Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756138AbaDHCxy (ORCPT ); Mon, 7 Apr 2014 22:53:54 -0400 Received: from mail-vc0-f178.google.com ([209.85.220.178]:38875 "EHLO mail-vc0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755242AbaDHCxt (ORCPT ); Mon, 7 Apr 2014 22:53:49 -0400 MIME-Version: 1.0 In-Reply-To: <20140407200022.GA20023@earth.universe> References: <1396736821-14395-1-git-send-email-sre@kernel.org> <1396736821-14395-2-git-send-email-sre@kernel.org> <20140407200022.GA20023@earth.universe> Date: Mon, 7 Apr 2014 21:53:48 -0500 Message-ID: Subject: Re: [PATCHv2 1/5] Input: add common DT binding for touchscreens From: Rob Herring To: Sebastian Reichel Cc: Dmitry Torokhov , Dmitry Torokhov , "linux-input@vger.kernel.org" , Tony Lindgren , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , "devicetree@vger.kernel.org" , linux-omap , "linux-kernel@vger.kernel.org" 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 On Mon, Apr 7, 2014 at 3:00 PM, Sebastian Reichel wrote: > On Mon, Apr 07, 2014 at 11:38:01AM -0500, Rob Herring wrote: >> On Sat, Apr 5, 2014 at 5:26 PM, Sebastian Reichel wrote: >> > Add common DT binding documentation for touchscreen devices and >> > implement input_parse_touchscreen_of_params, which parses the common >> > properties and configures the input device accordingly. >> >> Good. >> >> [...] >> > +Optional properties for Touchscreens: >> > + - touchscreen-size-x : horizontal resolution of touchscreen >> > + - touchscreen-size-y : vertical resolution of touchscreen >> >> While I like the consistency, x-size and y-size are already commonly >> used. Perhaps the common binding should have both and x-size/y-size be >> marked deprecated. > > So you want me to add something like the following? > > - x-size : deprecated name for touchscreen-size-x > - y-size : deprecated name for touchscreen-size-y Yes. > >> > + - touchscreen-max-pressure : maximum reported pressure >> > + - touchscreen-fuzz-x : horizontal noise value of the absolute input device >> > + - touchscreen-fuzz-y : vertical noise value of the absolute input device >> > + - touchscreen-fuzz-pressure : pressure noise value of the absolute input device >> >> What are the units or are they just an arbitrary range dependent on >> the controller? Several existing bindings appear to be in pixels, but >> that seems wrong to me. > > x/y related properties: pixels > pressure related properties: arbitrary range dependent on the controller Please make this clear in the binding description. >> There's also these various properties that should have common versions created: >> >> ti,x-plate-resistance and ti,x-plate-ohms (tsc2007) > > I think this is ti specific. But I should probably name the tsc2005 > property "ti,x-plate-ohms", so that its in sync with tsc2007. > >> - rohm,flip-x : Flip touch coordinates on the X axis >> - rohm,flip-y : Flip touch coordinates on the Y axis >> - x-invert: invert X axis >> - y-invert: invert Y axis > > like this? > > - touchscreen-inverted-x: X axis is inverted > - touchscreen-inverted-y: Y axis is inverted > - x-invert: deprecated name for touchscreen-inverted-x > - y-invert: deprecated name for touchscreen-inverted-y > > Inverting is currently not supported by the input system, though. So > adding support for it to input_parse_touchscreen_of_params() is not > trivial :/ Does not matter. I'm only asking you to define the property. Linux does not have to use it currently. >> - contact-threshold: >> - moving-threshold: > > I think those are hardware specific. The properties are currently > used by one driver, which writes them directly into some registers. > The DT binding does not give more information about them. moving-threshold is probably the same as fuzz. contact-threshold is sounds like min pressure. I remember having to tune the minimum pressure on a touchscreen I worked on long ago. So think think is definitely not an uncommon property. Rob -- 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/