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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47981C433F5 for ; Mon, 25 Apr 2022 06:41:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231655AbiDYGoi (ORCPT ); Mon, 25 Apr 2022 02:44:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40924 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231520AbiDYGof (ORCPT ); Mon, 25 Apr 2022 02:44:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DB7620188; Sun, 24 Apr 2022 23:41:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 97CF461264; Mon, 25 Apr 2022 06:41:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3AEE1C385A4; Mon, 25 Apr 2022 06:41:29 +0000 (UTC) Message-ID: <28526ccf-4ae4-bd20-af16-67cb6bb8286a@xs4all.nl> Date: Mon, 25 Apr 2022 08:41:27 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH v4 4/9] media: Documentation: dw100: Add user documentation for the DW100 driver Content-Language: en-US To: Xavier Roumegue , mchehab@kernel.org, stanimir.varbanov@linaro.org, laurent.pinchart@ideasonboard.com, tomi.valkeinen@ideasonboard.com, robh+dt@kernel.org, nicolas@ndufresne.ca, alexander.stein@ew.tq-group.com Cc: linux-media@vger.kernel.org, devicetree@vger.kernel.org References: <20220328141309.177611-1-xavier.roumegue@oss.nxp.com> <20220328141309.177611-5-xavier.roumegue@oss.nxp.com> From: Hans Verkuil In-Reply-To: <20220328141309.177611-5-xavier.roumegue@oss.nxp.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 28/03/2022 16:13, Xavier Roumegue wrote: > Add user documentation for the DW100 driver. > > Signed-off-by: Xavier Roumegue > --- > .../userspace-api/media/drivers/dw100.rst | 23 +++++++++++++++++++ > .../userspace-api/media/drivers/index.rst | 1 + > 2 files changed, 24 insertions(+) > create mode 100644 Documentation/userspace-api/media/drivers/dw100.rst > > diff --git a/Documentation/userspace-api/media/drivers/dw100.rst b/Documentation/userspace-api/media/drivers/dw100.rst > new file mode 100644 > index 000000000000..4cd55c75628e > --- /dev/null > +++ b/Documentation/userspace-api/media/drivers/dw100.rst > @@ -0,0 +1,23 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +DW100 dewarp driver > +=========================== > + > +The Vivante DW100 Dewarp Processor IP core found on i.MX8MP SoC applies a > +programmable geometrical transformation on input image to correct distorsion > +introduced by lenses. > + > +The transformation function is exposed by the hardware as a grid map with 16x16 > +pixel macroblocks indexed using X, Y vertex coordinates. Each x, y coordinate > +register uses 16 bits to record the coordinate address in UQ12.4 fixed point 'UQ12.4' is a mostly TI notation it seems: https://en.wikipedia.org/wiki/Q_(number_format) I would replace this with: ...in an unsigned 12.4 fixed point format And in the control documentation this can be documented more precisely (I'll comment on that patch). Regards, Hans > +format. > + > +The dewarping map can be set from application through a dedicated v4l2 control. > +If not set or invalid, the driver computes an identity map prior to start the > +processing engine. The map is evaluated as invalid if the array size does not > +match the expected size inherited from the destination image resolution. > + > +More details on the DW100 hardware operations can be found in > +*chapter 13.15 DeWarp* of IMX8MP_ reference manuel. > + > +.. _IMX8MP: https://www.nxp.com/webapp/Download?colCode=IMX8MPRM > diff --git a/Documentation/userspace-api/media/drivers/index.rst b/Documentation/userspace-api/media/drivers/index.rst > index 12e3c512d718..8826777321b0 100644 > --- a/Documentation/userspace-api/media/drivers/index.rst > +++ b/Documentation/userspace-api/media/drivers/index.rst > @@ -33,6 +33,7 @@ For more details see the file COPYING in the source distribution of Linux. > > ccs > cx2341x-uapi > + dw100 > hantro > imx-uapi > max2175