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/*******************************************************************************
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*
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*
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*/

#include "mbed.h"
#include "max17055.h"

/* POR Mask */
#define MAX17055_POR_MASK               (0xFFFD)
#define MAX17055_CYCLE_MASK             (0x0002)


/* MODELCFG register bits */
#define MAX17055_MODELCFG_REFRESH       (1 << 15)


/* FSTAT register bits */
#define MAX17055_FSTAT_DNR              (1)

/* LIBRARY FUNCTION SUCCESS*/
#define F_SUCCESS_0  0

/* LIBRARY FUNCTION ERROR CODES */
#define F_ERROR_1 -1    //-1 if I2C read/write errors exist         
#define F_ERROR_2 -2    //-2 if device is not present
#define F_ERROR_3 -3    //-3 if function error
#define F_ERROR_4 -4    //-4 if other error
#define F_ERROR_5 -5    //-5 if POR not detected



/**
 * @brief       max17055 Constructor
 * @details     max17055 Constructor with battery and i2c as parameters
 */
MAX17055::MAX17055(I2C &i2c):
    m_i2cBus(i2c)
{
    //empty block
}

/**
 * @brief       Fuel Gauge Destructor
 */
MAX17055::~MAX17055()
{
    //empty block
}

/**
 * @brief      Writes a register.
 *
 * @param[in]  reg_addr  The register address
 * @param[in]  reg_data  The register data
 *
 * @retval     0 on success
 * @retval     non-0 for errors
 */
int MAX17055::writeReg(Registers_e reg_addr, uint16_t reg_data)
{

    uint16_t mask = 0x00FF;
    uint8_t dataLSB;
    uint8_t dataMSB;

    dataLSB = reg_data & mask;
    dataMSB = (reg_data >> 8) & mask;

    char addr_plus_data[3] = {reg_addr, dataLSB, dataMSB};

    if ( m_i2cBus.write(I2C_W_ADRS, addr_plus_data, 3, false) == F_SUCCESS_0)
        return F_SUCCESS_0;
    else
        return F_ERROR_1;
}

/**
 * @brief      Reads from MAX17055 register.
 *
 * @param[in]  reg_addr  The register address
 * @param      value     The value
 *
 * @retval     0 on success
 * @retval     non-0 for errors
 */
int32_t MAX17055::readReg(Registers_e reg_addr, uint16_t &value)
{
    int32_t result;
    uint16_t mask = 0x00FF;
    char local_data[1];
    local_data[0] = reg_addr;
    char read_data[2];

    result = m_i2cBus.write(I2C_W_ADRS, local_data, 1);
    if(result == F_SUCCESS_0) {
        result = m_i2cBus.read(I2C_R_ADRS, read_data , 2, false);
        if (result == F_SUCCESS_0) {
            value = ( ((read_data[1] & mask) << 8) + (read_data[0]));
            result = F_SUCCESS_0;
        }
    }
    return result;
}

/**
 * @brief      Reads an specified register from the MAX17055 register.
 *
 * @param[in]  reg_addr  The register address
 * @param      value     The value
 *
 * @retval     reg_data register data
 * @retval     statusRead non-0 for errors
 */

int16_t MAX17055::get_regInfo(Registers_e reg_addr)
{
    uint16_t read_data;
    int statusRead;

    statusRead = readReg(reg_addr, read_data);
    if (statusRead != F_SUCCESS_0)
        return statusRead;
    else
        return read_data;

}

/**
 * @brief        Write and Verify a MAX17055 register
 * @par          Details
 *               This function writes and verifies if the writing process was successful
 *
 * @param[in]    reg_addr     - register address
 * @param[out]   reg_data     - the variable that contains the data to write
 *                               to the register address
 *
 * @retval       0 on success
 * @retval       non-0 for errors
 */
int MAX17055::write_and_verify_reg(Registers_e reg_addr, uint16_t reg_data2write)
{
    int retries = 0;
    int ret;
    int statusRead;
    int statusWrite;
    uint16_t read_data;


