Timer.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/Timer.h"
00018 #include "hal/ticker_api.h"
00019 #include "hal/us_ticker_api.h"
00020 #include "platform/mbed_critical.h"
00021 #include "hal/lp_ticker_api.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), _lock_deepsleep(true)
00031 {
00032     reset();
00033 #if DEVICE_LPTICKER
00034     _lock_deepsleep = (data != get_lp_ticker_data());
00035 #endif
00036 }
00037 
00038 Timer::~Timer()
00039 {
00040     core_util_critical_section_enter();
00041     if (_running) {
00042         if (_lock_deepsleep) {
00043             sleep_manager_unlock_deep_sleep();
00044         }
00045     }
00046     _running = 0;
00047     core_util_critical_section_exit();
00048 }
00049 
00050 void Timer::start()
00051 {
00052     core_util_critical_section_enter();
00053     if (!_running) {
00054         if (_lock_deepsleep) {
00055             sleep_manager_lock_deep_sleep();
00056         }
00057         _start = ticker_read_us(_ticker_data);
00058         _running = 1;
00059     }
00060     core_util_critical_section_exit();
00061 }
00062 
00063 void Timer::stop()
00064 {
00065     core_util_critical_section_enter();
00066     _time += slicetime();
00067     if (_running) {
00068         if (_lock_deepsleep) {
00069             sleep_manager_unlock_deep_sleep();
00070         }
00071     }
00072     _running = 0;
00073     core_util_critical_section_exit();
00074 }
00075 
00076 int Timer::read_us()
00077 {
00078     return read_high_resolution_us();
00079 }
00080 
00081 float Timer::read()
00082 {
00083     return (float)read_high_resolution_us() / 1000000.0f;
00084 }
00085 
00086 int Timer::read_ms()
00087 {
00088     return read_high_resolution_us() / 1000;
00089 }
00090 
00091 us_timestamp_t Timer::read_high_resolution_us()
00092 {
00093     core_util_critical_section_enter();
00094     us_timestamp_t time = _time + slicetime();
00095     core_util_critical_section_exit();
00096     return time;
00097 }
00098 
00099 us_timestamp_t Timer::slicetime()
00100 {
00101     us_timestamp_t ret = 0;
00102     core_util_critical_section_enter();
00103     if (_running) {
00104         ret = ticker_read_us(_ticker_data) - _start;
00105     }
00106     core_util_critical_section_exit();
00107     return ret;
00108 }
00109 
00110 void Timer::reset()
00111 {
00112     core_util_critical_section_enter();
00113     _start = ticker_read_us(_ticker_data);
00114     _time = 0;
00115     core_util_critical_section_exit();
00116 }
00117 
00118 Timer::operator float()
00119 {
00120     return read();
00121 }
00122 
00123 } // namespace mbed