From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934211AbaGXGeZ (ORCPT ); Thu, 24 Jul 2014 02:34:25 -0400 Received: from mho-03-ewr.mailhop.org ([204.13.248.66]:28801 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S934162AbaGXGeY (ORCPT ); Thu, 24 Jul 2014 02:34:24 -0400 X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 99.127.230.128 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX18xz6yi0hj5KRgSv3u7iJg2 Date: Wed, 23 Jul 2014 23:32:51 -0700 From: Tony Lindgren To: Sebastian Reichel Cc: Nishanth Menon , dbaryshkov@gmail.com, balbi@ti.com, linux@arm.linux.org.uk, dwmw2@infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org Subject: Re: [PATCH V2 1/2] power: twl4030_charger: detect battery presence prior to enabling charger Message-ID: <20140724063250.GG22006@atomide.com> References: <1401313610-14252-1-git-send-email-nm@ti.com> <1401313610-14252-2-git-send-email-nm@ti.com> <20140723092420.GE22006@atomide.com> <20140723120326.GA18172@earth.universe> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140723120326.GA18172@earth.universe> 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 * Sebastian Reichel [140723 05:05]: > On Wed, Jul 23, 2014 at 02:24:20AM -0700, Tony Lindgren wrote: > > * Nishanth Menon [140528 14:48]: > > > TWL4030's Battery Charger seems to be designed for non-hotpluggable > > > batteries. > > > > > > If battery is not present in the system, BATSTS is always set with the > > > expectation that software will take actions to move to a required safe > > > state (could be power down or disable various charger paths). > > > > > > It does not seem possible even by manipulating the edge detection > > > of the event (using BCIEDR2 register) to have a consistent hotplug > > > handling. This seems to be the result of BATSTS interrupt generated > > > when the thermistor of the battery pack is disconnected from the > > > dedicated ADIN1 pin. Clearing the status just results in the status > > > being regenerated by the monitoring ADC(MADC) and disabling the > > > edges of event just makes hotplug no longer function. The only > > > other option is to disable the detection of the MADC by disabling > > > BCIMFEN4::BATSTSMCHGEN (battery presence detector) - but then, we can > > > never again detect battery reconnection. > > > > > > So, detect battery presence based on precharge(which is hardware > > > automatic state) or default main charger configuration at the time of > > > probe and enable charger logic only if battery was present. > > > > > > Reported-by: Russell King > > > Tested-by: Tony Lindgren > > > Signed-off-by: Nishanth Menon > > > > Dmitry, can we please get this first patch merged? This is needed > > on some omap3 platforms for DT based booting when no battery is > > present. > > > > Only the second patch in this series is still being discussed AFAIK. > > applied to battery-2.6.git: > > http://git.infradead.org/battery-2.6.git/commit/61a7784efd3c89ffb6242f29bcee170dd7f55e6b Thanks! Tony