I2CLPF3.h

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/*!****************************************************************************
 *  @file       I2CLPF3.h
 *
 *  @brief      I2C driver implementation for a Low Power F3 device I2C
 *              controller.
 *
 *  # Driver Include #
 *  The I2C header file should be included in an application as follows:
 *  @code
 *  #include <ti/drivers/I2C.h>
 *  #include <ti/drivers/i2c/I2CLPF3.h>
 *  @endcode
 *
 *  Refer to @ref I2C.h for a complete description of APIs.
 *
 * # Overview #
 * The general I2C API is normally used in application code, e.g. I2C_open()
 * is used instead of I2CLPF3_open(). The board file will define the device
 * specific config, and casting in the general API will ensure that the correct
 * device specific functions are called.
 * This is also reflected in the example code in [Use Cases](@ref I2C_USE_CASES_LPF3).
 *
 * ## General Behavior #
 * Before using the I2C in LPF3:
 *   - The I2C driver is initialized by calling I2C_init().
 *   - The I2C HW is configured and system dependencies are declared (e.g. IOs,
 *     power, etc.) by calling I2C_open().
 *   .
 * The following is true for receive operation:
 *   - RX is enabled by calling I2C_transfer().
 *     The readCount of the ::I2C_Transaction must be set to a non-zero value.
 *   - If the I2C_transfer() succeeds, the I2C remains enabled.
 *   - The application must check the return value from I2C_transfer()
 *     to verify that the transfer succeeded.
 *   .
 * The following apply for transmit operation:
 *   - TX is enabled by calling I2C_transfer().
 *     The writeCount of the ::I2C_Transaction must be set to a non-zero value.
 *   - If the I2C_transfer() succeeds, the I2C remains enabled.
 *   - The application must check the return value from I2C_transfer()
 *     to verify that the transfer succeeded.
 *   .
 * After I2C operation has ended:
 *   - Release system dependencies for I2C by calling I2C_close().
 *
 * ### Known Issue #
 * @warning The I2C will transmit a single data byte in the event that the
 * I2C target address is not acknowledged (NACK'd). This is due to a known
 * hardware bug.
 *
 * ## Error handling #
 * If an error occurs during operation:
 *   - The I2C Controller transmits a stop bit and remains enabled.
 *   .
 *
 * ## Power Management #
 *  The I2CLPF3 driver sets a power constraint during transactions to keep
 *  the device out of standby; so when all tasks are blocked, the device will
 *  enter idle mode instead of standby.  When the transactions have finished,
 *  the power constraint to prohibit standby is released.
 *  The following statements are valid:
 *    - After I2C_open() call: I2C is enabled, there are no active I2C
 *      transactions, the device can enter standby.
 *    - After I2C_transfer() call: active I2C transactions exist, the device
 *      might enter idle, but not standby.
 *    - When I2C_transfer() completes, either after success or error, I2C
 *      remains enabled, and the device can enter standby.
 *    - After I2C_close() call: I2C is disabled
 *    - If the device goes into idle during a transaction, the state of
 *      SDA is undefined in the time between the transaction completing and
 *      the device waking up. SCL will go low until the device wakes up and
 *      starts another transaction or releases the bus. If this is a problem
 *      for another device on the I2C bus, you can set a power constraint for
 *      #PowerLPF3_DISALLOW_IDLE before the transaction and release it
 *      when the transaction completes.
 *
 * ## Supported Functions ##
 *  | Generic API Function | API Function             | Description                                       |
 *  |--------------------- |------------------------- |---------------------------------------------------|
 *  | I2C_init()           | I2CLPF3_init()         | Initialize I2C driver                             |
 *  | I2C_open()           | I2CLPF3_open()         | Initialize I2C HW and set system dependencies     |
 *  | I2C_close()          | I2CLPF3_close()        | Disable I2C HW and release system dependencies    |
 *  | I2C_transfer()       | I2CLPF3_transfer()     | Start I2C transfer                                |
 *
 *  @note All calls should go through the generic API.
 *
 *  ## Supported Bit Rates ##
 *    - #I2C_100kHz
 *    - #I2C_400kHz
 *
 *  ## Unsupported Functionality #
 *  The LPF3 I2C driver currently does not support:
 *    - Multi-controller mode
 *    - I2C target mode
 *
 * ## Use Cases @anchor I2C_USE_CASES_LPF3 ##
 * ### Basic Receive #
 *  Receive 10 bytes over I2C in ::I2C_MODE_BLOCKING.
 *  @code
 *  // Locals
 *  I2C_Handle handle;
 *  I2C_Params params;
 *  I2C_Transaction i2cTrans;
 *  uint8_t rxBuf[32];      // Receive buffer
