From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Beisert Subject: Re: [PATCH] input/touchscreen: add S3C24XX SoC touchscreen input driver Date: Mon, 19 Oct 2009 16:34:10 +0200 Message-ID: <200910191634.11341.jbe@pengutronix.de> References: <4ADC4D4D.5020508@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:55539 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756134AbZJSOeY (ORCPT ); Mon, 19 Oct 2009 10:34:24 -0400 In-Reply-To: <4ADC4D4D.5020508@gmail.com> Content-Disposition: inline Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: linux-arm-kernel Cc: Maurus Cuelenaere , Shine Liu , Nelson Castillo , dtor@mail.ru, dmitry.torokhov@gmail.com, linux-input@vger.kernel.org On Montag, 19. Oktober 2009, Maurus Cuelenaere wrote: > Op 19-10-09 12:55, linux-arm-kernel-request@lists.infradead.org schreef: > > This touchscreen driver is for touchscreen controller on Samsung > > S3C2410/S3C2440 SoC chip. S3C2410/S3C2440 has the on chip touchscreen > > controller based on it's analog to digital converter(8-channel analog > > inputs, touchscreen uses 4 of them). This driver uses the exsiting S3C > > ADC driver to make the touchscreen controller of S3C2410/S3C2440 work > > well together with other ADC devices connected to the S3C24XX SoC chip. > > > > The patch is created against kernel 2.6.32-rc4 and tested with S3C2440 > > SoC and Samsung LTE430WQ-F0C touchscreen. > > > > > > Signed-off-by: Shine Liu > > Signed-off-by: Shine Liu > > Do you know that there's another patch (at Openmoko) created by Nelson > Castillo that does the same, but also has support for kernel-space > touchscreen filters? (I think [1] is his latest version) > I don't know how your patch performs, but according to [2] the filters > should help a lot avoiding jitter etc. > > I'm not sure whether Nelson has submitted his patches for mainline > review yet and what the status is on the kernel filters, but IMHO doing > some filtering in kernel space (see the "Why are we doing filtering in > kernel space?" part of [2]) which results in a "cleaner" output is > preferred over reporting possible "jittery" data. Filtering can be done perfectly in userland (like all the other ts do). IMHO I can't see any need to do it in kernel space. jbe -- Pengutronix e.K. | Juergen Beisert | Linux Solutions for Science and Industry | Phone: +49-8766-939 228 | Vertretung Sued/Muenchen, Germany | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de/ |