root/drivers/mmc/host/sdhci-milbeaut.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2013 - 2015 Fujitsu Semiconductor, Ltd
 *              Vincent Yang <vincent.yang@tw.fujitsu.com>
 * Copyright (C) 2015 Linaro Ltd  Andy Green <andy.green@linaro.org>
 * Copyright (C) 2019 Socionext Inc.
 *              Takao Orito <orito.takao@socionext.com>
 */

#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/property.h>

#include "sdhci-pltfm.h"
#include "sdhci_f_sdh30.h"

/* milbeaut bridge controller register */
#define MLB_SOFT_RESET          0x0200
#define  MLB_SOFT_RESET_RSTX            BIT(0)

#define MLB_WP_CD_LED_SET       0x0210
#define  MLB_WP_CD_LED_SET_LED_INV  BIT(2)

#define MLB_CR_SET                      0x0220
#define  MLB_CR_SET_CR_TOCLKUNIT       BIT(24)
#define  MLB_CR_SET_CR_TOCLKFREQ_SFT   (16)
#define  MLB_CR_SET_CR_TOCLKFREQ_MASK  (0x3F << MLB_CR_SET_CR_TOCLKFREQ_SFT)
#define  MLB_CR_SET_CR_BCLKFREQ_SFT    (8)
#define  MLB_CR_SET_CR_BCLKFREQ_MASK   (0xFF << MLB_CR_SET_CR_BCLKFREQ_SFT)
#define  MLB_CR_SET_CR_RTUNTIMER_SFT   (4)
#define  MLB_CR_SET_CR_RTUNTIMER_MASK  (0xF << MLB_CR_SET_CR_RTUNTIMER_SFT)

#define MLB_SD_TOCLK_I_DIV  16
#define MLB_TOCLKFREQ_UNIT_THRES    16000000
#define MLB_CAL_TOCLKFREQ_MHZ(rate) (rate / MLB_SD_TOCLK_I_DIV / 1000000)
#define MLB_CAL_TOCLKFREQ_KHZ(rate) (rate / MLB_SD_TOCLK_I_DIV / 1000)
#define MLB_TOCLKFREQ_MAX   63
#define MLB_TOCLKFREQ_MIN    1

#define MLB_SD_BCLK_I_DIV   4
#define MLB_CAL_BCLKFREQ(rate)  (rate / MLB_SD_BCLK_I_DIV / 1000000)
#define MLB_BCLKFREQ_MAX        255
#define MLB_BCLKFREQ_MIN          1

#define MLB_CDR_SET                     0x0230
#define MLB_CDR_SET_CLK2POW16   3

struct f_sdhost_priv {
        struct clk *clk_iface;
        struct clk *clk;
        struct device *dev;
        bool enable_cmd_dat_delay;
};

static void sdhci_milbeaut_soft_voltage_switch(struct sdhci_host *host)
{
        u32 ctrl = 0;

        usleep_range(2500, 3000);
        ctrl = sdhci_readl(host, F_SDH30_IO_CONTROL2);
        ctrl |= F_SDH30_CRES_O_DN;
        sdhci_writel(host, ctrl, F_SDH30_IO_CONTROL2);
        ctrl |= F_SDH30_MSEL_O_1_8;
        sdhci_writel(host, ctrl, F_SDH30_IO_CONTROL2);

        ctrl &= ~F_SDH30_CRES_O_DN;
        sdhci_writel(host, ctrl, F_SDH30_IO_CONTROL2);
        usleep_range(2500, 3000);

        ctrl = sdhci_readl(host, F_SDH30_TUNING_SETTING);
        ctrl |= F_SDH30_CMD_CHK_DIS;
        sdhci_writel(host, ctrl, F_SDH30_TUNING_SETTING);
}

static unsigned int sdhci_milbeaut_get_min_clock(struct sdhci_host *host)
{
        return F_SDH30_MIN_CLOCK;
}

static void sdhci_milbeaut_reset(struct sdhci_host *host, u8 mask)
{
        struct f_sdhost_priv *priv = sdhci_priv(host);
        u16 clk;
        u32 ctl;
        ktime_t timeout;

        clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
        clk = (clk & ~SDHCI_CLOCK_CARD_EN) | SDHCI_CLOCK_INT_EN;
        sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

        sdhci_reset(host, mask);

        clk |= SDHCI_CLOCK_CARD_EN;
        sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

        timeout = ktime_add_ms(ktime_get(), 10);
        while (1) {
                bool timedout = ktime_after(ktime_get(), timeout);

                clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
                if (clk & SDHCI_CLOCK_INT_STABLE)
                        break;
                if (timedout) {
                        pr_err("%s: Internal clock never stabilised.\n",
                                mmc_hostname(host->mmc));
                        sdhci_dumpregs(host);
                        return;
                }
                udelay(10);
        }

        if (priv->enable_cmd_dat_delay) {
                ctl = sdhci_readl(host, F_SDH30_ESD_CONTROL);
                ctl |= F_SDH30_CMD_DAT_DELAY;
                sdhci_writel(host, ctl, F_SDH30_ESD_CONTROL);
        }
}

static const struct sdhci_ops sdhci_milbeaut_ops = {
        .voltage_switch = sdhci_milbeaut_soft_voltage_switch,
        .get_min_clock = sdhci_milbeaut_get_min_clock,
        .reset = sdhci_milbeaut_reset,
        .set_clock = sdhci_set_clock,
        .set_bus_width = sdhci_set_bus_width,
        .set_uhs_signaling = sdhci_set_uhs_signaling,
        .set_power = sdhci_set_power_and_bus_voltage,
};

static void sdhci_milbeaut_bridge_reset(struct sdhci_host *host,
                                                int reset_flag)
{
        if (reset_flag)
                sdhci_writel(host, 0, MLB_SOFT_RESET);
        else
                sdhci_writel(host, MLB_SOFT_RESET_RSTX, MLB_SOFT_RESET);
}

static void sdhci_milbeaut_bridge_init(struct sdhci_host *host,
                                                int rate)
{
        u32 val, clk;

        /* IO_SDIO_CR_SET should be set while reset */
        val = sdhci_readl(host, MLB_CR_SET);
        val &= ~(MLB_CR_SET_CR_TOCLKFREQ_MASK | MLB_CR_SET_CR_TOCLKUNIT |
                        MLB_CR_SET_CR_BCLKFREQ_MASK);
        if (rate >= MLB_TOCLKFREQ_UNIT_THRES) {
                clk = MLB_CAL_TOCLKFREQ_MHZ(rate);
                clk = min_t(u32, MLB_TOCLKFREQ_MAX, clk);
                val |= MLB_CR_SET_CR_TOCLKUNIT |
                        (clk << MLB_CR_SET_CR_TOCLKFREQ_SFT);
        } else {
                clk = MLB_CAL_TOCLKFREQ_KHZ(rate);
                clk = min_t(u32, MLB_TOCLKFREQ_MAX, clk);
                clk = max_t(u32, MLB_TOCLKFREQ_MIN, clk);
                val |= clk << MLB_CR_SET_CR_TOCLKFREQ_SFT;
        }

        clk = MLB_CAL_BCLKFREQ(rate);
        clk = min_t(u32, MLB_BCLKFREQ_MAX, clk);
        clk = max_t(u32, MLB_BCLKFREQ_MIN, clk);
        val |=  clk << MLB_CR_SET_CR_BCLKFREQ_SFT;
        val &= ~MLB_CR_SET_CR_RTUNTIMER_MASK;
        sdhci_writel(host, val, MLB_CR_SET);

        sdhci_writel(host, MLB_CDR_SET_CLK2POW16, MLB_CDR_SET);

        sdhci_writel(host, MLB_WP_CD_LED_SET_LED_INV, MLB_WP_CD_LED_SET);
}

static void sdhci_milbeaut_vendor_init(struct sdhci_host *host)
{
        struct f_sdhost_priv *priv = sdhci_priv(host);
        u32 ctl;

        ctl = sdhci_readl(host, F_SDH30_IO_CONTROL2);
        ctl |= F_SDH30_CRES_O_DN;
        sdhci_writel(host, ctl, F_SDH30_IO_CONTROL2);
        ctl &= ~F_SDH30_MSEL_O_1_8;
        sdhci_writel(host, ctl, F_SDH30_IO_CONTROL2);
        ctl &= ~F_SDH30_CRES_O_DN;
        sdhci_writel(host, ctl, F_SDH30_IO_CONTROL2);

        ctl = sdhci_readw(host, F_SDH30_AHB_CONFIG);
        ctl |= F_SDH30_SIN | F_SDH30_AHB_INCR_16 | F_SDH30_AHB_INCR_8 |
               F_SDH30_AHB_INCR_4;
        ctl &= ~(F_SDH30_AHB_BIGED | F_SDH30_BUSLOCK_EN);
        sdhci_writew(host, ctl, F_SDH30_AHB_CONFIG);

