Diff: targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/rtc_api.c

Revision:

76:aeb1df146756

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/hal/TARGET_STM/TARGET_NUCLEO_L152RE/rtc_api.c	Mon Jan 27 14:30:07 2014 +0000
@@ -0,0 +1,137 @@
+/* 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"
+
+static int rtc_inited = 0;
+
+void rtc_init(void) {
+    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE); // Enable PWR clock
+
+    PWR_RTCAccessCmd(ENABLE); // Enable access to RTC
+
+    // Note: the LSI is used as RTC source clock
+    // The RTC Clock may vary due to LSI frequency dispersion.  
+   
+    RCC_LSICmd(ENABLE); // Enable LSI
+  
+    while (RCC_GetFlagStatus(RCC_FLAG_LSIRDY) == RESET) {} // Wait until ready
+    
+    RCC_RTCCLKConfig(RCC_RTCCLKSource_LSI); // Select LSI as RTC Clock Source
+  
+    RCC_RTCCLKCmd(ENABLE); // Enable RTC Clock 
+      
+    RTC_WaitForSynchro(); // Wait for RTC registers synchronization
+
+    uint32_t lsi_freq = 40000; // *** TODO** To be measured precisely using a timer input capture
+
+    RTC_InitTypeDef RTC_InitStructure;
+    RTC_InitStructure.RTC_AsynchPrediv = 127;
+    RTC_InitStructure.RTC_SynchPrediv	 = (lsi_freq / 128) - 1;
+    RTC_InitStructure.RTC_HourFormat   = RTC_HourFormat_24;
+    RTC_Init(&RTC_InitStructure);
+    
+    PWR_RTCAccessCmd(DISABLE); // Disable access to RTC
+      
+    rtc_inited = 1;
+}
+
+void rtc_free(void) {
+    RCC_DeInit(); // Resets the RCC clock configuration to the default reset state
+    rtc_inited = 0;
+}
+
+int rtc_isenabled(void) {
+    return rtc_inited;
+}
+
+/*
+ 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;
+        
+    // Read actual date and time
+    RTC_GetTime(RTC_Format_BIN, &timeStruct);
+    RTC_GetDate(RTC_Format_BIN, &dateStruct);
+    
+    // Setup a tm structure based on the RTC
+    timeinfo.tm_wday = dateStruct.RTC_WeekDay;
+    timeinfo.tm_mon  = dateStruct.RTC_Month - 1;
+    timeinfo.tm_mday = dateStruct.RTC_Date;
+    timeinfo.tm_year = dateStruct.RTC_Year + 100;
+    timeinfo.tm_hour = timeStruct.RTC_Hours;
+    timeinfo.tm_min  = timeStruct.RTC_Minutes;
+    timeinfo.tm_sec  = timeStruct.RTC_Seconds;
+    
+    // Convert to timestamp
+    time_t t = mktime(&timeinfo);
+    
+    return t;    
+}
+
+void rtc_write(time_t t) {
+    RTC_DateTypeDef dateStruct;
+    RTC_TimeTypeDef timeStruct;
+
+    // Convert the time into a tm
+    struct tm *timeinfo = localtime(&t);
+    
+    // Fill RTC structures
+    dateStruct.RTC_WeekDay = timeinfo->tm_wday;
+    dateStruct.RTC_Month   = timeinfo->tm_mon + 1;
+    dateStruct.RTC_Date    = timeinfo->tm_mday;
+    dateStruct.RTC_Year    = timeinfo->tm_year - 100;
+    timeStruct.RTC_Hours   = timeinfo->tm_hour;
+    timeStruct.RTC_Minutes = timeinfo->tm_min;
+    timeStruct.RTC_Seconds = timeinfo->tm_sec;
+    timeStruct.RTC_H12     = RTC_HourFormat_24;
+    
+    // Change the RTC current date/time
+    PWR_RTCAccessCmd(ENABLE); // Enable access to RTC    
+    RTC_SetDate(RTC_Format_BIN, &dateStruct);
+    RTC_SetTime(RTC_Format_BIN, &timeStruct);    
+    PWR_RTCAccessCmd(DISABLE); // Disable access to RTC
+}