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/*
* Copyright 2008 Extreme Engineering Solutions, Inc.
* Copyright 2008 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <i2c.h>
#include <asm/fsl_ddr_sdram.h>
#include <asm/fsl_ddr_dimm_params.h>
void get_spd(ddr2_spd_eeprom_t *spd, u8 i2c_address)
{
i2c_read(i2c_address, SPD_EEPROM_OFFSET, 2, (uchar *)spd,
sizeof(ddr2_spd_eeprom_t));
}
/*
* There are four 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.) WR_DATA_DELAY (Write Command to Data Strobe Delay)
* - TIMING_CFG_2 register
* Source: Calculation based on board trace lengths.
* Unless clock and DQ lanes are very different
* lengths (>2"), this should be set to the nominal value
* of 1/2 clock delay.
* 3.) CLK_ADJUST (Clock and Addr/Cmd alignment control)
* - DDR_SDRAM_CLK_CNTL register
* Source: Signal Integrity Simulations
* 4.) 2T Timing on Addr/Ctl
* - TIMING_CFG_2 register
* Source: Signal Integrity Simulations
* Usually only needed with heavy load/very high speed (>DDR2-800)
*
* ====== XPedite5370 DDR2-600 read delay calculations ======
*
* See Freescale's App Note AN2583 as refrence. This document also
* contains the chip-specific delays for 8548E, 8572, etc.
*
* For MPC8572E
* Minimum chip delay (Ch 0): 1.372ns
* Maximum chip delay (Ch 0): 2.914ns
* Minimum chip delay (Ch 1): 1.220ns
* Maximum chip delay (Ch 1): 2.595ns
*
* CLK adjust = 5 (from simulations) = 5/8* 3.33ns = 2080ps
*
* Minimum delay calc (Ch 0):
* clock prop - dram skew + min dqs prop delay + clk_adjust + min chip dly
* 2.3" * 180 - 400ps + 1.9" * 180 + 2080ps + 1372ps
* = 3808ps
* = 3.808ns
*
* Maximum delay calc (Ch 0):
* clock prop + dram skew + max dqs prop delay + clk_adjust + max chip dly
* 2.3" * 180 + 400ps + 2.4" * 180 + 2080ps + 2914ps
* = 6240ps
* = 6.240ns
*
* Minimum delay calc (Ch 1):
* clock prop - dram skew + min dqs prop delay + clk_adjust + min chip dly
* 1.46" * 180- 400ps + 0.7" * 180 + 2080ps + 1220ps
* = 3288ps
* = 3.288ns
*
* Maximum delay calc (Ch 1):
* clock prop + dram skew + max dqs prop delay + clk_adjust + min chip dly
* 1.46" * 180+ 400ps + 1.1" * 180 + 2080ps + 2595ps
* = 5536ps
* = 5.536ns
*
* Ch.0: 3.808ns to 6.240ns additional delay needed (pick 5ns as target)
* This is 1.5 clock cycles, pick CPO = READ_LAT + 3/2 (0x8)
* Ch.1: 3.288ns to 5.536ns additional delay needed (pick 4.4ns as target)
* This is 1.32 clock cycles, pick CPO = READ_LAT + 5/4 (0x7)
*
*
* ====== XPedite5370 DDR2-800 read delay calculations ======
*
* See Freescale's App Note AN2583 as refrence. This document also
* contains the chip-specific delays for 8548E, 8572, etc.
*
* For MPC8572E
* Minimum chip delay (Ch 0): 1.372ns
* Maximum chip delay (Ch 0): 2.914ns
* Minimum chip delay (Ch 1): 1.220ns
* Maximum chip delay (Ch 1): 2.595ns
*
* CLK adjust = 5 (from simulations) = 5/8* 2.5ns = 1563ps
*
* Minimum delay calc (Ch 0):
* clock prop - dram skew + min dqs prop delay + clk_adjust + min chip dly
* 2.3" * 180 - 350ps + 1.9" * 180 + 1563ps + 1372ps
* = 3341ps
* = 3.341ns
*
* Maximum delay calc (Ch 0):
* clock prop + dram skew + max dqs prop delay + clk_adjust + max chip dly
* 2.3" * 180 + 350ps + 2.4" * 180 + 1563ps + 2914ps
* = 5673ps
* = 5.673ns
*
* Minimum delay calc (Ch 1):
* clock prop - dram skew + min dqs prop delay + clk_adjust + min chip dly
* 1.46" * 180- 350ps + 0.7" * 180 + 1563ps + 1220ps
* = 2822ps
* = 2.822ns
*
* Maximum delay calc (Ch 1):
* clock prop + dram skew + max dqs prop delay + clk_adjust + min chip dly
* 1.46" * 180+ 350ps + 1.1" * 180 + 1563ps + 2595ps
* = 4968ps
* = 4.968ns
*
* Ch.0: 3.341ns to 5.673ns additional delay needed (pick 4.5ns as target)
* This is 1.8 clock cycles, pick CPO = READ_LAT + 7/4 (0x9)
* Ch.1: 2.822ns to 4.968ns additional delay needed (pick 3.9ns as target)
* This is 1.56 clock cycles, pick CPO = READ_LAT + 3/2 (0x8)
*
* Write latency (WR_DATA_DELAY) is calculated by doing the following:
*
* The DDR SDRAM specification requires DQS be received no sooner than
* 75% of an SDRAM clock period—and no later than 125% of a clock
* period—from the capturing clock edge of the command/address at the
* SDRAM.
