drivers/ddr/fsl/ddr4_dimm_params.c - github/trini/u-boot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright 2014-2016 Freescale Semiconductor, Inc.
  * Copyright 2017-2018 NXP Semiconductor
  *
  * calculate the organization and timing parameter
  * from ddr3 spd, please refer to the spec
  * JEDEC standard No.21-C 4_01_02_12R23A.pdf
  *
  *
  */

 #include <fsl_ddr_sdram.h>
 #include <log.h>
 #include <linux/bug.h>
 #include <linux/string.h>

 #include <fsl_ddr.h>

 /*
  * Calculate the Density of each Physical Rank.
  * Returned size is in bytes.
  *
  * Total DIMM size =
  * sdram capacity(bit) / 8 * primary bus width / sdram width
  *                     * Logical Ranks per DIMM
  *
  * where: sdram capacity  = spd byte4[3:0]
  *        primary bus width = spd byte13[2:0]
  *        sdram width = spd byte12[2:0]
  *        Logical Ranks per DIMM = spd byte12[5:3] for SDP, DDP, QDP
  *                                 spd byte12{5:3] * spd byte6[6:4] for 3DS
  *
  * To simplify each rank size = total DIMM size / Number of Package Ranks
  * where Number of Package Ranks = spd byte12[5:3]
  *
  * SPD byte4 - sdram density and banks
  *	bit[3:0]	size(bit)	size(byte)
  *	0000		256Mb		32MB
  *	0001		512Mb		64MB
  *	0010		1Gb		128MB
  *	0011		2Gb		256MB
  *	0100		4Gb		512MB
  *	0101		8Gb		1GB
  *	0110		16Gb		2GB
  *      0111		32Gb		4GB
  *
  * SPD byte13 - module memory bus width
  *	bit[2:0]	primary bus width
  *	000		8bits
  *	001		16bits
  *	010		32bits
  *	011		64bits
  *
  * SPD byte12 - module organization
  *	bit[2:0]	sdram device width
  *	000		4bits
  *	001		8bits
  *	010		16bits
  *	011		32bits
  *
  * SPD byte12 - module organization
  *	bit[5:3]	number of package ranks per DIMM
  *	000		1
  *	001		2
  *	010		3
  *	011		4
  *
  * SPD byte6 - SDRAM package type
  *	bit[6:4]	Die count
  *	000		1
  *	001		2
  *	010		3
  *	011		4
  *	100		5
  *	101		6
  *	110		7
  *	111		8
  *
  * SPD byte6 - SRAM package type
  *	bit[1:0]	Signal loading
  *	00		Not specified
  *	01		Multi load stack
  *	10		Sigle load stack (3DS)
  *	11		Reserved
  */
 static unsigned long long
 compute_ranksize(const struct ddr4_spd_eeprom_s *spd)
 {
 	unsigned long long bsize;

 	int nbit_sdram_cap_bsize = 0;
 	int nbit_primary_bus_width = 0;
 	int nbit_sdram_width = 0;
 	int die_count = 0;
 	bool package_3ds;

 	if ((spd->density_banks & 0xf) <= 7)
 		nbit_sdram_cap_bsize = (spd->density_banks & 0xf) + 28;
 	if ((spd->bus_width & 0x7) < 4)
 		nbit_primary_bus_width = (spd->bus_width & 0x7) + 3;
 	if ((spd->organization & 0x7) < 4)
 		nbit_sdram_width = (spd->organization & 0x7) + 2;
 	package_3ds = (spd->package_type & 0x3) == 0x2;
 	if ((spd->package_type & 0x80) && !package_3ds) { /* other than 3DS */
 		printf("Warning: not supported SDRAM package type\n");
 		return 0;
 	}
 	if (package_3ds)
 		die_count = (spd->package_type >> 4) & 0x7;

 	bsize = 1ULL << (nbit_sdram_cap_bsize - 3 +
 			 nbit_primary_bus_width - nbit_sdram_width +
 			 die_count);

 	debug("DDR: DDR rank density = 0x%16llx\n", bsize);

