Support "no init access" feature of Kvaser interfaces (#1955)

* Add keyword argument and set flag accordingly

* Add test case

* Trim trailing whitespace

* Run black formatting

Author: fl0gee

can/interfaces/kvaser/canlib.py

@@ -439,7 +439,8 @@ def __init__(
         :param int data_bitrate:
             Which bitrate to use for data phase in CAN FD.
             Defaults to arbitration bitrate.
-
+        :param bool no_init_access:
+            Don't open the handle with init access.
         """
 
         log.info(f"CAN Filters: {can_filters}")
@@ -455,6 +456,7 @@ def __init__(
         exclusive = kwargs.get("exclusive", False)
         override_exclusive = kwargs.get("override_exclusive", False)
         accept_virtual = kwargs.get("accept_virtual", True)
+        no_init_access = kwargs.get("no_init_access", False)
         fd = isinstance(timing, BitTimingFd) if timing else kwargs.get("fd", False)
         data_bitrate = kwargs.get("data_bitrate", None)
         fd_non_iso = kwargs.get("fd_non_iso", False)
@@ -491,6 +493,8 @@ def __init__(
             flags |= canstat.canOPEN_OVERRIDE_EXCLUSIVE
         if accept_virtual:
             flags |= canstat.canOPEN_ACCEPT_VIRTUAL
+        if no_init_access:
+            flags |= canstat.canOPEN_NO_INIT_ACCESS
         if fd:
             if fd_non_iso:
                 flags |= canstat.canOPEN_CAN_FD_NONISO

test/test_kvaser.py

@@ -277,6 +277,19 @@ def test_bus_get_stats(self):
         self.assertTrue(canlib.canGetBusStatistics.called)
         self.assertIsInstance(stats, canlib.structures.BusStatistics)
 
+    def test_bus_no_init_access(self):
+        canlib.canOpenChannel.reset_mock()
+        bus = can.Bus(interface="kvaser", channel=0, no_init_access=True)
+
+        self.assertGreater(canlib.canOpenChannel.call_count, 0)
+        for call in canlib.canOpenChannel.call_args_list:
+            self.assertEqual(
+                call[0][1] & constants.canOPEN_NO_INIT_ACCESS,
+                constants.canOPEN_NO_INIT_ACCESS,
+            )
+
+        bus.shutdown()
+
     @staticmethod
     def canGetNumberOfChannels(count):
         count._obj.value = 2