src/main/common/time.c

   1 /*
   2  * This file is part of INAV.
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   6  * You can obtain one at http://mozilla.org/MPL/2.0/.
   7  *
   8  * Alternatively, the contents of this file may be used under the terms
   9  * of the GNU General Public License Version 3, as described below:
  10  *
  11  * This file is free software: you may copy, redistribute and/or modify
  12  * it under the terms of the GNU General Public License as published by the
  13  * Free Software Foundation, either version 3 of the License, or (at your
  14  * option) any later version.
  15  *
  16  * This file is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  19  * Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program. If not, see http://www.gnu.org/licenses/.
  23  *
  24  * @author Alberto Garcia Hierro <alberto@garciahierro.com>
  25  */
  26
  27 #include "common/maths.h"
  28 #include "common/printf.h"
  29 #include "common/time.h"
  30 #include "common/utils.h"
  31
  32 #include "config/parameter_group_ids.h"
  33
  34 #include "drivers/time.h"
  35
  36 #include "fc/settings.h"
  37
  38 // For the "modulo 4" arithmetic to work, we need a leap base year
  39 #define REFERENCE_YEAR 2000
  40 // Offset (seconds) from the UNIX epoch (1970-01-01) to 2000-01-01
  41 #define EPOCH_2000_OFFSET 946684800
  42
  43 #define MILLIS_PER_SECOND 1000
  44
  45 // rtcTime_t when the system was started.
  46 // Calculated in rtcSet().
  47 static rtcTime_t started = 0;
  48
  49 static const uint16_t days[4][12] =
  50 {
  51     {   0,  31,     60,     91,     121,    152,    182,    213,    244,    274,    305,    335},
  52     { 366,  397,    425,    456,    486,    517,    547,    578,    609,    639,    670,    700},
  53     { 731,  762,    790,    821,    851,    882,    912,    943,    974,    1004,   1035,   1065},
  54     {1096,  1127,   1155,   1186,   1216,   1247,   1277,   1308,   1339,   1369,   1400,   1430},
  55 };
  56
  57 PG_REGISTER_WITH_RESET_TEMPLATE(timeConfig_t, timeConfig, PG_TIME_CONFIG, 1);
  58
  59 PG_RESET_TEMPLATE(timeConfig_t, timeConfig,
  60     .tz_offset = SETTING_TZ_OFFSET_DEFAULT,
  61     .tz_automatic_dst = SETTING_TZ_AUTOMATIC_DST_DEFAULT,
  62 );
  63
  64 static rtcTime_t dateTimeToRtcTime(const dateTime_t *dt)
  65 {
  66     unsigned int second = dt->seconds;  // 0-59
  67     unsigned int minute = dt->minutes;  // 0-59
  68     unsigned int hour = dt->hours;      // 0-23
  69     unsigned int day = dt->day - 1;     // 0-30
  70     unsigned int month = dt->month - 1; // 0-11
  71     unsigned int year = dt->year - REFERENCE_YEAR; // 0-99
  72     int32_t unixTime = (((year / 4 * (365 * 4 + 1) + days[year % 4][month] + day) * 24 + hour) * 60 + minute) * 60 + second + EPOCH_2000_OFFSET;
  73     return rtcTimeMake(unixTime, dt->millis);
  74 }
  75
  76 static void rtcTimeToDateTime(dateTime_t *dt, rtcTime_t t)
  77 {
  78     int32_t unixTime = t / MILLIS_PER_SECOND - EPOCH_2000_OFFSET;
  79     dt->seconds = unixTime % 60;
  80     unixTime /= 60;
  81     dt->minutes = unixTime % 60;
  82     unixTime /= 60;
  83     dt->hours = unixTime % 24;
  84     unixTime /= 24;
  85
  86     unsigned int years = unixTime / (365 * 4 + 1) * 4;
  87     unixTime %= 365 * 4 + 1;
  88
  89     unsigned int year;
  90     for (year = 3; year > 0; year--) {
  91         if (unixTime >= days[year][0]) {
  92             break;
  93         }
  94     }
  95
  96     unsigned int month;
  97     for (month = 11; month > 0; month--) {
  98         if (unixTime >= days[year][month]) {
  99             break;
 100         }
 101     }
 102
 103     dt->year = years + year + REFERENCE_YEAR;
 104     dt->month = month + 1;
 105     dt->day = unixTime - days[year][month] + 1;
 106     dt->millis = t % MILLIS_PER_SECOND;
 107 }
 108
 109 static void rtcGetDefaultDateTime(dateTime_t *dateTime)
 110 {
 111     dateTime->year = 0;
 112     dateTime->month = 1;
 113     dateTime->day = 1;
 114     dateTime->hours = 0;
 115     dateTime->minutes = 0;
 116     dateTime->seconds = 0;
 117     dateTime->millis = 0;
 118 }
 119
