// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * omap-usb2.c - USB PHY, talking to USB controller on TI SoCs.
 *
 * Copyright (C) 2012-2020 Texas Instruments Incorporated - http://www.ti.com
 * Author: Kishon Vijay Abraham I <kishon@ti.com>
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/io.h>
#include <linux/phy/omap_usb.h>
#include <linux/usb/phy_companion.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/pm_runtime.h>
#include <linux/delay.h>
#include <linux/phy/omap_control_phy.h>
#include <linux/phy/phy.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/of_platform.h>
#include <linux/sys_soc.h>

#define USB2PHY_ANA_CONFIG1             0x4c
#define USB2PHY_DISCON_BYP_LATCH        BIT(31)

#define USB2PHY_CHRG_DET                        0x14
#define USB2PHY_CHRG_DET_USE_CHG_DET_REG        BIT(29)
#define USB2PHY_CHRG_DET_DIS_CHG_DET            BIT(28)

/* SoC Specific USB2_OTG register definitions */
#define AM654_USB2_OTG_PD               BIT(8)
#define AM654_USB2_VBUS_DET_EN          BIT(5)
#define AM654_USB2_VBUSVALID_DET_EN     BIT(4)

#define OMAP_DEV_PHY_PD         BIT(0)
#define OMAP_USB2_PHY_PD        BIT(28)

#define AM437X_USB2_PHY_PD              BIT(0)
#define AM437X_USB2_OTG_PD              BIT(1)
#define AM437X_USB2_OTGVDET_EN          BIT(19)
#define AM437X_USB2_OTGSESSEND_EN       BIT(20)

/* Driver Flags */
#define OMAP_USB2_HAS_START_SRP                 BIT(0)
#define OMAP_USB2_HAS_SET_VBUS                  BIT(1)
#define OMAP_USB2_CALIBRATE_FALSE_DISCONNECT    BIT(2)
#define OMAP_USB2_DISABLE_CHRG_DET              BIT(3)

struct omap_usb {
        struct usb_phy          phy;
        struct phy_companion    *comparator;
        void __iomem            *pll_ctrl_base;
        void __iomem            *phy_base;
        struct device           *dev;
        struct device           *control_dev;
        struct clk              *wkupclk;
        struct clk              *optclk;
        u8                      flags;
        struct regmap           *syscon_phy_power; /* ctrl. reg. acces */
        unsigned int            power_reg; /* power reg. index within syscon */
        u32                     mask;
        u32                     power_on;
        u32                     power_off;
};

#define phy_to_omapusb(x)       container_of((x), struct omap_usb, phy)

struct usb_phy_data {
        const char *label;
        u8 flags;
        u32 mask;
        u32 power_on;
        u32 power_off;
};

static inline u32 omap_usb_readl(void __iomem *addr, unsigned int offset)
{
        return __raw_readl(addr + offset);
}

static inline void omap_usb_writel(void __iomem *addr, unsigned int offset,
                                   u32 data)
{
        __raw_writel(data, addr + offset);
}

/**
 * omap_usb2_set_comparator - links the comparator present in the sytem with
 *      this phy
 * @comparator - the companion phy(comparator) for this phy
 *
 * The phy companion driver should call this API passing the phy_companion
 * filled with set_vbus and start_srp to be used by usb phy.
 *
 * For use by phy companion driver
 */
int omap_usb2_set_comparator(struct phy_companion *comparator)
{
        struct omap_usb *phy;
        struct usb_phy  *x = usb_get_phy(USB_PHY_TYPE_USB2);

        if (IS_ERR(x))
                return -ENODEV;

        phy = phy_to_omapusb(x);
        phy->comparator = comparator;
        return 0;
}
EXPORT_SYMBOL_GPL(omap_usb2_set_comparator);

static int omap_usb_set_vbus(struct usb_otg *otg, bool enabled)
{
        struct omap_usb *phy = phy_to_omapusb(otg->usb_phy);

        if (!phy->comparator)
                return -ENODEV;

        return phy->comparator->set_vbus(phy->comparator, enabled);
}

static int omap_usb_start_srp(struct usb_otg *otg)
{
        struct omap_usb *phy = phy_to_omapusb(otg->usb_phy);

        if (!phy->comparator)
                return -ENODEV;

        return phy->comparator->start_srp(phy->comparator);
}

static int omap_usb_set_host(struct usb_otg *otg, struct usb_bus *host)
{
        otg->host = host;
        if (!host)
                otg->state = OTG_STATE_UNDEFINED;

