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From f4f43f01cff2f29779343ade755191afd2581c77 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nuno=20S=C3=A1?= <nuno.sa@analog.com>
Date: Mon, 12 Sep 2022 10:12:21 +0200
Subject: [PATCH] iio: adc: ad7923: fix channel readings for some variants
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Git-commit: f4f43f01cff2f29779343ade755191afd2581c77
Patch-mainline: v6.1-rc1
References: git-fixes

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>
Link: https://lore.kernel.org/r/20220912081223.173584-2-nuno.sa@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 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;
 
-- 
2.35.3