int SerialDriver::getc(unsigned int timeoutMs)
{
// Let's read (isr will check readability itself)
onRxIrq();
// critical section, isr could modify cursors
disableRxInterrupt();
if(isRxBufferEmpty())
{
// wait for new byte
while(semRxBufferEmpty.wait(0) > 0); // clear semaphore
enableRxInterrupt();
// let isr work
semRxBufferEmpty.wait(timeoutMs);
disableRxInterrupt();
if(isRxBufferEmpty()) // still empty? nothing received!
{
enableRxInterrupt();
return -1;
}
}
// get byte from rx buffer
int c= (int)rxBuffer[rxOut];
rxOut= (rxOut+1) % rxBufferLength;
rxCount--;
// its over, isr can come
enableRxInterrupt();
return c;
}
void SerialDriver::onRxIrq()
{
// prevent fire another RxIrq now
disableRxInterrupt();
// read as long as you can
bool wasEmpty= isRxBufferEmpty();
while(SerialBase::readable())
{
// get byte and store it to the RX buffer
int c= SerialBase::_base_getc();
if(!isRxBufferFull())
{
rxBuffer[rxIn]= (unsigned char)c;
rxIn= (rxIn+1) % rxBufferLength;
rxCount++;
}
else // drop byte :(
numRxDrops++;
}
if(wasEmpty && !isRxBufferEmpty()) // more bytes can go
semRxBufferEmpty.release();
// ok, let's wait for next readability
enableRxInterrupt();
}
/**
* Function for notifying application about new bytes received.
*/
static void processReceive(void)
{
// Set head position to not be changed during read procedure.
uint16_t head = sReceiveHead;
otEXPECT(isRxBufferEmpty() == false);
// In case head roll back to the beginning of the buffer, notify about left
// bytes from the end of the buffer.
if (head < sReceiveTail)
{
otPlatUartReceived(&sReceiveBuffer[sReceiveTail], (UART_RX_BUFFER_SIZE - sReceiveTail));
sReceiveTail = 0;
}
// Notify about received bytes.
if (head > sReceiveTail)
{
otPlatUartReceived(&sReceiveBuffer[sReceiveTail], (head - sReceiveTail));
sReceiveTail = head;
}
exit:
return;
}
* Function for checking if RX buffer is empty.
*
* @retval true RX buffer is empty.
* @retval false RX buffer is not empty.
*/
static __INLINE bool isRxBufferEmpty()
{
return (sReceiveHead == sReceiveTail);
}
/**
* Function for notifying application about new bytes received.
*/
static void processReceive(void)
{
VerifyOrExit(isRxBufferEmpty() == false, ;);
// Set head position to not be changed during read procedure.
uint16_t head = sReceiveHead;
// In case head roll back to the beginning of the buffer, notify about left
// bytes from the end of the buffer.
if (head < sReceiveTail)
{
otPlatUartReceived(&sReceiveBuffer[sReceiveTail],
(UART_RX_BUFFER_SIZE - sReceiveTail));
sReceiveTail = 0;
}
// Notify about received bytes.
if (head > sReceiveTail)
