Create Control.FanSpeed interface

The Control.FanSpeed interface contains the 'Target' property that is
intended for setting the requested target RPM speed of a fan.

Change-Id: Id6c1870cdad980886f8a5a551b1da0ad74dc7af9
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/xyz/openbmc_project/Control/FanSpeed.interface.yaml b/xyz/openbmc_project/Control/FanSpeed.interface.yaml
new file mode 100644
index 0000000..3ce4497
--- /dev/null
+++ b/xyz/openbmc_project/Control/FanSpeed.interface.yaml
@@ -0,0 +1,18 @@
+description: >
+    Implement to provide fan speed control. The method of control is hardware
+    dependent and objects implementing Control.FanSpeed must be instantiated
+    within the sensors/fan_tach namespace.
+
+    Any service implementing Control.FanSpeed on one or more objects must
+    implement xyz.openbmc_project.Sensors.Value on the object and
+    org.freedesktop.DBus.ObjectManager on the sensors namespace root.
+
+    All Control.FanSpeed properties are read/write.
+
+properties:
+    - name: Target
+      type: uint64
+      description: >
+          The fan speed target RPM value.
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4