Re: [PATCH v5 0/8] media: Introduce V4L2 generic ISP support
From: Sakari Ailus <sakari.ailus@linux.intel.com>
Date: 2025-10-02 08:17:10
Also in:
linux-media, linux-rockchip, lkml
Hi Jacopo, On Mon, Sep 15, 2025 at 07:18:09PM +0200, Jacopo Mondi wrote:
Extensible parameters meta formats have been introduced in the Linux
kernel v6.12 initially to support different revision of the RkISP1 ISP
implemented in different SoC. In order to avoid breaking userspace
everytime an ISP configuration block is added or modified in the uAPI
these new formats, which are versionated and extensible by their
definition have been introduced.
See for reference:
e9d05e9d5db1 ("media: uapi: rkisp1-config: Add extensible params format")
6c53a7b68c5d ("media: rkisp1: Implement extensible params support")
The Amlogic C3 ISP driver followed shortly, introducing an extensible
format for the ISP configuration:
6d406187ebc0 ("media: uapi: Add stats info and parameters buffer for C3 ISP")
with a very similar, if not identical, implementation of the routines to
validate and handle the ISP configuration in the ISP driver in the
c3-isp-params.c file.
fb2e135208f3 ("media: platform: Add C3 ISP driver")
With the recent upstreaming attempt of the Mali C55 ISP driver from Dan,
a third user of extensible parameters is going to be itroduced in the
kernel, duplicating again in the driver the procedure for validating and
handling the ISP configuration blocks
https://patchwork.linuxtv.org/project/linux-media/patch/20250624-c55-v10-15-54f3d4196990@ideasonboard.com/
To avoid duplicating again the validation routines and common types
definition, this series introduces v4l2-isp.c/.h for the kAPI
and v4l2-isp.h for the uAPI and re-organize the RkISP1
and Amlogic C3 drivers to use the common types and the helper validation
routines.
The v4l2-isp abstraction will be augmented to support statistcs as well.
If the here proposed approach is accepted, I propose to rebase the Mali
C55 driver on top of this series, to use the new common types and
helpers.
I have been able to test this on RkISP1 but not on C3.Thank you for working on this. Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> -- Kind regards, Sakari Ailus