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Diff: mbed-os/drivers/UARTSerial.cpp
- Revision:
- 0:02dd72d1d465
diff -r 000000000000 -r 02dd72d1d465 mbed-os/drivers/UARTSerial.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/drivers/UARTSerial.cpp Tue Apr 24 11:45:18 2018 +0000
@@ -0,0 +1,341 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2017 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if (DEVICE_SERIAL && DEVICE_INTERRUPTIN)
+
+#include <errno.h>
+#include "UARTSerial.h"
+#include "platform/mbed_poll.h"
+
+#if MBED_CONF_RTOS_PRESENT
+#include "rtos/Thread.h"
+#else
+#include "platform/mbed_wait_api.h"
+#endif
+
+namespace mbed {
+
+UARTSerial::UARTSerial(PinName tx, PinName rx, int baud) :
+ SerialBase(tx, rx, baud),
+ _blocking(true),
+ _tx_irq_enabled(false),
+ _rx_irq_enabled(true),
+ _dcd_irq(NULL)
+{
+ /* Attatch IRQ routines to the serial device. */
+ SerialBase::attach(callback(this, &UARTSerial::rx_irq), RxIrq);
+}
+
+UARTSerial::~UARTSerial()
+{
+ delete _dcd_irq;
+}
+
+void UARTSerial::dcd_irq()
+{
+ wake();
+}
+
+void UARTSerial::set_baud(int baud)
+{
+ SerialBase::baud(baud);
+}
+
+void UARTSerial::set_data_carrier_detect(PinName dcd_pin, bool active_high)
+{
+ delete _dcd_irq;
+ _dcd_irq = NULL;
+
+ if (dcd_pin != NC) {
+ _dcd_irq = new InterruptIn(dcd_pin);
+ if (active_high) {
+ _dcd_irq->fall(callback(this, &UARTSerial::dcd_irq));
+ } else {
+ _dcd_irq->rise(callback(this, &UARTSerial::dcd_irq));
+ }
+ }
+}
+
+void UARTSerial::set_format(int bits, Parity parity, int stop_bits)
+{
+ api_lock();
+ SerialBase::format(bits, parity, stop_bits);
+ api_unlock();
+}
+
+#if DEVICE_SERIAL_FC
+void UARTSerial::set_flow_control(Flow type, PinName flow1, PinName flow2)
+{
+ api_lock();
+ SerialBase::set_flow_control(type, flow1, flow2);
+ api_unlock();
+}
+#endif
+
+int UARTSerial::close()
+{
+ /* Does not let us pass a file descriptor. So how to close ?
+ * Also, does it make sense to close a device type file descriptor*/
+ return 0;
+}
+
+int UARTSerial::isatty()
+{
+ return 1;
+
+}
+
+off_t UARTSerial::seek(off_t offset, int whence)
+{
+ /*XXX lseek can be done theoratically, but is it sane to mark positions on a dynamically growing/shrinking
+ * buffer system (from an interrupt context) */
+ return -ESPIPE;
+}
+
+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;
+}
+
+void UARTSerial::sigio(Callback<void()> func) {
+ core_util_critical_section_enter();
+ _sigio_cb = func;
+ if (_sigio_cb) {
+ short current_events = poll(0x7FFF);
+ if (current_events) {
+ _sigio_cb();
+ }
+ }
+ core_util_critical_section_exit();
+}
+
+ssize_t UARTSerial::write(const void* buffer, size_t length)
+{
+ size_t data_written = 0;
+ const char *buf_ptr = static_cast<const char *>(buffer);
+
+ if (length == 0) {
+ return 0;
+ }
+
+ api_lock();
+
+ // Unlike read, we should write the whole thing if blocking. POSIX only
+ // allows partial as a side-effect of signal handling; it normally tries to
+ // write everything if blocking. Without signals we can always write all.
+ while (data_written < length) {
+
+ if (_txbuf.full()) {
+ if (!_blocking) {
+ break;
+ }
+ do {
+ api_unlock();
+ wait_ms(1); // XXX todo - proper wait, WFE for non-rtos ?
+ api_lock();
+ } while (_txbuf.full());
+ }
+
+ 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 != 0 ? (ssize_t) data_written : (ssize_t) -EAGAIN;
+}
+
+ssize_t UARTSerial::read(void* buffer, size_t length)
+{
+ size_t data_read = 0;
+
+ char *ptr = static_cast<char *>(buffer);
+
+ if (length == 0) {
+ return 0;
+ }
+
+ 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;
+}
+
+bool UARTSerial::hup() const
+{
+ return _dcd_irq && _dcd_irq->read() != 0;
+}
+
+void UARTSerial::wake()
+{
+ if (_sigio_cb) {
+ _sigio_cb();
+ }
+}
+
+short UARTSerial::poll(short events) const {
+
+ short revents = 0;
+ /* Check the Circular Buffer if space available for writing out */
+
+
+ if (!_rxbuf.empty()) {
+ revents |= POLLIN;
+ }
+
+ /* POLLHUP and POLLOUT are mutually exclusive */
+ if (hup()) {
+ revents |= POLLHUP;
+ } else if (!_txbuf.full()) {
+ revents |= POLLOUT;
+ }
+
+ /*TODO Handle other event types */
+
+ return revents;
+}
+
+void UARTSerial::lock()
+{
+ // This is the override for SerialBase.
+ // No lock required as we only use SerialBase from interrupt or from
+ // inside our own critical section.
+}
+
+void UARTSerial::unlock()
+{
+ // This is the override for SerialBase.
+}
+
+void UARTSerial::api_lock(void)
+{
+ _mutex.lock();
+}
+
+void UARTSerial::api_unlock(void)
+{
+ _mutex.unlock();
+}
+
+void UARTSerial::rx_irq(void)
+{
+ bool was_empty = _rxbuf.empty();
+
+ /* Fill in the receive buffer if the peripheral is readable
+ * and receive buffer is not full. */
+ while (!_rxbuf.full() && SerialBase::readable()) {
+ char data = SerialBase::_base_getc();
+ _rxbuf.push(data);
+ }
+
+ if (_rx_irq_enabled && _rxbuf.full()) {
+ SerialBase::attach(NULL, RxIrq);
+ _rx_irq_enabled = false;
+ }
+
+ /* Report the File handler that data is ready to be read from the buffer. */
+ if (was_empty && !_rxbuf.empty()) {
+ wake();
+ }
+}
+
+// Also called from write to start transfer
+void UARTSerial::tx_irq(void)
+{
+ bool was_full = _txbuf.full();
+
+ /* Write to the peripheral if there is something to write
+ * and if the peripheral is available to write. */
+ while (!_txbuf.empty() && SerialBase::writeable()) {
+ char data;
+ _txbuf.pop(data);
+ SerialBase::_base_putc(data);
+ }
+
+ if (_tx_irq_enabled && _txbuf.empty()) {
+ SerialBase::attach(NULL, TxIrq);
+ _tx_irq_enabled = false;
+ }
+
+ /* Report the File handler that data can be written to peripheral. */
+ if (was_full && !_txbuf.full() && !hup()) {
+ wake();
+ }
+}
+
+void UARTSerial::wait_ms(uint32_t millisec)
+{
+ /* wait_ms implementation for RTOS spins until exact microseconds - we
+ * want to just sleep until next tick.
+ */
+#if MBED_CONF_RTOS_PRESENT
+ rtos::Thread::wait(millisec);
+#else
+ ::wait_ms(millisec);
+#endif
+}
+} //namespace mbed
+
+#endif //(DEVICE_SERIAL && DEVICE_INTERRUPTIN)