1 files changed, 100 insertions, 2 deletions
diff --git a/src/northbridge/intel/gm45/acpi/igd.asl b/src/northbridge/intel/gm45/acpi/igd.asl
index f44ce800f0..c5b4b6a007 100644
--- a/src/northbridge/intel/gm45/acpi/igd.asl
+++ b/src/northbridge/intel/gm45/acpi/igd.asl
@@ -161,6 +161,105 @@ Device (GFX0)
 		}
 	}
 
+#ifdef DISPLAY_DEVICE_2_IS_LCD_SCREEN
+	Device (LCD0)
+	{
+		/* Device Unique ID */
+		Method(_ADR, 0, Serialized)
+		{
+			If(LEqual(DID2, 0)) {
+				Return (2)
+			} Else {
+				Return (And(0xffff, DID2))
+			}
+		}
+
+		Name (BRCT, 0)
+
+		Name (BRIG, Package (0x12)
+		{
+			0x61,
+			0x61,
+			0x2,
+			0x4,
+			0x5,
+			0x7,
+			0x9,
+			0xb,
+			0xd,
+			0x11,
+			0x14,
+			0x17,
+			0x1c,
+			0x20,
+			0x27,
+			0x31,
+			0x41,
+			0x61,
+		})
+
+		Method (_BCL, 0, NotSerialized)
+		{
+			Store (1, BRCT)
+			Return (BRIG)
+		}
+
+		Method (_BCM, 1, NotSerialized)
+		{
+			Store (ShiftLeft (Arg0, 4), ^^BCLV)
+			Store (0x80000000, ^^CR1)
+			Store (0x0610, ^^BCLM)
+		}
+		Method (_BQC, 0, NotSerialized)
+		{
+			Store (^^BCLV, Local0)
+			ShiftRight (Local0, 4, Local0)
+			Return (Local0)
+		}
+
+		Method(BRID, 1, NotSerialized)
+		{
+			Store (Match (BRIG, MEQ, Arg0, MTR, Zero, 2), Local0)
+			If (LEqual (Local0, Ones))
+			{
+				Return (0x11)
+			}
+			Return (Local0)
+		}
+
+		/* Using Notify is the right way. But Windows doesn't handle
+		   it well. So use both method in a way to avoid double action.
+		 */
+		Method (DECB, 0, NotSerialized)
+		{
+			If (BRCT)
+			{
+				Notify (LCD0, 0x87)
+			} Else {
+				Store (BRID (_BQC ()), Local0)
+				If (LNotEqual (Local0, 2))
+				{
+					Decrement (Local0)
+				}
+				_BCM (DerefOf (Index (BRIG, Local0)))
+			}
+		}
+		Method (INCB, 0, NotSerialized)
+		{
+			If (BRCT)
+			{
+				Notify (LCD0, 0x86)
+			} Else {
+				Store (BRID (_BQC ()), Local0)
+				If (LNotEqual (Local0, 0x11))
+				{
+					Increment (Local0)
+				}
+				_BCM (DerefOf (Index (BRIG, Local0)))
+			}
+		}
+	}
+#else
 	Device(DD02)
 	{
 		/* Device Unique ID */
@@ -203,7 +302,7 @@ Device (GFX0)
 			}
 		}
 	}
-
+#endif
 
 	Device(DD03)
 	{
@@ -335,5 +434,4 @@ Device (GFX0)
 			}
 		}
 	}
-
 }