From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mga07.intel.com ([134.134.136.100]:14503 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751837AbdBOHPT (ORCPT ); Wed, 15 Feb 2017 02:15:19 -0500 Subject: Re: [PATCH v3 1/2] v4l: Add camera voice coil lens control class, current control To: Pavel Machek Cc: linux-media@vger.kernel.org References: <1487074823-28274-1-git-send-email-sakari.ailus@linux.intel.com> <1487074823-28274-2-git-send-email-sakari.ailus@linux.intel.com> <20170214224750.GE11317@amd> From: Sakari Ailus Message-ID: Date: Wed, 15 Feb 2017 09:15:03 +0200 MIME-Version: 1.0 In-Reply-To: <20170214224750.GE11317@amd> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="w6j5ULPA7r2gedNpgSo1NAM1NvHSdaHcM" Sender: linux-media-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --w6j5ULPA7r2gedNpgSo1NAM1NvHSdaHcM Content-Type: multipart/mixed; boundary="Xlt2covLlwa6sxNP5roCaK1EMTUfnQnI0"; protected-headers="v1" From: Sakari Ailus To: Pavel Machek Cc: linux-media@vger.kernel.org Message-ID: Subject: Re: [PATCH v3 1/2] v4l: Add camera voice coil lens control class, current control References: <1487074823-28274-1-git-send-email-sakari.ailus@linux.intel.com> <1487074823-28274-2-git-send-email-sakari.ailus@linux.intel.com> <20170214224750.GE11317@amd> In-Reply-To: <20170214224750.GE11317@amd> --Xlt2covLlwa6sxNP5roCaK1EMTUfnQnI0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi Pavel, On 02/15/17 00:47, Pavel Machek wrote: > On Tue 2017-02-14 14:20:22, Sakari Ailus wrote: >> Add a V4L2 control class for voice coil lens driver devices. These are= >> simple devices that are used to move a camera lens from its resting >> position. >> >> Signed-off-by: Sakari Ailus >=20 > Looks good to me. >=20 > I wonder... should we somehow expose the range of diopters to > userspace? I believe userland camera application will need that > information. It'd certainly be useful to be able to provide more information. The question is: where to store it, and how? It depends on the voice coil, the spring constant, the lens and the distance of the lens from the sensor --- at least. Probably the sensor size as well. On voice coil lenses it is also somewhat inexact. --=20 Kind regards, Sakari Ailus sakari.ailus@linux.intel.com --Xlt2covLlwa6sxNP5roCaK1EMTUfnQnI0-- --w6j5ULPA7r2gedNpgSo1NAM1NvHSdaHcM Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iF4EAREIAAYFAlikAAQACgkQbUA2G24owZNorwD8DP4YWoonm3JE/Psg1oQk5kGF uqVnq49oP07YZiDrmCEBAJj/IvS2+aziB9PJ3wdoU1mxtGdAObGxA6H1cfeWbOje =yjRb -----END PGP SIGNATURE----- --w6j5ULPA7r2gedNpgSo1NAM1NvHSdaHcM--