/*FUNCTION**********************************************************************
*
* Function Name : I2C_DRV_SlaveIRQHandler
* Description : I2C Slave Generic ISR.
* ISR action be called inside I2C IRQ handler entry.
*
*END*/
void I2C_DRV_SlaveIRQHandler(uint32_t instance)
{
assert(instance < I2C_INSTANCE_COUNT);
I2C_Type * base = g_i2cBase[instance];
uint8_t i2cData = 0x00;
bool doTransmit = false;
bool wasArbLost = I2C_HAL_GetStatusFlag(base, kI2CArbitrationLost);
bool addressed = I2C_HAL_GetStatusFlag(base, kI2CAddressAsSlave);
bool stopIntEnabled = false;
#if FSL_FEATURE_I2C_HAS_START_STOP_DETECT
bool startDetected = I2C_HAL_GetStartFlag(base);
bool startIntEnabled = I2C_HAL_GetStartStopIntCmd(base);
bool stopDetected = I2C_HAL_GetStopFlag(base);
stopIntEnabled = startIntEnabled;
#endif
#if FSL_FEATURE_I2C_HAS_STOP_DETECT
bool stopDetected = I2C_HAL_GetStopFlag(base);
stopIntEnabled = I2C_HAL_GetStopIntCmd(base);
#endif
/** Get current runtime structure */
i2c_slave_state_t * i2cSlaveState = (i2c_slave_state_t *)g_i2cStatePtr[instance];
/** Get current slave transfer direction */
i2c_direction_t direction = I2C_HAL_GetDirMode(base);
#if FSL_FEATURE_I2C_HAS_START_STOP_DETECT
/*--------------- Handle START ------------------*/
if (startIntEnabled && startDetected)
{
I2C_HAL_ClearStartFlag(base);
I2C_HAL_ClearInt(base);
if(i2cSlaveState->slaveCallback != NULL)
{
/*Call callback to handle when the driver detect START signal*/
i2cSlaveState->slaveCallback(instance,
kI2CSlaveStartDetect,
i2cSlaveState->callbackParam);
}
return;
}
#endif
#if FSL_FEATURE_I2C_HAS_START_STOP_DETECT || FSL_FEATURE_I2C_HAS_STOP_DETECT
/*--------------- Handle STOP ------------------*/
if (stopIntEnabled && stopDetected)
{
I2C_HAL_ClearStopFlag(base);
I2C_HAL_ClearInt(base);
if(!i2cSlaveState->slaveListening)
{
/** Disable I2C interrupt in the peripheral.*/
I2C_HAL_SetIntCmd(base, false);
}
if(i2cSlaveState->slaveCallback != NULL)
{
/*Call callback to handle when the driver detect STOP signal*/
i2cSlaveState->slaveCallback(instance,
kI2CSlaveStopDetect,
i2cSlaveState->callbackParam);
}
if (i2cSlaveState->isRxBlocking)
{
OSA_EventSet(&i2cSlaveState->irqEvent, kI2CSlaveStopDetect);
}
i2cSlaveState->status = kStatus_I2C_Idle;
return;
}
#endif
/** Clear I2C IRQ.*/
I2C_HAL_ClearInt(base);
if (wasArbLost)
{
I2C_HAL_ClearArbitrationLost(base);
if (!addressed)
{
i2cSlaveState->status = kStatus_I2C_AribtrationLost;
if(!i2cSlaveState->slaveListening)
{
/** Disable I2C interrupt in the peripheral.*/
I2C_HAL_SetIntCmd(base, false);
}
return;
}
}
/*--------------- Handle Address ------------------*/
/** Addressed only happens when receiving address. */
if (addressed) /** Slave is addressed. */
{
/** Master read from Slave. Slave transmit.*/
if (I2C_HAL_GetStatusFlag(base, kI2CSlaveTransmit))
{
/** Switch to TX mode*/
I2C_HAL_SetDirMode(base, kI2CSend);
if(i2cSlaveState->slaveCallback != NULL)
{
/*Call callback to handle when the driver get read request*/
i2cSlaveState->slaveCallback(instance,
kI2CSlaveTxReq,
i2cSlaveState->callbackParam);
}
doTransmit = true;
}
else /** Master write to Slave. Slave receive.*/
{
/** Switch to RX mode.*/
I2C_HAL_SetDirMode(base, kI2CReceive);
if(i2cSlaveState->slaveCallback != NULL)
{
/*Call callback to handle when the driver get write request*/
i2cSlaveState->slaveCallback(instance,
kI2CSlaveRxReq,
