isotp update

isotp_async/__init__.py

@@ -1,7 +1,9 @@
 from .carbus_iface import CarBusCanTransport
 from .transport import IsoTpChannel
+from .api import open_isotp
 
 __all__ = [
     "CarBusCanTransport",
     "IsoTpChannel",
+    "open_isotp",
 ]

isotp_async/api.py

@@ -0,0 +1,29 @@
+# isotp_async/api.py
+from __future__ import annotations
+from dataclasses import dataclass
+from typing import Any
+
+from isotp_async import IsoTpChannel, CarBusCanTransport
+
+
+@dataclass(frozen=True)
+class IsoTpEndpoint:
+    tx_id: int
+    rx_id: int
+    channel: int = 1
+
+
+async def open_isotp(dev: Any, *, endpoint: IsoTpEndpoint | None = None,
+                     channel: int = 1, tx_id: int | None = None, rx_id: int | None = None,
+                     **channel_kwargs) -> IsoTpChannel:
+
+    if endpoint is not None:
+        channel = endpoint.channel
+        tx_id = endpoint.tx_id
+        rx_id = endpoint.rx_id
+
+    if tx_id is None or rx_id is None:
+        raise ValueError("tx_id and rx_id are required (or pass endpoint=...)")
+
+    can_tr = CarBusCanTransport(dev, channel=channel, rx_id=rx_id)
+    return IsoTpChannel(can_tr, tx_id=tx_id, rx_id=rx_id, **channel_kwargs)