.. SPDX-License-Identifier: GPL-2.0

.. include:: <isonum.txt>

========================================================
Intel Image Processing Unit 6 (IPU6) Input System driver
========================================================

Copyright |copy| 2023--2024 Intel Corporation

Introduction
============

This file documents the Intel IPU6 (6th generation Image Processing Unit)
Input System (MIPI CSI2 receiver) drivers located under
drivers/media/pci/intel/ipu6.

The Intel IPU6 can be found in certain Intel SoCs but not in all SKUs:

* Tiger Lake
* Jasper Lake
* Alder Lake
* Raptor Lake
* Meteor Lake

Intel IPU6 is made up of two components - Input System (ISYS) and Processing
System (PSYS).

The Input System mainly works as MIPI CSI-2 receiver which receives and
processes the image data from the sensors and outputs the frames to memory.

There are 2 driver modules - intel-ipu6 and intel-ipu6-isys. intel-ipu6 is an
IPU6 common driver which does PCI configuration, firmware loading and parsing,
firmware authentication, DMA mapping and IPU-MMU (internal Memory mapping Unit)
configuration. intel_ipu6_isys implements V4L2, Media Controller and V4L2
sub-device interfaces. The IPU6 ISYS driver supports camera sensors connected
to the IPU6 ISYS through V4L2 sub-device sensor drivers.

.. Note:: See Documentation/driver-api/media/drivers/ipu6.rst for more
	  information about the IPU6 hardware.

Input system driver
===================

The Input System driver mainly configures CSI-2 D-PHY, constructs the firmware
stream configuration, sends commands to firmware, gets response from hardware
and firmware and then returns buffers to user.  The ISYS is represented as
several V4L2 sub-devices as well as video nodes.

.. kernel-figure::  ipu6_isys_graph.svg
   :alt: ipu6 isys media graph with multiple streams support

   IPU6 ISYS media graph with multiple streams support

The graph has been produced using the following command:

.. code-block:: none

   fdp -Gsplines=true -Tsvg < dot > dot.svg

Capturing frames with IPU6 ISYS
-------------------------------

IPU6 ISYS is used to capture frames from the camera sensors connected to the
CSI2 ports. The supported input formats of ISYS are listed in table below:

.. tabularcolumns:: |p{0.8cm}|p{4.0cm}|p{4.0cm}|

.. flat-table::
    :header-rows: 1

    * - IPU6 ISYS supported input formats

    * - RGB565, RGB888

    * - UYVY8, YUYV8

    * - RAW8, RAW10, RAW12

.. _ipu6_isys_capture_examples:

Examples
~~~~~~~~

Here is an example of IPU6 ISYS raw capture on Dell XPS 9315 laptop. On this
machine, ov01a10 sensor is connected to IPU ISYS CSI-2 port 2, which can
generate images at sBGGR10 with resolution 1280x800.

Using the media controller APIs, we can configure ov01a10 sensor by
media-ctl [#f1]_ and yavta [#f2]_ to transmit frames to IPU6 ISYS.

.. code-block:: none

    # Example 1 capture frame from ov01a10 camera sensor
    # This example assumes /dev/media0 as the IPU ISYS media device
    export MDEV=/dev/media0

    # Establish the link for the media devices using media-ctl
    media-ctl -d $MDEV -l "\"ov01a10 3-0036\":0 -> \"Intel IPU6 CSI2 2\":0[1]"

    # Set the format for the media devices
    media-ctl -d $MDEV -V "ov01a10:0 [fmt:SBGGR10/1280x800]"
    media-ctl -d $MDEV -V "Intel IPU6 CSI2 2:0 [fmt:SBGGR10/1280x800]"
    media-ctl -d $MDEV -V "Intel IPU6 CSI2 2:1 [fmt:SBGGR10/1280x800]"

Once the media pipeline is configured, desired sensor specific settings
(such as exposure and gain settings) can be set, using the yavta tool.

e.g

.. code-block:: none

    # and that ov01a10 sensor is connected to i2c bus 3 with address 0x36
    export SDEV=$(media-ctl -d $MDEV -e "ov01a10 3-0036")

    yavta -w 0x009e0903 400 $SDEV
    yavta -w 0x009e0913 1000 $SDEV
    yavta -w 0x009e0911 2000 $SDEV

Once the desired sensor settings are set, frame captures can be done as below.

e.g

.. code-block:: none

    yavta --data-prefix -u -c10 -n5 -I -s 1280x800 --file=/tmp/frame-#.bin \
            -f SBGGR10 $(media-ctl -d $MDEV -e "Intel IPU6 ISYS Capture 0")

With the above command, 10 frames are captured at 1280x800 resolution with
sBGGR10 format. The captured frames are available as /tmp/frame-#.bin files.

Here is another example of IPU6 ISYS RAW and metadata capture from camera
sensor ov2740 on Lenovo X1 Yoga laptop.

.. code-block:: none

    media-ctl -l "\"ov2740 14-0036\":0 -> \"Intel IPU6 CSI2 1\":0[1]"
    media-ctl -l "\"Intel IPU6 CSI2 1\":1 -> \"Intel IPU6 ISYS Capture 0\":0[1]"
    media-ctl -l "\"Intel IPU6 CSI2 1\":2 -> \"Intel IPU6 ISYS Capture 1\":0[1]"

    # set routing
    media-ctl -R "\"Intel IPU6 CSI2 1\" [0/0->1/0[1],0/1->2/1[1]]"

    media-ctl -V "\"Intel IPU6 CSI2 1\":0/0 [fmt:SGRBG10/1932x1092]"
    media-ctl -V "\"Intel IPU6 CSI2 1\":0/1 [fmt:GENERIC_8/97x1]"
    media-ctl -V "\"Intel IPU6 CSI2 1\":1/0 [fmt:SGRBG10/1932x1092]"
    media-ctl -V "\"Intel IPU6 CSI2 1\":2/1 [fmt:GENERIC_8/97x1]"

    CAPTURE_DEV=$(media-ctl -e "Intel IPU6 ISYS Capture 0")
    ./yavta --data-prefix -c100 -n5 -I -s1932x1092 --file=/tmp/frame-#.bin \
        -f SGRBG10 ${CAPTURE_DEV}

    CAPTURE_META=$(media-ctl -e "Intel IPU6 ISYS Capture 1")
    ./yavta --data-prefix -c100 -n5 -I -s97x1 -B meta-capture \
        --file=/tmp/meta-#.bin -f GENERIC_8 ${CAPTURE_META}

References
==========

.. [#f1] https://git.ideasonboard.org/media-ctl.git
.. [#f2] https://git.ideasonboard.org/yavta.git