u-boot/board/freescale/mpc8349emds/ddr.c

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/*
* Copyright 2011 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#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.
*/
static const struct board_specific_parameters udimm0[] = {
/*
* memory controller 0
* num| hi| clk| cpo|wrdata|2T
* ranks| mhz|adjst| | delay|
*/
{2, 300, 4, 4, 2, 0},
{2, 365, 4, 6, 2, 0},
{2, 450, 4, 7, 2, 0},
{2, 850, 4, 31, 2, 0},
{1, 300, 4, 4, 2, 0},
{1, 365, 4, 6, 2, 0},
{1, 450, 4, 7, 2, 0},
{1, 850, 4, 31, 2, 0},
{}
};
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;
unsigned int i;
ulong ddr_freq;
if (ctrl_num != 0) /* we have only one controller */
return;
for (i = 0; i < CONFIG_DIMM_SLOTS_PER_CTLR; i++) {
if (pdimm[i].n_ranks)
break;
}
if (i >= CONFIG_DIMM_SLOTS_PER_CTLR) /* no DIMM */
return;
pbsp = udimm0;
/* 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[i].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->DQS_config = 0; /* only true DQS signal is used on board */
}