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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 23A52C4320A for ; Wed, 25 Aug 2021 14:03:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08FD461042 for ; Wed, 25 Aug 2021 14:03:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240708AbhHYOEn (ORCPT ); Wed, 25 Aug 2021 10:04:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35216 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231927AbhHYOEk (ORCPT ); Wed, 25 Aug 2021 10:04:40 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27B25C061757; Wed, 25 Aug 2021 07:03:55 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 88FAB24F; Wed, 25 Aug 2021 16:03:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1629900233; bh=XStmeZO8laUiqm+2DGzqMZYC9eT61xuHqTB/62k3p1U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=cIEE9mrsTLqpabwSaeJh1pBEwOBJN00cPbceah7LZuwSaS2JoH+UyBOm9FOFRXFbR mj6aAs3ZaOQPkazphk/YZvtgfnMmFE/D5m/NYi0MHVSXtR0IG9ALByfqtEPmp/35qr P1/AUwJI+eTYUE4njzppa1S3rWTiIgpSa/DKZWQE= Date: Wed, 25 Aug 2021 17:03:41 +0300 From: Laurent Pinchart To: Mark Brown Cc: Andy Shevchenko , Daniel Scally , Linux Kernel Mailing List , Platform Driver , Liam Girdwood , Hans de Goede , Mark Gross , Maximilian Luz , Kieran Bingham , Sakari Ailus Subject: Re: [RFC PATCH v2 1/3] regulator: core: Add regulator_lookup_list Message-ID: References: <20210824230620.1003828-1-djrscally@gmail.com> <20210824230620.1003828-2-djrscally@gmail.com> <20210825103301.GC5186@sirena.org.uk> <20210825113013.GD5186@sirena.org.uk> <20210825131139.GG5186@sirena.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 25, 2021 at 04:59:36PM +0300, Laurent Pinchart wrote: > Hello, > > CC'ing Sakari. With Sakari's correct address. > On Wed, Aug 25, 2021 at 02:11:39PM +0100, Mark Brown wrote: > > On Wed, Aug 25, 2021 at 03:26:37PM +0300, Andy Shevchenko wrote: > > > On Wed, Aug 25, 2021 at 2:30 PM Mark Brown wrote: > > > > > > No, what was proposed for regulator was to duplicate all the the DT > > > > binding code in the regulator framework so it parses fwnodes then have > > > > an API for encoding fwnodes from C data structures at runtime. The bit > > > > where the data gets joined up with the devices isn't the problem, it's > > > > the duplication and fragility introduced by encoding everything into > > > > an intermediate representation that has no purpose and passing that > > > > around which is the problem. > > > > > The whole exercise with swnode is to minimize the driver intrusion and > > > evolving a unified way for (some) of the device properties. V4L2 won't > > > > The practical implementation for regulators was to duplicate a > > substantial amount of code in the core in order to give us a less type > > safe and more indirect way of passing data from onen C file in the > > kernel to another. This proposal is a lot better in that it uses the > > existing init_data and avoids the huge amounts of duplication, it's just > > not clear from the changelog why it's doing this in a regulator specific > > manner. > > > > *Please* stop trying to force swnodes in everywhere, take on board the > > feedback about why the swnode implementation is completely inappropriate > > for regulators. I don't understand why you continue to push this so > > hard. swnodes and fwnodes are a solution to a specific problem, they're > > not the answer to every problem out there and having to rehash this > > continually is getting in the way of actually discussing practical > > workarounds for these poorly implemented ACPI platforms. > > > > > like what you are suggesting exactly because they don't like the idea > > > of spreading the board code over the drivers. In some cases it might > > > even be not so straightforward and easy. > > > > > Laurent, do I understand correctly the v4l2 expectations? > > > > There will be some cases where swnodes make sense, for example where the > > data is going to be read through the fwnode API since the binding is > > firmware neutral which I think is the v4l case. On the other hand > > having a direct C representation is a very common way of implementing > > DMI quirk tables, and we have things like the regulator API where > > there's off the shelf platform data support and we actively don't want > > to support fwnode. > > From a camera sensor point of view, we want to avoid code duplication. > Having to look for regulators using OF lookups *and* platform data in > every single sensor driver is not a good solution. This means that, from > a camera sensor driver point of view, we want to call regulator_get() > (or the devm_ version) with a name, without caring about who establishes > the mapping and how the lookup is performed. I don't care much > personally if this would be implemented through swnode or a different > mechanism, as long as the implementation can be centralized. -- Regards, Laurent Pinchart