1 files changed, 33 insertions, 0 deletions
diff --git a/src/southbridge/intel/common/early_smbus.c b/src/southbridge/intel/common/early_smbus.c
new file mode 100644
index 0000000000..d65b4aaf81
--- /dev/null
+++ b/src/southbridge/intel/common/early_smbus.c
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <device/pci_def.h>
+#include <device/pci_ids.h>
+#include <device/pci_ops.h>
+#include <device/smbus_host.h>
+#include "early_smbus.h"
+
+uintptr_t smbus_base(void)
+{
+	return CONFIG_FIXED_SMBUS_IO_BASE;
+}
+
+int smbus_enable_iobar(uintptr_t base)
+{
+	/* Set the SMBus device statically. */
+	const pci_devfn_t dev = PCI_DEV_SMBUS;
+
+	/* Check to make sure we've got the right device. */
+	if (pci_read_config16(dev, PCI_VENDOR_ID) != PCI_VENDOR_ID_INTEL)
+		return -1;
+
+	/* Set SMBus I/O base. */
+	pci_write_config32(dev, SMB_BASE, base | PCI_BASE_ADDRESS_SPACE_IO);
+
+	/* Set SMBus enable. */
+	pci_write_config8(dev, HOSTC, HST_EN);
+
+	/* Set SMBus I/O space enable. */
+	pci_write_config16(dev, PCI_COMMAND, PCI_COMMAND_IO);
+
+	return 0;
+}