Re: [PATCH 0/4] drivers/misc: add Goodix GXFP5130 eSPI fingerprint sensor driver

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Jul 19, 2026 at 03:53:06AM -0700, Metehan Günen wrote:
> On Sat, Jul 18, 2026 at 11:05:30AM +0200, Greg KH wrote:
> > Is that the "normal" user/kernel api for these types of sensors?  I
> > thought we had a real api these days, and a vendor one was not generally
> > a good idea as you are just exposing raw hardware design to userspace.
> 
> The GXFP5130 communicates using a vendor-specific MP protocol over the
> eSPI mailbox — it is not USB HID-compliant and does not expose a
> standard fingerprint command set. The libfprint plugin that consumes
> this device speaks the protocol directly and handles enrollment and
> matching entirely in userspace, the same model used by other libfprint
> char-device backends (e.g. goodix-55x4, elan-i2c).
> 
> I am open to alternative approaches. If there is a preferred kernel-side
> abstraction for this class of device I should be targeting instead,
> please point me to it and I will rework the driver accordingly.

Why does it have to be a kernel driver at all?  Can't you just talk to
the device directly from userspace through the spi userspace api
instead?

thanks,

greg k-h