From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-vk1-f174.google.com (mail-vk1-f174.google.com [209.85.221.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CAD283BD25E for ; Wed, 24 Jun 2026 14:14:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782310488; cv=none; b=sxKojh3iLe4IzW9jlAzILWcae0bzcOaogskFWIKZ01xQ5Yce7U09BTgBtwPBmxd1tbjYtp+N453Dm+AD7aNqskMoLdryT1tSIYyapcohIKgbRU8eVP3gWsflKJFV1zlkaNtBodBfO02AGzzFuhCIwOYqKZTG6Q3WV3I0koDOmXw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782310488; c=relaxed/simple; bh=VElC9oMArW8E5DVw0C3OZ8uCAD3W1Xad/JX5R0ZfH4Y=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YDErJmhjQY+Z40lodXGCSS1n2rcaA4R++BFyQH8gEV4PyNGc2RN/MYkpCrY+k2PojgnRC2+57MKApUcR069PArLCqfhLaCOsBnQrT2WpUj8bMWPuBQpRI/+7MBcygfQHvMQ22mlZ7hifF5OUhjIDSadZmsPW0V82jGxrb5kHoOE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com; spf=pass smtp.mailfrom=baylibre.com; dkim=pass (2048-bit key) header.d=baylibre.com header.i=@baylibre.com header.b=Astq86Lv; arc=none smtp.client-ip=209.85.221.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=baylibre.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=baylibre.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=baylibre.com header.i=@baylibre.com header.b="Astq86Lv" Received: by mail-vk1-f174.google.com with SMTP id 71dfb90a1353d-59c2a81ca92so697028e0c.0 for ; Wed, 24 Jun 2026 07:14:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre.com; s=google; t=1782310486; x=1782915286; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=EKXkM/V9V+5iFe2v+ihivIbTjpQHj54cW+T1VhjBSuY=; b=Astq86LvePsh3PutKYaFFizihoqbeHKR/2P4MhRLIDcTqIZgPpYkQeo32E08fGgmsN oBR2hZvC3k3kwQJjIBdFcOcx6KybePc+fDET1E8XAhUcoM/XrAxgkYPj5Ef/RGSKzucW Ojg6QaMSK2QYO3FqEP4gO2H3Vp2isrXEDS+httJNBesTPX2EJ7YPmxwWp/WDe400s7t8 3hynz5BjwJiQACYezdZ+esMl2GifDQA8v6hmgXlC3KGrnyvHPXQN1R0KmHefvBcow6Yp 3AAr1RVD09NgjBvpjnxmIhzoUO05x08xwCnL5w2b16d9C/eDLXcBCA3rxgXzlQV7EBIj pi/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782310486; x=1782915286; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=EKXkM/V9V+5iFe2v+ihivIbTjpQHj54cW+T1VhjBSuY=; b=Ys1vtl3QaTqKRcOF6mu5EQ8Y3xUWePT38WWmzfPY2IzDkRluDn8nbneEzmGx5+VF0K +oHaY/D2aO20T9rJkKC1EhSnnw9MyfG0jPUu3NiNrHefu371hSdoitkVVPdC2qNnB8WO RJRXlGN88eni5miYdz3aYq25kkcdWioOz7r+/1pmrgBb1bjrahr+r4ZN0zuXXst3ODuR u9lx96oPr2z+wj7WtD67XG9ht4isMtqSzj+QguGXaWZb7QUWuwAXq9bS4jItF8s+AxHP QcPQfc2dbgiXTp2X01zIEVwqUuUq7OHwHa0Jrdku/WxS0qJ/AAWLwcUS+2tRXS3GMrr9 jNbg== X-Forwarded-Encrypted: i=1; AHgh+RqsWNke74noyLxWM/avQp9jczbgxb08EL7Nn2mhVQ0pxLGoMAWuaX6D4ZuQrsGGgRwEJI+Y9yzfKttXU58=@vger.kernel.org X-Gm-Message-State: AOJu0YzCKFsXsPnpoOn4N/Rz7fgwzEAfzkSu4b9gL1zAq9dqv9NUVU2N vPG/lRZYiqvDLrtyIRvE8wo0QSoDnjOfhillLBu25I/J0ZfAsmP/iMXrDnLkL0QF/pE= X-Gm-Gg: AfdE7cmn/47paGNRa6L7M4+8fLMG5a9DrdDYJZZfsQnjk0mcddQvFk4pi7DRnFI56T/ cMrkgUTdK5FPSvAPXvn2E9Ol4rtU43Umw9czSjc+d+w4ATUQmkXGLgKgaC8TaBmjAu8EZSOygp8 rVBCZbQn9FsQj7uPP5+AHylh9iBt38yx8DNDDQiHqEMMMGAz2frPsfJSGk00+NXQrEHAnTI0cU0 ORWO8QB+Jf9VfdpjcY63jewjjnPE8DClZPbsVKPsLLPnWbwTZcB6I+VA6LSQJh0sVTKHfkyWae9 VVhhfHzJeLsGzq4DZFF3Kv8cLuaZjbJHRrgwjJ8svMnqubh2DsMy9uQh19MKLMZR8QfrWXYksMQ 5CAI4c78jG+Kz+AUNmst2zDElWqSzXkamVNA/M1F7LGvSRXCygxwsPAEC3sVYhdlA/HKmnay5H5 VAttN4KK/bzOCApi5Oi+PPPx+4J2ZVOHUpWFJoi64t0G5kfGCV0Aug/T/Y5ziJZJc= X-Received: by 2002:a05:6122:6c02:b0:5bc:42be:f7c4 with SMTP id 71dfb90a1353d-5bc42bf0a82mr1061612e0c.3.1782310485652; Wed, 24 Jun 2026 07:14:45 -0700 (PDT) Received: from ?IPV6:2600:8803:e7e4:500:68dc:b788:b3ac:e34e? ([2600:8803:e7e4:500:68dc:b788:b3ac:e34e]) by smtp.gmail.com with ESMTPSA id 71dfb90a1353d-5bbfb878c91sm10694600e0c.6.2026.06.24.07.14.