From patchwork Sun Jun 16 02:09:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andr=C3=A9_Almeida?= X-Patchwork-Id: 10997263 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AFF4C112C for ; Sun, 16 Jun 2019 02:11:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A1E25287A2 for ; Sun, 16 Jun 2019 02:11:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9653A287B3; Sun, 16 Jun 2019 02:11:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4B8E3287AE for ; Sun, 16 Jun 2019 02:10:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727094AbfFPCKn (ORCPT ); Sat, 15 Jun 2019 22:10:43 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:43958 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725807AbfFPCKn (ORCPT ); Sat, 15 Jun 2019 22:10:43 -0400 Received: from turingmachine.home (unknown [IPv6:2804:431:d719:ae74:d711:794d:1c68:5ed3]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: tonyk) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id DE03C281DC3; Sun, 16 Jun 2019 03:10:38 +0100 (BST) From: =?utf-8?q?Andr=C3=A9_Almeida?= To: linux-media@vger.kernel.org Cc: mchehab@kernel.org, hverkuil@xs4all.nl, helen.koike@collabora.com, kernel@collabora.com, linux-kernel@vger.kernel.org, =?utf-8?q?Andr=C3=A9_Al?= =?utf-8?q?meida?= Subject: [PATCH v2 2/2] media: docs: create vimc documentation Date: Sat, 15 Jun 2019 23:09:59 -0300 Message-Id: <20190616020959.7360-2-andrealmeid@collabora.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190616020959.7360-1-andrealmeid@collabora.com> References: <20190616020959.7360-1-andrealmeid@collabora.com> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Create vimc documentation file to explain it basics features, it's topology, how to configure it and to document vimc's subdevices. Signed-off-by: André Almeida Suggested-by: Helen Koike --- Commit extracted from [PATCH 0/4] media: vimc: Minor code cleanup and documentation Changes in v2: - Fix typos - Make clear what does means scale factor Documentation/media/v4l-drivers/index.rst | 1 + Documentation/media/v4l-drivers/vimc.dot | 22 +++++ Documentation/media/v4l-drivers/vimc.rst | 98 +++++++++++++++++++++++ 3 files changed, 121 insertions(+) create mode 100644 Documentation/media/v4l-drivers/vimc.dot create mode 100644 Documentation/media/v4l-drivers/vimc.rst diff --git a/Documentation/media/v4l-drivers/index.rst b/Documentation/media/v4l-drivers/index.rst index 33a055907258..c4c78a28654c 100644 --- a/Documentation/media/v4l-drivers/index.rst +++ b/Documentation/media/v4l-drivers/index.rst @@ -64,5 +64,6 @@ For more details see the file COPYING in the source distribution of Linux. si476x soc-camera uvcvideo + vimc vivid zr364xx diff --git a/Documentation/media/v4l-drivers/vimc.dot b/Documentation/media/v4l-drivers/vimc.dot new file mode 100644 index 000000000000..57863a13fa39 --- /dev/null +++ b/Documentation/media/v4l-drivers/vimc.dot @@ -0,0 +1,22 @@ +# SPDX-License-Identifier: GPL-2.0 + +digraph board { + rankdir=TB + n00000001 [label="{{} | Sensor A\n/dev/v4l-subdev0 | { 0}}", shape=Mrecord, style=filled, fillcolor=green] + n00000001:port0 -> n00000005:port0 [style=bold] + n00000001:port0 -> n0000000b [style=bold] + n00000003 [label="{{} | Sensor B\n/dev/v4l-subdev1 | { 0}}", shape=Mrecord, style=filled, fillcolor=green] + n00000003:port0 -> n00000008:port0 [style=bold] + n00000003:port0 -> n0000000f [style=bold] + n00000005 [label="{{ 0} | Debayer A\n/dev/v4l-subdev2 | { 1}}", shape=Mrecord, style=filled, fillcolor=green] + n00000005:port1 -> n00000017:port0 + n00000008 [label="{{ 0} | Debayer B\n/dev/v4l-subdev3 | { 1}}", shape=Mrecord, style=filled, fillcolor=green] + n00000008:port1 -> n00000017:port0 [style=dashed] + n0000000b [label="Raw Capture 0\n/dev/video0", shape=box, style=filled, fillcolor=yellow] + n0000000f [label="Raw Capture 