// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2014-2020, NVIDIA CORPORATION.  All rights reserved.
 */

#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/of.h>

#include <soc/tegra/mc.h>

#include "tegra210-emc.h"
#include "tegra210-mc.h"

/*
 * Enable flags for specifying verbosity.
 */
#define INFO            (1 << 0)
#define STEPS           (1 << 1)
#define SUB_STEPS       (1 << 2)
#define PRELOCK         (1 << 3)
#define PRELOCK_STEPS   (1 << 4)
#define ACTIVE_EN       (1 << 5)
#define PRAMP_UP        (1 << 6)
#define PRAMP_DN        (1 << 7)
#define EMA_WRITES      (1 << 10)
#define EMA_UPDATES     (1 << 11)
#define PER_TRAIN       (1 << 16)
#define CC_PRINT        (1 << 17)
#define CCFIFO          (1 << 29)
#define REGS            (1 << 30)
#define REG_LISTS       (1 << 31)

#define emc_dbg(emc, flags, ...) dev_dbg(emc->dev, __VA_ARGS__)

#define DVFS_CLOCK_CHANGE_VERSION       21021
#define EMC_PRELOCK_VERSION             2101

enum {
        DVFS_SEQUENCE = 1,
        WRITE_TRAINING_SEQUENCE = 2,
        PERIODIC_TRAINING_SEQUENCE = 3,
        DVFS_PT1 = 10,
        DVFS_UPDATE = 11,
        TRAINING_PT1 = 12,
        TRAINING_UPDATE = 13,
        PERIODIC_TRAINING_UPDATE = 14
};

/*
 * PTFV defines - basically just indexes into the per table PTFV array.
 */
#define PTFV_DQSOSC_MOVAVG_C0D0U0_INDEX         0
#define PTFV_DQSOSC_MOVAVG_C0D0U1_INDEX         1
#define PTFV_DQSOSC_MOVAVG_C0D1U0_INDEX         2
#define PTFV_DQSOSC_MOVAVG_C0D1U1_INDEX         3
#define PTFV_DQSOSC_MOVAVG_C1D0U0_INDEX         4
#define PTFV_DQSOSC_MOVAVG_C1D0U1_INDEX         5
#define PTFV_DQSOSC_MOVAVG_C1D1U0_INDEX         6
#define PTFV_DQSOSC_MOVAVG_C1D1U1_INDEX         7
#define PTFV_DVFS_SAMPLES_INDEX                 9
#define PTFV_MOVAVG_WEIGHT_INDEX                10
#define PTFV_CONFIG_CTRL_INDEX                  11

#define PTFV_CONFIG_CTRL_USE_PREVIOUS_EMA       (1 << 0)

/*
 * Do arithmetic in fixed point.
 */
#define MOVAVG_PRECISION_FACTOR         100

/*
 * The division portion of the average operation.
 */
#define __AVERAGE_PTFV(dev)                                             \
        ({ next->ptfv_list[PTFV_DQSOSC_MOVAVG_ ## dev ## _INDEX] =      \
           next->ptfv_list[PTFV_DQSOSC_MOVAVG_ ## dev ## _INDEX] /      \
           next->ptfv_list[PTFV_DVFS_SAMPLES_INDEX]; })

/*
 * Convert val to fixed point and add it to the temporary average.
 */
#define __INCREMENT_PTFV(dev, val)                                      \
        ({ next->ptfv_list[PTFV_DQSOSC_MOVAVG_ ## dev ## _INDEX] +=     \
           ((val) * MOVAVG_PRECISION_FACTOR); })

/*
 * Convert a moving average back to integral form and return the value.
 */
#define __MOVAVG_AC(timing, dev)                                        \
        ((timing)->ptfv_list[PTFV_DQSOSC_MOVAVG_ ## dev ## _INDEX] /    \
         MOVAVG_PRECISION_FACTOR)

/* Weighted update. */
#define __WEIGHTED_UPDATE_PTFV(dev, nval)                               \
        do {                                                            \
                int w = PTFV_MOVAVG_WEIGHT_INDEX;                       \
                int dqs = PTFV_DQSOSC_MOVAVG_ ## dev ## _INDEX;         \
                                                                        \
                next->ptfv_list[dqs] =                                  \
                        ((nval * MOVAVG_PRECISION_FACTOR) +             \
                         (next->ptfv_list[dqs] *                        \
                          next->ptfv_list[w])) /                        \
                        (next->ptfv_list[w] + 1);                       \
                                                                        \
                emc_dbg(emc, EMA_UPDATES, "%s: (s=%lu) EMA: %u\n",      \
                        __stringify(dev), nval, next->ptfv_list[dqs]);  \
        } while (0)

/* Access a particular average. */
#define __MOVAVG(timing, dev)                      \
        ((timing)->ptfv_list[PTFV_DQSOSC_MOVAVG_ ## dev ## _INDEX])

static u32 update_clock_tree_delay(struct tegra210_emc *emc, int type)
{
        bool periodic_training_update = type == PERIODIC_TRAINING_UPDATE;
        struct tegra210_emc_timing *last = emc->last;
        struct tegra210_emc_timing *next = emc->next;
        u32 last_timing_rate_mhz = last->rate / 1000;
        u32 next_timing_rate_mhz = next->rate / 1000;
        bool dvfs_update = type == DVFS_UPDATE;
        s32 tdel = 0, tmdel = 0, adel = 0;
        bool dvfs_pt1 = type == DVFS_PT1;
        unsigned long cval = 0;
        u32 temp[2][2], value;
        unsigned int i;

        /*
         * Dev0 MSB.
         */
        if (dvfs_pt1 || periodic_training_update) {
                value = tegra210_emc_mrr_read(emc, 2, 19);

                for (i = 0; i < emc->num_channels; i++) {
                        temp[i][0] = (value & 0x00ff) << 8;
                        temp[i][1] = (value & 0xff00) << 0;
                        value >>= 16;
                }

                /*
                 * Dev0 LSB.
                 */
                value = tegra210_emc_mrr_read(emc, 2, 18);

                for (i = 0; i < emc->num_channels; i++) {
                        temp[i][0] |= (value & 0x00ff) >> 0;
                        temp[i][1] |= (value & 0xff00) >> 8;
                        value >>= 16;
                }
        }

        if (dvfs_pt1 || periodic_training_update) {
                cval = tegra210_emc_actual_osc_clocks(last->run_clocks);
                cval *= 1000000;
                cval /= last_timing_rate_mhz * 2 * temp[0][0];
        }

        if (dvfs_pt1)
                __INCREMENT_PTFV(C0D0U0, cval);
        else if (dvfs_update)
                __AVERAGE_PTFV(C0D0U0);
        else if (periodic_training_update)
                __WEIGHTED_UPDATE_PTFV(C0D0U0, cval);

        if (dvfs_update || periodic_training_update) {
                tdel = next->current_dram_clktree[C0D0U0] -
                                __MOVAVG_AC(next, C0D0U0);
                tmdel = (tdel < 0) ? -1 * tdel : tdel;
                adel = tmdel;

                if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
                    next->tree_margin)
                        next->current_dram_clktree[C0D0U0] =
                                __MOVAVG_AC(next, C0D0U0);
        }

        if (dvfs_pt1 || periodic_training_update) {
                cval = tegra210_emc_actual_osc_clocks(last->run_clocks);
                cval *= 1000000;
                cval /= last_timing_rate_mhz * 2 * temp[0][1];
        }

        if (dvfs_pt1)
                __INCREMENT_PTFV(C0D0U1, cval);
        else if (dvfs_update)
                __AVERAGE_PTFV(C0D0U1);
        else if (periodic_training_update)
                __WEIGHTED_UPDATE_PTFV(C0D0U1, cval);

        if (dvfs_update || periodic_training_update) {
                tdel = next->current_dram_clktree[C0D0U1] -
                                __MOVAVG_AC(next, C0D0U1);
                tmdel = (tdel < 0) ? -1 * tdel : tdel;

                if (tmdel > adel)
                        adel = tmdel;

                if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
                    next->tree_margin)
                        next->current_dram_clktree[C0D0U1] =
                                __MOVAVG_AC(next, C0D0U1);
        }

        if (emc->num_channels > 1) {
                if (dvfs_pt1 || periodic_training_update) {
                        cval = tegra210_emc_actual_osc_clocks(last->run_clocks);
                        cval *= 1000000;
                        cval /= last_timing_rate_mhz * 2 * temp[1][0];
                }

                if (dvfs_pt1)
                        __INCREMENT_PTFV(C1D0U0, cval);
                else if (dvfs_update)
                        __AVERAGE_PTFV(C1D0U0);
                else if (periodic_training_update)
                        __WEIGHTED_UPDATE_PTFV(C1D0U0, cval);

                if (dvfs_update || periodic_training_update) {
                        tdel = next->current_dram_clktree[C1D0U0] -
                                        __MOVAVG_AC(next, C1D0U0);
                        tmdel = (tdel < 0) ? -1 * tdel : tdel;

                        if (tmdel > adel)
                                adel = tmdel;

                        if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
                            next->tree_margin)
                                next->current_dram_clktree[C1D0U0] =
                                        __MOVAVG_AC(next, C1D0U0);
                }

                if (dvfs_pt1 || periodic_training_update) {
                        cval = tegra210_emc_actual_osc_clocks(last->run_clocks);
                        cval *= 1000000;
                        cval /= last_timing_rate_mhz * 2 * temp[1][1];
                }

                if (dvfs_pt1)
                        __INCREMENT_PTFV(C1D0U1, cval);
                else if (dvfs_update)
                        __AVERAGE_PTFV(C1D0U1);
                else if (periodic_training_update)
                        __WEIGHTED_UPDATE_PTFV(C1D0U1, cval);

                if (dvfs_update || periodic_training_update) {
                        tdel = next->current_dram_clktree[C1D0U1] -
                                        __MOVAVG_AC(next, C1D0U1);
                        tmdel = (tdel < 0) ? -1 * tdel : tdel;

