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 80F1DC433F5 for ; Mon, 16 May 2022 15:08:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245005AbiEPPIE (ORCPT ); Mon, 16 May 2022 11:08:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34242 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238196AbiEPPH7 (ORCPT ); Mon, 16 May 2022 11:07:59 -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 0FAE73B3DA for ; Mon, 16 May 2022 08:07:59 -0700 (PDT) Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1nqcK8-0004pp-1e; Mon, 16 May 2022 17:07:52 +0200 Message-ID: Date: Mon, 16 May 2022 17:07:50 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH v1 02/17] Revert "ARM: dts: imx6qdl-apalis: Avoid underscore in node name" Content-Language: en-US To: Francesco Dolcini Cc: Max Krummenacher , max.krummenacher@toradex.com, devicetree@vger.kernel.org, Shawn Guo , Sascha Hauer , linux-kernel@vger.kernel.org, Rob Herring , NXP Linux Team , Pengutronix Kernel Team , Krzysztof Kozlowski , Fabio Estevam , linux-arm-kernel@lists.infradead.org References: <20220516115846.58328-1-max.oss.09@gmail.com> <20220516115846.58328-3-max.oss.09@gmail.com> <86815346-209e-304e-3565-b4160afa48e8@pengutronix.de> <20220516145354.GA121079@francesco-nb.int.toradex.com> From: Ahmad Fatoum In-Reply-To: <20220516145354.GA121079@francesco-nb.int.toradex.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2a0a:edc0:0:900:1d::77 X-SA-Exim-Mail-From: a.fatoum@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 Hello Francesco, On 16.05.22 16:53, Francesco Dolcini wrote: > On Mon, May 16, 2022 at 02:49:12PM +0200, Ahmad Fatoum wrote: >> On 16.05.22 13:58, Max Krummenacher wrote: >>> From: Max Krummenacher >>> >>> The STMPE MFD device binding requires the child node to have a fixed >>> name, i.e. with '_', not '-'. Otherwise the stmpe_adc, stmpe_touchscreen >>> drivers will not be probed. >> >> IMO, the Linux driver should be fixed and the requirement to use a fixed >> node name be dropped from the binding. The driver itself already probes >> by compatible, the node name seems only to be used by the MFD driver to >> detect which functions to enable. It could do the same by checking for >> compatibles. Otherwise you invite a game of cat and mouse, where in >> future, this is changed back again reintroducing the regression.. > > How would you handle in general such kind of change? Would you keep the > driver probing for both the old name with the `_` and the compatible or > you just break the compatibility? The Binding requires child nodes to have both a specific node name and compatible. So if we remove the node name restriction, we stay compliant to the binding. The MFD driver requires specific node names, while the MFD cell drivers seem to be matched by compatibles. It's thus should be safe to replace the node name readout in the MFD driver with a compatible check. Existing device trees will continue to work. Newer device trees can use dashes. Once the binding is converted to YAML, we could enforce a name to get everyone aligned, but it will be just a binding checker warning, not a breakage on update. Cheers, Ahmad > > Francesco > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | 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 80FEBC433EF for ; Mon, 16 May 2022 15:09:16 +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-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To: Subject:MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=lXcGd3294qeIUn+hr40LeAudPNw0oVSmTUtNu/JZiV4=; b=y2vPoB1HKMNdQA QGIDYJfxGT/pnwFyAyZf8/ORwLiMv75xjTL3Eju+K6fcFfMV2Z+QHgbq+onf6Y6bPaoVw+GyoCGUq /KesMYHOZcvQfv1OzzcgMvTyULHTecQ/N0yugo1EJuF991qXy+bpWtTseEQJc1bQgwK/UHiEzMJxE jFXWg0ifFaPQJQCdVIB+CVLazptYkPzagxDTkCMx4TkBIxKRAk8wz1oLDCk8phPk1mpOgoVi/bYyu mz5UH096+8GNdSJ3wOXtaXu7MK9XRIEWhmziUvQnMq90gCJ1SmJdw9BgbUUm7ynvOjJtkrzqqI47B TA2oq8jdizmW8E4C03Mg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nqcKR-008YBd-84; Mon, 16 May 2022 15:08:11 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nqcKN-008YA4-Ir for linux-arm-kernel@lists.infradead.org; Mon, 16 May 2022 15:08:09 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1nqcK8-0004pp-1e; Mon, 16 May 2022 17:07:52 +0200 Message-ID: Date: Mon, 16 May 2022 17:07:50 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH v1 02/17] Revert "ARM: dts: imx6qdl-apalis: Avoid underscore in node name" Content-Language: en-US To: Francesco Dolcini Cc: Max Krummenacher , max.krummenacher@toradex.com, devicetree@vger.kernel.org, Shawn Guo , Sascha Hauer , linux-kernel@vger.kernel.org, Rob Herring , NXP Linux Team , Pengutronix Kernel Team , Krzysztof Kozlowski , Fabio Estevam , linux-arm-kernel@lists.infradead.org References: <20220516115846.58328-1-max.oss.09@gmail.com> <20220516115846.58328-3-max.oss.09@gmail.com> <86815346-209e-304e-3565-b4160afa48e8@pengutronix.de> <20220516145354.GA121079@francesco-nb.int.toradex.com> From: Ahmad Fatoum In-Reply-To: <20220516145354.GA121079@francesco-nb.int.toradex.com> X-SA-Exim-Connect-IP: 2a0a:edc0:0:900:1d::77 X-SA-Exim-Mail-From: a.fatoum@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220516_080807_646897_5963B0E8 X-CRM114-Status: GOOD ( 24.33 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hello Francesco, On 16.05.22 16:53, Francesco Dolcini wrote: > On Mon, May 16, 2022 at 02:49:12PM +0200, Ahmad Fatoum wrote: >> On 16.05.22 13:58, Max Krummenacher wrote: >>> From: Max Krummenacher >>> >>> The STMPE MFD device binding requires the child node to have a fixed >>> name, i.e. with '_', not '-'. Otherwise the stmpe_adc, stmpe_touchscreen >>> drivers will not be probed. >> >> IMO, the Linux driver should be fixed and the requirement to use a fixed >> node name be dropped from the binding. The driver itself already probes >> by compatible, the node name seems only to be used by the MFD driver to >> detect which functions to enable. It could do the same by checking for >> compatibles. Otherwise you invite a game of cat and mouse, where in >> future, this is changed back again reintroducing the regression.. > > How would you handle in general such kind of change? Would you keep the > driver probing for both the old name with the `_` and the compatible or > you just break the compatibility? The Binding requires child nodes to have both a specific node name and compatible. So if we remove the node name restriction, we stay compliant to the binding. The MFD driver requires specific node names, while the MFD cell drivers seem to be matched by compatibles. It's thus should be safe to replace the node name readout in the MFD driver with a compatible check. Existing device trees will continue to work. Newer device trees can use dashes. Once the binding is converted to YAML, we could enforce a name to get everyone aligned, but it will be just a binding checker warning, not a breakage on update. Cheers, Ahmad > > Francesco > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel