mbed-os/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/rtc_api.c

90 lines
2.2 KiB
C

/*
* Copyright (c) 2018 Arm Limited
*
* 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.
*/
#include "rtc_api.h"
#include "platform_devices.h"
#include "rtc_pl031_drv.h"
static uint32_t is_enabled = 0;
/**
* \defgroup hal_rtc RTC hal functions
* @{
*/
/**
* \brief Initialize the RTC peripheral.
* The RTC starts counting from 0x0 at reset and increments
* with a frequency of 1hz (clock source: CLK1HZ).
* The current value can be read through the DATA register
*/
void rtc_init(void)
{
rtc_pl031_init(&RTC_PL031_DEV);
rtc_pl031_dev_enable(&RTC_PL031_DEV);
is_enabled = 1;
}
/**
* \brief Deinitialize the RTC peripheral
* According to DDI0224B_RTC_PL031_TRM.pdf chapter 3.3.4 there is
* no reason to implement.
*/
void rtc_free(void)
{
is_enabled = 0;
}
/**
* \brief Get the RTC enable status
*
* \return 0 disabled, 1 enabled
*/
int rtc_isenabled(void)
{
return is_enabled;
}
/**
* \brief Get the current time from the RTC peripheral
*
* Sysclock and RTC clock may not be in sync which can cause reading
* out metastable values. It's usually prevented by adding a loop,
* however PL031 has a syncronisation block to prevent this, therefore
* no additional loop needed.
*
* \return The current time in seconds
*/
time_t rtc_read(void)
{
uint32_t val;
rtc_pl031_read_current_time(&RTC_PL031_DEV, &val);
return (time_t)val;
}
/**
* \brief Set the current time to the RTC peripheral, write it to LOAD register
*
* \param[in] t The current time to be set in seconds
*/
void rtc_write(time_t t)
{
rtc_pl031_write_current_time(&RTC_PL031_DEV, (uint32_t)t);
}
/**@}*/