                        if (tmdel > adel)
                                adel = tmdel;

                        if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
                            next->tree_margin)
                                next->current_dram_clktree[C1D0U1] =
                                        __MOVAVG_AC(next, C1D0U1);
                }
        }

        if (emc->num_devices < 2)
                goto done;

        /*
         * Dev1 MSB.
         */
        if (dvfs_pt1 || periodic_training_update) {
                value = tegra210_emc_mrr_read(emc, 1, 19);

                for (i = 0; i < emc->num_channels; i++) {
                        temp[i][0] = (value & 0x00ff) << 8;
                        temp[i][1] = (value & 0xff00) << 0;
                        value >>= 16;
                }

                /*
                 * Dev1 LSB.
                 */
                value = tegra210_emc_mrr_read(emc, 2, 18);

                for (i = 0; i < emc->num_channels; i++) {
                        temp[i][0] |= (value & 0x00ff) >> 0;
                        temp[i][1] |= (value & 0xff00) >> 8;
                        value >>= 16;
                }
        }

        if (dvfs_pt1 || periodic_training_update) {
                cval = tegra210_emc_actual_osc_clocks(last->run_clocks);
                cval *= 1000000;
                cval /= last_timing_rate_mhz * 2 * temp[0][0];
        }

        if (dvfs_pt1)
                __INCREMENT_PTFV(C0D1U0, cval);
        else if (dvfs_update)
                __AVERAGE_PTFV(C0D1U0);
        else if (periodic_training_update)
                __WEIGHTED_UPDATE_PTFV(C0D1U0, cval);

        if (dvfs_update || periodic_training_update) {
                tdel = next->current_dram_clktree[C0D1U0] -
                                __MOVAVG_AC(next, C0D1U0);
                tmdel = (tdel < 0) ? -1 * tdel : tdel;

                if (tmdel > adel)
                        adel = tmdel;

                if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
                    next->tree_margin)
                        next->current_dram_clktree[C0D1U0] =
                                __MOVAVG_AC(next, C0D1U0);
        }

        if (dvfs_pt1 || periodic_training_update) {
                cval = tegra210_emc_actual_osc_clocks(last->run_clocks);
                cval *= 1000000;
                cval /= last_timing_rate_mhz * 2 * temp[0][1];
        }

        if (dvfs_pt1)
                __INCREMENT_PTFV(C0D1U1, cval);
        else if (dvfs_update)
                __AVERAGE_PTFV(C0D1U1);
        else if (periodic_training_update)
                __WEIGHTED_UPDATE_PTFV(C0D1U1, cval);

        if (dvfs_update || periodic_training_update) {
                tdel = next->current_dram_clktree[C0D1U1] -
                                __MOVAVG_AC(next, C0D1U1);
                tmdel = (tdel < 0) ? -1 * tdel : tdel;

                if (tmdel > adel)
                        adel = tmdel;

                if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
                    next->tree_margin)
                        next->current_dram_clktree[C0D1U1] =
                                __MOVAVG_AC(next, C0D1U1);
        }

        if (emc->num_channels > 1) {
                if (dvfs_pt1 || periodic_training_update) {
                        cval = tegra210_emc_actual_osc_clocks(last->run_clocks);
                        cval *= 1000000;
                        cval /= last_timing_rate_mhz * 2 * temp[1][0];
                }

                if (dvfs_pt1)
                        __INCREMENT_PTFV(C1D1U0, cval);
                else if (dvfs_update)
                        __AVERAGE_PTFV(C1D1U0);
                else if (periodic_training_update)
                        __WEIGHTED_UPDATE_PTFV(C1D1U0, cval);

                if (dvfs_update || periodic_training_update) {
                        tdel = next->current_dram_clktree[C1D1U0] -
                                        __MOVAVG_AC(next, C1D1U0);
                        tmdel = (tdel < 0) ? -1 * tdel : tdel;

                        if (tmdel > adel)
                                adel = tmdel;

                        if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
                            next->tree_margin)
                                next->current_dram_clktree[C1D1U0] =
                                        __MOVAVG_AC(next, C1D1U0);
                }

                if (dvfs_pt1 || periodic_training_update) {
                        cval = tegra210_emc_actual_osc_clocks(last->run_clocks);
                        cval *= 1000000;
                        cval /= last_timing_rate_mhz * 2 * temp[1][1];
                }

                if (dvfs_pt1)
                        __INCREMENT_PTFV(C1D1U1, cval);
                else if (dvfs_update)
                        __AVERAGE_PTFV(C1D1U1);
                else if (periodic_training_update)
                        __WEIGHTED_UPDATE_PTFV(C1D1U1, cval);

                if (dvfs_update || periodic_training_update) {
                        tdel = next->current_dram_clktree[C1D1U1] -
                                        __MOVAVG_AC(next, C1D1U1);
                        tmdel = (tdel < 0) ? -1 * tdel : tdel;

                        if (tmdel > adel)
                                adel = tmdel;

                        if (tmdel * 128 * next_timing_rate_mhz / 1000000 >
                            next->tree_margin)
                                next->current_dram_clktree[C1D1U1] =
                                        __MOVAVG_AC(next, C1D1U1);
                }
        }

done:
        return adel;
}

static u32 periodic_compensation_handler(struct tegra210_emc *emc, u32 type,
                                         struct tegra210_emc_timing *last,
                                         struct tegra210_emc_timing *next)
{
#define __COPY_EMA(nt, lt, dev)                                         \
        ({ __MOVAVG(nt, dev) = __MOVAVG(lt, dev) *                      \
           (nt)->ptfv_list[PTFV_DVFS_SAMPLES_INDEX]; })

        u32 i, adel = 0, samples = next->ptfv_list[PTFV_DVFS_SAMPLES_INDEX];
        u32 delay;

        delay = tegra210_emc_actual_osc_clocks(last->run_clocks);
        delay *= 1000;
        delay = 2 + (delay / last->rate);

        if (!next->periodic_training)
                return 0;

        if (type == DVFS_SEQUENCE) {
                if (last->periodic_training &&
                    (next->ptfv_list[PTFV_CONFIG_CTRL_INDEX] &
                     PTFV_CONFIG_CTRL_USE_PREVIOUS_EMA)) {
                        /*
                         * If the previous frequency was using periodic
                         * calibration then we can reuse the previous
                         * frequencies EMA data.
                         */
                        __COPY_EMA(next, last, C0D0U0);
                        __COPY_EMA(next, last, C0D0U1);
                        __COPY_EMA(next, last, C1D0U0);
                        __COPY_EMA(next, last, C1D0U1);
                        __COPY_EMA(next, last, C0D1U0);
                        __COPY_EMA(next, last, C0D1U1);
                        __COPY_EMA(next, last, C1D1U0);
                        __COPY_EMA(next, last, C1D1U1);
                } else {
                        /* Reset the EMA.*/
                        __MOVAVG(next, C0D0U0) = 0;
                        __MOVAVG(next, C0D0U1) = 0;
                        __MOVAVG(next, C1D0U0) = 0;
                        __MOVAVG(next, C1D0U1) = 0;
                        __MOVAVG(next, C0D1U0) = 0;
                        __MOVAVG(next, C0D1U1) = 0;
                        __MOVAVG(next, C1D1U0) = 0;
                        __MOVAVG(next, C1D1U1) = 0;

                        for (i = 0; i < samples; i++) {
                                tegra210_emc_start_periodic_compensation(emc);
                                udelay(delay);

                                /*
                                 * Generate next sample of data.
                                 */
                                adel = update_clock_tree_delay(emc, DVFS_PT1);
                        }
                }

                /*
                 * Seems like it should be part of the
                 * 'if (last_timing->periodic_training)' conditional
                 * since is already done for the else clause.
                 */
                adel = update_clock_tree_delay(emc, DVFS_UPDATE);
        }

        if (type == PERIODIC_TRAINING_SEQUENCE) {
                tegra210_emc_start_periodic_compensation(emc);
                udelay(delay);

                adel = update_clock_tree_delay(emc, PERIODIC_TRAINING_UPDATE);
        }

        return adel;
}

static u32 tegra210_emc_r21021_periodic_compensation(struct tegra210_emc *emc)
{
        u32 emc_cfg, emc_cfg_o, emc_cfg_update, del, value;
        u32 list[] = {
                EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_0,
                EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_1,
                EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_2,
                EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_3,
                EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_0,
                EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_1,
                EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_2,
                EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_3,
                EMC_DATA_BRLSHFT_0,
                EMC_DATA_BRLSHFT_1
        };
        struct tegra210_emc_timing *last = emc->last;
        unsigned int items = ARRAY_SIZE(list), i;
        unsigned long delay;

        if (last->periodic_training) {
                emc_dbg(emc, PER_TRAIN, "Periodic training starting\n");

                value = emc_readl(emc, EMC_DBG);
                emc_cfg_o = emc_readl(emc, EMC_CFG);
                emc_cfg = emc_cfg_o & ~(EMC_CFG_DYN_SELF_REF |
                                        EMC_CFG_DRAM_ACPD |
                                        EMC_CFG_DRAM_CLKSTOP_PD);


                /*
                 * 1. Power optimizations should be off.
                 */
                emc_writel(emc, emc_cfg, EMC_CFG);

                /* Does emc_timing_update() for above changes. */
                tegra210_emc_dll_disable(emc);

                for (i = 0; i < emc->num_channels; i++)
                        tegra210_emc_wait_for_update(emc, i, EMC_EMC_STATUS,
                                                     EMC_EMC_STATUS_DRAM_IN_POWERDOWN_MASK,
                                                     0);

                for (i = 0; i < emc->num_channels; i++)
                        tegra210_emc_wait_for_update(emc, i, EMC_EMC_STATUS,
                                                     EMC_EMC_STATUS_DRAM_IN_SELF_REFRESH_MASK,
                                                     0);

                emc_cfg_update = value = emc_readl(emc, EMC_CFG_UPDATE);
                value &= ~EMC_CFG_UPDATE_UPDATE_DLL_IN_UPDATE_MASK;
                value |= (2 << EMC_CFG_UPDATE_UPDATE_DLL_IN_UPDATE_SHIFT);
                emc_writel(emc, value, EMC_CFG_UPDATE);

