1 files changed, 67 insertions, 0 deletions
diff --git a/src/mainboard/prodrive/hermes/eeprom.c b/src/mainboard/prodrive/hermes/eeprom.c
new file mode 100644
index 0000000000..bd5db5c851
--- /dev/null
+++ b/src/mainboard/prodrive/hermes/eeprom.c
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <device/pci_ops.h>
+#include <console/console.h>
+#include <device/smbus_host.h>
+#include "variants/baseboard/include/eeprom.h"
+
+/*
+ * Check Signature in EEPROM (M24C32-FMN6TP)
+ * If signature is there we assume that that the content is valid
+ */
+int check_signature(u8 addr)
+{
+	u8 blob[8] = {0};
+
+	if (!read_write_config(addr, blob, EEPROM_OFFSET_FSP_SIGNATURE, 0, ARRAY_SIZE(blob))) {
+		// Check Signature
+		if (*(uint64_t *)blob == FSP_UPD_SIGNATURE) {
+			printk(BIOS_DEBUG, "CFG EEPROM: Signature valid.\n");
+			return 1;
+		}
+		printk(BIOS_DEBUG, "CFG EEPROM: Signature invalid - skipping option write.\n");
+		return 0;
+	}
+	return 0;
+}
+
+// Read data from offset and write it to offset in UPD
+bool read_write_config(u8 addr, void *blob, size_t read_offset, size_t write_offset,
+		size_t size)
+{
+	int ret = 0;
+
+#if ENV_ROMSTAGE
+	pci_devfn_t dev = PCI_DEV(0, PCH_DEV_SLOT_LPC, 4);
+#else
+	const struct device *dev = pcidev_on_root(PCH_DEV_SLOT_LPC, 4);
+#endif
+
+	u32 smb_ctrl_reg = pci_read_config32(dev, HOSTC);
+	pci_write_config32(dev, HOSTC, smb_ctrl_reg | HOSTC_I2C_EN);
+
+	printk(BIOS_SPEW, "%s\tOffset: %04zx\tSize: %02zx\n", __func__,
+		read_offset, size);
+
+	/* We can always read two bytes at a time */
+	for (size_t i = 0; i < size; i = i + 2) {
+		u8 tmp[2] = {0};
+
+		ret = do_smbus_process_call(SMBUS_IO_BASE, addr, 0,
+			swab16(read_offset + i), (uint16_t *)&tmp[0]);
+		if (ret < 0)
+			break;
+
+		// Write to UPD
+		uint8_t *writePointer = (uint8_t *)blob + write_offset + i;
+		if (size > 1 && (size % 2 == 0))
+			memcpy(writePointer, tmp, 2);
+		else
+			*writePointer = tmp[0];
+	}
+
+	/* Restore I2C_EN bit */
+	pci_write_config32(dev, HOSTC, smb_ctrl_reg);
+
+	return ret;
+}