 120 static bool rtcIsDateTimeValid(dateTime_t *dateTime)
 121 {
 122     return (dateTime->year >= REFERENCE_YEAR) &&
 123            (dateTime->month >= 1 && dateTime->month <= 12) &&
 124            (dateTime->day >= 1 && dateTime->day <= 31) &&
 125            (dateTime->hours <= 23) &&
 126            (dateTime->minutes <= 59) &&
 127            (dateTime->seconds <= 59) &&
 128            (dateTime->millis <= 999);
 129 }
 130
 131 #if defined(RTC_AUTOMATIC_DST)
 132 static int lastSundayOfMonth(int currentYear, int wantedMonth)
 133 {
 134     int days[] = { 31 , 29 , 31 , 30 , 31 , 30 , 31 , 31 , 30 , 31 , 30 , 31 };
 135     days[1] -= (currentYear % 4) || (!(currentYear % 100) && (currentYear % 400));
 136     int w = currentYear * 365 + (currentYear - 1) / 4 - (currentYear - 1) / 100 + (currentYear - 1) / 400 + 6;
 137
 138         for (int m = 0; m < 12; m++) {
 139                 w = (w + days[m]) % 7;
 140         if (m == wantedMonth - 1) {
 141             return days[m] - w;
 142         }
 143         }
 144     return 0;
 145 }
 146
 147 static int nthSundayOfMonth(int lastSunday, int nth)
 148 {
 149     while (lastSunday > 7 * nth) {
 150         lastSunday -= 7;
 151     }
 152     return lastSunday;
 153 }
 154
 155 static bool isDST(rtcTime_t t)
 156 {
 157     dateTime_t dateTime;
 158     rtcTimeToDateTime(&dateTime, t);
 159     int lastSunday;
 160     switch ((tz_automatic_dst_e) timeConfig()->tz_automatic_dst) {
 161         case TZ_AUTO_DST_OFF:
 162             break;
 163         case TZ_AUTO_DST_EU: // begins at 1:00 a.m. on the last Sunday of March and ends at 1:00 a.m. on the last Sunday of October
 164             if (dateTime.month < 3 || dateTime.month > 10) {
 165                 return false;
 166             }
 167             if (dateTime.month > 3 && dateTime.month < 10) {
 168                 return true;
 169             }
 170             lastSunday = lastSundayOfMonth(dateTime.year, dateTime.month);
 171             if ((dateTime.day < lastSunday) || (dateTime.day > lastSunday)) {
 172                 return !(dateTime.month == 3);
 173             }
 174             if (dateTime.day == lastSunday) {
 175                 if (dateTime.month == 3) {
 176                     return dateTime.hours >= 1;
 177                 }
 178                 if (dateTime.month == 10) {
 179                     return dateTime.hours < 1;
 180                 }
 181             }
 182             break;
 183         case TZ_AUTO_DST_USA: // begins at 2:00 a.m. on the second Sunday of March and ends at 2:00 a.m. on the first Sunday of November
 184             if (dateTime.month < 3 || dateTime.month > 11) {
 185                 return false;
 186             }
 187             if (dateTime.month > 3 && dateTime.month < 11) {
 188                 return true;
 189             }
 190             lastSunday = lastSundayOfMonth(dateTime.year, dateTime.month);
 191             if (dateTime.month == 3) {
 192                 int secondSunday = nthSundayOfMonth(lastSunday, 2);
 193                 if (dateTime.day == secondSunday) {
 194                     return dateTime.hours >= 2;
 195                 }
 196                 return dateTime.day > secondSunday;
 197             }
 198             if (dateTime.month == 11) {
 199                 int firstSunday = nthSundayOfMonth(lastSunday, 1);
 200                 if (dateTime.day == firstSunday) {
 201                     return dateTime.hours < 2;
 202                 }
 203                 return dateTime.day < firstSunday;
 204             }
 205             break;
 206     }
 207     return false;
 208 }
 209 #endif
 210
 211 static void dateTimeWithOffset(dateTime_t *dateTimeOffset, const dateTime_t *dateTimeInitial, int16_t *minutes, bool automatic_dst)
 212 {
 213     rtcTime_t initialTime = dateTimeToRtcTime(dateTimeInitial);
 214     rtcTime_t offsetTime = rtcTimeMake(rtcTimeGetSeconds(&initialTime) + *minutes * 60, rtcTimeGetMillis(&initialTime));
 215 #if defined(RTC_AUTOMATIC_DST)
 216     if (automatic_dst && isDST(offsetTime)) {
 217         // Add one hour. Tell the caller that the
 218         // offset has changed.
