mbed-os/drivers/LowPowerClock.h

69 lines
2.0 KiB
C++

/* mbed Microcontroller Library
* Copyright (c) 2006-2019 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef MBED_LOWPOWERCLOCK_H
#define MBED_LOWPOWERCLOCK_H
#include <chrono>
#if DEVICE_LPTICKER
#include "hal/lp_ticker_api.h"
namespace mbed {
/**
* \defgroup drivers_LowPowerClock LowPowerClock class
* \ingroup drivers-public-api-ticker
* @{
*/
/**
* A C++11 Clock representing the HAL lp_ticker.
*
* Dummy lock/unlock methods are provided to have the same generic API
* as UnlockedHighPowerClock. No action is required as the lp_ticker
* runs continuously.
*/
class LowPowerClock {
public:
/* duration is C++11 standard microseconds, so representation will be 64-bit signed integer */
using duration = std::chrono::microseconds;
using rep = duration::rep;
using period = duration::period;
using time_point = std::chrono::time_point<LowPowerClock>;
static const bool is_steady = true;
/** Read the current time */
static time_point now()
{
return time_point{duration{ticker_read_us(get_lp_ticker_data())}};
}
/** Lock the clock to ensure it stays running; dummy for API compatibility with HighResClock */
static void lock()
{
}
/** Unlock the clock, allowing it to stop during power saving; dummy for API compatibility with HighResClock */
static void unlock()
{
}
};
/** @}*/
}
#endif /* DEVICE_LPTICKER */
#endif /* MBED_LOWPOWERCLOCK_H */