From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Smirl Subject: Re: [RFC] What are the goals for the architecture of an in-kernel IR system? Date: Fri, 4 Dec 2009 22:45:55 -0500 Message-ID: <9e4733910912041945g14732dcfgbb2ef6437ef62bb6@mail.gmail.com> References: <20091204220708.GD25669@core.coreip.homeip.net> <9e4733910912041628g5bedc9d2jbee3b0861aeb5511@mail.gmail.com> <1259977687.27969.18.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1259977687.27969.18.camel@localhost> Sender: linux-media-owner@vger.kernel.org To: Andy Walls Cc: Christoph Bartelmus , dmitry.torokhov@gmail.com, j@jannau.net, jarod@redhat.com, jarod@wilsonet.com, khc@pm.waw.pl, kraxel@redhat.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@redhat.com, superm1@ubuntu.com List-Id: linux-input@vger.kernel.org On Fri, Dec 4, 2009 at 8:48 PM, Andy Walls wrote: > On Fri, 2009-12-04 at 19:28 -0500, Jon Smirl wrote: >> On Fri, Dec 4, 2009 at 6:01 PM, Christoph Bartelmus wrote: >> > BTW, I just came across a XMP remote that seems to generate 3x64 b= it scan >> > codes. Anyone here has docs on the XMP protocol? >> >> Assuming a general purpose receiver (not one with fixed hardware >> decoding), is it important for Linux to receive IR signals from all >> possible remotes no matter how old or obscure? > > Importance of any particular requirement is relative/subjective. =A0A= s is > usefulness of any existing functionality. > > Personally, I just think it's cool to pick up a random remote and use > Linux to figure out its protocol and its codes and get it working. You are a technical user. > > > >> =A0Or is it acceptable to >> tell the user to throw away their dedicated remote and buy a univers= al >> multi-function one? > > Nope. =A0That other OS provider forces device obsolescence or arbitra= ry > constraints on users quite often and I don't like it myself. =A0That'= s why > I use Linux. > > >> =A0 Universal multi-function remotes are $12 in my >> grocery store - I don't even have to go to an electronics store. > > The old remote in my possession costs $0, and I don't even have to le= ave > the house. > > >> I've been working off the premise of getting rid of obscure remotes >> and replacing them with a universal one. The universal one can be se= t >> to send a common protocol like JVC or Sony. That implies that we onl= y >> need one or two protocol decoders in-kernel which greatly reduces th= e >> surface area of the problem. > > The design should serve the users, the users should not serve the > design. =A0If the reduction of requirements scope starts forcing user= s to > buy new hardware, are we really serving the users or just asking them= to > pay to compensate for our shortcomings? Use of arbitrary remotes is a complex process. It almost certainly can not be done in a transparent "just works" manner. Let me rephrase, is it ok to tell people to buy a new remote if they want to avoid a complex, technical configuration process that isn't even guaranteed to work (they might have a 56K remote and a 38K receiver or a Sony remote and a fixed RC-5 receiver). I'm not proposing that we prevent arbitrary remotes from working, you're just going to need to expend more effort to make them work. =46or example, you have to have a fair amount of IR knowledge to figure out why those two cases above don't work. You might have to install LIRC and futz with irrecord and build your own config files and mapping tables, etc... It doesn't have to only be a universal remote, we can pre-install mapping tables for the remotes commonly shipped with the v4l hardware. When the v4l drivers load they could even poke the default map for their bundled remotes directly into the input system if they wanted to. Doing that might save a lot of config issues. How this for new goals? Specific IR drivers autoload maps for their bundled remotes by poking them into the input subsystem during module load IR always has default map for a universal remote - it provides five devices and uses a common protocol like JVC (may not work for fixed hardware, you have to set these five common devices into the universal remote) All of these maps can be overriden with user space commands (which lets you configure funky remotes) --=20 Jon Smirl jonsmirl@gmail.com