ec/lenovo/h8/acpi: Add alternative Fn-F2 and Fn-F3 layout

thinkpad_acpi maps the battery hotkey (KEY_BATTERY) on scancode 0x01 and
the lock hotkey (KEY_COFFEE) on scancode 0x02.

On the Thinkpad X1 Carbon (and possibly others), the hotkeys for Fn-F2
and Fn-F3 are different from the default one so a new layout has to be
defined.

Change-Id: Ib2d96be1a7815d7d03e6e8c6d300fd671c8598ca
Signed-off-by: Nicola Corna <nicola@corna.info>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/31470
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>

src/ec/lenovo/h8/acpi/ec.asl

@@ -195,6 +195,26 @@ Device(EC)
 		^HKEY.RHK (0x01)
 	}
 
+	/*
+	 * Alternative layout (like in the Thinkpad X1 Carbon 1st generation):
+	 *  * Fn-F2 (_Q11) -> not mapped
+	 *  * Fn-F3 (_Q12) -> scancode 0x01 (KEY_COFFEE)
+	 *
+	 * Default layout (like in the Thinkpad X220):
+	 *  * Fn-F2 (_Q11) -> scancode 0x01 (KEY_COFFEE)
+	 *  * Fn-F3 (_Q12) -> scancode 0x02 (KEY_BATTERY)
+	 */
+#ifdef EC_LENOVO_H8_ALT_FN_F2F3_LAYOUT
+	Method (_Q11, 0, NotSerialized)
+	{
+		// Not mapped
+	}
+
+	Method (_Q12, 0, NotSerialized)
+	{
+		^HKEY.RHK (0x02)
+	}
+#else
 	Method (_Q11, 0, NotSerialized)
 	{
 		^HKEY.RHK (0x02)
@@ -204,6 +224,7 @@ Device(EC)
 	{
 		^HKEY.RHK (0x03)
 	}
+#endif
 
 	Method (_Q64, 0, NotSerialized)
 	{

src/mainboard/lenovo/x1_carbon_gen1/dsdt.asl

@@ -20,6 +20,7 @@
 #define BRIGHTNESS_DOWN \_SB.PCI0.GFX0.DECB
 #define ACPI_VIDEO_DEVICE \_SB.PCI0.GFX0
 #define EC_LENOVO_H8_ME_WORKAROUND 1
+#define EC_LENOVO_H8_ALT_FN_F2F3_LAYOUT 1
 
 #include <arch/acpi.h>
 DefinitionBlock(