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Message-ID: <9e4733910912080631r6fd306c5tdfd56482583b9bf5@mail.gmail.com> Date: Tue, 8 Dec 2009 09:31:57 -0500 From: Jon Smirl <jonsmirl@...il.com> To: Mauro Carvalho Chehab <mchehab@...hat.com> Cc: Andy Walls <awalls@...ix.net>, Dmitry Torokhov <dmitry.torokhov@...il.com>, Jarod Wilson <jarod@...sonet.com>, Krzysztof Halasa <khc@...waw.pl>, Christoph Bartelmus <lirc@...telmus.de>, j@...nau.net, jarod@...hat.com, linux-input@...r.kernel.org, linux-kernel@...r.kernel.org, linux-media@...r.kernel.org, superm1@...ntu.com Subject: Re: [RFC] Should we create a raw input interface for IR's ? - Was: Re: [PATCH 1/3 v2] lirc core device driver infrastructure On Tue, Dec 8, 2009 at 9:16 AM, Mauro Carvalho Chehab <mchehab@...hat.com> wrote: > Jon Smirl wrote: >> On Tue, Dec 8, 2009 at 8:40 AM, Mauro Carvalho Chehab >> <mchehab@...hat.com> wrote: >>> Jon Smirl wrote: >>>> On Tue, Dec 8, 2009 at 7:35 AM, Andy Walls <awalls@...ix.net> wrote: >>>>> On Mon, 2009-12-07 at 20:22 -0800, Dmitry Torokhov wrote: >>>>>> On Mon, Dec 07, 2009 at 09:42:22PM -0500, Andy Walls wrote: >>>>>>> So I'll whip up an RC-6 Mode 6A decoder for cx23885-input.c before the >>>>>>> end of the month. >>>>>>> >>>>>>> I can setup the CX2388[58] hardware to look for both RC-5 and RC-6 with >>>>>>> a common set of parameters, so I may be able to set up the decoders to >>>>>>> handle decoding from two different remote types at once. The HVR boards >>>>>>> can ship with either type of remote AFAIK. >>>>>>> >>>>>>> I wonder if I can flip the keytables on the fly or if I have to create >>>>>>> two different input devices? >>>>>>> >>>>>> Can you distinguish between the 2 remotes (not receivers)? >>>>> Yes. RC-6 and RC-5 are different enough to distinguish between the two. >>>>> (Honestly I could pile on more protocols that have similar pulse time >>>>> periods, but that's complexity for no good reason and I don't know of a >>>>> vendor that bundles 3 types of remotes per TV card.) >>>>> >>>>> >>>>>> Like I said, >>>>>> I think the preferred way is to represent every remote that can be >>>>>> distinguished from each other as a separate input device. >>>>> OK. With RC-5, NEC, and RC-6 at least there is also an address or >>>>> system byte or word to distingish different remotes. However creating >>>>> multiple input devices on the fly for detected remotes would be madness >>>>> - especially with a decoding error in the address bits. >>>> I agree that creating devices on the fly has problems. Another >>>> solution is to create one device for each map that is loaded. There >>>> would be a couple built-in maps for bundled remotes - each would >>>> create a device. Then the user could load more maps with each map >>>> creating a device. >>> No, please. We currently have already 89 different keymaps in-kernel. Creating >>> 89 different interfaces per IR receiver is not useful at all. >>> >>> IMO, the interfaces should be created as the keymaps are associated >>> to an specific IR receiver. >> >> Each IR receiver device driver would have a built-in keymap for the >> remote bundled with it. When you load the driver it will poke the >> input system and install the map. Any additional keymaps would get >> loaded from user space. You would load one keymap per input device. >> >> You might have 89 maps in the kernel with each map being built into >> the device driver for those 89 IR receivers. But you'll only own one >> or two of those devices so only one or two of the 89 maps will load. >> Building the map for the bundled receiver into the device driver is an >> important part of achieving "just works". >> >> I suspect we'll have a 1,000 maps defined after ten years, most of >> these maps will be loaded from user space. But you'll only have two or >> three loaded at any one time into your kernel. You need one map per >> input device created. These maps are tiny, less than 1KB. >> >> Having all of these maps is the price of allowing everyone to use any >> more that they please. If you force the use of universal remotes most >> of the maps can be eliminated. > > Makes sense. Yet, I would add an option at Kbuild to create a module or not > with the bundled IR keymaps. > > So, it should be possible to have all of them completely on userspace or > having them at kernelspace. Removing the maps for the bundled remotes from the receiver device drivers will break "just works". The map will be in an __init section of the IR device driver. When it is fed into the input system a RAM based structure will be created. If you really want the 1KB memory back, use sysfs to remove the default map. An embedded system will have a bundled remote so it is going to want the map. If you want to change the default map loading a new map will release the memory from the previous map. > > Cheers, > Mauro. > -- Jon Smirl jonsmirl@...il.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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