1 files changed, 33 insertions, 0 deletions
diff --git a/src/soc/amd/common/block/acpi/acpi.c b/src/soc/amd/common/block/acpi/acpi.c
new file mode 100644
index 0000000000..200b3c12f5
--- /dev/null
+++ b/src/soc/amd/common/block/acpi/acpi.c
@@ -0,0 +1,33 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2018 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/acpi.h>
+#include <soc/southbridge.h>
+#include <amdblocks/acpimmio.h>
+#include <halt.h>
+
+void poweroff(void)
+{
+	acpi_write32(MMIO_ACPI_PM1_CNT_BLK,
+			  (SLP_TYP_S5 << SLP_TYP_SHIFT) | SLP_EN);
+
+	/*
+	 * Setting SLP_TYP_S5 in PM1 triggers SLP_SMI, which is handled by SMM
+	 * to transition to S5 state. If halt is called in SMM, then it prevents
+	 * the SMI handler from being triggered and system never enters S5.
+	 */
+	if (!ENV_SMM)
+		halt();
+}