board/freescale/p2020ds/ddr.c

   1 /*
   2  * Copyright 2008-2009 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
  11 #include <asm/fsl_ddr_sdram.h>
  12 #include <asm/fsl_ddr_dimm_params.h>
  13
  14 struct board_specific_parameters {
  15         u32 n_ranks;
  16         u32 datarate_mhz_high;
  17         u32 clk_adjust;
  18         u32 cpo;
  19         u32 write_data_delay;
  20         u32 force_2t;
  21 };
  22
  23
  24 /*
  25  * This table contains all valid speeds we want to override with board
  26  * specific parameters. datarate_mhz_high values need to be in ascending order
  27  * for each n_ranks group.
  28  *
  29  * ranges for parameters:
  30  *  wr_data_delay = 0-6
  31  *  clk adjust = 0-8
  32  *  cpo 2-0x1E (30)
  33  */
  34 static const struct board_specific_parameters dimm0[] = {
  35         /*
  36          * memory controller 0
  37          *   num|  hi|  clk| cpo|wrdata|2T
  38          * ranks| mhz|adjst|    | delay|
  39          */
  40 #ifdef CONFIG_FSL_DDR2
  41         {2,  549,    4,   0x1f,    2,  0},
  42         {2,  680,    4,   0x1f,    3,  0},
  43         {2,  850,    4,   0x1f,    4,  0},
  44         {1,  549,    4,   0x1f,    2,  0},
  45         {1,  680,    4,   0x1f,    3,  0},
  46         {1,  850,    4,   0x1f,    4,  0},
  47 #else
  48         {2,  850,    6,   0x1f,    4,  0},
  49         {1,  850,    4,   0x1f,    4,  0},
  50 #endif
  51         {}
  52 };
  53
  54 void fsl_ddr_board_options(memctl_options_t *popts,
  55                                 dimm_params_t *pdimm,
  56                                 unsigned int ctrl_num)
  57 {
  58         const struct board_specific_parameters *pbsp, *pbsp_highest = NULL;
  59         ulong ddr_freq;
  60         int i;
  61
  62         if (ctrl_num) {
  63                 printf("Wrong parameter for controller number %d", ctrl_num);
  64                 return;
  65         }
  66         if (!pdimm->n_ranks)
  67                 return;
  68
  69         /*
  70          * set odt_rd_cfg and odt_wr_cfg. If the there is only one dimm in
  71          * that controller, set odt_wr_cfg to 4 for CS0, and 0 to CS1. If
  72          * there are two dimms in the controller, set odt_rd_cfg to 3 and
  73          * odt_wr_cfg to 3 for the even CS, 0 for the odd CS.
  74          */
  75         for (i = 0; i < CONFIG_CHIP_SELECTS_PER_CTRL; i++) {
  76                 popts->cs_local_opts[i].odt_rd_cfg = 0;
  77                 popts->cs_local_opts[i].odt_wr_cfg = 1;
  78         }
  79
  80         pbsp = dimm0;
  81
  82         /* Get clk_adjust, cpo, write_data_delay,2T, according to the board ddr
  83          * freqency and n_banks specified in board_specific_parameters table.
  84          */
  85         ddr_freq = get_ddr_freq(0) / 1000000;
  86         while (pbsp->datarate_mhz_high) {
  87                 if (pbsp->n_ranks == pdimm->n_ranks) {
  88                         if (ddr_freq <= pbsp->datarate_mhz_high) {
  89                                 popts->clk_adjust = pbsp->clk_adjust;
  90                                 popts->cpo_override = pbsp->cpo;
  91                                 popts->write_data_delay =
  92                                         pbsp->write_data_delay;
  93                                 popts->twot_en = pbsp->force_2t;
  94                                 goto found;
  95                         }
  96                         pbsp_highest = pbsp;
  97                 }
  98                 pbsp++;
  99         }
 100
 101         if (pbsp_highest) {
 102                 printf("Error: board specific timing not found "
 103                         "for data rate %lu MT/s!\n"
 104                         "Trying to use the highest speed (%u) parameters\n",
 105                         ddr_freq, pbsp_highest->datarate_mhz_high);
 106                 popts->clk_adjust = pbsp_highest->clk_adjust;
 107                 popts->cpo_override = pbsp_highest->cpo;
 108                 popts->write_data_delay = pbsp_highest->write_data_delay;
 109                 popts->twot_en = pbsp_highest->force_2t;
 110         } else {
 111                 panic("DIMM is not supported by this board");
 112         }
 113
 114 found:
 115         /*
 116          * Factors to consider for half-strength driver enable:
 117          *      - number of DIMMs installed
 118          */
 119         popts->half_strength_driver_enable = 0;
 120         popts->wrlvl_en = 1;
 121         /* Write leveling override */
 122         popts->wrlvl_override = 1;
 123         popts->wrlvl_sample = 0xa;
 124         popts->wrlvl_start = 0x8;
 125         /* Rtt and Rtt_WR override */
 126         popts->rtt_override = 1;
 127         popts->rtt_override_value = DDR3_RTT_120_OHM;
 128         popts->rtt_wr_override_value = 0; /* Rtt_WR= dynamic ODT off */
 129 }