From f308b682028a34874a376da649f99e7531dea15c Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Sat, 19 Oct 2019 22:49:35 +0200 Subject: [PATCH] rtc: ds1343: use burst write to set time To avoid possible race condition, use regmap_bulk_write to write all the date/time registers at once instead of sequentially. Link: https://lore.kernel.org/r/20191019204941.6203-3-alexandre.belloni@bootlin.com Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-ds1343.c | 52 +++++++++++------------------------------------- 1 file changed, 12 insertions(+), 40 deletions(-) diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c index 9d7d571..8a4f1fb 100644 --- a/drivers/rtc/rtc-ds1343.c +++ b/drivers/rtc/rtc-ds1343.c @@ -236,46 +236,18 @@ static int ds1343_read_time(struct device *dev, struct rtc_time *dt) static int ds1343_set_time(struct device *dev, struct rtc_time *dt) { struct ds1343_priv *priv = dev_get_drvdata(dev); - int res; - - res = regmap_write(priv->map, DS1343_SECONDS_REG, - bin2bcd(dt->tm_sec)); - if (res) - return res; - - res = regmap_write(priv->map, DS1343_MINUTES_REG, - bin2bcd(dt->tm_min)); - if (res) - return res; - - res = regmap_write(priv->map, DS1343_HOURS_REG, - bin2bcd(dt->tm_hour) & 0x3F); - if (res) - return res; - - res = regmap_write(priv->map, DS1343_DAY_REG, - bin2bcd(dt->tm_wday + 1)); - if (res) - return res; - - res = regmap_write(priv->map, DS1343_DATE_REG, - bin2bcd(dt->tm_mday)); - if (res) - return res; - - res = regmap_write(priv->map, DS1343_MONTH_REG, - bin2bcd(dt->tm_mon + 1)); - if (res) - return res; - - dt->tm_year %= 100; - - res = regmap_write(priv->map, DS1343_YEAR_REG, - bin2bcd(dt->tm_year)); - if (res) - return res; - - return 0; + u8 buf[7]; + + buf[0] = bin2bcd(dt->tm_sec); + buf[1] = bin2bcd(dt->tm_min); + buf[2] = bin2bcd(dt->tm_hour) & 0x3F; + buf[3] = bin2bcd(dt->tm_wday + 1); + buf[4] = bin2bcd(dt->tm_mday); + buf[5] = bin2bcd(dt->tm_mon + 1); + buf[6] = bin2bcd(dt->tm_year - 100); + + return regmap_bulk_write(priv->map, DS1343_SECONDS_REG, + buf, sizeof(buf)); } static int ds1343_update_alarm(struct device *dev) -- 2.7.4