Timer.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2019 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/Timer.h"
00018 #include "hal/ticker_api.h"
00019 #include "hal/us_ticker_api.h"
00020 #include "platform/mbed_critical.h"
00021 #include "platform/mbed_power_mgmt.h"
00022 
00023 namespace mbed {
00024 
00025 Timer::Timer() : _running(), _start(), _time(), _ticker_data(get_us_ticker_data()), _lock_deepsleep(true)
00026 {
00027     reset();
00028 }
00029 
00030 Timer::Timer(const ticker_data_t *data) : _running(), _start(), _time(), _ticker_data(data),
00031     _lock_deepsleep(!data->interface->runs_in_deep_sleep)
00032 {
00033     reset();
00034 }
00035 
00036 Timer::~Timer()
00037 {
00038     core_util_critical_section_enter();
00039     if (_running) {
00040         if (_lock_deepsleep) {
00041             sleep_manager_unlock_deep_sleep();
00042         }
00043     }
00044     _running = 0;
00045     core_util_critical_section_exit();
00046 }
00047 
00048 void Timer::start()
00049 {
00050     core_util_critical_section_enter();
00051     if (!_running) {
00052         if (_lock_deepsleep) {
00053             sleep_manager_lock_deep_sleep();
00054         }
00055         _start = ticker_read_us(_ticker_data);
00056         _running = 1;
00057     }
00058     core_util_critical_section_exit();
00059 }
00060 
00061 void Timer::stop()
00062 {
00063     core_util_critical_section_enter();
00064     _time += slicetime();
00065     if (_running) {
00066         if (_lock_deepsleep) {
00067             sleep_manager_unlock_deep_sleep();
00068         }
00069     }
00070     _running = 0;
00071     core_util_critical_section_exit();
00072 }
00073 
00074 int Timer::read_us()
00075 {
00076     return read_high_resolution_us();
00077 }
00078 
00079 float Timer::read()
00080 {
00081     return (float)read_high_resolution_us() / 1000000.0f;
00082 }
00083 
00084 int Timer::read_ms()
00085 {
00086     return read_high_resolution_us() / 1000;
00087 }
00088 
00089 us_timestamp_t Timer::read_high_resolution_us()
00090 {
00091     core_util_critical_section_enter();
00092     us_timestamp_t time = _time + slicetime();
00093     core_util_critical_section_exit();
00094     return time;
00095 }
00096 
00097 us_timestamp_t Timer::slicetime()
00098 {
00099     us_timestamp_t ret = 0;
00100     core_util_critical_section_enter();
00101     if (_running) {
00102         ret = ticker_read_us(_ticker_data) - _start;
00103     }
00104     core_util_critical_section_exit();
00105     return ret;
00106 }
00107 
00108 void Timer::reset()
00109 {
00110     core_util_critical_section_enter();
00111     _start = ticker_read_us(_ticker_data);
00112     _time = 0;
00113     core_util_critical_section_exit();
00114 }
00115 
00116 Timer::operator float()
00117 {
00118     return read();
00119 }
00120 
00121 } // namespace mbed