RawSerial.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2013 ARM Limited
00003  * SPDX-License-Identifier: Apache-2.0
00004  *
00005  * Licensed under the Apache License, Version 2.0 (the "License");
00006  * you may not use this file except in compliance with the License.
00007  * You may obtain a copy of the License at
00008  *
00009  *     http://www.apache.org/licenses/LICENSE-2.0
00010  *
00011  * Unless required by applicable law or agreed to in writing, software
00012  * distributed under the License is distributed on an "AS IS" BASIS,
00013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00014  * See the License for the specific language governing permissions and
00015  * limitations under the License.
00016  */
00017 #include "drivers/RawSerial.h"
00018 #include "platform/mbed_wait_api.h"
00019 #include <stdio.h>
00020 #include <cstdarg>
00021 
00022 
00023 #if DEVICE_SERIAL
00024 
00025 #define STRING_STACK_LIMIT    120
00026 
00027 namespace mbed {
00028 
00029 RawSerial::RawSerial(PinName tx, PinName rx, int baud) : SerialBase(tx, rx, baud)
00030 {
00031     // No lock needed in the constructor
00032 }
00033 
00034 int RawSerial::getc()
00035 {
00036     lock();
00037     int ret = _base_getc();
00038     unlock();
00039     return ret;
00040 }
00041 
00042 int RawSerial::putc(int c)
00043 {
00044     lock();
00045     int ret = _base_putc(c);
00046     unlock();
00047     return ret;
00048 }
00049 
00050 int RawSerial::puts(const char *str)
00051 {
00052     lock();
00053     while (*str) {
00054         putc(*str ++);
00055     }
00056     unlock();
00057     return 0;
00058 }
00059 
00060 // Experimental support for printf in RawSerial. No Stream inheritance
00061 // means we can't call printf() directly, so we use sprintf() instead.
00062 // We only call malloc() for the sprintf() buffer if the buffer
00063 // length is above a certain threshold, otherwise we use just the stack.
00064 int RawSerial::printf(const char *format, ...)
00065 {
00066     lock();
00067     std::va_list arg;
00068     va_start(arg, format);
00069     // ARMCC microlib does not properly handle a size of 0.
00070     // As a workaround supply a dummy buffer with a size of 1.
00071     char dummy_buf[1];
00072     int len = vsnprintf(dummy_buf, sizeof(dummy_buf), format, arg);
00073     if (len < STRING_STACK_LIMIT) {
00074         char temp[STRING_STACK_LIMIT];
00075         vsprintf(temp, format, arg);
00076         puts(temp);
00077     } else {
00078         char *temp = new char[len + 1];
00079         vsprintf(temp, format, arg);
00080         puts(temp);
00081         delete[] temp;
00082     }
00083     va_end(arg);
00084     unlock();
00085     return len;
00086 }
00087 
00088 /** Acquire exclusive access to this serial port
00089  */
00090 void RawSerial::lock()
00091 {
00092     // No lock used - external synchronization required
00093 }
00094 
00095 /** Release exclusive access to this serial port
00096  */
00097 void RawSerial::unlock()
00098 {
00099     // No lock used - external synchronization required
00100 }
00101 
00102 } // namespace mbed
00103 
00104 #endif