From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-lf1-f44.google.com (mail-lf1-f44.google.com [209.85.167.44]) (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 83BA6404BE9 for ; Wed, 8 Jul 2026 11:31:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783510264; cv=none; b=CAsgEN+ozNFpVNIwppauAMQiwSLKhT7rfHEAj4ex8mpd6BQwrovL+sH9bRB225WiIrv5kzYbL+eRctYG368kvf6gRGSH/+WCNQDP7IylSUKIxqRpRW+EfoSU96e9QISBGTqL8gEYy42o/4+beODNhXicNr/KIe22vxj+MvCqf9c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783510264; c=relaxed/simple; bh=UqVYtH1FlnS/aiysBtJjKkotNDawE18yaWKbuoyRfnk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LibGzFsN3w9WMUjGFbh9jVaHl33Embrl/uATKS2/KBfDeYwkmUjfJqFa8rs9PN0HVK3FASHSlR9Y9g3+5nx1P5IYWy+mxb70b9x91NQrMobvYr05XH80AMvSWit2w10rj4c7EztBXsWc+DPrR0mQWjxgY3W76k3kPrSGe0MbSjo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=sTW5MjST; arc=none smtp.client-ip=209.85.167.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="sTW5MjST" Received: by mail-lf1-f44.google.com with SMTP id 2adb3069b0e04-5aeae350e0aso621042e87.1 for ; Wed, 08 Jul 2026 04:31:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1783510260; x=1784115060; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :content-type:mime-version:references:message-id:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to:content-type; bh=39lBDIePAL1NkZjwy0kg0GS1VSHJ5/FOzCIFnS8mpzM=; b=sTW5MjSTnFr6r/JlPxnI3BE7aoTJeXE8JYAW37w3nGv6YRpTG+WJuytWtQ8RCEYO0z pzlxY+S7YzztULVvPDwJQPuDNWAQrpO02nvcnZAYta5y6QvNdGdQqMInEV+vc7y1vsLH aTIaKz6V03aszfCW+JjnwgOdo/iV3GE13GN/XXtNdJaUKc9Wf4+dw8NS5SZeuloJSi3+ pCJ9RgFdzQHLp8OMNX6zEZpR3Ec+SC+coiBStKA6/YDUIjx/xsSaScEQGC1i8ElkDuav 9ygcKPoZwJrymEaQoRf+G5nxVE3MdCEldttrNUHKiYS+oD0Xf8quxe2H5uRPMTRSQwHT Qu+Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1783510260; x=1784115060; h=in-reply-to:content-transfer-encoding:content-disposition :content-type:mime-version:references:message-id:subject:cc:to:from :date:x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=39lBDIePAL1NkZjwy0kg0GS1VSHJ5/FOzCIFnS8mpzM=; b=rRUBpPEGyVJqoECbo769zDhg3qpYJ+wXihRJCD2o9O+IpRFpl98e7SBFzJI7jKaG7m QaEiAZ5p5hLCxgZDHjA1JH7YsBx0eqbaVWZbogBHBhCEkP7eaiu6d8gQsd+wkmuvOQv3 b7PlmC6EhqlFq+uHbwGl/7CLcykXSrnZcU71gbpPIy8ilavTEG6RuY3/7OA05dI/z06l XCRbbWUdl0cVXKlMPlC25lJkX840kVw4Kwm7YlkEvkPKw0QnMrYwfjnAHKo8SkFjG/MG bnTIyo+yQVc6FHtnCSLjEwOaNv6CgxSITKuGpKLA0MH1gvKKaP9Lvfi0hsH4oKk4W3kv ekjA== X-Forwarded-Encrypted: i=1; AHgh+Rpw+jHpQ60ZDFOTvlQsPssiRnJUR1vh7oe3wvPASCe+lMnA9JsUjubb+YkkVUNt4BT7t5DQP1gTZHY=@vger.kernel.org X-Gm-Message-State: AOJu0Yw7A7y7ETKYht/FIwmcJtluwEE36SmC9p9Jklsw9GSMqezY0bPt ufReAp7MHBlJHox9X4ldMC99eNDFItSukCNATgatJDWihYGq3F0coyg8 X-Gm-Gg: AfdE7cnAzPX3nVc1QAzr+l/gvlEZ7KhUCqOpfpfmY3L42pZhGxq5ozLX6sY+dMk8G0J OixPre3+7dQf/DkWZGGQ56iqbcgU0oJwOc0kwFuSMI6V7tKJHkoZslvm9H99q2zhA96bArwhuzS 4Q8eaeBmr2d7KlmQ/xOV06VseFh+1GZ6/HenTIligSNseIm5mO2FS0BJaVhVjejRz4+zODiVZJO WB/orzJ89Nv26jqYA5+kjW0TcOCKrcOLrlKwz/RZJjjb6+J2YdI8Dlc7g+EivM53XK3kcRcxJ4r XVT2TUwTKi2WM9OmDb3RYwEuy2b7WkyBarElgjE3NJGMRTk2EKg2UgklRMiVvCJs5QlNW8HMaKJ YCM0/GrhJZxvOYW6+lVmJ5yikEapuIw/KmaW1FoLvi8UlinskxdG60YiKtQMuYFBrYED1NaXEMz KTQ4nqvkiF6ZXEDno= X-Received: by 2002:a05:6512:1417:b0:5ae:c8d9:dcf6 with SMTP id 2adb3069b0e04-5b011463131mr553458e87.37.1783510259389; Wed, 08 Jul 2026 04:30:59 -0700 (PDT) Received: from nsa ([148.63.225.166]) by smtp.gmail.com with ESMTPSA id 2adb3069b0e04-5aed13700fasm4437116e87.5.2026.07.08.04.30.