A 3G modem with GPS support built into some IBM/Lenovo ThinkPad laptops.

See also https://www.thinkwiki.org/wiki/Qualcomm_Gobi_2000

You can verify the ID with lsusb, on mine it's 05c6:9204. Take note of it, it's going to be important later.

Install gobi-loader from the AUR or whatever package manager your distro uses. It should have the necessary udev rules to load the necessary firmware at boot.

all of this could easily be a PKGBUILD

Next, obtain a copy of 7xwc48ww.exe, unpack it with innoextract and msitools, and copy the necessary files in the correct place.

innoextract 7xwc48ww.exe -I app/Driver/GobiInstaller.msi
msiextract -C GobiInstaller app/Driver/GobiInstaller.msi
cd GobiInstaller/Images/Lenovo
sudo mkdir -p /lib/firmware/gobi
sudo cp 6/* /lib/firmware/gobi
sudo cp UMTS/* /lib/firmware/gobi

This copies the generic ones, refer to this table if you have a carrier in the list.

Now you can reboot. If successful, the ID in lsusb should change to 05c6:9205, and you should have 3 devices starting with /dev/ttyUSB instead of only one. You should now be able to use it with ModemManager.

Create these two files, and make the script executable.

/etc/udev/enable_gps

#!/bin/sh
stty -F $1 speed 9600
echo "\$GPS_START" > $1

/etc/udev/rules.d/60-gps.rules

SUBSYSTEM=="tty", ATTRS{idVendor}=="05c6", ATTRS{idProduct}=="9205", SYMLINK+="gobi%n" GOTO="gobigps"
GOTO="gobigps_end"
 
LABEL="gobigps"
ATTRS{bInterfaceNumber}=="02", SYMLINK+="modem"
ATTRS{bInterfaceNumber}=="03", SYMLINK+="gps", RUN+="/etc/udev/enable_gps $devnode"
 
LABEL="gobigps_end"

sudo chmod +x /etc/udev/enable_gps

You should now be able to see NMEA data out of /dev/gps. If it doesn't, try with another set of firmware. Then, you can use gpsd and sync time with ntp.

/etc/default/gpsd

GPSD_OPTIONS="-n"
DEVICES="/dev/gps"

sudo systemctl enable gpsd
sudo systemctl start gpsd
cgps -s

use geoclue to get google maps working?

Start gpsd, then add something like this to your chrony.conf:

/etc/chrony.conf

refclock SHM 0 delay 0.0 refid NMEA

sudo systemctl enable chronyd
sudo systemctl start chronyd
watch -n1 chronyc sources