Implement TimeUSecRTC property

data/org.freedesktop.timedate1.xml

@@ -7,6 +7,7 @@
   <property name="NTP" type="b" access="read"/>
   <property name="CanNTP" type="b" access="read"/>
   <property name="NTPSynchronized" type="b" access="read"/>
+  <property name="TimeUSecRTC" type="t" access="read"/>
   <method name="SetTime">
    <arg name="usec_utc" type="x" direction="in"/>
    <arg name="relative" type="b" direction="in"/>

src/timedate.cpp

@@ -125,12 +125,16 @@ static void slack_get_property(Glib::VariantBase& result, const Glib::RefPtr<Gio
     {
         result = Glib::Variant<bool>::create(dlackware::timedate::ntp_synchronized());
     }
+    else if (prop_name == "TimeUSecRTC")
+    {
+        result = Glib::Variant<std::uint64_t>::create(dlackware::timedate::time_usec_rtc());
+    }
 }
 
 namespace dlackware::timedate
 {
-    constexpr const std::int32_t usec_per_sec = 1000000ULL;
+    constexpr const std::uint64_t usec_per_sec = 1000000ULL;
-    constexpr const std::int32_t nsec_per_usec = 1000ULL;
+    constexpr const std::uint64_t nsec_per_usec = 1000ULL;
 
     timedate1::timedate1()
         : interface_vtable{ &slack_method_call, &slack_get_property }
@@ -247,7 +251,7 @@ namespace dlackware::timedate
         }
     }
 
-    void set_time(gint64 seconds_since_epoch, bool relative, bool)
+    void set_time(std::int64_t seconds_since_epoch, bool relative, bool)
     {
         timespec ts;
 
@@ -333,4 +337,10 @@ namespace dlackware::timedate
         }
         return ntp_result != TIME_ERROR && (buffer.status & STA_UNSYNC) == 0;
     }
+
+    std::uint64_t time_usec_rtc()
+    {
+        return std::chrono::duration_cast<std::chrono::microseconds>(
+                std::chrono::system_clock::now().time_since_epoch()).count();
+    }
 }

src/timedate.h

@@ -43,6 +43,9 @@ namespace dlackware::timedate
     // Shows whether the kernel reports the time as synchronized.
     bool ntp_synchronized();
 
+    // Shows the current time in the RTC.
+    std::uint64_t time_usec_rtc();
+
     // Returns the timezones available on the system.
     std::vector<Glib::ustring> list_timezones();
 
@@ -57,7 +60,7 @@ namespace dlackware::timedate
     // Changes the date/time
     // Takes the amount of seconds since UNIX epoche and 
     // Throws std::system_error.
-    void set_time(gint64 seconds_since_epoch, bool relative, bool user_interaction);
+    void set_time(std::int64_t seconds_since_epoch, bool relative, bool user_interaction);
 
     class timedate1
     {