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 E90DA8834; Sat, 27 Dec 2025 17:06:16 +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=1766855177; cv=none; b=FnKYUQ9R/6CHTJAOLZLWClzJktynToFyQ7/w7CRE3w5VSOBFt4ls5zn2cz17ZDUvyodqiOD4gQHbeekOqQbUrz1GneG+LVUYRqoL6LmoYwCqS6lNvijzovEljyaGVBkc27z0cB7UzJXRcCB5VC6TBS4nsDSvlEJZYlea+ESyyXU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766855177; c=relaxed/simple; bh=NTpVw1MWKdQD5XzNEpyiLS5xNVoZRVpbvXKO2AcrC6g=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mGYBM2491EEaPmN1Ua/Bj2ZzWQ7hffS4pbc9MYbEzL2GO5zbRTtfyPLO5auqputBGXS2CA/qh8I05Z0hHy33aI4f4myg5JSOu1IusDNDevVP90RzLVNa5ek0GbXhToLc7j06t5YrcGdQVHu8aUwVPRU0Gn1icGU80aheUB5ii/0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nCaKuqA1; 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="nCaKuqA1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8EBE1C4CEF1; Sat, 27 Dec 2025 17:06:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766855176; bh=NTpVw1MWKdQD5XzNEpyiLS5xNVoZRVpbvXKO2AcrC6g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=nCaKuqA1cPzRNBaAz01qgKAnOtSoAwic5A4Y9zWaSOe17DBRUXXst8EprgLXvB6UT dR8TDyKi4rkYOnFj4chSZEW+BNzcbuPUgXFYAjnXwwmDlE2Qlgt2PDOElekoT8CxqO s9v6+slFiK+R7O8hNXexU2cEsc1z+7WINvU3rj9kj4jVzb3+zBHi96icbifD+3tHrK 46kMNg4VuzHG0xvDQY+W6+mXmI+QX5cZ55wdjQj00abHxQQ3mpAhN4CSzHLU9/EGee Y1ylrw/CoWPlEHgN64sAwHxsBm7wt60w7hRH39ktw2CjyM5exV4dYFT7f3nAz4GgzK EPfwIzPf8nBFg== Date: Sat, 27 Dec 2025 17:06:05 +0000 From: Jonathan Cameron To: Rodrigo Alencar <455.rodrigo.alencar@gmail.com> Cc: rodrigo.alencar@analog.com, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, David Lechner , Andy Shevchenko , Lars-Peter Clausen , Michael Hennerich , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Corbet Subject: Re: [PATCH v2 5/6] docs: iio: add documentation for adf41513 driver Message-ID: <20251227170453.66752435@jic23-huawei> In-Reply-To: <73sjjxkltm7a5ylpwv7jyiha3rsgmiwrjc4gwkva5u2vc36trk@sn4ctgr7v7ek> References: <20251219-adf41513-iio-driver-v2-0-be29a83d5793@analog.com> <20251219-adf41513-iio-driver-v2-5-be29a83d5793@analog.com> <20251221180018.488cbac5@jic23-huawei> <73sjjxkltm7a5ylpwv7jyiha3rsgmiwrjc4gwkva5u2vc36trk@sn4ctgr7v7ek> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; 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 > > > +2.3 Reference Input Control > > > +--------------------------- > > > + > > > +The ``refin_frequency`` attribute allows control of the reference in= put > > > +frequency when using a programmable reference clock. The supported r= ange is > > > +10 MHz to 800 MHz. =20 > > > > I'm not really sure why need this as opposed to having a standard clock > > provide it. =C2=A0What's the use case? =20 >=20 > I was thinking about, and for the application I am currently evaluating t= he part > the reference signal comes from a DDS, and that signal is not a clock it = is a > series of chirp patterns. The important thing about this property is to s= et > a center frequency for the DDS to work on. In that scenario the PLL will = not > really work as a frequency sythentizer, but as a frequency tracker of the > varying reference. Problem is that I've realized that recently after putt= ing > together a device driver for the DDS. Therefore this property is still im= portant, > and I need to make the reference clock input as an optional property. > I thought of making the DDS as a clock provider, but that center frequency > would have a "virtual" meaning, not attached to the hardware configs. Interesting use case! I'm not really sure how we support it. I can think o= f a a few approaches that might work. In some way it's a bit similar to an ampl= ifier in front of an ADC or other analog front end, just working in the frequency= domain. I've never been entirely happy with how we support those either though! >=20 > > > +2.5 Phase adjustment > > > +-------------------- > > > + > > > +The ``phase`` attribute allows adjustment of the output phase in deg= rees. =20 > > > > As per driver feedback, I don't think this is compliant with existing A= BI. =20 >=20 > ABI is not in degrees? the attribute is named out_altvoltage0_phase All angle things (including phase) in IIO are in Radians (we try to stick t= o SI units). Check these in Documentation/ABI/testing/sysfs-bus-iio* Note that is not always as complete as it should be so if anything is missi= ng and in use we should add it. We don't blanket add stuff the ABI constructi= on code allows as some cases will never occur in reality. Jonathan