// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2008-2014 Freescale Semiconductor, Inc.
 * Copyright 2021 NXP
 */

/*
 * Generic driver for Freescale DDR/DDR2/DDR3 memory controller.
 * Based on code from spd_sdram.c
 * Author: James Yang [at freescale.com]
 */

#include <common.h>
#include <display_options.h>
#include <dm.h>
#include <i2c.h>
#include <fsl_ddr_sdram.h>
#include <fsl_ddr.h>
#include <init.h>
#include <log.h>
#include <asm/bitops.h>

/*
 * CFG_SYS_FSL_DDR_SDRAM_BASE_PHY is the physical address from the view
 * of DDR controllers. It is the same as CONFIG_SYS_DDR_SDRAM_BASE for
 * all Power SoCs. But it could be different for ARM SoCs. For example,
 * fsl_lsch3 has a mapping mechanism to map DDR memory to ranges (in order) of
 * 0x00_8000_0000 ~ 0x00_ffff_ffff
 * 0x80_8000_0000 ~ 0xff_ffff_ffff
 */
#ifndef CFG_SYS_FSL_DDR_SDRAM_BASE_PHY
#ifdef CONFIG_MPC83xx
#define CFG_SYS_FSL_DDR_SDRAM_BASE_PHY CONFIG_SYS_SDRAM_BASE
#else
#define CFG_SYS_FSL_DDR_SDRAM_BASE_PHY CONFIG_SYS_DDR_SDRAM_BASE
#endif
#endif

#ifdef CONFIG_PPC
#include <asm/fsl_law.h>

void fsl_ddr_set_lawbar(
                const common_timing_params_t *memctl_common_params,
                unsigned int memctl_interleaved,
                unsigned int ctrl_num);
#endif

void fsl_ddr_set_intl3r(const unsigned int granule_size);
#if defined(SPD_EEPROM_ADDRESS) || \
    defined(SPD_EEPROM_ADDRESS1) || defined(SPD_EEPROM_ADDRESS2) || \
    defined(SPD_EEPROM_ADDRESS3) || defined(SPD_EEPROM_ADDRESS4)
#if (CONFIG_SYS_NUM_DDR_CTLRS == 1) && (CONFIG_DIMM_SLOTS_PER_CTLR == 1)
u8 spd_i2c_addr[CONFIG_SYS_NUM_DDR_CTLRS][CONFIG_DIMM_SLOTS_PER_CTLR] = {
        [0][0] = SPD_EEPROM_ADDRESS,
};
#elif (CONFIG_SYS_NUM_DDR_CTLRS == 1) && (CONFIG_DIMM_SLOTS_PER_CTLR == 2)
u8 spd_i2c_addr[CONFIG_SYS_NUM_DDR_CTLRS][CONFIG_DIMM_SLOTS_PER_CTLR] = {
        [0][0] = SPD_EEPROM_ADDRESS1,   /* controller 1 */
        [0][1] = SPD_EEPROM_ADDRESS2,   /* controller 1 */
};
#elif (CONFIG_SYS_NUM_DDR_CTLRS == 2) && (CONFIG_DIMM_SLOTS_PER_CTLR == 1)
u8 spd_i2c_addr[CONFIG_SYS_NUM_DDR_CTLRS][CONFIG_DIMM_SLOTS_PER_CTLR] = {
        [0][0] = SPD_EEPROM_ADDRESS1,   /* controller 1 */
        [1][0] = SPD_EEPROM_ADDRESS2,   /* controller 2 */
};
#elif (CONFIG_SYS_NUM_DDR_CTLRS == 2) && (CONFIG_DIMM_SLOTS_PER_CTLR == 2)
u8 spd_i2c_addr[CONFIG_SYS_NUM_DDR_CTLRS][CONFIG_DIMM_SLOTS_PER_CTLR] = {
        [0][0] = SPD_EEPROM_ADDRESS1,   /* controller 1 */
        [0][1] = SPD_EEPROM_ADDRESS2,   /* controller 1 */
        [1][0] = SPD_EEPROM_ADDRESS3,   /* controller 2 */
        [1][1] = SPD_EEPROM_ADDRESS4,   /* controller 2 */
};
#elif (CONFIG_SYS_NUM_DDR_CTLRS == 3) && (CONFIG_DIMM_SLOTS_PER_CTLR == 1)
u8 spd_i2c_addr[CONFIG_SYS_NUM_DDR_CTLRS][CONFIG_DIMM_SLOTS_PER_CTLR] = {
        [0][0] = SPD_EEPROM_ADDRESS1,   /* controller 1 */
        [1][0] = SPD_EEPROM_ADDRESS2,   /* controller 2 */
        [2][0] = SPD_EEPROM_ADDRESS3,   /* controller 3 */
};
#elif (CONFIG_SYS_NUM_DDR_CTLRS == 3) && (CONFIG_DIMM_SLOTS_PER_CTLR == 2)
u8 spd_i2c_addr[CONFIG_SYS_NUM_DDR_CTLRS][CONFIG_DIMM_SLOTS_PER_CTLR] = {
        [0][0] = SPD_EEPROM_ADDRESS1,   /* controller 1 */
        [0][1] = SPD_EEPROM_ADDRESS2,   /* controller 1 */
        [1][0] = SPD_EEPROM_ADDRESS3,   /* controller 2 */
        [1][1] = SPD_EEPROM_ADDRESS4,   /* controller 2 */
        [2][0] = SPD_EEPROM_ADDRESS5,   /* controller 3 */
        [2][1] = SPD_EEPROM_ADDRESS6,   /* controller 3 */
};

