root/drivers/mmc/host/dw_mmc-k3.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2013 Linaro Ltd.
 * Copyright (c) 2013 HiSilicon Limited.
 */

#include <linux/bitops.h>
#include <linux/bitfield.h>
#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"

/*
 * hi6220 sd only support io voltage 1.8v and 3v
 * Also need config AO_SCTRL_SEL18 accordingly
 */
#define AO_SCTRL_SEL18          BIT(10)
#define AO_SCTRL_CTRL3          0x40C

#define DWMMC_SDIO_ID 2

#define SOC_SCTRL_SCPERCTRL5    (0x314)
#define SDCARD_IO_SEL18         BIT(2)

#define SDCARD_RD_THRESHOLD  (512)

#define GENCLK_DIV (7)

#define GPIO_CLK_ENABLE                   BIT(16)
#define GPIO_CLK_DIV_MASK                 GENMASK(11, 8)
#define GPIO_USE_SAMPLE_DLY_MASK          GENMASK(13, 13)
#define UHS_REG_EXT_SAMPLE_PHASE_MASK     GENMASK(20, 16)
#define UHS_REG_EXT_SAMPLE_DRVPHASE_MASK  GENMASK(25, 21)
#define UHS_REG_EXT_SAMPLE_DLY_MASK       GENMASK(30, 26)

#define TIMING_MODE     3
#define TIMING_CFG_NUM 10

#define NUM_PHASES (40)

#define ENABLE_SHIFT_MIN_SMPL (4)
#define ENABLE_SHIFT_MAX_SMPL (12)
#define USE_DLY_MIN_SMPL (11)
#define USE_DLY_MAX_SMPL (14)

struct k3_priv {
        int ctrl_id;
        u32 cur_speed;
        struct regmap   *reg;
};

static unsigned long dw_mci_hi6220_caps[] = {
        MMC_CAP_CMD23,
        MMC_CAP_CMD23,
        0
};

struct hs_timing {
        u32 drv_phase;
        u32 smpl_dly;
        u32 smpl_phase_max;
        u32 smpl_phase_min;
};

static struct hs_timing hs_timing_cfg[TIMING_MODE][TIMING_CFG_NUM] = {
        { /* reserved */ },
        { /* SD */
                {7, 0, 15, 15,},  /* 0: LEGACY 400k */
                {6, 0,  4,  4,},  /* 1: MMC_HS */
                {6, 0,  3,  3,},  /* 2: SD_HS */
                {6, 0, 15, 15,},  /* 3: SDR12 */
                {6, 0,  2,  2,},  /* 4: SDR25 */
                {4, 0, 11,  0,},  /* 5: SDR50 */
                {6, 4, 15,  0,},  /* 6: SDR104 */
                {0},              /* 7: DDR50 */
                {0},              /* 8: DDR52 */
                {0},              /* 9: HS200 */
        },
        { /* SDIO */
                {7, 0, 15, 15,},  /* 0: LEGACY 400k */
                {0},              /* 1: MMC_HS */
                {6, 0, 15, 15,},  /* 2: SD_HS */
                {6, 0, 15, 15,},  /* 3: SDR12 */
                {6, 0,  0,  0,},  /* 4: SDR25 */
                {4, 0, 12,  0,},  /* 5: SDR50 */
                {5, 4, 15,  0,},  /* 6: SDR104 */
                {0},              /* 7: DDR50 */
                {0},              /* 8: DDR52 */
                {0},              /* 9: HS200 */
        }
};

static void dw_mci_k3_set_ios(struct dw_mci *host, struct mmc_ios *ios)
{
        int ret;

        ret = clk_set_rate(host->ciu_clk, ios->clock);
        if (ret)
                dev_warn(host->dev, "failed to set rate %uHz\n", ios->clock);

        host->bus_hz = clk_get_rate(host->ciu_clk);
}

static const struct dw_mci_drv_data k3_drv_data = {
        .set_ios                = dw_mci_k3_set_ios,
};

static int dw_mci_hi6220_parse_dt(struct dw_mci *host)
{
        struct k3_priv *priv;

