From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 2 Sep 2019 19:49:37 +0300 From: Laurent Pinchart Subject: Re: [PATCH v2 01/10] media: dt-bindings: Document 'location' property Message-ID: <20190902164937.GF12197@pendragon.ideasonboard.com> References: <20190827092339.8858-1-jacopo@jmondi.org> <20190827092339.8858-2-jacopo@jmondi.org> <20190827122126.GQ5054@pendragon.ideasonboard.com> <20190829124639.tzjp63tqnojnytlq@uno.localdomain> <5d6d1b60.1c69fb81.f3a3a.1619@mx.google.com> <20190902164031.yllajoj6duz27mun@uno.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190902164031.yllajoj6duz27mun@uno.localdomain> To: Jacopo Mondi Cc: Rob Herring , Mauro Carvalho Chehab , Hans Verkuil , Sakari Ailus , tfiga@google.com, "open list:MEDIA INPUT INFRASTRUCTURE (V4L/DVB)" , devicetree@vger.kernel.org List-ID: Hi Jacopo, On Mon, Sep 02, 2019 at 06:40:31PM +0200, Jacopo Mondi wrote: > On Mon, Sep 02, 2019 at 02:38:40PM +0100, Rob Herring wrote: > > On Thu, Aug 29, 2019 at 02:46:40PM +0200, Jacopo Mondi wrote: > >> On Tue, Aug 27, 2019 at 03:21:26PM +0300, Laurent Pinchart wrote: > >>> On Tue, Aug 27, 2019 at 11:23:27AM +0200, Jacopo Mondi wrote: > >>>> Add the 'location' device property, used to specify the camera device > >>>> mounting position. The property is particularly meaningful for mobile > >>>> devices with a well defined usage orientation. > >>>> > >>>> Signed-off-by: Jacopo Mondi > >>>> --- > >>>> .../devicetree/bindings/media/video-interfaces.txt | 10 ++++++++++ > >>>> 1 file changed, 10 insertions(+) > >>>> > >>>> diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt b/Documentation/devicetree/bindings/media/video-interfaces.txt > >>>> index f884ada0bffc..865f4142f432 100644 > >>>> --- a/Documentation/devicetree/bindings/media/video-interfaces.txt > >>>> +++ b/Documentation/devicetree/bindings/media/video-interfaces.txt > >>>> @@ -89,6 +89,16 @@ Optional properties > >>>> but a number of degrees counter clockwise. Typical values are 0 and 180 > >>>> (upside down). > >>>> > >>>> +- location: The camera sensor mounting location, expressed as a position > >>>> + relative to the usage orientation of the device the sensor is installed on. > >>> > >>> DT bindings being ABIs, we need to be precise and thorough there. One > >>> particular point that bothers me is that the property is named location, > >>> and its description refers to camera sensor mounting location. > >>> > >>> I see two options to fix this. One of them is to rename the property to > >>> camera-location, but that would limit its future usage for other types > >>> of devices. The other one is to document the property as applying to a > >>> "device" instead of a "camera sensor", and add one sentence stating that > >>> this property is valid for camera sensors only. > >>> > >>> This will require finding another name for the device that the device is > >>> mounted on though, as using device twice would be very confusing. > >> > >> I had the same concern, but I cannot find another term to convey > >> this... suggestions? > > > > For accelerometers and/or gyroscopes, we already have 'mount-matrix'. > > Pardon my ignorance, but I could not find it documented. Some binding > files refers to an iio/mount-matrix.txt file which I cannot find. Has > it been removed? Anyway, some individual bindings report examples of > mount matrices (ie > Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt) > > > That would replace 'rotation'. Maybe we can do something similar here? > > I think 'rotation' simply expressed as degrees is fine here, our > problem was to find a term that would make it possible to specify that > rotation/location are applied to a 'device' mounted on a 'device'. > Sakari suggested on irc to use 'system' in place of the second > 'device' and that seems to work well to me. > > Or were you suggesting to use a construct similar to mount-matrix for > a purpose I didn't get :) ? mount-matrix would allow exposing the rotation in a more generic way, and if there are standard DT bindings, I think this would make sense, especially given that we could have device with camera sensors not mounted parallel to the device side. -- Regards, Laurent Pinchart 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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3ADBC3A59E for ; Mon, 2 Sep 2019 16:49:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 83EF621744 for ; Mon, 2 Sep 2019 16:49:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="vRHRaGwT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726415AbfIBQtp (ORCPT ); Mon, 2 Sep 2019 12:49:45 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:36052 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725988AbfIBQtp (ORCPT ); Mon, 2 Sep 2019 12:49:45 -0400 Received: from pendragon.ideasonboard.com (231.125-247-81.adsl-dyn.isp.belgacom.be [81.247.125.