ddr: altera: Clean up of delay_for_n_mem_clocks() part 4

[karo-tx-uboot.git] / drivers / ddr / altera / sequencer.c

/*
 * Copyright Altera Corporation (C) 2012-2015
 *
 * SPDX-License-Identifier:    BSD-3-Clause
 */

#include <common.h>
#include <asm/io.h>
#include <asm/arch/sdram.h>
#include <errno.h>
#include "sequencer.h"
#include "sequencer_auto.h"
#include "sequencer_auto_ac_init.h"
#include "sequencer_auto_inst_init.h"
#include "sequencer_defines.h"

static struct socfpga_sdr_rw_load_manager *sdr_rw_load_mgr_regs =
        (struct socfpga_sdr_rw_load_manager *)(SDR_PHYGRP_RWMGRGRP_ADDRESS | 0x800);

static struct socfpga_sdr_rw_load_jump_manager *sdr_rw_load_jump_mgr_regs =
        (struct socfpga_sdr_rw_load_jump_manager *)(SDR_PHYGRP_RWMGRGRP_ADDRESS | 0xC00);

static struct socfpga_sdr_reg_file *sdr_reg_file =
        (struct socfpga_sdr_reg_file *)SDR_PHYGRP_REGFILEGRP_ADDRESS;

static struct socfpga_sdr_scc_mgr *sdr_scc_mgr =
        (struct socfpga_sdr_scc_mgr *)(SDR_PHYGRP_SCCGRP_ADDRESS | 0xe00);

static struct socfpga_phy_mgr_cmd *phy_mgr_cmd =
        (struct socfpga_phy_mgr_cmd *)SDR_PHYGRP_PHYMGRGRP_ADDRESS;

static struct socfpga_phy_mgr_cfg *phy_mgr_cfg =
        (struct socfpga_phy_mgr_cfg *)(SDR_PHYGRP_PHYMGRGRP_ADDRESS | 0x40);

static struct socfpga_data_mgr *data_mgr =
        (struct socfpga_data_mgr *)SDR_PHYGRP_DATAMGRGRP_ADDRESS;

static struct socfpga_sdr_ctrl *sdr_ctrl =
        (struct socfpga_sdr_ctrl *)SDR_CTRLGRP_ADDRESS;

#define DELTA_D         1

/*
 * In order to reduce ROM size, most of the selectable calibration steps are
 * decided at compile time based on the user's calibration mode selection,
 * as captured by the STATIC_CALIB_STEPS selection below.
 *
 * However, to support simulation-time selection of fast simulation mode, where
 * we skip everything except the bare minimum, we need a few of the steps to
 * be dynamic.  In those cases, we either use the DYNAMIC_CALIB_STEPS for the
 * check, which is based on the rtl-supplied value, or we dynamically compute
 * the value to use based on the dynamically-chosen calibration mode
 */

#define DLEVEL 0
#define STATIC_IN_RTL_SIM 0
#define STATIC_SKIP_DELAY_LOOPS 0

#define STATIC_CALIB_STEPS (STATIC_IN_RTL_SIM | CALIB_SKIP_FULL_TEST | \
        STATIC_SKIP_DELAY_LOOPS)

/* calibration steps requested by the rtl */
uint16_t dyn_calib_steps;

/*
 * To make CALIB_SKIP_DELAY_LOOPS a dynamic conditional option
 * instead of static, we use boolean logic to select between
 * non-skip and skip values
 *
 * The mask is set to include all bits when not-skipping, but is
 * zero when skipping
 */

uint16_t skip_delay_mask;       /* mask off bits when skipping/not-skipping */

#define SKIP_DELAY_LOOP_VALUE_OR_ZERO(non_skip_value) \
        ((non_skip_value) & skip_delay_mask)

struct gbl_type *gbl;
struct param_type *param;
uint32_t curr_shadow_reg;

static void set_failing_group_stage(uint32_t group, uint32_t stage,
        uint32_t substage)
{
        /*
         * Only set the global stage if there was not been any other
         * failing group
         */
        if (gbl->error_stage == CAL_STAGE_NIL)  {
                gbl->error_substage = substage;
                gbl->error_stage = stage;
                gbl->error_group = group;
        }
}

static void reg_file_set_group(u16 set_group)
{
        clrsetbits_le32(&sdr_reg_file->cur_stage, 0xffff0000, set_group << 16);
}

static void reg_file_set_stage(u8 set_stage)
{
        clrsetbits_le32(&sdr_reg_file->cur_stage, 0xffff, set_stage & 0xff);
}

static void reg_file_set_sub_stage(u8 set_sub_stage)
{
        set_sub_stage &= 0xff;
        clrsetbits_le32(&sdr_reg_file->cur_stage, 0xff00, set_sub_stage << 8);
}

/**
 * phy_mgr_initialize() - Initialize PHY Manager
 *
 * Initialize PHY Manager.
 */
static void phy_mgr_initialize(void)
{
        u32 ratio;

        debug("%s:%d\n", __func__, __LINE__);
        /* Calibration has control over path to memory */
        /*
         * In Hard PHY this is a 2-bit control:
         * 0: AFI Mux Select
         * 1: DDIO Mux Select
         */
        writel(0x3, &phy_mgr_cfg->mux_sel);

        /* USER memory clock is not stable we begin initialization  */
        writel(0, &phy_mgr_cfg->reset_mem_stbl);

        /* USER calibration status all set to zero */
        writel(0, &phy_mgr_cfg->cal_status);

        writel(0, &phy_mgr_cfg->cal_debug_info);

        /* Init params only if we do NOT skip calibration. */
        if ((dyn_calib_steps & CALIB_SKIP_ALL) == CALIB_SKIP_ALL)
                return;

        ratio = RW_MGR_MEM_DQ_PER_READ_DQS /
                RW_MGR_MEM_VIRTUAL_GROUPS_PER_READ_DQS;
        param->read_correct_mask_vg = (1 << ratio) - 1;
        param->write_correct_mask_vg = (1 << ratio) - 1;
        param->read_correct_mask = (1 << RW_MGR_MEM_DQ_PER_READ_DQS) - 1;
        param->write_correct_mask = (1 << RW_MGR_MEM_DQ_PER_WRITE_DQS) - 1;
        ratio = RW_MGR_MEM_DATA_WIDTH /
                RW_MGR_MEM_DATA_MASK_WIDTH;
        param->dm_correct_mask = (1 << ratio) - 1;
}

/**
 * set_rank_and_odt_mask() - Set Rank and ODT mask
 * @rank:       Rank mask
 * @odt_mode:   ODT mode, OFF or READ_WRITE
 *
 * Set Rank and ODT mask (On-Die Termination).
 */
static void set_rank_and_odt_mask(const u32 rank, const u32 odt_mode)
{
        u32 odt_mask_0 = 0;
        u32 odt_mask_1 = 0;
        u32 cs_and_odt_mask;

        if (odt_mode == RW_MGR_ODT_MODE_OFF) {
                odt_mask_0 = 0x0;
                odt_mask_1 = 0x0;
        } else {        /* RW_MGR_ODT_MODE_READ_WRITE */
                switch (RW_MGR_MEM_NUMBER_OF_RANKS) {
                case 1: /* 1 Rank */
                        /* Read: ODT = 0 ; Write: ODT = 1 */
                        odt_mask_0 = 0x0;
                        odt_mask_1 = 0x1;
                        break;
                case 2: /* 2 Ranks */
                        if (RW_MGR_MEM_NUMBER_OF_CS_PER_DIMM == 1) {
                                /*
                                 * - Dual-Slot , Single-Rank (1 CS per DIMM)
                                 *   OR
                                 * - RDIMM, 4 total CS (2 CS per DIMM, 2 DIMM)
                                 *
                                 * Since MEM_NUMBER_OF_RANKS is 2, they
                                 * are both single rank with 2 CS each
                                 * (special for RDIMM).
                                 *
                                 * Read: Turn on ODT on the opposite rank
                                 * Write: Turn on ODT on all ranks
                                 */
                                odt_mask_0 = 0x3 & ~(1 << rank);
                                odt_mask_1 = 0x3;
                        } else {
                                /*
                                 * - Single-Slot , Dual-Rank (2 CS per DIMM)
                                 *
                                 * Read: Turn on ODT off on all ranks
                                 * Write: Turn on ODT on active rank
                                 */
                                odt_mask_0 = 0x0;
                                odt_mask_1 = 0x3 & (1 << rank);
                        }
                        break;
                case 4: /* 4 Ranks */
                        /* Read:
                         * ----------+-----------------------+
                         *           |         ODT           |
                         * Read From +-----------------------+
                         *   Rank    |  3  |  2  |  1  |  0  |
                         * ----------+-----+-----+-----+-----+
                         *     0     |  0  |  1  |  0  |  0  |
                         *     1     |  1  |  0  |  0  |  0  |
                         *     2     |  0  |  0  |  0  |  1  |
                         *     3     |  0  |  0  |  1  |  0  |
                         * ----------+-----+-----+-----+-----+
                         *
                         * Write:
                         * ----------+-----------------------+
                         *           |         ODT           |
                         * Write To  +-----------------------+
                         *   Rank    |  3  |  2  |  1  |  0  |
                         * ----------+-----+-----+-----+-----+
                         *     0     |  0  |  1  |  0  |  1  |
                         *     1     |  1  |  0  |  1  |  0  |
                         *     2     |  0  |  1  |  0  |  1  |
                         *     3     |  1  |  0  |  1  |  0  |
                         * ----------+-----+-----+-----+-----+
                         */
                        switch (rank) {
                        case 0:
                                odt_mask_0 = 0x4;
                                odt_mask_1 = 0x5;
                                break;
                        case 1:
                                odt_mask_0 = 0x8;
                                odt_mask_1 = 0xA;
                                break;
                        case 2:
                                odt_mask_0 = 0x1;
                                odt_mask_1 = 0x5;
                                break;
                        case 3:
                                odt_mask_0 = 0x2;
                                odt_mask_1 = 0xA;
                                break;
                        }
                        break;
                }
        }

        cs_and_odt_mask = (0xFF & ~(1 << rank)) |
                          ((0xFF & odt_mask_0) << 8) |
                          ((0xFF & odt_mask_1) << 16);
        writel(cs_and_odt_mask, SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                RW_MGR_SET_CS_AND_ODT_MASK_OFFSET);
}

/**
 * scc_mgr_set() - Set SCC Manager register
 * @off:        Base offset in SCC Manager space
 * @grp:        Read/Write group
 * @val:        Value to be set
 *
 * This function sets the SCC Manager (Scan Chain Control Manager) register.
 */
static void scc_mgr_set(u32 off, u32 grp, u32 val)
{
        writel(val, SDR_PHYGRP_SCCGRP_ADDRESS | off | (grp << 2));
}

/**
 * scc_mgr_initialize() - Initialize SCC Manager registers
 *
 * Initialize SCC Manager registers.
 */
static void scc_mgr_initialize(void)
{
        /*
         * Clear register file for HPS. 16 (2^4) is the size of the
         * full register file in the scc mgr:
         *      RFILE_DEPTH = 1 + log2(MEM_DQ_PER_DQS + 1 + MEM_DM_PER_DQS +
         *                             MEM_IF_READ_DQS_WIDTH - 1);
         */
        int i;

        for (i = 0; i < 16; i++) {
                debug_cond(DLEVEL == 1, "%s:%d: Clearing SCC RFILE index %u\n",
                           __func__, __LINE__, i);
                scc_mgr_set(SCC_MGR_HHP_RFILE_OFFSET, 0, i);
        }
}

static void scc_mgr_set_dqdqs_output_phase(uint32_t write_group, uint32_t phase)
{
        scc_mgr_set(SCC_MGR_DQDQS_OUT_PHASE_OFFSET, write_group, phase);
}

static void scc_mgr_set_dqs_bus_in_delay(uint32_t read_group, uint32_t delay)
{
        scc_mgr_set(SCC_MGR_DQS_IN_DELAY_OFFSET, read_group, delay);
}

static void scc_mgr_set_dqs_en_phase(uint32_t read_group, uint32_t phase)
{
        scc_mgr_set(SCC_MGR_DQS_EN_PHASE_OFFSET, read_group, phase);
}

static void scc_mgr_set_dqs_en_delay(uint32_t read_group, uint32_t delay)
{
        scc_mgr_set(SCC_MGR_DQS_EN_DELAY_OFFSET, read_group, delay);
}

static void scc_mgr_set_dqs_io_in_delay(uint32_t delay)
{
        scc_mgr_set(SCC_MGR_IO_IN_DELAY_OFFSET, RW_MGR_MEM_DQ_PER_WRITE_DQS,
                    delay);
}

static void scc_mgr_set_dq_in_delay(uint32_t dq_in_group, uint32_t delay)
{
        scc_mgr_set(SCC_MGR_IO_IN_DELAY_OFFSET, dq_in_group, delay);
}

static void scc_mgr_set_dq_out1_delay(uint32_t dq_in_group, uint32_t delay)
{
        scc_mgr_set(SCC_MGR_IO_OUT1_DELAY_OFFSET, dq_in_group, delay);
}

static void scc_mgr_set_dqs_out1_delay(uint32_t delay)
{
        scc_mgr_set(SCC_MGR_IO_OUT1_DELAY_OFFSET, RW_MGR_MEM_DQ_PER_WRITE_DQS,
                    delay);
}

static void scc_mgr_set_dm_out1_delay(uint32_t dm, uint32_t delay)
{
        scc_mgr_set(SCC_MGR_IO_OUT1_DELAY_OFFSET,
                    RW_MGR_MEM_DQ_PER_WRITE_DQS + 1 + dm,
                    delay);
}

/* load up dqs config settings */
static void scc_mgr_load_dqs(uint32_t dqs)
{
        writel(dqs, &sdr_scc_mgr->dqs_ena);
}

/* load up dqs io config settings */
static void scc_mgr_load_dqs_io(void)
{
        writel(0, &sdr_scc_mgr->dqs_io_ena);
}

/* load up dq config settings */
static void scc_mgr_load_dq(uint32_t dq_in_group)
{
        writel(dq_in_group, &sdr_scc_mgr->dq_ena);
}

/* load up dm config settings */
static void scc_mgr_load_dm(uint32_t dm)
{
        writel(dm, &sdr_scc_mgr->dm_ena);
}

/**
 * scc_mgr_set_all_ranks() - Set SCC Manager register for all ranks
 * @off:        Base offset in SCC Manager space
 * @grp:        Read/Write group
 * @val:        Value to be set
 * @update:     If non-zero, trigger SCC Manager update for all ranks
 *
 * This function sets the SCC Manager (Scan Chain Control Manager) register
 * and optionally triggers the SCC update for all ranks.
 */
static void scc_mgr_set_all_ranks(const u32 off, const u32 grp, const u32 val,
                                  const int update)
{
        u32 r;

        for (r = 0; r < RW_MGR_MEM_NUMBER_OF_RANKS;
             r += NUM_RANKS_PER_SHADOW_REG) {
                scc_mgr_set(off, grp, val);

                if (update || (r == 0)) {
                        writel(grp, &sdr_scc_mgr->dqs_ena);
                        writel(0, &sdr_scc_mgr->update);
                }
        }
}

static void scc_mgr_set_dqs_en_phase_all_ranks(u32 read_group, u32 phase)
{
        /*
         * USER although the h/w doesn't support different phases per
         * shadow register, for simplicity our scc manager modeling
         * keeps different phase settings per shadow reg, and it's
         * important for us to keep them in sync to match h/w.
         * for efficiency, the scan chain update should occur only
         * once to sr0.
         */
        scc_mgr_set_all_ranks(SCC_MGR_DQS_EN_PHASE_OFFSET,
                              read_group, phase, 0);
}

static void scc_mgr_set_dqdqs_output_phase_all_ranks(uint32_t write_group,
                                                     uint32_t phase)
{
        /*
         * USER although the h/w doesn't support different phases per
         * shadow register, for simplicity our scc manager modeling
         * keeps different phase settings per shadow reg, and it's
         * important for us to keep them in sync to match h/w.
         * for efficiency, the scan chain update should occur only
         * once to sr0.
         */
        scc_mgr_set_all_ranks(SCC_MGR_DQDQS_OUT_PHASE_OFFSET,
                              write_group, phase, 0);
}

static void scc_mgr_set_dqs_en_delay_all_ranks(uint32_t read_group,
                                               uint32_t delay)
{
        /*
         * In shadow register mode, the T11 settings are stored in
         * registers in the core, which are updated by the DQS_ENA
         * signals. Not issuing the SCC_MGR_UPD command allows us to
         * save lots of rank switching overhead, by calling
         * select_shadow_regs_for_update with update_scan_chains
         * set to 0.
         */
        scc_mgr_set_all_ranks(SCC_MGR_DQS_EN_DELAY_OFFSET,
                              read_group, delay, 1);
        writel(0, &sdr_scc_mgr->update);
}

/**
 * scc_mgr_set_oct_out1_delay() - Set OCT output delay
 * @write_group:        Write group
 * @delay:              Delay value
 *
 * This function sets the OCT output delay in SCC manager.
 */
static void scc_mgr_set_oct_out1_delay(const u32 write_group, const u32 delay)
{
        const int ratio = RW_MGR_MEM_IF_READ_DQS_WIDTH /
                          RW_MGR_MEM_IF_WRITE_DQS_WIDTH;
        const int base = write_group * ratio;
        int i;
        /*
         * Load the setting in the SCC manager
         * Although OCT affects only write data, the OCT delay is controlled
         * by the DQS logic block which is instantiated once per read group.
         * For protocols where a write group consists of multiple read groups,
         * the setting must be set multiple times.
         */
        for (i = 0; i < ratio; i++)
                scc_mgr_set(SCC_MGR_OCT_OUT1_DELAY_OFFSET, base + i, delay);
}