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 24 Jun 2026 07:14:44 -0700 (PDT) Message-ID: Date: Wed, 24 Jun 2026 09:14:43 -0500 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] dt-bindings: iio: dac: Add DAC8163 To: Lukas Metz Cc: Jonathan Cameron , =?UTF-8?Q?Nuno_S=C3=A1?= , Andy Shevchenko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, devicetree@vger.kernel.org References: <20260623-dac8163-work-v1-0-5b508158faa0@gmx.net> <20260623-dac8163-work-v1-2-5b508158faa0@gmx.net> <5a19c272-e8fc-4fa9-b137-842b6ed6649b@baylibre.com> Content-Language: en-US From: David Lechner In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/24/26 1:25 AM, Lukas Metz wrote: > Thanks a lot for the review. This is my first time submitting a > patch so im grateful for the detailed comments and suggestions. > > On Tue, Jun 23, 2026 at 02:17:04PM -0500, David Lechner wrote: >> It is more logical to put the dt-bindings patch first in the series >> before the driver that makes use of it. > > I will reorder the commits in v2. For future reference, you don't need to respond to comments that you agree with (save us time reading). > >> There are a couple of more SPI properties needed since this is not a "normal" >> SPI device. We can only write and not read because there is no D_OUT pin. So >> >> spi-rx-bus-width: >> items: >> - const: 0 >> >> will describe this. > > I will the add the suggested changes to v2. Are there any other poperties > i have missed? Same for the other comments regarding vendor-prefix, > spi-max-frequency, avdd-supply and vref supply name. > >> We also want the binding to be complete even if the driver doesn't all of it, so >> `clear-gpios` and `sync-gpios` probably make sense too. > > SYNC pin is the chip select pin of the device as described below. In > that case i dont need to add it here right? Ah, OK. It is probably worth mentioning that in the top-level description here in the bindings. > >> Usually, we don't bother with a property like this since it is redundant. >> If an external reference supply is given, then it gets used, otherwise >> the internal reference is used. > > That sounds logical. I will remove the property completly. > >> These chips don't appear to have a chip select pin, so this comment >> doesn't make sense to me. More logical would be to just use dac@0 >> and reg = <0>; since it should just be ignored. > > The SYNC pin on the device acts like a chip select pin. > According to the datasheet: when the pin goes low it enables the input shift > register. At least that was my understanding. On my board i have tested the > driver with the chip select signal connected to the SYNC pin. The > example comes straight from my own device tree where i have two devices > on the bus. Thats why i used reg<1> here but i can change it to 0 and > remove the comment.> >> The pin is marked active low in the datasheet, so I would expect >> this to be GPIO_ACTIVE_LOW. > > I wasnt sure about that. The pin needs to be held low continuously. I > thought when the pin is marked active low and i initialize the pin with > GPIOD_OUT_LOW the result will be that the pin is held high. To match the > datasheet description seems logical though. > The GPIOD_OUT_LOW and GPIOD_OUT_HIGH names in the kernel are not ideal. Think of them as "deasserted" and "asserted". If the devicetree has GPIO_ACTIVE_LOW, then GPIOD_OUT_HIGH will "assert" the pin by pulling the voltage low (because it is active low).