    do {
        statusWrite = writeReg(reg_addr, reg_data2write);
        if (statusWrite != F_SUCCESS_0)
            return F_ERROR_1;      
        wait_ms(1);
        statusRead = readReg(reg_addr, read_data);
        if  (statusRead != F_SUCCESS_0)
            return F_ERROR_1;
    } while (reg_data2write != read_data && retries++<3);
    
    return F_SUCCESS_0;
}

/**
 * @brief       Initialization Function for MAX17055.
 * @par         Details
 *              This function initializes the MAX17055 for the implementation of the EZconfig model.\n
 *              The library needs to be customized for the implementation of customize model.\n
 *
 * @retval      0 on success
 * @retval      non-0 for errors
 */
int MAX17055::init(platform_data des_data)
{

    int ret;
    int time_out = 10;
    int32_t status;
    uint16_t hibcfg_value;
    uint16_t read_data;


    status = readReg(VERSION_REG, read_data);
    if (status != F_SUCCESS_0)
        return status;

    ///STEP 0. Check for POR (Skip load model if POR bit is cleared)

    if (check_POR_func() == F_ERROR_5)
        return F_ERROR_5;  //POR not detected. Skip Initialization.

    ///STEP 1. Check if FStat.DNR == 0 (Do not continue until FSTAT.DNR == 0)
    ret = poll_flag_clear(FSTAT_REG, MAX17055_FSTAT_DNR, time_out);
    if (ret < F_SUCCESS_0) {
        return ret;
    }

    ///STEP 1.2. Force exit from hibernate
    hibcfg_value = forcedExitHiberMode();


    ///STEP 2. Initialize configuration
    ///STEP 2.1. Load EZ Config
    EZconfig(des_data);

    ///STEP 2.2. Poll ModelCFG.ModelRefresh bit for clear
    ret = poll_flag_clear(MODELCFG_REG, MAX17055_MODELCFG_REFRESH, time_out);
    if(ret < F_SUCCESS_0) {
        return ret;
    }
    ///STEP3. Restore original HibCfg
    writeReg(HIBCFG_REG, hibcfg_value);


    /* Clear Status.POR */
    ret = clear_POR_bit();
    if (ret < F_SUCCESS_0)
        return ret; //See errors
    return F_SUCCESS_0;
    
}

/**
 * @brief      Check POR function
 * @par Details
 *     This function check is there was a power on reset event for the
 *     MAX17055
 *
 * @retval    0 on success (POR detected)
 * @retval    non-0 for errors (POR not detected)
 *
 */
int MAX17055::check_POR_func()
{
    uint16_t read_data;

    readReg(STATUS_REG, read_data);
//    printf("STATUS REF = %X \r\n", read_data);
    if (!(read_data & MAX17055_STATUS_POR ) ) {
        return F_ERROR_5;  //POR not detected.
    } else
        return F_SUCCESS_0;
}

/**
 * @brief        clear POR bit function
 * @par          Details
 *               This function clear the indicating bit for POR - MAX17055
 *
 * @retval       0 for Success
 * @retval      non-0 for errors
 */
int MAX17055::clear_POR_bit()
{
    int status;
    uint16_t read_data;


    status = readReg(STATUS_REG, read_data);
    if (status != F_SUCCESS_0)
        return F_ERROR_2;  //Device is not present in the i2c Bus
    status = write_and_verify_reg(STATUS_REG, (read_data & MAX17055_POR_MASK));
    if (status != F_SUCCESS_0)
        return F_ERROR_1; //read or write error
    else
        return F_SUCCESS_0;
}

