This patch is an example to demonstrate how to make rtc drivers
of time-safe hardwares time-safe based on our foregoing work.

Provided mc13xxx_rtc_set_mmss() has been already converted to use
64-bit seconds which will be done in my future patches, now we can
easily tackle all time problems in rtc-mc13xxx.c(time-safe hardware):
- Replace rtc_time_to_tm() with rtc_time64_to_tm()
- Replace rtc_tm_to_time() with rtc_tm_to_time64()

Then, this driver can work properly with no time issues.

Signed-off-by: pang.xunlei <[email protected]>
---
 drivers/rtc/rtc-mc13xxx.c |   25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
index 0765606..124996d 100644
--- a/drivers/rtc/rtc-mc13xxx.c
+++ b/drivers/rtc/rtc-mc13xxx.c
@@ -83,7 +83,7 @@ static int mc13xxx_rtc_read_time(struct device *dev, struct 
rtc_time *tm)
                        return ret;
        } while (days1 != days2);
 
-       rtc_time_to_tm(days1 * SEC_PER_DAY + seconds, tm);
+       rtc_time64_to_tm((time64_t)days1 * SEC_PER_DAY + seconds, tm);
 
        return rtc_valid_tm(tm);
 }
@@ -159,7 +159,7 @@ static int mc13xxx_rtc_read_alarm(struct device *dev, 
struct rtc_wkalrm *alarm)
 {
        struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
        unsigned seconds, days;
-       unsigned long s1970;
+       time64_t s1970;
        int enabled, pending;
        int ret;
 
@@ -189,10 +189,10 @@ out:
        alarm->enabled = enabled;
        alarm->pending = pending;
 
-       s1970 = days * SEC_PER_DAY + seconds;
+       s1970 = (time64_t)days * SEC_PER_DAY + seconds;
 
-       rtc_time_to_tm(s1970, &alarm->time);
-       dev_dbg(dev, "%s: %lu\n", __func__, s1970);
+       rtc_time64_to_tm(s1970, &alarm->time);
+       dev_dbg(dev, "%s: %lld\n", __func__, (long long)s1970);
 
        return 0;
 }
@@ -200,8 +200,8 @@ out:
 static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 {
        struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
-       unsigned long s1970;
-       unsigned seconds, days;
+       time64_t s1970;
+       u32 seconds, days;
        int ret;
 
        mc13xxx_lock(priv->mc13xxx);
@@ -215,20 +215,17 @@ static int mc13xxx_rtc_set_alarm(struct device *dev, 
struct rtc_wkalrm *alarm)
        if (unlikely(ret))
                goto out;
 
-       ret = rtc_tm_to_time(&alarm->time, &s1970);
-       if (unlikely(ret))
-               goto out;
+       s1970 = rtc_tm_to_time64(&alarm->time);
 
-       dev_dbg(dev, "%s: o%2.s %lu\n", __func__, alarm->enabled ? "n" : "ff",
-                       s1970);
+       dev_dbg(dev, "%s: o%2.s %lld\n", __func__, alarm->enabled ? "n" : "ff",
+                       (long long)s1970);
 
        ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
                        MC13XXX_IRQ_TODA);
        if (unlikely(ret))
                goto out;
 
-       seconds = s1970 % SEC_PER_DAY;
-       days = s1970 / SEC_PER_DAY;
+       days = div_s64_rem(s1970, SEC_PER_DAY, &seconds);
 
        ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
        if (unlikely(ret))
-- 
1.7.9.5

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