1 files changed, 22 insertions, 0 deletions
diff --git a/src/soc/amd/common/block/smn/smn.c b/src/soc/amd/common/block/smn/smn.c
new file mode 100644
index 0000000000..055f732cf7
--- /dev/null
+++ b/src/soc/amd/common/block/smn/smn.c
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <amdblocks/smn.h>
+#include <device/pci_ops.h>
+#include <soc/pci_devs.h>
+#include <types.h>
+
+/* SMN registers accessed indirectly using an index/data pair in D0F00 config space */
+#define SMN_INDEX_ADDR		0xb8 /* 32 bit */
+#define SMN_DATA_ADDR		0xbc /* 32 bit */
+
+uint32_t smn_read32(uint32_t reg)
+{
+	pci_write_config32(SOC_GNB_DEV, SMN_INDEX_ADDR, reg);
+	return pci_read_config32(SOC_GNB_DEV, SMN_DATA_ADDR);
+}
+
+void smn_write32(uint32_t reg, uint32_t val)
+{
+	pci_write_config32(SOC_GNB_DEV, SMN_INDEX_ADDR, reg);
+	pci_write_config32(SOC_GNB_DEV, SMN_DATA_ADDR, val);
+}