From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752790AbdHKJeq convert rfc822-to-8bit (ORCPT ); Fri, 11 Aug 2017 05:34:46 -0400 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:33605 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752767AbdHKJem (ORCPT ); Fri, 11 Aug 2017 05:34:42 -0400 Message-ID: <1502444067.1333.7.camel@pengutronix.de> Subject: Re: [RESEND PATCH 2/4] dt-bindings: add "reduced-width" property for Armada XP SDRAM controller From: Jan =?ISO-8859-1?Q?L=FCbbe?= To: Chris Packham , Rob Herring Cc: "gregory.clement@free-electrons.com" , "bp@alien8.de" , "linux-arm-kernel@lists.infradead.org" , "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Mark Rutland , "devicetree@vger.kernel.org" Date: Fri, 11 Aug 2017 11:34:27 +0200 In-Reply-To: <4935472b6a44447fa764fa811a645b9f@svr-chch-ex1.atlnz.lc> References: <20170807014641.4003-1-chris.packham@alliedtelesis.co.nz> <20170807014641.4003-3-chris.packham@alliedtelesis.co.nz> <20170810203801.jz5hl5onqci275ef@rob-hp-laptop> <4935472b6a44447fa764fa811a645b9f@svr-chch-ex1.atlnz.lc> Organization: Pengutronix Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.22.6-1 Mime-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c3 X-SA-Exim-Mail-From: jlu@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2017-08-10 at 21:17 +0000, Chris Packham wrote: > On 11/08/17 08:38, Rob Herring wrote: > > On Mon, Aug 07, 2017 at 01:46:39PM +1200, Chris Packham wrote: [...]   > > > +Optional properties: > > > + - marvell,reduced-width: some SoCs that use this SDRAM controller have > > > +   a reduced pin count. On such systems "full" width is 32-bits and > > > +   "half" width is 16-bits. Set this property to indicate that the SoC > > > +   used is such a system. > > > > Maybe you should just state what the width is. > > Specifying a number like 64/32/16 is done in for some other properties I  > dismissed that because what this is about how we interpret a  > pin-strapping option. I guess "max-width = <64>;" and "max-width =  > <32>"; would achieve the same. > > > Or your compatible string should just be specific enough to know the > > width. > > I decided against a new compatible sting that because the IP block  > really is the Armada-XP one and the existing compatible string is used  > in other places (using multiple compatible strings would solve that). > > I'm not too fussed which of the 3 options are used. Is there any  > particular preference? I'd prefer a specific compatible string, as it would avoid adding even more properties if further difference turn up. Rob, I seem to remember that some drivers match the top-level compatible against a list of SoC variants to detect SoC-dependent features in a generic IP block. Is that something you'd prefer instead? Regards, Jan