SerialWireOutput.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2017 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 
00017 #if defined(DEVICE_ITM)
00018 
00019 #include "hal/itm_api.h"
00020 #include "platform/FileHandle.h"
00021 
00022 namespace mbed {
00023   
00024 class SerialWireOutput : public FileHandle {
00025 
00026 public:
00027 
00028     SerialWireOutput(void)
00029     {
00030         /* Initialize ITM using internal init function. */
00031         mbed_itm_init();
00032     }
00033 
00034     virtual ssize_t write(const void *buffer, size_t size)
00035     {
00036         const unsigned char *buf = static_cast<const unsigned char *>(buffer);
00037 
00038         /* Send buffer one character at a time over the ITM SWO port */
00039         for (size_t i = 0; i < size; i++) {
00040             mbed_itm_send(ITM_PORT_SWO, buf[i]);
00041         }
00042         return size;
00043     }
00044 
00045     virtual ssize_t read(void *buffer, size_t size)
00046     {
00047         /* Reading is not supported by this file handle */
00048         return -EBADF;
00049     }
00050 
00051     virtual off_t seek(off_t offset, int whence = SEEK_SET)
00052     {
00053         /* Seeking is not support by this file handler */
00054         return -ESPIPE;
00055     }
00056 
00057     virtual off_t size()
00058     {
00059         /* Size is not defined for this file handle */
00060         return -EINVAL;
00061     }
00062 
00063     virtual int isatty()
00064     {
00065         /* File handle is used for terminal output */
00066         return true;
00067     }
00068 
00069     virtual int close()
00070     {
00071         return 0;
00072     }
00073 };
00074  
00075 } // namespace mbed
00076 
00077 #endif