 *  uint8_t txBuf[32];      // Transmit buffer
 *
 *  // Configure I2C parameters.
 *  I2C_Params_init(&params);
 *
 *  // Initialize I2C transaction structure
 *  i2cTrans.writeCount    = 0;
 *  i2cTrans.writeBuf      = txBuf;
 *  i2cTrans.readCount     = 10;
 *  i2cTrans.readBuf       = rxBuf;
 *  i2cTrans.targetAddress = 0x3C;
 *
 *  // Open I2C
 *  handle = I2C_open(CONFIG_I2C, &params);
 *
 *  // Do I2C transfer receive
 *  I2C_transfer(handle, &i2cTrans);
 *  @endcode
 *
 * ### Basic Transmit #
 *  Transmit 16 bytes over I2C in ::I2C_MODE_CALLBACK.
 *  @code
 *  uint8_t rxBuffer[32];            // Receive buffer
 *  uint8_t txBuffer[32];            // Transmit buffer
 *  bool transferDone = false;
 *
 *  static void transferCallback(I2C_Handle handle, I2C_Transaction *transac, bool result)
 *  {
 *      // Set length bytes
 *      if (result) {
 *          transferDone = true;
 *      } else {
 *          // Transaction failed, act accordingly...
 *          .
 *          .
 *      }
 *  }
 *
 *  static void taskFxn(uintptr_t a0, uintptr_t a1)
 *  {
 *      // Locals
 *      I2C_Handle handle;
 *      I2C_Params params;
 *      I2C_Transaction i2cTrans;
 *
 *      // Configure I2C parameters.
 *      I2C_Params_init(&params);
 *      params.transferMode = I2C_MODE_CALLBACK;
 *      params.transferCallbackFxn = transferCallback;
 *
 *      // Prepare data to send, send 0x00, 0x01, 0x02, ...0xFF, 0x00, 0x01...
 *      for(uint32_t i = 0; i < numTxBytes; i++)
 *          txBuffer[i] = (uint8_t) i;
 *
 *      // Initialize I2C transaction structure
 *      i2cTrans.writeCount    = 16;
 *      i2cTrans.writeBuf      = txBuffer;
 *      i2cTrans.readCount     = 0;
 *      i2cTrans.readBuf       = rxBuffer;
 *      i2cTrans.targetAddress = 0x3C;
 *
 *      // Open I2C
 *      handle = I2C_open(CONFIG_I2C, &params);
 *
 *      // Do I2C transfer (in callback mode)
 *      I2C_transfer(handle, &i2cTrans);
 *
 *      // Do other stuff while I2C is handling the transfer
 *      .
 *      .
 *
 *      // Do something if I2C transfer is finished
 *      if(transferDone) {
 *          .
 *          .
 *      }
 *
 *      // Continue...
 *      .
 *      .
 *  }
 *  @endcode
 *
 * ### Chained Transactions #
 *  Transmit 10 bytes and then 32 bytes over I2C in ::I2C_MODE_CALLBACK.
 *  @code
 *  uint8_t rxBuffer[32];            // Receive buffer
 *  uint8_t txBuffer[32];            // Transmit buffer
 *  uint8_t rxBuffer2[64];           // Receive buffer 2
 *  uint8_t txBuffer2[64];           // Transmit buffer 2
 *  bool transferDone = false;
 *
 *  static void writeCallbackDefault(I2C_Handle handle, I2C_Transaction *transac, bool result)
 *  {
 *      // Set length bytes
 *      if (result) {
 *          transferDone = true;
 *      } else {
 *          // Transaction failed, act accordingly...
 *          .
 *          .
 *      }
 *  }
 *
 *  static void taskFxn(uintptr_t a0, uintptr_t a1)
 *  {
 *      // Locals
 *      I2C_Handle handle;
 *      I2C_Params params;
 *      I2C_Transaction i2cTrans;
 *      I2C_Transaction i2cTrans2;
 *
 *      // Configure I2C parameters.
 *      I2C_Params_init(&params);
 *      params.transferMode = I2C_MODE_CALLBACK;
 *      params.transferCallbackFxn = writeCallbackDefault;
 *
 *      // Prepare data to send, send 0x00, 0x01, 0x02, ...0xFF, 0x00, 0x01...
 *      for(uint32_t i = 0; i < numTxBytes; i++)
 *          txBuffer[i] = (uint8_t) i;
 *
 *      // Initialize first I2C transaction structure
 *      i2cTrans.writeCount    = 10;
 *      i2cTrans.writeBuf      = txBuffer;
 *      i2cTrans.readCount     = 0;
 *      i2cTrans.readBuf       = rxBuffer;
 *      i2cTrans.targetAddress = 0x3C;
 *
 *      // Second transaction
 *      i2cTrans2.writeCount    = 32;
 *      i2cTrans2.writeBuf      = txBuffer2;
 *      i2cTrans2.readCount     = 0;
 *      i2cTrans2.readBuf       = rxBuffer2;
 *      i2cTrans2.targetAddress = 0x2E;
 *
 *      // Open I2C
 *      handle = I2C_open(CONFIG_I2C, &params);
 *
 *      // Do chained I2C transfers (in callback mode).
 *      I2C_transfer(handle, &i2cTrans);
 *      I2C_transfer(handle, &i2cTrans2);
 *
 *      // Do other stuff while I2C is handling the transfers
 *      .
 *      .
 *
 *      // Do something if I2C transfers are finished
 *      if(transferDone) {
 *          .
 *          .
 *      }
 *
 *      // Continue...
 *      .
 *      .
 *  }
 *  @endcode
 *
 *  # Instrumentation #
 *  The I2C driver interface produces log statements if instrumentation is
 *  enabled.
 *
 *  Diagnostics Mask | Log details |
 *  ---------------- | ----------- |
 *  Diags_USER1      | basic I2C operations performed |
 *  Diags_USER2      | detailed I2C operations performed |
 *
 ******************************************************************************
 */

