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 void __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 pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n", 64 expected_crc, crc); 65 } 66 67 u8 *bcm63xx_nvram_get_name(void) 68 { 69 return nvram.name; 70 } 71 EXPORT_SYMBOL(bcm63xx_nvram_get_name); 72 73 int bcm63xx_nvram_get_mac_address(u8 *mac) 74 { 75 u8 *oui; 76 int count; 77 78 if (mac_addr_used >= nvram.mac_addr_count) { 79 pr_err("not enough mac addresses\n"); 80 return -ENODEV; 81 } 82 83 memcpy(mac, nvram.mac_addr_base, ETH_ALEN); 84 oui = mac + ETH_ALEN/2 - 1; 85 count = mac_addr_used; 86 87 while (count--) { 88 u8 *p = mac + ETH_ALEN - 1; 89 90 do { 91 (*p)++; 92 if (*p != 0) 93 break; 94 p--; 95 } while (p != oui); 96 97 if (p == oui) { 98 pr_err("unable to fetch mac address\n"); 99 return -ENODEV; 100 } 101 } 102 103 mac_addr_used++; 104 return 0; 105 } 106 EXPORT_SYMBOL(bcm63xx_nvram_get_mac_address); 107