File content as of revision 2:0648c1561eb2:

/**
 ******************************************************************************
 * @file    m24sr_class.cpp
 * @author  MMY Application Team
 * @version V1.2.0
 * @date    20-October-2014
 * @brief   This file provides a set of functions to interface with the M24SR
 *          device.
 ******************************************************************************
 * @attention
 *
 * <h2><center>&copy; COPYRIGHT(c) 2014 STMicroelectronics</center></h2>
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *   1. Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *   2. Redistributions in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the documentation
 *      and/or other materials provided with the distribution.
 *   3. Neither the name of STMicroelectronics nor the names of its contributors
 *      may be used to endorse or promote products derived from this software
 *      without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 ******************************************************************************
 */



/* Includes ------------------------------------------------------------------*/
#include "m24sr_class.h"
#include "m24sr.h"

/**
 * default password, it is used also for reach the super user mode throught the i2c channel
 */
const uint8_t M24SR::DEFAULT_PASSWORD[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

/** @addtogroup M24SR_Driver
 * @{
 *	@brief  <b>This folder contains the driver layer of M24SR family (M24SR64, M24SR16, M24SR04, M24SR02)</b> 
 */

/** @defgroup drv_M24SR
 * @{
 *	@brief  This file contains the driver which implements all the M24SR commands.
 */

#ifndef errchk

/** value return by the NFC chip when a command is successfully done */
#define NFC_COMMAND_SUCCESS 0x9000

/** call the fCall funtion and check that the return status is NFC_COMMAND_SUCCESS,
 *  otherwise return the error status*/
#define errchk(fCall) {\
	const NFC_StatusTypeDef status = (fCall); \
	if((status!=NFC_SUCCESS)) \
		return status; \
	}\

#endif

/**
 * @brief  This function updates the CRC 
 * @param  None
 * @retval None
 */
uint16_t M24SR_UpdateCrc(uint8_t ch, uint16_t *lpwCrc) {
	ch = (ch ^ (uint8_t) ((*lpwCrc) & 0x00FF));
	ch = (ch ^ (ch << 4));
	*lpwCrc = (*lpwCrc >> 8) ^ ((uint16_t) ch << 8) ^ ((uint16_t) ch << 3)
			^ ((uint16_t) ch >> 4);

	return (*lpwCrc);
}

/**
 * @brief  This function returns the CRC 16 
 * @param  Data : pointer on the data used to compute the CRC16
 * @param  Length : number of byte of the data
 * @retval CRC16 
 */
uint16_t M24SR_ComputeCrc(uint8_t *Data, uint8_t Length) {
	uint8_t chBlock;
	uint16_t wCrc = 0x6363; // ITU-V.41

	do {
		chBlock = *Data++;
		M24SR_UpdateCrc(chBlock, &wCrc);
	} while (--Length);

	return wCrc;
}

/**  
 * @brief  	This function computes the CRC16 residue as defined by CRC ISO/IEC 13239
 * @param  	DataIn		:	input to data 
 * @param	Length 		: 	Number of bits of DataIn
 * @retval 	Status (SW1&SW2)  	:   CRC16 residue is correct	
 * @retval 	M24SR_ERROR_CRC  	:  CRC16 residue is false
 */
NFC_StatusTypeDef M24SR_IsCorrectCRC16Residue(uint8_t *DataIn, uint8_t Length) {
	uint16_t ResCRC = 0x0000;

	/* check the CRC16 Residue */
	if (Length != 0)
		ResCRC = M24SR_ComputeCrc(DataIn, Length);

	if (ResCRC == 0x0000) {
		/* Good CRC, but error status from M24SR */
		return (NFC_StatusTypeDef) (((DataIn[Length - UB_STATUS_OFFSET] << 8)
				& 0xFF00) | (DataIn[Length - LB_STATUS_OFFSET] & 0x00FF));
	} else {
		ResCRC = 0x0000;
		ResCRC = M24SR_ComputeCrc(DataIn, 5);
		if (ResCRC != 0x0000) {
			/* Bad CRC */
			return NFC_IO_ERROR_CRC;
		} else {
			/* Good CRC, but error status from M24SR */
			return (NFC_StatusTypeDef) (((DataIn[1] << 8) & 0xFF00)
					| (DataIn[2] & 0x00FF));
		}
	}
}

/**
 * @brief 		This functions creates an I block command according to the structures CommandStructure and data->command.
 * @param	 	Command : structue which contains the field of the different parameter
 * @param	 	CommandStructure : structure that contain the structure of the command (if the different field are presnet or not 
 * @param	 	NbByte : number of byte of the command
 * @param	 	pCommand : pointer of the command created
 */
void M24SR_BuildIBlockCommand(uint16_t CommandStructure, C_APDU *Command,
		uint8_t uDIDbyte, uint16_t *NbByte, uint8_t *pCommand) {
	uint16_t uCRC16;
	static uint8_t BlockNumber = 0x01;

