board/freescale/p2041rdb/ddr.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2011 Freescale Semiconductor, Inc.
 */

#include <i2c.h>
#include <hwconfig.h>
#include <init.h>
#include <log.h>
#include <asm/global_data.h>
#include <asm/mmu.h>
#include <fsl_ddr_sdram.h>
#include <fsl_ddr_dimm_params.h>
#include <asm/fsl_law.h>

DECLARE_GLOBAL_DATA_PTR;

struct board_specific_parameters {
	u32 n_ranks;
	u32 datarate_mhz_high;
	u32 clk_adjust;
	u32 wrlvl_start;
	u32 cpo;
	u32 write_data_delay;
	u32 force_2t;
};

/*
 * This table contains all valid speeds we want to override with board
 * specific parameters. datarate_mhz_high values need to be in ascending order
 * for each n_ranks group.
 *
 * ranges for parameters:
 *  wr_data_delay = 0-6
 *  clk adjust = 0-8
 *  cpo 2-0x1E (30)
 */
static const struct board_specific_parameters dimm0[] = {
	/*
	 * memory controller 0
	 *   num|  hi|  clk| wrlvl | cpo  |wrdata|2T
	 * ranks| mhz|adjst| start | delay|
	 */
	{2,   750,    3,     5,   0xff,    2,  0},
	{2,  1250,    4,     6,   0xff,    2,  0},
	{2,  1350,    5,     7,   0xff,    2,  0},
	{2,  1666,    5,     8,   0xff,    2,  0},
	{}
};

void fsl_ddr_board_options(memctl_options_t *popts,
				dimm_params_t *pdimm,
				unsigned int ctrl_num)
{
	const struct board_specific_parameters *pbsp, *pbsp_highest = NULL;
	ulong ddr_freq;

	if (ctrl_num) {
		printf("Wrong parameter for controller number %d", ctrl_num);
		return;
	}
	if (!pdimm->n_ranks)
		return;

	pbsp = dimm0;

	/*
	 * 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;
	while (pbsp->datarate_mhz_high) {
		if (pbsp->n_ranks == pdimm->n_ranks) {
			if (ddr_freq <= pbsp->datarate_mhz_high) {
				popts->cpo_override = pbsp->cpo;
				popts->write_data_delay =
					pbsp->write_data_delay;
				popts->clk_adjust = pbsp->clk_adjust;
				popts->wrlvl_start = pbsp->wrlvl_start;
				popts->twot_en = pbsp->force_2t;
				goto found;
			}
			pbsp_highest = pbsp;
		}
		pbsp++;
	}

	if (pbsp_highest) {
		printf("Error: board specific timing not found "
			"for data rate %lu MT/s!\n"
			"Trying to use the highest speed (%u) parameters\n",
			ddr_freq, pbsp_highest->datarate_mhz_high);
		popts->cpo_override = pbsp_highest->cpo;
		popts->write_data_delay = pbsp_highest->write_data_delay;
		popts->clk_adjust = pbsp_highest->clk_adjust;
		popts->wrlvl_start = pbsp_highest->wrlvl_start;
		popts->twot_en = pbsp_highest->force_2t;
	} else {
		panic("DIMM is not supported by this board");
	}

found:
	/*
	 * Factors to consider for half-strength driver enable:
	 *	- number of DIMMs installed
	 */
	popts->half_strength_driver_enable = 0;
	/* Write leveling override */
	popts->wrlvl_override = 1;
	popts->wrlvl_sample = 0xf;

	/* Rtt and Rtt_WR override */
	popts->rtt_override = 0;

	/* Enable ZQ calibration */
	popts->zq_en = 1;

	/* DHC_EN =1, ODT = 60 Ohm */
	popts->ddr_cdr1 = DDR_CDR1_DHC_EN;
}

int dram_init(void)
{
	phys_size_t dram_size = 0;

	puts("Initializing....");

	if (fsl_use_spd()) {
		puts("using SPD\n");
		dram_size = fsl_ddr_sdram();
	} else {
		puts("no SPD and fixed parameters\n");
		return -ENXIO;
	}

	dram_size = setup_ddr_tlbs(dram_size / 0x100000);
	dram_size *= 0x100000;

	debug("    DDR: ");
	gd->ram_size = dram_size;

	return 0;
}