TM4C129 I2C read

uint32_t gSysCtlClock;  					//the system clock
uint8_t  endPointAddress = 0x77;			//I2C bus address
uint8_t  data[2];							//data to read

#define I2C_WRITE_DIRECTION      0x00
#define I2C_READ_DIRECTION       0x01
#define I2C_MASTER_MAX_RETRIES   1000        // Number of retries

void main() {

	clockInit();
	GPIO_Init();
	I2C_Init();

	while(1) {

		//Write the command
		I2CMasterSlaveAddrSet(	I2C2_BASE,
								endPointAddress,		//7-bit slave address
								I2C_WRITE_DIRECTION);	//write
		I2CMasterDataPut(I2C2_BASE, 0x00);				//cmd = read registers
		if(I2CMasterBusBusyTimeOut(I2C2_BASE))	return BUSY;
		I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_BURST_SEND_START);

		if(I2CMasterBusyTimeOut(I2C2_BASE)) {
			I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_BURST_SEND_STOP);
			return FAIL;
		}

		//read 1th word
		I2CMasterSlaveAddrSet(	I2C2_BASE,
								endPointAddress,		//7-bit slave address
								I2C_READ_DIRECTION);	//read
		I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START);

		if(I2CMasterBusyTimeOut(I2C2_BASE)) {
			I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_BURST_SEND_STOP);
			return FAIL;
		}
		data_p[i++] = I2CMasterDataGet(I2C2_BASE);
		I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH);

		if(I2CMasterBusyTimeOut(I2C2_BASE)) {
			return FAIL;
		}

		//read the last word
		data_p[i] = I2CMasterDataGet(I2C2_BASE);

	}//while(1)
}//main



//wait for the bus to be ready
uint16_t I2CMasterBusBusyTimeOut(unsigned long ulBase){

	uint16_t i;

	//wait for the bus to be idle
	for(i = 0; i < I2C_MASTER_MAX_RETRIES; i++) {
		if(!I2CMasterBusBusy(ulBase))			return FALSE;
		SysCtlDelay(gSysCtlClock * 10e-6);		//wait 10us
	}
	if(I2CMasterBusBusy(ulBase))				return TRUE;
	else 										return FALSE;
}
void I2C_Init(void) {
	// Initialize the I2C master.
	I2CMasterInitExpClk(I2C2_BASE,
						gSysCtlClock,
						true);				//400 kbps
	I2CMasterEnable(	I2C2_BASE);			//set as master
}
void clockInit() {
	SysCtlMOSCConfigSet(SYSCTL_MOSC_HIGHFREQ);
	gSysCtlClock = SysCtlClockFreqSet(
						SYSCTL_USE_PLL    |
						SYSCTL_OSC_MAIN   |
						SYSCTL_XTAL_25MHZ |
						SYSCTL_CFG_VCO_400,
						120000000);		//desired system frequency
}

void GPIO_Init(void) {

	SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C2);		//I2C: bus expander
	SysCtlPeripheralReset(SYSCTL_PERIPH_I2C2);

	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOL);
	SysCtlPeripheralReset(SYSCTL_PERIPH_GPIOL);
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);
	SysCtlPeripheralReset(SYSCTL_PERIPH_GPION);


	GPIOPinConfigure(GPIO_PL1_I2C2SCL); //I2C2 SCL
	GPIOPinConfigure(GPIO_PN4_I2C2SDA); //I2C2 SDA

	GPIOPinTypeI2CSCL(GPIO_PORTL_BASE, GPIO_PIN_1);	//I2C2 SCL
	GPIOPinTypeI2C   (GPIO_PORTN_BASE, GPIO_PIN_4);	//I2C2 SDA
}