/**
 * scc_mgr_set_hhp_extras() - Set HHP extras.
 *
 * Load the fixed setting in the SCC manager HHP extras.
 */
static void scc_mgr_set_hhp_extras(void)
{
        /*
         * Load the fixed setting in the SCC manager
         * bits: 0:0 = 1'b1     - DQS bypass
         * bits: 1:1 = 1'b1     - DQ bypass
         * bits: 4:2 = 3'b001   - rfifo_mode
         * bits: 6:5 = 2'b01    - rfifo clock_select
         * bits: 7:7 = 1'b0     - separate gating from ungating setting
         * bits: 8:8 = 1'b0     - separate OE from Output delay setting
         */
        const u32 value = (0 << 8) | (0 << 7) | (1 << 5) |
                          (1 << 2) | (1 << 1) | (1 << 0);
        const u32 addr = SDR_PHYGRP_SCCGRP_ADDRESS |
                         SCC_MGR_HHP_GLOBALS_OFFSET |
                         SCC_MGR_HHP_EXTRAS_OFFSET;

        debug_cond(DLEVEL == 1, "%s:%d Setting HHP Extras\n",
                   __func__, __LINE__);
        writel(value, addr);
        debug_cond(DLEVEL == 1, "%s:%d Done Setting HHP Extras\n",
                   __func__, __LINE__);
}

/**
 * scc_mgr_zero_all() - Zero all DQS config
 *
 * Zero all DQS config.
 */
static void scc_mgr_zero_all(void)
{
        int i, r;

        /*
         * USER Zero all DQS config settings, across all groups and all
         * shadow registers
         */
        for (r = 0; r < RW_MGR_MEM_NUMBER_OF_RANKS;
             r += NUM_RANKS_PER_SHADOW_REG) {
                for (i = 0; i < RW_MGR_MEM_IF_READ_DQS_WIDTH; i++) {
                        /*
                         * The phases actually don't exist on a per-rank basis,
                         * but there's no harm updating them several times, so
                         * let's keep the code simple.
                         */
                        scc_mgr_set_dqs_bus_in_delay(i, IO_DQS_IN_RESERVE);
                        scc_mgr_set_dqs_en_phase(i, 0);
                        scc_mgr_set_dqs_en_delay(i, 0);
                }

                for (i = 0; i < RW_MGR_MEM_IF_WRITE_DQS_WIDTH; i++) {
                        scc_mgr_set_dqdqs_output_phase(i, 0);
                        /* Arria V/Cyclone V don't have out2. */
                        scc_mgr_set_oct_out1_delay(i, IO_DQS_OUT_RESERVE);
                }
        }

        /* Multicast to all DQS group enables. */
        writel(0xff, &sdr_scc_mgr->dqs_ena);
        writel(0, &sdr_scc_mgr->update);
}

/**
 * scc_set_bypass_mode() - Set bypass mode and trigger SCC update
 * @write_group:        Write group
 *
 * Set bypass mode and trigger SCC update.
 */
static void scc_set_bypass_mode(const u32 write_group)
{
        /* Multicast to all DQ enables. */
        writel(0xff, &sdr_scc_mgr->dq_ena);
        writel(0xff, &sdr_scc_mgr->dm_ena);

        /* Update current DQS IO enable. */
        writel(0, &sdr_scc_mgr->dqs_io_ena);

        /* Update the DQS logic. */
        writel(write_group, &sdr_scc_mgr->dqs_ena);

        /* Hit update. */
        writel(0, &sdr_scc_mgr->update);
}

/**
 * scc_mgr_load_dqs_for_write_group() - Load DQS settings for Write Group
 * @write_group:        Write group
 *
 * Load DQS settings for Write Group, do not trigger SCC update.
 */
static void scc_mgr_load_dqs_for_write_group(const u32 write_group)
{
        const int ratio = RW_MGR_MEM_IF_READ_DQS_WIDTH /
                          RW_MGR_MEM_IF_WRITE_DQS_WIDTH;
        const int base = write_group * ratio;
        int i;
        /*
         * Load the setting in the SCC manager
         * Although OCT affects only write data, the OCT delay is controlled
         * by the DQS logic block which is instantiated once per read group.
         * For protocols where a write group consists of multiple read groups,
         * the setting must be set multiple times.
         */
        for (i = 0; i < ratio; i++)
                writel(base + i, &sdr_scc_mgr->dqs_ena);
}

/**
 * scc_mgr_zero_group() - Zero all configs for a group
 *
 * Zero DQ, DM, DQS and OCT configs for a group.
 */
static void scc_mgr_zero_group(const u32 write_group, const int out_only)
{
        int i, r;

        for (r = 0; r < RW_MGR_MEM_NUMBER_OF_RANKS;
             r += NUM_RANKS_PER_SHADOW_REG) {
                /* Zero all DQ config settings. */
                for (i = 0; i < RW_MGR_MEM_DQ_PER_WRITE_DQS; i++) {
                        scc_mgr_set_dq_out1_delay(i, 0);
                        if (!out_only)
                                scc_mgr_set_dq_in_delay(i, 0);
                }

                /* Multicast to all DQ enables. */
                writel(0xff, &sdr_scc_mgr->dq_ena);

                /* Zero all DM config settings. */
                for (i = 0; i < RW_MGR_NUM_DM_PER_WRITE_GROUP; i++)
                        scc_mgr_set_dm_out1_delay(i, 0);

                /* Multicast to all DM enables. */
                writel(0xff, &sdr_scc_mgr->dm_ena);

                /* Zero all DQS IO settings. */
                if (!out_only)
                        scc_mgr_set_dqs_io_in_delay(0);

                /* Arria V/Cyclone V don't have out2. */
                scc_mgr_set_dqs_out1_delay(IO_DQS_OUT_RESERVE);
                scc_mgr_set_oct_out1_delay(write_group, IO_DQS_OUT_RESERVE);
                scc_mgr_load_dqs_for_write_group(write_group);

                /* Multicast to all DQS IO enables (only 1 in total). */
                writel(0, &sdr_scc_mgr->dqs_io_ena);

                /* Hit update to zero everything. */
                writel(0, &sdr_scc_mgr->update);
        }
}

/*
 * apply and load a particular input delay for the DQ pins in a group
 * group_bgn is the index of the first dq pin (in the write group)
 */
static void scc_mgr_apply_group_dq_in_delay(uint32_t group_bgn, uint32_t delay)
{
        uint32_t i, p;

        for (i = 0, p = group_bgn; i < RW_MGR_MEM_DQ_PER_READ_DQS; i++, p++) {
                scc_mgr_set_dq_in_delay(p, delay);
                scc_mgr_load_dq(p);
        }
}

/**
 * scc_mgr_apply_group_dq_out1_delay() - Apply and load an output delay for the DQ pins in a group
 * @delay:              Delay value
 *
 * Apply and load a particular output delay for the DQ pins in a group.
 */
static void scc_mgr_apply_group_dq_out1_delay(const u32 delay)
{
        int i;

        for (i = 0; i < RW_MGR_MEM_DQ_PER_WRITE_DQS; i++) {
                scc_mgr_set_dq_out1_delay(i, delay);
                scc_mgr_load_dq(i);
        }
}

/* apply and load a particular output delay for the DM pins in a group */
static void scc_mgr_apply_group_dm_out1_delay(uint32_t delay1)
{
        uint32_t i;

        for (i = 0; i < RW_MGR_NUM_DM_PER_WRITE_GROUP; i++) {
                scc_mgr_set_dm_out1_delay(i, delay1);
                scc_mgr_load_dm(i);
        }
}


/* apply and load delay on both DQS and OCT out1 */
static void scc_mgr_apply_group_dqs_io_and_oct_out1(uint32_t write_group,
                                                    uint32_t delay)
{
        scc_mgr_set_dqs_out1_delay(delay);
        scc_mgr_load_dqs_io();

        scc_mgr_set_oct_out1_delay(write_group, delay);
        scc_mgr_load_dqs_for_write_group(write_group);
}

/**
 * scc_mgr_apply_group_all_out_delay_add() - Apply a delay to the entire output side: DQ, DM, DQS, OCT
 * @write_group:        Write group
 * @delay:              Delay value
 *
 * Apply a delay to the entire output side: DQ, DM, DQS, OCT.
 */
static void scc_mgr_apply_group_all_out_delay_add(const u32 write_group,
                                                  const u32 delay)
{
        u32 i, new_delay;

        /* DQ shift */
        for (i = 0; i < RW_MGR_MEM_DQ_PER_WRITE_DQS; i++)
                scc_mgr_load_dq(i);

        /* DM shift */
        for (i = 0; i < RW_MGR_NUM_DM_PER_WRITE_GROUP; i++)
                scc_mgr_load_dm(i);

        /* DQS shift */
        new_delay = READ_SCC_DQS_IO_OUT2_DELAY + delay;
        if (new_delay > IO_IO_OUT2_DELAY_MAX) {
                debug_cond(DLEVEL == 1,
                           "%s:%d (%u, %u) DQS: %u > %d; adding %u to OUT1\n",
                           __func__, __LINE__, write_group, delay, new_delay,
                           IO_IO_OUT2_DELAY_MAX,
                           new_delay - IO_IO_OUT2_DELAY_MAX);
                new_delay -= IO_IO_OUT2_DELAY_MAX;
                scc_mgr_set_dqs_out1_delay(new_delay);
        }

        scc_mgr_load_dqs_io();

        /* OCT shift */
        new_delay = READ_SCC_OCT_OUT2_DELAY + delay;
        if (new_delay > IO_IO_OUT2_DELAY_MAX) {
                debug_cond(DLEVEL == 1,
                           "%s:%d (%u, %u) DQS: %u > %d; adding %u to OUT1\n",
                           __func__, __LINE__, write_group, delay,
                           new_delay, IO_IO_OUT2_DELAY_MAX,
                           new_delay - IO_IO_OUT2_DELAY_MAX);
                new_delay -= IO_IO_OUT2_DELAY_MAX;
                scc_mgr_set_oct_out1_delay(write_group, new_delay);
        }

        scc_mgr_load_dqs_for_write_group(write_group);
}

/**
 * scc_mgr_apply_group_all_out_delay_add() - Apply a delay to the entire output side to all ranks
 * @write_group:        Write group
 * @delay:              Delay value
 *
 * Apply a delay to the entire output side (DQ, DM, DQS, OCT) to all ranks.
 */
static void
scc_mgr_apply_group_all_out_delay_add_all_ranks(const u32 write_group,
                                                const u32 delay)
{
        int r;

        for (r = 0; r < RW_MGR_MEM_NUMBER_OF_RANKS;
             r += NUM_RANKS_PER_SHADOW_REG) {
                scc_mgr_apply_group_all_out_delay_add(write_group, delay);
                writel(0, &sdr_scc_mgr->update);
        }
}

/**
 * set_jump_as_return() - Return instruction optimization
 *
 * Optimization used to recover some slots in ddr3 inst_rom could be
 * applied to other protocols if we wanted to
 */
static void set_jump_as_return(void)
{
        /*
         * To save space, we replace return with jump to special shared
         * RETURN instruction so we set the counter to large value so that
         * we always jump.
         */
        writel(0xff, &sdr_rw_load_mgr_regs->load_cntr0);
        writel(RW_MGR_RETURN, &sdr_rw_load_jump_mgr_regs->load_jump_add0);
}

/*
 * should always use constants as argument to ensure all computations are
 * performed at compile time
 */
static void delay_for_n_mem_clocks(const u32 clocks)
{
        u32 afi_clocks;
        u16 c_loop;
        u8 inner;
        u8 outer;

        debug("%s:%d: clocks=%u ... start\n", __func__, __LINE__, clocks);

        /* Scale (rounding up) to get afi clocks. */
        afi_clocks = DIV_ROUND_UP(clocks, AFI_RATE_RATIO);
        if (afi_clocks) /* Temporary underflow protection */
                afi_clocks--;

        /*
         * Note, we don't bother accounting for being off a little
         * bit because of a few extra instructions in outer loops.
         * Note, the loops have a test at the end, and do the test
         * before the decrement, and so always perform the loop
         * 1 time more than the counter value
         */
        c_loop = afi_clocks >> 16;
        outer = c_loop ? 0xff : (afi_clocks >> 8);
        inner = outer ? 0xff : afi_clocks;

        /*
         * rom instructions are structured as follows:
         *
         *    IDLE_LOOP2: jnz cntr0, TARGET_A
         *    IDLE_LOOP1: jnz cntr1, TARGET_B
         *                return
         *
         * so, when doing nested loops, TARGET_A is set to IDLE_LOOP2, and
         * TARGET_B is set to IDLE_LOOP2 as well
         *
         * if we have no outer loop, though, then we can use IDLE_LOOP1 only,
         * and set TARGET_B to IDLE_LOOP1 and we skip IDLE_LOOP2 entirely
         *
         * a little confusing, but it helps save precious space in the inst_rom
         * and sequencer rom and keeps the delays more accurate and reduces
         * overhead
         */
        if (afi_clocks < 0x100) {
                writel(SKIP_DELAY_LOOP_VALUE_OR_ZERO(inner),
                        &sdr_rw_load_mgr_regs->load_cntr1);

                writel(RW_MGR_IDLE_LOOP1,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add1);

                writel(RW_MGR_IDLE_LOOP1, SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                          RW_MGR_RUN_SINGLE_GROUP_OFFSET);
        } else {
                writel(SKIP_DELAY_LOOP_VALUE_OR_ZERO(inner),
                        &sdr_rw_load_mgr_regs->load_cntr0);

                writel(SKIP_DELAY_LOOP_VALUE_OR_ZERO(outer),
                        &sdr_rw_load_mgr_regs->load_cntr1);

                writel(RW_MGR_IDLE_LOOP2,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add0);

                writel(RW_MGR_IDLE_LOOP2,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add1);

                do {
                        writel(RW_MGR_IDLE_LOOP2,
                                SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                RW_MGR_RUN_SINGLE_GROUP_OFFSET);
                } while (c_loop-- != 0);
        }
        debug("%s:%d clocks=%u ... end\n", __func__, __LINE__, clocks);
}

/**
 * rw_mgr_mem_init_load_regs() - Load instruction registers
 * @cntr0:      Counter 0 value
 * @cntr1:      Counter 1 value
 * @cntr2:      Counter 2 value
 * @jump:       Jump instruction value
 *
 * Load instruction registers.
 */
static void rw_mgr_mem_init_load_regs(u32 cntr0, u32 cntr1, u32 cntr2, u32 jump)
{
        uint32_t grpaddr = SDR_PHYGRP_RWMGRGRP_ADDRESS |
                           RW_MGR_RUN_SINGLE_GROUP_OFFSET;

        /* Load counters */
        writel(SKIP_DELAY_LOOP_VALUE_OR_ZERO(cntr0),
               &sdr_rw_load_mgr_regs->load_cntr0);
        writel(SKIP_DELAY_LOOP_VALUE_OR_ZERO(cntr1),
               &sdr_rw_load_mgr_regs->load_cntr1);
        writel(SKIP_DELAY_LOOP_VALUE_OR_ZERO(cntr2),
               &sdr_rw_load_mgr_regs->load_cntr2);

        /* Load jump address */
        writel(jump, &sdr_rw_load_jump_mgr_regs->load_jump_add0);
        writel(jump, &sdr_rw_load_jump_mgr_regs->load_jump_add1);
        writel(jump, &sdr_rw_load_jump_mgr_regs->load_jump_add2);

        /* Execute count instruction */
        writel(jump, grpaddr);
}

/**
 * rw_mgr_mem_load_user() - Load user calibration values
 * @fin1:       Final instruction 1
 * @fin2:       Final instruction 2
 * @precharge:  If 1, precharge the banks at the end
 *
 * Load user calibration values and optionally precharge the banks.
 */
static void rw_mgr_mem_load_user(const u32 fin1, const u32 fin2,
                                 const int precharge)
{
        u32 grpaddr = SDR_PHYGRP_RWMGRGRP_ADDRESS |
                      RW_MGR_RUN_SINGLE_GROUP_OFFSET;
        u32 r;

        for (r = 0; r < RW_MGR_MEM_NUMBER_OF_RANKS; r++) {
                if (param->skip_ranks[r]) {
                        /* request to skip the rank */
                        continue;
                }

                /* set rank */
                set_rank_and_odt_mask(r, RW_MGR_ODT_MODE_OFF);

                /* precharge all banks ... */
                if (precharge)
                        writel(RW_MGR_PRECHARGE_ALL, grpaddr);

                /*
                 * USER Use Mirror-ed commands for odd ranks if address
                 * mirrorring is on
                 */
                if ((RW_MGR_MEM_ADDRESS_MIRRORING >> r) & 0x1) {
                        set_jump_as_return();
                        writel(RW_MGR_MRS2_MIRR, grpaddr);
                        delay_for_n_mem_clocks(4);
                        set_jump_as_return();
                        writel(RW_MGR_MRS3_MIRR, grpaddr);
                        delay_for_n_mem_clocks(4);
                        set_jump_as_return();
                        writel(RW_MGR_MRS1_MIRR, grpaddr);
                        delay_for_n_mem_clocks(4);
                        set_jump_as_return();
                        writel(fin1, grpaddr);
                } else {
                        set_jump_as_return();
                        writel(RW_MGR_MRS2, grpaddr);
                        delay_for_n_mem_clocks(4);
                        set_jump_as_return();
                        writel(RW_MGR_MRS3, grpaddr);
                        delay_for_n_mem_clocks(4);
                        set_jump_as_return();
                        writel(RW_MGR_MRS1, grpaddr);
                        set_jump_as_return();
                        writel(fin2, grpaddr);
                }

                if (precharge)
                        continue;

                set_jump_as_return();
                writel(RW_MGR_ZQCL, grpaddr);

                /* tZQinit = tDLLK = 512 ck cycles */
                delay_for_n_mem_clocks(512);
        }
}

/**
 * rw_mgr_mem_initialize() - Initialize RW Manager
 *
 * Initialize RW Manager.
 */
static void rw_mgr_mem_initialize(void)
{
        debug("%s:%d\n", __func__, __LINE__);

        /* The reset / cke part of initialization is broadcasted to all ranks */
        writel(RW_MGR_RANK_ALL, SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                RW_MGR_SET_CS_AND_ODT_MASK_OFFSET);

        /*
         * Here's how you load register for a loop
         * Counters are located @ 0x800
         * Jump address are located @ 0xC00
         * For both, registers 0 to 3 are selected using bits 3 and 2, like
         * in 0x800, 0x804, 0x808, 0x80C and 0xC00, 0xC04, 0xC08, 0xC0C
         * I know this ain't pretty, but Avalon bus throws away the 2 least
         * significant bits
         */

