The SVDSwiftMMIO tool reads "System View Description" (SVD) files and emits Swift source code from the contained peripheral descriptions.
The emitted code (a "Peripheral Access Package") provides access to the MCU's memory mapped registers. It is based on Swift MMIO.
I'm currently using the tool to generate source code for the RP2040:
> SVDSwiftMMIO $(PICO_SDK_PATH)/src/rp2040/hardware_regs/rp2040.svd ~/Desktop/RP2040MMIO
This will generate a folder "RP2040MMIO" on your Desktop containing a swift implementation file for each of the RP2040's peripherals.