1/* 2 Retrieve encoded MAC address from 24C16 serial 2-wire EEPROM, 3 decode it and store it in the associated adapter struct for 4 use by dvb_net.c 5 6 This card appear to have the 24C16 write protect held to ground, 7 thus permitting normal read/write operation. Theoretically it 8 would be possible to write routines to burn a different (encoded) 9 MAC address into the EEPROM. 10 11 Robert Schlabbach GMX 12 Michael Glaum KVH Industries 13 Holger Waechtler Convergence 14 15 Copyright (C) 2002-2003 Ralph Metzler <rjkm@metzlerbros.de> 16 Metzler Brothers Systementwicklung GbR 17 18 This program is free software; you can redistribute it and/or modify 19 it under the terms of the GNU General Public License as published by 20 the Free Software Foundation; either version 2 of the License, or 21 (at your option) any later version. 22 23 This program is distributed in the hope that it will be useful, 24 but WITHOUT ANY WARRANTY; without even the implied warranty of 25 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 26 GNU General Public License for more details. 27 28 You should have received a copy of the GNU General Public License 29 along with this program; if not, write to the Free Software 30 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 31 32*/ 33 34#include <asm/errno.h> 35#include <linux/init.h> 36#include <linux/module.h> 37#include <linux/string.h> 38#include <linux/i2c.h> 39#include <linux/etherdevice.h> 40 41#include "ttpci-eeprom.h" 42 43#if 1 44#define dprintk(x...) do { printk(x); } while (0) 45#else 46#define dprintk(x...) do { } while (0) 47#endif 48 49 50static int check_mac_tt(u8 *buf) 51{ 52 int i; 53 u16 tmp = 0xffff; 54 55 for (i = 0; i < 8; i++) { 56 tmp = (tmp << 8) | ((tmp >> 8) ^ buf[i]); 57 tmp ^= (tmp >> 4) & 0x0f; 58 tmp ^= (tmp << 12) ^ ((tmp & 0xff) << 5); 59 } 60 tmp ^= 0xffff; 61 return (((tmp >> 8) ^ buf[8]) | ((tmp & 0xff) ^ buf[9])); 62} 63 64static int getmac_tt(u8 * decodedMAC, u8 * encodedMAC) 65{ 66 u8 xor[20] = { 0x72, 0x23, 0x68, 0x19, 0x5c, 0xa8, 0x71, 0x2c, 67 0x54, 0xd3, 0x7b, 0xf1, 0x9E, 0x23, 0x16, 0xf6, 68 0x1d, 0x36, 0x64, 0x78}; 69 u8 data[20]; 70 int i; 71 72 /* In case there is a sig check failure have the orig contents available */ 73 memcpy(data, encodedMAC, 20); 74 75 for (i = 0; i < 20; i++) 76 data[i] ^= xor[i]; 77 for (i = 0; i < 10; i++) 78 data[i] = ((data[2 * i + 1] << 8) | data[2 * i]) 79 >> ((data[2 * i + 1] >> 6) & 3); 80 81 if (check_mac_tt(data)) 82 return -ENODEV; 83 84 decodedMAC[0] = data[2]; decodedMAC[1] = data[1]; decodedMAC[2] = data[0]; 85 decodedMAC[3] = data[6]; decodedMAC[4] = data[5]; decodedMAC[5] = data[4]; 86 return 0; 87} 88 89int ttpci_eeprom_decode_mac(u8 *decodedMAC, u8 *encodedMAC) 90{ 91 u8 xor[20] = { 0x72, 0x23, 0x68, 0x19, 0x5c, 0xa8, 0x71, 0x2c, 92 0x54, 0xd3, 0x7b, 0xf1, 0x9E, 0x23, 0x16, 0xf6, 93 0x1d, 0x36, 0x64, 0x78}; 94 u8 data[20]; 95 int i; 96 97 memcpy(data, encodedMAC, 20); 98 99 for (i = 0; i < 20; i++) 100 data[i] ^= xor[i]; 101 for (i = 0; i < 10; i++) 102 data[i] = ((data[2 * i + 1] << 8) | data[2 * i]) 103 >> ((data[2 * i + 1] >> 6) & 3); 104 105 if (check_mac_tt(data)) 106 return -ENODEV; 107 108 decodedMAC[0] = data[2]; 109 decodedMAC[1] = data[1]; 110 decodedMAC[2] = data[0]; 111 decodedMAC[3] = data[6]; 112 decodedMAC[4] = data[5]; 113 decodedMAC[5] = data[4]; 114 return 0; 115} 116EXPORT_SYMBOL(ttpci_eeprom_decode_mac); 117 118static int ttpci_eeprom_read_encodedMAC(struct i2c_adapter *adapter, u8 * encodedMAC) 119{ 120 int ret; 121 u8 b0[] = { 0xcc }; 122 123 struct i2c_msg msg[] = { 124 { .addr = 0x50, .flags = 0, .buf = b0, .len = 1 }, 125 { .addr = 0x50, .flags = I2C_M_RD, .buf = encodedMAC, .len = 20 } 126 }; 127 128 /* dprintk("%s\n", __func__); */ 129 130 ret = i2c_transfer(adapter, msg, 2); 131 132 if (ret != 2) /* Assume EEPROM isn't there */ 133 return (-ENODEV); 134 135 return 0; 136} 137 138 139int ttpci_eeprom_parse_mac(struct i2c_adapter *adapter, u8 *proposed_mac) 140{ 141 int ret, i; 142 u8 encodedMAC[20]; 143 u8 decodedMAC[6]; 144 145 ret = ttpci_eeprom_read_encodedMAC(adapter, encodedMAC); 146 147 if (ret != 0) { /* Will only be -ENODEV */ 148 dprintk("Couldn't read from EEPROM: not there?\n"); 149 eth_zero_addr(proposed_mac); 150 return ret; 151 } 152 153 ret = getmac_tt(decodedMAC, encodedMAC); 154 if( ret != 0 ) { 155 dprintk("adapter failed MAC signature check\n"); 156 dprintk("encoded MAC from EEPROM was " ); 157 for(i=0; i<19; i++) { 158 dprintk( "%.2x:", encodedMAC[i]); 159 } 160 dprintk("%.2x\n", encodedMAC[19]); 161 eth_zero_addr(proposed_mac); 162 return ret; 163 } 164 165 memcpy(proposed_mac, decodedMAC, 6); 166 dprintk("adapter has MAC addr = %pM\n", decodedMAC); 167 return 0; 168} 169 170EXPORT_SYMBOL(ttpci_eeprom_parse_mac); 171 172MODULE_LICENSE("GPL"); 173MODULE_AUTHOR("Ralph Metzler, Marcus Metzler, others"); 174MODULE_DESCRIPTION("Decode dvb_net MAC address from EEPROM of PCI DVB cards " 175 "made by Siemens, Technotrend, Hauppauge"); 176