ssize_t UARTSerial::read(void* buffer, size_t length)
{
size_t data_read = 0;
char *ptr = static_cast<char *>(buffer);
api_lock();
while (_rxbuf.empty()) {
if (!_blocking) {
api_unlock();
return -EAGAIN;
}
api_unlock();
wait_ms(1); // XXX todo - proper wait, WFE for non-rtos ?
api_lock();
}
while (data_read < length && !_rxbuf.empty()) {
_rxbuf.pop(*ptr++);
data_read++;
}
api_unlock();
return data_read;
}
int UARTSerial::sync()
{
api_lock();
while (!_txbuf.empty()) {
api_unlock();
// Doing better than wait would require TxIRQ to also do wake() when becoming empty. Worth it?
wait_ms(1);
api_lock();
}
api_unlock();
return 0;
}
ssize_t UARTSerial::read(void* buffer, size_t length)
{
size_t data_read = 0;
char *ptr = static_cast<char *>(buffer);
api_lock();
while (_rxbuf.empty()) {
if (!_blocking) {
api_unlock();
return -EAGAIN;
}
api_unlock();
wait_ms(1); // XXX todo - proper wait, WFE for non-rtos ?
api_lock();
}
while (data_read < length && !_rxbuf.empty()) {
_rxbuf.pop(*ptr++);
data_read++;
}
core_util_critical_section_enter();
if (!_rx_irq_enabled) {
UARTSerial::rx_irq(); // only read from hardware in one place
if (!_rxbuf.full()) {
SerialBase::attach(callback(this, &UARTSerial::rx_irq), RxIrq);
_rx_irq_enabled = true;
}
}
core_util_critical_section_exit();
api_unlock();
return data_read;
}
ssize_t UARTSerial::write(const void* buffer, size_t length)
{
size_t data_written = 0;
const char *buf_ptr = static_cast<const char *>(buffer);
api_lock();
while (_txbuf.full()) {
if (!_blocking) {
api_unlock();
return -EAGAIN;
}
api_unlock();
wait_ms(1); // XXX todo - proper wait, WFE for non-rtos ?
api_lock();
}
while (data_written < length && !_txbuf.full()) {
_txbuf.push(*buf_ptr++);
data_written++;
}
core_util_critical_section_enter();
if (!_tx_irq_enabled) {
UARTSerial::tx_irq(); // only write to hardware in one place
if (!_txbuf.empty()) {
SerialBase::attach(callback(this, &UARTSerial::tx_irq), TxIrq);
_tx_irq_enabled = true;
}
}
core_util_critical_section_exit();
api_unlock();
return data_written;
}
void UARTSerial::set_flow_control(Flow type, PinName flow1, PinName flow2)
{
api_lock();
SerialBase::set_flow_control(type, flow1, flow2);
api_unlock();
}
void UARTSerial::set_format(int bits, Parity parity, int stop_bits)
{
api_lock();
SerialBase::format(bits, parity, stop_bits);
api_unlock();
}