u-boot-brain/board/freescale/mpc8544ds/ddr.c
Dave Liu b4983e16d1 fsl-ddr: use the 1T timing as default configuration
For light loaded system, we use the 1T timing to gain better
memory performance, but for some heavily loaded system,
you have to add the 2T timing options to board files.

Signed-off-by: Dave Liu <daveliu@freescale.com>
Acked-by: Andy Fleming <afleming@freescale.com>
2009-01-23 17:03:14 -06:00

87 lines
1.8 KiB
C

/*
* Copyright 2008 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 <i2c.h>
#include <asm/fsl_ddr_sdram.h>
#include <asm/fsl_ddr_dimm_params.h>
static void
get_spd(ddr2_spd_eeprom_t *spd, unsigned char i2c_address)
{
i2c_read(i2c_address, 0, 1, (uchar *)spd, sizeof(ddr2_spd_eeprom_t));
}
unsigned int fsl_ddr_get_mem_data_rate(void)
{
return get_ddr_freq(0);
}
void fsl_ddr_get_spd(ddr2_spd_eeprom_t *ctrl_dimms_spd,
unsigned int ctrl_num)
{
unsigned int i;
if (ctrl_num) {
printf("%s unexpected ctrl_num = %u\n", __FUNCTION__, ctrl_num);
return;
}
for (i = 0; i < CONFIG_DIMM_SLOTS_PER_CTLR; i++) {
get_spd(&(ctrl_dimms_spd[i]), SPD_EEPROM_ADDRESS);
}
}
void fsl_ddr_board_options(memctl_options_t *popts,
dimm_params_t *pdimm,
unsigned int ctrl_num)
{
/*
* Factors to consider for clock adjust:
* - number of chips on bus
* - position of slot
* - DDR1 vs. DDR2?
* - ???
*
* This needs to be determined on a board-by-board basis.
* 0110 3/4 cycle late
* 0111 7/8 cycle late
*/
popts->clk_adjust = 7;
/*
* Factors to consider for CPO:
* - frequency
* - ddr1 vs. ddr2
*/
popts->cpo_override = 10;
/*
* Factors to consider for write data delay:
* - number of DIMMs
*
* 1 = 1/4 clock delay
* 2 = 1/2 clock delay
* 3 = 3/4 clock delay
* 4 = 1 clock delay
* 5 = 5/4 clock delay
* 6 = 3/2 clock delay
*/
popts->write_data_delay = 3;
/* 2T timing enable */
popts->twoT_en = 1;
/*
* Factors to consider for half-strength driver enable:
* - number of DIMMs installed
*/
popts->half_strength_driver_enable = 0;
}