                /*
                 * 2. osc kick off - this assumes training and dvfs have set
                 *    correct MR23.
                 */
                tegra210_emc_start_periodic_compensation(emc);

                /*
                 * 3. Let dram capture its clock tree delays.
                 */
                delay = tegra210_emc_actual_osc_clocks(last->run_clocks);
                delay *= 1000;
                delay /= last->rate + 1;
                udelay(delay);

                /*
                 * 4. Check delta wrt previous values (save value if margin
                 *    exceeds what is set in table).
                 */
                del = periodic_compensation_handler(emc,
                                                    PERIODIC_TRAINING_SEQUENCE,
                                                    last, last);

                /*
                 * 5. Apply compensation w.r.t. trained values (if clock tree
                 *    has drifted more than the set margin).
                 */
                if (last->tree_margin < ((del * 128 * (last->rate / 1000)) / 1000000)) {
                        for (i = 0; i < items; i++) {
                                value = tegra210_emc_compensate(last, list[i]);
                                emc_dbg(emc, EMA_WRITES, "0x%08x <= 0x%08x\n",
                                        list[i], value);
                                emc_writel(emc, value, list[i]);
                        }
                }

                emc_writel(emc, emc_cfg_o, EMC_CFG);

                /*
                 * 6. Timing update actally applies the new trimmers.
                 */
                tegra210_emc_timing_update(emc);

                /* 6.1. Restore the UPDATE_DLL_IN_UPDATE field. */
                emc_writel(emc, emc_cfg_update, EMC_CFG_UPDATE);

                /* 6.2. Restore the DLL. */
                tegra210_emc_dll_enable(emc);
        }

        return 0;
}

/*
 * Do the clock change sequence.
 */
static void tegra210_emc_r21021_set_clock(struct tegra210_emc *emc, u32 clksrc)
{
        /* state variables */
        static bool fsp_for_next_freq;
        /* constant configuration parameters */
        const bool save_restore_clkstop_pd = true;
        const u32 zqcal_before_cc_cutoff = 2400;
        const bool cya_allow_ref_cc = false;
        const bool cya_issue_pc_ref = false;
        const bool opt_cc_short_zcal = true;
        const bool ref_b4_sref_en = false;
        const u32 tZQCAL_lpddr4 = 1000000;
        const bool opt_short_zcal = true;
        const bool opt_do_sw_qrst = true;
        const u32 opt_dvfs_mode = MAN_SR;
        /*
         * This is the timing table for the source frequency. It does _not_
         * necessarily correspond to the actual timing values in the EMC at the
         * moment. If the boot BCT differs from the table then this can happen.
         * However, we need it for accessing the dram_timings (which are not
         * really registers) array for the current frequency.
         */
        struct tegra210_emc_timing *fake, *last = emc->last, *next = emc->next;
        u32 tRTM, RP_war, R2P_war, TRPab_war, deltaTWATM, W2P_war, tRPST;
        u32 mr13_flip_fspwr, mr13_flip_fspop, ramp_up_wait, ramp_down_wait;
        u32 zq_wait_long, zq_latch_dvfs_wait_time, tZQCAL_lpddr4_fc_adj;
        u32 emc_auto_cal_config, auto_cal_en, emc_cfg, emc_sel_dpd_ctrl;
        u32 tFC_lpddr4 = 1000 * next->dram_timings[T_FC_LPDDR4];
        u32 bg_reg_mode_change, enable_bglp_reg, enable_bg_reg;
        bool opt_zcal_en_cc = false, is_lpddr3 = false;
        bool compensate_trimmer_applicable = false;
        u32 emc_dbg, emc_cfg_pipe_clk, emc_pin;
        u32 src_clk_period, dst_clk_period; /* in picoseconds */
        bool shared_zq_resistor = false;
        u32 value, dram_type;
        u32 opt_dll_mode = 0;
        unsigned long delay;
        unsigned int i;

        emc_dbg(emc, INFO, "Running clock change.\n");

        /* XXX fake == last */
        fake = tegra210_emc_find_timing(emc, last->rate * 1000UL);
        fsp_for_next_freq = !fsp_for_next_freq;

        value = emc_readl(emc, EMC_FBIO_CFG5) & EMC_FBIO_CFG5_DRAM_TYPE_MASK;
        dram_type = value >> EMC_FBIO_CFG5_DRAM_TYPE_SHIFT;

        if (last->burst_regs[EMC_ZCAL_WAIT_CNT_INDEX] & BIT(31))
                shared_zq_resistor = true;

        if ((next->burst_regs[EMC_ZCAL_INTERVAL_INDEX] != 0 &&
             last->burst_regs[EMC_ZCAL_INTERVAL_INDEX] == 0) ||
            dram_type == DRAM_TYPE_LPDDR4)
                opt_zcal_en_cc = true;

        if (dram_type == DRAM_TYPE_DDR3)
                opt_dll_mode = tegra210_emc_get_dll_state(next);

        if ((next->burst_regs[EMC_FBIO_CFG5_INDEX] & BIT(25)) &&
            (dram_type == DRAM_TYPE_LPDDR2))
                is_lpddr3 = true;

        emc_readl(emc, EMC_CFG);
        emc_readl(emc, EMC_AUTO_CAL_CONFIG);

        src_clk_period = 1000000000 / last->rate;
        dst_clk_period = 1000000000 / next->rate;

        if (dst_clk_period <= zqcal_before_cc_cutoff)
                tZQCAL_lpddr4_fc_adj = tZQCAL_lpddr4 - tFC_lpddr4;
        else
                tZQCAL_lpddr4_fc_adj = tZQCAL_lpddr4;

        tZQCAL_lpddr4_fc_adj /= dst_clk_period;

        emc_dbg = emc_readl(emc, EMC_DBG);
        emc_pin = emc_readl(emc, EMC_PIN);
        emc_cfg_pipe_clk = emc_readl(emc, EMC_CFG_PIPE_CLK);

        emc_cfg = next->burst_regs[EMC_CFG_INDEX];
        emc_cfg &= ~(EMC_CFG_DYN_SELF_REF | EMC_CFG_DRAM_ACPD |
                     EMC_CFG_DRAM_CLKSTOP_SR | EMC_CFG_DRAM_CLKSTOP_PD);
        emc_sel_dpd_ctrl = next->emc_sel_dpd_ctrl;
        emc_sel_dpd_ctrl &= ~(EMC_SEL_DPD_CTRL_CLK_SEL_DPD_EN |
                              EMC_SEL_DPD_CTRL_CA_SEL_DPD_EN |
                              EMC_SEL_DPD_CTRL_RESET_SEL_DPD_EN |
                              EMC_SEL_DPD_CTRL_ODT_SEL_DPD_EN |
                              EMC_SEL_DPD_CTRL_DATA_SEL_DPD_EN);

        emc_dbg(emc, INFO, "Clock change version: %d\n",
                DVFS_CLOCK_CHANGE_VERSION);
        emc_dbg(emc, INFO, "DRAM type = %d\n", dram_type);
        emc_dbg(emc, INFO, "DRAM dev #: %u\n", emc->num_devices);
        emc_dbg(emc, INFO, "Next EMC clksrc: 0x%08x\n", clksrc);
        emc_dbg(emc, INFO, "DLL clksrc:      0x%08x\n", next->dll_clk_src);
        emc_dbg(emc, INFO, "last rate: %u, next rate %u\n", last->rate,
                next->rate);
        emc_dbg(emc, INFO, "last period: %u, next period: %u\n",
                src_clk_period, dst_clk_period);
        emc_dbg(emc, INFO, "  shared_zq_resistor: %d\n", !!shared_zq_resistor);
        emc_dbg(emc, INFO, "  num_channels: %u\n", emc->num_channels);
        emc_dbg(emc, INFO, "  opt_dll_mode: %d\n", opt_dll_mode);

        /*
         * Step 1:
         *   Pre DVFS SW sequence.
         */
        emc_dbg(emc, STEPS, "Step 1\n");
        emc_dbg(emc, STEPS, "Step 1.1: Disable DLL temporarily.\n");

        value = emc_readl(emc, EMC_CFG_DIG_DLL);
        value &= ~EMC_CFG_DIG_DLL_CFG_DLL_EN;
        emc_writel(emc, value, EMC_CFG_DIG_DLL);

        tegra210_emc_timing_update(emc);

        for (i = 0; i < emc->num_channels; i++)
                tegra210_emc_wait_for_update(emc, i, EMC_CFG_DIG_DLL,
                                             EMC_CFG_DIG_DLL_CFG_DLL_EN, 0);

        emc_dbg(emc, STEPS, "Step 1.2: Disable AUTOCAL temporarily.\n");

        emc_auto_cal_config = next->emc_auto_cal_config;
        auto_cal_en = emc_auto_cal_config & EMC_AUTO_CAL_CONFIG_AUTO_CAL_ENABLE;
        emc_auto_cal_config &= ~EMC_AUTO_CAL_CONFIG_AUTO_CAL_START;
        emc_auto_cal_config |= EMC_AUTO_CAL_CONFIG_AUTO_CAL_MEASURE_STALL;
        emc_auto_cal_config |= EMC_AUTO_CAL_CONFIG_AUTO_CAL_UPDATE_STALL;
        emc_auto_cal_config |= auto_cal_en;
        emc_writel(emc, emc_auto_cal_config, EMC_AUTO_CAL_CONFIG);
        emc_readl(emc, EMC_AUTO_CAL_CONFIG); /* Flush write. */

        emc_dbg(emc, STEPS, "Step 1.3: Disable other power features.\n");

        tegra210_emc_set_shadow_bypass(emc, ACTIVE);
        emc_writel(emc, emc_cfg, EMC_CFG);
        emc_writel(emc, emc_sel_dpd_ctrl, EMC_SEL_DPD_CTRL);
        tegra210_emc_set_shadow_bypass(emc, ASSEMBLY);

