board/socrates/ddr.c

   1 /*
   2  * Copyright 2008 Freescale Semiconductor, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * Version 2 as published by the Free Software Foundation.
   7  */
   8
   9 #include <common.h>
  10 #include <i2c.h>
  11
  12 #include <asm/fsl_ddr_sdram.h>
  13
  14 static void
  15 get_spd(ddr2_spd_eeprom_t *spd, unsigned char i2c_address)
  16 {
  17         i2c_read(i2c_address, 0, 1, (uchar *)spd, sizeof(ddr2_spd_eeprom_t));
  18 }
  19
  20 unsigned int fsl_ddr_get_mem_data_rate(void)
  21 {
  22         return get_ddr_freq(0);
  23 }
  24
  25 void fsl_ddr_get_spd(ddr2_spd_eeprom_t *ctrl_dimms_spd,
  26                       unsigned int ctrl_num)
  27 {
  28         unsigned int i;
  29
  30         if (ctrl_num) {
  31                 printf("%s unexpected ctrl_num = %u\n", __FUNCTION__, ctrl_num);
  32                 return;
  33         }
  34
  35         for (i = 0; i < CONFIG_DIMM_SLOTS_PER_CTLR; i++) {
  36                 get_spd(&(ctrl_dimms_spd[i]), SPD_EEPROM_ADDRESS);
  37         }
  38 }
  39
  40 void fsl_ddr_board_options(memctl_options_t *popts, unsigned int ctrl_num)
  41 {
  42         /*
  43          * Factors to consider for clock adjust:
  44          *      - number of chips on bus
  45          *      - position of slot
  46          *      - DDR1 vs. DDR2?
  47          *      - ???
  48          *
  49          * This needs to be determined on a board-by-board basis.
  50          *      0110    3/4 cycle late
  51          *      0111    7/8 cycle late
  52          */
  53         popts->clk_adjust = 7;
  54
  55         /*
  56          * Factors to consider for CPO:
  57          *      - frequency
  58          *      - ddr1 vs. ddr2
  59          */
  60         popts->cpo_override = 10;
  61
  62         /*
  63          * Factors to consider for write data delay:
  64          *      - number of DIMMs
  65          *
  66          * 1 = 1/4 clock delay
  67          * 2 = 1/2 clock delay
  68          * 3 = 3/4 clock delay
  69          * 4 = 1   clock delay
  70          * 5 = 5/4 clock delay
  71          * 6 = 3/2 clock delay
  72          */
  73         popts->write_data_delay = 3;
  74
  75         /*
  76          * Factors to consider for half-strength driver enable:
  77          *      - number of DIMMs installed
  78          */
  79         popts->half_strength_driver_enable = 0;
  80 }