/* SPDX-License-Identifier: GPL-2.0-or-later */

/*
 * Serial Presence Detect (SPD) data stored on SDRAM modules.
 *
 * Datasheet:
 *   - Name: PC SDRAM Serial Presence Detect (SPD) Specification
 *           Revision 1.2A, December, 1997
 *   - PDF: http://www.intel.com/design/chipsets/memory/spdsd12a.pdf
 *
 * Datasheet (alternative):
 *   - Name: SERIAL PRESENCE DETECT STANDARD, General Standard
 *           JEDEC Standard No. 21-C
 *     Annex J: Serial Presence Detects for DDR2 SDRAM (Revision 1.3):
 *   - PDF: http://www.jedec.org/download/search/4_01_02_10R17.pdf
 */

#ifndef _SPD_H_
#define _SPD_H_

/* Byte numbers. */
/* Number of bytes used by module manufacturer */
#define SPD_NUM_MANUFACTURER_BYTES          0
#define SPD_TOTAL_SPD_MEMORY_SIZE           1  /* Total SPD memory size */
#define SPD_MEMORY_TYPE                     2  /* (Fundamental) memory type */
#define SPD_NUM_ROWS                        3  /* Number of row address bits */
/* Number of column address bits */
#define SPD_NUM_COLUMNS                     4
/* Number of module rows (banks) */
#define SPD_NUM_DIMM_BANKS                  5
#define SPD_MODULE_DATA_WIDTH_LSB           6  /* Module data width (LSB) */
#define SPD_MODULE_DATA_WIDTH_MSB           7  /* Module data width (MSB) */
/* Module interface signal levels */
#define SPD_MODULE_VOLTAGE                  8
/* SDRAM cycle time (highest CAS latency), RAS access time (tRAC) */
#define SPD_MIN_CYCLE_TIME_AT_CAS_MAX       9
/* SDRAM access time from clock (highest CAS latency), CAS access time (Tac,
 * tCAC)
 */
#define SPD_ACCESS_TIME_FROM_CLOCK          10
#define SPD_DIMM_CONFIG_TYPE                11 /* Module configuration type */
#define SPD_REFRESH                         12 /* Refresh rate/type */
#define SPD_PRIMARY_SDRAM_WIDTH             13 /* SDRAM width (primary SDRAM) */
/* Error checking SDRAM (data) width */
#define SPD_ERROR_CHECKING_SDRAM_WIDTH      14
/* SDRAM device attributes, minimum clock delay for back to back random
 * column
 */
#define SPD_MIN_CLOCK_DELAY_B2B_RAND_COLUMN 15
/* SDRAM device attributes, burst lengths supported */
#define SPD_SUPPORTED_BURST_LENGTHS         16
/* SDRAM device attributes, number of banks on SDRAM device */
#define SPD_NUM_BANKS_PER_SDRAM             17
/* SDRAM device attributes, CAS latency */
#define SPD_ACCEPTABLE_CAS_LATENCIES        18
/* SDRAM device attributes, CS latency */
#define SPD_CS_LATENCY                      19
/* SDRAM device attributes, WE latency */
#define SPD_WE_LATENCY                      20
#define SPD_MODULE_ATTRIBUTES               21 /* SDRAM module attributes */
/* SDRAM device attributes, general */
#define SPD_DEVICE_ATTRIBUTES_GENERAL       22
/* SDRAM cycle time (2nd highest CAS latency) */
#define SPD_SDRAM_CYCLE_TIME_2ND            23
/* SDRAM access from clock (2nd highest CAS latency) */
#define SPD_ACCESS_TIME_FROM_CLOCK_2ND      24
/* SDRAM cycle time (3rd highest CAS latency) */
