Add Interface definition yaml file for physical LED manager

This adds the interface definition file for LED manager daemon that deals with
physical LEDs. It has a property named 'State' which can be written onto for
getting the desired operation triggered on the real LED.

For example, to turn on the LED, write 'ON' to property 'State'

Change-Id: Iee641ab1d4f890f255f1d73e807a57b30d488d16
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>
diff --git a/xyz/openbmc_project/Led/Physical.interface.yaml b/xyz/openbmc_project/Led/Physical.interface.yaml
new file mode 100644
index 0000000..d0ca460
--- /dev/null
+++ b/xyz/openbmc_project/Led/Physical.interface.yaml
@@ -0,0 +1,56 @@
+description: >
+    Interface to control physical LED.
+
+properties:
+    - name: State
+      type: enum[self.Action]
+      default: Off
+      description: >
+        Current State of the LED.
+
+    - name: DutyOn
+      type: byte
+      default: 50
+      description: >
+        Percentage time the LED needs to be ON while blinking.
+
+    - name: Color
+      type: enum[self.Palette]
+      default: Unknown
+      description: >
+        Color that the LED can emit.
+
+enumerations:
+    - name: Action
+      description: >
+          Possible states a LED can be in.
+      values:
+        - name: Off
+          description: >
+            LED is in OFF state
+        - name: On
+          description: >
+            LED is in solid ON state
+        - name: Blink
+          description: >
+            LED is blinking
+
+    - name: Palette
+      description: >
+          Possible colors that the LED can emit.
+      values:
+        - name: Unknown
+          description: >
+            Color emitted by LED is unknown.
+        - name: Red
+          description: >
+            LED can emit Red color.
+        - name: Green
+          description: >
+            LED can emit Green color.
+        - name: Blue
+          description: >
+            LED can emit Blue color.
+        - name: Yellow
+          description: >
+            LED can emit Yellow color.