[PATCH 21/29] rtc: spear: fix spear_rtc_read_time

From: Alexandre Belloni
Date: Wed Mar 09 2022 - 11:41:50 EST


The reference manual doesn't specify whether the registers are latched and
they probably aren't, ensure the read time and date are consistent.

Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
---
drivers/rtc/rtc-spear.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-spear.c b/drivers/rtc/rtc-spear.c
index c395af3ebc91..d4777b01ab22 100644
--- a/drivers/rtc/rtc-spear.c
+++ b/drivers/rtc/rtc-spear.c
@@ -204,8 +204,10 @@ static int spear_rtc_read_time(struct device *dev, struct rtc_time *tm)
/* we don't report wday/yday/isdst ... */
rtc_wait_not_busy(config);

- time = readl(config->ioaddr + TIME_REG);
- date = readl(config->ioaddr + DATE_REG);
+ do {
+ time = readl(config->ioaddr + TIME_REG);
+ date = readl(config->ioaddr + DATE_REG);
+ } while (time == readl(config->ioaddr + TIME_REG));
tm->tm_sec = (time >> SECOND_SHIFT) & SECOND_MASK;
tm->tm_min = (time >> MINUTE_SHIFT) & MIN_MASK;
tm->tm_hour = (time >> HOUR_SHIFT) & HOUR_MASK;
--
2.35.1