Implement BitTiming/BitTimingFD handling for PCAN Bus (#1514)

* add BitTiming parameter to PcanBus

* Move valid CAN/FD clocks to pcan/basic

* Add additional PCAN constructor tests

* Add tests for BitTiming with PCAN constructor

* Unify PCAN constructor code paths for FD with/without timing

---------

Co-authored-by: zariiii9003 <[email protected]>

Author: lumagi

can/interfaces/pcan/basic.py

@@ -655,6 +655,16 @@ class TPCANChannelInformation(Structure):
     "PCAN_LANBUS16": PCAN_LANBUS16,
 }
 
+VALID_PCAN_CAN_CLOCKS = [8_000_000]
+
+VALID_PCAN_FD_CLOCKS = [
+    20_000_000,
+    24_000_000,
+    30_000_000,
+    40_000_000,
+    60_000_000,
+    80_000_000,
+]
 
 # ///////////////////////////////////////////////////////////
 # PCAN-Basic API function declarations

can/interfaces/pcan/pcan.py

@@ -5,20 +5,21 @@
 import time
 from datetime import datetime
 import platform
-from typing import Optional, List, Tuple
+from typing import Optional, List, Tuple, Union, Any
 
 from packaging import version
 
 from can import (
     BusABC,
     BusState,
+    BitTiming,
+    BitTimingFd,
+    Message,
     CanError,
     CanOperationError,
     CanInitializationError,
-    Message,
 )
-from can.util import len2dlc, dlc2len
-
+from can.util import check_or_adjust_timing_clock, dlc2len, len2dlc
 from .basic import (
     PCAN_BITRATES,
     PCAN_FD_PARAMETER_LIST,
@@ -61,8 +62,11 @@
     FEATURE_FD_CAPABLE,
     PCAN_DICT_STATUS,
     PCAN_BUSOFF_AUTORESET,
+    TPCANBaudrate,
     PCAN_ATTACHED_CHANNELS,
     TPCANChannelInformation,
+    VALID_PCAN_FD_CLOCKS,
+    VALID_PCAN_CAN_CLOCKS,
 )
 
 
@@ -112,12 +116,12 @@
 class PcanBus(BusABC):
     def __init__(
         self,
-        channel="PCAN_USBBUS1",
-        device_id=None,
-        state=BusState.ACTIVE,
-        bitrate=500000,
-        *args,
-        **kwargs,
+        channel: str = "PCAN_USBBUS1",
+        device_id: Optional[int] = None,
+        state: BusState = BusState.ACTIVE,
+        timing: Optional[Union[BitTiming, BitTimingFd]] = None,
+        bitrate: int = 500000,
+        **kwargs: Any,
     ):
         """A PCAN USB interface to CAN.
 
@@ -142,6 +146,18 @@ def __init__(
             BusState of the channel.
             Default is ACTIVE
 
+        :param timing:
+            An instance of :class:`~can.BitTiming` or :class:`~can.BitTimingFd`
+            to specify the bit timing parameters for the PCAN interface. If this parameter
+            is provided, it takes precedence over all other timing-related parameters.
+            If this parameter is not provided, the bit timing parameters can be specified
+            using the `bitrate` parameter for standard CAN or the `fd`, `f_clock`,
+            `f_clock_mhz`, `nom_brp`, `nom_tseg1`, `nom_tseg2`, `nom_sjw`, `data_brp`,
+            `data_tseg1`, `data_tseg2`, and `data_sjw` parameters for CAN FD.
+            Note that the `f_clock` value of the `timing` instance must be 8_000_000
+            for standard CAN or any of the following values for CAN FD: 20_000_000,
+            24_000_000, 30_000_000, 40_000_000, 60_000_000, 80_000_000.
+
         :param int bitrate:
             Bitrate of channel in bit/s.
             Default is 500 kbit/s.
@@ -231,8 +247,7 @@ def __init__(
                 raise ValueError(err_msg)
 
         self.channel_info = str(channel)
-        self.fd = kwargs.get("fd", False)
-        pcan_bitrate = PCAN_BITRATES.get(bitrate, PCAN_BAUD_500K)
+        self.fd = isinstance(timing, BitTimingFd) if timing else kwargs.get("fd", False)
 
         hwtype = PCAN_TYPE_ISA
         ioport = 0x02A0
@@ -245,30 +260,41 @@ def __init__(
 
         self.check_api_version()
 
