// SPDX-License-Identifier: GPL-2.0
/*
 * Artinchip EHCI driver
 *
 * Copyright (C) 2020-2025 ARTINCHIP – All Rights Reserved
 *
 * Author: Matteo <duanmt@artinchip.com>
 *
 */

#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/hrtimer.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/usb/otg.h>
#include <linux/usb/ehci_pdriver.h>
#include <linux/pinctrl/consumer.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>

#include "ehci.h"

#define USB_MAX_CLKS_RSTS 2

#define SYSCFG_USB_RES_CAL_EN_SHIFT		8
#define SYSCFG_USB_RES_CAL_EN_MASK		BIT(8)
#define SYSCFG_USB_RES_CAL_VAL_SHIFT		0
#define SYSCFG_USB_RES_CAL_VAL_MASK		GENMASK(7, 0)
#define SYSCFG_USB_RES_CAL_VAL_DEF		0x40

struct aic_usb_res_cfg {
	void __iomem *addr;
	u32 resis;
};

struct aic_ehci_platform_priv {
	struct aic_usb_res_cfg usb_res_cfg;
	struct clk *clks[USB_MAX_CLKS_RSTS];
	struct clk *clk48;
	struct reset_control *rst[USB_MAX_CLKS_RSTS];
	struct reset_control *pwr;
	struct phy *phy;
	struct gpio_desc *gpio_vbus_en;
};

#define DRIVER_DESC "Artinchip EHCI driver"

#define hcd_to_ehci_priv(h) \
	((struct aic_ehci_platform_priv *)hcd_to_ehci(h)->priv)

static const char hcd_name[] = "ehci-aic";

#define EHCI_CAPS_SIZE 0x10
#define AHB2STBUS_INSREG01 (EHCI_CAPS_SIZE + 0x84)

extern void syscfg_usb_phy0_sw_host(int sw);

#ifndef CONFIG_DEBUG_ON_FPGA_BOARD_ARTINCHIP
#define USB_HOST_CTRL_REG_OFFSE 0x800
#define ULPI_BYPASS_EN 0x1
#define PHY_TYPE_ULPI 0
#define PHY_TYPE_UTMI 1

static void aic_ehci_set_usb_res(void __iomem *ctl_reg, u32 resis)
{
	u32 val;

	if (ctl_reg == NULL)
		return;

	resis &= SYSCFG_USB_RES_CAL_VAL_MASK;

	val = readl(ctl_reg);
	val &= ~SYSCFG_USB_RES_CAL_VAL_MASK;
	val |= resis << SYSCFG_USB_RES_CAL_VAL_SHIFT;
	val |= 1 << SYSCFG_USB_RES_CAL_EN_SHIFT;

	writel(val, ctl_reg);
}

static int aic_ehci_get_res_cfg(struct device_node *np, struct aic_usb_res_cfg *cfg,
				const char *property)
{
	int len, index, offset, res;
	const __be32 *prop;
	struct device_node *child_np;

	prop = of_get_property(np, property, &len);
	if (!prop || len < 4 * sizeof(__be32))
		return -ENODEV;

	child_np = of_find_node_by_phandle(be32_to_cpup(prop++));
	if (!child_np)
		return -ENODEV;

	index = be32_to_cpup(prop++);
	offset = be32_to_cpup(prop++);
	res = be32_to_cpup(prop);

	cfg->addr = of_iomap(child_np, index);
	if (!cfg->addr)
		return -ENOMEM;
	cfg->addr += offset;
	cfg->resis = res;

	pr_debug("property : %s \n", property);
	pr_debug("child_np : %s \n", child_np->name);
	pr_debug("offset : %#x  res : %#x \n", offset, res);

	return 0;
}

static void aic_ehci_set_phy_type(struct usb_hcd *hcd, int phy_type)
{
	u32 val = 0;

	val = readl(hcd->regs + USB_HOST_CTRL_REG_OFFSE);

	if (phy_type == PHY_TYPE_ULPI) {
		writel(val & ~ULPI_BYPASS_EN,
		       hcd->regs + USB_HOST_CTRL_REG_OFFSE);
	} else {
		writel(val | ULPI_BYPASS_EN,
		       hcd->regs + USB_HOST_CTRL_REG_OFFSE);
	}
}
#endif

static int aic_ehci_platform_reset(struct usb_hcd *hcd)
{
	struct platform_device *pdev = to_platform_device(hcd->self.controller);
	struct usb_ehci_pdata *pdata = dev_get_platdata(&pdev->dev);
	struct aic_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
	u32 threshold;

	aic_ehci_set_usb_res(priv->usb_res_cfg.addr, priv->usb_res_cfg.resis);

