From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753422AbaHMQQG (ORCPT ); Wed, 13 Aug 2014 12:16:06 -0400 Received: from avon.wwwdotorg.org ([70.85.31.133]:57360 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751749AbaHMQQD (ORCPT ); Wed, 13 Aug 2014 12:16:03 -0400 Message-ID: <53EB8F50.7090505@wwwdotorg.org> Date: Wed, 13 Aug 2014 10:16:16 -0600 From: Stephen Warren User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.0 MIME-Version: 1.0 To: Javier Martinez Canillas , Kukjin Kim CC: Doug Anderson , Olof Johansson , Yuvaraj Kumar C D , Mark Brown , linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/6] ARM: dts: Add tps65090 FETs constraints References: <1407861868-20097-1-git-send-email-javier.martinez@collabora.co.uk> <1407861868-20097-7-git-send-email-javier.martinez@collabora.co.uk> In-Reply-To: <1407861868-20097-7-git-send-email-javier.martinez@collabora.co.uk> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/12/2014 10:44 AM, Javier Martinez Canillas wrote: > The tps65090 PMU data manual [0] has a table that list the > "Recommended operating conditions" for each regulator. Add > the information about the FET constraints to its dtsi file. > > [0]: http://www.ti.com/lit/ds/symlink/tps65090.pdf I'm worried that this file represents the limits of the PMIC itself, whereas the DT should be representing the limits of the circuits that the various PMIC regulators are attached to on the board. For example: > diff --git a/arch/arm/boot/dts/tps65090.dtsi b/arch/arm/boot/dts/tps65090.dtsi > tps65090_fet3: fet3 { > + regulator-min-microvolt = <3000000>; > + regulator-max-microvolt = <5500000>; > }; I guess that on some boards, this output rail might be attached to devices that must run at 3.3V exactly, and on other boards it might be attached to devices that must run at 5V exactly. The DT for those two boards should each have regulator-{min,max}-microvolt set to the same value, which describes the board requirements. It feels dangerous/misleading to define the PMIC range by default. It might lead people to think that since the property already has a defined value, they don't need to think about what the correct value for their board is, and hence not change the value in their board file.