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 1645DC433EF for ; Thu, 20 Jan 2022 08:49:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240749AbiATItq (ORCPT ); Thu, 20 Jan 2022 03:49:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238141AbiATItp (ORCPT ); Thu, 20 Jan 2022 03:49:45 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 44697C061574 for ; Thu, 20 Jan 2022 00:49:45 -0800 (PST) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nAT8C-00017W-Kz; Thu, 20 Jan 2022 09:49:20 +0100 Received: from pengutronix.de (unknown [195.138.59.174]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mkl-all@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id C732A1E389; Thu, 20 Jan 2022 08:49:17 +0000 (UTC) Date: Thu, 20 Jan 2022 09:49:14 +0100 From: Marc Kleine-Budde To: Marek =?utf-8?B?QmVow7pu?= Cc: Rob Herring , devicetree@vger.kernel.org, Vladimir Oltean , Holger Brunck , Andrew Lunn , "netdev@vger.kernel.org" , Russell King , linux-phy@lists.infradead.org, Vinod Koul , Kishon Vijay Abraham I , ore@pengutronix.de, alexandru.tachici@analog.com Subject: Re: [PATCH devicetree v3] dt-bindings: phy: Add `tx-p2p-microvolt` property binding Message-ID: <20220120084914.ga7o372lyynbn4ly@pengutronix.de> References: <20220119131117.30245-1-kabel@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="kvv4ypl26cp5w72m" Content-Disposition: inline In-Reply-To: <20220119131117.30245-1-kabel@kernel.org> X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --kvv4ypl26cp5w72m Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 19.01.2022 14:11:17, Marek Beh=C3=BAn wrote: > Common PHYs and network PCSes often have the possibility to specify > peak-to-peak voltage on the differential pair - the default voltage > sometimes needs to be changed for a particular board. >=20 > Add properties `tx-p2p-microvolt` and `tx-p2p-microvolt-names` for this > purpose. The second property is needed to specify the mode for the > corresponding voltage in the `tx-p2p-microvolt` property, if the voltage > is to be used only for speficic mode. More voltage-mode pairs can be > specified. >=20 > Example usage with only one voltage (it will be used for all supported > PHY modes, the `tx-p2p-microvolt-names` property is not needed in this > case): >=20 > tx-p2p-microvolt =3D <915000>; >=20 > Example usage with voltages for multiple modes: >=20 > tx-p2p-microvolt =3D <915000>, <1100000>, <1200000>; > tx-p2p-microvolt-names =3D "2500base-x", "usb", "pcie"; >=20 > Add these properties into a separate file phy/transmit-amplitude.yaml, > which should be referenced by any binding that uses it. If I understand your use-case correctly, you need different voltage p2p levels in the connection between the Ethernet MAC and the Ethernet switch or Ethernet-PHY? Some of the two wire Ethernet standards (10base-T1S, 10base-T1L, 100base-T1, 1000base-T1) defines several p2p voltage levels on the wire, i.e. between the PHYs. Alexandru has posed a series where you can specify the between-PHY voltage levels: | https://lore.kernel.org/all/20211210110509.20970-8-alexandru.tachici@anal= og.com/ Can we make clear that your binding specifies the voltage level on the MII interface, in contrast Alexandru's binding? regards, Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | --kvv4ypl26cp5w72m Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEK3kIWJt9yTYMP3ehqclaivrt76kFAmHpIgcACgkQqclaivrt 76m0QAf8CHZs1OBGLvXK0xMTJjOnlBpk4Ey7SjdgyBAKSqVuzT5CsLxxz0pjaN5m +oJDadaBGfmLJ7EhSferqbHSyScH6GcPtExGWX3zTauRLYNU2SO7zIlseR29/Pc0 1iPUOHsthgJkH7tTuC1UOvaECCjLqTjD6Awj4qj3UGe/XpJz6PUoLjLlw3tjrMl8 1lCbHU/Kx9TA3+udo5n/ah3BZ2AjiQ//yB6xOclo0jK774hx2laAbSJYfK1a+4lP qQ6T5tAFCEfbGYeX5jZey2i1jTwBWLnTUqeluowKQn6H1HxyuI4LWuTcmiVdJOJC qJ+1uMyDgbMNZXoy6Q8c4GoJPXTQbQ== =KE6p -----END PGP SIGNATURE----- --kvv4ypl26cp5w72m--