	(*NbByte) = 0;

	/* add the PCD byte */
	if ((CommandStructure & M24SR_PCB_NEEDED) != 0) {
		/* toggle the block number */
		BlockNumber = TOGGLE(BlockNumber);
		/* Add the I block byte */
		pCommand[(*NbByte)++] = 0x02 | BlockNumber;
	}

	/* add the DID byte */
	if ((BlockNumber & M24SR_DID_NEEDED) != 0) {
		/* Add the I block byte */
		pCommand[(*NbByte)++] = uDIDbyte;
	}

	/* add the Class byte */
	if ((CommandStructure & M24SR_CLA_NEEDED) != 0) {
		pCommand[(*NbByte)++] = Command->Header.CLA;
	}
	/* add the instruction byte byte */
	if ((CommandStructure & M24SR_INS_NEEDED) != 0) {
		pCommand[(*NbByte)++] = Command->Header.INS;
	}
	/* add the Selection Mode byte */
	if ((CommandStructure & M24SR_P1_NEEDED) != 0) {
		pCommand[(*NbByte)++] = Command->Header.P1;
	}
	/* add the Selection Mode byte */
	if ((CommandStructure & M24SR_P2_NEEDED) != 0) {
		pCommand[(*NbByte)++] = Command->Header.P2;
	}
	/* add Data field lengthbyte */
	if ((CommandStructure & M24SR_LC_NEEDED) != 0) {
		pCommand[(*NbByte)++] = Command->Body.LC;
	}
	/* add Data field  */
	if ((CommandStructure & M24SR_DATA_NEEDED) != 0) {
		memcpy(&(pCommand[(*NbByte)]), Command->Body.pData, Command->Body.LC);
		(*NbByte) += Command->Body.LC;
	}
	/* add Le field  */
	if ((CommandStructure & M24SR_LE_NEEDED) != 0) {
		pCommand[(*NbByte)++] = Command->Body.LE;
	}
	/* add CRC field  */
	if ((CommandStructure & M24SR_CRC_NEEDED) != 0) {
		uCRC16 = M24SR_ComputeCrc(pCommand, (uint8_t) (*NbByte));
		/* append the CRC16 */
		pCommand[(*NbByte)++] = GETLSB(uCRC16);
		pCommand[(*NbByte)++] = GETMSB(uCRC16);
	}

}

#if 0
/**  
 * @brief  	This function return M24SR_STATUS_SUCCESS if the pBuffer is an I-block
 * @param  	pBuffer		:	pointer of the data
 * @retval 	M24SR_STATUS_SUCCESS  :  the data is a I-Block
 * @retval 	M24SR_ERROR_DEFAULT  	:  the data is not a I-Block
 */
static int8_t IsIBlock (uint8_t *pBuffer)
{

	if ((pBuffer[M24SR_OFFSET_PCB] & M24SR_MASK_BLOCK) == M24SR_MASK_IBLOCK)
	{
		return M24SR_STATUS_SUCCESS;
	}
	else
	{
		return M24SR_ERROR_DEFAULT;
	}

}

/**  
 * @brief  	This function return M24SR_STATUS_SUCCESS if the pBuffer is an R-block
 * @param  	pBuffer		:	pointer of the data
 * @retval 	M24SR_STATUS_SUCCESS  :  the data is a R-Block
 * @retval 	M24SR_ERROR_DEFAULT  	:  the data is not a R-Block
 */
static int8_t IsRBlock (uint8_t *pBuffer)
{

	if ((pBuffer[M24SR_OFFSET_PCB] & M24SR_MASK_BLOCK) == M24SR_MASK_RBLOCK)
	{
		return M24SR_STATUS_SUCCESS;
	}
	else
	{
		return M24SR_ERROR_DEFAULT;
	}

}
#endif	

/**  
 * @brief  	This function return M24SR_STATUS_SUCCESS if the pBuffer is an s-block
 * @param  	pBuffer		:	pointer of the data
 * @retval 	M24SR_STATUS_SUCCESS  :  the data is a S-Block
 * @retval 	M24SR_ERROR_DEFAULT  	:  the data is not a S-Block
 */
static NFC_StatusTypeDef IsSBlock(uint8_t *pBuffer) {

	if ((pBuffer[M24SR_OFFSET_PCB] & M24SR_MASK_BLOCK) == M24SR_MASK_SBLOCK) {
		return NFC_SUCCESS;
	} else {
		return NFC_ERROR;
	}

}

/**
 * @brief  This function sends the FWT extension command (S-Block format)
 * @param	FWTbyte : FWT value
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_FWTExtension(uint8_t FWTbyte) {
	uint8_t pBuffer[M24SR_STATUSRESPONSE_NBBYTE];
	NFC_StatusTypeDef status;
	uint8_t NthByte = 0;
	uint16_t uCRC16;

