ddr4.h

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/* SPDX-License-Identifier: GPL-2.0-only */
 
/*
 * JEDEC Standard No. 21-C
 * Annex L: Serial Presence Detect (SPD) for DDR4 SDRAM Modules
 */
 
#ifndef DEVICE_DRAM_DDR4L_H
#define DEVICE_DRAM_DDR4L_H
 
/**
 * @file ddr4.h
 *
 * \brief Utilities for decoding DDR4 SPDs
 */
 
#include <spd.h>
#include <device/dram/common.h>
#include <types.h>
 
#define SPD_DDR4_PART_OFF       329
#define SPD_DDR4_PART_LEN       20
 
/*
 * Module type (byte 3, bits 3:0) of SPD
 * This definition is specific to DDR4. DDR2/3 SPDs have a different structure.
 */
enum spd_dimm_type_ddr4 {
        SPD_DDR4_DIMM_TYPE_EXTENDED             = 0x0,
        SPD_DDR4_DIMM_TYPE_RDIMM                = 0x1,
        SPD_DDR4_DIMM_TYPE_UDIMM                = 0x2,
        SPD_DDR4_DIMM_TYPE_SO_DIMM              = 0x3,
        SPD_DDR4_DIMM_TYPE_LRDIMM               = 0x4,
        SPD_DDR4_DIMM_TYPE_MINI_RDIMM           = 0x5,
        SPD_DDR4_DIMM_TYPE_MINI_UDIMM           = 0x6,
        SPD_DDR4_DIMM_TYPE_72B_SO_RDIMM         = 0x8,
        SPD_DDR4_DIMM_TYPE_72B_SO_UDIMM         = 0x9,
        SPD_DDR4_DIMM_TYPE_16B_SO_DIMM          = 0xc,
        SPD_DDR4_DIMM_TYPE_32B_SO_DIMM          = 0xd,
        /* Masks to bits 3:0 to give the dimm type */
        SPD_DDR4_DIMM_TYPE_MASK                 = 0xf
};
 
/**
 * \brief DIMM characteristics
 *
 * The characteristics of each DIMM, as presented by the SPD
 */
struct dimm_attr_ddr4_st {
        enum spd_memory_type dram_type;
        enum spd_dimm_type_ddr4 dimm_type;
        char part_number[SPD_DDR4_PART_LEN + 1];
        u8 serial_number[4];
        u8 bus_width;
        u8 ranks;
        u8 sdram_width;
        u16 cap_per_die_mbit;
        u16 size_mb;
        u16 manufacturer_id;
        u16 vdd_voltage;
        bool ecc_extension;
};
 
typedef u8 spd_raw_data[512];
 
int spd_decode_ddr4(struct dimm_attr_ddr4_st *dimm, spd_raw_data spd);
 
enum cb_err spd_add_smbios17_ddr4(const u8 channel, const u8 slot,
                                const u16 selected_freq,
                                const struct dimm_attr_ddr4_st *info);
 
/**
 * Converts DDR4 clock speed in MHz to the standard reported speed in MT/s
 */
uint16_t ddr4_speed_mhz_to_reported_mts(uint16_t speed_mhz);
 
#endif /* DEVICE_DRAM_DDR4L_H */