rtc: ds1343: use regmap_update_bits for glitch filter

Use regmap_update_bits to update DS1343_CONTROL_REG in a race free manner
when setting the glitch filter.

Link: https://lore.kernel.org/r/20191019204941.6203-5-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c
index ec8d1e8..28f9463 100644 (file)
--- a/drivers/rtc/rtc-ds1343.c
+++ b/drivers/rtc/rtc-ds1343.c
@@ -108,20 +108,18 @@ static ssize_t ds1343_store_glitchfilter(struct device *dev,
                                        const char *buf, size_t count)
 {
        struct ds1343_priv *priv = dev_get_drvdata(dev->parent);
-       int data;
-
-       regmap_read(priv->map, DS1343_CONTROL_REG, &data);
+       int data = 0;
+       int res;
 
        if (strncmp(buf, "enabled", 7) == 0)
-               data |= DS1343_EGFIL;
-
-       else if (strncmp(buf, "disabled", 8) == 0)
-               data &= ~(DS1343_EGFIL);
-
-       else
+               data = DS1343_EGFIL;
+       else if (strncmp(buf, "disabled", 8))
                return -EINVAL;
 
-       regmap_write(priv->map, DS1343_CONTROL_REG, data);
+       res = regmap_update_bits(priv->map, DS1343_CONTROL_REG,
+                                DS1343_EGFIL, data);
+       if (res)
+               return res;
 
        return count;
 }