 	return bsize;
 }

 #define spd_to_ps(mtb, ftb)	\
 	(mtb * pdimm->mtb_ps + (ftb * pdimm->ftb_10th_ps) / 10)
 /*
  * ddr_compute_dimm_parameters for DDR4 SPD
  *
  * Compute DIMM parameters based upon the SPD information in spd.
  * Writes the results to the dimm_params_t structure pointed by pdimm.
  *
  */
 unsigned int ddr_compute_dimm_parameters(const unsigned int ctrl_num,
 					 const generic_spd_eeprom_t *spd,
 					 dimm_params_t *pdimm,
 					 unsigned int dimm_number)
 {
 	unsigned int retval;
 	int i;
 	const u8 udimm_rc_e_dq[18] = {
 		0x0c, 0x2c, 0x15, 0x35, 0x15, 0x35, 0x0b, 0x2c, 0x15,
 		0x35, 0x0b, 0x35, 0x0b, 0x2c, 0x0b, 0x35, 0x15, 0x36
 	};
 	int spd_error = 0;
 	u8 *ptr;
 	u8 val;

 	if (spd->mem_type) {
 		if (spd->mem_type != SPD_MEMTYPE_DDR4) {
 			printf("Ctrl %u DIMM %u: is not a DDR4 SPD.\n",
 			       ctrl_num, dimm_number);
 			return 1;
 		}
 	} else {
 		memset(pdimm, 0, sizeof(dimm_params_t));
 		return 1;
 	}

 	retval = ddr4_spd_check(spd);
 	if (retval) {
 		printf("DIMM %u: failed checksum\n", dimm_number);
 		return 2;
 	}

 	/*
 	 * The part name in ASCII in the SPD EEPROM is not null terminated.
 	 * Guarantee null termination here by presetting all bytes to 0
 	 * and copying the part name in ASCII from the SPD onto it
 	 */
 	memset(pdimm->mpart, 0, sizeof(pdimm->mpart));
 	if ((spd->info_size_crc & 0xF) > 2)
 		memcpy(pdimm->mpart, spd->mpart, sizeof(pdimm->mpart) - 1);

 	/* DIMM organization parameters */
 	pdimm->n_ranks = ((spd->organization >> 3) & 0x7) + 1;
 	pdimm->rank_density = compute_ranksize(spd);
 	pdimm->capacity = pdimm->n_ranks * pdimm->rank_density;
 	pdimm->die_density = spd->density_banks & 0xf;
 	pdimm->primary_sdram_width = 1 << (3 + (spd->bus_width & 0x7));
 	if ((spd->bus_width >> 3) & 0x3)
 		pdimm->ec_sdram_width = 8;
 	else
 		pdimm->ec_sdram_width = 0;
 	pdimm->data_width = pdimm->primary_sdram_width
 			  + pdimm->ec_sdram_width;
 	pdimm->device_width = 1 << ((spd->organization & 0x7) + 2);
 	pdimm->package_3ds = (spd->package_type & 0x3) == 0x2 ?
 			     (spd->package_type >> 4) & 0x7 : 0;

 	/* These are the types defined by the JEDEC SPD spec */
 	pdimm->mirrored_dimm = 0;
 	pdimm->registered_dimm = 0;
 	switch (spd->module_type & DDR4_SPD_MODULETYPE_MASK) {
 	case DDR4_SPD_MODULETYPE_RDIMM:
 		/* Registered/buffered DIMMs */
 		pdimm->registered_dimm = 1;
 		if (spd->mod_section.registered.reg_map & 0x1)
 			pdimm->mirrored_dimm = 1;
 		val = spd->mod_section.registered.ca_stren;
 		pdimm->rcw[3] = val >> 4;
 		pdimm->rcw[4] = ((val & 0x3) << 2) | ((val & 0xc) >> 2);
 		val = spd->mod_section.registered.clk_stren;
 		pdimm->rcw[5] = ((val & 0x3) << 2) | ((val & 0xc) >> 2);
 		/* Not all in SPD. For convience only. Boards may overwrite. */
 		pdimm->rcw[6] = 0xf;
 		/*
 		 * A17 only used for 16Gb and above devices.
 		 * C[2:0] only used for 3DS.
 		 */
 		pdimm->rcw[8] = pdimm->die_density >= 0x6 ? 0x0 : 0x8 |
 				(pdimm->package_3ds > 0x3 ? 0x0 :
 				 (pdimm->package_3ds > 0x1 ? 0x1 :
 				  (pdimm->package_3ds > 0 ? 0x2 : 0x3)));
 		if (pdimm->package_3ds || pdimm->n_ranks != 4)
 			pdimm->rcw[13] = 0xc;
 		else
 			pdimm->rcw[13] = 0xd;	/* Fix encoded by board */

