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authorAlexander Shiyan <shc_work@mail.ru>2014-04-03 14:50:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-03 16:21:21 -0700
commit6a2b342228b98432a585c83d59ed6aa0620be7c4 (patch)
tree3f70e81e8757a79d192405ca5ae669510b1a3431 /drivers
parent12de362108d5ec24cce1bbe520570dc8fdccca9c (diff)
downloadlinux-6a2b342228b98432a585c83d59ed6aa0620be7c4.tar.bz2
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/rtc/rtc-mc13xxx.c59
1 files changed, 23 insertions, 36 deletions
diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
index 7b39852eb542..9b1a77eb91a9 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 @@ static int mc13xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
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_RTCTOD, &seconds);
- if (unlikely(ret))
- goto out;
-
- ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
-out:
- mc13xxx_unlock(priv->mc13xxx);
-
- if (ret)
- return ret;
-
- if (days2 == days1 + 1) {
- if (seconds >= 86400 / 2)
- days2 = days1;
- else
- days1 = days2;
- }
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
+ if (ret)
+ return ret;
- if (days1 != days2)
- return -EIO;
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
+ if (ret)
+ return ret;
- s1970 = days1 * 86400 + seconds;
+ ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
+ if (ret)
+ return ret;
+ } while (days1 != days2);
- 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 @@ static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
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 @@ static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
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 @@ static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
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 @@ static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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 @@ out:
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 @@ static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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))