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 48D85303; Mon, 2 Sep 2019 18:49:43 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1567442983; bh=hmQ0CxYzeDkmEaZW4Qk6VHt9ToW/VD04aLtEx+gCdpk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=vRHRaGwTD8H9iRm7CXJHLdeg257dpz7jlbd0vz+b8weZW1F+POx8Mxi0duIglvPd5 yrwKmfpUsbHfdaeRJlQhyAk4j2WGWV4pXdNlQYfi2CEAU1O3mrDhrKSXDMNGNtMQ5h EhugFlB8evVZQMrp9V43RR7OLwooTUY0RioA5g38= Date: Mon, 2 Sep 2019 19:49:37 +0300 From: Laurent Pinchart To: Jacopo Mondi Cc: Rob Herring , Mauro Carvalho Chehab , Hans Verkuil , Sakari Ailus , tfiga@google.com, "open list:MEDIA INPUT INFRASTRUCTURE (V4L/DVB)" , devicetree@vger.kernel.org Subject: Re: [PATCH v2 01/10] media: dt-bindings: Document 'location' property Message-ID: <20190902164937.GF12197@pendragon.ideasonboard.com> References: <20190827092339.8858-1-jacopo@jmondi.org> <20190827092339.8858-2-jacopo@jmondi.org> <20190827122126.GQ5054@pendragon.ideasonboard.com> <20190829124639.tzjp63tqnojnytlq@uno.localdomain> <5d6d1b60.1c69fb81.f3a3a.1619@mx.google.com> <20190902164031.yllajoj6duz27mun@uno.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190902164031.yllajoj6duz27mun@uno.localdomain> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Jacopo, On Mon, Sep 02, 2019 at 06:40:31PM +0200, Jacopo Mondi wrote: > On Mon, Sep 02, 2019 at 02:38:40PM +0100, Rob Herring wrote: > > On Thu, Aug 29, 2019 at 02:46:40PM +0200, Jacopo Mondi wrote: > >> On Tue, Aug 27, 2019 at 03:21:26PM +0300, Laurent Pinchart wrote: > >>> On Tue, Aug 27, 2019 at 11:23:27AM +0200, Jacopo Mondi wrote: > >>>> Add the 'location' device property, used to specify the camera device > >>>> mounting position. The property is particularly meaningful for mobile > >>>> devices with a well defined usage orientation. > >>>> > >>>> Signed-off-by: Jacopo Mondi > >>>> --- > >>>> .../devicetree/bindings/media/video-interfaces.txt | 10 ++++++++++ > >>>> 1 file changed, 10 insertions(+) > >>>> > >>>> diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt b/Documentation/devicetree/bindings/media/video-interfaces.txt > >>>> index f884ada0bffc..865f4142f432 100644 > >>>> --- a/Documentation/devicetree/bindings/media/video-interfaces.txt > >>>> +++ b/Documentation/devicetree/bindings/media/video-interfaces.txt > >>>> @@ -89,6 +89,16 @@ Optional properties > >>>> but a number of degrees counter clockwise. Typical values are 0 and 180 > >>>> (upside down). > >>>> > >>>> +- location: The camera sensor mounting location, expressed as a position > >>>> + relative to the usage orientation of the device the sensor is installed on. > >>> > >>> DT bindings being ABIs, we need to be precise and thorough there. One > >>> particular point that bothers me is that the property is named location, > >>> and its description refers to camera sensor mounting location. > >>> > >>> I see two options to fix this. One of them is to rename the property to > >>> camera-location, but that would limit its future usage for other types > >>> of devices. The other one is to document the property as applying to a > >>> "device" instead of a "camera sensor", and add one sentence stating that > >>> this property is valid for camera sensors only. > >>> > >>> This will require finding another name for the device that the device is > >>> mounted on though, as using device twice would be very confusing. > >> > >> I had the same concern, but I cannot find another term to convey > >> this... suggestions? > > > > For accelerometers and/or gyroscopes, we already have 'mount-matrix'. > > Pardon my ignorance, but I could not find it documented. Some binding > files refers to an iio/mount-matrix.txt file which I cannot find. Has > it been removed? Anyway, some individual bindings report examples of > mount matrices (ie > Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt) > > > That would replace 'rotation'. Maybe we can do something similar here? > > I think 'rotation' simply expressed as degrees is fine here, our > problem was to find a term that would make it possible to specify that > rotation/location are applied to a 'device' mounted on a 'device'. > Sakari suggested on irc to use 'system' in place of the second > 'device' and that seems to work well to me. > > Or were you suggesting to use a construct similar to mount-matrix for > a purpose I didn't get :) ? mount-matrix would allow exposing the rotation in a more generic way, and if there are standard DT bindings, I think this would make sense, especially given that we could have device with camera sensors not mounted parallel to the device side. -- Regards, Laurent Pinchart