) {
 *      // Unsuccessful I2C transfer
 *  }
 *  @endcode
 *
 *  @anchor ti_drivers_I2C_Example_callback
 *  ## Using callback mode
 *  This final example shows usage of #I2C_MODE_CALLBACK, with queuing
 *  of multiple transactions. Because multiple transactions are simultaneously
 *  queued, separate #I2C_Transaction structures must be used. Each
 *  #I2C_Transaction will contain a custom application argument of a
 *  semaphore handle. The #I2C_Transaction.arg will point to the semaphore
 *  handle. When the callback function is called, the #I2C_Transaction.arg is
 *  checked for @p NULL. If this value is not @p NULL, then it can be assumed
 *  the @p arg is pointing to a valid semaphore handle. The semaphore handle
 *  is then used to call @p sem_post(). Hypothetically, this can be used to
 *  signal transaction completion to the task(s) that queued the
 *  transaction(s).
 *
 *  @code
 *  void callbackFxn(I2C_Handle handle, I2C_Transaction *msg, bool status)
 *  {
 *
 *      if (status == false) {
 *          //transaction failed
 *      }
 *
 *      // Check for a semaphore handle
 *      if (msg->arg != NULL) {
 *
 *          // Perform a semaphore post
 *          sem_post((sem_t *) (msg->arg));
 *      }
 *  }
 *  @endcode
 *
 *  Snippets of the thread code that initiates the transactions are shown below.
 *  Note the use of multiple #I2C_Transaction structures. The handle of the
 *  semaphore to be posted is specified via @p i2cTransaction2.arg.
 *  I2C_transfer() is called three times to initiate each transaction.
 *  Since callback mode is used, these functions return immediately. After
 *  the transactions have been queued, other work can be done. Eventually,
 *  @p sem_wait() is called causing the thread to block until the transaction
 *  completes. When the transaction completes, the application's callback
 *  function, @p callbackFxn will be called. Once #I2C_CallbackFxn posts the
 *  semaphore, the thread will be unblocked and can resume execution.
 *
 *  @code
 *  void thread(arg0, arg1)
 *  {
 *
 *      I2C_Transaction i2cTransaction0 = {0};
 *      I2C_Transaction i2cTransaction1 = {0};
 *      I2C_Transaction i2cTransaction2 = {0};
 *
 *      // ...
 *
 *      i2cTransaction0.arg = NULL;
 *      i2cTransaction1.arg = NULL;
 *      i2cTransaction2.arg = semaphoreHandle;
 *
 *      // ...
 *
 *      I2C_transfer(i2c, &i2cTransaction0);
 *      I2C_transfer(i2c, &i2cTransaction1);
 *      I2C_transfer(i2c, &i2cTransaction2);
 *
 *      // ...
 *
 *      sem_wait(semaphoreHandle);
 *  }
 *  @endcode
 *
 *  <hr>
 *  @anchor ti_drivers_I2C_Configuration
 *  # Configuration
 *
 *  Refer to the @ref driver_configuration "Driver's Configuration" section
 *  for driver configuration information.
 *  <hr>
 ******************************************************************************
 */

#ifndef ti_drivers_I2C__include
#define ti_drivers_I2C__include

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif

#define I2C_CMD_RESERVED           (32)

#define I2C_STATUS_RESERVED        (-32)

#define I2C_STATUS_SUCCESS         (0)

#define I2C_STATUS_ERROR           (-1)

 #define I2C_STATUS_TIMEOUT         (-2)

#define I2C_STATUS_UNDEFINEDCMD    (-2)

/* Add I2C_CMD_<commands> here */

#define I2C_WAIT_FOREVER           (~(0U))

typedef struct I2C_Config_ *I2C_Handle;

typedef struct {
    void         *writeBuf;

    size_t        writeCount;

    void         *readBuf;

    size_t        readCount;

    uint_least8_t slaveAddress;

    void         *arg;

    void         *nextPtr;
} I2C_Transaction;

typedef enum {
    I2C_MODE_BLOCKING,

    I2C_MODE_CALLBACK
} I2C_TransferMode;

typedef void (*I2C_CallbackFxn)(I2C_Handle handle, I2C_Transaction *transaction,
    bool transferStatus);

typedef enum {
    I2C_100kHz     = 0,    
    I2C_400kHz     = 1,    
    I2C_1000kHz    = 2,    
    I2C_3330kHz    = 3,    
    I2C_3400kHz    = 3,    
} I2C_BitRate;

typedef struct {
    I2C_TransferMode transferMode;

    I2C_CallbackFxn transferCallbackFxn;

    I2C_BitRate bitRate;

    void *custom;
} I2C_Params;

typedef void (*I2C_CancelFxn) (I2C_Handle handle);

typedef void (*I2C_CloseFxn) (I2C_Handle handle);

typedef int_fast16_t (*I2C_ControlFxn) (I2C_Handle handle, uint_fast16_t cmd,
    void *controlArg);

typedef void (*I2C_InitFxn) (I2C_Handle handle);

typedef I2C_Handle (*I2C_OpenFxn) (I2C_Handle handle, I2C_Params *params);

typedef int_fast16_t (*I2C_TransferFxn) (I2C_Handle handle,
                      I2C_Transaction *transaction, uint32_t timeout);

typedef struct {
    I2C_CancelFxn   cancelFxn;
    I2C_CloseFxn    closeFxn;
    I2C_ControlFxn  controlFxn;
    I2C_InitFxn     initFxn;
    I2C_OpenFxn     openFxn;
    I2C_TransferFxn transferFxn;
} I2C_FxnTable;

typedef struct I2C_Config_ {
    I2C_FxnTable const *fxnTablePtr;

    void               *object;

    void         const *hwAttrs;
} I2C_Config;

extern void I2C_cancel(I2C_Handle handle);

extern void I2C_close(I2C_Handle handle);

extern int_fast16_t I2C_control(I2C_Handle handle, uint_fast16_t cmd,
    void *controlArg);

extern void I2C_init(void);

extern I2C_Handle I2C_open(uint_least8_t index, I2C_Params *params);

extern void I2C_Params_init(I2C_Params *params);

extern bool I2C_transfer(I2C_Handle handle, I2C_Transaction *transaction);

extern int_fast16_t I2C_transferTimeout(I2C_Handle handle, I2C_Transaction *transaction, uint32_t timeout);

#ifdef __cplusplus
}
#endif

#endif /* ti_drivers_I2C__include */