	/* Set EHCI packet buffer IN/OUT threshold (in DWORDs) */
#ifdef CONFIG_USB_EHCI_HCD_AIC
	/* Must increase the OUT threshold to avoid underrun. (FIFO size - 4) */
	threshold = 32 | (127 << 16);
#else
	/* According the databook. (FIFO size / 4) */
	threshold = 32 | (32 << 16);
#endif
	writel(threshold, hcd->regs + AHB2STBUS_INSREG01);

	ehci->caps = hcd->regs + pdata->caps_offset;
	return ehci_setup(hcd);
}

static int aic_ehci_platform_power_on(struct platform_device *dev)
{
	struct usb_hcd *hcd = platform_get_drvdata(dev);
	struct aic_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
	int i, ret;

	if (of_property_read_bool(dev->dev.of_node,
				  "artinchip,sw_usb_phy0")) {
		syscfg_usb_phy0_sw_host(1);
		dev_info(&dev->dev, "switch usb_phy0 to host.");

#ifndef CONFIG_USB_OTG
		if (priv->gpio_vbus_en && !IS_ERR(priv->gpio_vbus_en))
			gpiod_set_value(priv->gpio_vbus_en, 1);
#endif

		dev_info(&dev->dev, "enable host vbus.");
	}

	//ret = reset_control_deassert(priv->pwr);
	//if (ret)
	//	return ret;

	for (i = 0; i < USB_MAX_CLKS_RSTS && priv->rst[i]; i++) {
		ret = reset_control_deassert(priv->rst[i]);
		if (ret)
			goto err_assert_power;
	}

	/* some SoCs don't have a dedicated 48Mhz clock, but those that do
	 * need the rate to be explicitly set
	 */
	if (priv->clk48) {
		ret = clk_set_rate(priv->clk48, 48000000);
		if (ret)
			goto err_assert_reset;
	}

	for (i = 0; i < USB_MAX_CLKS_RSTS && priv->clks[i]; i++) {
		ret = clk_prepare_enable(priv->clks[i]);
		if (ret)
			goto err_disable_clks;
	}

#ifndef CONFIG_USB_EHCI_HCD_AIC
	ret = phy_init(priv->phy);
	if (ret)
		goto err_disable_clks;

	ret = phy_power_on(priv->phy);
	if (ret)
		goto err_exit_phy;
#endif

	return 0;

#ifndef CONFIG_USB_EHCI_HCD_AIC
err_exit_phy:
	phy_exit(priv->phy);
#endif
err_disable_clks:
	while (--i >= 0)
		clk_disable_unprepare(priv->clks[i]);
err_assert_reset:
	for (i = 0; i < USB_MAX_CLKS_RSTS && priv->rst[i]; i++)
		reset_control_assert(priv->rst[i]);
err_assert_power:
//	reset_control_assert(priv->pwr);

	return ret;
}

static void aic_ehci_platform_power_off(struct platform_device *dev)
{
	struct usb_hcd *hcd = platform_get_drvdata(dev);
	struct aic_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
	int i;

	if (of_property_read_bool(dev->dev.of_node,
				  "artinchip,sw_usb_phy0")) {
#ifndef CONFIG_USB_OTG
		if (priv->gpio_vbus_en && !IS_ERR(priv->gpio_vbus_en))
			gpiod_set_value(priv->gpio_vbus_en, 0);
#endif

		dev_info(&dev->dev, "disable host vbus.");
	}

	// reset_control_assert(priv->pwr);

	for (i = 0; i < USB_MAX_CLKS_RSTS && priv->rst[i]; i++)
		reset_control_assert(priv->rst[i]);

