AP_BattMonitor: Add architecture to shutdown batteries

libraries/AP_BattMonitor/AP_BattMonitor.cpp

@@ -1176,6 +1176,68 @@ bool AP_BattMonitor::handle_scripting(uint8_t idx, const BattMonitorScript_State
 }
 #endif
 
+// Returns true if the battery has shutdown functionality
+bool AP_BattMonitor::can_shutdown(uint8_t instance) const
+{
+    if (instance >= AP_BATT_MONITOR_MAX_INSTANCES || drivers[instance] == nullptr) {
+        return false;
+    }
+
+    return drivers[instance]->can_shutdown();
+}
+
+// Returns true if all connected batteries have shutdown functionality
+bool AP_BattMonitor::can_shutdown() const
+{
+    if (_num_instances == 0) {
+        return false;
+    }
+
+    for (uint8_t i=0; i< _num_instances; i++) {
+        if (configured_type(i) != Type::NONE && !can_shutdown(i)) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+// Attempts to shut down a battery (if supported)
+bool AP_BattMonitor::shutdown(uint8_t instance)
+{
+    if (instance >= AP_BATT_MONITOR_MAX_INSTANCES || drivers[instance] == nullptr) {
+        return false;
+    }
+
+    if (configured_type(instance) == Type::NONE) {
+        return true;
+    }
+
+    return drivers[instance]->shutdown();
+}
+
+// Attempts to shut down all batteries that support doing so
+bool AP_BattMonitor::shutdown()
+{
+    if (!can_shutdown() || _num_instances == 0) {
+        return false;
+    }
+
+    for (uint8_t i=0; i< _num_instances; i++) {
+        // Save primary battery for last
+        if (i == AP_BATT_PRIMARY_INSTANCE) {
+            continue;
+        }
+
+        if (!shutdown(i)) {
+            return false;
+        }
+    }
+
+    return shutdown(AP_BATT_PRIMARY_INSTANCE);
+}
+
+
 namespace AP {
 
 AP_BattMonitor &battery()

libraries/AP_BattMonitor/AP_BattMonitor.h

@@ -275,6 +275,15 @@ class AP_BattMonitor
     // sends powering off mavlink broadcasts and sets notify flag
     void checkPoweringOff(void);
 
+    // returns true if all connected batteries can be shutdown by the AP
+    bool can_shutdown(void) const;
+    // returns true if the battery has the capability to be shutdown by the AP
+    bool can_shutdown(uint8_t instance) const;
+    // attempts to shut down all batteries that support doing so
+    bool shutdown(void);
+    // attempts to shut down a battery (if supported)
+    bool shutdown(uint8_t instance);
+
     // reset battery remaining percentage
     bool reset_remaining_mask(uint16_t battery_mask, float percentage);
     bool reset_remaining(uint8_t instance, float percentage) { return reset_remaining_mask(1U<<instance, percentage);}

libraries/AP_BattMonitor/AP_BattMonitor_Backend.h

@@ -85,13 +85,18 @@ class AP_BattMonitor_Backend
     // return mavlink fault bitmask (see MAV_BATTERY_FAULT enum)
     virtual uint32_t get_mavlink_fault_bitmask() const { return 0; }
 
-    // logging functions 
+    // logging functions
     void Log_Write_BAT(const uint8_t instance, const uint64_t time_us) const;
     void Log_Write_BCL(const uint8_t instance, const uint64_t time_us) const;
 
     // set desired MPPT powered state (enabled/disabled)
     virtual void mppt_set_powered_state(bool power_on) {};
 
+    // returns true if the battery can be shutdown with shutdown()
+    virtual bool can_shutdown() { return false; };
+    // shuts the battery down if supported
+    virtual bool shutdown() { return false; };
+
     // Update an ESC telemetry channel's power information
     void update_esc_telem_outbound();
 

libraries/GCS_MAVLink/GCS_Common.cpp

@@ -3389,7 +3389,7 @@ MAV_RESULT GCS_MAVLINK::handle_preflight_reboot(const mavlink_command_int_t &pac
 #endif
     }
 
-    // refuse reboot when armed:
+    // refuse shutdown/reboot when armed:
     if (hal.util->get_soft_armed()) {
         /// but allow it if forced:
         const uint32_t magic_force_reboot_value = 20190226;
@@ -3398,6 +3398,18 @@ MAV_RESULT GCS_MAVLINK::handle_preflight_reboot(const mavlink_command_int_t &pac
         }
     }
 
+#if AP_BATTERY_ENABLED
+    // Check if shutdown is requested
+    if (is_equal(packet.param1, 2.0f)) {
+        // If the battery monitor in use doesn't support shutdown
+        if (!AP::battery().shutdown()){
+            return MAV_RESULT_FAILED;
+        }
+
+        return MAV_RESULT_ACCEPTED;
+    }
+#endif
+
     if (!(is_equal(packet.param1, 1.0f) || is_equal(packet.param1, 3.0f))) {
         // param1 must be 1 or 3 - 1 being reboot, 3 being reboot-to-bootloader
         return MAV_RESULT_UNSUPPORTED;