-        if state is BusState.ACTIVE or state is BusState.PASSIVE:
+        if state in [BusState.ACTIVE, BusState.PASSIVE]:
             self.state = state
         else:
             raise ValueError("BusState must be Active or Passive")
 
-        if self.fd:
-            f_clock_val = kwargs.get("f_clock", None)
-            if f_clock_val is None:
-                f_clock = "{}={}".format("f_clock_mhz", kwargs.get("f_clock_mhz", None))
-            else:
-                f_clock = "{}={}".format("f_clock", kwargs.get("f_clock", None))
-
-            fd_parameters_values = [f_clock] + [
-                f"{key}={kwargs.get(key, None)}"
-                for key in PCAN_FD_PARAMETER_LIST
-                if kwargs.get(key, None) is not None
+        if isinstance(timing, BitTiming):
+            timing = check_or_adjust_timing_clock(timing, VALID_PCAN_CAN_CLOCKS)
+            pcan_bitrate = TPCANBaudrate(timing.btr0 << 8 | timing.btr1)
+            result = self.m_objPCANBasic.Initialize(
+                self.m_PcanHandle, pcan_bitrate, hwtype, ioport, interrupt
+            )
+        elif self.fd:
+            if isinstance(timing, BitTimingFd):
+                timing = check_or_adjust_timing_clock(
+                    timing, sorted(VALID_PCAN_FD_CLOCKS, reverse=True)
+                )
+                # We dump the timing parameters into the kwargs because they have equal names
+                # as the kwargs parameters and this saves us one additional code path
+                kwargs.update(timing)
+
+            clock_param = "f_clock" if "f_clock" in kwargs else "f_clock_mhz"
+            fd_parameters_values = [
+                f"{key}={kwargs[key]}"
+                for key in (clock_param,) + PCAN_FD_PARAMETER_LIST
+                if key in kwargs
             ]
 
-            self.fd_bitrate = " ,".join(fd_parameters_values).encode("ascii")
+            self.fd_bitrate = ", ".join(fd_parameters_values).encode("ascii")
 
             result = self.m_objPCANBasic.InitializeFD(
                 self.m_PcanHandle, self.fd_bitrate
             )
+
         else:
+            pcan_bitrate = PCAN_BITRATES.get(bitrate, PCAN_BAUD_500K)
             result = self.m_objPCANBasic.Initialize(
                 self.m_PcanHandle, pcan_bitrate, hwtype, ioport, interrupt
             )
@@ -312,7 +338,7 @@ def __init__(
             if result != PCAN_ERROR_OK:
                 raise PcanCanInitializationError(self._get_formatted_error(result))
 
-        super().__init__(channel=channel, state=state, bitrate=bitrate, *args, **kwargs)
+        super().__init__(channel=channel, state=state, bitrate=bitrate, **kwargs)
 
     def _find_channel_by_dev_id(self, device_id):
         """

test/test_pcan.py

@@ -3,20 +3,18 @@
 """
 
 import ctypes
-import platform
 import unittest
 from unittest import mock
 from unittest.mock import Mock, patch
 
-
 import pytest
 from parameterized import parameterized
 
 import can
 from can.bus import BusState
 from can.exceptions import CanInitializationError
-from can.interfaces.pcan.basic import *
 from can.interfaces.pcan import PcanBus, PcanError
+from can.interfaces.pcan.basic import *
 
 
 class TestPCANBus(unittest.TestCase):
@@ -53,22 +51,52 @@ def _mockGetValue(self, channel, parameter):
 
     def test_bus_creation(self) -> None:
         self.bus = can.Bus(interface="pcan")
+
         self.assertIsInstance(self.bus, PcanBus)
         self.MockPCANBasic.assert_called_once()
+
         self.mock_pcan.Initialize.assert_called_once()
         self.mock_pcan.InitializeFD.assert_not_called()
 
     def test_bus_creation_state_error(self) -> None:
         with self.assertRaises(ValueError):
             can.Bus(interface="pcan", state=BusState.ERROR)
 
-    def test_bus_creation_fd(self) -> None:
-        self.bus = can.Bus(interface="pcan", fd=True)
+    @parameterized.expand([("f_clock", 8_000_000), ("f_clock_mhz", 8)])
+    def test_bus_creation_fd(self, clock_param: str, clock_val: int) -> None:
+        self.bus = can.Bus(
+            interface="pcan",
+            fd=True,
+            nom_brp=1,
+            nom_tseg1=129,
+            nom_tseg2=30,
+            nom_sjw=1,
+            data_brp=1,
+            data_tseg1=9,
+            data_tseg2=6,
+            data_sjw=1,
+            channel="PCAN_USBBUS1",
+            **{clock_param: clock_val},
+        )
+
         self.assertIsInstance(self.bus, PcanBus)
         self.MockPCANBasic.assert_called_once()
         self.mock_pcan.Initialize.assert_not_called()
         self.mock_pcan.InitializeFD.assert_called_once()
 
