/*
Retrieve encoded MAC address from 24C16 serial 2-wire EEPROM,
decode it and store it in the associated adapter struct for
use by dvb_net.c
This card appear to have the 24C16 write protect held to ground,
thus permitting normal read/write operation. Theoretically it
would be possible to write routines to burn a different (encoded)
MAC address into the EEPROM.
Robert Schlabbach GMX
Michael Glaum KVH Industries
Holger Waechtler Convergence
Copyright (C) 2002-2003 Ralph Metzler <rjkm@metzlerbros.de>
Metzler Brothers Systementwicklung GbR
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <asm/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/i2c.h>
#if 1
#define dprintk(x...) do { printk(x); } while (0)
#else
#define dprintk(x...) do { } while (0)
#endif
static int check_mac_tt(u8 *buf)
{
int i;
u16 tmp = 0xffff;
for (i = 0; i < 8; i++) {
tmp = (tmp << 8) | ((tmp >> 8) ^ buf[i]);
tmp ^= (tmp >> 4) & 0x0f;
tmp ^= (tmp << 12) ^ ((tmp & 0xff) << 5);
}
tmp ^= 0xffff;
return (((tmp >> 8) ^ buf[8]) | ((tmp & 0xff) ^ buf[9]));
}
static int getmac_tt(u8 * decodedMAC, u8 * encodedMAC)
{
u8 xor[20] = { 0x72, 0x23, 0x68, 0x19, 0x5c, 0xa8, 0x71, 0x2c,
0x54, 0xd3, 0x7b, 0xf1, 0x9E, 0x23, 0x16, 0xf6,
0x1d, 0x36, 0x64, 0x78};
u8 data[20];
int i;
/* In case there is a sig check failure have the orig contents available */
memcpy(data, encodedMAC, 20);
for (i = 0; i < 20; i++)
data[i] ^= xor[i];
for (i = 0; i < 10; i++)
data[i] = ((data[2 * i + 1] << 8) | data[2 * i])
>> ((data[2 * i + 1] >> 6) & 3);
if (check_mac_tt(data))
return -ENODEV;
decodedMAC[0] = data[2]; decodedMAC[1] = data[1]; decodedMAC[2] = data[0];
decodedMAC[3] = data[6]; decodedMAC[4] = data[5]; decodedMAC[5] = data[4];
return 0;
}
static int ttpci_eeprom_read_encodedMAC(struct i2c_adapter *adapter, u8 * encodedMAC)
{
int ret;
u8 b0[] = { 0xcc };
struct i2c_msg msg[] = {
{ .addr = 0x50, .flags = 0, .buf = b0, .len = 1 },
{ .addr = 0x50, .flags = I2C_M_RD, .buf = encodedMAC, .len = 20 }
};
/* dprintk("%s\n", __FUNCTION__); */
ret = i2c_transfer(adapter, msg, 2);
if (ret != 2) /* Assume EEPROM isn't there */
return (-ENODEV);
return 0;
}
int ttpci_eeprom_parse_mac(struct i2c_adapter *adapter, u8 *proposed_mac)
{
int ret, i;
u8 encodedMAC[20];
u8 decodedMAC[6];
ret = ttpci_eeprom_read_encodedMAC(adapter, encodedMAC);
if (ret != 0) { /* Will only be -ENODEV */
dprintk("Couldn't read from EEPROM: not there?\n");
memset(proposed_mac, 0, 6);
return ret;
}
ret = getmac_tt(decodedMAC, encodedMAC);
if( ret != 0 ) {
dprintk("adapter failed MAC signature check\n");
dprintk("encoded MAC from EEPROM was " );
for(i=0; i<19; i++) {
dprintk( "%.2x:", encodedMAC[i]);
}
dprintk("%.2x\n", encodedMAC[19]);
memset(proposed_mac, 0, 6);
return ret;
}
memcpy(proposed_mac, decodedMAC, 6);
dprintk("adapter has MAC addr = %.2x:%.2x:%.2x:%.2x:%.2x:%.2x\n",
decodedMAC[0], decodedMAC[1], decodedMAC[2],
decodedMAC[3], decodedMAC[4], decodedMAC[5]);
return 0;
}
EXPORT_SYMBOL(ttpci_eeprom_parse_mac);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ralph Metzler, Marcus Metzler, others");
MODULE_DESCRIPTION("Decode dvb_net MAC address from EEPROM of PCI DVB cards "
"made by Siemens, Technotrend, Hauppauge");
