cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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flexcop-eeprom.c (3303B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Linux driver for digital TV devices equipped with B2C2 FlexcopII(b)/III
      4 * flexcop-eeprom.c - eeprom access methods (currently only MAC address reading)
      5 * see flexcop.c for copyright information
      6 */
      7#include "flexcop.h"
      8
      9#if 0
     10/*EEPROM (Skystar2 has one "24LC08B" chip on board) */
     11static int eeprom_write(struct adapter *adapter, u16 addr, u8 *buf, u16 len)
     12{
     13	return flex_i2c_write(adapter, 0x20000000, 0x50, addr, buf, len);
     14}
     15
     16static int eeprom_lrc_write(struct adapter *adapter, u32 addr,
     17		u32 len, u8 *wbuf, u8 *rbuf, int retries)
     18{
     19int i;
     20
     21for (i = 0; i < retries; i++) {
     22	if (eeprom_write(adapter, addr, wbuf, len) == len) {
     23		if (eeprom_lrc_read(adapter, addr, len, rbuf, retries) == 1)
     24			return 1;
     25		}
     26	}
     27	return 0;
     28}
     29
     30/* These functions could be used to unlock SkyStar2 cards. */
     31
     32static int eeprom_writeKey(struct adapter *adapter, u8 *key, u32 len)
     33{
     34	u8 rbuf[20];
     35	u8 wbuf[20];
     36
     37	if (len != 16)
     38		return 0;
     39
     40	memcpy(wbuf, key, len);
     41	wbuf[16] = 0;
     42	wbuf[17] = 0;
     43	wbuf[18] = 0;
     44	wbuf[19] = calc_lrc(wbuf, 19);
     45	return eeprom_lrc_write(adapter, 0x3e4, 20, wbuf, rbuf, 4);
     46}
     47
     48static int eeprom_readKey(struct adapter *adapter, u8 *key, u32 len)
     49{
     50	u8 buf[20];
     51
     52	if (len != 16)
     53		return 0;
     54
     55	if (eeprom_lrc_read(adapter, 0x3e4, 20, buf, 4) == 0)
     56		return 0;
     57
     58	memcpy(key, buf, len);
     59	return 1;
     60}
     61
     62static char eeprom_set_mac_addr(struct adapter *adapter, char type, u8 *mac)
     63{
     64	u8 tmp[8];
     65
     66	if (type != 0) {
     67		tmp[0] = mac[0];
     68		tmp[1] = mac[1];
     69		tmp[2] = mac[2];
     70		tmp[3] = mac[5];
     71		tmp[4] = mac[6];
     72		tmp[5] = mac[7];
     73	} else {
     74		tmp[0] = mac[0];
     75		tmp[1] = mac[1];
     76		tmp[2] = mac[2];
     77		tmp[3] = mac[3];
     78		tmp[4] = mac[4];
     79		tmp[5] = mac[5];
     80	}
     81
     82	tmp[6] = 0;
     83	tmp[7] = calc_lrc(tmp, 7);
     84
     85	if (eeprom_write(adapter, 0x3f8, tmp, 8) == 8)
     86		return 1;
     87	return 0;
     88}
     89
     90static int flexcop_eeprom_read(struct flexcop_device *fc,
     91		u16 addr, u8 *buf, u16 len)
     92{
     93	return fc->i2c_request(fc,FC_READ,FC_I2C_PORT_EEPROM,0x50,addr,buf,len);
     94}
     95
     96#endif
     97
     98static u8 calc_lrc(u8 *buf, int len)
     99{
    100	int i;
    101	u8 sum = 0;
    102	for (i = 0; i < len; i++)
    103		sum = sum ^ buf[i];
    104	return sum;
    105}
    106
    107static int flexcop_eeprom_request(struct flexcop_device *fc,
    108	flexcop_access_op_t op, u16 addr, u8 *buf, u16 len, int retries)
    109{
    110	int i,ret = 0;
    111	u8 chipaddr =  0x50 | ((addr >> 8) & 3);
    112	for (i = 0; i < retries; i++) {
    113		ret = fc->i2c_request(&fc->fc_i2c_adap[1], op, chipaddr,
    114			addr & 0xff, buf, len);
    115		if (ret == 0)
    116			break;
    117	}
    118	return ret;
    119}
    120
    121static int flexcop_eeprom_lrc_read(struct flexcop_device *fc, u16 addr,
    122		u8 *buf, u16 len, int retries)
    123{
    124	int ret = flexcop_eeprom_request(fc, FC_READ, addr, buf, len, retries);
    125	if (ret == 0)
    126		if (calc_lrc(buf, len - 1) != buf[len - 1])
    127			ret = -EINVAL;
    128	return ret;
    129}
    130
    131/* JJ's comment about extended == 1: it is not presently used anywhere but was
    132 * added to the low-level functions for possible support of EUI64 */
    133int flexcop_eeprom_check_mac_addr(struct flexcop_device *fc, int extended)
    134{
    135	u8 buf[8];
    136	int ret = 0;
    137
    138	if ((ret = flexcop_eeprom_lrc_read(fc,0x3f8,buf,8,4)) == 0) {
    139		if (extended != 0) {
    140			err("TODO: extended (EUI64) MAC addresses aren't completely supported yet");
    141			ret = -EINVAL;
    142		} else
    143			memcpy(fc->dvb_adapter.proposed_mac,buf,6);
    144	}
    145	return ret;
    146}
    147EXPORT_SYMBOL(flexcop_eeprom_check_mac_addr);