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Jul 2026 04:30:58 -0700 (PDT) Date: Wed, 8 Jul 2026 12:32:00 +0100 From: Nuno =?utf-8?B?U8Oh?= To: Krzysztof Kozlowski Cc: Guenter Roeck , Fred Chen , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Corbet , Shuah Khan , Jonathan Cameron , Wensheng Wang , Frank Li , Brian Chiang , Cosmo Chou , Dixit Parmar , Eddie James , Antoni Pokusinski , Thorsten Blum , Ashish Yadav , Alexis Czezar Torreno , Syed Arif , ChiShih Tsai , Abdurrahman Hussain , Kim Seer Paller , Colin Huang , Yuxi Wang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH 2/2] hwmon: (pmbus) Add driver for Analog Devices MAX20912 and MAX20916 Message-ID: References: <20260707122701.751878-1-fredchen.openbmc@gmail.com> <20260707122701.751878-3-fredchen.openbmc@gmail.com> <20260708-true-carp-of-champagne-a0dcca@quoll> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260708-true-carp-of-champagne-a0dcca@quoll> On Wed, Jul 08, 2026 at 12:50:25PM +0200, Krzysztof Kozlowski wrote: > On Wed, Jul 08, 2026 at 10:19:56AM +0100, Nuno Sá wrote: > > On Tue, Jul 07, 2026 at 06:52:48AM -0700, Guenter Roeck wrote: > > > On 7/7/26 05:26, Fred Chen wrote: > > > > Add support for the Analog Devices MAX20912 and MAX20916 dual-output > > > > multiphase voltage regulators with PMBus interfaces. > > > > > > > > Signed-off-by: Fred Chen > > > > > > Please provide evidence that those chips actually exist. > > > Internet search comes up blank. I'll need confirmation > > > from someone at Analog. > > > > Hi Guenter, > > > > Well, in fact I'm in the middle of preparing a series that adds support > > for: > > > > "max20826" > > "max20855b" > > "max20908" > > "max20912" > > "max20916" > > > > All the above parts have the datasheet under NDA. But before we had a > > one page "datasheet" in analog.com but I guess that is gone! For context > > I mainly did the base (core) driver for max20826 and then Alexis added > > the other ones. > > > > Not sure how to proceed... I can wait and then work on top of what Fred > > has but this patch is very minimal when compared with what we have. > > Like: > > > > * No regulator support; > > * No direct mode. The chip has two ways to access registers (paging and > > * direct mode). > > * No way to count how many phases we have or if RAIL_B (func[1]) is being used at > > all. > > > > > > Some other things more intriguing is that these chips, as far as I'm > > aware (at least for max20826), always have bit 2 set in ON_OFF_CONFIG so > > a gpio vout. Also we needed some special handling to read phase current > > which I'm not seeing in the driver. So I would like to understand how > > the chip was tested? > > > > Anyways, if Fred is ok with it I can just finish what I'm doing and send > > the patches. It would make sense to have something more complete on > > submission but I don't want to just "steal" the work already done. > > Binding should be in such case posted complete, so probably not a > trivial device. Yes, in my series bindings are not in trivial as we support the enable gpios. - Nuno Sá