soc/amd/cezanne: add SMU support

BUG=b:181766974

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I5b9b4c3d57945ea7c3287cf47f3d9704f42ff24b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51233
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/src/soc/amd/cezanne/smu.c b/src/soc/amd/cezanne/smu.c
new file mode 100644
index 0000000000..1496957117
--- /dev/null
+++ b/src/soc/amd/cezanne/smu.c
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <amdblocks/smu.h>
+#include <soc/smu.h>
+
+/*
+ * Request the SMU to put system into S3, S4, or S5. On entry, SlpTyp determines S-State and
+ * SlpTypeEn gets set by the SMU. Function does not return if successful.
+ */
+void smu_sx_entry(void)
+{
+	struct smu_payload msg = { 0 }; /* Unused for SMC_MSG_S3ENTRY */
+
+	printk(BIOS_DEBUG, "SMU: Put system into S3/S4/S5\n");
+	send_smu_message(SMC_MSG_S3ENTRY, &msg);
+}