// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018 HiSilicon Technologies Co., Ltd.
 */

#include <linux/clk.h>
#include <linux/mfd/syscon.h>
#include <linux/mmc/host.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>

#include "dw_mmc.h"
#include "dw_mmc-pltfm.h"

#define ALL_INT_CLR             0x1ffff

struct hi3798cv200_priv {
        struct clk *sample_clk;
        struct clk *drive_clk;
};

static void dw_mci_hi3798cv200_set_ios(struct dw_mci *host, struct mmc_ios *ios)
{
        struct hi3798cv200_priv *priv = host->priv;
        u32 val;

        val = mci_readl(host, UHS_REG);
        if (ios->timing == MMC_TIMING_MMC_DDR52 ||
            ios->timing == MMC_TIMING_UHS_DDR50)
                val |= SDMMC_UHS_DDR;
        else
                val &= ~SDMMC_UHS_DDR;
        mci_writel(host, UHS_REG, val);

        val = mci_readl(host, ENABLE_SHIFT);
        if (ios->timing == MMC_TIMING_MMC_DDR52)
                val |= SDMMC_ENABLE_PHASE;
        else
                val &= ~SDMMC_ENABLE_PHASE;
        mci_writel(host, ENABLE_SHIFT, val);

        val = mci_readl(host, DDR_REG);
        if (ios->timing == MMC_TIMING_MMC_HS400)
                val |= SDMMC_DDR_HS400;
        else
                val &= ~SDMMC_DDR_HS400;
        mci_writel(host, DDR_REG, val);

        if (ios->timing == MMC_TIMING_MMC_HS ||
            ios->timing == MMC_TIMING_LEGACY)
                clk_set_phase(priv->drive_clk, 180);
        else if (ios->timing == MMC_TIMING_MMC_HS200)
                clk_set_phase(priv->drive_clk, 135);
}

static int dw_mci_hi3798cv200_execute_tuning(struct dw_mci_slot *slot,
                                             u32 opcode)
{
        static const int degrees[] = { 0, 45, 90, 135, 180, 225, 270, 315 };
        struct dw_mci *host = slot->host;
        struct hi3798cv200_priv *priv = host->priv;
        int raise_point = -1, fall_point = -1;
        int err, prev_err = -1;
        int found = 0;
        int i;

        for (i = 0; i < ARRAY_SIZE(degrees); i++) {
                clk_set_phase(priv->sample_clk, degrees[i]);
                mci_writel(host, RINTSTS, ALL_INT_CLR);

                err = mmc_send_tuning(slot->mmc, opcode, NULL);
                if (!err)
                        found = 1;

                if (i > 0) {
                        if (err && !prev_err)
                                fall_point = i - 1;
                        if (!err && prev_err)
                                raise_point = i;
                }

                if (raise_point != -1 && fall_point != -1)
                        goto tuning_out;

                prev_err = err;
        }

tuning_out:
        if (found) {
                if (raise_point == -1)
                        raise_point = 0;
                if (fall_point == -1)
                        fall_point = ARRAY_SIZE(degrees) - 1;
                if (fall_point < raise_point) {
                        if ((raise_point + fall_point) >
                            (ARRAY_SIZE(degrees) - 1))
                                i = fall_point / 2;
                        else
                                i = (raise_point + ARRAY_SIZE(degrees) - 1) / 2;
                } else {
                        i = (raise_point + fall_point) / 2;
                }

                clk_set_phase(priv->sample_clk, degrees[i]);
                dev_dbg(host->dev, "Tuning clk_sample[%d, %d], set[%d]\n",
                        raise_point, fall_point, degrees[i]);
        } else {
                dev_err(host->dev, "No valid clk_sample shift! use default\n");
                err = -EINVAL;
        }

        mci_writel(host, RINTSTS, ALL_INT_CLR);
        return err;
}

static int dw_mci_hi3798cv200_init(struct dw_mci *host)
{
        struct hi3798cv200_priv *priv;
        int ret;

        priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        priv->sample_clk = devm_clk_get(host->dev, "ciu-sample");
        if (IS_ERR(priv->sample_clk)) {
                dev_err(host->dev, "failed to get ciu-sample clock\n");
                return PTR_ERR(priv->sample_clk);
        }

        priv->drive_clk = devm_clk_get(host->dev, "ciu-drive");
        if (IS_ERR(priv->drive_clk)) {
                dev_err(host->dev, "failed to get ciu-drive clock\n");
                return PTR_ERR(priv->drive_clk);
        }

        ret = clk_prepare_enable(priv->sample_clk);
        if (ret) {
                dev_err(host->dev, "failed to enable ciu-sample clock\n");
                return ret;
        }

        ret = clk_prepare_enable(priv->drive_clk);
        if (ret) {
                dev_err(host->dev, "failed to enable ciu-drive clock\n");
                goto disable_sample_clk;
        }

        host->priv = priv;
        return 0;

disable_sample_clk:
        clk_disable_unprepare(priv->sample_clk);
        return ret;
}

static const struct dw_mci_drv_data hi3798cv200_data = {
        .common_caps = MMC_CAP_CMD23,
        .init = dw_mci_hi3798cv200_init,
        .set_ios = dw_mci_hi3798cv200_set_ios,
        .execute_tuning = dw_mci_hi3798cv200_execute_tuning,
};

static int dw_mci_hi3798cv200_probe(struct platform_device *pdev)
{
        return dw_mci_pltfm_register(pdev, &hi3798cv200_data);
}

static void dw_mci_hi3798cv200_remove(struct platform_device *pdev)
{
        struct dw_mci *host = platform_get_drvdata(pdev);
        struct hi3798cv200_priv *priv = host->priv;

        clk_disable_unprepare(priv->drive_clk);
        clk_disable_unprepare(priv->sample_clk);

        dw_mci_pltfm_remove(pdev);
}

static const struct of_device_id dw_mci_hi3798cv200_match[] = {
        { .compatible = "hisilicon,hi3798cv200-dw-mshc", },
        {},
};

MODULE_DEVICE_TABLE(of, dw_mci_hi3798cv200_match);
static struct platform_driver dw_mci_hi3798cv200_driver = {
        .probe = dw_mci_hi3798cv200_probe,
        .remove = dw_mci_hi3798cv200_remove,
        .driver = {
                .name = "dwmmc_hi3798cv200",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .of_match_table = dw_mci_hi3798cv200_match,
        },
};
module_platform_driver(dw_mci_hi3798cv200_driver);

MODULE_DESCRIPTION("HiSilicon Hi3798CV200 Specific DW-MSHC Driver Extension");
MODULE_LICENSE("GPL v2");