[PATCH 5.10 014/390] iio: adc: ad7923: fix channel readings for some variants

[Greg Kroah-Hartman]

From: Nuno Sá <nuno.sa@xxxxxxxxxx>

commit f4f43f01cff2f29779343ade755191afd2581c77 upstream.

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@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220912081223.173584-2-nuno.sa@xxxxxxxxxx
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/iio/adc/ad7923.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- 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,				\
 		},							\
 	}
@@ -274,7 +275,8 @@ static int ad7923_read_raw(struct iio_de
 			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;