mbed-os/targets/TARGET_STM/rtc_api_hal.h

/* mbed Microcontroller Library
*******************************************************************************
* Copyright (c) 2017, STMicroelectronics
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
*    this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
*    this list of conditions and the following disclaimer in the documentation
*    and/or other materials provided with the distribution.
* 3. Neither the name of STMicroelectronics nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*******************************************************************************
*/

#ifndef MBED_RTC_API_HAL_H
#define MBED_RTC_API_HAL_H

#include <stdint.h>
#include "rtc_api.h"
#include "ticker_api.h"
#include "lp_ticker_api.h"
#include "us_ticker_api.h"
#include "hal_tick.h"
#include "mbed_critical.h"
#include "mbed_error.h"
#include "mbed_debug.h"

#ifdef __cplusplus
extern "C" {
#endif

#if MBED_CONF_TARGET_LSE_AVAILABLE
#define RTC_CLOCK LSE_VALUE
#else
#define RTC_CLOCK LSI_VALUE
#endif

/* PREDIV_A : 7-bit asynchronous prescaler */
/* PREDIV_S : 15-bit synchronous prescaler */
/* PREDIV_S is set in order to get a 1 Hz clock */
#if DEVICE_LPTICKER && !MBED_CONF_TARGET_LPTICKER_LPTIM
/* PREDIV_A is set to a small value to improve the SubSeconds resolution */
/* with a 32768Hz clock, PREDIV_A=7 gives a precision of 244us */
#define PREDIV_A_VALUE 7
#else /* DEVICE_LPTICKER && !MBED_CONF_TARGET_LPTICKER_LPTIM */
/* PREDIV_A is set to the maximum value to improve the consumption */
#define PREDIV_A_VALUE 127
#endif /* DEVICE_LPTICKER && !MBED_CONF_TARGET_LPTICKER_LPTIM */

#define PREDIV_S_VALUE RTC_CLOCK / (PREDIV_A_VALUE + 1) - 1

/** Read RTC time with subsecond precision.
 *
 * @return Time is microsecond
 */
uint32_t rtc_read_us(void);

/** Program a wake up timer event in delta microseconds.
 *
 * @param delta    The time to wait
 */
void rtc_set_wake_up_timer(uint32_t delta);

/** Disable the wake up timer event.
 *
 * The wake up timer use auto reload, you have to deactivate it manually.
 */
void rtc_deactivate_wake_up_timer(void);

/** Synchronise the RTC shadow registers.
 *
 * Must be called after a deepsleep.
 */
void rtc_synchronize(void);


#ifdef __cplusplus
}
#endif

#endif