board/compulab/common/eeprom.c

   1 /*
   2  * (C) Copyright 2011 CompuLab, Ltd. <www.compulab.co.il>
   3  *
   4  * Authors: Nikita Kiryanov <nikita@compulab.co.il>
   5  *          Igor Grinberg <grinberg@compulab.co.il>
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #include <common.h>
  11 #include <i2c.h>
  12
  13 #ifndef CONFIG_SYS_I2C_EEPROM_ADDR
  14 # define CONFIG_SYS_I2C_EEPROM_ADDR     0x50
  15 # define CONFIG_SYS_I2C_EEPROM_ADDR_LEN 1
  16 #endif
  17
  18 #ifndef CONFIG_SYS_I2C_EEPROM_BUS
  19 #define CONFIG_SYS_I2C_EEPROM_BUS       0
  20 #endif
  21
  22 #define EEPROM_LAYOUT_VER_OFFSET        44
  23 #define BOARD_SERIAL_OFFSET             20
  24 #define BOARD_SERIAL_OFFSET_LEGACY      8
  25 #define BOARD_REV_OFFSET                0
  26 #define BOARD_REV_OFFSET_LEGACY         6
  27 #define BOARD_REV_SIZE                  2
  28 #define MAC_ADDR_OFFSET                 4
  29 #define MAC_ADDR_OFFSET_LEGACY          0
  30
  31 #define LAYOUT_INVALID  0
  32 #define LAYOUT_LEGACY   0xff
  33
  34 static int cl_eeprom_layout; /* Implicitly LAYOUT_INVALID */
  35
  36 static int cl_eeprom_read(uint offset, uchar *buf, int len)
  37 {
  38         int res;
  39         unsigned int current_i2c_bus = i2c_get_bus_num();
  40
  41         res = i2c_set_bus_num(CONFIG_SYS_I2C_EEPROM_BUS);
  42         if (res < 0)
  43                 return res;
  44
  45         res = i2c_read(CONFIG_SYS_I2C_EEPROM_ADDR, offset,
  46                         CONFIG_SYS_I2C_EEPROM_ADDR_LEN, buf, len);
  47
  48         i2c_set_bus_num(current_i2c_bus);
  49
  50         return res;
  51 }
  52
  53 static int cl_eeprom_setup_layout(void)
  54 {
  55         int res;
  56
  57         if (cl_eeprom_layout != LAYOUT_INVALID)
  58                 return 0;
  59
  60         res = cl_eeprom_read(EEPROM_LAYOUT_VER_OFFSET,
  61                              (uchar *)&cl_eeprom_layout, 1);
  62         if (res) {
  63                 cl_eeprom_layout = LAYOUT_INVALID;
  64                 return res;
  65         }
  66
  67         if (cl_eeprom_layout == 0 || cl_eeprom_layout >= 0x20)
  68                 cl_eeprom_layout = LAYOUT_LEGACY;
  69
  70         return 0;
  71 }
  72
  73 void get_board_serial(struct tag_serialnr *serialnr)
  74 {
  75         u32 serial[2];
  76         uint offset;
  77
  78         memset(serialnr, 0, sizeof(*serialnr));
  79
  80         if (cl_eeprom_setup_layout())
  81                 return;
  82
  83         offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
  84                 BOARD_SERIAL_OFFSET : BOARD_SERIAL_OFFSET_LEGACY;
  85
  86         if (cl_eeprom_read(offset, (uchar *)serial, 8))
  87                 return;
  88
  89         if (serial[0] != 0xffffffff && serial[1] != 0xffffffff) {
  90                 serialnr->low = serial[0];
  91                 serialnr->high = serial[1];
  92         }
  93 }
  94
  95 /*
  96  * Routine: cl_eeprom_read_mac_addr
  97  * Description: read mac address and store it in buf.
  98  */
  99 int cl_eeprom_read_mac_addr(uchar *buf)
 100 {
 101         uint offset;
 102
 103         if (cl_eeprom_setup_layout())
 104                 return 0;
 105
 106         offset = (cl_eeprom_layout != LAYOUT_LEGACY) ?
 107                         MAC_ADDR_OFFSET : MAC_ADDR_OFFSET_LEGACY;
 108
 109         return cl_eeprom_read(offset, buf, 6);
 110 }
 111
 112 static u32 board_rev;
 113
 114 /*
 115  * Routine: cl_eeprom_get_board_rev
 116  * Description: read system revision from eeprom
 117  */
 118 u32 cl_eeprom_get_board_rev(void)
 119 {
 120         char str[5]; /* Legacy representation can contain at most 4 digits */
 121         uint offset = BOARD_REV_OFFSET_LEGACY;
 122
 123         if (board_rev)
 124                 return board_rev;
 125
 126         if (cl_eeprom_setup_layout())
 127                 return 0;
 128
 129         if (cl_eeprom_layout != LAYOUT_LEGACY)
 130                 offset = BOARD_REV_OFFSET;
 131
 132         if (cl_eeprom_read(offset, (uchar *)&board_rev, BOARD_REV_SIZE))
 133                 return 0;
 134
 135         /*
 136          * Convert legacy syntactic representation to semantic
 137          * representation. i.e. for rev 1.00: 0x100 --> 0x64
 138          */
 139         if (cl_eeprom_layout == LAYOUT_LEGACY) {
 140                 sprintf(str, "%x", board_rev);
 141                 board_rev = simple_strtoul(str, NULL, 10);
 142         }
 143
 144         return board_rev;
 145 };