--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 SiFive, Inc.
+ *
+ * Based on board/freescale/common/sys_eeprom.c:
+ * Copyright 2006, 2008-2009, 2011 Freescale Semiconductor
+ * York Sun (yorksun@freescale.com)
+ * Haiying Wang (haiying.wang@freescale.com)
+ * Timur Tabi (timur@freescale.com)
+ */
+
+#include <common.h>
+#include <command.h>
+#include <env.h>
+#include <i2c.h>
+#include <init.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <u-boot/crc.h>
+
+#ifndef CONFIG_SYS_EEPROM_BUS_NUM
+#error Requires CONFIG_SYS_EEPROM_BUS_NUM to be defined
+#endif
+
+#define FORMAT_VERSION 0x1
+
+/* Options for the manuf_test_status field */
+#define SIFIVE_MANUF_TEST_STATUS_UNKNOWN 0
+#define SIFIVE_MANUF_TEST_STATUS_PASS 1
+#define SIFIVE_MANUF_TEST_STATUS_FAIL 2
+
+/*
+ * BYTES_PER_EEPROM_PAGE: the AT24C02 datasheet says that data can
+ * only be written in page mode, which means 8 bytes at a time
+ */
+#define BYTES_PER_EEPROM_PAGE 8
+
+/*
+ * EEPROM_WRITE_DELAY_MS: the AT24C02 datasheet says it takes up to
+ * 5ms to complete a given write
+ */
+#define EEPROM_WRITE_DELAY_MS 5000
+
+/*
+ * MAGIC_NUMBER_BYTES: number of bytes used by the magic number
+ */
+#define MAGIC_NUMBER_BYTES 4
+
+/*
+ * SERIAL_NUMBER_BYTES: number of bytes used by the board serial
+ * number
+ */
+#define SERIAL_NUMBER_BYTES 16
+
+/*
+ * MAC_ADDR_BYTES: number of bytes used by the Ethernet MAC address
+ */
+#define MAC_ADDR_BYTES 6
+
+/*
+ * MAC_ADDR_STRLEN: length of mac address string
+ */
+#define MAC_ADDR_STRLEN 17
+
+/*
+ * SiFive OUI. Registration Date is 2018-02-15
+ */
+#define SIFIVE_OUI_PREFIX "70:B3:D5:92:F"
+
+/**
+ * static eeprom: EEPROM layout for the SiFive platform I2C format
+ */
+static struct __attribute__ ((__packed__)) sifive_eeprom {
+ u8 magic[MAGIC_NUMBER_BYTES];
+ u8 format_ver;
+ u16 product_id;
+ u8 pcb_revision;
+ u8 bom_revision;
+ u8 bom_variant;
+ u8 serial[SERIAL_NUMBER_BYTES];
+ u8 manuf_test_status;
+ u8 mac_addr[MAC_ADDR_BYTES];
+ u32 crc;
+} e;
+
+struct sifive_product {
+ u16 id;
+ const char *name;
+};
+
+/* Set to 1 if we've read EEPROM into memory */
+static int has_been_read;
+
+/* Magic number at the first four bytes of EEPROM */
+static const unsigned char magic[MAGIC_NUMBER_BYTES] = { 0xf1, 0x5e, 0x50, 0x45 };
+
+/* Does the magic number match that of a SiFive EEPROM? */
+static inline int is_match_magic(void)
+{
+ return (memcmp(&e.magic, &magic, MAGIC_NUMBER_BYTES) == 0);
+}
+
+/* Calculate the current CRC */
+static inline u32 calculate_crc32(void)
+{
+ return crc32(0, (void *)&e, sizeof(struct sifive_eeprom) - sizeof(e.crc));
+}
+
+/* This function should be called after each update to the EEPROM structure */
+static inline void update_crc(void)
+{
+ e.crc = calculate_crc32();
+}
+
+static struct sifive_product sifive_products[] = {
+ { 0, "Unknown"},
+ { 2, "HiFive Unmatched" },
+};
+
+/**
+ * dump_raw_eeprom - display the raw contents of the EEPROM
+ */
+static void dump_raw_eeprom(void)
+{
+ unsigned int i;
+
+ printf("EEPROM dump: (0x%lx bytes)\n", sizeof(e));
+ for (i = 0; i < sizeof(e); i++) {
+ if ((i % 16) == 0)
+ printf("%02X: ", i);
+ printf("%02X ", ((u8 *)&e)[i]);
+ if (((i % 16) == 15) || (i == sizeof(e) - 1))
+ printf("\n");
+ }
+}
+
+/**
