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