Re: [PATCH v2 10/15] staging: vc04_services: bcm2835-isp: Add a more complex ISP processing component

[Stefan Wahren]

Hi Umang,

Am 09.11.23 um 22:03 schrieb Umang Jain:
> From: Naushir Patuck <naush@xxxxxxxxxxxxxxx>
>
> Driver for the BCM2835 ISP hardware block.  This driver uses the MMAL
> component to program the ISP hardware through the VC firmware.
>
> The ISP component can produce two video stream outputs, and Bayer
> image statistics. This can't be encompassed in a simple V4L2
> M2M device, so create a new device that registers 4 video nodes.

sorry, i don't have much knowledge about V4L2, so someone else should
review this in depth.

But from my PoV, patch 11, 12, 13 and 15 should be squash into this one.

> Signed-off-by: Naushir Patuck <naush@xxxxxxxxxxxxxxx>
> Signed-off-by: Umang Jain <umang.jain@xxxxxxxxxxxxxxxx>
> ---
>   MAINTAINERS                                   |    9 +
>   drivers/staging/vc04_services/Kconfig         |    2 +
>   drivers/staging/vc04_services/Makefile        |    1 +
>   .../staging/vc04_services/bcm2835-isp/Kconfig |   14 +
>   .../vc04_services/bcm2835-isp/Makefile        |    4 +
>   .../bcm2835-isp/bcm2835-isp-ctrls.h           |   72 +
>   .../bcm2835-isp/bcm2835-isp-fmts.h            |  482 +++++
>   .../bcm2835-isp/bcm2835-v4l2-isp.c            | 1712 +++++++++++++++++
>   .../vc04_services/vchiq-mmal/mmal-encodings.h |    4 +
>   .../vchiq-mmal/mmal-parameters.h              |  165 +-
>   include/uapi/linux/bcm2835-isp.h              |   27 +
>   11 files changed, 2491 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/staging/vc04_services/bcm2835-isp/Kconfig
>   create mode 100644 drivers/staging/vc04_services/bcm2835-isp/Makefile
>   create mode 100644 drivers/staging/vc04_services/bcm2835-isp/bcm2835-isp-ctrls.h
>   create mode 100644 drivers/staging/vc04_services/bcm2835-isp/bcm2835-isp-fmts.h
>   create mode 100644 drivers/staging/vc04_services/bcm2835-isp/bcm2835-v4l2-isp.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 0748cc15588c..8670a8d95400 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3976,6 +3976,15 @@ F:	Documentation/devicetree/bindings/mips/brcm/
>   F:	arch/mips/bcm47xx/*
>   F:	arch/mips/include/asm/mach-bcm47xx/*
>
> +BROADCOM BCM2835 ISP DRIVER
> +M:	Raspberry Pi Kernel Maintenance <kernel-list@xxxxxxxxxxxxxxx>
> +L:	linux-media@xxxxxxxxxxxxxxx
> +S:	Maintained
> +F:	Documentation/media/uapi/v4l/pixfmt-meta-bcm2835-isp-stats.rst
> +F:	Documentation/media/v4l-drivers/bcm2835-isp.rst
> +F:	drivers/staging/vc04_services/bcm2835-isp
> +F:	include/uapi/linux/bcm2835-isp.h
> +
>   BROADCOM BCM4908 ETHERNET DRIVER
>   M:	Rafał Miłecki <rafal@xxxxxxxxxx>
>   R:	Broadcom internal kernel review list <bcm-kernel-feedback-list@xxxxxxxxxxxx>
> diff --git a/drivers/staging/vc04_services/Kconfig b/drivers/staging/vc04_services/Kconfig
> index 6c0e77d64376..e71e5a8b820a 100644
> --- a/drivers/staging/vc04_services/Kconfig
> +++ b/drivers/staging/vc04_services/Kconfig
> @@ -44,6 +44,8 @@ source "drivers/staging/vc04_services/bcm2835-audio/Kconfig"
>
>   source "drivers/staging/vc04_services/bcm2835-camera/Kconfig"
>
> +source "drivers/staging/vc04_services/bcm2835-isp/Kconfig"
> +
>   source "drivers/staging/vc04_services/vchiq-mmal/Kconfig"
>
>   source "drivers/staging/vc04_services/vc-sm-cma/Kconfig"
> diff --git a/drivers/staging/vc04_services/Makefile b/drivers/staging/vc04_services/Makefile
> index 1f61a263f22d..2cebf92525a0 100644
> --- a/drivers/staging/vc04_services/Makefile
> +++ b/drivers/staging/vc04_services/Makefile
> @@ -16,3 +16,4 @@ obj-$(CONFIG_SND_BCM2835)		+= bcm2835-audio/
>   obj-$(CONFIG_VIDEO_BCM2835)		+= bcm2835-camera/
>   obj-$(CONFIG_BCM2835_VCHIQ_MMAL)	+= vchiq-mmal/
>   obj-$(CONFIG_BCM_VC_SM_CMA)		+= vc-sm-cma/
> +obj-$(CONFIG_VIDEO_ISP_BCM2835) 	+= bcm2835-isp/
> diff --git a/drivers/staging/vc04_services/bcm2835-isp/Kconfig b/drivers/staging/vc04_services/bcm2835-isp/Kconfig
> new file mode 100644
> index 000000000000..6222799ebe16
> --- /dev/null
> +++ b/drivers/staging/vc04_services/bcm2835-isp/Kconfig
> @@ -0,0 +1,14 @@
> +config VIDEO_ISP_BCM2835
> +	tristate "BCM2835 ISP support"
> +	depends on MEDIA_SUPPORT
> +	depends on VIDEO_DEV && (ARCH_BCM2835 || COMPILE_TEST)
> +	depends on MEDIA_CONTROLLER
> +	select BCM2835_VCHIQ_MMAL
> +	select VIDEOBUF2_DMA_CONTIG
> +	help
> +	  This is the V4L2 driver for the Broadcom BCM2835 ISP hardware.

I think the description is not helpful for all users. Not everybody
knows what ISP is for. Please describe it more for an end user.

Best regards

> +	  This operates over the VCHIQ interface to a service running on
> +	  VideoCore.
> +
> +	  To compile this driver as a module, choose M here: the module
> +	  will be called bcm2835-isp.