// SPDX-License-Identifier: GPL-2.0+
/*
 * Central probing code for the FOTG210 dual role driver
 * We register one driver for the hardware and then we decide
 * whether to proceed with probing the host or the peripheral
 * driver.
 */
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/string_choices.h>
#include <linux/usb.h>
#include <linux/usb/otg.h>

#include "fotg210.h"

/* Role Register 0x80 */
#define FOTG210_RR                      0x80
#define FOTG210_RR_ID                   BIT(21) /* 1 = B-device, 0 = A-device */
#define FOTG210_RR_CROLE                BIT(20) /* 1 = device, 0 = host */

/*
 * Gemini-specific initialization function, only executed on the
 * Gemini SoC using the global misc control register.
 *
 * The gemini USB blocks are connected to either Mini-A (host mode) or
 * Mini-B (peripheral mode) plugs. There is no role switch support on the
 * Gemini SoC, just either-or.
 */
#define GEMINI_GLOBAL_MISC_CTRL         0x30
#define GEMINI_MISC_USB0_WAKEUP         BIT(14)
#define GEMINI_MISC_USB1_WAKEUP         BIT(15)
#define GEMINI_MISC_USB0_VBUS_ON        BIT(22)
#define GEMINI_MISC_USB1_VBUS_ON        BIT(23)
#define GEMINI_MISC_USB0_MINI_B         BIT(29)
#define GEMINI_MISC_USB1_MINI_B         BIT(30)

static int fotg210_gemini_init(struct fotg210 *fotg, struct resource *res,
                               enum usb_dr_mode mode)
{
        struct device *dev = fotg->dev;
        struct device_node *np = dev->of_node;
        struct regmap *map;
        bool wakeup;
        u32 mask, val;
        int ret;

        map = syscon_regmap_lookup_by_phandle(np, "syscon");
        if (IS_ERR(map))
                return dev_err_probe(dev, PTR_ERR(map), "no syscon\n");
        fotg->map = map;
        wakeup = of_property_read_bool(np, "wakeup-source");

        /*
         * Figure out if this is USB0 or USB1 by simply checking the
         * physical base address.
         */
        mask = 0;
        if (res->start == 0x69000000) {
                fotg->port = GEMINI_PORT_1;
                mask = GEMINI_MISC_USB1_VBUS_ON | GEMINI_MISC_USB1_MINI_B |
                        GEMINI_MISC_USB1_WAKEUP;
                if (mode == USB_DR_MODE_HOST)
                        val = GEMINI_MISC_USB1_VBUS_ON;
                else
                        val = GEMINI_MISC_USB1_MINI_B;
                if (wakeup)
                        val |= GEMINI_MISC_USB1_WAKEUP;
        } else {
                fotg->port = GEMINI_PORT_0;
                mask = GEMINI_MISC_USB0_VBUS_ON | GEMINI_MISC_USB0_MINI_B |
                        GEMINI_MISC_USB0_WAKEUP;
                if (mode == USB_DR_MODE_HOST)
                        val = GEMINI_MISC_USB0_VBUS_ON;
                else
                        val = GEMINI_MISC_USB0_MINI_B;
                if (wakeup)
                        val |= GEMINI_MISC_USB0_WAKEUP;
        }

        ret = regmap_update_bits(map, GEMINI_GLOBAL_MISC_CTRL, mask, val);
        if (ret) {
                dev_err(dev, "failed to initialize Gemini PHY\n");
                return ret;
        }

        dev_info(dev, "initialized Gemini PHY in %s mode\n",
                 (mode == USB_DR_MODE_HOST) ? "host" : "gadget");
        return 0;
}

/**
 * fotg210_vbus() - Called by gadget driver to enable/disable VBUS
 * @fotg: pointer to a private fotg210 object
 * @enable: true to enable VBUS, false to disable VBUS
 */
void fotg210_vbus(struct fotg210 *fotg, bool enable)
{
        u32 mask;
        u32 val;
        int ret;

        switch (fotg->port) {
        case GEMINI_PORT_0:
                mask = GEMINI_MISC_USB0_VBUS_ON;
                val = enable ? GEMINI_MISC_USB0_VBUS_ON : 0;
                break;
        case GEMINI_PORT_1:
                mask = GEMINI_MISC_USB1_VBUS_ON;
                val = enable ? GEMINI_MISC_USB1_VBUS_ON : 0;
                break;
        default:
                return;
        }
        ret = regmap_update_bits(fotg->map, GEMINI_GLOBAL_MISC_CTRL, mask, val);
        if (ret)
                dev_err(fotg->dev, "failed to %s VBUS\n",
                        str_enable_disable(enable));
        dev_info(fotg->dev, "%s: %s VBUS\n", __func__, str_enable_disable(enable));
}

static int fotg210_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        enum usb_dr_mode mode;
        struct fotg210 *fotg;
        u32 val;
        int ret;

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

        fotg->base = devm_platform_get_and_ioremap_resource(pdev, 0, &fotg->res);
        if (IS_ERR(fotg->base))
                return PTR_ERR(fotg->base);

        fotg->pclk = devm_clk_get_optional_enabled(dev, "PCLK");
        if (IS_ERR(fotg->pclk))
                return PTR_ERR(fotg->pclk);

        mode = usb_get_dr_mode(dev);

        if (of_device_is_compatible(dev->of_node, "cortina,gemini-usb")) {
                ret = fotg210_gemini_init(fotg, fotg->res, mode);
                if (ret)
                        return ret;
        }

        val = readl(fotg->base + FOTG210_RR);
        if (mode == USB_DR_MODE_PERIPHERAL) {
                if (!(val & FOTG210_RR_CROLE))
                        dev_err(dev, "block not in device role\n");
                ret = fotg210_udc_probe(pdev, fotg);
        } else {
                if (val & FOTG210_RR_CROLE)
                        dev_err(dev, "block not in host role\n");
                ret = fotg210_hcd_probe(pdev, fotg);
        }

        return ret;
}

static void fotg210_remove(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        enum usb_dr_mode mode;

        mode = usb_get_dr_mode(dev);

        if (mode == USB_DR_MODE_PERIPHERAL)
                fotg210_udc_remove(pdev);
        else
                fotg210_hcd_remove(pdev);
}

#ifdef CONFIG_OF
static const struct of_device_id fotg210_of_match[] = {
        { .compatible = "faraday,fotg200" },
        { .compatible = "faraday,fotg210" },
        /* TODO: can we also handle FUSB220? */
        {},
};
MODULE_DEVICE_TABLE(of, fotg210_of_match);
#endif

static struct platform_driver fotg210_driver = {
        .driver = {
                .name   = "fotg210",
                .of_match_table = of_match_ptr(fotg210_of_match),
        },
        .probe  = fotg210_probe,
        .remove = fotg210_remove,
};

static int __init fotg210_init(void)
{
        if (IS_ENABLED(CONFIG_USB_FOTG210_HCD) && !usb_disabled())
                fotg210_hcd_init();
        return platform_driver_register(&fotg210_driver);
}
module_init(fotg210_init);

static void __exit fotg210_cleanup(void)
{
        platform_driver_unregister(&fotg210_driver);
        if (IS_ENABLED(CONFIG_USB_FOTG210_HCD))
                fotg210_hcd_cleanup();
}
module_exit(fotg210_cleanup);

MODULE_AUTHOR("Yuan-Hsin Chen, Feng-Hsin Chiang");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("FOTG210 Dual Role Controller Driver");