Remove the inheritance between epoch base and bmc epoch

The epoch_base exists because it was managing bmc_time and host_time
before, and now the host_time has been removed, so the dependency on
epoch_base and bmc_epoch should be removed.

Tested: Built phosphor-time-manager successfully and CI passed.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: Iff87f18d450095f8a673b2d73c50092c65adca20
diff --git a/bmc_epoch.cpp b/bmc_epoch.cpp
index 9fc3097..db4051a 100644
--- a/bmc_epoch.cpp
+++ b/bmc_epoch.cpp
@@ -9,6 +9,7 @@
 #include <phosphor-logging/elog.hpp>
 #include <phosphor-logging/lg2.hpp>
 #include <xyz/openbmc_project/Common/error.hpp>
+#include <xyz/openbmc_project/Time/error.hpp>
 
 // Need to do this since its not exported outside of the kernel.
 // Refer : https://gist.github.com/lethean/446cea944b7441228298
@@ -23,15 +24,17 @@
 {
 namespace time
 {
+namespace // anonymous
+{
+constexpr auto SYSTEMD_TIME_SERVICE = "org.freedesktop.timedate1";
+constexpr auto SYSTEMD_TIME_PATH = "/org/freedesktop/timedate1";
+constexpr auto SYSTEMD_TIME_INTERFACE = "org.freedesktop.timedate1";
+constexpr auto METHOD_SET_TIME = "SetTime";
+} // namespace
+
 namespace server = sdbusplus::xyz::openbmc_project::Time::server;
 using namespace phosphor::logging;
-
-BmcEpoch::BmcEpoch(sdbusplus::bus_t& bus, const char* objPath,
-                   Manager& manager) :
-    EpochBase(bus, objPath, manager)
-{
-    initialize();
-}
+using FailedError = sdbusplus::xyz::openbmc_project::Time::Error::Failed;
 
 void BmcEpoch::initialize()
 {
@@ -109,5 +112,37 @@
     return 0;
 }
 
+void BmcEpoch::onModeChanged(Mode mode)
+{
+    manager.setTimeMode(mode);
+}
+
+bool BmcEpoch::setTime(const microseconds& usec)
+{
+    auto method = bus.new_method_call(SYSTEMD_TIME_SERVICE, SYSTEMD_TIME_PATH,
+                                      SYSTEMD_TIME_INTERFACE, METHOD_SET_TIME);
+    method.append(static_cast<int64_t>(usec.count()),
+                  false,  // relative
+                  false); // user_interaction
+
+    try
+    {
+        bus.call_noreply(method);
+    }
+    catch (const sdbusplus::exception_t& ex)
+    {
+        lg2::error("Error in setting system time: {ERROR}", "ERROR", ex);
+        using namespace xyz::openbmc_project::Time;
+        elog<FailedError>(Failed::REASON(ex.what()));
+    }
+    return true;
+}
+
+microseconds BmcEpoch::getTime() const
+{
+    auto now = system_clock::now();
+    return duration_cast<microseconds>(now.time_since_epoch());
+}
+
 } // namespace time
 } // namespace phosphor