// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2009-2018, Linux Foundation. All rights reserved.
 * Copyright (c) 2018-2020, Linaro Limited
 */

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include <linux/slab.h>

/* PHY register and bit definitions */
#define PHY_CTRL_COMMON0                0x078
#define SIDDQ                           BIT(2)
#define PHY_IRQ_CMD                     0x0d0
#define PHY_INTR_MASK0                  0x0d4
#define PHY_INTR_CLEAR0                 0x0dc
#define DPDM_MASK                       0x1e
#define DP_1_0                          BIT(4)
#define DP_0_1                          BIT(3)
#define DM_1_0                          BIT(2)
#define DM_0_1                          BIT(1)

enum hsphy_voltage {
        VOL_NONE,
        VOL_MIN,
        VOL_MAX,
        VOL_NUM,
};

enum hsphy_vreg {
        VDD,
        VDDA_1P8,
        VDDA_3P3,
        VREG_NUM,
};

struct hsphy_init_seq {
        int offset;
        int val;
        int delay;
};

struct hsphy_data {
        const struct hsphy_init_seq *init_seq;
        unsigned int init_seq_num;
};

struct hsphy_priv {
        void __iomem *base;
        struct clk_bulk_data *clks;
        int num_clks;
        struct reset_control *phy_reset;
        struct reset_control *por_reset;
        struct regulator_bulk_data vregs[VREG_NUM];
        const struct hsphy_data *data;
        enum phy_mode mode;
};

static int qcom_snps_hsphy_set_mode(struct phy *phy, enum phy_mode mode,
                                    int submode)
{
        struct hsphy_priv *priv = phy_get_drvdata(phy);

        priv->mode = PHY_MODE_INVALID;

        if (mode > 0)
                priv->mode = mode;

        return 0;
}

static void qcom_snps_hsphy_enable_hv_interrupts(struct hsphy_priv *priv)
{
        u32 val;

        /* Clear any existing interrupts before enabling the interrupts */
        val = readb(priv->base + PHY_INTR_CLEAR0);
        val |= DPDM_MASK;
        writeb(val, priv->base + PHY_INTR_CLEAR0);

        writeb(0x0, priv->base + PHY_IRQ_CMD);
        usleep_range(200, 220);
        writeb(0x1, priv->base + PHY_IRQ_CMD);

        /* Make sure the interrupts are cleared */
        usleep_range(200, 220);

        val = readb(priv->base + PHY_INTR_MASK0);
        switch (priv->mode) {
        case PHY_MODE_USB_HOST_HS:
        case PHY_MODE_USB_HOST_FS:
        case PHY_MODE_USB_DEVICE_HS:
        case PHY_MODE_USB_DEVICE_FS:
                val |= DP_1_0 | DM_0_1;
                break;
        case PHY_MODE_USB_HOST_LS:
        case PHY_MODE_USB_DEVICE_LS:
                val |= DP_0_1 | DM_1_0;
                break;
        default:
                /* No device connected */
                val |= DP_0_1 | DM_0_1;
                break;
        }
        writeb(val, priv->base + PHY_INTR_MASK0);
}

static void qcom_snps_hsphy_disable_hv_interrupts(struct hsphy_priv *priv)
{
        u32 val;

        val = readb(priv->base + PHY_INTR_MASK0);
        val &= ~DPDM_MASK;
        writeb(val, priv->base + PHY_INTR_MASK0);

        /* Clear any pending interrupts */
        val = readb(priv->base + PHY_INTR_CLEAR0);
        val |= DPDM_MASK;
        writeb(val, priv->base + PHY_INTR_CLEAR0);

        writeb(0x0, priv->base + PHY_IRQ_CMD);
        usleep_range(200, 220);

        writeb(0x1, priv->base + PHY_IRQ_CMD);
        usleep_range(200, 220);
}

static void qcom_snps_hsphy_enter_retention(struct hsphy_priv *priv)
{
        u32 val;

        val = readb(priv->base + PHY_CTRL_COMMON0);
        val |= SIDDQ;
        writeb(val, priv->base + PHY_CTRL_COMMON0);
}

static void qcom_snps_hsphy_exit_retention(struct hsphy_priv *priv)
{
        u32 val;