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

        priv->reg = syscon_regmap_lookup_by_phandle(host->dev->of_node,
                                         "hisilicon,peripheral-syscon");
        if (IS_ERR(priv->reg))
                priv->reg = NULL;

        priv->ctrl_id = of_alias_get_id(host->dev->of_node, "mshc");
        if (priv->ctrl_id < 0)
                priv->ctrl_id = 0;

        if (priv->ctrl_id >= TIMING_MODE)
                return -EINVAL;

        host->priv = priv;
        return 0;
}

static int dw_mci_hi6220_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
{
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct k3_priv *priv;
        struct dw_mci *host;
        int min_uv, max_uv;
        int ret;

        host = slot->host;
        priv = host->priv;

        if (!priv || !priv->reg)
                return 0;

        if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
                ret = regmap_update_bits(priv->reg, AO_SCTRL_CTRL3,
                                         AO_SCTRL_SEL18, 0);
                min_uv = 3000000;
                max_uv = 3000000;
        } else if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
                ret = regmap_update_bits(priv->reg, AO_SCTRL_CTRL3,
                                         AO_SCTRL_SEL18, AO_SCTRL_SEL18);
                min_uv = 1800000;
                max_uv = 1800000;
        } else {
                dev_dbg(host->dev, "voltage not supported\n");
                return -EINVAL;
        }

        if (ret) {
                dev_dbg(host->dev, "switch voltage failed\n");
                return ret;
        }

        if (IS_ERR_OR_NULL(mmc->supply.vqmmc))
                return 0;

        ret = regulator_set_voltage(mmc->supply.vqmmc, min_uv, max_uv);
        if (ret) {
                dev_dbg(host->dev, "Regulator set error %d: %d - %d\n",
                                 ret, min_uv, max_uv);
                return ret;
        }

        return 0;
}

static void dw_mci_hi6220_set_ios(struct dw_mci *host, struct mmc_ios *ios)
{
        int ret;
        unsigned int clock;

        clock = (ios->clock <= 25000000) ? 25000000 : ios->clock;

        ret = clk_set_rate(host->biu_clk, clock);
        if (ret)
                dev_warn(host->dev, "failed to set rate %uHz\n", clock);

        host->bus_hz = clk_get_rate(host->biu_clk);
}

static int dw_mci_hi6220_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
{
        return 0;
}

static const struct dw_mci_drv_data hi6220_data = {
        .caps                   = dw_mci_hi6220_caps,
        .num_caps               = ARRAY_SIZE(dw_mci_hi6220_caps),
        .switch_voltage         = dw_mci_hi6220_switch_voltage,
        .set_ios                = dw_mci_hi6220_set_ios,
        .parse_dt               = dw_mci_hi6220_parse_dt,
        .execute_tuning         = dw_mci_hi6220_execute_tuning,
};

static void dw_mci_hs_set_timing(struct dw_mci *host, int timing,
                                     int smpl_phase)
{
        u32 drv_phase;
        u32 smpl_dly;
        u32 use_smpl_dly = 0;
        u32 enable_shift = 0;
        u32 reg_value;
        int ctrl_id;
        struct k3_priv *priv;

        priv = host->priv;
        ctrl_id = priv->ctrl_id;

        drv_phase = hs_timing_cfg[ctrl_id][timing].drv_phase;
        smpl_dly   = hs_timing_cfg[ctrl_id][timing].smpl_dly;
        if (smpl_phase == -1)
                smpl_phase = (hs_timing_cfg[ctrl_id][timing].smpl_phase_max +
                             hs_timing_cfg[ctrl_id][timing].smpl_phase_min) / 2;

        switch (timing) {
        case MMC_TIMING_UHS_SDR104:
                if (smpl_phase >= USE_DLY_MIN_SMPL &&
                                smpl_phase <= USE_DLY_MAX_SMPL)
                        use_smpl_dly = 1;
                fallthrough;
        case MMC_TIMING_UHS_SDR50:
                if (smpl_phase >= ENABLE_SHIFT_MIN_SMPL &&
                                smpl_phase <= ENABLE_SHIFT_MAX_SMPL)
                        enable_shift = 1;
                break;
        }

