jyoung/panda/board/safety/safety_chrysler.h

const int CHRYSLER_MAX_STEER = 261;
const int CHRYSLER_MAX_RT_DELTA = 112;        // max delta torque allowed for real time checks
const uint32_t CHRYSLER_RT_INTERVAL = 250000;  // 250ms between real time checks
const int CHRYSLER_MAX_RATE_UP = 3;
const int CHRYSLER_MAX_RATE_DOWN = 3;
const int CHRYSLER_MAX_TORQUE_ERROR = 80;    // max torque cmd in excess of torque motor

bool chrysler_camera_detected = 0;             // is giraffe switch 2 high?
int chrysler_rt_torque_last = 0;
int chrysler_desired_torque_last = 0;
int chrysler_cruise_engaged_last = 0;
uint32_t chrysler_ts_last = 0;
struct sample_t chrysler_torque_meas;         // last few torques measured

static void chrysler_rx_hook(CAN_FIFOMailBox_TypeDef *to_push) {
  int bus = GET_BUS(to_push);
  int addr = GET_ADDR(to_push);

  // Measured eps torque
  if (addr == 544) {
    int torque_meas_new = ((GET_BYTE(to_push, 4) & 0x7U) << 8) + GET_BYTE(to_push, 5) - 1024U;

    // update array of samples
    update_sample(&chrysler_torque_meas, torque_meas_new);
  }

  // enter controls on rising edge of ACC, exit controls on ACC off
  if (addr == 0x1F4) {
    int cruise_engaged = ((GET_BYTE(to_push, 2) & 0x38) >> 3) == 7;
    if (cruise_engaged && !chrysler_cruise_engaged_last) {
      controls_allowed = 1;
    }
    if (!cruise_engaged) {
      controls_allowed = 0;
    }
    chrysler_cruise_engaged_last = cruise_engaged;
  }

  // check if stock camera ECU is still online
  if ((bus == 0) && (addr == 0x292)) {
    chrysler_camera_detected = 1;
    controls_allowed = 0;
  }
}

static int chrysler_tx_hook(CAN_FIFOMailBox_TypeDef *to_send) {

  int tx = 1;

  // If camera is on bus 0, then nothing can be sent
  if (chrysler_camera_detected) {
    tx = 0;
  }

  int addr = GET_ADDR(to_send);

  // LKA STEER
  if (addr == 0x292) {
    int desired_torque = ((GET_BYTE(to_send, 0) & 0x7U) << 8) + GET_BYTE(to_send, 1) - 1024U;
    uint32_t ts = TIM2->CNT;
    bool violation = 0;

    if (controls_allowed) {

      // *** global torque limit check ***
      violation |= max_limit_check(desired_torque, CHRYSLER_MAX_STEER, -CHRYSLER_MAX_STEER);

      // *** torque rate limit check ***
      violation |= dist_to_meas_check(desired_torque, chrysler_desired_torque_last,
        &chrysler_torque_meas, CHRYSLER_MAX_RATE_UP, CHRYSLER_MAX_RATE_DOWN, CHRYSLER_MAX_TORQUE_ERROR);

      // used next time
      chrysler_desired_torque_last = desired_torque;

      // *** torque real time rate limit check ***
      violation |= rt_rate_limit_check(desired_torque, chrysler_rt_torque_last, CHRYSLER_MAX_RT_DELTA);

      // every RT_INTERVAL set the new limits
      uint32_t ts_elapsed = get_ts_elapsed(ts, chrysler_ts_last);
      if (ts_elapsed > CHRYSLER_RT_INTERVAL) {
        chrysler_rt_torque_last = desired_torque;
        chrysler_ts_last = ts;
      }
    }

    // no torque if controls is not allowed
    if (!controls_allowed && (desired_torque != 0)) {
      violation = 1;
    }

    // reset to 0 if either controls is not allowed or there's a violation
    if (violation || !controls_allowed) {
      chrysler_desired_torque_last = 0;
      chrysler_rt_torque_last = 0;
      chrysler_ts_last = ts;
    }

    if (violation) {
      tx = 0;
    }
  }

  // FORCE CANCEL: safety check only relevant when spamming the cancel button.
  // ensuring that only the cancel button press is sent when controls are off.
  // This avoids unintended engagements while still allowing resume spam
  // TODO: fix bug preventing the button msg to be fwd'd on bus 2

  // 1 allows the message through
  return tx;
}

static void chrysler_init(int16_t param) {
  UNUSED(param);
  controls_allowed = 0;
  chrysler_camera_detected = 0;
}

static int chrysler_fwd_hook(int bus_num, CAN_FIFOMailBox_TypeDef *to_fwd) {

  int bus_fwd = -1;
  int addr = GET_ADDR(to_fwd);
  // forward CAN 0 -> 2 so stock LKAS camera sees messages
  if ((bus_num == 0) && !chrysler_camera_detected) {
    bus_fwd = 2;
  }
  // forward all messages from camera except LKAS_COMMAND and LKAS_HUD
  if ((bus_num == 2) && !chrysler_camera_detected && (addr != 658) && (addr != 678)) {
    bus_fwd = 0;
  }
  return bus_fwd;
}


const safety_hooks chrysler_hooks = {
  .init = chrysler_init,
  .rx = chrysler_rx_hook,
  .tx = chrysler_tx_hook,
  .tx_lin = nooutput_tx_lin_hook,
  .ignition = default_ign_hook,
  .fwd = chrysler_fwd_hook,
};