+        # Retrieve second argument of first call
+        bitrate_arg = self.mock_pcan.InitializeFD.call_args[0][-1]
+
+        self.assertTrue(f"{clock_param}={clock_val}".encode("ascii") in bitrate_arg)
+        self.assertTrue(b"nom_brp=1" in bitrate_arg)
+        self.assertTrue(b"nom_tseg1=129" in bitrate_arg)
+        self.assertTrue(b"nom_tseg2=30" in bitrate_arg)
+        self.assertTrue(b"nom_sjw=1" in bitrate_arg)
+        self.assertTrue(b"data_brp=1" in bitrate_arg)
+        self.assertTrue(b"data_tseg1=9" in bitrate_arg)
+        self.assertTrue(b"data_tseg2=6" in bitrate_arg)
+        self.assertTrue(b"data_sjw=1" in bitrate_arg)
+
     def test_api_version_low(self) -> None:
         self.PCAN_API_VERSION_SIM = "1.0"
         with self.assertLogs("can.pcan", level="WARNING") as cm:
@@ -333,6 +361,11 @@ def test_state(self, name, bus_state: BusState, expected_parameter) -> None:
                 (PCAN_USBBUS1, PCAN_LISTEN_ONLY, expected_parameter),
             )
 
+    def test_state_constructor(self):
+        for state in [BusState.ACTIVE, BusState.PASSIVE]:
+            bus = can.Bus(interface="pcan", state=state)
+            assert bus.state == state
+
     def test_detect_available_configs(self) -> None:
         if platform.system() == "Darwin":
             self.mock_pcan.GetValue = Mock(
@@ -381,7 +414,8 @@ def get_value_side_effect(handle, param):
         self.mock_pcan.GetValue = Mock(side_effect=get_value_side_effect)
 
         if expected_result == "error":
-            self.assertRaises(ValueError, can.Bus, interface="pcan", device_id=dev_id)
+            with self.assertRaises(ValueError):
+                can.Bus(interface="pcan", device_id=dev_id)
         else:
             self.bus = can.Bus(interface="pcan", device_id=dev_id)
             self.assertEqual(expected_result, self.bus.channel_info)
@@ -416,6 +450,39 @@ def test_peak_fd_bus_constructor_regression(self):
 
         can.Bus(**params)
 
+    def test_constructor_bit_timing(self):
+        timing = can.BitTiming.from_registers(f_clock=8_000_000, btr0=0x47, btr1=0x2F)
+        can.Bus(interface="pcan", channel="PCAN_USBBUS1", timing=timing)
+
+        bitrate_arg = self.mock_pcan.Initialize.call_args[0][1]
+        self.assertEqual(bitrate_arg.value, 0x472F)
+
+    def test_constructor_bit_timing_fd(self):
+        timing = can.BitTimingFd(
+            f_clock=40_000_000,
+            nom_brp=1,
+            nom_tseg1=129,
+            nom_tseg2=30,
+            nom_sjw=1,
+            data_brp=1,
+            data_tseg1=9,
+            data_tseg2=6,
+            data_sjw=1,
+        )
+        can.Bus(interface="pcan", channel="PCAN_USBBUS1", timing=timing)
+
+        bitrate_arg = self.mock_pcan.InitializeFD.call_args[0][-1]
+
+        self.assertTrue(b"f_clock=40000000" in bitrate_arg)
+        self.assertTrue(b"nom_brp=1" in bitrate_arg)
+        self.assertTrue(b"nom_tseg1=129" in bitrate_arg)
+        self.assertTrue(b"nom_tseg2=30" in bitrate_arg)
+        self.assertTrue(b"nom_sjw=1" in bitrate_arg)
+        self.assertTrue(b"data_brp=1" in bitrate_arg)
+        self.assertTrue(b"data_tseg1=9" in bitrate_arg)
+        self.assertTrue(b"data_tseg2=6" in bitrate_arg)
+        self.assertTrue(b"data_sjw=1" in bitrate_arg)
+
 
 if __name__ == "__main__":
     unittest.main()