u-boot/board/freescale/p2020ds/ddr.c

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/*
* Copyright 2008-2009 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* Version 2 as published by the Free Software Foundation.
*/
#include <common.h>
#include <asm/fsl_ddr_sdram.h>
#include <asm/fsl_ddr_dimm_params.h>
struct board_specific_parameters {
u32 n_ranks;
u32 datarate_mhz_high;
u32 clk_adjust;
u32 cpo;
u32 write_data_delay;
u32 force_2T;
};
/*
* This table contains all valid speeds we want to override with board
* specific parameters. datarate_mhz_high values need to be in ascending order
* for each n_ranks group.
*
* ranges for parameters:
* wr_data_delay = 0-6
* clk adjust = 0-8
* cpo 2-0x1E (30)
*/
static const struct board_specific_parameters dimm0[] = {
/*
* memory controller 0
* num| hi| clk| cpo|wrdata|2T
* ranks| mhz|adjst| | delay|
*/
#ifdef CONFIG_FSL_DDR2
{2, 549, 4, 0x1f, 2, 0},
{2, 680, 4, 0x1f, 3, 0},
{2, 850, 4, 0x1f, 4, 0},
{1, 549, 4, 0x1f, 2, 0},
{1, 680, 4, 0x1f, 3, 0},
{1, 850, 4, 0x1f, 4, 0},
#else
{2, 850, 6, 0x1f, 4, 0},
{1, 850, 4, 0x1f, 4, 0},
#endif
{}
};
void fsl_ddr_board_options(memctl_options_t *popts,
dimm_params_t *pdimm,
unsigned int ctrl_num)
{
const struct board_specific_parameters *pbsp, *pbsp_highest = NULL;
ulong ddr_freq;
int i;
if (ctrl_num) {
printf("Wrong parameter for controller number %d", ctrl_num);
return;
}
if (!pdimm->n_ranks)
return;
/*
* set odt_rd_cfg and odt_wr_cfg. If the there is only one dimm in
* that controller, set odt_wr_cfg to 4 for CS0, and 0 to CS1. If
* there are two dimms in the controller, set odt_rd_cfg to 3 and
* odt_wr_cfg to 3 for the even CS, 0 for the odd CS.
*/
for (i = 0; i < CONFIG_CHIP_SELECTS_PER_CTRL; i++) {
popts->cs_local_opts[i].odt_rd_cfg = 0;
popts->cs_local_opts[i].odt_wr_cfg = 1;
}
pbsp = dimm0;
/* Get clk_adjust, cpo, write_data_delay,2T, according to the board ddr
* freqency and n_banks specified in board_specific_parameters table.
*/
ddr_freq = get_ddr_freq(0) / 1000000;
while (pbsp->datarate_mhz_high) {
if (pbsp->n_ranks == pdimm->n_ranks) {
if (ddr_freq <= pbsp->datarate_mhz_high) {
popts->clk_adjust = pbsp->clk_adjust;
popts->cpo_override = pbsp->cpo;
popts->write_data_delay =
pbsp->write_data_delay;
popts->twoT_en = pbsp->force_2T;
goto found;
}
pbsp_highest = pbsp;
}
pbsp++;
}
if (pbsp_highest) {
printf("Error: board specific timing not found "
"for data rate %lu MT/s!\n"
"Trying to use the highest speed (%u) parameters\n",
ddr_freq, pbsp_highest->datarate_mhz_high);
popts->clk_adjust = pbsp_highest->clk_adjust;
popts->cpo_override = pbsp_highest->cpo;
popts->write_data_delay = pbsp_highest->write_data_delay;
popts->twoT_en = pbsp_highest->force_2T;
} else {
panic("DIMM is not supported by this board");
}
found:
/*
* Factors to consider for half-strength driver enable:
* - number of DIMMs installed
*/
popts->half_strength_driver_enable = 0;
popts->wrlvl_en = 1;
/* Write leveling override */
popts->wrlvl_override = 1;
popts->wrlvl_sample = 0xa;
popts->wrlvl_start = 0x8;
/* Rtt and Rtt_WR override */
popts->rtt_override = 1;
popts->rtt_override_value = DDR3_RTT_120_OHM;
popts->rtt_wr_override_value = 0; /* Rtt_WR= dynamic ODT off */
}