#endif

#if CONFIG_IS_ENABLED(DM_I2C)
#define DEV_TYPE struct udevice
#else
/* Local udevice */
struct ludevice {
        u8 chip;
};

#define DEV_TYPE struct ludevice

#endif

#define SPD_SPA0_ADDRESS        0x36
#define SPD_SPA1_ADDRESS        0x37

static int ddr_i2c_read(DEV_TYPE *dev, unsigned int addr,
                        int alen, uint8_t *buf, int len)
{
        int ret;

#if CONFIG_IS_ENABLED(DM_I2C)
        ret = dm_i2c_read(dev, 0, buf, len);
#else
        ret = i2c_read(dev->chip, addr, alen, buf, len);
#endif

        return ret;
}

#ifdef CONFIG_SYS_FSL_DDR4
static int ddr_i2c_dummy_write(unsigned int chip_addr)
{
        uint8_t buf = 0;

#if CONFIG_IS_ENABLED(DM_I2C)
        struct udevice *dev;
        int ret;

        ret = i2c_get_chip_for_busnum(CONFIG_SYS_SPD_BUS_NUM, chip_addr,
                                      1, &dev);
        if (ret) {
                printf("%s: Cannot find udev for a bus %d\n", __func__,
                       CONFIG_SYS_SPD_BUS_NUM);
                return ret;
        }

        return dm_i2c_write(dev, 0, &buf, 1);
#else
        return i2c_write(chip_addr, 0, 1, &buf, 1);
#endif

        return 0;
}
#endif

static void __get_spd(generic_spd_eeprom_t *spd, u8 i2c_address)
{
        int ret;
        DEV_TYPE *dev;

#if CONFIG_IS_ENABLED(DM_I2C)
        ret = i2c_get_chip_for_busnum(CONFIG_SYS_SPD_BUS_NUM, i2c_address,
                                      1, &dev);
        if (ret) {
                printf("%s: Cannot find udev for a bus %d\n", __func__,
                       CONFIG_SYS_SPD_BUS_NUM);
                return;
        }
#else /* Non DM I2C support - will be removed */
        struct ludevice ldev = {
                .chip = i2c_address,
        };
        dev = &ldev;

        i2c_set_bus_num(CONFIG_SYS_SPD_BUS_NUM);
#endif

#ifdef CONFIG_SYS_FSL_DDR4
        /*
         * DDR4 SPD has 384 to 512 bytes
         * To access the lower 256 bytes, we need to set EE page address to 0
         * To access the upper 256 bytes, we need to set EE page address to 1
         * See Jedec standar No. 21-C for detail
         */
        ddr_i2c_dummy_write(SPD_SPA0_ADDRESS);
        ret = ddr_i2c_read(dev, 0, 1, (uchar *)spd, 256);
        if (!ret) {
                ddr_i2c_dummy_write(SPD_SPA1_ADDRESS);
                ret = ddr_i2c_read(dev, 0, 1, (uchar *)((ulong)spd + 256),
                                   min(256,
                                       (int)sizeof(generic_spd_eeprom_t)
                                       - 256));
        }

#else
        ret = ddr_i2c_read(dev, 0, 1, (uchar *)spd,
                           sizeof(generic_spd_eeprom_t));
#endif

        if (ret) {
                if (i2c_address ==
#ifdef SPD_EEPROM_ADDRESS
                                SPD_EEPROM_ADDRESS
#elif defined(SPD_EEPROM_ADDRESS1)
                                SPD_EEPROM_ADDRESS1
#endif
                                ) {
                        printf("DDR: failed to read SPD from address %u\n",
                                i2c_address);
                } else {
                        debug("DDR: failed to read SPD from address %u\n",
                                i2c_address);
                }
                memset(spd, 0, sizeof(generic_spd_eeprom_t));
        }
}

