// SPDX-License-Identifier: GPL-2.0
/*
 * dwc3-xilinx.c - Xilinx DWC3 controller specific glue driver
 *
 * Authors: Manish Narani <manish.narani@xilinx.com>
 *          Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/gpio/consumer.h>
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/of_address.h>
#include <linux/delay.h>
#include <linux/firmware/xlnx-zynqmp.h>
#include <linux/io.h>

#include <linux/phy/phy.h>

/* USB phy reset mask register */
#define XLNX_USB_PHY_RST_EN                     0x001C
#define XLNX_PHY_RST_MASK                       0x1

/* Xilinx USB 3.0 IP Register */
#define XLNX_USB_TRAFFIC_ROUTE_CONFIG           0x005C
#define XLNX_USB_TRAFFIC_ROUTE_FPD              0x1

/* USB 2.0 IP Register */
#define XLNX_USB2_TRAFFIC_ROUTE_CONFIG          0x0044

#define XLNX_USB_FPD_PIPE_CLK                   0x7c
#define PIPE_CLK_DESELECT                       1
#define PIPE_CLK_SELECT                         0
#define XLNX_USB_FPD_POWER_PRSNT                0x80
#define FPD_POWER_PRSNT_OPTION                  BIT(0)

struct dwc3_xlnx {
        int                             num_clocks;
        struct clk_bulk_data            *clks;
        struct device                   *dev;
        void __iomem                    *regs;
        int                             (*pltfm_init)(struct dwc3_xlnx *data);
        struct phy                      *usb3_phy;
};

static void dwc3_xlnx_mask_phy_rst(struct dwc3_xlnx *priv_data, bool mask)
{
        u32 reg;

        /*
         * Enable or disable ULPI PHY reset from USB Controller.
         * This does not actually reset the phy, but just controls
         * whether USB controller can or cannot reset ULPI PHY.
         */
        reg = readl(priv_data->regs + XLNX_USB_PHY_RST_EN);

        if (mask)
                reg &= ~XLNX_PHY_RST_MASK;
        else
                reg |= XLNX_PHY_RST_MASK;

        writel(reg, priv_data->regs + XLNX_USB_PHY_RST_EN);
}

static void dwc3_xlnx_set_coherency(struct dwc3_xlnx *priv_data, u32 coherency_offset)
{
        struct device           *dev = priv_data->dev;
        u32                     reg;

        /*
         * This routes the USB DMA traffic to go through FPD path instead
         * of reaching DDR directly. This traffic routing is needed to
         * make SMMU and CCI work with USB DMA.
         */
        if (of_dma_is_coherent(dev->of_node) || device_iommu_mapped(dev)) {
                reg = readl(priv_data->regs + coherency_offset);
                reg |= XLNX_USB_TRAFFIC_ROUTE_FPD;
                writel(reg, priv_data->regs + coherency_offset);
        }
}

static int dwc3_xlnx_init_versal(struct dwc3_xlnx *priv_data)
{
        struct device           *dev = priv_data->dev;
        struct reset_control    *crst;
        int                     ret;

        crst = devm_reset_control_get_exclusive(dev, NULL);
        if (IS_ERR(crst))
                return dev_err_probe(dev, PTR_ERR(crst), "failed to get reset signal\n");

        dwc3_xlnx_mask_phy_rst(priv_data, false);

        /* Assert and De-assert reset */
        ret = reset_control_assert(crst);
        if (ret < 0) {
                dev_err_probe(dev, ret, "failed to assert Reset\n");
                return ret;
        }

        ret = reset_control_deassert(crst);
        if (ret < 0) {
                dev_err_probe(dev, ret, "failed to De-assert Reset\n");
                return ret;
        }

        dwc3_xlnx_mask_phy_rst(priv_data, true);
        dwc3_xlnx_set_coherency(priv_data, XLNX_USB2_TRAFFIC_ROUTE_CONFIG);

        return 0;
}

static int dwc3_xlnx_init_zynqmp(struct dwc3_xlnx *priv_data)
{
        struct device           *dev = priv_data->dev;
        struct reset_control    *crst, *hibrst, *apbrst;
        struct gpio_desc        *reset_gpio;
        int                     ret = 0;

        priv_data->usb3_phy = devm_phy_optional_get(dev, "usb3-phy");
        if (IS_ERR(priv_data->usb3_phy)) {
                ret = PTR_ERR(priv_data->usb3_phy);
                dev_err_probe(dev, ret,
                              "failed to get USB3 PHY\n");
                goto err;
        }

        crst = devm_reset_control_get_exclusive(dev, "usb_crst");
        if (IS_ERR(crst)) {
                ret = PTR_ERR(crst);
                dev_err_probe(dev, ret,
                              "failed to get core reset signal\n");
                goto err;
        }

        hibrst = devm_reset_control_get_exclusive(dev, "usb_hibrst");
        if (IS_ERR(hibrst)) {
                ret = PTR_ERR(hibrst);
                dev_err_probe(dev, ret,
                              "failed to get hibernation reset signal\n");
                goto err;
        }

        apbrst = devm_reset_control_get_exclusive(dev, "usb_apbrst");
        if (IS_ERR(apbrst)) {
                ret = PTR_ERR(apbrst);
                dev_err_probe(dev, ret,
                              "failed to get APB reset signal\n");
                goto err;
        }