        if (next->periodic_training) {
                tegra210_emc_reset_dram_clktree_values(next);

                for (i = 0; i < emc->num_channels; i++)
                        tegra210_emc_wait_for_update(emc, i, EMC_EMC_STATUS,
                                                     EMC_EMC_STATUS_DRAM_IN_POWERDOWN_MASK,
                                                     0);

                for (i = 0; i < emc->num_channels; i++)
                        tegra210_emc_wait_for_update(emc, i, EMC_EMC_STATUS,
                                                     EMC_EMC_STATUS_DRAM_IN_SELF_REFRESH_MASK,
                                                     0);

                tegra210_emc_start_periodic_compensation(emc);

                delay = 1000 * tegra210_emc_actual_osc_clocks(last->run_clocks);
                udelay((delay / last->rate) + 2);

                value = periodic_compensation_handler(emc, DVFS_SEQUENCE, fake,
                                                      next);
                value = (value * 128 * next->rate / 1000) / 1000000;

                if (next->periodic_training && value > next->tree_margin)
                        compensate_trimmer_applicable = true;
        }

        emc_writel(emc, EMC_INTSTATUS_CLKCHANGE_COMPLETE, EMC_INTSTATUS);
        tegra210_emc_set_shadow_bypass(emc, ACTIVE);
        emc_writel(emc, emc_cfg, EMC_CFG);
        emc_writel(emc, emc_sel_dpd_ctrl, EMC_SEL_DPD_CTRL);
        emc_writel(emc, emc_cfg_pipe_clk | EMC_CFG_PIPE_CLK_CLK_ALWAYS_ON,
                   EMC_CFG_PIPE_CLK);
        emc_writel(emc, next->emc_fdpd_ctrl_cmd_no_ramp &
                        ~EMC_FDPD_CTRL_CMD_NO_RAMP_CMD_DPD_NO_RAMP_ENABLE,
                   EMC_FDPD_CTRL_CMD_NO_RAMP);

        bg_reg_mode_change =
                ((next->burst_regs[EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                  EMC_PMACRO_BG_BIAS_CTRL_0_BGLP_E_PWRD) ^
                 (last->burst_regs[EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                  EMC_PMACRO_BG_BIAS_CTRL_0_BGLP_E_PWRD)) ||
                ((next->burst_regs[EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                  EMC_PMACRO_BG_BIAS_CTRL_0_BG_E_PWRD) ^
                 (last->burst_regs[EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                  EMC_PMACRO_BG_BIAS_CTRL_0_BG_E_PWRD));
        enable_bglp_reg =
                (next->burst_regs[EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                 EMC_PMACRO_BG_BIAS_CTRL_0_BGLP_E_PWRD) == 0;
        enable_bg_reg =
                (next->burst_regs[EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                 EMC_PMACRO_BG_BIAS_CTRL_0_BG_E_PWRD) == 0;

        if (bg_reg_mode_change) {
                if (enable_bg_reg)
                        emc_writel(emc, last->burst_regs
                                   [EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                                   ~EMC_PMACRO_BG_BIAS_CTRL_0_BG_E_PWRD,
                                   EMC_PMACRO_BG_BIAS_CTRL_0);

                if (enable_bglp_reg)
                        emc_writel(emc, last->burst_regs
                                   [EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                                   ~EMC_PMACRO_BG_BIAS_CTRL_0_BGLP_E_PWRD,
                                   EMC_PMACRO_BG_BIAS_CTRL_0);
        }

        /* Check if we need to turn on VREF generator. */
        if ((((last->burst_regs[EMC_PMACRO_DATA_PAD_TX_CTRL_INDEX] &
               EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQ_E_IVREF) == 0) &&
             ((next->burst_regs[EMC_PMACRO_DATA_PAD_TX_CTRL_INDEX] &
               EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQ_E_IVREF) == 1)) ||
            (((last->burst_regs[EMC_PMACRO_DATA_PAD_TX_CTRL_INDEX] &
               EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQS_E_IVREF) == 0) &&
             ((next->burst_regs[EMC_PMACRO_DATA_PAD_TX_CTRL_INDEX] &
               EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQS_E_IVREF) != 0))) {
                u32 pad_tx_ctrl =
                    next->burst_regs[EMC_PMACRO_DATA_PAD_TX_CTRL_INDEX];
                u32 last_pad_tx_ctrl =
                    last->burst_regs[EMC_PMACRO_DATA_PAD_TX_CTRL_INDEX];
                u32 next_dq_e_ivref, next_dqs_e_ivref;

                next_dqs_e_ivref = pad_tx_ctrl &
                                   EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQS_E_IVREF;
                next_dq_e_ivref = pad_tx_ctrl &
                                  EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQ_E_IVREF;
                value = (last_pad_tx_ctrl &
                                ~EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQ_E_IVREF &
                                ~EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQS_E_IVREF) |
                        next_dq_e_ivref | next_dqs_e_ivref;
                emc_writel(emc, value, EMC_PMACRO_DATA_PAD_TX_CTRL);
                udelay(1);
        } else if (bg_reg_mode_change) {
                udelay(1);
        }

        tegra210_emc_set_shadow_bypass(emc, ASSEMBLY);

        /*
         * Step 2:
         *   Prelock the DLL.
         */
        emc_dbg(emc, STEPS, "Step 2\n");

        if (next->burst_regs[EMC_CFG_DIG_DLL_INDEX] &
            EMC_CFG_DIG_DLL_CFG_DLL_EN) {
                emc_dbg(emc, INFO, "Prelock enabled for target frequency.\n");
                value = tegra210_emc_dll_prelock(emc, clksrc);
                emc_dbg(emc, INFO, "DLL out: 0x%03x\n", value);
        } else {
                emc_dbg(emc, INFO, "Disabling DLL for target frequency.\n");
                tegra210_emc_dll_disable(emc);
        }

        /*
         * Step 3:
         *   Prepare autocal for the clock change.
         */
        emc_dbg(emc, STEPS, "Step 3\n");

        tegra210_emc_set_shadow_bypass(emc, ACTIVE);
        emc_writel(emc, next->emc_auto_cal_config2, EMC_AUTO_CAL_CONFIG2);
        emc_writel(emc, next->emc_auto_cal_config3, EMC_AUTO_CAL_CONFIG3);
        emc_writel(emc, next->emc_auto_cal_config4, EMC_AUTO_CAL_CONFIG4);
        emc_writel(emc, next->emc_auto_cal_config5, EMC_AUTO_CAL_CONFIG5);
        emc_writel(emc, next->emc_auto_cal_config6, EMC_AUTO_CAL_CONFIG6);
        emc_writel(emc, next->emc_auto_cal_config7, EMC_AUTO_CAL_CONFIG7);
        emc_writel(emc, next->emc_auto_cal_config8, EMC_AUTO_CAL_CONFIG8);
        tegra210_emc_set_shadow_bypass(emc, ASSEMBLY);

        emc_auto_cal_config |= (EMC_AUTO_CAL_CONFIG_AUTO_CAL_COMPUTE_START |
                                auto_cal_en);
        emc_writel(emc, emc_auto_cal_config, EMC_AUTO_CAL_CONFIG);

        /*
         * Step 4:
         *   Update EMC_CFG. (??)
         */
        emc_dbg(emc, STEPS, "Step 4\n");

        if (src_clk_period > 50000 && dram_type == DRAM_TYPE_LPDDR4)
                ccfifo_writel(emc, 1, EMC_SELF_REF, 0);
        else
                emc_writel(emc, next->emc_cfg_2, EMC_CFG_2);

        /*
         * Step 5:
         *   Prepare reference variables for ZQCAL regs.
         */
        emc_dbg(emc, STEPS, "Step 5\n");

        if (dram_type == DRAM_TYPE_LPDDR4)
                zq_wait_long = max((u32)1, div_o3(1000000, dst_clk_period));
        else if (dram_type == DRAM_TYPE_LPDDR2 || is_lpddr3)
                zq_wait_long = max(next->min_mrs_wait,
                                   div_o3(360000, dst_clk_period)) + 4;
        else if (dram_type == DRAM_TYPE_DDR3)
                zq_wait_long = max((u32)256,
                                   div_o3(320000, dst_clk_period) + 2);
        else
                zq_wait_long = 0;

        /*
         * Step 6:
         *   Training code - removed.
         */
        emc_dbg(emc, STEPS, "Step 6\n");

        /*
         * Step 7:
         *   Program FSP reference registers and send MRWs to new FSPWR.
         */
        emc_dbg(emc, STEPS, "Step 7\n");
        emc_dbg(emc, SUB_STEPS, "Step 7.1: Bug 200024907 - Patch RP R2P");

        /* WAR 200024907 */
        if (dram_type == DRAM_TYPE_LPDDR4) {
                u32 nRTP = 16;

                if (src_clk_period >= 1000000 / 1866) /* 535.91 ps */
                        nRTP = 14;

                if (src_clk_period >= 1000000 / 1600) /* 625.00 ps */
                        nRTP = 12;

                if (src_clk_period >= 1000000 / 1333) /* 750.19 ps */
                        nRTP = 10;

                if (src_clk_period >= 1000000 / 1066) /* 938.09 ps */
                        nRTP = 8;

                deltaTWATM = max_t(u32, div_o3(7500, src_clk_period), 8);

                /*
                 * Originally there was a + .5 in the tRPST calculation.
                 * However since we can't do FP in the kernel and the tRTM
                 * computation was in a floating point ceiling function, adding
                 * one to tRTP should be ok. There is no other source of non
                 * integer values, so the result was always going to be
                 * something for the form: f_ceil(N + .5) = N + 1;
                 */
                tRPST = (last->emc_mrw & 0x80) >> 7;
                tRTM = fake->dram_timings[RL] + div_o3(3600, src_clk_period) +
                        max_t(u32, div_o3(7500, src_clk_period), 8) + tRPST +
                        1 + nRTP;

                emc_dbg(emc, INFO, "tRTM = %u, EMC_RP = %u\n", tRTM,
                        next->burst_regs[EMC_RP_INDEX]);

                if (last->burst_regs[EMC_RP_INDEX] < tRTM) {
                        if (tRTM > (last->burst_regs[EMC_R2P_INDEX] +
                                    last->burst_regs[EMC_RP_INDEX])) {
                                R2P_war = tRTM - last->burst_regs[EMC_RP_INDEX];
                                RP_war = last->burst_regs[EMC_RP_INDEX];
                                TRPab_war = last->burst_regs[EMC_TRPAB_INDEX];

