I too was searching this topic for a way to find which physical USB device was assigned/connected to a logical /dev device name. So, after some trial and error, this is what worked best for me:
See what logical ttyUSBx devices exist (where x is 0, 1, 2...):
$ ls /dev
Show bus and device numbers for all usb-serial adapters:
$ lsusb
Finally, use:
$ udevadm info --name=ttyUSBx --attribute-walk | grep num
Now inspect the udevadm output to match the logical device name to the actual physical device. Here my listing when I did it:
$ lsusb
Bus 002 Device 005: ID 0403:6001 Future Technology Devices International, Ltd FT232 USB-Serial (UART) IC
Bus 002 Device 004: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
Bus 002 Device 002: ID 80ee:0021
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
$ udevadm info --name=ttyUSB0 --attribute-walk | grep num
ATTRS{port_number}=="0"
ATTRS{urbnum}=="812"
ATTRS{busnum}=="2"
ATTRS{devnum}=="5"
ATTRS{urbnum}=="115"
ATTRS{busnum}=="2"
ATTRS{devnum}=="1"
ATTRS{numa_node}=="-1"
$ udevadm info --name=ttyUSB1 --attribute-walk | grep num
ATTRS{port_number}=="0"
ATTRS{urbnum}=="465"
ATTRS{busnum}=="2"
ATTRS{devnum}=="4"
ATTRS{urbnum}=="115"
ATTRS{busnum}=="2"
ATTRS{devnum}=="1"
ATTRS{numa_node}=="-1"
So, in my case, ttyUSB0 is associated with the device on bus2, device5, which is the Future Technology Devices International USB to Serial Adapter; and likewise, ttyUSB1 is associated with the device on bus2, device4, which is the Prolific Technology, Inc. USB to Serial adapter.
And as has been pointed out, the command:
$ usb-devices
Will get you the same info in a one-line manner. I thought I'd post the details that helped me learn how the stuff worked behind the scenes...
Hope that was helpful :)
