Accessing I2C-Bus via ELV USB-I2C

From: Axel Rau <Axel.Rau_at_chaos1.de>
Date: Wed, 27 Apr 2022 21:08:11 UTC
Next journey starts:

For the home2l project, I need a supported I2C interface via USB.
I got this one:
https://de.elv.com/elv-usb-ic-interface-usb-i2c-092255?fs=1805459039
Unfortunately it shows up as a serial device on FreeBSD:

ugen0.2: <Silicon Labs ELV USB-I2C-Interface> at usbus0, cfg=0 md=HOST 
spd=FULL (12Mbps) pwr=ON (500mA)

   bLength = 0x0012
   bDescriptorType = 0x0001
   bcdUSB = 0x0110
   bDeviceClass = 0x0000  <Probed by interface class>
   bDeviceSubClass = 0x0000
   bDeviceProtocol = 0x0000
   bMaxPacketSize0 = 0x0040
   idVendor = 0x10c4
   idProduct = 0xea60
   bcdDevice = 0x0100
   iManufacturer = 0x0001  <Silicon Labs>
   iProduct = 0x0002  <ELV USB-I2C-Interface>
   iSerialNumber = 0x0003  <B5AAP0EEUK6A3CIZ>
   bNumConfigurations = 0x0001

In loader.conf, I have:
uslcom_load="YES"
iic_load="YES"
iicbus_loa

But the i2c utility does not show a new bus.

 From dmesg:
root@axels-bsdbox:~ # dmesg | grep iic
ig4iic0: <Intel Sunrise Point-H I2C Controller-0> mem 
0xdf230000-0xdf230fff irq 16 at device 21.0 on pci0
ig4iic0: Using MSI
iicbus0: <Philips I2C bus (ACPI-hinted)> on ig4iic0
iic0: <I2C generic I/O> on iicbus0
ig4iic1: <Intel Sunrise Point-H I2C Controller-1> mem 
0xdf22f000-0xdf22ffff irq 17 at device 21.1 on pci0
ig4iic1: Using MSI
iicbus1: <Philips I2C bus (ACPI-hinted)> on ig4iic1
iic1: <I2C generic I/O> on iicbus1
root@axels-bsdbox:~ # dmesg | grep I2C
ig4iic0: <Intel Sunrise Point-H I2C Controller-0> mem 
0xdf230000-0xdf230fff irq 16 at device 21.0 on pci0
iicbus0: <Philips I2C bus (ACPI-hinted)> on ig4iic0
iic0: <I2C generic I/O> on iicbus0
ig4iic1: <Intel Sunrise Point-H I2C Controller-1> mem 
0xdf22f000-0xdf22ffff irq 17 at device 21.1 on pci0
iicbus1: <Philips I2C bus (ACPI-hinted)> on ig4iic1
iic1: <I2C generic I/O> on iicbus1
ugen0.2: <Silicon Labs ELV USB-I2C-Interface> at usbus0
uslcom0: <ELV USB-I2C-Interface> on usbus0

They provide a (linux) driver ("Treiber") which seems to implement the 
I2C protocoll on top of the serial interface.
Do we have such a driver on FreeBSD, or exist other supported I2C 
devices to be plugged into USB?

Any help appreciated,
Axel
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