#ifndef CONFIG_USB_EHCI_HCD_AIC
	phy_power_off(priv->phy);

	phy_exit(priv->phy);
#endif

	for (i = USB_MAX_CLKS_RSTS - 1; i >= 0 && priv->clks[i]; i--)
		clk_disable_unprepare(priv->clks[i]);
}

static struct hc_driver __read_mostly ehci_platform_hc_driver;

static const struct ehci_driver_overrides platform_overrides __initconst = {
	.reset =		aic_ehci_platform_reset,
	.extra_priv_size =	sizeof(struct aic_ehci_platform_priv),
};

static struct usb_ehci_pdata ehci_platform_defaults = {
	.power_on      = aic_ehci_platform_power_on,
	.power_suspend = aic_ehci_platform_power_off,
	.power_off     = aic_ehci_platform_power_off,
};

static int aic_ehci_platform_probe(struct platform_device *dev)
{
	struct usb_hcd *hcd;
	struct resource *res_mem;
	struct usb_ehci_pdata *pdata = &ehci_platform_defaults;
	struct aic_ehci_platform_priv *priv;
	int err, irq, i = 0;

	if (usb_disabled())
		return -ENODEV;

	irq = platform_get_irq(dev, 0);
	if (irq < 0)
		return irq;
	res_mem = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res_mem) {
		dev_err(&dev->dev, "no memory resource provided");
		return -ENXIO;
	}

	hcd = usb_create_hcd(&ehci_platform_hc_driver, &dev->dev,
			     dev_name(&dev->dev));
	if (!hcd)
		return -ENOMEM;

	platform_set_drvdata(dev, hcd);
	dev->dev.platform_data = pdata;
	priv = hcd_to_ehci_priv(hcd);

#ifndef CONFIG_USB_EHCI_HCD_AIC
	priv->phy = devm_phy_get(&dev->dev, "usb");
	if (IS_ERR(priv->phy)) {
		err = PTR_ERR(priv->phy);
		goto err_put_hcd;
	}
#endif
	aic_ehci_get_res_cfg(dev->dev.of_node, &priv->usb_res_cfg, "aic,usbh-ext-resistance");

	for (i = 0; i < USB_MAX_CLKS_RSTS; i++) {
		priv->clks[i] = of_clk_get(dev->dev.of_node, i);
		if (IS_ERR(priv->clks[i])) {
			err = PTR_ERR(priv->clks[i]);
			if (err == -EPROBE_DEFER)
				goto err_put_clks;
			priv->clks[i] = NULL;
			break;
		}
	}

	/* some SoCs don't have a dedicated 48Mhz clock, but those that
	 * do need the rate to be explicitly set
	 */
	priv->clk48 = devm_clk_get(&dev->dev, "clk48");
	if (IS_ERR(priv->clk48)) {
		dev_info(&dev->dev, "48MHz clk not found\n");
		priv->clk48 = NULL;
	}

	for (i = 0; i < USB_MAX_CLKS_RSTS; i++) {
		priv->rst[i] = devm_reset_control_get_shared_by_index(&dev->dev, i);
		if (IS_ERR(priv->rst[i])) {
			err = PTR_ERR(priv->rst[i]);
			if (err == -EPROBE_DEFER)
				goto err_put_clks;
			priv->rst[i] = NULL;
		}
	}

	if (pdata->power_on) {
		err = pdata->power_on(dev);
		if (err < 0)
			goto err_put_clks;
	}

	hcd->rsrc_start = res_mem->start;
	hcd->rsrc_len = resource_size(res_mem);

	hcd->regs = devm_ioremap_resource(&dev->dev, res_mem);
	if (IS_ERR(hcd->regs)) {
		err = PTR_ERR(hcd->regs);
		goto err_put_clks;
	}

#ifndef CONFIG_DEBUG_ON_FPGA_BOARD_ARTINCHIP
	aic_ehci_set_phy_type(hcd, PHY_TYPE_UTMI);
#endif

#ifdef CONFIG_USB_OTG
	if (of_property_read_bool(dev->dev.of_node, "aic,otg-support")) {
		struct ehci_hcd *ehci = hcd_to_ehci(hcd);

		hcd->usb_phy = usb_get_phy(USB_PHY_TYPE_USB2);
		dev_dbg(&dev->dev, "hcd=0x%p  ehci=0x%p, phy=0x%p\n",
			hcd, ehci, hcd->usb_phy);

		if (!IS_ERR_OR_NULL(hcd->usb_phy)) {
			err = otg_set_host(hcd->usb_phy->otg,
					   &ehci_to_hcd(ehci)->self);
			if (err) {
				usb_put_phy(hcd->usb_phy);
				goto err_put_clks;
			}
		} else {
			dev_err(&dev->dev, "can't find phy\n");
			err = -ENODEV;
			goto err_put_clks;
		}

