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 E8204C43219 for ; Fri, 4 Nov 2022 13:31:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231567AbiKDNb1 (ORCPT ); Fri, 4 Nov 2022 09:31:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229539AbiKDNbX (ORCPT ); Fri, 4 Nov 2022 09:31:23 -0400 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 569221C9; Fri, 4 Nov 2022 06:31:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=7tLMpJgWljDAlxmwj9PUYVBNLxVIZhvlNdcukf0xZoM=; b=0nGRgygsAdOuKnuDCTsgZVCxf2 nbqDLEyiDDF8b8HmGZcc2IFGoZDmoGfL90yq+SalAmQrYjAKR38DEA2XLVC4sVXXdKGFExLO+1iSx X1P1sYSm0dSJtBEpnGkpeJc99ne+G6oVmtxOQTNsPhVGhkWo1a51pXX0AjCHNRxNOvWU=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1oqwlv-001QWI-71; Fri, 04 Nov 2022 14:30:11 +0100 Date: Fri, 4 Nov 2022 14:30:11 +0100 From: Andrew Lunn To: Chester Lin Cc: Andreas =?iso-8859-1?Q?F=E4rber?= , Rob Herring , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Krzysztof Kozlowski , Jan Petrous , netdev@vger.kernel.org, s32@nxp.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Matthias Brugger Subject: Re: [PATCH 2/5] dt-bindings: net: add schema for NXP S32CC dwmac glue driver Message-ID: References: <20221031101052.14956-1-clin@suse.com> <20221031101052.14956-3-clin@suse.com> <20221102155515.GA3959603-robh@kernel.org> <2a7ebef4-77cc-1c26-ec6d-86db5ee5a94b@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Here I just focus on GMAC since there are other LAN interfaces that S32 family > uses [e.g. PFE]. According to the public GMACSUBSYS ref manual rev2[1] provided > on NXP website, theoretically GMAC can run SGMII in 1000Mbps and 2500Mbps so I > assume that supporting 1000BASE-X could be achievable. I'm not sure if any S32 > board variant might have SFP ports but RJ-45 [1000BASE-T] should be the major > type used on S32G-EVB and S32G-RDB2. SGMII at 2500Mbps does not exist. Lots of people get this wrong. It will be 2500Base-X. Does the clock need to change in order to support 2500Base-X? If i understand you correctly, Linux does not control the clocks, and so cannot change the clocks? So that probably means you cannot actually support 2500Base-X? Once you have Linux actually controlling the hardware, you can then make use of an SFP or a copper PHY which supports 2.5G. The PHY will swap its host side between SGMII and 2500Base-X depending on what the line side negotiates, 1000Base-T or 2500Base-T. The MAC driver then needs to change its configuration to suite. Andrew