#ifndef ti_drivers_i2c_I2CLPF3__include
#define ti_drivers_i2c_I2CLPF3__include

#include <stdint.h>
#include <stdbool.h>

#include <ti/drivers/I2C.h>
#include <ti/drivers/Power.h>

#include <ti/drivers/dpl/SwiP.h>

#ifdef __cplusplus
extern "C" {
#endif

typedef struct
{
    uint8_t pinSDA;
    uint8_t pinSCL;
} I2CLPF3_I2CPinCfg;

typedef struct
{
    I2C_BASE_HWATTRS

    /* I2C peripheral's Power driver ID */
    unsigned long powerMngrId;

    /*
     *  I2C Swi priority.
     *  The higher the number, the higher the priority.
     *  The minimum is 0 and the maximum is 15 by default.
     *  The maximum can be reduced to save RAM by adding or modifying
     *  Swi.numPriorities in the kernel configuration file.
     */
    uint32_t swiPriority;
    /* SDA pin index and mux */
    uint8_t sdaPin;
    uint8_t sdaPinMux;
    /* SCL pin index and mux */
    uint8_t sclPin;
    uint8_t sclPinMux;
} I2CLPF3_HWAttrs;

typedef struct
{
    I2C_BASE_OBJECT

    /* Swi object */
    SwiP_Struct swi;

    /* Bitrate of the I2C module */
    uint32_t bitRate;

    /* Pin indexes. We need to cache these because we might have custom pins */
    uint8_t sdaPin;
    uint8_t sclPin;

    /* I2C power notification */
    void *i2cPostFxn;
    Power_NotifyObj i2cPostObj;
} I2CLPF3_Object;

#ifdef __cplusplus
}
#endif

#endif /* ti_drivers_i2c_I2CLPF3__include */