public List<UsbSerialDriver> findAllDrivers(final UsbManager usbManager) {
        final List<UsbSerialDriver> result = new ArrayList<>();

        for (final UsbDevice usbDevice : usbManager.getDeviceList().values()) {
            final UsbSerialDriver driver = probeDevice(usbDevice);
            if (driver != null) {
                result.add(driver);
            }
        }
        return result;
    }
Finds and builds all possible {@link UsbSerialDriver UsbSerialDrivers}
from the currently-attached {@link UsbDevice} hierarchy. This method does
not require permission from the Android USB system, since it does not
open any of the devices.

@param usbManager usb manager
@return a list, possibly empty, of all compatible drivers
usbSerialForAndroid/src/main/java/com/hoho/android/usbserial/driver/UsbSerialProber.java