68 lines
1.7 KiB
C
68 lines
1.7 KiB
C
/* Copyright 2017 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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/* RTC cross-platform code for Chrome EC */
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/* TODO(chromium:733844): Move this conversion to kernel rtc-cros-ec driver */
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#include "rtc.h"
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static uint16_t days_since_year_start[12] = {
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0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
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/* Conversion between calendar date and seconds eclapsed since 1970-01-01 */
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uint32_t date_to_sec(struct calendar_date time)
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{
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int i;
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uint32_t sec;
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sec = time.year * SECS_PER_YEAR;
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for (i = 0; i < time.year; i++) {
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if (IS_LEAP_YEAR(i))
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sec += SECS_PER_DAY;
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}
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sec += (days_since_year_start[time.month - 1] +
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(IS_LEAP_YEAR(time.year) && time.month > 2) +
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(time.day - 1)) * SECS_PER_DAY;
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/* add the accumulated time in seconds from 1970 to 2000 */
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return sec + SECS_TILL_YEAR_2K;
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}
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struct calendar_date sec_to_date(uint32_t sec)
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{
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struct calendar_date time;
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int day_tmp; /* for intermediate calculation */
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int i;
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/* RTC time must be after year 2000. */
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sec = (sec > SECS_TILL_YEAR_2K) ? (sec - SECS_TILL_YEAR_2K) : 0;
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day_tmp = sec / SECS_PER_DAY;
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time.year = day_tmp / 365;
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day_tmp %= 365;
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for (i = 0; i < time.year; i++) {
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if (IS_LEAP_YEAR(i))
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day_tmp -= 1;
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}
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day_tmp++;
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if (day_tmp <= 0) {
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time.year -= 1;
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day_tmp += IS_LEAP_YEAR(time.year) ? 366 : 365;
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}
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for (i = 1; i < 12; i++) {
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if (days_since_year_start[i] +
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(IS_LEAP_YEAR(time.year) && (i >= 2)) >= day_tmp)
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break;
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}
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time.month = i;
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day_tmp -= days_since_year_start[time.month - 1] +
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(IS_LEAP_YEAR(time.year) && (time.month > 2));
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time.day = day_tmp;
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return time;
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}
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