Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754291AbYGWO5L (ORCPT ); Wed, 23 Jul 2008 10:57:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752753AbYGWO4z (ORCPT ); Wed, 23 Jul 2008 10:56:55 -0400 Received: from rtsoft3.corbina.net ([85.21.88.6]:10141 "EHLO buildserver.ru.mvista.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752810AbYGWO4y (ORCPT ); Wed, 23 Jul 2008 10:56:54 -0400 Date: Wed, 23 Jul 2008 18:56:50 +0400 From: Anton Vorontsov To: Trent Piepho Cc: Grant Likely , linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org Subject: Re: PIXIS gpio controller and gpio flags Message-ID: <20080723145650.GA13792@polina.dev.rtsoft.ru> Reply-To: avorontsov@ru.mvista.com References: <20080717150422.GC31932@secretlab.ca> <20080717152006.GA26120@polina.dev.rtsoft.ru> <20080717234201.GA15745@polina.dev.rtsoft.ru> <20080718100549.GA28741@polina.dev.rtsoft.ru> <20080721175357.GA1773@polina.dev.rtsoft.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1486 Lines: 33 On Mon, Jul 21, 2008 at 02:12:20PM -0700, Trent Piepho wrote: > On Mon, 21 Jul 2008, Anton Vorontsov wrote: > > On Sat, Jul 19, 2008 at 02:08:01PM -0700, Trent Piepho wrote: > >> It doesn't look like you have any way to unset the active low flag. What if > >> I unload the leds-gpio driver (or another gpio user) and then try to use the > >> gpio with something else? The active low flag is stuck on! > > > > Why would you want to unset the flags? It is specified in the device > > tree, and can't be changed. Specifying different flags for the same GPIO > > would be an error (plus, Linux forbids shared gpios, so you simply can't > > specify one gpio for several devices). > > You can't use the same gpio for two different things at the same time, but you > can load a driver, unload it, and then load another. Hm.. yeah, this might happen. Now I tend to think that transparent active-low handling wasn't that good idea after all. So, something like of_gpio_is_active_low(device_node, gpioidx) should be implemented instead. This function will parse the gpio's = <> flags. Please speak up if you have any better ideas though. Thanks for bringing this up, -- Anton Vorontsov email: cbouatmailru@gmail.com irc://irc.freenode.net/bd2 -- 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/