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 63F0A34F25C; Fri, 8 May 2026 13:08:26 +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=1778245706; cv=none; b=lJdEC9nB5CCchbTLuhqpHLc7oDiMfz7Qt224fxna7fKoLDRhlvEZRLpDmZZRPbN04qsPPSDw3XKmPw5vbf4it6sV/hYK0egTYxy0/GGqwXKIhCOxwE/uBm48x8DJzC7fzKd1kIW+fnvmq+fwlwuFW/d2Bio7SGLMAeo/Vf6l9z0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778245706; c=relaxed/simple; bh=bFhsQUUgbH4CR1FXDxZX6IdtumKmj/CzQUkHgqKyqoE=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=aQQ76pPp+S1ajlmBSndYfDwN+D6c0mg97vEOXDHELdjUIt8hwA32zNqurVADGuIPSdvm/cWEOYwdq1ixyzGaXLnbCKCcqeog7mf1WEkKm5KI2065Ff9AOahdVC2C6Rv3pZKlNzK1X6g0uM1i9il80BXqiNIdg/+srm07TT5tAdY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a2xbvvRz; 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="a2xbvvRz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7282AC2BCB0; Fri, 8 May 2026 13:08:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778245706; bh=bFhsQUUgbH4CR1FXDxZX6IdtumKmj/CzQUkHgqKyqoE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=a2xbvvRzwgTBTG2ae30TeZeSoNFqlATe8KpcHeaei5ULg2iokFXE9xPZHgl5CJBCJ MxLJxLAZQ392k+zPSvyyc6n3gCuCEV8+C1DoO/8fFtGFT0HN9fQ1qcQYzEqVbIGSK7 HLMV/ruczRcjxkg49I9pCd4zctvxFPHXAx6bO6lmdqP21aAJKJGkWo8GmqgwHgUQ0b fgy1kUPCPK3tYqmN4OOAHRxnzoKnMMyZfqSWr+1eKMPux+QM2//UzphBpvCqTcQXvp xYzWmeGYZjaatSDLjP/Ve1EG4VpY9pS7yfqsV+60rgdNowuBu5MGezk5R1nkHyQwhP AGx8+/PwviAUQ== Date: Fri, 8 May 2026 14:08:14 +0100 From: Jonathan Cameron To: Janani Sunil Cc: Lars-Peter Clausen , Michael Hennerich , "David Lechner" , Nuno =?UTF-8?B?U8Oh?= , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Philipp Zabel , "Jonathan Corbet" , Shuah Khan , , , , , Janani Sunil , rodrigo.alencar@analog.com Subject: Re: [PATCH v2 1/3] dt-bindings: iio: dac: Add AD5529R Message-ID: <20260508140814.67800e4a@jic23-huawei> In-Reply-To: <20260508134843.7646c4f5@jic23-huawei> References: <20260508-ad5529r-driver-v2-0-e315441685d7@analog.com> <20260508-ad5529r-driver-v2-1-e315441685d7@analog.com> <20260508134843.7646c4f5@jic23-huawei> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-iio@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 Fri, 8 May 2026 13:48:43 +0100 Jonathan Cameron wrote: > On Fri, 8 May 2026 13:55:47 +0200 > Janani Sunil wrote: > > > Devicetree bindings for AD5529R 16 channel 12/16 bit high voltage, > > buffered voltage output digital-to-analog converter (DAC) with an > > integrated precision reference. > > > > Signed-off-by: Janani Sunil > > --- > > .../devicetree/bindings/iio/dac/adi,ad5529r.yaml | 96 ++++++++++++++++++++++ > > MAINTAINERS | 7 ++ > > 2 files changed, 103 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5529r.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5529r.yaml > > new file mode 100644 > > index 000000000000..f531b4865b01 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5529r.yaml > > @@ -0,0 +1,96 @@ > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/iio/dac/adi,ad5529r.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Analog Devices AD5529R 16-Channel 12/16-bit High Voltage DAC > > How is one device bother 12 and 16-bit? That sometimes happens for > ADCs where it is really reflecting oversampling or for device with hardware > FIFOs where storage space is saved by using lower bit rate. I'm not sure either > applies here. Having read the driver I now understand. This is supporting two parts and doing device ID based detection. In an unusual step for Analog they have the same base part number with a post fix. Whilst this approach works today it fundamentally breaks fallback dt-compatibles being used in future (the driver fails for any non match of WHOAMI value as it needs them to look up device specific data) As such I think you need to have separate compatibles for the 12 and 16 bit versions.