userspace/tools/wr_irig: use mktime for day in month calculations

Signed-off-by: Adam Wujek <dev_public@wujek.eu>

userspace/tools/wr_irig.c

@@ -125,47 +125,45 @@ static int irig_get_date(struct irig_slave *irig, struct irig_time *t){
     uint32_t yr_raw = (date & IRIG_SLAVE_DATE_YEARS_MASK) >> IRIG_SLAVE_DATE_YEARS_SHIFT;
     uint32_t valid = (date & IRIG_SLAVE_DATE_VALID);
 
-    uint32_t days = (day_raw & 0x0f);
+    uint32_t ydays = (day_raw & 0x0f);
     uint32_t yrs = (yr_raw & 0x0f);
-    uint32_t mon = 0;
 
-    const int m_to_d[12] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304,
-			     334};
+    struct tm t0;
+
+    int ret;
     int i = 0;
     for (i = 0; i < 6; i++) {
 	if ((day_raw >> 5) & 1 << i) {
 	    if (i >= 4) {
-		days += 100 * (1 << (i - 4));
+		ydays += 100 * (1 << (i - 4));
 	    } else {
-		days += 10 * (1 << i);
+		ydays += 10 * (1 << i);
 	    }
 	}
     }
 
-    //fixme
-    days -= 1;
-
     for (i = 0; i < 4; i++) {
 	if ((yr_raw >> 5) & (1 << i)){
 	yrs += 10 * (1 << i);
 	}
     }
 
-    yrs += 2000;
-
-    for (i = 0; i < 11; i++){
-	if (days >= m_to_d[i] && days < m_to_d[i + 1]) {
-	    mon = i+1;
-	    days -= m_to_d[i];
-	}
-    }
-
-    if (valid){
-	t->day = days;
-	t->mon = mon;
-	t->year = yrs;
+    memset(&t0, 0, sizeof(struct tm));
+    t0.tm_isdst = -1;
+    /* mktime counts year from 1900, irigb counts from 2000 */
+    t0.tm_year = yrs + 100;
+    /* Give days in a year as days in a month (tm_mday) to mktime to give
+     * month/day */
+    t0.tm_mday = ydays;
+    ret = mktime(&t0);
+
+    if (valid && ret > 0){
+	t->day = t0.tm_mday;
+	t->mon = t0.tm_mon + 1; /* t0.tm_mon is 0..11 */
+	t->year = t0.tm_year + 1900;
 	return 0;
     }
+
     return -1;
 }
 
@@ -194,35 +192,18 @@ static int irig_get_sbs(struct irig_slave *irig, struct irig_time *t)
 
 static int64_t irig_time_to_seconds(struct irig_time *t)
 {
-    short month, year;
     int64_t result;
-    const int m_to_d[12] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304,
-			     334 };
-
-    month = t->mon;
-    year = t->year + month / 12 + 1900;
-    month %= 12;
-    if (month < 0) {
-	year -= 1;
-	month += 12;
-    }
-    result = (year - 1970) * 365 + (year - 1969) / 4 + m_to_d[month];
-    result = (year - 1970) * 365 + m_to_d[month];
-
-    if (month <= 1)
-	year -= 1;
-
-    result += (year - 1968) / 4;
-    result -= (year - 1900) / 100;
-    result += (year - 1600) / 400;
-    result += t->day;
-    result -= 1;
-    result *= 24;
-    result += t->hour;
-    result *= 60;
-    result += t->min;
-    result *= 60;
-    result += t->sec;
+    struct tm t0;
+
+    memset(&t0, 0, sizeof(struct tm));
+    t0.tm_isdst = -1;
+    t0.tm_year = t->year;
+    t0.tm_mon = t->mon;
+    t0.tm_mday = t->day;
+    t0.tm_hour = t->hour;
+    t0.tm_min = t->min;
+    t0.tm_sec = t->sec;
+    result = mktime(&t0);
 
     return result;
 }