tmk_core/tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32F3XX/rtc_api.c

   1 /* mbed Microcontroller Library
   2  *******************************************************************************
   3  * Copyright (c) 2014, STMicroelectronics
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright notice,
  10  *    this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright notice,
  12  *    this list of conditions and the following disclaimer in the documentation
  13  *    and/or other materials provided with the distribution.
  14  * 3. Neither the name of STMicroelectronics nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  25  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  27  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  *******************************************************************************
  29  */
  30 #include "rtc_api.h"
  31
  32 static int rtc_inited = 0;
  33
  34 void rtc_init(void) {
  35     RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE); // Enable PWR clock
  36
  37     PWR_BackupAccessCmd(ENABLE); // Enable access to RTC
  38
  39     // Be sure to start correctly
  40     RCC_BackupResetCmd(ENABLE);
  41     RCC_BackupResetCmd(DISABLE);
  42
  43     // Note: the LSI is used as RTC source clock
  44     // The RTC Clock may vary due to LSI frequency dispersion.
  45     RCC_LSICmd(ENABLE); // Enable LSI
  46
  47     while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET) {} // Wait until ready
  48
  49     RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI); // Select LSI as RTC Clock Source
  50
  51     RCC_RTCCLKCmd(ENABLE); // Enable RTC Clock
  52
  53     RTC_WaitForSynchro(); // Wait for RTC registers synchronization
  54
  55     uint32_t lsi_freq = 40000; // [TODO] To be measured precisely using a timer input capture
  56
  57     RTC_InitTypeDef RTC_InitStructure;
  58     RTC_InitStructure.RTC_AsynchPrediv = 127;
  59     RTC_InitStructure.RTC_SynchPrediv  = (lsi_freq / 128) - 1;
  60     RTC_InitStructure.RTC_HourFormat   = RTC_HourFormat_24;
  61     RTC_Init(&RTC_InitStructure);
  62
  63     rtc_inited = 1;
  64 }
  65
  66 void rtc_free(void) {
  67     RCC_DeInit(); // Resets the RCC clock configuration to the default reset state
  68     rtc_inited = 0;
  69 }
  70
  71 int rtc_isenabled(void) {
  72     return rtc_inited;
  73 }
  74
  75 /*
  76  RTC Registers
  77    RTC_WeekDay 1=monday, 2=tuesday, ..., 7=sunday
  78    RTC_Month   1=january, 2=february, ..., 12=december
  79    RTC_Date    day of the month 1-31
  80    RTC_Year    year 0-99
  81  struct tm
  82    tm_sec      seconds after the minute 0-61
  83    tm_min      minutes after the hour 0-59
  84    tm_hour     hours since midnight 0-23
  85    tm_mday     day of the month 1-31
  86    tm_mon      months since January 0-11
  87    tm_year     years since 1900
  88    tm_wday     days since Sunday 0-6
  89    tm_yday     days since January 1 0-365
  90    tm_isdst    Daylight Saving Time flag
  91 */
  92 time_t rtc_read(void) {
  93     RTC_DateTypeDef dateStruct;
  94     RTC_TimeTypeDef timeStruct;
  95     struct tm timeinfo;
  96
  97     // Read actual date and time
  98     RTC_GetTime(RTC_Format_BIN, &timeStruct);
  99     RTC_GetDate(RTC_Format_BIN, &dateStruct);
 100
 101     // Setup a tm structure based on the RTC
 102     timeinfo.tm_wday = dateStruct.RTC_WeekDay;
 103     timeinfo.tm_mon  = dateStruct.RTC_Month - 1;
 104     timeinfo.tm_mday = dateStruct.RTC_Date;
 105     timeinfo.tm_year = dateStruct.RTC_Year + 100;
 106     timeinfo.tm_hour = timeStruct.RTC_Hours;
 107     timeinfo.tm_min  = timeStruct.RTC_Minutes;
 108     timeinfo.tm_sec  = timeStruct.RTC_Seconds;
 109
 110     // Convert to timestamp
 111     time_t t = mktime(&timeinfo);
 112
 113     return t;
 114 }
 115
 116 void rtc_write(time_t t) {
 117     RTC_DateTypeDef dateStruct;
 118     RTC_TimeTypeDef timeStruct;
 119
 120     // Convert the time into a tm
 121     struct tm *timeinfo = localtime(&t);
 122
 123     // Fill RTC structures
 124     dateStruct.RTC_WeekDay = timeinfo->tm_wday;
 125     dateStruct.RTC_Month   = timeinfo->tm_mon + 1;
 126     dateStruct.RTC_Date    = timeinfo->tm_mday;
 127     dateStruct.RTC_Year    = timeinfo->tm_year - 100;
 128     timeStruct.RTC_Hours   = timeinfo->tm_hour;
 129     timeStruct.RTC_Minutes = timeinfo->tm_min;
 130     timeStruct.RTC_Seconds = timeinfo->tm_sec;
 131     timeStruct.RTC_H12     = RTC_HourFormat_24;
 132
 133     // Change the RTC current date/time
 134     PWR_BackupAccessCmd(ENABLE); // Enable access to RTC
 135     RTC_SetDate(RTC_Format_BIN, &dateStruct);
 136     RTC_SetTime(RTC_Format_BIN, &timeStruct);
 137     PWR_BackupAccessCmd(DISABLE); // Disable access to RTC
 138 }