Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753575Ab0HaQmM (ORCPT ); Tue, 31 Aug 2010 12:42:12 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:45151 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753345Ab0HaQmK (ORCPT ); Tue, 31 Aug 2010 12:42:10 -0400 Date: Tue, 31 Aug 2010 17:59:37 +0100 From: Alan Cox To: Dmitry Torokhov Cc: 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: <20100831175937.70a59a91@lxorguk.ukuu.org.uk> In-Reply-To: <20100831161730.GA30947@core.coreip.homeip.net> References: <15445.10.24.255.17.1274424777.squirrel@dbdmail.itg.ti.com> <20100829184904.GC26209@core.coreip.homeip.net> <36abcb34cfbf34724d9a581a75b53e76@secure211.sgcpanel.com> <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> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2236 Lines: 55 > > If non-input uses later need non-input interfaces they can switch to that > > with an input bridge when there is one and when it happens, which > > probably won't. > > Would there even be an argument which subsystem to use if IIO->input > bridge existed today? Because if the answer is "no" then push into input > is driven by convenience and not because it is the right solution. Probably because most of these devices have nothing to do with industrial I/O at all. > If application does take something as an input it does not make it > necessarily a human interface device. By this reasoning cameras should > be represented as an input devices (why, some applications take input That's not what I asked. > I really believe that input should represent purely human interface > devices, not arbitrary data acquisition devices. That tends to make little sense where the API is the same and applications benefit enormously from consistency. I'd rather have an input->IIO bridge because that is the real world today ! The question is what does the API make *sense* for. Not what can you use the API for. Unix (and Linux) are enormously powerful because of the use of common interfaces and APIs. 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. See it as a curse of success - because you got the API right and made it flexible people want to use it. 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. > > In a game > > context can I suggest the Zombies game is an example ? > > I am not familiar with this game, sorry. It uses GPS and networking to stage an 'in real world' zombie dodging game. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/