p402: Make HOMING_TIMEOUT_DEFAULT configurable per instance. (#258)

When the HOMING_TIMEOUT_DEFAULT class attribute is overridden as an
object attribute, the argument default value definition in homing()
still uses the old value from the class attribute.  Check the argument
and apply the default value at runtime to pick up the updated default
timeout if the argument is omitted.

Co-authored-by: André Filipe Silva <af-silva@users.noreply.github.com>

Author: acolomb

canopen/profiles/p402.py

@@ -316,6 +316,8 @@ def homing(self, timeout=TIMEOUT_HOMING_DEFAULT):
         :return: If the homing was complete with success.
         :rtype: bool
         """
+        if timeout is None:
+            timeout = self.TIMEOUT_HOMING_DEFAULT
         previus_op_mode = self.op_mode
         self.op_mode = 'HOMING'
         # The homing process will initialize at operation enabled
@@ -335,7 +337,7 @@ def homing(self, timeout=TIMEOUT_HOMING_DEFAULT):
                                     'ERROR VELOCITY IS ZERO'):
                     raise RuntimeError('Unable to home. Reason: {0}'.format(homingstatus))
                 time.sleep(self.INTERVAL_CHECK_STATE)
-                if time.monotonic() > t:
+                if timeout and time.monotonic() > t:
                     raise RuntimeError('Unable to home, timeout reached')
             logger.info('Homing mode carried out successfully.')
             return True