From mboxrd@z Thu Jan 1 00:00:00 1970 From: Antonio Ospite Subject: Re: Rewriting wheels HID descriptor for complete functionality Date: Wed, 1 Dec 2010 22:20:22 +0100 Message-ID: <20101201222022.b2e49a1b.ospite@studenti.unina.it> References: Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg="PGP-SHA1"; boundary="Signature=_Wed__1_Dec_2010_22_20_23_+0100_7VLuNB1Wo1jVg7sl" Return-path: Received: from smtp206.alice.it ([82.57.200.102]:53954 "EHLO smtp206.alice.it" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752752Ab0LAVUn (ORCPT ); Wed, 1 Dec 2010 16:20:43 -0500 In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: simon@mungewell.org Cc: linux-input@vger.kernel.org, Marcin Tolysz --Signature=_Wed__1_Dec_2010_22_20_23_+0100_7VLuNB1Wo1jVg7sl Content-Type: text/plain; charset=US-ASCII Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, 1 Dec 2010 13:23:15 -0500 simon@mungewell.org wrote: > I am working on a driver for a Logitech gaming wheel where the HID > descriptor presents a 'joystick' with X and Y axis, the Y is a combined > acc/brake value even though the wheel has separate paddles for each. >=20 > There are 'vendor defined' variables for both the acc/brake within the HID > descriptor, but these are not (by Linux) tied to their function. > > On the Windows, the specialised Logitech driver gives the option to use > either combined or separate acc/brake. >=20 > I am considering re-writing the HID descriptor to expose these separate > values as 'proper' axis, as they would provide both better resolution and > better functionality (ie. left foot braking). > Simon, have you tried Marcin Tolysz's approach of loading the new HID descriptor from an external file? Look at: https://patchwork.kernel.org/patch/69723/ If there is interest maybe Marcin's way could be brought back on the discussion table (Marcin added to CC). I'll be needing descriptor patching for Sony Sixaxis too, after I solved some other issues, so I am also interested on settling on a "standard" way to achieve that. > Q1. Is this an acceptable thing to do? >=20 > Q2. In the case where there is significant change to the HID descriptor, > is it OK to just re-write the whole block (rather than patch/swap a couple > of bytes)? >=20 > Q3. In re-writing descriptor for the combined acc/brake. Is there a > particular 'variable' I should change it to (X, Y and Z would already be > used), or should I just make it 'vendor defined'? >=20 > Thanks in advance, > Simon > (aka Mungewell) >=20 Regards, Antonio --=20 Antonio Ospite http://ao2.it PGP public key ID: 0x4553B001 A: Because it messes up the order in which people normally read text. See http://en.wikipedia.org/wiki/Posting_style Q: Why is top-posting such a bad thing? --Signature=_Wed__1_Dec_2010_22_20_23_+0100_7VLuNB1Wo1jVg7sl Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEARECAAYFAkz2vBcACgkQ5xr2akVTsAH8SQCaA9sEzKFleAtPU6ehpjhoCp0Y /lEAnjFTB+9XICplEci/sIkeBy62s+6/ =aOfh -----END PGP SIGNATURE----- --Signature=_Wed__1_Dec_2010_22_20_23_+0100_7VLuNB1Wo1jVg7sl--