From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935776AbcCQPrH (ORCPT ); Thu, 17 Mar 2016 11:47:07 -0400 Received: from mail.kernel.org ([198.145.29.136]:60237 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934944AbcCQPrB (ORCPT ); Thu, 17 Mar 2016 11:47:01 -0400 Date: Thu, 17 Mar 2016 10:46:56 -0500 From: Rob Herring To: Laxman Dewangan Cc: Markus Pargmann , Stephen Warren , linus.walleij@linaro.org, pawel.moll@arm.com, mark.rutland@arm.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, treding@nvidia.com, Benoit Parrot , Alexandre Courbot Subject: Re: [PATCH 4/5] gpio: of: Add support to have multiple gpios in gpio-hog Message-ID: <20160317154656.GA9444@rob-hp-laptop> References: <1457438528-29054-1-git-send-email-ldewangan@nvidia.com> <56E05AA9.8000503@wwwdotorg.org> <56E11D34.60401@nvidia.com> <2337414.ntEtcfKnX0@hermes> <56E16053.60802@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <56E16053.60802@nvidia.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 10, 2016 at 05:23:55PM +0530, Laxman Dewangan wrote: > > On Thursday 10 March 2016 04:46 PM, Markus Pargmann wrote: > >On Thursday 10 March 2016 12:37:32 Laxman Dewangan wrote: > >>On Wednesday 09 March 2016 10:47 PM, Stephen Warren wrote: > >>>On 03/09/2016 06:20 AM, Laxman Dewangan wrote: > >>>The problem with that is the description used when acquiring the GPIO > >>>is just "wlan_input", "wlan_output", or "wlan_control". There's > >>>nothing to indicate what those individual pins do (perhaps one is a > >>>reset signal, one is a regulator enable, etc.?) By requiring separate > >>>nodes for each GPIO, then the node name can provide a meaningful > >>>semantic name/description for each GPIO, which provides much more > >>>information. I agree. > >>On this case, we have already property "line-name" and passed the name > >>of the gpio via this property. > >>The property names is "line-name" which is good for one string. We can > >>support other property "line-names" with multiple string per GPIO index. > >> > >>line-names = "wlan-reset", "wlan-enable"; Then what happens when someone wants to selectively disable gpio hogs? status = "okay", "disabled", "okay"; While I often push things to fewer nodes and more compact descriptions, I don't think that is the right direction in this case. > >There is currently a discussion about the future bindings for subnodes in GPIO > >controller nodes. Please have a look at these two mail threads: > > > > "Device tree binding documentation for gpio-switch" > > "gpio: of: Add support to have multiple gpios in gpio-hog" > > Second one is this patch only. Is it by intention? > > The binding details about the gpio-switch and names are given by property > "lable". I think property "label" is standard way of going forward i.e. I > post similar patch for gpio-keys device name from DT after got review > comment. > > So here, we can have the gpio names under property "label" or "labels". label is standard. labels you just made up. > Or am I missing anything? The point is the more one off changes I see that are all inter-related, the less willing I am to accept any that don't consider all the cases. The inter-relationship here is how do we describe gpio lines that don't otherwise have a connection to another node and how to deal with them if that changes. Rob