void i2c_stop(i2c_connection conn) {
struct i2c_state *c = (struct i2c_state *) conn;
dprintf(("stop mcs %lx\n", HWREG(c->base + I2C_O_MCS)));
if (I2CMasterBusBusy(c->base)) {
i2c_command(c, I2C_MASTER_CMD_BURST_SEND_FINISH);
}
}
//Initialize as a master
void TwoWire::begin(void)
{
if(i2cModule == NOT_ACTIVE) {
i2cModule = BOOST_PACK_WIRE;
}
SysCtlPeripheralEnable(g_uli2cPeriph[i2cModule]);
//Configure GPIO pins for I2C operation
GPIOPinConfigure(g_uli2cConfig[i2cModule][0]);
GPIOPinConfigure(g_uli2cConfig[i2cModule][1]);
GPIOPinTypeI2C(g_uli2cBase[i2cModule], g_uli2cSDAPins[i2cModule]);
GPIOPinTypeI2CSCL(g_uli2cBase[i2cModule], g_uli2cSCLPins[i2cModule]);
I2CMasterInitExpClk(MASTER_BASE, F_CPU, false);//max bus speed=400kHz for gyroscope
//force a stop condition
if(!GPIOPinRead(g_uli2cBase[i2cModule], g_uli2cSCLPins[i2cModule]))
forceStop();
//Handle any startup issues by pulsing SCL
if(I2CMasterBusBusy(MASTER_BASE) || I2CMasterErr(MASTER_BASE)
|| !GPIOPinRead(g_uli2cBase[i2cModule], g_uli2cSCLPins[i2cModule])){
uint8_t doI = 0;
GPIOPinTypeGPIOOutput(g_uli2cBase[i2cModule], g_uli2cSCLPins[i2cModule]);
unsigned long mask = 0;
do{
for(unsigned long i = 0; i < 10 ; i++) {
SysCtlDelay(F_CPU/100000/3);//100Hz=desired frequency, delay iteration=3 cycles
mask = (i%2) ? g_uli2cSCLPins[i2cModule] : 0;
GPIOPinWrite(g_uli2cBase[i2cModule], g_uli2cSCLPins[i2cModule], mask);
}
doI++;
}while(I2CMasterBusBusy(MASTER_BASE) && doI < 100);
GPIOPinTypeI2CSCL(g_uli2cBase[i2cModule], g_uli2cSCLPins[i2cModule]);
if(!GPIOPinRead(g_uli2cBase[i2cModule], g_uli2cSCLPins[i2cModule]))
forceStop();
}
}
/**
* \brief This function reads data from EEPROM.
*
* \param data Address where data is to be read.
* \param length Length of data to be read
* \param offset Address of the byte from which data to be read.
*
* \return None.
*
* \note This muxing depends on the profile in which the EVM is configured.
* EEPROMI2CSetUp Shall be called Before this API is used
*/
void EEPROMI2CRead(unsigned char *data, unsigned int length,
unsigned short offset)
{
unsigned int idx = 0;
/* First send the register offset - TX operation */
I2CSetDataCount(I2C_BASE_ADDR, 2);
StatusClear();
I2CMasterControl(I2C_BASE_ADDR, I2C_CFG_MST_TX);
I2CMasterStart(I2C_BASE_ADDR);
/* Wait for the START to actually occir on the bus */
while (0 == I2CMasterBusBusy(I2C_BASE_ADDR));
I2CMasterDataPut(I2C_BASE_ADDR, (unsigned char)((offset >> 8) & 0xFF));
/* Wait for the Tx register to be empty */
while (0 == I2CMasterIntRawStatusEx(I2C_BASE_ADDR,
I2C_INT_TRANSMIT_READY));
/* Push offset out and tell CPLD from where we intend to read the data */
I2CMasterDataPut(I2C_BASE_ADDR, (unsigned char)(offset & 0xFF));
I2CMasterIntClearEx(I2C_BASE_ADDR, I2C_INT_TRANSMIT_READY);
while(0 == (I2CMasterIntRawStatus(I2C_BASE_ADDR) & I2C_INT_ADRR_READY_ACESS));
StatusClear();
I2CSetDataCount(I2C_BASE_ADDR, length);
/* Now that we have sent the register offset, start a RX operation*/
I2CMasterControl(I2C_BASE_ADDR, I2C_CFG_MST_RX);
/* Repeated start condition */
I2CMasterStart(I2C_BASE_ADDR);
while (length--)
{
while (0 == I2CMasterIntRawStatusEx(I2C_BASE_ADDR,
I2C_INT_RECV_READY));
data[idx++] = (unsigned char)I2CMasterDataGet(I2C_BASE_ADDR);
I2CMasterIntClearEx(I2C_BASE_ADDR, I2C_INT_RECV_READY);
}
I2CMasterStop(I2C_BASE_ADDR);
while(0 == (I2CMasterIntRawStatus(I2C_BASE_ADDR) & I2C_INT_STOP_CONDITION));
I2CMasterIntClearEx(I2C_BASE_ADDR, I2C_INT_STOP_CONDITION);
}
uint8_t TwoWire::getRxData(unsigned long cmd) {
if (currentState == IDLE) while(I2CMasterBusBusy(MASTER_BASE));
HWREG(MASTER_BASE + I2C_O_MCS) = cmd;
while(I2CMasterBusy(MASTER_BASE));
uint8_t error = I2CMasterErr(MASTER_BASE);
if (error != I2C_MASTER_ERR_NONE) {
I2CMasterControl(MASTER_BASE, I2C_MASTER_CMD_BURST_RECEIVE_ERROR_STOP);
}
else {
while(I2CMasterBusy(MASTER_BASE));
rxBuffer[rxWriteIndex] = I2CMasterDataGet(MASTER_BASE);
rxWriteIndex = (rxWriteIndex + 1) % BUFFER_LENGTH;
}
return error;
}
uint8_t TwoWire::endTransmission(uint8_t sendStop)
{
uint8_t error = I2C_MASTER_ERR_NONE;
if(TX_BUFFER_EMPTY) return 0;
//Wait for any previous transaction to complete
while(I2CMasterBusBusy(MASTER_BASE));
while(I2CMasterBusy(MASTER_BASE));
//Select which slave we are requesting data from
//false indicates we are writing to the slave
I2CMasterSlaveAddrSet(MASTER_BASE, txAddress, false);
while(I2CMasterBusy(MASTER_BASE));
unsigned long cmd = RUN_BIT | START_BIT;
error = sendTxData(cmd,txBuffer[txReadIndex]);
txReadIndex = (txReadIndex + 1) % BUFFER_LENGTH;
if(error) return error;
while(!TX_BUFFER_EMPTY) {
error = sendTxData(RUN_BIT,txBuffer[txReadIndex]);
txReadIndex = (txReadIndex + 1) % BUFFER_LENGTH;
if(error) return getError(error);
}
if(sendStop) {
while(I2CMasterBusy(MASTER_BASE));
HWREG(MASTER_BASE + I2C_O_MCS) = STOP_BIT;
while(I2CMasterBusy(MASTER_BASE));
currentState = IDLE;
}
else {
currentState = MASTER_TX;
}
// indicate that we are done transmitting
transmitting = 0;
return error;
}
bool I2CGenIsNotIdle() {
return !I2CMasterBusBusy(I2C0_BASE);
}