	/* create the response */
	pBuffer[NthByte++] = 0xF2;
	pBuffer[NthByte++] = FWTbyte;
	/* compute the CRC */
	uCRC16 = M24SR_ComputeCrc(pBuffer, 0x02);
	/* append the CRC16 */
	pBuffer[NthByte++] = GETLSB(uCRC16);
	pBuffer[NthByte++] = GETMSB(uCRC16);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NthByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer, M24SR_STATUSRESPONSE_NBBYTE);

	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;
}

/**
 * @brief  This function sends the KillSession command to the M24SR device
 * @param  None
 * @retval NFC_SUCCESS : the function is successful.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_KillSession(void) {
	uint8_t commandBuffer[] = M24SR_KILLSESSION_COMMAND;

	errchk(M24SR_IO_SendI2Ccommand(sizeof(commandBuffer), commandBuffer));

	/* Insure no access will be done just after open session */
	/* The only way here is to poll I2C to know when M24SR is ready */
	/* GPO can not be use with KillSession command */
	errchk(M24SR_IO_PollI2C());

	return NFC_SUCCESS;
}

/**
 * @brief  This function sends the Deselect command (S-Block format)
 * @retval NFC_SUCCESS : the function is successful.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_Deselect(void) {
	uint8_t pBuffer[] = M24SR_DESELECTREQUEST_COMMAND;

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(sizeof(pBuffer), pBuffer));

	errchk(M24SR_IO_IsAnswerReady());
	/* flush the M24SR buffer */
	errchk(M24SR_IO_ReceiveI2Cresponse(sizeof(pBuffer), pBuffer));

	return NFC_SUCCESS;
}

/**
 * @brief  This function sends the SelectApplication command
 * @retval NFC_SUCCESS : the function is successful.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_SelectApplication(void) {

	C_APDU command;
	uint8_t *pBuffer = uM24SRbuffer;
	uint8_t pDataIn[M24SR_STATUSRESPONSE_NBBYTE];
	uint8_t pDataOut[] = M24SR_SELECTAPPLICATION_COMMAND;
	uint8_t uLe = 0x00;
	NFC_StatusTypeDef status;
	uint16_t uP1P2 =0x0400,
	NbByte;

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_SELECT_FILE;
	/* copy the offset */
	command.Header.P1 = GETMSB(uP1P2);
	command.Header.P2 = GETLSB(uP1P2);
	/* copy the number of byte of the data field */
	command.Body.LC = sizeof(pDataOut);
	/* copy the data */
	command.Body.pData = pDataOut;
	/* copy the number of byte to read */
	command.Body.LE = uLe;
	/* build the I²C command */
	M24SR_BuildIBlockCommand( M24SR_CMDSTRUCT_SELECTAPPLICATION, &command,
			uDIDbyte, &NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(M24SR_IO_ReceiveI2Cresponse(sizeof(pDataIn), pDataIn));

	status= M24SR_IsCorrectCRC16Residue(pDataIn, sizeof(pDataIn));

	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;

}

/**
 * @brief  This function initialize the M24SR device
 * @retval None
 */
NFC_StatusTypeDef M24SR::M24SR_Init(NFC_InitTypeDef *notUsed) {
	(void) notUsed;

	errchk(M24SR_KillSession())
	errchk(M24SR_ManageI2CGPO(I2C_ANSWER_READY))
	errchk(M24SR_Deselect())

	return NFC_SUCCESS;
}

NFC_StatusTypeDef M24SR::M24SR_ReadID(uint8_t *nfc_id) {
	if (!nfc_id) {
		return NFC_ERROR;
	}

	errchk(M24SR_SelectApplication())

	return M24SR_ReadBinary(0x0011, 1, nfc_id);
}

/**
 * @brief  This function sends the GetSession command to the M24SR device
 * @retval NFC_SUCCESS : the function is successful.
 * @retval Status (SW1&SW2) : if operation does not complete.
 */
NFC_StatusTypeDef M24SR::M24SR_GetSession(void) {
	uint8_t commandBuffer[] = M24SR_OPENSESSION_COMMAND;

	errchk(M24SR_IO_SendI2Ccommand(sizeof(commandBuffer), commandBuffer));

	/* Insure no access will be done just after open session */
	/* The only way here is to poll I2C to know when M24SR is ready */
	/* GPO can not be use with GetSession command */
	errchk(M24SR_IO_PollI2C());

	return NFC_SUCCESS;

}

/**
 * @brief  This function sends the SelectCCFile command
 * @retval NFC_SUCCESS : the function is successful.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 * @retval Status (SW1&SW2) : if operation does not complete for another reason.
 */
NFC_StatusTypeDef M24SR::M24SR_SelectCCfile(void) {
	C_APDU command;

	uint8_t *pBuffer = uM24SRbuffer;
	uint8_t pDataIn[M24SR_STATUSRESPONSE_NBBYTE];
	uint8_t pDataOut[] = CC_FILE_ID_BYTES;
	NFC_StatusTypeDef status;
	uint16_t uP1P2 =0x000C,
	NbByte;

