gma ACPI: Make brightness levels a per board setting

Those are actually board specific. Keep the old value as defaults,
though. The defaults are included by all affected boards.

Change-Id: Ib865c7b4274f2ea3181a89fc52701b740f9bab7d
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/11705
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/src/drivers/intel/gma/acpi/configure_brightness_levels.asl b/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
new file mode 100644
index 0000000000..38eb116c67
--- /dev/null
+++ b/src/drivers/intel/gma/acpi/configure_brightness_levels.asl
@@ -0,0 +1,24 @@
+	Method (XBCM, 1, NotSerialized)
+	{
+		Store (Divide (Multiply (Arg0, BCLM), 100), BCLV)
+	}
+
+	Method (XBQC, 0, NotSerialized)
+	{
+		/* Find value close to BCLV in BRIG (which must be ordered) */
+		Store (BCLV, Local0)			// Current value
+		Store (BCLM, Local1)			// For calculations
+		Store (2, Local2)			// Loop index
+		While (LLess (Local2, Subtract (SizeOf (BRIG), 1))) {
+			Store (DeRefOf (Index (BRIG, Local2)), Local3)
+			/* Use same calculation as XBCM, to get exact matches */
+			Store (Divide (Multiply (Local3, Local1), 100), Local3)
+
+			If (LLessEqual (Local0, Local3)) {
+				Return (DeRefOf (Index (BRIG, Local2)))
+			}
+			Add (Local2, 1, Local2)
+		}
+		/* Didn't find greater/equal value: use the last */
+		Return (DeRefOf (Index (BRIG, Local2)))
+	}