ddr.c
3.78 KB
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/*
* Copyright 2010 Extreme Engineering Solutions, Inc.
* Copyright 2007-2008 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <i2c.h>
#include <fsl_ddr_sdram.h>
#include <fsl_ddr_dimm_params.h>
void get_spd(ddr3_spd_eeprom_t *spd, u8 i2c_address)
{
i2c_read(i2c_address, SPD_EEPROM_OFFSET, 2, (uchar *)spd,
sizeof(ddr3_spd_eeprom_t));
}
/*
* There are traditionally three board-specific SDRAM timing parameters
* which must be calculated based on the particular PCB artwork. These are:
* 1.) CPO (Read Capture Delay)
* - TIMING_CFG_2 register
* Source: Calculation based on board trace lengths and
* chip-specific internal delays.
* 2.) CLK_ADJUST (Clock and Addr/Cmd alignment control)
* - DDR_SDRAM_CLK_CNTL register
* Source: Signal Integrity Simulations
* 3.) 2T Timing on Addr/Ctl
* - TIMING_CFG_2 register
* Source: Signal Integrity Simulations
* Usually only needed with heavy load/very high speed (>DDR2-800)
*
* ====== XPedite550x DDR3-800 read delay calculations ======
*
* The P2020 processor provides an autoleveling option. Setting CPO to
* 0x1f enables this auto configuration.
*/
typedef struct {
unsigned short datarate_mhz_low;
unsigned short datarate_mhz_high;
unsigned char clk_adjust;
unsigned char cpo;
} board_specific_parameters_t;
const board_specific_parameters_t board_specific_parameters[][20] = {
{
/* Controller 0 */
{
/* DDR3-600/667 */
.datarate_mhz_low = 500,
.datarate_mhz_high = 750,
.clk_adjust = 5,
.cpo = 31,
},
{
/* DDR3-800 */
.datarate_mhz_low = 750,
.datarate_mhz_high = 850,
.clk_adjust = 5,
.cpo = 31,
},
},
};
void fsl_ddr_board_options(memctl_options_t *popts,
dimm_params_t *pdimm,
unsigned int ctrl_num)
{
const board_specific_parameters_t *pbsp =
&(board_specific_parameters[ctrl_num][0]);
u32 num_params = sizeof(board_specific_parameters[ctrl_num]) /
sizeof(board_specific_parameters[0][0]);
u32 i;
ulong ddr_freq;
/*
* 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++) {
if (i&1) { /* odd CS */
popts->cs_local_opts[i].odt_rd_cfg = 0;
popts->cs_local_opts[i].odt_wr_cfg = 0;
} else { /* even CS */
if (CONFIG_DIMM_SLOTS_PER_CTLR == 1) {
popts->cs_local_opts[i].odt_rd_cfg = 0;
popts->cs_local_opts[i].odt_wr_cfg = 4;
} else if (CONFIG_DIMM_SLOTS_PER_CTLR == 2) {
popts->cs_local_opts[i].odt_rd_cfg = 3;
popts->cs_local_opts[i].odt_wr_cfg = 3;
}
}
}
/*
* 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;
for (i = 0; i < num_params; i++) {
if (ddr_freq >= pbsp->datarate_mhz_low &&
ddr_freq <= pbsp->datarate_mhz_high) {
popts->clk_adjust = pbsp->clk_adjust;
popts->cpo_override = pbsp->cpo;
popts->twot_en = 0;
break;
}
pbsp++;
}
if (i == num_params) {
printf("Warning: board specific timing not found "
"for data rate %lu MT/s!\n", ddr_freq);
}
/*
* Factors to consider for half-strength driver enable:
* - number of DIMMs installed
*/
popts->half_strength_driver_enable = 0;
/*
* Enable on-die termination.
* From the Micron Technical Node TN-41-04, RTT_Nom should typically
* be 30 to 40 ohms, while RTT_WR should be 120 ohms. Setting RTT_WR
* is handled in the Freescale DDR3 driver. Set RTT_Nom here.
*/
popts->rtt_override = 1;
popts->rtt_override_value = 3;
}