 		break;

 	case DDR4_SPD_MODULETYPE_UDIMM:
 	case DDR4_SPD_MODULETYPE_SO_DIMM:
 		/* Unbuffered DIMMs */
 		if (spd->mod_section.unbuffered.addr_mapping & 0x1)
 			pdimm->mirrored_dimm = 1;
 		if ((spd->mod_section.unbuffered.mod_height & 0xe0) == 0 &&
 		    (spd->mod_section.unbuffered.ref_raw_card == 0x04)) {
 			/* Fix SPD error found on DIMMs with raw card E0 */
 			for (i = 0; i < 18; i++) {
 				if (spd->mapping[i] == udimm_rc_e_dq[i])
 					continue;
 				spd_error = 1;
 				debug("SPD byte %d: 0x%x, should be 0x%x\n",
 				      60 + i, spd->mapping[i],
 				      udimm_rc_e_dq[i]);
 				ptr = (u8 *)&spd->mapping[i];
 				*ptr = udimm_rc_e_dq[i];
 			}
 			if (spd_error)
 				puts("SPD DQ mapping error fixed\n");
 		}
 		break;

 	default:
 		printf("unknown module_type 0x%02X\n", spd->module_type);
 		return 1;
 	}

 	/* SDRAM device parameters */
 	pdimm->n_row_addr = ((spd->addressing >> 3) & 0x7) + 12;
 	pdimm->n_col_addr = (spd->addressing & 0x7) + 9;
 	pdimm->bank_addr_bits = ((spd->density_banks >> 4) & 0x3) + 2;
 	pdimm->bank_group_bits = (spd->density_banks >> 6) & 0x3;

 	/*
 	 * The SPD spec has not the ECC bit,
 	 * We consider the DIMM as ECC capability
 	 * when the extension bus exist
 	 */
 	if (pdimm->ec_sdram_width)
 		pdimm->edc_config = 0x02;
 	else
 		pdimm->edc_config = 0x00;

 	/*
 	 * The SPD spec has not the burst length byte
 	 * but DDR4 spec has nature BL8 and BC4,
 	 * BL8 -bit3, BC4 -bit2
 	 */
 	pdimm->burst_lengths_bitmask = 0x0c;

 	/* MTB - medium timebase
 	 * The MTB in the SPD spec is 125ps,
 	 *
 	 * FTB - fine timebase
 	 * use 1/10th of ps as our unit to avoid floating point
 	 * eg, 10 for 1ps, 25 for 2.5ps, 50 for 5ps
 	 */
 	if ((spd->timebases & 0xf) == 0x0) {
 		pdimm->mtb_ps = 125;
 		pdimm->ftb_10th_ps = 10;

 	} else {
 		printf("Unknown Timebases\n");
 	}

 	/* sdram minimum cycle time */
 	pdimm->tckmin_x_ps = spd_to_ps(spd->tck_min, spd->fine_tck_min);

 	/* sdram max cycle time */
 	pdimm->tckmax_ps = spd_to_ps(spd->tck_max, spd->fine_tck_max);

 	/*
 	 * CAS latency supported
 	 * bit0 - CL7
 	 * bit4 - CL11
 	 * bit8 - CL15
 	 * bit12- CL19
 	 * bit16- CL23
 	 */
 	pdimm->caslat_x  = (spd->caslat_b1 << 7)	|
 			   (spd->caslat_b2 << 15)	|
 			   (spd->caslat_b3 << 23);

 	BUG_ON(spd->caslat_b4 != 0);

 	/*
 	 * min CAS latency time
 	 */
 	pdimm->taa_ps = spd_to_ps(spd->taa_min, spd->fine_taa_min);

 	/*
 	 * min RAS to CAS delay time
 	 */
 	pdimm->trcd_ps = spd_to_ps(spd->trcd_min, spd->fine_trcd_min);

 	/*
 	 * Min Row Precharge Delay Time
 	 */
 	pdimm->trp_ps = spd_to_ps(spd->trp_min, spd->fine_trp_min);

