1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
7 * Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
8 * Copyright (C) 2012 Jonas Gorski <jonas.gorski@gmail.com>
9 */
10
11#define pr_fmt(fmt) "bcm63xx_nvram: " fmt
12
13#include <linux/init.h>
14#include <linux/crc32.h>
15#include <linux/export.h>
16#include <linux/kernel.h>
17#include <linux/if_ether.h>
18
19#include <bcm63xx_nvram.h>
20
21/*
22 * nvram structure
23 */
24struct bcm963xx_nvram {
25	u32	version;
26	u8	reserved1[256];
27	u8	name[16];
28	u32	main_tp_number;
29	u32	psi_size;
30	u32	mac_addr_count;
31	u8	mac_addr_base[ETH_ALEN];
32	u8	reserved2[2];
33	u32	checksum_old;
34	u8	reserved3[720];
35	u32	checksum_high;
36};
37
38#define BCM63XX_DEFAULT_PSI_SIZE	64
39
40static struct bcm963xx_nvram nvram;
41static int mac_addr_used;
42
43void __init bcm63xx_nvram_init(void *addr)
44{
45	unsigned int check_len;
46	u32 crc, expected_crc;
47	u8 hcs_mac_addr[ETH_ALEN] = { 0x00, 0x10, 0x18, 0xff, 0xff, 0xff };
48
49	/* extract nvram data */
50	memcpy(&nvram, addr, sizeof(nvram));
51
52	/* check checksum before using data */
53	if (nvram.version <= 4) {
54		check_len = offsetof(struct bcm963xx_nvram, reserved3);
55		expected_crc = nvram.checksum_old;
56		nvram.checksum_old = 0;
57	} else {
58		check_len = sizeof(nvram);
59		expected_crc = nvram.checksum_high;
60		nvram.checksum_high = 0;
61	}
62
63	crc = crc32_le(~0, (u8 *)&nvram, check_len);
64
65	if (crc != expected_crc)
66		pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
67			expected_crc, crc);
68
69	/* Cable modems have a different NVRAM which is embedded in the eCos
70	 * firmware and not easily extractible, give at least a MAC address
71	 * pool.
72	 */
73	if (BCMCPU_IS_3368()) {
74		memcpy(nvram.mac_addr_base, hcs_mac_addr, ETH_ALEN);
75		nvram.mac_addr_count = 2;
76	}
77}
78
79u8 *bcm63xx_nvram_get_name(void)
80{
81	return nvram.name;
82}
83EXPORT_SYMBOL(bcm63xx_nvram_get_name);
84
85int bcm63xx_nvram_get_mac_address(u8 *mac)
86{
87	u8 *oui;
88	int count;
89
90	if (mac_addr_used >= nvram.mac_addr_count) {
91		pr_err("not enough mac addresses\n");
92		return -ENODEV;
93	}
94
95	memcpy(mac, nvram.mac_addr_base, ETH_ALEN);
96	oui = mac + ETH_ALEN/2 - 1;
97	count = mac_addr_used;
98
99	while (count--) {
100		u8 *p = mac + ETH_ALEN - 1;
101
102		do {
103			(*p)++;
104			if (*p != 0)
105				break;
106			p--;
107		} while (p != oui);
108
109		if (p == oui) {
110			pr_err("unable to fetch mac address\n");
111			return -ENODEV;
112		}
113	}
114
115	mac_addr_used++;
116	return 0;
117}
118EXPORT_SYMBOL(bcm63xx_nvram_get_mac_address);
119
120int bcm63xx_nvram_get_psi_size(void)
121{
122	if (nvram.psi_size > 0)
123		return nvram.psi_size;
124
125	return BCM63XX_DEFAULT_PSI_SIZE;
126}
127EXPORT_SYMBOL(bcm63xx_nvram_get_psi_size);
128