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_SELECT_FILE;
	/* copy the offset */
	command.Header.P1 = GETMSB(uP1P2);
	command.Header.P2 = GETLSB(uP1P2);
	/* copy the number of byte of the data field */
	command.Body.LC = sizeof(pDataOut);
	command.Body.pData = pDataOut;
	/* build the I²C command */
	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_SELECTCCFILE, &command, uDIDbyte,
			&NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(M24SR_IO_ReceiveI2Cresponse(sizeof(pDataIn), pDataIn));

	status = M24SR_IsCorrectCRC16Residue(pDataIn, sizeof(pDataIn));

	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;
}

/**
 * @brief  This function sends the SelectSystemFile command
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_SelectSystemfile(void) {
	C_APDU command;

	uint8_t *pBuffer = uM24SRbuffer;
	uint8_t pDataIn[M24SR_STATUSRESPONSE_NBBYTE];
	uint8_t pDataOut[] = SYSTEM_FILE_ID_BYTES;
	NFC_StatusTypeDef status;
	uint16_t uP1P2 =0x000C,
	NbByte;

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_SELECT_FILE;
	/* copy the offset */
	command.Header.P1 = GETMSB(uP1P2);
	command.Header.P2 = GETLSB(uP1P2);
	/* copy the number of byte of the data field */
	command.Body.LC = sizeof(pDataOut);
	command.Body.pData = pDataOut;
	/* build the I²C command */
	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_SELECTCCFILE, &command, uDIDbyte,
			&NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(M24SR_IO_ReceiveI2Cresponse(sizeof(pDataIn), pDataIn));

	status = M24SR_IsCorrectCRC16Residue(pDataIn, sizeof(pDataIn));

	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;
}

/**
 * @brief  This function sends the SelectNDEFfile command
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_SelectNDEFfile(uint16_t NDEFfileId) {
	C_APDU command;
	uint8_t *pBuffer = uM24SRbuffer;
	uint8_t pDataIn[M24SR_STATUSRESPONSE_NBBYTE];
	uint8_t pDataOut[] = { GETMSB(NDEFfileId), GETLSB(NDEFfileId) };
	NFC_StatusTypeDef status;
	uint16_t uP1P2 = 0x000C, NbByte;

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_SELECT_FILE;
	/* copy the offset */
	command.Header.P1 = GETMSB(uP1P2);
	command.Header.P2 = GETLSB(uP1P2);
	/* copy the number of byte of the data field */
	command.Body.LC = sizeof(pDataOut);
	command.Body.pData = pDataOut;
	/* copy the offset */
	/* build the I²C command */
	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_SELECTNDEFFILE, &command, uDIDbyte,
			&NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(M24SR_IO_ReceiveI2Cresponse(sizeof(pDataIn), pDataIn));

	status = M24SR_IsCorrectCRC16Residue(pDataIn, sizeof(pDataIn));
	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;

}

/**
 * @brief  This function sends a read binary command
 * @param	Offset : first byte to read
 * @param	NbByteToRead : number of byte to read
 * @param	pBufferRead : pointer of the buffer read from the M24SR device
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_ReadBinary(uint16_t Offset, uint8_t NbByteToRead,
		uint8_t *pBufferRead) {
	C_APDU command;
	uint8_t *pBuffer = uM24SRbuffer;
	NFC_StatusTypeDef status;
	uint16_t NbByte;

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_READ_BINARY;
	/* copy the offset */
	command.Header.P1 = GETMSB(Offset);
	command.Header.P2 = GETLSB(Offset);
	/* copy the number of byte to read */
	command.Body.LE = NbByteToRead;

	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_READBINARY, &command, uDIDbyte,
			&NbByte, pBuffer);

	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	errchk(
			M24SR_IO_ReceiveI2Cresponse (NbByteToRead + M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer,
			NbByteToRead + M24SR_STATUSRESPONSE_NBBYTE);
	if(status != NFC_COMMAND_SUCCESS)
		return status;
	/* retrieve the data without SW1 & SW2 as provided as return value of the function */
	memcpy(pBufferRead, &pBuffer[1], NbByteToRead);
	return NFC_SUCCESS;

}

/**
 * @brief  This function sends a ST read binary command (no error if access is not inside NDEF file)
 * @param	Offset : first byte to read
 * @param	NbByteToRead : number of byte to read
 * @param	pBufferRead : pointer of the buffer read from the M24SR device
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_STReadBinary(uint16_t Offset,
		uint8_t NbByteToRead, uint8_t *pBufferRead) {
	C_APDU command;
	uint8_t *pBuffer = uM24SRbuffer;
	NFC_StatusTypeDef status;
	uint16_t NbByte;

