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 07EC314267; Sat, 1 Jun 2024 18:35:28 +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=1717266929; cv=none; b=jxob1CSNfzzzNtIX4UKG2W7vRinAG6GGeLwh9JvmqYoI8IlDN7FnzuBbUYRGX0+nJ2KcbOZvYps1VpO7+okk6p3kXnYDtQJTo4ylkphEnJ01s+BbLyQZ79crI6miHBBTfbdotCqOf5oqDJShbxltP1aci/ANCUAnih2aJEs6zfA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717266929; c=relaxed/simple; bh=mtgb8tUEskvemeJcAOPUnubgObdTQkeV31omALLO7pc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=boP76NWG6DnvsAJWDrjazHcRzm233t8rBlouaTEe0se3h0k+zgpe5EchRgv2NDGpQjDYzAwRe2r15v8BZ5IMxvuzHNooiqRePrWgbOhj6C+CCP2DJvglgzvOpSnr3ejsqJ6uo3a9Wqy+MkzH/uuWze3sv6BHmUB1AgGvRgdH66k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iNlH+UiJ; 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="iNlH+UiJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C63A3C116B1; Sat, 1 Jun 2024 18:35:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717266928; bh=mtgb8tUEskvemeJcAOPUnubgObdTQkeV31omALLO7pc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=iNlH+UiJ3HzSbTmjUVHal1OZKAIrt+6ksY0CblgBD5MNtmimFpmsnRp7mtPSF0Rhz 98QnTgIJBWgrjYrdIvo6KYy3QlVcsbgTYywb9eKykXtma8dU5CQnjIISDeVKb0TRDv V4Sg1dG/b/qQqN+Fr8226DrJRFWPjgDrRs73vuSnzWi73OYeScF406fbLjtFXbb5cC q65YQbnMvWIg0c1/oKW8yVHe/XISnPCTSx05AgyVnQIqHFHKsRTihXU+z194wUAb2F Tta2LGLlZXFoVCfufH3OgHQu3bTIl49cI24FO0UjXIWYIU82JHffaRu+93H4N5S+fK FZLsfW2g8Xl4w== Date: Sat, 1 Jun 2024 19:35:12 +0100 From: Jonathan Cameron To: Dumitru Ceclan via B4 Relay Cc: dumitru.ceclan@analog.com, Lars-Peter Clausen , Michael Hennerich , Rob Herring , Krzysztof Kozlowski , Conor Dooley , David Lechner , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Dumitru Ceclan Subject: Re: [PATCH v4 1/6] dt-bindings: adc: ad7173: add support for ad411x Message-ID: <20240601193512.0e17992b@jic23-huawei> In-Reply-To: <20240531-ad4111-v4-1-64607301c057@analog.com> References: <20240531-ad4111-v4-0-64607301c057@analog.com> <20240531-ad4111-v4-1-64607301c057@analog.com> X-Mailer: Claws Mail 4.2.0 (GTK 3.24.42; 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=UTF-8 Content-Transfer-Encoding: quoted-printable On Fri, 31 May 2024 22:42:27 +0300 Dumitru Ceclan via B4 Relay = wrote: > From: Dumitru Ceclan >=20 > Add support for: AD4111, AD4112, AD4114, AD4115, AD4116. >=20 > AD411x family ADCs support a VCOM pin. The purpose of this pin is to > offer a dedicated common-mode voltage input for single-ended channels. > This pin is specified as supporting a differential channel with VIN10 on > model AD4116. >=20 > AD4111/AD4112 support current channels. Support is implemented using > single-channel and "adi,current-channel". >=20 > Signed-off-by: Dumitru Ceclan I like the common-mode-channel solution to the pseudo differential description. It makes things explicit whilst avoiding an ugly differential but not differential mess. However, it feels like a general thing to me not a vendor specific one. Perhaps makes sense to put in adc.yaml? One other question that is more me being curious and failing to understand the datasheet than a request to change anything. > --- > .../devicetree/bindings/iio/adc/adi,ad7173.yaml | 192 +++++++++++++++= +++++- > 1 file changed, 190 insertions(+), 2 deletions(-) >=20 > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml b/= Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml > index ea6cfcd0aff4..d8474eee553e 100644 > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml > @@ -19,7 +19,18 @@ description: | > primarily for measurement of signals close to DC but also delivers > outstanding performance with input bandwidths out to ~10kHz. > =20 > + Analog Devices AD411x ADC's: > + The AD411X family encompasses a series of low power, low noise, 24-bit, > + sigma-delta analog-to-digital converters that offer a versatile range = of > + specifications. They integrate an analog front end suitable for proces= sing > + fully differential/single-ended and bipolar voltage inputs. > + > Datasheets for supported chips: > + https://www.analog.com/media/en/technical-documentation/data-sheets/= AD4111.pdf > + https://www.analog.com/media/en/technical-documentation/data-sheets/= AD4112.pdf > + https://www.analog.com/media/en/technical-documentation/data-sheets/= AD4114.pdf > + https://www.analog.com/media/en/technical-documentation/data-sheets/= AD4115.pdf > + https://www.analog.com/media/en/technical-documentation/data-sheets/= AD4116.pdf > https://www.analog.com/media/en/technical-documentation/data-sheets/= AD7172-2.pdf > https://www.analog.com/media/en/technical-documentation/data-sheets/= AD7172-4.pdf > https://www.analog.com/media/en/technical-documentation/data-sheets/= AD7173-8.pdf > @@ -31,6 +42,11 @@ description: | > properties: > compatible: > enum: > + - adi,ad4111 > + - adi,ad4112 > + - adi,ad4114 > + - adi,ad4115 > + - adi,ad4116 > - adi,ad7172-2 > - adi,ad7172-4 > - adi,ad7173-8 > @@ -129,10 +145,54 @@ patternProperties: > maximum: 15 > =20 > diff-channels: > + description: | > + This property is used for defining the inputs of a differential > + voltage channel. The first value is the positive input and the= second > + value is the negative input of the channel. > + > + Family AD411x supports a dedicated VINCOM voltage input. > + To select it set the second channel to 16. > + (VIN2, VINCOM) -> diff-channels =3D <2 16> > + > + There are special values that can be selected besides the volt= age > + analog inputs: > + 21: REF+ > + 22: REF=E2=88=92 > + Supported only by AD7172-2, AD7172-4, AD7175-2, AD7175-8, AD71= 77-2: > + 19: ((AVDD1 =E2=88=92 AVSS)/5)+ > + 20: ((AVDD1 =E2=88=92 AVSS)/5)=E2=88=92 That's what it says on the datasheet (so fine to copy that here) but I'm cu= rious, what does that mean in practice? How can we have negative and postive signals of the= difference between two power supply voltages where I'm fairly sure AVDD1 always greate= r than AVSS. Anyhow, that's a problem for the person reading the datasheet to figure out= :) =20 > + > items: > minimum: 0 > maximum: 31 > =20 > + single-channel: > + description: | > + This property is used for defining a current channel or the po= sitive > + input of a voltage channel (single-ended or pseudo-differentia= l). > + > + Models AD4111 and AD4112 support current channels. > + Example: (IIN2+, IIN2=E2=88=92) -> single-channel =3D <2> > + To correctly configure a current channel set the "adi,current-= channel" > + property to true. > + > + To configure a single-ended/pseudo-differential channel set the > + "adi,common-mode-channel" property to the desired negative vol= tage input. > + > + When used as a voltage channel, special inputs are valid as we= ll. > + minimum: 0 > + maximum: 31 > + > + adi,common-mode-channel: > + $ref: /schemas/types.yaml#/definitions/uint32 > + description: > + This property is used for defining the negative input of a > + single-ended or pseudo-differential voltage channel. > + > + Special inputs are valid as well. > + minimum: 0 > + maximum: 31 > +