From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753948AbaIHNwr (ORCPT ); Mon, 8 Sep 2014 09:52:47 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:56539 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753795AbaIHNwp (ORCPT ); Mon, 8 Sep 2014 09:52:45 -0400 Date: Mon, 8 Sep 2014 15:52:42 +0200 From: Pavel Machek To: Mark Rutland Cc: Matti Vaittinen , ext Guenter Roeck , Jason Cooper , "a.zummo@towertech.it" , "jic23@kernel.org" , "arno@natisbad.org" , "jgunthorpe@obsidianresearch.com" , "san@rosetechnology.dk" , "hs@denx.de" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "rtc-linux@googlegroups.com" , Sverdlin Alexander Subject: Re: [PATCH] rtc: ds1307: add trickle charger device tree binding Message-ID: <20140908135242.GA21412@amd> References: <20140828124237.GA29102@fi-ourus-dhcp00977.emea.nsn-net.net> <20140828125915.GJ14650@leverpostej> <20140828155157.GB23677@roeck-us.net> <20140828161025.GO14650@leverpostej> <20140828164825.GA12153@roeck-us.net> <20140828172842.GF12769@titan.lakedaemon.net> <20140828174034.GC15307@roeck-us.net> <20140829073413.GN4587@fi-ourus-dhcp00977.emea.nsn-net.net> <20140829104001.GB19424@leverpostej> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140829104001.GB19424@leverpostej> 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 Hi! > I would suggest we have two properties that describe the resistor's > rating and whether or not there is a diode: > > trickle-resistor-ohms = <250> > diode-connected; > > That's easy for a human to write and/or validate, we can easily extend > it in future, requires no proliferation of macros, and describes the > hardware rather than telling software what to do. > > The driver becomes a little more complicated, but gains sanity checking, > which is a good thing. Certainly looks better than register bit defines. As rtc-bq32k has similar options, I'm interested, too. I believe we should add trickle-charge-enable; (we may not want to charge at all), and I believe the diode should be disconnect-diode; ... With diode connected, charge is slower, and that probably should be the default value. We don't want to give too much current in default case. (bq32k has hard-coded resistor value for diode/not-diode case). Thanks and best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html