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Dependents: ros_lib_kinetic ds
BufferedSerial.cpp
00001 /** 00002 * @file BufferedSerial.cpp 00003 * @brief Software Buffer - Extends mbed Serial functionallity adding irq driven TX and RX 00004 * @author sam grove 00005 * @version 1.0 00006 * @see 00007 * 00008 * Copyright (c) 2013 00009 * 00010 * Licensed under the Apache License, Version 2.0 (the "License"); 00011 * you may not use this file except in compliance with the License. 00012 * You may obtain a copy of the License at 00013 * 00014 * http://www.apache.org/licenses/LICENSE-2.0 00015 * 00016 * Unless required by applicable law or agreed to in writing, software 00017 * distributed under the License is distributed on an "AS IS" BASIS, 00018 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 00019 * See the License for the specific language governing permissions and 00020 * limitations under the License. 00021 */ 00022 00023 #include "BufferedSerial.h" 00024 #include <stdarg.h> 00025 00026 BufferedSerial::BufferedSerial(PinName tx, PinName rx, uint32_t buf_size, uint32_t tx_multiple, const char* name) 00027 : RawSerial(tx, rx) , _rxbuf(buf_size), _txbuf((uint32_t)(tx_multiple*buf_size)) 00028 { 00029 RawSerial::attach(this, &BufferedSerial::rxIrq, Serial::RxIrq); 00030 this->_buf_size = buf_size; 00031 this->_tx_multiple = tx_multiple; 00032 return; 00033 } 00034 00035 BufferedSerial::~BufferedSerial(void) 00036 { 00037 RawSerial::attach(NULL, RawSerial::RxIrq); 00038 RawSerial::attach(NULL, RawSerial::TxIrq); 00039 00040 return; 00041 } 00042 00043 int BufferedSerial::readable(void) 00044 { 00045 return _rxbuf.available(); // note: look if things are in the buffer 00046 } 00047 00048 int BufferedSerial::writeable(void) 00049 { 00050 return 1; // buffer allows overwriting by design, always true 00051 } 00052 00053 int BufferedSerial::getc(void) 00054 { 00055 return _rxbuf; 00056 } 00057 00058 int BufferedSerial::putc(int c) 00059 { 00060 _txbuf = (char)c; 00061 BufferedSerial::prime(); 00062 00063 return c; 00064 } 00065 00066 int BufferedSerial::puts(const char *s) 00067 { 00068 if (s != NULL) { 00069 const char* ptr = s; 00070 00071 while(*(ptr) != 0) { 00072 _txbuf = *(ptr++); 00073 } 00074 _txbuf = '\n'; // done per puts definition 00075 BufferedSerial::prime(); 00076 00077 return (ptr - s) + 1; 00078 } 00079 return 0; 00080 } 00081 00082 int BufferedSerial::printf(const char* format, ...) 00083 { 00084 char buffer[this->_buf_size]; 00085 memset(buffer,0,this->_buf_size); 00086 int r = 0; 00087 00088 va_list arg; 00089 va_start(arg, format); 00090 r = vsprintf(buffer, format, arg); 00091 // this may not hit the heap but should alert the user anyways 00092 if(r > this->_buf_size) { 00093 error("%s %d buffer overwrite (max_buf_size: %d exceeded: %d)!\r\n", __FILE__, __LINE__,this->_buf_size,r); 00094 va_end(arg); 00095 return 0; 00096 } 00097 va_end(arg); 00098 r = BufferedSerial::write(buffer, r); 00099 00100 return r; 00101 } 00102 00103 ssize_t BufferedSerial::write(const void *s, size_t length) 00104 { 00105 if (s != NULL && length > 0) { 00106 const char* ptr = (const char*)s; 00107 const char* end = ptr + length; 00108 00109 while (ptr != end) { 00110 _txbuf = *(ptr++); 00111 } 00112 BufferedSerial::prime(); 00113 00114 return ptr - (const char*)s; 00115 } 00116 return 0; 00117 } 00118 00119 00120 void BufferedSerial::rxIrq(void) 00121 { 00122 // read from the peripheral and make sure something is available 00123 if(serial_readable(&_serial)) { 00124 _rxbuf = serial_getc(&_serial); // if so load them into a buffer 00125 } 00126 00127 return; 00128 } 00129 00130 void BufferedSerial::txIrq(void) 00131 { 00132 // see if there is room in the hardware fifo and if something is in the software fifo 00133 while(serial_writable(&_serial)) { 00134 if(_txbuf.available()) { 00135 serial_putc(&_serial, (int)_txbuf.get()); 00136 } else { 00137 // disable the TX interrupt when there is nothing left to send 00138 RawSerial::attach(NULL, RawSerial::TxIrq); 00139 break; 00140 } 00141 } 00142 00143 return; 00144 } 00145 00146 void BufferedSerial::prime(void) 00147 { 00148 // if already busy then the irq will pick this up 00149 if(serial_writable(&_serial)) { 00150 RawSerial::attach(NULL, RawSerial::TxIrq); // make sure not to cause contention in the irq 00151 BufferedSerial::txIrq(); // only write to hardware in one place 00152 RawSerial::attach(this, &BufferedSerial::txIrq, RawSerial::TxIrq); 00153 } 00154 00155 return; 00156 } 00157 00158
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