Plane: Use new landing interfaces

ArduPlane/ArduPlane.cpp

@@ -559,7 +559,7 @@ void Plane::handle_auto_mode(void)
         // allow landing to restrict the roll limits
         nav_roll_cd = landing.constrain_roll(nav_roll_cd, g.level_roll_limit*100UL);
 
-        if (landing.is_complete()) {
+        if (landing.is_throttle_suppressed()) {
             // if landing is considered complete throttle is never allowed, regardless of landing type
             SRV_Channels::set_output_scaled(SRV_Channel::k_throttle, 0);
         } else {
@@ -950,7 +950,6 @@ void Plane::update_flight_stage(void)
                 } else {
                     set_flight_stage(AP_Vehicle::FixedWing::FLIGHT_LAND);
                 }
-
             } else if (quadplane.in_assisted_flight()) {
                 set_flight_stage(AP_Vehicle::FixedWing::FLIGHT_VTOL);
             } else {

ArduPlane/Attitude.cpp

@@ -226,7 +226,7 @@ void Plane::stabilize_yaw(float speed_scaler)
         // are below the GROUND_STEER_ALT
         steering_control.ground_steering = (channel_roll->get_control_in() == 0 && 
                                             fabsf(relative_altitude) < g.ground_steer_alt);
-        if (landing.is_on_approach()) {
+        if (!landing.is_ground_steering_allowed()) {
             // don't use ground steering on landing approach
             steering_control.ground_steering = false;
         }

ArduPlane/altitude.cpp

@@ -25,6 +25,8 @@
  */
 void Plane::adjust_altitude_target()
 {
+    Location target_location;
+
     if (control_mode == FLY_BY_WIRE_B ||
         control_mode == CRUISE) {
         return;
@@ -36,6 +38,8 @@ void Plane::adjust_altitude_target()
     } else if (landing.is_on_approach()) {
         landing.setup_landing_glide_slope(prev_WP_loc, next_WP_loc, current_loc, target_altitude.offset_cm);
         landing.adjust_landing_slope_for_rangefinder_bump(rangefinder_state, prev_WP_loc, next_WP_loc, current_loc, auto_state.wp_distance, target_altitude.offset_cm);
+    } else if (landing.get_target_altitude_location(target_location)) {
+       set_target_altitude_location(target_location);
     } else if (reached_loiter_target()) {
         // once we reach a loiter target then lock to the final
         // altitude target

ArduPlane/servos.cpp

@@ -48,6 +48,8 @@ void Plane::throttle_slew_limit(void)
    *       4 - We are not performing a takeoff in Auto mode or takeoff speed/accel not yet reached
    *       OR
    *       5 - Home location is not set
+   *       OR
+   *       6- Landing does not want to allow throttle
 */
 bool Plane::suppress_throttle(void)
 {
@@ -59,6 +61,10 @@ bool Plane::suppress_throttle(void)
     }
 #endif
 
+    if (landing.is_throttle_suppressed()) {
+        return true;
+    }
+
     if (!throttle_suppressed) {
         // we've previously met a condition for unsupressing the throttle
         return false;