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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 4021DC3A59B for ; Mon, 2 Sep 2019 08:19:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 14E69215EA for ; Mon, 2 Sep 2019 08:19:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="ddESnutp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730619AbfIBITw (ORCPT ); Mon, 2 Sep 2019 04:19:52 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:58484 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729964AbfIBITv (ORCPT ); Mon, 2 Sep 2019 04:19:51 -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 54748303; Mon, 2 Sep 2019 10:19:49 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1567412389; bh=5HBvswllGaiODYjSIoZK0GflOekHiZSNfmmM72aXnHo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ddESnutpxySaQ/3OkWOw3E0FVnOw68ZIr0ANYsVmiRXVIziGPIOVS4k0hcZquq8yP tcAbH9x6nM6+Tf7h3nu9gNOw0JjmVEcqqIrA6IH2Lp9iEVehsHh3/GILJbqOIeEFQ3 RHnEDJc/VTN463sjn5hHj4hojUwkb9SHET+w1x28= Date: Mon, 2 Sep 2019 11:19:42 +0300 From: Laurent Pinchart To: Pavel Machek Cc: Hans Verkuil , Jacopo Mondi , Mauro Carvalho Chehab , Sakari Ailus , "open list:MEDIA INPUT INFRASTRUCTURE (V4L/DVB)" , open list Subject: Re: [RFC 2/5] media: v4l2-ctrl: Document V4L2_CID_LOCATION Message-ID: <20190902081942.GE4777@pendragon.ideasonboard.com> References: <20190814202815.32491-1-jacopo@jmondi.org> <20190814202815.32491-3-jacopo@jmondi.org> <20190814224340.GD5015@pendragon.ideasonboard.com> <664fe7b3-9051-30da-736e-710a4e9cecde@xs4all.nl> <20190815143423.vaoswb4jvzd2blxp@uno.localdomain> <20190901172457.GC1047@bug> <20190902080002.GC4777@pendragon.ideasonboard.com> <20190902080657.GC15850@amd> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190902080657.GC15850@amd> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 02, 2019 at 10:06:57AM +0200, Pavel Machek wrote: > >>> Single integer. It's read-only, so it just reports the location. > >>> > >>> It would be different if this was a writable control: then you need to > >>> know which locations are possible to set, and that requires a menu type. > >>> > >>> But it doesn't make sense to set the location from software. However, the > >>> location might change as a result of other changes: e.g. if the camera > >>> has motor control of the tilt and the tilt changes from forward facing to > >>> downward facing, then the driver might change the location from FRONT > >>> to DOWN. A convoluted example perhaps, but this is just brainstorming. > >> > >> There are phones with exactly such camera setup. And yes, it makes > >> sense to be writable in that case, as software can move the camera in > >> such case. > > > > Out of curiosity, what phones are those ? > > This one: > > https://www.samsung.com/global/galaxy/galaxy-a80/ Interesting device. I'm not sure we should control that through a location control though, as it seems there's more than the rotation of the camera involved. In any case I wouldn't care about it for now, and turn the location control from read-only to read-write later if needed. We need more information and more thought to support that use case. -- Regards, Laurent Pinchart