1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright 2008 Extreme Engineering Solutions, Inc. 4 * Copyright 2008 Freescale Semiconductor, Inc. 5 */ 6 7 #include <common.h> 8 #include <i2c.h> 9 10 #include <fsl_ddr_sdram.h> 11 #include <fsl_ddr_dimm_params.h> 12 13 void get_spd(ddr2_spd_eeprom_t *spd, u8 i2c_address) 14 { 15 i2c_read(i2c_address, SPD_EEPROM_OFFSET, 2, (uchar *)spd, 16 sizeof(ddr2_spd_eeprom_t)); 17 } 18 19 /* 20 * There are four board-specific SDRAM timing parameters which must be 21 * calculated based on the particular PCB artwork. These are: 22 * 1.) CPO (Read Capture Delay) 23 * - TIMING_CFG_2 register 24 * Source: Calculation based on board trace lengths and 25 * chip-specific internal delays. 26 * 2.) WR_DATA_DELAY (Write Command to Data Strobe Delay) 27 * - TIMING_CFG_2 register 28 * Source: Calculation based on board trace lengths. 29 * Unless clock and DQ lanes are very different 30 * lengths (>2"), this should be set to the nominal value 31 * of 1/2 clock delay. 32 * 3.) CLK_ADJUST (Clock and Addr/Cmd alignment control) 33 * - DDR_SDRAM_CLK_CNTL register 34 * Source: Signal Integrity Simulations 35 * 4.) 2T Timing on Addr/Ctl 36 * - TIMING_CFG_2 register 37 * Source: Signal Integrity Simulations 38 * Usually only needed with heavy load/very high speed (>DDR2-800) 39 * 40 * ====== XPedite5370 DDR2-600 read delay calculations ====== 41 * 42 * See Freescale's App Note AN2583 as refrence. This document also 43 * contains the chip-specific delays for 8548E, 8572, etc. 44 * 45 * For MPC8572E 46 * Minimum chip delay (Ch 0): 1.372ns 47 * Maximum chip delay (Ch 0): 2.914ns 48 * Minimum chip delay (Ch 1): 1.220ns 49 * Maximum chip delay (Ch 1): 2.595ns 50 * 51 * CLK adjust = 5 (from simulations) = 5/8* 3.33ns = 2080ps 52 * 53 * Minimum delay calc (Ch 0): 54 * clock prop - dram skew + min dqs prop delay + clk_adjust + min chip dly 55 * 2.3" * 180 - 400ps + 1.9" * 180 + 2080ps + 1372ps 56 * = 3808ps 57 * = 3.808ns 58 * 59 * Maximum delay calc (Ch 0): 60 * clock prop + dram skew + max dqs prop delay + clk_adjust + max chip dly 61 * 2.3" * 180 + 400ps + 2.4" * 180 + 2080ps + 2914ps 62 * = 6240ps 63 * = 6.240ns 64 * 65 * Minimum delay calc (Ch 1): 66 * clock prop - dram skew + min dqs prop delay + clk_adjust + min chip dly 67 * 1.46" * 180- 400ps + 0.7" * 180 + 2080ps + 1220ps 68 * = 3288ps 69 * = 3.288ns 70 * 71 * Maximum delay calc (Ch 1): 72 * clock prop + dram skew + max dqs prop delay + clk_adjust + min chip dly 73 * 1.46" * 180+ 400ps + 1.1" * 180 + 2080ps + 2595ps 74 * = 5536ps 75 * = 5.536ns 76 * 77 * Ch.0: 3.808ns to 6.240ns additional delay needed (pick 5ns as target) 78 * This is 1.5 clock cycles, pick CPO = READ_LAT + 3/2 (0x8) 79 * Ch.1: 3.288ns to 5.536ns additional delay needed (pick 4.4ns as target) 80 * This is 1.32 clock cycles, pick CPO = READ_LAT + 5/4 (0x7) 81 * 82 * 83 * ====== XPedite5370 DDR2-800 read delay calculations ====== 84 * 85 * See Freescale's App Note AN2583 as refrence. This document also 86 * contains the chip-specific delays for 8548E, 8572, etc. 87 * 88 * For MPC8572E 89 * Minimum chip delay (Ch 0): 1.372ns 90 * Maximum chip delay (Ch 0): 2.914ns 91 * Minimum chip delay (Ch 1): 1.220ns 92 * Maximum chip delay (Ch 1): 2.595ns 93 * 94 * CLK adjust = 5 (from simulations) = 5/8* 2.5ns = 1563ps 95 * 96 * Minimum delay calc (Ch 0): 97 * clock prop - dram skew + min dqs prop delay + clk_adjust + min chip dly 98 * 2.3" * 180 - 350ps + 1.9" * 180 + 1563ps + 1372ps 99 * = 3341ps 100 * = 3.341ns 101 * 102 * Maximum delay calc (Ch 0): 103 * clock prop + dram skew + max dqs prop delay + clk_adjust + max chip dly 104 * 2.3" * 180 + 350ps + 2.4" * 180 + 1563ps + 2914ps 105 * = 5673ps 106 * = 5.673ns 107 * 108 * Minimum delay calc (Ch 1): 109 * clock prop - dram skew + min dqs prop delay + clk_adjust + min chip dly 110 * 1.46" * 180- 350ps + 0.7" * 180 + 1563ps + 1220ps 111 * = 2822ps 112 * = 2.822ns 