__attribute__((weak, alias("__get_spd")))
void get_spd(generic_spd_eeprom_t *spd, u8 i2c_address);

/* This function allows boards to update SPD address */
__weak void update_spd_address(unsigned int ctrl_num,
                               unsigned int slot,
                               unsigned int *addr)
{
}

void fsl_ddr_get_spd(generic_spd_eeprom_t *ctrl_dimms_spd,
                      unsigned int ctrl_num, unsigned int dimm_slots_per_ctrl)
{
        unsigned int i;
        unsigned int i2c_address = 0;

        if (ctrl_num >= CONFIG_SYS_NUM_DDR_CTLRS) {
                printf("%s unexpected ctrl_num = %u\n", __FUNCTION__, ctrl_num);
                return;
        }

        for (i = 0; i < dimm_slots_per_ctrl; i++) {
                i2c_address = spd_i2c_addr[ctrl_num][i];
                update_spd_address(ctrl_num, i, &i2c_address);
                get_spd(&(ctrl_dimms_spd[i]), i2c_address);
        }
}
#else
void fsl_ddr_get_spd(generic_spd_eeprom_t *ctrl_dimms_spd,
                      unsigned int ctrl_num, unsigned int dimm_slots_per_ctrl)
{
}
#endif /* SPD_EEPROM_ADDRESSx */

/*
 * ASSUMPTIONS:
 *    - Same number of CONFIG_DIMM_SLOTS_PER_CTLR on each controller
 *    - Same memory data bus width on all controllers
 *
 * NOTES:
 *
 * The memory controller and associated documentation use confusing
 * terminology when referring to the orgranization of DRAM.
 *
 * Here is a terminology translation table:
 *
 * memory controller/documention  |industry   |this code  |signals
 * -------------------------------|-----------|-----------|-----------------
 * physical bank/bank             |rank       |rank       |chip select (CS)
 * logical bank/sub-bank          |bank       |bank       |bank address (BA)
 * page/row                       |row        |page       |row address
 * ???                            |column     |column     |column address
 *
 * The naming confusion is further exacerbated by the descriptions of the
 * memory controller interleaving feature, where accesses are interleaved
 * _BETWEEN_ two seperate memory controllers.  This is configured only in
 * CS0_CONFIG[INTLV_CTL] of each memory controller.
 *
 * memory controller documentation | number of chip selects
 *                                 | per memory controller supported
 * --------------------------------|-----------------------------------------
 * cache line interleaving         | 1 (CS0 only)
 * page interleaving               | 1 (CS0 only)
 * bank interleaving               | 1 (CS0 only)
 * superbank interleraving         | depends on bank (chip select)
 *                                 |   interleraving [rank interleaving]
 *                                 |   mode used on every memory controller
 *
 * Even further confusing is the existence of the interleaving feature
 * _WITHIN_ each memory controller.  The feature is referred to in
 * documentation as chip select interleaving or bank interleaving,
 * although it is configured in the DDR_SDRAM_CFG field.
 *
 * Name of field                | documentation name    | this code
 * -----------------------------|-----------------------|------------------
 * DDR_SDRAM_CFG[BA_INTLV_CTL]  | Bank (chip select)    | rank interleaving
 *                              |  interleaving
 */

const char *step_string_tbl[] = {
        "STEP_GET_SPD",
        "STEP_COMPUTE_DIMM_PARMS",
        "STEP_COMPUTE_COMMON_PARMS",
        "STEP_GATHER_OPTS",
        "STEP_ASSIGN_ADDRESSES",
        "STEP_COMPUTE_REGS",
        "STEP_PROGRAM_REGS",
        "STEP_ALL"
};

const char * step_to_string(unsigned int step) {

        unsigned int s = __ilog2(step);

        if (s <= 31) {
                if ((1 << s) != step)
                        return step_string_tbl[7];
        } else {
                if ((1 << (s - 32)) != step)
                        return step_string_tbl[7];
        }
        if (s >= ARRAY_SIZE(step_string_tbl)) {
                printf("Error for the step in %s\n", __func__);
                s = 0;
        }

        return step_string_tbl[s];
}

static unsigned long long __step_assign_addresses(fsl_ddr_info_t *pinfo,
                          unsigned int dbw_cap_adj[])
{
        unsigned int i, j;
        unsigned long long total_mem, current_mem_base, total_ctlr_mem;
        unsigned long long rank_density, ctlr_density = 0;
        unsigned int first_ctrl = pinfo->first_ctrl;
        unsigned int last_ctrl = first_ctrl + pinfo->num_ctrls - 1;

        /*
         * If a reduced data width is requested, but the SPD
         * specifies a physically wider device, adjust the
         * computed dimm capacities accordingly before
         * assigning addresses.
         */
        for (i = first_ctrl; i <= last_ctrl; i++) {
                unsigned int found = 0;

                switch (pinfo->memctl_opts[i].data_bus_width) {
                case 2:
                        /* 16-bit */
                        for (j = 0; j < CONFIG_DIMM_SLOTS_PER_CTLR; j++) {
                                unsigned int dw;
                                if (!pinfo->dimm_params[i][j].n_ranks)
                                        continue;
                                dw = pinfo->dimm_params[i][j].primary_sdram_width;
                                if ((dw == 72 || dw == 64)) {
                                        dbw_cap_adj[i] = 2;
                                        break;
                                } else if ((dw == 40 || dw == 32)) {
                                        dbw_cap_adj[i] = 1;
                                        break;
                                }
                        }
                        break;

