1 files changed, 39 insertions, 6 deletions

diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c
index f87f971a72c2..da18a8ae3c1d 100644
--- a/drivers/rtc/rtc-zynqmp.c
+++ b/drivers/rtc/rtc-zynqmp.c
@@ -64,7 +64,12 @@ static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
 	unsigned long new_time;
 
-	new_time = rtc_tm_to_time64(tm);
+	/*
+	 * The value written will be updated after 1 sec into the
+	 * seconds read register, so we need to program time +1 sec
+	 * to get the correct time on read.
+	 */
+	new_time = rtc_tm_to_time64(tm) + 1;
 
 	if (new_time > RTC_SEC_MAX_VAL)
 		return -EINVAL;
@@ -78,14 +83,44 @@ static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm)
 
 	writel(new_time, xrtcdev->reg_base + RTC_SET_TM_WR);
 
+	/*
+	 * Clear the rtc interrupt status register after setting the
+	 * time. During a read_time function, the code should read the
+	 * RTC_INT_STATUS register and if bit 0 is still 0, it means
+	 * that one second has not elapsed yet since RTC was set and
+	 * the current time should be read from SET_TIME_READ register;
+	 * otherwise, CURRENT_TIME register is read to report the time
+	 */
+	writel(RTC_INT_SEC, xrtcdev->reg_base + RTC_INT_STS);
+
 	return 0;
 }
 
 static int xlnx_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
+	u32 status;
+	unsigned long read_time;
 	struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
 
-	rtc_time64_to_tm(readl(xrtcdev->reg_base + RTC_CUR_TM), tm);
+	status = readl(xrtcdev->reg_base + RTC_INT_STS);
+
+	if (status & RTC_INT_SEC) {
+		/*
+		 * RTC has updated the CURRENT_TIME with the time written into
+		 * SET_TIME_WRITE register.
+		 */
+		rtc_time64_to_tm(readl(xrtcdev->reg_base + RTC_CUR_TM), tm);
+	} else {
+		/*
+		 * Time written in SET_TIME_WRITE has not yet updated into
+		 * the seconds read register, so read the time from the
+		 * SET_TIME_WRITE instead of CURRENT_TIME register.
+		 * Since we add +1 sec while writing, we need to -1 sec while
+		 * reading.
+		 */
+		read_time = readl(xrtcdev->reg_base + RTC_SET_TM_RD) - 1;
+		rtc_time64_to_tm(read_time, tm);
+	}
 
 	return rtc_valid_tm(tm);
 }
@@ -166,11 +201,9 @@ static irqreturn_t xlnx_rtc_interrupt(int irq, void *id)
 	if (!(status & (RTC_INT_SEC | RTC_INT_ALRM)))
 		return IRQ_NONE;
 
-	/* Clear interrupt */
-	writel(status, xrtcdev->reg_base + RTC_INT_STS);
+	/* Clear RTC_INT_ALRM interrupt only */
+	writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_STS);
 
-	if (status & RTC_INT_SEC)
-		rtc_update_irq(xrtcdev->rtc, 1, RTC_IRQF | RTC_UF);
 	if (status & RTC_INT_ALRM)
 		rtc_update_irq(xrtcdev->rtc, 1, RTC_IRQF | RTC_AF);