rtc: rtc-s3c: fix RTC initialization method

Change RTC initialization method in probe().  The 'rtc_valid_tm(tm)' can
check whether RTC BCD is valid or not.  And change the method of checking
because the previous method cannot validate RTC BCD registers properly.
Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-s3c.c

@@ -456,8 +456,8 @@ static int __devexit s3c_rtc_remove(struct platform_device *dev)
 static int __devinit s3c_rtc_probe(struct platform_device *pdev)
 {
 	struct rtc_device *rtc;
+	struct rtc_time rtc_tm;
 	struct resource *res;
-	unsigned int tmp, i;
 	int ret;
 
 	pr_debug("%s: probe=%p\n", __func__, pdev);
@@ -538,11 +538,19 @@ static int __devinit s3c_rtc_probe(struct platform_device *pdev)
 
 	/* Check RTC Time */
 
-	for (i = S3C2410_RTCSEC; i <= S3C2410_RTCYEAR; i += 0x4) {
-		tmp = readb(s3c_rtc_base + i);
+	s3c_rtc_gettime(NULL, &rtc_tm);
 
-		if ((tmp & 0xf) > 0x9 || ((tmp >> 4) & 0xf) > 0x9)
-			writeb(0, s3c_rtc_base + i);
+	if (rtc_valid_tm(&rtc_tm)) {
+		rtc_tm.tm_year	= 100;
+		rtc_tm.tm_mon	= 0;
+		rtc_tm.tm_mday	= 1;
+		rtc_tm.tm_hour	= 0;
+		rtc_tm.tm_min	= 0;
+		rtc_tm.tm_sec	= 0;
+
+		s3c_rtc_settime(NULL, &rtc_tm);
+
+		dev_warn(&pdev->dev, "warning: invalid RTC value so initializing it\n");
 	}
 
 	if (s3c_rtc_cpu_type == TYPE_S3C64XX)