        /*
         * Asserting the core resets is not required unless a USB3 PHY is used.
         * They may also break the configuration if USB3 is actually in use but
         * the usb3-phy entry is missing from the device tree. Therefore, skip
         * a full reset cycle and just deassert the resets if the phy is
         * absent.
         */
        if (priv_data->usb3_phy) {
                ret = reset_control_assert(crst);
                if (ret < 0) {
                        dev_err(dev, "Failed to assert core reset\n");
                        goto err;
                }

                ret = reset_control_assert(hibrst);
                if (ret < 0) {
                        dev_err(dev, "Failed to assert hibernation reset\n");
                        goto err;
                }

                ret = reset_control_assert(apbrst);
                if (ret < 0) {
                        dev_err(dev, "Failed to assert APB reset\n");
                        goto err;
                }
        }

        ret = phy_init(priv_data->usb3_phy);
        if (ret < 0) {
                phy_exit(priv_data->usb3_phy);
                goto err;
        }

        ret = reset_control_deassert(apbrst);
        if (ret < 0) {
                dev_err(dev, "Failed to release APB reset\n");
                goto err;
        }

        if (priv_data->usb3_phy) {
                /* Set PIPE Power Present signal in FPD Power Present Register*/
                writel(FPD_POWER_PRSNT_OPTION, priv_data->regs + XLNX_USB_FPD_POWER_PRSNT);
                /* Set the PIPE Clock Select bit in FPD PIPE Clock register */
                writel(PIPE_CLK_SELECT, priv_data->regs + XLNX_USB_FPD_PIPE_CLK);
        } else {
                /* Deselect the PIPE Clock Select bit in FPD PIPE Clock register */
                writel(PIPE_CLK_DESELECT, priv_data->regs + XLNX_USB_FPD_PIPE_CLK);
        }

        ret = reset_control_deassert(crst);
        if (ret < 0) {
                dev_err(dev, "Failed to release core reset\n");
                goto err;
        }

        ret = reset_control_deassert(hibrst);
        if (ret < 0) {
                dev_err(dev, "Failed to release hibernation reset\n");
                goto err;
        }

        ret = phy_power_on(priv_data->usb3_phy);
        if (ret < 0) {
                phy_exit(priv_data->usb3_phy);
                goto err;
        }

        /* ulpi reset via gpio-modepin or gpio-framework driver */
        reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
        if (IS_ERR(reset_gpio)) {
                return dev_err_probe(dev, PTR_ERR(reset_gpio),
                                     "Failed to request reset GPIO\n");
        }

        if (reset_gpio) {
                usleep_range(5000, 10000);
                gpiod_set_value_cansleep(reset_gpio, 0);
                usleep_range(5000, 10000);
        }

        dwc3_xlnx_set_coherency(priv_data, XLNX_USB_TRAFFIC_ROUTE_CONFIG);
err:
        return ret;
}

static const struct of_device_id dwc3_xlnx_of_match[] = {
        {
                .compatible = "xlnx,zynqmp-dwc3",
                .data = &dwc3_xlnx_init_zynqmp,
        },
        {
                .compatible = "xlnx,versal-dwc3",
                .data = &dwc3_xlnx_init_versal,
        },
        { /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, dwc3_xlnx_of_match);

static int dwc3_set_swnode(struct device *dev)
{
        struct device_node *np = dev->of_node, *dwc3_np;
        struct property_entry props[2];
        int prop_idx = 0, ret = 0;

        dwc3_np = of_get_compatible_child(np, "snps,dwc3");
        if (!dwc3_np) {
                ret = -ENODEV;
                dev_err(dev, "failed to find dwc3 core child\n");
                return ret;
        }

        memset(props, 0, sizeof(struct property_entry) * ARRAY_SIZE(props));
        if (of_dma_is_coherent(dwc3_np))
                props[prop_idx++] = PROPERTY_ENTRY_U16("snps,gsbuscfg0-reqinfo",
                                                       0xffff);
        of_node_put(dwc3_np);

        if (prop_idx)
                ret = device_create_managed_software_node(dev, props, NULL);

        return ret;
}

static int dwc3_xlnx_probe(struct platform_device *pdev)
{
        struct dwc3_xlnx                *priv_data;
        struct device                   *dev = &pdev->dev;
        struct device_node              *np = dev->of_node;
        const struct of_device_id       *match;
        void __iomem                    *regs;
        int                             ret;

