1 files changed, 60 insertions, 0 deletions
diff --git a/src/mainboard/prodrive/atlas/vpd.c b/src/mainboard/prodrive/atlas/vpd.c
new file mode 100644
index 000000000000..12371f71e6b7
--- /dev/null
+++ b/src/mainboard/prodrive/atlas/vpd.c
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <console/console.h>
+#include <string.h>
+#include <types.h>
+
+#include "ec.h"
+#include "mainboard.h"
+#include "vpd.h"
+
+const union emi_eeprom_vpd *get_emi_eeprom_vpd(void)
+{
+	static union emi_eeprom_vpd vpd = {0};
+
+	/* Check if cached VPD is valid */
+	if (vpd.header.revision == VPD_LATEST_REVISION)
+		return &vpd;
+
+	ec_emi_read(vpd.raw, EMI_0_IO_BASE_ADDR, 0, 0, sizeof(vpd.raw));
+
+	/* If the magic value doesn't match, consider EEPROM VPD unreliable */
+	if (vpd.header.magic != VPD_MAGIC) {
+		printk(BIOS_WARNING, "Atlas VPD: Bad magic value, using fallback defaults\n");
+		vpd.header.revision = 0;
+	} else {
+		printk(BIOS_DEBUG, "Atlas VPD: Got revision %u from EC\n", vpd.header.revision);
+	}
+
+	/*
+	 * For backwards compatibility, if the VPD from the EC is an older
+	 * version, uprev it to the latest version coreboot knows about by
+	 * filling in the remaining fields with default values. Should the
+	 * EC provide a newer VPD revision, coreboot would downgrade it to
+	 * the latest version it knows about as the VPD layout is designed
+	 * to be backwards compatible.
+	 *
+	 * Whenever the value of `VPD_LATEST_REVISION` is incremented, add
+	 * a new `case` label just before the `default` label that matches
+	 * the second latest revision to initialise the newly-added fields
+	 * of the VPD structure with a reasonable fallback value. Note the
+	 * intentional falling through.
+	 */
+	switch (vpd.header.revision) {
+	case 0:
+		memset(vpd.raw, 0, sizeof(vpd.raw));
+		vpd.header.magic = VPD_MAGIC;
+		vpd.serial_number[0] = '\0';
+		vpd.part_number[0] = '\0';
+		vpd.profile = ATLAS_PROF_UNPROGRAMMED;
+		__fallthrough;
+	default:
+		/* Ensure serial numbers are NULL-terminated, update revision last */
+		vpd.serial_number[ATLAS_SN_PN_LENGTH - 1] = '\0';
+		vpd.part_number[ATLAS_SN_PN_LENGTH - 1] = '\0';
+		vpd.header.revision = VPD_LATEST_REVISION;
+		break;
+	}
+
+	return &vpd;
+}