RawSerial.cpp

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