i2cSlaveState->callbackParam);
}
/** Read dummy character.*/
I2C_HAL_ReadByte(base);
}
}
/*--------------- Handle Transfer ------------------*/
else
{
/** Handle transmit */
if (direction == kI2CSend)
{
if (I2C_HAL_GetStatusFlag(base, kI2CReceivedNak))
{
/** Switch to RX mode.*/
I2C_HAL_SetDirMode(base, kI2CReceive);
/** Read dummy character to release bus */
I2C_HAL_ReadByte(base);
if ((!i2cSlaveState->slaveListening) && (!stopIntEnabled))
{
/** Disable I2C interrupt in the peripheral.*/
I2C_HAL_SetIntCmd(base, false);
}
if(i2cSlaveState->slaveCallback != NULL)
{
/** Receive TX NAK, mean transaction is finished, call callback to handle */
i2cSlaveState->slaveCallback(instance,
kI2CSlaveTxNAK,
i2cSlaveState->callbackParam);
}
if (i2cSlaveState->isTxBlocking)
{
OSA_EventSet(&i2cSlaveState->irqEvent, kI2CSlaveTxNAK);
}
i2cSlaveState->txSize = 0;
i2cSlaveState->txBuff = NULL;
i2cSlaveState->isTxBusy = false;
}
else /** ACK from receiver.*/
{
doTransmit = true;
}
}
/** Handle receive */
else
{
/** Get byte from data register */
i2cData = I2C_HAL_ReadByte(base);
if (i2cSlaveState->rxSize)
{
*(i2cSlaveState->rxBuff) = i2cData;
++ i2cSlaveState->rxBuff;
-- i2cSlaveState->rxSize;
if (!i2cSlaveState->rxSize)
{
if (!stopIntEnabled)
{
if(!i2cSlaveState->slaveListening)
{
/** Disable I2C interrupt in the peripheral.*/
I2C_HAL_SetIntCmd(base, false);
}
/** All bytes are received, so we're done with this transfer */
if (i2cSlaveState->isRxBlocking)
{
OSA_EventSet(&i2cSlaveState->irqEvent, kI2CSlaveRxFull);
}
}
i2cSlaveState->isRxBusy = false;
i2cSlaveState->rxBuff = NULL;
if(i2cSlaveState->slaveCallback != NULL)
{
/** Rx buffer is full, call callback to handle */
i2cSlaveState->slaveCallback(instance,
kI2CSlaveRxFull,
i2cSlaveState->callbackParam);
}
}
}
else
{
/** The Rxbuff is full --> Set kStatus_I2C_SlaveRxOverrun*/
i2cSlaveState->status = kStatus_I2C_SlaveRxOverrun;
}
}
}
/** DO TRANSMIT*/
if (doTransmit)
{
/** Send byte to data register */
if (i2cSlaveState->txSize)
{
i2cData = *(i2cSlaveState->txBuff);
I2C_HAL_WriteByte(base, i2cData);
++ i2cSlaveState->txBuff;
-- i2cSlaveState->txSize;
if (!i2cSlaveState->txSize)
{
/** All bytes are received, so we're done with this transfer */
i2cSlaveState->txBuff = NULL;
i2cSlaveState->isTxBusy = false;
if(i2cSlaveState->slaveCallback != NULL)
{
/** Tx buffer is empty, finish transaction, call callback to handle */
i2cSlaveState->slaveCallback(instance,
kI2CSlaveTxEmpty,
i2cSlaveState->callbackParam);
}
}
}
else
{
/** The Txbuff is empty --> set kStatus_I2C_SlaveTxUnderrun*/
i2cSlaveState->status = kStatus_I2C_SlaveTxUnderrun ;
}
}
}
void TwoWire::onService(void)
{
//interrupt handler
uint8_t i2cData = 0x00;
bool wasArbLost = I2C_HAL_GetStatusFlag(instance, kI2CArbitrationLost);
bool addressed = I2C_HAL_GetStatusFlag(instance, kI2CAddressAsSlave);
bool stopIntEnabled = false;
bool startDetected = I2C_HAL_GetStartFlag(instance);
bool startIntEnabled = I2C_HAL_GetStartStopIntCmd(instance);
bool stopDetected = I2C_HAL_GetStopFlag(instance);
stopIntEnabled = startIntEnabled;
/* Get current slave transfer direction */
i2c_direction_t direction = I2C_HAL_GetDirMode(instance);
/*--------------- Handle START, STOP or REPEAT START ------------------*/
if (stopIntEnabled && (startDetected || stopDetected))
{
if(startDetected)
I2C_HAL_ClearStartFlag(instance);
if(stopDetected)
I2C_HAL_ClearStopFlag(instance);
