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