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Date:   Thu, 8 Jun 2023 12:23:09 +0200
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Subject: Re: [RESEND PATCH v6 1/1] Added Digiteq Automotive MGB4 driver
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To:     =?UTF-8?Q?Martin_T=c5=afma?= <tumic@gpxsee.org>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
Cc:     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        =?UTF-8?Q?Martin_T=c5=afma?= <martin.tuma@digiteqautomotive.com>
References: <20230524112126.2242-1-tumic@gpxsee.org>
 <20230524112126.2242-2-tumic@gpxsee.org>
 <3a7da3cd-8d03-a2c4-0534-a75565aefc13@xs4all.nl>
 <7072a8f3-5c9e-1170-e480-6fb57b95110f@gpxsee.org>
From:   Hans Verkuil <hverkuil-cisco@xs4all.nl>
In-Reply-To: <7072a8f3-5c9e-1170-e480-6fb57b95110f@gpxsee.org>
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On 08/06/2023 11:27, Martin Tůma wrote:
> Hi Hans,
> Thanks for taking the time to review the updated driver. I will reply to the findings one by one in a further email, but first of all I would like to explain/discuss why we use the sysfs for setting
> the card parameters while some of them may seem they can be set in S_FMT and DV_TIMINGS.
> 
> Unlike most of the other cards/drivers, the FG4 card does not produce some known set of video streams. It is designed to work with streams that can vary in almost any of the signal properties
> (including car infotainment systems that have not yet been produced) and the hardware has to be adjusted (including some low level FPGA logic like the CMT) for that otherwise you will get no video at
> all. This means you __have__ to set some parameters, you do not choose from some options. If the setting would be done using v4l2, you would end with a card that is unusable with most common SW like
> VLC or ffmpeg as there is no support for S_FMT and DV_TIMINGS settings in any common SW. When sysfs is used, you can simply create some UDEV rules (or use simple "echo X > /sys/property" shell
> commands) for the current signal source and than use any generic video player.
> 
> When some of the settings (as there is not support for all of them in v4l2) would be moved to v4l2, the situation for the user would get even worse. He would need to set some parameters using some
> special SW and some using sysfs.
> 
> Finally, we already ship the card/driver to customers with the current API (you really can not wait more than a year with bringing your product to the market until a driver gets its way into the
> upstream kernels) and they would definitely not be happy to change their ecosystem to some new API that is much worse for them as it would force them to use(write) some special tools that will allow
> them to configure the cards.
> 
> So with one exception - the temperature which makes sense to move to the hwmon subsystem to allow an easier integration/usage for the user - I would really strongly prefer to keep the configuration on
> one place in sysfs and allow the users to use standard SW/OS mechanism to configure it.

Can you make a list of which sysfs properties correspond to existing V4L2
format or timing fields and which are 'new'?

What I definitely want to see in this driver is that the values provided
through sysfs also end up in the timings struct. E.g. front/backporch values,
etc. They might be set via sysfs, but they should appear when you query
the dv timings using e.g. v4l2-ctl.

There are a few ways to sort this out, but I first need a better picture
of which sysfs properties correspond to which existing V4L2 fields and which
do not.

One option is to keep it as-is, except report the various timing properties
through G_DV_TIMINGS as well.

Another is to keep the sysfs properties, but *also* allow them to be set
through V4L2.

A third option is similar to the previous one, except there the sysfs properties
that can be set through V4L2 are put under a kernel config option. So if
enabled, they appear in sysfs, if disabled, then you need to use e.g. v4l2-ctl
--set-dv-bt-timings to set them.

Regards,

	Hans

> 
> Martin Tůma
> 
> On 07. 06. 23 10:41, Hans Verkuil wrote:
>> Hi Martin,
>>
>> Some comments below:
>>
>> On 24/05/2023 13:21, tumic@gpxsee.org wrote:
>>> From: Martin Tůma <martin.tuma@digiteqautomotive.com>
>>>
>>> Digiteq Automotive MGB4 is a modular frame grabber PCIe card for automotive
>>> video interfaces. As for now, two modules - FPD-Link and GMSL - are
>>> available and supported by the driver. The card has two inputs and two
>>> outputs (FPD-Link only).
>>>
>>> In addition to the video interfaces it also provides a trigger signal
>>> interface and a MTD interface for FPGA firmware upload.
>>>
>>> Signed-off-by: Martin Tůma <martin.tuma@digiteqautomotive.com>
>>> ---
>>>   Documentation/admin-guide/media/mgb4.rst      | 352 ++++++++
>>>   .../admin-guide/media/pci-cardlist.rst        |   1 +
>>>   .../admin-guide/media/v4l-drivers.rst         |   1 +
>>>   MAINTAINERS                                   |   7 +
>>>   drivers/media/pci/Kconfig                     |   1 +
>>>   drivers/media/pci/Makefile                    |   1 +
>>>   drivers/media/pci/mgb4/Kconfig                |  17 +
>>>   drivers/media/pci/mgb4/Makefile               |   6 +
>>>   drivers/media/pci/mgb4/mgb4_cmt.c             | 247 ++++++
>>>   drivers/media/pci/mgb4/mgb4_cmt.h             |  16 +
>>>   drivers/media/pci/mgb4/mgb4_core.c            | 641 ++++++++++++++
>>>   drivers/media/pci/mgb4/mgb4_core.h            |  65 ++
>>>   drivers/media/pci/mgb4/mgb4_dma.c             | 123 +++
>>>   drivers/media/pci/mgb4/mgb4_dma.h             |  18 +
>>>   drivers/media/pci/mgb4/mgb4_i2c.c             | 140 +++
>>>   drivers/media/pci/mgb4/mgb4_i2c.h             |  35 +
>>>   drivers/media/pci/mgb4/mgb4_io.h              |  39 +
>>>   drivers/media/pci/mgb4/mgb4_regs.c            |  30 +
>>>   drivers/media/pci/mgb4/mgb4_regs.h            |  35 +
>>>   drivers/media/pci/mgb4/mgb4_sysfs.h           |  18 +
>>>   drivers/media/pci/mgb4/mgb4_sysfs_in.c        | 780 ++++++++++++++++
>>>   drivers/media/pci/mgb4/mgb4_sysfs_out.c       | 732 +++++++++++++++
>>>   drivers/media/pci/mgb4/mgb4_sysfs_pci.c       |  86 ++
>>>   drivers/media/pci/mgb4/mgb4_trigger.c         | 208 +++++
>>>   drivers/media/pci/mgb4/mgb4_trigger.h         |   8 +
>>>   drivers/media/pci/mgb4/mgb4_vin.c             | 830 ++++++++++++++++++
>>>   drivers/media/pci/mgb4/mgb4_vin.h             |  63 ++
>>>   drivers/media/pci/mgb4/mgb4_vout.c            | 501 +++++++++++
>>>   drivers/media/pci/mgb4/mgb4_vout.h            |  58 ++
>>>   29 files changed, 5059 insertions(+)
>>>   create mode 100644 Documentation/admin-guide/media/mgb4.rst
>>>   create mode 100644 drivers/media/pci/mgb4/Kconfig
>>>   create mode 100644 drivers/media/pci/mgb4/Makefile
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_cmt.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_cmt.h
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_core.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_core.h
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_dma.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_dma.h
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_i2c.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_i2c.h
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_io.h
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_regs.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_regs.h
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_sysfs.h
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_sysfs_in.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_sysfs_out.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_sysfs_pci.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_trigger.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_trigger.h
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_vin.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_vin.h
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_vout.c
>>>   create mode 100644 drivers/media/pci/mgb4/mgb4_vout.h
>>>
>>> diff --git a/Documentation/admin-guide/media/mgb4.rst b/Documentation/admin-guide/media/mgb4.rst
>>> new file mode 100644
>>> index 000000000000..77db2fa64ab4
>>> --- /dev/null
>>> +++ b/Documentation/admin-guide/media/mgb4.rst
>>> @@ -0,0 +1,352 @@
>>> +.. SPDX-License-Identifier: GPL-2.0
>>> +
>>
>> Perhaps it is a good idea to start with a high level overview of the
>> hardware blocks. That might help understand how the various parts are
>> connected.
>>
>>> +====================
>>> +mgb4 sysfs interface
>>> +====================
>>> +
>>> +The mgb4 driver provides a sysfs interface, that is used to configure video
>>> +stream related parameters (some of them must be set properly before the v4l2
>>> +device can be opened) and obtain the video device/stream status.
>>> +
>>> +There are two types of parameters - global / PCI card related, found under
>>> +``/sys/class/video4linux/videoX/device`` and module specific found under
>>> +``/sys/class/video4linux/videoX``.
>>> +
>>> +
>>> +Global (PCI card) parameters
>>> +============================
>>> +
>>> +**module_type** (R):
>>> +    Module type.
>>> +
>>> +    | 0 - No module present
>>> +    | 1 - FPDL3
>>> +    | 2 - GMSL
>>> +
>>> +**module_version** (R):
>>> +    Module version number. Zero in case of a missing module.
>>> +
>>> +**fw_type** (R):
>>> +    Firmware type.
>>> +
>>> +    | 1 - FPDL3
>>> +    | 2 - GMSL
>>> +
>>> +**fw_version** (R):
>>> +    Firmware version number.
>>> +
>>> +**serial_number** (R):
>>> +    Card serial number. The format is::
>>> +
>>> +        PRODUCT-REVISION-SERIES-SERIAL
>>> +
>>> +    where each component is a 8b number.
>>> +
>>> +**temperature** (R):
>>> +    FPGA core temperature in Celsius degree.
>>
>> I'm not sure if this is the right place for this. Shouldn't this
>> be exposed through the hwmon subsystem? That way you will see it
>> with e.g. the 'sensors' command. The drivers/media/i2c/video-i2c.c
>> driver uses hwmon in that way.
>>
>>> +
>>> +Common FPDL3/GMSL input parameters
>>> +==================================
>>> +
>>> +**input_id** (R):
>>> +    Input number ID, zero based.
>>
>> Input of what? I assume that the HW modules have multiple inputs?
>>
>>> +
>>> +**oldi_lane_width** (RW):
>>> +    Number of deserializer output lanes.
>>> +
>>> +    | 0 - single
>>> +    | 1 - dual
>>> +
>>> +**color_mapping** (RW):
>>> +    Mapping of the incoming bits in the signal to the colour bits of the pixels.
>>> +
>>> +    | 0 - OLDI/JEIDA
>>> +    | 1 - SPWG/VESA
>>> +
>>> +**link_status** (R):
>>> +    Video link status. If the link is locked, chips are properly connected and
>>> +    communicating at the same speed and protocol. The link can be locked without
>>> +    an active video stream.
>>> +
>>> +    | 0 - unlocked
>>> +    | 1 - locked
>>
>> What is the relationship of this link status and the status bits returned by
>> VIDIOC_ENUMINPUT?
>>
>>> +
>>> +**stream_status** (R):
>>> +    Video stream status. A stream is detected if the link is locked, the input
>>> +    pixel clock is running and the DE signal is moving.
>>> +
>>> +    | 0 - not detected
>>> +    | 1 - detected
>>
>> This definitely looks like this should be handled by ENUMINPUT.
>>
>>> +
>>> +**video_width** (R):
>>> +    Video stream width. This is the actual width as detected by the HW. You may
>>> +    see a different width in the v4l2 APIs as those values can not be arbitrary
>>> +    changed by the driver.
>>> +
>>> +**video_height** (R):
>>> +    Video stream height. This is the actual height as detected by the HW. You
>>> +    may see a different height in the v4l2 APIs as those values can not be
>>> +    arbitrary changed by the driver.
>>
>> Is this the width/height of the active video? Or active + blanking video?
>>
>> It is not quite clear to me what you mean with 'those values can not be arbitrary
>> changed by the driver'. With QUERY_DV_TIMINGS you can get all this info.
>>
>>> +
>>> +**vsync_status** (R):
>>> +    The type of VSYNC pulses as detected by the video format detector.
>>> +
>>> +    | 0 - active low
>>> +    | 1 - active high
>>> +    | 2 - not available
>>> +
>>> +**hsync_status** (R):
>>> +    The type of HSYNC pulses as detected by the video format detector.
>>> +
>>> +    | 0 - active low
>>> +    | 1 - active high
>>> +    | 2 - not available
>>
>> Why do you need this?
>>
>>> +
>>> +**vsync_gap_length** (RW):
>>> +    If the incoming video signal does not contain synchronization VSYNC and
>>> +    HSYNC pulses, these must be generated internally in the FPGA to achieve
>>> +    the correct frame ordering. This value indicates, how many "empty" pixels
>>> +    (pixels with deasserted Data Enable signal) are necessary to generate the
>>> +    internal VSYNC pulse.
>>> +
>>> +**hsync_gap_length** (RW):
>>> +    If the incoming video signal does not contain synchronization VSYNC and
>>> +    HSYNC pulses, these must be generated internally in the FPGA to achieve
>>> +    the correct frame ordering. This value indicates, how many "empty" pixels
>>> +    (pixels with deasserted Data Enable signal) are necessary to generate the
>>> +    internal HSYNC pulse. The value must be greater than 1 and smaller than
>>> +    vsync_gap_length.
>>> +
>>> +**pclk_frequency** (R):
>>> +    Input pixel clock frequency in kHz.
>>> +
>>> +    *Note: The frequency_range parameter must be set properly first to get
>>> +    a valid frequency here.*
>>
>> Wouldn't QUERY_DV_TIMINGS return this?
>>
>>> +
>>> +**hsync_width** (R):
>>> +    Width of the HSYNC signal in PCLK clock ticks.
>>> +
>>> +**vsync_width** (R):
>>> +    Width of the VSYNC signal in PCLK clock ticks.
>>> +
>>> +**hback_porch** (R):
>>> +    Number of PCLK pulses between deassertion of the HSYNC signal and the first
>>> +    valid pixel in the video line (marked by DE=1).
>>> +
>>> +**hfront_porch** (R):
>>> +    Number of PCLK pulses between the end of the last valid pixel in the video
>>> +    line (marked by DE=1) and assertion of the HSYNC signal.
>>> +
>>> +**vback_porch** (R):
>>> +    Number of video lines between deassertion of the VSYNC signal and the video
>>> +    line with the first valid pixel (marked by DE=1).
>>> +
>>> +**vfront_porch** (R):
>>> +    Number of video lines between the end of the last valid pixel line (marked
>>> +    by DE=1) and assertion of the VSYNC signal.
>>
>> Ditto for all these.
>>
>>> +
>>> +**frequency_range** (RW)
>>> +    PLL frequency range of the OLDI input clock generator. The PLL frequency is
>>> +    derived from the Pixel Clock Frequency (PCLK) and is equal to PCLK if
>>> +    oldi_lane_width is set to "single" and PCLK/2 if oldi_lane_width is set to
>>> +    "dual".
>>> +
>>> +    | 0 - PLL < 50MHz
>>> +    | 1 - PLL >= 50MHz
>>> +
>>> +    *Note: This parameter can not be changed while the input v4l2 device is
>>> +    open.*
>>> +
>>> +**alignment** (RW)
>>> +    Pixel line alignment. Sets the pixel line alignment in bytes of the frame
>>> +    buffers provided via the v4l2 interface. The number must be a power of 2.
>>
>> A bit vague what you mean here. I wonder if this isn't something that userspace
>> can't set through the bytesperline field of struct v4l2_pix_format.
>>
>>> +
>>> +    *Note: This parameter can not be changed while the input v4l2 device is
>>> +    open.*
>>> +
>>> +Common FPDL3/GMSL output parameters
>>> +===================================
>>> +
>>> +**output_id** (R):
>>> +    Output number ID, zero based.
>>
>> Output of what to what?
>>
>>> +
>>> +**video_source** (RW):
>>> +    Output video source. If set to 0 or 1, the source is the corresponding card
>>> +    input and the v4l2 output devices are disabled. If set to 2 or 3, the source
>>> +    is the corresponding v4l2 video output device.
>>> +
>>> +    | 0 - input 0
>>> +    | 1 - input 1
>>> +    | 2 - v4l2 output 0
>>> +    | 3 - v4l2 output 1
>>> +
>>> +    *Note: This parameter can not be changed while ANY of the input/output v4l2
>>> +    devices is open.*
>>> +
>>> +**display_width** (RW):
>>> +    Display width. There is no autodetection of the connected display, so the
>>> +    propper value must be set before the start of streaming.
>>
>> propper -> proper
>>
>>> +
>>> +    *Note: This parameter can not be changed while the output v4l2 device is
>>> +    open.*
>>> +
>>> +**display_height** (RW):
>>> +    Display height. There is no autodetection of the connected display, so the
>>> +    propper value must be set before the start of streaming.
>>> +
>>> +    *Note: This parameter can not be changed while the output v4l2 device is
>>> +    open.*
>>> +
>>> +**frame_rate** (RW):
>>> +    Output video frame rate in frames per second.
>>> +
>>> +**hsync_polarity** (RW):
>>> +    HSYNC signal polarity.
>>> +
>>> +    | 0 - active low
>>> +    | 1 - active high
>>> +
>>> +**vsync_polarity** (RW):
>>> +    VSYNC signal polarity.
>>> +
>>> +    | 0 - active low
>>> +    | 1 - active high
>>> +
>>> +**de_polarity** (RW):
>>> +    DE signal polarity.
>>> +
>>> +    | 0 - active low
>>> +    | 1 - active high
>>> +
>>> +**pclk_frequency** (RW):
>>> +    Output pixel clock frequency. Allowed values are between 25000-190000(kHz)
>>> +    and there is a non-linear stepping between two consecutive allowed
>>> +    frequencies. The driver finds the nearest allowed frequency to the given
>>> +    value and sets it. When reading this property, you get the exact
>>> +    frequency set by the driver.
>>> +
>>> +    *Note: This parameter can not be changed while the output v4l2 device is
>>> +    open.*
>>> +
>>> +**hsync_width** (RW):
>>> +    Width of the HSYNC signal in PCLK clock ticks.
>>> +
>>> +**vsync_width** (RW):
>>> +    Width of the VSYNC signal in PCLK clock ticks.
>>> +
>>> +**hback_porch** (RW):
>>> +    Number of PCLK pulses between deassertion of the HSYNC signal and the first
>>> +    valid pixel in the video line (marked by DE=1).
>>> +
>>> +**hfront_porch** (RW):
>>> +    Number of PCLK pulses between the end of the last valid pixel in the video
>>> +    line (marked by DE=1) and assertion of the HSYNC signal.
>>> +
>>> +**vback_porch** (RW):
>>> +    Number of video lines between deassertion of the VSYNC signal and the video
>>> +    line with the first valid pixel (marked by DE=1).
>>> +
>>> +**vfront_porch** (RW):
>>> +    Number of video lines between the end of the last valid pixel line (marked
>>> +    by DE=1) and assertion of the VSYNC signal.
>>
>> For these as well I wonder how much can be done with VIDIOC_DV_S_TIMINGS.
>>
>>> +
>>> +**alignment** (RW)
>>> +    Pixel line alignment. Sets the pixel line alignment in bytes of the frame
>>> +    buffers provided via the v4l2 interface. The number must be a power of 2.
>>> +
>>> +    *Note: This parameter can not be changed while the output v4l2 device is
>>> +    open.*
>>> +
>>> +    *Note: This parameter can not be changed when loopback mode is active
>>> +    (video_source is 0 or 1). When loopback mode is enabled, the alignment is
>>> +    automatically set to the alignment of the input device.*
>>> +
>>> +FPDL3 specific input parameters
>>> +===============================
>>> +
>>> +**fpdl3_input_width** (RW):
>>> +    Number of deserializer input lines.
>>> +
>>> +    | 0 - auto
>>> +    | 1 - single
>>> +    | 2 - dual
>>> +
>>> +FPDL3 specific output parameters
>>> +================================
>>> +
>>> +**fpdl3_output_width** (RW):
>>> +    Number of serializer output lines.
>>> +
>>> +    | 0 - auto
>>> +    | 1 - single
>>> +    | 2 - dual
>>> +
>>> +GMSL specific input parameters
>>> +==============================
>>> +
>>> +**gmsl_mode** (RW):
>>> +    GMSL speed mode.
>>> +
>>> +    | 0 - 12Gb/s
>>> +    | 1 - 6Gb/s
>>> +    | 2 - 3Gb/s
>>> +    | 3 - 1.5Gb/s
>>> +
>>> +**gmsl_stream_id** (RW):
>>> +    The GMSL multi-stream contains up to four video streams. This parameter
>>> +    selects which stream is captured by the video input. The value is the
>>> +    zero-based index of the stream.
>>> +
>>> +    *Note: This parameter can not be changed while the input v4l2 device is
>>> +    open.*
>>> +
>>> +**gmsl_fec** (RW):
>>> +    GMSL Forward Error Correction (FEC).
>>> +
>>> +    | 0 - disabled
>>> +    | 1 - enabled
>>> +
>>> +
>>> +====================
>>> +mgb4 mtd partitions
>>> +====================
>>> +
>>> +The mgb4 driver creates a MTD device with two partitions:
>>> + - mgb4-fw.X - FPGA firmware.
>>> + - mgb4-data.X - Factory settings, e.g. card serial number.
>>> +
>>> +The *mgb4-fw* partition is writable and is used for FW updates, *mgb4-data* is
>>> +read-only. The *X* attached to the partition name represents the card number.
>>> +Depending on the CONFIG_MTD_PARTITIONED_MASTER kernel configuration, you may
>>> +also have a third partition named *mgb4-flash* available in the system. This
>>> +partition represents the whole, unpartitioned, card's FLASH memory and one should
>>> +not fiddle with it...
>>> +
>>> +====================
>>> +mgb4 iio (triggers)
>>> +====================
>>> +
>>> +The mgb4 driver creates an Industrial I/O (IIO) device that provides trigger and
>>> +signal level status capability. The following scan elements are available:
>>> +
>>> +**activity**:
>>> +    The trigger levels and pending status.
>>> +
>>> +    | bit 1 - trigger 1 pending
>>> +    | bit 2 - trigger 2 pending
>>> +    | bit 5 - trigger 1 level
>>> +    | bit 6 - trigger 2 level
>>> +
>>> +**timestamp**:
>>> +    The trigger event timestamp.
>>> +
>>> +The iio device can operate either in "raw" mode where you can fetch the signal
>>> +levels (activity bits 5 and 6) using sysfs access or in triggered buffer mode.
>>> +In the triggered buffer mode you can follow the signal level changes (activity
>>> +bits 1 and 2) using the iio device in /dev. If you enable the timestamps, you
>>> +will also get the exact trigger event time that can be matched to a video frame
>>> +(every mgb4 video frame has a timestamp with the same clock source).
>>> +
>>> +*Note: although the activity sample always contains all the status bits, it makes
>>> +no sense to get the pending bits in raw mode or the level bits in the triggered
>>> +buffer mode - the values do not represent valid data in such case.*
>>> diff --git a/Documentation/admin-guide/media/pci-cardlist.rst b/Documentation/admin-guide/media/pci-cardlist.rst
>>> index 42528795d4da..7d8e3c8987db 100644
>>> --- a/Documentation/admin-guide/media/pci-cardlist.rst
>>> +++ b/Documentation/admin-guide/media/pci-cardlist.rst
>>> @@ -77,6 +77,7 @@ ipu3-cio2         Intel ipu3-cio2 driver
>>>   ivtv              Conexant cx23416/cx23415 MPEG encoder/decoder
>>>   ivtvfb            Conexant cx23415 framebuffer
>>>   mantis            MANTIS based cards
>>> +mgb4              Digiteq Automotive MGB4 frame grabber
>>>   mxb               Siemens-Nixdorf 'Multimedia eXtension Board'
>>>   netup-unidvb      NetUP Universal DVB card
>>>   ngene             Micronas nGene
>>> diff --git a/Documentation/admin-guide/media/v4l-drivers.rst b/Documentation/admin-guide/media/v4l-drivers.rst
>>> index 1c41f87c3917..61283d67ceef 100644
>>> --- a/Documentation/admin-guide/media/v4l-drivers.rst
>>> +++ b/Documentation/admin-guide/media/v4l-drivers.rst
>>> @@ -17,6 +17,7 @@ Video4Linux (V4L) driver-specific documentation
>>>       imx7
>>>       ipu3
>>>       ivtv
>>> +    mgb4
>>>       omap3isp
>>>       omap4_camera
>>>       philips
>>
>> A general note: I suggest that you split off the documentation part in
>> a separate patch rather than it being part of the driver.
>>
>>> diff --git a/MAINTAINERS b/MAINTAINERS
>>> index 27ef11624748..65454d93a413 100644
>>> --- a/MAINTAINERS
>>> +++ b/MAINTAINERS
>>> @@ -6050,6 +6050,13 @@ L:    linux-gpio@vger.kernel.org
>>>   S:    Maintained
>>>   F:    drivers/gpio/gpio-gpio-mm.c
>>>   +DIGITEQ AUTOMOTIVE MGB4 V4L2 DRIVER
>>> +M:    Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> +L:    linux-media@vger.kernel.org
>>> +S:    Maintained
>>> +F:    Documentation/admin-guide/media/mgb4.rst
>>> +F:    drivers/media/pci/mgb4/
>>> +
>>>   DIOLAN U2C-12 I2C DRIVER
>>>   M:    Guenter Roeck <linux@roeck-us.net>
>>>   L:    linux-i2c@vger.kernel.org
>>> diff --git a/drivers/media/pci/Kconfig b/drivers/media/pci/Kconfig
>>> index 480194543d05..28cea9675d71 100644
>>> --- a/drivers/media/pci/Kconfig
>>> +++ b/drivers/media/pci/Kconfig
>>> @@ -13,6 +13,7 @@ if MEDIA_PCI_SUPPORT
>>>   if MEDIA_CAMERA_SUPPORT
>>>       comment "Media capture support"
>>>   +source "drivers/media/pci/mgb4/Kconfig"
>>>   source "drivers/media/pci/solo6x10/Kconfig"
>>>   source "drivers/media/pci/sta2x11/Kconfig"
>>>   source "drivers/media/pci/tw5864/Kconfig"
>>> diff --git a/drivers/media/pci/Makefile b/drivers/media/pci/Makefile
>>> index 8bed619b7130..f18c7e15abe3 100644
>>> --- a/drivers/media/pci/Makefile
>>> +++ b/drivers/media/pci/Makefile
>>> @@ -32,6 +32,7 @@ obj-$(CONFIG_VIDEO_CX25821) += cx25821/
>>>   obj-$(CONFIG_VIDEO_CX88) += cx88/
>>>   obj-$(CONFIG_VIDEO_DT3155) += dt3155/
>>>   obj-$(CONFIG_VIDEO_IVTV) += ivtv/
>>> +obj-$(CONFIG_VIDEO_MGB4) += mgb4/
>>>   obj-$(CONFIG_VIDEO_SAA7134) += saa7134/
>>>   obj-$(CONFIG_VIDEO_SAA7164) += saa7164/
>>>   obj-$(CONFIG_VIDEO_SOLO6X10) += solo6x10/
>>> diff --git a/drivers/media/pci/mgb4/Kconfig b/drivers/media/pci/mgb4/Kconfig
>>> new file mode 100644
>>> index 000000000000..13fad15a434c
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/Kconfig
>>> @@ -0,0 +1,17 @@
>>> +# SPDX-License-Identifier: GPL-2.0-only
>>> +config VIDEO_MGB4
>>> +    tristate "Digiteq Automotive MGB4 support"
>>> +    depends on VIDEO_DEV && PCI && I2C && DMADEVICES && SPI && MTD && IIO
>>> +    select VIDEOBUF2_DMA_SG
>>> +    select IIO_BUFFER
>>> +    select IIO_TRIGGERED_BUFFER
>>> +    select I2C_XILINX
>>> +    select SPI_XILINX
>>> +    select MTD_SPI_NOR
>>> +    select XILINX_XDMA
>>> +    help
>>> +      This is a video4linux driver for Digiteq Automotive MGB4 grabber
>>> +      cards.
>>> +
>>> +      To compile this driver as a module, choose M here: the
>>> +      module will be called mgb4.
>>> diff --git a/drivers/media/pci/mgb4/Makefile b/drivers/media/pci/mgb4/Makefile
>>> new file mode 100644
>>> index 000000000000..e92ead18bed0
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/Makefile
>>> @@ -0,0 +1,6 @@
>>> +# SPDX-License-Identifier: GPL-2.0
>>> +mgb4-objs    := mgb4_regs.o mgb4_core.o mgb4_vin.o mgb4_vout.o \
>>> +               mgb4_sysfs_pci.o mgb4_sysfs_in.o mgb4_sysfs_out.o \
>>> +               mgb4_i2c.o mgb4_cmt.o mgb4_trigger.o mgb4_dma.o
>>> +
>>> +obj-$(CONFIG_VIDEO_MGB4) += mgb4.o
>>> diff --git a/drivers/media/pci/mgb4/mgb4_cmt.c b/drivers/media/pci/mgb4/mgb4_cmt.c
>>> new file mode 100644
>>> index 000000000000..80776771ee9b
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_cmt.c
>>> @@ -0,0 +1,247 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * The CMT module configures the FPGA Clock Management Tile (CMT) registers. For
>>> + * different video signal frequencies (FPGA input signal frequencies), the FPGA
>>> + * CMT registers need to be adjusted for the FPGA to work properly. The values
>>> + * are precomputed based on formulas given by Xilinx in their FPGA documentation
>>> + * (which are in turn full of some magic values/tables...).
>>> + */
>>> +
>>> +#include <linux/types.h>
>>> +#include <linux/kernel.h>
>>> +#include "mgb4_core.h"
>>> +#include "mgb4_cmt.h"
>>> +
>>> +static const u16 cmt_vals_out[][15] = {
>>> +    {0x1208, 0x0000, 0x171C, 0x0000, 0x1E38, 0x0000, 0x11C7, 0x0000, 0x1041, 0x01BC, 0x7C01, 0x7DE9, 0xFFFF, 0x9900, 0x8100, },
>>> +    {0x11C7, 0x0000, 0x1619, 0x0080, 0x1C71, 0x0000, 0x130D, 0x0080, 0x0041, 0x0090, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x9000, },
>>> +    {0x11C7, 0x0000, 0x1619, 0x0080, 0x1C71, 0x0000, 0x165A, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x11C7, 0x0000, 0x1619, 0x0080, 0x1C71, 0x0000, 0x1187, 0x0080, 0x1041, 0x01EE, 0x7C01, 0x7DE9, 0xFFFF, 0x9900, 0x8100, },
>>> +    {0x1186, 0x0000, 0x1555, 0x0000, 0x1AAA, 0x0000, 0x1451, 0x0000, 0x0042, 0x0013, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x11C7, 0x0000, 0x1619, 0x0080, 0x1C71, 0x0000, 0x134E, 0x0080, 0x0041, 0x005E, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x1619, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x179E, 0x0000, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x179F, 0x0080, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x17DF, 0x0000, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x8800, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x128B, 0x0080, 0x0041, 0x00DB, 0x7C01, 0x7DE9, 0xFFFF, 0x9000, 0x0100, },
>>> +    {0x1186, 0x0000, 0x1555, 0x0000, 0x1AAA, 0x0000, 0x1820, 0x0000, 0x0083, 0x00FA, 0x7DE9, 0x7DE8, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1186, 0x0000, 0x1555, 0x0000, 0x1AAA, 0x0000, 0x1187, 0x0080, 0x1041, 0x01EE, 0x7C01, 0x7DE9, 0xFFFF, 0x9900, 0x8100, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x169B, 0x0080, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1800, 0x0100, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x171C, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x1186, 0x0000, 0x1555, 0x0000, 0x1AAA, 0x0000, 0x1515, 0x0080, 0x0042, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x1493, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x15D8, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1900, 0x0100, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x124A, 0x0080, 0x0041, 0x010D, 0x7C01, 0x7DE9, 0xFFFF, 0x9000, 0x0100, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x175D, 0x0000, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x1619, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x17DF, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x8800, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x17E0, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x1820, 0x0000, 0x0083, 0x00FA, 0x7DE9, 0x7DE8, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x13D0, 0x0080, 0x0042, 0x002C, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x128B, 0x0080, 0x0041, 0x00DB, 0x7C01, 0x7DE9, 0xFFFF, 0x9000, 0x0100, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x1820, 0x0000, 0x00C3, 0x00FA, 0x7DE9, 0x7DE8, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x134E, 0x0080, 0x0041, 0x005E, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x1515, 0x0080, 0x0042, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x175D, 0x0000, 0x00C4, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1145, 0x0000, 0x1452, 0x0080, 0x18E3, 0x0000, 0x11C7, 0x0000, 0x1041, 0x01BC, 0x7C01, 0x7DE9, 0xFFFF, 0x9900, 0x8100, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1209, 0x0080, 0x0041, 0x013F, 0x7C01, 0x7DE9, 0xFFFF, 0x9900, 0x1100, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1556, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x8000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x179F, 0x0080, 0x00C4, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x15D8, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1900, 0x0100, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1105, 0x0080, 0x1041, 0x01E8, 0x6401, 0x65E9, 0xFFFF, 0x9800, 0x1100, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1820, 0x0000, 0x00C4, 0x00FA, 0x7DE9, 0x7DE8, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x1493, 0x0080, 0x0042, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x138E, 0x0000, 0x0042, 0x005E, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x17E0, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x165A, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x175D, 0x0000, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x1187, 0x0080, 0x1041, 0x01EE, 0x7C01, 0x7DE9, 0xFFFF, 0x9900, 0x8100, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x175E, 0x0080, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x179E, 0x0000, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x134E, 0x0080, 0x0041, 0x005E, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x165A, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x16DC, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x169A, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x11C7, 0x0000, 0x1041, 0x01BC, 0x7C01, 0x7DE9, 0xFFFF, 0x9900, 0x8100, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x169B, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1800, 0x0100, },
>>> +    {0x1104, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x171D, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x16DB, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1800, 0x0100, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1146, 0x0080, 0x1041, 0x0184, 0x7C01, 0x7DE9, 0xFFFF, 0x9900, 0x8100, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x171C, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1451, 0x0000, 0x0042, 0x0013, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x171D, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x175D, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1452, 0x0080, 0x0042, 0x0013, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x15D8, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1900, 0x0100, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1104, 0x0000, 0x1041, 0x01E8, 0x5801, 0x59E9, 0xFFFF, 0x9900, 0x0900, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x179F, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1515, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x17DF, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x8800, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1659, 0x0000, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1555, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x8000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x14D3, 0x0000, 0x0042, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1820, 0x0000, 0x0083, 0x00FA, 0x7DE9, 0x7DE8, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1556, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x8000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1187, 0x0080, 0x1041, 0x01EE, 0x7C01, 0x7DE9, 0xFFFF, 0x9900, 0x8100, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1452, 0x0080, 0x0082, 0x0013, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x169B, 0x0080, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1800, 0x0100, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1514, 0x0000, 0x0042, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x17E0, 0x0080, 0x00C4, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x1515, 0x0080, 0x0042, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x10C3, 0x0000, 0x128B, 0x0080, 0x1555, 0x0000, 0x16DC, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1493, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x15D8, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1900, 0x0100, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x171D, 0x0080, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1618, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1900, 0x0100, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x175D, 0x0000, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x14D4, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1619, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x179E, 0x0000, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x179F, 0x0080, 0x00C3, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1515, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x13D0, 0x0080, 0x0042, 0x002C, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x169A, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x128B, 0x0080, 0x0041, 0x00DB, 0x7C01, 0x7DE9, 0xFFFF, 0x9000, 0x0100, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x169B, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1800, 0x0100, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1820, 0x0000, 0x00C3, 0x00FA, 0x7DE9, 0x7DE8, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1556, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x8000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x16DB, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1800, 0x0100, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1411, 0x0080, 0x0042, 0x002C, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x171C, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1597, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x8000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1451, 0x0000, 0x0042, 0x0013, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x171D, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x1800, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x12CC, 0x0080, 0x0041, 0x00A9, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x175D, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1452, 0x0080, 0x0042, 0x0013, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x15D8, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1900, 0x0100, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x175E, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1492, 0x0000, 0x0042, 0x0013, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x179F, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0800, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1619, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1493, 0x0080, 0x0042, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x17DF, 0x0000, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x8800, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x130D, 0x0080, 0x0041, 0x0090, 0x7C01, 0x7DE9, 0xFFFF, 0x1100, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x17E0, 0x0080, 0x0083, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x14D3, 0x0000, 0x0042, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x165A, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1000, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x1820, 0x0000, 0x0083, 0x00FA, 0x7DE9, 0x7DE8, 0xFFFF, 0x0900, 0x9000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x14D4, 0x0080, 0x0042, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x0900, 0x1000, },
>>> +    {0x1082, 0x0000, 0x11C7, 0x0000, 0x138E, 0x0000, 0x169B, 0x0080, 0x0082, 0x00FA, 0x7C01, 0x7DE9, 0xFFFF, 0x1800, 0x0100, },
>>> +};
>>> +
>>> +static const u16 cmt_vals_in[][13] = {
>>> +    {0x1082, 0x0000, 0x5104, 0x0000, 0x11C7, 0x0000, 0x1041, 0x02BC, 0x7C01, 0xFFE9, 0x9900, 0x9908, 0x8100},
>>> +    {0x1104, 0x0000, 0x9208, 0x0000, 0x138E, 0x0000, 0x1041, 0x015E, 0x7C01, 0xFFE9, 0x0100, 0x0908, 0x1000},
>>> +};
>>> +
>>> +static const u32 cmt_addrs_out[][15] = {
>>> +    {0x420, 0x424, 0x428, 0x42C, 0x430, 0x434, 0x450, 0x454, 0x458, 0x460, 0x464, 0x468, 0x4A0, 0x538, 0x53C},
>>> +    {0x620, 0x624, 0x628, 0x62C, 0x630, 0x634, 0x650, 0x654, 0x658, 0x660, 0x664, 0x668, 0x6A0, 0x738, 0x73C},
>>> +};
>>> +
>>> +static const u32 cmt_addrs_in[][13] = {
>>> +    {0x020, 0x024, 0x028, 0x02C, 0x050, 0x054, 0x058, 0x060, 0x064, 0x068, 0x0A0, 0x138, 0x13C},
>>> +    {0x220, 0x224, 0x228, 0x22C, 0x250, 0x254, 0x258, 0x260, 0x264, 0x268, 0x2A0, 0x338, 0x33C},
>>> +};
>>> +
>>> +static const u32 cmt_freq[] = {
>>> +    25000, 25510, 26020, 26530, 26983, 27551, 28000, 28570,
>>> +    29046, 29522, 30000, 30476, 30952, 31546, 32000, 32539,
>>> +    33035, 33571, 33928, 34522, 35000, 35428, 36000, 36571,
>>> +    36904, 37500, 38093, 38571, 39047, 39453, 40000, 40476,
>>> +    40952, 41494, 41964, 42857, 43535, 44047, 44444, 45000,
>>> +    45535, 46029, 46428, 46823, 47617, 48214, 48571, 49107,
>>> +    49523, 50000, 50476, 50892, 51428, 52380, 53333, 53967,
>>> +    54285, 55238, 55555, 55952, 57142, 58095, 58571, 59047,
>>> +    59521, 60000, 60316, 60952, 61428, 61904, 62500, 63092,
>>> +    63491, 64282, 65078, 65476, 66071, 66664, 67142, 67854,
>>> +    68571, 69044, 69642, 70000, 71425, 72616, 73214, 73808,
>>> +    74285, 75000, 75714, 76187, 76785, 77142, 78570, 80000,
>>> +    80357, 80951, 81428, 82142, 82857, 83332, 83928, 84285,
>>> +    85713, 87142, 87500, 88094, 88571, 89285, 90000, 90475,
>>> +    91071, 91428, 92856, 94642,
>>> +};
>>> +
>>> +static size_t freq_srch(u32 key, const u32 *array, size_t size)
>>> +{
>>> +    int l = 0;
>>> +    int r = size - 1;
>>> +    int m;
>>> +
>>> +    while (l <= r) {
>>> +        m = (l + r) / 2;
>>> +        if (array[m] < key)
>>> +            l = m + 1;
>>> +        else if (array[m] > key)
>>> +            r = m - 1;
>>> +        else
>>> +            return m;
>>> +    }
>>> +
>>> +    if (r < 0 || l > size - 1)
>>> +        return m;
>>> +    else
>>> +        return (abs(key - array[l]) < abs(key - array[r])) ? l : r;
>>> +}
>>
>> Can you use the bsearch function? (see lib/bsearch.c)
>>
>>> +
>>> +u32 mgb4_cmt_set_vout(struct mgb4_vout_dev *voutdev, unsigned int freq)
>>
>> Isn't mgb4_cmt_set_vout_freq a better name? At least that makes it clear
>> this sets the frequency.
>>
>>> +{
>>> +    const u16 *reg_set;
>>> +    const u32 *addr;
>>> +    u32 config;
>>> +    size_t i, index;
>>> +
>>> +    index = freq_srch(freq, cmt_freq, ARRAY_SIZE(cmt_freq));
>>> +    addr = cmt_addrs_out[voutdev->config->id];
>>> +    reg_set = cmt_vals_out[index];
>>> +
>>> +    config = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.config);
>>> +
>>> +    mgb4_write_reg(&voutdev->mgbdev->video, voutdev->config->regs.config,
>>> +               0x1 | (config & ~0x3));
>>> +
>>> +    for (i = 0; i < ARRAY_SIZE(cmt_addrs_out[0]); i++)
>>> +        mgb4_write_reg(&voutdev->mgbdev->cmt, addr[i], reg_set[i]);
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.config,
>>> +              0x100, 0x100);
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.config,
>>> +              0x100, 0x0);
>>> +
>>> +    mgb4_write_reg(&voutdev->mgbdev->video, voutdev->config->regs.config,
>>> +               config & ~0x1);
>>> +
>>> +    return cmt_freq[index];
>>> +}
>>> +
>>> +void mgb4_cmt_set_vin(struct mgb4_vin_dev *vindev, unsigned int freq_range)
>>
>> mgb4_cmt_set_vin_freq_range?
>>
>>> +{
>>> +    const u16 *reg_set;
>>> +    const u32 *addr;
>>> +    u32 config;
>>> +    size_t i;
>>> +
>>> +    addr = cmt_addrs_in[vindev->config->id];
>>> +    reg_set = cmt_vals_in[freq_range];
>>> +
>>> +    config = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.config);
>>> +
>>> +    mgb4_write_reg(&vindev->mgbdev->video, vindev->config->regs.config,
>>> +               0x1 | (config & ~0x3));
>>> +
>>> +    for (i = 0; i < ARRAY_SIZE(cmt_addrs_in[0]); i++)
>>> +        mgb4_write_reg(&vindev->mgbdev->cmt, addr[i], reg_set[i]);
>>> +
>>> +    mgb4_mask_reg(&vindev->mgbdev->video, vindev->config->regs.config,
>>> +              0x1000, 0x1000);
>>> +    mgb4_mask_reg(&vindev->mgbdev->video, vindev->config->regs.config,
>>> +              0x1000, 0x0);
>>> +
>>> +    mgb4_write_reg(&vindev->mgbdev->video, vindev->config->regs.config,
>>> +               config & ~0x1);
>>> +}
>>> diff --git a/drivers/media/pci/mgb4/mgb4_cmt.h b/drivers/media/pci/mgb4/mgb4_cmt.h
>>> new file mode 100644
>>> index 000000000000..353966654c95
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_cmt.h
>>> @@ -0,0 +1,16 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#ifndef __MGB4_CMT_H__
>>> +#define __MGB4_CMT_H__
>>> +
>>> +#include "mgb4_vout.h"
>>> +#include "mgb4_vin.h"
>>> +
>>> +u32 mgb4_cmt_set_vout(struct mgb4_vout_dev *voutdev, unsigned int freq);
>>> +void mgb4_cmt_set_vin(struct mgb4_vin_dev *vindev, unsigned int freq_range);
>>> +
>>> +#endif
>>> diff --git a/drivers/media/pci/mgb4/mgb4_core.c b/drivers/media/pci/mgb4/mgb4_core.c
>>> new file mode 100644
>>> index 000000000000..cdf9d3287b4c
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_core.c
>>> @@ -0,0 +1,641 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * This is the driver for the MGB4 video grabber card by Digiteq Automotive.
>>> + *
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * This is the main driver module. The DMA, I2C and SPI sub-drivers are
>>> + * initialized here and the input/output v4l2 devices are created.
>>> + *
>>> + * The mgb4 card uses different expansion modules for different video sources
>>> + * (GMSL and FPDL3 for now) so in probe() we detect the module type based on
>>> + * what we see on the I2C bus and check if it matches the FPGA bitstream (there
>>> + * are different bitstreams for different expansion modules). When no expansion
>>> + * module is present, we still let the driver initialize to allow flashing of
>>> + * the FPGA firmware using the SPI FLASH device. No v4l2 video devices are
>>> + * created in this case.
>>> + */
>>> +
>>> +#include <linux/types.h>
>>> +#include <linux/module.h>
>>> +#include <linux/pci.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/clk.h>
>>> +#include <linux/clk-provider.h>
>>> +#include <linux/clkdev.h>
>>> +#include <linux/i2c.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/dma/amd_xdma.h>
>>> +#include <linux/platform_data/amd_xdma.h>
>>> +#include <linux/spi/xilinx_spi.h>
>>> +#include <linux/mtd/mtd.h>
>>> +#include "mgb4_dma.h"
>>> +#include "mgb4_i2c.h"
>>> +#include "mgb4_sysfs.h"
>>> +#include "mgb4_vout.h"
>>> +#include "mgb4_vin.h"
>>> +#include "mgb4_trigger.h"
>>> +#include "mgb4_core.h"
>>> +
>>> +#define MGB4_USER_IRQS 16
>>> +
>>> +static int flashid;
>>> +
>>> +static struct xdma_chan_info h2c_chan_info = {
>>> +    .dir = DMA_MEM_TO_DEV,
>>> +};
>>> +
>>> +static struct xdma_chan_info c2h_chan_info = {
>>> +    .dir = DMA_DEV_TO_MEM,
>>> +};
>>> +
>>> +static struct xspi_platform_data spi_platform_data = {
>>> +    .num_chipselect = 1,
>>> +    .bits_per_word = 8
>>> +};
>>> +
>>> +static const struct i2c_board_info extender_info = {
>>> +    I2C_BOARD_INFO("extender", 0x21)
>>> +};
>>> +
>>> +static int match_i2c_adap(struct device *dev, void *data)
>>> +{
>>> +    return i2c_verify_adapter(dev) ? 1 : 0;
>>> +}
>>> +
>>> +static struct i2c_adapter *get_i2c_adap(struct platform_device *pdev)
>>> +{
>>> +    struct device *dev;
>>> +    int i;
>>> +
>>> +    for (i = 0; i < 10; i++) {
>>> +        msleep(100);
>>
>> What's the purpose of this msleep? That should be documented since it
>> is unexpected.
>>
>>> +        mutex_lock(&pdev->dev.mutex);
>>> +        dev = device_find_child(&pdev->dev, NULL, match_i2c_adap);
>>> +        mutex_unlock(&pdev->dev.mutex);
>>> +        if (dev)
>>> +            return to_i2c_adapter(dev);
>>> +    }
>>> +
>>> +    return NULL;
>>> +}
>>> +
>>> +static int match_spi_adap(struct device *dev, void *data)
>>> +{
>>> +    return to_spi_device(dev) ? 1 : 0;
>>> +}
>>> +
>>> +static struct spi_master *get_spi_adap(struct platform_device *pdev)
>>> +{
>>> +    struct device *dev;
>>> +    int i;
>>> +
>>> +    for (i = 0; i < 10; i++) {
>>> +        msleep(100);
>>> +        mutex_lock(&pdev->dev.mutex);
>>> +        dev = device_find_child(&pdev->dev, NULL, match_spi_adap);
>>> +        mutex_unlock(&pdev->dev.mutex);
>>> +        if (dev)
>>> +            return container_of(dev, struct spi_master, dev);
>>> +    }
>>> +
>>> +    return NULL;
>>> +}
>>> +
>>> +static int init_spi(struct mgb4_dev *mgbdev)
>>> +{
>>> +    struct resource spi_resources[] = {
>>> +        {
>>> +            .start    = 0x400,
>>> +            .end    = 0x47f,
>>> +            .flags    = IORESOURCE_MEM,
>>> +            .name    = "io-memory",
>>> +        },
>>> +        {
>>> +            .start    = 14,
>>> +            .end    = 14,
>>> +            .flags    = IORESOURCE_IRQ,
>>> +            .name    = "irq",
>>> +        },
>>> +    };
>>> +    struct spi_board_info spi_info = {
>>> +        .max_speed_hz = 10000000,
>>> +        .modalias = "m25p80",
>>> +        .chip_select = 0,
>>> +        .mode = SPI_MODE_3,
>>> +    };
>>> +    struct pci_dev *pdev = mgbdev->pdev;
>>> +    struct device *dev = &pdev->dev;
>>> +    struct spi_master *master;
>>> +    struct spi_device *spi_dev;
>>> +    u32 irq;
>>> +    int rv, id;
>>> +    resource_size_t mapbase = pci_resource_start(pdev, MGB4_MGB4_BAR_ID);
>>> +
>>> +    irq = xdma_get_user_irq(mgbdev->xdev, 14);
>>> +    xdma_enable_user_irq(mgbdev->xdev, irq);
>>> +
>>> +    spi_resources[0].parent = &pdev->resource[MGB4_MGB4_BAR_ID];
>>> +    spi_resources[0].start += mapbase;
>>> +    spi_resources[0].end += mapbase;
>>> +    spi_resources[1].start = irq;
>>> +    spi_resources[1].end = irq;
>>> +
>>> +    id = pci_dev_id(pdev);
>>> +    mgbdev->spi_pdev = platform_device_register_resndata(dev, "xilinx_spi",
>>> +                                 id, spi_resources,
>>> +                                 ARRAY_SIZE(spi_resources),
>>> +                                 &spi_platform_data,
>>> +                                 sizeof(spi_platform_data));
>>> +    if (IS_ERR(mgbdev->spi_pdev)) {
>>> +        dev_err(dev, "failed to register SPI device\n");
>>> +        return PTR_ERR(mgbdev->spi_pdev);
>>> +    }
>>> +
>>> +    master = get_spi_adap(mgbdev->spi_pdev);
>>> +    if (!master) {
>>> +        dev_err(dev, "failed to get SPI adapter\n");
>>> +        rv = -EINVAL;
>>> +        goto err_pdev;
>>> +    }
>>> +
>>> +    snprintf(mgbdev->fw_part_name, sizeof(mgbdev->fw_part_name), "mgb4-fw.%d",
>>> +         flashid);
>>> +    mgbdev->partitions[0].name = mgbdev->fw_part_name;
>>> +    mgbdev->partitions[0].size = 0x400000;
>>> +    mgbdev->partitions[0].offset = 0x400000;
>>> +    mgbdev->partitions[0].mask_flags = 0;
>>> +
>>> +    snprintf(mgbdev->data_part_name, sizeof(mgbdev->data_part_name),
>>> +         "mgb4-data.%d", flashid);
>>> +    mgbdev->partitions[1].name = mgbdev->data_part_name;
>>> +    mgbdev->partitions[1].size = 0x10000;
>>> +    mgbdev->partitions[1].offset = 0xFF0000;
>>> +    mgbdev->partitions[1].mask_flags = MTD_CAP_NORFLASH;
>>> +
>>> +    snprintf(mgbdev->flash_name, sizeof(mgbdev->flash_name), "mgb4-flash.%d",
>>> +         flashid);
>>> +    mgbdev->flash_data.name = mgbdev->flash_name;
>>> +    mgbdev->flash_data.parts = mgbdev->partitions;
>>> +    mgbdev->flash_data.nr_parts = ARRAY_SIZE(mgbdev->partitions);
>>> +    mgbdev->flash_data.type = "spi-nor";
>>> +
>>> +    spi_info.platform_data = &mgbdev->flash_data;
>>> +
>>> +    spi_dev = spi_new_device(master, &spi_info);
>>> +    put_device(&master->dev);
>>> +    if (!spi_dev) {
>>> +        dev_err(dev, "failed to create MTD device\n");
>>> +        rv = -EINVAL;
>>> +        goto err_pdev;
>>> +    }
>>> +
>>> +    return 0;
>>> +
>>> +err_pdev:
>>> +    platform_device_unregister(mgbdev->spi_pdev);
>>> +
>>> +    return rv;
>>> +}
>>> +
>>> +static void free_spi(struct mgb4_dev *mgbdev)
>>> +{
>>> +    platform_device_unregister(mgbdev->spi_pdev);
>>> +}
>>> +
>>> +static int init_i2c(struct mgb4_dev *mgbdev)
>>> +{
>>> +    struct resource i2c_resources[] = {
>>> +        {
>>> +            .start    = 0x200,
>>> +            .end    = 0x3ff,
>>> +            .flags    = IORESOURCE_MEM,
>>> +            .name    = "io-memory",
>>> +        },
>>> +        {
>>> +            .start    = 15,
>>> +            .end    = 15,
>>> +            .flags    = IORESOURCE_IRQ,
>>> +            .name    = "irq",
>>> +        },
>>> +    };
>>> +    struct pci_dev *pdev = mgbdev->pdev;
>>> +    struct device *dev = &pdev->dev;
>>> +    char clk_name[16];
>>> +    u32 irq;
>>> +    int rv, id;
>>> +    resource_size_t mapbase = pci_resource_start(pdev, MGB4_MGB4_BAR_ID);
>>> +
>>> +    irq = xdma_get_user_irq(mgbdev->xdev, 15);
>>> +    xdma_enable_user_irq(mgbdev->xdev, irq);
>>> +
>>> +    i2c_resources[0].parent = &pdev->resource[MGB4_MGB4_BAR_ID];
>>> +    i2c_resources[0].start += mapbase;
>>> +    i2c_resources[0].end += mapbase;
>>> +    i2c_resources[1].start = irq;
>>> +    i2c_resources[1].end = irq;
>>> +
>>> +    id = pci_dev_id(pdev);
>>> +
>>> +    // create dummy clock required by the xiic-i2c adapter
>>> +    snprintf(clk_name, sizeof(clk_name), "xiic-i2c.%d", id);
>>> +    mgbdev->i2c_clk = clk_hw_register_fixed_rate(NULL, clk_name, NULL, 0, 125000000);
>>> +    if (IS_ERR(mgbdev->i2c_clk)) {
>>> +        dev_err(dev, "failed to register I2C clock\n");
>>> +        return PTR_ERR(mgbdev->i2c_clk);
>>> +    }
>>> +    mgbdev->i2c_cl = clkdev_hw_create(mgbdev->i2c_clk, NULL, "xiic-i2c.%d", id);
>>> +    if (!mgbdev->i2c_cl) {
>>> +        dev_err(dev, "failed to register I2C clockdev\n");
>>> +        rv = -ENOMEM;
>>> +        goto err_clk;
>>> +    }
>>> +
>>> +    mgbdev->i2c_pdev = platform_device_register_resndata(dev, "xiic-i2c",
>>> +                                 id, i2c_resources,
>>> +                                 ARRAY_SIZE(i2c_resources),
>>> +                                 NULL, 0);
>>> +    if (IS_ERR(mgbdev->i2c_pdev)) {
>>> +        dev_err(dev, "failed to register I2C device\n");
>>> +        rv = PTR_ERR(mgbdev->i2c_pdev);
>>> +        goto err_clkdev;
>>> +    }
>>> +
>>> +    mgbdev->i2c_adap = get_i2c_adap(mgbdev->i2c_pdev);
>>> +    if (!mgbdev->i2c_adap) {
>>> +        dev_err(dev, "failed to get I2C adapter\n");
>>> +        rv = -EINVAL;
>>> +        goto err_pdev;
>>> +    }
>>> +
>>> +    mutex_init(&mgbdev->i2c_lock);
>>> +
>>> +    return 0;
>>> +
>>> +err_pdev:
>>> +    platform_device_unregister(mgbdev->i2c_pdev);
>>> +err_clkdev:
>>> +    clkdev_drop(mgbdev->i2c_cl);
>>> +err_clk:
>>> +    clk_hw_unregister(mgbdev->i2c_clk);
>>> +
>>> +    return rv;
>>> +}
>>> +
>>> +static void free_i2c(struct mgb4_dev *mgbdev)
>>> +{
>>> +    put_device(&mgbdev->i2c_adap->dev);
>>> +    platform_device_unregister(mgbdev->i2c_pdev);
>>> +    clkdev_drop(mgbdev->i2c_cl);
>>> +    clk_hw_unregister(mgbdev->i2c_clk);
>>> +}
>>> +
>>> +static int init_sysfs(struct pci_dev *pdev)
>>> +{
>>> +    struct device_attribute **attr, **eattr;
>>> +    int rv;
>>> +
>>> +    for (attr = mgb4_pci_attrs; *attr; attr++) {
>>> +        rv = device_create_file(&pdev->dev, *attr);
>>> +        if (rv < 0)
>>> +            goto err_file;
>>> +    }
>>> +
>>> +    return 0;
>>> +
>>> +err_file:
>>> +    for (eattr = mgb4_pci_attrs; eattr != attr; eattr++)
>>> +        device_remove_file(&pdev->dev, *eattr);
>>> +
>>> +    return rv;
>>> +}
>>> +
>>> +static void free_sysfs(struct pci_dev *pdev)
>>> +{
>>> +    struct device_attribute **attr;
>>> +
>>> +    for (attr = mgb4_pci_attrs; *attr; attr++)
>>> +        device_remove_file(&pdev->dev, *attr);
>>> +}
>>> +
>>> +static int get_serial_number(struct mgb4_dev *mgbdev)
>>> +{
>>> +    struct device *dev = &mgbdev->pdev->dev;
>>> +    struct mtd_info *mtd;
>>> +    size_t rs;
>>> +    int rv;
>>> +
>>> +    mgbdev->serial_number = 0;
>>> +
>>> +    mtd = get_mtd_device_nm(mgbdev->data_part_name);
>>> +    if (IS_ERR(mtd)) {
>>> +        dev_warn(dev, "failed to get data MTD device\n");
>>> +        return -ENOENT;
>>> +    }
>>> +    rv = mtd_read(mtd, 0, sizeof(mgbdev->serial_number), &rs,
>>> +              (u_char *)&mgbdev->serial_number);
>>> +    put_mtd_device(mtd);
>>> +    if (rv < 0 || rs != sizeof(mgbdev->serial_number)) {
>>> +        dev_warn(dev, "error reading MTD device\n");
>>> +        return -EIO;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int get_module_version(struct mgb4_dev *mgbdev)
>>> +{
>>> +    struct device *dev = &mgbdev->pdev->dev;
>>> +    struct mgb4_i2c_client extender;
>>> +    s32 version;
>>> +    u32 fw_version;
>>> +    int rv;
>>> +
>>> +    rv = mgb4_i2c_init(&extender, mgbdev->i2c_adap, &extender_info, 8);
>>> +    if (rv < 0) {
>>> +        dev_err(dev, "failed to create extender I2C device\n");
>>> +        return rv;
>>> +    }
>>> +    version = mgb4_i2c_read_byte(&extender, 0x00);
>>> +    mgb4_i2c_free(&extender);
>>> +    if (version < 0) {
>>> +        dev_err(dev, "error reading module version\n");
>>> +        return -EIO;
>>> +    }
>>> +
>>> +    mgbdev->module_version = ~((u32)version) & 0xff;
>>> +    if (!(MGB4_IS_FPDL3(mgbdev) || MGB4_IS_GMSL(mgbdev))) {
>>> +        dev_err(dev, "unknown module type\n");
>>> +        return -EINVAL;
>>> +    }
>>> +    fw_version = mgb4_read_reg(&mgbdev->video, 0xC4);
>>> +    if (fw_version >> 24 != mgbdev->module_version >> 4) {
>>> +        dev_err(dev, "module/firmware type mismatch\n");
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    dev_info(dev, "%s module detected\n",
>>> +         MGB4_IS_FPDL3(mgbdev) ? "FPDL3" : "GMSL");
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int map_regs(struct pci_dev *pdev, struct resource *res,
>>> +            struct mgb4_regs *regs)
>>> +{
>>> +    int rv;
>>> +    resource_size_t mapbase = pci_resource_start(pdev, MGB4_MGB4_BAR_ID);
>>> +
>>> +    res->start += mapbase;
>>> +    res->end += mapbase;
>>> +
>>> +    rv = mgb4_regs_map(res, regs);
>>> +    if (rv < 0) {
>>> +        dev_err(&pdev->dev, "failed to map %s registers\n", res->name);
>>> +        return rv;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int init_xdma(struct mgb4_dev *mgbdev)
>>> +{
>>> +    struct xdma_platdata data;
>>> +    struct resource res[2] = { 0 };
>>> +    struct dma_slave_map *map;
>>> +    struct pci_dev *pdev = mgbdev->pdev;
>>> +    struct device *dev = &pdev->dev;
>>> +    int i;
>>> +
>>> +    res[0].start = pci_resource_start(pdev, MGB4_XDMA_BAR_ID);
>>> +    res[0].end = pci_resource_end(pdev, MGB4_XDMA_BAR_ID);
>>> +    res[0].flags = IORESOURCE_MEM;
>>> +    res[0].parent = &pdev->resource[MGB4_XDMA_BAR_ID];
>>> +    res[1].start = pci_irq_vector(pdev, 0);
>>> +    res[1].end = res[1].start + MGB4_VIN_DEVICES + MGB4_VOUT_DEVICES
>>> +             + MGB4_USER_IRQS - 1;
>>> +    res[1].flags = IORESOURCE_IRQ;
>>> +
>>> +    data.max_dma_channels = MGB4_VIN_DEVICES + MGB4_VOUT_DEVICES;
>>> +    data.device_map = mgbdev->slave_map;
>>> +    data.device_map_cnt = MGB4_VIN_DEVICES + MGB4_VOUT_DEVICES;
>>> +
>>> +    for (i = 0; i < MGB4_VIN_DEVICES; i++) {
>>> +        sprintf(mgbdev->channel_names[i], "c2h%d", i);
>>> +        map = &data.device_map[i];
>>> +        map->slave = mgbdev->channel_names[i];
>>> +        map->devname = dev_name(dev);
>>> +        map->param = XDMA_FILTER_PARAM(&c2h_chan_info);
>>> +    }
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++) {
>>> +        sprintf(mgbdev->channel_names[i + MGB4_VIN_DEVICES], "h2c%d", i);
>>> +        map = &data.device_map[i + MGB4_VIN_DEVICES];
>>> +        map->slave = mgbdev->channel_names[i + MGB4_VIN_DEVICES];
>>> +        map->devname = dev_name(dev);
>>> +        map->param = XDMA_FILTER_PARAM(&h2c_chan_info);
>>> +    }
>>> +
>>> +    mgbdev->xdev = platform_device_register_resndata(dev, "xdma",
>>> +                             PLATFORM_DEVID_AUTO, res,
>>> +                             2, &data, sizeof(data));
>>> +    if (IS_ERR(mgbdev->xdev)) {
>>> +        dev_err(dev, "failed to register XDMA device\n");
>>> +        return PTR_ERR(mgbdev->xdev);
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static void free_xdma(struct mgb4_dev *mgbdev)
>>> +{
>>> +    platform_device_unregister(mgbdev->xdev);
>>> +}
>>> +
>>> +static int mgb4_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>>> +{
>>> +    int i, rv;
>>> +    struct mgb4_dev *mgbdev;
>>> +    struct resource video = {
>>> +        .start    = 0x0,
>>> +        .end    = 0x100,
>>> +        .flags    = IORESOURCE_MEM,
>>> +        .name    = "mgb4-video",
>>> +    };
>>> +    struct resource cmt = {
>>> +        .start    = 0x1000,
>>> +        .end    = 0x1800,
>>> +        .flags    = IORESOURCE_MEM,
>>> +        .name    = "mgb4-cmt",
>>> +    };
>>> +    int irqs = pci_msix_vec_count(pdev);
>>> +
>>> +    mgbdev = kzalloc(sizeof(*mgbdev), GFP_KERNEL);
>>> +    if (!mgbdev)
>>> +        return -ENOMEM;
>>> +
>>> +    mgbdev->pdev = pdev;
>>> +    pci_set_drvdata(pdev, mgbdev);
>>> +
>>> +    /* PCIe related stuff */
>>> +    rv = pci_enable_device(pdev);
>>> +    if (rv) {
>>> +        dev_err(&pdev->dev, "error enabling PCI device\n");
>>> +        goto err_mgbdev;
>>> +    }
>>> +
>>> +    rv = pcie_capability_set_word(pdev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_RELAX_EN);
>>> +    if (rv)
>>> +        dev_warn(&pdev->dev, "error enabling PCIe relaxed ordering\n");
>>> +    rv = pcie_capability_set_word(pdev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_EXT_TAG);
>>> +    if (rv)
>>> +        dev_warn(&pdev->dev, "error enabling PCIe extended tag field\n");
>>> +    rv = pcie_set_readrq(pdev, 512);
>>> +    if (rv)
>>> +        dev_warn(&pdev->dev, "error setting PCIe max. memory read size\n");
>>> +    pci_set_master(pdev);
>>> +
>>> +    rv = pci_alloc_irq_vectors(pdev, irqs, irqs, PCI_IRQ_MSIX);
>>> +    if (rv < 0) {
>>> +        dev_err(&pdev->dev, "error allocating MSI-X IRQs\n");
>>> +        goto err_enable_pci;
>>> +    }
>>> +
>>> +    rv = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
>>> +    if (rv) {
>>> +        dev_err(&pdev->dev, "error setting DMA mask\n");
>>> +        goto err_enable_pci;
>>> +    }
>>> +
>>> +    /* DMA + IRQ engine */
>>> +    rv = init_xdma(mgbdev);
>>> +    if (rv)
>>> +        goto err_alloc_irq;
>>> +    rv = mgb4_dma_channel_init(mgbdev);
>>> +    if (rv)
>>> +        goto err_dma_chan;
>>> +
>>> +    /* mgb4 video registers */
>>> +    rv = map_regs(pdev, &video, &mgbdev->video);
>>> +    if (rv < 0)
>>> +        goto err_dma_chan;
>>> +    /* mgb4 cmt registers */
>>> +    rv = map_regs(pdev, &cmt, &mgbdev->cmt);
>>> +    if (rv < 0)
>>> +        goto err_video_regs;
>>> +
>>> +    /* SPI FLASH */
>>> +    rv = init_spi(mgbdev);
>>> +    if (rv < 0)
>>> +        goto err_cmt_regs;
>>> +
>>> +    /* I2C controller */
>>> +    rv = init_i2c(mgbdev);
>>> +    if (rv < 0)
>>> +        goto err_spi;
>>> +
>>> +    /* PCI card related sysfs attributes */
>>> +    rv = init_sysfs(pdev);
>>> +    if (rv < 0)
>>> +        goto err_i2c;
>>> +
>>> +    /* Get card serial number. On systems without MTD flash support we may
>>> +     * get an error thus ignore the return value. An invalid serial number
>>> +     * should not break anything...
>>> +     */
>>> +    if (get_serial_number(mgbdev) < 0)
>>> +        dev_warn(&pdev->dev, "error reading card serial number\n");
>>> +
>>> +    /* Get module type. If no valid module is found, skip the video device
>>> +     * creation part but do not exit with error to allow flashing the card.
>>> +     */
>>> +    rv = get_module_version(mgbdev);
>>> +    if (rv < 0)
>>> +        goto exit;
>>> +
>>> +    /* Video input v4l2 devices */
>>> +    for (i = 0; i < MGB4_VIN_DEVICES; i++)
>>> +        mgbdev->vin[i] = mgb4_vin_create(mgbdev, i);
>>> +
>>> +    /* Video output v4l2 devices */
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++)
>>> +        mgbdev->vout[i] = mgb4_vout_create(mgbdev, i);
>>> +
>>> +    /* Triggers */
>>> +    mgbdev->indio_dev = mgb4_trigger_create(mgbdev);
>>> +
>>> +exit:
>>> +    flashid++;
>>> +
>>> +    return 0;
>>> +
>>> +err_i2c:
>>> +    free_i2c(mgbdev);
>>> +err_spi:
>>> +    free_spi(mgbdev);
>>> +err_cmt_regs:
>>> +    mgb4_regs_free(&mgbdev->cmt);
>>> +err_video_regs:
>>> +    mgb4_regs_free(&mgbdev->video);
>>> +err_dma_chan:
>>> +    mgb4_dma_channel_free(mgbdev);
>>> +    free_xdma(mgbdev);
>>> +err_alloc_irq:
>>> +    pci_disable_msix(pdev);
>>> +err_enable_pci:
>>> +    pci_disable_device(pdev);
>>> +err_mgbdev:
>>> +    kfree(mgbdev);
>>> +
>>> +    return rv;
>>> +}
>>> +
>>> +static void mgb4_remove(struct pci_dev *pdev)
>>> +{
>>> +    struct mgb4_dev *mgbdev = pci_get_drvdata(pdev);
>>> +    int i;
>>> +
>>> +    if (mgbdev->indio_dev)
>>> +        mgb4_trigger_free(mgbdev->indio_dev);
>>> +
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++)
>>> +        if (mgbdev->vout[i])
>>> +            mgb4_vout_free(mgbdev->vout[i]);
>>> +    for (i = 0; i < MGB4_VIN_DEVICES; i++)
>>> +        if (mgbdev->vin[i])
>>> +            mgb4_vin_free(mgbdev->vin[i]);
>>> +
>>> +    free_sysfs(mgbdev->pdev);
>>> +    free_spi(mgbdev);
>>> +    free_i2c(mgbdev);
>>> +    mgb4_regs_free(&mgbdev->video);
>>> +    mgb4_regs_free(&mgbdev->cmt);
>>> +
>>> +    mgb4_dma_channel_free(mgbdev);
>>> +    free_xdma(mgbdev);
>>> +
>>> +    pci_disable_msix(mgbdev->pdev);
>>> +    pci_disable_device(mgbdev->pdev);
>>> +
>>> +    kfree(mgbdev);
>>> +}
>>> +
>>> +static const struct pci_device_id mgb4_pci_ids[] = {
>>> +    { PCI_DEVICE(0x1ed8, 0x0101), },
>>> +    { 0, }
>>> +};
>>> +MODULE_DEVICE_TABLE(pci, mgb4_pci_ids);
>>> +
>>> +static struct pci_driver mgb4_pci_driver = {
>>> +    .name = KBUILD_MODNAME,
>>> +    .id_table = mgb4_pci_ids,
>>> +    .probe = mgb4_probe,
>>> +    .remove = mgb4_remove,
>>> +};
>>> +
>>> +module_pci_driver(mgb4_pci_driver);
>>> +
>>> +MODULE_AUTHOR("Digiteq Automotive s.r.o.");
>>> +MODULE_DESCRIPTION("Digiteq Automotive MGB4 Driver");
>>> +MODULE_LICENSE("GPL");
>>> +MODULE_SOFTDEP("pre: platform:xiic-i2c platform:xilinx_spi spi-nor");
>>> diff --git a/drivers/media/pci/mgb4/mgb4_core.h b/drivers/media/pci/mgb4/mgb4_core.h
>>> new file mode 100644
>>> index 000000000000..de519f91d734
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_core.h
>>> @@ -0,0 +1,65 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#ifndef __MGB4_CORE_H__
>>> +#define __MGB4_CORE_H__
>>> +
>>> +#include <linux/spi/flash.h>
>>> +#include <linux/mtd/partitions.h>
>>> +#include <linux/mutex.h>
>>> +#include <linux/dmaengine.h>
>>> +#include "mgb4_regs.h"
>>> +
>>> +#define MGB4_VIN_DEVICES  2
>>> +#define MGB4_VOUT_DEVICES 2
>>> +
>>> +#define MGB4_MGB4_BAR_ID  0
>>> +#define MGB4_XDMA_BAR_ID  1
>>> +
>>> +#define MGB4_IS_GMSL(mgbdev) \
>>> +    ((mgbdev)->module_version >> 4 == 2)
>>> +#define MGB4_IS_FPDL3(mgbdev) \
>>> +    ((mgbdev)->module_version >> 4 == 1)
>>> +
>>> +struct mgb4_dma_channel {
>>> +    struct dma_chan *chan;
>>> +    struct completion req_compl;
>>> +};
>>> +
>>> +struct mgb4_dev {
>>> +    struct pci_dev *pdev;
>>> +    struct platform_device *xdev;
>>> +    struct mgb4_vin_dev *vin[MGB4_VIN_DEVICES];
>>> +    struct mgb4_vout_dev *vout[MGB4_VOUT_DEVICES];
>>> +
>>> +    struct mgb4_dma_channel c2h_chan[MGB4_VIN_DEVICES];
>>> +    struct mgb4_dma_channel h2c_chan[MGB4_VOUT_DEVICES];
>>> +    struct dma_slave_map slave_map[MGB4_VIN_DEVICES + MGB4_VOUT_DEVICES];
>>> +
>>> +    struct mgb4_regs video;
>>> +    struct mgb4_regs cmt;
>>> +
>>> +    struct clk_hw *i2c_clk;
>>> +    struct clk_lookup *i2c_cl;
>>> +    struct platform_device *i2c_pdev;
>>> +    struct i2c_adapter *i2c_adap;
>>> +    struct mutex i2c_lock; /* I2C bus access lock */
>>> +
>>> +    struct platform_device *spi_pdev;
>>> +    struct flash_platform_data flash_data;
>>> +    struct mtd_partition partitions[2];
>>> +    char flash_name[16];
>>> +    char fw_part_name[16];
>>> +    char data_part_name[16];
>>> +    char channel_names[MGB4_VIN_DEVICES + MGB4_VOUT_DEVICES][16];
>>> +
>>> +    struct iio_dev *indio_dev;
>>> +
>>> +    u8 module_version;
>>> +    u32 serial_number;
>>> +};
>>> +
>>> +#endif
>>> diff --git a/drivers/media/pci/mgb4/mgb4_dma.c b/drivers/media/pci/mgb4/mgb4_dma.c
>>> new file mode 100644
>>> index 000000000000..cae888e6504b
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_dma.c
>>> @@ -0,0 +1,123 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * This module handles the DMA transfers. A standard dmaengine API as provided
>>> + * by the XDMA module is used.
>>> + */
>>> +
>>> +#include <linux/pci.h>
>>> +#include <linux/dma-direction.h>
>>> +#include "mgb4_core.h"
>>> +#include "mgb4_dma.h"
>>> +
>>> +static void chan_irq(void *param)
>>> +{
>>> +    struct mgb4_dma_channel *chan = param;
>>> +
>>> +    complete(&chan->req_compl);
>>> +}
>>> +
>>> +int mgb4_dma_transfer(struct mgb4_dev *mgbdev, u32 channel, bool write,
>>> +              u64 paddr, struct sg_table *sgt)
>>> +{
>>> +    struct dma_slave_config cfg;
>>> +    struct mgb4_dma_channel *chan;
>>> +    struct dma_async_tx_descriptor *tx;
>>> +    struct pci_dev *pdev = mgbdev->pdev;
>>> +    int ret;
>>> +
>>> +    memset(&cfg, 0, sizeof(cfg));
>>> +
>>> +    if (write) {
>>> +        cfg.direction = DMA_MEM_TO_DEV;
>>> +        cfg.dst_addr = paddr;
>>> +        cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>>> +        chan = &mgbdev->h2c_chan[channel];
>>> +    } else {
>>> +        cfg.direction = DMA_DEV_TO_MEM;
>>> +        cfg.src_addr = paddr;
>>> +        cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
>>> +        chan = &mgbdev->c2h_chan[channel];
>>> +    }
>>> +
>>> +    ret = dmaengine_slave_config(chan->chan, &cfg);
>>> +    if (ret) {
>>> +        dev_err(&pdev->dev, "failed to config dma: %d\n", ret);
>>> +        return ret;
>>> +    }
>>> +
>>> +    tx = dmaengine_prep_slave_sg(chan->chan, sgt->sgl, sgt->nents,
>>> +                     cfg.direction, 0);
>>> +    if (!tx) {
>>> +        dev_err(&pdev->dev, "failed to prep slave sg\n");
>>> +        return -EIO;
>>> +    }
>>> +
>>> +    tx->callback = chan_irq;
>>> +    tx->callback_param = chan;
>>> +
>>> +    ret = dma_submit_error(dmaengine_submit(tx));
>>> +    if (ret) {
>>> +        dev_err(&pdev->dev, "failed to submit sg\n");
>>> +        return -EIO;
>>> +    }
>>> +
>>> +    dma_async_issue_pending(chan->chan);
>>> +
>>> +    if (!wait_for_completion_timeout(&chan->req_compl,
>>> +                     msecs_to_jiffies(10000))) {
>>> +        dev_err(&pdev->dev, "dma timeout\n");
>>> +        dmaengine_terminate_sync(chan->chan);
>>> +        return -EIO;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +int mgb4_dma_channel_init(struct mgb4_dev *mgbdev)
>>> +{
>>> +    int i, ret;
>>> +    char name[16];
>>> +    struct pci_dev *pdev = mgbdev->pdev;
>>> +
>>> +    for (i = 0; i < MGB4_VIN_DEVICES; i++) {
>>> +        sprintf(name, "c2h%d", i);
>>> +        mgbdev->c2h_chan[i].chan = dma_request_chan(&pdev->dev, name);
>>> +        if (IS_ERR(mgbdev->c2h_chan[i].chan)) {
>>> +            dev_err(&pdev->dev, "failed to initialize %s", name);
>>> +            ret = PTR_ERR(mgbdev->c2h_chan[i].chan);
>>> +            mgbdev->c2h_chan[i].chan = NULL;
>>> +            return ret;
>>> +        }
>>> +        init_completion(&mgbdev->c2h_chan[i].req_compl);
>>> +    }
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++) {
>>> +        sprintf(name, "h2c%d", i);
>>> +        mgbdev->h2c_chan[i].chan = dma_request_chan(&pdev->dev, name);
>>> +        if (IS_ERR(mgbdev->h2c_chan[i].chan)) {
>>> +            dev_err(&pdev->dev, "failed to initialize %s", name);
>>> +            ret = PTR_ERR(mgbdev->h2c_chan[i].chan);
>>> +            mgbdev->h2c_chan[i].chan = NULL;
>>> +            return ret;
>>> +        }
>>> +        init_completion(&mgbdev->h2c_chan[i].req_compl);
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +void mgb4_dma_channel_free(struct mgb4_dev *mgbdev)
>>> +{
>>> +    int i;
>>> +
>>> +    for (i = 0; i < MGB4_VIN_DEVICES; i++) {
>>> +        if (mgbdev->c2h_chan[i].chan)
>>> +            dma_release_channel(mgbdev->c2h_chan[i].chan);
>>> +    }
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++) {
>>> +        if (mgbdev->h2c_chan[i].chan)
>>> +            dma_release_channel(mgbdev->h2c_chan[i].chan);
>>> +    }
>>> +}
>>> diff --git a/drivers/media/pci/mgb4/mgb4_dma.h b/drivers/media/pci/mgb4/mgb4_dma.h
>>> new file mode 100644
>>> index 000000000000..3710c2c893c7
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_dma.h
>>> @@ -0,0 +1,18 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#ifndef __MGB4_DMA_H__
>>> +#define __MGB4_DMA_H__
>>> +
>>> +#include "mgb4_core.h"
>>> +
>>> +int mgb4_dma_channel_init(struct mgb4_dev *mgbdev);
>>> +void mgb4_dma_channel_free(struct mgb4_dev *mgbdev);
>>> +
>>> +int mgb4_dma_transfer(struct mgb4_dev *mgbdev, u32 channel, bool write, u64 paddr,
>>> +              struct sg_table *sgt);
>>> +
>>> +#endif
>>> diff --git a/drivers/media/pci/mgb4/mgb4_i2c.c b/drivers/media/pci/mgb4/mgb4_i2c.c
>>> new file mode 100644
>>> index 000000000000..999a0490a321
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_i2c.c
>>> @@ -0,0 +1,140 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * The i2c module unifies the I2C access to the serializes/deserializes. The I2C
>>> + * chips on the GMSL module use 16b addressing, the FPDL3 chips use standard
>>> + * 8b addressing.
>>> + */
>>> +
>>> +#include "mgb4_i2c.h"
>>> +
>>> +static int read_r16(struct i2c_client *client, u16 reg, u8 *val, int len)
>>> +{
>>> +    int ret;
>>> +    u8 buf[2];
>>> +    struct i2c_msg msg[2] = {
>>> +        {
>>> +            .addr = client->addr,
>>> +            .flags = 0,
>>> +            .len = 2,
>>> +            .buf = buf,
>>> +        }, {
>>> +            .addr = client->addr,
>>> +            .flags = I2C_M_RD,
>>> +            .len = len,
>>> +            .buf = val,
>>> +        }
>>> +    };
>>> +
>>> +    buf[0] = (reg >> 8) & 0xff;
>>> +    buf[1] = (reg >> 0) & 0xff;
>>> +
>>> +    ret = i2c_transfer(client->adapter, msg, 2);
>>> +    if (ret < 0)
>>> +        return ret;
>>> +    else if (ret != 2)
>>> +        return -EREMOTEIO;
>>> +    else
>>> +        return 0;
>>> +}
>>> +
>>> +static int write_r16(struct i2c_client *client, u16 reg, const u8 *val, int len)
>>> +{
>>> +    int ret;
>>> +    u8 buf[4];
>>> +    struct i2c_msg msg[1] = {
>>> +        {
>>> +            .addr = client->addr,
>>> +            .flags = 0,
>>> +            .len = 2 + len,
>>> +            .buf = buf,
>>> +        }
>>> +    };
>>> +
>>> +    if (2 + len > sizeof(buf))
>>> +        return -EINVAL;
>>> +
>>> +    buf[0] = (reg >> 8) & 0xff;
>>> +    buf[1] = (reg >> 0) & 0xff;
>>> +    memcpy(&buf[2], val, len);
>>> +
>>> +    ret = i2c_transfer(client->adapter, msg, 1);
>>> +    if (ret < 0)
>>> +        return ret;
>>> +    else if (ret != 1)
>>> +        return -EREMOTEIO;
>>> +    else
>>> +        return 0;
>>> +}
>>> +
>>> +int mgb4_i2c_init(struct mgb4_i2c_client *client, struct i2c_adapter *adap,
>>> +          struct i2c_board_info const *info, int addr_size)
>>> +{
>>> +    client->client = i2c_new_client_device(adap, info);
>>> +    if (IS_ERR(client->client))
>>> +        return PTR_ERR(client->client);
>>> +
>>> +    client->addr_size = addr_size;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +void mgb4_i2c_free(struct mgb4_i2c_client *client)
>>> +{
>>> +    i2c_unregister_device(client->client);
>>> +}
>>> +
>>> +s32 mgb4_i2c_read_byte(struct mgb4_i2c_client *client, u16 reg)
>>> +{
>>> +    int ret;
>>> +    u8 b;
>>> +
>>> +    if (client->addr_size == 8)
>>> +        return i2c_smbus_read_byte_data(client->client, reg);
>>> +
>>> +    ret = read_r16(client->client, reg, &b, 1);
>>> +    if (ret < 0)
>>> +        return ret;
>>> +
>>> +    return (s32)b;
>>> +}
>>> +
>>> +s32 mgb4_i2c_write_byte(struct mgb4_i2c_client *client, u16 reg, u8 val)
>>> +{
>>> +    if (client->addr_size == 8)
>>> +        return i2c_smbus_write_byte_data(client->client, reg, val);
>>> +    else
>>> +        return write_r16(client->client, reg, &val, 1);
>>> +}
>>> +
>>> +s32 mgb4_i2c_mask_byte(struct mgb4_i2c_client *client, u16 reg, u8 mask, u8 val)
>>> +{
>>> +    s32 ret;
>>> +
>>> +    if (mask != 0xFF) {
>>> +        ret = mgb4_i2c_read_byte(client, reg);
>>> +        if (ret < 0)
>>> +            return ret;
>>> +        val |= (u8)ret & ~mask;
>>> +    }
>>> +
>>> +    return mgb4_i2c_write_byte(client, reg, val);
>>> +}
>>> +
>>> +int mgb4_i2c_configure(struct mgb4_i2c_client *client,
>>> +               const struct mgb4_i2c_kv *values, size_t count)
>>> +{
>>> +    size_t i;
>>> +    s32 res;
>>> +
>>> +    for (i = 0; i < count; i++) {
>>> +        res = mgb4_i2c_mask_byte(client, values[i].reg, values[i].mask,
>>> +                     values[i].val);
>>> +        if (res < 0)
>>> +            return res;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> diff --git a/drivers/media/pci/mgb4/mgb4_i2c.h b/drivers/media/pci/mgb4/mgb4_i2c.h
>>> new file mode 100644
>>> index 000000000000..9f3c1b7c2c99
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_i2c.h
>>> @@ -0,0 +1,35 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#ifndef __MGB4_I2C_H__
>>> +#define __MGB4_I2C_H__
>>> +
>>> +#include <linux/i2c.h>
>>> +
>>> +struct mgb4_i2c_client {
>>> +    struct i2c_client *client;
>>> +    int addr_size;
>>> +};
>>> +
>>> +struct mgb4_i2c_kv {
>>> +    u16 reg;
>>> +    u8 mask;
>>> +    u8 val;
>>> +};
>>> +
>>> +int mgb4_i2c_init(struct mgb4_i2c_client *client, struct i2c_adapter *adap,
>>> +          struct i2c_board_info const *info, int addr_size);
>>> +void mgb4_i2c_free(struct mgb4_i2c_client *client);
>>> +
>>> +s32 mgb4_i2c_read_byte(struct mgb4_i2c_client *client, u16 reg);
>>> +s32 mgb4_i2c_write_byte(struct mgb4_i2c_client *client, u16 reg, u8 val);
>>> +s32 mgb4_i2c_mask_byte(struct mgb4_i2c_client *client, u16 reg, u8 mask,
>>> +               u8 val);
>>> +
>>> +int mgb4_i2c_configure(struct mgb4_i2c_client *client,
>>> +               const struct mgb4_i2c_kv *values, size_t count);
>>> +
>>> +#endif
>>> diff --git a/drivers/media/pci/mgb4/mgb4_io.h b/drivers/media/pci/mgb4/mgb4_io.h
>>> new file mode 100644
>>> index 000000000000..5e8a5e0495b7
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_io.h
>>> @@ -0,0 +1,39 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#ifndef __MGB4_IO_H__
>>> +#define __MGB4_IO_H__
>>> +
>>> +#include <media/v4l2-dev.h>
>>> +
>>> +#define DEFAULT_WIDTH     1280
>>> +#define DEFAULT_HEIGHT    640
>>> +#define DEFAULT_PERIOD    (125000000 / 60)
>>> +
>>> +#define ERR_NO_REG        0xFFFFFFFE
>>> +#define ERR_QUEUE_TIMEOUT 0xFFFFFFFD
>>> +#define ERR_QUEUE_EMPTY   0xFFFFFFFC
>>> +#define ERR_QUEUE_FULL    0xFFFFFFFB
>>> +
>>> +#define BYTESPERLINE(width, alignment) \
>>> +    (((((width) * 4) - 1) | ((alignment) - 1)) + 1)
>>> +
>>> +struct frame_buffer {
>>> +    struct vb2_v4l2_buffer vb;
>>> +    struct list_head list;
>>> +};
>>> +
>>> +static inline struct frame_buffer *to_frame_buffer(struct vb2_v4l2_buffer *vbuf)
>>> +{
>>> +    return container_of(vbuf, struct frame_buffer, vb);
>>> +}
>>> +
>>> +static inline u32 PADDING(u32 width, u32 alignment)
>>> +{
>>> +    return ((BYTESPERLINE(width, alignment) - (width * 4)) / 4);
>>> +}
>>> +
>>> +#endif
>>> diff --git a/drivers/media/pci/mgb4/mgb4_regs.c b/drivers/media/pci/mgb4/mgb4_regs.c
>>> new file mode 100644
>>> index 000000000000..53d4e4503a74
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_regs.c
>>> @@ -0,0 +1,30 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#include <linux/ioport.h>
>>> +#include "mgb4_regs.h"
>>> +
>>> +int mgb4_regs_map(struct resource *res, struct mgb4_regs *regs)
>>> +{
>>> +    regs->mapbase = res->start;
>>> +    regs->mapsize = res->end - res->start;
>>> +
>>> +    if (!request_mem_region(regs->mapbase, regs->mapsize, res->name))
>>> +        return -EINVAL;
>>> +    regs->membase = ioremap(regs->mapbase, regs->mapsize);
>>> +    if (!regs->membase) {
>>> +        release_mem_region(regs->mapbase, regs->mapsize);
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +void mgb4_regs_free(struct mgb4_regs *regs)
>>> +{
>>> +    iounmap(regs->membase);
>>> +    release_mem_region(regs->mapbase, regs->mapsize);
>>> +}
>>> diff --git a/drivers/media/pci/mgb4/mgb4_regs.h b/drivers/media/pci/mgb4/mgb4_regs.h
>>> new file mode 100644
>>> index 000000000000..c45180890730
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_regs.h
>>> @@ -0,0 +1,35 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#ifndef __MGB4_REGS_H__
>>> +#define __MGB4_REGS_H__
>>> +
>>> +#include <linux/io.h>
>>> +
>>> +struct mgb4_regs {
>>> +    resource_size_t mapbase;
>>> +    resource_size_t mapsize;
>>> +    void __iomem *membase;
>>> +};
>>> +
>>> +#define mgb4_write_reg(regs, offset, val) \
>>> +    iowrite32(val, (regs)->membase + (offset))
>>> +#define  mgb4_read_reg(regs, offset) \
>>> +    ioread32((regs)->membase + (offset))
>>> +
>>> +static inline void mgb4_mask_reg(struct mgb4_regs *regs, u32 reg, u32 mask,
>>> +                 u32 val)
>>> +{
>>> +    u32 ret = mgb4_read_reg(regs, reg);
>>> +
>>> +    val |= ret & ~mask;
>>> +    mgb4_write_reg(regs, reg, val);
>>> +}
>>> +
>>> +int mgb4_regs_map(struct resource *res, struct mgb4_regs *regs);
>>> +void mgb4_regs_free(struct mgb4_regs *regs);
>>> +
>>> +#endif
>>> diff --git a/drivers/media/pci/mgb4/mgb4_sysfs.h b/drivers/media/pci/mgb4/mgb4_sysfs.h
>>> new file mode 100644
>>> index 000000000000..2b42a8ba37f7
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_sysfs.h
>>> @@ -0,0 +1,18 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#ifndef __MGB4_SYSFS_H__
>>> +#define __MGB4_SYSFS_H__
>>> +
>>> +#include <linux/sysfs.h>
>>> +
>>> +extern struct device_attribute *mgb4_pci_attrs[];
>>> +extern struct device_attribute *mgb4_fpdl3_in_attrs[];
>>> +extern struct device_attribute *mgb4_gmsl_in_attrs[];
>>> +extern struct device_attribute *mgb4_fpdl3_out_attrs[];
>>> +extern struct device_attribute *mgb4_gmsl_out_attrs[];
>>> +
>>> +#endif
>>> diff --git a/drivers/media/pci/mgb4/mgb4_sysfs_in.c b/drivers/media/pci/mgb4/mgb4_sysfs_in.c
>>> new file mode 100644
>>> index 000000000000..f8aedf33507c
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_sysfs_in.c
>>> @@ -0,0 +1,780 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * This module handles all the sysfs info/configuration that is related to the
>>> + * v4l2 input devices.
>>> + */
>>> +
>>> +#include <linux/device.h>
>>> +#include "mgb4_core.h"
>>> +#include "mgb4_i2c.h"
>>> +#include "mgb4_vin.h"
>>> +#include "mgb4_cmt.h"
>>> +#include "mgb4_sysfs.h"
>>> +
>>> +/* Common for both FPDL3 and GMSL */
>>> +
>>> +static ssize_t read_input_id(struct device *dev,
>>> +                 struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +
>>> +    return sprintf(buf, "%d\n", vindev->config->id);
>>> +}
>>> +
>>> +static ssize_t read_oldi_lane_width(struct device *dev,
>>> +                    struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u16 i2c_reg;
>>> +    u8 i2c_mask, i2c_single_val, i2c_dual_val;
>>> +    u32 config;
>>> +    int ret;
>>> +
>>> +    i2c_reg = MGB4_IS_GMSL(vindev->mgbdev) ? 0x1CE : 0x49;
>>> +    i2c_mask = MGB4_IS_GMSL(vindev->mgbdev) ? 0x0E : 0x03;
>>> +    i2c_single_val = MGB4_IS_GMSL(vindev->mgbdev) ? 0x00 : 0x02;
>>> +    i2c_dual_val = MGB4_IS_GMSL(vindev->mgbdev) ? 0x0E : 0x00;
>>> +
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_read_byte(&vindev->deser, i2c_reg);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    config = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.config);
>>> +
>>> +    if (((config & (1U << 9)) && ((ret & i2c_mask) != i2c_dual_val)) ||
>>> +        (!(config & (1U << 9)) && ((ret & i2c_mask) != i2c_single_val))) {
>>> +        dev_err(dev, "I2C/FPGA register value mismatch\n");
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    return sprintf(buf, "%s\n", config & (1U << 9) ? "1" : "0");
>>> +}
>>> +
>>> +static ssize_t write_oldi_lane_width(struct device *dev,
>>> +                     struct device_attribute *attr,
>>> +                     const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 fpga_data;
>>> +    u16 i2c_reg;
>>> +    u8 i2c_mask, i2c_data;
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    switch (val) {
>>> +    case 0: /* single */
>>> +        fpga_data = 0;
>>> +        i2c_data = MGB4_IS_GMSL(vindev->mgbdev) ? 0x00 : 0x02;
>>> +        break;
>>> +    case 1: /* dual */
>>> +        fpga_data = 1U << 9;
>>> +        i2c_data = MGB4_IS_GMSL(vindev->mgbdev) ? 0x0E : 0x00;
>>> +        break;
>>> +    default:
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    i2c_reg = MGB4_IS_GMSL(vindev->mgbdev) ? 0x1CE : 0x49;
>>> +    i2c_mask = MGB4_IS_GMSL(vindev->mgbdev) ? 0x0E : 0x03;
>>> +
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_mask_byte(&vindev->deser, i2c_reg, i2c_mask, i2c_data);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +    mgb4_mask_reg(&vindev->mgbdev->video, vindev->config->regs.config,
>>> +              1U << 9, fpga_data);
>>> +    if (MGB4_IS_GMSL(vindev->mgbdev)) {
>>> +        /* reset input link */
>>> +        mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +        ret = mgb4_i2c_mask_byte(&vindev->deser, 0x10, 1U << 5, 1U << 5);
>>> +        mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +        if (ret < 0)
>>> +            return -EIO;
>>> +    }
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_color_mapping(struct device *dev,
>>> +                  struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 config = mgb4_read_reg(&vindev->mgbdev->video,
>>> +      vindev->config->regs.config);
>>> +
>>> +    return sprintf(buf, "%s\n", config & (1U << 8) ? "0" : "1");
>>> +}
>>> +
>>> +static ssize_t write_color_mapping(struct device *dev,
>>> +                   struct device_attribute *attr,
>>> +                   const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 fpga_data;
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    switch (val) {
>>> +    case 0: /* OLDI/JEIDA */
>>> +        fpga_data = (1U << 8);
>>> +        break;
>>> +    case 1: /* SPWG/VESA */
>>> +        fpga_data = 0;
>>> +        break;
>>> +    default:
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    mgb4_mask_reg(&vindev->mgbdev->video, vindev->config->regs.config,
>>> +              1U << 8, fpga_data);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_link_status(struct device *dev, struct device_attribute *attr,
>>> +                char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 status = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.status);
>>> +
>>> +    return sprintf(buf, "%s\n", status & (1U << 2) ? "1" : "0");
>>> +}
>>> +
>>> +static ssize_t read_stream_status(struct device *dev, struct device_attribute *attr,
>>> +                  char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 status = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.status);
>>> +
>>> +    return sprintf(buf, "%s\n", ((status & (1 << 14)) &&
>>> +               (status & (1 << 2)) && (status & (3 << 9))) ? "1" : "0");
>>> +}
>>> +
>>> +static ssize_t read_video_width(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 config = mgb4_read_reg(&vindev->mgbdev->video,
>>> +      vindev->config->regs.resolution);
>>> +
>>> +    return sprintf(buf, "%u\n", config >> 16);
>>> +}
>>> +
>>> +static ssize_t read_video_height(struct device *dev,
>>> +                 struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 config = mgb4_read_reg(&vindev->mgbdev->video,
>>> +      vindev->config->regs.resolution);
>>> +
>>> +    return sprintf(buf, "%u\n", config & 0xFFFF);
>>> +}
>>> +
>>> +static ssize_t read_hsync_status(struct device *dev, struct device_attribute *attr,
>>> +                 char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 status = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.status);
>>> +    u32 res;
>>> +
>>> +    if (!(status & (1U << 11)))
>>> +        res = 0x02; // not available
>>> +    else if (status & (1U << 12))
>>> +        res = 0x01; // active high
>>> +    else
>>> +        res = 0x00; // active low
>>> +
>>> +    return sprintf(buf, "%u\n", res);
>>> +}
>>> +
>>> +static ssize_t read_vsync_status(struct device *dev, struct device_attribute *attr,
>>> +                 char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 status = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.status);
>>> +    u32 res;
>>> +
>>> +    if (!(status & (1U << 11)))
>>> +        res = 0x02; // not available
>>> +    else if (status & (1U << 13))
>>> +        res = 0x01; // active high
>>> +    else
>>> +        res = 0x00; // active low
>>> +
>>> +    return sprintf(buf, "%u\n", res);
>>> +}
>>> +
>>> +static ssize_t read_hsync_gap(struct device *dev, struct device_attribute *attr,
>>> +                  char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 sync = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.sync);
>>> +
>>> +    return sprintf(buf, "%u\n", sync >> 16);
>>> +}
>>> +
>>> +static ssize_t write_hsync_gap(struct device *dev,
>>> +                   struct device_attribute *attr, const char *buf,
>>> +                   size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFFFF)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&vindev->mgbdev->video, vindev->config->regs.sync,
>>> +              0xFFFF0000, val << 16);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_vsync_gap(struct device *dev, struct device_attribute *attr,
>>> +                  char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 sync = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.sync);
>>> +
>>> +    return sprintf(buf, "%u\n", sync & 0xFFFF);
>>> +}
>>> +
>>> +static ssize_t write_vsync_gap(struct device *dev,
>>> +                   struct device_attribute *attr, const char *buf,
>>> +                   size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFFFF)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&vindev->mgbdev->video, vindev->config->regs.sync, 0xFFFF, val);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_pclk_frequency(struct device *dev,
>>> +                   struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 freq = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.pclk);
>>> +
>>> +    return sprintf(buf, "%u\n", freq);
>>> +}
>>> +
>>> +static ssize_t read_hsync_width(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.signal);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x00FF0000) >> 16);
>>> +}
>>> +
>>> +static ssize_t read_vsync_width(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.signal2);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x00FF0000) >> 16);
>>> +}
>>> +
>>> +static ssize_t read_hback_porch(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.signal);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x0000FF00) >> 8);
>>> +}
>>> +
>>> +static ssize_t read_hfront_porch(struct device *dev,
>>> +                 struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.signal);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x000000FF));
>>> +}
>>> +
>>> +static ssize_t read_vback_porch(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.signal2);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x0000FF00) >> 8);
>>> +}
>>> +
>>> +static ssize_t read_vfront_porch(struct device *dev,
>>> +                 struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.signal2);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x000000FF));
>>> +}
>>> +
>>> +static ssize_t read_frequency_range(struct device *dev,
>>> +                    struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +
>>> +    return sprintf(buf, "%d\n", vindev->freq_range);
>>> +}
>>> +
>>> +static ssize_t write_frequency_range(struct device *dev,
>>> +                     struct device_attribute *attr,
>>> +                     const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    unsigned long val, flags;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 1)
>>> +        return -EINVAL;
>>> +
>>> +    spin_lock_irqsave(&vindev->vdev.fh_lock, flags);
>>> +    if (!list_empty(&vindev->vdev.fh_list)) {
>>> +        spin_unlock_irqrestore(&vindev->vdev.fh_lock, flags);
>>> +        return -EBUSY;
>>> +    }
>>> +
>>> +    mgb4_cmt_set_vin(vindev, val);
>>> +    vindev->freq_range = val;
>>> +
>>> +    spin_unlock_irqrestore(&vindev->vdev.fh_lock, flags);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_alignment(struct device *dev,
>>> +                  struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +
>>> +    return sprintf(buf, "%d\n", vindev->alignment);
>>> +}
>>> +
>>> +static ssize_t write_alignment(struct device *dev,
>>> +                   struct device_attribute *attr, const char *buf,
>>> +                   size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    unsigned long val, flags;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (!val || (val & (val - 1)))
>>> +        return -EINVAL;
>>> +
>>> +    spin_lock_irqsave(&vindev->vdev.fh_lock, flags);
>>> +    if (!list_empty(&vindev->vdev.fh_list)) {
>>> +        spin_unlock_irqrestore(&vindev->vdev.fh_lock, flags);
>>> +        return -EBUSY;
>>> +    }
>>> +
>>> +    vindev->alignment = val;
>>> +
>>> +    spin_unlock_irqrestore(&vindev->vdev.fh_lock, flags);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +/* FPDL3 only */
>>> +
>>> +static ssize_t read_fpdl3_input_width(struct device *dev,
>>> +                      struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    s32 ret;
>>> +
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_read_byte(&vindev->deser, 0x34);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    switch ((u8)ret & 0x18) {
>>> +    case 0:
>>> +        return sprintf(buf, "0\n");
>>> +    case 0x10:
>>> +        return sprintf(buf, "1\n");
>>> +    case 0x08:
>>> +        return sprintf(buf, "2\n");
>>> +    default:
>>> +        return -EINVAL;
>>> +    }
>>> +}
>>> +
>>> +static ssize_t write_fpdl3_input_width(struct device *dev,
>>> +                       struct device_attribute *attr,
>>> +                       const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    u8 i2c_data;
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    switch (val) {
>>> +    case 0: /* auto */
>>> +        i2c_data = 0x00;
>>> +        break;
>>> +    case 1: /* single */
>>> +        i2c_data = 0x10;
>>> +        break;
>>> +    case 2: /* dual */
>>> +        i2c_data = 0x08;
>>> +        break;
>>> +    default:
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_mask_byte(&vindev->deser, 0x34, 0x18, i2c_data);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +/* GMSL only */
>>> +
>>> +static ssize_t read_gmsl_mode(struct device *dev,
>>> +                  struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    s32 r1, r300, r3;
>>> +
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    r1 = mgb4_i2c_read_byte(&vindev->deser, 0x01);
>>> +    r300 = mgb4_i2c_read_byte(&vindev->deser, 0x300);
>>> +    r3 = mgb4_i2c_read_byte(&vindev->deser, 0x03);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (r1 < 0 || r300 < 0 || r3 < 0)
>>> +        return -EIO;
>>> +
>>> +    if ((r1 & 0x03) == 0x03 && (r300 & 0x0C) == 0x0C && (r3 & 0xC0) == 0xC0)
>>> +        return sprintf(buf, "0\n");
>>> +    else if ((r1 & 0x03) == 0x02 && (r300 & 0x0C) == 0x08 && (r3 & 0xC0) == 0x00)
>>> +        return sprintf(buf, "1\n");
>>> +    else if ((r1 & 0x03) == 0x01 && (r300 & 0x0C) == 0x04 && (r3 & 0xC0) == 0x00)
>>> +        return sprintf(buf, "2\n");
>>> +    else if ((r1 & 0x03) == 0x00 && (r300 & 0x0C) == 0x00 && (r3 & 0xC0) == 0x00)
>>> +        return sprintf(buf, "3\n");
>>> +    else
>>> +        return -EINVAL;
>>> +}
>>> +
>>> +static ssize_t write_gmsl_mode(struct device *dev,
>>> +                   struct device_attribute *attr, const char *buf,
>>> +                   size_t count)
>>> +{
>>> +    static const struct mgb4_i2c_kv G12[] = {
>>> +        {0x01, 0x03, 0x03}, {0x300, 0x0C, 0x0C}, {0x03, 0xC0, 0xC0}};
>>> +    static const struct mgb4_i2c_kv G6[] = {
>>> +        {0x01, 0x03, 0x02}, {0x300, 0x0C, 0x08}, {0x03, 0xC0, 0x00}};
>>> +    static const struct mgb4_i2c_kv G3[] = {
>>> +        {0x01, 0x03, 0x01}, {0x300, 0x0C, 0x04}, {0x03, 0xC0, 0x00}};
>>> +    static const struct mgb4_i2c_kv G1[] = {
>>> +        {0x01, 0x03, 0x00}, {0x300, 0x0C, 0x00}, {0x03, 0xC0, 0x00}};
>>> +    static const struct mgb4_i2c_kv reset[] = {
>>> +        {0x10, 1U << 5, 1U << 5}, {0x300, 1U << 6, 1U << 6}};
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    const struct mgb4_i2c_kv *values;
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    switch (val) {
>>> +    case 0: /* 12Gb/s */
>>> +        values = G12;
>>> +        break;
>>> +    case 1: /* 6Gb/s */
>>> +        values = G6;
>>> +        break;
>>> +    case 2: /* 3Gb/s */
>>> +        values = G3;
>>> +        break;
>>> +    case 3: /* 1.5Gb/s */
>>> +        values = G1;
>>> +        break;
>>> +    default:
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_configure(&vindev->deser, values, 3);
>>> +    ret |= mgb4_i2c_configure(&vindev->deser, reset, 2);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_gmsl_stream_id(struct device *dev,
>>> +                   struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    s32 ret;
>>> +
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_read_byte(&vindev->deser, 0xA0);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    return sprintf(buf, "%d\n", ret & 0x03);
>>> +}
>>> +
>>> +static ssize_t write_gmsl_stream_id(struct device *dev,
>>> +                    struct device_attribute *attr,
>>> +                    const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    unsigned long val, flags;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 3)
>>> +        return -EINVAL;
>>> +
>>> +    spin_lock_irqsave(&vindev->vdev.fh_lock, flags);
>>> +    ret = list_empty(&vindev->vdev.fh_list);
>>> +    spin_unlock_irqrestore(&vindev->vdev.fh_lock, flags);
>>> +    if (!ret)
>>> +        return -EBUSY;
>>> +
>>> +    /* Formaly, there is a race condition here as the change should be formaly
>>> +     * done under the spinlock, but we only want to prevent a resolution change
>>> +     * where possible. However, resolution changes can happen anyway and the
>>> +     * driver can handle them (they only break the image, not the system).
>>> +     *
>>> +     * So instead of trying to workaround the spinlock - mgb4_i2c_mask_byte()
>>> +     * does sleep - we simply let the rare race condition happen...
>>> +     */
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_mask_byte(&vindev->deser, 0xA0, 0x03, (u8)val);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_gmsl_fec(struct device *dev, struct device_attribute *attr,
>>> +                 char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    s32 r3e0, r308;
>>> +
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    r3e0 = mgb4_i2c_read_byte(&vindev->deser, 0x3E0);
>>> +    r308 = mgb4_i2c_read_byte(&vindev->deser, 0x308);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (r3e0 < 0 || r308 < 0)
>>> +        return -EIO;
>>> +
>>> +    if ((r3e0 & 0x07) == 0x00 && (r308 & 0x01) == 0x00)
>>> +        return sprintf(buf, "0\n");
>>> +    else if ((r3e0 & 0x07) == 0x07 && (r308 & 0x01) == 0x01)
>>> +        return sprintf(buf, "1\n");
>>> +    else
>>> +        return -EINVAL;
>>> +}
>>> +
>>> +static ssize_t write_gmsl_fec(struct device *dev, struct device_attribute *attr,
>>> +                  const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vin_dev *vindev = video_get_drvdata(vdev);
>>> +    static const struct mgb4_i2c_kv enable[] = {
>>> +        {0x3E0, 0x07, 0x07}, {0x308, 0x01, 0x01}};
>>> +    static const struct mgb4_i2c_kv disable[] = {
>>> +        {0x3E0, 0x07, 0x00}, {0x308, 0x01, 0x00}};
>>> +    static const struct mgb4_i2c_kv reset[] = {
>>> +        {0x10, 1U << 5, 1U << 5}, {0x300, 1U << 6, 1U << 6}};
>>> +    const struct mgb4_i2c_kv *values;
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    switch (val) {
>>> +    case 0: /* disabled */
>>> +        values = disable;
>>> +        break;
>>> +    case 1: /* enabled */
>>> +        values = enable;
>>> +        break;
>>> +    default:
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    mutex_lock(&vindev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_configure(&vindev->deser, values, 2);
>>> +    ret |= mgb4_i2c_configure(&vindev->deser, reset, 2);
>>> +    mutex_unlock(&vindev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static DEVICE_ATTR(input_id, 0444, read_input_id, NULL);
>>> +static DEVICE_ATTR(oldi_lane_width, 0644, read_oldi_lane_width,
>>> +           write_oldi_lane_width);
>>> +static DEVICE_ATTR(color_mapping, 0644, read_color_mapping,
>>> +           write_color_mapping);
>>> +static DEVICE_ATTR(link_status, 0444, read_link_status, NULL);
>>> +static DEVICE_ATTR(stream_status, 0444, read_stream_status, NULL);
>>> +static DEVICE_ATTR(video_width, 0444, read_video_width, NULL);
>>> +static DEVICE_ATTR(video_height, 0444, read_video_height, NULL);
>>> +static DEVICE_ATTR(hsync_status, 0444, read_hsync_status, NULL);
>>> +static DEVICE_ATTR(vsync_status, 0444, read_vsync_status, NULL);
>>> +static DEVICE_ATTR(hsync_gap_length, 0644, read_hsync_gap, write_hsync_gap);
>>> +static DEVICE_ATTR(vsync_gap_length, 0644, read_vsync_gap, write_vsync_gap);
>>> +static DEVICE_ATTR(pclk_frequency, 0444, read_pclk_frequency, NULL);
>>> +static DEVICE_ATTR(hsync_width, 0444, read_hsync_width, NULL);
>>> +static DEVICE_ATTR(vsync_width, 0444, read_vsync_width, NULL);
>>> +static DEVICE_ATTR(hback_porch, 0444, read_hback_porch, NULL);
>>> +static DEVICE_ATTR(hfront_porch, 0444, read_hfront_porch, NULL);
>>> +static DEVICE_ATTR(vback_porch, 0444, read_vback_porch, NULL);
>>> +static DEVICE_ATTR(vfront_porch, 0444, read_vfront_porch, NULL);
>>> +static DEVICE_ATTR(frequency_range, 0644, read_frequency_range,
>>> +           write_frequency_range);
>>> +static DEVICE_ATTR(alignment, 0644, read_alignment, write_alignment);
>>> +
>>> +static DEVICE_ATTR(fpdl3_input_width, 0644, read_fpdl3_input_width,
>>> +           write_fpdl3_input_width);
>>> +
>>> +static DEVICE_ATTR(gmsl_mode, 0644, read_gmsl_mode, write_gmsl_mode);
>>> +static DEVICE_ATTR(gmsl_stream_id, 0644, read_gmsl_stream_id,
>>> +           write_gmsl_stream_id);
>>> +static DEVICE_ATTR(gmsl_fec, 0644, read_gmsl_fec, write_gmsl_fec);
>>> +
>>> +struct device_attribute *mgb4_fpdl3_in_attrs[] = {
>>> +    &dev_attr_input_id,
>>> +    &dev_attr_link_status,
>>> +    &dev_attr_stream_status,
>>> +    &dev_attr_video_width,
>>> +    &dev_attr_video_height,
>>> +    &dev_attr_hsync_status,
>>> +    &dev_attr_vsync_status,
>>> +    &dev_attr_oldi_lane_width,
>>> +    &dev_attr_color_mapping,
>>> +    &dev_attr_hsync_gap_length,
>>> +    &dev_attr_vsync_gap_length,
>>> +    &dev_attr_pclk_frequency,
>>> +    &dev_attr_hsync_width,
>>> +    &dev_attr_vsync_width,
>>> +    &dev_attr_hback_porch,
>>> +    &dev_attr_hfront_porch,
>>> +    &dev_attr_vback_porch,
>>> +    &dev_attr_vfront_porch,
>>> +    &dev_attr_frequency_range,
>>> +    &dev_attr_alignment,
>>> +    &dev_attr_fpdl3_input_width,
>>> +    NULL
>>> +};
>>> +
>>> +struct device_attribute *mgb4_gmsl_in_attrs[] = {
>>> +    &dev_attr_input_id,
>>> +    &dev_attr_link_status,
>>> +    &dev_attr_stream_status,
>>> +    &dev_attr_video_width,
>>> +    &dev_attr_video_height,
>>> +    &dev_attr_hsync_status,
>>> +    &dev_attr_vsync_status,
>>> +    &dev_attr_oldi_lane_width,
>>> +    &dev_attr_color_mapping,
>>> +    &dev_attr_hsync_gap_length,
>>> +    &dev_attr_vsync_gap_length,
>>> +    &dev_attr_pclk_frequency,
>>> +    &dev_attr_hsync_width,
>>> +    &dev_attr_vsync_width,
>>> +    &dev_attr_hback_porch,
>>> +    &dev_attr_hfront_porch,
>>> +    &dev_attr_vback_porch,
>>> +    &dev_attr_vfront_porch,
>>> +    &dev_attr_frequency_range,
>>> +    &dev_attr_alignment,
>>> +    &dev_attr_gmsl_mode,
>>> +    &dev_attr_gmsl_stream_id,
>>> +    &dev_attr_gmsl_fec,
>>> +    NULL
>>> +};
>>> diff --git a/drivers/media/pci/mgb4/mgb4_sysfs_out.c b/drivers/media/pci/mgb4/mgb4_sysfs_out.c
>>> new file mode 100644
>>> index 000000000000..c75599bc6372
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_sysfs_out.c
>>> @@ -0,0 +1,732 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * This module handles all the sysfs info/configuration that is related to the
>>> + * v4l2 output devices.
>>> + */
>>> +
>>> +#include <linux/device.h>
>>> +#include "mgb4_core.h"
>>> +#include "mgb4_i2c.h"
>>> +#include "mgb4_vout.h"
>>> +#include "mgb4_vin.h"
>>> +#include "mgb4_cmt.h"
>>> +#include "mgb4_sysfs.h"
>>> +
>>> +static int loopin_cnt(struct mgb4_vin_dev *vindev)
>>> +{
>>> +    struct mgb4_vout_dev *voutdev;
>>> +    u32 config;
>>> +    int i, cnt = 0;
>>> +
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++) {
>>> +        voutdev = vindev->mgbdev->vout[i];
>>> +        if (!voutdev)
>>> +            continue;
>>> +
>>> +        config = mgb4_read_reg(&voutdev->mgbdev->video,
>>> +                       voutdev->config->regs.config);
>>> +        if ((config & 0xc) >> 2 == vindev->config->id)
>>> +            cnt++;
>>> +    }
>>> +
>>> +    return cnt;
>>> +}
>>> +
>>> +/* Common for both FPDL3 and GMSL */
>>> +
>>> +static ssize_t read_output_id(struct device *dev,
>>> +                  struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +
>>> +    return sprintf(buf, "%d\n", voutdev->config->id);
>>> +}
>>> +
>>> +static ssize_t read_video_source(struct device *dev,
>>> +                 struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 config = mgb4_read_reg(&voutdev->mgbdev->video,
>>> +      voutdev->config->regs.config);
>>> +
>>> +    return sprintf(buf, "%u\n", (config & 0xc) >> 2);
>>> +}
>>> +
>>> +static ssize_t write_video_source(struct device *dev,
>>> +                  struct device_attribute *attr,
>>> +                  const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    struct mgb4_dev *mgbdev = voutdev->mgbdev;
>>> +    struct mgb4_vin_dev *loopin_new = 0, *loopin_old = 0;
>>> +    unsigned long val;
>>> +    unsigned long flags_in[MGB4_VIN_DEVICES], flags_out[MGB4_VOUT_DEVICES];
>>> +    ssize_t ret;
>>> +    u32 config;
>>> +    int i;
>>> +
>>> +    memset(flags_in, 0, sizeof(flags_in));
>>> +    memset(flags_out, 0, sizeof(flags_out));
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 3)
>>> +        return -EINVAL;
>>> +
>>> +    for (i = 0; i < MGB4_VIN_DEVICES; i++)
>>> +        if (mgbdev->vin[i])
>>> +            spin_lock_irqsave(&mgbdev->vin[i]->vdev.fh_lock, flags_in[i]);
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++)
>>> +        if (mgbdev->vout[i])
>>> +            spin_lock_irqsave(&mgbdev->vout[i]->vdev.fh_lock, flags_out[i]);
>>> +
>>> +    ret = -EBUSY;
>>> +    for (i = 0; i < MGB4_VIN_DEVICES; i++)
>>> +        if (mgbdev->vin[i] && !list_empty(&mgbdev->vin[i]->vdev.fh_list))
>>> +            goto error;
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++)
>>> +        if (mgbdev->vout[i] && !list_empty(&mgbdev->vout[i]->vdev.fh_list))
>>> +            goto error;
>>> +
>>> +    config = mgb4_read_reg(&mgbdev->video, voutdev->config->regs.config);
>>> +
>>> +    if (((config & 0xc) >> 2) < MGB4_VIN_DEVICES)
>>> +        loopin_old = mgbdev->vin[(config & 0xc) >> 2];
>>> +    if (val < MGB4_VIN_DEVICES)
>>> +        loopin_new = mgbdev->vin[val];
>>> +    if (loopin_old && loopin_cnt(loopin_old) == 1)
>>> +        mgb4_mask_reg(&mgbdev->video, loopin_old->config->regs.config, 0x2, 0x0);
>>> +    if (loopin_new)
>>> +        mgb4_mask_reg(&mgbdev->video, loopin_new->config->regs.config, 0x2, 0x2);
>>> +
>>> +    if (val == voutdev->config->id + MGB4_VIN_DEVICES)
>>> +        mgb4_write_reg(&mgbdev->video, voutdev->config->regs.config,
>>> +                   config & ~(1 << 1));
>>> +    else
>>> +        mgb4_write_reg(&mgbdev->video, voutdev->config->regs.config,
>>> +                   config | (1U << 1));
>>> +
>>> +    mgb4_mask_reg(&mgbdev->video, voutdev->config->regs.config, 0xc, val << 2);
>>> +
>>> +    ret = count;
>>> +
>>> +error:
>>> +    for (i = MGB4_VOUT_DEVICES - 1; i >= 0; i--)
>>> +        if (mgbdev->vout[i])
>>> +            spin_unlock_irqrestore(&mgbdev->vout[i]->vdev.fh_lock, flags_out[i]);
>>> +    for (i = MGB4_VIN_DEVICES - 1; i >= 0; i--)
>>> +        if (mgbdev->vin[i])
>>> +            spin_unlock_irqrestore(&mgbdev->vin[i]->vdev.fh_lock, flags_in[i]);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static ssize_t read_display_width(struct device *dev,
>>> +                  struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 config = mgb4_read_reg(&voutdev->mgbdev->video,
>>> +      voutdev->config->regs.resolution);
>>> +
>>> +    return sprintf(buf, "%u\n", config >> 16);
>>> +}
>>> +
>>> +static ssize_t write_display_width(struct device *dev,
>>> +                   struct device_attribute *attr,
>>> +                   const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val, flags;
>>> +    int ret, busy;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFFFF)
>>> +        return -EINVAL;
>>> +
>>> +    spin_lock_irqsave(&voutdev->vdev.fh_lock, flags);
>>> +    busy = !list_empty(&voutdev->vdev.fh_list);
>>> +    if (busy) {
>>> +        spin_unlock_irqrestore(&voutdev->vdev.fh_lock, flags);
>>> +        return -EBUSY;
>>> +    }
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.resolution,
>>> +              0xFFFF0000, val << 16);
>>> +
>>> +    spin_unlock_irqrestore(&voutdev->vdev.fh_lock, flags);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_display_height(struct device *dev,
>>> +                   struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 config = mgb4_read_reg(&voutdev->mgbdev->video,
>>> +      voutdev->config->regs.resolution);
>>> +
>>> +    return sprintf(buf, "%u\n", config & 0xFFFF);
>>> +}
>>> +
>>> +static ssize_t write_display_height(struct device *dev,
>>> +                    struct device_attribute *attr,
>>> +                    const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val, flags;
>>> +    int ret, busy;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFFFF)
>>> +        return -EINVAL;
>>> +
>>> +    spin_lock_irqsave(&voutdev->vdev.fh_lock, flags);
>>> +    busy = !list_empty(&voutdev->vdev.fh_list);
>>> +    if (busy) {
>>> +        spin_unlock_irqrestore(&voutdev->vdev.fh_lock, flags);
>>> +        return -EBUSY;
>>> +    }
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.resolution,
>>> +              0xFFFF, val);
>>> +
>>> +    spin_unlock_irqrestore(&voutdev->vdev.fh_lock, flags);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_frame_rate(struct device *dev,
>>> +                   struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 period = mgb4_read_reg(&voutdev->mgbdev->video,
>>> +                   voutdev->config->regs.frame_period);
>>> +
>>> +    return sprintf(buf, "%u\n", 125000000 / period);
>>> +}
>>> +
>>> +static ssize_t write_frame_rate(struct device *dev,
>>> +                struct device_attribute *attr, const char *buf,
>>> +                size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    mgb4_write_reg(&voutdev->mgbdev->video, voutdev->config->regs.frame_period,
>>> +               125000000 / val);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_hsync_width(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.hsync);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x00FF0000) >> 16);
>>> +}
>>> +
>>> +static ssize_t write_hsync_width(struct device *dev,
>>> +                 struct device_attribute *attr, const char *buf,
>>> +                 size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFF)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.hsync,
>>> +              0x00FF0000, val << 16);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_vsync_width(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.vsync);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x00FF0000) >> 16);
>>> +}
>>> +
>>> +static ssize_t write_vsync_width(struct device *dev,
>>> +                 struct device_attribute *attr, const char *buf,
>>> +                 size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFF)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.vsync,
>>> +              0x00FF0000, val << 16);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_hback_porch(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.hsync);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x0000FF00) >> 8);
>>> +}
>>> +
>>> +static ssize_t write_hback_porch(struct device *dev,
>>> +                 struct device_attribute *attr, const char *buf,
>>> +                 size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFF)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.hsync,
>>> +              0x0000FF00, val << 8);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_vback_porch(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.vsync);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x0000FF00) >> 8);
>>> +}
>>> +
>>> +static ssize_t write_vback_porch(struct device *dev,
>>> +                 struct device_attribute *attr, const char *buf,
>>> +                 size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFF)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.vsync,
>>> +              0x0000FF00, val << 8);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_hfront_porch(struct device *dev,
>>> +                 struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.hsync);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x000000FF));
>>> +}
>>> +
>>> +static ssize_t write_hfront_porch(struct device *dev,
>>> +                  struct device_attribute *attr,
>>> +                  const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFF)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.hsync,
>>> +              0x000000FF, val);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_vfront_porch(struct device *dev,
>>> +                 struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 sig = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.vsync);
>>> +
>>> +    return sprintf(buf, "%u\n", (sig & 0x000000FF));
>>> +}
>>> +
>>> +static ssize_t write_vfront_porch(struct device *dev,
>>> +                  struct device_attribute *attr, const char *buf,
>>> +                  size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 0xFF)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.vsync,
>>> +              0x000000FF, val);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_alignment(struct device *dev,
>>> +                  struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +
>>> +    return sprintf(buf, "%d\n", voutdev->alignment);
>>> +}
>>> +
>>> +static ssize_t write_alignment(struct device *dev, struct device_attribute *attr,
>>> +                   const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val, flags;
>>> +    u32 config;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (!val || (val & (val - 1)))
>>> +        return -EINVAL;
>>> +
>>> +    spin_lock_irqsave(&voutdev->vdev.fh_lock, flags);
>>> +    if (!list_empty(&voutdev->vdev.fh_list)) {
>>> +        spin_unlock_irqrestore(&voutdev->vdev.fh_lock, flags);
>>> +        return -EBUSY;
>>> +    }
>>> +    /* Do not allow the change if loopback is active */
>>> +    config = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.config);
>>> +    if (((config & 0xc) >> 2) < 2) {
>>> +        spin_unlock_irqrestore(&voutdev->vdev.fh_lock, flags);
>>> +        return -EPERM;
>>> +    }
>>> +
>>> +    voutdev->alignment = val;
>>> +
>>> +    spin_unlock_irqrestore(&voutdev->vdev.fh_lock, flags);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +/* FPDL3 only */
>>> +
>>> +static ssize_t read_hsync_polarity(struct device *dev,
>>> +                   struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 config = mgb4_read_reg(&voutdev->mgbdev->video,
>>> +      voutdev->config->regs.hsync);
>>> +
>>> +    return sprintf(buf, "%u\n", (config & (1U << 31)) >> 31);
>>> +}
>>> +
>>> +static ssize_t write_hsync_polarity(struct device *dev,
>>> +                    struct device_attribute *attr,
>>> +                    const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 1)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.hsync,
>>> +              (1U << 31), val << 31);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_vsync_polarity(struct device *dev,
>>> +                   struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 config = mgb4_read_reg(&voutdev->mgbdev->video,
>>> +      voutdev->config->regs.vsync);
>>> +
>>> +    return sprintf(buf, "%u\n", (config & (1U << 31)) >> 31);
>>> +}
>>> +
>>> +static ssize_t write_vsync_polarity(struct device *dev,
>>> +                    struct device_attribute *attr,
>>> +                    const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 1)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.vsync,
>>> +              (1U << 31), val << 31);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_de_polarity(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u32 config = mgb4_read_reg(&voutdev->mgbdev->video,
>>> +      voutdev->config->regs.vsync);
>>> +
>>> +    return sprintf(buf, "%u\n", (config & (1U << 30)) >> 30);
>>> +}
>>> +
>>> +static ssize_t write_de_polarity(struct device *dev,
>>> +                 struct device_attribute *attr, const char *buf,
>>> +                 size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +    if (val > 1)
>>> +        return -EINVAL;
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.vsync,
>>> +              (1U << 30), val << 30);
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_fpdl3_output_width(struct device *dev,
>>> +                       struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    s32 ret;
>>> +
>>> +    mutex_lock(&voutdev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_read_byte(&voutdev->ser, 0x5B);
>>> +    mutex_unlock(&voutdev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    switch ((u8)ret & 0x03) {
>>> +    case 0:
>>> +        return sprintf(buf, "0\n");
>>> +    case 1:
>>> +        return sprintf(buf, "1\n");
>>> +    case 3:
>>> +        return sprintf(buf, "2\n");
>>> +    default:
>>> +        return -EINVAL;
>>> +    }
>>> +}
>>> +
>>> +static ssize_t write_fpdl3_output_width(struct device *dev,
>>> +                    struct device_attribute *attr,
>>> +                    const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    u8 i2c_data;
>>> +    unsigned long val;
>>> +    int ret;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    switch (val) {
>>> +    case 0: /* auto */
>>> +        i2c_data = 0x00;
>>> +        break;
>>> +    case 1: /* single */
>>> +        i2c_data = 0x01;
>>> +        break;
>>> +    case 2: /* dual */
>>> +        i2c_data = 0x03;
>>> +        break;
>>> +    default:
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    mutex_lock(&voutdev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_mask_byte(&voutdev->ser, 0x5B, 0x03, i2c_data);
>>> +    mutex_unlock(&voutdev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static ssize_t read_pclk_frequency(struct device *dev,
>>> +                   struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +
>>> +    return sprintf(buf, "%u\n", voutdev->freq);
>>> +}
>>> +
>>> +static ssize_t write_pclk_frequency(struct device *dev,
>>> +                    struct device_attribute *attr,
>>> +                    const char *buf, size_t count)
>>> +{
>>> +    struct video_device *vdev = to_video_device(dev);
>>> +    struct mgb4_vout_dev *voutdev = video_get_drvdata(vdev);
>>> +    unsigned long val, flags;
>>> +    int ret, busy;
>>> +    unsigned int dp;
>>> +
>>> +    ret = kstrtoul(buf, 10, &val);
>>> +    if (ret)
>>> +        return ret;
>>> +
>>> +    spin_lock_irqsave(&voutdev->vdev.fh_lock, flags);
>>> +    busy = !list_empty(&voutdev->vdev.fh_list);
>>> +    if (busy) {
>>> +        spin_unlock_irqrestore(&voutdev->vdev.fh_lock, flags);
>>> +        return -EBUSY;
>>> +    }
>>> +
>>> +    dp = (val > 50000) ? 1 : 0;
>>> +    voutdev->freq = mgb4_cmt_set_vout(voutdev, val >> dp) << dp;
>>> +
>>> +    spin_unlock_irqrestore(&voutdev->vdev.fh_lock, flags);
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.config,
>>> +              0x10, dp << 4);
>>> +    mutex_lock(&voutdev->mgbdev->i2c_lock);
>>> +    ret = mgb4_i2c_mask_byte(&voutdev->ser, 0x4F, 1 << 6, ((~dp) & 1) << 6);
>>> +    mutex_unlock(&voutdev->mgbdev->i2c_lock);
>>> +    if (ret < 0)
>>> +        return -EIO;
>>> +
>>> +    return count;
>>> +}
>>> +
>>> +static DEVICE_ATTR(output_id, 0444, read_output_id, NULL);
>>> +static DEVICE_ATTR(video_source, 0644, read_video_source, write_video_source);
>>> +static DEVICE_ATTR(display_width, 0644, read_display_width,
>>> +           write_display_width);
>>> +static DEVICE_ATTR(display_height, 0644, read_display_height,
>>> +           write_display_height);
>>> +static DEVICE_ATTR(frame_rate, 0644, read_frame_rate, write_frame_rate);
>>> +static DEVICE_ATTR(hsync_polarity, 0644, read_hsync_polarity,
>>> +           write_hsync_polarity);
>>> +static DEVICE_ATTR(vsync_polarity, 0644, read_vsync_polarity,
>>> +           write_vsync_polarity);
>>> +static DEVICE_ATTR(de_polarity, 0644, read_de_polarity,
>>> +           write_de_polarity);
>>> +static DEVICE_ATTR(pclk_frequency, 0644, read_pclk_frequency,
>>> +           write_pclk_frequency);
>>> +static DEVICE_ATTR(hsync_width, 0644, read_hsync_width, write_hsync_width);
>>> +static DEVICE_ATTR(vsync_width, 0644, read_vsync_width, write_vsync_width);
>>> +static DEVICE_ATTR(hback_porch, 0644, read_hback_porch, write_hback_porch);
>>> +static DEVICE_ATTR(hfront_porch, 0644, read_hfront_porch, write_hfront_porch);
>>> +static DEVICE_ATTR(vback_porch, 0644, read_vback_porch, write_vback_porch);
>>> +static DEVICE_ATTR(vfront_porch, 0644, read_vfront_porch, write_vfront_porch);
>>> +static DEVICE_ATTR(alignment, 0644, read_alignment, write_alignment);
>>> +
>>> +static DEVICE_ATTR(fpdl3_output_width, 0644, read_fpdl3_output_width,
>>> +           write_fpdl3_output_width);
>>> +
>>> +struct device_attribute *mgb4_fpdl3_out_attrs[] = {
>>> +    &dev_attr_output_id,
>>> +    &dev_attr_video_source,
>>> +    &dev_attr_display_width,
>>> +    &dev_attr_display_height,
>>> +    &dev_attr_frame_rate,
>>> +    &dev_attr_hsync_polarity,
>>> +    &dev_attr_vsync_polarity,
>>> +    &dev_attr_de_polarity,
>>> +    &dev_attr_pclk_frequency,
>>> +    &dev_attr_hsync_width,
>>> +    &dev_attr_vsync_width,
>>> +    &dev_attr_hback_porch,
>>> +    &dev_attr_hfront_porch,
>>> +    &dev_attr_vback_porch,
>>> +    &dev_attr_vfront_porch,
>>> +    &dev_attr_alignment,
>>> +    &dev_attr_fpdl3_output_width,
>>> +    NULL
>>> +};
>>> +
>>> +struct device_attribute *mgb4_gmsl_out_attrs[] = {
>>> +    &dev_attr_output_id,
>>> +    &dev_attr_video_source,
>>> +    &dev_attr_display_width,
>>> +    &dev_attr_display_height,
>>> +    &dev_attr_frame_rate,
>>> +    NULL
>>> +};
>>> diff --git a/drivers/media/pci/mgb4/mgb4_sysfs_pci.c b/drivers/media/pci/mgb4/mgb4_sysfs_pci.c
>>> new file mode 100644
>>> index 000000000000..6f729af488dd
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_sysfs_pci.c
>>> @@ -0,0 +1,86 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * This module handles all the sysfs info/configuration that is related to the
>>> + * PCI card device.
>>> + */
>>> +
>>> +#include <linux/device.h>
>>> +#include "mgb4_core.h"
>>> +#include "mgb4_sysfs.h"
>>> +
>>> +static ssize_t read_module_version(struct device *dev,
>>> +                   struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct mgb4_dev *mgbdev = dev_get_drvdata(dev);
>>> +
>>> +    return sprintf(buf, "%u\n", mgbdev->module_version & 0x0F);
>>> +}
>>> +
>>> +static ssize_t read_module_type(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct mgb4_dev *mgbdev = dev_get_drvdata(dev);
>>> +
>>> +    return sprintf(buf, "%u\n", mgbdev->module_version >> 4);
>>> +}
>>> +
>>> +static ssize_t read_fw_version(struct device *dev,
>>> +                   struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct mgb4_dev *mgbdev = dev_get_drvdata(dev);
>>> +    u32 config = mgb4_read_reg(&mgbdev->video, 0xC4);
>>> +
>>> +    return sprintf(buf, "%u\n", config & 0xFFFF);
>>> +}
>>> +
>>> +static ssize_t read_fw_type(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct mgb4_dev *mgbdev = dev_get_drvdata(dev);
>>> +    u32 config = mgb4_read_reg(&mgbdev->video, 0xC4);
>>> +
>>> +    return sprintf(buf, "%u\n", config >> 24);
>>> +}
>>> +
>>> +static ssize_t read_serial_number(struct device *dev,
>>> +                  struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct mgb4_dev *mgbdev = dev_get_drvdata(dev);
>>> +    u32 sn = mgbdev->serial_number;
>>> +
>>> +    return sprintf(buf, "%03d-%03d-%03d-%03d\n", sn >> 24, (sn >> 16) & 0xFF,
>>> +      (sn >> 8) & 0xFF, sn & 0xFF);
>>> +}
>>> +
>>> +static ssize_t read_temperature(struct device *dev,
>>> +                struct device_attribute *attr, char *buf)
>>> +{
>>> +    struct mgb4_dev *mgbdev = dev_get_drvdata(dev);
>>> +    u32 val10, val;
>>> +
>>> +    val  = mgb4_read_reg(&mgbdev->video, 0xD0);
>>> +    val10 = ((((val >> 20) & 0xFFF) * 503975) - 1118822400) / 409600;
>>> +
>>> +    return sprintf(buf, "%u\n", ((val10 % 10) > 4)
>>> +      ? (val10 / 10) + 1 : val10 / 10);
>>> +}
>>> +
>>> +static DEVICE_ATTR(module_version, 0444, read_module_version, NULL);
>>> +static DEVICE_ATTR(module_type, 0444, read_module_type, NULL);
>>> +static DEVICE_ATTR(fw_version, 0444, read_fw_version, NULL);
>>> +static DEVICE_ATTR(fw_type, 0444, read_fw_type, NULL);
>>> +static DEVICE_ATTR(serial_number, 0444, read_serial_number, NULL);
>>> +static DEVICE_ATTR(temperature, 0444, read_temperature, NULL);
>>> +
>>> +struct device_attribute *mgb4_pci_attrs[] = {
>>> +    &dev_attr_module_type,
>>> +    &dev_attr_module_version,
>>> +    &dev_attr_fw_type,
>>> +    &dev_attr_fw_version,
>>> +    &dev_attr_serial_number,
>>> +    &dev_attr_temperature,
>>> +    NULL
>>> +};
>>> diff --git a/drivers/media/pci/mgb4/mgb4_trigger.c b/drivers/media/pci/mgb4/mgb4_trigger.c
>>> new file mode 100644
>>> index 000000000000..964daf177fb1
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_trigger.c
>>> @@ -0,0 +1,208 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * This module handles the IIO trigger device. The card has two signal inputs
>>
>> 'signal inputs': I assume that means it has two input pins (GPIO like) that an
>> external device can trigger? Or is it something else?
>>
>>> + * for event triggers that can be used to record events related to the video
>>> + * stream. A standard linux IIO device with triggered buffer capability is
>>> + * created and configured that can be used to fetch the events with the same
>>> + * clock source as the video frames.
>>> + */
>>> +
>>> +#include <linux/iio/iio.h>
>>> +#include <linux/iio/buffer.h>
>>> +#include <linux/iio/trigger.h>
>>> +#include <linux/iio/trigger_consumer.h>
>>> +#include <linux/iio/triggered_buffer.h>
>>> +#include <linux/pci.h>
>>> +#include <linux/dma/amd_xdma.h>
>>> +#include "mgb4_core.h"
>>> +#include "mgb4_trigger.h"
>>> +
>>> +struct trigger_data {
>>> +    struct mgb4_dev *mgbdev;
>>> +    struct iio_trigger *trig;
>>> +};
>>> +
>>> +static int trigger_read_raw(struct iio_dev *indio_dev,
>>> +                struct iio_chan_spec const *chan, int *val,
>>> +                int *val2, long mask)
>>> +{
>>> +    struct trigger_data *st = iio_priv(indio_dev);
>>> +
>>> +    switch (mask) {
>>> +    case IIO_CHAN_INFO_RAW:
>>> +        if (iio_buffer_enabled(indio_dev))
>>> +            return -EBUSY;
>>> +        *val = mgb4_read_reg(&st->mgbdev->video, 0xA0);
>>> +
>>> +        return IIO_VAL_INT;
>>> +    }
>>> +
>>> +    return -EINVAL;
>>> +}
>>> +
>>> +static int trigger_set_state(struct iio_trigger *trig, bool state)
>>> +{
>>> +    struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
>>> +    struct trigger_data *st = iio_priv(indio_dev);
>>> +    int irq = xdma_get_user_irq(st->mgbdev->xdev, 11);
>>> +
>>> +    if (state)
>>> +        xdma_enable_user_irq(st->mgbdev->xdev, irq);
>>> +    else
>>> +        xdma_disable_user_irq(st->mgbdev->xdev, irq);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static const struct iio_trigger_ops trigger_ops = {
>>> +    .set_trigger_state = &trigger_set_state,
>>> +};
>>> +
>>> +static const struct iio_info trigger_info = {
>>> +    .read_raw         = trigger_read_raw,
>>> +};
>>> +
>>> +#define TRIGGER_CHANNEL(_si) {                    \
>>> +    .type = IIO_ACTIVITY,                         \
>>> +    .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>>> +    .scan_index = _si,                            \
>>> +    .scan_type = {                                \
>>> +        .sign = 'u',                              \
>>> +        .realbits = 32,                           \
>>> +        .storagebits = 32,                        \
>>> +        .shift = 0,                               \
>>> +        .endianness = IIO_CPU                     \
>>> +    },                                            \
>>> +}
>>> +
>>> +static const struct iio_chan_spec trigger_channels[] = {
>>> +    TRIGGER_CHANNEL(0),
>>> +    IIO_CHAN_SOFT_TIMESTAMP(1),
>>> +};
>>> +
>>> +static irqreturn_t trigger_handler(int irq, void *p)
>>> +{
>>> +    struct iio_poll_func *pf = p;
>>> +    struct iio_dev *indio_dev = pf->indio_dev;
>>> +    struct trigger_data *st = iio_priv(indio_dev);
>>> +    struct {
>>> +        u32 data;
>>> +        s64 ts __aligned(8);
>>> +    } scan;
>>> +
>>> +    scan.data = mgb4_read_reg(&st->mgbdev->video, 0xA0);
>>> +    mgb4_write_reg(&st->mgbdev->video, 0xA0, scan.data);
>>> +
>>> +    iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp);
>>> +    iio_trigger_notify_done(indio_dev->trig);
>>> +
>>> +    mgb4_write_reg(&st->mgbdev->video, 0xB4, 1U << 11);
>>> +
>>> +    return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int probe_trigger(struct iio_dev *indio_dev, int irq)
>>> +{
>>> +    int ret;
>>> +    struct trigger_data *st = iio_priv(indio_dev);
>>> +
>>> +    st->trig = iio_trigger_alloc(&st->mgbdev->pdev->dev, "%s-dev%d",
>>> +                     indio_dev->name, iio_device_id(indio_dev));
>>> +    if (!st->trig)
>>> +        return -ENOMEM;
>>> +
>>> +    ret = request_irq(irq, &iio_trigger_generic_data_rdy_poll, 0,
>>> +              "mgb4-trigger", st->trig);
>>> +    if (ret)
>>> +        goto error_free_trig;
>>> +
>>> +    st->trig->ops = &trigger_ops;
>>> +    iio_trigger_set_drvdata(st->trig, indio_dev);
>>> +    ret = iio_trigger_register(st->trig);
>>> +    if (ret)
>>> +        goto error_free_irq;
>>> +
>>> +    indio_dev->trig = iio_trigger_get(st->trig);
>>> +
>>> +    return 0;
>>> +
>>> +error_free_irq:
>>> +    free_irq(irq, st->trig);
>>> +error_free_trig:
>>> +    iio_trigger_free(st->trig);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static void remove_trigger(struct iio_dev *indio_dev, int irq)
>>> +{
>>> +    struct trigger_data *st = iio_priv(indio_dev);
>>> +
>>> +    iio_trigger_unregister(st->trig);
>>> +    free_irq(irq, st->trig);
>>> +    iio_trigger_free(st->trig);
>>> +}
>>> +
>>> +struct iio_dev *mgb4_trigger_create(struct mgb4_dev *mgbdev)
>>> +{
>>> +    struct iio_dev *indio_dev;
>>> +    struct trigger_data *data;
>>> +    struct pci_dev *pdev = mgbdev->pdev;
>>> +    struct device *dev = &pdev->dev;
>>> +    int rv, irq;
>>> +
>>> +    indio_dev = iio_device_alloc(dev, sizeof(*data));
>>> +    if (!indio_dev)
>>> +        return NULL;
>>> +
>>> +    indio_dev->info = &trigger_info;
>>> +    indio_dev->name = "mgb4";
>>> +    indio_dev->modes = INDIO_DIRECT_MODE;
>>> +    indio_dev->channels = trigger_channels;
>>> +    indio_dev->num_channels = ARRAY_SIZE(trigger_channels);
>>> +
>>> +    data = iio_priv(indio_dev);
>>> +    data->mgbdev = mgbdev;
>>> +
>>> +    irq = xdma_get_user_irq(mgbdev->xdev, 11);
>>> +    rv = probe_trigger(indio_dev, irq);
>>> +    if (rv < 0) {
>>> +        dev_err(dev, "iio triggered setup failed\n");
>>> +        goto error_alloc;
>>> +    }
>>> +    rv = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
>>> +                    trigger_handler, NULL);
>>> +    if (rv < 0) {
>>> +        dev_err(dev, "iio triggered buffer setup failed\n");
>>> +        goto error_trigger;
>>> +    }
>>> +    rv = iio_device_register(indio_dev);
>>> +    if (rv < 0) {
>>> +        dev_err(dev, "iio device register failed\n");
>>> +        goto error_buffer;
>>> +    }
>>> +
>>> +    return indio_dev;
>>> +
>>> +error_buffer:
>>> +    iio_triggered_buffer_cleanup(indio_dev);
>>> +error_trigger:
>>> +    remove_trigger(indio_dev, irq);
>>> +error_alloc:
>>> +    iio_device_free(indio_dev);
>>> +
>>> +    return NULL;
>>> +}
>>> +
>>> +void mgb4_trigger_free(struct iio_dev *indio_dev)
>>> +{
>>> +    struct trigger_data *st = iio_priv(indio_dev);
>>> +
>>> +    iio_device_unregister(indio_dev);
>>> +    iio_triggered_buffer_cleanup(indio_dev);
>>> +    remove_trigger(indio_dev, xdma_get_user_irq(st->mgbdev->xdev, 11));
>>> +    iio_device_free(indio_dev);
>>> +}
>>> diff --git a/drivers/media/pci/mgb4/mgb4_trigger.h b/drivers/media/pci/mgb4/mgb4_trigger.h
>>> new file mode 100644
>>> index 000000000000..6c25bc4576f6
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_trigger.h
>>> @@ -0,0 +1,8 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +struct iio_dev *mgb4_trigger_create(struct mgb4_dev *mgbdev);
>>> +void mgb4_trigger_free(struct iio_dev *indio_dev);
>>> diff --git a/drivers/media/pci/mgb4/mgb4_vin.c b/drivers/media/pci/mgb4/mgb4_vin.c
>>> new file mode 100644
>>> index 000000000000..2e3790ae5124
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_vin.c
>>> @@ -0,0 +1,830 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>
>> Note that you can update the copyright year from 2022 to 2023 in all
>> these sources.
>>
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * This is the v4l2 input device module. It initializes the signal deserializers
>>> + * and creates the v4l2 video devices. The input signal can change at any time
>>> + * which is handled by the "timings" callbacks and an IRQ based watcher, that
>>> + * emits the V4L2_EVENT_SOURCE_CHANGE event in case of a signal source change.
>>> + *
>>> + * When the device is in loopback mode (a direct, in HW, in->out frame passing
>>> + * mode) the cards's frame queue must be running regardles whether a v4l2 stream
>>
>> cards's -> card's
>> regardles -> regardless of
>>
>>> + * is running and the output parameters like frame buffers padding must be in
>>> + * sync with the input parameters.
>>> + */
>>> +
>>> +#include <linux/pci.h>
>>> +#include <linux/workqueue.h>
>>> +#include <media/v4l2-ioctl.h>
>>> +#include <media/videobuf2-v4l2.h>
>>> +#include <media/videobuf2-dma-sg.h>
>>> +#include <media/v4l2-dv-timings.h>
>>> +#include <media/v4l2-event.h>
>>> +#include <linux/dma/amd_xdma.h>
>>> +#include "mgb4_core.h"
>>> +#include "mgb4_dma.h"
>>> +#include "mgb4_sysfs.h"
>>> +#include "mgb4_io.h"
>>> +#include "mgb4_vout.h"
>>> +#include "mgb4_vin.h"
>>> +
>>> +static const struct mgb4_vin_config vin_cfg[] = {
>>> +    {0, 0, 0, 6, {0x10, 0x00, 0x04, 0x08, 0x1C, 0x14, 0x18, 0x20, 0x24, 0x28}},
>>> +    {1, 1, 1, 7, {0x40, 0x30, 0x34, 0x38, 0x4C, 0x44, 0x48, 0x50, 0x54, 0x58}}
>>> +};
>>> +
>>> +static const struct i2c_board_info fpdl3_deser_info[] = {
>>> +    {I2C_BOARD_INFO("deserializer1", 0x36)},
>>> +    {I2C_BOARD_INFO("deserializer2", 0x38)},
>>> +};
>>> +
>>> +static const struct i2c_board_info gmsl_deser_info[] = {
>>> +    {I2C_BOARD_INFO("deserializer1", 0x4C)},
>>> +    {I2C_BOARD_INFO("deserializer2", 0x2A)},
>>> +};
>>> +
>>> +static const struct mgb4_i2c_kv fpdl3_i2c[] = {
>>> +    {0x06, 0xFF, 0x04}, {0x07, 0xFF, 0x01}, {0x45, 0xFF, 0xE8},
>>> +    {0x49, 0xFF, 0x00}, {0x34, 0xFF, 0x00}, {0x23, 0xFF, 0x00}
>>> +};
>>> +
>>> +static const struct mgb4_i2c_kv gmsl_i2c[] = {
>>> +    {0x01, 0x03, 0x03}, {0x300, 0x0C, 0x0C}, {0x03, 0xC0, 0xC0},
>>> +    {0x1CE, 0x0E, 0x0E}, {0x11, 0x05, 0x00}, {0x05, 0xC0, 0x40},
>>> +    {0x307, 0x0F, 0x00}, {0xA0, 0x03, 0x00}, {0x3E0, 0x07, 0x07},
>>> +    {0x308, 0x01, 0x01}, {0x10, 0x20, 0x20}, {0x300, 0x40, 0x40}
>>> +};
>>> +
>>> +static const struct v4l2_dv_timings_cap video_timings_cap = {
>>> +    .type = V4L2_DV_BT_656_1120,
>>> +    .bt = {
>>> +        .min_width = 320,
>>> +        .max_width = 4096,
>>> +        .min_height = 240,
>>> +        .max_height = 2160,
>>> +        .min_pixelclock = 1843200, /* 320 x 240 x 24Hz */
>>> +        .max_pixelclock = 530841600, /* 4096 x 2160 x 60Hz */
>>> +        .standards = V4L2_DV_BT_STD_CEA861 | V4L2_DV_BT_STD_DMT |
>>> +            V4L2_DV_BT_STD_CVT | V4L2_DV_BT_STD_GTF,
>>> +        .capabilities = V4L2_DV_BT_CAP_PROGRESSIVE |
>>> +            V4L2_DV_BT_CAP_CUSTOM,
>>> +    },
>>> +};
>>> +
>>> +/*
>>> + * Returns the video output connected with the given video input if the input
>>> + * is in loopback mode.
>>> + */
>>> +static struct mgb4_vout_dev *loopback_dev(struct mgb4_vin_dev *vindev, int i)
>>> +{
>>> +    struct mgb4_vout_dev *voutdev;
>>> +    u32 config;
>>> +
>>> +    voutdev = vindev->mgbdev->vout[i];
>>> +    if (!voutdev)
>>> +        return NULL;
>>> +
>>> +    config = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.config);
>>> +    if ((config & 0xc) >> 2 == vindev->config->id)
>>> +        return voutdev;
>>> +
>>> +    return NULL;
>>> +}
>>> +
>>> +/*
>>> + * Check, whether the loopback mode - a HW INPUT->OUTPUT transmission - is
>>> + * enabled on the given input.
>>> + */
>>> +static int loopback_active(struct mgb4_vin_dev *vindev)
>>> +{
>>> +    int i;
>>> +
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++)
>>> +        if (loopback_dev(vindev, i))
>>> +            return 1;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +/*
>>> + * Set the output frame buffer padding of all outputs connected with the given
>>> + * input when the video input is set to loopback mode. The paddings must be
>>> + * the same for the loopback to work properly.
>>> + */
>>> +static void set_loopback_padding(struct mgb4_vin_dev *vindev, u32 padding)
>>> +{
>>> +    struct mgb4_regs *video = &vindev->mgbdev->video;
>>> +    struct mgb4_vout_dev *voutdev;
>>> +    int i;
>>> +
>>> +    for (i = 0; i < MGB4_VOUT_DEVICES; i++) {
>>> +        voutdev = loopback_dev(vindev, i);
>>> +        if (voutdev)
>>> +            mgb4_write_reg(video, voutdev->config->regs.padding,
>>> +                       padding);
>>> +    }
>>> +}
>>> +
>>> +static u32 detect_resolution(struct mgb4_vin_dev *vindev)
>>> +{
>>> +    struct mgb4_regs *video = &vindev->mgbdev->video;
>>> +    u32 resolution;
>>> +
>>> +    resolution = mgb4_read_reg(video, vindev->config->regs.resolution);
>>> +    if (resolution >= ERR_NO_REG)
>>> +        return 0;
>>> +
>>> +    return ((resolution >> 16) == 0 || (resolution & 0xFFFF) == 0)
>>> +        ? 0 : resolution;
>>> +}
>>> +
>>> +static int res_cmp(u32 width, u32 height, u32 resolution)
>>> +{
>>> +    return (width != (resolution >> 16) || height != (resolution & 0xFFFF))
>>> +        ? 1 : 0;
>>> +}
>>> +
>>> +static void return_all_buffers(struct mgb4_vin_dev *vindev,
>>> +                   enum vb2_buffer_state state)
>>> +{
>>> +    struct frame_buffer *buf, *node;
>>> +    unsigned long flags;
>>> +
>>> +    spin_lock_irqsave(&vindev->qlock, flags);
>>> +    list_for_each_entry_safe(buf, node, &vindev->buf_list, list) {
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, state);
>>> +        list_del(&buf->list);
>>> +    }
>>> +    spin_unlock_irqrestore(&vindev->qlock, flags);
>>> +}
>>> +
>>> +static int queue_setup(struct vb2_queue *q, unsigned int *nbuffers,
>>> +               unsigned int *nplanes, unsigned int sizes[],
>>> +               struct device *alloc_devs[])
>>> +{
>>> +    struct mgb4_vin_dev *vindev = vb2_get_drv_priv(q);
>>> +    unsigned int size = BYTESPERLINE(vindev->width, vindev->alignment)
>>> +      * vindev->height;
>>> +
>>> +    if (*nbuffers < 2)
>>> +        *nbuffers = 2;
>>
>> I recommend setting min_buffers_needed to 2 in struct vb2_queue.
>> Then you can drop these two lines. It's the recommended way of
>> dealing with this.
>>
>>> +
>>> +    if (*nplanes)
>>> +        return sizes[0] < size ? -EINVAL : 0;
>>> +    *nplanes = 1;
>>> +    sizes[0] = size;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int buffer_init(struct vb2_buffer *vb)
>>> +{
>>> +    struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>>> +    struct frame_buffer *buf = to_frame_buffer(vbuf);
>>> +
>>> +    INIT_LIST_HEAD(&buf->list);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int buffer_prepare(struct vb2_buffer *vb)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = vb2_get_drv_priv(vb->vb2_queue);
>>> +    struct device *dev = &vindev->mgbdev->pdev->dev;
>>> +    unsigned int size = BYTESPERLINE(vindev->width, vindev->alignment)
>>> +      * vindev->height;
>>> +
>>> +    if (vb2_plane_size(vb, 0) < size) {
>>> +        dev_err(dev, "buffer too small (%lu < %u)\n",
>>> +            vb2_plane_size(vb, 0), size);
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    vb2_set_plane_payload(vb, 0, size);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static void buffer_queue(struct vb2_buffer *vb)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = vb2_get_drv_priv(vb->vb2_queue);
>>> +    struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>>> +    struct frame_buffer *buf = to_frame_buffer(vbuf);
>>> +    unsigned long flags;
>>> +
>>> +    spin_lock_irqsave(&vindev->qlock, flags);
>>> +    list_add_tail(&buf->list, &vindev->buf_list);
>>> +    spin_unlock_irqrestore(&vindev->qlock, flags);
>>> +}
>>> +
>>> +static void stop_streaming(struct vb2_queue *vq)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = vb2_get_drv_priv(vq);
>>> +    int irq = xdma_get_user_irq(vindev->mgbdev->xdev, vindev->config->vin_irq);
>>> +
>>> +    xdma_disable_user_irq(vindev->mgbdev->xdev, irq);
>>> +
>>> +    /*
>>> +     * In loopback mode, the HW frame queue must be left running for
>>> +     * the IN->OUT transmission to work!
>>> +     */
>>> +    if (!loopback_active(vindev))
>>> +        mgb4_mask_reg(&vindev->mgbdev->video, vindev->config->regs.config,
>>> +                  0x2, 0x0);
>>> +
>>> +    cancel_work_sync(&vindev->dma_work);
>>> +    return_all_buffers(vindev, VB2_BUF_STATE_ERROR);
>>> +}
>>> +
>>> +static int start_streaming(struct vb2_queue *vq, unsigned int count)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = vb2_get_drv_priv(vq);
>>> +    int irq = xdma_get_user_irq(vindev->mgbdev->xdev, vindev->config->vin_irq);
>>> +    u32 resolution = detect_resolution(vindev);
>>> +
>>> +    if (res_cmp(vindev->width, vindev->height, resolution)) {
>>> +        return_all_buffers(vindev, VB2_BUF_STATE_QUEUED);
>>> +        return -EIO;
>>> +    }
>>> +
>>> +    vindev->sequence = 0;
>>> +
>>> +    /*
>>> +     * In loopback mode, the HW frame queue is already running.
>>> +     */
>>> +    if (!loopback_active(vindev))
>>> +        mgb4_mask_reg(&vindev->mgbdev->video, vindev->config->regs.config,
>>> +                  0x2, 0x2);
>>> +
>>> +    xdma_enable_user_irq(vindev->mgbdev->xdev, irq);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static const struct vb2_ops queue_ops = {
>>> +    .queue_setup = queue_setup,
>>> +    .buf_init = buffer_init,
>>> +    .buf_prepare = buffer_prepare,
>>> +    .buf_queue = buffer_queue,
>>> +    .start_streaming = start_streaming,
>>> +    .stop_streaming = stop_streaming,
>>> +    .wait_prepare = vb2_ops_wait_prepare,
>>> +    .wait_finish = vb2_ops_wait_finish
>>> +};
>>> +
>>> +static int fh_open(struct file *file)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +    struct mgb4_regs *video = &vindev->mgbdev->video;
>>> +    u32 resolution, padding;
>>> +    int ret;
>>> +
>>> +    mutex_lock(&vindev->lock);
>>> +
>>> +    ret = v4l2_fh_open(file);
>>> +    if (ret)
>>> +        goto out;
>>> +
>>> +    if (!v4l2_fh_is_singular_file(file))
>>> +        goto out;
>>> +
>>> +    resolution = detect_resolution(vindev);
>>> +    if (!resolution)
>>> +        goto out;
>>> +
>>> +    vindev->width = resolution >> 16;
>>> +    vindev->height = resolution & 0xFFFF;
>>> +    padding = PADDING(vindev->width, vindev->alignment);
>>> +    mgb4_write_reg(video, vindev->config->regs.padding, padding);
>>> +    set_loopback_padding(vindev, padding);
>>> +
>>> +out:
>>> +    mutex_unlock(&vindev->lock);
>>> +    return ret;
>>> +}
>>> +
>>> +static int fh_release(struct file *file)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +    struct mgb4_regs *video = &vindev->mgbdev->video;
>>> +    int ret;
>>> +
>>> +    mutex_lock(&vindev->lock);
>>> +
>>> +    if (v4l2_fh_is_singular_file(file)) {
>>> +        mgb4_write_reg(video, vindev->config->regs.padding, 0);
>>> +        set_loopback_padding(vindev, 0);
>>> +    }
>>> +
>>> +    ret = _vb2_fop_release(file, NULL);
>>> +
>>> +    mutex_unlock(&vindev->lock);
>>> +
>>> +    return ret;
>>> +}
>>> +
>>> +static const struct v4l2_file_operations video_fops = {
>>> +    .owner = THIS_MODULE,
>>> +    .open = fh_open,
>>> +    .release = fh_release,
>>> +    .unlocked_ioctl = video_ioctl2,
>>> +    .read = vb2_fop_read,
>>> +    .mmap = vb2_fop_mmap,
>>> +    .poll = vb2_fop_poll,
>>> +};
>>> +
>>> +static int vidioc_querycap(struct file *file, void *priv,
>>> +               struct v4l2_capability *cap)
>>> +{
>>> +    strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
>>> +    strscpy(cap->card, "MGB4 PCIe Card", sizeof(cap->card));
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_enum_fmt(struct file *file, void *priv,
>>> +               struct v4l2_fmtdesc *f)
>>> +{
>>> +    if (f->index != 0)
>>> +        return -EINVAL;
>>> +
>>> +    f->pixelformat = V4L2_PIX_FMT_ABGR32;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_enum_frameintervals(struct file *file, void *priv,
>>> +                      struct v4l2_frmivalenum *ival)
>>
>> I don't think this is needed: this is specific to camera sensor inputs,
>> but this is video input.
>>
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +
>>> +    if (ival->index != 0)
>>> +        return -EINVAL;
>>> +    if (ival->pixel_format != V4L2_PIX_FMT_ABGR32)
>>> +        return -EINVAL;
>>> +    if (ival->width != vindev->width || ival->height != vindev->height)
>>> +        return -EINVAL;
>>> +
>>> +    ival->type = V4L2_FRMIVAL_TYPE_CONTINUOUS;
>>> +    ival->stepwise.min.denominator = 60;
>>> +    ival->stepwise.min.numerator = 1;
>>> +    ival->stepwise.max.denominator = 1;
>>> +    ival->stepwise.max.numerator = 1;
>>> +    ival->stepwise.step = ival->stepwise.max;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_fmt(struct file *file, void *priv, struct v4l2_format *f)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +
>>> +    f->fmt.pix.pixelformat = V4L2_PIX_FMT_ABGR32;
>>> +    f->fmt.pix.width = vindev->width;
>>> +    f->fmt.pix.height = vindev->height;
>>> +    f->fmt.pix.field = V4L2_FIELD_NONE;
>>> +    f->fmt.pix.colorspace = V4L2_COLORSPACE_RAW;
>>> +    f->fmt.pix.bytesperline = BYTESPERLINE(vindev->width, vindev->alignment);
>>> +    f->fmt.pix.sizeimage = f->fmt.pix.bytesperline * f->fmt.pix.height;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_enum_input(struct file *file, void *priv, struct v4l2_input *i)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +
>>> +    if (i->index != 0)
>>> +        return -EINVAL;
>>> +
>>> +    strscpy(i->name, "MGB4", sizeof(i->name));
>>> +    i->type = V4L2_INPUT_TYPE_CAMERA;
>>> +    i->capabilities = V4L2_IN_CAP_DV_TIMINGS;
>>> +    i->status = detect_resolution(vindev) ? 0 : V4L2_IN_ST_NO_SIGNAL;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_enum_framesizes(struct file *file, void *fh,
>>> +                  struct v4l2_frmsizeenum *fsize)
>>
>> Ditto.
>>
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +
>>> +    if (fsize->index != 0 || fsize->pixel_format != V4L2_PIX_FMT_ABGR32)
>>> +        return -EINVAL;
>>> +
>>> +    fsize->discrete.width = vindev->width;
>>> +    fsize->discrete.height = vindev->height;
>>> +    fsize->type = V4L2_FRMSIZE_TYPE_DISCRETE;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_s_input(struct file *file, void *priv, unsigned int i)
>>> +{
>>> +    return (i == 0) ? 0 : -EINVAL;
>>> +}
>>> +
>>> +static int vidioc_g_input(struct file *file, void *priv, unsigned int *i)
>>> +{
>>> +    *i = 0;
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_parm(struct file *file, void *priv,
>>> +               struct v4l2_streamparm *parm)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +    struct mgb4_regs *video = &vindev->mgbdev->video;
>>> +    struct v4l2_fract timeperframe = {
>>> +        .numerator = mgb4_read_reg(video, vindev->config->regs.frame_period),
>>> +        .denominator = 125000000,
>>> +    };
>>> +
>>> +    if (parm->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
>>> +        return -EINVAL;
>>> +
>>> +    parm->parm.capture.readbuffers = 2;
>>> +    parm->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
>>> +    parm->parm.capture.timeperframe = timeperframe;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_s_dv_timings(struct file *file, void *fh,
>>> +                   struct v4l2_dv_timings *timings)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +    struct mgb4_regs *video = &vindev->mgbdev->video;
>>> +    u32 padding;
>>> +
>>> +    if (timings->bt.width == vindev->width &&
>>> +        timings->bt.height == vindev->height)
>>> +        return 0;
>>> +    if (vb2_is_busy(&vindev->queue))
>>> +        return -EBUSY;
>>> +
>>> +    vindev->width = timings->bt.width;
>>> +    vindev->height = timings->bt.height;
>>> +    padding = PADDING(vindev->width, vindev->alignment);
>>> +    mgb4_write_reg(video, vindev->config->regs.padding, padding);
>>> +    set_loopback_padding(vindev, padding);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_g_dv_timings(struct file *file, void *fh,
>>> +                   struct v4l2_dv_timings *timings)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +
>>> +    memset(timings, 0, sizeof(*timings));
>>> +    timings->type = V4L2_DV_BT_656_1120;
>>> +    timings->bt.width = vindev->width;
>>> +    timings->bt.height = vindev->height;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_query_dv_timings(struct file *file, void *fh,
>>> +                   struct v4l2_dv_timings *timings)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = video_drvdata(file);
>>> +    u32 resolution = detect_resolution(vindev);
>>> +
>>> +    if (!resolution)
>>> +        return -ENOLINK;
>>> +
>>> +    memset(timings, 0, sizeof(*timings));
>>> +    timings->type = V4L2_DV_BT_656_1120;
>>> +    timings->bt.width = resolution >> 16;
>>> +    timings->bt.height = resolution & 0xFFFF;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_enum_dv_timings(struct file *file, void *fh,
>>> +                  struct v4l2_enum_dv_timings *timings)
>>> +{
>>> +    return v4l2_enum_dv_timings_cap(timings, &video_timings_cap, NULL, NULL);
>>> +}
>>> +
>>> +static int vidioc_dv_timings_cap(struct file *file, void *fh,
>>> +                 struct v4l2_dv_timings_cap *cap)
>>> +{
>>> +    *cap = video_timings_cap;
>>> +
>>> +    return 0;
>>> +}
>>
>> Looking at what the dv_timings ioctls do and the sysfs properties, it seems to me
>> that a lot of the sysfs timings properties can be handle here instead.
>>
>> If some of the sysfs properties are missing here, then we can consider either
>> extending the dv timings API or keeping them as sysfs properties.
>>
>>> +
>>> +static int vidioc_subscribe_event(struct v4l2_fh *fh,
>>> +                  const struct v4l2_event_subscription *sub)
>>> +{
>>> +    switch (sub->type) {
>>> +    case V4L2_EVENT_SOURCE_CHANGE:
>>> +        return v4l2_src_change_event_subscribe(fh, sub);
>>> +    }
>>> +
>>> +    return v4l2_ctrl_subscribe_event(fh, sub);
>>> +}
>>> +
>>> +static const struct v4l2_ioctl_ops video_ioctl_ops = {
>>> +    .vidioc_querycap = vidioc_querycap,
>>> +    .vidioc_enum_fmt_vid_cap = vidioc_enum_fmt,
>>> +    .vidioc_try_fmt_vid_cap = vidioc_fmt,
>>> +    .vidioc_s_fmt_vid_cap = vidioc_fmt,
>>> +    .vidioc_g_fmt_vid_cap = vidioc_fmt,
>>
>> The handling of padding seems something that should be handled
>> by a vidioc_s_fmt function based on the provided bytesperline
>> field. That's how it is typically done.
>>
>> So when you set the new timings (S_DV_TIMINGS), then the padding
>> and width/height are reset to default values for the new timing,
>> but userspace can set the format with a different bytesperline
>> value.
>>
>>> +    .vidioc_enum_framesizes = vidioc_enum_framesizes,
>>> +    .vidioc_enum_frameintervals = vidioc_enum_frameintervals,
>>> +    .vidioc_enum_input = vidioc_enum_input,
>>> +    .vidioc_g_input = vidioc_g_input,
>>> +    .vidioc_s_input = vidioc_s_input,
>>> +    .vidioc_reqbufs = vb2_ioctl_reqbufs,
>>> +    .vidioc_create_bufs = vb2_ioctl_create_bufs,
>>> +    .vidioc_prepare_buf = vb2_ioctl_prepare_buf,
>>> +    .vidioc_querybuf = vb2_ioctl_querybuf,
>>> +    .vidioc_qbuf = vb2_ioctl_qbuf,
>>> +    .vidioc_dqbuf = vb2_ioctl_dqbuf,
>>> +    .vidioc_expbuf = vb2_ioctl_expbuf,
>>> +    .vidioc_streamon = vb2_ioctl_streamon,
>>> +    .vidioc_streamoff = vb2_ioctl_streamoff,
>>> +    .vidioc_g_parm = vidioc_parm,
>>> +    .vidioc_s_parm = vidioc_parm,
>>> +    .vidioc_dv_timings_cap = vidioc_dv_timings_cap,
>>> +    .vidioc_enum_dv_timings = vidioc_enum_dv_timings,
>>> +    .vidioc_g_dv_timings = vidioc_g_dv_timings,
>>> +    .vidioc_s_dv_timings = vidioc_s_dv_timings,
>>> +    .vidioc_query_dv_timings = vidioc_query_dv_timings,
>>> +    .vidioc_subscribe_event = vidioc_subscribe_event,
>>> +    .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
>>> +};
>>> +
>>> +static void dma_transfer(struct work_struct *work)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = container_of(work, struct mgb4_vin_dev, dma_work);
>>> +    struct device *dev = &vindev->mgbdev->pdev->dev;
>>> +    struct frame_buffer *buf = 0;
>>> +    unsigned long flags;
>>> +    u32 addr;
>>> +
>>> +    spin_lock_irqsave(&vindev->qlock, flags);
>>> +    if (!list_empty(&vindev->buf_list)) {
>>> +        buf = list_first_entry(&vindev->buf_list, struct frame_buffer, list);
>>> +        list_del_init(vindev->buf_list.next);
>>> +    }
>>> +    spin_unlock_irqrestore(&vindev->qlock, flags);
>>> +
>>> +    if (!buf)
>>> +        return;
>>> +
>>> +    addr = mgb4_read_reg(&vindev->mgbdev->video, vindev->config->regs.address);
>>> +    if (addr >= ERR_QUEUE_FULL) {
>>> +        dev_warn(dev, "frame queue error (%d)\n", (int)addr);
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
>>> +        return;
>>> +    }
>>> +
>>> +    if (mgb4_dma_transfer(vindev->mgbdev, vindev->config->dma_channel, false,
>>> +                  addr, vb2_dma_sg_plane_desc(&buf->vb.vb2_buf, 0)) < 0) {
>>> +        dev_warn(dev, "DMA transfer error\n");
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
>>> +    } else {
>>> +        buf->vb.vb2_buf.timestamp = ktime_get_ns();
>>> +        buf->vb.sequence = vindev->sequence++;
>>> +        buf->vb.field = V4L2_FIELD_NONE;
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
>>> +    }
>>> +}
>>> +
>>> +static void signal_change(struct work_struct *work)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = container_of(work, struct mgb4_vin_dev, err_work);
>>> +    struct device *dev = &vindev->mgbdev->pdev->dev;
>>> +    u32 resolution = detect_resolution(vindev);
>>> +
>>> +    if (res_cmp(vindev->width, vindev->height, resolution)) {
>>> +        static const struct v4l2_event ev = {
>>> +            .type = V4L2_EVENT_SOURCE_CHANGE,
>>> +            .u.src_change.changes = V4L2_EVENT_SRC_CH_RESOLUTION,
>>> +        };
>>> +
>>> +        v4l2_event_queue(&vindev->vdev, &ev);
>>> +
>>> +        if (vb2_is_streaming(&vindev->queue))
>>> +            vb2_queue_error(&vindev->queue);
>>> +    }
>>> +
>>> +    dev_warn(dev, "stream changed to %ux%u\n", resolution >> 16,
>>> +         resolution & 0xFFFF);
>>
>> Not a warning. Change to dev_dbg or drop it. You don't want this to spam the
>> kernel log.
>>
>>> +}
>>> +
>>> +static irqreturn_t vin_handler(int irq, void *ctx)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = (struct mgb4_vin_dev *)ctx;
>>> +
>>> +    schedule_work(&vindev->dma_work);
>>> +
>>> +    mgb4_write_reg(&vindev->mgbdev->video, 0xB4, 1U << vindev->config->vin_irq);
>>> +
>>> +    return IRQ_HANDLED;
>>> +}
>>> +
>>> +static irqreturn_t err_handler(int irq, void *ctx)
>>> +{
>>> +    struct mgb4_vin_dev *vindev = (struct mgb4_vin_dev *)ctx;
>>> +
>>> +    schedule_work(&vindev->err_work);
>>> +
>>> +    mgb4_write_reg(&vindev->mgbdev->video, 0xB4, 1U << vindev->config->err_irq);
>>> +
>>> +    return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int deser_init(struct mgb4_vin_dev *vindev, int id)
>>> +{
>>> +    int rv, addr_size;
>>> +    size_t values_count;
>>> +    const struct mgb4_i2c_kv *values;
>>> +    const struct i2c_board_info *info;
>>> +    struct device *dev = &vindev->mgbdev->pdev->dev;
>>> +
>>> +    if (MGB4_IS_GMSL(vindev->mgbdev)) {
>>> +        info = &gmsl_deser_info[id];
>>> +        addr_size = 16;
>>> +        values = gmsl_i2c;
>>> +        values_count = ARRAY_SIZE(gmsl_i2c);
>>> +    } else {
>>> +        info = &fpdl3_deser_info[id];
>>> +        addr_size = 8;
>>> +        values = fpdl3_i2c;
>>> +        values_count = ARRAY_SIZE(fpdl3_i2c);
>>> +    }
>>> +
>>> +    rv = mgb4_i2c_init(&vindev->deser, vindev->mgbdev->i2c_adap, info, addr_size);
>>
>> Consider using v4l2_i2c_new_subdev_board() instead. That's what V4L2 PCI drivers
>> normally use. The advantage is that this will call request_module() and avoids
>> having to wait for the module to be loaded by the kernel. I think that's why the
>> msleep(100) was needed in this driver.
>>
>>> +    if (rv < 0) {
>>> +        dev_err(dev, "failed to create deserializer\n");
>>> +        return rv;
>>> +    }
>>> +    rv = mgb4_i2c_configure(&vindev->deser, values, values_count);
>>> +    if (rv < 0) {
>>> +        dev_err(dev, "failed to configure deserializer\n");
>>> +        goto err_i2c_dev;
>>> +    }
>>> +
>>> +    return 0;
>>> +
>>> +err_i2c_dev:
>>> +    mgb4_i2c_free(&vindev->deser);
>>> +
>>> +    return rv;
>>> +}
>>> +
>>> +struct mgb4_vin_dev *mgb4_vin_create(struct mgb4_dev *mgbdev, int id)
>>> +{
>>> +    int rv;
>>> +    struct device_attribute **attr, **module_attr;
>>> +    struct mgb4_vin_dev *vindev;
>>> +    struct pci_dev *pdev = mgbdev->pdev;
>>> +    struct device *dev = &pdev->dev;
>>> +    int vin_irq, err_irq;
>>> +
>>> +    vindev = kzalloc(sizeof(*vindev), GFP_KERNEL);
>>> +    if (!vindev)
>>> +        return NULL;
>>> +
>>> +    vindev->mgbdev = mgbdev;
>>> +    vindev->config = &vin_cfg[id];
>>> +
>>> +    /* Frame queue*/
>>> +    INIT_LIST_HEAD(&vindev->buf_list);
>>> +    spin_lock_init(&vindev->qlock);
>>> +
>>> +    /* Work queues */
>>> +    INIT_WORK(&vindev->dma_work, dma_transfer);
>>> +    INIT_WORK(&vindev->err_work, signal_change);
>>> +
>>> +    /* IRQ callback */
>>> +    vin_irq = xdma_get_user_irq(mgbdev->xdev, vindev->config->vin_irq);
>>> +    rv = request_irq(vin_irq, vin_handler, 0, "mgb4-vin", vindev);
>>> +    if (rv) {
>>> +        dev_err(dev, "failed to register vin irq handler\n");
>>> +        goto err_alloc;
>>> +    }
>>> +    /* Error IRQ callback */
>>> +    err_irq = xdma_get_user_irq(mgbdev->xdev, vindev->config->err_irq);
>>> +    rv = request_irq(err_irq, err_handler, 0, "mgb4-err", vindev);
>>> +    if (rv) {
>>> +        dev_err(dev, "failed to register err irq handler\n");
>>> +        goto err_vin_irq;
>>> +    }
>>> +
>>> +    /* V4L2 */
>>> +    rv = v4l2_device_register(dev, &vindev->v4l2dev);
>>> +    if (rv) {
>>> +        dev_err(dev, "failed to register v4l2 device\n");
>>> +        goto err_err_irq;
>>> +    }
>>> +
>>> +    mutex_init(&vindev->lock);
>>> +
>>> +    vindev->queue.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
>>> +    vindev->queue.io_modes = VB2_MMAP | VB2_DMABUF | VB2_READ;
>>
>> The use of VB2_READ is discouraged for raw video devices. It's up to
>> you, though.
>>
>>> +    vindev->queue.buf_struct_size = sizeof(struct frame_buffer);
>>> +    vindev->queue.ops = &queue_ops;
>>> +    vindev->queue.mem_ops = &vb2_dma_sg_memops;
>>> +    vindev->queue.gfp_flags = GFP_DMA32;
>>> +    vindev->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
>>> +    vindev->queue.min_buffers_needed = 2;
>>
>> Ah, this is already set, so in the setup callback you can just drop the
>> *nbuffers < 2 check.
>>
>>> +    vindev->queue.drv_priv = vindev;
>>> +    vindev->queue.lock = &vindev->lock;
>>> +    vindev->queue.dev = dev;
>>> +    rv = vb2_queue_init(&vindev->queue);
>>> +    if (rv) {
>>> +        dev_err(dev, "failed to initialize vb2 queue\n");
>>> +        goto err_v4l2_dev;
>>> +    }
>>> +
>>> +    snprintf(vindev->vdev.name, sizeof(vindev->vdev.name), "mgb4-in%d", id + 1);
>>> +    vindev->vdev.device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE
>>> +      | V4L2_CAP_STREAMING;
>>> +    vindev->vdev.fops = &video_fops;
>>> +    vindev->vdev.ioctl_ops = &video_ioctl_ops;
>>> +    vindev->vdev.release = video_device_release_empty;
>>> +    vindev->vdev.v4l2_dev = &vindev->v4l2dev;
>>> +    vindev->vdev.lock = &vindev->lock;
>>> +    vindev->vdev.queue = &vindev->queue;
>>> +    video_set_drvdata(&vindev->vdev, vindev);
>>> +
>>> +    rv = video_register_device(&vindev->vdev, VFL_TYPE_VIDEO, -1);
>>
>> This should be the last thing this function does. You still do more
>> initialization below, but that should be done first.
>>
>> As soon as the video device is registered it can be used, so you
>> want everything it relies on to be ready before you call this.
>>
>>> +    if (rv) {
>>> +        dev_err(dev, "failed to register video device\n");
>>> +        goto err_v4l2_dev;
>>> +    }
>>> +
>>> +    /* Deserializer */
>>> +    rv = deser_init(vindev, id);
>>> +    if (rv)
>>> +        goto err_video_dev;
>>> +
>>> +    /* Set FPGA regs to comply with the deserializer state */
>>> +    mgb4_mask_reg(&vindev->mgbdev->video, vindev->config->regs.config,
>>> +              1U << 9, 1U << 9);
>>> +
>>> +    /*
>>> +     * Video buffer & signal defaults; something must be set even if we
>>> +     * have no signal at all.
>>> +     */
>>> +    vindev->width = DEFAULT_WIDTH;
>>> +    vindev->height = DEFAULT_HEIGHT;
>>> +    vindev->alignment = 1;
>>> +
>>> +    /* Module sysfs attributes */
>>> +    module_attr = MGB4_IS_GMSL(mgbdev)
>>> +      ? mgb4_gmsl_in_attrs : mgb4_fpdl3_in_attrs;
>>> +    for (attr = module_attr; *attr; attr++)
>>> +        device_create_file(&vindev->vdev.dev, *attr);
>>> +
>>> +    /* Enable the video signal change watcher */
>>> +    xdma_enable_user_irq(vindev->mgbdev->xdev, err_irq);
>>> +
>>> +    return vindev;
>>> +
>>> +err_video_dev:
>>> +    video_unregister_device(&vindev->vdev);
>>> +err_v4l2_dev:
>>> +    v4l2_device_unregister(&vindev->v4l2dev);
>>> +err_err_irq:
>>> +    free_irq(err_irq, vindev);
>>> +err_vin_irq:
>>> +    free_irq(vin_irq, vindev);
>>> +err_alloc:
>>> +    kfree(vindev);
>>> +
>>> +    return NULL;
>>> +}
>>> +
>>> +void mgb4_vin_free(struct mgb4_vin_dev *vindev)
>>> +{
>>> +    struct device_attribute **attr, **module_attr;
>>> +    int vin_irq = xdma_get_user_irq(vindev->mgbdev->xdev,
>>> +                    vindev->config->vin_irq);
>>> +    int err_irq = xdma_get_user_irq(vindev->mgbdev->xdev,
>>> +                    vindev->config->err_irq);
>>> +
>>> +    xdma_disable_user_irq(vindev->mgbdev->xdev, err_irq);
>>> +
>>> +    free_irq(vin_irq, vindev);
>>> +    free_irq(err_irq, vindev);
>>> +
>>> +    module_attr = MGB4_IS_GMSL(vindev->mgbdev)
>>> +      ? mgb4_gmsl_in_attrs : mgb4_fpdl3_in_attrs;
>>> +    for (attr = module_attr; *attr; attr++)
>>> +        device_remove_file(&vindev->vdev.dev, *attr);
>>> +
>>> +    mgb4_i2c_free(&vindev->deser);
>>> +    video_unregister_device(&vindev->vdev);
>>> +    v4l2_device_unregister(&vindev->v4l2dev);
>>> +
>>> +    kfree(vindev);
>>> +}
>>> diff --git a/drivers/media/pci/mgb4/mgb4_vin.h b/drivers/media/pci/mgb4/mgb4_vin.h
>>> new file mode 100644
>>> index 000000000000..95cf21f42fa7
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_vin.h
>>> @@ -0,0 +1,63 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#ifndef __MGB4_VIN_H__
>>> +#define __MGB4_VIN_H__
>>> +
>>> +#include <media/v4l2-device.h>
>>> +#include <media/v4l2-dev.h>
>>> +#include <media/v4l2-ctrls.h>
>>> +#include <media/videobuf2-core.h>
>>> +#include "mgb4_i2c.h"
>>> +
>>> +struct mgb4_vin_regs {
>>> +    u32 address;
>>> +    u32 config;
>>> +    u32 status;
>>> +    u32 resolution;
>>> +    u32 frame_period;
>>> +    u32 sync;
>>> +    u32 pclk;
>>> +    u32 signal;
>>> +    u32 signal2;
>>> +    u32 padding;
>>> +};
>>> +
>>> +struct mgb4_vin_config {
>>> +    int id;
>>> +    int dma_channel;
>>> +    int vin_irq;
>>> +    int err_irq;
>>> +    struct mgb4_vin_regs regs;
>>> +};
>>> +
>>> +struct mgb4_vin_dev {
>>> +    struct mgb4_dev *mgbdev;
>>> +    struct v4l2_device v4l2dev;
>>> +    struct video_device vdev;
>>> +    struct vb2_queue queue;
>>> +    struct mutex lock; /* vdev lock */
>>> +
>>> +    spinlock_t qlock; /* video buffer queue lock */
>>> +    struct list_head buf_list;
>>> +    struct work_struct dma_work, err_work;
>>> +
>>> +    unsigned int sequence;
>>> +
>>> +    u32 width;
>>> +    u32 height;
>>> +    u32 freq_range;
>>> +    u32 alignment;
>>> +
>>> +    struct mgb4_i2c_client deser;
>>> +
>>> +    const struct mgb4_vin_config *config;
>>> +};
>>> +
>>> +struct mgb4_vin_dev *mgb4_vin_create(struct mgb4_dev *mgbdev, int id);
>>> +void mgb4_vin_free(struct mgb4_vin_dev *vindev);
>>> +
>>> +#endif
>>> diff --git a/drivers/media/pci/mgb4/mgb4_vout.c b/drivers/media/pci/mgb4/mgb4_vout.c
>>> new file mode 100644
>>> index 000000000000..47800d191b84
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_vout.c
>>> @@ -0,0 +1,501 @@
>>> +// SPDX-License-Identifier: GPL-2.0-only
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + *
>>> + * This is the v4l2 output device module. It initializes the signal serializers
>>> + * and creates the v4l2 video devices.
