Diff: mbed-os/drivers/UARTSerial.h

Revision:

0:9b3d4731edbb

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/drivers/UARTSerial.h	Thu Jun 21 13:51:43 2018 +0000
@@ -0,0 +1,279 @@
+/* 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.
+ */
+
+#ifndef MBED_UARTSERIAL_H
+#define MBED_UARTSERIAL_H
+
+#include "platform/platform.h"
+
+#if (DEVICE_SERIAL && DEVICE_INTERRUPTIN) || defined(DOXYGEN_ONLY)
+
+#include "FileHandle.h"
+#include "SerialBase.h"
+#include "InterruptIn.h"
+#include "PlatformMutex.h"
+#include "serial_api.h"
+#include "CircularBuffer.h"
+#include "platform/NonCopyable.h"
+
+#ifndef MBED_CONF_DRIVERS_UART_SERIAL_RXBUF_SIZE
+#define MBED_CONF_DRIVERS_UART_SERIAL_RXBUF_SIZE  256
+#endif
+
+#ifndef MBED_CONF_DRIVERS_UART_SERIAL_TXBUF_SIZE
+#define MBED_CONF_DRIVERS_UART_SERIAL_TXBUF_SIZE  256
+#endif
+
+namespace mbed {
+
+/** \addtogroup drivers */
+
+/** Class providing buffered UART communication functionality using separate circular buffer for send and receive channels
+ *  
+ * @ingroup drivers
+ */
+
+class UARTSerial : private SerialBase, public FileHandle, private NonCopyable<UARTSerial> {
+
+public:
+
+    /** Create a UARTSerial port, connected to the specified transmit and receive pins, with a particular baud rate.
+     *  @param tx Transmit pin
+     *  @param rx Receive pin
+     *  @param baud The baud rate of the serial port (optional, defaults to MBED_CONF_PLATFORM_DEFAULT_SERIAL_BAUD_RATE)
+     */
+    UARTSerial(PinName tx, PinName rx, int baud = MBED_CONF_PLATFORM_DEFAULT_SERIAL_BAUD_RATE);
+    virtual ~UARTSerial();
+
+    /** Equivalent to POSIX poll(). Derived from FileHandle.
+     *  Provides a mechanism to multiplex input/output over a set of file handles.
+     */
+    virtual short poll(short events) const;
+
+    /* Resolve ambiguities versus our private SerialBase
+     * (for writable, spelling differs, but just in case)
+     */
+    using FileHandle::readable;
+    using FileHandle::writable;
+
+    /** Write the contents of a buffer to a file
+     *
+     *  Follows POSIX semantics:
+     *
+     * * if blocking, block until all data is written
+     * * if no data can be written, and non-blocking set, return -EAGAIN
+     * * if some data can be written, and non-blocking set, write partial
+     *
+     *  @param buffer   The buffer to write from
+     *  @param length   The number of bytes to write
+     *  @return         The number of bytes written, negative error on failure
+     */
+    virtual ssize_t write(const void* buffer, size_t length);
+
+    /** Read the contents of a file into a buffer
+     *
+     *  Follows POSIX semantics:
+     *
+     *  * if no data is available, and non-blocking set return -EAGAIN
+     *  * if no data is available, and blocking set, wait until data is available
+     *  * If any data is available, call returns immediately
+     *
+     *  @param buffer   The buffer to read in to
+     *  @param length   The number of bytes to read
+     *  @return         The number of bytes read, 0 at end of file, negative error on failure
+     */
+    virtual ssize_t read(void* buffer, size_t length);
+
+    /** Close a file
+     *
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int close();
+
+    /** Check if the file in an interactive terminal device
+     *
+     *  @return         True if the file is a terminal
+     *  @return         False if the file is not a terminal
+     *  @return         Negative error code on failure
+     */
+    virtual int isatty();
+
+    /** Move the file position to a given offset from from a given location
+     *
+     * Not valid for a device type FileHandle like UARTSerial.
+     * In case of UARTSerial, returns ESPIPE
+     *
+     *  @param offset   The offset from whence to move to
+     *  @param whence   The start of where to seek
+     *      SEEK_SET to start from beginning of file,
+     *      SEEK_CUR to start from current position in file,
+     *      SEEK_END to start from end of file
+     *  @return         The new offset of the file, negative error code on failure
+     */
+    virtual off_t seek(off_t offset, int whence);
+
+    /** Flush any buffers associated with the file
+     *
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int sync();
+
+    /** Set blocking or non-blocking mode
+     *  The default is blocking.
+     *
+     *  @param blocking true for blocking mode, false for non-blocking mode.
+     */
+    virtual int set_blocking(bool blocking)
