From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH 1/3] Input: zforce - use irq handler instead of gpio polling Date: Thu, 16 Jul 2015 10:43:41 -0700 Message-ID: <20150716174341.GC32571@dtor-ws> References: <1436791779-21798-1-git-send-email-dirk.behme@de.bosch.com> <20150713170413.GB5039@dtor-ws> <55A4BD48.9000705@de.bosch.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-ie0-f196.google.com ([209.85.223.196]:33115 "EHLO mail-ie0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756516AbbGPRnp (ORCPT ); Thu, 16 Jul 2015 13:43:45 -0400 Received: by iesj1 with SMTP id j1so4437766ies.0 for ; Thu, 16 Jul 2015 10:43:45 -0700 (PDT) Content-Disposition: inline In-Reply-To: <55A4BD48.9000705@de.bosch.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Dirk Behme Cc: linux-input@vger.kernel.org, Oleksij Rempel On Tue, Jul 14, 2015 at 09:42:00AM +0200, Dirk Behme wrote: > Hi Dmitry, > > On 13.07.2015 19:04, Dmitry Torokhov wrote: > >On Mon, Jul 13, 2015 at 02:49:37PM +0200, Dirk Behme wrote: > >>From: Oleksij Rempel > >> > >>Remove the IRQ GPIO polling and request. Existing DTS should not be affected > >>since the IRQ registration was and is based on "interrupts" descriptor of DTS. > > > >But this means that consecutive touchscreen readings will be delayed by > >the time it takes to schedule the thread. > > > >What is the motivation for this change? > > > This is the generic part we've done for a special hardware > configuration: There is some hardware which uses an I2C Serializer / > Deserializer (SerDes) to communicate with the zFroce touch driver. > In this case the SerDes will be configured as an interrupt > controller and the zForce driver will have no access to poll the > GPIO line. In this case can we make gpio optional and use it if it is specified falling back on one read per ISR invocation in its absence? Thanks. -- Dmitry