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 D09D6C433F5 for ; Mon, 7 Feb 2022 06:54:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234986AbiBGGyr (ORCPT ); Mon, 7 Feb 2022 01:54:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239618AbiBGGbh (ORCPT ); Mon, 7 Feb 2022 01:31:37 -0500 X-Greylist: delayed 64 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Sun, 06 Feb 2022 22:31:35 PST Received: from mx1.tq-group.com (mx1.tq-group.com [93.104.207.81]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07DA8C043181; Sun, 6 Feb 2022 22:31:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tq-group.com; i=@tq-group.com; q=dns/txt; s=key1; t=1644215495; x=1675751495; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Wq/xULOuP/jvk92XmnTa8NRyCBGFLagVj5mIPmhXCgg=; b=KcmvVb4bNLLQtmC9DQEwxG3EYkMR5ZUqy1F+h6KHtqlfKng4Jqxoddz3 xISbzygx0HjRCqC+QRnw3NfS9fxfknMAoHIozm8giM0yE6DomIWlyHlz9 Dl/6eUXJ0CAJydJEeq1PCRyIQGcSQG9afA7tZI1gz8dx9KKFnF0yI5lt0 5ndt8clHeVHMygZwsmlD3fDkvf+DEfqabaOoh/FfwetomPia7VyNdY7v6 lD8xQxzQEjfH6YKydd2gPlWn030o3abTmd5GBT1pic1gncPogMm9ryqBP X73t75lwNaSl6mXOV80dpWVdCCMhNHKgdDnUN/tgKpy+cPBt/yqUVrDiW g==; X-IronPort-AV: E=Sophos;i="5.88,349,1635199200"; d="scan'208";a="21920108" Received: from unknown (HELO tq-pgp-pr1.tq-net.de) ([192.168.6.15]) by mx1-pgp.tq-group.com with ESMTP; 07 Feb 2022 07:30:28 +0100 Received: from mx1.tq-group.com ([192.168.6.7]) by tq-pgp-pr1.tq-net.de (PGP Universal service); Mon, 07 Feb 2022 07:30:28 +0100 X-PGP-Universal: processed; by tq-pgp-pr1.tq-net.de on Mon, 07 Feb 2022 07:30:28 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tq-group.com; i=@tq-group.com; q=dns/txt; s=key1; t=1644215428; x=1675751428; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Wq/xULOuP/jvk92XmnTa8NRyCBGFLagVj5mIPmhXCgg=; b=BE0+XcqqIwWe058GxcNFZCo42yRP3dWCit9o/vKc3X3X15RT+j+FU+Zr 8gK0oqDorM5nZjRBv5XA2kF1KL63x5LpgA/o+3ZWDhNtU7KmE8wPWefqw AlWejtC8LwB8p1WUriQOIuiWxOdz/kIqFZgwVrIO3O12tu5hG4yLR+Ypy k7xlJLG6qqEG2FxGa/4Qbw4eIyYhoPsq1eF8K4deBBnn7QlAnLXXrYdko Ve1MfxW2h9gj4oqLCGxSrcIHhdyn+W5rGGF9y22rKtx5JxS2eOBmKKLeo c1549qmR9KRNIQSrTDSgGSMPYH70F77GfP1IToZ4njAaic/kfUWPvKBnD g==; X-IronPort-AV: E=Sophos;i="5.88,349,1635199200"; d="scan'208";a="21920107" Received: from vtuxmail01.tq-net.de ([10.115.0.20]) by mx1.tq-group.com with ESMTP; 07 Feb 2022 07:30:28 +0100 Received: from steina-w.localnet (unknown [10.123.49.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by vtuxmail01.tq-net.de (Postfix) with ESMTPSA id 16B47280065; Mon, 7 Feb 2022 07:30:28 +0100 (CET) From: Alexander Stein To: Laurent Pinchart Cc: jeanmichel.hautbois@ideasonboard.com, linux-arm-kernel@lists.infradead.org, dave.stevenson@raspberrypi.com, devicetree@vger.kernel.org, kernel-list@raspberrypi.com, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, lukasz@jany.st, mchehab@kernel.org, naush@raspberrypi.com, robh@kernel.org, tomi.valkeinen@ideasonboard.com, nsaenz@kernel.org, bcm-kernel-feedback-list@broadcom.com Subject: Re: (EXT) Re: (EXT) [RFC PATCH v4 03/12] dt-bindings: media: Add bindings for bcm2835-unicam Date: Mon, 07 Feb 2022 07:30:25 +0100 Message-ID: <5541132.DvuYhMxLoT@steina-w> Organization: TQ-Systems GmbH In-Reply-To: References: <20220203175009.558868-1-jeanmichel.hautbois@ideasonboard.com> <7954256.DvuYhMxLoT@steina-w> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Laurent, Am Samstag, 5. Februar 2022, 03:22:51 CET schrieb Laurent Pinchart: > Hi Alexander, > > On Fri, Feb 04, 2022 at 09:50:06AM +0100, Alexander Stein wrote: > > Am Donnerstag, 3. Februar 2022, 18:50:00 CET schrieb Jean-Michel Hautbois: > > > Introduce the