// SPDX-License-Identifier: GPL-1.0+
/*
 * Open Host Controller Interface (OHCI) driver for USB.
 *
 * Maintainer: Alan Stern <stern@rowland.harvard.edu>
 *
 * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
 * (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
 *
 * [ Initialisation is based on Linus'  ]
 * [ uhci code and gregs ohci fragments ]
 * [ (C) Copyright 1999 Linus Torvalds  ]
 * [ (C) