Hello Laurent,

-----Original Message-----
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Sent: Friday, August 2, 2024 1:06 AM
To: ishikawa yuji(石川 悠司 ○ＲＤＣ□ＡＩＴＣ○ＥＡ開)
[off-list ref]
Cc: hverkuil@xs4all.nl; mchehab@kernel.org; robh@kernel.org;
krzk+dt@kernel.org; conor+dt@kernel.org; broonie@kernel.org;
sakari.ailus@linux.intel.com; iwamatsu nobuhiro(岩松 信洋 ○ＤＩＴＣ□ＤＩ
Ｔ○ＯＳＴ) [off-list ref];
linux-media@vger.kernel.org; devicetree@vger.kernel.org;
linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org
Subject: Re: [PATCH v11 5/6] documentation: media: add documentation for
Toshiba Visconti Video Input Interface driver

Hello Ishikawa-san,

On Thu, Aug 01, 2024 at 09:23:43AM +0000, yuji2.ishikawa@toshiba.co.jp
wrote:

quoted

On Tuesday, July 23, 2024 3:03 AM, Laurent Pinchart wrote:

quoted

On Tue, Jul 09, 2024 at 09:08:47AM +0900, Yuji Ishikawa wrote:

quoted

Added description of Video Input Interface driver of Toshiba
Visconti architecture.
It includes hardware organization, structure of the driver and
metadata format for embedded image signal processor.

Signed-off-by: Yuji Ishikawa <redacted>
---
Changelog v3:
- Newly add documentation to describe SW and HW

Changelog v4:
- no change

Changelog v5:
- no change

Changelog v6:
- add description of CSI2RX subdevice
- add ordering of ioctl(S_FMT) and ioctl(S_EXT_CTRLS)

Changelog v7:
- no change

Changelog v8:
- add usage of V4L2_CTRL_TYPE_VISCONTI_ISP

Changelog v9:
- fix warning: set reference target for keyword
V4L2_CTRL_TYPE_VISCONTI_ISP

Changelog v10:
- use parameter buffers instead of compound control
  - removed description of vendor specific compound control
  - add description of parameter buffers for ISP control
- update directory structure
  - remove documents under driver-api
  - add documents to admin-guide, userspace-api

Changelog v11:
- update usage of the driver

 .../admin-guide/media/v4l-drivers.rst         |   1 +
 .../admin-guide/media/visconti-viif.dot       |  18 ++
 .../admin-guide/media/visconti-viif.rst       | 255

++++++++++++++++++

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 .../userspace-api/media/v4l/meta-formats.rst  |   1 +
 .../media/v4l/metafmt-visconti-viif.rst       |  48 ++++
 5 files changed, 323 insertions(+)  create mode 100644
Documentation/admin-guide/media/visconti-viif.dot
 create mode 100644
Documentation/admin-guide/media/visconti-viif.rst
 create mode 100644
Documentation/userspace-api/media/v4l/metafmt-visconti-viif.rst

[snip]

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diff --git a/Documentation/admin-guide/media/visconti-viif.rst

b/Documentation/admin-guide/media/visconti-viif.rst
new file mode 100644
index 0000000000..4ef676754c

--- /dev/null
+++ b/Documentation/admin-guide/media/visconti-viif.rst

@@ -0,0 +1,255 @@

[snip]

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+viif_capture_sub - Raw Image Capture Video Node
+-----------------------------------------------
+
+This video node is used for capturing bayer image from the sensor.
+The output picture has exactly the same resolution and format as the

sensor input.

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+The following depth of bayer format is supported:
+
+- 8bit
+- 10bit
+- 12bit
+- 14bit

Does the hardware support capturing embedded data from the sensor ?

The hardware supports capturing embdded data, however the software is
not fully tested for that feature.

OK. Support for this can be added later. I recommend already checking what it
would imply in terms of changes to the media graph. Changing the media graph
later in a way that could break userspace won't be allowed, so it's worth it
preparing for embedded data support in the media graph design already.
Adding new pads to existing entities and adding new entities later are fine, but
renumbering existing pads or inserting new entities between two existing
entities could break userspace.

Thank you for the advice. I will be careful not to break the userspace in future releases.

[snip]

--
Regards,

Laurent Pinchart

Regards,
Yuji Ishikawa