// SPDX-License-Identifier: GPL-2.0
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/usb/otg.h>
#include "phy-am335x-control.h"

struct am335x_control_usb {
        struct device *dev;
        void __iomem *phy_reg;
        void __iomem *wkup;
        spinlock_t lock;
        struct phy_control phy_ctrl;
};

#define AM335X_USB0_CTRL                0x0
#define AM335X_USB1_CTRL                0x8
#define AM335x_USB_WKUP                 0x0

#define USBPHY_CM_PWRDN         (1 << 0)
#define USBPHY_OTG_PWRDN        (1 << 1)
#define USBPHY_OTGVDET_EN       (1 << 19)
#define USBPHY_OTGSESSEND_EN    (1 << 20)

#define AM335X_PHY0_WK_EN       (1 << 0)
#define AM335X_PHY1_WK_EN       (1 << 8)

static void am335x_phy_wkup(struct  phy_control *phy_ctrl, u32 id, bool on)
{
        struct am335x_control_usb *usb_ctrl;
        u32 val;
        u32 reg;

        usb_ctrl = container_of(phy_ctrl, struct am335x_control_usb, phy_ctrl);

        switch (id) {
        case 0:
                reg = AM335X_PHY0_WK_EN;
                break;
        case 1:
                reg = AM335X_PHY1_WK_EN;
                break;
        default:
                WARN_ON(1);
                return;
        }

        spin_lock(&usb_ctrl->lock);
        val = readl(usb_ctrl->wkup);

        if (on)
                val |= reg;
        else
                val &= ~reg;

        writel(val, usb_ctrl->wkup);
        spin_unlock(&usb_ctrl->lock);
}

static void am335x_phy_power(struct phy_control *phy_ctrl, u32 id,
                                enum usb_dr_mode dr_mode, bool on)
{
        struct am335x_control_usb *usb_ctrl;
        u32 val;
        u32 reg;

        usb_ctrl = container_of(phy_ctrl, struct am335x_control_usb, phy_ctrl);

        switch (id) {
        case 0:
                reg = AM335X_USB0_CTRL;
                break;
        case 1:
                reg = AM335X_USB1_CTRL;
                break;
        default:
                WARN_ON(1);
                return;
        }

        val = readl(usb_ctrl->phy_reg + reg);
        if (on) {
                if (dr_mode == USB_DR_MODE_HOST) {
                        val &= ~(USBPHY_CM_PWRDN | USBPHY_OTG_PWRDN |
                                        USBPHY_OTGVDET_EN);
                        val |= USBPHY_OTGSESSEND_EN;
                } else {
                        val &= ~(USBPHY_CM_PWRDN | USBPHY_OTG_PWRDN);
                        val |= USBPHY_OTGVDET_EN | USBPHY_OTGSESSEND_EN;
                }
        } else {
                val |= USBPHY_CM_PWRDN | USBPHY_OTG_PWRDN;
        }

        writel(val, usb_ctrl->phy_reg + reg);

        /*
         * Give the PHY ~1ms to complete the power up operation.
         * Tests have shown unstable behaviour if other USB PHY related
         * registers are written too shortly after such a transition.
         */
        if (on)
                mdelay(1);
}

static const struct phy_control ctrl_am335x = {
        .phy_power = am335x_phy_power,
        .phy_wkup = am335x_phy_wkup,
};

static const struct of_device_id omap_control_usb_id_table[] = {
        { .compatible = "ti,am335x-usb-ctrl-module", .data = &ctrl_am335x },
        {}
};
MODULE_DEVICE_TABLE(of, omap_control_usb_id_table);

static struct platform_driver am335x_control_driver;
static int match(struct device *dev, const void *data)
{
        const struct device_node *node = (const struct device_node *)data;
        return dev->of_node == node &&
                dev->driver == &am335x_control_driver.driver;
}

struct phy_control *am335x_get_phy_control(struct device *dev)
{
        struct device_node *node;
        struct am335x_control_usb *ctrl_usb;

        node = of_parse_phandle(dev->of_node, "ti,ctrl_mod", 0);
        if (!node)
                return NULL;

        dev = bus_find_device(&platform_bus_type, NULL, node, match);
        of_node_put(node);
        if (!dev)
                return NULL;

        ctrl_usb = dev_get_drvdata(dev);
        put_device(dev);
        if (!ctrl_usb)
                return NULL;
        return &ctrl_usb->phy_ctrl;
}
EXPORT_SYMBOL_GPL(am335x_get_phy_control);

static int am335x_control_usb_probe(struct platform_device *pdev)
{
        struct am335x_control_usb *ctrl_usb;
        const struct of_device_id *of_id;
        const struct phy_control *phy_ctrl;

        of_id = of_match_node(omap_control_usb_id_table, pdev->dev.of_node);
        if (!of_id)
                return -EINVAL;

        phy_ctrl = of_id->data;

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

        ctrl_usb->dev = &pdev->dev;

        ctrl_usb->phy_reg = devm_platform_ioremap_resource_byname(pdev, "phy_ctrl");
        if (IS_ERR(ctrl_usb->phy_reg))
                return PTR_ERR(ctrl_usb->phy_reg);

        ctrl_usb->wkup = devm_platform_ioremap_resource_byname(pdev, "wakeup");
        if (IS_ERR(ctrl_usb->wkup))
                return PTR_ERR(ctrl_usb->wkup);

        spin_lock_init(&ctrl_usb->lock);
        ctrl_usb->phy_ctrl = *phy_ctrl;

        dev_set_drvdata(ctrl_usb->dev, ctrl_usb);
        return 0;
}

static struct platform_driver am335x_control_driver = {
        .probe          = am335x_control_usb_probe,
        .driver         = {
                .name   = "am335x-control-usb",
                .of_match_table = omap_control_usb_id_table,
        },
};

module_platform_driver(am335x_control_driver);
MODULE_DESCRIPTION("AM335x USB PHY Control Driver");
MODULE_LICENSE("GPL v2");