        return 0;
}

static int omap_usb_set_peripheral(struct usb_otg *otg,
                struct usb_gadget *gadget)
{
        otg->gadget = gadget;
        if (!gadget)
                otg->state = OTG_STATE_UNDEFINED;

        return 0;
}

static int omap_usb_phy_power(struct omap_usb *phy, int on)
{
        u32 val;
        int ret;

        if (!phy->syscon_phy_power) {
                omap_control_phy_power(phy->control_dev, on);
                return 0;
        }

        if (on)
                val = phy->power_on;
        else
                val = phy->power_off;

        ret = regmap_update_bits(phy->syscon_phy_power, phy->power_reg,
                                 phy->mask, val);
        return ret;
}

static int omap_usb_power_off(struct phy *x)
{
        struct omap_usb *phy = phy_get_drvdata(x);

        return omap_usb_phy_power(phy, false);
}

static int omap_usb_power_on(struct phy *x)
{
        struct omap_usb *phy = phy_get_drvdata(x);

        return omap_usb_phy_power(phy, true);
}

static int omap_usb2_disable_clocks(struct omap_usb *phy)
{
        clk_disable_unprepare(phy->wkupclk);
        if (!IS_ERR(phy->optclk))
                clk_disable_unprepare(phy->optclk);

        return 0;
}

static int omap_usb2_enable_clocks(struct omap_usb *phy)
{
        int ret;

        ret = clk_prepare_enable(phy->wkupclk);
        if (ret < 0) {
                dev_err(phy->dev, "Failed to enable wkupclk %d\n", ret);
                goto err0;
        }

        if (!IS_ERR(phy->optclk)) {
                ret = clk_prepare_enable(phy->optclk);
                if (ret < 0) {
                        dev_err(phy->dev, "Failed to enable optclk %d\n", ret);
                        goto err1;
                }
        }

        return 0;

err1:
        clk_disable(phy->wkupclk);

err0:
        return ret;
}

static int omap_usb_init(struct phy *x)
{
        struct omap_usb *phy = phy_get_drvdata(x);
        u32 val;

        omap_usb2_enable_clocks(phy);

        if (phy->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT) {
                /*
                 *
                 * Reduce the sensitivity of internal PHY by enabling the
                 * DISCON_BYP_LATCH of the USB2PHY_ANA_CONFIG1 register. This
                 * resolves issues with certain devices which can otherwise
                 * be prone to false disconnects.
                 *
                 */
                val = omap_usb_readl(phy->phy_base, USB2PHY_ANA_CONFIG1);
                val |= USB2PHY_DISCON_BYP_LATCH;
                omap_usb_writel(phy->phy_base, USB2PHY_ANA_CONFIG1, val);
        }

        if (phy->flags & OMAP_USB2_DISABLE_CHRG_DET) {
                val = omap_usb_readl(phy->phy_base, USB2PHY_CHRG_DET);
                val |= USB2PHY_CHRG_DET_USE_CHG_DET_REG |
                       USB2PHY_CHRG_DET_DIS_CHG_DET;
                omap_usb_writel(phy->phy_base, USB2PHY_CHRG_DET, val);
        }

        return 0;
}

static int omap_usb_exit(struct phy *x)
{
        struct omap_usb *phy = phy_get_drvdata(x);

        return omap_usb2_disable_clocks(phy);
}

static const struct phy_ops ops = {
        .init           = omap_usb_init,
        .exit           = omap_usb_exit,
        .power_on       = omap_usb_power_on,
        .power_off      = omap_usb_power_off,
        .owner          = THIS_MODULE,
};

static const struct usb_phy_data omap_usb2_data = {
        .label = "omap_usb2",
        .flags = OMAP_USB2_HAS_START_SRP | OMAP_USB2_HAS_SET_VBUS,
        .mask = OMAP_DEV_PHY_PD,
        .power_off = OMAP_DEV_PHY_PD,
};

static const struct usb_phy_data omap5_usb2_data = {
        .label = "omap5_usb2",
        .flags = 0,
        .mask = OMAP_DEV_PHY_PD,
        .power_off = OMAP_DEV_PHY_PD,
};

static const struct usb_phy_data dra7x_usb2_data = {
        .label = "dra7x_usb2",
        .flags = OMAP_USB2_CALIBRATE_FALSE_DISCONNECT,
        .mask = OMAP_DEV_PHY_PD,
        .power_off = OMAP_DEV_PHY_PD,
};

