drivers/media/common/b2c2/flexcop-eeprom.c

   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) */
  11 static 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
  16 static int eeprom_lrc_write(struct adapter *adapter, u32 addr,
  17                 u32 len, u8 *wbuf, u8 *rbuf, int retries)
  18 {
  19 int i;
  20
  21 for (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
  32 static 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
  48 static 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
  62 static 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
  90 static 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
  98 static 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
 107 static 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
 121 static 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 */
 133 int 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 }
 147 EXPORT_SYMBOL(flexcop_eeprom_check_mac_addr);