 219         *minutes += 60;
 220         offsetTime += 60 * 60 * MILLIS_PER_SECOND;
 221     }
 222 #else
 223     UNUSED(automatic_dst);
 224 #endif
 225     rtcTimeToDateTime(dateTimeOffset, offsetTime);
 226 }
 227
 228 static bool dateTimeFormat(char *buf, dateTime_t *dateTime, int16_t offset, bool automatic_dst)
 229 {
 230     dateTime_t local;
 231
 232     int tz_hours = 0;
 233     int tz_minutes = 0;
 234     bool retVal = true;
 235
 236     // Apply offset if necessary
 237     if (offset != 0 || automatic_dst) {
 238         dateTimeWithOffset(&local, dateTime, &offset, automatic_dst);
 239         tz_hours = offset / 60;
 240         tz_minutes = ABS(offset % 60);
 241         dateTime = &local;
 242     }
 243
 244     if (!rtcIsDateTimeValid(dateTime)) {
 245         rtcGetDefaultDateTime(&local);
 246         dateTime = &local;
 247         retVal = false;
 248     }
 249
 250     // XXX: Changes to this format might require updates in
 251     // dateTimeSplitFormatted()
 252     tfp_sprintf(buf, "%04u-%02u-%02uT%02u:%02u:%02u.%03u%c%02d:%02d",
 253         dateTime->year, dateTime->month, dateTime->day,
 254         dateTime->hours, dateTime->minutes, dateTime->seconds, dateTime->millis,
 255         tz_hours >= 0 ? '+' : '-', ABS(tz_hours), tz_minutes);
 256
 257     return retVal;
 258 }
 259
 260 rtcTime_t rtcTimeMake(int32_t secs, uint16_t millis)
 261 {
 262     return ((rtcTime_t)secs) * MILLIS_PER_SECOND + millis;
 263 }
 264
 265 int32_t rtcTimeGetSeconds(rtcTime_t *t)
 266 {
 267     return *t / MILLIS_PER_SECOND;
 268 }
 269
 270 uint16_t rtcTimeGetMillis(rtcTime_t *t)
 271 {
 272     return *t % MILLIS_PER_SECOND;
 273 }
 274
 275 bool dateTimeFormatUTC(char *buf, dateTime_t *dt)
 276 {
 277     return dateTimeFormat(buf, dt, 0, false);
 278 }
 279
 280 bool dateTimeFormatLocal(char *buf, dateTime_t *dt)
 281 {
 282     return dateTimeFormat(buf, dt, timeConfig()->tz_offset, true);
 283 }
 284
 285 void dateTimeUTCToLocal(dateTime_t *localDateTime, const dateTime_t *utcDateTime)
 286 {
 287     int16_t offset = timeConfig()->tz_offset;
 288     dateTimeWithOffset(localDateTime, utcDateTime, &offset, true);
 289 }
 290
 291 bool dateTimeSplitFormatted(char *formatted, char **date, char **time)
 292 {
 293     // Just look for the T and replace it with a zero
 294     // XXX: Keep in sync with dateTimeFormat()
 295     for (char *p = formatted; *p; p++) {
 296         if (*p == 'T') {
 297             *date = formatted;
 298             *time = (p+1);
 299             *p = '\0';
 300             return true;
 301         }
 302     }
 303     return false;
 304 }
 305
 306 bool rtcHasTime(void)
 307 {
 308     return started != 0;
 309 }
 310
 311 bool rtcGet(rtcTime_t *t)
 312 {
 313     if (!rtcHasTime()) {
 314         return false;
 315     }
 316     *t = started + millis();
 317     return true;
 318 }
 319
 320 bool rtcSet(rtcTime_t *t)
 321 {
 322     started = *t - millis();
 323     return true;
 324 }
 325
 326 bool rtcGetDateTime(dateTime_t *dt)
 327 {
 328     rtcTime_t t;
 329     if (rtcGet(&t)) {
 330         rtcTimeToDateTime(dt, t);
 331         return true;
 332     }
 333     // No time stored, fill dt with 0000-01-01T00:00:00.000
 334     rtcGetDefaultDateTime(dt);
 335     return false;
 336 }
 337
 338 bool rtcGetDateTimeLocal(dateTime_t *dt)
 339 {
 340     if (rtcGetDateTime(dt)) {
 341         dateTimeUTCToLocal(dt, dt);
 342         return true;
 343     }
 344     return false;
 345 }
 346
 347 bool rtcSetDateTime(dateTime_t *dt)
 348 {
 349     rtcTime_t t = dateTimeToRtcTime(dt);
 350     return rtcSet(&t);
 351 }