Re: [PATCH 00/18] media: microchip-isc: Color correction and histogram stats

Hans Verkuil
2025-11-10T09:26:45Z

On 09/10/2025 17:52, Balamanikandan Gunasundar wrote:
> Hi,
>
> This patch series has a set of enhancements to the Microchip Image Sensor
> Controller driver. The objective is to expand its image processing
> capabilities and to improve the colors.
>
> This series also introduces a new stats driver that exposes the histogram
> data to userspace via v4l2 controls. This allows applications such as
> libcamera to access real time image statistics for advanced image
> processing like automatic exposure, white balance adjustments etc.

Note that bisect of this series failed: some patches seem to have dependencies
on later patches, which is obviously wrong. Make sure you double check that
for v2.

The documentation also fails to build since there is no documentation for the
new meta format, but I already commented on that.

Regards,

Hans

>
> Balakrishnan Sambath (11):
> media: microchip-isc: Enable GDC and CBC module flags for RGB formats
> media: microchip-isc: Improve histogram calculation with outlier
> rejection
> media: microchip-isc: Use channel averages for Grey World AWB
> media: microchip-isc: Add range based black level correction
> media: platform: microchip: Extend gamma table and control range
> media: platform: microchip: Add new histogram submodule
> media: microchip-isc: Register and unregister statistics device
> media: microchip-isc: Always enable histogram for all RAW formats
> media: microchip-isc: fix histogram state initialization order
> media: microchip-isc: decouple histogram cycling from AWB mode
> media: microchip-isc: enable userspace histogram statistics export
>
> Balamanikandan Gunasundar (7):
> media: platform: microchip: set maximum resolution for sam9x7
> media: platform: microchip: Include DPC modules flags in pipeline
> media: microchip-isc: expose hue and saturation as v4l2 controls
> media: microchip-isc: Rename CBC to CBHS
> media: microchip-isc: Store histogram data of all channels
> media: videodev2.h, v4l2-ioctl: Add microchip statistics format
> media: microchip-isc: expose color correction registers as v4l2
> controls
>
> drivers/media/platform/microchip/Kconfig | 2 +
> drivers/media/platform/microchip/Makefile | 2 +-
> .../platform/microchip/microchip-isc-base.c | 373 ++++++++++--
> .../platform/microchip/microchip-isc-regs.h | 3 +
> .../platform/microchip/microchip-isc-stats.c | 549 ++++++++++++++++++
> .../media/platform/microchip/microchip-isc.h | 44 +-
> .../microchip/microchip-sama5d2-isc.c | 2 +-
> .../microchip/microchip-sama7g5-isc.c | 73 ++-
> drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
> include/linux/atmel-isc-media.h | 13 +
> include/uapi/linux/videodev2.h | 3 +
> 11 files changed, 1001 insertions(+), 64 deletions(-)
> create mode 100644 drivers/media/platform/microchip/microchip-isc-stats.c
>