+ * show_eeprom - display the contents of the EEPROM
+ */
+static void show_eeprom(void)
+{
+ unsigned int i;
+ u32 crc;
+ const char *product_name = "Unknown";
+ char board_serial[SERIAL_NUMBER_BYTES + 1] = { 0 };
+
+ if (!is_match_magic()) {
+ printf("Not a SiFive HiFive EEPROM data format - magic bytes don't match\n");
+ dump_raw_eeprom();
+ return;
+ };
+
+ snprintf(board_serial, sizeof(board_serial), "%s", e.serial);
+
+ for (i = 0; i < ARRAY_SIZE(sifive_products); i++) {
+ if (sifive_products[i].id == e.product_id) {
+ product_name = sifive_products[i].name;
+ break;
+ }
+ };
+
+ printf("SiFive PCB EEPROM format v%u\n", e.format_ver);
+ printf("Product ID: %04hx (%s)\n", e.product_id, product_name);
+ printf("PCB revision: %x\n", e.pcb_revision);
+ printf("BOM revision: %c\n", e.bom_revision);
+ printf("BOM variant: %x\n", e.bom_variant);
+ printf("Serial number: %s\n", board_serial);
+ printf("Ethernet MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
+ e.mac_addr[0], e.mac_addr[1], e.mac_addr[2],
+ e.mac_addr[3], e.mac_addr[4], e.mac_addr[5]);
+
+ crc = calculate_crc32();
+ if (crc == e.crc) {
+ printf("CRC: %08x\n", e.crc);
+ } else {
+ printf("CRC: %08x (should be %08x)\n", e.crc, crc);
+ dump_raw_eeprom();
+ }
+}
+
+/**
+ * read_eeprom() - read the EEPROM into memory, if it hasn't been read already
+ */
+static int read_eeprom(void)
+{
+ int ret;
+ struct udevice *dev;
+
+ if (has_been_read)
+ return 0;
+
+ ret = i2c_get_chip_for_busnum(CONFIG_SYS_EEPROM_BUS_NUM,
+ CONFIG_SYS_I2C_EEPROM_ADDR,
+ 1,
+ &dev);
+ if (!ret)
+ dm_i2c_read(dev, 0, (void *)&e,
+ sizeof(struct sifive_eeprom));
+
+ show_eeprom();
+
+ has_been_read = (ret == 0) ? 1 : 0;
+
+ return ret;
+}
+
+/**
+ * prog_eeprom() - write the EEPROM from memory
+ */
+static int prog_eeprom(void)
+{
+ int ret = 0;
+ unsigned int i;
+ void *p;
+
+ if (!is_match_magic()) {
+ printf("Please read the EEPROM ('read_eeprom') and/or initialize the EEPROM ('initialize') first.\n");
+ return 0;
+ }
+
+ for (i = 0, p = &e; i < sizeof(e);
+ i += BYTES_PER_EEPROM_PAGE, p += BYTES_PER_EEPROM_PAGE) {
+ struct udevice *dev;
+
+ ret = i2c_get_chip_for_busnum(CONFIG_SYS_EEPROM_BUS_NUM,
+ CONFIG_SYS_I2C_EEPROM_ADDR,
+ CONFIG_SYS_I2C_EEPROM_ADDR_LEN,
+ &dev);
+ if (!ret)
+ ret = dm_i2c_write(dev, i, p,
+ min((int)(sizeof(e) - i),
+ BYTES_PER_EEPROM_PAGE));
+
+ if (ret)
+ break;
+
+ udelay(EEPROM_WRITE_DELAY_MS);
+ }
+
+ if (!ret) {
+ /* Verify the write by reading back the EEPROM and comparing */
+ struct sifive_eeprom e2;
+ struct udevice *dev;
+
+ ret = i2c_get_chip_for_busnum(CONFIG_SYS_EEPROM_BUS_NUM,
+ CONFIG_SYS_I2C_EEPROM_ADDR,
+ CONFIG_SYS_I2C_EEPROM_ADDR_LEN,
+ &dev);
+ if (!ret)
+ ret = dm_i2c_read(dev, 0, (void *)&e2, sizeof(e2));
+ if (!ret && memcmp(&e, &e2, sizeof(e)))
+ ret = -1;
+ }
+
+ if (ret) {
+ printf("Programming failed.\n");
+ has_been_read = 0;
+ return -1;
+ }
+
+ printf("Programming passed.\n");
+ return 0;
+}
+
+/**
+ * set_mac_address() - stores a MAC address into the local EEPROM copy
+ *
+ * This function takes a pointer to MAC address string
+ * (i.e."XX:XX:XX:XX:XX:XX", where "XX" is a two-digit hex number),
+ * stores it in the MAC address field of the EEPROM local copy, and
+ * updates the local copy of the CRC.
