From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756068Ab0IXNGZ (ORCPT ); Fri, 24 Sep 2010 09:06:25 -0400 Received: from ksp.mff.cuni.cz ([195.113.26.206]:57510 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752237Ab0IXNGX (ORCPT ); Fri, 24 Sep 2010 09:06:23 -0400 Date: Fri, 24 Sep 2010 15:02:41 +0200 From: Pavel Machek To: Dmitry Torokhov Cc: Alan Cox , Linus Torvalds , Felipe Balbi , Hemanth V , "linux-input@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-omap@vger.kernel.org" , "igor.stoppa@nokia.com" , "kai.svahn@nokia.com" , "matthias.nyman@nokia.com" Subject: Re: Sensors and the input layer (was Re: [RFC] [PATCH V2 1/2] input: CMA3000 Accelerometer driver) Message-ID: <20100924130241.GB1810@ucw.cz> References: <20100830214025.2f9677a1@lxorguk.ukuu.org.uk> <20100830204412.GA28711@core.coreip.homeip.net> <20100830214355.GB28865@core.coreip.homeip.net> <20100830224352.GF28865@core.coreip.homeip.net> <20100831104446.321fd4f4@lxorguk.ukuu.org.uk> <20100831161730.GA30947@core.coreip.homeip.net> <20100831175937.70a59a91@lxorguk.ukuu.org.uk> <20100831170923.GB30947@core.coreip.homeip.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100831170923.GB30947@core.coreip.homeip.net> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > So a voltmeter really makes no sense. It's not a set of keys and it > > doesn't give X/Y/Z style readings. Nor does a camera. But a lot of things > > do fit this to varying degrees. > > > > I'm actually more dubious than Linus about ALS - because ALS tends not > > produce 'events' but to be sampled, and there are significant power > > implications to unnecessary polling. That's very similar to analog joysticks, no? > > And the more it's used the less special > > code is needed in user or kernel space for PDAs and phones - instead they > > just work. > > OK, so let's say we start moving some of the devices into input. Which > ones we consider suitable for input? I guess some 3-digit > accelerometers, what else? Also, what new event types would we need? > Let's take GPS - I do not think that ABS_X and ABS_Y are the best events > to be used for such devices: I am trying to allow applications being I'd not put GPS into input; yes, they do present 'x,y,z' in meters, but that's not what users want. 'lat,lon,alt' is better, but it is actually 'lat,lon,herror,alt,verror,time' and a lot of other metadata... Also, we already have driver for GPSes, its called gpsd. I'd leave GPSes out of input. > Also, GPS, liek ALS, would probably be polling, no? Normally, GPS just sends you position info once a second. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html