                                if (R2P_war > 63) {
                                        RP_war = R2P_war +
                                                 last->burst_regs[EMC_RP_INDEX] - 63;

                                        if (TRPab_war < RP_war)
                                                TRPab_war = RP_war;

                                        R2P_war = 63;
                                }
                        } else {
                                R2P_war = last->burst_regs[EMC_R2P_INDEX];
                                RP_war = last->burst_regs[EMC_RP_INDEX];
                                TRPab_war = last->burst_regs[EMC_TRPAB_INDEX];
                        }

                        if (RP_war < deltaTWATM) {
                                W2P_war = last->burst_regs[EMC_W2P_INDEX]
                                          + deltaTWATM - RP_war;
                                if (W2P_war > 63) {
                                        RP_war = RP_war + W2P_war - 63;
                                        if (TRPab_war < RP_war)
                                                TRPab_war = RP_war;
                                        W2P_war = 63;
                                }
                        } else {
                                W2P_war = last->burst_regs[
                                          EMC_W2P_INDEX];
                        }

                        if ((last->burst_regs[EMC_W2P_INDEX] ^ W2P_war) ||
                            (last->burst_regs[EMC_R2P_INDEX] ^ R2P_war) ||
                            (last->burst_regs[EMC_RP_INDEX] ^ RP_war) ||
                            (last->burst_regs[EMC_TRPAB_INDEX] ^ TRPab_war)) {
                                emc_writel(emc, RP_war, EMC_RP);
                                emc_writel(emc, R2P_war, EMC_R2P);
                                emc_writel(emc, W2P_war, EMC_W2P);
                                emc_writel(emc, TRPab_war, EMC_TRPAB);
                        }

                        tegra210_emc_timing_update(emc);
                } else {
                        emc_dbg(emc, INFO, "Skipped WAR\n");
                }
        }

        if (!fsp_for_next_freq) {
                mr13_flip_fspwr = (next->emc_mrw3 & 0xffffff3f) | 0x80;
                mr13_flip_fspop = (next->emc_mrw3 & 0xffffff3f) | 0x00;
        } else {
                mr13_flip_fspwr = (next->emc_mrw3 & 0xffffff3f) | 0x40;
                mr13_flip_fspop = (next->emc_mrw3 & 0xffffff3f) | 0xc0;
        }

        if (dram_type == DRAM_TYPE_LPDDR4) {
                emc_writel(emc, mr13_flip_fspwr, EMC_MRW3);
                emc_writel(emc, next->emc_mrw, EMC_MRW);
                emc_writel(emc, next->emc_mrw2, EMC_MRW2);
        }

        /*
         * Step 8:
         *   Program the shadow registers.

         */
        emc_dbg(emc, STEPS, "Step 8\n");
        emc_dbg(emc, SUB_STEPS, "Writing burst_regs\n");

        for (i = 0; i < next->num_burst; i++) {
                const u16 *offsets = emc->offsets->burst;
                u16 offset;

                if (!offsets[i])
                        continue;

                value = next->burst_regs[i];
                offset = offsets[i];

                if (dram_type != DRAM_TYPE_LPDDR4 &&
                    (offset == EMC_MRW6 || offset == EMC_MRW7 ||
                     offset == EMC_MRW8 || offset == EMC_MRW9 ||
                     offset == EMC_MRW10 || offset == EMC_MRW11 ||
                     offset == EMC_MRW12 || offset == EMC_MRW13 ||
                     offset == EMC_MRW14 || offset == EMC_MRW15 ||
                     offset == EMC_TRAINING_CTRL))
                        continue;

                /* Pain... And suffering. */
                if (offset == EMC_CFG) {
                        value &= ~EMC_CFG_DRAM_ACPD;
                        value &= ~EMC_CFG_DYN_SELF_REF;

                        if (dram_type == DRAM_TYPE_LPDDR4) {
                                value &= ~EMC_CFG_DRAM_CLKSTOP_SR;
                                value &= ~EMC_CFG_DRAM_CLKSTOP_PD;
                        }
                } else if (offset == EMC_MRS_WAIT_CNT &&
                           dram_type == DRAM_TYPE_LPDDR2 &&
                           opt_zcal_en_cc && !opt_cc_short_zcal &&
                           opt_short_zcal) {
                        value = (value & ~(EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK <<
                                           EMC_MRS_WAIT_CNT_SHORT_WAIT_SHIFT)) |
                                ((zq_wait_long & EMC_MRS_WAIT_CNT_SHORT_WAIT_MASK) <<
                                                 EMC_MRS_WAIT_CNT_SHORT_WAIT_SHIFT);
                } else if (offset == EMC_ZCAL_WAIT_CNT &&
                           dram_type == DRAM_TYPE_DDR3 && opt_zcal_en_cc &&
                           !opt_cc_short_zcal && opt_short_zcal) {
                        value = (value & ~(EMC_ZCAL_WAIT_CNT_ZCAL_WAIT_CNT_MASK <<
                                           EMC_ZCAL_WAIT_CNT_ZCAL_WAIT_CNT_SHIFT)) |
                                ((zq_wait_long & EMC_ZCAL_WAIT_CNT_ZCAL_WAIT_CNT_MASK) <<
                                                 EMC_MRS_WAIT_CNT_SHORT_WAIT_SHIFT);
                } else if (offset == EMC_ZCAL_INTERVAL && opt_zcal_en_cc) {
                        value = 0; /* EMC_ZCAL_INTERVAL reset value. */
                } else if (offset == EMC_PMACRO_AUTOCAL_CFG_COMMON) {
                        value |= EMC_PMACRO_AUTOCAL_CFG_COMMON_E_CAL_BYPASS_DVFS;
                } else if (offset == EMC_PMACRO_DATA_PAD_TX_CTRL) {
                        value &= ~(EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQSP_TX_E_DCC |
                                   EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQSN_TX_E_DCC |
                                   EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_DQ_TX_E_DCC |
                                   EMC_PMACRO_DATA_PAD_TX_CTRL_DATA_CMD_TX_E_DCC);
                } else if (offset == EMC_PMACRO_CMD_PAD_TX_CTRL) {
                        value |= EMC_PMACRO_CMD_PAD_TX_CTRL_CMD_DQ_TX_DRVFORCEON;
                        value &= ~(EMC_PMACRO_CMD_PAD_TX_CTRL_CMD_DQSP_TX_E_DCC |
                                   EMC_PMACRO_CMD_PAD_TX_CTRL_CMD_DQSN_TX_E_DCC |
                                   EMC_PMACRO_CMD_PAD_TX_CTRL_CMD_DQ_TX_E_DCC |
                                   EMC_PMACRO_CMD_PAD_TX_CTRL_CMD_CMD_TX_E_DCC);
                } else if (offset == EMC_PMACRO_BRICK_CTRL_RFU1) {
                        value &= 0xf800f800;
                } else if (offset == EMC_PMACRO_COMMON_PAD_TX_CTRL) {
                        value &= 0xfffffff0;
                }

                emc_writel(emc, value, offset);
        }

        /* SW addition: do EMC refresh adjustment here. */
        tegra210_emc_adjust_timing(emc, next);

        if (dram_type == DRAM_TYPE_LPDDR4) {
                value = (23 << EMC_MRW_MRW_MA_SHIFT) |
                        (next->run_clocks & EMC_MRW_MRW_OP_MASK);
                emc_writel(emc, value, EMC_MRW);
        }

        /* Per channel burst registers. */
        emc_dbg(emc, SUB_STEPS, "Writing burst_regs_per_ch\n");

        for (i = 0; i < next->num_burst_per_ch; i++) {
                const struct tegra210_emc_per_channel_regs *burst =
                                emc->offsets->burst_per_channel;

                if (!burst[i].offset)
                        continue;

                if (dram_type != DRAM_TYPE_LPDDR4 &&
                    (burst[i].offset == EMC_MRW6 ||
                     burst[i].offset == EMC_MRW7 ||
                     burst[i].offset == EMC_MRW8 ||
                     burst[i].offset == EMC_MRW9 ||
                     burst[i].offset == EMC_MRW10 ||
                     burst[i].offset == EMC_MRW11 ||
                     burst[i].offset == EMC_MRW12 ||
                     burst[i].offset == EMC_MRW13 ||
                     burst[i].offset == EMC_MRW14 ||
                     burst[i].offset == EMC_MRW15))
                        continue;

                /* Filter out second channel if not in DUAL_CHANNEL mode. */
                if (emc->num_channels < 2 && burst[i].bank >= 1)
                        continue;

                emc_dbg(emc, REG_LISTS, "(%u) 0x%08x => 0x%08x\n", i,
                        next->burst_reg_per_ch[i], burst[i].offset);
                emc_channel_writel(emc, burst[i].bank,
                                   next->burst_reg_per_ch[i],
                                   burst[i].offset);
        }

        /* Vref regs. */
        emc_dbg(emc, SUB_STEPS, "Writing vref_regs\n");

        for (i = 0; i < next->vref_num; i++) {
                const struct tegra210_emc_per_channel_regs *vref =
                                        emc->offsets->vref_per_channel;

                if (!vref[i].offset)
                        continue;

                if (emc->num_channels < 2 && vref[i].bank >= 1)
                        continue;

                emc_dbg(emc, REG_LISTS, "(%u) 0x%08x => 0x%08x\n", i,
                        next->vref_perch_regs[i], vref[i].offset);
                emc_channel_writel(emc, vref[i].bank, next->vref_perch_regs[i],
                                   vref[i].offset);
        }

