1 /* mbed Microcontroller Library
2 *******************************************************************************
3 * Copyright (c) 2014, STMicroelectronics
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7 * modification, are permitted provided that the following conditions are met:
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10 * this list of conditions and the following disclaimer.
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12 * this list of conditions and the following disclaimer in the documentation
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15 * may be used to endorse or promote products derived from this software
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18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *******************************************************************************
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.
42 #include "mbed_error.h"
44 static int rtc_inited = 0;
46 static RTC_HandleTypeDef RtcHandle;
50 RCC_OscInitTypeDef RCC_OscInitStruct;
51 uint32_t rtc_freq = 0;
53 if (rtc_inited) return;
56 RtcHandle.Instance = RTC;
61 // Enable access to Backup domain
62 HAL_PWR_EnableBkUpAccess();
64 // Reset Backup domain
65 __HAL_RCC_BACKUPRESET_FORCE();
66 __HAL_RCC_BACKUPRESET_RELEASE();
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
73 if (HAL_RCC_OscConfig(&RCC_OscInitStruct) == HAL_OK) {
75 __HAL_RCC_RTC_CLKPRESCALER(RCC_RTCCLKSOURCE_LSE);
76 __HAL_RCC_RTC_CONFIG(RCC_RTCCLKSOURCE_LSE);
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.");
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.
98 __HAL_RCC_RTC_ENABLE();
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;
107 if (HAL_RTC_Init(&RtcHandle) != HAL_OK) {
108 error("RTC error: RTC initialization failed.");
114 // Enable Power clock
117 // Enable access to Backup domain
118 HAL_PWR_EnableBkUpAccess();
120 // Reset Backup domain
121 __HAL_RCC_BACKUPRESET_FORCE();
122 __HAL_RCC_BACKUPRESET_RELEASE();
124 // Disable access to Backup domain
125 HAL_PWR_DisableBkUpAccess();
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);
138 int rtc_isenabled(void)
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
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
160 time_t rtc_read(void)
162 RTC_DateTypeDef dateStruct;
163 RTC_TimeTypeDef timeStruct;
166 RtcHandle.Instance = RTC;
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);
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;
182 // Convert to timestamp
183 time_t t = mktime(&timeinfo);
188 void rtc_write(time_t t)
190 RTC_DateTypeDef dateStruct;
191 RTC_TimeTypeDef timeStruct;
193 RtcHandle.Instance = RTC;
195 // Convert the time into a tm
196 struct tm *timeinfo = localtime(&t);
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;
210 // Change the RTC current date/time
211 HAL_RTC_SetDate(&RtcHandle, &dateStruct, FORMAT_BIN);
212 HAL_RTC_SetTime(&RtcHandle, &timeStruct, FORMAT_BIN);