Squashed 'tmk_core/' changes from 7967731..b9e0ea0

b9e0ea0 Merge commit '7fa9d8bdea3773d1195b04d98fcf27cf48ddd81d' as 'tool/mbed/mbed-sdk'
7fa9d8b Squashed 'tool/mbed/mbed-sdk/' content from commit 7c21ce5

git-subtree-dir: tmk_core
git-subtree-split: b9e0ea08cb940de20b3610ecdda18e9d8cd7c552

tool/mbed/mbed-sdk/libraries/tests/libs/SerialHalfDuplex/SerialHalfDuplex.cpp

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+/* mbed Microcontroller Library - SerialHalfDuplex
+ * Copyright (c) 2010-2011 ARM Limited. All rights reserved.
+ */
+#include "SerialHalfDuplex.h"
+
+#if DEVICE_SERIAL
+
+#include "pinmap.h"
+#include "serial_api.h"
+
+namespace mbed {
+
+SerialHalfDuplex::SerialHalfDuplex(PinName tx, PinName rx)
+    : Serial(tx, rx) {
+
+    gpio_init(&gpio, tx, PIN_INPUT);
+    gpio_mode(&gpio, PullNone); // no pull
+}
+
+// To transmit a byte in half duplex mode:
+// 1. Disable interrupts, so we don't trigger on loopback byte
+// 2. Set tx pin to UART out
+// 3. Transmit byte as normal
+// 4. Read back byte from looped back tx pin - this both confirms that the
+//    transmit has occurred, and also clears the byte from the buffer.
+// 5. Return pin to input mode
+// 6. Re-enable interrupts
+int SerialHalfDuplex::_putc(int c) {
+    int retc;
+
+    // TODO: We should not disable all interrupts
+    __disable_irq();
+
+    serial_pinout_tx(gpio.pin);
+
+    Serial::_putc(c);
+    retc = Serial::getc();       // reading also clears any interrupt
+
+    pin_function(gpio.pin, 0);
+
+    __enable_irq();
+
+    return retc;
+}
+
+int SerialHalfDuplex::_getc(void) {
+    return Serial::_getc();
+}
+
+} // End namespace
+
+#endif

tool/mbed/mbed-sdk/libraries/tests/libs/SerialHalfDuplex/SerialHalfDuplex.h

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+/* mbed Microcontroller Library - SerialHalfDuplex
+ * Copyright (c) 2010-2011 ARM Limited. All rights reserved.
+ */
+#ifndef MBED_SERIALHALFDUPLEX_H
+#define MBED_SERIALHALFDUPLEX_H
+
+#include "platform.h"
+
+#if DEVICE_SERIAL
+
+#include "Serial.h"
+#include "gpio_api.h"
+
+namespace mbed {
+
+/** A serial port (UART) for communication with other devices using
+ * Half-Duplex, allowing transmit and receive on a single
+ * shared transmit and receive line. Only one end should be transmitting
+ * at a time.
+ *
+ * Both the tx and rx pin should be defined, and wired together.
+ * This is in addition to them being wired to the other serial
+ * device to allow both read and write functions to operate.
+ *
+ *  For Simplex and Full-Duplex Serial communication, see Serial()
+ *
+ *  Example:
+ * @code
+ * // Send a byte to a second HalfDuplex device, and read the response
+ *
+ * #include "mbed.h"
+ *
+ * // p9 and p10 should be wired together to form "a"
+ * // p28 and p27 should be wired together to form "b"
+ * // p9/p10 should be wired to p28/p27 as the Half Duplex connection
+ *
+ * SerialHalfDuplex a(p9, p10);
+ * SerialHalfDuplex b(p28, p27);
+ *
+ * void b_rx() { // second device response
+ *     b.putc(b.getc() + 4);
+ * }
+ *
+ * int main() {
+ *     b.attach(&b_rx);
+ *     for (int c = 'A'; c < 'Z'; c++) {
+ *         a.putc(c);
+ *         printf("sent [%c]\n", c);
+ *         wait(0.5);   // b should respond
+ *         if (a.readable()) {
+ *             printf("received [%c]\n", a.getc());
+ *         }
+ *     }
+ * }
+ * @endcode
+ */
+class SerialHalfDuplex : public Serial {
+
+public:
+    /** Create a half-duplex serial port, connected to the specified transmit
+     * and receive pins.
+     *
+     * These pins should be wired together, as well as to the target device
+     *
+     *  @param tx Transmit pin
+     *  @param rx Receive pin
+     */
+    SerialHalfDuplex(PinName tx, PinName rx);
+
+protected:
+    gpio_object gpio;
+
+    virtual int _putc(int c);
+    virtual int _getc(void);
+
+}; // End class SerialHalfDuplex
+
+} // End namespace
+
+#endif
+
+#endif