		hcd->skip_phy_initialization = 1;
	}
#else
	priv->gpio_vbus_en = devm_gpiod_get_optional(&dev->dev, "vbus-en",
						  GPIOD_OUT_HIGH);
#endif

	err = usb_add_hcd(hcd, irq, IRQF_SHARED);
	if (err)
		goto err_put_clks;

	device_wakeup_enable(hcd->self.controller);
	platform_set_drvdata(dev, hcd);

	return err;

err_put_clks:
	while (--i >= 0)
		clk_put(priv->clks[i]);
#ifndef CONFIG_USB_EHCI_HCD_AIC
err_put_hcd:
#endif
	if (pdata == &ehci_platform_defaults)
		dev->dev.platform_data = NULL;

	usb_put_hcd(hcd);

	return err;
}

static int aic_ehci_platform_remove(struct platform_device *dev)
{
	struct usb_hcd *hcd = platform_get_drvdata(dev);
	struct usb_ehci_pdata *pdata = dev_get_platdata(&dev->dev);
	struct aic_ehci_platform_priv *priv = hcd_to_ehci_priv(hcd);
	int clk;

#ifdef CONFIG_USB_OTG
	if (!IS_ERR_OR_NULL(hcd->usb_phy)) {
		otg_set_host(hcd->usb_phy->otg, NULL);
		usb_put_phy(hcd->usb_phy);
	}
#else
	if (priv->gpio_vbus_en && !IS_ERR(priv->gpio_vbus_en))
		devm_gpiod_put(&dev->dev, priv->gpio_vbus_en);
#endif

	usb_remove_hcd(hcd);

	if (pdata->power_off)
		pdata->power_off(dev);

	for (clk = 0; clk < USB_MAX_CLKS_RSTS && priv->clks[clk]; clk++)
		clk_put(priv->clks[clk]);

	usb_put_hcd(hcd);

	if (pdata == &ehci_platform_defaults)
		dev->dev.platform_data = NULL;

	return 0;
}

#ifdef CONFIG_PM_SLEEP

static int aic_ehci_suspend(struct device *dev)
{
	struct usb_hcd *hcd = dev_get_drvdata(dev);
	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
	struct platform_device *pdev = to_platform_device(dev);
	bool do_wakeup = device_may_wakeup(dev);
	int ret;

	ret = ehci_suspend(hcd, do_wakeup);
	if (ret)
		return ret;

	if (pdata->power_suspend)
		pdata->power_suspend(pdev);

	pinctrl_pm_select_sleep_state(dev);

	return ret;
}

static int aic_ehci_resume(struct device *dev)
{
	struct usb_hcd *hcd = dev_get_drvdata(dev);
	struct usb_ehci_pdata *pdata = dev_get_platdata(dev);
	struct platform_device *pdev = to_platform_device(dev);
	int err;

	pinctrl_pm_select_default_state(dev);

	if (pdata->power_on) {
		err = pdata->power_on(pdev);
		if (err < 0)
			return err;
	}

	ehci_resume(hcd, false);
	return 0;
}

static SIMPLE_DEV_PM_OPS(aic_ehci_pm_ops, aic_ehci_suspend, aic_ehci_resume);

#endif /* CONFIG_PM_SLEEP */

static const struct of_device_id aic_ehci_ids[] = {
	{ .compatible = "artinchip,aic-usbh-v1.0", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, aic_ehci_ids);

static struct platform_driver ehci_platform_driver = {
	.probe		= aic_ehci_platform_probe,
	.remove		= aic_ehci_platform_remove,
	.shutdown	= usb_hcd_platform_shutdown,
	.driver		= {
		.name	= "aic-ehci",
#ifdef CONFIG_PM_SLEEP
		.pm	= &aic_ehci_pm_ops,
#endif
		.of_match_table = aic_ehci_ids,
	}
};

static int __init ehci_platform_init(void)
{
	if (usb_disabled())
		return -ENODEV;

	pr_info("%s: " DRIVER_DESC "\n", hcd_name);

	ehci_init_driver(&ehci_platform_hc_driver, &platform_overrides);
	return platform_driver_register(&ehci_platform_driver);
}
module_init(ehci_platform_init);

static void __exit ehci_platform_cleanup(void)
{
	platform_driver_unregister(&ehci_platform_driver);
}
module_exit(ehci_platform_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR(" Matteo <duanmt@artinchip.com>");
MODULE_LICENSE("GPL");