rtc: sh: stop resetting time to epoch

There is no point in resetting the time to epoch as this means that
userspace will never get the valuable information that time is actually
invalid.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
[Anders Roxell <anders.roxell@linaro.org>: remove unused variable r]
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/rtc-sh.c

@@ -276,6 +276,9 @@ static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	struct sh_rtc *rtc = dev_get_drvdata(dev);
 	unsigned int sec128, sec2, yr, yr100, cf_bit;
 
+	if (!(readb(rtc->regbase + RCR2) & RCR2_RTCEN))
+		return -EINVAL;
+
 	do {
 		unsigned int tmp;
 
@@ -466,7 +469,6 @@ static int __init sh_rtc_probe(struct platform_device *pdev)
 {
 	struct sh_rtc *rtc;
 	struct resource *res;
-	struct rtc_time r;
 	char clk_name[6];
 	int clk_id, ret;
 
@@ -600,12 +602,6 @@ static int __init sh_rtc_probe(struct platform_device *pdev)
 
 	rtc->rtc_dev->max_user_freq = 256;
 
-	/* reset rtc to epoch 0 if time is invalid */
-	if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
-		rtc_time_to_tm(0, &r);
-		rtc_set_time(rtc->rtc_dev, &r);
-	}
-
 	device_init_wakeup(&pdev->dev, 1);
 	return 0;