        /* Trimmers. */
        emc_dbg(emc, SUB_STEPS, "Writing trim_regs\n");

        for (i = 0; i < next->num_trim; i++) {
                const u16 *offsets = emc->offsets->trim;

                if (!offsets[i])
                        continue;

                if (compensate_trimmer_applicable &&
                    (offsets[i] == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_0 ||
                     offsets[i] == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_1 ||
                     offsets[i] == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_2 ||
                     offsets[i] == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_3 ||
                     offsets[i] == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_0 ||
                     offsets[i] == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_1 ||
                     offsets[i] == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_2 ||
                     offsets[i] == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_3 ||
                     offsets[i] == EMC_DATA_BRLSHFT_0 ||
                     offsets[i] == EMC_DATA_BRLSHFT_1)) {
                        value = tegra210_emc_compensate(next, offsets[i]);
                        emc_dbg(emc, REG_LISTS, "(%u) 0x%08x => 0x%08x\n", i,
                                value, offsets[i]);
                        emc_dbg(emc, EMA_WRITES, "0x%08x <= 0x%08x\n",
                                (u32)(u64)offsets[i], value);
                        emc_writel(emc, value, offsets[i]);
                } else {
                        emc_dbg(emc, REG_LISTS, "(%u) 0x%08x => 0x%08x\n", i,
                                next->trim_regs[i], offsets[i]);
                        emc_writel(emc, next->trim_regs[i], offsets[i]);
                }
        }

        /* Per channel trimmers. */
        emc_dbg(emc, SUB_STEPS, "Writing trim_regs_per_ch\n");

        for (i = 0; i < next->num_trim_per_ch; i++) {
                const struct tegra210_emc_per_channel_regs *trim =
                                &emc->offsets->trim_per_channel[0];
                unsigned int offset;

                if (!trim[i].offset)
                        continue;

                if (emc->num_channels < 2 && trim[i].bank >= 1)
                        continue;

                offset = trim[i].offset;

                if (compensate_trimmer_applicable &&
                    (offset == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_0 ||
                     offset == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_1 ||
                     offset == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_2 ||
                     offset == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK0_3 ||
                     offset == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_0 ||
                     offset == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_1 ||
                     offset == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_2 ||
                     offset == EMC_PMACRO_OB_DDLL_LONG_DQ_RANK1_3 ||
                     offset == EMC_DATA_BRLSHFT_0 ||
                     offset == EMC_DATA_BRLSHFT_1)) {
                        value = tegra210_emc_compensate(next, offset);
                        emc_dbg(emc, REG_LISTS, "(%u) 0x%08x => 0x%08x\n", i,
                                value, offset);
                        emc_dbg(emc, EMA_WRITES, "0x%08x <= 0x%08x\n", offset,
                                value);
                        emc_channel_writel(emc, trim[i].bank, value, offset);
                } else {
                        emc_dbg(emc, REG_LISTS, "(%u) 0x%08x => 0x%08x\n", i,
                                next->trim_perch_regs[i], offset);
                        emc_channel_writel(emc, trim[i].bank,
                                           next->trim_perch_regs[i], offset);
                }
        }

        emc_dbg(emc, SUB_STEPS, "Writing burst_mc_regs\n");

        for (i = 0; i < next->num_mc_regs; i++) {
                const u16 *offsets = emc->offsets->burst_mc;
                u32 *values = next->burst_mc_regs;

                emc_dbg(emc, REG_LISTS, "(%u) 0x%08x => 0x%08x\n", i,
                        values[i], offsets[i]);
                mc_writel(emc->mc, values[i], offsets[i]);
        }

        /* Registers to be programmed on the faster clock. */
        if (next->rate < last->rate) {
                const u16 *la = emc->offsets->la_scale;

                emc_dbg(emc, SUB_STEPS, "Writing la_scale_regs\n");

                for (i = 0; i < next->num_up_down; i++) {
                        emc_dbg(emc, REG_LISTS, "(%u) 0x%08x => 0x%08x\n", i,
                                next->la_scale_regs[i], la[i]);
                        mc_writel(emc->mc, next->la_scale_regs[i], la[i]);
                }
        }

        /* Flush all the burst register writes. */
        mc_readl(emc->mc, MC_EMEM_ADR_CFG);

        /*
         * Step 9:
         *   LPDDR4 section A.
         */
        emc_dbg(emc, STEPS, "Step 9\n");

        value = next->burst_regs[EMC_ZCAL_WAIT_CNT_INDEX];
        value &= ~EMC_ZCAL_WAIT_CNT_ZCAL_WAIT_CNT_MASK;

        if (dram_type == DRAM_TYPE_LPDDR4) {
                emc_writel(emc, 0, EMC_ZCAL_INTERVAL);
                emc_writel(emc, value, EMC_ZCAL_WAIT_CNT);

                value = emc_dbg | (EMC_DBG_WRITE_MUX_ACTIVE |
                                   EMC_DBG_WRITE_ACTIVE_ONLY);

                emc_writel(emc, value, EMC_DBG);
                emc_writel(emc, 0, EMC_ZCAL_INTERVAL);
                emc_writel(emc, emc_dbg, EMC_DBG);
        }

        /*
         * Step 10:
         *   LPDDR4 and DDR3 common section.
         */
        emc_dbg(emc, STEPS, "Step 10\n");

        if (opt_dvfs_mode == MAN_SR || dram_type == DRAM_TYPE_LPDDR4) {
                if (dram_type == DRAM_TYPE_LPDDR4)
                        ccfifo_writel(emc, 0x101, EMC_SELF_REF, 0);
                else
                        ccfifo_writel(emc, 0x1, EMC_SELF_REF, 0);

                if (dram_type == DRAM_TYPE_LPDDR4 &&
                    dst_clk_period <= zqcal_before_cc_cutoff) {
                        ccfifo_writel(emc, mr13_flip_fspwr ^ 0x40, EMC_MRW3, 0);
                        ccfifo_writel(emc, (next->burst_regs[EMC_MRW6_INDEX] &
                                                0xFFFF3F3F) |
                                           (last->burst_regs[EMC_MRW6_INDEX] &
                                                0x0000C0C0), EMC_MRW6, 0);
                        ccfifo_writel(emc, (next->burst_regs[EMC_MRW14_INDEX] &
                                                0xFFFF0707) |
                                           (last->burst_regs[EMC_MRW14_INDEX] &
                                                0x00003838), EMC_MRW14, 0);

                        if (emc->num_devices > 1) {
                                ccfifo_writel(emc,
                                      (next->burst_regs[EMC_MRW7_INDEX] &
                                       0xFFFF3F3F) |
                                      (last->burst_regs[EMC_MRW7_INDEX] &
                                       0x0000C0C0), EMC_MRW7, 0);
                                ccfifo_writel(emc,
                                     (next->burst_regs[EMC_MRW15_INDEX] &
                                      0xFFFF0707) |
                                     (last->burst_regs[EMC_MRW15_INDEX] &
                                      0x00003838), EMC_MRW15, 0);
                        }

                        if (opt_zcal_en_cc) {
                                if (emc->num_devices < 2)
                                        ccfifo_writel(emc,
                                                2UL << EMC_ZQ_CAL_DEV_SEL_SHIFT
                                                | EMC_ZQ_CAL_ZQ_CAL_CMD,
                                                EMC_ZQ_CAL, 0);
                                else if (shared_zq_resistor)
                                        ccfifo_writel(emc,
                                                2UL << EMC_ZQ_CAL_DEV_SEL_SHIFT
                                                | EMC_ZQ_CAL_ZQ_CAL_CMD,
                                                EMC_ZQ_CAL, 0);
                                else
                                        ccfifo_writel(emc,
                                                      EMC_ZQ_CAL_ZQ_CAL_CMD,
                                                      EMC_ZQ_CAL, 0);
                        }
                }
        }

        if (dram_type == DRAM_TYPE_LPDDR4) {
                value = (1000 * fake->dram_timings[T_RP]) / src_clk_period;
                ccfifo_writel(emc, mr13_flip_fspop | 0x8, EMC_MRW3, value);
                ccfifo_writel(emc, 0, 0, tFC_lpddr4 / src_clk_period);
        }

        if (dram_type == DRAM_TYPE_LPDDR4 || opt_dvfs_mode != MAN_SR) {
                delay = 30;

                if (cya_allow_ref_cc) {
                        delay += (1000 * fake->dram_timings[T_RP]) /
                                        src_clk_period;
                        delay += 4000 * fake->dram_timings[T_RFC];
                }

                ccfifo_writel(emc, emc_pin & ~(EMC_PIN_PIN_CKE_PER_DEV |
                                               EMC_PIN_PIN_CKEB |
                                               EMC_PIN_PIN_CKE),
                              EMC_PIN, delay);
        }

        /* calculate reference delay multiplier */
        value = 1;

        if (ref_b4_sref_en)
                value++;

        if (cya_allow_ref_cc)
                value++;

        if (cya_issue_pc_ref)
                value++;

        if (dram_type != DRAM_TYPE_LPDDR4) {
                delay = ((1000 * fake->dram_timings[T_RP] / src_clk_period) +
                         (1000 * fake->dram_timings[T_RFC] / src_clk_period));
                delay = value * delay + 20;
        } else {
                delay = 0;
        }

        /*
         * Step 11:
         *   Ramp down.
         */
        emc_dbg(emc, STEPS, "Step 11\n");

        ccfifo_writel(emc, 0x0, EMC_CFG_SYNC, delay);

        value = emc_dbg | EMC_DBG_WRITE_MUX_ACTIVE | EMC_DBG_WRITE_ACTIVE_ONLY;
        ccfifo_writel(emc, value, EMC_DBG, 0);

        ramp_down_wait = tegra210_emc_dvfs_power_ramp_down(emc, src_clk_period,
                                                           0);