/**
 * @brief      Poll Flag clear Function.
 * @par Details
 *     This function clears status flags for the MAX17055
 *
 * @param[in]  reg_addr  - register address
 * @param[in]  mask      - register address
 * @param[in]  timeout   - register data
 *
 * @retval     0 on success
 * @retval    non-0 negative for errors
 */
int MAX17055::poll_flag_clear (Registers_e reg_addr, int mask, int timeout)
{
    uint16_t data;
    int ret;

    do {
        wait_ms(50);
        ret = readReg(reg_addr, data);
//        printf("read reg %X\r\n", data);
//        printf("mask %X\r\n", mask);
        if(ret < F_SUCCESS_0)
            return F_ERROR_1;
            

        if(!(data & mask))
            return F_SUCCESS_0;

        timeout -= 1;
//        printf("end timeout %d \r\n", timeout);
    } while(timeout > 0);

    return F_ERROR_4;
}

/**
 * @brief        Get Temperature Function from the MAX17055 TEMP register.
 * @par          Details
 *               This function sends a request to access the TEMP register
 *               of the MAX17055, which reflects the temperature measured for the fuel gauge.
 *               The temperature values will reflect the Config Register (0x1D) selections for Tsel bit (D15).
 *               For this library the setting are for die temperature.
 *               The MAX32620FTHR thermistor bias pin is not connected. The biasing of the thermistor is
 *               done by the MAX77650. See MAX77650 library for how to enable the thermistor biasing.
 *
 *
 * @retval      temp - Temperature value from TEMP register in &deg;C
 * @retval      non-0 negative values check for errors
 */
int MAX17055::get_temperature()
{

    int ret;
    uint16_t temp;

    ret = readReg(TEMP_REG, temp);
    if (ret < F_SUCCESS_0)
        return ret;

    /* The value is signed. */
    if (temp & 0x8000)
        temp |= 0xFFFF0000;

    /* The value is converted into centigrade scale */
    /* Units of LSB = 1 / 256 degree Celsius */
    temp >>= 8;

    return temp;
}

/**
 * @brief        Forced Exit Hibernate Mode Function for MAX17055
 * @par          Details
 *               This function executes a force exit from hibernate mode.
 *
 * @retval       HibCFG original value before forced Exit Hibernate mode *
 */
uint16_t MAX17055::forcedExitHiberMode()
{
    uint16_t hibcfg;

    /* Force exit from hibernate */
    //STEP 0: Store original HibCFG value
    readReg(HIBCFG_REG, hibcfg);

    //STEP 1: Write to Soft-Wakeup Command Register
    writeReg(VFSOC0_QH0_LOCK_REG, 0x90); //Soft-Wakeup from hibernate

    //STEP 2: Write to Hibernate Configuration register
    writeReg(HIBCFG_REG, 0x0); //disable hibernate mode

    //STEP 3:Write to Soft-Wakeup Command Register
    writeReg(VFSOC0_QH0_LOCK_REG, 0x0); //Clear All commands

    return hibcfg;
}

/**
 * @brief        EZ Config function
 * @par          Details
 *               This function implements the steps for the EZ config m5 FuelGauge
 * @param[in]    des_data - Plataform_data struct with information about the design.
 * @retval       0 on success
 * @retval       non-zero for errors
 */
uint16_t MAX17055::EZconfig(platform_data des_data)
{
    ///STEP 2.1.1 EZ config values suggested by manufacturer.
    const int charger_th = 4275;
    const int chg_V_high = 51200; // scaling factor high voltage charger
    const int chg_V_low = 44138;
    const int param_EZ_FG1 = 0x8400; // Sets config bit for the charge voltage for the m5
    const int param_EZ_FG2 = 0x8000;
    uint16_t dpacc, ret;
    const int DIV_32 = 5;//DesignCap divide by 32 for EZ config
    const int DIV_16 = 4;//DesignCap divide by 16 only for custom ini files

    ///STEP 2.1.2 Store the EZ Config values into the appropriate registers.
    ret = writeReg(DESIGNCAP_REG, des_data.designcap);
    ret = writeReg(DQACC_REG, des_data.designcap >> DIV_32);  
    ret = writeReg(ICHGTERM_REG, des_data.ichgterm);
    ret = writeReg(VEMPTY_REG, des_data.vempty);

    if (des_data.vcharge > charger_th) {
        dpacc = (des_data.designcap >> DIV_32) * chg_V_high / des_data.designcap;
        ret = writeReg(DPACC_REG, dpacc);
        ret = writeReg(MODELCFG_REG, param_EZ_FG1); //
    } else {
        dpacc = (des_data.designcap >> DIV_32) * chg_V_low / des_data.designcap;
        ret = writeReg(DPACC_REG, dpacc);
        ret = writeReg(MODELCFG_REG, param_EZ_FG2);
    }
    return ret;
}


