dm: rtc: Rename to_tm() to rtc_to_tm() and add error code

Rename this function so that it is clear that it is provided by the RTC.
Also return an error when it cannot function as expected. This is unlikely
to occur since it works for dates since 1752 and many RTCs do not support
such old dates. Still it is better to be accurate.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Heiko Schocher <hs@denx.de>

common/image.c

@@ -533,7 +533,7 @@ void genimg_print_time(time_t timestamp)
 #ifndef USE_HOSTCC
 	struct rtc_time tm;
 
-	to_tm(timestamp, &tm);
+	rtc_to_tm(timestamp, &tm);
 	printf("%4d-%02d-%02d  %2d:%02d:%02d UTC\n",
 			tm.tm_year, tm.tm_mon, tm.tm_mday,
 			tm.tm_hour, tm.tm_min, tm.tm_sec);

drivers/rtc/at91sam9_rtt.c

@@ -44,7 +44,7 @@ int rtc_get (struct rtc_time *tmp)
 	} while (tim!=tim2);
 	off = readl(&gpbr->reg[AT91_GPBR_INDEX_TIMEOFF]);
 	/* off==0 means time is invalid, but we ignore that */
-	to_tm (tim+off, tmp);
+	rtc_to_tm(tim+off, tmp);
 	return 0;
 }
 

drivers/rtc/bfin_rtc.c

@@ -114,7 +114,7 @@ int rtc_get(struct rtc_time *tmp)
 
 	/* Calculate the total number of seconds since epoch */
 	time_in_sec = (tm_sec) + MIN_TO_SECS(tm_min) + HRS_TO_SECS(tm_hr) + DAYS_TO_SECS(tm_day);
-	to_tm(time_in_sec, tmp);
+	rtc_to_tm(time_in_sec, tmp);
 
 	return 0;
 }

drivers/rtc/date.c

@@ -71,7 +71,7 @@ int rtc_calc_weekday(struct rtc_time *tm)
 	return 0;
 }
 
-void to_tm(int tim, struct rtc_time * tm)
+int rtc_to_tm(int tim, struct rtc_time *tm)
 {
 	register int    i;
 	register long   hms, day;
@@ -103,10 +103,14 @@ void to_tm(int tim, struct rtc_time * tm)
 	/* Days are what is left over (+1) from all that. */
 	tm->tm_mday = day + 1;
 
+	/* Zero unused fields */
+	tm->tm_yday = 0;
+	tm->tm_isdst = 0;
+
 	/*
 	 * Determine the day of week
 	 */
-	rtc_calc_weekday(tm);
+	return rtc_calc_weekday(tm);
 }
 
 /* Converts Gregorian date to seconds since 1970-01-01 00:00:00.

drivers/rtc/ds1374.c

@@ -118,7 +118,7 @@ int rtc_get (struct rtc_time *tm){
 
 	DEBUGR ("Get RTC s since 1.1.1970: %ld\n", time1);
 
-	to_tm(time1, tm); /* To Gregorian Date */
+	rtc_to_tm(time1, tm); /* To Gregorian Date */
 
 	if (rtc_read(RTC_SR_ADDR) & RTC_SR_BIT_OSF) {
 		printf ("### Warning: RTC oscillator has stopped\n");

drivers/rtc/ftrtc010.c

@@ -86,7 +86,7 @@ int rtc_get(struct rtc_time *tmp)
 	now = ftrtc010_time() + readl(&rtc->record);
 #endif
 
-	to_tm(now, tmp);
+	rtc_to_tm(now, tmp);
 
 	return 0;
 }

drivers/rtc/imxdi.c

@@ -192,7 +192,7 @@ int rtc_get(struct rtc_time *tmp)
 	}
 
 	now = __raw_readl(&data.regs->dtcmr);
-	to_tm(now, tmp);
+	rtc_to_tm(now, tmp);
 
 err:
 	return rc;

drivers/rtc/mc13xxx-rtc.c

@@ -36,7 +36,7 @@ int rtc_get(struct rtc_time *rtc)
 
 	tim = day1 * 86400 + time;
 
-	to_tm(tim, rtc);
+	rtc_to_tm(tim, rtc);
 
 	rtc->tm_yday = 0;
 	rtc->tm_isdst = 0;

drivers/rtc/mcfrtc.c

@@ -38,7 +38,7 @@ int rtc_get(struct rtc_time *tmp)
 	tim = (tim * 60) + rtc_mins;
 	tim = (tim * 60) + rtc->seconds;
 
