simple_can_simulator: support different interface for LIN messages

Add a "--lin-interface" option to simple_can_simulator.py to allow
specifying a different CAN interface for the cruise control LIN
messages from the steering wheel in the demo setup.  This allows
pointing at the sllin0 interface in the full demo setup that is
configured with the agl-demo-preload feature.  Previously the
CAN messages for the LIN events were bridged to the primary CAN
interface, but this has proven unreliable in practice.

Bug-AGL: SPEC-4431

Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: I18b2bb8042569e220c79445d310c620dcebac9fc

diff --git a/recipes-demo/simple-can-simulator/files/simple_can_simulator.py b/recipes-demo/simple-can-simulator/files/simple_can_simulator.py
index 83f8870..3d6c85d 100755 (executable)
--- a/recipes-demo/simple-can-simulator/files/simple_can_simulator.py
+++ b/recipes-demo/simple-can-simulator/files/simple_can_simulator.py
@@ -350,13 +350,18 @@ class StatusMessageSender(object):
 def main():
     parser = argparse.ArgumentParser(description='Simple CAN vehicle simulator.')
     parser.add_argument('interface', type=str, help='interface name (e.g. vcan0)')
+    parser.add_argument('--lin-interface', help='Separate LIN interface name (e.g. sllin0)')
     parser.add_argument('-v', '--verbose', help='increase output verbosity', action='store_true')
     args = parser.parse_args()
 
+    lin_interface = args.lin_interface
+    if lin_interface == None:
+        lin_interface = args.interface
+
     try:
         can_sock = CANSocket(args.interface)
         diag_can_sock = CANSocket(args.interface)
-        steeringwheel_can_sock = CANSocket(args.interface)
+        steeringwheel_can_sock = CANSocket(lin_interface)
     except OSError as e:
         sys.stderr.write('Could not listen on interface {0}\n'.format(args.interface))
         sys.exit(e.errno)