	/* build the command */
	command.Header.CLA = C_APDU_CLA_ST;
	command.Header.INS = C_APDU_READ_BINARY;
	/* copy the offset */
	command.Header.P1 = GETMSB(Offset);
	command.Header.P2 = GETLSB(Offset);
	/* copy the number of byte to read */
	command.Body.LE = NbByteToRead;

	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_READBINARY, &command, uDIDbyte,
			&NbByte, pBuffer);

	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	errchk(
			M24SR_IO_ReceiveI2Cresponse (NbByteToRead + M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer,
			NbByteToRead + M24SR_STATUSRESPONSE_NBBYTE);

	if(status != NFC_COMMAND_SUCCESS)
		return status;
	/* retrieve the data without SW1 & SW2 as provided as return value of the function */
	memcpy(pBufferRead, &pBuffer[1], NbByteToRead);
	return NFC_SUCCESS;
}

/**
 * @brief  This function sends a Update binary command
 * @param	Offset : first byte to read
 * @param	NbByteToWrite : number of byte to write
 * @param	pBufferRead : pointer of the buffer read from the M24SR device
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_UpdateBinary(uint16_t Offset,
		uint8_t NbByteToWrite, uint8_t *pDataToWrite) {
	//TODO check the length of the data to write
	C_APDU command;

	uint8_t *pBuffer = uM24SRbuffer;
	NFC_StatusTypeDef status;
	uint16_t NbByte;

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_UPDATE_BINARY;
	/* copy the offset */
	command.Header.P1 = GETMSB(Offset);
	command.Header.P2 = GETLSB(Offset);
	/* copy the number of byte of the data field */
	command.Body.LC = NbByteToWrite;
	command.Body.pData = pDataToWrite;
	/* copy the File Id */
	//memcpy(command.Body.pData ,pDataToWrite, NbByteToWrite );
	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_UPDATEBINARY, &command, uDIDbyte,
			&NbByte, pBuffer);

	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));
	/* if the response is a Watiting frame extenstion request */

	if (IsSBlock(pBuffer) == NFC_SUCCESS) {
		/*check the CRC */
		status =M24SR_IsCorrectCRC16Residue(pBuffer,
				M24SR_WATINGTIMEEXTRESPONSE_NBBYTE);
		// TODO: why if we check ==NFC_Commandsuccess it fail?
		if (status != NFC_IO_ERROR_CRC) {
			/* send the FrameExension response*/
			errchk(M24SR_FWTExtension(pBuffer[M24SR_OFFSET_PCB + 1]));
		}else
			return status;
	} else {
		status = M24SR_IsCorrectCRC16Residue(pBuffer,
				M24SR_STATUSRESPONSE_NBBYTE);
		if(status!=NFC_COMMAND_SUCCESS)
			return status;
	}

	return NFC_SUCCESS;

}

/**
 * @brief  This function sends the Verify command
 * @param	uPwdId : PasswordId ( 0x0001 : Read NDEF pwd or 0x0002 : Write NDEF pwd or 0x0003 : I2C pwd)
 * @param	NbPwdByte : Number of byte ( 0x00 or 0x10)
 * @param	pPwd : pointer on the passwaord
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_Verify(uint16_t uPwdId, uint8_t NbPwdByte,
		const uint8_t *pPwd) {
	C_APDU command;

	uint8_t *pBuffer = uM24SRbuffer;
	NFC_StatusTypeDef status = NFC_SUCCESS;
	uint16_t NbByte;

	/*check the parameters */
	if (uPwdId > 0x0003) {
		return NFC_IO_ERROR_PARAMETER;
	}
	if ((NbPwdByte != 0x00) && (NbPwdByte != 0x10)) {
		return NFC_IO_ERROR_PARAMETER;
	}

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_VERIFY;
	/* copy the Password Id */
	command.Header.P1 = GETMSB(uPwdId);
	command.Header.P2 = GETLSB(uPwdId);
	/* copy the number of byte of the data field */
	command.Body.LC = NbPwdByte;

	if (NbPwdByte == 0x10) {
		/* copy the password */
		command.Body.pData = pPwd;
		/* build the I2C command */
		M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_VERIFYBINARYWITHPWD, &command,
				uDIDbyte, &NbByte, pBuffer);
	} else {
		command.Body.pData = NULL;
		/* build the I2C command */
		M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_VERIFYBINARYWOPWD, &command,
				uDIDbyte, &NbByte, pBuffer);
	}

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	/* wait for answer ready */
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer, M24SR_STATUSRESPONSE_NBBYTE);
	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;

}

/**
 * @brief  This function sends the ChangeReferenceData command
 * @param	uPwdId : PasswordId ( 0x0001 : Read NDEF pwd or 0x0002 : Write NDEF pwd or 0x0003 : I2C pwd)
 * @param	pPwd : pointer on the passwaord
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_ChangeReferenceData(uint16_t uPwdId,
		uint8_t *pPwd) {
	C_APDU command;
	uint8_t *pBuffer = uM24SRbuffer;
	NFC_StatusTypeDef status;
	uint16_t NbByte;

