v4.19.13 snapshot.
diff --git a/include/acpi/button.h b/include/acpi/button.h
new file mode 100644
index 0000000..3a2b853
--- /dev/null
+++ b/include/acpi/button.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ACPI_BUTTON_H
+#define ACPI_BUTTON_H
+
+#include <linux/notifier.h>
+
+#if IS_ENABLED(CONFIG_ACPI_BUTTON)
+extern int acpi_lid_notifier_register(struct notifier_block *nb);
+extern int acpi_lid_notifier_unregister(struct notifier_block *nb);
+extern int acpi_lid_open(void);
+#else
+static inline int acpi_lid_notifier_register(struct notifier_block *nb)
+{
+ return 0;
+}
+static inline int acpi_lid_notifier_unregister(struct notifier_block *nb)
+{
+ return 0;
+}
+static inline int acpi_lid_open(void)
+{
+ return 1;
+}
+#endif /* IS_ENABLED(CONFIG_ACPI_BUTTON) */
+
+#endif /* ACPI_BUTTON_H */