From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trilok Soni Subject: Re: [PATCH 1/6] Haptic: add haptic class Date: Wed, 14 Oct 2009 16:08:41 +0530 Message-ID: <5d5443650910140338y38be86bdpfc819f0d2a7e915@mail.gmail.com> References: <20091007061701.GA7567@july> <359ed6810910130335m45919d6ala921d4cbfa5a341a@mail.gmail.com> <5d5443650910130413t6ecd3d54p214d8f80972ed128@mail.gmail.com> <20091014075919.GD5318@core.coreip.homeip.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Received: from mail-qy0-f172.google.com ([209.85.221.172]:62242 "EHLO mail-qy0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932680AbZJNKjR (ORCPT ); Wed, 14 Oct 2009 06:39:17 -0400 In-Reply-To: <20091014075919.GD5318@core.coreip.homeip.net> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Dmitry Torokhov Cc: Jani Nikula , Kyungmin Park , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org Hi Dmitry, On Wed, Oct 14, 2009 at 1:29 PM, Dmitry Torokhov wrote: > On Tue, Oct 13, 2009 at 04:43:43PM +0530, Trilok Soni wrote: >> Hi Kyungmin, Dmitry, >> >> On Tue, Oct 13, 2009 at 4:05 PM, Jani Nikula >> wrote: >> > On Wed, Oct 7, 2009 at 09:17, Kyungmin Park wrote: >> >> New haptic class support. >> >> This class handles the haptic devices. >> > >> > I'm wondering why a haptic class is needed when there is force >> > feedback support. Admittedly, I don't know the force feedback >> > implementation too well, but could someone please enlighten me on >> > this? Am I missing something here? >> > >> > I see haptics as simple force feedback, just with (usually) small >> > force and short duration. There are devices out there doing haptics >> > using vibra motors, which I think would be limited if implemented >> > using this haptics class driver. Would it be somehow problematic >> > interfacing with the simple haptic hardware using the force feedback >> > API? >> >> Please share your inputs on ff_device usage instead of haptics class. >> I think Dmitry could add some points here as I don't see much users of >> ff_device and I don't see any embedded device (like mobile) using it. >> > > Using ff_device was considered when Jiri Slaby was trying to merge > PHANTOM driver, bit for that device FF infrastructure was too limited > and this it was decided that phantom would need a special userpsace that > knows what it is and how to handle it. > > The curtrent haptic class seems to be bery limited and may be served via > FF (constant or other effect in a single direction) but I don't know > what kind of plans you have to extend it. I guess it warrants another > discussion. Probably Kyungmin is the right person to analyze the ff_device infrastructure in input_device framework and see it fits haptics class or not. As per me, for the mobile like applications current haptics class should meet the needs. -- ---Trilok Soni http://triloksoni.wordpress.com http://www.linkedin.com/in/triloksoni