From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pz0-f188.google.com ([209.85.222.188]:62580 "EHLO mail-pz0-f188.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757183AbZLONnK convert rfc822-to-8bit (ORCPT ); Tue, 15 Dec 2009 08:43:10 -0500 MIME-Version: 1.0 In-Reply-To: <4B279017.3080303@redhat.com> References: <20091206065512.GA14651@core.coreip.homeip.net> <4B1B99A5.2080903@redhat.com> <9e4733910912060952h4aad49dake8e8486acb6566bc@mail.gmail.com> <20091207184153.GD998@core.coreip.homeip.net> <4B24DABA.9040007@redhat.com> <20091215115011.GB1385@ucw.cz> <4B279017.3080303@redhat.com> Date: Tue, 15 Dec 2009 08:43:07 -0500 Message-ID: <9e4733910912150543m31938bddv384bd3195bbffcbe@mail.gmail.com> Subject: Re: [RFC] What are the goals for the architecture of an in-kernel IR system? From: Jon Smirl To: Mauro Carvalho Chehab Cc: Pavel Machek , Dmitry Torokhov , Krzysztof Halasa , hermann pitton , Christoph Bartelmus , awalls@radix.net, j@jannau.net, jarod@redhat.com, jarod@wilsonet.com, kraxel@redhat.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, superm1@ubuntu.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-media-owner@vger.kernel.org List-ID: On Tue, Dec 15, 2009 at 8:33 AM, Mauro Carvalho Chehab wrote: > Pavel Machek wrote: >>>> That is why I think we should go the other way around - introduce the >>>> core which receivers could plug into and decoder framework and once it >>>> is ready register lirc-dev as one of the available decoders. >>>> >>> I've committed already some IR restruct code on my linux-next -git tree: >>> >>> http://git.kernel.org/?p=linux/kernel/git/mchehab/linux-next.git >>> >>> The code there basically moves the input/evdev registering code and >>> scancode/keycode management code into a separate ir-core module. >>> >>> To make my life easy, I've moved the code temporarily into drivers/media/IR. >>> This way, it helps me to move V4L specific code outside ir-core and to later >>> use it for DVB. After having it done, probably the better is to move it to >>> be under /drivers or /drivers/input. >> >> Well, -next is for stuff to be merged into 2.6.34. You are quite an >> optimist. >>                                                                       Pavel > > Well, we need those changes anyway for the in-kernel drivers, and I'm not seeing > on the current patches any reason for not having them for 2.6.34. > > I've added all the ir-core patches I did so far at linux-next. This helps people > to review and contribute. > > The patches are already working with the in-kernel em28xx driver, allowing to > replace the keycode table and the protocol used by the hardware IR decoder. > I tested here by replacing an RC-5 based IR table (Hauppauge Grey) by a NEC > based IR table (Terratec Cinergy XS remote controller). > > The current Remote Controller core module (ir-core) is currently doing: > >        - Implementation of the existing EVIO[G|S]KEYCODE, expanding/feeing memory > dynamically, based on the needed size for scancode/keycode table; > >        - scancodes can be up to 16 bits currently; > >        - sysfs is registering /sys/class/irrcv and creating one branch for each > different RC receiver, numbering from irrcv0 to irrcv255; > >        - one irrcv note is created: current_protocol; > >        - reading /sys/class/irrcv/irrcv*/current_protocol returns the protocol > currently used by the driver; > >        - writing to /sys/class/irrcv/irrcv*/current_protocol changes the protocol > to a new one, by calling a callback, asking the driver to change the protocol. If > the protocol is not support, it returns -EINVAL; > >        - all V4L drivers are already using ir-core; > >        - em28xx driver is implementing current_protocol show/store support. > > TODO: I'd add a pulse based receiver like a MSMCE to make sure the core API is right. MSME has transmit hardware too. What about creating multiple evdev devices with their own keymaps off from a single receiver? That's a key part of making multi-function remotes work. >        1) Port DVB drivers to use ir-core, removing the duplicated (and incomplete >          - as table size can't change on DVB's implementation) code that exists there; > >        2) add current_protocol support on other drivers; > >        3) link the corresponding input/evdev interfaces with /sys/class/irrcv/irrcv*; > >        4) make the keytable.c application aware of the sysfs vars; > >        5) add an attribute to uniquely identify a remote controller; > >        6) write or convert an existing application to load IR tables at runtime; > >        7) get the complete 16-bit scancodes used by V4L drivers; > >        8) add decoder/lirc_dev glue to ir-core; > >        9) add lirc_dev module and in-kernel decoders; > >        10) extend keycode table replacement to support big/variable sized scancodes; > >        11) rename IR->RC; > >        12) redesign or remove ir-common module. It currently handles in-kernel >            keycode tables and a few helper routines for raw pulse/space decode; > >        13) move drivers/media/IR to a better place; > > > comments: > >        Tasks (1) to (6) for sure can happen to 2.6.34, depending on people's spare > time for it; > >        (7) is probably the more complex task, since it requires to re-test all in-kernel > supported remote controlle scancode/keycode tables, to get the complete IR keycode > and rewrite the getkeycode functions that are currently masking the IR code into 7 bits. > We'll need users help on this task, but this can be done gradually, like I did with > two RC keytables on em28xx driver, while preserving the other keytables as-is. > >        (8) I suggest that this glue will be submitted together with lirc_dev patch > series, as the biggest client for it is lirc. In principle, kfifo seems the better > interface for lirc_dev -> decoders interface. For the decoders -> RC core interface, > there's an interface already used on V4L drivers, provided by ir-common, using evdev > kernel API. This may need some review. > >        (9) depends on lirc API discusions. My proposal is that people submit an RFC > with the lirc API reviewed to the ML's, for people to ack/nack/comment. After that, > re-submit the lirc_dev module integrating it into ir-core and with the reviewed API; > >        (10) depends on EVIO[G|S]KEYCODE discussions we've already started. I did a proposal > about it. I'll review, based on the comments and re-submit it; > >        (11) if none is against renaming IR as RC, I'll do it on a next patch; > >        (12) depends on having lirc_dev added, for the removal of ir-functions.c. With > respect to the keytables, maybe one interesting alternative is to use a logic close to > nls tables that exists at fs, allowing to individually insert or remove an IR keytable > in-kernel. > >        (13) has low priority. While not finishing the DVB integration with RC core > and reviewing the remaining bits of the ir-common module. > > Cheers, > Mauro. > -- Jon Smirl jonsmirl@gmail.com