        /* Start with memory RESET activated */

        /* tINIT = 200us */

        /*
         * 200us @ 266MHz (3.75 ns) ~ 54000 clock cycles
         * If a and b are the number of iteration in 2 nested loops
         * it takes the following number of cycles to complete the operation:
         * number_of_cycles = ((2 + n) * a + 2) * b
         * where n is the number of instruction in the inner loop
         * One possible solution is n = 0 , a = 256 , b = 106 => a = FF,
         * b = 6A
         */
        rw_mgr_mem_init_load_regs(SEQ_TINIT_CNTR0_VAL, SEQ_TINIT_CNTR1_VAL,
                                  SEQ_TINIT_CNTR2_VAL,
                                  RW_MGR_INIT_RESET_0_CKE_0);

        /* Indicate that memory is stable. */
        writel(1, &phy_mgr_cfg->reset_mem_stbl);

        /*
         * transition the RESET to high
         * Wait for 500us
         */

        /*
         * 500us @ 266MHz (3.75 ns) ~ 134000 clock cycles
         * If a and b are the number of iteration in 2 nested loops
         * it takes the following number of cycles to complete the operation
         * number_of_cycles = ((2 + n) * a + 2) * b
         * where n is the number of instruction in the inner loop
         * One possible solution is n = 2 , a = 131 , b = 256 => a = 83,
         * b = FF
         */
        rw_mgr_mem_init_load_regs(SEQ_TRESET_CNTR0_VAL, SEQ_TRESET_CNTR1_VAL,
                                  SEQ_TRESET_CNTR2_VAL,
                                  RW_MGR_INIT_RESET_1_CKE_0);

        /* Bring up clock enable. */

        /* tXRP < 250 ck cycles */
        delay_for_n_mem_clocks(250);

        rw_mgr_mem_load_user(RW_MGR_MRS0_DLL_RESET_MIRR, RW_MGR_MRS0_DLL_RESET,
                             0);
}

/**
 * rw_mgr_mem_handoff() - Hand off the memory to user
 *
 * At the end of calibration we have to program the user settings in
 * and hand off the memory to the user.
 */
static void rw_mgr_mem_handoff(void)
{
        rw_mgr_mem_load_user(RW_MGR_MRS0_USER_MIRR, RW_MGR_MRS0_USER, 1);
        /*
         * Need to wait tMOD (12CK or 15ns) time before issuing other
         * commands, but we will have plenty of NIOS cycles before actual
         * handoff so its okay.
         */
}

/**
 * rw_mgr_mem_calibrate_write_test_issue() - Issue write test command
 * @group:      Write Group
 * @use_dm:     Use DM
 *
 * Issue write test command. Two variants are provided, one that just tests
 * a write pattern and another that tests datamask functionality.
 */
static void rw_mgr_mem_calibrate_write_test_issue(u32 group,
                                                  u32 test_dm)
{
        const u32 quick_write_mode =
                (STATIC_CALIB_STEPS & CALIB_SKIP_WRITES) &&
                ENABLE_SUPER_QUICK_CALIBRATION;
        u32 mcc_instruction;
        u32 rw_wl_nop_cycles;

        /*
         * Set counter and jump addresses for the right
         * number of NOP cycles.
         * The number of supported NOP cycles can range from -1 to infinity
         * Three different cases are handled:
         *
         * 1. For a number of NOP cycles greater than 0, the RW Mgr looping
         *    mechanism will be used to insert the right number of NOPs
         *
         * 2. For a number of NOP cycles equals to 0, the micro-instruction
         *    issuing the write command will jump straight to the
         *    micro-instruction that turns on DQS (for DDRx), or outputs write
         *    data (for RLD), skipping
         *    the NOP micro-instruction all together
         *
         * 3. A number of NOP cycles equal to -1 indicates that DQS must be
         *    turned on in the same micro-instruction that issues the write
         *    command. Then we need
         *    to directly jump to the micro-instruction that sends out the data
         *
         * NOTE: Implementing this mechanism uses 2 RW Mgr jump-counters
         *       (2 and 3). One jump-counter (0) is used to perform multiple
         *       write-read operations.
         *       one counter left to issue this command in "multiple-group" mode
         */

        rw_wl_nop_cycles = gbl->rw_wl_nop_cycles;

        if (rw_wl_nop_cycles == -1) {
                /*
                 * CNTR 2 - We want to execute the special write operation that
                 * turns on DQS right away and then skip directly to the
                 * instruction that sends out the data. We set the counter to a
                 * large number so that the jump is always taken.
                 */
                writel(0xFF, &sdr_rw_load_mgr_regs->load_cntr2);

                /* CNTR 3 - Not used */
                if (test_dm) {
                        mcc_instruction = RW_MGR_LFSR_WR_RD_DM_BANK_0_WL_1;
                        writel(RW_MGR_LFSR_WR_RD_DM_BANK_0_DATA,
                               &sdr_rw_load_jump_mgr_regs->load_jump_add2);
                        writel(RW_MGR_LFSR_WR_RD_DM_BANK_0_NOP,
                               &sdr_rw_load_jump_mgr_regs->load_jump_add3);
                } else {
                        mcc_instruction = RW_MGR_LFSR_WR_RD_BANK_0_WL_1;
                        writel(RW_MGR_LFSR_WR_RD_BANK_0_DATA,
                                &sdr_rw_load_jump_mgr_regs->load_jump_add2);
                        writel(RW_MGR_LFSR_WR_RD_BANK_0_NOP,
                                &sdr_rw_load_jump_mgr_regs->load_jump_add3);
                }
        } else if (rw_wl_nop_cycles == 0) {
                /*
                 * CNTR 2 - We want to skip the NOP operation and go straight
                 * to the DQS enable instruction. We set the counter to a large
                 * number so that the jump is always taken.
                 */
                writel(0xFF, &sdr_rw_load_mgr_regs->load_cntr2);

                /* CNTR 3 - Not used */
                if (test_dm) {
                        mcc_instruction = RW_MGR_LFSR_WR_RD_DM_BANK_0;
                        writel(RW_MGR_LFSR_WR_RD_DM_BANK_0_DQS,
                               &sdr_rw_load_jump_mgr_regs->load_jump_add2);
                } else {
                        mcc_instruction = RW_MGR_LFSR_WR_RD_BANK_0;
                        writel(RW_MGR_LFSR_WR_RD_BANK_0_DQS,
                                &sdr_rw_load_jump_mgr_regs->load_jump_add2);
                }
        } else {
                /*
                 * CNTR 2 - In this case we want to execute the next instruction
                 * and NOT take the jump. So we set the counter to 0. The jump
                 * address doesn't count.
                 */
                writel(0x0, &sdr_rw_load_mgr_regs->load_cntr2);
                writel(0x0, &sdr_rw_load_jump_mgr_regs->load_jump_add2);

                /*
                 * CNTR 3 - Set the nop counter to the number of cycles we
                 * need to loop for, minus 1.
                 */
                writel(rw_wl_nop_cycles - 1, &sdr_rw_load_mgr_regs->load_cntr3);
                if (test_dm) {
                        mcc_instruction = RW_MGR_LFSR_WR_RD_DM_BANK_0;
                        writel(RW_MGR_LFSR_WR_RD_DM_BANK_0_NOP,
                                &sdr_rw_load_jump_mgr_regs->load_jump_add3);
                } else {
                        mcc_instruction = RW_MGR_LFSR_WR_RD_BANK_0;
                        writel(RW_MGR_LFSR_WR_RD_BANK_0_NOP,
                                &sdr_rw_load_jump_mgr_regs->load_jump_add3);
                }
        }

        writel(0, SDR_PHYGRP_RWMGRGRP_ADDRESS |
                  RW_MGR_RESET_READ_DATAPATH_OFFSET);

        if (quick_write_mode)
                writel(0x08, &sdr_rw_load_mgr_regs->load_cntr0);
        else
                writel(0x40, &sdr_rw_load_mgr_regs->load_cntr0);

        writel(mcc_instruction, &sdr_rw_load_jump_mgr_regs->load_jump_add0);

        /*
         * CNTR 1 - This is used to ensure enough time elapses
         * for read data to come back.
         */
        writel(0x30, &sdr_rw_load_mgr_regs->load_cntr1);

        if (test_dm) {
                writel(RW_MGR_LFSR_WR_RD_DM_BANK_0_WAIT,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add1);
        } else {
                writel(RW_MGR_LFSR_WR_RD_BANK_0_WAIT,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add1);
        }

        writel(mcc_instruction, (SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                RW_MGR_RUN_SINGLE_GROUP_OFFSET) +
                                (group << 2));
}

/**
 * rw_mgr_mem_calibrate_write_test() - Test writes, check for single/multiple pass
 * @rank_bgn:           Rank number
 * @write_group:        Write Group
 * @use_dm:             Use DM
 * @all_correct:        All bits must be correct in the mask
 * @bit_chk:            Resulting bit mask after the test
 * @all_ranks:          Test all ranks
 *
 * Test writes, can check for a single bit pass or multiple bit pass.
 */
static int
rw_mgr_mem_calibrate_write_test(const u32 rank_bgn, const u32 write_group,
                                const u32 use_dm, const u32 all_correct,
                                u32 *bit_chk, const u32 all_ranks)
{
        const u32 rank_end = all_ranks ?
                                RW_MGR_MEM_NUMBER_OF_RANKS :
                                (rank_bgn + NUM_RANKS_PER_SHADOW_REG);
        const u32 shift_ratio = RW_MGR_MEM_DQ_PER_WRITE_DQS /
                                RW_MGR_MEM_VIRTUAL_GROUPS_PER_WRITE_DQS;
        const u32 correct_mask_vg = param->write_correct_mask_vg;

        u32 tmp_bit_chk, base_rw_mgr;
        int vg, r;

        *bit_chk = param->write_correct_mask;

        for (r = rank_bgn; r < rank_end; r++) {
                /* Request to skip the rank */
                if (param->skip_ranks[r])
                        continue;

                /* Set rank */
                set_rank_and_odt_mask(r, RW_MGR_ODT_MODE_READ_WRITE);

                tmp_bit_chk = 0;
                for (vg = RW_MGR_MEM_VIRTUAL_GROUPS_PER_WRITE_DQS - 1;
                     vg >= 0; vg--) {
                        /* Reset the FIFOs to get pointers to known state. */
                        writel(0, &phy_mgr_cmd->fifo_reset);

                        rw_mgr_mem_calibrate_write_test_issue(
                                write_group *
                                RW_MGR_MEM_VIRTUAL_GROUPS_PER_WRITE_DQS + vg,
                                use_dm);

                        base_rw_mgr = readl(SDR_PHYGRP_RWMGRGRP_ADDRESS);
                        tmp_bit_chk <<= shift_ratio;
                        tmp_bit_chk |= (correct_mask_vg & ~(base_rw_mgr));
                }

                *bit_chk &= tmp_bit_chk;
        }

        set_rank_and_odt_mask(0, RW_MGR_ODT_MODE_OFF);
        if (all_correct) {
                debug_cond(DLEVEL == 2,
                           "write_test(%u,%u,ALL) : %u == %u => %i\n",
                           write_group, use_dm, *bit_chk,
                           param->write_correct_mask,
                           *bit_chk == param->write_correct_mask);
                return *bit_chk == param->write_correct_mask;
        } else {
                set_rank_and_odt_mask(0, RW_MGR_ODT_MODE_OFF);
                debug_cond(DLEVEL == 2,
                           "write_test(%u,%u,ONE) : %u != %i => %i\n",
                           write_group, use_dm, *bit_chk, 0, *bit_chk != 0);
                return *bit_chk != 0x00;
        }
}

/**
 * rw_mgr_mem_calibrate_read_test_patterns() - Read back test patterns
 * @rank_bgn:   Rank number
 * @group:      Read/Write Group
 * @all_ranks:  Test all ranks
 *
 * Performs a guaranteed read on the patterns we are going to use during a
 * read test to ensure memory works.
 */
static int
rw_mgr_mem_calibrate_read_test_patterns(const u32 rank_bgn, const u32 group,
                                        const u32 all_ranks)
{
        const u32 addr = SDR_PHYGRP_RWMGRGRP_ADDRESS |
                         RW_MGR_RUN_SINGLE_GROUP_OFFSET;
        const u32 addr_offset =
                         (group * RW_MGR_MEM_VIRTUAL_GROUPS_PER_READ_DQS) << 2;
        const u32 rank_end = all_ranks ?
                                RW_MGR_MEM_NUMBER_OF_RANKS :
                                (rank_bgn + NUM_RANKS_PER_SHADOW_REG);
        const u32 shift_ratio = RW_MGR_MEM_DQ_PER_READ_DQS /
                                RW_MGR_MEM_VIRTUAL_GROUPS_PER_READ_DQS;
        const u32 correct_mask_vg = param->read_correct_mask_vg;

        u32 tmp_bit_chk, base_rw_mgr, bit_chk;
        int vg, r;
        int ret = 0;

        bit_chk = param->read_correct_mask;

        for (r = rank_bgn; r < rank_end; r++) {
                /* Request to skip the rank */
                if (param->skip_ranks[r])
                        continue;

                /* Set rank */
                set_rank_and_odt_mask(r, RW_MGR_ODT_MODE_READ_WRITE);

                /* Load up a constant bursts of read commands */
                writel(0x20, &sdr_rw_load_mgr_regs->load_cntr0);
                writel(RW_MGR_GUARANTEED_READ,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add0);

                writel(0x20, &sdr_rw_load_mgr_regs->load_cntr1);
                writel(RW_MGR_GUARANTEED_READ_CONT,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add1);

                tmp_bit_chk = 0;
                for (vg = RW_MGR_MEM_VIRTUAL_GROUPS_PER_READ_DQS - 1;
                     vg >= 0; vg--) {
                        /* Reset the FIFOs to get pointers to known state. */
                        writel(0, &phy_mgr_cmd->fifo_reset);
                        writel(0, SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                  RW_MGR_RESET_READ_DATAPATH_OFFSET);
                        writel(RW_MGR_GUARANTEED_READ,
                               addr + addr_offset + (vg << 2));

                        base_rw_mgr = readl(SDR_PHYGRP_RWMGRGRP_ADDRESS);
                        tmp_bit_chk <<= shift_ratio;
                        tmp_bit_chk |= correct_mask_vg & ~base_rw_mgr;
                }

                bit_chk &= tmp_bit_chk;
        }

        writel(RW_MGR_CLEAR_DQS_ENABLE, addr + (group << 2));

        set_rank_and_odt_mask(0, RW_MGR_ODT_MODE_OFF);

        if (bit_chk != param->read_correct_mask)
                ret = -EIO;

        debug_cond(DLEVEL == 1,
                   "%s:%d test_load_patterns(%u,ALL) => (%u == %u) => %i\n",
                   __func__, __LINE__, group, bit_chk,
                   param->read_correct_mask, ret);

        return ret;
}

/**
 * rw_mgr_mem_calibrate_read_load_patterns() - Load up the patterns for read test
 * @rank_bgn:   Rank number
 * @all_ranks:  Test all ranks
 *
 * Load up the patterns we are going to use during a read test.
 */
static void rw_mgr_mem_calibrate_read_load_patterns(const u32 rank_bgn,
                                                    const int all_ranks)
{
        const u32 rank_end = all_ranks ?
                        RW_MGR_MEM_NUMBER_OF_RANKS :
                        (rank_bgn + NUM_RANKS_PER_SHADOW_REG);
        u32 r;

        debug("%s:%d\n", __func__, __LINE__);

        for (r = rank_bgn; r < rank_end; r++) {
                if (param->skip_ranks[r])
                        /* request to skip the rank */
                        continue;

                /* set rank */
                set_rank_and_odt_mask(r, RW_MGR_ODT_MODE_READ_WRITE);

                /* Load up a constant bursts */
                writel(0x20, &sdr_rw_load_mgr_regs->load_cntr0);

                writel(RW_MGR_GUARANTEED_WRITE_WAIT0,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add0);

                writel(0x20, &sdr_rw_load_mgr_regs->load_cntr1);

                writel(RW_MGR_GUARANTEED_WRITE_WAIT1,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add1);

                writel(0x04, &sdr_rw_load_mgr_regs->load_cntr2);

                writel(RW_MGR_GUARANTEED_WRITE_WAIT2,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add2);

                writel(0x04, &sdr_rw_load_mgr_regs->load_cntr3);

                writel(RW_MGR_GUARANTEED_WRITE_WAIT3,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add3);

                writel(RW_MGR_GUARANTEED_WRITE, SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                                RW_MGR_RUN_SINGLE_GROUP_OFFSET);
        }

        set_rank_and_odt_mask(0, RW_MGR_ODT_MODE_OFF);
}

/**
 * rw_mgr_mem_calibrate_read_test() - Perform READ test on single rank
 * @rank_bgn:           Rank number
 * @group:              Read/Write group
 * @num_tries:          Number of retries of the test
 * @all_correct:        All bits must be correct in the mask
 * @bit_chk:            Resulting bit mask after the test
 * @all_groups:         Test all R/W groups
 * @all_ranks:          Test all ranks
 *
 * Try a read and see if it returns correct data back. Test has dummy reads
 * inserted into the mix used to align DQS enable. Test has more thorough
 * checks than the regular read test.
 */
static int
rw_mgr_mem_calibrate_read_test(const u32 rank_bgn, const u32 group,
                               const u32 num_tries, const u32 all_correct,
                               u32 *bit_chk,
                               const u32 all_groups, const u32 all_ranks)
{
        const u32 rank_end = all_ranks ? RW_MGR_MEM_NUMBER_OF_RANKS :
                (rank_bgn + NUM_RANKS_PER_SHADOW_REG);
        const u32 quick_read_mode =
                ((STATIC_CALIB_STEPS & CALIB_SKIP_DELAY_SWEEPS) &&
                 ENABLE_SUPER_QUICK_CALIBRATION);
        u32 correct_mask_vg = param->read_correct_mask_vg;
        u32 tmp_bit_chk;
        u32 base_rw_mgr;
        u32 addr;

        int r, vg, ret;

        *bit_chk = param->read_correct_mask;

        for (r = rank_bgn; r < rank_end; r++) {
                if (param->skip_ranks[r])
                        /* request to skip the rank */
                        continue;

