From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 373BA19004A; Sat, 1 Feb 2025 15:27:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738423646; cv=none; b=jN5vXH2GyE9ZwayYrKgP5cw/xobkBqOvcdEEoPNrnGiMH6BPcvJOwCRKhIn+Ej+mnHwRt/9/qB2k7O9nTorB0a3f57SG/AZMrhg1dmgT62+zEryUzPpJL8lHqKr7E8GFzLGzDOKhGGiKH3KTqZQDy1C5oHuZcxVMlfrDLoOX3T4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738423646; c=relaxed/simple; bh=mAYmnKj8g/RiOgH0ptBAlOdmMm+uAmURkuHCE5d0P7w=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=knh2uTJYj2SVVbbMxlSrTZi+JPi6H3YO7KxlYBO7Lw23Rqmdd6B2sNBDfKGbA8VnTirS791/NKH1/gIKCrnUHnBCISlCF2KzAHZQFO1SKHFbLFCv0mIcsVXa0r1ukqNraoUgVyt1y85L6C9ACa8gqyQPOOBrUGJRZ9a00/KmUfs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=omdrj+hi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="omdrj+hi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F7DAC4CED3; Sat, 1 Feb 2025 15:27:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738423646; bh=mAYmnKj8g/RiOgH0ptBAlOdmMm+uAmURkuHCE5d0P7w=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=omdrj+hiFVzpMS5suOTo9tyhXANVHq2kmjVOCuM44Ogi5SwQ9XyK6n3sG5zZWnLZh eabFc8hJIpE+l3dpUxl6QSBJWbgimy6oz93g+Z2ZX/6qfiq/+mfa0nAP7dJWxsIbLg i2X3p5zEBtYNCujE/hqPcbnoEgVK1Y2Yq/edQodFX1x1n+RvUsrG8krYY5giyf2u0S burUw526tU0DnrKkOQ2u2G9eFHHMxWqITDCl98co4/N7tkIf4GRBMBQ6zzhZh7cdd2 PhKxWMzCH1Tor3fZKnLJnWoRbabPvRCvQCbhEar1khCn57TWy750mB0Y66N+E+Us6r mIFDxH/QrDJeQ== Date: Sat, 1 Feb 2025 15:27:20 +0000 From: Jonathan Cameron To: Jonathan Santos Cc: , , , Sergiu Cuciurean , , , , , , , , , David Lechner Subject: Re: [PATCH v2 01/16] iio: adc: ad7768-1: Fix conversion result sign Message-ID: <20250201152720.137bb3ee@jic23-huawei> In-Reply-To: <64e32c0ac7357ca7ddea813ba932bf957cbbeca2.1737985435.git.Jonathan.Santos@analog.com> References: <64e32c0ac7357ca7ddea813ba932bf957cbbeca2.1737985435.git.Jonathan.Santos@analog.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.48; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 27 Jan 2025 12:11:01 -0300 Jonathan Santos wrote: > From: Sergiu Cuciurean > > 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 > --- > v2 Changes: > * Patch moved to the start of the patch series. Applied to the fixes-togreg branch of iio.git. Thanks, Jonathan > --- > 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 113703fb7245..c3cf04311c40 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, > @@ -371,7 +371,7 @@ static int ad7768_read_raw(struct iio_dev *indio_dev, > > ret = ad7768_scan_direct(indio_dev); > if (ret >= 0) > - *val = ret; > + *val = sign_extend32(ret, chan->scan_type.realbits - 1); > > iio_device_release_direct_mode(indio_dev); > if (ret < 0)