        /*
         * Step 12:
         *   And finally - trigger the clock change.
         */
        emc_dbg(emc, STEPS, "Step 12\n");

        ccfifo_writel(emc, 1, EMC_STALL_THEN_EXE_AFTER_CLKCHANGE, 0);
        value &= ~EMC_DBG_WRITE_ACTIVE_ONLY;
        ccfifo_writel(emc, value, EMC_DBG, 0);

        /*
         * Step 13:
         *   Ramp up.
         */
        emc_dbg(emc, STEPS, "Step 13\n");

        ramp_up_wait = tegra210_emc_dvfs_power_ramp_up(emc, dst_clk_period, 0);
        ccfifo_writel(emc, emc_dbg, EMC_DBG, 0);

        /*
         * Step 14:
         *   Bringup CKE pins.
         */
        emc_dbg(emc, STEPS, "Step 14\n");

        if (dram_type == DRAM_TYPE_LPDDR4) {
                value = emc_pin | EMC_PIN_PIN_CKE;

                if (emc->num_devices <= 1)
                        value &= ~(EMC_PIN_PIN_CKEB | EMC_PIN_PIN_CKE_PER_DEV);
                else
                        value |= EMC_PIN_PIN_CKEB | EMC_PIN_PIN_CKE_PER_DEV;

                ccfifo_writel(emc, value, EMC_PIN, 0);
        }

        /*
         * Step 15: (two step 15s ??)
         *   Calculate zqlatch wait time; has dependency on ramping times.
         */
        emc_dbg(emc, STEPS, "Step 15\n");

        if (dst_clk_period <= zqcal_before_cc_cutoff) {
                s32 t = (s32)(ramp_up_wait + ramp_down_wait) /
                        (s32)dst_clk_period;
                zq_latch_dvfs_wait_time = (s32)tZQCAL_lpddr4_fc_adj - t;
        } else {
                zq_latch_dvfs_wait_time = tZQCAL_lpddr4_fc_adj -
                        div_o3(1000 * next->dram_timings[T_PDEX],
                               dst_clk_period);
        }

        emc_dbg(emc, INFO, "tZQCAL_lpddr4_fc_adj = %u\n", tZQCAL_lpddr4_fc_adj);
        emc_dbg(emc, INFO, "dst_clk_period = %u\n",
                dst_clk_period);
        emc_dbg(emc, INFO, "next->dram_timings[T_PDEX] = %u\n",
                next->dram_timings[T_PDEX]);
        emc_dbg(emc, INFO, "zq_latch_dvfs_wait_time = %d\n",
                max_t(s32, 0, zq_latch_dvfs_wait_time));

        if (dram_type == DRAM_TYPE_LPDDR4 && opt_zcal_en_cc) {
                delay = div_o3(1000 * next->dram_timings[T_PDEX],
                               dst_clk_period);

                if (emc->num_devices < 2) {
                        if (dst_clk_period > zqcal_before_cc_cutoff)
                                ccfifo_writel(emc,
                                              2UL << EMC_ZQ_CAL_DEV_SEL_SHIFT |
                                              EMC_ZQ_CAL_ZQ_CAL_CMD, EMC_ZQ_CAL,
                                              delay);

                        value = (mr13_flip_fspop & 0xfffffff7) | 0x0c000000;
                        ccfifo_writel(emc, value, EMC_MRW3, delay);
                        ccfifo_writel(emc, 0, EMC_SELF_REF, 0);
                        ccfifo_writel(emc, 0, EMC_REF, 0);
                        ccfifo_writel(emc, 2UL << EMC_ZQ_CAL_DEV_SEL_SHIFT |
                                      EMC_ZQ_CAL_ZQ_LATCH_CMD,
                                      EMC_ZQ_CAL,
                                      max_t(s32, 0, zq_latch_dvfs_wait_time));
                } else if (shared_zq_resistor) {
                        if (dst_clk_period > zqcal_before_cc_cutoff)
                                ccfifo_writel(emc,
                                              2UL << EMC_ZQ_CAL_DEV_SEL_SHIFT |
                                              EMC_ZQ_CAL_ZQ_CAL_CMD, EMC_ZQ_CAL,
                                              delay);

                        ccfifo_writel(emc, 2UL << EMC_ZQ_CAL_DEV_SEL_SHIFT |
                                      EMC_ZQ_CAL_ZQ_LATCH_CMD, EMC_ZQ_CAL,
                                      max_t(s32, 0, zq_latch_dvfs_wait_time) +
                                        delay);
                        ccfifo_writel(emc, 1UL << EMC_ZQ_CAL_DEV_SEL_SHIFT |
                                      EMC_ZQ_CAL_ZQ_LATCH_CMD,
                                      EMC_ZQ_CAL, 0);

                        value = (mr13_flip_fspop & 0xfffffff7) | 0x0c000000;
                        ccfifo_writel(emc, value, EMC_MRW3, 0);
                        ccfifo_writel(emc, 0, EMC_SELF_REF, 0);
                        ccfifo_writel(emc, 0, EMC_REF, 0);

                        ccfifo_writel(emc, 1UL << EMC_ZQ_CAL_DEV_SEL_SHIFT |
                                      EMC_ZQ_CAL_ZQ_LATCH_CMD, EMC_ZQ_CAL,
                                      tZQCAL_lpddr4 / dst_clk_period);
                } else {
                        if (dst_clk_period > zqcal_before_cc_cutoff)
                                ccfifo_writel(emc, EMC_ZQ_CAL_ZQ_CAL_CMD,
                                              EMC_ZQ_CAL, delay);

                        value = (mr13_flip_fspop & 0xfffffff7) | 0x0c000000;
                        ccfifo_writel(emc, value, EMC_MRW3, delay);
                        ccfifo_writel(emc, 0, EMC_SELF_REF, 0);
                        ccfifo_writel(emc, 0, EMC_REF, 0);

                        ccfifo_writel(emc, EMC_ZQ_CAL_ZQ_LATCH_CMD, EMC_ZQ_CAL,
                                      max_t(s32, 0, zq_latch_dvfs_wait_time));
                }
        }

        /* WAR: delay for zqlatch */
        ccfifo_writel(emc, 0, 0, 10);

        /*
         * Step 16:
         *   LPDDR4 Conditional Training Kickoff. Removed.
         */

        /*
         * Step 17:
         *   MANSR exit self refresh.
         */
        emc_dbg(emc, STEPS, "Step 17\n");

        if (opt_dvfs_mode == MAN_SR && dram_type != DRAM_TYPE_LPDDR4)
                ccfifo_writel(emc, 0, EMC_SELF_REF, 0);

        /*
         * Step 18:
         *   Send MRWs to LPDDR3/DDR3.
         */
        emc_dbg(emc, STEPS, "Step 18\n");

        if (dram_type == DRAM_TYPE_LPDDR2) {
                ccfifo_writel(emc, next->emc_mrw2, EMC_MRW2, 0);
                ccfifo_writel(emc, next->emc_mrw,  EMC_MRW,  0);
                if (is_lpddr3)
                        ccfifo_writel(emc, next->emc_mrw4, EMC_MRW4, 0);
        } else if (dram_type == DRAM_TYPE_DDR3) {
                if (opt_dll_mode)
                        ccfifo_writel(emc, next->emc_emrs &
                                      ~EMC_EMRS_USE_EMRS_LONG_CNT, EMC_EMRS, 0);
                ccfifo_writel(emc, next->emc_emrs2 &
                              ~EMC_EMRS2_USE_EMRS2_LONG_CNT, EMC_EMRS2, 0);
                ccfifo_writel(emc, next->emc_mrs |
                              EMC_EMRS_USE_EMRS_LONG_CNT, EMC_MRS, 0);
        }

        /*
         * Step 19:
         *   ZQCAL for LPDDR3/DDR3
         */
        emc_dbg(emc, STEPS, "Step 19\n");

        if (opt_zcal_en_cc) {
                if (dram_type == DRAM_TYPE_LPDDR2) {
                        value = opt_cc_short_zcal ? 90000 : 360000;
                        value = div_o3(value, dst_clk_period);
                        value = value <<
                                EMC_MRS_WAIT_CNT2_MRS_EXT2_WAIT_CNT_SHIFT |
                                value <<
                                EMC_MRS_WAIT_CNT2_MRS_EXT1_WAIT_CNT_SHIFT;
                        ccfifo_writel(emc, value, EMC_MRS_WAIT_CNT2, 0);

                        value = opt_cc_short_zcal ? 0x56 : 0xab;
                        ccfifo_writel(emc, 2 << EMC_MRW_MRW_DEV_SELECTN_SHIFT |
                                           EMC_MRW_USE_MRW_EXT_CNT |
                                           10 << EMC_MRW_MRW_MA_SHIFT |
                                           value << EMC_MRW_MRW_OP_SHIFT,
                                      EMC_MRW, 0);

                        if (emc->num_devices > 1) {
                                value = 1 << EMC_MRW_MRW_DEV_SELECTN_SHIFT |
                                        EMC_MRW_USE_MRW_EXT_CNT |
                                        10 << EMC_MRW_MRW_MA_SHIFT |
                                        value << EMC_MRW_MRW_OP_SHIFT;
                                ccfifo_writel(emc, value, EMC_MRW, 0);
                        }
                } else if (dram_type == DRAM_TYPE_DDR3) {
                        value = opt_cc_short_zcal ? 0 : EMC_ZQ_CAL_LONG;

                        ccfifo_writel(emc, value |
                                           2 << EMC_ZQ_CAL_DEV_SEL_SHIFT |
                                           EMC_ZQ_CAL_ZQ_CAL_CMD, EMC_ZQ_CAL,
                                           0);