1\n/dev/video1", shape=box, style=filled, fillcolor=yellow] + n00000013 [label="RGB/YUV Input\n/dev/video2", shape=box, style=filled, fillcolor=yellow] + n00000013 -> n00000017:port0 [style=dashed] + n00000017 [label="{{ 0} | Scaler\n/dev/v4l-subdev4 | { 1}}", shape=Mrecord, style=filled, fillcolor=green] + n00000017:port1 -> n0000001a [style=bold] + n0000001a [label="RGB/YUV Capture\n/dev/video3", shape=box, style=filled, fillcolor=yellow] +} diff --git a/Documentation/media/v4l-drivers/vimc.rst b/Documentation/media/v4l-drivers/vimc.rst new file mode 100644 index 000000000000..e235f806e252 --- /dev/null +++ b/Documentation/media/v4l-drivers/vimc.rst @@ -0,0 +1,98 @@ +.. SPDX-License-Identifier: GPL-2.0 + +The Virtual Media Controller Driver (vimc) +========================================== + +The vimc driver emulates complex video hardware using the V4L2 API and the Media +API. It has a capture device and three subdevices: sensor, debayer and scaler. + +Topology +-------- + +The topology is hardcoded, although you could modify it in vimc-core and +recompile the driver to achieve your own topology. This is the default topology: + +.. _vimc_topology_graph: + +.. kernel-figure:: vimc.dot + :alt: vimc.dot + :align: center + + Media pipeline graph on vimc + +Configuring the topology +~~~~~~~~~~~~~~~~~~~~~~~~ + +Each subdevice will come with its default configuration (pixelformat, height, +width, ...). One needs to configure the topology in order to match the +configuration on each linked subdevice to stream frames through the pipeline. +If the configuration doesn't match, the stream will fail. The ``v4l2-utils`` +is a bundle of user-space applications, that comes with ``media-ctl`` and +``v4l2-ctl`` that can be used to configure the vimc configuration. This sequence +of commands fits for the default topology: + +.. code-block:: bash + + media-ctl -d platform:vimc -V '"Sensor A":0[fmt:SBGGR8_1X8/640x480]' + media-ctl -d platform:vimc -V '"Debayer A":0[fmt:SBGGR8_1X8/640x480]' + media-ctl -d platform:vimc -V '"Sensor B":0[fmt:SBGGR8_1X8/640x480]' + media-ctl -d platform:vimc -V '"Debayer B":0[fmt:SBGGR8_1X8/640x480]' + v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440 + v4l2-ctl -z platform:vimc -d "Raw Capture 0" -v pixelformat=BA81 + v4l2-ctl -z platform:vimc -d "Raw Capture 1" -v pixelformat=BA81 + +Subdevices +---------- + +Subdevices define the behavior of an entity in the topology. Depending on the +subdevice, the entity can have multiple pads of type source or sink. + +vimc-sensor: + Generates images in several formats using video test pattern generator. + Exposes: + + * 1 Pad source + +vimc-debayer: + Transforms images in bayer format into a non-bayer format. + Exposes: + + * 1 Pad sink + * 1 Pad source + +vimc-scaler: + Scale up the image by a factor of 3. E.g.: a 640x480 image becomes a + 1920x1440 image. (this value can be configured, see at + `Module options`_). + Exposes: + + * 1 Pad sink + * 1 Pad source + +vimc-capture: + Exposes node /dev/videoX to allow userspace to capture the stream. + Exposes: + + * 1 Pad sink + * 1 Pad source + +Module options +--------------- + +Vimc has a few module parameters to configure the driver. You should pass +those arguments to each subdevice, not to the vimc module. For example:: + + vimc_subdevice.param=value + +* ``vimc_scaler.sca_mult=`` + + Image size multiplier factor to be used to multiply both width and + height, so the image size will be ``sca_mult^2`` bigger than the + original one. Currently, only supports scaling up (the default value + is 3). + +* ``vimc_debayer.deb_mean_win_size=`` + + Window size to calculate the mean. Note: the window size needs to be an + odd number, as the main pixel stays in the center of the window, + otherwise the next odd number is considered (the default value is 3).