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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A04C0C54E60 for ; Tue, 19 Mar 2024 12:09:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: MIME-Version:List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe :List-Id:In-Reply-To:References:To:From:Cc:Subject:Message-Id:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UTMMs6MVU6goI4XDAYADfkcNKYN7Pkd/ntXbkEu18/4=; b=ZsaObLqAQrog7pT1QzN+1UBDs4 l1Cza1BF11yzJwCApNojVANTkle0d/+MUbN7deMf7GreC9PuPEdLcKgLgwKRdQrpGXJoOMKCMgel4 TN4hGi5kt1rdgwsBQSkqWbimp3FieRUxS8cwM3Dfz/0Z5ipk8h+LhuS9ajxkTjBgYScze4RicMcI3 gHu3/hYW7ufrQYn7/V+BvHZBnClzuIe5FCorFMYJL43M1kiWC3qZPUlBOwg/z0qiLP+ETYI3D5Nn4 lx/7WHA2mpQvXM060yU7qrtxzis4YUJdhK6g/jX4+TeybRBufMMhzcTJDrdGOWw0XfJmy4ir62aXL mbnRFv3A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmYGt-0000000CZgJ-3mjv; Tue, 19 Mar 2024 12:08:47 +0000 Received: from sin.source.kernel.org ([2604:1380:40e1:4800::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rmYGq-0000000CZfe-143Q for linux-arm-kernel@lists.infradead.org; Tue, 19 Mar 2024 12:08:46 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 29458CE0DF9; Tue, 19 Mar 2024 12:08:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF96AC433C7; Tue, 19 Mar 2024 12:08:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710850121; bh=hnSVsLiLejS2+H2QkSYnP/1VC+dBGjS25lGVUBroTNM=; h=Date:Subject:Cc:From:To:References:In-Reply-To:From; b=S/6qC1ANHMIvVNMlBpY/FEIfzg21ybAe6BjNnNSWe8VX2Vi9A9XudWvAdNx8j3uzE 03fdkU/dTxYfY0WC10r3RaK90sK8IRwKczX5EcXA6TkbvCdm0ZyVrnCBtVmzF5/l1N OFYILoRBkXVG3NdZP7iKDcLTKEX1q/32L1nNVy+0adleyZttizwpNd6uemATz4pUgw 72rca3a2DSz5SzoAiDwOKYbSd/+ukCpCNZVRdudSoUIznilfrnizhX8RXqAJRvChP6 M7S4iIIqDRjikI/KpbcctbztXR6V+Fxo23LkHwnyRJilvGAZ1nYFph1dBYdlirp6ZX UqHT4RLzgE+hQ== Date: Tue, 19 Mar 2024 13:08:33 +0100 Message-Id: Subject: Re: [PATCH v4 1/5] dt-bindings: misc: Add mikrobus-connector Cc: , , , "Rob Herring" , "Krzysztof Kozlowski" , "Conor Dooley" , "Nishanth Menon" , "Vignesh Raghavendra" , "Tero Kristo" , "Derek Kiernan" , "Dragan Cvetic" , "Arnd Bergmann" , "Greg Kroah-Hartman" , "Vaishnav M A" , "Mark Brown" , "Johan Hovold" , "Alex Elder" , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , "moderated list:ARM/TEXAS INSTRUMENTS K3 ARCHITECTURE" , "open list:SPI SUBSYSTEM" , "moderated list:GREYBUS SUBSYSTEM" , "Vaishnav M A" From: "Michael Walle" To: "Ayush Singh" , "Krzysztof Kozlowski" , "open list" X-Mailer: aerc 0.16.0 References: <20240317193714.403132-1-ayushdevel1325@gmail.com> <20240317193714.403132-2-ayushdevel1325@gmail.com> <0f3f56d4-3381-44f1-91bc-c126f3ced085@linaro.org> <5a9b1cd9-05ec-4606-92b6-eadbc7af6202@gmail.com> In-Reply-To: <5a9b1cd9-05ec-4606-92b6-eadbc7af6202@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240319_050844_808037_E1813D19 X-CRM114-Status: GOOD ( 29.01 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2581751948196757173==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============2581751948196757173== Content-Type: multipart/signed; boundary=c332393a90d01da165088274218ef3aba6b575ac7f9169419f630293fb78; micalg=pgp-sha256; protocol="application/pgp-signature" --c332393a90d01da165088274218ef3aba6b575ac7f9169419f630293fb78 Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 On Tue Mar 19, 2024 at 12:36 PM CET, Ayush Singh wrote: > >> Regardless, this patch actually does not contain any code for