+    {
+        _blocking = blocking;
+        return 0;
+    }
+
+    /** Check current blocking or non-blocking mode for file operations.
+     *
+     *  @return             true for blocking mode, false for non-blocking mode.
+     */
+    virtual bool is_blocking() const
+    {
+        return _blocking;
+    }
+
+    /** Register a callback on state change of the file.
+     *
+     *  The specified callback will be called on state changes such as when
+     *  the file can be written to or read from.
+     *
+     *  The callback may be called in an interrupt context and should not
+     *  perform expensive operations.
+     *
+     *  Note! This is not intended as an attach-like asynchronous api, but rather
+     *  as a building block for constructing  such functionality.
+     *
+     *  The exact timing of when the registered function
+     *  is called is not guaranteed and susceptible to change. It should be used
+     *  as a cue to make read/write/poll calls to find the current state.
+     *
+     *  @param func     Function to call on state change
+     */
+    virtual void sigio(Callback<void()> func);
+
+    /** Setup interrupt handler for DCD line
+     *
+     *  If DCD line is connected, an IRQ handler will be setup.
+     *  Does nothing if DCD is NC, i.e., not connected.
+     *
+     *  @param dcd_pin         Pin-name for DCD
+     *  @param active_high     a boolean set to true if DCD polarity is active low
+     */
+    void set_data_carrier_detect(PinName dcd_pin, bool active_high = false);
+
+    /** Set the baud rate
+     *
+     *  @param baud   The baud rate
+     */
+    void set_baud(int baud);
+
+    // Expose private SerialBase::Parity as UARTSerial::Parity
+    using SerialBase::Parity;
+    // In C++11, we wouldn't need to also have using directives for each value
+    using SerialBase::None;
+    using SerialBase::Odd;
+    using SerialBase::Even;
+    using SerialBase::Forced1;
+    using SerialBase::Forced0;
+
+    /** Set the transmission format used by the serial port
+     *
+     *  @param bits The number of bits in a word (5-8; default = 8)
+     *  @param parity The parity used (None, Odd, Even, Forced1, Forced0; default = None)
+     *  @param stop_bits The number of stop bits (1 or 2; default = 1)
+     */
+    void set_format(int bits=8, Parity parity=UARTSerial::None, int stop_bits=1);
+
+#if DEVICE_SERIAL_FC
+    // For now use the base enum - but in future we may have extra options
+    // such as XON/XOFF or manual GPIO RTSCTS.
+    using SerialBase::Flow;
+    // In C++11, we wouldn't need to also have using directives for each value
+    using SerialBase::Disabled;
+    using SerialBase::RTS;
+    using SerialBase::CTS;
+    using SerialBase::RTSCTS;
+
+    /** Set the flow control type on the serial port
+     *
+     *  @param type the flow control type (Disabled, RTS, CTS, RTSCTS)
+     *  @param flow1 the first flow control pin (RTS for RTS or RTSCTS, CTS for CTS)
+     *  @param flow2 the second flow control pin (CTS for RTSCTS)
+     */
+    void set_flow_control(Flow type, PinName flow1=NC, PinName flow2=NC);
+#endif
+
+private:
+
+    void wait_ms(uint32_t millisec);
+
+    /** SerialBase lock override */
+    virtual void lock(void);
+
+    /** SerialBase unlock override */
+    virtual void unlock(void);
+
+    /** Acquire mutex */
+    virtual void api_lock(void);
+
+    /** Release mutex */
+    virtual void api_unlock(void);
+
+    /** Software serial buffers
+     *  By default buffer size is 256 for TX and 256 for RX. Configurable through mbed_app.json
+     */
+    CircularBuffer<char, MBED_CONF_DRIVERS_UART_SERIAL_RXBUF_SIZE> _rxbuf;
+    CircularBuffer<char, MBED_CONF_DRIVERS_UART_SERIAL_TXBUF_SIZE> _txbuf;
+
+    PlatformMutex _mutex;
+
+    Callback<void()> _sigio_cb;
+
+    bool _blocking;
+    bool _tx_irq_enabled;
+    bool _rx_irq_enabled;
+    InterruptIn *_dcd_irq;
+
+    /** Device Hanged up
+     *  Determines if the device hanged up on us.
+     *
+     *  @return True, if hanged up
+     */
+    bool hup() const;
+
+    /** ISRs for serial
+     *  Routines to handle interrupts on serial pins.
+     *  Copies data into Circular Buffer.
+     *  Reports the state change to File handle.
+     */
+    void tx_irq(void);
+    void rx_irq(void);
+
+    void wake(void);
+
+    void dcd_irq(void);
+
+};
+} //namespace mbed
+
+#endif //(DEVICE_SERIAL && DEVICE_INTERRUPTIN) || defined(DOXYGEN_ONLY)
+#endif //MBED_UARTSERIAL_H