[PATCH v2 1/3] iio: adc: ad7923: fix channel readings for some variants

["Nuno Sá" <nuno.sa@analog.com>]

Some of the supported devices have 4 or 2 LSB trailing bits that should
not be taken into account. Hence we need to shift these bits out which
fits perfectly on the scan type shift property. This change fixes both
raw and buffered reads.

Fixes: f2f7a449707e ("iio:adc:ad7923: Add support for the ad7904/ad7914/ad7924")
Fixes: 851644a60d20 ("iio: adc: ad7923: Add support for the ad7908/ad7918/ad7928")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
---
 drivers/iio/adc/ad7923.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ad7923.c b/drivers/iio/adc/ad7923.c
index edad1f30121d..502253f53d96 100644
--- a/drivers/iio/adc/ad7923.c
+++ b/drivers/iio/adc/ad7923.c
@@ -93,6 +93,7 @@ enum ad7923_id {
 			.sign = 'u',					\
 			.realbits = (bits),				\
 			.storagebits = 16,				\
+			.shift = 12 - (bits),				\
 			.endianness = IIO_BE,				\
 		},							\
 	}
@@ -268,7 +269,8 @@ static int ad7923_read_raw(struct iio_dev *indio_dev,
 			return ret;
 
 		if (chan->address == EXTRACT(ret, 12, 4))
-			*val = EXTRACT(ret, 0, 12);
+			*val = EXTRACT(ret, chan->scan_type.shift,
+				       chan->scan_type.realbits);
 		else
 			return -EIO;
 
-- 
2.37.3