 	/* min active to precharge delay time */
 	pdimm->tras_ps = (((spd->tras_trc_ext & 0xf) << 8) +
 			  spd->tras_min_lsb) * pdimm->mtb_ps;

 	/* min active to actice/refresh delay time */
 	pdimm->trc_ps = spd_to_ps((((spd->tras_trc_ext & 0xf0) << 4) +
 				   spd->trc_min_lsb), spd->fine_trc_min);
 	/* Min Refresh Recovery Delay Time */
 	pdimm->trfc1_ps = ((spd->trfc1_min_msb << 8) | (spd->trfc1_min_lsb)) *
 		       pdimm->mtb_ps;
 	pdimm->trfc2_ps = ((spd->trfc2_min_msb << 8) | (spd->trfc2_min_lsb)) *
 		       pdimm->mtb_ps;
 	pdimm->trfc4_ps = ((spd->trfc4_min_msb << 8) | (spd->trfc4_min_lsb)) *
 			pdimm->mtb_ps;
 	/* min four active window delay time */
 	pdimm->tfaw_ps = (((spd->tfaw_msb & 0xf) << 8) | spd->tfaw_min) *
 			pdimm->mtb_ps;

 	/* min row active to row active delay time, different bank group */
 	pdimm->trrds_ps = spd_to_ps(spd->trrds_min, spd->fine_trrds_min);
 	/* min row active to row active delay time, same bank group */
 	pdimm->trrdl_ps = spd_to_ps(spd->trrdl_min, spd->fine_trrdl_min);
 	/* min CAS to CAS Delay Time (tCCD_Lmin), same bank group */
 	pdimm->tccdl_ps = spd_to_ps(spd->tccdl_min, spd->fine_tccdl_min);

 	if (pdimm->package_3ds) {
 		if (pdimm->die_density <= 0x4) {
 			pdimm->trfc_slr_ps = 260000;
 		} else if (pdimm->die_density <= 0x5) {
 			pdimm->trfc_slr_ps = 350000;
 		} else {
 			printf("WARN: Unsupported logical rank density 0x%x\n",
 			       pdimm->die_density);
 		}
 	}

 	/*
 	 * Average periodic refresh interval
 	 * tREFI = 7.8 us at normal temperature range
 	 */
 	pdimm->refresh_rate_ps = 7800000;

 	for (i = 0; i < 18; i++)
 		pdimm->dq_mapping[i] = spd->mapping[i];

 	pdimm->dq_mapping_ors = ((spd->mapping[0] >> 6) & 0x3) == 0 ? 1 : 0;

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Copyright 2014-2016 Freescale Semiconductor, Inc.
	* Copyright 2017-2018 NXP Semiconductor
	*
	* calculate the organization and timing parameter
	* from ddr3 spd, please refer to the spec
	* JEDEC standard No.21-C 4_01_02_12R23A.pdf
	*
	*
	*/

	#include <fsl_ddr_sdram.h>
	#include <log.h>
	#include <linux/bug.h>
	#include <linux/string.h>

	#include <fsl_ddr.h>

	/*
	* Calculate the Density of each Physical Rank.
	* Returned size is in bytes.
	*
	* Total DIMM size =
	* sdram capacity(bit) / 8 * primary bus width / sdram width
	* * Logical Ranks per DIMM
	*
	* where: sdram capacity = spd byte4[3:0]
	* primary bus width = spd byte13[2:0]
	* sdram width = spd byte12[2:0]
	* Logical Ranks per DIMM = spd byte12[5:3] for SDP, DDP, QDP
	* spd byte12{5:3] * spd byte6[6:4] for 3DS
	*
	* To simplify each rank size = total DIMM size / Number of Package Ranks
	* where Number of Package Ranks = spd byte12[5:3]
	*
	* SPD byte4 - sdram density and banks
	* bit[3:0] size(bit) size(byte)
	* 0000 256Mb 32MB
	* 0001 512Mb 64MB
	* 0010 1Gb 128MB
	* 0011 2Gb 256MB
	* 0100 4Gb 512MB
	* 0101 8Gb 1GB
	* 0110 16Gb 2GB
	* 0111 32Gb 4GB
	*
	* SPD byte13 - module memory bus width
	* bit[2:0] primary bus width
	* 000 8bits
	* 001 16bits
	* 010 32bits
	* 011 64bits
	*
	* SPD byte12 - module organization
	* bit[2:0] sdram device width
	* 000 4bits
	* 001 8bits
	* 010 16bits
	* 011 32bits
	*
	* SPD byte12 - module organization
	* bit[5:3] number of package ranks per DIMM
	* 000 1
	* 001 2
	* 010 3
	* 011 4
	*
	* SPD byte6 - SDRAM package type
	* bit[6:4] Die count
	* 000 1
	* 001 2
	* 010 3
	* 011 4
	* 100 5
	* 101 6
	* 110 7
	* 111 8
	*
	* SPD byte6 - SRAM package type
	* bit[1:0] Signal loading
	* 00 Not specified
	* 01 Multi load stack
	* 10 Sigle load stack (3DS)
	* 11 Reserved
	*/
	static unsigned long long
	compute_ranksize(const struct ddr4_spd_eeprom_s *spd)
	{
	unsigned long long bsize;