+ */
+static void set_mac_address(char *string)
+{
+ unsigned int i;
+
+ if (strncasecmp(SIFIVE_OUI_PREFIX, string, 13)) {
+ printf("The MAC address doesn't match SiFive OUI %s\n",
+ SIFIVE_OUI_PREFIX);
+ return;
+ }
+
+ for (i = 0; *string && (i < MAC_ADDR_BYTES); i++) {
+ e.mac_addr[i] = simple_strtoul(string, &string, 16);
+ if (*string == ':')
+ string++;
+ }
+
+ update_crc();
+}
+
+/**
+ * set_manuf_test_status() - stores a test status byte into the in-memory copy
+ *
+ * Takes a pointer to a manufacturing test status string ("unknown",
+ * "pass", "fail") and stores the corresponding numeric ID to the
+ * manuf_test_status field of the EEPROM local copy, and updates the
+ * CRC of the local copy.
+ */
+static void set_manuf_test_status(char *string)
+{
+ if (!strcasecmp(string, "unknown")) {
+ e.manuf_test_status = SIFIVE_MANUF_TEST_STATUS_UNKNOWN;
+ } else if (!strcasecmp(string, "pass")) {
+ e.manuf_test_status = SIFIVE_MANUF_TEST_STATUS_PASS;
+ } else if (!strcasecmp(string, "fail")) {
+ e.manuf_test_status = SIFIVE_MANUF_TEST_STATUS_FAIL;
+ } else {
+ printf("Usage: mac manuf_test_status (unknown|pass|fail)\n");
+ return;
+ }
+
+ update_crc();
+}
+
+/**
+ * set_pcb_revision() - stores a SiFive PCB revision into the local EEPROM copy
+ *
+ * Takes a pointer to a string representing the numeric PCB revision in
+ * decimal ("0" - "255"), stores it in the pcb_revision field of the
+ * EEPROM local copy, and updates the CRC of the local copy.
+ */
+static void set_pcb_revision(char *string)
+{
+ unsigned long p;
+
+ p = simple_strtoul(string, &string, 10);
+ if (p > U8_MAX) {
+ printf("%s must not be greater than %d\n", "PCB revision",
+ U8_MAX);
+ return;
+ }
+
+ e.pcb_revision = p;
+
+ update_crc();
+}
+
+/**
+ * set_bom_revision() - stores a SiFive BOM revision into the local EEPROM copy
+ *
+ * Takes a pointer to a uppercase ASCII character representing the BOM
+ * revision ("A" - "Z"), stores it in the bom_revision field of the
+ * EEPROM local copy, and updates the CRC of the local copy.
+ */
+static void set_bom_revision(char *string)
+{
+ if (string[0] < 'A' || string[0] > 'Z') {
+ printf("BOM revision must be an uppercase letter between A and Z\n");
+ return;
+ }
+
+ e.bom_revision = string[0];
+
+ update_crc();
+}
+
+/**
+ * set_bom_variant() - stores a SiFive BOM variant into the local EEPROM copy
+ *
+ * Takes a pointer to a string representing the numeric BOM variant in
+ * decimal ("0" - "255"), stores it in the bom_variant field of the
+ * EEPROM local copy, and updates the CRC of the local copy.
+ */
+static void set_bom_variant(char *string)
+{
+ unsigned long p;
+
+ p = simple_strtoul(string, &string, 10);
+ if (p > U8_MAX) {
+ printf("%s must not be greater than %d\n", "BOM variant",
+ U8_MAX);
+ return;
+ }
+
+ e.bom_variant = p;
+
+ update_crc();
+}
+
+/**
+ * set_product_id() - stores a SiFive product ID into the local EEPROM copy
+ *
+ * Takes a pointer to a string representing the numeric product ID in
+ * decimal ("0" - "65535"), stores it in the product ID field of the
+ * EEPROM local copy, and updates the CRC of the local copy.
