From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4EB5D2DCC07; Wed, 25 Jun 2025 19:27:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750879650; cv=none; b=lzv8wcgXhgG+sqV6PG39YzxvrzDnEH9jZg9bLt0UP/7Im5oMLyqFCtVtDVJtUPMA6FK+hjZtTeXxZXcSMzr3mQvzBUS6NgJpBhmUHOocIHS5C5pQw2J6E28VxD9CjJto7QWYuVG95by6cEymc3fi/wH72DmfbgisLFSXHQUCKaw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750879650; c=relaxed/simple; bh=3+KxWYSRYr+i2rrsePfYRIGA1+vuieUTUyp4a4VljZ8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MdfQcgtic7e290iOfbn3slD2rRaD0/JTW7HPY+G3Jl6pZj8n8CpHJJ1shbE1XuFKmvG2YJ3bo22jK49OUnGsT+TS2wzWpZqUrk46yFppAnNV2Mf60v93jh5j5cYhV/LL9IdvzExzK4K+GjimNszUjX/nHnA+j3yG8RwtF8aBdWc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FLMMs/1H; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FLMMs/1H" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 960A4C4CEEA; Wed, 25 Jun 2025 19:27:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750879649; bh=3+KxWYSRYr+i2rrsePfYRIGA1+vuieUTUyp4a4VljZ8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FLMMs/1H+ZNmKkXWFEstI/NVo87FvFXK4/w7DwKqunRn63z0YvdKyox2jG/7ESXU7 HXWYHGS3wLcWBjhG/hOAKbRMKSPv+a6HPksQI48LIug3pYpwSlApoiB1zn6lUv+7Zu Q+SlhSRK7gLrv0sEx6JJg70mJxRZHaOy6zHUVPJHlNucMh7f+kRz7zrseBvsna6gCB rmkEyDq3gqFPlNyAeE9PLPLPFswKIc9pIwcAIAwbQpPIY8BTCkfW5KusOCe0bJ4XAf V1zC+zEt9FaBLGnZamKQoD86+yuKoH3S8zmmKDnIpjtBOkvQfyOyRUkPODp3jlJust Vu7Rv/017I3vQ== Date: Wed, 25 Jun 2025 14:27:28 -0500 From: Rob Herring To: Laurent Pinchart Cc: Krzysztof Kozlowski , Conor Dooley , Adam Ford , Frank Li , Isaac Scott , Rui Miguel Silva , Martin Kepplinger , Mauro Carvalho Chehab , Shawn Guo , Sascha Hauer , Fabio Estevam , linux-media@vger.kernel.org, devicetree@vger.kernel.org, imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org, Purism Kernel Team , Pengutronix Kernel Team Subject: Re: [PATCH 6/8] dt-bindings: media: nxp,imx-mipi-csi2: Add fsl,num-channels property Message-ID: <20250625192728.GA2072001-robh@kernel.org> References: <20250608235840.23871-1-laurent.pinchart@ideasonboard.com> <20250608235840.23871-7-laurent.pinchart@ideasonboard.com> <20250609182033.GA11428@pendragon.ideasonboard.com> <20250610081829.GC11428@pendragon.ideasonboard.com> <20250619210237.GA21935@pendragon.ideasonboard.com> Precedence: bulk X-Mailing-List: imx@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250619210237.GA21935@pendragon.ideasonboard.com> On Fri, Jun 20, 2025 at 12:02:37AM +0300, Laurent Pinchart wrote: > On Tue, Jun 10, 2025 at 11:18:29AM +0300, Laurent Pinchart wrote: > > On Mon, Jun 09, 2025 at 03:08:39PM -0400, Frank Li wrote: > > > On Mon, Jun 09, 2025 at 09:20:33PM +0300, Laurent Pinchart wrote: > > > > On Mon, Jun 09, 2025 at 12:53:48PM -0500, Adam Ford wrote: > > > > > On Mon, Jun 9, 2025 at 10:32 AM Frank Li wrote: > > > > > > On Mon, Jun 09, 2025 at 02:58:38AM +0300, Laurent Pinchart wrote: > > > > > > > The CSI-2 receiver can be instantiated with up to four output channels. > > > > > > > This is an integration-specific property, specify the number of > > > > > > > instantiated channels through a new fsl,num-channels property. The > > > > > > > property is optional, and defaults to 1 as only one channel is currently > > > > > > > supported by drivers. > > > > > > > > > > > > > > The only known SoC to have more than one channel is the i.MX8MP. As the > > > > > > > binding examples do not cover that SoC, don't update them. > > > > > > > > > > > > > > Signed-off-by: Laurent Pinchart > > > > > > > --- > > > > > > > .../devicetree/bindings/media/nxp,imx-mipi-csi2.yaml | 7 +++++++ > > > > > > > 1 file changed, 7 insertions(+) > > > > > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml b/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml > > > > > > > index db4889bf881e..41ad5b84eaeb 100644 > > > > > > > --- a/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml > > > > > > > +++ b/Documentation/devicetree/bindings/media/nxp,imx-mipi-csi2.yaml > > > > > > > @@ -68,6 +68,13 @@ properties: > > > > > > > default: 166000000 > > > > > > > deprecated: true > > > > > > > > > > > > > > + fsl,num-channels: > > > > > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > > > > > + description: Number of output channels > > > > > > > + minimum: 1 > > > > > > > + maximum: 4 > > > > > > > + default: 1 > > > > > > > + > > > > > > > > > > > > Look like it is fixed value for each compabiable string, So it is not > > > > > > suitable for adding new property. It should be in driver data of each > > > > > > compatible strings. > > > > > > > > > > > > I met similar case before. DT team generally don't agree on add such > > > > > > property, unless there are two instances in the same chip, which have > > > > > > difference channel number. > > > > > > > > > > If the DT changes are rejected, can the number of channels be added to > > > > > the data structure inside mipi_csis_of_match? We have compatibles for > > > > > 8mm and imx7. If we add an imx8mp compatible we could add a reference > > > > > to the number of channels. > > > > > > > > I thought about it, and decided to add a new property because the number > > > > of channels is really a synthesis time configuration parameter, and > > > > could differ between different CSIS instances in the same SoC. > > > > > > Need add such information at binding doc's commit message, > > > > I'll update the commit message. > > The commit message in v2 will state > > dt-bindings: media: nxp,imx-mipi-csi2: Add fsl,num-channels property > > The CSI-2 receiver can be instantiated with up to four output channels. > This is an integration-specific property, specify the number of > instantiated channels through a new fsl,num-channels property. The > property is optional, and defaults to 1 as only one channel is currently > supported by drivers. > > Using the compatible string to infer the number of channels has been > considered, but multiple instances of the same CSIS in the same SoC > could conceptually be synthesized with a different number of channels. > An explicit property is therefore more appropriate. > > The only known SoC to have more than one channel is the i.MX8MP. As the > binding examples do not cover that SoC, don't update them. So how many channels does i.MX8MP have in a DT without this property? It's either 1 or the driver overrides it to 2. > Rob, Krzysztof, Conor, are you fine with adding this property ? Yes, but seems a little late. Rob