From 7562eef4c1e4e7ef1200db567f3c8b3203689b9a Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Mon, 19 Oct 2020 21:34:56 +1100
Subject: [PATCH] AP_Filesystem: use mktime from AP_RTC

---
 .../AP_Filesystem/AP_Filesystem_FATFS.cpp     | 45 +------------------
 1 file changed, 2 insertions(+), 43 deletions(-)

diff --git a/libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp b/libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp
index 366c9b6b86..87e8f5170c 100644
--- a/libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp
+++ b/libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp
@@ -5,6 +5,7 @@
 #include <AP_HAL/AP_HAL.h>
 #include <AP_Math/AP_Math.h>
 #include <stdio.h>
+#include <AP_RTC/AP_RTC.h>
 
 #if HAVE_FILESYSTEM_SUPPORT && CONFIG_HAL_BOARD == HAL_BOARD_CHIBIOS
 
@@ -540,48 +541,6 @@ off_t AP_Filesystem_FATFS::lseek(int fileno, off_t position, int whence)
     return fh->fptr;
 }
 
-/*
-  mktime replacement from Samba
- */
-static time_t replace_mktime(const struct tm *t)
-{
-    time_t  epoch = 0;
-    int n;
-    int mon [] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, y, m, i;
-    const unsigned MINUTE = 60;
-    const unsigned HOUR = 60*MINUTE;
-    const unsigned DAY = 24*HOUR;
-    const unsigned YEAR = 365*DAY;
-
-    if (t->tm_year < 70) {
-        return (time_t)-1;
-    }
-
-    n = t->tm_year + 1900 - 1;
-    epoch = (t->tm_year - 70) * YEAR +
-            ((n / 4 - n / 100 + n / 400) - (1969 / 4 - 1969 / 100 + 1969 / 400)) * DAY;
-
-    y = t->tm_year + 1900;
-    m = 0;
-
-    for (i = 0; i < t->tm_mon; i++) {
-        epoch += mon [m] * DAY;
-        if (m == 1 && y % 4 == 0 && (y % 100 != 0 || y % 400 == 0)) {
-            epoch += DAY;
-        }
-
-        if (++m > 11) {
-            m = 0;
-            y++;
-        }
-    }
-
-    epoch += (t->tm_mday - 1) * DAY;
-    epoch += t->tm_hour * HOUR + t->tm_min * MINUTE + t->tm_sec;
-
-    return epoch;
-}
-
 static time_t fat_time_to_unix(uint16_t date, uint16_t time)
 {
     struct tm tp;
@@ -595,7 +554,7 @@ static time_t fat_time_to_unix(uint16_t date, uint16_t time)
     tp.tm_mday = (date & 0x1f);
     tp.tm_mon = ((date >> 5) & 0x0f) - 1;
     tp.tm_year = ((date >> 9) & 0x7f) + 80;
-    unix = replace_mktime( &tp );
+    unix = AP::rtc().mktime(&tp);
     return unix;
 }