goodix-gxfp5130-userspace/libfprint-driver

libfprint GXFP5130 integration skeleton

This driver connects libfprint's FpImageDevice state machine to the hardware-tested gxfp_session API. Blocking sensor operations run in a GLib worker thread; all libfprint callbacks run in the main context.

Current discovery is intentionally explicit because the sensor is an ACPI platform/character device, while upstream libfprint has no generic ACPI char device discovery type. Build the driver as an optional virtual-type driver and start libfprint/fprintd with:

FP_GXFP5130=/dev/gxfp

The integration must add gxfp5130 to drivers_info and libfprint_drivers_sources in upstream Meson, include this file, add the GXFP headers, and link the PIC-built libgxfp.a plus mbedTLS libraries.

The first image path uses the verified 64x80 sample order and the deterministic gxfp_image12_to_u8() conversion. No transpose, flip, inversion, percentile clipping, or unverified 0x21 command is applied.

Before upstreaming, replace the environment-backed discovery with a dedicated udev/ACPI character-device discovery mechanism and install permissions for /dev/gxfp.