        if (priv->enable_cmd_dat_delay) {
                ctl = sdhci_readl(host, F_SDH30_ESD_CONTROL);
                ctl |= F_SDH30_CMD_DAT_DELAY;
                sdhci_writel(host, ctl, F_SDH30_ESD_CONTROL);
        }
}

static const struct of_device_id mlb_dt_ids[] = {
        {
                .compatible = "socionext,milbeaut-m10v-sdhci-3.0",
        },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mlb_dt_ids);

static void sdhci_milbeaut_init(struct sdhci_host *host)
{
        struct f_sdhost_priv *priv = sdhci_priv(host);
        int rate = clk_get_rate(priv->clk);
        u16 ctl;

        sdhci_milbeaut_bridge_reset(host, 0);

        ctl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
        ctl &= ~(SDHCI_CLOCK_CARD_EN | SDHCI_CLOCK_INT_EN);
        sdhci_writew(host, ctl, SDHCI_CLOCK_CONTROL);

        sdhci_milbeaut_bridge_reset(host, 1);

        sdhci_milbeaut_bridge_init(host, rate);
        sdhci_milbeaut_bridge_reset(host, 0);

        sdhci_milbeaut_vendor_init(host);
}

static int sdhci_milbeaut_probe(struct platform_device *pdev)
{
        struct sdhci_host *host;
        struct device *dev = &pdev->dev;
        int irq, ret = 0;
        struct f_sdhost_priv *priv;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

        host = sdhci_alloc_host(dev, sizeof(struct f_sdhost_priv));
        if (IS_ERR(host))
                return PTR_ERR(host);

        priv = sdhci_priv(host);
        priv->dev = dev;

        host->quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
                           SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
                           SDHCI_QUIRK_CLOCK_BEFORE_RESET |
                           SDHCI_QUIRK_DELAY_AFTER_POWER;
        host->quirks2 = SDHCI_QUIRK2_SUPPORT_SINGLE |
                        SDHCI_QUIRK2_TUNING_WORK_AROUND |
                        SDHCI_QUIRK2_PRESET_VALUE_BROKEN;

        priv->enable_cmd_dat_delay = device_property_read_bool(dev,
                                                "fujitsu,cmd-dat-delay-select");

        ret = mmc_of_parse(host->mmc);
        if (ret)
                return ret;

        platform_set_drvdata(pdev, host);

        host->hw_name = "f_sdh30";
        host->ops = &sdhci_milbeaut_ops;
        host->irq = irq;

        host->ioaddr = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(host->ioaddr))
                return PTR_ERR(host->ioaddr);

        if (dev_of_node(dev)) {
                sdhci_get_of_property(pdev);

                priv->clk_iface = devm_clk_get(&pdev->dev, "iface");
                if (IS_ERR(priv->clk_iface))
                        return PTR_ERR(priv->clk_iface);

                ret = clk_prepare_enable(priv->clk_iface);
                if (ret)
                        return ret;

                priv->clk = devm_clk_get(&pdev->dev, "core");
                if (IS_ERR(priv->clk)) {
                        ret = PTR_ERR(priv->clk);
                        goto err_clk;
                }

                ret = clk_prepare_enable(priv->clk);
                if (ret)
                        goto err_clk;
        }

        sdhci_milbeaut_init(host);

        ret = sdhci_add_host(host);
        if (ret)
                goto err_add_host;

        return 0;

err_add_host:
        clk_disable_unprepare(priv->clk);
err_clk:
        clk_disable_unprepare(priv->clk_iface);
        return ret;
}

static void sdhci_milbeaut_remove(struct platform_device *pdev)
{
        struct sdhci_host *host = platform_get_drvdata(pdev);
        struct f_sdhost_priv *priv = sdhci_priv(host);

        sdhci_remove_host(host, readl(host->ioaddr + SDHCI_INT_STATUS) ==
                          0xffffffff);

        clk_disable_unprepare(priv->clk_iface);
        clk_disable_unprepare(priv->clk);

        platform_set_drvdata(pdev, NULL);
}

static struct platform_driver sdhci_milbeaut_driver = {
        .driver = {
                .name = "sdhci-milbeaut",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .of_match_table = mlb_dt_ids,
        },
        .probe  = sdhci_milbeaut_probe,
        .remove = sdhci_milbeaut_remove,
};

module_platform_driver(sdhci_milbeaut_driver);

MODULE_DESCRIPTION("MILBEAUT SD Card Controller driver");
MODULE_AUTHOR("Takao Orito <orito.takao@socionext.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:sdhci-milbeaut");