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 A4F0F405C32; Sun, 17 May 2026 15:45:54 +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=1779032754; cv=none; b=fwFa8n+txeKH1KkNTmrxR3JCuSWejndEH1AnSQM2j6DmOurYkBiZGrgemf00TYyuZJ0jQQn/r4IKeCdD0RqiHMnN0i6yG8iTMQ4E1RocF5qBq6XEqVu+2f7pIpN8c56wBDSckUp8UgdFrcHIShCEQitzkykKhM5DyFDLSuDZ0Tg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779032754; c=relaxed/simple; bh=ItD4S9x0mFpUzIadUXek7CMnVOMmle1JXqnbR7Ej58g=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=s/0v2itPlwZOk/K7Os/pluUjqALG7c+ajwQR8VqNbgo71Wd3GiUqP4x2TLC7UGH5nMNx41VqPKBlmXZfB/oX1zzkegnWgJl+9b/pyCUxHYP8XY+KlKtLu4Fwoez1FG7wdrM/KkvIsxg+udm2pjE1LOVhjDZRKCGXmzrrfxAWvYU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IfYRzgM+; 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="IfYRzgM+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C353AC2BCB0; Sun, 17 May 2026 15:45:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1779032754; bh=ItD4S9x0mFpUzIadUXek7CMnVOMmle1JXqnbR7Ej58g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=IfYRzgM+DtGlBgcpGCMVW9sJTrzrixPXuJyw0fhPxM2ihHniQBzBNs1hdgapnL5zc 8z/WLxtVND1yu8Ykr0+gIpC6SbhlOW9BY3zMMLmA2RG/0AnHATz3E6ofMe95ac2JJB TANEW4BpLOVEdaxXontvxyIx1xnQe246wa8YD2bTBJo9BkfHBrcSX1GENL23+/JMtA GIVMkpAaH77UpQfA790chUZBuuDp/+JsJioX1uDnOUF9DemFLk8F4yoyo4OgC/8PLO SFmtpFoc93xWXY57QZ1P9fehEbbs3wkZQhWNt99PRFDg/bpM0cTc1VbJSLWYuGeXl6 zUYzGZvyllbbg== Date: Sun, 17 May 2026 16:45:43 +0100 From: Jonathan Cameron To: Rodrigo Alencar via B4 Relay Cc: rodrigo.alencar@analog.com, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-hardening@vger.kernel.org, Lars-Peter Clausen , Michael Hennerich , David Lechner , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Philipp Zabel , Jonathan Corbet , Shuah Khan , Kees Cook , "Gustavo A. R. Silva" Subject: Re: [PATCH RFC v4 09/10] Documentation: ABI: testing: add docs for ad9910 sysfs entries Message-ID: <20260517164543.0d9a12fd@jic23-huawei> In-Reply-To: <20260517155843.7f833658@jic23-huawei> References: <20260508-ad9910-iio-driver-v4-0-d26bfd20ee3d@analog.com> <20260508-ad9910-iio-driver-v4-9-d26bfd20ee3d@analog.com> <20260517155843.7f833658@jic23-huawei> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-doc@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 Sun, 17 May 2026 15:58:43 +0100 Jonathan Cameron wrote: > On Fri, 08 May 2026 18:00:25 +0100 > Rodrigo Alencar via B4 Relay wrote: > > > From: Rodrigo Alencar > > > > Add custom ABI documentation file for the DDS AD9910 with sysfs entries to > > control Parallel Port, Digital Ramp Generator and OSK parameters. > > > > Signed-off-by: Rodrigo Alencar > I'm fine with phase and frequency as defined, but for the scaling it made me wonder. > For outvoltage0 channels the assumption the value is the peak voltage so if > we know what input to be modulated by the ramp generator can we express them > in volts (well milivolts) rather than as a scaling multiplier? > > That seems to me like it fits better with the overall ABI. > > > +What: /sys/bus/iio/devices/iio:deviceX/out_altvoltageY_scale_offset > > +KernelVersion: > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + For a channel that allows amplitude control through buffers, this > > + represents the value for a base amplitude scale. The actual output > > + amplitude scale is a result with the sum of this value. > > + > > > + > > +What: /sys/bus/iio/devices/iio:deviceX/out_altvoltageY_scale_roc > > Silly question perhaps but can work out how this related to millivolts/sec > That might make a more intuitive interface than scaling multiplier per sec > Perhaps the combination with offset makes this impossible though maybe that > could be a expressed as a voltage offset? Afterall if the amplitude being > scaled is 5V then 5 * (offset + scale) = 5 * offset + 5 * scale > See thread on next patch. I think I argued myself out of this. > > +KernelVersion: > > +Contact: linux-iio@vger.kernel.org > > +Description: > > + Amplitude scale rate of change in 1/s for channels that ramp > > + amplitude. This value may be influenced by the channel's > > + sampling_frequency setting. > > >