From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933201Ab0I0QNI (ORCPT ); Mon, 27 Sep 2010 12:13:08 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:54590 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759046Ab0I0QNH (ORCPT ); Mon, 27 Sep 2010 12:13:07 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=iL5UCmvMngpATfdq0/T90fNzq4OPkKwtikGgxXhDdvY/fXmeABwSycCKHUsyif1smo 6S9OSNU2Q+PDAJXQ1mSfKUmNMQGySERq46EYqZhrepATcPotkIMMMCXrrrPodqkdTlOI x+kye/Rl3ukJrANzKaTRadPBDqiHrtZB8GPj4= MIME-Version: 1.0 In-Reply-To: References: <1285529740-28232-1-git-send-email-notasas@gmail.com> Date: Mon, 27 Sep 2010 21:43:05 +0530 Message-ID: Subject: Re: [PATCH v3] power_supply: Add driver for TWL4030/TPS65950 BCI charger From: Arun Murthy To: Grazvydas Ignotas Cc: Anton Vorontsov , linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, Felipe Balbi , Madhusudhan Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 27, 2010 at 6:38 PM, Grazvydas Ignotas wrote: > On Mon, Sep 27, 2010 at 3:35 PM, Arun Murthy wrote: >> On Mon, Sep 27, 2010 at 4:24 PM, Grazvydas Ignotas wrote: >>> On Mon, Sep 27, 2010 at 10:21 AM, Arun Murthy wrote: >>> The problem is that BCI is only active while charging, when it is not >>> charging most (all?) monitoring registers freeze and no monitoring >>> happens (BCI registers read frozen values from last charge). So I >>> don't register battery as it has no useful data to report. I heard it >>> is possible to use MADC to perform monitoring while not charging, so >>> battery can be added when MADC driver is merged and corresponding code >>> is written for this driver. >>> >> How do I check the battery voltage? >> I need to check the battery voltage/current/temp and, if I am not >> wrong these are obtained from MADC. >> MADC driver has to be added first and then the battery. >> With being able to read the basic parameter battery voltage, this >> driver becomes incomplete. > > Incomplete driver is better than no driver, don't you think? There are > some boards like pandora or oswald that have additional battery > monitoring chips (as twl monitoring is pretty crude anyway), those > boards would have fully functional charging now. Currently mainline > kernel is not very useful with them simply because the battery runs > flat. I agree, but I feel it would be better to make driver compatible with all boards(Zoom2, OMAP3430SDP, Chameleon, BeagleBoard etc). Even support for back-up battery is not supported. This is just a suggestion to have a full fledged driver for twl4030 Battery Charger Interface as a module. You may discard this if you have some strong reasons. > >> How do I get notified if battery voltage is low and needs charging >> from user space? > > Either additional monitoring chip notifies you (if you are lucky and > have one), or wait for update of this driver :) There are efforts to > merge MADC driver [1], but it may take some time. But using MADC, I can get the battery voltage and by means of monitoring battery voltage we can get to know low battery notification. > > [1] http://marc.info/?t=128461535700002&r=1&w=2 > Thanks and Regards, Arun R Murthy --------------------