From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32163C4338F for ; Fri, 30 Jul 2021 14:32:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0AC4260F46 for ; Fri, 30 Jul 2021 14:32:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239108AbhG3OcR convert rfc822-to-8bit (ORCPT ); Fri, 30 Jul 2021 10:32:17 -0400 Received: from mslow1.mail.gandi.net ([217.70.178.240]:38691 "EHLO mslow1.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239042AbhG3OcR (ORCPT ); Fri, 30 Jul 2021 10:32:17 -0400 Received: from relay6-d.mail.gandi.net (unknown [217.70.183.198]) by mslow1.mail.gandi.net (Postfix) with ESMTP id EACA7C4997 for ; Fri, 30 Jul 2021 14:29:19 +0000 (UTC) Received: (Authenticated sender: gregory.clement@bootlin.com) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id 755BEC0004; Fri, 30 Jul 2021 14:28:58 +0000 (UTC) From: Gregory CLEMENT To: Hermann Lauer Cc: linux-i2c@vger.kernel.org Subject: Re: I2C MV64XXX: Showing Allwinner debug LCR register in bus lock case In-Reply-To: <20210729073100.GA8757@lemon.iwr.uni-heidelberg.de> References: <20210729073100.GA8757@lemon.iwr.uni-heidelberg.de> Date: Fri, 30 Jul 2021 16:28:58 +0200 Message-ID: <87mtq3zxhx.fsf@BL-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Hello Hermann, > Dear Maintainers, > > if Allwinner i2c locks, the is a LCR register (reg_base + 0x20), > which shows directly the state of the SCL and SDA lines. So you can > see which line (if any) is pulled externally low. > > Is there a similar usefull register in the original MV64XXX MARVELL > chip? I've check on the Armada 38x datasheet and at least on this one there is no such register or register with similar information. That's mean you won't be able to use it for any device only the Allwinner ones. Grégory > > I'd like to make the patch https://bitbucket.org/hlauer/kernel/src/master/patches/i2c-buslock.patchl working for that chip, too. > > Thanks for any ideas. > > Greetings > Hermann > > -- > Administration/Zentrale Dienste, Interdiziplinaeres > Zentrum fuer wissenschaftliches Rechnen der Universitaet Heidelberg > IWR; INF 205; 69120 Heidelberg; Tel: (06221)54-14405 Fax: -14427 > Email: Hermann.Lauer@iwr.uni-heidelberg.de -- Gregory Clement, Bootlin Embedded Linux and Kernel engineering http://bootlin.com