Diff: BufferedSerial/BufferedSerial.cpp

Revision:

12:046346a16ff4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BufferedSerial/BufferedSerial.cpp	Sat May 19 15:42:38 2018 +0000
@@ -0,0 +1,158 @@
+/**
+ * @file    BufferedSerial.cpp
+ * @brief   Software Buffer - Extends mbed Serial functionallity adding irq driven TX and RX
+ * @author  sam grove
+ * @version 1.0
+ * @see
+ *
+ * Copyright (c) 2013
+ *
+ * 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.
+ */
+
+#include "BufferedSerial.h"
+#include <stdarg.h>
+
+BufferedSerial::BufferedSerial(PinName tx, PinName rx, uint32_t buf_size, uint32_t tx_multiple, const char* name)
+    : RawSerial(tx, rx) , _rxbuf(buf_size), _txbuf((uint32_t)(tx_multiple*buf_size))
+{
+    RawSerial::attach(this, &BufferedSerial::rxIrq, Serial::RxIrq);
+    this->_buf_size = buf_size;
+    this->_tx_multiple = tx_multiple;   
+    return;
+}
+
+BufferedSerial::~BufferedSerial(void)
+{
+    RawSerial::attach(NULL, RawSerial::RxIrq);
+    RawSerial::attach(NULL, RawSerial::TxIrq);
+
+    return;
+}
+
+int BufferedSerial::readable(void)
+{
+    return _rxbuf.available();  // note: look if things are in the buffer
+}
+
+int BufferedSerial::writeable(void)
+{
+    return 1;   // buffer allows overwriting by design, always true
+}
+
+int BufferedSerial::getc(void)
+{
+    return _rxbuf;
+}
+
+int BufferedSerial::putc(int c)
+{
+    _txbuf = (char)c;
+    BufferedSerial::prime();
+
+    return c;
+}
+
+int BufferedSerial::puts(const char *s)
+{
+    if (s != NULL) {
+        const char* ptr = s;
+    
+        while(*(ptr) != 0) {
+            _txbuf = *(ptr++);
+        }
+        _txbuf = '\n';  // done per puts definition
+        BufferedSerial::prime();
+    
+        return (ptr - s) + 1;
+    }
+    return 0;
+}
+
+int BufferedSerial::printf(const char* format, ...)
+{
+    char buffer[this->_buf_size];
+    memset(buffer,0,this->_buf_size);
+    int r = 0;
+
+    va_list arg;
+    va_start(arg, format);
+    r = vsprintf(buffer, format, arg);
+    // this may not hit the heap but should alert the user anyways
+    if(r > this->_buf_size) {
+        error("%s %d buffer overwrite (max_buf_size: %d exceeded: %d)!\r\n", __FILE__, __LINE__,this->_buf_size,r);
+        va_end(arg);
+        return 0;
+    }
+    va_end(arg);
+    r = BufferedSerial::write(buffer, r);
+
+    return r;
+}
+
+ssize_t BufferedSerial::write(const void *s, size_t length)
+{
+    if (s != NULL && length > 0) {
+        const char* ptr = (const char*)s;
+        const char* end = ptr + length;
+    
+        while (ptr != end) {
+            _txbuf = *(ptr++);
+        }
+        BufferedSerial::prime();
+    
+        return ptr - (const char*)s;
+    }
+    return 0;
+}
+
+
+void BufferedSerial::rxIrq(void)
+{
+    // read from the peripheral and make sure something is available
+    if(serial_readable(&_serial)) {
+        _rxbuf = serial_getc(&_serial); // if so load them into a buffer
+    }
+
+    return;
+}
+
+void BufferedSerial::txIrq(void)
+{
+    // see if there is room in the hardware fifo and if something is in the software fifo
+    while(serial_writable(&_serial)) {
+        if(_txbuf.available()) {
+            serial_putc(&_serial, (int)_txbuf.get());
+        } else {
+            // disable the TX interrupt when there is nothing left to send
+            RawSerial::attach(NULL, RawSerial::TxIrq);
+            break;
+        }
+    }
+
+    return;
+}
+
+void BufferedSerial::prime(void)
+{
+    // if already busy then the irq will pick this up
+    if(serial_writable(&_serial)) {
+        RawSerial::attach(NULL, RawSerial::TxIrq);    // make sure not to cause contention in the irq
+        BufferedSerial::txIrq();                // only write to hardware in one place
+        RawSerial::attach(this, &BufferedSerial::txIrq, RawSerial::TxIrq);
+    }
+
+    return;
+}
+
+