rtc: Factor out the RTC range validation into rtc_valid_range()

The RTC range validation code can be factored into rtc_valid_range()
function to avoid duplicate code.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/interface.c

@@ -23,6 +23,18 @@
 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);
 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);
 
+static int rtc_valid_range(struct rtc_device *rtc, struct rtc_time *tm)
+{
+	if (rtc->range_min != rtc->range_max) {
+		time64_t time = rtc_tm_to_time64(tm);
+
+		if (time < rtc->range_min || time > rtc->range_max)
+			return -ERANGE;
+	}
+
+	return 0;
+}
+
 static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
 {
 	int err;
@@ -70,12 +82,9 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
 	if (err != 0)
 		return err;
 
-	if (rtc->range_min != rtc->range_max) {
-		time64_t time = rtc_tm_to_time64(tm);
-
-		if (time < rtc->range_min || time > rtc->range_max)
-			return -ERANGE;
-	}
+	err = rtc_valid_range(rtc, tm);
+	if (err)
+		return err;
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
 	if (err)
@@ -381,12 +390,9 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 	if (err != 0)
 		return err;
 
-	if (rtc->range_min != rtc->range_max) {
-		time64_t time = rtc_tm_to_time64(&alarm->time);
-
-		if (time < rtc->range_min || time > rtc->range_max)
-			return -ERANGE;
-	}
+	err = rtc_valid_range(rtc, &alarm->time);
+	if (err)
+		return err;
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
 	if (err)