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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 8F453CA9ED5 for ; Tue, 5 Nov 2019 06:22:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6BDF820869 for ; Tue, 5 Nov 2019 06:22:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730435AbfKEGW1 (ORCPT ); Tue, 5 Nov 2019 01:22:27 -0500 Received: from sauhun.de ([88.99.104.3]:33816 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725806AbfKEGW1 (ORCPT ); Tue, 5 Nov 2019 01:22:27 -0500 Received: from localhost (p54B339C1.dip0.t-ipconnect.de [84.179.57.193]) by pokefinder.org (Postfix) with ESMTPSA id 199742C04C4; Tue, 5 Nov 2019 07:22:24 +0100 (CET) Date: Tue, 5 Nov 2019 07:22:23 +0100 From: Wolfram Sang To: Eugeniu Rosca Cc: Ulf Hansson , Adrian Hunter , Wolfram Sang , linux-mmc@vger.kernel.org, Linus Walleij , Mathieu Malaterre , Pavel Machek , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Eugeniu Rosca Subject: Re: [PATCH 1/3] dt-bindings: mmc: Add 'fixed-emmc-driver-type-hs{200,400}' Message-ID: <20191105062223.GB1048@kunai> References: <20191105055015.23656-1-erosca@de.adit-jv.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="3lcZGd9BuhuYXNfi" Content-Disposition: inline In-Reply-To: <20191105055015.23656-1-erosca@de.adit-jv.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --3lcZGd9BuhuYXNfi Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Eugeniu, thanks for this work! > A certain eMMC manufacturer provided below requirement: > ---snip--- > Use "drive strength" value of 4 or 1 for HS400 or 0 for HS200. > ---snip--- I see. > The existing "fixed-emmc-driver-type" property [1] is the closest one > to implement the above, but it falls short due to being unable to define > two values to differentiate between HS200 and HS400 (both modes may be > supported by the same non-removable MMC device). >=20 > To allow users to set a preferred HS200/HS400 "drive strength", provide > two more bindings inspired from [1]: > - fixed-emmc-driver-type-hs200 > - fixed-emmc-driver-type-hs400 Main question before looking at the code: Can't we just extend the existing binding with an optional second parameter? minItems: 1 maxItems: 2 I tend to favour this approach... > For more details about eMMC I/O driver strength types, see Jedec spec. > Keep "fixed-emmc-driver-type" in place for backward compatibility. If we decide for the path proposed here, should the old binding be deprecated then? Happy hacking, Wolfram --3lcZGd9BuhuYXNfi Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl3BFR8ACgkQFA3kzBSg KbY0cA//YZ6N9IHHaKq423ABXNnBXaT4hOB/WYncPHRaK6cijvTKtR+eE10CRPpa ebYVYr6UatR/vR+Pq4QZixmmF5bn1mT2HbzC7nw1QIJm8OKNghOewSSWAoT3HrYn aBlen9t61+u/wC+Wnv8JZh/3A7XWG4gqkocWUTEihWrJv0uJ/f0rIR78mIV3ADAi ho5B7QBmmt2Bwsls4SEnpPvwgXwaKay0HoGOyITKE6eIk8Xokbx65KwYa50WTslR /q2bIZNeIrYx3Tk0zC2Qkof1brwfg9UxhCHPD7+6cbZCRvnI7nHFPQa1FCxqwTtm XOvB7Afzf5rowAEUnQ7Kofxp7l+zbPGo0BvuBxAQsUYsJjG/AXpso/owQKzM7ob7 +NnKgpkqHtg5wnxtTjOmLJZwfOLLmAEp7z9ibPalFpX2s4WT9kEdqNpkSanwnXSx bF69QHSM4nPsSCrhPLyowditB/FjtkAHceAiiBHIDcN4v+ytXVTsJbjiESudaQdZ co0K/mYz3VfdcJ3wDhYUUOx/Lg1ejxhYDV+V9iHxYTeWoYHS9NNny8lnP6U9Bz1v /E4VBIhDm+LvNE9DH1b9yMxzrD5TnISC8XBtgqkjW9m1DVu1wmtCE/WTeG+0NdNl zlox2HdI0G4JEJIdLrbNtVfpNMRwurT4UMLKFFPcvpSvIAaIaNw= =bGHK -----END PGP SIGNATURE----- --3lcZGd9BuhuYXNfi--