dt-bindings documentation for bcm2835 CCP2/CSI2 Unicam > > > camera interface. Also add a MAINTAINERS entry for it. > > > > > > Signed-off-by: Dave Stevenson > > > Signed-off-by: Naushir Patuck > > > Signed-off-by: Jean-Michel Hautbois > > > > > > > > > --- > > > v4: > > > - make MAINTAINERS its own patch > > > - describe the reg and clocks correctly > > > - use a vendor entry for the number of data lanes > > > --- > > > > > > .../bindings/media/brcm,bcm2835-unicam.yaml | 110 ++++++++++++++++++ > > > 1 file changed, 110 insertions(+) > > > create mode 100644 > > > > > > Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml > > > > > > diff --git > > > a/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml > > > b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml new > > > file > > > mode 100644 > > > index 000000000000..0725a0267c60 > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/media/brcm,bcm2835-unicam.yaml > > > @@ -0,0 +1,110 @@ > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > > +%YAML 1.2 > > > +--- > > > +$id: http://devicetree.org/schemas/media/brcm,bcm2835-unicam.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: Broadcom BCM283x Camera Interface (Unicam) > > > + > > > +maintainers: > > > + - Raspberry Pi Kernel Maintenance > > > + > > > +description: |- > > > + The Unicam block on BCM283x SoCs is the receiver for either > > > + CSI-2 or CCP2 data from image sensors or similar devices. > > > + > > > + The main platform using this SoC is the Raspberry Pi family of > > > boards. > > > + On the Pi the VideoCore firmware can also control this hardware > > > block, > > > + and driving it from two different processors will cause issues. > > > + To avoid this, the firmware checks the device tree configuration > > > + during boot. If it finds device tree nodes starting by csi then > > > + it will stop the firmware accessing the block, and it can then > > > + safely be used via the device tree binding. > > > + > > > +properties: > > > + compatible: > > > + const: brcm,bcm2835-unicam > > > + > > > + reg: > > > + items: > > > + - description: Unicam block. > > > + - description: Clock Manager Image (CMI) block. > > > + > > > + interrupts: > > > + maxItems: 1 > > > + > > > + clocks: > > > + items: > > > + - description: Clock to drive the LP state machine of Unicam. > > > + - description: Clock for the vpu (core clock). > > > + > > > + clock-names: > > > + items: > > > + - const: lp > > > + - const: vpu > > > + > > > + power-domains: > > > + items: > > > + - description: Unicam power domain > > > + > > > + brcm,num-data-lanes: > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > + enum: [ 2, 4 ] > > > + description: Number of data lanes on the csi bus > > > > There is already data-lanes in > > Documentation/devicetree/bindings/media/video- interfaces.yaml. AFAICS > > these two are identical. Can't the video- > > interface.yaml be used for this? I'm no expert TBH. > > This is the number of data lanes that the Unicam instance supports. > There are two Unicam instances, and they can have 2 or 4 data lanes > depending on the SoC. The data-lanes endpoint property indicates the > number of lanes used on a particular board. Thanks for the explanation. Isn't this something which could be derived from the compatible, e.g. having 2 different ones for 2 and 4 lanes respectively? See [1] for a similar situation in the SPI subsystem. I don't have a strong opinion, just want to share my feedback. Regards, Alexander [1] https://patchwork.kernel.org/project/spi-devel-general/patch/ 20211207104114.2720764-1-alexander.stein@ew.tq-group.com/#24641405