                /* set rank */
                set_rank_and_odt_mask(r, RW_MGR_ODT_MODE_READ_WRITE);

                writel(0x10, &sdr_rw_load_mgr_regs->load_cntr1);

                writel(RW_MGR_READ_B2B_WAIT1,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add1);

                writel(0x10, &sdr_rw_load_mgr_regs->load_cntr2);
                writel(RW_MGR_READ_B2B_WAIT2,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add2);

                if (quick_read_mode)
                        writel(0x1, &sdr_rw_load_mgr_regs->load_cntr0);
                        /* need at least two (1+1) reads to capture failures */
                else if (all_groups)
                        writel(0x06, &sdr_rw_load_mgr_regs->load_cntr0);
                else
                        writel(0x32, &sdr_rw_load_mgr_regs->load_cntr0);

                writel(RW_MGR_READ_B2B,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add0);
                if (all_groups)
                        writel(RW_MGR_MEM_IF_READ_DQS_WIDTH *
                               RW_MGR_MEM_VIRTUAL_GROUPS_PER_READ_DQS - 1,
                               &sdr_rw_load_mgr_regs->load_cntr3);
                else
                        writel(0x0, &sdr_rw_load_mgr_regs->load_cntr3);

                writel(RW_MGR_READ_B2B,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add3);

                tmp_bit_chk = 0;
                for (vg = RW_MGR_MEM_VIRTUAL_GROUPS_PER_READ_DQS - 1; vg >= 0;
                     vg--) {
                        /* Reset the FIFOs to get pointers to known state. */
                        writel(0, &phy_mgr_cmd->fifo_reset);
                        writel(0, SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                  RW_MGR_RESET_READ_DATAPATH_OFFSET);

                        if (all_groups) {
                                addr = SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                       RW_MGR_RUN_ALL_GROUPS_OFFSET;
                        } else {
                                addr = SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                       RW_MGR_RUN_SINGLE_GROUP_OFFSET;
                        }

                        writel(RW_MGR_READ_B2B, addr +
                               ((group * RW_MGR_MEM_VIRTUAL_GROUPS_PER_READ_DQS +
                               vg) << 2));

                        base_rw_mgr = readl(SDR_PHYGRP_RWMGRGRP_ADDRESS);
                        tmp_bit_chk <<= RW_MGR_MEM_DQ_PER_READ_DQS /
                                        RW_MGR_MEM_VIRTUAL_GROUPS_PER_READ_DQS;
                        tmp_bit_chk |= correct_mask_vg & ~(base_rw_mgr);
                }

                *bit_chk &= tmp_bit_chk;
        }

        addr = SDR_PHYGRP_RWMGRGRP_ADDRESS | RW_MGR_RUN_SINGLE_GROUP_OFFSET;
        writel(RW_MGR_CLEAR_DQS_ENABLE, addr + (group << 2));

        set_rank_and_odt_mask(0, RW_MGR_ODT_MODE_OFF);

        if (all_correct) {
                ret = (*bit_chk == param->read_correct_mask);
                debug_cond(DLEVEL == 2,
                           "%s:%d read_test(%u,ALL,%u) => (%u == %u) => %i\n",
                           __func__, __LINE__, group, all_groups, *bit_chk,
                           param->read_correct_mask, ret);
        } else  {
                ret = (*bit_chk != 0x00);
                debug_cond(DLEVEL == 2,
                           "%s:%d read_test(%u,ONE,%u) => (%u != %u) => %i\n",
                           __func__, __LINE__, group, all_groups, *bit_chk,
                           0, ret);
        }

        return ret;
}

/**
 * rw_mgr_mem_calibrate_read_test_all_ranks() - Perform READ test on all ranks
 * @grp:                Read/Write group
 * @num_tries:          Number of retries of the test
 * @all_correct:        All bits must be correct in the mask
 * @all_groups:         Test all R/W groups
 *
 * Perform a READ test across all memory ranks.
 */
static int
rw_mgr_mem_calibrate_read_test_all_ranks(const u32 grp, const u32 num_tries,
                                         const u32 all_correct,
                                         const u32 all_groups)
{
        u32 bit_chk;
        return rw_mgr_mem_calibrate_read_test(0, grp, num_tries, all_correct,
                                              &bit_chk, all_groups, 1);
}

/**
 * rw_mgr_incr_vfifo() - Increase VFIFO value
 * @grp:        Read/Write group
 *
 * Increase VFIFO value.
 */
static void rw_mgr_incr_vfifo(const u32 grp)
{
        writel(grp, &phy_mgr_cmd->inc_vfifo_hard_phy);
}

/**
 * rw_mgr_decr_vfifo() - Decrease VFIFO value
 * @grp:        Read/Write group
 *
 * Decrease VFIFO value.
 */
static void rw_mgr_decr_vfifo(const u32 grp)
{
        u32 i;

        for (i = 0; i < VFIFO_SIZE - 1; i++)
                rw_mgr_incr_vfifo(grp);
}

/**
 * find_vfifo_failing_read() - Push VFIFO to get a failing read
 * @grp:        Read/Write group
 *
 * Push VFIFO until a failing read happens.
 */
static int find_vfifo_failing_read(const u32 grp)
{
        u32 v, ret, fail_cnt = 0;

        for (v = 0; v < VFIFO_SIZE; v++) {
                debug_cond(DLEVEL == 2, "%s:%d: vfifo %u\n",
                           __func__, __LINE__, v);
                ret = rw_mgr_mem_calibrate_read_test_all_ranks(grp, 1,
                                                PASS_ONE_BIT, 0);
                if (!ret) {
                        fail_cnt++;

                        if (fail_cnt == 2)
                                return v;
                }

                /* Fiddle with FIFO. */
                rw_mgr_incr_vfifo(grp);
        }

        /* No failing read found! Something must have gone wrong. */
        debug_cond(DLEVEL == 2, "%s:%d: vfifo failed\n", __func__, __LINE__);
        return 0;
}

/**
 * sdr_find_phase_delay() - Find DQS enable phase or delay
 * @working:    If 1, look for working phase/delay, if 0, look for non-working
 * @delay:      If 1, look for delay, if 0, look for phase
 * @grp:        Read/Write group
 * @work:       Working window position
 * @work_inc:   Working window increment
 * @pd:         DQS Phase/Delay Iterator
 *
 * Find working or non-working DQS enable phase setting.
 */
static int sdr_find_phase_delay(int working, int delay, const u32 grp,
                                u32 *work, const u32 work_inc, u32 *pd)
{
        const u32 max = delay ? IO_DQS_EN_DELAY_MAX : IO_DQS_EN_PHASE_MAX;
        u32 ret;

        for (; *pd <= max; (*pd)++) {
                if (delay)
                        scc_mgr_set_dqs_en_delay_all_ranks(grp, *pd);
                else
                        scc_mgr_set_dqs_en_phase_all_ranks(grp, *pd);

                ret = rw_mgr_mem_calibrate_read_test_all_ranks(grp, 1,
                                        PASS_ONE_BIT, 0);
                if (!working)
                        ret = !ret;

                if (ret)
                        return 0;

                if (work)
                        *work += work_inc;
        }

        return -EINVAL;
}
/**
 * sdr_find_phase() - Find DQS enable phase
 * @working:    If 1, look for working phase, if 0, look for non-working phase
 * @grp:        Read/Write group
 * @work:       Working window position
 * @i:          Iterator
 * @p:          DQS Phase Iterator
 *
 * Find working or non-working DQS enable phase setting.
 */
static int sdr_find_phase(int working, const u32 grp, u32 *work,
                          u32 *i, u32 *p)
{
        const u32 end = VFIFO_SIZE + (working ? 0 : 1);
        int ret;

        for (; *i < end; (*i)++) {
                if (working)
                        *p = 0;

                ret = sdr_find_phase_delay(working, 0, grp, work,
                                           IO_DELAY_PER_OPA_TAP, p);
                if (!ret)
                        return 0;

                if (*p > IO_DQS_EN_PHASE_MAX) {
                        /* Fiddle with FIFO. */
                        rw_mgr_incr_vfifo(grp);
                        if (!working)
                                *p = 0;
                }
        }

        return -EINVAL;
}

/**
 * sdr_working_phase() - Find working DQS enable phase
 * @grp:        Read/Write group
 * @work_bgn:   Working window start position
 * @d:          dtaps output value
 * @p:          DQS Phase Iterator
 * @i:          Iterator
 *
 * Find working DQS enable phase setting.
 */
static int sdr_working_phase(const u32 grp, u32 *work_bgn, u32 *d,
                             u32 *p, u32 *i)
{
        const u32 dtaps_per_ptap = IO_DELAY_PER_OPA_TAP /
                                   IO_DELAY_PER_DQS_EN_DCHAIN_TAP;
        int ret;

        *work_bgn = 0;

        for (*d = 0; *d <= dtaps_per_ptap; (*d)++) {
                *i = 0;
                scc_mgr_set_dqs_en_delay_all_ranks(grp, *d);
                ret = sdr_find_phase(1, grp, work_bgn, i, p);
                if (!ret)
                        return 0;
                *work_bgn += IO_DELAY_PER_DQS_EN_DCHAIN_TAP;
        }

        /* Cannot find working solution */
        debug_cond(DLEVEL == 2, "%s:%d find_dqs_en_phase: no vfifo/ptap/dtap\n",
                   __func__, __LINE__);
        return -EINVAL;
}

/**
 * sdr_backup_phase() - Find DQS enable backup phase
 * @grp:        Read/Write group
 * @work_bgn:   Working window start position
 * @p:          DQS Phase Iterator
 *
 * Find DQS enable backup phase setting.
 */
static void sdr_backup_phase(const u32 grp, u32 *work_bgn, u32 *p)
{
        u32 tmp_delay, d;
        int ret;

        /* Special case code for backing up a phase */
        if (*p == 0) {
                *p = IO_DQS_EN_PHASE_MAX;
                rw_mgr_decr_vfifo(grp);
        } else {
                (*p)--;
        }
        tmp_delay = *work_bgn - IO_DELAY_PER_OPA_TAP;
        scc_mgr_set_dqs_en_phase_all_ranks(grp, *p);

        for (d = 0; d <= IO_DQS_EN_DELAY_MAX && tmp_delay < *work_bgn; d++) {
                scc_mgr_set_dqs_en_delay_all_ranks(grp, d);

                ret = rw_mgr_mem_calibrate_read_test_all_ranks(grp, 1,
                                        PASS_ONE_BIT, 0);
                if (ret) {
                        *work_bgn = tmp_delay;
                        break;
                }

                tmp_delay += IO_DELAY_PER_DQS_EN_DCHAIN_TAP;
        }

        /* Restore VFIFO to old state before we decremented it (if needed). */
        (*p)++;
        if (*p > IO_DQS_EN_PHASE_MAX) {
                *p = 0;
                rw_mgr_incr_vfifo(grp);
        }

        scc_mgr_set_dqs_en_delay_all_ranks(grp, 0);
}

/**
 * sdr_nonworking_phase() - Find non-working DQS enable phase
 * @grp:        Read/Write group
 * @work_end:   Working window end position
 * @p:          DQS Phase Iterator
 * @i:          Iterator
 *
 * Find non-working DQS enable phase setting.
 */
static int sdr_nonworking_phase(const u32 grp, u32 *work_end, u32 *p, u32 *i)
{
        int ret;

        (*p)++;
        *work_end += IO_DELAY_PER_OPA_TAP;
        if (*p > IO_DQS_EN_PHASE_MAX) {
                /* Fiddle with FIFO. */
                *p = 0;
                rw_mgr_incr_vfifo(grp);
        }

        ret = sdr_find_phase(0, grp, work_end, i, p);
        if (ret) {
                /* Cannot see edge of failing read. */
                debug_cond(DLEVEL == 2, "%s:%d: end: failed\n",
                           __func__, __LINE__);
        }

        return ret;
}

/**
 * sdr_find_window_center() - Find center of the working DQS window.
 * @grp:        Read/Write group
 * @work_bgn:   First working settings
 * @work_end:   Last working settings
 *
 * Find center of the working DQS enable window.
 */
static int sdr_find_window_center(const u32 grp, const u32 work_bgn,
                                  const u32 work_end)
{
        u32 work_mid;
        int tmp_delay = 0;
        int i, p, d;

        work_mid = (work_bgn + work_end) / 2;

        debug_cond(DLEVEL == 2, "work_bgn=%d work_end=%d work_mid=%d\n",
                   work_bgn, work_end, work_mid);
        /* Get the middle delay to be less than a VFIFO delay */
        tmp_delay = (IO_DQS_EN_PHASE_MAX + 1) * IO_DELAY_PER_OPA_TAP;

        debug_cond(DLEVEL == 2, "vfifo ptap delay %d\n", tmp_delay);
        work_mid %= tmp_delay;
        debug_cond(DLEVEL == 2, "new work_mid %d\n", work_mid);

        tmp_delay = rounddown(work_mid, IO_DELAY_PER_OPA_TAP);
        if (tmp_delay > IO_DQS_EN_PHASE_MAX * IO_DELAY_PER_OPA_TAP)
                tmp_delay = IO_DQS_EN_PHASE_MAX * IO_DELAY_PER_OPA_TAP;
        p = tmp_delay / IO_DELAY_PER_OPA_TAP;

        debug_cond(DLEVEL == 2, "new p %d, tmp_delay=%d\n", p, tmp_delay);

        d = DIV_ROUND_UP(work_mid - tmp_delay, IO_DELAY_PER_DQS_EN_DCHAIN_TAP);
        if (d > IO_DQS_EN_DELAY_MAX)
                d = IO_DQS_EN_DELAY_MAX;
        tmp_delay += d * IO_DELAY_PER_DQS_EN_DCHAIN_TAP;

        debug_cond(DLEVEL == 2, "new d %d, tmp_delay=%d\n", d, tmp_delay);

        scc_mgr_set_dqs_en_phase_all_ranks(grp, p);
        scc_mgr_set_dqs_en_delay_all_ranks(grp, d);

        /*
         * push vfifo until we can successfully calibrate. We can do this
         * because the largest possible margin in 1 VFIFO cycle.
         */
        for (i = 0; i < VFIFO_SIZE; i++) {
                debug_cond(DLEVEL == 2, "find_dqs_en_phase: center\n");
                if (rw_mgr_mem_calibrate_read_test_all_ranks(grp, 1,
                                                             PASS_ONE_BIT,
                                                             0)) {
                        debug_cond(DLEVEL == 2,
                                   "%s:%d center: found: ptap=%u dtap=%u\n",
                                   __func__, __LINE__, p, d);
                        return 0;
                }

                /* Fiddle with FIFO. */
                rw_mgr_incr_vfifo(grp);
        }

        debug_cond(DLEVEL == 2, "%s:%d center: failed.\n",
                   __func__, __LINE__);
        return -EINVAL;
}

/**
 * rw_mgr_mem_calibrate_vfifo_find_dqs_en_phase() - Find a good DQS enable to use
 * @grp:        Read/Write Group
 *
 * Find a good DQS enable to use.
 */
static int rw_mgr_mem_calibrate_vfifo_find_dqs_en_phase(const u32 grp)
{
        u32 d, p, i;
        u32 dtaps_per_ptap;
        u32 work_bgn, work_end;
        u32 found_passing_read, found_failing_read, initial_failing_dtap;
        int ret;

        debug("%s:%d %u\n", __func__, __LINE__, grp);

        reg_file_set_sub_stage(CAL_SUBSTAGE_VFIFO_CENTER);

        scc_mgr_set_dqs_en_delay_all_ranks(grp, 0);
        scc_mgr_set_dqs_en_phase_all_ranks(grp, 0);

        /* Step 0: Determine number of delay taps for each phase tap. */
        dtaps_per_ptap = IO_DELAY_PER_OPA_TAP / IO_DELAY_PER_DQS_EN_DCHAIN_TAP;

        /* Step 1: First push vfifo until we get a failing read. */
        find_vfifo_failing_read(grp);

        /* Step 2: Find first working phase, increment in ptaps. */
        work_bgn = 0;
        ret = sdr_working_phase(grp, &work_bgn, &d, &p, &i);
        if (ret)
                return ret;

        work_end = work_bgn;

        /*
         * If d is 0 then the working window covers a phase tap and we can
         * follow the old procedure. Otherwise, we've found the beginning
         * and we need to increment the dtaps until we find the end.
         */
        if (d == 0) {
                /*
                 * Step 3a: If we have room, back off by one and
                 *          increment in dtaps.
                 */
                sdr_backup_phase(grp, &work_bgn, &p);

                /*
                 * Step 4a: go forward from working phase to non working
                 * phase, increment in ptaps.
                 */
                ret = sdr_nonworking_phase(grp, &work_end, &p, &i);
                if (ret)
                        return ret;

                /* Step 5a: Back off one from last, increment in dtaps. */

                /* Special case code for backing up a phase */
                if (p == 0) {
                        p = IO_DQS_EN_PHASE_MAX;
                        rw_mgr_decr_vfifo(grp);
                } else {
                        p = p - 1;
                }

                work_end -= IO_DELAY_PER_OPA_TAP;
                scc_mgr_set_dqs_en_phase_all_ranks(grp, p);

                d = 0;

                debug_cond(DLEVEL == 2, "%s:%d p: ptap=%u\n",
                           __func__, __LINE__, p);
        }

        /* The dtap increment to find the failing edge is done here. */
        sdr_find_phase_delay(0, 1, grp, &work_end,
                             IO_DELAY_PER_DQS_EN_DCHAIN_TAP, &d);

        /* Go back to working dtap */
        if (d != 0)
                work_end -= IO_DELAY_PER_DQS_EN_DCHAIN_TAP;

        debug_cond(DLEVEL == 2,
                   "%s:%d p/d: ptap=%u dtap=%u end=%u\n",
                   __func__, __LINE__, p, d - 1, work_end);

        if (work_end < work_bgn) {
                /* nil range */
                debug_cond(DLEVEL == 2, "%s:%d end-2: failed\n",
                           __func__, __LINE__);
                return -EINVAL;
        }

        debug_cond(DLEVEL == 2, "%s:%d found range [%u,%u]\n",
                   __func__, __LINE__, work_bgn, work_end);