        val = readb(priv->base + PHY_CTRL_COMMON0);
        val &= ~SIDDQ;
        writeb(val, priv->base + PHY_CTRL_COMMON0);
}

static int qcom_snps_hsphy_power_on(struct phy *phy)
{
        struct hsphy_priv *priv = phy_get_drvdata(phy);
        int ret;

        ret = regulator_bulk_enable(VREG_NUM, priv->vregs);
        if (ret)
                return ret;

        qcom_snps_hsphy_disable_hv_interrupts(priv);
        qcom_snps_hsphy_exit_retention(priv);

        return 0;
}

static int qcom_snps_hsphy_power_off(struct phy *phy)
{
        struct hsphy_priv *priv = phy_get_drvdata(phy);

        qcom_snps_hsphy_enter_retention(priv);
        qcom_snps_hsphy_enable_hv_interrupts(priv);
        regulator_bulk_disable(VREG_NUM, priv->vregs);

        return 0;
}

static int qcom_snps_hsphy_reset(struct hsphy_priv *priv)
{
        int ret;

        ret = reset_control_assert(priv->phy_reset);
        if (ret)
                return ret;

        usleep_range(10, 15);

        ret = reset_control_deassert(priv->phy_reset);
        if (ret)
                return ret;

        usleep_range(80, 100);

        return 0;
}

static void qcom_snps_hsphy_init_sequence(struct hsphy_priv *priv)
{
        const struct hsphy_data *data = priv->data;
        const struct hsphy_init_seq *seq;
        int i;

        /* Device match data is optional. */
        if (!data)
                return;

        seq = data->init_seq;

        for (i = 0; i < data->init_seq_num; i++, seq++) {
                writeb(seq->val, priv->base + seq->offset);
                if (seq->delay)
                        usleep_range(seq->delay, seq->delay + 10);
        }
}

static int qcom_snps_hsphy_por_reset(struct hsphy_priv *priv)
{
        int ret;

        ret = reset_control_assert(priv->por_reset);
        if (ret)
                return ret;

        /*
         * The Femto PHY is POR reset in the following scenarios.
         *
         * 1. After overriding the parameter registers.
         * 2. Low power mode exit from PHY retention.
         *
         * Ensure that SIDDQ is cleared before bringing the PHY
         * out of reset.
         */
        qcom_snps_hsphy_exit_retention(priv);

        /*
         * As per databook, 10 usec delay is required between
         * PHY POR assert and de-assert.
         */
        usleep_range(10, 20);
        ret = reset_control_deassert(priv->por_reset);
        if (ret)
                return ret;

        /*
         * As per databook, it takes 75 usec for PHY to stabilize
         * after the reset.
         */
        usleep_range(80, 100);

        return 0;
}

static int qcom_snps_hsphy_init(struct phy *phy)
{
        struct hsphy_priv *priv = phy_get_drvdata(phy);
        int ret;

        ret = clk_bulk_prepare_enable(priv->num_clks, priv->clks);
        if (ret)
                return ret;

        ret = qcom_snps_hsphy_reset(priv);
        if (ret)
                goto disable_clocks;

        qcom_snps_hsphy_init_sequence(priv);

        ret = qcom_snps_hsphy_por_reset(priv);
        if (ret)
                goto disable_clocks;

        return 0;

disable_clocks:
        clk_bulk_disable_unprepare(priv->num_clks, priv->clks);
        return ret;
}

static int qcom_snps_hsphy_exit(struct phy *phy)
{
        struct hsphy_priv *priv = phy_get_drvdata(phy);

        clk_bulk_disable_unprepare(priv->num_clks, priv->clks);

        return 0;
}

static const struct phy_ops qcom_snps_hsphy_ops = {
        .init = qcom_snps_hsphy_init,
        .exit = qcom_snps_hsphy_exit,
        .power_on = qcom_snps_hsphy_power_on,
        .power_off = qcom_snps_hsphy_power_off,
        .set_mode = qcom_snps_hsphy_set_mode,
        .owner = THIS_MODULE,
};

static const char * const qcom_snps_hsphy_clks[] = {
        "ref",
        "ahb",
        "sleep",
};

static int qcom_snps_hsphy_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct phy_provider *provider;
        struct hsphy_priv *priv;
        struct phy *phy;
        int ret;
        int i;

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

        priv->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(priv->base))
                return PTR_ERR(priv->base);

        priv->num_clks = ARRAY_SIZE(qcom_snps_hsphy_clks);
        priv->clks = devm_kcalloc(dev, priv->num_clks, sizeof(*priv->clks),
                                  GFP_KERNEL);
        if (!priv->clks)
                return -ENOMEM;

        for (i = 0; i < priv->num_clks; i++)
                priv->clks[i].id = qcom_snps_hsphy_clks[i];

        ret = devm_clk_bulk_get(dev, priv->num_clks, priv->clks);
        if (ret)
                return ret;

        priv->phy_reset = devm_reset_control_get_exclusive(dev, "phy");
        if (IS_ERR(priv->phy_reset))
                return PTR_ERR(priv->phy_reset);

        priv->por_reset = devm_reset_control_get_exclusive(dev, "por");
        if (IS_ERR(priv->por_reset))
                return PTR_ERR(priv->por_reset);

        priv->vregs[VDD].supply = "vdd";
        priv->vregs[VDDA_1P8].supply = "vdda1p8";
        priv->vregs[VDDA_3P3].supply = "vdda3p3";

        ret = devm_regulator_bulk_get(dev, VREG_NUM, priv->vregs);
        if (ret)
                return ret;

        /* Get device match data */
        priv->data = device_get_match_data(dev);

        phy = devm_phy_create(dev, dev->of_node, &qcom_snps_hsphy_ops);
        if (IS_ERR(phy))
                return PTR_ERR(phy);

        phy_set_drvdata(phy, priv);

        provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
        if (IS_ERR(provider))
                return PTR_ERR(provider);

        ret = regulator_set_load(priv->vregs[VDDA_1P8].consumer, 19000);
        if (ret < 0)
                return ret;

        ret = regulator_set_load(priv->vregs[VDDA_3P3].consumer, 16000);
        if (ret < 0)
                goto unset_1p8_load;

        return 0;

unset_1p8_load:
        regulator_set_load(priv->vregs[VDDA_1P8].consumer, 0);

        return ret;
}

/*
 * The macro is used to define an initialization sequence.  Each tuple
 * is meant to program 'value' into phy register at 'offset' with 'delay'
 * in us followed.
 */
#define HSPHY_INIT_CFG(o, v, d) { .offset = o, .val = v, .delay = d, }

static const struct hsphy_init_seq init_seq_femtophy[] = {
        HSPHY_INIT_CFG(0xc0, 0x01, 0),
        HSPHY_INIT_CFG(0xe8, 0x0d, 0),
        HSPHY_INIT_CFG(0x74, 0x12, 0),
        HSPHY_INIT_CFG(0x98, 0x63, 0),
        HSPHY_INIT_CFG(0x9c, 0x03, 0),
        HSPHY_INIT_CFG(0xa0, 0x1d, 0),
        HSPHY_INIT_CFG(0xa4, 0x03, 0),
        HSPHY_INIT_CFG(0x8c, 0x23, 0),
        HSPHY_INIT_CFG(0x78, 0x08, 0),
        HSPHY_INIT_CFG(0x7c, 0xdc, 0),
        HSPHY_INIT_CFG(0x90, 0xe0, 20),
        HSPHY_INIT_CFG(0x74, 0x10, 0),
        HSPHY_INIT_CFG(0x90, 0x60, 0),
};

static const struct hsphy_data hsphy_data_femtophy = {
        .init_seq = init_seq_femtophy,
        .init_seq_num = ARRAY_SIZE(init_seq_femtophy),
};

static const struct of_device_id qcom_snps_hsphy_match[] = {
        { .compatible = "qcom,usb-hs-28nm-femtophy", .data = &hsphy_data_femtophy, },
        { },
};
MODULE_DEVICE_TABLE(of, qcom_snps_hsphy_match);

static struct platform_driver qcom_snps_hsphy_driver = {
        .probe = qcom_snps_hsphy_probe,
        .driver = {
                .name = "qcom,usb-hs-28nm-phy",
                .of_match_table = qcom_snps_hsphy_match,
        },
};
module_platform_driver(qcom_snps_hsphy_driver);

MODULE_DESCRIPTION("Qualcomm 28nm Hi-Speed USB PHY driver");
MODULE_LICENSE("GPL v2");