Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753041AbZI1RDX (ORCPT ); Mon, 28 Sep 2009 13:03:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753017AbZI1RDW (ORCPT ); Mon, 28 Sep 2009 13:03:22 -0400 Received: from mail-bw0-f210.google.com ([209.85.218.210]:39859 "EHLO mail-bw0-f210.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752997AbZI1RDT (ORCPT ); Mon, 28 Sep 2009 13:03:19 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=oueuRmHJAnE8tzjuk2G9lk4wjWYrtYYVIPjbeZapND+sWJh9NnmBIGZzeQQDLoi1ER FvvGTfxhpIrGkgTA5J63cJ4LAMPMYQOzMNKSqfV9SZuDIDNgFf8hWDz6TaVqfOxwJAab zbi9VLZMdwk4ULGz+sDLZWWToeHwolzxJBsY4= Date: Mon, 28 Sep 2009 10:03:14 -0700 From: Dmitry Torokhov To: Henrique de Moraes Holschuh Cc: "Rick L. Vinyard, Jr." , Trilok Soni , Linux USB , LKML , linux-input@vger.kernel.org Subject: Re: Using EV_MSC or extending KEY_* Message-ID: <20090928170314.GI21455@core.coreip.homeip.net> References: <5d5443650909151011k4b21a6d0n28ac6142c3d7161d@mail.gmail.com> <20090915183406.GA5696@core.coreip.homeip.net> <0debc76f26fe85e28adf642396233928.squirrel@intranet.cs.nmsu.edu> <20090916034642.GC2756@core.coreip.homeip.net> <2c0ac825ebe78da99328b896faae04a2.squirrel@intranet.cs.nmsu.edu> <20090917175707.GB789@khazad-dum.debian.net> <20090918064627.GG18668@core.coreip.homeip.net> <20090918135601.GA25109@khazad-dum.debian.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090918135601.GA25109@khazad-dum.debian.net> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2631 Lines: 60 On Fri, Sep 18, 2009 at 10:56:01AM -0300, Henrique de Moraes Holschuh wrote: > On Thu, 17 Sep 2009, Dmitry Torokhov wrote: > > On Thu, Sep 17, 2009 at 02:57:07PM -0300, Henrique de Moraes Holschuh wrote: > > > On Wed, 16 Sep 2009, Rick L. Vinyard, Jr. wrote: > > > > The M* keys are intended to provide a quick way to switch between key > > > > mappings, with each mode having their own user-defined mappings. > > > > > > What I'd do in this case would be this: > > > > > > 1. Initially have the M* level-shift keys assigned KEY_RESERVED > > > > > > 2. Have a big enough keymap to map all keys in all M*-level shift states > > > possible. > > > > > > Eg: > > > START OF KEYMAP > > > M* keys > > > 1st set of G* keys > > > 2nd set of G* keys > > > 3rd set of G* keys... > > > ... > > > last set of G* keys > > > END OF KEYMAP > > > > > > 3. Have the driver special-process M* level-shift keys *as long as they are > > > still set to KEY_RESERVED* to select which part of the keymap is used to > > > translate the other keys. Note that this likely means pressing a M* key > > > would be transparent to userspace in this case, i.e. no events would be > > > issued when a M* key is doing a level shift. > > > > > > So, you'd be able to set all mappings you want in the driver, and the M* > > > keys would do what they're expected to do without any userland help at all, > > > but you'd still be able to program the M* keys to be normal keys if you > > > want. > > > > > > Of course, this assumes you don't do chording on multiple M* keys to end up > > > with a huge number of keymaps :p > > > > Actually I think that the device should just emit KEY_PROG1..KEY_PROG4 > > for the M keys and have userspace daemon load alternate keymaps on the > > fly in resaponse to KEY_PROGx. The device is just a set of completely > > generic buttons... User will have to tell the kernel what to map them > > to. > > It would work, but it is a big trip through userspace. If quickly pressing > M#+G# is a common use pattern (and it will be, for gaming), i.e. you often > want to access quickly a function on one level then another on a different > level, asking userspace to upload a new keymap to switch levels at every M# > press is going to be way too racy. I'd say it should be pretty quick, compared to what a game needs to do to render a single frame. -- Dmitry -- 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/