Add power control interface

methods:
    forcePowerOff
properties:
    PGood
    State

Note:
All the interfaces are the low level interfaces to handle hardware.
And provides supporting the high level interfaces like state-manager.
They are the common interfaces and all the platforms implement them all.

Change-Id: I6d90439879f5a4940cad03fd588dd233f81f2802
Signed-off-by: Kuiying Wang <kuiying.wang@intel.com>
diff --git a/xyz/openbmc_project/Chassis/Control/Power.interface.yaml b/xyz/openbmc_project/Chassis/Control/Power.interface.yaml
new file mode 100644
index 0000000..082586f
--- /dev/null
+++ b/xyz/openbmc_project/Chassis/Control/Power.interface.yaml
@@ -0,0 +1,31 @@
+description: >
+    Power control service
+methods:
+    - name: forcePowerOff
+      description: >
+        Force power off the host.
+      returns:
+        - name: status
+          type: boolean
+          description: >
+            The result of power off command.
+      errors:
+       - xyz.openbmc_project.Chassis.Common.Error.UnsupportedCommand
+       - xyz.openbmc_project.Chassis.Common.Error.IOError
+
+properties:
+    - name: PGood
+      type: boolean
+      default: false
+      description: >
+       PSU Power good property
+       It is a read-only property.
+    - name: State
+      type: int32
+      default: 0
+      description: >
+       System power status
+       0: power is off
+       1: power is on
+       Setting its value to change the system state
+       Read its value to get the system state.
\ No newline at end of file