rtc: mc13xxx: make rtc_read_time() more readable
Remove unnecessary locks when reading the time and make the read
operation until the values of day matched between reading the seconds,
it will make the mc13xxx_rtc_read_time() procedure more readable.
Additionally, patch introduced a "seconds in a day" definition.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
index 7b39852..9b1a77e 100644
--- a/drivers/rtc/rtc-mc13xxx.c
+++ b/drivers/rtc/rtc-mc13xxx.c
@@ -23,6 +23,8 @@
#define MC13XXX_RTCDAY 22
#define MC13XXX_RTCDAYA 23
+#define SEC_PER_DAY (24 * 60 * 60)
+
struct mc13xxx_rtc {
struct rtc_device *rtc;
struct mc13xxx *mc13xxx;
@@ -61,42 +63,27 @@
{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
unsigned int seconds, days1, days2;
- unsigned long s1970;
- int ret;
if (!priv->valid)
return -ENODATA;
- mc13xxx_lock(priv->mc13xxx);
+ do {
+ int ret;
- ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
- if (unlikely(ret))
- goto out;
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
+ if (ret)
+ return ret;
- ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
- if (unlikely(ret))
- goto out;
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
+ if (ret)
+ return ret;
- ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
-out:
- mc13xxx_unlock(priv->mc13xxx);
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
+ if (ret)
+ return ret;
+ } while (days1 != days2);
- if (ret)
- return ret;
-
- if (days2 == days1 + 1) {
- if (seconds >= 86400 / 2)
- days2 = days1;
- else
- days1 = days2;
- }
-
- if (days1 != days2)
- return -EIO;
-
- s1970 = days1 * 86400 + seconds;
-
- rtc_time_to_tm(s1970, tm);
+ rtc_time_to_tm(days1 * SEC_PER_DAY + seconds, tm);
return rtc_valid_tm(tm);
}
@@ -108,8 +95,8 @@
unsigned int alarmseconds;
int ret;
- seconds = secs % 86400;
- days = secs / 86400;
+ seconds = secs % SEC_PER_DAY;
+ days = secs / SEC_PER_DAY;
mc13xxx_lock(priv->mc13xxx);
@@ -121,7 +108,7 @@
if (unlikely(ret))
goto out;
- if (alarmseconds < 86400) {
+ if (alarmseconds < SEC_PER_DAY) {
ret = mc13xxx_reg_write(priv->mc13xxx,
MC13XXX_RTCTODA, 0x1ffff);
if (unlikely(ret))
@@ -145,7 +132,7 @@
goto out;
/* restore alarm */
- if (alarmseconds < 86400) {
+ if (alarmseconds < SEC_PER_DAY) {
ret = mc13xxx_reg_write(priv->mc13xxx,
MC13XXX_RTCTODA, alarmseconds);
if (unlikely(ret))
@@ -181,7 +168,7 @@
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds);
if (unlikely(ret))
goto out;
- if (seconds >= 86400) {
+ if (seconds >= SEC_PER_DAY) {
ret = -ENODATA;
goto out;
}
@@ -202,7 +189,7 @@
alarm->enabled = enabled;
alarm->pending = pending;
- s1970 = days * 86400 + seconds;
+ s1970 = days * SEC_PER_DAY + seconds;
rtc_time_to_tm(s1970, &alarm->time);
dev_dbg(dev, "%s: %lu\n", __func__, s1970);
@@ -240,8 +227,8 @@
if (unlikely(ret))
goto out;
- seconds = s1970 % 86400;
- days = s1970 / 86400;
+ seconds = s1970 % SEC_PER_DAY;
+ days = s1970 / SEC_PER_DAY;
ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
if (unlikely(ret))