-	to_tm(tim, tmp);
+	rtc_to_tm(tim, tmp);
 
 	tmp->tm_yday = 0;
 	tmp->tm_isdst = 0;

drivers/rtc/mpc8xx.c

@@ -26,7 +26,7 @@ int rtc_get (struct rtc_time *tmp)
 
 	tim = immr->im_sit.sit_rtc;
 
-	to_tm (tim, tmp);
+	rtc_to_tm(tim, tmp);
 
 	debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,

drivers/rtc/mx27rtc.c

@@ -30,7 +30,7 @@ int rtc_get(struct rtc_time *time)
 
 	sec += min * 60 + hour * 3600 + day * 24 * 3600;
 
-	to_tm(sec, time);
+	rtc_to_tm(sec, time);
 
 	return 0;
 }

drivers/rtc/mxsrtc.c

@@ -43,7 +43,7 @@ int rtc_get(struct rtc_time *time)
 	uint32_t secs;
 
 	secs = readl(&rtc_regs->hw_rtc_seconds);
-	to_tm(secs, time);
+	rtc_to_tm(secs, time);
 
 	return 0;
 }

drivers/rtc/pl031.c

@@ -97,7 +97,7 @@ int rtc_get(struct rtc_time *tmp)
 
 	tim = RTC_READ_REG(RTC_DR);
 
-	to_tm (tim, tmp);
+	rtc_to_tm(tim, tmp);
 
 	debug ( "Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
 		tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,

include/rtc.h

@@ -45,7 +45,6 @@ int rtc_get (struct rtc_time *);
 int rtc_set (struct rtc_time *);
 void rtc_reset (void);
 
-void to_tm (int, struct rtc_time *);
 unsigned long mktime (unsigned int, unsigned int, unsigned int,
 		      unsigned int, unsigned int, unsigned int);
 
@@ -97,4 +96,18 @@ void rtc_init(void);
  */
 int rtc_calc_weekday(struct rtc_time *time);
 
+/**
+ * rtc_to_tm() - Convert a time_t value into a broken-out time
+ *
+ * The following fields are set up by this function:
+ *	tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year, tm_wday
+ *
+ * Note that tm_yday and tm_isdst are set to 0.
+ *
+ * @time_t:	Number of seconds since 1970-01-01 00:00:00
+ * @time:	Place to put the broken-out time
+ * @return 0 if OK, -EINVAL if the weekday could not be determined
+ */
+int rtc_to_tm(int time_t, struct rtc_time *time);
+
 #endif	/* _RTC_H_ */

net/sntp.c

@@ -68,7 +68,7 @@ static void sntp_handler(uchar *pkt, unsigned dest, struct in_addr sip,
 	 */
 	memcpy(&seconds, &rpktp->transmit_timestamp, sizeof(ulong));
 
-	to_tm(ntohl(seconds) - 2208988800UL + net_ntp_time_offset, &tm);
+	rtc_to_tm(ntohl(seconds) - 2208988800UL + net_ntp_time_offset, &tm);
 #if defined(CONFIG_CMD_DATE)
 	rtc_set(&tm);
 #endif

post/drivers/rtc.c

@@ -63,7 +63,7 @@ static void rtc_post_restore (struct rtc_time *tm, unsigned int sec)
 					   tm->tm_min, tm->tm_sec) + sec;
 	struct rtc_time ntm;
 
-	to_tm (t, &ntm);
+	rtc_to_tm(t, &ntm);
 
 	rtc_set (&ntm);
 }
@@ -119,7 +119,7 @@ int rtc_post_test (int flags)
 		time_t t = mktime (ynl, i + 1, daysnl[i], 23, 59, 59);
 		struct rtc_time tm;
 
-		to_tm (t, &tm);
+		rtc_to_tm(t, &tm);
 		rtc_set (&tm);
 
 		skipped++;
@@ -143,7 +143,7 @@ int rtc_post_test (int flags)
 		time_t t = mktime (yl, i + 1, daysl[i], 23, 59, 59);
 		struct rtc_time tm;
 
-		to_tm (t, &tm);
+		rtc_to_tm(t, &tm);
 		rtc_set (&tm);
 
 		skipped++;