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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 0FE7EC433E0 for ; Tue, 30 Mar 2021 10:48:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0042619B7 for ; Tue, 30 Mar 2021 10:48:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231847AbhC3Kr5 (ORCPT ); Tue, 30 Mar 2021 06:47:57 -0400 Received: from ni.piap.pl ([195.187.100.5]:55740 "EHLO ni.piap.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231370AbhC3Kr3 (ORCPT ); Tue, 30 Mar 2021 06:47:29 -0400 Received: from t19.piap.pl (OSB1819.piap.pl [10.0.9.19]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ni.piap.pl (Postfix) with ESMTPSA id E1C8F443A5A; Tue, 30 Mar 2021 12:47:27 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 ni.piap.pl E1C8F443A5A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=piap.pl; s=mail; t=1617101248; bh=U0yRFlMai+XiaM5nJzXcxdtqBQs+FxFrRSEuzCSHy/8=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=fzvqHznbZQWt+uCDJwAy9lPzCdPVwm4mrZql71J8WaTl1bR+5h5m7Yie6FGUIepmY HbBZZxt9abq7153e1ekpSpDrTIx/8bVSh0tyfkQEULK59rsJJmBcccg7FO3JXI1hf9 zJ6/34JLt4PxuJQ8TtLUP6S5F9S0edOT16QmtR34= From: =?utf-8?Q?Krzysztof_Ha=C5=82asa?= To: Laurent Pinchart Cc: Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: RFC: MEDIA: Driver for ON Semi AR0521 camera sensor References: Sender: khalasa@piap.pl Date: Tue, 30 Mar 2021 12:47:27 +0200 In-Reply-To: (Laurent Pinchart's message of "Tue, 16 Mar 2021 21:19:57 +0200") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-KLMS-Rule-ID: 4 X-KLMS-Message-Action: skipped X-KLMS-AntiSpam-Status: not scanned, whitelist X-KLMS-AntiPhishing: not scanned, whitelist X-KLMS-AntiVirus: Kaspersky Security for Linux Mail Server, version 8.0.3.30, not scanned, whitelist Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Laurent, There is an additional issue: >> +static const struct v4l2_subdev_video_ops ar0521_video_ops =3D { >> + .g_frame_interval =3D ar0521_g_frame_interval, >> + .s_frame_interval =3D ar0521_s_frame_interval, > > For raw sensors, frame intervals should be configured using > V4L2_CID_HBLANK and V4L2_CID_VBLANK instead. These two operations should > be dropped. Unfortunately, I require a way to specify an exact timings for the sensor. The frame interval gives me a way to do this, but it requires setting HBLANK and VBLANK _and_ an extra register (AR0521_REG_EXTRA_DELAY) which is specified in pixels, not lines. E.g. the total number of pixels (active or otherwise) is not (width + h blank) * (heigth + v blank) but rather: (width + h blank) * (heigth + v blank) + extra_delay How do I do that with HBLANK/VBLANK controls? BTW there are specific constraints on the pixel clock as well (the active scanning must be as fast as possible, which means fast pixel clock, minimum possible hblank and thus long vblank). All comments are appreciated. --=20 Krzysztof Ha=C5=82asa Sie=C4=87 Badawcza =C5=81ukasiewicz Przemys=C5=82owy Instytut Automatyki i Pomiar=C3=B3w PIAP Al. Jerozolimskie 202, 02-486 Warszawa