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rtc: mc13xxx: make rtc_read_time() more readable

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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>
This commit is contained in:
Alexander Shiyan 2014-04-03 14:50:01 -07:00 committed by Linus Torvalds
parent 12de362108
commit 6a2b342228
1 changed files with 23 additions and 36 deletions
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59
drivers/rtc/rtc-mc13xxx.c
View file

@ -23,6 +23,8 @@
#define MC13XXX_RTCDAY 22 #define MC13XXX_RTCDAY 22
#define MC13XXX_RTCDAYA 23 #define MC13XXX_RTCDAYA 23
#define SEC_PER_DAY (24 * 60 * 60)
struct mc13xxx_rtc { struct mc13xxx_rtc {
struct rtc_device *rtc; struct rtc_device *rtc;
struct mc13xxx *mc13xxx; 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); struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
unsigned int seconds, days1, days2; unsigned int seconds, days1, days2;
unsigned long s1970;
int ret;
if (!priv->valid) if (!priv->valid)
return -ENODATA; return -ENODATA;
mc13xxx_lock(priv->mc13xxx); do {
int ret;
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1); ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
if (unlikely(ret)) if (ret)
goto out; return ret;
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds); ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
if (unlikely(ret)) if (ret)
goto out; return ret;
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2); ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
out: if (ret)
mc13xxx_unlock(priv->mc13xxx); return ret;
} while (days1 != days2);
if (ret) rtc_time_to_tm(days1 * SEC_PER_DAY + seconds, tm);
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);
return rtc_valid_tm(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; unsigned int alarmseconds;
int ret; int ret;
seconds = secs % 86400; seconds = secs % SEC_PER_DAY;
days = secs / 86400; days = secs / SEC_PER_DAY;
mc13xxx_lock(priv->mc13xxx); mc13xxx_lock(priv->mc13xxx);
@ -121,7 +108,7 @@ static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
if (unlikely(ret)) if (unlikely(ret))
goto out; goto out;
if (alarmseconds < 86400) { if (alarmseconds < SEC_PER_DAY) {
ret = mc13xxx_reg_write(priv->mc13xxx, ret = mc13xxx_reg_write(priv->mc13xxx,
MC13XXX_RTCTODA, 0x1ffff); MC13XXX_RTCTODA, 0x1ffff);
if (unlikely(ret)) if (unlikely(ret))
@ -145,7 +132,7 @@ static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
goto out; goto out;
/* restore alarm */ /* restore alarm */
if (alarmseconds < 86400) { if (alarmseconds < SEC_PER_DAY) {
ret = mc13xxx_reg_write(priv->mc13xxx, ret = mc13xxx_reg_write(priv->mc13xxx,
MC13XXX_RTCTODA, alarmseconds); MC13XXX_RTCTODA, alarmseconds);
if (unlikely(ret)) 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); ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds);
if (unlikely(ret)) if (unlikely(ret))
goto out; goto out;
if (seconds >= 86400) { if (seconds >= SEC_PER_DAY) {
ret = -ENODATA; ret = -ENODATA;
goto out; goto out;
} }
@ -202,7 +189,7 @@ static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
alarm->enabled = enabled; alarm->enabled = enabled;
alarm->pending = pending; alarm->pending = pending;
s1970 = days * 86400 + seconds; s1970 = days * SEC_PER_DAY + seconds;
rtc_time_to_tm(s1970, &alarm->time); rtc_time_to_tm(s1970, &alarm->time);
dev_dbg(dev, "%s: %lu\n", __func__, s1970); 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)) if (unlikely(ret))
goto out; goto out;
seconds = s1970 % 86400; seconds = s1970 % SEC_PER_DAY;
days = s1970 / 86400; days = s1970 / SEC_PER_DAY;
ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days); ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
if (unlikely(ret)) if (unlikely(ret))