/**
 * @brief        Get reported Battery Capacity Function from MAX17055 Fuel Gauge
 * @par          Details
 *               This function sends a request to access the RepCAP register
 *               of the MAX17055. RepCAP is the reported Battery Capacity in mAh of the battery based on the calculation by the Fuel Gauge algorithm.
 *
 * @retval      repcap_data - Reported SOC data from the RepSOC register in % value.
 * @retval      non-0 negative values check for errors
 */

int MAX17055::get_battCAP(platform_data des_data)
{
    int ret, design_rsense;
    uint16_t repcap_data;

    ret = readReg(REPCAP_REG, repcap_data);
    if (ret < F_SUCCESS_0)
        return ret;
    else
        design_rsense = des_data.rsense;
    ret = raw_cap_to_uAh((uint32_t)repcap_data, design_rsense);
    if (ret < F_SUCCESS_0)
        return ret;
    else
        return ret;
}

/**
 * @brief        Get reported State Of Charge(SOC) Function from MAX17055 Fuel Gauge.
 * @par          Details
 *               This function sends a request to access the RepSOC register
 *               of the MAX17055. RepSOC is the reported state-of-charge percentage output of the fuel gauge.
 *
 * @retval      soc_data - Reported SOC data from the RepSOC register in % value.
 * @retval      non-0 negative values check for errors
 */
int MAX17055::get_SOC()
{

    int ret;
    uint16_t soc_data;

    ret = readReg(REPSOC_REG, soc_data);
    if (ret < F_SUCCESS_0)
        return ret;

    soc_data = soc_data >> 8; /* RepSOC LSB: 1/256 % */

    return soc_data;
}

/**
 * @brief       Get at rate Average State Of Charge(SOC) Function from MAX17055 Fuel Gauge.
 * @par          Details
 *               This function sends a request to access the atAvSOC register of the MAX17055.
 *               The AvSOC registers hold the calculated available capacity and percentage of the
 *               battery based on all inputs from the ModelGauge m5 algorithm including empty
 *               compensation. These registers provide unfiltered results. Jumps in the reported
 *               values can be caused by abrupt changes in load current or temperature.
 *
 * @retval       atAvSOC_data - Average SOC data from the atAVSOC register in % value.
 * @retval       non-0 negative values check for errors
 */
int MAX17055::get_atAvSOC()
{
    int ret;
    uint16_t atAvSOC_data;

    ret = readReg(AVSOC_REG, atAvSOC_data);
    if (ret < F_SUCCESS_0)
        return ret; //Check errors if data is not correct

    atAvSOC_data = atAvSOC_data >> 8; /* avSOC LSB: 1/256 % */

    return atAvSOC_data;
}

/**
 * @brief        Get mix State Of Charge(SOC) Function for MAX17055 Fuel Gauge.
 * @par          Details
 *               This function sends a request to access mixSOC register
 *               of the MAX17055. The MixSOC registers holds the calculated
 *               remaining capacity and percentage of the cell before any empty compensation
 *               adjustments are performed.
 *
 * @retval       mixSOC_data - Mixed SOC register values from the mixSOC register in % value.
 * @retval       non-0 for errors
 */
int MAX17055::get_mixSOC()
{
    int ret;
    uint16_t mixSOC_data;

    ret = readReg(MIXSOC_REG, mixSOC_data);
    if (ret < F_SUCCESS_0)
        return ret;

    mixSOC_data = mixSOC_data >> 8; /* RepSOC LSB: 1/256 % */

    return mixSOC_data;
}

/**
 * @brief       Get the Time to Empty(TTE) Function form MAX17055 Fuel Gauge.
 * @par         Details
 *              This function sends a request to access the TTE register
 *              of the MAX17055
 *              The TTE register holds the estimated time to empty for the
 *              application under present temperature and load conditions. The TTE value is
 *              determined by relating AvCap with AvgCurrent. The corresponding AvgCurrent
 *              filtering gives a delay in TTE, but provides more stable results.
 *
 * @retval      tte_data - Time to Empty data from the TTE register in seconds.
 * @retval      non-0 negative values check for errors
 */
float MAX17055::get_TTE()
{

