From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH v2 2/4] dt-bindings: net: qcom: Add binding for shared mdio bus Date: Mon, 17 Sep 2018 09:54:29 -0700 Message-ID: <13018118-9883-4b26-9017-b324d745cc58@gmail.com> References: <1537174411-34510-1-git-send-email-dongsheng.wang@hxt-semitech.com> <1537174411-34510-3-git-send-email-dongsheng.wang@hxt-semitech.com> <20180917145028.GC5458@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: "timur@kernel.org" , "davem@davemloft.net" , "Zheng, Joey" , "netdev@vger.kernel.org" , "devicetree@vger.kernel.org" To: "Wang, Dongsheng" , Andrew Lunn Return-path: Received: from mail-wr1-f66.google.com ([209.85.221.66]:44228 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726795AbeIQWWy (ORCPT ); Mon, 17 Sep 2018 18:22:54 -0400 In-Reply-To: Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 09/17/2018 09:47 AM, Wang, Dongsheng wrote: > On 9/17/2018 10:50 PM, Andrew Lunn wrote: >> On Mon, Sep 17, 2018 at 04:53:29PM +0800, Wang Dongsheng wrote: >>> This property copy from "ibm,emac.txt" to describe a shared MIDO bus. >>> Since emac include MDIO, so If the motherboard has more than one PHY >>> connected to an MDIO bus, this property will point to the MAC device >>> that has the MDIO bus. >>> >>> Signed-off-by: Wang Dongsheng >>> --- >>> V2: s/Since QDF2400 emac/Since emac/ >>> --- >>> Documentation/devicetree/bindings/net/qcom-emac.txt | 4 ++++ >>> 1 file changed, 4 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/net/qcom-emac.txt b/Documentation/devicetree/bindings/net/qcom-emac.txt >>> index 346e6c7f47b7..50db71771358 100644 >>> --- a/Documentation/devicetree/bindings/net/qcom-emac.txt >>> +++ b/Documentation/devicetree/bindings/net/qcom-emac.txt >>> @@ -24,6 +24,9 @@ Internal PHY node: >>> The external phy child node: >>> - reg : The phy address >>> >>> +Optional properties: >>> +- mdio-device : Shared MIDO bus. >> Hi Dongsheng >> >> I don't see why you need this property. The ethernet interface has a >> phy-handle which points to a PHY. That is all you need to find the PHY. > phy-handle is description PHY address. This property is describing an > MDIO controller. > Each QCOM emac include an MDIO controller, normally each emac only > connect one > PHY device, but when all of the PHY devices mdio lines connect one MDIO > controller > that is included in EMAC, we need to share this MDIO controller for > others EMAC. If you want to describe the MDIO controller, then you embed a mdio subnode into your Ethernet MAC node: emac0: ethernet@feb20000 { mdio { #address-cells = <1>; #size-cells = <0>; phy0: ethernet-phy@0 { reg = <0>; }; }; }; And then each Ethernet MAC controller refers to their appropriate PHY device tree node using a phy-handle property to point to either their own MDIO controller, or another MAC's MDIO controller. The IBM Emac is a old (not to say bad) example and it does not use the PHY library and the standard Device Tree node property, please don't use it as a reference. -- Florian