1 files changed, 237 insertions, 0 deletions
diff --git a/lib/msp430/HardwareSerial.cpp b/lib/msp430/HardwareSerial.cpp
new file mode 100644
index 0000000..1195262
--- /dev/null
+++ b/lib/msp430/HardwareSerial.cpp
@@ -0,0 +1,237 @@
+/*
+  ************************************************************************
+  *	HardwareSerial.cpp
+  *
+  *	Arduino core files for MSP430
+  *		Copyright (c) 2012 Robert Wessels. All right reserved.
+  *
+  *
+  ***********************************************************************
+  Derived from:
+  HardwareSerial.cpp - Hardware serial library for Wiring
+  Copyright (c) 2006 Nicholas Zambetti.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+  
+  Modified 23 November 2006 by David A. Mellis
+  Modified 28 September 2010 by Mark Sproul
+*/
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include "Energia.h"
+#include "wiring_private.h"
+#include "usci_isr_handler.h"
+
+#if defined(__MSP430_HAS_USCI__) || defined(__MSP430_HAS_EUSCI_A0__)
+
+#include "HardwareSerial.h"
+
+HardwareSerial *SerialPtr;
+
+
+
+#define SERIAL_BUFFER_SIZE 64
+
+struct ring_buffer
+{
+	unsigned char buffer[SERIAL_BUFFER_SIZE];
+	volatile unsigned int head;
+	volatile unsigned int tail;
+};
+
+ring_buffer rx_buffer  =  { { 0 }, 0, 0 };
+ring_buffer tx_buffer  =  { { 0 }, 0, 0 };
+
+inline void store_char(unsigned char c, ring_buffer *buffer)
+{
+	unsigned int i = (unsigned int)(buffer->head + 1) % SERIAL_BUFFER_SIZE;
+
+	// if we should be storing the received character into the location
+	// just before the tail (meaning that the head would advance to the
+	// current location of the tail), we're about to overflow the buffer
+	// and so we don't write the character or advance the head.
+	if (i != buffer->tail) {
+		buffer->buffer[buffer->head] = c;
+		buffer->head = i;
+	}
+}
+
+void serialEvent() __attribute__((weak));
+void serialEvent() {}
+
+void serialEventRun(void)
+{
+  if (Serial.available()) serialEvent();
+}
+// Constructors ////////////////////////////////////////////////////////////////
+
+HardwareSerial::HardwareSerial(ring_buffer *rx_buffer, ring_buffer *tx_buffer)
+{
+	_rx_buffer = rx_buffer;
+	_tx_buffer = tx_buffer;
+}
+
+// Public Methods //////////////////////////////////////////////////////////////
+#define SMCLK F_CPU //SMCLK = F_CPU for now
+
+void HardwareSerial::begin(unsigned long baud)
+{
+	unsigned int mod, divider;
+	unsigned char oversampling;
+	
+	/* Calling this dummy function prevents the linker
+	 * from stripping the USCI interupt vectors.*/ 
+	usci_isr_install();
+	if (SMCLK/baud>=48) {                                                // requires SMCLK for oversampling
+		oversampling = 1;
+	}
+	else {
+		oversampling= 0;
+	}
+
+	divider=(SMCLK<<4)/baud;
+
+	SerialPtr = this;
+
+	pinMode_int(UARTRXD, UARTRXD_SET_MODE);
+	pinMode_int(UARTTXD, UARTTXD_SET_MODE);	
+
+	UCA0CTL1 = UCSWRST;
+	UCA0CTL1 = UCSSEL_2;                                // SMCLK
