resource: restore ModbusRTU resource but mark as deprecated,

ensuring backwards compatibility

Signed-off-by: Felix Zwettler <[email protected]>

labgrid/resource/__init__.py

@@ -2,6 +2,7 @@
 from .ethernetport import SNMPEthernetPort
 from .serialport import RawSerialPort, NetworkSerialPort
 from .modbus import ModbusTCPCoil
+from .modbusrtu import ModbusRTU
 from .networkservice import NetworkService
 from .onewireport import OneWirePIO
 from .power import NetworkPowerPort, PDUDaemonPort

labgrid/resource/modbusrtu.py

@@ -0,0 +1,17 @@
+import warnings
+import attr
+
+from ..factory import target_factory
+from .base import SerialPort
+
+
+@target_factory.reg_resource
+@attr.s(eq=False)
+class ModbusRTU():
+    def __new__(cls, *args, **kwargs):
+        warnings.warn(
+            "The ModbusRTU class is deprecated. Use SerialPort instead.",
+            DeprecationWarning,
+            stacklevel=2,
+        )
+        return SerialPort(*args, **kwargs)