        mci_writel(host, GPIO, 0x0);
        usleep_range(5, 10);

        reg_value = FIELD_PREP(UHS_REG_EXT_SAMPLE_PHASE_MASK, smpl_phase) |
                    FIELD_PREP(UHS_REG_EXT_SAMPLE_DLY_MASK, smpl_dly) |
                    FIELD_PREP(UHS_REG_EXT_SAMPLE_DRVPHASE_MASK, drv_phase);
        mci_writel(host, UHS_REG_EXT, reg_value);

        mci_writel(host, ENABLE_SHIFT, enable_shift);

        reg_value = FIELD_PREP(GPIO_CLK_DIV_MASK, GENCLK_DIV) |
                             FIELD_PREP(GPIO_USE_SAMPLE_DLY_MASK, use_smpl_dly);
        mci_writel(host, GPIO, (unsigned int)reg_value | GPIO_CLK_ENABLE);

        /* We should delay 1ms wait for timing setting finished. */
        usleep_range(1000, 2000);
}

static int dw_mci_hi3660_init(struct dw_mci *host)
{
        mci_writel(host, CDTHRCTL, SDMMC_SET_THLD(SDCARD_RD_THRESHOLD,
                    SDMMC_CARD_RD_THR_EN));

        dw_mci_hs_set_timing(host, MMC_TIMING_LEGACY, -1);
        host->bus_hz /= (GENCLK_DIV + 1);

        return 0;
}

static int dw_mci_set_sel18(struct dw_mci *host, bool set)
{
        int ret;
        unsigned int val;
        struct k3_priv *priv;

        priv = host->priv;

        val = set ? SDCARD_IO_SEL18 : 0;
        ret = regmap_update_bits(priv->reg, SOC_SCTRL_SCPERCTRL5,
                                 SDCARD_IO_SEL18, val);
        if (ret) {
                dev_err(host->dev, "sel18 %u error\n", val);
                return ret;
        }

        return 0;
}

static void dw_mci_hi3660_set_ios(struct dw_mci *host, struct mmc_ios *ios)
{
        int ret;
        unsigned long wanted;
        unsigned long actual;
        struct k3_priv *priv = host->priv;

        if (!ios->clock || ios->clock == priv->cur_speed)
                return;

        wanted = ios->clock * (GENCLK_DIV + 1);
        ret = clk_set_rate(host->ciu_clk, wanted);
        if (ret) {
                dev_err(host->dev, "failed to set rate %luHz\n", wanted);
                return;
        }
        actual = clk_get_rate(host->ciu_clk);

        dw_mci_hs_set_timing(host, ios->timing, -1);
        host->bus_hz = actual / (GENCLK_DIV + 1);
        host->current_speed = 0;
        priv->cur_speed = host->bus_hz;
}

static int dw_mci_get_best_clksmpl(unsigned int sample_flag)
{
        int i;
        int interval;
        unsigned int v;
        unsigned int len;
        unsigned int range_start = 0;
        unsigned int range_length = 0;
        unsigned int middle_range = 0;

        if (!sample_flag)
                return -EIO;

        if (~sample_flag == 0)
                return 0;

        i = ffs(sample_flag) - 1;

        /*
        * A clock cycle is divided into 32 phases,
        * each of which is represented by a bit,
        * finding the optimal phase.
        */
        while (i < 32) {
                v = ror32(sample_flag, i);
                len = ffs(~v) - 1;

                if (len > range_length) {
                        range_length = len;
                        range_start = i;
                }

                interval = ffs(v >> len) - 1;
                if (interval < 0)
                        break;

                i += len + interval;
        }

        middle_range = range_start + range_length / 2;
        if (middle_range >= 32)
                middle_range %= 32;

