tool/mbed/mbed-sdk/libraries/mbed/targets/hal/TARGET_STM/TARGET_STM32L0/TARGET_DISCO_L053C8/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 /* The mcu STM32L053C8 seems to have a problem in the RCC - LSE hardware block. The Disco_L053 don't have a 32kHz crystal connected to LSE port pins.
  33  * During initialization the HAL tests if it can start the LSE oscillator. The Flag LSERDY in RCC_CSR should be set to 1 by RCC clock control when
  34  * the oscillator runs stable. Without a crystal the flag shouldn't be set and the HAL trys to start the internal LSI oscillator.
  35  * But the flag is also set to 1 without a crystal. That's why the RTC doesn't start.
  36  *
  37  */
  38 #define DONT_USE_LSE
  39
  40 #if DEVICE_RTC
  41
  42 #include "mbed_error.h"
  43
  44 static int rtc_inited = 0;
  45
  46 static RTC_HandleTypeDef RtcHandle;
  47
  48 void rtc_init(void)
  49 {
  50     RCC_OscInitTypeDef RCC_OscInitStruct;
  51     uint32_t rtc_freq = 0;
  52
  53     if (rtc_inited) return;
  54     rtc_inited = 1;
  55
  56     RtcHandle.Instance = RTC;
  57
  58     // Enable Power clock
  59     __PWR_CLK_ENABLE();
  60
  61     // Enable access to Backup domain
  62     HAL_PWR_EnableBkUpAccess();
  63
  64     // Reset Backup domain
  65     __HAL_RCC_BACKUPRESET_FORCE();
  66     __HAL_RCC_BACKUPRESET_RELEASE();
  67
  68     // Enable LSE Oscillator
  69     RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE;
  70     RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE; // Mandatory, otherwise the PLL is reconfigured!
  71     RCC_OscInitStruct.LSEState       = RCC_LSE_ON; // External 32.768 kHz clock on OSC_IN/OSC_OUT
  72 #ifndef DONT_USE_LSE
  73     if (HAL_RCC_OscConfig(&RCC_OscInitStruct) == HAL_OK) {
  74         // Connect LSE to RTC
  75         __HAL_RCC_RTC_CLKPRESCALER(RCC_RTCCLKSOURCE_LSE);
  76         __HAL_RCC_RTC_CONFIG(RCC_RTCCLKSOURCE_LSE);
  77         rtc_freq = LSE_VALUE;
  78     } else {
  79 #endif
  80         // Enable LSI clock
  81         RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI | RCC_OSCILLATORTYPE_LSE;
  82         RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE; // Mandatory, otherwise the PLL is reconfigured!
  83         RCC_OscInitStruct.LSEState       = RCC_LSE_OFF;
  84         RCC_OscInitStruct.LSIState       = RCC_LSI_ON;
  85         if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
  86             error("RTC error: LSI clock initialization failed.");
  87         }
  88         // Connect LSI to RTC
  89         __HAL_RCC_RTC_CLKPRESCALER(RCC_RTCCLKSOURCE_LSI);
  90         __HAL_RCC_RTC_CONFIG(RCC_RTCCLKSOURCE_LSI);
  91         // This value is LSI typical value. To be measured precisely using a timer input capture for example.
