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| 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 | + // Note: the LSI is used as RTC source clock |
| 40 | + // The RTC Clock may vary due to LSI frequency dispersion. |
| 41 | + |
| 42 | + RCC_LSICmd(ENABLE); // Enable LSI |
| 43 | + |
| 44 | + while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET) {} // Wait until ready |
| 45 | + |
| 46 | + RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI); // Select LSI as RTC Clock Source |
| 47 | + |
| 48 | + RCC_RTCCLKCmd(ENABLE); // Enable RTC Clock |
| 49 | + |
| 50 | + RTC_WaitForSynchro(); // Wait for RTC registers synchronization |
| 51 | + |
| 52 | + uint32_t lsi_freq = 40000; // *** TODO** To be measured precisely using a timer input capture |
| 53 | + |
| 54 | + RTC_InitTypeDef RTC_InitStructure; |
| 55 | + RTC_InitStructure.RTC_AsynchPrediv = 127; |
| 56 | + RTC_InitStructure.RTC_SynchPrediv = (lsi_freq / 128) - 1; |
| 57 | + RTC_InitStructure.RTC_HourFormat = RTC_HourFormat_24; |
| 58 | + RTC_Init(&RTC_InitStructure); |
| 59 | + |
| 60 | + PWR_BackupAccessCmd(DISABLE); // Disable access to RTC |
| 61 | + |
| 62 | + rtc_inited = 1; |
| 63 | +} |
| 64 | + |
| 65 | +void rtc_free(void) { |
| 66 | + RCC_DeInit(); // Resets the RCC clock configuration to the default reset state |
| 67 | + rtc_inited = 0; |
| 68 | +} |
| 69 | + |
| 70 | +int rtc_isenabled(void) { |
| 71 | + return rtc_inited; |
| 72 | +} |
| 73 | + |
| 74 | +/* |
| 75 | + RTC Registers |
| 76 | + RTC_WeekDay 1=monday, 2=tuesday, ..., 7=sunday |
| 77 | + RTC_Month 1=january, 2=february, ..., 12=december |
| 78 | + RTC_Date day of the month 1-31 |
| 79 | + RTC_Year year 0-99 |
| 80 | + struct tm |
| 81 | + tm_sec seconds after the minute 0-61 |
| 82 | + tm_min minutes after the hour 0-59 |
| 83 | + tm_hour hours since midnight 0-23 |
| 84 | + tm_mday day of the month 1-31 |
| 85 | + tm_mon months since January 0-11 |
| 86 | + tm_year years since 1900 |
| 87 | + tm_wday days since Sunday 0-6 |
| 88 | + tm_yday days since January 1 0-365 |
| 89 | + tm_isdst Daylight Saving Time flag |
| 90 | +*/ |
| 91 | +time_t rtc_read(void) { |
| 92 | + RTC_DateTypeDef dateStruct; |
| 93 | + RTC_TimeTypeDef timeStruct; |
| 94 | + struct tm timeinfo; |
| 95 | + |
| 96 | + // Read actual date and time |
| 97 | + RTC_GetTime(RTC_Format_BIN, &timeStruct); |
| 98 | + RTC_GetDate(RTC_Format_BIN, &dateStruct); |
| 99 | + |
| 100 | + // Setup a tm structure based on the RTC |
| 101 | + timeinfo.tm_wday = dateStruct.RTC_WeekDay; |
| 102 | + timeinfo.tm_mon = dateStruct.RTC_Month - 1; |
| 103 | + timeinfo.tm_mday = dateStruct.RTC_Date; |
| 104 | + timeinfo.tm_year = dateStruct.RTC_Year + 100; |
| 105 | + timeinfo.tm_hour = timeStruct.RTC_Hours; |
| 106 | + timeinfo.tm_min = timeStruct.RTC_Minutes; |
| 107 | + timeinfo.tm_sec = timeStruct.RTC_Seconds; |
| 108 | + |
| 109 | + // Convert to timestamp |
| 110 | + time_t t = mktime(&timeinfo); |
| 111 | + |
| 112 | + return t; |
| 113 | +} |
| 114 | + |
| 115 | +void rtc_write(time_t t) { |
| 116 | + RTC_DateTypeDef dateStruct; |
| 117 | + RTC_TimeTypeDef timeStruct; |
| 118 | + |
| 119 | + // Convert the time into a tm |
| 120 | + struct tm *timeinfo = localtime(&t); |
| 121 | + |
| 122 | + // Fill RTC structures |
| 123 | + dateStruct.RTC_WeekDay = timeinfo->tm_wday; |
| 124 | + dateStruct.RTC_Month = timeinfo->tm_mon + 1; |
| 125 | + dateStruct.RTC_Date = timeinfo->tm_mday; |
| 126 | + dateStruct.RTC_Year = timeinfo->tm_year - 100; |
| 127 | + timeStruct.RTC_Hours = timeinfo->tm_hour; |
| 128 | + timeStruct.RTC_Minutes = timeinfo->tm_min; |
| 129 | + timeStruct.RTC_Seconds = timeinfo->tm_sec; |
| 130 | + timeStruct.RTC_H12 = RTC_HourFormat_24; |
| 131 | + |
| 132 | + // Change the RTC current date/time |
| 133 | + PWR_BackupAccessCmd(ENABLE); // Enable access to RTC |
| 134 | + RTC_SetDate(RTC_Format_BIN, &dateStruct); |
| 135 | + RTC_SetTime(RTC_Format_BIN, &timeStruct); |
| 136 | + PWR_BackupAccessCmd(DISABLE); // Disable access to RTC |
| 137 | +} |
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