From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B1C9C43382 for ; Wed, 26 Sep 2018 18:51:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A90DE2154B for ; Wed, 26 Sep 2018 18:51:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A90DE2154B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727649AbeI0BFw (ORCPT ); Wed, 26 Sep 2018 21:05:52 -0400 Received: from mail.bootlin.com ([62.4.15.54]:60127 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725806AbeI0BFw (ORCPT ); Wed, 26 Sep 2018 21:05:52 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id 0272320731; Wed, 26 Sep 2018 20:51:31 +0200 (CEST) Received: from localhost (unknown [88.191.26.124]) by mail.bootlin.com (Postfix) with ESMTPSA id CFDE720379; Wed, 26 Sep 2018 20:51:20 +0200 (CEST) Date: Wed, 26 Sep 2018 20:51:21 +0200 From: Alexandre Belloni To: Rob Herring Cc: Sam Ravnborg , Alessandro Zummo , Andrew Jeffery , Fabio Estevam , Joel Stanley , Mark Rutland , Russell King , Sascha Hauer , Shawn Guo , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rtc@vger.kernel.org, =?iso-8859-1?Q?S=F8ren?= Andersen Subject: Re: [PATCH v1 1/5] dt-binding: rtci-pcf8523: add quartz_load property Message-ID: <20180926185121.GF16644@piout.net> References: <20180822183555.GA24084@ravnborg.org> <20180907193508.24974-2-sam@ravnborg.org> <20180913190516.GG14988@piout.net> <20180926154708.GA3264@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180926154708.GA3264@bogus> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26/09/2018 10:47:08-0500, Rob Herring wrote: > > > +Optional property: > > > +- nxp,quartz_load_12.5pF: The capacitive load on the quartz is 12.5 pF, > > > + which differ from the default value of 7 pF > > > + > > > > The boolean properties usually don't work well for RTCs because people > > usually want to keep any previous configuration that may have been done > > at the factory or in the bootloader so I would use: > > > > nxp,quartz_load_fF and this would be either 7000 or 12500. > > Use '-' rather than '_'. > > There's already a defined unit suffix of '-picofarads'. If you need > '-femtofarads', then please add to property-units.txt. Though I'd prefer > not as wouldn't a value of 12 (or 13) be close enough for the needs > here? > For that particular RTC, yes but the isl1208 has 0.5pF steps and the x1205 has 0.25pf steps. I'd prefer having a single generic property for all the RTCs: quartz-load-femtofarads. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com