    int ret;
    uint16_t tte_data;
    float f_tte_data;

    ret = readReg(TTE_REG, tte_data);
    if (ret < F_SUCCESS_0)
        return ret;
    else
        f_tte_data = ((float)tte_data * 5.625); /* TTE LSB: 5.625 sec */

    return f_tte_data;
}

/**
 * @brief       Get the at Time to Empty(atTTE) value Function for MAX17055 Fuel Gauge.
 * @par         Details
 *              This function sends a request to access the internal register
 *              of the MAX17055
 *
 * @retval      atTTE_data - Time to Empty data from the atTTE register in seconds.
 * @retval      non-0 negative values check for errors
 */
float MAX17055::get_atTTE()
{

    int ret;
    uint16_t atTTE_data;
    float f_atTTE_data;

    ret = readReg(ATTTE_REG, atTTE_data);
    if (ret < F_SUCCESS_0)
        return ret; //Check for errors
    else
        f_atTTE_data = ((float)atTTE_data * 5.625); /* TTE LSB: 5.625 sec */

    return  f_atTTE_data;
}

/**
 * @brief      Get the Time to Full(TTE) values Function for MAX17055 Fuel Gauge.
 * @par        Details
 *             This function sends a request to access the internal register of the MAX17055
 *             The TTF register holds the estimated time to full for the application
 *             under present conditions. The TTF value is determined by learning the
 *             constant current and constant voltage portions of the charge cycle based
 *             on experience of prior charge cycles. Time to full is then estimate
 *             by comparing present charge current to the charge termination current.
 *             Operation of the TTF register assumes all charge profiles are consistent in the application.
 *
 * @retval     ttf_data - Time to Full data from the TTF register in seconds.
 * @retval     non-0 negative values check for errors
 */
float MAX17055::get_TTF()
{

    int ret;
    uint16_t ttf_data;
    float f_ttf_data;

    ret = readReg(TTF_REG, ttf_data);
    if (ret < F_SUCCESS_0)
        return ret;
    else
        f_ttf_data = ((float)ttf_data * 5.625); /* TTE LSB: 5.625 sec */

    return  f_ttf_data;
}

/**
 * @brief       Get voltage of the cell Function for MAX17055 Fuel Gauge.
 * @par         Details
 *              This function sends a request to access the VCell Register
 *              of the MAX17055 to read the measured voltage from the cell.
 *
 * @retval      vcell_data  - vcell data from the VCELL_REG register in uVolts.
 * @retval      non-0 negative values check for errors
 */
int MAX17055::get_Vcell()
{

    int ret;
    uint16_t vcell_data;

    ret = readReg(VCELL_REG, vcell_data);
    if (ret < F_SUCCESS_0)
        return ret;
    else
        ret = lsb_to_uvolts(vcell_data);
    return ret;
}

/**
 * @brief       Gets Average voltage of the cell Function for MAX17055 Fuel Gauge.
 * @par         Details
 *              This function sends a request to access the AvgVCell Register
 *              of the MAX17055 to read the measured voltage from the cell.
 *
 * @retval      avgVcell_data  - avgvcell data from the AVGVCELL_REG register in uVolts.
 * @retval      non-0 negative values check for errors
 */
int MAX17055::get_avgVcell()
{

    int ret;
    uint16_t avgVcell_data;

    ret = readReg(AVGVCELL_REG, avgVcell_data);
    if (ret < F_SUCCESS_0)
        return ret;
    else
        ret = lsb_to_uvolts(avgVcell_data);
    return ret;
}