        /*
         * We need to calculate the number of dtaps that equal a ptap.
         * To do that we'll back up a ptap and re-find the edge of the
         * window using dtaps
         */
        debug_cond(DLEVEL == 2, "%s:%d calculate dtaps_per_ptap for tracking\n",
                   __func__, __LINE__);

        /* Special case code for backing up a phase */
        if (p == 0) {
                p = IO_DQS_EN_PHASE_MAX;
                rw_mgr_decr_vfifo(grp);
                debug_cond(DLEVEL == 2, "%s:%d backedup cycle/phase: p=%u\n",
                           __func__, __LINE__, p);
        } else {
                p = p - 1;
                debug_cond(DLEVEL == 2, "%s:%d backedup phase only: p=%u",
                           __func__, __LINE__, p);
        }

        scc_mgr_set_dqs_en_phase_all_ranks(grp, p);

        /*
         * Increase dtap until we first see a passing read (in case the
         * window is smaller than a ptap), and then a failing read to
         * mark the edge of the window again.
         */

        /* Find a passing read. */
        debug_cond(DLEVEL == 2, "%s:%d find passing read\n",
                   __func__, __LINE__);

        initial_failing_dtap = d;

        found_passing_read = !sdr_find_phase_delay(1, 1, grp, NULL, 0, &d);
        if (found_passing_read) {
                /* Find a failing read. */
                debug_cond(DLEVEL == 2, "%s:%d find failing read\n",
                           __func__, __LINE__);
                d++;
                found_failing_read = !sdr_find_phase_delay(0, 1, grp, NULL, 0,
                                                           &d);
        } else {
                debug_cond(DLEVEL == 1,
                           "%s:%d failed to calculate dtaps per ptap. Fall back on static value\n",
                           __func__, __LINE__);
        }

        /*
         * The dynamically calculated dtaps_per_ptap is only valid if we
         * found a passing/failing read. If we didn't, it means d hit the max
         * (IO_DQS_EN_DELAY_MAX). Otherwise, dtaps_per_ptap retains its
         * statically calculated value.
         */
        if (found_passing_read && found_failing_read)
                dtaps_per_ptap = d - initial_failing_dtap;

        writel(dtaps_per_ptap, &sdr_reg_file->dtaps_per_ptap);
        debug_cond(DLEVEL == 2, "%s:%d dtaps_per_ptap=%u - %u = %u",
                   __func__, __LINE__, d, initial_failing_dtap, dtaps_per_ptap);

        /* Step 6: Find the centre of the window. */
        ret = sdr_find_window_center(grp, work_bgn, work_end);

        return ret;
}

/**
 * search_stop_check() - Check if the detected edge is valid
 * @write:              Perform read (Stage 2) or write (Stage 3) calibration
 * @d:                  DQS delay
 * @rank_bgn:           Rank number
 * @write_group:        Write Group
 * @read_group:         Read Group
 * @bit_chk:            Resulting bit mask after the test
 * @sticky_bit_chk:     Resulting sticky bit mask after the test
 * @use_read_test:      Perform read test
 *
 * Test if the found edge is valid.
 */
static u32 search_stop_check(const int write, const int d, const int rank_bgn,
                             const u32 write_group, const u32 read_group,
                             u32 *bit_chk, u32 *sticky_bit_chk,
                             const u32 use_read_test)
{
        const u32 ratio = RW_MGR_MEM_IF_READ_DQS_WIDTH /
                          RW_MGR_MEM_IF_WRITE_DQS_WIDTH;
        const u32 correct_mask = write ? param->write_correct_mask :
                                         param->read_correct_mask;
        const u32 per_dqs = write ? RW_MGR_MEM_DQ_PER_WRITE_DQS :
                                    RW_MGR_MEM_DQ_PER_READ_DQS;
        u32 ret;
        /*
         * Stop searching when the read test doesn't pass AND when
         * we've seen a passing read on every bit.
         */
        if (write) {                    /* WRITE-ONLY */
                ret = !rw_mgr_mem_calibrate_write_test(rank_bgn, write_group,
                                                         0, PASS_ONE_BIT,
                                                         bit_chk, 0);
        } else if (use_read_test) {     /* READ-ONLY */
                ret = !rw_mgr_mem_calibrate_read_test(rank_bgn, read_group,
                                                        NUM_READ_PB_TESTS,
                                                        PASS_ONE_BIT, bit_chk,
                                                        0, 0);
        } else {                        /* READ-ONLY */
                rw_mgr_mem_calibrate_write_test(rank_bgn, write_group, 0,
                                                PASS_ONE_BIT, bit_chk, 0);
                *bit_chk = *bit_chk >> (per_dqs *
                        (read_group - (write_group * ratio)));
                ret = (*bit_chk == 0);
        }
        *sticky_bit_chk = *sticky_bit_chk | *bit_chk;
        ret = ret && (*sticky_bit_chk == correct_mask);
        debug_cond(DLEVEL == 2,
                   "%s:%d center(left): dtap=%u => %u == %u && %u",
                   __func__, __LINE__, d,
                   *sticky_bit_chk, correct_mask, ret);
        return ret;
}

/**
 * search_left_edge() - Find left edge of DQ/DQS working phase
 * @write:              Perform read (Stage 2) or write (Stage 3) calibration
 * @rank_bgn:           Rank number
 * @write_group:        Write Group
 * @read_group:         Read Group
 * @test_bgn:           Rank number to begin the test
 * @sticky_bit_chk:     Resulting sticky bit mask after the test
 * @left_edge:          Left edge of the DQ/DQS phase
 * @right_edge:         Right edge of the DQ/DQS phase
 * @use_read_test:      Perform read test
 *
 * Find left edge of DQ/DQS working phase.
 */
static void search_left_edge(const int write, const int rank_bgn,
        const u32 write_group, const u32 read_group, const u32 test_bgn,
        u32 *sticky_bit_chk,
        int *left_edge, int *right_edge, const u32 use_read_test)
{
        const u32 delay_max = write ? IO_IO_OUT1_DELAY_MAX : IO_IO_IN_DELAY_MAX;
        const u32 dqs_max = write ? IO_IO_OUT1_DELAY_MAX : IO_DQS_IN_DELAY_MAX;
        const u32 per_dqs = write ? RW_MGR_MEM_DQ_PER_WRITE_DQS :
                                    RW_MGR_MEM_DQ_PER_READ_DQS;
        u32 stop, bit_chk;
        int i, d;

        for (d = 0; d <= dqs_max; d++) {
                if (write)
                        scc_mgr_apply_group_dq_out1_delay(d);
                else
                        scc_mgr_apply_group_dq_in_delay(test_bgn, d);

                writel(0, &sdr_scc_mgr->update);

                stop = search_stop_check(write, d, rank_bgn, write_group,
                                         read_group, &bit_chk, sticky_bit_chk,
                                         use_read_test);
                if (stop == 1)
                        break;

                /* stop != 1 */
                for (i = 0; i < per_dqs; i++) {
                        if (bit_chk & 1) {
                                /*
                                 * Remember a passing test as
                                 * the left_edge.
                                 */
                                left_edge[i] = d;
                        } else {
                                /*
                                 * If a left edge has not been seen
                                 * yet, then a future passing test
                                 * will mark this edge as the right
                                 * edge.
                                 */
                                if (left_edge[i] == delay_max + 1)
                                        right_edge[i] = -(d + 1);
                        }
                        bit_chk >>= 1;
                }
        }

        /* Reset DQ delay chains to 0 */
        if (write)
                scc_mgr_apply_group_dq_out1_delay(0);
        else
                scc_mgr_apply_group_dq_in_delay(test_bgn, 0);

        *sticky_bit_chk = 0;
        for (i = per_dqs - 1; i >= 0; i--) {
                debug_cond(DLEVEL == 2,
                           "%s:%d vfifo_center: left_edge[%u]: %d right_edge[%u]: %d\n",
                           __func__, __LINE__, i, left_edge[i],
                           i, right_edge[i]);

                /*
                 * Check for cases where we haven't found the left edge,
                 * which makes our assignment of the the right edge invalid.
                 * Reset it to the illegal value.
                 */
                if ((left_edge[i] == delay_max + 1) &&
                    (right_edge[i] != delay_max + 1)) {
                        right_edge[i] = delay_max + 1;
                        debug_cond(DLEVEL == 2,
                                   "%s:%d vfifo_center: reset right_edge[%u]: %d\n",
                                   __func__, __LINE__, i, right_edge[i]);
                }

                /*
                 * Reset sticky bit
                 * READ: except for bits where we have seen both
                 *       the left and right edge.
                 * WRITE: except for bits where we have seen the
                 *        left edge.
                 */
                *sticky_bit_chk <<= 1;
                if (write) {
                        if (left_edge[i] != delay_max + 1)
                                *sticky_bit_chk |= 1;
                } else {
                        if ((left_edge[i] != delay_max + 1) &&
                            (right_edge[i] != delay_max + 1))
                                *sticky_bit_chk |= 1;
                }
        }


}

/**
 * search_right_edge() - Find right edge of DQ/DQS working phase
 * @write:              Perform read (Stage 2) or write (Stage 3) calibration
 * @rank_bgn:           Rank number
 * @write_group:        Write Group
 * @read_group:         Read Group
 * @start_dqs:          DQS start phase
 * @start_dqs_en:       DQS enable start phase
 * @sticky_bit_chk:     Resulting sticky bit mask after the test
 * @left_edge:          Left edge of the DQ/DQS phase
 * @right_edge:         Right edge of the DQ/DQS phase
 * @use_read_test:      Perform read test
 *
 * Find right edge of DQ/DQS working phase.
 */
static int search_right_edge(const int write, const int rank_bgn,
        const u32 write_group, const u32 read_group,
        const int start_dqs, const int start_dqs_en,
        u32 *sticky_bit_chk,
        int *left_edge, int *right_edge, const u32 use_read_test)
{
        const u32 delay_max = write ? IO_IO_OUT1_DELAY_MAX : IO_IO_IN_DELAY_MAX;
        const u32 dqs_max = write ? IO_IO_OUT1_DELAY_MAX : IO_DQS_IN_DELAY_MAX;
        const u32 per_dqs = write ? RW_MGR_MEM_DQ_PER_WRITE_DQS :
                                    RW_MGR_MEM_DQ_PER_READ_DQS;
        u32 stop, bit_chk;
        int i, d;

        for (d = 0; d <= dqs_max - start_dqs; d++) {
                if (write) {    /* WRITE-ONLY */
                        scc_mgr_apply_group_dqs_io_and_oct_out1(write_group,
                                                                d + start_dqs);
                } else {        /* READ-ONLY */
                        scc_mgr_set_dqs_bus_in_delay(read_group, d + start_dqs);
                        if (IO_SHIFT_DQS_EN_WHEN_SHIFT_DQS) {
                                uint32_t delay = d + start_dqs_en;
                                if (delay > IO_DQS_EN_DELAY_MAX)
                                        delay = IO_DQS_EN_DELAY_MAX;
                                scc_mgr_set_dqs_en_delay(read_group, delay);
                        }
                        scc_mgr_load_dqs(read_group);
                }

                writel(0, &sdr_scc_mgr->update);

                stop = search_stop_check(write, d, rank_bgn, write_group,
                                         read_group, &bit_chk, sticky_bit_chk,
                                         use_read_test);
                if (stop == 1) {
                        if (write && (d == 0)) {        /* WRITE-ONLY */
                                for (i = 0; i < RW_MGR_MEM_DQ_PER_WRITE_DQS; i++) {
                                        /*
                                         * d = 0 failed, but it passed when
                                         * testing the left edge, so it must be
                                         * marginal, set it to -1
                                         */
                                        if (right_edge[i] == delay_max + 1 &&
                                            left_edge[i] != delay_max + 1)
                                                right_edge[i] = -1;
                                }
                        }
                        break;
                }

                /* stop != 1 */
                for (i = 0; i < per_dqs; i++) {
                        if (bit_chk & 1) {
                                /*
                                 * Remember a passing test as
                                 * the right_edge.
                                 */
                                right_edge[i] = d;
                        } else {
                                if (d != 0) {
                                        /*
                                         * If a right edge has not
                                         * been seen yet, then a future
                                         * passing test will mark this
                                         * edge as the left edge.
                                         */
                                        if (right_edge[i] == delay_max + 1)
                                                left_edge[i] = -(d + 1);
                                } else {
                                        /*
                                         * d = 0 failed, but it passed
                                         * when testing the left edge,
                                         * so it must be marginal, set
                                         * it to -1
                                         */
                                        if (right_edge[i] == delay_max + 1 &&
                                            left_edge[i] != delay_max + 1)
                                                right_edge[i] = -1;
                                        /*
                                         * If a right edge has not been
                                         * seen yet, then a future
                                         * passing test will mark this
                                         * edge as the left edge.
                                         */
                                        else if (right_edge[i] == delay_max + 1)
                                                left_edge[i] = -(d + 1);
                                }
                        }

                        debug_cond(DLEVEL == 2, "%s:%d center[r,d=%u]: ",
                                   __func__, __LINE__, d);
                        debug_cond(DLEVEL == 2,
                                   "bit_chk_test=%i left_edge[%u]: %d ",
                                   bit_chk & 1, i, left_edge[i]);
                        debug_cond(DLEVEL == 2, "right_edge[%u]: %d\n", i,
                                   right_edge[i]);
                        bit_chk >>= 1;
                }
        }

        /* Check that all bits have a window */
        for (i = 0; i < per_dqs; i++) {
                debug_cond(DLEVEL == 2,
                           "%s:%d write_center: left_edge[%u]: %d right_edge[%u]: %d",
                           __func__, __LINE__, i, left_edge[i],
                           i, right_edge[i]);
                if ((left_edge[i] == dqs_max + 1) ||
                    (right_edge[i] == dqs_max + 1))
                        return i + 1;   /* FIXME: If we fail, retval > 0 */
        }

        return 0;
}

/**
 * get_window_mid_index() - Find the best middle setting of DQ/DQS phase
 * @write:              Perform read (Stage 2) or write (Stage 3) calibration
 * @left_edge:          Left edge of the DQ/DQS phase
 * @right_edge:         Right edge of the DQ/DQS phase
 * @mid_min:            Best DQ/DQS phase middle setting
 *
 * Find index and value of the middle of the DQ/DQS working phase.
 */
static int get_window_mid_index(const int write, int *left_edge,
                                int *right_edge, int *mid_min)
{
        const u32 per_dqs = write ? RW_MGR_MEM_DQ_PER_WRITE_DQS :
                                    RW_MGR_MEM_DQ_PER_READ_DQS;
        int i, mid, min_index;

        /* Find middle of window for each DQ bit */
        *mid_min = left_edge[0] - right_edge[0];
        min_index = 0;
        for (i = 1; i < per_dqs; i++) {
                mid = left_edge[i] - right_edge[i];
                if (mid < *mid_min) {
                        *mid_min = mid;
                        min_index = i;
                }
        }

        /*
         * -mid_min/2 represents the amount that we need to move DQS.
         * If mid_min is odd and positive we'll need to add one to make
         * sure the rounding in further calculations is correct (always
         * bias to the right), so just add 1 for all positive values.
         */
        if (*mid_min > 0)
                (*mid_min)++;
        *mid_min = *mid_min / 2;

        debug_cond(DLEVEL == 1, "%s:%d vfifo_center: *mid_min=%d (index=%u)\n",
                   __func__, __LINE__, *mid_min, min_index);
        return min_index;
}

/**
 * center_dq_windows() - Center the DQ/DQS windows
 * @write:              Perform read (Stage 2) or write (Stage 3) calibration
 * @left_edge:          Left edge of the DQ/DQS phase
 * @right_edge:         Right edge of the DQ/DQS phase
 * @mid_min:            Adjusted DQ/DQS phase middle setting
 * @orig_mid_min:       Original DQ/DQS phase middle setting
 * @min_index:          DQ/DQS phase middle setting index
 * @test_bgn:           Rank number to begin the test
 * @dq_margin:          Amount of shift for the DQ
 * @dqs_margin:         Amount of shift for the DQS
 *
 * Align the DQ/DQS windows in each group.
 */
static void center_dq_windows(const int write, int *left_edge, int *right_edge,
                              const int mid_min, const int orig_mid_min,
                              const int min_index, const int test_bgn,
                              int *dq_margin, int *dqs_margin)
{
        const u32 delay_max = write ? IO_IO_OUT1_DELAY_MAX : IO_IO_IN_DELAY_MAX;
        const u32 per_dqs = write ? RW_MGR_MEM_DQ_PER_WRITE_DQS :
                                    RW_MGR_MEM_DQ_PER_READ_DQS;
        const u32 delay_off = write ? SCC_MGR_IO_OUT1_DELAY_OFFSET :
                                      SCC_MGR_IO_IN_DELAY_OFFSET;
        const u32 addr = SDR_PHYGRP_SCCGRP_ADDRESS | delay_off;

        u32 temp_dq_io_delay1, temp_dq_io_delay2;
        int shift_dq, i, p;

        /* Initialize data for export structures */
        *dqs_margin = delay_max + 1;
        *dq_margin  = delay_max + 1;

        /* add delay to bring centre of all DQ windows to the same "level" */
        for (i = 0, p = test_bgn; i < per_dqs; i++, p++) {
                /* Use values before divide by 2 to reduce round off error */
                shift_dq = (left_edge[i] - right_edge[i] -
                        (left_edge[min_index] - right_edge[min_index]))/2  +
                        (orig_mid_min - mid_min);

                debug_cond(DLEVEL == 2,
                           "vfifo_center: before: shift_dq[%u]=%d\n",
                           i, shift_dq);

                temp_dq_io_delay1 = readl(addr + (p << 2));
                temp_dq_io_delay2 = readl(addr + (i << 2));

                if (shift_dq + temp_dq_io_delay1 > delay_max)
                        shift_dq = delay_max - temp_dq_io_delay2;
                else if (shift_dq + temp_dq_io_delay1 < 0)
                        shift_dq = -temp_dq_io_delay1;

                debug_cond(DLEVEL == 2,
                           "vfifo_center: after: shift_dq[%u]=%d\n",
                           i, shift_dq);

                if (write)
                        scc_mgr_set_dq_out1_delay(i, temp_dq_io_delay1 + shift_dq);
                else
                        scc_mgr_set_dq_in_delay(p, temp_dq_io_delay1 + shift_dq);

                scc_mgr_load_dq(p);

                debug_cond(DLEVEL == 2,
                           "vfifo_center: margin[%u]=[%d,%d]\n", i,
                           left_edge[i] - shift_dq + (-mid_min),
                           right_edge[i] + shift_dq - (-mid_min));

