From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bo Shen Subject: Re: [RFC] QT1070: change the trigger mode of QT1070 Date: Mon, 14 May 2012 10:57:09 +0800 Message-ID: <4FB07485.8050809@atmel.com> References: <1336357653-18663-1-git-send-email-voice.shen@atmel.com> <20120507070424.GC22074@core.coreip.homeip.net> <4FACCDA6.7040506@atmel.com> <4FACF8F4.2090302@atmel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from newsmtp5.atmel.com ([204.2.163.5]:65293 "EHLO sjogate2.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753922Ab2ENC5t (ORCPT ); Sun, 13 May 2012 22:57:49 -0400 In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: javier Martin Cc: Josh Wu , Dmitry Torokhov , khali@linux-fr.org, w.sang@pengutronix.de, jm.lin@atmel.com, linux-input@vger.kernel.org Hi Javier, On 5/11/2012 20:47, javier Martin wrote: > Hi, > > On 11 May 2012 13:33, Josh Wu wrote: >> Hi, Javier >> >> >> On 5/11/2012 5:13 PM, javier Martin wrote: >> >>> Hi all, >>> let's take a chip which presents a similar issue like the pca953x [1]. >>> This chip has an IRQ line that is meant to be connected to a SoC input >>> like the qt1070. >>> >>> The flags that are used for pca953x are: (IRQF_TRIGGER_LOW | IRQF_ONESHOT) >>> >>> Can't we do the same for qt1070? >> >> I did a simple test in my board in 2.6.39, This flag doesn't work. But >> IRQF_TRIGGER_FALLING works fine. >> So the question is what is different between this flag with >> IRQF_TRIGGER_FALLING? > I don't know but IRQF_TRIGGER_FALLING works for me too. There is no need to change the driver of QT1070. Please try the suggestion of Dmitry. Using the irq_set_irq_type() to set the trigger mode of the GPIO. > >>> And even more important, can you give me an example of an architecture >>> in mainline which cannot support these irq flags and still be able to >>> detect a change from high to low in a GPIO as qt1070 requires? >> >> For now, AT91SAM9M10 can only detect GPIO input change, it cannot tell is >> falling or rising. So in theory it cannot support falling flags. >> The strange thing is, currently we use IRQF_TRIGGER_NONE in 2.6.39 kernel >> for both AT91SAM9M10 and 9X5 chips, and they all work fine. So I need check >> the code of GPIO part. >> >> >>> Moreover, if you try a grep for IRQ_TRIGGER_NONE in the kernel tree >>> you won't find any driver doing this strange thing. >>> >>> Do you agree at least that we must change IRQ_TRIGGER_NONE flag into a >>> more sensible choice? >> >> Yes. I agreed. >> >>> Regards. >>> >>> [1] http://lxr.linux.no/#linux+v3.3.4/drivers/gpio/gpio-pca953x.c#L495 > > >