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=-0.6 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 90285C352BE for ; Thu, 16 Apr 2020 21:54:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66ACD218AC for ; Thu, 16 Apr 2020 21:54:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="nZ3mWs5M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728294AbgDPVyW (ORCPT ); Thu, 16 Apr 2020 17:54:22 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:42718 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725272AbgDPVyW (ORCPT ); Thu, 16 Apr 2020 17:54:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=sJoGlhke6RR1kM1TPJ0UiaTv4A4MkV9oORpm3epxYVo=; b=nZ3mWs5Mhk/fuDnxYopkcIKFaE LshpNurBHLFjJUZxbiuJacFvfKjdEEOgJeVcPm7Rrn1WS20bJJ8PUwAXd+IKXuBFVpnS3sWr91Hfr G2BtgK95aGgvhkCtY0nDAau4JvHXufNdeHebUHj4R4BqodB35M2iPaivoSO7q07zPp6k=; Received: from andrew by vps0.lunn.ch with local (Exim 4.93) (envelope-from ) id 1jPCSa-0039j7-Qz; Thu, 16 Apr 2020 23:54:12 +0200 Date: Thu, 16 Apr 2020 23:54:12 +0200 From: Andrew Lunn To: Jernej Skrabec Cc: robh+dt@kernel.org, f.fainelli@gmail.com, hkallweit1@gmail.com, devicetree@vger.kernel.org, netdev@vger.kernel.org, linux@armlinux.org.uk, mripard@kernel.org, linux-kernel@vger.kernel.org, wens@csie.org, lee.jones@linaro.org, davem@davemloft.net, linux-arm-kernel@lists.infradead.org Subject: Re: [RFC PATCH 0/4] net: mfd: AC200 Ethernet PHY Message-ID: <20200416215412.GD744226@lunn.ch> References: <20200416185758.1388148-1-jernej.skrabec@siol.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200416185758.1388148-1-jernej.skrabec@siol.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 16, 2020 at 08:57:54PM +0200, Jernej Skrabec wrote: > This is attempt to support Ethernet PHY on AC200 MFD chip. I'm sending > this as RFC because I stumbled on a problem how to properly describe it > in DT. Proper DT documentation will be added later, once DT issue is > solved. > > Before Ethernet PHY can be actually used, few things must happen: > 1. 24 MHz clock must be enabled and connected to input pin of this > chip. In this case, PWM is set to generate 24 MHz signal with 50% > duty cycle. > 2. Chip must be put out of reset through I2C > 3. Ethernet PHY must be enabled and configured through I2C Hi Jernej This is going to be interesting to describe in DT. At what point does the PHY start responding to MDIO request? In particular, you can read the ID registers 2 and 3? You list above what is needed to make it usable. But we are also interested in what is required to make is probe'able on the MDIO bus. We have more flexibility if we can first probe it, and then later make it usable. Thanks Andrew