From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 9159C274656 for ; Mon, 19 May 2025 11:56:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747655814; cv=none; b=RSwGfu2vV7q5pvuifXtWBfHFom26JYTQ1+Z3sXLurD865b7cyZJhybg1s9oiEQCXp4Kc1oO/KAlt8MnuoA6xvogqPFJQCD52QR9NgILAMzOwp34IjNRf3SQbW4kpNxSeKVrnEXLK4BnMyforRDUUtKa8fuwn2Khs1LW0o1qWsMc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747655814; c=relaxed/simple; bh=d6W8WsKL/Su4cw5zA1yzSqmSFabp12gnUvGJSpVCkxk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=prUTkJWkRCBhbQmidgSEBGkLDhWsERruVvQSAtQ4VnjBVqJvLHFANy1wIPcKjvrwelZbzZKoWwjQoeuPdI8oJOzfp3ZK4rgEZJu4/pqn6bMfuwXKQShYxhWob1Dr8r4n+3io+isGVTeEMrH4VvOnpp+QgAhGuYEYNeWs1qUF3B8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=ANg2mois; arc=none smtp.client-ip=192.198.163.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ANg2mois" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1747655813; x=1779191813; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=d6W8WsKL/Su4cw5zA1yzSqmSFabp12gnUvGJSpVCkxk=; b=ANg2moispHb6/+zEisD5h7I2USRDQs66DzeyYW0WtGpnApZV72tfQNWS yQUz75e/K0HQr/8dzLLnffpWNM2C7arYQ1mvoqIrv/J/R6XR4MbCbLyjm 81voDqs1F32kwuBXorhf8TNhxins9QfrQnumUxtD8dxtgbswntX2pwLuQ 8xwcsACmG8UFlZJi2UKipcO6f14+2oFG9j8/NrtBHNaRWHWJi7GuZMer1 yq6ZBsu5NAH6T69CIbFDhEhH4LfaxuoLMOBU6v/ktivEpk3NUb+dZ+Jg6 9bi+BWDl66nkx+ky1Cdy8uv6KknaOqWKOzLutFO8EmBG4Uc3LGjzIxKKu g==; X-CSE-ConnectionGUID: W1s0r0N6RpCiLSPEUUE4xA== X-CSE-MsgGUID: xiYIktgaQ9mtC3+TmmA6JQ== X-IronPort-AV: E=McAfee;i="6700,10204,11438"; a="60186032" X-IronPort-AV: E=Sophos;i="6.15,300,1739865600"; d="scan'208";a="60186032" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2025 04:56:51 -0700 X-CSE-ConnectionGUID: CedvRqOvR9qSRpXZZrLCVA== X-CSE-MsgGUID: oHMdxRizSo6oDRnw4WF9aA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,300,1739865600"; d="scan'208";a="143349535" Received: from smoticic-mobl1.ger.corp.intel.com (HELO kekkonen.fi.intel.com) ([10.245.244.190]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 May 2025 04:56:44 -0700 Received: from kekkonen.localdomain (localhost [127.0.0.1]) by kekkonen.fi.intel.com (Postfix) with SMTP id BC206120297; Mon, 19 May 2025 14:56:41 +0300 (EEST) Date: Mon, 19 May 2025 11:56:41 +0000 Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo From: Sakari Ailus To: Kieran Bingham Cc: linux-media@vger.kernel.org, Mauro Carvalho Chehab , Laurent Pinchart , Sean Young , Ricardo Ribalda , Nicolas Dufresne , Jacopo Mondi , Niklas =?iso-8859-1?Q?S=F6derlund?= , Tomi Valkeinen , Alain Volmat , Bryan O'Donoghue , Dave Stevenson , Daniel Almeida , Michael Tretter , Tomasz Figa , "Hu, Jerry W" , Steve Cho , Kevin Hilman , Paul Kocialkowski , Benjamin Mugnier , Hans Verkuil , Arthur Vinchon , Marco Felsch , Jackson Lee , Mirela Rabulea , Hans de Goede , Jai Luthra , Devarsh Thakkar , Maxime Ripard , Stefan Klug , Sylvain Petinot , Naushir Patuck Subject: Re: [PATCH 1/1] media: dt-bindings: Add bindings for camera modules Message-ID: References: <20250507081338.53614-1-sakari.ailus@linux.intel.com> <174682345593.819131.7462679299915630940@ping.linuxembedded.co.uk> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <174682345593.819131.7462679299915630940@ping.linuxembedded.co.uk> Hi Kieran, On Fri, May 09, 2025 at 09:44:15PM +0100, Kieran Bingham wrote: > Hi Sakari, > > Quoting Sakari Ailus (2025-05-07 09:13:38) > > Add bindings for camera modules to allow telling especially the user space > > which module is found in the system. Camera modules do not have a device > > node so this is a property for the camera sensor device node. This allows > > describing modules that contain a single camera sensor. > > > > Signed-off-by: Sakari Ailus > > --- > > Hi all, > > > > Here's the patch to give some advance warning for the camera module > > discussion. The good thing is that it's quite short. > > > > Thanks for starting this! Definitely something I would like to see a > solution for indeed. > > > The intent indeed is to address the regular use case where we have a > > single sensor in a camera module. For cases where we have more, we'll need > > something else, not based on individual properties. I believe this is > > still the way to go, to address current issues and for a couple of > > additional reasons: > > > > - Cameras with more than one sensor tend to be collections of camera > > modules so this is still relevant in most cases. > > > > - It's much simpler to have a single property than begin having new nodes > > in DT. In practice such nodes would be a poor fit for DT generally as > > they have (few or) no functions. > > > > The biggest difficulty is still in module identification. These components > > tend to be often ignored and the best we have for a module name in that > > case is random-looking string if even that. Besides DT bindings, we need > > an additional (git?) tree to describe the modules that have no proper > > names but it could be also useful for those that do, for instance to > > include information on lens, field of view, IR filter, photos of the > > module etc. There is some overlap with what libcamera needs, too. > > > > One aspect that jumps to my mind here - is how do we handle variations > of modules? > > For instance I have two IMX335 modules from Arducam - which are > otherwise identical except for different lenses with different > field-of-view. > > Do we need more properties (later?) to express the different > configuration options of the module? I think I'd document these as two different modules. Arducam SKU identifiers are probably best to be used as models here and I presume SKU is different between your modules? > > > At some point I would love to be able to describe a 'module' as the > whole component including a VCM for instance - in a way that can be > abstracted as something that could be connected to a 'port' (see [0], > [1]) where it would be helpful to be able to group/abstract a movable > component and identify the full camera module in a way that doesn't have > to be duplicated in every platform configuration that it could be > connected. This would likely require having a node for the module, too. It's a heavy-weight solution compared to just a property (or a few). How commonly do you swap lenses outside R&D in practice? > > [0] https://www.konsulko.com/wp-content/uploads/2016/09/portable-device-tree-connector.pdf > [1] https://lore.kernel.org/all/1464986273-12039-2-git-send-email-pantelis.antoniou@konsulko.com/ -- Kind regards, Sakari Ailus