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

        regs = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(regs))
                return dev_err_probe(dev, PTR_ERR(regs), "failed to map registers\n");

        match = of_match_node(dwc3_xlnx_of_match, pdev->dev.of_node);

        priv_data->pltfm_init = match->data;
        priv_data->regs = regs;
        priv_data->dev = dev;

        platform_set_drvdata(pdev, priv_data);

        ret = devm_clk_bulk_get_all(priv_data->dev, &priv_data->clks);
        if (ret < 0)
                return ret;

        priv_data->num_clocks = ret;

        ret = clk_bulk_prepare_enable(priv_data->num_clocks, priv_data->clks);
        if (ret)
                return ret;

        ret = priv_data->pltfm_init(priv_data);
        if (ret)
                goto err_clk_put;

        ret = dwc3_set_swnode(dev);
        if (ret)
                goto err_clk_put;

        ret = of_platform_populate(np, NULL, NULL, dev);
        if (ret)
                goto err_clk_put;

        pm_runtime_set_active(dev);
        ret = devm_pm_runtime_enable(dev);
        if (ret < 0)
                goto err_pm_set_suspended;

        pm_suspend_ignore_children(dev, false);
        ret = pm_runtime_resume_and_get(dev);
        if (ret < 0)
                goto err_pm_set_suspended;

        return 0;

err_pm_set_suspended:
        of_platform_depopulate(dev);
        pm_runtime_set_suspended(dev);

err_clk_put:
        clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);

        return ret;
}

static void dwc3_xlnx_remove(struct platform_device *pdev)
{
        struct dwc3_xlnx        *priv_data = platform_get_drvdata(pdev);
        struct device           *dev = &pdev->dev;

        of_platform_depopulate(dev);

        clk_bulk_disable_unprepare(priv_data->num_clocks, priv_data->clks);
        priv_data->num_clocks = 0;

        pm_runtime_put_noidle(dev);
        pm_runtime_set_suspended(dev);
}

static int __maybe_unused dwc3_xlnx_runtime_suspend(struct device *dev)
{
        struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);

        clk_bulk_disable(priv_data->num_clocks, priv_data->clks);

        return 0;
}

static int __maybe_unused dwc3_xlnx_runtime_resume(struct device *dev)
{
        struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);

        return clk_bulk_enable(priv_data->num_clocks, priv_data->clks);
}

static int __maybe_unused dwc3_xlnx_runtime_idle(struct device *dev)
{
        pm_runtime_autosuspend(dev);

        return 0;
}

static int __maybe_unused dwc3_xlnx_suspend(struct device *dev)
{
        struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);

        phy_exit(priv_data->usb3_phy);

        /* Disable the clocks */
        clk_bulk_disable(priv_data->num_clocks, priv_data->clks);

        return 0;
}

static int __maybe_unused dwc3_xlnx_resume(struct device *dev)
{
        struct dwc3_xlnx *priv_data = dev_get_drvdata(dev);
        int ret;

        ret = clk_bulk_enable(priv_data->num_clocks, priv_data->clks);
        if (ret)
                return ret;

        ret = phy_init(priv_data->usb3_phy);
        if (ret < 0)
                return ret;

        ret = phy_power_on(priv_data->usb3_phy);
        if (ret < 0) {
                phy_exit(priv_data->usb3_phy);
                return ret;
        }

        return 0;
}

static const struct dev_pm_ops dwc3_xlnx_dev_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(dwc3_xlnx_suspend, dwc3_xlnx_resume)
        SET_RUNTIME_PM_OPS(dwc3_xlnx_runtime_suspend,
                           dwc3_xlnx_runtime_resume, dwc3_xlnx_runtime_idle)
};

static struct platform_driver dwc3_xlnx_driver = {
        .probe          = dwc3_xlnx_probe,
        .remove         = dwc3_xlnx_remove,
        .shutdown       = dwc3_xlnx_remove,
        .driver         = {
                .name           = "dwc3-xilinx",
                .of_match_table = dwc3_xlnx_of_match,
                .pm             = &dwc3_xlnx_dev_pm_ops,
        },
};

module_platform_driver(dwc3_xlnx_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Xilinx DWC3 controller specific glue driver");
MODULE_AUTHOR("Manish Narani <manish.narani@xilinx.com>");
MODULE_AUTHOR("Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>");