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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 3235EC433DF for ; Wed, 1 Jul 2020 14:57:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B42D20760 for ; Wed, 1 Jul 2020 14:57:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b="PAbP2lGQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727014AbgGAO5U (ORCPT ); Wed, 1 Jul 2020 10:57:20 -0400 Received: from www.zeus03.de ([194.117.254.33]:43138 "EHLO mail.zeus03.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726854AbgGAO5U (ORCPT ); Wed, 1 Jul 2020 10:57:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=sang-engineering.com; h= date:from:to:subject:message-id:references:mime-version :content-type:in-reply-to; s=k1; bh=ixsaqyBVatpjFGlKvxteR7MZYNGi CdYi3qR8OOCYrOw=; b=PAbP2lGQCaYaVequRWufII7gAi3d8c61yHxifXAN5YRm hr/9w06qZzetaUzVHDwK4cPQz7LBigqRbIAU3jgJeIM2X7C4Lr6AcYKFxKCTgKdV p2pmooTxdX6Sp22srl+xUpXpA+U+AhB0LS9XX5H/KhHUPaZw3G9v6kY0ilZ38vo= Received: (qmail 587987 invoked from network); 1 Jul 2020 16:57:17 +0200 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 1 Jul 2020 16:57:17 +0200 X-UD-Smtp-Session: l3s3148p1@uLAVgmKpAuAgAwDPXwRGAHjapuWXvfu/ Date: Wed, 1 Jul 2020 16:57:14 +0200 From: Wolfram Sang To: linux-i2c@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Alain Volmat Subject: Re: [RFC PATCH] WIP: i2c: rcar: add HostNotify support Message-ID: <20200701145714.GA2808@kunai> References: <20200701080904.11022-1-wsa+renesas@sang-engineering.com> <20200701092731.GD2261@ninjato> <20200701121633.GI2261@ninjato> <20200701123207.GC3457@gnbcxd0016.gnb.st.com> <20200701132145.GJ2261@ninjato> <20200701143738.GF3457@gnbcxd0016.gnb.st.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="Qxx1br4bt0+wmkIi" Content-Disposition: inline In-Reply-To: <20200701143738.GF3457@gnbcxd0016.gnb.st.com> Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org --Qxx1br4bt0+wmkIi Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > Hum ... sorry ... I'm having some doubt about such a generic 'smbus' nami= ng. > I mean, stating 'smbus' within the controller node kind of says > "I am working in SMBus mode", and not only "I am supporting Host-Notify &= Alert". > In such case, NOT having 'smbus' would mean that the driver do not support > SMBUS and SMBus xfer and all smbus related stuff would get disabled ... > We for sure do not want to have everybody add a smbus property in their DT > if they support SMBus xfer for example. >=20 > This is probably too wide, don't you think ? It would be, yet I don't think this is case. The "smbus" property means that _additional_ SMBus restrictions apply to that bus. Like additional timeout values, reserved addresses etc... It does not mean that we can't use SMBus style communication on an I2C bus. We can because we can easily emulate it. This is not an additional restriction. So it rather means "SMBus restrictions apply here". No such properties means no such restrictions. But then you can't have HostNotify and Alert because the addresses are not reserved. We can update the binding to "smbus-restrictions" perhaps, although it doesn't really sound nice to me. Maybe Rob also has an idea. I'll send a patch later and then we will see what he says. D'accord? --Qxx1br4bt0+wmkIi Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl78pEcACgkQFA3kzBSg KbaP8w/+IkbpGpmiBMjJPMoV428Q8QibtzE0DmO00+hg6JDKiOH66/h1Ajramcgj mSB4zbu3RuQaAhudtrZo+IeQNHKATGNB5C77pFwu6dXRx+0hceiG4lV9rUzwg1PD g3QWqOk7+KONqLI6AkK6igxUaaQa2aeM6LaFmPFy90Ia8oMoVN8UI+l/0GWqGsqy tIYe5kxPo/PMIXknC5nGOAq9yulU3e2w9/cUSNgcJvKMnNClJ1JE67hEQZQ/DIKR fVCX9I8gkp6K3d/2d8kQIoalJtM8Ou9TRbBAM2DLexnkIX2T5nMIwQR//v0c5iuX NH0tjyE+IQmagmakRJjqUQeAW0vFbEXGHpUO2cGv7WS0UwxfYfYLadZX8Nq2uoXM 7z7oG/9aJ+bn2bDBk+I3WuBRndxkTnvu2tfByRMPobp/eVT5rjELKwGlPN2pFnx9 KtH2SeuLZzC424XUUiiCSEOXDffQRsB3LkGjFCRDGZXy2xy6QBCh/e/EzlbjXWln Cof79HHjF5tZAMfu16NDixd9b24ZKwTlnObB2vjgtErRPan3YiL9QTUCayo0rwPO otieSBc7aefSo84Uvmv+fv/MNKgYK+HSB4LCXVObJq5lVgGNRCUoeIuhikbyQXTN io+bx7DOKaKjHrN1s1ZXrFrBtOPZMUJq7tv0+bNd3Vdnr1roiqo= =twv3 -----END PGP SIGNATURE----- --Qxx1br4bt0+wmkIi--