I2C_HAL_ClearInt(instance);
if(slaveBufferLength)
{
if(onReceiveCallback)
{
receiving_slave = true;
onReceiveCallback(slaveBufferLength);
receiving_slave = false;
}
slaveBufferIndex = 0;
slaveBufferLength = 0;
}
return;
}
/* Clear I2C IRQ.*/
I2C_HAL_ClearInt(instance);
if (wasArbLost)
{
I2C_HAL_ClearArbitrationLost(instance);
if (!addressed)
{
master_state = MASTER_STATE_ARB_LOST;
return;
}
}
if(I2C_HAL_IsMaster(instance))
{
if (direction == kI2CSend)
{
//check for NAK
/* Check whether we got an ACK or NAK from the former byte we sent */
if (I2C_HAL_GetStatusFlag(instance, kI2CReceivedNak))
{
master_state = MASTER_STATE_TX_NAK;
}
else if(transmitting_master)
{
/* Continue send if still have data. TxSize/txBuff index need
* increment first because one byte is already sent in order
* to trigger interrupt */
if (txBufferIndex < txBufferLength)
{
/* Transmit next byte and update buffer index */
I2C_HAL_WriteByte(instance, txBuffer[txBufferIndex++]);
}
else
{
/* Finish send data, send STOP, disable interrupt */
master_state = MASTER_STATE_COMPLETE;
}
}
else
{
master_state = MASTER_STATE_READ_READY; //address sent for a read
}
}
else
{
switch (--rxBufferQuantity)
{
case 0x0U:
/* Finish receive data, send STOP, disable interrupt */
master_state = MASTER_STATE_COMPLETE;
if(master_send_stop)
I2C_HAL_SendStop(instance);
else
I2C_HAL_SendStart(instance);
break;
case 0x1U:
/* For the byte before last, we need to set NAK */
I2C_HAL_SendNak(instance);
break;
default :
I2C_HAL_SendAck(instance);
break;
}
rxBuffer[rxBufferLength++] = I2C_HAL_ReadByte(instance);
}
return;
}
/*--------------- Handle Address ------------------*/
/* Addressed only happens when receiving address. */
if (addressed) /* Slave is addressed. */
{
/* Master read from Slave. Slave transmit.*/
if (I2C_HAL_GetStatusFlag(instance, kI2CSlaveTransmit))
{
/* Switch to TX mode*/
I2C_HAL_SetDirMode(instance, kI2CSend);
transmitting_slave = true;
slaveBufferIndex = 0;
slaveBufferLength = 0;
if (onRequestCallback)
onRequestCallback(); //this needs to load the transmit buffer
else
// create a default 1-byte response
write((uint8_t) 0);
}
else /* Master write to Slave. Slave receive.*/
{
/* Switch to RX mode.*/
I2C_HAL_SetDirMode(instance, kI2CReceive);
I2C_HAL_SendAck(instance);
/* Read dummy character.*/
I2C_HAL_ReadByte(instance);
slaveBufferIndex = 0;
slaveBufferLength = 0;
}
}
/*--------------- Handle Transfer ------------------*/
else
{
/* Handle transmit */
if (direction == kI2CSend)
{
if (I2C_HAL_GetStatusFlag(instance, kI2CReceivedNak))
{
/* Switch to RX mode.*/
I2C_HAL_SetDirMode(instance, kI2CReceive);
/* Read dummy character to release bus */
I2C_HAL_ReadByte(instance);
transmitting_slave = false;
slaveBufferIndex = 0;
slaveBufferLength = 0;
}
else /* ACK from receiver.*/
{
transmitting_slave = true;
}
}
/* Handle receive */
else
{
/* Get byte from data register */
I2C_HAL_SendAck(instance);
i2cData = I2C_HAL_ReadByte(instance);
if(slaveBufferLength < BUFFER_LENGTH)
slaveBuffer[slaveBufferLength++] = i2cData;
}
}
if (transmitting_slave)
{
/* Send byte to data register */
if (slaveBufferIndex < slaveBufferLength)
{
I2C_HAL_WriteByte(instance, slaveBuffer[slaveBufferIndex++]);
if (slaveBufferIndex >= slaveBufferLength)
{
slaveBufferIndex = 0;
slaveBufferLength = 0;
transmitting_slave = false;
}
}
else
transmitting_slave = false;
}
}
