Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755825Ab2JVRM0 (ORCPT ); Mon, 22 Oct 2012 13:12:26 -0400 Received: from mail-qa0-f53.google.com ([209.85.216.53]:34347 "EHLO mail-qa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755608Ab2JVRMX (ORCPT ); Mon, 22 Oct 2012 13:12:23 -0400 MIME-Version: 1.0 In-Reply-To: <20121022160705.GC13791@core.coreip.homeip.net> References: <1350424679-20725-1-git-send-email-scott.liu@emc.com.tw> <87hapnnp5t.fsf@emc.com.tw> <20121022160705.GC13791@core.coreip.homeip.net> Date: Mon, 22 Oct 2012 19:12:22 +0200 Message-ID: Subject: Re: [PATCH v1] Support Elan Touchscreen eKTF product. From: Benjamin Tissoires To: Dmitry Torokhov Cc: Jian-Jhong Ding , Scott Liu , linux-input@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, Jesse , Vincent Wang , Paul Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2419 Lines: 60 On Mon, Oct 22, 2012 at 6:07 PM, Dmitry Torokhov wrote: > On Mon, Oct 22, 2012 at 11:47:42AM +0800, Jian-Jhong Ding wrote: >> Scott Liu writes: >> > + >> > +struct mt_device { >> > + struct mt_slot curdata; /* placeholder of incoming data */ >> > + __u8 num_received; /* how many contacts we received */ >> > + __u8 num_expected; /* expected last contact index */ >> > + __u8 maxcontacts; >> > + bool curvalid; /* is the current contact valid? */ >> > + struct mt_slot *slots; >> > +}; >> >> With Benjamin's i2c-hid implimentation, is it possible to make >> hid-multitouch not depend on USBHID and reuse it to drive this device? We can already use hid-multitouch with hid over I2C devices (I'm testing my i2c devices with this module). But it's true that hid-multitouch depends on usbhid, and I the funny think is that I was removing this dependency today. The fact is that currently, i2c devices do not segfault with hid-multitouch because win8 devices do not require anymore to set some feature at plug. > > Exactly. Before looking any further - is this the same part that Tom Lin > posted a driver for earlier this summer? I'm not Elan, and I can not be sure, but judging from the "hello packets" and the other commands, I doubt this device is an I2C over HID one. Anyway, reusing hid-multitouch for this specific case seams to be a little bit difficult. You would have first to provide a fake report descriptor (or inject commands as if you were hid-core) and then, you would have to reformat the incoming data into valid win7 (or 8) packets. Judging by the functions elan_touch_parse_fid, elan_touch_parse_wid and elants_parse_xy, the data seem to be mixed (all the finger ids at the beginning, and not one per touch), so it is definitively needed to recreate a valid HID packet. So I'm not surprised with the duplicated code. However, Henrik did a big job in kernel 3.7 to factorize mt code, and some part of the duplication can be achieve with these functions (look at input_mt_sync_frame and input_mt_get_slot_by_key for example). Cheers, Benjamin > > Thanks. > > -- > 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/