	/*check the parameters */
	if (uPwdId > 0x0003) {
		return NFC_IO_ERROR_PARAMETER;
	}

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_CHANGE;
	/* copy the Password Id */
	command.Header.P1 = GETMSB(uPwdId);
	command.Header.P2 = GETLSB(uPwdId);
	/* copy the number of byte of the data field */
	command.Body.LC = M24SR_PASSWORD_NBBYTE;
	/* copy the password */
	command.Body.pData = pPwd;
	/* build the I²C command */
	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_CHANGEREFDATA, &command, uDIDbyte,
			&NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer, M24SR_STATUSRESPONSE_NBBYTE);

	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;
}

/**
 * @brief  This function sends the EnableVerificationRequirement command
 * @param	uReadOrWrite : enable the read or write protection ( 0x0001 : Read or 0x0002 : Write  )
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_EnableVerificationRequirement(
		uint16_t uReadOrWrite) {
	C_APDU command;
	uint8_t *pBuffer = uM24SRbuffer;
	NFC_StatusTypeDef status = NFC_SUCCESS;
	uint16_t NbByte;

	/*check the parameters */
	if ((uReadOrWrite != 0x0001) && (uReadOrWrite != 0x0002)) {
		return NFC_IO_ERROR_PARAMETER;
	}

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_ENABLE;
	/* copy the Password Id */
	command.Header.P1 = GETMSB(uReadOrWrite);
	command.Header.P2 = GETLSB(uReadOrWrite);
	/* build the I²C command */
	M24SR_BuildIBlockCommand( M24SR_CMDSTRUCT_ENABLEVERIFREQ, &command,
			uDIDbyte, &NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	/* The right access to be updated in EEPROM need at least 6ms */
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer, M24SR_STATUSRESPONSE_NBBYTE);
	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;
}

/**
 * @brief  This function sends the DisableVerificationRequirement command
 * @param	uReadOrWrite : enable the read or write protection ( 0x0001 : Read or 0x0002 : Write  )
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_DisableVerificationRequirement(
		uint16_t uReadOrWrite) {
	C_APDU command;
	uint8_t *pBuffer = uM24SRbuffer;
	NFC_StatusTypeDef status = NFC_SUCCESS;
	uint16_t NbByte;

	/*check the parameters */
	if ((uReadOrWrite != 0x0001) && (uReadOrWrite != 0x0002)) {
		return NFC_IO_ERROR_PARAMETER;
	}

	/* build the command */
	command.Header.CLA = C_APDU_CLA_DEFAULT;
	command.Header.INS = C_APDU_DISABLE;
	/* copy the Password Id */
	command.Header.P1 = GETMSB(uReadOrWrite);
	command.Header.P2 = GETLSB(uReadOrWrite);
	/* build the I²C command */
	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_DISABLEVERIFREQ, &command,
			uDIDbyte, &NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	/* The right access to be updated in EEPROM need at least 6ms */
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer, M24SR_STATUSRESPONSE_NBBYTE);

	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;

}

/**
 * @brief  This function sends the EnablePermananentState command
 * @param	uReadOrWrite : enable the read or write protection ( 0x0001 : Read or 0x0002 : Write  )
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_EnablePermanentState(uint16_t uReadOrWrite) {
	C_APDU command;

	uint8_t *pBuffer = uM24SRbuffer;
	NFC_StatusTypeDef status = NFC_SUCCESS;
	uint16_t NbByte;

	/*check the parameters */
	if ((uReadOrWrite != 0x0001) && (uReadOrWrite != 0x0002)) {
		return NFC_IO_ERROR_PARAMETER;
	}

	/* build the command */
	command.Header.CLA = C_APDU_CLA_ST;
	command.Header.INS = C_APDU_ENABLE;
	/* copy the Password Id */
	command.Header.P1 = GETMSB(uReadOrWrite);
	command.Header.P2 = GETLSB(uReadOrWrite);
	/* build the I²C command */
	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_ENABLEVERIFREQ, &command, uDIDbyte,
			&NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer, M24SR_STATUSRESPONSE_NBBYTE);
	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;
}

/**
 * @brief  This function sends the DisablePermanentState command
 * @param	uReadOrWrite : enable the read or write protection ( 0x0001 : Read or 0x0002 : Write  )
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_DisablePermanentState(uint16_t uReadOrWrite) {
	C_APDU command;

	uint8_t *pBuffer = uM24SRbuffer;
	NFC_StatusTypeDef status = NFC_SUCCESS;
	uint16_t NbByte;

	/*check the parameters */
	if ((uReadOrWrite != 0x0001) && (uReadOrWrite != 0x0002)) {
		return NFC_IO_ERROR_PARAMETER;
	}

