From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756711AbcHXOG0 (ORCPT ); Wed, 24 Aug 2016 10:06:26 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:35023 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756177AbcHXOGY (ORCPT ); Wed, 24 Aug 2016 10:06:24 -0400 Date: Wed, 24 Aug 2016 14:02:21 +0200 From: LABBE Corentin To: Maxime Ripard Cc: robh+dt@kernel.org, mark.rutland@arm.com, wens@csie.org, linux@armlinux.org.uk, davem@davemloft.net, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com Subject: Re: [PATCH v2 1/5] ethernet: add sun8i-emac driver Message-ID: <20160824120221.GB29212@Red> References: <1469001800-11615-1-git-send-email-clabbe.montjoie@gmail.com> <1469001800-11615-2-git-send-email-clabbe.montjoie@gmail.com> <20160725195455.GQ7419@lukather> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160725195455.GQ7419@lukather> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > +/* Set Management Data Clock, must be call after device reset */ > > +static void sun8i_emac_set_mdc(struct net_device *ndev) > > +{ > > + struct sun8i_emac_priv *priv = netdev_priv(ndev); > > + unsigned long rate; > > + u32 reg; > > + > > + rate = clk_get_rate(priv->ahb_clk); > > + if (rate > 160000000) > > + reg = 0x3 << 20; /* AHB / 128 */ > > + else if (rate > 80000000) > > + reg = 0x2 << 20; /* AHB / 64 */ > > + else if (rate > 40000000) > > + reg = 0x1 << 20; /* AHB / 32 */ > > + else > > + reg = 0x0 << 20; /* AHB / 16 */ > > + netif_dbg(priv, link, ndev, "MDC auto : %x\n", reg); > > + writel(reg, priv->base + SUN8I_EMAC_MDIO_CMD); > > You could also expose that as a clock. > For which purpose ? No ethernet driver expose the MDC as clock and I dont see any interest: - I dont think that tuning it give any gain - Knowing it's value is of little interest Regards