EEPROM > >> support I have just mentioned it to give more context on why mikroBUS > >> manifest is the focus of this patch instead of DT overlay or something > >> else. > > Right, and I think this is the crux here. Why can't you use DT > > overlays? The manifest files, seem to be yet another hardware > > description (method) and we already have DT. Can't we have some kind > > of userspace helper that could translate them to DT overlays? That > > way, you could also handle the EEPROM vs non-EEPROM case, or have > > some other kind of method to load a DT overlay. > > > > Admittedly, I've never worked with in-kernel overlays, but AFAIK > > they work with some subsystems. > > > > -michael > > > So let me 1st go over 3 cases that the driver needs to support: > > 1. Non EEPROM boards: > > Using overlays should be pretty similar to current solution. If the=20 > manifest is converted to overlay in userspace, then we do not even need= =20 > to do manifest parsing, setting up spi, i2c etc in the kernel driver. > > > 2. EEPROM boards > > How do you propose handling these. If you are proposing storing dt=20 > overlay in EEPROM, then this raises some questions regarding support=20 > outside of Linux. > > The other option would be generating overlay from manifest in the kernel= =20 > driver, which I'm not sure is significantly better than registering the= =20 > i2c, spi, etc. interfaces separately using standard kernel APIs. You did answer that yourself in (1): you could use a user space helper to translate it to a DT overlay, I don't think this has to be done in the kernel. Also how do you know whether there is an EEPROM or not? > 3. Over Greybus > > It is quite important to have mikroBUS over greybus for BeagleConnect.=20 > This is one of the major reasons why greybus manifest was chosen for the= =20 > manifest format. > > Also, it is important to note that mikroBUS manifest is being used since= =20 > 2020 now and thus manifests for a lot of boards (both supporting clickID= =20 > and not supporting it exist). So I would prefer using it, unless of=20 > course there are strong reasons not to. And also here, I'm not really familiar with greybus. Could you give a more complex example? My concern is that some driver might need additional properties from DT (or software nodes) to function properly. It might not only be a node with a compatible string but also more advanced bindings. How would that play together with this? My gut feeling is that you can handle any missing properties easier/better (eg. for existing modules) in user space. But maybe that is already solved in/with greybus? Here's a random one: the manifest [1] just lists the compatible string apparently, but the actual DT binding has also reset-gpios, some -supply and interrupt properties. -michael [1] https://github.com/MikroElektronika/click_id/blob/main/manifests/WEATHE= R-CLICK.mnfs --c332393a90d01da165088274218ef3aba6b575ac7f9169419f630293fb78 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iIgEABYIADAWIQQCnWSOYTtih6UXaxvNyh2jtWxG+wUCZfmAQRIcbXdhbGxlQGtl cm5lbC5vcmcACgkQzcodo7VsRvssqgEA04NYkPfPrSqNNIGZGNCkWoEFhm0cSpD1 0kMsQQMcLz8BAMO9O7XV3ER/VGUaI2mQh9OOZ4XJDT0M2vanXUGYPBMA =d2XY -----END PGP SIGNATURE----- --c332393a90d01da165088274218ef3aba6b575ac7f9169419f630293fb78-- --===============2581751948196757173== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============2581751948196757173==--