i2c_base.hpp

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/*
 *     SocialLedge.com - Copyright (C) 2013
 *
 *     This file is part of free software framework for embedded processors.
 *     You can use it and/or distribute it as long as this copyright header
 *     remains unmodified.  The code is free for personal use and requires
 *     permission to use in a commercial product.
 *
 *      THIS SOFTWARE IS PROVIDED "AS IS".  NO WARRANTIES, WHETHER EXPRESS, IMPLIED
 *      OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
 *      MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
 *      I SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR
 *      CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
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 */

#ifndef I2C_BASE_HPP_
#define I2C_BASE_HPP_

#include <stdint.h>

#include "FreeRTOS.h"
#include "task.h"       // xTaskGetSchedulerState()
#include "semphr.h"     // Semaphores used in I2C
#include "LPC17xx.h"



#define I2C_TIMEOUT_MS          1000


class I2C_Base
{
    public:
        void handleInterrupt();

        uint8_t readReg(uint8_t deviceAddress, uint8_t registerAddress);

        bool writeReg(uint8_t deviceAddress, uint8_t registerAddress, uint8_t value);

        bool readRegisters(uint8_t deviceAddress, uint8_t firstReg, uint8_t* pData, uint32_t transferSize);

        bool writeRegisters(uint8_t deviceAddress, uint8_t firstReg, uint8_t* pData, uint32_t transferSize);

        bool checkDeviceResponse(uint8_t deviceAddress);



    protected:
        I2C_Base(LPC_I2C_TypeDef* pI2CBaseAddr);

        bool init(uint32_t pclk, uint32_t busRateInKhz);

        void disableOperation() { mDisableOperation = true; }


    private:
        LPC_I2C_TypeDef* mpI2CRegs;    
        IRQn_Type        mIRQ;         
        bool mDisableOperation;        
        SemaphoreHandle_t mI2CMutex;   
        SemaphoreHandle_t mTransferCompleteSignal; 

        typedef enum {
            busy,
            readComplete,
            writeComplete
        } __attribute__((packed)) mStateMachineStatus_t;

        typedef struct
        {
            uint32_t trxSize;   
            uint8_t slaveAddr;  
            uint8_t firstReg;   
            uint8_t error;      
            uint8_t *pMasterData;  
        } mI2CTransaction_t;

        mI2CTransaction_t mTransaction;

        mStateMachineStatus_t i2cStateMachine();

        bool transfer(uint8_t deviceAddress, uint8_t firstReg, uint8_t* pData, uint32_t transferSize);

        void i2cKickOffTransfer(uint8_t devAddr, uint8_t regStart, uint8_t* pBytes, uint32_t len);
};




#endif /* I2C_BASE_HPP_ */