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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 43B12CD5BD1 for ; Tue, 19 Sep 2023 15:02:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233019AbjISPCL (ORCPT ); Tue, 19 Sep 2023 11:02:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233004AbjISPCK (ORCPT ); Tue, 19 Sep 2023 11:02:10 -0400 Received: from mail.zeus03.de (www.zeus03.de [194.117.254.33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1B75FE5 for ; Tue, 19 Sep 2023 08:02:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to; s=k1; bh=Z0cS dtdCQ00W7uzzuBGbsOFl4pgCUIFxScbps3z/eAE=; b=QNR/9h4PaTCvEnoE5rw3 avA714OFhfvIUz+2eHPeQWP64qLAtwHYIcBs7wvTjG/Dxj7UdF0I28ofpW3KUcyG 0l0UhcFHuNyzl9SR+PCfX+QJe/M492ff7bohQm7wyVL6Kbfoi84EwxuuuhVimX1V Vf2mEX7/KIua5KLQNwB5XUeOCVzCLCrFjiZ75MDEc21X2yROigAcLqKLlNmqBh09 +wor/2eoX7I3/mH1NlH+Qq3u3b/UWgirpKjT7NVOwCH9gFbzurZfuWrUo5Y4L/Tk PbIoroOlj5NYEYJ/W83+7ZmiHcNT2dUH8QUuVYEdJXV3LbOe1MZUJgrPRoNNP9kI JQ== Received: (qmail 251185 invoked from network); 19 Sep 2023 17:02:02 +0200 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 19 Sep 2023 17:02:02 +0200 X-UD-Smtp-Session: l3s3148p1@vTSKircF9xIucrQg Date: Tue, 19 Sep 2023 17:02:01 +0200 From: Wolfram Sang To: Geert Uytterhoeven Cc: linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda , Andi Shyti , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] i2c: rcar: add FastMode+ support for Gen4 Message-ID: Mail-Followup-To: Wolfram Sang , Geert Uytterhoeven , linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda , Andi Shyti , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org References: <20230913203242.31505-1-wsa+renesas@sang-engineering.com> <20230913203242.31505-3-wsa+renesas@sang-engineering.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="vVCqwtsTzpx3t2Sh" Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org --vVCqwtsTzpx3t2Sh Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > > + /* FM+ needs lower SMD and no filters */ > > + priv->smd /=3D 2; > > + cdf =3D 0; >=20 > Is this documented somewhere in the R-Car Gen4 docs? Sadly, there are no recommended values for FM+ in the docs. With cdf=3D6, I got speeds around 800kHz. After seeing the BSP also uses cdf=3D0, I got speeds close to 1MHz. There is a note in Gen3 and later docs for ICCCR2 saying that cdf=3D0 is recommended for devices with a data hold time less than 100ns. I don't have the PMIC docs here to verify if that is the case here. However, I recalled there are some generic filter bindings for I2C. I will check if we can make use of them here. --vVCqwtsTzpx3t2Sh Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmUJt+kACgkQFA3kzBSg KbbD6xAAsU8C+txBnNyPnyuIDx6ppzSmC+V+hfzW2+2Ke7nbqQIhwOQwerj9Ysg1 xEsetQ/KNQhK6pX7ueWVsi0YcnOYdzHzcTeYy9XfL9GuHcSr8UFFu31K1U4+WI6l DQBRPGlOEfGvJb/nICt06r0WYBbFR73HF9z6sjfJH+lCADk85qiiL4Wt5gyzPW5X QBowLweliHUszj5g9SGTy5qBDE92fi+u05wbpuCNMXeFZNry5el6fHLrc0y/J+Ex 6Kcckld/vy9KqVZ13d7irgbU5cxPaoR3zcYHSGurCZXg2r129RII/HCwmbJIObP2 zLPVkgSCP+xaZNz7VSsU9ii5OzFDPDWaoeMtK+mYGKkgxfT4PSk42RWF9oAkHTGr 0bh47pdqo1Nfdj1QEXcPHv8Z2CRbnt4j0lqne2e3ND15JsCLOxDPRebOthkgY8c6 Mz8o5mubMEZha2uNRGrMKy+NdkC1i59ibY7CV0PyYmAA+eYwa+ww+gmV2BOnrMB8 EL++7DT1sgT8niFss4sd1J+B8LYYwUj4aYTRTU0gAdNTghZk4KaNAgfozo8PHoIR 6i5I/8bRMnRT0QIgwAxvRPOiyrfpBRhYK0rPF3lwpYOnM8ckAagUQTxDVwKr0UYp fHJRA82b7wc4bJWs7xjRCOuLqgx/2eJbiNVlYQ1av4wtyA2FI4A= =J32p -----END PGP SIGNATURE----- --vVCqwtsTzpx3t2Sh--