/**
 * @brief       Get current Function for MAX17055 Fuel Gauge.
 * @par         Details
 *              This function sends a request to access the CURRENT register
 *              of the MAX17055 to read the current readings.
 *
 * @param[in]   des_data - Plataform_data struct with information about the design.
 *
 * @retval      curr_data  - current data from the CURRENT register in uAmps.
 * @retval      non-0 negative values check for errors.
 */
float MAX17055::get_Current( platform_data des_data )
{

    int ret,design_rsense;
    uint16_t curr_data;
    float f_ret;

    ret = readReg(CURRENT_REG, curr_data);
    if (ret < F_SUCCESS_0)
        return ret;
    else
        design_rsense = des_data.rsense;
    f_ret = raw_current_to_uamps((uint32_t)curr_data, design_rsense);
    return f_ret;
}

/**
 * @brief       Get average current Function for MAX17055 Fuel Gauge.
 * @par         Details
 *              This function sends a request to access the aveCURRENT register
 *              of the MAX17055 to read the average current readings.
 *
 * @param[in]   des_data - Plataform_data struct with information about the design.
 *
 * @retval      aveCurr_data - current data from the AVGCURRENT register in uAmps.
 * @retval      non-0 negative values check for errors.
 */
float MAX17055::get_AvgCurrent( platform_data des_data )
{
    int ret, design_rsense;
    uint16_t data;
    float avgCurr_data;

    ret = readReg(AVGCURRENT_REG, data);
    if (ret < F_SUCCESS_0)
        return ret;
    else
        avgCurr_data = data;
    design_rsense = des_data.rsense;
    avgCurr_data = raw_current_to_uamps((uint32_t)data, design_rsense);
    return avgCurr_data;
}

/**
 * @brief        lsb_to_uvolts Conversion Function
 * @par          Details
 *               This function takes the lsb value of the register and convert it
 *               to uvolts
 *
 * @param[in]   lsb - value of register lsb
 * @retval      conv_2_uvolts - value converted lsb to uvolts
 */
int MAX17055:: lsb_to_uvolts(uint16_t lsb)
{
    int conv_2_uvolts;
    conv_2_uvolts = (lsb * 625) / 8; /* 78.125uV per bit */
    return conv_2_uvolts;
}

/**
 * @brief        raw_current_to_uamp Conversion Function
 * @par          Details
 *               This function takes the raw current value of the register and
 *               converts it to uamps
 *
 * @param[in]   curr - raw current value of register
 * @retval      res  - converted raw current to uamps (Signed 2's complement)
 */
float MAX17055::raw_current_to_uamps(uint32_t curr, int rsense_value)
{
    int res = curr;
    float final_res;
    /* Negative Check*/
    if (res & 0x8000){
        res |= 0xFFFF0000;
    }
    final_res = (float)res;
    final_res *= 1562500 /(float)(rsense_value*10000);

    return final_res;
}

/**
 * @brief        raw_cap_to_uAh Conversion Function
 * @par          Details
 *               This function takes the raw battery capacity value of the register and
 *               converts it to uAh
 *
 * @param[in]   raw_cap - raw capacity value of register
 * @retval      res  - converted raw capacity to uAh
 */
int MAX17055::raw_cap_to_uAh(uint32_t raw_cap, int rsense_value)
{
    int res = raw_cap ;
    res *=  5000000/(rsense_value * 1000000);
    return res;
}

/**
 * @brief        Save Learned Parameters Function for battery Fuel Gauge model.
 * @par          Details
 *               It is recommended to save the learned capacity parameters every
 *               time bit 2 of the Cycles register toggles
 *               (so that it is saved every 64% change in the battery)
 *               so that if power is lost the values can easily be restored. Make sure
 *               the data is saved on a non-volatile memory. Call this function after first initialization for reference in future function calls.
 *               Max number of cycles is 655.35 cycles with a LSB of 1% for the cycles register.
 *
 * @param[in]   FG_params Fuel Gauge Parameters based on design details.
 *
 * @retval      0 for success
 * @retval      non-0 negative for errors
 */
int MAX17055::save_Params(saved_FG_params_t FG_params)
{
    int ret;
    uint16_t data[5], value;
    ///STEP 1. Checks if the cycle register bit 2 has changed.
    ret = readReg(CYCLES_REG, data[3]);
    value = data[3];
    if (ret < F_SUCCESS_0)
        return ret;
    //Check if the stored cycles value is different from the read Cycles_reg value
    else if (FG_params.cycles == value)
        return ret; //exits the function without saving, when initializing or value did not change (calculate when the function is called in you application).
    else {
        value = FG_params.cycles^value;
        //check with mask
        value = (value & MAX17055_POR_MASK);

        if (value == 0)
            return ret;