                        if (emc->num_devices > 1) {
                                value = value | 1 << EMC_ZQ_CAL_DEV_SEL_SHIFT |
                                                EMC_ZQ_CAL_ZQ_CAL_CMD;
                                ccfifo_writel(emc, value, EMC_ZQ_CAL, 0);
                        }
                }
        }

        if (bg_reg_mode_change) {
                tegra210_emc_set_shadow_bypass(emc, ACTIVE);

                if (ramp_up_wait <= 1250000)
                        delay = (1250000 - ramp_up_wait) / dst_clk_period;
                else
                        delay = 0;

                ccfifo_writel(emc,
                              next->burst_regs[EMC_PMACRO_BG_BIAS_CTRL_0_INDEX],
                              EMC_PMACRO_BG_BIAS_CTRL_0, delay);
                tegra210_emc_set_shadow_bypass(emc, ASSEMBLY);
        }

        /*
         * Step 20:
         *   Issue ref and optional QRST.
         */
        emc_dbg(emc, STEPS, "Step 20\n");

        if (dram_type != DRAM_TYPE_LPDDR4)
                ccfifo_writel(emc, 0, EMC_REF, 0);

        if (opt_do_sw_qrst) {
                ccfifo_writel(emc, 1, EMC_ISSUE_QRST, 0);
                ccfifo_writel(emc, 0, EMC_ISSUE_QRST, 2);
        }

        /*
         * Step 21:
         *   Restore ZCAL and ZCAL interval.
         */
        emc_dbg(emc, STEPS, "Step 21\n");

        if (save_restore_clkstop_pd || opt_zcal_en_cc) {
                ccfifo_writel(emc, emc_dbg | EMC_DBG_WRITE_MUX_ACTIVE,
                              EMC_DBG, 0);
                if (opt_zcal_en_cc && dram_type != DRAM_TYPE_LPDDR4)
                        ccfifo_writel(emc, next->burst_regs[EMC_ZCAL_INTERVAL_INDEX],
                                      EMC_ZCAL_INTERVAL, 0);

                if (save_restore_clkstop_pd)
                        ccfifo_writel(emc, next->burst_regs[EMC_CFG_INDEX] &
                                                ~EMC_CFG_DYN_SELF_REF,
                                      EMC_CFG, 0);
                ccfifo_writel(emc, emc_dbg, EMC_DBG, 0);
        }

        /*
         * Step 22:
         *   Restore EMC_CFG_PIPE_CLK.
         */
        emc_dbg(emc, STEPS, "Step 22\n");

        ccfifo_writel(emc, emc_cfg_pipe_clk, EMC_CFG_PIPE_CLK, 0);

        if (bg_reg_mode_change) {
                if (enable_bg_reg)
                        emc_writel(emc,
                                   next->burst_regs[EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                                        ~EMC_PMACRO_BG_BIAS_CTRL_0_BGLP_E_PWRD,
                                   EMC_PMACRO_BG_BIAS_CTRL_0);
                else
                        emc_writel(emc,
                                   next->burst_regs[EMC_PMACRO_BG_BIAS_CTRL_0_INDEX] &
                                        ~EMC_PMACRO_BG_BIAS_CTRL_0_BG_E_PWRD,
                                   EMC_PMACRO_BG_BIAS_CTRL_0);
        }

        /*
         * Step 23:
         */
        emc_dbg(emc, STEPS, "Step 23\n");

        value = emc_readl(emc, EMC_CFG_DIG_DLL);
        value |= EMC_CFG_DIG_DLL_CFG_DLL_STALL_ALL_TRAFFIC;
        value &= ~EMC_CFG_DIG_DLL_CFG_DLL_STALL_RW_UNTIL_LOCK;
        value &= ~EMC_CFG_DIG_DLL_CFG_DLL_STALL_ALL_UNTIL_LOCK;
        value &= ~EMC_CFG_DIG_DLL_CFG_DLL_EN;
        value = (value & ~EMC_CFG_DIG_DLL_CFG_DLL_MODE_MASK) |
                (2 << EMC_CFG_DIG_DLL_CFG_DLL_MODE_SHIFT);
        emc_writel(emc, value, EMC_CFG_DIG_DLL);

        tegra210_emc_do_clock_change(emc, clksrc);

        /*
         * Step 24:
         *   Save training results. Removed.
         */

        /*
         * Step 25:
         *   Program MC updown registers.
         */
        emc_dbg(emc, STEPS, "Step 25\n");

        if (next->rate > last->rate) {
                for (i = 0; i < next->num_up_down; i++)
                        mc_writel(emc->mc, next->la_scale_regs[i],
                                  emc->offsets->la_scale[i]);

                tegra210_emc_timing_update(emc);
        }

        /*
         * Step 26:
         *   Restore ZCAL registers.
         */
        emc_dbg(emc, STEPS, "Step 26\n");

        if (dram_type == DRAM_TYPE_LPDDR4) {
                tegra210_emc_set_shadow_bypass(emc, ACTIVE);
                emc_writel(emc, next->burst_regs[EMC_ZCAL_WAIT_CNT_INDEX],
                           EMC_ZCAL_WAIT_CNT);
                emc_writel(emc, next->burst_regs[EMC_ZCAL_INTERVAL_INDEX],
                           EMC_ZCAL_INTERVAL);
                tegra210_emc_set_shadow_bypass(emc, ASSEMBLY);
        }

        if (dram_type != DRAM_TYPE_LPDDR4 && opt_zcal_en_cc &&
            !opt_short_zcal && opt_cc_short_zcal) {
                udelay(2);

                tegra210_emc_set_shadow_bypass(emc, ACTIVE);
                if (dram_type == DRAM_TYPE_LPDDR2)
                        emc_writel(emc, next->burst_regs[EMC_MRS_WAIT_CNT_INDEX],
                                   EMC_MRS_WAIT_CNT);
                else if (dram_type == DRAM_TYPE_DDR3)
                        emc_writel(emc, next->burst_regs[EMC_ZCAL_WAIT_CNT_INDEX],
                                   EMC_ZCAL_WAIT_CNT);
                tegra210_emc_set_shadow_bypass(emc, ASSEMBLY);
        }

        /*
         * Step 27:
         *   Restore EMC_CFG, FDPD registers.
         */
        emc_dbg(emc, STEPS, "Step 27\n");

        tegra210_emc_set_shadow_bypass(emc, ACTIVE);
        emc_writel(emc, next->burst_regs[EMC_CFG_INDEX], EMC_CFG);
        tegra210_emc_set_shadow_bypass(emc, ASSEMBLY);
        emc_writel(emc, next->emc_fdpd_ctrl_cmd_no_ramp,
                   EMC_FDPD_CTRL_CMD_NO_RAMP);
        emc_writel(emc, next->emc_sel_dpd_ctrl, EMC_SEL_DPD_CTRL);

        /*
         * Step 28:
         *   Training recover. Removed.
         */
        emc_dbg(emc, STEPS, "Step 28\n");

        tegra210_emc_set_shadow_bypass(emc, ACTIVE);
        emc_writel(emc,
                   next->burst_regs[EMC_PMACRO_AUTOCAL_CFG_COMMON_INDEX],
                   EMC_PMACRO_AUTOCAL_CFG_COMMON);
        tegra210_emc_set_shadow_bypass(emc, ASSEMBLY);

        /*
         * Step 29:
         *   Power fix WAR.
         */
        emc_dbg(emc, STEPS, "Step 29\n");

        emc_writel(emc, EMC_PMACRO_CFG_PM_GLOBAL_0_DISABLE_CFG_BYTE0 |
                   EMC_PMACRO_CFG_PM_GLOBAL_0_DISABLE_CFG_BYTE1 |
                   EMC_PMACRO_CFG_PM_GLOBAL_0_DISABLE_CFG_BYTE2 |
                   EMC_PMACRO_CFG_PM_GLOBAL_0_DISABLE_CFG_BYTE3 |
                   EMC_PMACRO_CFG_PM_GLOBAL_0_DISABLE_CFG_BYTE4 |
                   EMC_PMACRO_CFG_PM_GLOBAL_0_DISABLE_CFG_BYTE5 |
                   EMC_PMACRO_CFG_PM_GLOBAL_0_DISABLE_CFG_BYTE6 |
                   EMC_PMACRO_CFG_PM_GLOBAL_0_DISABLE_CFG_BYTE7,
                   EMC_PMACRO_CFG_PM_GLOBAL_0);
        emc_writel(emc, EMC_PMACRO_TRAINING_CTRL_0_CH0_TRAINING_E_WRPTR,
                   EMC_PMACRO_TRAINING_CTRL_0);
        emc_writel(emc, EMC_PMACRO_TRAINING_CTRL_1_CH1_TRAINING_E_WRPTR,
                   EMC_PMACRO_TRAINING_CTRL_1);
        emc_writel(emc, 0, EMC_PMACRO_CFG_PM_GLOBAL_0);

        /*
         * Step 30:
         *   Re-enable autocal.
         */
        emc_dbg(emc, STEPS, "Step 30: Re-enable DLL and AUTOCAL\n");

        if (next->burst_regs[EMC_CFG_DIG_DLL_INDEX] & EMC_CFG_DIG_DLL_CFG_DLL_EN) {
                value = emc_readl(emc, EMC_CFG_DIG_DLL);
                value |=  EMC_CFG_DIG_DLL_CFG_DLL_STALL_ALL_TRAFFIC;
                value |=  EMC_CFG_DIG_DLL_CFG_DLL_EN;
                value &= ~EMC_CFG_DIG_DLL_CFG_DLL_STALL_RW_UNTIL_LOCK;
                value &= ~EMC_CFG_DIG_DLL_CFG_DLL_STALL_ALL_UNTIL_LOCK;
                value = (value & ~EMC_CFG_DIG_DLL_CFG_DLL_MODE_MASK) |
                        (2 << EMC_CFG_DIG_DLL_CFG_DLL_MODE_SHIFT);
                emc_writel(emc, value, EMC_CFG_DIG_DLL);
                tegra210_emc_timing_update(emc);
        }

        emc_writel(emc, next->emc_auto_cal_config, EMC_AUTO_CAL_CONFIG);

        /* Done! Yay. */
}

const struct tegra210_emc_sequence tegra210_emc_r21021 = {
        .revision = 0x7,
        .set_clock = tegra210_emc_r21021_set_clock,
        .periodic_compensation = tegra210_emc_r21021_periodic_compensation,
};