pid/zone: split zone interface into its own header

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I8f516353ddf7777ec750549e748c96afa211ea6e
diff --git a/pid/zone.hpp b/pid/zone.hpp
index 9dc433a..dd90fc5 100644
--- a/pid/zone.hpp
+++ b/pid/zone.hpp
@@ -6,6 +6,7 @@
 #include "sensors/manager.hpp"
 #include "sensors/sensor.hpp"
 #include "tuning.hpp"
+#include "zone_interface.hpp"
 
 #include <sdbusplus/bus.hpp>
 #include <sdbusplus/server.hpp>
@@ -26,20 +27,6 @@
 namespace pid_control
 {
 
-class ZoneInterface
-{
-  public:
-    virtual ~ZoneInterface() = default;
-
-    virtual double getCachedValue(const std::string& name) = 0;
-    virtual void addSetPoint(double setpoint) = 0;
-    virtual void addRPMCeiling(double ceiling) = 0;
-    virtual double getMaxSetPointRequest() const = 0;
-    virtual bool getFailSafeMode() const = 0;
-    virtual double getFailSafePercent() const = 0;
-    virtual Sensor* getSensor(const std::string& name) = 0;
-};
-
 /*
  * The PIDZone inherits from the Mode object so that it can listen for control
  * mode changes.  It primarily holds all PID loops and holds the sensor value
diff --git a/pid/zone_interface.hpp b/pid/zone_interface.hpp
new file mode 100644
index 0000000..f701064
--- /dev/null
+++ b/pid/zone_interface.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include "sensors/sensor.hpp"
+
+#include <string>
+
+namespace pid_control
+{
+
+class ZoneInterface
+{
+  public:
+    virtual ~ZoneInterface() = default;
+
+    virtual double getCachedValue(const std::string& name) = 0;
+    virtual void addSetPoint(double setpoint) = 0;
+    virtual void addRPMCeiling(double ceiling) = 0;
+    virtual double getMaxSetPointRequest() const = 0;
+    virtual bool getFailSafeMode() const = 0;
+    virtual double getFailSafePercent() const = 0;
+    virtual Sensor* getSensor(const std::string& name) = 0;
+};
+
+} // namespace pid_control
diff --git a/test/zone_mock.hpp b/test/zone_mock.hpp
index 541f95c..f5044f8 100644
--- a/test/zone_mock.hpp
+++ b/test/zone_mock.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "pid/zone.hpp"
+#include "pid/zone_interface.hpp"
 
 #include <string>