*
* Based on the above tracelengths, the following are calculated:
* Ch. 0 8572 to DRAM propagation (DQ lanes) : 1.9" * 180 = 0.342ns
* Ch. 0 8572 to DRAM propagation (CLKs) : 2.3" * 180 = 0.414ns
* Ch. 1 8572 to DRAM propagation (DQ lanes) : 0.7" * 180 = 0.126ns
* Ch. 1 8572 to DRAM propagation (CLKs ) : 1.47" * 180 = 0.264ns
*
* Difference in arrival time CLK vs. DQS:
* Ch. 0 0.072ns
* Ch. 1 0.138ns
*
* Both of these values are much less than 25% of the clock
* period at DDR2-600 or DDR2-800, so no additional delay is needed over
* the 1/2 cycle which normally aligns the first DQS transition
* exactly WL (CAS latency minus one cycle) after the CAS strobe.
* See Figure 9-53 in MPC8572E manual: "1/2 delay" in Freescale's
* terminology corresponds to exactly one clock period delay after
* the CAS strobe. (due to the fact that the "delay" is referenced
* from the *falling* edge of the CLK, just after the rising edge
* which the CAS strobe is latched on.
*/
typedef struct board_memctl_options {
uint16_t datarate_mhz_low;
uint16_t datarate_mhz_high;
uint8_t clk_adjust;
uint8_t cpo_override;
uint8_t write_data_delay;
} board_memctl_options_t;
static struct board_memctl_options bopts_ctrl[][2] = {
{
/* Controller 0 */
{
/* DDR2 600/667 */
.datarate_mhz_low = 500,
.datarate_mhz_high = 750,
.clk_adjust = 5,
.cpo_override = 8,
.write_data_delay = 2,
},
{
/* DDR2 800 */
.datarate_mhz_low = 750,
.datarate_mhz_high = 850,
.clk_adjust = 5,
.cpo_override = 9,
.write_data_delay = 2,
},
},
{
/* Controller 1 */
{
/* DDR2 600/667 */
.datarate_mhz_low = 500,
.datarate_mhz_high = 750,
.clk_adjust = 5,
.cpo_override = 7,
.write_data_delay = 2,
},
{
/* DDR2 800 */
.datarate_mhz_low = 750,
.datarate_mhz_high = 850,
.clk_adjust = 5,
.cpo_override = 8,
.write_data_delay = 2,
},
},
};
void fsl_ddr_board_options(memctl_options_t *popts,
dimm_params_t *pdimm,
unsigned int ctrl_num)
{
struct board_memctl_options *bopts = bopts_ctrl[ctrl_num];
sys_info_t sysinfo;
int i;
unsigned int datarate;
get_sys_info(&sysinfo);
datarate = sysinfo.freq_ddrbus / 1000 / 1000;
for (i = 0; i < ARRAY_SIZE(bopts_ctrl[ctrl_num]); i++) {
if ((bopts[i].datarate_mhz_low <= datarate) &&
(bopts[i].datarate_mhz_high >= datarate)) {
debug("controller %d:\n", ctrl_num);
debug(" clk_adjust = %d\n", bopts[i].clk_adjust);
debug(" cpo = %d\n", bopts[i].cpo_override);
debug(" write_data_delay = %d\n",
bopts[i].write_data_delay);
popts->clk_adjust = bopts[i].clk_adjust;
popts->cpo_override = bopts[i].cpo_override;
popts->write_data_delay = bopts[i].write_data_delay;
}
}
/*
* Factors to consider for half-strength driver enable:
* - number of DIMMs installed
*/
popts->half_strength_driver_enable = 0;
}
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