From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754222Ab1HQQcf (ORCPT ); Wed, 17 Aug 2011 12:32:35 -0400 Received: from mail-gw0-f46.google.com ([74.125.83.46]:52824 "EHLO mail-gw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753946Ab1HQQcd (ORCPT ); Wed, 17 Aug 2011 12:32:33 -0400 Date: Wed, 17 Aug 2011 09:32:26 -0700 From: Dmitry Torokhov To: Daniel Kurtz Cc: Henrik Rydberg , chase.douglas@canonical.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, olofj@chromium.org, chris@cnpbagwell.com Subject: Re: [PATCH 4/8 v3] Input: synaptics - add image sensor support Message-ID: <20110817163226.GB4877@core.coreip.homeip.net> References: <1313169407-4358-1-git-send-email-djkurtz@chromium.org> <1313169407-4358-5-git-send-email-djkurtz@chromium.org> <20110812210911.GA9124@polaris.bitmath.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 17, 2011 at 10:05:48PM +0800, Daniel Kurtz wrote: > On Mon, Aug 15, 2011 at 3:17 PM, Daniel Kurtz wrote: > > > > Hi Henrik, > > > > Thanks for the great feedback. > > > > On Sat, Aug 13, 2011 at 5:09 AM, Henrik Rydberg wrote: > > > Hi Daniel, > > > > > > looks good, some details below. > > > > > > The ABS_MT_TOUCH_MAJOR is supposed to have zero intercept, to remain > > > compatible with user space handling of type A devices. Also, the scale > > > should match the screen/pad size, such that the actual size of the > > > touch area can be deduced. In addition, based on the current sensor > > > technologies, ABS_MT_PRESSURE and ABS_MT_TOUCH_MAJOR are normally > > > mutually exclusive. > > > > > > All in all, I would prefer to only report width via (the single-finger > > > axis) ABS_TOOL_WIDTH, and only for compatibility reasons. > > > > > > + > > > +static void synaptics_report_slot_agm(struct input_dev *dev, int slot, > > > +                                   const struct synaptics_hw_state *agm) > > > +{ > > > +     input_mt_slot(dev, slot); > > > +     input_mt_report_slot_state(dev, MT_TOOL_FINGER, true); > > > +     input_report_abs(dev, ABS_MT_POSITION_X, agm->x); > > > +     input_report_abs(dev, ABS_MT_POSITION_Y, invert_y(agm->y)); > > > +     input_report_abs(dev, ABS_MT_PRESSURE, agm->z); > > > +} > > > > With ABS_MT_TOUCH_MAJOR dropped, sgm and agm seems to coincide... > > .... > > > > > > Looks good otherwise. > > > > > > Thanks, > > > Henrik > > > > > > > Ahh....  ok, this makes sense.  I missed this detail previously. > > Basically: > >  * Only report synaptics "w" as ABS_TOOL_WIDTH (for backwards compatibility) > >  * Report synaptics "z" as ABS_MT_TOUCH_MAJOR (assuming it is really > > 'width of finger in surface units'), and ABS_PRESSURE (for backwards > > compatibility). > >  * Don't use ABS_MT_PRESSURE. > >  * This will simplify agm/sgm reporting by making them both reoprt > > the same axes. > > Hi Henrik, > > I think I was wrong in my previous comment. > > I agree we should drop reporting synaptics 'w' (4-15, arbitrary units) > in ABS_MT_TOUCH_MAJOR. > Instead, to support legacy, report 'w' in ABS_TOOL_WIDTH, and do not > report ABS_MT_TOUCH_MAJOR at all. > > However, I believe we should still report synaptics 'z' (0-255, in > arbitrary units) as ABS_MT_PRESSURE. > This will, in turn, be used by input_mt_report_pointer_emulation() to > determine the correct ABS_PRESSURE to report for legacy userspace > uses. Alternatively, you can use input_mt_set_value() to save Z value to be used by input_mt_report_pointer_emulation() later, but not report it as part of MT packet. -- Dmitry