Diff: mbed-os/platform/mbed_mktime.h

Revision:

0:fbdae7e6d805

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/platform/mbed_mktime.h	Mon May 14 11:29:06 2018 +0000
@@ -0,0 +1,131 @@
+
+/** \addtogroup platform */
+/** @{*/
+/* mbed Microcontroller Library
+ * Copyright (c) 2017-2017 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef MBED_MKTIME_H
+#define MBED_MKTIME_H
+
+#include <time.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \defgroup platform_mktime mktime functions
+ * @{
+ */
+
+/* Time range across the whole 32-bit range should be supported which means that years in range 1970 - 2106 can be
+ * encoded. We have two types of RTC devices:
+ * a) RTCs which handles all leap years in the mentioned year range correctly. Leap year is determined by checking if
+ *    the year counter value is divisible by 400, 100, and 4. No problem here.
+ * b) RTCs which handles leap years correctly up to 2100. The RTC does a simple bit comparison to see if the two
+ *    lowest order bits of the year counter are zero. In this case 2100 year will be considered
+ *    incorrectly as a leap year, so the last valid point in time will be 28.02.2100 23:59:59 and next day will be
+ *    29.02.2100 (invalid). So after 28.02.2100 the day counter will be off by a day.
+ */
+typedef enum {
+    RTC_FULL_LEAP_YEAR_SUPPORT,
+    RTC_4_YEAR_LEAP_YEAR_SUPPORT
+} rtc_leap_year_support_t;
+
+/** Compute if a year is a leap year or not.
+ *
+ * @param year The year to test it shall be in the range [70:206]. Year 0 is
+ * translated into year 1900 CE.
+ * @param leap_year_support use RTC_FULL_LEAP_YEAR_SUPPORT if RTC device is able
+ * to correctly detect all leap years in range [70:206] otherwise use RTC_4_YEAR_LEAP_YEAR_SUPPORT.
+ *
+ * @return true if the year in input is a leap year and false otherwise.
+ *
+ * @note For use by the HAL only
+ * @note Year 2100 is treated differently for devices with full leap year support and devices with
+ * partial leap year support. Devices with partial leap year support treats 2100 as a leap year.
+ */
+bool _rtc_is_leap_year(int year, rtc_leap_year_support_t leap_year_support);
+
+/* Convert a calendar time into time since UNIX epoch as a time_t.
+ *
+ * This function is a thread safe (partial) replacement for mktime. It is
+ * tailored around RTC peripherals needs and is not by any mean a complete
+ * replacement of mktime.
+ *
+ * @param time The calendar time to convert into a time_t since epoch.
+ * The fields from tm used for the computation are:
+ *   - tm_sec
+ *   - tm_min
+ *   - tm_hour
+ *   - tm_mday
+ *   - tm_mon
+ *   - tm_year
+ * Other fields are ignored and won't be renormalized by a call to this function.
+ * A valid calendar time is comprised between:
+ * the 1st of January 1970 at 00:00:00 to the 7th of February 2106 at 06:28:15.
+ * @param leap_year_support use RTC_FULL_LEAP_YEAR_SUPPORT if RTC device is able
+ * to correctly detect all leap years in range [70:206] otherwise use RTC_4_YEAR_LEAP_YEAR_SUPPORT.
+ * @param seconds holder for the result - calendar time as seconds since UNIX epoch.
+ *
+ * @return true on success, false if conversion error occurred.
+ *
+ * @note Leap seconds are not supported.
+ * @note Values in output range from 0 to UINT_MAX.
+ * @note Full and partial leap years support.
+ * @note For use by the HAL only
+ */
+bool _rtc_maketime(const struct tm* time, time_t * seconds, rtc_leap_year_support_t leap_year_support);
+
+/* Convert a given time in seconds since epoch into calendar time.
+ *
+ * This function is a thread safe (partial) replacement for localtime. It is
+ * tailored around RTC peripherals specification and is not by any means a
+ * complete of localtime.
+ *
+ * @param timestamp The time (in seconds) to convert into calendar time. Valid
+ * input are in the range [0 : UINT32_MAX].
+ * @param calendar_time Pointer to the object which will contain the result of
+ * the conversion. The tm fields filled by this function are:
+ *   - tm_sec
+ *   - tm_min
+ *   - tm_hour
+ *   - tm_mday
+ *   - tm_mon
+ *   - tm_year
+ *   - tm_wday
+ *   - tm_yday
+ * The object remains untouched if the time in input is invalid.
+ * @param leap_year_support use RTC_FULL_LEAP_YEAR_SUPPORT if RTC device is able
+ * to correctly detect all leap years in range [70:206] otherwise use RTC_4_YEAR_LEAP_YEAR_SUPPORT.
+ * @return true if the conversion was successful, false otherwise.
+ *
+ * @note For use by the HAL only.
+ * @note Full and partial leap years support.
+ */
+bool _rtc_localtime(time_t timestamp, struct tm* time_info, rtc_leap_year_support_t leap_year_support);
+
+/** @}*/
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MBED_MKTIME_H */
+
+/** @}*/