Add OLED screen toggle

src/ec/system76/ec/Kconfig

@@ -12,3 +12,8 @@ config EC_SYSTEM76_EC_DGPU
 	depends on EC_SYSTEM76_EC
 	bool
 	default n
+
+config EC_SYSTEM76_EC_OLED
+	depends on EC_SYSTEM76_EC
+	bool
+	default n

src/ec/system76/ec/acpi/ec.asl

@@ -97,6 +97,9 @@ Device (\_SB.PCI0.LPCB.EC0)
 	Method (_Q0B, 0, NotSerialized) // Screen Toggle
 	{
 		Debug = "EC: Screen Toggle"
+#if CONFIG(EC_SYSTEM76_EC_OLED)
+		Notify (^^^^S76D, 0x85)
+#endif // CONFIG(EC_SYSTEM76_EC_OLED)
 	}
 
 	Method (_Q0C, 0, NotSerialized)  // Mute

src/ec/system76/ec/acpi/s76.asl

@@ -6,6 +6,7 @@
 //   0x82 - backlight down
 //   0x83 - backlight up
 //   0x84 - backlight color change
+//   0x85 - OLED screen toggle
 Device (S76D) {
 	Name (_HID, "17761776")
 	Name (_UID, 0)

src/mainboard/system76/addw2/Kconfig

@@ -9,6 +9,7 @@ config BOARD_SPECIFIC_OPTIONS
 	select EC_SYSTEM76_EC
 	select EC_SYSTEM76_EC_COLOR_KEYBOARD
 	select EC_SYSTEM76_EC_DGPU
+	select EC_SYSTEM76_EC_OLED
 	select HAVE_ACPI_RESUME
 	select HAVE_ACPI_TABLES
 	select HAVE_SMI_HANDLER