From 6f21dfc4fadbe7076b89aa2fcb275001af2fa566 Mon Sep 17 00:00:00 2001 From: Sergiu Cuciurean Date: Thu, 6 Mar 2025 18:00:29 -0300 Subject: [PATCH] iio: adc: ad7768-1: Fix conversion result sign [ Upstream commit 8236644f5ecb180e80ad92d691c22bc509b747bb ] The ad7768-1 ADC output code is two's complement, meaning that the voltage conversion result is a signed value.. Since the value is a 24 bit one, stored in a 32 bit variable, the sign should be extended in order to get the correct representation. Also the channel description has been updated to signed representation, to match the ADC specifications. Fixes: a5f8c7da3dbe ("iio: adc: Add AD7768-1 ADC basic support") Reviewed-by: David Lechner Reviewed-by: Marcelo Schmitt Signed-off-by: Sergiu Cuciurean Signed-off-by: Jonathan Santos Cc: Link: https://patch.msgid.link/505994d3b71c2aa38ba714d909a68e021f12124c.1741268122.git.Jonathan.Santos@analog.com Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/iio/adc/ad7768-1.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c index 19d604f5701d..74b0c85944bd 100644 --- a/drivers/iio/adc/ad7768-1.c +++ b/drivers/iio/adc/ad7768-1.c @@ -142,7 +142,7 @@ static const struct iio_chan_spec ad7768_channels[] = { .channel = 0, .scan_index = 0, .scan_type = { - .sign = 'u', + .sign = 's', .realbits = 24, .storagebits = 32, .shift = 8, @@ -374,7 +374,7 @@ static int ad7768_read_raw(struct iio_dev *indio_dev, iio_device_release_direct_mode(indio_dev); if (ret < 0) return ret; - *val = ret; + *val = sign_extend32(ret, chan->scan_type.realbits - 1); return IIO_VAL_INT;