// SPDX-License-Identifier: GPL-2.0
/*
 * Cadence USBSSP PCI Glue driver.
 *
 * Copyright (C) 2019 Cadence.
 *
 * Author: Pawel Laszczak <pawell@cadence.com>
 *
 */

#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/pci.h>

#include "core.h"

struct cdnsp_wrap {
        struct platform_device *plat_dev;
        struct property_entry prop[3];
        struct resource dev_res[6];
        int devfn;
};

#define RES_IRQ_HOST_ID         0
#define RES_IRQ_PERIPHERAL_ID   1
#define RES_IRQ_OTG_ID          2
#define RES_HOST_ID             3
#define RES_DEV_ID              4
#define RES_DRD_ID              5
/* DRD PCI configuration - 64-bit addressing */
/* First PCI function */
#define PCI_BAR_HOST            0
#define PCI_BAR_DEV             2
/* Second PCI function */
#define PCI_BAR_OTG             0
/* Device only PCI configuration - 32-bit addressing */
/* First PCI function */
#define PCI_BAR_ONLY_DEV        1

#define PCI_DEV_FN_HOST_DEVICE  0
#define PCI_DEV_FN_OTG          1

#define PCI_DRIVER_NAME         "cdns-pci-usbssp"
#define PLAT_DRIVER_NAME        "cdns-usb3"

#define PCI_DEVICE_ID_CDNS_UDC_USBSSP   0x0400
#define CHICKEN_APB_TIMEOUT_VALUE       0x1C20

static struct pci_dev *cdnsp_get_second_fun(struct pci_dev *pdev)
{
        /*
         * Gets the second function.
         * Platform has two function. The first keeps resources for
         * Host/Device while the second keeps resources for DRD/OTG.
         */
        if (pdev->device == PCI_DEVICE_ID_CDNS_USBSSP)
                return pci_get_device(pdev->vendor, PCI_DEVICE_ID_CDNS_USBSS, NULL);
        if (pdev->device == PCI_DEVICE_ID_CDNS_USBSS)
                return pci_get_device(pdev->vendor, PCI_DEVICE_ID_CDNS_USBSSP, NULL);

        return NULL;
}

static int cdnsp_pci_probe(struct pci_dev *pdev,
                           const struct pci_device_id *id)
{
        struct platform_device_info plat_info;
        static struct cdns3_platform_data pdata;
        struct cdnsp_wrap *wrap;
        struct resource *res;
        struct pci_dev *func;
        bool no_drd = false;
        int ret = 0;

        /*
         * For GADGET/HOST PCI (devfn) function number is 0,
         * for OTG PCI (devfn) function number is 1.
         */
        if (!id || (pdev->devfn != PCI_DEV_FN_HOST_DEVICE &&
                    pdev->devfn != PCI_DEV_FN_OTG))
                return -EINVAL;

        if (pdev->device == PCI_DEVICE_ID_CDNS_UDC_USBSSP)
                no_drd = true;

        func = cdnsp_get_second_fun(pdev);
        if (!func && !no_drd)
                return -EINVAL;

        if ((func && func->class == PCI_CLASS_SERIAL_USB_XHCI) ||
            pdev->class == PCI_CLASS_SERIAL_USB_XHCI) {
                ret = -EINVAL;
                goto put_pci;
        }

        ret = pcim_enable_device(pdev);
        if (ret) {
                dev_err(&pdev->dev, "Enabling PCI device has failed %d\n", ret);
                goto put_pci;
        }

        pci_set_master(pdev);

        if (func && pci_is_enabled(func)) {
                wrap = pci_get_drvdata(func);
        } else {
                wrap = kzalloc_obj(*wrap);
                if (!wrap) {
                        ret = -ENOMEM;
                        goto put_pci;
                }
        }

        res = wrap->dev_res;

        if (pdev->devfn == PCI_DEV_FN_HOST_DEVICE) {
                int bar_dev = no_drd ? PCI_BAR_ONLY_DEV : PCI_BAR_DEV;

                /* Function 0: host(BAR_0) + device(BAR_2). */
                dev_dbg(&pdev->dev, "Initialize Device resources\n");
                res[RES_DEV_ID].start = pci_resource_start(pdev, bar_dev);
                res[RES_DEV_ID].end = pci_resource_end(pdev, bar_dev);
                res[RES_DEV_ID].name = "dev";
                res[RES_DEV_ID].flags = IORESOURCE_MEM;
                dev_dbg(&pdev->dev, "USBSSP-DEV physical base addr: %pa\n",
                        &res[RES_DEV_ID].start);

                res[RES_HOST_ID].start = pci_resource_start(pdev, PCI_BAR_HOST);
                res[RES_HOST_ID].end = pci_resource_end(pdev, PCI_BAR_HOST);
                res[RES_HOST_ID].name = "xhci";
                res[RES_HOST_ID].flags = IORESOURCE_MEM;
                dev_dbg(&pdev->dev, "USBSSP-XHCI physical base addr: %pa\n",
                        &res[RES_HOST_ID].start);