static const struct usb_phy_data dra7x_usb2_phy2_data = {
        .label = "dra7x_usb2_phy2",
        .flags = OMAP_USB2_CALIBRATE_FALSE_DISCONNECT,
        .mask = OMAP_USB2_PHY_PD,
        .power_off = OMAP_USB2_PHY_PD,
};

static const struct usb_phy_data am437x_usb2_data = {
        .label = "am437x_usb2",
        .flags =  0,
        .mask = AM437X_USB2_PHY_PD | AM437X_USB2_OTG_PD |
                AM437X_USB2_OTGVDET_EN | AM437X_USB2_OTGSESSEND_EN,
        .power_on = AM437X_USB2_OTGVDET_EN | AM437X_USB2_OTGSESSEND_EN,
        .power_off = AM437X_USB2_PHY_PD | AM437X_USB2_OTG_PD,
};

static const struct usb_phy_data am654_usb2_data = {
        .label = "am654_usb2",
        .flags = OMAP_USB2_CALIBRATE_FALSE_DISCONNECT,
        .mask = AM654_USB2_OTG_PD | AM654_USB2_VBUS_DET_EN |
                AM654_USB2_VBUSVALID_DET_EN,
        .power_on = AM654_USB2_VBUS_DET_EN | AM654_USB2_VBUSVALID_DET_EN,
        .power_off = AM654_USB2_OTG_PD,
};

static const struct of_device_id omap_usb2_id_table[] = {
        {
                .compatible = "ti,omap-usb2",
                .data = &omap_usb2_data,
        },
        {
                .compatible = "ti,omap5-usb2",
                .data = &omap5_usb2_data,
        },
        {
                .compatible = "ti,dra7x-usb2",
                .data = &dra7x_usb2_data,
        },
        {
                .compatible = "ti,dra7x-usb2-phy2",
                .data = &dra7x_usb2_phy2_data,
        },
        {
                .compatible = "ti,am437x-usb2",
                .data = &am437x_usb2_data,
        },
        {
                .compatible = "ti,am654-usb2",
                .data = &am654_usb2_data,
        },
        {},
};
MODULE_DEVICE_TABLE(of, omap_usb2_id_table);

static void omap_usb2_init_errata(struct omap_usb *phy)
{
        static const struct soc_device_attribute am65x_sr10_soc_devices[] = {
                { .family = "AM65X", .revision = "SR1.0" },
                { /* sentinel */ }
        };

        /*
         * Errata i2075: USB2PHY: USB2PHY Charger Detect is Enabled by
         * Default Without VBUS Presence.
         *
         * AM654x SR1.0 has a silicon bug due to which D+ is pulled high after
         * POR, which could cause enumeration failure with some USB hubs.
         * Disabling the USB2_PHY Charger Detect function will put D+
         * into the normal state.
         */
        if (soc_device_match(am65x_sr10_soc_devices))
                phy->flags |= OMAP_USB2_DISABLE_CHRG_DET;
}

static int omap_usb2_probe(struct platform_device *pdev)
{
        struct omap_usb *phy;
        struct phy *generic_phy;
        struct resource *res;
        struct phy_provider *phy_provider;
        struct usb_otg *otg;
        struct device_node *node = pdev->dev.of_node;
        struct device_node *control_node;
        struct platform_device *control_pdev;
        const struct of_device_id *of_id;
        struct usb_phy_data *phy_data;

        of_id = of_match_device(omap_usb2_id_table, &pdev->dev);

        if (!of_id)
                return -EINVAL;

        phy_data = (struct usb_phy_data *)of_id->data;

        phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
        if (!phy)
                return -ENOMEM;

        otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
        if (!otg)
                return -ENOMEM;

        phy->dev                = &pdev->dev;

        phy->phy.dev            = phy->dev;
        phy->phy.label          = phy_data->label;
        phy->phy.otg            = otg;
        phy->phy.type           = USB_PHY_TYPE_USB2;
        phy->mask               = phy_data->mask;
        phy->power_on           = phy_data->power_on;
        phy->power_off          = phy_data->power_off;
        phy->flags              = phy_data->flags;

        omap_usb2_init_errata(phy);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        phy->phy_base = devm_ioremap_resource(&pdev->dev, res);
        if (IS_ERR(phy->phy_base))
                return PTR_ERR(phy->phy_base);

        phy->syscon_phy_power = syscon_regmap_lookup_by_phandle(node,
                                                        "syscon-phy-power");
        if (IS_ERR(phy->syscon_phy_power)) {
                dev_dbg(&pdev->dev,
                        "can't get syscon-phy-power, using control device\n");
                phy->syscon_phy_power = NULL;