                /* To determine values for export structures */
                if (left_edge[i] - shift_dq + (-mid_min) < *dq_margin)
                        *dq_margin = left_edge[i] - shift_dq + (-mid_min);

                if (right_edge[i] + shift_dq - (-mid_min) < *dqs_margin)
                        *dqs_margin = right_edge[i] + shift_dq - (-mid_min);
        }

}

/**
 * rw_mgr_mem_calibrate_vfifo_center() - Per-bit deskew DQ and centering
 * @rank_bgn:           Rank number
 * @rw_group:           Read/Write Group
 * @test_bgn:           Rank at which the test begins
 * @use_read_test:      Perform a read test
 * @update_fom:         Update FOM
 *
 * Per-bit deskew DQ and centering.
 */
static int rw_mgr_mem_calibrate_vfifo_center(const u32 rank_bgn,
                        const u32 rw_group, const u32 test_bgn,
                        const int use_read_test, const int update_fom)
{
        const u32 addr =
                SDR_PHYGRP_SCCGRP_ADDRESS + SCC_MGR_DQS_IN_DELAY_OFFSET +
                (rw_group << 2);
        /*
         * Store these as signed since there are comparisons with
         * signed numbers.
         */
        uint32_t sticky_bit_chk;
        int32_t left_edge[RW_MGR_MEM_DQ_PER_READ_DQS];
        int32_t right_edge[RW_MGR_MEM_DQ_PER_READ_DQS];
        int32_t orig_mid_min, mid_min;
        int32_t new_dqs, start_dqs, start_dqs_en, final_dqs_en;
        int32_t dq_margin, dqs_margin;
        int i, min_index;
        int ret;

        debug("%s:%d: %u %u", __func__, __LINE__, rw_group, test_bgn);

        start_dqs = readl(addr);
        if (IO_SHIFT_DQS_EN_WHEN_SHIFT_DQS)
                start_dqs_en = readl(addr - IO_DQS_EN_DELAY_OFFSET);

        /* set the left and right edge of each bit to an illegal value */
        /* use (IO_IO_IN_DELAY_MAX + 1) as an illegal value */
        sticky_bit_chk = 0;
        for (i = 0; i < RW_MGR_MEM_DQ_PER_READ_DQS; i++) {
                left_edge[i]  = IO_IO_IN_DELAY_MAX + 1;
                right_edge[i] = IO_IO_IN_DELAY_MAX + 1;
        }

        /* Search for the left edge of the window for each bit */
        search_left_edge(0, rank_bgn, rw_group, rw_group, test_bgn,
                         &sticky_bit_chk,
                         left_edge, right_edge, use_read_test);


        /* Search for the right edge of the window for each bit */
        ret = search_right_edge(0, rank_bgn, rw_group, rw_group,
                                start_dqs, start_dqs_en,
                                &sticky_bit_chk,
                                left_edge, right_edge, use_read_test);
        if (ret) {
                /*
                 * Restore delay chain settings before letting the loop
                 * in rw_mgr_mem_calibrate_vfifo to retry different
                 * dqs/ck relationships.
                 */
                scc_mgr_set_dqs_bus_in_delay(rw_group, start_dqs);
                if (IO_SHIFT_DQS_EN_WHEN_SHIFT_DQS)
                        scc_mgr_set_dqs_en_delay(rw_group, start_dqs_en);

                scc_mgr_load_dqs(rw_group);
                writel(0, &sdr_scc_mgr->update);

                debug_cond(DLEVEL == 1,
                           "%s:%d vfifo_center: failed to find edge [%u]: %d %d",
                           __func__, __LINE__, i, left_edge[i], right_edge[i]);
                if (use_read_test) {
                        set_failing_group_stage(rw_group *
                                RW_MGR_MEM_DQ_PER_READ_DQS + i,
                                CAL_STAGE_VFIFO,
                                CAL_SUBSTAGE_VFIFO_CENTER);
                } else {
                        set_failing_group_stage(rw_group *
                                RW_MGR_MEM_DQ_PER_READ_DQS + i,
                                CAL_STAGE_VFIFO_AFTER_WRITES,
                                CAL_SUBSTAGE_VFIFO_CENTER);
                }
                return -EIO;
        }

        min_index = get_window_mid_index(0, left_edge, right_edge, &mid_min);

        /* Determine the amount we can change DQS (which is -mid_min) */
        orig_mid_min = mid_min;
        new_dqs = start_dqs - mid_min;
        if (new_dqs > IO_DQS_IN_DELAY_MAX)
                new_dqs = IO_DQS_IN_DELAY_MAX;
        else if (new_dqs < 0)
                new_dqs = 0;

        mid_min = start_dqs - new_dqs;
        debug_cond(DLEVEL == 1, "vfifo_center: new mid_min=%d new_dqs=%d\n",
                   mid_min, new_dqs);

        if (IO_SHIFT_DQS_EN_WHEN_SHIFT_DQS) {
                if (start_dqs_en - mid_min > IO_DQS_EN_DELAY_MAX)
                        mid_min += start_dqs_en - mid_min - IO_DQS_EN_DELAY_MAX;
                else if (start_dqs_en - mid_min < 0)
                        mid_min += start_dqs_en - mid_min;
        }
        new_dqs = start_dqs - mid_min;

        debug_cond(DLEVEL == 1,
                   "vfifo_center: start_dqs=%d start_dqs_en=%d new_dqs=%d mid_min=%d\n",
                   start_dqs,
                   IO_SHIFT_DQS_EN_WHEN_SHIFT_DQS ? start_dqs_en : -1,
                   new_dqs, mid_min);

        /* Add delay to bring centre of all DQ windows to the same "level". */
        center_dq_windows(0, left_edge, right_edge, mid_min, orig_mid_min,
                          min_index, test_bgn, &dq_margin, &dqs_margin);

        /* Move DQS-en */
        if (IO_SHIFT_DQS_EN_WHEN_SHIFT_DQS) {
                final_dqs_en = start_dqs_en - mid_min;
                scc_mgr_set_dqs_en_delay(rw_group, final_dqs_en);
                scc_mgr_load_dqs(rw_group);
        }

        /* Move DQS */
        scc_mgr_set_dqs_bus_in_delay(rw_group, new_dqs);
        scc_mgr_load_dqs(rw_group);
        debug_cond(DLEVEL == 2,
                   "%s:%d vfifo_center: dq_margin=%d dqs_margin=%d",
                   __func__, __LINE__, dq_margin, dqs_margin);

        /*
         * Do not remove this line as it makes sure all of our decisions
         * have been applied. Apply the update bit.
         */
        writel(0, &sdr_scc_mgr->update);

        if ((dq_margin < 0) || (dqs_margin < 0))
                return -EINVAL;

        return 0;
}

/**
 * rw_mgr_mem_calibrate_guaranteed_write() - Perform guaranteed write into the device
 * @rw_group:   Read/Write Group
 * @phase:      DQ/DQS phase
 *
 * Because initially no communication ca be reliably performed with the memory
 * device, the sequencer uses a guaranteed write mechanism to write data into
 * the memory device.
 */
static int rw_mgr_mem_calibrate_guaranteed_write(const u32 rw_group,
                                                 const u32 phase)
{
        int ret;

        /* Set a particular DQ/DQS phase. */
        scc_mgr_set_dqdqs_output_phase_all_ranks(rw_group, phase);

        debug_cond(DLEVEL == 1, "%s:%d guaranteed write: g=%u p=%u\n",
                   __func__, __LINE__, rw_group, phase);

        /*
         * Altera EMI_RM 2015.05.04 :: Figure 1-25
         * Load up the patterns used by read calibration using the
         * current DQDQS phase.
         */
        rw_mgr_mem_calibrate_read_load_patterns(0, 1);

        if (gbl->phy_debug_mode_flags & PHY_DEBUG_DISABLE_GUARANTEED_READ)
                return 0;

        /*
         * Altera EMI_RM 2015.05.04 :: Figure 1-26
         * Back-to-Back reads of the patterns used for calibration.
         */
        ret = rw_mgr_mem_calibrate_read_test_patterns(0, rw_group, 1);
        if (ret)
                debug_cond(DLEVEL == 1,
                           "%s:%d Guaranteed read test failed: g=%u p=%u\n",
                           __func__, __LINE__, rw_group, phase);
        return ret;
}

/**
 * rw_mgr_mem_calibrate_dqs_enable_calibration() - DQS Enable Calibration
 * @rw_group:   Read/Write Group
 * @test_bgn:   Rank at which the test begins
 *
 * DQS enable calibration ensures reliable capture of the DQ signal without
 * glitches on the DQS line.
 */
static int rw_mgr_mem_calibrate_dqs_enable_calibration(const u32 rw_group,
                                                       const u32 test_bgn)
{
        /*
         * Altera EMI_RM 2015.05.04 :: Figure 1-27
         * DQS and DQS Eanble Signal Relationships.
         */

        /* We start at zero, so have one less dq to devide among */
        const u32 delay_step = IO_IO_IN_DELAY_MAX /
                               (RW_MGR_MEM_DQ_PER_READ_DQS - 1);
        int ret;
        u32 i, p, d, r;

        debug("%s:%d (%u,%u)\n", __func__, __LINE__, rw_group, test_bgn);

        /* Try different dq_in_delays since the DQ path is shorter than DQS. */
        for (r = 0; r < RW_MGR_MEM_NUMBER_OF_RANKS;
             r += NUM_RANKS_PER_SHADOW_REG) {
                for (i = 0, p = test_bgn, d = 0;
                     i < RW_MGR_MEM_DQ_PER_READ_DQS;
                     i++, p++, d += delay_step) {
                        debug_cond(DLEVEL == 1,
                                   "%s:%d: g=%u r=%u i=%u p=%u d=%u\n",
                                   __func__, __LINE__, rw_group, r, i, p, d);

                        scc_mgr_set_dq_in_delay(p, d);
                        scc_mgr_load_dq(p);
                }

                writel(0, &sdr_scc_mgr->update);
        }

        /*
         * Try rw_mgr_mem_calibrate_vfifo_find_dqs_en_phase across different
         * dq_in_delay values
         */
        ret = rw_mgr_mem_calibrate_vfifo_find_dqs_en_phase(rw_group);

        debug_cond(DLEVEL == 1,
                   "%s:%d: g=%u found=%u; Reseting delay chain to zero\n",
                   __func__, __LINE__, rw_group, !ret);

        for (r = 0; r < RW_MGR_MEM_NUMBER_OF_RANKS;
             r += NUM_RANKS_PER_SHADOW_REG) {
                scc_mgr_apply_group_dq_in_delay(test_bgn, 0);
                writel(0, &sdr_scc_mgr->update);
        }

        return ret;
}

/**
 * rw_mgr_mem_calibrate_dq_dqs_centering() - Centering DQ/DQS
 * @rw_group:           Read/Write Group
 * @test_bgn:           Rank at which the test begins
 * @use_read_test:      Perform a read test
 * @update_fom:         Update FOM
 *
 * The centerin DQ/DQS stage attempts to align DQ and DQS signals on reads
 * within a group.
 */
static int
rw_mgr_mem_calibrate_dq_dqs_centering(const u32 rw_group, const u32 test_bgn,
                                      const int use_read_test,
                                      const int update_fom)

{
        int ret, grp_calibrated;
        u32 rank_bgn, sr;

        /*
         * Altera EMI_RM 2015.05.04 :: Figure 1-28
         * Read per-bit deskew can be done on a per shadow register basis.
         */
        grp_calibrated = 1;
        for (rank_bgn = 0, sr = 0;
             rank_bgn < RW_MGR_MEM_NUMBER_OF_RANKS;
             rank_bgn += NUM_RANKS_PER_SHADOW_REG, sr++) {
                /* Check if this set of ranks should be skipped entirely. */
                if (param->skip_shadow_regs[sr])
                        continue;

                ret = rw_mgr_mem_calibrate_vfifo_center(rank_bgn, rw_group,
                                                        test_bgn,
                                                        use_read_test,
                                                        update_fom);
                if (!ret)
                        continue;

                grp_calibrated = 0;
        }

        if (!grp_calibrated)
                return -EIO;

        return 0;
}

/**
 * rw_mgr_mem_calibrate_vfifo() - Calibrate the read valid prediction FIFO
 * @rw_group:           Read/Write Group
 * @test_bgn:           Rank at which the test begins
 *
 * Stage 1: Calibrate the read valid prediction FIFO.
 *
 * This function implements UniPHY calibration Stage 1, as explained in
 * detail in Altera EMI_RM 2015.05.04 , "UniPHY Calibration Stages".
 *
 * - read valid prediction will consist of finding:
 *   - DQS enable phase and DQS enable delay (DQS Enable Calibration)
 *   - DQS input phase  and DQS input delay (DQ/DQS Centering)
 *  - we also do a per-bit deskew on the DQ lines.
 */
static int rw_mgr_mem_calibrate_vfifo(const u32 rw_group, const u32 test_bgn)
{
        uint32_t p, d;
        uint32_t dtaps_per_ptap;
        uint32_t failed_substage;

        int ret;

        debug("%s:%d: %u %u\n", __func__, __LINE__, rw_group, test_bgn);

        /* Update info for sims */
        reg_file_set_group(rw_group);
        reg_file_set_stage(CAL_STAGE_VFIFO);
        reg_file_set_sub_stage(CAL_SUBSTAGE_GUARANTEED_READ);

        failed_substage = CAL_SUBSTAGE_GUARANTEED_READ;

        /* USER Determine number of delay taps for each phase tap. */
        dtaps_per_ptap = DIV_ROUND_UP(IO_DELAY_PER_OPA_TAP,
                                      IO_DELAY_PER_DQS_EN_DCHAIN_TAP) - 1;

        for (d = 0; d <= dtaps_per_ptap; d += 2) {
                /*
                 * In RLDRAMX we may be messing the delay of pins in
                 * the same write rw_group but outside of the current read
                 * the rw_group, but that's ok because we haven't calibrated
                 * output side yet.
                 */
                if (d > 0) {
                        scc_mgr_apply_group_all_out_delay_add_all_ranks(
                                                                rw_group, d);
                }

                for (p = 0; p <= IO_DQDQS_OUT_PHASE_MAX; p++) {
                        /* 1) Guaranteed Write */
                        ret = rw_mgr_mem_calibrate_guaranteed_write(rw_group, p);
                        if (ret)
                                break;

                        /* 2) DQS Enable Calibration */
                        ret = rw_mgr_mem_calibrate_dqs_enable_calibration(rw_group,
                                                                          test_bgn);
                        if (ret) {
                                failed_substage = CAL_SUBSTAGE_DQS_EN_PHASE;
                                continue;
                        }

                        /* 3) Centering DQ/DQS */
                        /*
                         * If doing read after write calibration, do not update
                         * FOM now. Do it then.
                         */
                        ret = rw_mgr_mem_calibrate_dq_dqs_centering(rw_group,
                                                                test_bgn, 1, 0);
                        if (ret) {
                                failed_substage = CAL_SUBSTAGE_VFIFO_CENTER;
                                continue;
                        }

                        /* All done. */
                        goto cal_done_ok;
                }
        }

        /* Calibration Stage 1 failed. */
        set_failing_group_stage(rw_group, CAL_STAGE_VFIFO, failed_substage);
        return 0;

        /* Calibration Stage 1 completed OK. */
cal_done_ok:
        /*
         * Reset the delay chains back to zero if they have moved > 1
         * (check for > 1 because loop will increase d even when pass in
         * first case).
         */
        if (d > 2)
                scc_mgr_zero_group(rw_group, 1);

        return 1;
}

/**
 * rw_mgr_mem_calibrate_vfifo_end() - DQ/DQS Centering.
 * @rw_group:           Read/Write Group
 * @test_bgn:           Rank at which the test begins
 *
 * Stage 3: DQ/DQS Centering.
 *
 * This function implements UniPHY calibration Stage 3, as explained in
 * detail in Altera EMI_RM 2015.05.04 , "UniPHY Calibration Stages".
 */
static int rw_mgr_mem_calibrate_vfifo_end(const u32 rw_group,
                                          const u32 test_bgn)
{
        int ret;

        debug("%s:%d %u %u", __func__, __LINE__, rw_group, test_bgn);

        /* Update info for sims. */
        reg_file_set_group(rw_group);
        reg_file_set_stage(CAL_STAGE_VFIFO_AFTER_WRITES);
        reg_file_set_sub_stage(CAL_SUBSTAGE_VFIFO_CENTER);

        ret = rw_mgr_mem_calibrate_dq_dqs_centering(rw_group, test_bgn, 0, 1);
        if (ret)
                set_failing_group_stage(rw_group,
                                        CAL_STAGE_VFIFO_AFTER_WRITES,
                                        CAL_SUBSTAGE_VFIFO_CENTER);
        return ret;
}

/**
 * rw_mgr_mem_calibrate_lfifo() - Minimize latency
 *
 * Stage 4: Minimize latency.
 *
 * This function implements UniPHY calibration Stage 4, as explained in
 * detail in Altera EMI_RM 2015.05.04 , "UniPHY Calibration Stages".
 * Calibrate LFIFO to find smallest read latency.
 */
static uint32_t rw_mgr_mem_calibrate_lfifo(void)
{
        int found_one = 0;

        debug("%s:%d\n", __func__, __LINE__);

        /* Update info for sims. */
        reg_file_set_stage(CAL_STAGE_LFIFO);
        reg_file_set_sub_stage(CAL_SUBSTAGE_READ_LATENCY);

        /* Load up the patterns used by read calibration for all ranks */
        rw_mgr_mem_calibrate_read_load_patterns(0, 1);

        do {
                writel(gbl->curr_read_lat, &phy_mgr_cfg->phy_rlat);
                debug_cond(DLEVEL == 2, "%s:%d lfifo: read_lat=%u",
                           __func__, __LINE__, gbl->curr_read_lat);

                if (!rw_mgr_mem_calibrate_read_test_all_ranks(0, NUM_READ_TESTS,
                                                              PASS_ALL_BITS, 1))
                        break;

                found_one = 1;
                /*
                 * Reduce read latency and see if things are
                 * working correctly.
                 */
                gbl->curr_read_lat--;
        } while (gbl->curr_read_lat > 0);

