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 40#include "ttpci-eeprom.h" 41 42#define dprintk(x...) do { printk(x); } while (0) 43 44 45static int check_mac_tt(u8 *buf) 46{ 47 int i; 48 u16 tmp = 0xffff; 49 50 for (i = 0; i < 8; i++) { 51 tmp = (tmp << 8) | ((tmp >> 8) ^ buf[i]); 52 tmp ^= (tmp >> 4) & 0x0f; 53 tmp ^= (tmp << 12) ^ ((tmp & 0xff) << 5); 54 } 55 tmp ^= 0xffff; 56 return (((tmp >> 8) ^ buf[8]) | ((tmp & 0xff) ^ buf[9])); 57} 58 59static int getmac_tt(u8 * decodedMAC, u8 * encodedMAC) 60{ 61 u8 xor[20] = { 0x72, 0x23, 0x68, 0x19, 0x5c, 0xa8, 0x71, 0x2c, 62 0x54, 0xd3, 0x7b, 0xf1, 0x9E, 0x23, 0x16, 0xf6, 63 0x1d, 0x36, 0x64, 0x78}; 64 u8 data[20]; 65 int i; 66 67 /* In case there is a sig check failure have the orig contents available */ 68 memcpy(data, encodedMAC, 20); 69 70 for (i = 0; i < 20; i++) 71 data[i] ^= xor[i]; 72 for (i = 0; i < 10; i++) 73 data[i] = ((data[2 * i + 1] << 8) | data[2 * i]) 74 >> ((data[2 * i + 1] >> 6) & 3); 75 76 if (check_mac_tt(data)) 77 return -ENODEV; 78 79 decodedMAC[0] = data[2]; decodedMAC[1] = data[1]; decodedMAC[2] = data[0]; 80 decodedMAC[3] = data[6]; decodedMAC[4] = data[5]; decodedMAC[5] = data[4]; 81 return 0; 82} 83 84static int ttpci_eeprom_read_encodedMAC(struct i2c_adapter *adapter, u8 * encodedMAC) 85{ 86 int ret; 87 u8 b0[] = { 0xcc }; 88 89 struct i2c_msg msg[] = { 90 { .addr = 0x50, .flags = 0, .buf = b0, .len = 1 }, 91 { .addr = 0x50, .flags = I2C_M_RD, .buf = encodedMAC, .len = 20 } 92 }; 93 94 /* dprintk("%s\n", __func__); */ 95 96 ret = i2c_transfer(adapter, msg, 2); 97 98 if (ret != 2) /* Assume EEPROM isn't there */ 99 return (-ENODEV); 100 101 return 0; 102} 103 104 105int ttpci_eeprom_parse_mac(struct i2c_adapter *adapter, u8 *proposed_mac) 106{ 107 int ret, i; 108 u8 encodedMAC[20]; 109 u8 decodedMAC[6]; 110 111 ret = ttpci_eeprom_read_encodedMAC(adapter, encodedMAC); 112 113 if (ret != 0) { /* Will only be -ENODEV */ 114 dprintk("Couldn't read from EEPROM: not there?\n"); 115 memset(proposed_mac, 0, 6); 116 return ret; 117 } 118 119 ret = getmac_tt(decodedMAC, encodedMAC); 120 if( ret != 0 ) { 121 dprintk("adapter failed MAC signature check\n"); 122 dprintk("encoded MAC from EEPROM was " ); 123 for(i=0; i<19; i++) { 124 dprintk( "%.2x:", encodedMAC[i]); 125 } 126 dprintk("%.2x\n", encodedMAC[19]); 127 memset(proposed_mac, 0, 6); 128 return ret; 129 } 130 131 memcpy(proposed_mac, decodedMAC, 6); 132 dprintk("adapter has MAC addr = %.2x:%.2x:%.2x:%.2x:%.2x:%.2x\n", 133 decodedMAC[0], decodedMAC[1], decodedMAC[2], 134 decodedMAC[3], decodedMAC[4], decodedMAC[5]); 135 return 0; 136} 137 138EXPORT_SYMBOL(ttpci_eeprom_parse_mac); 139 140MODULE_LICENSE("GPL"); 141MODULE_AUTHOR("Ralph Metzler, Marcus Metzler, others"); 142MODULE_DESCRIPTION("Decode dvb_net MAC address from EEPROM of PCI DVB cards " 143 "made by Siemens, Technotrend, Hauppauge"); 144