+ */
+static void set_product_id(char *string)
+{
+ unsigned long p;
+
+ p = simple_strtoul(string, &string, 10);
+ if (p > U16_MAX) {
+ printf("%s must not be greater than %d\n", "Product ID",
+ U16_MAX);
+ return;
+ }
+
+ e.product_id = p;
+
+ update_crc();
+}
+
+/**
+ * set_serial_number() - set the PCB serial number in the in-memory copy
+ *
+ * Set the board serial number in the in-memory EEPROM copy from the supplied
+ * string argument, and update the CRC.
+ */
+static void set_serial_number(char *string)
+{
+ if (strlen(string) > SERIAL_NUMBER_BYTES) {
+ printf("Serial number must not be greater than 16 bytes\n");
+ return;
+ }
+
+ memset(e.serial, 0, sizeof(e.serial));
+ strncpy((char *)e.serial, string, sizeof(e.serial));
+ update_crc();
+}
+
+/**
+ * init_local_copy() - initialize the in-memory EEPROM copy
+ *
+ * Initialize the in-memory EEPROM copy with the magic number. Must
+ * be done when preparing to initialize a blank EEPROM, or overwrite
+ * one with a corrupted magic number.
+ */
+static void init_local_copy(void)
+{
+ memset(&e, 0, sizeof(e));
+ memcpy(e.magic, magic, sizeof(e.magic));
+ e.format_ver = FORMAT_VERSION;
+ update_crc();
+}
+
+int do_mac(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+{
+ char *cmd;
+
+ if (argc == 1) {
+ show_eeprom();
+ return 0;
+ }
+
+ if (argc > 3)
+ return cmd_usage(cmdtp);
+
+ cmd = argv[1];
+
+ /* Commands with no argument */
+ if (!strcmp(cmd, "read_eeprom")) {
+ read_eeprom();
+ return 0;
+ } else if (!strcmp(cmd, "initialize")) {
+ init_local_copy();
+ return 0;
+ } else if (!strcmp(cmd, "write_eeprom")) {
+ prog_eeprom();
+ return 0;
+ }
+
+ if (argc != 3)
+ return cmd_usage(cmdtp);
+
+ if (!is_match_magic()) {
+ printf("Please read the EEPROM ('read_eeprom') and/or initialize the EEPROM ('initialize') first.\n");
+ return 0;
+ }
+
+ if (!strcmp(cmd, "serial_number")) {
+ set_serial_number(argv[2]);
+ return 0;
+ } else if (!strcmp(cmd, "manuf_test_status")) {
+ set_manuf_test_status(argv[2]);
+ return 0;
+ } else if (!strcmp(cmd, "mac_address")) {
+ set_mac_address(argv[2]);
+ return 0;
+ } else if (!strcmp(cmd, "pcb_revision")) {
+ set_pcb_revision(argv[2]);
+ return 0;
+ } else if (!strcmp(cmd, "bom_variant")) {
+ set_bom_variant(argv[2]);
+ return 0;
+ } else if (!strcmp(cmd, "bom_revision")) {
+ set_bom_revision(argv[2]);
+ return 0;
+ } else if (!strcmp(cmd, "product_id")) {
+ set_product_id(argv[2]);
+ return 0;
+ }
+
+ return cmd_usage(cmdtp);
+}
+
+/**
+ * mac_read_from_eeprom() - read the MAC address from EEPROM
+ *
+ * This function reads the MAC address from EEPROM and sets the
+ * appropriate environment variables for each one read.
+ *
+ * The environment variables are only set if they haven't been set already.
+ * This ensures that any user-saved variables are never overwritten.
+ *
+ * This function must be called after relocation.
+ */
+int mac_read_from_eeprom(void)
+{
+ u32 crc;
+ char board_serial[SERIAL_NUMBER_BYTES + 1] = { 0 };
+
+ puts("EEPROM: ");
+
+ if (read_eeprom()) {
+ printf("Read failed.\n");
+ return 0;
+ }
+
+ if (!is_match_magic()) {
+ printf("Invalid ID (%02x %02x %02x %02x)\n",
+ e.magic[0], e.magic[1], e.magic[2], e.magic[3]);
+ dump_raw_eeprom();
+ return 0;
+ }
+
+ crc = calculate_crc32();
+ if (crc != e.crc) {
+ printf("CRC mismatch (%08x != %08x)\n", crc, e.crc);
+ dump_raw_eeprom();
+ return 0;
+ }
+
+ eth_env_set_enetaddr("ethaddr", e.mac_addr);
+
+ if (!env_get("serial#")) {
+ snprintf(board_serial, sizeof(board_serial), "%s", e.serial);
+ env_set("serial#", board_serial);
+ }
+
+ return 0;
+}