File content as of revision 7:fa32602e23ec:

#if 0
/* mbed Microcontroller Library
 *******************************************************************************
 * Copyright (c) 2014, 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
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * 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.
 *******************************************************************************
 */
#include "rtc_api.h"

#if DEVICE_RTC

#include "mbed_error.h"

static int rtc_inited = 0;

static RTC_HandleTypeDef RtcHandle;

//#define ORIGINAL
#if defined(ORIGINAL)
#warning "You cannot use SetRTC functions"
#else
#warning "You modified mbed-src rtc_api.c for SetRTC functions"
#endif

#if defined(ORIGINAL)   // modify part1 of 4 (Start)
#else
#define RTC_DAT0    0x55aa55aa
#define RTC_DAT1    0xaa55aa55

uint32_t RTC_ReadBackupRegister(uint32_t RTC_BKP_DR)
{
    __IO uint32_t tmp = 0;

    // Check the parameters
    assert_param(IS_RTC_BKP(RTC_BKP_DR));
    tmp = RTC_BASE + 0x50;
    tmp += (RTC_BKP_DR * 4);
    // Read the specified register
    return (*(__IO uint32_t *)tmp);
}

/* Check RTC Backup registers contents */
uint32_t Check_Rtc_backup_reg( void )
{
    if ( RTC_ReadBackupRegister( RTC_BKP_DR0 ) == RTC_DAT0 ) {
        if ( RTC_ReadBackupRegister( RTC_BKP_DR1 ) == RTC_DAT1 ) {
            return 1;
        }
    }
    return 0;
}

void RTC_WriteBackupRegister(uint32_t RTC_BKP_DR, uint32_t Data)
{
    __IO uint32_t tmp = 0;

    // Check the parameters/
    assert_param(IS_RTC_BKP(RTC_BKP_DR));
    tmp = RTC_BASE + 0x50;
    tmp += (RTC_BKP_DR * 4);
    // Write the specified register/
    *(__IO uint32_t *)tmp = (uint32_t)Data;
}
#endif   // modify part1 of 4 (End)

void rtc_init(void)
{
    RCC_OscInitTypeDef RCC_OscInitStruct;
    uint32_t rtc_freq = 0;

#if defined(ORIGINAL)   // modify part2 of 4 (Start)
    if (rtc_inited) return;
    rtc_inited = 1;

    RtcHandle.Instance = RTC;

    // Enable Power clock
    __PWR_CLK_ENABLE();

    // Enable access to Backup domain
    HAL_PWR_EnableBkUpAccess();
#else
    RtcHandle.Instance = RTC;

    // Enable Power clock
    __PWR_CLK_ENABLE();

    // Enable access to Backup domain
    HAL_PWR_EnableBkUpAccess();

    // Check backup condition
    if ( Check_Rtc_backup_reg() ) {
        return;
    }
#endif   // modify part2 of 4 (End)

    // Reset Backup domain
    __HAL_RCC_BACKUPRESET_FORCE();
    __HAL_RCC_BACKUPRESET_RELEASE();

    // Enable LSE Oscillator
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE;
    RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE; // Mandatory, otherwise the PLL is reconfigured!
    RCC_OscInitStruct.LSEState       = RCC_LSE_ON; // External 32.768 kHz clock on OSC_IN/OSC_OUT
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) == HAL_OK) {
        // Connect LSE to RTC
        __HAL_RCC_RTC_CLKPRESCALER(RCC_RTCCLKSOURCE_LSE);
        __HAL_RCC_RTC_CONFIG(RCC_RTCCLKSOURCE_LSE);
        rtc_freq = LSE_VALUE;
    } else {
        // Enable LSI clock
        RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI | RCC_OSCILLATORTYPE_LSE;
        RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE; // Mandatory, otherwise the PLL is reconfigured!
        RCC_OscInitStruct.LSEState       = RCC_LSE_OFF;
        RCC_OscInitStruct.LSIState       = RCC_LSI_ON;
        if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
            error("RTC error: LSI clock initialization failed.");
        }
        // Connect LSI to RTC
        __HAL_RCC_RTC_CLKPRESCALER(RCC_RTCCLKSOURCE_LSI);
        __HAL_RCC_RTC_CONFIG(RCC_RTCCLKSOURCE_LSI);
        // This value is LSI typical value. To be measured precisely using a timer input capture for example.
        rtc_freq = 40000;
    }

    // Enable RTC
    __HAL_RCC_RTC_ENABLE();

    RtcHandle.Init.HourFormat     = RTC_HOURFORMAT_24;
#ifdef TARGET_MOTE_L152RC
    /* SubSecond resolution of 16384Hz */
    RtcHandle.Init.AsynchPrediv   = 1;
    RtcHandle.Init.SynchPrediv    = (rtc_freq / 2) - 1;
#else
    RtcHandle.Init.AsynchPrediv   = 127;
    RtcHandle.Init.SynchPrediv    = (rtc_freq / 128) - 1;
#endif
    RtcHandle.Init.OutPut         = RTC_OUTPUT_DISABLE;
    RtcHandle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
    RtcHandle.Init.OutPutType     = RTC_OUTPUT_TYPE_OPENDRAIN;