#define SPD_SDRAM_CYCLE_TIME_3RD            25
/* SDRAM access from clock (3rd highest CAS latency) */
#define SPD_ACCESS_TIME_FROM_CLOCK_3RD      26
/* Minimum row precharge time (Trp) */
#define SPD_MIN_ROW_PRECHARGE_TIME          27
/* Minimum row active to row active (Trrd) */
#define SPD_MIN_ROWACTIVE_TO_ROWACTIVE      28
/* Minimum RAS to CAS delay (Trcd) */
#define SPD_MIN_RAS_TO_CAS_DELAY            29
/* Minimum RAS pulse width (Tras) */
#define SPD_MIN_ACTIVE_TO_PRECHARGE_DELAY   30
/* Density of each row on module */
#define SPD_DENSITY_OF_EACH_ROW_ON_MODULE   31
/* Command and address signal input setup time */
#define SPD_CMD_SIGNAL_INPUT_SETUP_TIME     32
/* Command and address signal input hold time */
#define SPD_CMD_SIGNAL_INPUT_HOLD_TIME      33
/* Data signal input setup time */
#define SPD_DATA_SIGNAL_INPUT_SETUP_TIME    34
#define SPD_DATA_SIGNAL_INPUT_HOLD_TIME     35 /* Data signal input hold time */
#define SPD_WRITE_RECOVERY_TIME             36 /* Write recovery time (tWR) */
/* Internal write to read command delay (tWTR) */
#define SPD_INT_WRITE_TO_READ_DELAY         37
/* Internal read to precharge command delay (tRTP) */
#define SPD_INT_READ_TO_PRECHARGE_DELAY     38
/* Memory analysis probe characteristics */
#define SPD_MEM_ANALYSIS_PROBE_PARAMS       39
/* Extension of byte 41 (tRC) and byte 42 (tRFC) */
#define SPD_BYTE_41_42_EXTENSION            40
/* Minimum active to active auto refresh (tRCmin) */
#define SPD_MIN_ACT_TO_ACT_AUTO_REFRESH     41
/* Minimum auto refresh to active/auto refresh (tRFC) */
#define SPD_MIN_AUTO_REFRESH_TO_ACT         42
/* Maximum device cycle time (tCKmax) */
#define SPD_MAX_DEVICE_CYCLE_TIME           43
/* Maximum skew between DQS and DQ (tDQSQ) */
#define SPD_MAX_DQS_DQ_SKEW                 44
/* Maximum read data-hold skew factor (tQHS) */
#define SPD_MAX_READ_DATAHOLD_SKEW          45
#define SPD_PLL_RELOCK_TIME                 46 /* PLL relock time */
#define SPD_SPD_DATA_REVISION_CODE          62 /* SPD data revision code */
#define SPD_CHECKSUM_FOR_BYTES_0_TO_62      63 /* Checksum for bytes 0-62 */
/* Manufacturer's JEDEC ID code, per EIA/JEP106 (bytes 64-71) */
#define SPD_MANUFACTURER_JEDEC_ID_CODE      64
#define SPD_MANUFACTURING_LOCATION          72 /* Manufacturing location */
/* Manufacturer's part number, in 6-bit ASCII (bytes 73-90) */
#define SPD_MANUFACTURER_PART_NUMBER        73
#define SPD_REVISION_CODE                   91 /* Revision code (bytes 91-92) */
/* Manufacturing date (byte 93: year, byte 94: week) */
#define SPD_MANUFACTURING_DATE              93
/* Assembly serial number (bytes 95-98) */
#define SPD_ASSEMBLY_SERIAL_NUMBER          95
/* Manufacturer specific data (bytes 99-125) */
#define SPD_MANUFACTURER_SPECIFIC_DATA      99
/* Intel specification for frequency */
#define SPD_INTEL_SPEC_FOR_FREQUENCY       126
/* Intel specification details for 100MHz support */
#define SPD_INTEL_SPEC_100_MHZ             127

/* DRAM specifications use the following naming conventions for SPD locations */
#define SPD_tRP                             SPD_MIN_ROW_PRECHARGE_TIME
#define SPD_tRRD                            SPD_MIN_ROWACTIVE_TO_ROWACTIVE
#define SPD_tRCD                            SPD_MIN_RAS_TO_CAS_DELAY
#define SPD_tRAS                            SPD_MIN_ACTIVE_TO_PRECHARGE_DELAY
#define SPD_BANK_DENSITY                    SPD_DENSITY_OF_EACH_ROW_ON_MODULE
#define SPD_ADDRESS_CMD_HOLD                SPD_CMD_SIGNAL_INPUT_HOLD_TIME
/* SDRAM Device Minimum Active to Active/Auto Refresh Time (tRC) */
#define SPD_tRC				    41
/* SDRAM Device Minimum Auto Refresh to Active/Auto Refresh (tRFC) */
#define SPD_tRFC			    42

/* SPD_MEMORY_TYPE values. */
enum spd_memory_type {
	SPD_MEMORY_TYPE_UNDEFINED		= 0x00,
	SPD_MEMORY_TYPE_FPM_DRAM		= 0x01,
	SPD_MEMORY_TYPE_EDO			= 0x02,
	SPD_MEMORY_TYPE_PIPELINED_NIBBLE	= 0x03,
	SPD_MEMORY_TYPE_SDRAM			= 0x04,
	SPD_MEMORY_TYPE_MULTIPLEXED_ROM		= 0x05,
	SPD_MEMORY_TYPE_SGRAM_DDR		= 0x06,
	SPD_MEMORY_TYPE_SDRAM_DDR		= 0x07,
	SPD_MEMORY_TYPE_SDRAM_DDR2		= 0x08,
	SPD_MEMORY_TYPE_FBDIMM_DDR2		= 0x09,
	SPD_MEMORY_TYPE_FB_PROBE_DDR2		= 0x0a,
	SPD_MEMORY_TYPE_SDRAM_DDR3		= 0x0b,
	SPD_MEMORY_TYPE_DDR4_SDRAM		= 0x0c,
	SPD_MEMORY_TYPE_DDR4E_SDRAM		= 0x0e,
	SPD_MEMORY_TYPE_LPDDR3_SDRAM		= 0x0f,
	SPD_MEMORY_TYPE_LPDDR4_SDRAM		= 0x10,
};

/* SPD_MODULE_VOLTAGE values. */
#define SPD_VOLTAGE_TTL                  0 /* 5.0 Volt/TTL */
#define SPD_VOLTAGE_LVTTL                1 /* LVTTL */
#define SPD_VOLTAGE_HSTL                 2 /* HSTL 1.5 */
#define SPD_VOLTAGE_SSTL3                3 /* SSTL 3.3 */
#define SPD_VOLTAGE_SSTL2                4 /* SSTL 2.5 */
#define SPD_VOLTAGE_SSTL1                5 /* SSTL 1.8 */

/* SPD_DIMM_CONFIG_TYPE values. */
#define ERROR_SCHEME_NONE                0
#define ERROR_SCHEME_PARITY              1
#define ERROR_SCHEME_ECC                 2

/* SPD_ACCEPTABLE_CAS_LATENCIES values. */
// TODO: Check values.
#define SPD_CAS_LATENCY_1_0              0x01
#define SPD_CAS_LATENCY_1_5              0x02
#define SPD_CAS_LATENCY_2_0              0x04
#define SPD_CAS_LATENCY_2_5              0x08
#define SPD_CAS_LATENCY_3_0              0x10
#define SPD_CAS_LATENCY_3_5              0x20
#define SPD_CAS_LATENCY_4_0              0x40

#define SPD_CAS_LATENCY_DDR2_2		(1 << 2)
#define SPD_CAS_LATENCY_DDR2_3		(1 << 3)
#define SPD_CAS_LATENCY_DDR2_4		(1 << 4)
#define SPD_CAS_LATENCY_DDR2_5		(1 << 5)
#define SPD_CAS_LATENCY_DDR2_6		(1 << 6)
#define SPD_CAS_LATENCY_DDR2_7		(1 << 7)

/* SPD_SUPPORTED_BURST_LENGTHS values. */
#define SPD_BURST_LENGTH_1               1
#define SPD_BURST_LENGTH_2               2
#define SPD_BURST_LENGTH_4               4
#define SPD_BURST_LENGTH_8               8
#define SPD_BURST_LENGTH_PAGE            (1 << 7)

/* SPD_MODULE_ATTRIBUTES values. */
#define MODULE_BUFFERED                  1
#define MODULE_REGISTERED                2

/* Byte 3: Module type information */
#define SPD_UNDEFINED 0x00
#define SPD_RDIMM 0x01
#define SPD_UDIMM 0x02
#define SPD_SODIMM 0x04
#define SPD_72B_SO_CDIMM 0x06
#define SPD_72B_SO_RDIMM 0x07
#define SPD_MICRO_DIMM 0x08
#define SPD_MINI_RDIMM 0x10
#define SPD_MINI_UDIMM 0x20

#define SPD_ECC_8BIT (1<<3)
#define SPD_ECC_8BIT_LP5_DDR5 (1<<4)

#endif