                case 1:
                        /* 32-bit */
                        for (j = 0; j < CONFIG_DIMM_SLOTS_PER_CTLR; j++) {
                                unsigned int dw;
                                dw = pinfo->dimm_params[i][j].data_width;
                                if (pinfo->dimm_params[i][j].n_ranks
                                    && (dw == 72 || dw == 64)) {
                                        /*
                                         * FIXME: can't really do it
                                         * like this because this just
                                         * further reduces the memory
                                         */
                                        found = 1;
                                        break;
                                }
                        }
                        if (found) {
                                dbw_cap_adj[i] = 1;
                        }
                        break;

                case 0:
                        /* 64-bit */
                        break;

                default:
                        printf("unexpected data bus width "
                                "specified controller %u\n", i);
                        return 1;
                }
                debug("dbw_cap_adj[%d]=%d\n", i, dbw_cap_adj[i]);
        }

        current_mem_base = pinfo->mem_base;
        total_mem = 0;
        if (pinfo->memctl_opts[first_ctrl].memctl_interleaving) {
                rank_density = pinfo->dimm_params[first_ctrl][0].rank_density >>
                                        dbw_cap_adj[first_ctrl];
                switch (pinfo->memctl_opts[first_ctrl].ba_intlv_ctl &
                                        FSL_DDR_CS0_CS1_CS2_CS3) {
                case FSL_DDR_CS0_CS1_CS2_CS3:
                        ctlr_density = 4 * rank_density;
                        break;
                case FSL_DDR_CS0_CS1:
                case FSL_DDR_CS0_CS1_AND_CS2_CS3:
                        ctlr_density = 2 * rank_density;
                        break;
                case FSL_DDR_CS2_CS3:
                default:
                        ctlr_density = rank_density;
                        break;
                }
                debug("rank density is 0x%llx, ctlr density is 0x%llx\n",
                        rank_density, ctlr_density);
                for (i = first_ctrl; i <= last_ctrl; i++) {
                        if (pinfo->memctl_opts[i].memctl_interleaving) {
                                switch (pinfo->memctl_opts[i].memctl_interleaving_mode) {
                                case FSL_DDR_256B_INTERLEAVING:
                                case FSL_DDR_CACHE_LINE_INTERLEAVING:
                                case FSL_DDR_PAGE_INTERLEAVING:
                                case FSL_DDR_BANK_INTERLEAVING:
                                case FSL_DDR_SUPERBANK_INTERLEAVING:
                                        total_ctlr_mem = 2 * ctlr_density;
                                        break;
                                case FSL_DDR_3WAY_1KB_INTERLEAVING:
                                case FSL_DDR_3WAY_4KB_INTERLEAVING:
                                case FSL_DDR_3WAY_8KB_INTERLEAVING:
                                        total_ctlr_mem = 3 * ctlr_density;
                                        break;
                                case FSL_DDR_4WAY_1KB_INTERLEAVING:
                                case FSL_DDR_4WAY_4KB_INTERLEAVING:
                                case FSL_DDR_4WAY_8KB_INTERLEAVING:
                                        total_ctlr_mem = 4 * ctlr_density;
                                        break;
                                default:
                                        panic("Unknown interleaving mode");
                                }
                                pinfo->common_timing_params[i].base_address =
                                                        current_mem_base;
                                pinfo->common_timing_params[i].total_mem =
                                                        total_ctlr_mem;
                                total_mem = current_mem_base + total_ctlr_mem;
                                debug("ctrl %d base 0x%llx\n", i, current_mem_base);
                                debug("ctrl %d total 0x%llx\n", i, total_ctlr_mem);
                        } else {
                                /* when 3rd controller not interleaved */
                                current_mem_base = total_mem;
                                total_ctlr_mem = 0;
                                pinfo->common_timing_params[i].base_address =
                                                        current_mem_base;
                                for (j = 0; j < CONFIG_DIMM_SLOTS_PER_CTLR; j++) {
                                        unsigned long long cap =
                                                pinfo->dimm_params[i][j].capacity >> dbw_cap_adj[i];
                                        pinfo->dimm_params[i][j].base_address =
                                                current_mem_base;
                                        debug("ctrl %d dimm %d base 0x%llx\n", i, j, current_mem_base);
                                        current_mem_base += cap;
                                        total_ctlr_mem += cap;
                                }
                                debug("ctrl %d total 0x%llx\n", i, total_ctlr_mem);
                                pinfo->common_timing_params[i].total_mem =
                                                        total_ctlr_mem;
                                total_mem += total_ctlr_mem;
                        }
                }
        } else {
                /*
                 * Simple linear assignment if memory
                 * controllers are not interleaved.
                 */
                for (i = first_ctrl; i <= last_ctrl; i++) {
                        total_ctlr_mem = 0;
                        pinfo->common_timing_params[i].base_address =
                                                current_mem_base;
                        for (j = 0; j < CONFIG_DIMM_SLOTS_PER_CTLR; j++) {
                                /* Compute DIMM base addresses. */
                                unsigned long long cap =
                                        pinfo->dimm_params[i][j].capacity >> dbw_cap_adj[i];
                                pinfo->dimm_params[i][j].base_address =
                                        current_mem_base;
                                debug("ctrl %d dimm %d base 0x%llx\n", i, j, current_mem_base);
                                current_mem_base += cap;
                                total_ctlr_mem += cap;
                        }
                        debug("ctrl %d total 0x%llx\n", i, total_ctlr_mem);
                        pinfo->common_timing_params[i].total_mem =
                                                        total_ctlr_mem;
                        total_mem += total_ctlr_mem;
                }
        }
        debug("Total mem by %s is 0x%llx\n", __func__, total_mem);

        return total_mem;
}

/* Use weak function to allow board file to override the address assignment */
__attribute__((weak, alias("__step_assign_addresses")))
unsigned long long step_assign_addresses(fsl_ddr_info_t *pinfo,
                          unsigned int dbw_cap_adj[]);

unsigned long long
fsl_ddr_compute(fsl_ddr_info_t *pinfo, unsigned int start_step,
                                       unsigned int size_only)
{
        unsigned int i, j;
        unsigned long long total_mem = 0;
        int assert_reset = 0;
        unsigned int first_ctrl =  pinfo->first_ctrl;
        unsigned int last_ctrl = first_ctrl + pinfo->num_ctrls - 1;
        __maybe_unused int retval;
        __maybe_unused bool goodspd = false;
        __maybe_unused int dimm_slots_per_ctrl = pinfo->dimm_slots_per_ctrl;

        fsl_ddr_cfg_regs_t *ddr_reg = pinfo->fsl_ddr_config_reg;
        common_timing_params_t *timing_params = pinfo->common_timing_params;
        if (pinfo->board_need_mem_reset)
                assert_reset = pinfo->board_need_mem_reset();

        /* data bus width capacity adjust shift amount */
        unsigned int dbw_capacity_adjust[CONFIG_SYS_NUM_DDR_CTLRS];

        for (i = first_ctrl; i <= last_ctrl; i++)
                dbw_capacity_adjust[i] = 0;

        debug("starting at step %u (%s)\n",
              start_step, step_to_string(start_step));

        switch (start_step) {
        case STEP_GET_SPD:
#if defined(CONFIG_DDR_SPD) || defined(CONFIG_SPD_EEPROM)
                /* STEP 1:  Gather all DIMM SPD data */
                for (i = first_ctrl; i <= last_ctrl; i++) {
                        fsl_ddr_get_spd(pinfo->spd_installed_dimms[i], i,
                                        dimm_slots_per_ctrl);
                }

        case STEP_COMPUTE_DIMM_PARMS:
                /* STEP 2:  Compute DIMM parameters from SPD data */

                for (i = first_ctrl; i <= last_ctrl; i++) {
                        for (j = 0; j < CONFIG_DIMM_SLOTS_PER_CTLR; j++) {
                                generic_spd_eeprom_t *spd =
                                        &(pinfo->spd_installed_dimms[i][j]);
                                dimm_params_t *pdimm =
                                        &(pinfo->dimm_params[i][j]);
                                retval = compute_dimm_parameters(
                                                        i, spd, pdimm, j);
#ifdef CONFIG_SYS_DDR_RAW_TIMING
                                if (!j && retval) {
                                        printf("SPD error on controller %d! "
                                        "Trying fallback to raw timing "
                                        "calculation\n", i);
                                        retval = fsl_ddr_get_dimm_params(pdimm,
                                                                         i, j);
                                }
#else
                                if (retval == 2) {
                                        printf("Error: compute_dimm_parameters"
                                        " non-zero returned FATAL value "
                                        "for memctl=%u dimm=%u\n", i, j);
                                        return 0;
                                }
#endif
                                if (retval) {
                                        debug("Warning: compute_dimm_parameters"
                                        " non-zero return value for memctl=%u "
                                        "dimm=%u\n", i, j);
                                } else {
                                        goodspd = true;
                                }
                        }
                }
                if (!goodspd) {
                        /*
                         * No valid SPD found
                         * Throw an error if this is for main memory, i.e.
                         * first_ctrl == 0. Otherwise, siliently return 0
                         * as the memory size.
                         */
                        if (first_ctrl == 0)
                                printf("Error: No valid SPD detected.\n");

                        return 0;
                }
#elif defined(CONFIG_SYS_DDR_RAW_TIMING)
        case STEP_COMPUTE_DIMM_PARMS:
                for (i = first_ctrl; i <= last_ctrl; i++) {
                        for (j = 0; j < CONFIG_DIMM_SLOTS_PER_CTLR; j++) {
                                dimm_params_t *pdimm =
                                        &(pinfo->dimm_params[i][j]);
                                fsl_ddr_get_dimm_params(pdimm, i, j);
                        }
                }
                debug("Filling dimm parameters from board specific file\n");
#endif
        case STEP_COMPUTE_COMMON_PARMS:
                /*
                 * STEP 3: Compute a common set of timing parameters
                 * suitable for all of the DIMMs on each memory controller
                 */
                for (i = first_ctrl; i <= last_ctrl; i++) {
                        debug("Computing lowest common DIMM"
                                " parameters for memctl=%u\n", i);
                        compute_lowest_common_dimm_parameters
                                (i,
                                 pinfo->dimm_params[i],
                                 &timing_params[i],
                                 CONFIG_DIMM_SLOTS_PER_CTLR);
                }

        case STEP_GATHER_OPTS:
                /* STEP 4:  Gather configuration requirements from user */
                for (i = first_ctrl; i <= last_ctrl; i++) {
                        debug("Reloading memory controller "
                                "configuration options for memctl=%u\n", i);
                        /*
                         * This "reloads" the memory controller options
                         * to defaults.  If the user "edits" an option,
                         * next_step points to the step after this,
                         * which is currently STEP_ASSIGN_ADDRESSES.
                         */
                        populate_memctl_options(
                                        &timing_params[i],
                                        &pinfo->memctl_opts[i],
                                        pinfo->dimm_params[i], i);
                        /*
                         * For RDIMMs, JEDEC spec requires clocks to be stable
                         * before reset signal is deasserted. For the boards
                         * using fixed parameters, this function should be
                         * be called from board init file.
                         */
                        if (timing_params[i].all_dimms_registered)
                                assert_reset = 1;
                }
                if (assert_reset && !size_only) {
                        if (pinfo->board_mem_reset) {
                                debug("Asserting mem reset\n");
                                pinfo->board_mem_reset();
                        } else {
                                debug("Asserting mem reset missing\n");
                        }
                }

        case STEP_ASSIGN_ADDRESSES:
                /* STEP 5:  Assign addresses to chip selects */
                check_interleaving_options(pinfo);
                total_mem = step_assign_addresses(pinfo, dbw_capacity_adjust);
                debug("Total mem %llu assigned\n", total_mem);

        case STEP_COMPUTE_REGS:
                /* STEP 6:  compute controller register values */
                debug("FSL Memory ctrl register computation\n");
                for (i = first_ctrl; i <= last_ctrl; i++) {
                        if (timing_params[i].ndimms_present == 0) {
                                memset(&ddr_reg[i], 0,
                                        sizeof(fsl_ddr_cfg_regs_t));
                                continue;
                        }

                        compute_fsl_memctl_config_regs
                                (i,
                                 &pinfo->memctl_opts[i],
                                 &ddr_reg[i], &timing_params[i],
                                 pinfo->dimm_params[i],
                                 dbw_capacity_adjust[i],
                                 size_only);
                }

        default:
                break;
        }

        {
                /*
                 * Compute the amount of memory available just by
                 * looking for the highest valid CSn_BNDS value.
                 * This allows us to also experiment with using
                 * only CS0 when using dual-rank DIMMs.
                 */
                unsigned int max_end = 0;

                for (i = first_ctrl; i <= last_ctrl; i++) {
                        for (j = 0; j < CONFIG_CHIP_SELECTS_PER_CTRL; j++) {
                                fsl_ddr_cfg_regs_t *reg = &ddr_reg[i];
                                if (reg->cs[j].config & 0x80000000) {
                                        unsigned int end;
                                        /*
                                         * 0xfffffff is a special value we put
                                         * for unused bnds
                                         */
                                        if (reg->cs[j].bnds == 0xffffffff)
                                                continue;
                                        end = reg->cs[j].bnds & 0xffff;
                                        if (end > max_end) {
                                                max_end = end;
                                        }
                                }
                        }
                }

                total_mem = 1 + (((unsigned long long)max_end << 24ULL) |
                            0xFFFFFFULL) - pinfo->mem_base;
        }

        return total_mem;
}

phys_size_t __fsl_ddr_sdram(fsl_ddr_info_t *pinfo)
{
        unsigned int i, first_ctrl, last_ctrl;
#ifdef CONFIG_PPC
        unsigned int law_memctl = LAW_TRGT_IF_DDR_1;
#endif
        unsigned long long total_memory;
        int deassert_reset = 0;

        first_ctrl = pinfo->first_ctrl;
        last_ctrl = first_ctrl + pinfo->num_ctrls - 1;

        /* Compute it once normally. */
#ifdef CONFIG_FSL_DDR_INTERACTIVE
        if (tstc() && (getchar() == 'd')) {     /* we got a key press of 'd' */
                total_memory = fsl_ddr_interactive(pinfo, 0);
        } else if (fsl_ddr_interactive_env_var_exists()) {
                total_memory = fsl_ddr_interactive(pinfo, 1);
        } else
#endif
                total_memory = fsl_ddr_compute(pinfo, STEP_GET_SPD, 0);

        /* setup 3-way interleaving before enabling DDRC */
        switch (pinfo->memctl_opts[first_ctrl].memctl_interleaving_mode) {
        case FSL_DDR_3WAY_1KB_INTERLEAVING:
        case FSL_DDR_3WAY_4KB_INTERLEAVING:
        case FSL_DDR_3WAY_8KB_INTERLEAVING:
                fsl_ddr_set_intl3r(
                        pinfo->memctl_opts[first_ctrl].
                        memctl_interleaving_mode);
                break;
        default:
                break;
        }

        /*
         * Program configuration registers.
         * JEDEC specs requires clocks to be stable before deasserting reset
         * for RDIMMs. Clocks start after chip select is enabled and clock
         * control register is set. During step 1, all controllers have their
         * registers set but not enabled. Step 2 proceeds after deasserting
         * reset through board FPGA or GPIO.
         * For non-registered DIMMs, initialization can go through but it is
         * also OK to follow the same flow.
         */
        if (pinfo->board_need_mem_reset)
                deassert_reset = pinfo->board_need_mem_reset();
        for (i = first_ctrl; i <= last_ctrl; i++) {
                if (pinfo->common_timing_params[i].all_dimms_registered)
                        deassert_reset = 1;
        }
        for (i = first_ctrl; i <= last_ctrl; i++) {
                debug("Programming controller %u\n", i);
                if (pinfo->common_timing_params[i].ndimms_present == 0) {
                        debug("No dimms present on controller %u; "
                                        "skipping programming\n", i);
                        continue;
                }
                /*
                 * The following call with step = 1 returns before enabling
                 * the controller. It has to finish with step = 2 later.
                 */
                fsl_ddr_set_memctl_regs(&(pinfo->fsl_ddr_config_reg[i]), i,
                                        deassert_reset ? 1 : 0);
        }
        if (deassert_reset) {
                /* Use board FPGA or GPIO to deassert reset signal */
                if (pinfo->board_mem_de_reset) {
                        debug("Deasserting mem reset\n");
                        pinfo->board_mem_de_reset();
                } else {
                        debug("Deasserting mem reset missing\n");
                }
                for (i = first_ctrl; i <= last_ctrl; i++) {
                        /* Call with step = 2 to continue initialization */
                        fsl_ddr_set_memctl_regs(&(pinfo->fsl_ddr_config_reg[i]),
                                                i, 2);
                }
        }

#ifdef CONFIG_FSL_DDR_SYNC_REFRESH
        fsl_ddr_sync_memctl_refresh(first_ctrl, last_ctrl);
#endif

#ifdef CONFIG_PPC
        /* program LAWs */
        for (i = first_ctrl; i <= last_ctrl; i++) {
                if (pinfo->memctl_opts[i].memctl_interleaving) {
                        switch (pinfo->memctl_opts[i].
                                memctl_interleaving_mode) {
                        case FSL_DDR_CACHE_LINE_INTERLEAVING:
                        case FSL_DDR_PAGE_INTERLEAVING:
                        case FSL_DDR_BANK_INTERLEAVING:
                        case FSL_DDR_SUPERBANK_INTERLEAVING:
                                if (i % 2)
                                        break;
                                if (i == 0) {
                                        law_memctl = LAW_TRGT_IF_DDR_INTRLV;
                                        fsl_ddr_set_lawbar(
                                                &pinfo->common_timing_params[i],
                                                law_memctl, i);
                                }
#if CONFIG_SYS_NUM_DDR_CTLRS > 3
                                else if (i == 2) {
                                        law_memctl = LAW_TRGT_IF_DDR_INTLV_34;
                                        fsl_ddr_set_lawbar(
                                                &pinfo->common_timing_params[i],
                                                law_memctl, i);
                                }
#endif
                                break;
                        case FSL_DDR_3WAY_1KB_INTERLEAVING:
                        case FSL_DDR_3WAY_4KB_INTERLEAVING:
                        case FSL_DDR_3WAY_8KB_INTERLEAVING:
                                law_memctl = LAW_TRGT_IF_DDR_INTLV_123;
                                if (i == 0) {
                                        fsl_ddr_set_lawbar(
                                                &pinfo->common_timing_params[i],
                                                law_memctl, i);
                                }
                                break;
                        case FSL_DDR_4WAY_1KB_INTERLEAVING:
                        case FSL_DDR_4WAY_4KB_INTERLEAVING:
                        case FSL_DDR_4WAY_8KB_INTERLEAVING:
                                law_memctl = LAW_TRGT_IF_DDR_INTLV_1234;
                                if (i == 0)
                                        fsl_ddr_set_lawbar(
                                                &pinfo->common_timing_params[i],
                                                law_memctl, i);
                                /* place holder for future 4-way interleaving */
                                break;
                        default:
                                break;
                        }
                } else {
                        switch (i) {
                        case 0:
                                law_memctl = LAW_TRGT_IF_DDR_1;
                                break;
                        case 1:
                                law_memctl = LAW_TRGT_IF_DDR_2;
                                break;
                        case 2:
                                law_memctl = LAW_TRGT_IF_DDR_3;
                                break;
                        case 3:
                                law_memctl = LAW_TRGT_IF_DDR_4;
                                break;
                        default:
                                break;
                        }
                        fsl_ddr_set_lawbar(&pinfo->common_timing_params[i],
                                           law_memctl, i);
                }
        }
#endif

        debug("total_memory by %s = %llu\n", __func__, total_memory);

#if !defined(CONFIG_PHYS_64BIT)
        /*
         * Show warning about big DDR moodules. But avoid warning for 4 GB DDR
         * modules when U-Boot supports RAM of maximal size 4 GB - 1 byte.
         */
        if ((first_ctrl == 0) && (total_memory - 1 > (phys_size_t)~0ULL)) {
                puts("Detected ");
                print_size(total_memory, " of memory\n");
#ifndef CONFIG_SPL_BUILD
                puts("       "); /* re-align to match init_dram print */
#endif
                puts("This U-Boot only supports <= ");
                print_size((unsigned long long)((phys_size_t)~0ULL)+1, " of DDR\n");
#ifndef CONFIG_SPL_BUILD
                puts("       "); /* re-align to match init_dram print */
#endif
                puts("You could rebuild it with CONFIG_PHYS_64BIT\n");
#ifndef CONFIG_SPL_BUILD
                puts("       "); /* re-align to match init_dram print */
#endif
        }
#endif

        /* Ensure that total_memory does not overflow on return */
        if (total_memory > (phys_size_t)~0ULL)
                total_memory = (phys_size_t)~0ULL;

        return total_memory;
}

/*
 * fsl_ddr_sdram(void) -- this is the main function to be
 * called by dram_init() in the board file.
 *
 * It returns amount of memory configured in bytes.
 */
phys_size_t fsl_ddr_sdram(void)
{
        fsl_ddr_info_t info;

        /* Reset info structure. */
        memset(&info, 0, sizeof(fsl_ddr_info_t));
        info.mem_base = CFG_SYS_FSL_DDR_SDRAM_BASE_PHY;
        info.first_ctrl = 0;
        info.num_ctrls = CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS;
        info.dimm_slots_per_ctrl = CONFIG_DIMM_SLOTS_PER_CTLR;
        info.board_need_mem_reset = board_need_mem_reset;
        info.board_mem_reset = board_assert_mem_reset;
        info.board_mem_de_reset = board_deassert_mem_reset;
        remove_unused_controllers(&info);

        return __fsl_ddr_sdram(&info);
}

#ifdef CONFIG_SYS_FSL_OTHER_DDR_NUM_CTRLS
phys_size_t fsl_other_ddr_sdram(unsigned long long base,
                                unsigned int first_ctrl,
                                unsigned int num_ctrls,
                                unsigned int dimm_slots_per_ctrl,
                                int (*board_need_reset)(void),
                                void (*board_reset)(void),
                                void (*board_de_reset)(void))
{
        fsl_ddr_info_t info;

        /* Reset info structure. */
        memset(&info, 0, sizeof(fsl_ddr_info_t));
        info.mem_base = base;
        info.first_ctrl = first_ctrl;
        info.num_ctrls = num_ctrls;
        info.dimm_slots_per_ctrl = dimm_slots_per_ctrl;
        info.board_need_mem_reset = board_need_reset;
        info.board_mem_reset = board_reset;
        info.board_mem_de_reset = board_de_reset;

        return __fsl_ddr_sdram(&info);
}
#endif

/*
 * fsl_ddr_sdram_size(first_ctrl, last_intlv) - This function only returns the
 * size of the total memory without setting ddr control registers.
 */
phys_size_t
fsl_ddr_sdram_size(void)
{
        fsl_ddr_info_t  info;
        unsigned long long total_memory = 0;

        memset(&info, 0 , sizeof(fsl_ddr_info_t));
        info.mem_base = CFG_SYS_FSL_DDR_SDRAM_BASE_PHY;
        info.first_ctrl = 0;
        info.num_ctrls = CONFIG_SYS_FSL_DDR_MAIN_NUM_CTRLS;
        info.dimm_slots_per_ctrl = CONFIG_DIMM_SLOTS_PER_CTLR;
        info.board_need_mem_reset = NULL;
        remove_unused_controllers(&info);

        /* Compute it once normally. */
        total_memory = fsl_ddr_compute(&info, STEP_GET_SPD, 1);

        /* Ensure that total_memory does not overflow on return */
        if (total_memory > (phys_size_t)~0ULL)
                total_memory = (phys_size_t)~0ULL;

        return total_memory;
}