        /* Reset the fifos to get pointers to known state. */
        writel(0, &phy_mgr_cmd->fifo_reset);

        if (found_one) {
                /* Add a fudge factor to the read latency that was determined */
                gbl->curr_read_lat += 2;
                writel(gbl->curr_read_lat, &phy_mgr_cfg->phy_rlat);
                debug_cond(DLEVEL == 2,
                           "%s:%d lfifo: success: using read_lat=%u\n",
                           __func__, __LINE__, gbl->curr_read_lat);
        } else {
                set_failing_group_stage(0xff, CAL_STAGE_LFIFO,
                                        CAL_SUBSTAGE_READ_LATENCY);

                debug_cond(DLEVEL == 2,
                           "%s:%d lfifo: failed at initial read_lat=%u\n",
                           __func__, __LINE__, gbl->curr_read_lat);
        }

        return found_one;
}

/**
 * search_window() - Search for the/part of the window with DM/DQS shift
 * @search_dm:          If 1, search for the DM shift, if 0, search for DQS shift
 * @rank_bgn:           Rank number
 * @write_group:        Write Group
 * @bgn_curr:           Current window begin
 * @end_curr:           Current window end
 * @bgn_best:           Current best window begin
 * @end_best:           Current best window end
 * @win_best:           Size of the best window
 * @new_dqs:            New DQS value (only applicable if search_dm = 0).
 *
 * Search for the/part of the window with DM/DQS shift.
 */
static void search_window(const int search_dm,
                          const u32 rank_bgn, const u32 write_group,
                          int *bgn_curr, int *end_curr, int *bgn_best,
                          int *end_best, int *win_best, int new_dqs)
{
        u32 bit_chk;
        const int max = IO_IO_OUT1_DELAY_MAX - new_dqs;
        int d, di;

        /* Search for the/part of the window with DM/DQS shift. */
        for (di = max; di >= 0; di -= DELTA_D) {
                if (search_dm) {
                        d = di;
                        scc_mgr_apply_group_dm_out1_delay(d);
                } else {
                        /* For DQS, we go from 0...max */
                        d = max - di;
                        /*
                         * Note: This only shifts DQS, so are we limiting ourselve to
                         * width of DQ unnecessarily.
                         */
                        scc_mgr_apply_group_dqs_io_and_oct_out1(write_group,
                                                                d + new_dqs);
                }

                writel(0, &sdr_scc_mgr->update);

                if (rw_mgr_mem_calibrate_write_test(rank_bgn, write_group, 1,
                                                    PASS_ALL_BITS, &bit_chk,
                                                    0)) {
                        /* Set current end of the window. */
                        *end_curr = search_dm ? -d : d;

                        /*
                         * If a starting edge of our window has not been seen
                         * this is our current start of the DM window.
                         */
                        if (*bgn_curr == IO_IO_OUT1_DELAY_MAX + 1)
                                *bgn_curr = search_dm ? -d : d;

                        /*
                         * If current window is bigger than best seen.
                         * Set best seen to be current window.
                         */
                        if ((*end_curr - *bgn_curr + 1) > *win_best) {
                                *win_best = *end_curr - *bgn_curr + 1;
                                *bgn_best = *bgn_curr;
                                *end_best = *end_curr;
                        }
                } else {
                        /* We just saw a failing test. Reset temp edge. */
                        *bgn_curr = IO_IO_OUT1_DELAY_MAX + 1;
                        *end_curr = IO_IO_OUT1_DELAY_MAX + 1;

                        /* Early exit is only applicable to DQS. */
                        if (search_dm)
                                continue;

                        /*
                         * Early exit optimization: if the remaining delay
                         * chain space is less than already seen largest
                         * window we can exit.
                         */
                        if (*win_best - 1 > IO_IO_OUT1_DELAY_MAX - new_dqs - d)
                                break;
                }
        }
}

/*
 * rw_mgr_mem_calibrate_writes_center() - Center all windows
 * @rank_bgn:           Rank number
 * @write_group:        Write group
 * @test_bgn:           Rank at which the test begins
 *
 * Center all windows. Do per-bit-deskew to possibly increase size of
 * certain windows.
 */
static int
rw_mgr_mem_calibrate_writes_center(const u32 rank_bgn, const u32 write_group,
                                   const u32 test_bgn)
{
        int i;
        u32 sticky_bit_chk;
        u32 min_index;
        int left_edge[RW_MGR_MEM_DQ_PER_WRITE_DQS];
        int right_edge[RW_MGR_MEM_DQ_PER_WRITE_DQS];
        int mid;
        int mid_min, orig_mid_min;
        int new_dqs, start_dqs;
        int dq_margin, dqs_margin, dm_margin;
        int bgn_curr = IO_IO_OUT1_DELAY_MAX + 1;
        int end_curr = IO_IO_OUT1_DELAY_MAX + 1;
        int bgn_best = IO_IO_OUT1_DELAY_MAX + 1;
        int end_best = IO_IO_OUT1_DELAY_MAX + 1;
        int win_best = 0;

        int ret;

        debug("%s:%d %u %u", __func__, __LINE__, write_group, test_bgn);

        dm_margin = 0;

        start_dqs = readl((SDR_PHYGRP_SCCGRP_ADDRESS |
                          SCC_MGR_IO_OUT1_DELAY_OFFSET) +
                          (RW_MGR_MEM_DQ_PER_WRITE_DQS << 2));

        /* Per-bit deskew. */

        /*
         * Set the left and right edge of each bit to an illegal value.
         * Use (IO_IO_OUT1_DELAY_MAX + 1) as an illegal value.
         */
        sticky_bit_chk = 0;
        for (i = 0; i < RW_MGR_MEM_DQ_PER_WRITE_DQS; i++) {
                left_edge[i]  = IO_IO_OUT1_DELAY_MAX + 1;
                right_edge[i] = IO_IO_OUT1_DELAY_MAX + 1;
        }

        /* Search for the left edge of the window for each bit. */
        search_left_edge(1, rank_bgn, write_group, 0, test_bgn,
                         &sticky_bit_chk,
                         left_edge, right_edge, 0);

        /* Search for the right edge of the window for each bit. */
        ret = search_right_edge(1, rank_bgn, write_group, 0,
                                start_dqs, 0,
                                &sticky_bit_chk,
                                left_edge, right_edge, 0);
        if (ret) {
                set_failing_group_stage(test_bgn + ret - 1, CAL_STAGE_WRITES,
                                        CAL_SUBSTAGE_WRITES_CENTER);
                return -EINVAL;
        }

        min_index = get_window_mid_index(1, left_edge, right_edge, &mid_min);

        /* Determine the amount we can change DQS (which is -mid_min). */
        orig_mid_min = mid_min;
        new_dqs = start_dqs;
        mid_min = 0;
        debug_cond(DLEVEL == 1,
                   "%s:%d write_center: start_dqs=%d new_dqs=%d mid_min=%d\n",
                   __func__, __LINE__, start_dqs, new_dqs, mid_min);

        /* Add delay to bring centre of all DQ windows to the same "level". */
        center_dq_windows(1, left_edge, right_edge, mid_min, orig_mid_min,
                          min_index, 0, &dq_margin, &dqs_margin);

        /* Move DQS */
        scc_mgr_apply_group_dqs_io_and_oct_out1(write_group, new_dqs);
        writel(0, &sdr_scc_mgr->update);

        /* Centre DM */
        debug_cond(DLEVEL == 2, "%s:%d write_center: DM\n", __func__, __LINE__);

        /*
         * Set the left and right edge of each bit to an illegal value.
         * Use (IO_IO_OUT1_DELAY_MAX + 1) as an illegal value.
         */
        left_edge[0]  = IO_IO_OUT1_DELAY_MAX + 1;
        right_edge[0] = IO_IO_OUT1_DELAY_MAX + 1;

        /* Search for the/part of the window with DM shift. */
        search_window(1, rank_bgn, write_group, &bgn_curr, &end_curr,
                      &bgn_best, &end_best, &win_best, 0);

        /* Reset DM delay chains to 0. */
        scc_mgr_apply_group_dm_out1_delay(0);

        /*
         * Check to see if the current window nudges up aganist 0 delay.
         * If so we need to continue the search by shifting DQS otherwise DQS
         * search begins as a new search.
         */
        if (end_curr != 0) {
                bgn_curr = IO_IO_OUT1_DELAY_MAX + 1;
                end_curr = IO_IO_OUT1_DELAY_MAX + 1;
        }

        /* Search for the/part of the window with DQS shifts. */
        search_window(0, rank_bgn, write_group, &bgn_curr, &end_curr,
                      &bgn_best, &end_best, &win_best, new_dqs);

        /* Assign left and right edge for cal and reporting. */
        left_edge[0] = -1 * bgn_best;
        right_edge[0] = end_best;

        debug_cond(DLEVEL == 2, "%s:%d dm_calib: left=%d right=%d\n",
                   __func__, __LINE__, left_edge[0], right_edge[0]);

        /* Move DQS (back to orig). */
        scc_mgr_apply_group_dqs_io_and_oct_out1(write_group, new_dqs);

        /* Move DM */

        /* Find middle of window for the DM bit. */
        mid = (left_edge[0] - right_edge[0]) / 2;

        /* Only move right, since we are not moving DQS/DQ. */
        if (mid < 0)
                mid = 0;

        /* dm_marign should fail if we never find a window. */
        if (win_best == 0)
                dm_margin = -1;
        else
                dm_margin = left_edge[0] - mid;

        scc_mgr_apply_group_dm_out1_delay(mid);
        writel(0, &sdr_scc_mgr->update);

        debug_cond(DLEVEL == 2,
                   "%s:%d dm_calib: left=%d right=%d mid=%d dm_margin=%d\n",
                   __func__, __LINE__, left_edge[0], right_edge[0],
                   mid, dm_margin);
        /* Export values. */
        gbl->fom_out += dq_margin + dqs_margin;

        debug_cond(DLEVEL == 2,
                   "%s:%d write_center: dq_margin=%d dqs_margin=%d dm_margin=%d\n",
                   __func__, __LINE__, dq_margin, dqs_margin, dm_margin);

        /*
         * Do not remove this line as it makes sure all of our
         * decisions have been applied.
         */
        writel(0, &sdr_scc_mgr->update);

        if ((dq_margin < 0) || (dqs_margin < 0) || (dm_margin < 0))
                return -EINVAL;

        return 0;
}

/**
 * rw_mgr_mem_calibrate_writes() - Write Calibration Part One
 * @rank_bgn:           Rank number
 * @group:              Read/Write Group
 * @test_bgn:           Rank at which the test begins
 *
 * Stage 2: Write Calibration Part One.
 *
 * This function implements UniPHY calibration Stage 2, as explained in
 * detail in Altera EMI_RM 2015.05.04 , "UniPHY Calibration Stages".
 */
static int rw_mgr_mem_calibrate_writes(const u32 rank_bgn, const u32 group,
                                       const u32 test_bgn)
{
        int ret;

        /* Update info for sims */
        debug("%s:%d %u %u\n", __func__, __LINE__, group, test_bgn);

        reg_file_set_group(group);
        reg_file_set_stage(CAL_STAGE_WRITES);
        reg_file_set_sub_stage(CAL_SUBSTAGE_WRITES_CENTER);

        ret = rw_mgr_mem_calibrate_writes_center(rank_bgn, group, test_bgn);
        if (ret)
                set_failing_group_stage(group, CAL_STAGE_WRITES,
                                        CAL_SUBSTAGE_WRITES_CENTER);

        return ret;
}

/**
 * mem_precharge_and_activate() - Precharge all banks and activate
 *
 * Precharge all banks and activate row 0 in bank "000..." and bank "111...".
 */
static void mem_precharge_and_activate(void)
{
        int r;

        for (r = 0; r < RW_MGR_MEM_NUMBER_OF_RANKS; r++) {
                /* Test if the rank should be skipped. */
                if (param->skip_ranks[r])
                        continue;

                /* Set rank. */
                set_rank_and_odt_mask(r, RW_MGR_ODT_MODE_OFF);

                /* Precharge all banks. */
                writel(RW_MGR_PRECHARGE_ALL, SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                             RW_MGR_RUN_SINGLE_GROUP_OFFSET);

                writel(0x0F, &sdr_rw_load_mgr_regs->load_cntr0);
                writel(RW_MGR_ACTIVATE_0_AND_1_WAIT1,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add0);

                writel(0x0F, &sdr_rw_load_mgr_regs->load_cntr1);
                writel(RW_MGR_ACTIVATE_0_AND_1_WAIT2,
                        &sdr_rw_load_jump_mgr_regs->load_jump_add1);

                /* Activate rows. */
                writel(RW_MGR_ACTIVATE_0_AND_1, SDR_PHYGRP_RWMGRGRP_ADDRESS |
                                                RW_MGR_RUN_SINGLE_GROUP_OFFSET);
        }
}

/**
 * mem_init_latency() - Configure memory RLAT and WLAT settings
 *
 * Configure memory RLAT and WLAT parameters.
 */
static void mem_init_latency(void)
{
        /*
         * For AV/CV, LFIFO is hardened and always runs at full rate
         * so max latency in AFI clocks, used here, is correspondingly
         * smaller.
         */
        const u32 max_latency = (1 << MAX_LATENCY_COUNT_WIDTH) - 1;
        u32 rlat, wlat;

        debug("%s:%d\n", __func__, __LINE__);

        /*
         * Read in write latency.
         * WL for Hard PHY does not include additive latency.
         */
        wlat = readl(&data_mgr->t_wl_add);
        wlat += readl(&data_mgr->mem_t_add);

        gbl->rw_wl_nop_cycles = wlat - 1;

        /* Read in readl latency. */
        rlat = readl(&data_mgr->t_rl_add);

        /* Set a pretty high read latency initially. */
        gbl->curr_read_lat = rlat + 16;
        if (gbl->curr_read_lat > max_latency)
                gbl->curr_read_lat = max_latency;

        writel(gbl->curr_read_lat, &phy_mgr_cfg->phy_rlat);

        /* Advertise write latency. */
        writel(wlat, &phy_mgr_cfg->afi_wlat);
}

/**
 * @mem_skip_calibrate() - Set VFIFO and LFIFO to instant-on settings
 *
 * Set VFIFO and LFIFO to instant-on settings in skip calibration mode.
 */
static void mem_skip_calibrate(void)
{
        uint32_t vfifo_offset;
        uint32_t i, j, r;

        debug("%s:%d\n", __func__, __LINE__);
        /* Need to update every shadow register set used by the interface */
        for (r = 0; r < RW_MGR_MEM_NUMBER_OF_RANKS;
             r += NUM_RANKS_PER_SHADOW_REG) {
                /*
                 * Set output phase alignment settings appropriate for
                 * skip calibration.
                 */
                for (i = 0; i < RW_MGR_MEM_IF_READ_DQS_WIDTH; i++) {
                        scc_mgr_set_dqs_en_phase(i, 0);
#if IO_DLL_CHAIN_LENGTH == 6
                        scc_mgr_set_dqdqs_output_phase(i, 6);
#else
                        scc_mgr_set_dqdqs_output_phase(i, 7);
#endif
                        /*
                         * Case:33398
                         *
                         * Write data arrives to the I/O two cycles before write
                         * latency is reached (720 deg).
                         *   -> due to bit-slip in a/c bus
                         *   -> to allow board skew where dqs is longer than ck
                         *      -> how often can this happen!?
                         *      -> can claim back some ptaps for high freq
                         *       support if we can relax this, but i digress...
                         *
                         * The write_clk leads mem_ck by 90 deg
                         * The minimum ptap of the OPA is 180 deg
                         * Each ptap has (360 / IO_DLL_CHAIN_LENGH) deg of delay
                         * The write_clk is always delayed by 2 ptaps
                         *
                         * Hence, to make DQS aligned to CK, we need to delay
                         * DQS by:
                         *    (720 - 90 - 180 - 2 * (360 / IO_DLL_CHAIN_LENGTH))
                         *
                         * Dividing the above by (360 / IO_DLL_CHAIN_LENGTH)
                         * gives us the number of ptaps, which simplies to:
                         *
                         *    (1.25 * IO_DLL_CHAIN_LENGTH - 2)
                         */
                        scc_mgr_set_dqdqs_output_phase(i,
                                        1.25 * IO_DLL_CHAIN_LENGTH - 2);
                }
                writel(0xff, &sdr_scc_mgr->dqs_ena);
                writel(0xff, &sdr_scc_mgr->dqs_io_ena);

                for (i = 0; i < RW_MGR_MEM_IF_WRITE_DQS_WIDTH; i++) {
                        writel(i, SDR_PHYGRP_SCCGRP_ADDRESS |
                                  SCC_MGR_GROUP_COUNTER_OFFSET);
                }
                writel(0xff, &sdr_scc_mgr->dq_ena);
                writel(0xff, &sdr_scc_mgr->dm_ena);
                writel(0, &sdr_scc_mgr->update);
        }

        /* Compensate for simulation model behaviour */
        for (i = 0; i < RW_MGR_MEM_IF_READ_DQS_WIDTH; i++) {
                scc_mgr_set_dqs_bus_in_delay(i, 10);
                scc_mgr_load_dqs(i);
        }
        writel(0, &sdr_scc_mgr->update);

        /*
         * ArriaV has hard FIFOs that can only be initialized by incrementing
         * in sequencer.
         */
        vfifo_offset = CALIB_VFIFO_OFFSET;
        for (j = 0; j < vfifo_offset; j++)
                writel(0xff, &phy_mgr_cmd->inc_vfifo_hard_phy);
        writel(0, &phy_mgr_cmd->fifo_reset);

        /*
         * For Arria V and Cyclone V with hard LFIFO, we get the skip-cal
         * setting from generation-time constant.
         */
        gbl->curr_read_lat = CALIB_LFIFO_OFFSET;
        writel(gbl->curr_read_lat, &phy_mgr_cfg->phy_rlat);
}