113 * 114 * Maximum delay calc (Ch 1): 115 * clock prop + dram skew + max dqs prop delay + clk_adjust + min chip dly 116 * 1.46" * 180+ 350ps + 1.1" * 180 + 1563ps + 2595ps 117 * = 4968ps 118 * = 4.968ns 119 * 120 * Ch.0: 3.341ns to 5.673ns additional delay needed (pick 4.5ns as target) 121 * This is 1.8 clock cycles, pick CPO = READ_LAT + 7/4 (0x9) 122 * Ch.1: 2.822ns to 4.968ns additional delay needed (pick 3.9ns as target) 123 * This is 1.56 clock cycles, pick CPO = READ_LAT + 3/2 (0x8) 124 * 125 * Write latency (WR_DATA_DELAY) is calculated by doing the following: 126 * 127 * The DDR SDRAM specification requires DQS be received no sooner than 128 * 75% of an SDRAM clock period—and no later than 125% of a clock 129 * period—from the capturing clock edge of the command/address at the 130 * SDRAM. 131 * 132 * Based on the above tracelengths, the following are calculated: 133 * Ch. 0 8572 to DRAM propagation (DQ lanes) : 1.9" * 180 = 0.342ns 134 * Ch. 0 8572 to DRAM propagation (CLKs) : 2.3" * 180 = 0.414ns 135 * Ch. 1 8572 to DRAM propagation (DQ lanes) : 0.7" * 180 = 0.126ns 136 * Ch. 1 8572 to DRAM propagation (CLKs ) : 1.47" * 180 = 0.264ns 137 * 138 * Difference in arrival time CLK vs. DQS: 139 * Ch. 0 0.072ns 140 * Ch. 1 0.138ns 141 * 142 * Both of these values are much less than 25% of the clock 143 * period at DDR2-600 or DDR2-800, so no additional delay is needed over 144 * the 1/2 cycle which normally aligns the first DQS transition 145 * exactly WL (CAS latency minus one cycle) after the CAS strobe. 146 * See Figure 9-53 in MPC8572E manual: "1/2 delay" in Freescale's 147 * terminology corresponds to exactly one clock period delay after 148 * the CAS strobe. (due to the fact that the "delay" is referenced 149 * from the *falling* edge of the CLK, just after the rising edge 150 * which the CAS strobe is latched on. 151 */ 152 153 typedef struct board_memctl_options { 154 uint16_t datarate_mhz_low; 155 uint16_t datarate_mhz_high; 156 uint8_t clk_adjust; 157 uint8_t cpo_override; 158 uint8_t write_data_delay; 159 } board_memctl_options_t; 160 161 static struct board_memctl_options bopts_ctrl[][2] = { 162 { 163 /* Controller 0 */ 164 { 165 /* DDR2 600/667 */ 166 .datarate_mhz_low = 500, 167 .datarate_mhz_high = 750, 168 .clk_adjust = 5, 169 .cpo_override = 8, 170 .write_data_delay = 2, 171 }, 172 { 173 /* DDR2 800 */ 174 .datarate_mhz_low = 750, 175 .datarate_mhz_high = 850, 176 .clk_adjust = 5, 177 .cpo_override = 9, 178 .write_data_delay = 2, 179 }, 180 }, 181 { 182 /* Controller 1 */ 183 { 184 /* DDR2 600/667 */ 185 .datarate_mhz_low = 500, 186 .datarate_mhz_high = 750, 187 .clk_adjust = 5, 188 .cpo_override = 7, 189 .write_data_delay = 2, 190 }, 191 { 192 /* DDR2 800 */ 193 .datarate_mhz_low = 750, 194 .datarate_mhz_high = 850, 195 .clk_adjust = 5, 196 .cpo_override = 8, 197 .write_data_delay = 2, 198 }, 199 }, 200 }; 201 202 void fsl_ddr_board_options(memctl_options_t *popts, 203 dimm_params_t *pdimm, 204 unsigned int ctrl_num) 205 { 206 struct board_memctl_options *bopts = bopts_ctrl[ctrl_num]; 207 sys_info_t sysinfo; 208 int i; 209 unsigned int datarate; 210 211 get_sys_info(&sysinfo); 212 datarate = sysinfo.freq_ddrbus / 1000 / 1000; 213 214 for (i = 0; i < ARRAY_SIZE(bopts_ctrl[ctrl_num]); i++) { 215 if ((bopts[i].datarate_mhz_low <= datarate) && 216 (bopts[i].datarate_mhz_high >= datarate)) { 217 debug("controller %d:\n", ctrl_num); 218 debug(" clk_adjust = %d\n", bopts[i].clk_adjust); 219 debug(" cpo = %d\n", bopts[i].cpo_override); 220 debug(" write_data_delay = %d\n", 221 bopts[i].write_data_delay); 222 popts->clk_adjust = bopts[i].clk_adjust; 223 popts->cpo_override = bopts[i].cpo_override; 224 popts->write_data_delay = bopts[i].write_data_delay; 225 } 226 } 227 228 /* 229 * Factors to consider for half-strength driver enable: 230 * - number of DIMMs installed 231 */ 232 popts->half_strength_driver_enable = 0; 233 } 234