	int nbit_sdram_cap_bsize = 0;
	int nbit_primary_bus_width = 0;
	int nbit_sdram_width = 0;
	int die_count = 0;
	bool package_3ds;

	if ((spd->density_banks & 0xf) <= 7)
	nbit_sdram_cap_bsize = (spd->density_banks & 0xf) + 28;
	if ((spd->bus_width & 0x7) < 4)
	nbit_primary_bus_width = (spd->bus_width & 0x7) + 3;
	if ((spd->organization & 0x7) < 4)
	nbit_sdram_width = (spd->organization & 0x7) + 2;
	package_3ds = (spd->package_type & 0x3) == 0x2;
	if ((spd->package_type & 0x80) && !package_3ds) { /* other than 3DS */
	printf("Warning: not supported SDRAM package type\n");
	return 0;
	}
	if (package_3ds)
	die_count = (spd->package_type >> 4) & 0x7;

	bsize = 1ULL << (nbit_sdram_cap_bsize - 3 +
	nbit_primary_bus_width - nbit_sdram_width +
	die_count);

	debug("DDR: DDR rank density = 0x%16llx\n", bsize);

	return bsize;
	}

	#define spd_to_ps(mtb, ftb) \
	(mtb * pdimm->mtb_ps + (ftb * pdimm->ftb_10th_ps) / 10)
	/*
	* ddr_compute_dimm_parameters for DDR4 SPD
	*
	* Compute DIMM parameters based upon the SPD information in spd.
	* Writes the results to the dimm_params_t structure pointed by pdimm.
	*
	*/
	unsigned int ddr_compute_dimm_parameters(const unsigned int ctrl_num,
	const generic_spd_eeprom_t *spd,
	dimm_params_t *pdimm,
	unsigned int dimm_number)
	{
	unsigned int retval;
	int i;
	const u8 udimm_rc_e_dq[18] = {
	0x0c, 0x2c, 0x15, 0x35, 0x15, 0x35, 0x0b, 0x2c, 0x15,
	0x35, 0x0b, 0x35, 0x0b, 0x2c, 0x0b, 0x35, 0x15, 0x36
	};
	int spd_error = 0;
	u8 *ptr;
	u8 val;

	if (spd->mem_type) {
	if (spd->mem_type != SPD_MEMTYPE_DDR4) {
	printf("Ctrl %u DIMM %u: is not a DDR4 SPD.\n",
	ctrl_num, dimm_number);
	return 1;
	}
	} else {
	memset(pdimm, 0, sizeof(dimm_params_t));
	return 1;
	}

	retval = ddr4_spd_check(spd);
	if (retval) {
	printf("DIMM %u: failed checksum\n", dimm_number);
	return 2;
	}

	/*
	* The part name in ASCII in the SPD EEPROM is not null terminated.
	* Guarantee null termination here by presetting all bytes to 0
	* and copying the part name in ASCII from the SPD onto it
	*/
	memset(pdimm->mpart, 0, sizeof(pdimm->mpart));
	if ((spd->info_size_crc & 0xF) > 2)
	memcpy(pdimm->mpart, spd->mpart, sizeof(pdimm->mpart) - 1);