                /* Interrupt for XHCI */
                wrap->dev_res[RES_IRQ_HOST_ID].start = pdev->irq;
                wrap->dev_res[RES_IRQ_HOST_ID].name = "host";
                wrap->dev_res[RES_IRQ_HOST_ID].flags = IORESOURCE_IRQ;

                /* Interrupt for device. It's the same as for HOST. */
                wrap->dev_res[RES_IRQ_PERIPHERAL_ID].start = pdev->irq;
                wrap->dev_res[RES_IRQ_PERIPHERAL_ID].name = "peripheral";
                wrap->dev_res[RES_IRQ_PERIPHERAL_ID].flags = IORESOURCE_IRQ;
        } else {
                res[RES_DRD_ID].start = pci_resource_start(pdev, PCI_BAR_OTG);
                res[RES_DRD_ID].end = pci_resource_end(pdev, PCI_BAR_OTG);
                res[RES_DRD_ID].name = "otg";
                res[RES_DRD_ID].flags = IORESOURCE_MEM;
                dev_dbg(&pdev->dev, "CDNSP-DRD physical base addr: %pa\n",
                        &res[RES_DRD_ID].start);

                /* Interrupt for OTG/DRD. */
                wrap->dev_res[RES_IRQ_OTG_ID].start = pdev->irq;
                wrap->dev_res[RES_IRQ_OTG_ID].name = "otg";
                wrap->dev_res[RES_IRQ_OTG_ID].flags = IORESOURCE_IRQ;
        }

        if (no_drd || pci_is_enabled(func)) {
                u8 idx = 0;

                /* set up platform device info */
                pdata.override_apb_timeout = CHICKEN_APB_TIMEOUT_VALUE;

                if (no_drd) {
                        wrap->prop[idx++] = PROPERTY_ENTRY_STRING("compatible",
                                                                  "cdns,cdnsp");
                        wrap->prop[idx++] = PROPERTY_ENTRY_STRING("dr_mode", "peripheral");
                } else {
                        wrap->prop[idx++] = PROPERTY_ENTRY_STRING("dr_mode", "otg");
                        wrap->prop[idx++] = PROPERTY_ENTRY_BOOL("usb-role-switch");
                }

                memset(&plat_info, 0, sizeof(plat_info));
                plat_info.parent = &pdev->dev;
                plat_info.fwnode = pdev->dev.fwnode;
                plat_info.name = PLAT_DRIVER_NAME;
                plat_info.id = pdev->devfn;
                plat_info.res = wrap->dev_res;
                plat_info.num_res = ARRAY_SIZE(wrap->dev_res);
                plat_info.dma_mask = pdev->dma_mask;
                plat_info.data = &pdata;
                plat_info.size_data = sizeof(pdata);
                plat_info.properties = wrap->prop;
                wrap->devfn = pdev->devfn;
                /* register platform device */
                wrap->plat_dev = platform_device_register_full(&plat_info);
                if (IS_ERR(wrap->plat_dev)) {
                        ret = PTR_ERR(wrap->plat_dev);
                        kfree(wrap);
                        goto put_pci;
                }
        }

        pci_set_drvdata(pdev, wrap);
put_pci:
        pci_dev_put(func);
        return ret;
}

static void cdnsp_pci_remove(struct pci_dev *pdev)
{
        struct cdnsp_wrap *wrap;
        struct pci_dev *func;

        func = cdnsp_get_second_fun(pdev);
        wrap = pci_get_drvdata(pdev);

        if (wrap->devfn == pdev->devfn)
                platform_device_unregister(wrap->plat_dev);

        if (!func || !pci_is_enabled(func))
                kfree(wrap);

        pci_dev_put(func);
}

static const struct pci_device_id cdnsp_pci_ids[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_UDC_USBSSP),
          .class = PCI_CLASS_SERIAL_USB_DEVICE },
        { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_UDC_USBSSP),
          .class = PCI_CLASS_SERIAL_USB_CDNS },
        { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_USBSSP),
          .class = PCI_CLASS_SERIAL_USB_DEVICE },
        { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_USBSSP),
          .class = PCI_CLASS_SERIAL_USB_CDNS },
        { PCI_DEVICE(PCI_VENDOR_ID_CDNS, PCI_DEVICE_ID_CDNS_USBSS),
          .class = PCI_CLASS_SERIAL_USB_CDNS },
        { 0, }
};

static struct pci_driver cdnsp_pci_driver = {
        .name = PCI_DRIVER_NAME,
        .id_table = cdnsp_pci_ids,
        .probe = cdnsp_pci_probe,
        .remove = cdnsp_pci_remove,
};

module_pci_driver(cdnsp_pci_driver);
MODULE_DEVICE_TABLE(pci, cdnsp_pci_ids);

MODULE_ALIAS("pci:cdnsp");
MODULE_AUTHOR("Pawel Laszczak <pawell@cadence.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Cadence CDNSP PCI wrapper");