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 BAC9BC433F5 for ; Thu, 24 Mar 2022 11:11:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349695AbiCXLNB (ORCPT ); Thu, 24 Mar 2022 07:13:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53074 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349692AbiCXLM6 (ORCPT ); Thu, 24 Mar 2022 07:12:58 -0400 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 AD450A66C8 for ; Thu, 24 Mar 2022 04:11:26 -0700 (PDT) Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nXLMx-00053I-B5; Thu, 24 Mar 2022 12:11:07 +0100 Received: from [2a0a:edc0:0:900:1d::77] (helo=ptz.office.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtp (Exim 4.94.2) (envelope-from ) id 1nXLMs-002gI2-DH; Thu, 24 Mar 2022 12:11:05 +0100 Received: from ukl by ptz.office.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1nXLMu-00BKEP-DC; Thu, 24 Mar 2022 12:11:04 +0100 Date: Thu, 24 Mar 2022 12:11:04 +0100 From: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= To: "Peng Fan (OSS)" Cc: ulf.hansson@linaro.org, robh+dt@kernel.org, krzk+dt@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, wg@grandegger.com, mkl@pengutronix.de, davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, qiangqing.zhang@nxp.com, devicetree@vger.kernel.org, Peng Fan , netdev@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-can@vger.kernel.org, linux-imx@nxp.com, kernel@pengutronix.de, festevam@gmail.com, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 0/4] dt-bindings: imx: add nvmem property Message-ID: <20220324111104.cd7clpkzzedtcrja@pengutronix.de> References: <20220324042024.26813-1-peng.fan@oss.nxp.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="wgkvs6aazjig7tcg" Content-Disposition: inline In-Reply-To: <20220324042024.26813-1-peng.fan@oss.nxp.com> X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --wgkvs6aazjig7tcg Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hello, On Thu, Mar 24, 2022 at 12:20:20PM +0800, Peng Fan (OSS) wrote: > From: Peng Fan >=20 > To i.MX SoC, there are many variants, such as i.MX8M Plus which > feature 4 A53, GPU, VPU, SDHC, FLEXCAN, FEC, eQOS and etc. > But i.MX8M Plus has many parts, one part may not have FLEXCAN, > the other part may not have eQOS or GPU. > But we use one device tree to support i.MX8MP including its parts, > then we need update device tree to mark the disabled IP status "disabled". >=20 > In NXP U-Boot, we hardcoded node path and runtime update device tree > status in U-Boot according to fuse value. But this method is not > scalable and need encoding all the node paths that needs check. >=20 > By introducing nvmem property for each node that needs runtime update > status property accoridng fuse value, we could use one Bootloader > code piece to support all i.MX SoCs. >=20 > The drawback is we need nvmem property for all the nodes which maybe > fused out. I'd rather not have that in an official binding as the syntax is orthogonal to status =3D "..." but the semantic isn't. Also if we want something like that, I'd rather not want to adapt all bindings, but would like to see this being generic enough to be described in a single catch-all binding. I also wonder if it would be nicer to abstract that as something like: / { fuse-info { compatible =3D "otp-fuse-info"; flexcan { devices =3D <&flexcan1>, <&flexcan2>; nvmem-cells =3D <&flexcan_disabled>; nvmem-cell-names =3D "disabled"; }; m7 { .... }; }; }; as then the driver evaluating this wouldn't need to iterate over the whole dtb but just over this node. But I'd still keep this private to the bootloader and not describe it in the generic binding. Just my 0.02=E2=82=AC Uwe --wgkvs6aazjig7tcg Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEfnIqFpAYrP8+dKQLwfwUeK3K7AkFAmI8UcQACgkQwfwUeK3K 7Am9+Af/TL19J0ba7ItLW+bNEISHsBaSaOLd2ifYXQclP0TkgvgsPpvr+ZFan0HB W2lomfRdTS4NSas5aNAopvU1h+NkDot8iQAK65FIFAaSPqVZ5NTACag7zjN2wxKh Op2qcQycHc8n6kOZsVI7hBLTPpPST3L53MHRzwiZ2CTuRdfp/f/ISmhEJ0nyijyv +qE21d99fSrCBh6tXBCqbQCwbIBq6ujU07fkO3EXapDrYsskghCRmtcPcnV0bD93 UiKvwg5+UAFezAiGM9WFXQD61b2PJ/t+PkjR1sra0jOFdA58YKKh98uZN7yIuZ2q nANoUKO0g3cpTR0HxCu8yvaa6luAhw== =VM/f -----END PGP SIGNATURE----- --wgkvs6aazjig7tcg--