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 3F7FDCE7A81 for ; Mon, 25 Sep 2023 10:28:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230467AbjIYK2O (ORCPT ); Mon, 25 Sep 2023 06:28:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229475AbjIYK2O (ORCPT ); Mon, 25 Sep 2023 06:28:14 -0400 Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::225]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 679DF8E; Mon, 25 Sep 2023 03:28:06 -0700 (PDT) Received: by mail.gandi.net (Postfix) with ESMTPSA id 0A3201C0002; Mon, 25 Sep 2023 10:27:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1695637685; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CtO8T+sDShN7p7U0G6qKR0fuN42cZzhkfeW3eGEM+Oc=; b=LVvprKIVChYwTJzlxBd2ZNYXBHm9J7hWY1K7wpTo7zgvqzqBZGISmFtj5OfIFjje66P6S6 HlEwH3l0nVjpj8nD5vuMQ04HpzK0kR9ZM/U4jh0pWSEMRb4F5bMp+1A6JeZwWYC3nZTpNn /U6LnsAPSh0QZnEt3y0Lr0BoJp0UQrIcws9zjf3FD4NOdCmt44AIAujr+TSxw3+AlvXtxH hfW+hGSVKZ+Hawd0vhvwNMVNosgsJYz2ky2HPFjrWkgsQ6PX7giQJvvsZAQmr4u96kgbX/ 2NKS6FPh8EB5P2zy/eURoCGbCNJb1KY9NL1nF8B1faIJpM3bP2F6JtT1GYIe7w== Date: Mon, 25 Sep 2023 12:27:58 +0200 From: Herve Codina To: Krzysztof Kozlowski Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Andrew Lunn , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Lee Jones , Linus Walleij , Qiang Zhao , Li Yang , Liam Girdwood , Mark Brown , Jaroslav Kysela , Takashi Iwai , Shengjiu Wang , Xiubo Li , Fabio Estevam , Nicolin Chen , Christophe Leroy , Randy Dunlap , netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, alsa-devel@alsa-project.org, Simon Horman , Christophe JAILLET , Thomas Petazzoni Subject: Re: [PATCH v6 08/30] dt-bindings: soc: fsl: cpm_qe: cpm1-scc-qmc: Add support for QMC HDLC Message-ID: <20230925122758.43963736@bootlin.com> In-Reply-To: <5b804a1a-6bfd-429d-ad84-696b7ecef72d@linaro.org> References: <20230922075913.422435-1-herve.codina@bootlin.com> <20230922075913.422435-9-herve.codina@bootlin.com> <5efae150-3d92-81b8-5c25-68846d27132e@linaro.org> <20230925101703.1bf083f1@bootlin.com> <5b804a1a-6bfd-429d-ad84-696b7ecef72d@linaro.org> Organization: Bootlin X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-GND-Sasl: herve.codina@bootlin.com Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Mon, 25 Sep 2023 10:21:15 +0200 Krzysztof Kozlowski wrote: > On 25/09/2023 10:17, Herve Codina wrote: > > Hi Krzysztof, > > > > On Sat, 23 Sep 2023 19:39:49 +0200 > > Krzysztof Kozlowski wrote: > > > >> On 22/09/2023 09:58, Herve Codina wrote: > >>> The QMC (QUICC mutichannel controller) is a controller present in some > >>> PowerQUICC SoC such as MPC885. > >>> The QMC HDLC uses the QMC controller to transfer HDLC data. > >>> > >>> Additionally, a framer can be connected to the QMC HDLC. > >>> If present, this framer is the interface between the TDM bus used by the > >>> QMC HDLC and the E1/T1 line. > >>> The QMC HDLC can use this framer to get information about the E1/T1 line > >>> and configure the E1/T1 line. > >>> > >>> Signed-off-by: Herve Codina > >>> --- > >>> .../soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml | 24 +++++++++++++++++++ > >>> 1 file changed, 24 insertions(+) > >>> > >>> diff --git a/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml > >>> index 82d9beb48e00..61dfd5ef7407 100644 > >>> --- a/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml > >>> +++ b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml > >>> @@ -101,6 +101,27 @@ patternProperties: > >>> Channel assigned Rx time-slots within the Rx time-slots routed by the > >>> TSA to this cell. > >>> > >>> + compatible: > >>> + const: fsl,qmc-hdlc > >> > >> Why this is not a device/SoC specific compatible? > > > > This compatible is present in a QMC channel. > > The parent node (the QMC itself) contains a compatible with device/SoC: > > --- 8< --- > > compatible: > > items: > > - enum: > > - fsl,mpc885-scc-qmc > > - fsl,mpc866-scc-qmc > > - const: fsl,cpm1-scc-qmc > > --- 8< --- > > > > At the child level (ie QMC channel), I am not sure that adding device/SoC > > makes sense. This compatible indicates that the QMC channel is handled by > > the QMC HDLC driver. > > At this level, whatever the device/SoC, we have to be QMC compliant. > > > > With these details, do you still think I need to change the child (channel) > > compatible ? > > From OS point of view, you have a driver binding to this child-level > compatible. How do you enforce Linux driver binding based on parent > compatible? I looked at your next patch and I did not see it. We do not need to have the child driver binding based on parent. We have to ensure that the child handles a QMC channel and the parent provides a QMC channel. A QMC controller (parent) has to implement the QMC API (include/soc/fsl/qe/qmc.h) and a QMC channel driver (child) has to use the QMC API. Best regards, Hervé > > Best regards, > Krzysztof >