Hi Laurent,
Thank you for your comment.
We had never imagined that affine driver can be a V4L2 driver. Affine is one of the accelerators in Visconti, and some accelerators receive/yield non-picture data. Also, as the original accelerator drivers were implemented for kernel 4.19.x, we were not aware of the latest V4L2 architecture. Currently, we assume accelerator drivers are kicked individually, not in an image processing pipeline, therefore simple misc driver is enough solution.
Is there any memory-to-memory driver sample/skelton to bring me better understanding?
Best regards, Yuji
-----Original Message----- From: Laurent Pinchart laurent.pinchart@ideasonboard.com Sent: Thursday, April 28, 2022 7:04 AM To: ishikawa yuji(石川 悠司 ○ＲＤＣ□ＡＩＴＣ○ＥＡ開) yuji2.ishikawa@toshiba.co.jp Cc: Rob Herring robh+dt@kernel.org; iwamatsu nobuhiro(岩松 信洋 □ＳＷ Ｃ◯ＡＣＴ) nobuhiro1.iwamatsu@toshiba.co.jp; Sumit Semwal sumit.semwal@linaro.org; Christian König christian.koenig@amd.com; linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; linux-media@vger.kernel.org; dri-devel@lists.freedesktop.org; linaro-mm-sig@lists.linaro.org Subject: Re: [PATCH v2 0/4] Add Toshiba Visconti AFFINE image processing accelerator driver
Hi Yuji,
Thank you for the patch. It's nice to see contributions from Toshiba in the image acceleration domain :-)
I'll start with a high-level question before diving into detailed review. Why is this implemented in drivers/soc/ with a custom userspace API, and not as a V4L2 memory-to-memory driver ?
On Wed, Apr 27, 2022 at 10:23:41PM +0900, Yuji Ishikawa wrote:
This series is the AFFINE image processing accelerator driver for Toshiba's
ARM SoC, Visconti[0].
This provides DT binding documentation, device driver, MAINTAINER files.
The second patch "soc: visconti: Add Toshiba Visconti image processing
accelerator common source"
is commonly used among acclerator drivers (affine, dnn, dspif, pyramid).
Best regards, Yuji
[0]:
https://toshiba.semicon-storage.com/ap-en/semiconductor/product/image-
recognition-processors-visconti.html
dt-bindings: soc: visconti: Add Toshiba Visconti AFFINE image v1 -> v2: - No update
soc: visconti: Add Toshiba Visconti image processing accelerator common
source
v1 -> v2: - apply checkpatch.pl --strictsoc: visconti: Add Toshiba Visconti AFFINE image processing accelerator v1 -> v2: - apply checkpatch.pl --strict - rename hwd_AFFINE_xxxx to hwd_affine_xxxx
MAINTAINERS: Add entries for Toshiba Visconti AFFINE image processing
accelerator
v1 -> v2: - No updateChange in V2:
- apply checkpatch.pl --strict
- rename hwd_AFFINE_xxxx to hwd_affine_xxxx
Yuji Ishikawa (4): dt-bindings: soc: visconti: Add Toshiba Visconti AFFINE image processing accelerator bindings soc: visconti: Add Toshiba Visconti image processing accelerator common source soc: visconti: Add Toshiba Visconti AFFINE image processing accelerator MAINTAINERS: Add entries for Toshiba Visconti AFFINE image processing accelerator
.../soc/visconti/toshiba,visconti-affine.yaml | 53 ++ MAINTAINERS | 2 + drivers/soc/Kconfig | 1 + drivers/soc/Makefile | 1 + drivers/soc/visconti/Kconfig | 7 + drivers/soc/visconti/Makefile | 8 + drivers/soc/visconti/affine/Makefile | 6 + drivers/soc/visconti/affine/affine.c | 451
++++++++++++++++++
drivers/soc/visconti/affine/hwd_affine.c | 206 ++++++++ drivers/soc/visconti/affine/hwd_affine.h | 83 ++++ drivers/soc/visconti/affine/hwd_affine_reg.h | 45 ++ drivers/soc/visconti/ipa_common.c | 55 +++ drivers/soc/visconti/ipa_common.h | 18 + drivers/soc/visconti/uapi/affine.h | 87 ++++ drivers/soc/visconti/uapi/ipa.h | 88 ++++ 15 files changed, 1111 insertions(+) create mode 100644 Documentation/devicetree/bindings/soc/visconti/toshiba,visconti-affine .yaml create mode 100644 drivers/soc/visconti/Kconfig create mode 100644 drivers/soc/visconti/Makefile create mode 100644 drivers/soc/visconti/affine/Makefile create mode 100644 drivers/soc/visconti/affine/affine.c create mode 100644 drivers/soc/visconti/affine/hwd_affine.c create mode 100644 drivers/soc/visconti/affine/hwd_affine.h create mode 100644 drivers/soc/visconti/affine/hwd_affine_reg.h create mode 100644 drivers/soc/visconti/ipa_common.c create mode 100644 drivers/soc/visconti/ipa_common.h create mode 100644 drivers/soc/visconti/uapi/affine.h create mode 100644 drivers/soc/visconti/uapi/ipa.h
-- Regards,
Laurent Pinchart