From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758185Ab1GDP5U (ORCPT ); Mon, 4 Jul 2011 11:57:20 -0400 Received: from www.linutronix.de ([62.245.132.108]:52917 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758008Ab1GDP5S (ORCPT ); Mon, 4 Jul 2011 11:57:18 -0400 Message-ID: <4E11E2DC.2070601@linutronix.de> Date: Mon, 04 Jul 2011 17:57:16 +0200 From: Sebastian Andrzej Siewior User-Agent: Mozilla-Thunderbird 2.0.0.24 (X11/20100329) MIME-Version: 1.0 To: Grant Likely CC: linux-kernel@vger.kernel.org, sodaville@linutronix.de Subject: Re: [PATCH 1/2] gpio/gpio-generic: read set register for caching if available References: <1309159583-11339-1-git-send-email-bigeasy@linutronix.de> <20110704154447.GG29977@ponder.secretlab.ca> In-Reply-To: <20110704154447.GG29977@ponder.secretlab.ca> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Grant Likely wrote: >> diff --git a/drivers/gpio/gpio-generic.c b/drivers/gpio/gpio-generic.c >> index 231714d..9f8b5c6 100644 >> --- a/drivers/gpio/gpio-generic.c >> +++ b/drivers/gpio/gpio-generic.c >> @@ -398,7 +398,10 @@ int __devinit bgpio_init(struct bgpio_chip *bgc, >> if (ret) >> return ret; >> >> - bgc->data = bgc->read_reg(bgc->reg_dat); >> + if (bgc->reg_set) >> + bgc->data = bgc->read_reg(bgc->reg_set); > > On most of the gpio controllers that I've seen, the 'set' register > isn't something that you can actually read. I don't think this is > something that can be done for all gpio controllers. I see. So if (bgc->reg_set && ! bgc->reg_clr) instead should be fine, right? > g. > Sebastian