	/* DIMM organization parameters */
	pdimm->n_ranks = ((spd->organization >> 3) & 0x7) + 1;
	pdimm->rank_density = compute_ranksize(spd);
	pdimm->capacity = pdimm->n_ranks * pdimm->rank_density;
	pdimm->die_density = spd->density_banks & 0xf;
	pdimm->primary_sdram_width = 1 << (3 + (spd->bus_width & 0x7));
	if ((spd->bus_width >> 3) & 0x3)
	pdimm->ec_sdram_width = 8;
	else
	pdimm->ec_sdram_width = 0;
	pdimm->data_width = pdimm->primary_sdram_width
	+ pdimm->ec_sdram_width;
	pdimm->device_width = 1 << ((spd->organization & 0x7) + 2);
	pdimm->package_3ds = (spd->package_type & 0x3) == 0x2 ?
	(spd->package_type >> 4) & 0x7 : 0;

	/* These are the types defined by the JEDEC SPD spec */
	pdimm->mirrored_dimm = 0;
	pdimm->registered_dimm = 0;
	switch (spd->module_type & DDR4_SPD_MODULETYPE_MASK) {
	case DDR4_SPD_MODULETYPE_RDIMM:
	/* Registered/buffered DIMMs */
	pdimm->registered_dimm = 1;
	if (spd->mod_section.registered.reg_map & 0x1)
	pdimm->mirrored_dimm = 1;
	val = spd->mod_section.registered.ca_stren;
	pdimm->rcw[3] = val >> 4;
	pdimm->rcw[4] = ((val & 0x3) << 2) \| ((val & 0xc) >> 2);
	val = spd->mod_section.registered.clk_stren;
	pdimm->rcw[5] = ((val & 0x3) << 2) \| ((val & 0xc) >> 2);
	/* Not all in SPD. For convience only. Boards may overwrite. */
	pdimm->rcw[6] = 0xf;
	/*
	* A17 only used for 16Gb and above devices.
	* C[2:0] only used for 3DS.
	*/
	pdimm->rcw[8] = pdimm->die_density >= 0x6 ? 0x0 : 0x8 \|
	(pdimm->package_3ds > 0x3 ? 0x0 :
	(pdimm->package_3ds > 0x1 ? 0x1 :
	(pdimm->package_3ds > 0 ? 0x2 : 0x3)));
	if (pdimm->package_3ds \|\| pdimm->n_ranks != 4)
	pdimm->rcw[13] = 0xc;
	else
	pdimm->rcw[13] = 0xd; /* Fix encoded by board */

	break;

	case DDR4_SPD_MODULETYPE_UDIMM:
	case DDR4_SPD_MODULETYPE_SO_DIMM:
	/* Unbuffered DIMMs */
	if (spd->mod_section.unbuffered.addr_mapping & 0x1)
	pdimm->mirrored_dimm = 1;
	if ((spd->mod_section.unbuffered.mod_height & 0xe0) == 0 &&
	(spd->mod_section.unbuffered.ref_raw_card == 0x04)) {
	/* Fix SPD error found on DIMMs with raw card E0 */
	for (i = 0; i < 18; i++) {
	if (spd->mapping[i] == udimm_rc_e_dq[i])
	continue;
	spd_error = 1;
	debug("SPD byte %d: 0x%x, should be 0x%x\n",
	60 + i, spd->mapping[i],
	udimm_rc_e_dq[i]);
	ptr = (u8 *)&spd->mapping[i];
	*ptr = udimm_rc_e_dq[i];
	}
	if (spd_error)
	puts("SPD DQ mapping error fixed\n");
	}
	break;

	default:
	printf("unknown module_type 0x%02X\n", spd->module_type);
	return 1;
	}

	/* SDRAM device parameters */
	pdimm->n_row_addr = ((spd->addressing >> 3) & 0x7) + 12;
	pdimm->n_col_addr = (spd->addressing & 0x7) + 9;
	pdimm->bank_addr_bits = ((spd->density_banks >> 4) & 0x3) + 2;
	pdimm->bank_group_bits = (spd->density_banks >> 6) & 0x3;

	/*
	* The SPD spec has not the ECC bit,
	* We consider the DIMM as ECC capability
	* when the extension bus exist
	*/
	if (pdimm->ec_sdram_width)
	pdimm->edc_config = 0x02;
	else
	pdimm->edc_config = 0x00;

	/*
	* The SPD spec has not the burst length byte
	* but DDR4 spec has nature BL8 and BC4,
	* BL8 -bit3, BC4 -bit2
	*/
	pdimm->burst_lengths_bitmask = 0x0c;

	/* MTB - medium timebase
	* The MTB in the SPD spec is 125ps,
	*
	* FTB - fine timebase
	* use 1/10th of ps as our unit to avoid floating point
	* eg, 10 for 1ps, 25 for 2.5ps, 50 for 5ps
	*/
	if ((spd->timebases & 0xf) == 0x0) {
	pdimm->mtb_ps = 125;
	pdimm->ftb_10th_ps = 10;

	} else {
	printf("Unknown Timebases\n");
	}

	/* sdram minimum cycle time */
	pdimm->tckmin_x_ps = spd_to_ps(spd->tck_min, spd->fine_tck_min);

	/* sdram max cycle time */
	pdimm->tckmax_ps = spd_to_ps(spd->tck_max, spd->fine_tck_max);

	/*
	* CAS latency supported
	* bit0 - CL7
	* bit4 - CL11
	* bit8 - CL15
	* bit12- CL19
	* bit16- CL23
	*/
	pdimm->caslat_x = (spd->caslat_b1 << 7) \|
	(spd->caslat_b2 << 15) \|
	(spd->caslat_b3 << 23);

	BUG_ON(spd->caslat_b4 != 0);

	/*
	* min CAS latency time
	*/
	pdimm->taa_ps = spd_to_ps(spd->taa_min, spd->fine_taa_min);

	/*
	* min RAS to CAS delay time
	*/
	pdimm->trcd_ps = spd_to_ps(spd->trcd_min, spd->fine_trcd_min);

	/*
	* Min Row Precharge Delay Time
	*/
	pdimm->trp_ps = spd_to_ps(spd->trp_min, spd->fine_trp_min);

	/* min active to precharge delay time */
	pdimm->tras_ps = (((spd->tras_trc_ext & 0xf) << 8) +
	spd->tras_min_lsb) * pdimm->mtb_ps;

	/* min active to actice/refresh delay time */
	pdimm->trc_ps = spd_to_ps((((spd->tras_trc_ext & 0xf0) << 4) +
	spd->trc_min_lsb), spd->fine_trc_min);
	/* Min Refresh Recovery Delay Time */
	pdimm->trfc1_ps = ((spd->trfc1_min_msb << 8) \| (spd->trfc1_min_lsb)) *
	pdimm->mtb_ps;
	pdimm->trfc2_ps = ((spd->trfc2_min_msb << 8) \| (spd->trfc2_min_lsb)) *
	pdimm->mtb_ps;
	pdimm->trfc4_ps = ((spd->trfc4_min_msb << 8) \| (spd->trfc4_min_lsb)) *
	pdimm->mtb_ps;
	/* min four active window delay time */
	pdimm->tfaw_ps = (((spd->tfaw_msb & 0xf) << 8) \| spd->tfaw_min) *
	pdimm->mtb_ps;

	/* min row active to row active delay time, different bank group */
	pdimm->trrds_ps = spd_to_ps(spd->trrds_min, spd->fine_trrds_min);
	/* min row active to row active delay time, same bank group */
	pdimm->trrdl_ps = spd_to_ps(spd->trrdl_min, spd->fine_trrdl_min);
	/* min CAS to CAS Delay Time (tCCD_Lmin), same bank group */
	pdimm->tccdl_ps = spd_to_ps(spd->tccdl_min, spd->fine_tccdl_min);

	if (pdimm->package_3ds) {
	if (pdimm->die_density <= 0x4) {
	pdimm->trfc_slr_ps = 260000;
	} else if (pdimm->die_density <= 0x5) {
	pdimm->trfc_slr_ps = 350000;
	} else {
	printf("WARN: Unsupported logical rank density 0x%x\n",
	pdimm->die_density);
	}
	}

	/*
	* Average periodic refresh interval
	* tREFI = 7.8 us at normal temperature range
	*/
	pdimm->refresh_rate_ps = 7800000;

	for (i = 0; i < 18; i++)
	pdimm->dq_mapping[i] = spd->mapping[i];

	pdimm->dq_mapping_ors = ((spd->mapping[0] >> 6) & 0x3) == 0 ? 1 : 0;

	return 0;
	}