code: def read_data_chunksize
        p = FFI::MemoryPointer.new(:uint, 1)
        check_result(Ftdi.ftdi_read_data_get_chunksize(ctx, p))
        p.read_uint
      end
docs: Gets read buffer chunk size.
   @return [Fixnum] Read buffer chunk size.
   @raise [StatusCodeError] libftdi reports error.
   @see #read_data_chunksize=