From patchwork Wed Mar 24 13:52:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dinh Nguyen X-Patchwork-Id: 12161193 X-Patchwork-Delegate: kuba@kernel.org 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=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 3F8ADC433DB for ; Wed, 24 Mar 2021 13:53:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10C4261A07 for ; Wed, 24 Mar 2021 13:53:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235719AbhCXNwt (ORCPT ); Wed, 24 Mar 2021 09:52:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:50514 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235459AbhCXNwX (ORCPT ); Wed, 24 Mar 2021 09:52:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8096E61A01; Wed, 24 Mar 2021 13:52:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616593943; bh=cHOHMXVQ+yn3s7ZWXL7fRhJN7XJst2LEeIiATt8XCc8=; h=From:To:Cc:Subject:Date:From; b=X1I/uyBrMwFF8ZbyYK5TzANtHVt+2KVbbCzAihjbpJvcprSe47vwn6oUDnClOzpEq /lTwZL3iompfsgUcWXQ63eNVJ5HICxe/MHMIi02fsPh1DcFCZAJgH0BxCtNiwvrJiU CjxsEiIh1ZEMFj0QlUS5WUBdyeXuWslnCYFF1JHZlzSvcSNk8o55vPcFodmaTINsVA WZMPHu7EN9mldxabdCcbT0R9ZaL+y+CBaTMBk56FX2agJtuJJj1l1j4xyBkWWFZXEi wg7GSpYDkNOWO3FDgBWCgrlh8jPG62rECHHwjcdQiplBmpXBz376qNhutXeva9nSIA GCBC5uCoyWLwQ== From: Dinh Nguyen To: davem@davemloft.net Cc: dinguyen@kernel.org, kuba@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] dt-bindings: net: micrel-ksz90x1.txt: correct documentation Date: Wed, 24 Mar 2021 08:52:19 -0500 Message-Id: <20210324135219.2951959-1-dinguyen@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org Correct the Micrel phy documentation for the ksz9021 and ksz9031 phys for how the phy skews are set. Signed-off-by: Dinh Nguyen --- .../bindings/net/micrel-ksz90x1.txt | 96 ++++++++++++++++++- 1 file changed, 94 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt b/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt index b921731cd970..df9e844dd6bc 100644 --- a/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt +++ b/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt @@ -65,6 +65,71 @@ KSZ9031: step is 60ps. The default value is the neutral setting, so setting rxc-skew-ps=<0> actually results in -900 picoseconds adjustment. + The KSZ9031 hardware supports a range of skew values from negative to + positive, where the specific range is property dependent. All values + specified in the devicetree are offset by the minimum value so they + can be represented as positive integers in the devicetree since it's + difficult to represent a negative number in the devictree. + + The following 5-bit values table apply to rxc-skew-ps and txc-skew-ps. + + Pad Skew Value Delay (ps) Devicetree Value + ------------------------------------------------------ + 0_0000 -900ps 0 + 0_0001 -840ps 60 + 0_0010 -780ps 120 + 0_0011 -720ps 180 + 0_0100 -660ps 240 + 0_0101 -600ps 300 + 0_0110 -540ps 360 + 0_0111 -480ps 420 + 0_1000 -420ps 480 + 0_1001 -360ps 540 + 0_1010 -300ps 600 + 0_1011 -240ps 660 + 0_1100 -180ps 720 + 0_1101 -120ps 780 + 0_1110 -60ps 840 + 0_1111 0ps 900 + 1_0000 60ps 960 + 1_0001 120ps 1020 + 1_0010 180ps 1080 + 1_0011 240ps 1140 + 1_0100 300ps 1200 + 1_0101 360ps 1260 + 1_0110 420ps 1320 + 1_0111 480ps 1380 + 1_1000 540ps 1440 + 1_1001 600ps 1500 + 1_1010 660ps 1560 + 1_1011 720ps 1620 + 1_1100 780ps 1680 + 1_1101 840ps 1740 + 1_1110 900ps 1800 + 1_1111 960ps 1860 + + The following 4-bit values table apply to the txdX-skew-ps, rxdX-skew-ps + data pads, and the rxdv-skew-ps, txen-skew-ps control pads. + + Pad Skew Value Delay (ps) Devicetree Value + ------------------------------------------------------ + 0000 -420ps 0 + 0001 -360ps 60 + 0010 -300ps 120 + 0011 -240ps 180 + 0100 -180ps 240 + 0101 -120ps 300 + 0110 -60ps 360 + 0111 0ps 420 + 1000 60ps 480 + 1001 120ps 540 + 1010 180ps 600 + 1011 240ps 660 + 1100 300ps 720 + 1101 360ps 780 + 1110 420ps 840 + 1111 480ps 900 + Optional properties: Maximum value of 1860, default value 900: @@ -120,11 +185,21 @@ KSZ9131: Examples: + /* Attach to an Ethernet device with autodetected PHY */ + &enet { + rxc-skew-ps = <1800>; + rxdv-skew-ps = <0>; + txc-skew-ps = <1800>; + txen-skew-ps = <0>; + status = "okay"; + }; + + /* Attach to an explicitly-specified PHY */ mdio { phy0: ethernet-phy@0 { - rxc-skew-ps = <3000>; + rxc-skew-ps = <1800>; rxdv-skew-ps = <0>; - txc-skew-ps = <3000>; + txc-skew-ps = <1800>; txen-skew-ps = <0>; reg = <0>; }; @@ -133,3 +208,20 @@ Examples: phy = <&phy0>; phy-mode = "rgmii-id"; }; + +References + + Micrel ksz9021rl/rn Data Sheet, Revision 1.2. Dated 2/13/2014. + http://www.micrel.com/_PDF/Ethernet/datasheets/ksz9021rl-rn_ds.pdf + + Micrel ksz9031rnx Data Sheet, Revision 2.1. Dated 11/20/2014. + http://www.micrel.com/_PDF/Ethernet/datasheets/KSZ9031RNX.pdf + +Notes: + + Note that a previous version of the Micrel ksz9021rl/rn Data Sheet + was missing extended register 106 (transmit data pad skews), and + incorrectly specified the ps per step as 200ps/step instead of + 120ps/step. The latest update to this document reflects the latest + revision of the Micrel specification even though usage in the kernel + still reflects that incorrect document.