DataFlash: add reason to MODE

libraries/DataFlash/DataFlash.cpp

@@ -187,9 +187,9 @@ void DataFlash_Class::Log_Write_Message(const char *message)
     FOR_EACH_BACKEND(Log_Write_Message(message));
 }
 
-void DataFlash_Class::Log_Write_Mode(uint8_t mode)
+void DataFlash_Class::Log_Write_Mode(uint8_t mode, uint8_t reason)
 {
-    FOR_EACH_BACKEND(Log_Write_Mode(mode));
+    FOR_EACH_BACKEND(Log_Write_Mode(mode, reason));
 }
 
 void DataFlash_Class::Log_Write_Parameter(const char *name, float value)

libraries/DataFlash/DataFlash.h

@@ -121,7 +121,7 @@ public:
     void Log_Write_Attitude(AP_AHRS &ahrs, const Vector3f &targets);
     void Log_Write_Current(const AP_BattMonitor &battery, int16_t throttle);
     void Log_Write_Compass(const Compass &compass);
-    void Log_Write_Mode(uint8_t mode);
+    void Log_Write_Mode(uint8_t mode, uint8_t reason = 0);
 
     void Log_Write_EntireMission(const AP_Mission &mission);
     void Log_Write_Mission_Cmd(const AP_Mission &mission,

libraries/DataFlash/DataFlash_Backend.h

@@ -88,7 +88,7 @@ public:
     bool Log_Write_Message(const char *message);
     bool Log_Write_Mission_Cmd(const AP_Mission &mission,
                                const AP_Mission::Mission_Command &cmd);
-    bool Log_Write_Mode(uint8_t mode);;
+    bool Log_Write_Mode(uint8_t mode, uint8_t reason = 0);
     bool Log_Write_Parameter(const char *name, float value);
     bool Log_Write_Parameter(const AP_Param *ap,
                              const AP_Param::ParamToken &token,

libraries/DataFlash/LogFile.cpp

@@ -1687,13 +1687,14 @@ void DataFlash_Class::Log_Write_Compass(const Compass &compass)
 }
 
 // Write a mode packet.
-bool DataFlash_Backend::Log_Write_Mode(uint8_t mode)
+bool DataFlash_Backend::Log_Write_Mode(uint8_t mode, uint8_t reason)
 {
     struct log_Mode pkt = {
         LOG_PACKET_HEADER_INIT(LOG_MODE_MSG),
         time_us  : AP_HAL::micros64(),
         mode     : mode,
-        mode_num : mode
+        mode_num : mode,
+        mode_reason : reason
     };
     return WriteCriticalBlock(&pkt, sizeof(pkt));
 }

libraries/DataFlash/LogStructure.h

@@ -445,6 +445,7 @@ struct PACKED log_Mode {
     uint64_t time_us;
     uint8_t mode;
     uint8_t mode_num;
+    uint8_t mode_reason;
 };
 
 /*
@@ -750,7 +751,7 @@ Format characters in the format string for binary log messages
     { LOG_COMPASS_MSG, sizeof(log_Compass), \
       "MAG", "QhhhhhhhhhB",    "TimeUS,MagX,MagY,MagZ,OfsX,OfsY,OfsZ,MOfsX,MOfsY,MOfsZ,Health" }, \
     { LOG_MODE_MSG, sizeof(log_Mode), \
-      "MODE", "QMB",         "TimeUS,Mode,ModeNum" }, \
+      "MODE", "QMBB",         "TimeUS,Mode,ModeNum,Rsn" }, \
     { LOG_RFND_MSG, sizeof(log_RFND), \
       "RFND", "QCC",         "TimeUS,Dist1,Dist2" }, \
     { LOG_DF_MAV_STATS, sizeof(log_DF_MAV_Stats), \