xref: /openbmc/u-boot/board/xes/xpedite517x/ddr.c (revision 83d290c56fab2d38cd1ab4c4cc7099559c1d5046)

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright 2009 Extreme Engineering Solutions, Inc.
 * Copyright 2007-2008 Freescale Semiconductor, Inc.
 */

#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)
 *
 *     PCB routing on the XPedite5170 is nearly identical to the XPedite5370
 *     so we use the XPedite5370 settings as a basis for the XPedite5170.
 */

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 = get_ddr_freq(0) / 1000000;

	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;
}