xref: /openbmc/linux/arch/mips/bcm63xx/nvram.c (revision 287dcc2b)
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/bcm963xx_nvram.h>
14 #include <linux/init.h>
15 #include <linux/crc32.h>
16 #include <linux/export.h>
17 #include <linux/kernel.h>
18 #include <linux/if_ether.h>
19 
20 #include <bcm63xx_nvram.h>
21 
22 #define BCM63XX_DEFAULT_PSI_SIZE	64
23 
24 static struct bcm963xx_nvram nvram;
25 static int mac_addr_used;
26 
27 void __init bcm63xx_nvram_init(void *addr)
28 {
29 	u32 crc, expected_crc;
30 	u8 hcs_mac_addr[ETH_ALEN] = { 0x00, 0x10, 0x18, 0xff, 0xff, 0xff };
31 
32 	/* extract nvram data */
33 	memcpy(&nvram, addr, BCM963XX_NVRAM_V5_SIZE);
34 
35 	/* check checksum before using data */
36 	if (bcm963xx_nvram_checksum(&nvram, &expected_crc, &crc))
37 		pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
38 			expected_crc, crc);
39 
40 	/* Cable modems have a different NVRAM which is embedded in the eCos
41 	 * firmware and not easily extractible, give at least a MAC address
42 	 * pool.
43 	 */
44 	if (BCMCPU_IS_3368()) {
45 		memcpy(nvram.mac_addr_base, hcs_mac_addr, ETH_ALEN);
46 		nvram.mac_addr_count = 2;
47 	}
48 }
49 
50 u8 *bcm63xx_nvram_get_name(void)
51 {
52 	return nvram.name;
53 }
54 EXPORT_SYMBOL(bcm63xx_nvram_get_name);
55 
56 int bcm63xx_nvram_get_mac_address(u8 *mac)
57 {
58 	u8 *oui;
59 	int count;
60 
61 	if (mac_addr_used >= nvram.mac_addr_count) {
62 		pr_err("not enough mac addresses\n");
63 		return -ENODEV;
64 	}
65 
66 	memcpy(mac, nvram.mac_addr_base, ETH_ALEN);
67 	oui = mac + ETH_ALEN/2 - 1;
68 	count = mac_addr_used;
69 
70 	while (count--) {
71 		u8 *p = mac + ETH_ALEN - 1;
72 
73 		do {
74 			(*p)++;
75 			if (*p != 0)
76 				break;
77 			p--;
78 		} while (p != oui);
79 
80 		if (p == oui) {
81 			pr_err("unable to fetch mac address\n");
82 			return -ENODEV;
83 		}
84 	}
85 
86 	mac_addr_used++;
87 	return 0;
88 }
89 EXPORT_SYMBOL(bcm63xx_nvram_get_mac_address);
90 
91 int bcm63xx_nvram_get_psi_size(void)
92 {
93 	if (nvram.psi_size > 0)
94 		return nvram.psi_size;
95 
96 	return BCM63XX_DEFAULT_PSI_SIZE;
97 }
98 EXPORT_SYMBOL(bcm63xx_nvram_get_psi_size);
99