From 3cbb88ae20ccbcaa3e14b8a9d4c3e4c2f8791c91 Mon Sep 17 00:00:00 2001
From: Peter Barker <pbarker@barker.dropbear.id.au>
Date: Wed, 23 May 2018 16:58:46 +1000
Subject: [PATCH] AP_AHRS: split home-set and home-locked state

---
 libraries/AP_AHRS/AP_AHRS.h          | 19 +++++++++++--------
 libraries/AP_AHRS/AP_AHRS_DCM.cpp    |  1 +
 libraries/AP_AHRS/AP_AHRS_NavEKF.cpp |  5 -----
 libraries/AP_AHRS/AP_AHRS_NavEKF.h   |  3 ---
 4 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/libraries/AP_AHRS/AP_AHRS.h b/libraries/AP_AHRS/AP_AHRS.h
index cd29d6db28..c1a8d62f0d 100644
--- a/libraries/AP_AHRS/AP_AHRS.h
+++ b/libraries/AP_AHRS/AP_AHRS.h
@@ -436,14 +436,18 @@ public:
         return _home;
     }
 
-    enum HomeState home_status(void) const {
-        return _home_status;
+    // functions to handle locking of home.  Some vehicles use this to
+    // allow GCS to lock in a home location.
+    void lock_home() {
+        _home_locked = true;
     }
-    void set_home_status(enum HomeState new_status) {
-        _home_status = new_status;
+    bool home_is_locked() const {
+        return _home_locked;
     }
+
+    // returns true if home is set
     bool home_is_set(void) const {
-        return _home_status != HOME_UNSET;
+        return _home_is_set;
     }
 
     // set the home location in 10e7 degrees. This should be called
@@ -649,6 +653,8 @@ protected:
 
     // reference position for NED positions
     struct Location _home;
+    bool _home_is_set :1;
+    bool _home_locked :1;
 
     // helper trig variables
     float _cos_roll, _cos_pitch, _cos_yaw;
@@ -667,9 +673,6 @@ protected:
 private:
     static AP_AHRS *_singleton;
 
-    // Flag for if we have g_gps lock and have set the home location in AHRS
-    enum HomeState _home_status = HOME_UNSET;
-
 };
 
 #include "AP_AHRS_DCM.h"
diff --git a/libraries/AP_AHRS/AP_AHRS_DCM.cpp b/libraries/AP_AHRS/AP_AHRS_DCM.cpp
index e905140dad..c63f708c7b 100644
--- a/libraries/AP_AHRS/AP_AHRS_DCM.cpp
+++ b/libraries/AP_AHRS/AP_AHRS_DCM.cpp
@@ -1012,6 +1012,7 @@ void AP_AHRS_DCM::set_home(const Location &loc)
 {
     _home = loc;
     _home.options = 0;
+    _home_is_set = true;
 }
 
 //  a relative ground position to home in meters, Down
diff --git a/libraries/AP_AHRS/AP_AHRS_NavEKF.cpp b/libraries/AP_AHRS/AP_AHRS_NavEKF.cpp
index 900aa23b38..a68bb8a464 100644
--- a/libraries/AP_AHRS/AP_AHRS_NavEKF.cpp
+++ b/libraries/AP_AHRS/AP_AHRS_NavEKF.cpp
@@ -587,11 +587,6 @@ Vector2f AP_AHRS_NavEKF::groundspeed_vector(void)
     }
 }
 
-void AP_AHRS_NavEKF::set_home(const Location &loc)
-{
-    AP_AHRS_DCM::set_home(loc);
-}
-
 // set the EKF's origin location in 10e7 degrees.  This should only
 // be called when the EKF has no absolute position reference (i.e. GPS)
 // from which to decide the origin on its own
diff --git a/libraries/AP_AHRS/AP_AHRS_NavEKF.h b/libraries/AP_AHRS/AP_AHRS_NavEKF.h
index cbf14af867..56d3789a18 100644
--- a/libraries/AP_AHRS/AP_AHRS_NavEKF.h
+++ b/libraries/AP_AHRS/AP_AHRS_NavEKF.h
@@ -125,9 +125,6 @@ public:
     // blended accelerometer values in the earth frame in m/s/s
     const Vector3f &get_accel_ef_blended() const override;
 
-    // set home location
-    void set_home(const Location &loc) override;
-
     // set the EKF's origin location in 10e7 degrees.  This should only
     // be called when the EKF has no absolute position reference (i.e. GPS)
     // from which to decide the origin on its own