        return middle_range;
}

static int dw_mci_hi3660_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
{
        int i = 0;
        struct dw_mci *host = slot->host;
        struct mmc_host *mmc = slot->mmc;
        int smpl_phase = 0;
        u32 tuning_sample_flag = 0;
        int best_clksmpl = 0;

        for (i = 0; i < NUM_PHASES; ++i, ++smpl_phase) {
                smpl_phase %= 32;

                mci_writel(host, TMOUT, ~0);
                dw_mci_hs_set_timing(host, mmc->ios.timing, smpl_phase);

                if (!mmc_send_tuning(mmc, opcode, NULL))
                        tuning_sample_flag |= (1 << smpl_phase);
                else
                        tuning_sample_flag &= ~(1 << smpl_phase);
        }

        best_clksmpl = dw_mci_get_best_clksmpl(tuning_sample_flag);
        if (best_clksmpl < 0) {
                dev_err(host->dev, "All phases bad!\n");
                return -EIO;
        }

        dw_mci_hs_set_timing(host, mmc->ios.timing, best_clksmpl);

        dev_info(host->dev, "tuning ok best_clksmpl %u tuning_sample_flag %x\n",
                 best_clksmpl, tuning_sample_flag);
        return 0;
}

static int dw_mci_hi3660_switch_voltage(struct mmc_host *mmc,
                                        struct mmc_ios *ios)
{
        int ret = 0;
        struct dw_mci_slot *slot = mmc_priv(mmc);
        struct k3_priv *priv;
        struct dw_mci *host;

        host = slot->host;
        priv = host->priv;

        if (!priv || !priv->reg)
                return 0;

        if (priv->ctrl_id == DWMMC_SDIO_ID)
                return 0;

        if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
                ret = dw_mci_set_sel18(host, 0);
        else if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
                ret = dw_mci_set_sel18(host, 1);
        if (ret)
                return ret;

        if (!IS_ERR(mmc->supply.vqmmc)) {
                ret = mmc_regulator_set_vqmmc(mmc, ios);
                if (ret < 0) {
                        dev_err(host->dev, "Regulator set error %d\n", ret);
                        return ret;
                }
        }

        return 0;
}

static const struct dw_mci_drv_data hi3660_data = {
        .init = dw_mci_hi3660_init,
        .set_ios = dw_mci_hi3660_set_ios,
        .parse_dt = dw_mci_hi6220_parse_dt,
        .execute_tuning = dw_mci_hi3660_execute_tuning,
        .switch_voltage  = dw_mci_hi3660_switch_voltage,
};

static const struct of_device_id dw_mci_k3_match[] = {
        { .compatible = "hisilicon,hi3660-dw-mshc", .data = &hi3660_data, },
        { .compatible = "hisilicon,hi4511-dw-mshc", .data = &k3_drv_data, },
        { .compatible = "hisilicon,hi6220-dw-mshc", .data = &hi6220_data, },
        {},
};
MODULE_DEVICE_TABLE(of, dw_mci_k3_match);

static int dw_mci_k3_probe(struct platform_device *pdev)
{
        const struct dw_mci_drv_data *drv_data;
        const struct of_device_id *match;

        match = of_match_node(dw_mci_k3_match, pdev->dev.of_node);
        drv_data = match->data;

        return dw_mci_pltfm_register(pdev, drv_data);
}

static const struct dev_pm_ops dw_mci_k3_dev_pm_ops = {
        SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
        RUNTIME_PM_OPS(dw_mci_runtime_suspend, dw_mci_runtime_resume, NULL)
};

static struct platform_driver dw_mci_k3_pltfm_driver = {
        .probe          = dw_mci_k3_probe,
        .remove         = dw_mci_pltfm_remove,
        .driver         = {
                .name           = "dwmmc_k3",
                .probe_type     = PROBE_PREFER_ASYNCHRONOUS,
                .of_match_table = dw_mci_k3_match,
                .pm             = pm_ptr(&dw_mci_k3_dev_pm_ops),
        },
};

module_platform_driver(dw_mci_k3_pltfm_driver);

MODULE_DESCRIPTION("K3 Specific DW-MSHC Driver Extension");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:dwmmc_k3");