#if defined(ORIGINAL)   // modify part3 of 4 (Start)
#else
    /* Write backup data into the backup RAM */
    RTC_WriteBackupRegister( RTC_BKP_DR0, RTC_DAT0 );
    RTC_WriteBackupRegister( RTC_BKP_DR1, RTC_DAT1 );
#endif   // modify part3 of 4 (End)

    if (HAL_RTC_Init(&RtcHandle) != HAL_OK) {
        error("RTC error: RTC initialization failed.");
    }
}

void rtc_free(void)
{
    // Enable Power clock
    __PWR_CLK_ENABLE();

    // Enable access to Backup domain
    HAL_PWR_EnableBkUpAccess();

    // Reset Backup domain
    __HAL_RCC_BACKUPRESET_FORCE();
    __HAL_RCC_BACKUPRESET_RELEASE();

    // Disable access to Backup domain
    HAL_PWR_DisableBkUpAccess();

    // Disable LSI and LSE clocks
    RCC_OscInitTypeDef RCC_OscInitStruct;
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI | RCC_OSCILLATORTYPE_LSE;
    RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE;
    RCC_OscInitStruct.LSIState       = RCC_LSI_OFF;
    RCC_OscInitStruct.LSEState       = RCC_LSE_OFF;
    HAL_RCC_OscConfig(&RCC_OscInitStruct);

    rtc_inited = 0;
}

int rtc_isenabled(void)
{
#if defined(ORIGINAL)   // modify part4 of 4 (Start)
    return rtc_inited;
#else
    return Check_Rtc_backup_reg();
#endif   // modify part4 of 4 (End)
}

/*
 RTC Registers
   RTC_WeekDay 1=monday, 2=tuesday, ..., 7=sunday
   RTC_Month   1=january, 2=february, ..., 12=december
   RTC_Date    day of the month 1-31
   RTC_Year    year 0-99
 struct tm
   tm_sec      seconds after the minute 0-61
   tm_min      minutes after the hour 0-59
   tm_hour     hours since midnight 0-23
   tm_mday     day of the month 1-31
   tm_mon      months since January 0-11
   tm_year     years since 1900
   tm_wday     days since Sunday 0-6
   tm_yday     days since January 1 0-365
   tm_isdst    Daylight Saving Time flag
*/
time_t rtc_read(void)
{
    RTC_DateTypeDef dateStruct;
    RTC_TimeTypeDef timeStruct;
    struct tm timeinfo;

    RtcHandle.Instance = RTC;

    // Read actual date and time
    // Warning: the time must be read first!
    HAL_RTC_GetTime(&RtcHandle, &timeStruct, FORMAT_BIN);
    HAL_RTC_GetDate(&RtcHandle, &dateStruct, FORMAT_BIN);

    // Setup a tm structure based on the RTC
    timeinfo.tm_wday = dateStruct.WeekDay;
    timeinfo.tm_mon  = dateStruct.Month - 1;
    timeinfo.tm_mday = dateStruct.Date;
    timeinfo.tm_year = dateStruct.Year + 100;
    timeinfo.tm_hour = timeStruct.Hours;
    timeinfo.tm_min  = timeStruct.Minutes;
    timeinfo.tm_sec  = timeStruct.Seconds;

    // Convert to timestamp
    time_t t = mktime(&timeinfo);

    return t;
}

void rtc_write(time_t t)
{
    RTC_DateTypeDef dateStruct;
    RTC_TimeTypeDef timeStruct;

    RtcHandle.Instance = RTC;

    // Convert the time into a tm
    struct tm *timeinfo = localtime(&t);

    // Fill RTC structures
    dateStruct.WeekDay        = timeinfo->tm_wday;
    dateStruct.Month          = timeinfo->tm_mon + 1;
    dateStruct.Date           = timeinfo->tm_mday;
    dateStruct.Year           = timeinfo->tm_year - 100;
    timeStruct.Hours          = timeinfo->tm_hour;
    timeStruct.Minutes        = timeinfo->tm_min;
    timeStruct.Seconds        = timeinfo->tm_sec;
    timeStruct.TimeFormat     = RTC_HOURFORMAT12_PM;
    timeStruct.DayLightSaving = RTC_DAYLIGHTSAVING_NONE;
    timeStruct.StoreOperation = RTC_STOREOPERATION_RESET;

    // Change the RTC current date/time
    HAL_RTC_SetDate(&RtcHandle, &dateStruct, FORMAT_BIN);
    HAL_RTC_SetTime(&RtcHandle, &timeStruct, FORMAT_BIN);
}

#endif

#endif