From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javier Martinez Canillas Subject: Re: [PATCH v2 1/1] Input: atmel_mxt_ts - Get IRQ edge/level flags on DT booting Date: Fri, 08 Aug 2014 20:29:32 +0200 Message-ID: <53E5170C.10302@collabora.co.uk> References: <1407397492-17475-1-git-send-email-javier.martinez@collabora.co.uk> <53E4D9A5.908@itdev.co.uk> <20140808162146.GC26820@core.coreip.homeip.net> <53E4FD1B.6060600@collabora.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from bhuna.collabora.co.uk ([93.93.135.160]:36207 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751002AbaHHS3o (ORCPT ); Fri, 8 Aug 2014 14:29:44 -0400 In-Reply-To: <53E4FD1B.6060600@collabora.co.uk> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Dmitry Torokhov , Nick Dyer Cc: Stephen Warren , Yufeng Shen , Benson Leung , Doug Anderson , Olof Johansson , Tomasz Figa , linux-input@vger.kernel.org, devicetree@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Gleixner , Jason Cooper , Benjamin Herrenschmidt , Thomas Abraham Hello, On 08/08/2014 06:38 PM, Javier Martinez Canillas wrote: > > > It seems as if the first call to exynos_irq_set_type() that is made by OF is a > no-op while the second call is the one that actually setups the hw correctly. > Does this make any sense? Maybe is related to the pin not being muxed in the > correct function when the "interrupts" property is parsed by OF? > So after a conversation with Tomasz Figa over IRC the problem was after all that the pin was reconfigured. The IRQ trigger type resulted to be just a red herring and not a direct cause. The pinctrl-eyxnos driver does the IRQ pinmux setup in the .irq_set_type function handler. So what happened was that OF parsed the "interrupts" property and called exynos_irq_set_type() which did the pinmux setup. But after that, due a DTS pinctrl configuration the pin function was changed as a GPIO input and that happened before the atmel driver was probed. So when the driver called request_threaded_irq(), the correct flags were used but the pin was not configured as an IRQ anymore so IRQ were not fired. Setting a trigger type just had the side effect of calling exynos_irq_set_type() which again setup the pin as an IRQ. To fix the issue a variation of patch [0] will be posted that moves the IRQ pinmux setup from .irq_set_type to the .irq_request_resources function handler. That way the pin will be setup as IRQ regardless of the the trigger type [1] when someone calls request_[threaded]_irq(). Only the mentioned patch fixes the issue but Tomasz said that even a call to gpio_direction_{input,output} can change the pin configuration so he will post another patch that will add a bit mask to samsung_pin_bank to prevent any pinmux reconfiguration. Thanks a lot and best regards, Javier [0]: http://thread.gmane.org/gmane.linux.kernel.samsung-soc/34259/focus=34261 [1]: http://lxr.free-electrons.com/source/kernel/irq/manage.c#L1162