// SPDX-License-Identifier: GPL-2.0+
/*
 * EHCI HCD (Host Controller Driver) for USB.
 *
 * Bus Glue for Xilinx EHCI core on the of_platform bus
 *
 * Copyright (c) 2009 Xilinx, Inc.
 *
 * Based on "ehci-ppc-of.c" by Valentine Barshak <vbarshak@ru.mvista.com>
 * and "ehci-ppc-soc.c" by Stefan Roese <sr@denx.de>
 * and "ohci-ppc-of.c" by Sylvain Munaut <tnt@246tNt.com>
 */

#include <linux/err.h>
#include <linux/signal.h>

#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>

/**
 * ehci_xilinx_port_handed_over - hand the port out if failed to enable it
 * @hcd:        Pointer to the usb_hcd device to which the host controller bound
 * @portnum:Port number to which the device is attached.
 *
 * This function is used as a place to tell the user that the Xilinx USB host
 * controller does support LS devices. And in an HS only configuration, it
 * does not support FS devices either. It is hoped that this can help a
 * confused user.
 *
 * There are cases when the host controller fails to enable the port due to,
 * for example, insufficient power that can be supplied to the device from
 * the USB bus. In those cases, the messages printed here are not helpful.
 *
 * Return: Always return 0
 */
static int ehci_xilinx_port_handed_over(struct usb_hcd *hcd, int portnum)
{
        dev_warn(hcd->self.controller, "port %d cannot be enabled\n", portnum);
        if (hcd->has_tt) {
                dev_warn(hcd->self.controller,
                        "Maybe you have connected a low speed device?\n");

                dev_warn(hcd->self.controller,
                        "We do not support low speed devices\n");
        } else {
                dev_warn(hcd->self.controller,
                        "Maybe your device is not a high speed device?\n");
                dev_warn(hcd->self.controller,
                        "The USB host controller does not support full speed nor low speed devices\n");
                dev_warn(hcd->self.controller,
                        "You can reconfigure the host controller to have full speed support\n");
        }

        return 0;
}


static const struct hc_driver ehci_xilinx_of_hc_driver = {
        .description            = hcd_name,
        .product_desc           = "OF EHCI",
        .hcd_priv_size          = sizeof(struct ehci_hcd),

        /*
         * generic hardware linkage
         */
        .irq                    = ehci_irq,
        .flags                  = HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,

        /*
         * basic lifecycle operations
         */
        .reset                  = ehci_setup,
        .start                  = ehci_run,
        .stop                   = ehci_stop,
        .shutdown               = ehci_shutdown,

        /*
         * managing i/o requests and associated device resources
         */
        .urb_enqueue            = ehci_urb_enqueue,
        .urb_dequeue            = ehci_urb_dequeue,
        .endpoint_disable       = ehci_endpoint_disable,
        .endpoint_reset         = ehci_endpoint_reset,

        /*
         * scheduling support
         */
        .get_frame_number       = ehci_get_frame,

        /*
         * root hub support
         */
        .hub_status_data        = ehci_hub_status_data,
        .hub_control            = ehci_hub_control,
#ifdef  CONFIG_PM
        .bus_suspend            = ehci_bus_suspend,
        .bus_resume             = ehci_bus_resume,
#endif
        .relinquish_port        = NULL,
        .port_handed_over       = ehci_xilinx_port_handed_over,

        .clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
};

/**
 * ehci_hcd_xilinx_of_probe - Probe method for the USB host controller
 * @op:         pointer to the platform_device bound to the host controller
 *
 * This function requests resources and sets up appropriate properties for the
 * host controller. Because the Xilinx USB host controller can be configured
 * as HS only or HS/FS only, it checks the configuration in the device tree
 * entry, and sets an appropriate value for hcd->has_tt.
 *
 * Return: zero on success, negative error code otherwise
 */
static int ehci_hcd_xilinx_of_probe(struct platform_device *op)
{
        struct device_node *dn = op->dev.of_node;
        struct usb_hcd *hcd;
        struct ehci_hcd *ehci;
        struct resource res;
        int irq;
        int rv;
        int *value;

        if (usb_disabled())
                return -ENODEV;

        dev_dbg(&op->dev, "initializing XILINX-OF USB Controller\n");

        rv = of_address_to_resource(dn, 0, &res);
        if (rv)
                return rv;

        hcd = usb_create_hcd(&ehci_xilinx_of_hc_driver, &op->dev,
                                "XILINX-OF USB");
        if (!hcd)
                return -ENOMEM;

        hcd->rsrc_start = res.start;
        hcd->rsrc_len = resource_size(&res);

        irq = irq_of_parse_and_map(dn, 0);
        if (!irq) {
                dev_err(&op->dev, "%s: irq_of_parse_and_map failed\n",
                        __FILE__);
                rv = -EBUSY;
                goto err_irq;
        }

        hcd->regs = devm_ioremap_resource(&op->dev, &res);
        if (IS_ERR(hcd->regs)) {
                rv = PTR_ERR(hcd->regs);
                goto err_irq;
        }

        ehci = hcd_to_ehci(hcd);

        /* This core always has big-endian register interface and uses
         * big-endian memory descriptors.
         */
        ehci->big_endian_mmio = 1;
        ehci->big_endian_desc = 1;

        /* Check whether the FS support option is selected in the hardware.
         */
        value = (int *)of_get_property(dn, "xlnx,support-usb-fs", NULL);
        if (value && (*value == 1)) {
                ehci_dbg(ehci, "USB host controller supports FS devices\n");
                hcd->has_tt = 1;
        } else {
                ehci_dbg(ehci,
                        "USB host controller is HS only\n");
                hcd->has_tt = 0;
        }

        /* Debug registers are at the first 0x100 region
         */
        ehci->caps = hcd->regs + 0x100;

        rv = usb_add_hcd(hcd, irq, 0);
        if (rv == 0) {
                device_wakeup_enable(hcd->self.controller);
                return 0;
        }

err_irq:
        usb_put_hcd(hcd);

        return rv;
}

/**
 * ehci_hcd_xilinx_of_remove - shutdown hcd and release resources
 * @op:         pointer to platform_device structure that is to be removed
 *
 * Remove the hcd structure, and release resources that has been requested
 * during probe.
 *
 * Return: Always return 0
 */
static void ehci_hcd_xilinx_of_remove(struct platform_device *op)
{
        struct usb_hcd *hcd = platform_get_drvdata(op);

        dev_dbg(&op->dev, "stopping XILINX-OF USB Controller\n");

        usb_remove_hcd(hcd);

        usb_put_hcd(hcd);
}

static const struct of_device_id ehci_hcd_xilinx_of_match[] = {
                {.compatible = "xlnx,xps-usb-host-1.00.a",},
        {},
};
MODULE_DEVICE_TABLE(of, ehci_hcd_xilinx_of_match);

static struct platform_driver ehci_hcd_xilinx_of_driver = {
        .probe          = ehci_hcd_xilinx_of_probe,
        .remove         = ehci_hcd_xilinx_of_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .driver = {
                .name = "xilinx-of-ehci",
                .of_match_table = ehci_hcd_xilinx_of_match,
        },
};