        ///STEP 2. Save the capacity parameters for the specific battery.
        ret = readReg(RCOMP0_REG, data[0]);
        if (ret < F_SUCCESS_0)
            return ret;
        else
            FG_params.rcomp0 = data[0];

        ret = readReg(TEMPCO_REG, data[1]);
        if (ret < F_SUCCESS_0)
            return ret;
        else
            FG_params.temp_co = data[1];

        ret = readReg(FULLCAPREP_REG, data[2]);
        if (ret < F_SUCCESS_0)
            return ret;
        else
            FG_params.full_cap_rep = data[2];

        FG_params.cycles = data[3];

        ret = readReg(FULLCAPNOM_REG, data[4]);
        if (ret < F_SUCCESS_0)
            return ret;
        else
            FG_params.full_cap_nom = data[4];
        return ret;
    }
}



/**
 * @brief        Restore Parameters Function for battery Fuel Gauge model.
 * @par          Details
 *               If power is lost, then the capacity information
 *               can be easily restored with this function.
 *
 * @param[in]   FG_params Struct for Fuel Gauge Parameters
 * @retval      0 for success
 * @retval      non-0 negative for errors
 */
int MAX17055::restore_Params(saved_FG_params_t FG_params)
{
    int ret;
    uint16_t temp_data, fullcapnom_data, mixCap_calc, dQacc_calc;
    uint16_t dPacc_value = 0x0C80;//Set it to 200%

    ///STEP 1. Restoring capacity parameters
    write_and_verify_reg(RCOMP0_REG, FG_params.rcomp0);
    write_and_verify_reg(TEMPCO_REG, FG_params.temp_co);
    write_and_verify_reg(FULLCAPNOM_REG, FG_params.full_cap_nom);

    wait_ms(350);//check the type of wait

    ///STEP 2. Restore FullCap
    ret = readReg(FULLCAPNOM_REG, fullcapnom_data);
    if (ret < F_SUCCESS_0)
        return ret;

    ret = readReg(MIXSOC_REG, temp_data); 
    if (ret < F_SUCCESS_0)
        return ret;

    mixCap_calc = (temp_data*fullcapnom_data)/25600;

    write_and_verify_reg(MIXCAP_REG, mixCap_calc);
    write_and_verify_reg(FULLCAPREP_REG, FG_params.full_cap_rep);

    ///STEP 3. Write DQACC to 200% of Capacity and DPACC to 200%
    dQacc_calc = (FG_params.full_cap_nom/ 16) ;

    write_and_verify_reg(DPACC_REG, dPacc_value);
    write_and_verify_reg(DQACC_REG, dQacc_calc);

    wait_ms(350);

    ///STEP 4. Restore Cycles register
    ret = write_and_verify_reg(CYCLES_REG, FG_params.cycles);
    if (ret < F_SUCCESS_0)
        return ret;
    return ret;
}

/**
 * @brief        Function to Save Average Current to At Rate register.
 * @par          Details
 *               For User friendliness display of atTTE, atAvSOC, atAvCAP
 *               write the average current to At Rate registers every 10sec
 *               when the battery is in use.
 *               NOTE: do not use this function when the Battery is charging.
 *
 * @retval      0 for success
 * @retval      non-0 negative for errors
 */
int MAX17055::avCurr_2_atRate()
{
    int ret;
    uint16_t avCurr_data;

    ret = readReg(AVGCURRENT_REG, avCurr_data);
    if (ret < F_SUCCESS_0) {
        return ret = -3;
    }

    //Write avCurrent to atRate Register
    ret = writeReg(ATRATE_REG, avCurr_data);
    if (ret < F_SUCCESS_0) {
        return ret;
    }
    return F_SUCCESS_0;
}