// SPDX-License-Identifier: GPL-1.0+
/*
 * EHCI HCD (Host Controller Driver) for USB.
 *
 * Bus Glue for PPC On-Chip EHCI driver on the of_platform bus
 * Tested on AMCC PPC 440EPx
 *
 * Valentine Barshak <vbarshak@ru.mvista.com>
 *
 * Based on "ehci-ppc-soc.c" by Stefan Roese <sr@denx.de>
 * and "ohci-ppc-of.c" by Sylvain Munaut <tnt@246tNt.com>
 *
 * This file is licenced under the GPL.
 */

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

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


static const struct hc_driver ehci_ppc_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        = ehci_relinquish_port,
        .port_handed_over       = ehci_port_handed_over,

        .clear_tt_buffer_complete       = ehci_clear_tt_buffer_complete,
};


/*
 * 440EPx Errata USBH_3
 * Fix: Enable Break Memory Transfer (BMT) in INSNREG3
 */
#define PPC440EPX_EHCI0_INSREG_BMT      (0x1 << 0)
static int
ppc44x_enable_bmt(struct device_node *dn)
{
        __iomem u32 *insreg_virt;

        insreg_virt = of_iomap(dn, 1);
        if (!insreg_virt)
                return  -EINVAL;

        out_be32(insreg_virt + 3, PPC440EPX_EHCI0_INSREG_BMT);

        iounmap(insreg_virt);
        return 0;
}


static int ehci_hcd_ppc_of_probe(struct platform_device *op)
{
        struct device_node *dn = op->dev.of_node;
        struct usb_hcd *hcd;
        struct ehci_hcd *ehci = NULL;
        struct resource res;
        int irq;
        int rv;

        struct device_node *np;

        if (usb_disabled())
                return -ENODEV;

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

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

        hcd = usb_create_hcd(&ehci_ppc_of_hc_driver, &op->dev, "PPC-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_ioremap;
        }

        ehci = hcd_to_ehci(hcd);
        np = of_find_compatible_node(NULL, NULL, "ibm,usb-ohci-440epx");
        if (np != NULL) {
                /* claim we really affected by usb23 erratum */
                if (!of_address_to_resource(np, 0, &res))
                        ehci->ohci_hcctrl_reg =
                                devm_ioremap(&op->dev,
                                             res.start + OHCI_HCCTRL_OFFSET,
                                             OHCI_HCCTRL_LEN);
                else
                        pr_debug("%s: no ohci offset in fdt\n", __FILE__);
                if (!ehci->ohci_hcctrl_reg) {
                        pr_debug("%s: ioremap for ohci hcctrl failed\n", __FILE__);
                } else {
                        ehci->has_amcc_usb23 = 1;
                }
                of_node_put(np);
        }

        if (of_property_read_bool(dn, "big-endian")) {
                ehci->big_endian_mmio = 1;
                ehci->big_endian_desc = 1;
        }
        if (of_property_read_bool(dn, "big-endian-regs"))
                ehci->big_endian_mmio = 1;
        if (of_property_read_bool(dn, "big-endian-desc"))
                ehci->big_endian_desc = 1;

        ehci->caps = hcd->regs;

        if (of_device_is_compatible(dn, "ibm,usb-ehci-440epx")) {
                rv = ppc44x_enable_bmt(dn);
                ehci_dbg(ehci, "Break Memory Transfer (BMT) is %senabled!\n",
                                rv ? "NOT ": "");
        }

        rv = usb_add_hcd(hcd, irq, 0);
        if (rv)
                goto err_ioremap;

        device_wakeup_enable(hcd->self.controller);
        return 0;

err_ioremap:
        irq_dispose_mapping(irq);
err_irq:
        usb_put_hcd(hcd);

        return rv;
}


static void ehci_hcd_ppc_of_remove(struct platform_device *op)
{
        struct usb_hcd *hcd = platform_get_drvdata(op);
        struct ehci_hcd *ehci = hcd_to_ehci(hcd);

        struct device_node *np;
        struct resource res;

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

        usb_remove_hcd(hcd);

        irq_dispose_mapping(hcd->irq);

        /* use request_mem_region to test if the ohci driver is loaded.  if so
         * ensure the ohci core is operational.
         */
        if (ehci->has_amcc_usb23) {
                np = of_find_compatible_node(NULL, NULL, "ibm,usb-ohci-440epx");
                if (np != NULL) {
                        if (!of_address_to_resource(np, 0, &res))
                                if (!request_mem_region(res.start,
                                                            0x4, hcd_name))
                                        set_ohci_hcfs(ehci, 1);
                                else
                                        release_mem_region(res.start, 0x4);
                        else
                                pr_debug("%s: no ohci offset in fdt\n", __FILE__);
                        of_node_put(np);
                }
        }
        usb_put_hcd(hcd);
}


static const struct of_device_id ehci_hcd_ppc_of_match[] = {
        {
                .compatible = "usb-ehci",
        },
        {},
};
MODULE_DEVICE_TABLE(of, ehci_hcd_ppc_of_match);


static struct platform_driver ehci_hcd_ppc_of_driver = {
        .probe          = ehci_hcd_ppc_of_probe,
        .remove         = ehci_hcd_ppc_of_remove,
        .shutdown       = usb_hcd_platform_shutdown,
        .driver = {
                .name = "ppc-of-ehci",
                .of_match_table = ehci_hcd_ppc_of_match,
        },
};