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 */ 24 struct 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 static struct bcm963xx_nvram nvram; 39 static int mac_addr_used; 40 41 int __init bcm63xx_nvram_init(void *addr) 42 { 43 unsigned int check_len; 44 u32 crc, expected_crc; 45 46 /* extract nvram data */ 47 memcpy(&nvram, addr, sizeof(nvram)); 48 49 /* check checksum before using data */ 50 if (nvram.version <= 4) { 51 check_len = offsetof(struct bcm963xx_nvram, reserved3); 52 expected_crc = nvram.checksum_old; 53 nvram.checksum_old = 0; 54 } else { 55 check_len = sizeof(nvram); 56 expected_crc = nvram.checksum_high; 57 nvram.checksum_high = 0; 58 } 59 60 crc = crc32_le(~0, (u8 *)&nvram, check_len); 61 62 if (crc != expected_crc) 63 return -EINVAL; 64 65 return 0; 66 } 67 68 u8 *bcm63xx_nvram_get_name(void) 69 { 70 return nvram.name; 71 } 72 EXPORT_SYMBOL(bcm63xx_nvram_get_name); 73 74 int bcm63xx_nvram_get_mac_address(u8 *mac) 75 { 76 u8 *oui; 77 int count; 78 79 if (mac_addr_used >= nvram.mac_addr_count) { 80 pr_err("not enough mac addresses\n"); 81 return -ENODEV; 82 } 83 84 memcpy(mac, nvram.mac_addr_base, ETH_ALEN); 85 oui = mac + ETH_ALEN/2 - 1; 86 count = mac_addr_used; 87 88 while (count--) { 89 u8 *p = mac + ETH_ALEN - 1; 90 91 do { 92 (*p)++; 93 if (*p != 0) 94 break; 95 p--; 96 } while (p != oui); 97 98 if (p == oui) { 99 pr_err("unable to fetch mac address\n"); 100 return -ENODEV; 101 } 102 } 103 104 mac_addr_used++; 105 return 0; 106 } 107 EXPORT_SYMBOL(bcm63xx_nvram_get_mac_address); 108