                control_node = of_parse_phandle(node, "ctrl-module", 0);
                if (!control_node) {
                        dev_err(&pdev->dev,
                                "Failed to get control device phandle\n");
                        return -EINVAL;
                }

                control_pdev = of_find_device_by_node(control_node);
                if (!control_pdev) {
                        dev_err(&pdev->dev, "Failed to get control device\n");
                        return -EINVAL;
                }
                phy->control_dev = &control_pdev->dev;
        } else {
                if (of_property_read_u32_index(node,
                                               "syscon-phy-power", 1,
                                               &phy->power_reg)) {
                        dev_err(&pdev->dev,
                                "couldn't get power reg. offset\n");
                        return -EINVAL;
                }
        }


        phy->wkupclk = devm_clk_get(phy->dev, "wkupclk");
        if (IS_ERR(phy->wkupclk)) {
                if (PTR_ERR(phy->wkupclk) == -EPROBE_DEFER)
                        return -EPROBE_DEFER;

                dev_warn(&pdev->dev, "unable to get wkupclk %ld, trying old name\n",
                         PTR_ERR(phy->wkupclk));
                phy->wkupclk = devm_clk_get(phy->dev, "usb_phy_cm_clk32k");

                if (IS_ERR(phy->wkupclk)) {
                        if (PTR_ERR(phy->wkupclk) != -EPROBE_DEFER)
                                dev_err(&pdev->dev, "unable to get usb_phy_cm_clk32k\n");
                        return PTR_ERR(phy->wkupclk);
                } else {
                        dev_warn(&pdev->dev,
                                 "found usb_phy_cm_clk32k, please fix DTS\n");
                }
        }

        phy->optclk = devm_clk_get(phy->dev, "refclk");
        if (IS_ERR(phy->optclk)) {
                if (PTR_ERR(phy->optclk) == -EPROBE_DEFER)
                        return -EPROBE_DEFER;

                dev_dbg(&pdev->dev, "unable to get refclk, trying old name\n");
                phy->optclk = devm_clk_get(phy->dev, "usb_otg_ss_refclk960m");

                if (IS_ERR(phy->optclk)) {
                        if (PTR_ERR(phy->optclk) != -EPROBE_DEFER) {
                                dev_dbg(&pdev->dev,
                                        "unable to get usb_otg_ss_refclk960m\n");
                        }
                } else {
                        dev_warn(&pdev->dev,
                                 "found usb_otg_ss_refclk960m, please fix DTS\n");
                }
        }

        otg->set_host = omap_usb_set_host;
        otg->set_peripheral = omap_usb_set_peripheral;
        if (phy_data->flags & OMAP_USB2_HAS_SET_VBUS)
                otg->set_vbus = omap_usb_set_vbus;
        if (phy_data->flags & OMAP_USB2_HAS_START_SRP)
                otg->start_srp = omap_usb_start_srp;
        otg->usb_phy = &phy->phy;

        platform_set_drvdata(pdev, phy);
        pm_runtime_enable(phy->dev);

        generic_phy = devm_phy_create(phy->dev, NULL, &ops);
        if (IS_ERR(generic_phy)) {
                pm_runtime_disable(phy->dev);
                return PTR_ERR(generic_phy);
        }

        phy_set_drvdata(generic_phy, phy);
        omap_usb_power_off(generic_phy);

        phy_provider = devm_of_phy_provider_register(phy->dev,
                                                     of_phy_simple_xlate);
        if (IS_ERR(phy_provider)) {
                pm_runtime_disable(phy->dev);
                return PTR_ERR(phy_provider);
        }


        usb_add_phy_dev(&phy->phy);

        return 0;
}

static int omap_usb2_remove(struct platform_device *pdev)
{
        struct omap_usb *phy = platform_get_drvdata(pdev);

        usb_remove_phy(&phy->phy);
        pm_runtime_disable(phy->dev);

        return 0;
}

static struct platform_driver omap_usb2_driver = {
        .probe          = omap_usb2_probe,
        .remove         = omap_usb2_remove,
        .driver         = {
                .name   = "omap-usb2",
                .of_match_table = omap_usb2_id_table,
        },
};

module_platform_driver(omap_usb2_driver);

MODULE_ALIAS("platform:omap_usb2");
MODULE_AUTHOR("Texas Instruments Inc.");
MODULE_DESCRIPTION("OMAP USB2 phy driver");
MODULE_LICENSE("GPL v2");