Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754080AbZLMT4O (ORCPT ); Sun, 13 Dec 2009 14:56:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754044AbZLMT4N (ORCPT ); Sun, 13 Dec 2009 14:56:13 -0500 Received: from metis.ext.pengutronix.de ([92.198.50.35]:38594 "HELO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754046AbZLMT4M (ORCPT ); Sun, 13 Dec 2009 14:56:12 -0500 Date: Sun, 13 Dec 2009 20:56:07 +0100 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Alberto Panizzo Cc: Samuel Ortiz , Mark Brown , Sascha linux-arm , linux-arm-kernel-infradead , linux-kernel Subject: Re: [PATCH 1/4] mfd: mc13783: Take care of semantic inversion between read and write value of two bits in POWER_MISCELLANEUS register. Message-ID: <20091213195606.GA14024@pengutronix.de> References: <1260635829.2054.16.camel@climbing-alby> <1260636523.2054.28.camel@climbing-alby> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1260636523.2054.28.camel@climbing-alby> User-Agent: Mutt/1.5.18 (2008-05-17) X-SA-Exim-Connect-IP: 2001:6f8:1178:2:215:17ff:fe12:23b0 X-SA-Exim-Mail-From: ukl@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 Content-Length: 1256 Lines: 30 On Sat, Dec 12, 2009 at 05:48:43PM +0100, Alberto Panizzo wrote: > MC13783_REGCTRL_PWGTnSPIEN controls the states of the corresponding > PWGTn_DRV output. > Reading 1 on the corresponding bit mean that the output is enabled > Writing 1 on the corresponding bit disable that output! > > So, if not asked directly to modify those bits, write the inverted > value. Hmm, I'm not sure this completely right. The Spec has: Bit PWGTxSPIEN | Pin PWGTxEN | PWGTxDRV | Read Back 0 = default | | | PWGTxSPIEN ---------------+-------------+----------+------------ 1 | x | Low | 0 0 | 0 | High | 1 0 | 1 | Low | 0 So it looks a bit harder than just inverting the read bit. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/