/*
 * This file is part of the coreboot project.
 *
 * Copyright 2016 Google Inc.
 * Copyright (C) 2017 Siemens AG
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <device/device.h>
#include <console/console.h>
#include <string.h>
#include <hwilib.h>
#include <i210.h>

#define MAX_PATH_DEPTH		12
#define MAX_NUM_MAPPINGS	10

/** \brief This function can decide if a given MAC address is valid or not.
 *         Currently, addresses filled with 0xff or 0x00 are not valid.
 * @param  mac  Buffer to the MAC address to check
 * @return 0    if address is not valid, otherwise 1
 */
static uint8_t is_mac_adr_valid(uint8_t mac[6])
{
	uint8_t buf[6];

	memset(buf, 0, sizeof(buf));
	if (!memcmp(buf, mac, sizeof(buf)))
		return 0;
	memset(buf, 0xff, sizeof(buf));
	if (!memcmp(buf, mac, sizeof(buf)))
		return 0;
	return 1;
}

/** \brief This function will search for a MAC address which can be assigned
 *         to a MACPHY.
 * @param  dev     pointer to PCI device
 * @param  mac     buffer where to store the MAC address
 * @return cb_err  CB_ERR or CB_SUCCESS
 */
enum cb_err mainboard_get_mac_address(struct device *dev, uint8_t mac[6])
{
	struct bus *parent = dev->bus;
	uint8_t buf[16], mapping[16], i = 0, chain_len = 0;

	memset(buf, 0, sizeof(buf));
	memset(mapping, 0, sizeof(mapping));

	/* The first entry in the tree is the device itself. */
	buf[0] = dev->path.pci.devfn;
	chain_len = 1;
	for (i = 1; i < MAX_PATH_DEPTH && parent->dev->bus->subordinate; i++) {
		buf[i] = parent->dev->path.pci.devfn;
		chain_len++;
		parent = parent->dev->bus;
	}
	if (i == MAX_PATH_DEPTH) {
		/* The path is deeper than MAX_PATH_DEPTH devices, error. */
		printk(BIOS_ERR, "Too many bridges for %s\n", dev_path(dev));
		return CB_ERR;
	}
	/*
	 * Now construct the mapping based on the device chain starting from
	 * root bridge device to the device itself.
	 */
	mapping[0] = 1;
	mapping[1] = chain_len;
	for (i = 0; i < chain_len; i++)
		mapping[i + 4] = buf[chain_len - i - 1];

	/* Open main hwinfo block */
	if (hwilib_find_blocks("hwinfo.hex") != CB_SUCCESS)
		return CB_ERR;
	/* Now try to find a valid MAC address in hwinfo for this mapping.*/
	for (i = 0; i < MAX_NUM_MAPPINGS; i++) {
		if ((hwilib_get_field(XMac1Mapping + i, buf, 16) == 16) &&
			!(memcmp(buf, mapping, chain_len + 4))) {
		/* There is a matching mapping available, get MAC address. */
			if ((hwilib_get_field(XMac1 + i, mac, 6) == 6) &&
			    (is_mac_adr_valid(mac))) {
				return CB_SUCCESS;
			} else {
				return CB_ERR;
			}
		} else
			continue;
	}
	/* No MAC address found for */
	return CB_ERR;
}

static void mainboard_init(void *chip_info)
{
	/* Nothing Here Yet */
}

struct chip_operations mainboard_ops = {
	.init = mainboard_init,
};