/**
 * mem_calibrate() - Memory calibration entry point.
 *
 * Perform memory calibration.
 */
static uint32_t mem_calibrate(void)
{
        uint32_t i;
        uint32_t rank_bgn, sr;
        uint32_t write_group, write_test_bgn;
        uint32_t read_group, read_test_bgn;
        uint32_t run_groups, current_run;
        uint32_t failing_groups = 0;
        uint32_t group_failed = 0;

        const u32 rwdqs_ratio = RW_MGR_MEM_IF_READ_DQS_WIDTH /
                                RW_MGR_MEM_IF_WRITE_DQS_WIDTH;

        debug("%s:%d\n", __func__, __LINE__);

        /* Initialize the data settings */
        gbl->error_substage = CAL_SUBSTAGE_NIL;
        gbl->error_stage = CAL_STAGE_NIL;
        gbl->error_group = 0xff;
        gbl->fom_in = 0;
        gbl->fom_out = 0;

        /* Initialize WLAT and RLAT. */
        mem_init_latency();

        /* Initialize bit slips. */
        mem_precharge_and_activate();

        for (i = 0; i < RW_MGR_MEM_IF_READ_DQS_WIDTH; i++) {
                writel(i, SDR_PHYGRP_SCCGRP_ADDRESS |
                          SCC_MGR_GROUP_COUNTER_OFFSET);
                /* Only needed once to set all groups, pins, DQ, DQS, DM. */
                if (i == 0)
                        scc_mgr_set_hhp_extras();

                scc_set_bypass_mode(i);
        }

        /* Calibration is skipped. */
        if ((dyn_calib_steps & CALIB_SKIP_ALL) == CALIB_SKIP_ALL) {
                /*
                 * Set VFIFO and LFIFO to instant-on settings in skip
                 * calibration mode.
                 */
                mem_skip_calibrate();

                /*
                 * Do not remove this line as it makes sure all of our
                 * decisions have been applied.
                 */
                writel(0, &sdr_scc_mgr->update);
                return 1;
        }

        /* Calibration is not skipped. */
        for (i = 0; i < NUM_CALIB_REPEAT; i++) {
                /*
                 * Zero all delay chain/phase settings for all
                 * groups and all shadow register sets.
                 */
                scc_mgr_zero_all();

                run_groups = ~param->skip_groups;

                for (write_group = 0, write_test_bgn = 0; write_group
                        < RW_MGR_MEM_IF_WRITE_DQS_WIDTH; write_group++,
                        write_test_bgn += RW_MGR_MEM_DQ_PER_WRITE_DQS) {

                        /* Initialize the group failure */
                        group_failed = 0;

                        current_run = run_groups & ((1 <<
                                RW_MGR_NUM_DQS_PER_WRITE_GROUP) - 1);
                        run_groups = run_groups >>
                                RW_MGR_NUM_DQS_PER_WRITE_GROUP;

                        if (current_run == 0)
                                continue;

                        writel(write_group, SDR_PHYGRP_SCCGRP_ADDRESS |
                                            SCC_MGR_GROUP_COUNTER_OFFSET);
                        scc_mgr_zero_group(write_group, 0);

                        for (read_group = write_group * rwdqs_ratio,
                             read_test_bgn = 0;
                             read_group < (write_group + 1) * rwdqs_ratio;
                             read_group++,
                             read_test_bgn += RW_MGR_MEM_DQ_PER_READ_DQS) {
                                if (STATIC_CALIB_STEPS & CALIB_SKIP_VFIFO)
                                        continue;

                                /* Calibrate the VFIFO */
                                if (rw_mgr_mem_calibrate_vfifo(read_group,
                                                               read_test_bgn))
                                        continue;

                                if (!(gbl->phy_debug_mode_flags & PHY_DEBUG_SWEEP_ALL_GROUPS))
                                        return 0;

                                /* The group failed, we're done. */
                                goto grp_failed;
                        }

                        /* Calibrate the output side */
                        for (rank_bgn = 0, sr = 0;
                             rank_bgn < RW_MGR_MEM_NUMBER_OF_RANKS;
                             rank_bgn += NUM_RANKS_PER_SHADOW_REG, sr++) {
                                if (STATIC_CALIB_STEPS & CALIB_SKIP_WRITES)
                                        continue;

                                /* Not needed in quick mode! */
                                if (STATIC_CALIB_STEPS & CALIB_SKIP_DELAY_SWEEPS)
                                        continue;

                                /*
                                 * Determine if this set of ranks
                                 * should be skipped entirely.
                                 */
                                if (param->skip_shadow_regs[sr])
                                        continue;

                                /* Calibrate WRITEs */
                                if (!rw_mgr_mem_calibrate_writes(rank_bgn,
                                                write_group, write_test_bgn))
                                        continue;

                                group_failed = 1;
                                if (!(gbl->phy_debug_mode_flags & PHY_DEBUG_SWEEP_ALL_GROUPS))
                                        return 0;
                        }

                        /* Some group failed, we're done. */
                        if (group_failed)
                                goto grp_failed;

                        for (read_group = write_group * rwdqs_ratio,
                             read_test_bgn = 0;
                             read_group < (write_group + 1) * rwdqs_ratio;
                             read_group++,
                             read_test_bgn += RW_MGR_MEM_DQ_PER_READ_DQS) {
                                if (STATIC_CALIB_STEPS & CALIB_SKIP_WRITES)
                                        continue;

                                if (!rw_mgr_mem_calibrate_vfifo_end(read_group,
                                                                read_test_bgn))
                                        continue;

                                if (!(gbl->phy_debug_mode_flags & PHY_DEBUG_SWEEP_ALL_GROUPS))
                                        return 0;

                                /* The group failed, we're done. */
                                goto grp_failed;
                        }

                        /* No group failed, continue as usual. */
                        continue;

grp_failed:             /* A group failed, increment the counter. */
                        failing_groups++;
                }

                /*
                 * USER If there are any failing groups then report
                 * the failure.
                 */
                if (failing_groups != 0)
                        return 0;

                if (STATIC_CALIB_STEPS & CALIB_SKIP_LFIFO)
                        continue;

                /*
                 * If we're skipping groups as part of debug,
                 * don't calibrate LFIFO.
                 */
                if (param->skip_groups != 0)
                        continue;

                /* Calibrate the LFIFO */
                if (!rw_mgr_mem_calibrate_lfifo())
                        return 0;
        }

        /*
         * Do not remove this line as it makes sure all of our decisions
         * have been applied.
         */
        writel(0, &sdr_scc_mgr->update);
        return 1;
}

/**
 * run_mem_calibrate() - Perform memory calibration
 *
 * This function triggers the entire memory calibration procedure.
 */
static int run_mem_calibrate(void)
{
        int pass;

        debug("%s:%d\n", __func__, __LINE__);

        /* Reset pass/fail status shown on afi_cal_success/fail */
        writel(PHY_MGR_CAL_RESET, &phy_mgr_cfg->cal_status);

        /* Stop tracking manager. */
        clrbits_le32(&sdr_ctrl->ctrl_cfg, 1 << 22);

        phy_mgr_initialize();
        rw_mgr_mem_initialize();

        /* Perform the actual memory calibration. */
        pass = mem_calibrate();

        mem_precharge_and_activate();
        writel(0, &phy_mgr_cmd->fifo_reset);

        /* Handoff. */
        rw_mgr_mem_handoff();
        /*
         * In Hard PHY this is a 2-bit control:
         * 0: AFI Mux Select
         * 1: DDIO Mux Select
         */
        writel(0x2, &phy_mgr_cfg->mux_sel);

        /* Start tracking manager. */
        setbits_le32(&sdr_ctrl->ctrl_cfg, 1 << 22);

        return pass;
}

/**
 * debug_mem_calibrate() - Report result of memory calibration
 * @pass:       Value indicating whether calibration passed or failed
 *
 * This function reports the results of the memory calibration
 * and writes debug information into the register file.
 */
static void debug_mem_calibrate(int pass)
{
        uint32_t debug_info;

        if (pass) {
                printf("%s: CALIBRATION PASSED\n", __FILE__);

                gbl->fom_in /= 2;
                gbl->fom_out /= 2;

                if (gbl->fom_in > 0xff)
                        gbl->fom_in = 0xff;

                if (gbl->fom_out > 0xff)
                        gbl->fom_out = 0xff;

                /* Update the FOM in the register file */
                debug_info = gbl->fom_in;
                debug_info |= gbl->fom_out << 8;
                writel(debug_info, &sdr_reg_file->fom);

                writel(debug_info, &phy_mgr_cfg->cal_debug_info);
                writel(PHY_MGR_CAL_SUCCESS, &phy_mgr_cfg->cal_status);
        } else {
                printf("%s: CALIBRATION FAILED\n", __FILE__);

                debug_info = gbl->error_stage;
                debug_info |= gbl->error_substage << 8;
                debug_info |= gbl->error_group << 16;

                writel(debug_info, &sdr_reg_file->failing_stage);
                writel(debug_info, &phy_mgr_cfg->cal_debug_info);
                writel(PHY_MGR_CAL_FAIL, &phy_mgr_cfg->cal_status);

                /* Update the failing group/stage in the register file */
                debug_info = gbl->error_stage;
                debug_info |= gbl->error_substage << 8;
                debug_info |= gbl->error_group << 16;
                writel(debug_info, &sdr_reg_file->failing_stage);
        }

        printf("%s: Calibration complete\n", __FILE__);
}

/**
 * hc_initialize_rom_data() - Initialize ROM data
 *
 * Initialize ROM data.
 */
static void hc_initialize_rom_data(void)
{
        u32 i, addr;

        addr = SDR_PHYGRP_RWMGRGRP_ADDRESS | RW_MGR_INST_ROM_WRITE_OFFSET;
        for (i = 0; i < ARRAY_SIZE(inst_rom_init); i++)
                writel(inst_rom_init[i], addr + (i << 2));

        addr = SDR_PHYGRP_RWMGRGRP_ADDRESS | RW_MGR_AC_ROM_WRITE_OFFSET;
        for (i = 0; i < ARRAY_SIZE(ac_rom_init); i++)
                writel(ac_rom_init[i], addr + (i << 2));
}

/**
 * initialize_reg_file() - Initialize SDR register file
 *
 * Initialize SDR register file.
 */
static void initialize_reg_file(void)
{
        /* Initialize the register file with the correct data */
        writel(REG_FILE_INIT_SEQ_SIGNATURE, &sdr_reg_file->signature);
        writel(0, &sdr_reg_file->debug_data_addr);
        writel(0, &sdr_reg_file->cur_stage);
        writel(0, &sdr_reg_file->fom);
        writel(0, &sdr_reg_file->failing_stage);
        writel(0, &sdr_reg_file->debug1);
        writel(0, &sdr_reg_file->debug2);
}

/**
 * initialize_hps_phy() - Initialize HPS PHY
 *
 * Initialize HPS PHY.
 */
static void initialize_hps_phy(void)
{
        uint32_t reg;
        /*
         * Tracking also gets configured here because it's in the
         * same register.
         */
        uint32_t trk_sample_count = 7500;
        uint32_t trk_long_idle_sample_count = (10 << 16) | 100;
        /*
         * Format is number of outer loops in the 16 MSB, sample
         * count in 16 LSB.
         */

        reg = 0;
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_0_ACDELAYEN_SET(2);
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_0_DQDELAYEN_SET(1);
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_0_DQSDELAYEN_SET(1);
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_0_DQSLOGICDELAYEN_SET(1);
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_0_RESETDELAYEN_SET(0);
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_0_LPDDRDIS_SET(1);
        /*
         * This field selects the intrinsic latency to RDATA_EN/FULL path.
         * 00-bypass, 01- add 5 cycles, 10- add 10 cycles, 11- add 15 cycles.
         */
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_0_ADDLATSEL_SET(0);
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_0_SAMPLECOUNT_19_0_SET(
                trk_sample_count);
        writel(reg, &sdr_ctrl->phy_ctrl0);

        reg = 0;
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_1_SAMPLECOUNT_31_20_SET(
                trk_sample_count >>
                SDR_CTRLGRP_PHYCTRL_PHYCTRL_0_SAMPLECOUNT_19_0_WIDTH);
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_1_LONGIDLESAMPLECOUNT_19_0_SET(
                trk_long_idle_sample_count);
        writel(reg, &sdr_ctrl->phy_ctrl1);

        reg = 0;
        reg |= SDR_CTRLGRP_PHYCTRL_PHYCTRL_2_LONGIDLESAMPLECOUNT_31_20_SET(
                trk_long_idle_sample_count >>
                SDR_CTRLGRP_PHYCTRL_PHYCTRL_1_LONGIDLESAMPLECOUNT_19_0_WIDTH);
        writel(reg, &sdr_ctrl->phy_ctrl2);
}

/**
 * initialize_tracking() - Initialize tracking
 *
 * Initialize the register file with usable initial data.
 */
static void initialize_tracking(void)
{
        /*
         * Initialize the register file with the correct data.
         * Compute usable version of value in case we skip full
         * computation later.
         */
        writel(DIV_ROUND_UP(IO_DELAY_PER_OPA_TAP, IO_DELAY_PER_DCHAIN_TAP) - 1,
               &sdr_reg_file->dtaps_per_ptap);

        /* trk_sample_count */
        writel(7500, &sdr_reg_file->trk_sample_count);

        /* longidle outer loop [15:0] */
        writel((10 << 16) | (100 << 0), &sdr_reg_file->trk_longidle);

        /*
         * longidle sample count [31:24]
         * trfc, worst case of 933Mhz 4Gb [23:16]
         * trcd, worst case [15:8]
         * vfifo wait [7:0]
         */
        writel((243 << 24) | (14 << 16) | (10 << 8) | (4 << 0),
               &sdr_reg_file->delays);

        /* mux delay */
        writel((RW_MGR_IDLE << 24) | (RW_MGR_ACTIVATE_1 << 16) |
               (RW_MGR_SGLE_READ << 8) | (RW_MGR_PRECHARGE_ALL << 0),
               &sdr_reg_file->trk_rw_mgr_addr);

        writel(RW_MGR_MEM_IF_READ_DQS_WIDTH,
               &sdr_reg_file->trk_read_dqs_width);

        /* trefi [7:0] */
        writel((RW_MGR_REFRESH_ALL << 24) | (1000 << 0),
               &sdr_reg_file->trk_rfsh);
}

int sdram_calibration_full(void)
{
        struct param_type my_param;
        struct gbl_type my_gbl;
        uint32_t pass;

        memset(&my_param, 0, sizeof(my_param));
        memset(&my_gbl, 0, sizeof(my_gbl));

        param = &my_param;
        gbl = &my_gbl;

        /* Set the calibration enabled by default */
        gbl->phy_debug_mode_flags |= PHY_DEBUG_ENABLE_CAL_RPT;
        /*
         * Only sweep all groups (regardless of fail state) by default
         * Set enabled read test by default.
         */
#if DISABLE_GUARANTEED_READ
        gbl->phy_debug_mode_flags |= PHY_DEBUG_DISABLE_GUARANTEED_READ;
#endif
        /* Initialize the register file */
        initialize_reg_file();

        /* Initialize any PHY CSR */
        initialize_hps_phy();

        scc_mgr_initialize();

        initialize_tracking();

        printf("%s: Preparing to start memory calibration\n", __FILE__);

        debug("%s:%d\n", __func__, __LINE__);
        debug_cond(DLEVEL == 1,
                   "DDR3 FULL_RATE ranks=%u cs/dimm=%u dq/dqs=%u,%u vg/dqs=%u,%u ",
                   RW_MGR_MEM_NUMBER_OF_RANKS, RW_MGR_MEM_NUMBER_OF_CS_PER_DIMM,
                   RW_MGR_MEM_DQ_PER_READ_DQS, RW_MGR_MEM_DQ_PER_WRITE_DQS,
                   RW_MGR_MEM_VIRTUAL_GROUPS_PER_READ_DQS,
                   RW_MGR_MEM_VIRTUAL_GROUPS_PER_WRITE_DQS);
        debug_cond(DLEVEL == 1,
                   "dqs=%u,%u dq=%u dm=%u ptap_delay=%u dtap_delay=%u ",
                   RW_MGR_MEM_IF_READ_DQS_WIDTH, RW_MGR_MEM_IF_WRITE_DQS_WIDTH,
                   RW_MGR_MEM_DATA_WIDTH, RW_MGR_MEM_DATA_MASK_WIDTH,
                   IO_DELAY_PER_OPA_TAP, IO_DELAY_PER_DCHAIN_TAP);
        debug_cond(DLEVEL == 1, "dtap_dqsen_delay=%u, dll=%u",
                   IO_DELAY_PER_DQS_EN_DCHAIN_TAP, IO_DLL_CHAIN_LENGTH);
        debug_cond(DLEVEL == 1, "max values: en_p=%u dqdqs_p=%u en_d=%u dqs_in_d=%u ",
                   IO_DQS_EN_PHASE_MAX, IO_DQDQS_OUT_PHASE_MAX,
                   IO_DQS_EN_DELAY_MAX, IO_DQS_IN_DELAY_MAX);
        debug_cond(DLEVEL == 1, "io_in_d=%u io_out1_d=%u io_out2_d=%u ",
                   IO_IO_IN_DELAY_MAX, IO_IO_OUT1_DELAY_MAX,
                   IO_IO_OUT2_DELAY_MAX);
        debug_cond(DLEVEL == 1, "dqs_in_reserve=%u dqs_out_reserve=%u\n",
                   IO_DQS_IN_RESERVE, IO_DQS_OUT_RESERVE);

        hc_initialize_rom_data();

        /* update info for sims */
        reg_file_set_stage(CAL_STAGE_NIL);
        reg_file_set_group(0);

        /*
         * Load global needed for those actions that require
         * some dynamic calibration support.
         */
        dyn_calib_steps = STATIC_CALIB_STEPS;
        /*
         * Load global to allow dynamic selection of delay loop settings
         * based on calibration mode.
         */
        if (!(dyn_calib_steps & CALIB_SKIP_DELAY_LOOPS))
                skip_delay_mask = 0xff;
        else
                skip_delay_mask = 0x0;

        pass = run_mem_calibrate();
        debug_mem_calibrate(pass);
        return pass;
}