	/* build the command */
	command.Header.CLA = C_APDU_CLA_ST;
	command.Header.INS = C_APDU_DISABLE;
	/* copy the Password Id */
	command.Header.P1 = GETMSB(uReadOrWrite);
	command.Header.P2 = GETLSB(uReadOrWrite);
	/* build the I²C command */
	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_DISABLEVERIFREQ, &command,
			uDIDbyte, &NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer, M24SR_STATUSRESPONSE_NBBYTE);

	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;
}

/**
 * @brief  This function generates a interrupt on GPO pin
 * @param	None
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_SendInterrupt(void) {
	C_APDU command;

	uint8_t *pBuffer = uM24SRbuffer;
	uint16_t uP1P2 = 0x001E;
	NFC_StatusTypeDef status = NFC_SUCCESS;
	uint16_t NbByte;

	status = M24SR_ManageI2CGPO(INTERRUPT);

	/* build the command */
	command.Header.CLA = C_APDU_CLA_ST;
	command.Header.INS = C_APDU_INTERRUPT;
	/* copy the Password Id */
	command.Header.P1 = GETMSB(uP1P2);
	command.Header.P2 = GETLSB(uP1P2);
	command.Body.LC = 0x00;
	/* build the I²C command */
	M24SR_BuildIBlockCommand(M24SR_CMDSTRUCT_SENDINTERRUPT, &command, uDIDbyte,
			&NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer, M24SR_STATUSRESPONSE_NBBYTE);

	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;

}

/**
 * @brief  This function force GPO pin to low state or high Z
 * @param	uSetOrReset : select if GPO must be low (reset) or HiZ
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 * @retval M24SR_ERROR_I2CTIMEOUT : The I2C timeout occurred.
 */
NFC_StatusTypeDef M24SR::M24SR_StateControl(uint8_t uSetOrReset) {
	C_APDU command;
	uint8_t *pBuffer = uM24SRbuffer;
	uint16_t uP1P2 = 0x001F;
	NFC_StatusTypeDef status = NFC_SUCCESS;
	uint16_t NbByte;

	/*check the parameters */
	if ((uSetOrReset != 0x01) && (uSetOrReset != 0x00)) {
		return NFC_IO_ERROR_PARAMETER;
	}

	status = M24SR_ManageI2CGPO(STATE_CONTROL);

	/* build the command */
	command.Header.CLA = C_APDU_CLA_ST;
	command.Header.INS = C_APDU_INTERRUPT;
	/* copy the Password Id */
	command.Header.P1 = GETMSB(uP1P2);
	command.Header.P2 = GETLSB(uP1P2);
	command.Body.LC = 0x01;
	command.Body.pData = &uSetOrReset;
	/* copy the data */
	//memcpy(command.Body.pData , &uSetOrReset, 0x01 );
	//command.Body.LE = 0x00 ;
	/* build the I²C command */
	M24SR_BuildIBlockCommand( M24SR_CMDSTRUCT_GPOSTATE, &command, uDIDbyte,
			&NbByte, pBuffer);

	/* send the request */
	errchk(M24SR_IO_SendI2Ccommand(NbByte, pBuffer));
	errchk(M24SR_IO_IsAnswerReady());
	/* read the response */
	errchk(
			M24SR_IO_ReceiveI2Cresponse (M24SR_STATUSRESPONSE_NBBYTE , pBuffer ));

	status = M24SR_IsCorrectCRC16Residue(pBuffer, M24SR_STATUSRESPONSE_NBBYTE);

	if(status == NFC_COMMAND_SUCCESS)
		return NFC_SUCCESS;
	else
		return status;
}

/**
 * @brief  This function configure GPO purpose for I2C session
 * @param	GPO_I2Cconfig: GPO configuration to set
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 */
NFC_StatusTypeDef M24SR::M24SR_ManageI2CGPO(M24SR_GPO_MGMT GPO_I2Cconfig) {
	uint8_t GPO_config = 0;

	if (GPO_I2Cconfig > STATE_CONTROL) {
		return NFC_IO_ERROR_PARAMETER;
	}

	/* we must not be in interrupt mode for I2C synchro as we will change GPO purpose */
	M24SR_IO_SetI2CSynchroMode(M24SR_WAITINGTIME_POLLING);

	errchk(M24SR_SelectApplication());

	errchk(M24SR_SelectSystemfile());

	errchk(M24SR_ReadBinary(0x0004, 0x01, &GPO_config))

	/* Update only GPO purpose for I2C */
	GPO_config = (GPO_config & 0xF0) | GPO_I2Cconfig;

	errchk(M24SR_Verify(I2C_PWD, 0x10, DEFAULT_PASSWORD));

	errchk(M24SR_UpdateBinary(0x0004, 0x01, &(GPO_config)));

