GM Camera: use ECM brake pressed bit

board/safety/safety_gm.h

@@ -61,6 +61,7 @@ AddrCheckStruct gm_addr_checks[] = {
            {190, 0, 7, .expected_timestep = 100000U},    // Bolt EUV
            {190, 0, 8, .expected_timestep = 100000U}}},  // Escalade
   {.msg = {{452, 0, 8, .expected_timestep = 100000U}, { 0 }, { 0 }}},
+  {.msg = {{201, 0, 8, .expected_timestep = 100000U}, { 0 }, { 0 }}},
 };
 #define GM_RX_CHECK_LEN (sizeof(gm_addr_checks) / sizeof(gm_addr_checks[0]))
 addr_checks gm_rx_checks = {gm_addr_checks, GM_RX_CHECK_LEN};
@@ -119,12 +120,16 @@ static int gm_rx_hook(CANPacket_t *to_push) {
       cruise_button_prev = button;
     }
 
-    if (addr == 190) {
-      // Reference for signal and threshold:
-      // https://github.com/commaai/openpilot/blob/master/selfdrive/car/gm/carstate.py
+    // Reference for brake pressed signals:
+    // https://github.com/commaai/openpilot/blob/master/selfdrive/car/gm/carstate.py
+    if ((addr == 190) && (gm_hw == GM_ASCM)) {
       brake_pressed = GET_BYTE(to_push, 1) >= 8U;
     }
 
+    if ((addr == 201) && (gm_hw == GM_CAM)) {
+      brake_pressed = GET_BIT(to_push, 40U) != 0U;
+    }
+
     if (addr == 452) {
       gas_pressed = GET_BYTE(to_push, 5) != 0U;
 

tests/safety/test_gm.py

@@ -15,9 +15,10 @@ class Buttons:
 
 
 class GmLongitudinalBase(common.PandaSafetyTest):
+  # pylint: disable=no-member,abstract-method
+
   PCM_CRUISE = False  # openpilot can control the PCM state if longitudinal
 
-  # pylint: disable=no-member,abstract-method
   def test_set_resume_buttons(self):
     """
       SET and RESUME enter controls allowed on their falling edge.
@@ -176,11 +177,26 @@ def setUp(self):
     self.safety.init_tests()
 
 
-class TestGmCameraSafety(TestGmSafetyBase):
+class TestGmCameraSafetyBase(TestGmSafetyBase):
+
+  FWD_BUS_LOOKUP = {0: 2, 2: 0}
+
+  @classmethod
+  def setUpClass(cls):
+    if cls.__name__ == "TestGmCameraSafetyBase":
+      cls.packer = None
+      cls.safety = None
+      raise unittest.SkipTest
+
+  def _user_brake_msg(self, brake):
+    values = {"BrakePressed": brake}
+    return self.packer.make_can_msg_panda("ECMEngineStatus", 0, values)
+
+
+class TestGmCameraSafety(TestGmCameraSafetyBase):
   TX_MSGS = [[384, 0],  # pt bus
              [388, 2]]  # camera bus
   FWD_BLACKLISTED_ADDRS = {2: [384], 0: [388]}  # block LKAS message and PSCMStatus
-  FWD_BUS_LOOKUP = {0: 2, 2: 0}
   BUTTONS_BUS = 2  # tx only
 
   def setUp(self):
@@ -212,11 +228,10 @@ def test_gas_safety_check(self):
     pass
 
 
-class TestGmCameraLongitudinalSafety(GmLongitudinalBase, TestGmSafetyBase):
+class TestGmCameraLongitudinalSafety(GmLongitudinalBase, TestGmCameraSafetyBase):
   TX_MSGS = [[384, 0], [789, 0], [715, 0], [880, 0],  # pt bus
              [388, 2]]  # camera bus
   FWD_BLACKLISTED_ADDRS = {2: [384, 715, 880, 789], 0: [388]}  # block LKAS, ACC messages and PSCMStatus
-  FWD_BUS_LOOKUP = {0: 2, 2: 0}
   BUTTONS_BUS = 0  # rx only
 
   MAX_GAS = 3400