>>> + *
>>> + * When the device is in loopback mode (a direct, in HW, in->out frame passing
>>> + * mode) we disable the v4l2 output by returning EBUSY in the open() syscall.
>>> + */
>>> +
>>> +#include <linux/pci.h>
>>> +#include <media/v4l2-ioctl.h>
>>> +#include <media/videobuf2-v4l2.h>
>>> +#include <media/videobuf2-dma-sg.h>
>>> +#include <linux/dma/amd_xdma.h>
>>> +#include "mgb4_core.h"
>>> +#include "mgb4_dma.h"
>>> +#include "mgb4_sysfs.h"
>>> +#include "mgb4_io.h"
>>> +#include "mgb4_vout.h"
>>> +
>>> +static const struct mgb4_vout_config vout_cfg[] = {
>>> +    {0, 0, 8, {0x78, 0x60, 0x64, 0x68, 0x74, 0x6C, 0x70, 0x7c}},
>>> +    {1, 1, 9, {0x98, 0x80, 0x84, 0x88, 0x94, 0x8c, 0x90, 0x9c}}
>>> +};
>>> +
>>> +static const struct i2c_board_info fpdl3_ser_info[] = {
>>> +    {I2C_BOARD_INFO("serializer1", 0x14)},
>>> +    {I2C_BOARD_INFO("serializer2", 0x16)},
>>> +};
>>> +
>>> +static const struct mgb4_i2c_kv fpdl3_i2c[] = {
>>> +    {0x05, 0xFF, 0x04}, {0x06, 0xFF, 0x01}, {0xC2, 0xFF, 0x80}
>>> +};
>>> +
>>> +static void return_all_buffers(struct mgb4_vout_dev *voutdev,
>>> +                   enum vb2_buffer_state state)
>>> +{
>>> +    struct frame_buffer *buf, *node;
>>> +    unsigned long flags;
>>> +
>>> +    spin_lock_irqsave(&voutdev->qlock, flags);
>>> +    list_for_each_entry_safe(buf, node, &voutdev->buf_list, list) {
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, state);
>>> +        list_del(&buf->list);
>>> +    }
>>> +    spin_unlock_irqrestore(&voutdev->qlock, flags);
>>> +}
>>> +
>>> +static int queue_setup(struct vb2_queue *q, unsigned int *nbuffers,
>>> +               unsigned int *nplanes, unsigned int sizes[],
>>> +               struct device *alloc_devs[])
>>> +{
>>> +    struct mgb4_vout_dev *voutdev = vb2_get_drv_priv(q);
>>> +    unsigned long size = BYTESPERLINE(voutdev->width, voutdev->alignment)
>>> +      * voutdev->height;
>>> +
>>> +    if (*nbuffers < 2)
>>> +        *nbuffers = 2;
>>
>> I assume that min_buffers_needed is set to 2 for output as well, so just drop
>> this check.
>>
>>> +
>>> +    if (*nplanes)
>>> +        return sizes[0] < size ? -EINVAL : 0;
>>> +    *nplanes = 1;
>>> +    sizes[0] = size;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int buffer_init(struct vb2_buffer *vb)
>>> +{
>>> +    struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>>> +    struct frame_buffer *buf = to_frame_buffer(vbuf);
>>> +
>>> +    INIT_LIST_HEAD(&buf->list);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int buffer_prepare(struct vb2_buffer *vb)
>>> +{
>>> +    struct mgb4_vout_dev *voutdev = vb2_get_drv_priv(vb->vb2_queue);
>>> +    struct device *dev = &voutdev->mgbdev->pdev->dev;
>>> +    unsigned long size = BYTESPERLINE(voutdev->width, voutdev->alignment)
>>> +      * voutdev->height;
>>> +
>>> +    if (vb2_plane_size(vb, 0) < size) {
>>> +        dev_err(dev, "buffer too small (%lu < %lu)\n",
>>> +            vb2_plane_size(vb, 0), size);
>>> +        return -EINVAL;
>>> +    }
>>> +
>>> +    vb2_set_plane_payload(vb, 0, size);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static void buffer_queue(struct vb2_buffer *vb)
>>> +{
>>> +    struct mgb4_vout_dev *vindev = vb2_get_drv_priv(vb->vb2_queue);
>>> +    struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
>>> +    struct frame_buffer *buf = to_frame_buffer(vbuf);
>>> +    unsigned long flags;
>>> +
>>> +    spin_lock_irqsave(&vindev->qlock, flags);
>>> +    list_add_tail(&buf->list, &vindev->buf_list);
>>> +    spin_unlock_irqrestore(&vindev->qlock, flags);
>>> +}
>>> +
>>> +static void stop_streaming(struct vb2_queue *vq)
>>> +{
>>> +    struct mgb4_vout_dev *voutdev = vb2_get_drv_priv(vq);
>>> +    int irq = xdma_get_user_irq(voutdev->mgbdev->xdev, voutdev->config->irq);
>>> +
>>> +    xdma_disable_user_irq(voutdev->mgbdev->xdev, irq);
>>> +
>>> +    cancel_work_sync(&voutdev->dma_work);
>>> +
>>> +    mgb4_mask_reg(&voutdev->mgbdev->video, voutdev->config->regs.config,
>>> +              0x2, 0x0);
>>> +
>>> +    return_all_buffers(voutdev, VB2_BUF_STATE_ERROR);
>>> +}
>>> +
>>> +static int start_streaming(struct vb2_queue *vq, unsigned int count)
>>> +{
>>> +    struct mgb4_vout_dev *voutdev = vb2_get_drv_priv(vq);
>>> +    struct device *dev = &voutdev->mgbdev->pdev->dev;
>>> +    struct frame_buffer *buf = 0;
>>> +    struct mgb4_regs *video = &voutdev->mgbdev->video;
>>> +    int irq = xdma_get_user_irq(voutdev->mgbdev->xdev, voutdev->config->irq);
>>> +    u32 addr;
>>> +
>>> +    mgb4_mask_reg(video, voutdev->config->regs.config, 0x2, 0x2);
>>> +
>>> +    addr = mgb4_read_reg(video, voutdev->config->regs.address);
>>> +    if (addr >= ERR_QUEUE_FULL) {
>>> +        dev_err(dev, "frame queue error (%d)\n", (int)addr);
>>> +        return_all_buffers(voutdev, VB2_BUF_STATE_QUEUED);
>>> +        return -EIO;
>>
>> Should this perhaps be EBUSY? What exactly does this error mean?
>> Some comments would be helpful.
>>
>>> +    }
>>> +
>>> +    buf = list_first_entry(&voutdev->buf_list, struct frame_buffer, list);
>>> +    list_del_init(voutdev->buf_list.next);
>>> +
>>> +    if (mgb4_dma_transfer(voutdev->mgbdev, voutdev->config->dma_channel, true,
>>> +                  addr, vb2_dma_sg_plane_desc(&buf->vb.vb2_buf, 0)) < 0) {
>>> +        dev_warn(dev, "DMA transfer error\n");
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
>>> +    } else {
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
>>> +    }
>>> +
>>> +    xdma_enable_user_irq(voutdev->mgbdev->xdev, irq);
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static const struct vb2_ops queue_ops = {
>>> +    .queue_setup = queue_setup,
>>> +    .buf_init = buffer_init,
>>> +    .buf_prepare = buffer_prepare,
>>> +    .buf_queue = buffer_queue,
>>> +    .start_streaming = start_streaming,
>>> +    .stop_streaming = stop_streaming,
>>> +    .wait_prepare = vb2_ops_wait_prepare,
>>> +    .wait_finish = vb2_ops_wait_finish
>>> +};
>>> +
>>> +static int vidioc_querycap(struct file *file, void *priv,
>>> +               struct v4l2_capability *cap)
>>> +{
>>> +    strscpy(cap->driver, KBUILD_MODNAME, sizeof(cap->driver));
>>> +    strscpy(cap->card, "MGB4 PCIe Card", sizeof(cap->card));
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_enum_fmt(struct file *file, void *priv,
>>> +               struct v4l2_fmtdesc *f)
>>> +{
>>> +    if (f->index != 0)
>>> +        return -EINVAL;
>>> +
>>> +    f->pixelformat = V4L2_PIX_FMT_ABGR32;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_fmt(struct file *file, void *priv, struct v4l2_format *f)
>>> +{
>>> +    struct mgb4_vout_dev *voutdev = video_drvdata(file);
>>> +
>>> +    f->fmt.pix.pixelformat = V4L2_PIX_FMT_ABGR32;
>>> +    f->fmt.pix.width = voutdev->width;
>>> +    f->fmt.pix.height = voutdev->height;
>>> +    f->fmt.pix.field = V4L2_FIELD_NONE;
>>> +    f->fmt.pix.colorspace = V4L2_COLORSPACE_RAW;
>>> +    f->fmt.pix.bytesperline = BYTESPERLINE(voutdev->width, voutdev->alignment);
>>> +    f->fmt.pix.sizeimage = f->fmt.pix.width * 4 * f->fmt.pix.height;
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_g_output(struct file *file, void *priv, unsigned int *i)
>>> +{
>>> +    *i = 0;
>>> +    return 0;
>>> +}
>>> +
>>> +static int vidioc_s_output(struct file *file, void *priv, unsigned int i)
>>> +{
>>> +    return i ? -EINVAL : 0;
>>> +}
>>> +
>>> +static int vidioc_enum_output(struct file *file, void *priv, struct v4l2_output *out)
>>> +{
>>> +    if (out->index != 0)
>>> +        return -EINVAL;
>>> +
>>> +    out->type = V4L2_OUTPUT_TYPE_ANALOG;
>>> +    strscpy(out->name, "MGB4", sizeof(out->name));
>>> +
>>> +    return 0;
>>> +}
>>> +
>>> +static const struct v4l2_ioctl_ops video_ioctl_ops = {
>>> +    .vidioc_querycap = vidioc_querycap,
>>> +    .vidioc_enum_fmt_vid_out = vidioc_enum_fmt,
>>> +    .vidioc_try_fmt_vid_out = vidioc_fmt,
>>> +    .vidioc_s_fmt_vid_out = vidioc_fmt,
>>> +    .vidioc_g_fmt_vid_out = vidioc_fmt,
>>> +    .vidioc_enum_output = vidioc_enum_output,
>>> +    .vidioc_g_output = vidioc_g_output,
>>> +    .vidioc_s_output = vidioc_s_output,
>>> +    .vidioc_reqbufs = vb2_ioctl_reqbufs,
>>> +    .vidioc_create_bufs = vb2_ioctl_create_bufs,
>>> +    .vidioc_prepare_buf = vb2_ioctl_prepare_buf,
>>> +    .vidioc_querybuf = vb2_ioctl_querybuf,
>>> +    .vidioc_qbuf = vb2_ioctl_qbuf,
>>> +    .vidioc_dqbuf = vb2_ioctl_dqbuf,
>>> +    .vidioc_expbuf = vb2_ioctl_expbuf,
>>> +    .vidioc_streamon = vb2_ioctl_streamon,
>>> +    .vidioc_streamoff = vb2_ioctl_streamoff,
>>> +};
>>> +
>>> +static int fh_open(struct file *file)
>>> +{
>>> +    struct mgb4_vout_dev *voutdev = video_drvdata(file);
>>> +    struct mgb4_regs *video = &voutdev->mgbdev->video;
>>> +    u32 config, resolution;
>>> +    int ret;
>>> +
>>> +    /* Return EBUSY when the device is in loopback mode */
>>> +    config = mgb4_read_reg(video, voutdev->config->regs.config);
>>> +    if ((config & 0xc) >> 2 != voutdev->config->id + MGB4_VIN_DEVICES)
>>> +        return -EBUSY;
>>
>> A dev_dbg() line might be helpful in this case. Up to you, though.
>>
>>> +
>>> +    mutex_lock(&voutdev->lock);
>>> +
>>> +    ret = v4l2_fh_open(file);
>>> +    if (ret)
>>> +        goto out;
>>> +
>>> +    if (!v4l2_fh_is_singular_file(file))
>>> +        goto out;
>>> +
>>> +    resolution = mgb4_read_reg(video, voutdev->config->regs.resolution);
>>> +    voutdev->width = resolution >> 16;
>>> +    voutdev->height = resolution & 0xFFFF;
>>> +    mgb4_write_reg(video, voutdev->config->regs.padding,
>>> +               PADDING(voutdev->width, voutdev->alignment));
>>> +
>>> +out:
>>> +    mutex_unlock(&voutdev->lock);
>>> +    return ret;
>>> +}
>>> +
>>> +static const struct v4l2_file_operations video_fops = {
>>> +    .owner = THIS_MODULE,
>>> +    .open = fh_open,
>>> +    .release = vb2_fop_release,
>>> +    .unlocked_ioctl = video_ioctl2,
>>> +    .write = vb2_fop_write,
>>> +    .mmap = vb2_fop_mmap,
>>> +    .poll = vb2_fop_poll,
>>> +};
>>> +
>>> +static void dma_transfer(struct work_struct *work)
>>> +{
>>> +    struct mgb4_vout_dev *voutdev = container_of(work, struct mgb4_vout_dev,
>>> +      dma_work);
>>> +    struct device *dev = &voutdev->mgbdev->pdev->dev;
>>> +    struct frame_buffer *buf = 0;
>>> +    unsigned long flags;
>>> +    u32 addr;
>>> +
>>> +    spin_lock_irqsave(&voutdev->qlock, flags);
>>> +    if (!list_empty(&voutdev->buf_list)) {
>>> +        buf = list_first_entry(&voutdev->buf_list, struct frame_buffer, list);
>>> +        list_del_init(voutdev->buf_list.next);
>>> +    }
>>> +    spin_unlock_irqrestore(&voutdev->qlock, flags);
>>> +
>>> +    if (!buf)
>>> +        return;
>>> +
>>> +    addr = mgb4_read_reg(&voutdev->mgbdev->video, voutdev->config->regs.address);
>>> +    if (addr >= ERR_QUEUE_FULL) {
>>> +        dev_warn(dev, "frame queue error (%d)\n", (int)addr);
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
>>> +        return;
>>> +    }
>>> +
>>> +    if (mgb4_dma_transfer(voutdev->mgbdev, voutdev->config->dma_channel, true,
>>> +                  addr, vb2_dma_sg_plane_desc(&buf->vb.vb2_buf, 0)) < 0) {
>>> +        dev_warn(dev, "DMA transfer error\n");
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
>>> +    } else {
>>> +        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
>>> +    }
>>> +}
>>> +
>>> +static irqreturn_t handler(int irq, void *ctx)
>>> +{
>>> +    struct mgb4_vout_dev *voutdev = (struct mgb4_vout_dev *)ctx;
>>> +
>>> +    schedule_work(&voutdev->dma_work);
>>> +
>>> +    mgb4_write_reg(&voutdev->mgbdev->video, 0xB4, 1U << voutdev->config->irq);
>>> +
>>> +    return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int ser_init(struct mgb4_vout_dev *voutdev, int id)
>>> +{
>>> +    int rv, addr_size;
>>> +    size_t values_count;
>>> +    const struct mgb4_i2c_kv *values;
>>> +    const struct i2c_board_info *info;
>>> +    struct device *dev = &voutdev->mgbdev->pdev->dev;
>>> +
>>> +    if (MGB4_IS_GMSL(voutdev->mgbdev))
>>> +        return 0;
>>> +
>>> +    info = &fpdl3_ser_info[id];
>>> +    addr_size = 8;
>>> +    values = fpdl3_i2c;
>>> +    values_count = ARRAY_SIZE(fpdl3_i2c);
>>> +
>>> +    rv = mgb4_i2c_init(&voutdev->ser, voutdev->mgbdev->i2c_adap, info, addr_size);
>>> +    if (rv < 0) {
>>> +        dev_err(dev, "failed to create serializer\n");
>>> +        return rv;
>>> +    }
>>> +    rv = mgb4_i2c_configure(&voutdev->ser, values, values_count);
>>> +    if (rv < 0) {
>>> +        dev_err(dev, "failed to configure serializer\n");
>>> +        goto err_i2c_dev;
>>> +    }
>>> +
>>> +    return 0;
>>> +
>>> +err_i2c_dev:
>>> +    mgb4_i2c_free(&voutdev->ser);
>>> +
>>> +    return rv;
>>> +}
>>> +
>>> +struct mgb4_vout_dev *mgb4_vout_create(struct mgb4_dev *mgbdev, int id)
>>> +{
>>> +    int rv, irq;
>>> +    struct device_attribute **attr, **module_attr;
>>> +    struct mgb4_vout_dev *voutdev;
>>> +    struct mgb4_regs *video;
>>> +    struct pci_dev *pdev = mgbdev->pdev;
>>> +    struct device *dev = &pdev->dev;
>>> +
>>> +    voutdev = kzalloc(sizeof(*voutdev), GFP_KERNEL);
>>> +    if (!voutdev)
>>> +        return NULL;
>>> +
>>> +    voutdev->mgbdev = mgbdev;
>>> +    voutdev->config = &vout_cfg[id];
>>> +    video = &voutdev->mgbdev->video;
>>> +
>>> +    /* Frame queue*/
>>
>> Add space before */
>>
>>> +    INIT_LIST_HEAD(&voutdev->buf_list);
>>> +    spin_lock_init(&voutdev->qlock);
>>> +
>>> +    /* DMA transfer stuff */
>>> +    INIT_WORK(&voutdev->dma_work, dma_transfer);
>>> +
>>> +    /* IRQ callback */
>>> +    irq = xdma_get_user_irq(mgbdev->xdev, voutdev->config->irq);
>>> +    rv = request_irq(irq, handler, 0, "mgb4-vout", voutdev);
>>> +    if (rv) {
>>> +        dev_err(dev, "failed to register irq handler\n");
>>> +        goto err_alloc;
>>> +    }
>>> +
>>> +    /* V4L2 */
>>> +    rv = v4l2_device_register(dev, &voutdev->v4l2dev);
>>> +    if (rv) {
>>> +        dev_err(dev, "failed to register v4l2 device\n");
>>> +        goto err_irq;
>>> +    }
>>> +
>>> +    mutex_init(&voutdev->lock);
>>> +
>>> +    voutdev->queue.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
>>> +    voutdev->queue.io_modes = VB2_MMAP | VB2_DMABUF | VB2_WRITE;
>>
>> Are you sure you want to support VB2_WRITE? Just checking.
>>
>>> +    voutdev->queue.buf_struct_size = sizeof(struct frame_buffer);
>>> +    voutdev->queue.ops = &queue_ops;
>>> +    voutdev->queue.mem_ops = &vb2_dma_sg_memops;
>>> +    voutdev->queue.gfp_flags = GFP_DMA32;
>>> +    voutdev->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
>>> +    voutdev->queue.min_buffers_needed = 2;
>>> +    voutdev->queue.drv_priv = voutdev;
>>> +    voutdev->queue.lock = &voutdev->lock;
>>> +    voutdev->queue.dev = dev;
>>> +    rv = vb2_queue_init(&voutdev->queue);
>>> +    if (rv) {
>>> +        dev_err(dev, "failed to initialize vb2 queue\n");
>>> +        goto err_v4l2_dev;
>>> +    }
>>> +
>>> +    snprintf(voutdev->vdev.name, sizeof(voutdev->vdev.name), "mgb4-out%d", id + 1);
>>> +    voutdev->vdev.device_caps = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_READWRITE
>>> +      | V4L2_CAP_STREAMING;
>>> +    voutdev->vdev.vfl_dir = VFL_DIR_TX;
>>> +    voutdev->vdev.fops = &video_fops;
>>> +    voutdev->vdev.ioctl_ops = &video_ioctl_ops;
>>> +    voutdev->vdev.release = video_device_release_empty;
>>> +    voutdev->vdev.v4l2_dev = &voutdev->v4l2dev;
>>> +    voutdev->vdev.lock = &voutdev->lock;
>>> +    voutdev->vdev.queue = &voutdev->queue;
>>> +    video_set_drvdata(&voutdev->vdev, voutdev);
>>> +
>>> +    rv = video_register_device(&voutdev->vdev, VFL_TYPE_VIDEO, -1);
>>
>> Same as with the input: this should be the last thing in the probe().
>>
>>> +    if (rv) {
>>> +        dev_err(dev, "failed to register video device\n");
>>> +        goto err_v4l2_dev;
>>> +    }
>>> +
>>> +    /* Serializer */
>>> +    rv = ser_init(voutdev, id);
>>> +    if (rv)
>>> +        goto err_video_dev;
>>> +
>>> +    /* Set the FPGA registers default values */
>>> +    mgb4_mask_reg(video, voutdev->config->regs.config, 0xc,
>>> +              (voutdev->config->id + MGB4_VIN_DEVICES) << 2);
>>> +    mgb4_write_reg(video, voutdev->config->regs.resolution,
>>> +               (DEFAULT_WIDTH << 16) | DEFAULT_HEIGHT);
>>> +    mgb4_write_reg(video, voutdev->config->regs.frame_period,
>>> +               DEFAULT_PERIOD);
>>> +
>>> +    /* Module sysfs attributes */
>>> +    voutdev->alignment = 1;
>>> +    module_attr = MGB4_IS_GMSL(mgbdev)
>>> +      ? mgb4_gmsl_out_attrs : mgb4_fpdl3_out_attrs;
>>> +    for (attr = module_attr; *attr; attr++)
>>> +        device_create_file(&voutdev->vdev.dev, *attr);
>>> +
>>> +    /* Set the output frequency according to the FPGA defaults */
>>> +    voutdev->freq = 70000;
>>> +
>>> +    return voutdev;
>>> +
>>> +err_video_dev:
>>> +    video_unregister_device(&voutdev->vdev);
>>> +err_v4l2_dev:
>>> +    v4l2_device_unregister(&voutdev->v4l2dev);
>>> +err_irq:
>>> +    free_irq(irq, voutdev);
>>> +err_alloc:
>>> +    kfree(voutdev);
>>> +
>>> +    return NULL;
>>> +}
>>> +
>>> +void mgb4_vout_free(struct mgb4_vout_dev *voutdev)
>>> +{
>>> +    struct device_attribute **attr, **module_attr;
>>> +    int irq = xdma_get_user_irq(voutdev->mgbdev->xdev, voutdev->config->irq);
>>> +
>>> +    free_irq(irq, voutdev);
>>> +
>>> +    module_attr = MGB4_IS_GMSL(voutdev->mgbdev)
>>> +      ? mgb4_gmsl_out_attrs : mgb4_fpdl3_out_attrs;
>>> +    for (attr = module_attr; *attr; attr++)
>>> +        device_remove_file(&voutdev->vdev.dev, *attr);
>>> +
>>> +    mgb4_i2c_free(&voutdev->ser);
>>> +    video_unregister_device(&voutdev->vdev);
>>> +    v4l2_device_unregister(&voutdev->v4l2dev);
>>> +
>>> +    kfree(voutdev);
>>> +}
>>> diff --git a/drivers/media/pci/mgb4/mgb4_vout.h b/drivers/media/pci/mgb4/mgb4_vout.h
>>> new file mode 100644
>>> index 000000000000..d52676d37b04
>>> --- /dev/null
>>> +++ b/drivers/media/pci/mgb4/mgb4_vout.h
>>> @@ -0,0 +1,58 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-only */
>>> +/*
>>> + * Copyright (C) 2021-2022 Digiteq Automotive
>>> + *     author: Martin Tuma <martin.tuma@digiteqautomotive.com>
>>> + */
>>> +
>>> +#ifndef __MGB4_VOUT_H__
>>> +#define __MGB4_VOUT_H__
>>> +
>>> +#include <media/v4l2-device.h>
>>> +#include <media/v4l2-dev.h>
>>> +#include <media/v4l2-ctrls.h>
>>> +#include <media/videobuf2-core.h>
>>> +#include "mgb4_i2c.h"
>>> +
>>> +struct mgb4_vout_regs {
>>> +    u32 address;
>>> +    u32 config;
>>> +    u32 status;
>>> +    u32 resolution;
>>> +    u32 frame_period;
>>> +    u32 hsync;
>>> +    u32 vsync;
>>> +    u32 padding;
>>> +};
>>> +
>>> +struct mgb4_vout_config {
>>> +    int id;
>>> +    int dma_channel;
>>> +    int irq;
>>> +    struct mgb4_vout_regs regs;
>>> +};
>>> +
>>> +struct mgb4_vout_dev {
>>> +    struct mgb4_dev *mgbdev;
>>> +    struct v4l2_device v4l2dev;
>>> +    struct video_device vdev;
>>> +    struct vb2_queue queue;
>>> +    struct mutex lock; /* vdev lock */
>>> +
>>> +    spinlock_t qlock; /* buffer queue lock */
>>> +    struct list_head buf_list;
>>> +    struct work_struct dma_work;
>>> +
>>> +    u32 width;
>>> +    u32 height;
>>> +    u32 freq;
>>> +    u32 alignment;
>>> +
>>> +    struct mgb4_i2c_client ser;
>>> +
>>> +    const struct mgb4_vout_config *config;
>>> +};
>>> +
>>> +struct mgb4_vout_dev *mgb4_vout_create(struct mgb4_dev *mgbdev, int id);
>>> +void mgb4_vout_free(struct mgb4_vout_dev *voutdev);
>>> +
>>> +#endif
>>
>> Besides the small stuff, the main issue with this driver is how much is
>> done via sysfs. I think that should be reduced and where possible
>> properties should be moved to S_FMT and DV_TIMINGS.
>>
>> Regards,
>>
>>     Hans
>