options.c

/*
 * Copyright 2008 Freescale Semiconductor, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * Version 2 as published by the Free Software Foundation.
 */

#include <common.h>
#include <asm/fsl_ddr_sdram.h>

#include "ddr.h"

/* Board-specific functions defined in each board's ddr.c */
extern void fsl_ddr_board_options(memctl_options_t *popts,
		unsigned int ctrl_num);

unsigned int populate_memctl_options(int all_DIMMs_registered,
			memctl_options_t *popts,
			unsigned int ctrl_num)
{
	unsigned int i;

	/* Chip select options. */

	/* Pick chip-select local options. */
	for (i = 0; i < CONFIG_CHIP_SELECTS_PER_CTRL; i++) {
		/* If not DDR2, odt_rd_cfg and odt_wr_cfg need to be 0. */

		/* only for single CS? */
		popts->cs_local_opts[i].odt_rd_cfg = 0;

		popts->cs_local_opts[i].odt_wr_cfg = 1;
		popts->cs_local_opts[i].auto_precharge = 0;
	}

	/* Pick interleaving mode. */

	/*
	 * 0 = no interleaving
	 * 1 = interleaving between 2 controllers
	 */
	popts->memctl_interleaving = 0;

	/*
	 * 0 = cacheline
	 * 1 = page
	 * 2 = (logical) bank
	 * 3 = superbank (only if CS interleaving is enabled)
	 */
	popts->memctl_interleaving_mode = 0;

	/*
	 * 0: cacheline: bit 30 of the 36-bit physical addr selects the memctl
	 * 1: page:      bit to the left of the column bits selects the memctl
	 * 2: bank:      bit to the left of the bank bits selects the memctl
	 * 3: superbank: bit to the left of the chip select selects the memctl
	 *
	 * NOTE: ba_intlv (rank interleaving) is independent of memory
	 * controller interleaving; it is only within a memory controller.
	 * Must use superbank interleaving if rank interleaving is used and
	 * memory controller interleaving is enabled.
	 */

	/*
	 * 0 = no
	 * 0x40 = CS0,CS1
	 * 0x20 = CS2,CS3
	 * 0x60 = CS0,CS1 + CS2,CS3
	 * 0x04 = CS0,CS1,CS2,CS3
	 */
	popts->ba_intlv_ctl = 0;

	/* Memory Organization Parameters */
	popts->registered_dimm_en = all_DIMMs_registered;

	/* Operational Mode Paramters */

	/* Pick ECC modes */
#ifdef CONFIG_DDR_ECC
	popts->ECC_mode = 1;		  /* 0 = disabled, 1 = enabled */
#else
	popts->ECC_mode = 0;		  /* 0 = disabled, 1 = enabled */
#endif
	popts->ECC_init_using_memctl = 1; /* 0 = use DMA, 1 = use memctl */

	/*
	 * Choose DQS config
	 * 0 for DDR1
	 * 1 for DDR2
	 */
#if defined(CONFIG_FSL_DDR1)
	popts->DQS_config = 0;
#elif defined(CONFIG_FSL_DDR2)
	popts->DQS_config = 1;
#else
#error "Fix DQS for DDR3"
#endif

	/* Choose self-refresh during sleep. */
	popts->self_refresh_in_sleep = 1;

	/* Choose dynamic power management mode. */
	popts->dynamic_power = 0;

	/* 0 = 64-bit, 1 = 32-bit, 2 = 16-bit */
	popts->data_bus_width = 0;

	/* Choose burst length. */
	popts->burst_length = 4;	/* has to be 4 for DDR2 */

	/* Global Timing Parameters. */
	debug("mclk_ps = %u ps\n", get_memory_clk_period_ps());

	/* Pick a caslat override. */
	popts->cas_latency_override = 0;
	popts->cas_latency_override_value = 3;
	if (popts->cas_latency_override) {
		debug("using caslat override value = %u\n",
		       popts->cas_latency_override_value);
	}

	/* Decide whether to use the computed derated latency */
	popts->use_derated_caslat = 0;

	/* Choose an additive latency. */
	popts->additive_latency_override = 0;
	popts->additive_latency_override_value = 3;
	if (popts->additive_latency_override) {
		debug("using additive latency override value = %u\n",
		       popts->additive_latency_override_value);
	}

	/*
	 * 2T_EN setting
	 *
	 * Factors to consider for 2T_EN:
	 *	- number of DIMMs installed
	 *	- number of components, number of active ranks
	 *	- how much time you want to spend playing around
	 */
	popts->twoT_en = 1;
	popts->threeT_en = 0;

	/*
	 * BSTTOPRE precharge interval
	 *
	 * Set this to 0 for global auto precharge
	 *
	 * FIXME: Should this be configured in picoseconds?
	 * Why it should be in ps:  better understanding of this
	 * relative to actual DRAM timing parameters such as tRAS.
	 * e.g. tRAS(min) = 40 ns
	 */
	popts->bstopre = 0x100;

	/* Minimum CKE pulse width -- tCKE(MIN) */
	popts->tCKE_clock_pulse_width_ps
		= mclk_to_picos(FSL_DDR_MIN_TCKE_PULSE_WIDTH_DDR);

	/*
	 * Window for four activates -- tFAW
	 *
	 * FIXME: UM: applies only to DDR2/DDR3 with eight logical banks only
	 * FIXME: varies depending upon number of column addresses or data
	 * FIXME: width, was considering looking at pdimm->primary_sdram_width
	 */
#if defined(CONFIG_FSL_DDR1)
	popts->tFAW_window_four_activates_ps = mclk_to_picos(1);

#elif defined(CONFIG_FSL_DDR2)
	/*
	 * x4/x8;  some datasheets have 35000
	 * x16 wide columns only?  Use 50000?
	 */
	popts->tFAW_window_four_activates_ps = 37500;

#elif defined(CONFIG_FSL_DDR3)
#error "FIXME determine four activates for DDR3"
#endif

	/* ODT should only be used for DDR2 */

	/* FIXME? */

	/*
	 * Interleaving checks.
	 *
	 * If memory controller interleaving is enabled, then the data
	 * bus widths must be programmed identically for the 2 memory
	 * controllers.
	 */

	fsl_ddr_board_options(popts, ctrl_num);

	return 0;
}