Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752680Ab2FRTuF (ORCPT ); Mon, 18 Jun 2012 15:50:05 -0400 Received: from mail-wi0-f178.google.com ([209.85.212.178]:61802 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751388Ab2FRTuD convert rfc822-to-8bit (ORCPT ); Mon, 18 Jun 2012 15:50:03 -0400 MIME-Version: 1.0 In-Reply-To: <4FDF4345.40508@itdev.co.uk> References: <1339992522-22073-1-git-send-email-djkurtz@chromium.org> <1339992522-22073-15-git-send-email-djkurtz@chromium.org> <4FDF4345.40508@itdev.co.uk> Date: Mon, 18 Jun 2012 15:50:01 -0400 Message-ID: Subject: Re: [PATCH 14/22 v4] Input: atmel_mxt_ts - don't re-read matrix after applying pdata From: Yufeng Shen To: Nick Dyer Cc: Daniel Kurtz , Dmitry Torokhov , Henrik Rydberg , Joonyoung Shim , linux-input@vger.kernel.org, Iiro Valkonen , Benson Leung , Olof Johansson , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1596 Lines: 48 On Mon, Jun 18, 2012 at 11:03 AM, Nick Dyer wrote: > Daniel Kurtz wrote: >> The matrix x/y size in the Info ID Block represents the number of x/y >> trace lines on the device. ?There is no need to re-read them after >> applying pdata config, since pdata only configures the object table >> etnries. ?The matrix size read from the ID can only be updated by a >> firmware update. > > This isn't correct. For example, mXT224 can be configured as 16x14, 17x13, > 18x12, etc. This only takes effect when the chip is reset, which is why it > is necessary to re-read them after applying the config. > so look at structure mxt_info struct mxt_info { u8 family_id; u8 variant_id; u8 version; u8 build; u8 matrix_xsize; u8 matrix_ysize; u8 object_num; }; I think it is meant to be corresponding to Information Block of the device, of which the matrix_xsize and matrix_ysize mean "The size of the matrix the device supports", which should be fixed for a certain chip. The configurable matrix size is in T9 XSIZE/YSIZE, which, if ever needed to be read back, probably read back into something other than mxt_info struct. > cheers > > -- > Nick Dyer > Software Engineer, ITDev Ltd > Hardware and Software Development Consultancy > Website: http://www.itdev.co.uk -- 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/