	/* if we have set interrupt mode for I2C synchro we can enable interrupt mode */
	if (GPO_I2Cconfig == I2C_ANSWER_READY)
		M24SR_IO_SetI2CSynchroMode(M24SR_INTERRUPT_GPO);

	return NFC_SUCCESS;
}

/**
 * @brief  This function configure GPO purpose for RF session
 *
 * @param	GPO_RFconfig: GPO configuration to set
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 */
NFC_StatusTypeDef M24SR::M24SR_ManageRFGPO(M24SR_GPO_MGMT GPO_RFconfig) {
	uint8_t GPO_config;

	if (GPO_RFconfig > STATE_CONTROL) {
		return NFC_IO_ERROR_PARAMETER;
	}

	errchk(M24SR_SelectApplication())
	errchk(M24SR_SelectSystemfile())
	errchk(M24SR_ReadBinary(0x0004, 0x01, &GPO_config))

	/* Update only GPO purpose for I2C */
	GPO_config = (GPO_config & 0x0F) | (GPO_RFconfig << 4);

	errchk(M24SR_SelectSystemfile())
	errchk(M24SR_Verify(I2C_PWD, 0x10, DEFAULT_PASSWORD))
	errchk(M24SR_UpdateBinary(0x0004, 0x01, &(GPO_config)))

	return NFC_SUCCESS;
}

/**
 * @brief  This function enable or disable RF communication
 * @param	OnOffChoice: GPO configuration to set
 * @retval Status (SW1&SW2) : Status of the operation to complete.
 */
NFC_StatusTypeDef M24SR::M24SR_RFConfig(uint8_t OnOffChoice) {
	/* Disable RF */
	if (OnOffChoice != 0) {
		M24SR_IO_RFDIS_WritePin(GPIO_PIN_RESET);
	} else {
		M24SR_IO_RFDIS_WritePin(GPIO_PIN_SET);
	}
	return NFC_SUCCESS;
}

NFC_StatusTypeDef M24SR::M24SR_IO_SendI2Ccommand(uint8_t NbByte,
		uint8_t *pBuffer) {
	int ret = dev_i2c.write(address, (char*) pBuffer, NbByte);
	if (ret == 0)
		return NFC_SUCCESS;
	return NFC_IO_ERROR_I2CTIMEOUT;
}

NFC_StatusTypeDef M24SR::M24SR_IO_ReceiveI2Cresponse(uint8_t NbByte,
		uint8_t *pBuffer) {
	int ret = dev_i2c.read(address, (char*) pBuffer, NbByte);
	if (ret == 0)
		return NFC_SUCCESS;

	return NFC_IO_ERROR_I2CTIMEOUT;
}

#define M24SR_POLL_DELAY 10
#define M24SR_I2C_POLLING       200 /* In case M24SR will reply ACK failed allow to perform retry before returning error (HAL option not used) */

NFC_StatusTypeDef M24SR::M24SR_IO_PollI2C(void) {

	int status = 1;
	uint32_t nbTry = 0;
	char buffer;
	//
	wait_ms(M24SR_POLL_DELAY);
	while (status != 0 && nbTry < M24SR_I2C_POLLING) {
		status = dev_i2c.read(address, &buffer, 1, false);
		nbTry++;
	}

	if (status == 0)
		return NFC_SUCCESS;
	//else
	return NFC_IO_ERROR_I2CTIMEOUT;
}

NFC_StatusTypeDef M24SR::M24SR_IO_IsAnswerReady(void) {
	uint32_t retry = 0xFFFFF;
	int8_t stable = 0;
	GPIO_PinState PinState;

	switch (syncMode) {
	case M24SR_WAITINGTIME_POLLING:
		return M24SR_IO_PollI2C();

	case M24SR_WAITINGTIME_TIMEOUT:
		// M24SR FWI=5 => (256*16/fc)*2^5=9.6ms but M24SR ask for extended time to program up to 246Bytes.
		// can be improved by
		wait_ms(80);
		return NFC_SUCCESS;

	case M24SR_WAITINGTIME_GPO:
		do {
			M24SR_IO_GPO_ReadPin(&PinState);
			if (PinState == GPIO_PIN_RESET) {
				stable++;
			}
			retry--;
		} while (stable < 5 && retry > 0);
		if (!retry)
			goto Error;
		return NFC_SUCCESS;

	case M24SR_INTERRUPT_GPO:

		/* Check if the GPIO is not already low before calling this function */
		M24SR_IO_GPO_ReadPin(&PinState);
		answerReadyInterrupt.enable_irq();
		if (PinState == GPIO_PIN_SET) {
			while (!interruptIsFired)
				__WFE();
		}
		//the interrupt is disable insde the interrupt callback
		//answerReadyInterrupt.disable_irq();
		interruptIsFired = false;
		return NFC_SUCCESS;

	default:
		return NFC_IO_ERROR_I2CTIMEOUT;
	}

	Error: return NFC_IO_ERROR_I2CTIMEOUT;
}

/******************* (C) COPYRIGHT 2013 STMicroelectronics *****END OF FILE****/