+	UCA0CTL0 = 0;
+	UCA0ABCTL = 0;
+#if defined(__MSP430_HAS_EUSCI_A0__)
+	if(!oversampling) {
+		mod = ((divider&0xF)+1)&0xE;                    // UCBRSx (bit 1-3)
+		divider >>=4;
+	} else {
+		mod = divider&0xFFF0;                           // UCBRFx = INT([(N/16) – INT(N/16)] × 16)
+		divider>>=8;
+	}
+	UCA0BR0 = divider;
+	UCA0BR1 = divider>>8;
+	UCA0MCTLW = (oversampling ? UCOS16:0) | mod;
+#else
+	if(!oversampling) {
+		mod = ((divider&0xF)+1)&0xE;                    // UCBRSx (bit 1-3)
+		divider >>=4;
+	} else {
+		mod = ((divider&0xf8)+0x8)&0xf0;                // UCBRFx (bit 4-7)
+		divider>>=8;
+	}
+	UCA0BR0 = divider;
+	UCA0BR1 = divider>>8;
+	UCA0MCTL = (unsigned char)(oversampling ? UCOS16:0) | mod;
+#endif	
+	UCA0CTL1 &= ~UCSWRST;
+#if defined(__MSP430_HAS_EUSCI_A0__)
+	UCA0IE |= UCRXIE;
+#else
+	UC0IE |= UCA0RXIE;
+#endif	
+}
+
+void HardwareSerial::end()
+{
+	// wait for transmission of outgoing data
+	while (_tx_buffer->head != _tx_buffer->tail);
+
+	_rx_buffer->head = _rx_buffer->tail;
+}
+
+int HardwareSerial::available(void)
+{
+	return (unsigned int)(SERIAL_BUFFER_SIZE + _rx_buffer->head - _rx_buffer->tail) % SERIAL_BUFFER_SIZE;
+}
+
+int HardwareSerial::peek(void)
+{
+	if (_rx_buffer->head == _rx_buffer->tail) {
+		return -1;
+	} else {
+		return _rx_buffer->buffer[_rx_buffer->tail];
+	}
+}
+
+int HardwareSerial::read(void)
+{
+	// if the head isn't ahead of the tail, we don't have any characters
+	if (_rx_buffer->head == _rx_buffer->tail) {
+		return -1;
+	} else {
+		unsigned char c = _rx_buffer->buffer[_rx_buffer->tail];
+		_rx_buffer->tail = (unsigned int)(_rx_buffer->tail + 1) % SERIAL_BUFFER_SIZE;
+		return c;
+	}
+}
+
+void HardwareSerial::flush()
+{
+	while (_tx_buffer->head != _tx_buffer->tail);
+}
+
+size_t HardwareSerial::write(uint8_t c)
+{
+	unsigned int i = (_tx_buffer->head + 1) % SERIAL_BUFFER_SIZE;
+	
+	// If the output buffer is full, there's nothing for it other than to
+	// wait for the interrupt handler to empty it a bit
+	// ???: return 0 here instead?
+	while (i == _tx_buffer->tail);
+	
+	_tx_buffer->buffer[_tx_buffer->head] = c;
+	_tx_buffer->head = i;
+
+#if defined(__MSP430_HAS_EUSCI_A0__)
+	UCA0IE |= UCTXIE;
+#else
+	UC0IE |= UCA0TXIE;
+#endif	
+
+	return 1;
+}
+
+void uart_rx_isr(void)
+{
+	unsigned char c = UCA0RXBUF;
+	store_char(c, &rx_buffer);
+}
+
+void uart_tx_isr(void)
+{
+	if (tx_buffer.head == tx_buffer.tail) {
+		// Buffer empty, so disable interrupts
+#if defined(__MSP430_HAS_EUSCI_A0__)
+		UCA0IE &= ~UCTXIE;
+		UCA0IFG |= UCTXIFG;    // Set Flag again
+#else
+		UC0IE &= ~UCA0TXIE;
+#endif	
+		return;
+	}
+
+	unsigned char c = tx_buffer.buffer[tx_buffer.tail];
+	tx_buffer.tail = (tx_buffer.tail + 1) % SERIAL_BUFFER_SIZE;
+	UCA0TXBUF = c;
+}
+
+// Preinstantiate Objects //////////////////////////////////////////////////////
+
+HardwareSerial Serial(&rx_buffer, &tx_buffer);
+
+#endif