  92         rtc_freq = 37000;
  93 #ifndef DONT_USE_LSE
  94     }
  95 #endif
  96
  97     // Enable RTC
  98     __HAL_RCC_RTC_ENABLE();
  99
 100     RtcHandle.Init.HourFormat     = RTC_HOURFORMAT_24;
 101     RtcHandle.Init.AsynchPrediv   = 127;
 102     RtcHandle.Init.SynchPrediv    = (rtc_freq / 128) - 1;
 103     RtcHandle.Init.OutPut         = RTC_OUTPUT_DISABLE;
 104     RtcHandle.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
 105     RtcHandle.Init.OutPutType     = RTC_OUTPUT_TYPE_OPENDRAIN;
 106
 107     if (HAL_RTC_Init(&RtcHandle) != HAL_OK) {
 108         error("RTC error: RTC initialization failed.");
 109     }
 110 }
 111
 112 void rtc_free(void)
 113 {
 114     // Enable Power clock
 115     __PWR_CLK_ENABLE();
 116
 117     // Enable access to Backup domain
 118     HAL_PWR_EnableBkUpAccess();
 119
 120     // Reset Backup domain
 121     __HAL_RCC_BACKUPRESET_FORCE();
 122     __HAL_RCC_BACKUPRESET_RELEASE();
 123
 124     // Disable access to Backup domain
 125     HAL_PWR_DisableBkUpAccess();
 126
 127     // Disable LSI and LSE clocks
 128     RCC_OscInitTypeDef RCC_OscInitStruct;
 129     RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI | RCC_OSCILLATORTYPE_LSE;
 130     RCC_OscInitStruct.PLL.PLLState   = RCC_PLL_NONE;
 131     RCC_OscInitStruct.LSIState       = RCC_LSI_OFF;
 132     RCC_OscInitStruct.LSEState       = RCC_LSE_OFF;
 133     HAL_RCC_OscConfig(&RCC_OscInitStruct);
 134
 135     rtc_inited = 0;
 136 }
 137
 138 int rtc_isenabled(void)
 139 {
 140     return rtc_inited;
 141 }
 142
 143 /*
 144  RTC Registers
 145    RTC_WeekDay 1=monday, 2=tuesday, ..., 7=sunday
 146    RTC_Month   1=january, 2=february, ..., 12=december
 147    RTC_Date    day of the month 1-31
 148    RTC_Year    year 0-99
 149  struct tm
 150    tm_sec      seconds after the minute 0-61
 151    tm_min      minutes after the hour 0-59
 152    tm_hour     hours since midnight 0-23
 153    tm_mday     day of the month 1-31
 154    tm_mon      months since January 0-11
 155    tm_year     years since 1900
 156    tm_wday     days since Sunday 0-6
 157    tm_yday     days since January 1 0-365
 158    tm_isdst    Daylight Saving Time flag
 159 */
 160 time_t rtc_read(void)
 161 {
 162     RTC_DateTypeDef dateStruct;
 163     RTC_TimeTypeDef timeStruct;
 164     struct tm timeinfo;
 165
 166     RtcHandle.Instance = RTC;
 167
 168     // Read actual date and time
 169     // Warning: the time must be read first!
 170     HAL_RTC_GetTime(&RtcHandle, &timeStruct, FORMAT_BIN);
 171     HAL_RTC_GetDate(&RtcHandle, &dateStruct, FORMAT_BIN);
 172
 173     // Setup a tm structure based on the RTC
 174     timeinfo.tm_wday = dateStruct.WeekDay;
 175     timeinfo.tm_mon  = dateStruct.Month - 1;
 176     timeinfo.tm_mday = dateStruct.Date;
 177     timeinfo.tm_year = dateStruct.Year + 100;
 178     timeinfo.tm_hour = timeStruct.Hours;
 179     timeinfo.tm_min  = timeStruct.Minutes;
 180     timeinfo.tm_sec  = timeStruct.Seconds;
 181
 182     // Convert to timestamp
 183     time_t t = mktime(&timeinfo);
 184
 185     return t;
 186 }
 187
 188 void rtc_write(time_t t)
 189 {
 190     RTC_DateTypeDef dateStruct;
 191     RTC_TimeTypeDef timeStruct;
 192
 193     RtcHandle.Instance = RTC;
 194
 195     // Convert the time into a tm
 196     struct tm *timeinfo = localtime(&t);
 197
 198     // Fill RTC structures
 199     dateStruct.WeekDay        = timeinfo->tm_wday;
 200     dateStruct.Month          = timeinfo->tm_mon + 1;
 201     dateStruct.Date           = timeinfo->tm_mday;
 202     dateStruct.Year           = timeinfo->tm_year - 100;
 203     timeStruct.Hours          = timeinfo->tm_hour;
 204     timeStruct.Minutes        = timeinfo->tm_min;
 205     timeStruct.Seconds        = timeinfo->tm_sec;
 206     timeStruct.TimeFormat     = RTC_HOURFORMAT12_PM;
 207     timeStruct.DayLightSaving = RTC_DAYLIGHTSAVING_NONE;
 208     timeStruct.StoreOperation = RTC_STOREOPERATION_RESET;
 209
 210     // Change the RTC current date/time
 211     HAL_RTC_SetDate(&RtcHandle, &dateStruct, FORMAT_BIN);
 212     HAL_RTC_SetTime(&RtcHandle, &timeStruct, FORMAT_BIN);
 213 }
 214
 215 #endif