/sys/class/tty/ttyd1/subsystem/ttyS0/device/bus/devices/rt3xxx-ehci/usb2/2-0%3A1.0/

../
bAlternateSetting                4096
bInterfaceClass                  4096
bInterfaceNumber                 4096
bInterfaceProtocol               4096
bInterfaceSubClass               4096
bNumEndpoints                    4096
bus/
driver/
ep_81/
modalias                         4096
subsystem/
uevent                           4096
usb_endpoint:usbdev2.1_ep81/