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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 8DEB8C43331 for ; Thu, 2 Apr 2020 09:28:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6BBDB206D3 for ; Thu, 2 Apr 2020 09:28:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387937AbgDBJ2Y (ORCPT ); Thu, 2 Apr 2020 05:28:24 -0400 Received: from sauhun.de ([88.99.104.3]:56018 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725965AbgDBJ2T (ORCPT ); Thu, 2 Apr 2020 05:28:19 -0400 Received: from localhost (p54B333EE.dip0.t-ipconnect.de [84.179.51.238]) by pokefinder.org (Postfix) with ESMTPSA id DB7882C0590; Thu, 2 Apr 2020 11:28:16 +0200 (CEST) Date: Thu, 2 Apr 2020 11:28:13 +0200 From: Wolfram Sang To: Laine Jaakko EXT , Rob Herring Cc: Shubhrajyoti Datta , "linux-i2c@vger.kernel.org" , "michal.simek@xilinx.com" , "linux-arm-kernel@lists.infradead.org" , devicetree@vger.kernel.org Subject: Re: [PATCH] i2c: xiic: Support disabling multi-master in DT Message-ID: <20200402092813.GA986@ninjato> References: <20200218135627.24739-1-ext-jaakko.laine@vaisala.com> <20200401143254.GA2409@ninjato> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="17pEHd4RhPHOinZp" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --17pEHd4RhPHOinZp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi Jaako, > > My best bet is to introduce another binding "single-master" which says > > clearly that we are the only bus master on that bus. > > > > Both bindings missing means then "unclear". > > > > I think this matches reality best. > > > > Opinions? > I agree that this sounds like the best option if original binding > can't be used, even though it can also be a bit confusing to have 2 > similar bindings. I think it becomes understandable if we emphasize that "no bindings" means "unclear". We need to document it. > How would both bindings existing simultaneously be interpreted? Maybe > both existing simultaneously should be considered as an invalid > configuration, so that it would be enough to just check the one you > need? The other option would be to treat both existing similarly to > neither existing, which would require the driver to always check both > if checking one. I am clearly for saying that this is an illegal combination. I'd hope this can be expressed in a YAML binding. Yet, my research didn't give me an answer. Adding Rob and DT list to CC. Question is: Can we check if the boolean bindings "multi-master" and "single-master" are not applied at the same time? Any other combination is okay, i.e. just one of them or none of them. > Should the new single-master binding also be a general binding for all > I2C drivers or a binding just defined for the XIIC driver? Having it It should definately be global. Thanks, Wolfram --17pEHd4RhPHOinZp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl6FsCkACgkQFA3kzBSg Kbbvtw/+L5wD8ARrOmtDVYzMRtJvbyu1XsD4cZdfx/fHNB3oOKbL65t9dnKWiuRy Np7KViYB9VbVGTYtRWPT5EPWUqhtNbRWfEoxONZ02IVVBq8qfl9iIgcXpvrbVU2J 7m3AJSB8x2A9FJ4iE1o3hPw7zkUKtnXui1nn7MIFO34d6QaU7UgxpQ3pIdITKtIm BqUedfcI2zj0cV+V4RsZFUlZLZ7QsVUkcXDd3tsXt/yKnBxPVV/pzqmsQzNrXI3Q evWAjIFHmBJzM4B3teelLwsE2toVGVtK/j4x5ZhTSkEpPBnkA++02xAVq+krdM+z AMBD8ZIoHwQzjoSNGcoEXprLkQmN2nbfl1dgvRGUPotJ8LDIYo5NyaRy4WYBh6xF QjnMQFg29QuuWCfXDKC8vNG1BN/DYUh+8Bzo7HCGiEPd7B/unsFqz7QxW6WCg29G MmHi+253Xq9LKDvC6OqB2+Dvc764BGI2xiVu4t4/iXXvWI0VkhCeoZkUdLkx19OR LKEw7ipKmhiX4sPvhtD38J6c4XKz1izB+4rzTq7ZZH+Vg1cNtYL3/riIfE9BwxjF A6KwJi6vXetZxROIxWTxj8BX9qjbhErOYDCTWPxFlj815S4RfDgqC5oiHIhGGr4m Vv3egui9LAtlne0QsqmR0PjP5hQ4fFp+78rjdoHgyyFAtKA9fnA= =KFqX -----END PGP SIGNATURE----- --17pEHd4RhPHOinZp--