Re: [PATCH v2 2/2] mfd: Add initial synology microp driver

[Greg Kroah-Hartman]

On Sun, Mar 08, 2026 at 06:41:20PM +0000, Markus Probst wrote:
> Add a initial synology microp driver, written in Rust.
> The driver targets a microcontroller found in Synology NAS devices. It
> currently only supports controlling of the power led, status led, alert
> led and usb led. Other components such as fan control or handling
> on-device buttons will be added once the required rust abstractions are
> there.

Why is this a mfd device?  Shouldn't it be an aux device?

But this is just a serial port connection, so why is a kernel driver
needed at all?

> Signed-off-by: Markus Probst <markus.probst@xxxxxxxxx>
> ---
>  MAINTAINERS                                    |   6 +
>  drivers/mfd/Kconfig                            |   2 +
>  drivers/mfd/Makefile                           |   2 +
>  drivers/mfd/synology_microp/Kconfig            |  14 ++
>  drivers/mfd/synology_microp/Makefile           |   2 +
>  drivers/mfd/synology_microp/TODO               |   7 +
>  drivers/mfd/synology_microp/command.rs         |  50 +++++
>  drivers/mfd/synology_microp/led.rs             | 275 +++++++++++++++++++++++++
>  drivers/mfd/synology_microp/synology_microp.rs |  82 ++++++++
>  rust/uapi/uapi_helper.h                        |   2 +
>  10 files changed, 442 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e9e83ab552c7..092cd9e8a730 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -25550,6 +25550,12 @@ F:	drivers/dma-buf/sync_*
>  F:	include/linux/sync_file.h
>  F:	include/uapi/linux/sync_file.h
>  
> +SYNOLOGY MICROP DRIVER
> +M:	Markus Probst <markus.probst@xxxxxxxxx>
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/mfd/synology,microp.yaml
> +F:	drivers/mfd/synology_microp/
> +
>  SYNOPSYS ARC ARCHITECTURE
>  M:	Vineet Gupta <vgupta@xxxxxxxxxx>
>  L:	linux-snps-arc@xxxxxxxxxxxxxxxxxxx
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 7192c9d1d268..bc269719749f 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -2580,5 +2580,7 @@ config MFD_MAX7360
>  	  additional drivers must be enabled in order to use the functionality
>  	  of the device.
>  
> +source "drivers/mfd/synology_microp/Kconfig"
> +
>  endmenu
>  endif
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index e75e8045c28a..0a6fa33d5c35 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -304,3 +304,5 @@ obj-$(CONFIG_MFD_RSMU_SPI)	+= rsmu_spi.o rsmu_core.o
>  obj-$(CONFIG_MFD_UPBOARD_FPGA)	+= upboard-fpga.o
>  
>  obj-$(CONFIG_MFD_LOONGSON_SE)	+= loongson-se.o
> +
> +obj-$(CONFIG_MFD_SYNOLOGY_MICROP)	+= synology_microp/
> diff --git a/drivers/mfd/synology_microp/Kconfig b/drivers/mfd/synology_microp/Kconfig
> new file mode 100644
> index 000000000000..4bbbcf0b6e94
> --- /dev/null
> +++ b/drivers/mfd/synology_microp/Kconfig
> @@ -0,0 +1,14 @@
> +
> +config MFD_SYNOLOGY_MICROP
> +	tristate "Synology Microp driver"
> +	depends on RUST
> +	depends on SERIAL_DEV_BUS

We don't have rust serdev bindings yet, but if we do, shouldn't you just
depend on them instead of two different things here?


> +	depends on LEDS_CLASS && LEDS_CLASS_MULTICOLOR
> +	default n

n is always the default, no need to say it again :)

thanks,

greg k-h