--- /dev/null
+/*
+ * Copyright 2008 Extreme Engineering Solutions, Inc.
+ * Copyright 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(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;
+}
Code Review / kvmfornfv.git / blobdiff