drivers/rtc/mc13xxx: Update driver to address y2038/y2106 issues

This driver has a number of y2038/y2106 issues.

This patch resolves them by:

  - Replacing rtc_time_to_tm() with rtc_time64_to_tm()
  - Changing mc13xxx_rtc_set_mmss() to use rtc_class_ops's set_mmss64()

After this patch, the driver should not have any remaining
y2038/y2106 issues.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427945681-29972-11-git-send-email-john.stultz@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 14 insertions, 18 deletions

diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
index 5bce904b7ee6..32df1d812367 100644
--- a/drivers/rtc/rtc-mc13xxx.c
+++ b/drivers/rtc/rtc-mc13xxx.c
@@ -83,20 +83,19 @@ 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);
 }
 
-static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
+static int mc13xxx_rtc_set_mmss(struct device *dev, time64_t secs)
 {
         struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
         unsigned int seconds, days;
         unsigned int alarmseconds;
         int ret;
 
-        seconds = secs % SEC_PER_DAY;
-        days = secs / SEC_PER_DAY;
+        days = div_s64_rem(secs, SEC_PER_DAY, &seconds);
 
         mc13xxx_lock(priv->mc13xxx);
 
@@ -159,7 +158,7 @@ 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 +188,10 @@ 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 +199,8 @@ 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 +214,17 @@ 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))
@@ -268,7 +264,7 @@ static irqreturn_t mc13xxx_rtc_update_handler(int irq, void *dev)
 
 static const struct rtc_class_ops mc13xxx_rtc_ops = {
         .read_time = mc13xxx_rtc_read_time,
-        .set_mmss = mc13xxx_rtc_set_mmss,
+        .set_mmss64 = mc13xxx_rtc_set_mmss,
         .read_alarm = mc13xxx_rtc_read_alarm,
         .set_alarm = mc13xxx_rtc_set_alarm,
         .alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable,