/*
 * 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.
 */

/*
 * 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 <asm/fsl_ddr_sdram.h>

#include "ddr.h"

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

/* processor specific function */
extern void fsl_ddr_set_memctl_regs(const fsl_ddr_cfg_regs_t *regs,
                                   unsigned int ctrl_num);

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

/*
 * 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
 */

#ifdef DEBUG
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 ((1 << s) != step)
                return step_string_tbl[7];

        return step_string_tbl[s];
}
#endif

int step_assign_addresses(fsl_ddr_info_t *pinfo,
                          unsigned int dbw_cap_adj[],
                          unsigned int *memctl_interleaving,
                          unsigned int *rank_interleaving)
{
        int i, j;

        /*
         * 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 = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                unsigned int found = 0;

                switch (pinfo->memctl_opts[i].data_bus_width) {
                case 2:
                        /* 16-bit */
                        printf("can't handle 16-bit mode yet\n");
                        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;
                }
        }

        /*
         * Check if all controllers are configured for memory
         * controller interleaving.
         */
        j = 0;
        for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                if (pinfo->memctl_opts[i].memctl_interleaving) {
                        j++;
                }
        }
        if (j == 2)
                *memctl_interleaving = 1;

        /* Check that all controllers are rank interleaving. */
        j = 0;
        for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                if (pinfo->memctl_opts[i].ba_intlv_ctl) {
                        j++;
                }
        }
        if (j == 2)
                *rank_interleaving = 1;

        if (*memctl_interleaving) {
                unsigned long long addr, total_mem_per_ctlr = 0;
                /*
                 * If interleaving between memory controllers,
                 * make each controller start at a base address
                 * of 0.
                 *
                 * Also, if bank interleaving (chip select
                 * interleaving) is enabled on each memory
                 * controller, CS0 needs to be programmed to
                 * cover the entire memory range on that memory
                 * controller
                 *
                 * Bank interleaving also implies that each
                 * addressed chip select is identical in size.
                 */

                for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                        addr = 0;
                        pinfo->common_timing_params[i].base_address = 0ull;
                        for (j = 0; j < CONFIG_DIMM_SLOTS_PER_CTLR; j++) {
                                unsigned long long cap
                                        = pinfo->dimm_params[i][j].capacity;

                                pinfo->dimm_params[i][j].base_address = addr;
                                addr += cap >> dbw_cap_adj[i];
                                total_mem_per_ctlr += cap >> dbw_cap_adj[i];
                        }
                }
                pinfo->common_timing_params[0].total_mem = total_mem_per_ctlr;
        } else {
                /*
                 * Simple linear assignment if memory
                 * controllers are not interleaved.
                 */
                unsigned long long cur_memsize = 0;
                for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                        u64 total_mem_per_ctlr = 0;
                        pinfo->common_timing_params[i].base_address =
                                                cur_memsize;
                        for (j = 0; j < CONFIG_DIMM_SLOTS_PER_CTLR; j++) {
                                /* Compute DIMM base addresses. */
                                unsigned long long cap =
                                        pinfo->dimm_params[i][j].capacity;
                                pinfo->dimm_params[i][j].base_address =
                                        cur_memsize;
                                cur_memsize += cap >> dbw_cap_adj[i];
                                total_mem_per_ctlr += cap >> dbw_cap_adj[i];
                        }
                        pinfo->common_timing_params[i].total_mem =
                                                        total_mem_per_ctlr;
                }
        }

        return 0;
}

unsigned long long
fsl_ddr_compute(fsl_ddr_info_t *pinfo, unsigned int start_step)
{
        unsigned int i, j;
        unsigned int all_controllers_memctl_interleaving = 0;
        unsigned int all_controllers_rank_interleaving = 0;
        unsigned long long total_mem = 0;

        fsl_ddr_cfg_regs_t *ddr_reg = pinfo->fsl_ddr_config_reg;
        common_timing_params_t *timing_params = pinfo->common_timing_params;

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

        for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; 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:
                /* STEP 1:  Gather all DIMM SPD data */
                for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                        fsl_ddr_get_spd(pinfo->spd_installed_dimms[i], i);
                }

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

                for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                        for (j = 0; j < CONFIG_DIMM_SLOTS_PER_CTLR; j++) {
                                unsigned int retval;
                                generic_spd_eeprom_t *spd =
                                        &(pinfo->spd_installed_dimms[i][j]);
                                dimm_params_t *pdimm =
                                        &(pinfo->dimm_params[i][j]);

                                retval = compute_dimm_parameters(spd, pdimm, i);
                                if (retval == 2) {
                                        printf("Error: compute_dimm_parameters"
                                        " non-zero returned FATAL value "
                                        "for memctl=%u dimm=%u\n", i, j);
                                        return 0;
                                }
                                if (retval) {
                                        debug("Warning: compute_dimm_parameters"
                                        " non-zero return value for memctl=%u "
                                        "dimm=%u\n", i, j);
                                }
                        }
                }

        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 = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                        debug("Computing lowest common DIMM"
                                " parameters for memctl=%u\n", i);
                        compute_lowest_common_dimm_parameters(
                                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 = 0; i < CONFIG_NUM_DDR_CONTROLLERS; 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].all_DIMMs_registered,
                                        &pinfo->memctl_opts[i],
                                        pinfo->dimm_params[i], i);
                }

        case STEP_ASSIGN_ADDRESSES:
                /* STEP 5:  Assign addresses to chip selects */
                step_assign_addresses(pinfo,
                                dbw_capacity_adjust,
                                &all_controllers_memctl_interleaving,
                                &all_controllers_rank_interleaving);

        case STEP_COMPUTE_REGS:
                /* STEP 6:  compute controller register values */
                debug("FSL Memory ctrl cg register computation\n");
                for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; 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(
                                        &pinfo->memctl_opts[i],
                                        &ddr_reg[i], &timing_params[i],
                                        pinfo->dimm_params[i],
                                        dbw_capacity_adjust[i]);
                }

        default:
                break;
        }

        /* Compute the total amount of memory. */

        /*
         * If bank interleaving but NOT memory controller interleaving
         * CS_BNDS describe the quantity of memory on each memory
         * controller, so the total is the sum across.
         */
        if (!all_controllers_memctl_interleaving
            && all_controllers_rank_interleaving) {
                total_mem = 0;
                for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                        total_mem += timing_params[i].total_mem;
                }

        } else {
                /*
                 * 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 = 0; i < CONFIG_NUM_DDR_CONTROLLERS; 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;
                                        end = reg->cs[j].bnds & 0xFFF;
                                        if (end > max_end) {
                                                max_end = end;
                                        }
                                }
                        }
                }

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

        return total_mem;
}

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

        /* Reset info structure. */
        memset(&info, 0, sizeof(fsl_ddr_info_t));

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

        /* Check for memory controller interleaving. */
        memctl_interleaved = 0;
        for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                memctl_interleaved +=
                        info.memctl_opts[i].memctl_interleaving;
        }

        if (memctl_interleaved) {
                if (memctl_interleaved == CONFIG_NUM_DDR_CONTROLLERS) {
                        debug("memctl interleaving\n");
                        /*
                         * Change the meaning of memctl_interleaved
                         * to be "boolean".
                         */
                        memctl_interleaved = 1;
                } else {
                        printf("Warning: memctl interleaving not "
                                "properly configured on all controllers\n");
                        memctl_interleaved = 0;
                        for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++)
                                info.memctl_opts[i].memctl_interleaving = 0;
                        debug("Recomputing with memctl_interleaving off.\n");
                        total_memory = fsl_ddr_compute(&info,
                                                       STEP_ASSIGN_ADDRESSES);
                }
        }

        /* Program configuration registers. */
        for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                debug("Programming controller %u\n", i);
                if (info.common_timing_params[i].ndimms_present == 0) {
                        debug("No dimms present on controller %u; "
                                        "skipping programming\n", i);
                        continue;
                }

                fsl_ddr_set_memctl_regs(&(info.fsl_ddr_config_reg[i]), i);
        }

        if (memctl_interleaved) {
                const unsigned int ctrl_num = 0;

                /* Only set LAWBAR1 if memory controller interleaving is on. */
                fsl_ddr_set_lawbar(&info.common_timing_params[0],
                                         memctl_interleaved, ctrl_num);
        } else {
                /*
                 * Memory controller interleaving is NOT on;
                 * set each lawbar individually.
                 */
                for (i = 0; i < CONFIG_NUM_DDR_CONTROLLERS; i++) {
                        fsl_ddr_set_lawbar(&info.common_timing_params[i],
                                                 0, i);
                }
        }

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

#if !defined(CONFIG_PHYS_64BIT)
        /* Check for 4G or more.  Bad. */
        if (total_memory >= (1ull << 32)) {
                printf("Detected %lld MB of memory\n", total_memory >> 20);
                printf("This U-Boot only supports < 4G of DDR\n");
                printf("You could rebuild it with CONFIG_PHYS_64BIT\n");
                total_memory = CONFIG_MAX_MEM_MAPPED;
        }
#endif

        return total_memory;
}