[PATCH v2 4/4] iio: light: opt4001: Fix power down clearing bits of the wrong register

[Nikhil Gautam <nikhilgtr@gmail.com>]

opt4001_power_down() intends to clear the operating mode bits in the
CTRL register but reads OPT4001_DEVICE_ID instead of OPT4001_CTRL, so
the value written back to CTRL contains device ID bits rather than the
current configuration.

Fix and simplify this by using regmap_clear_bits() on the CTRL register
directly in the devm action, and drop opt4001_power_down() which has no
other users.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Fixes: 9a9608418292 ("iio: light: Add support for TI OPT4001 light sensor")
Signed-off-by: Nikhil Gautam <nikhilgtr@gmail.com>
---
 drivers/iio/light/opt4001.c | 27 ++++-----------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/drivers/iio/light/opt4001.c b/drivers/iio/light/opt4001.c
index 9f877c5798b9..b7e9d361c2e3 100644
--- a/drivers/iio/light/opt4001.c
+++ b/drivers/iio/light/opt4001.c
@@ -223,33 +223,14 @@ static int opt4001_set_conf(struct opt4001_chip *chip)
 	return ret;
 }
 
-static int opt4001_power_down(struct opt4001_chip *chip)
-{
-	struct device *dev = &chip->client->dev;
-	int ret;
-	unsigned int reg;
-
-	ret = regmap_read(chip->regmap, OPT4001_DEVICE_ID, &reg);
-	if (ret) {
-		dev_err(dev, "Failed to read configuration\n");
-		return ret;
-	}
-
-	/* MODE_OFF is 0x0 so just set bits to 0 */
-	reg &= ~OPT4001_CTRL_OPER_MODE_MASK;
-
-	ret = regmap_write(chip->regmap, OPT4001_CTRL, reg);
-	if (ret)
-		dev_err(dev, "Failed to set configuration to power down\n");
-
-	return ret;
-}
-
 static void opt4001_chip_off_action(void *data)
 {
 	struct opt4001_chip *chip = data;
+	int ret;
 
-	opt4001_power_down(chip);
+	ret = regmap_clear_bits(chip->regmap, OPT4001_CTRL, OPT4001_CTRL_OPER_MODE_MASK);
+	if (ret)
+		dev_err(&chip->client->dev, "Failed to power down\n");
 }
 
 static const struct iio_chan_spec opt4001_channels[] = {
-- 
2.39.5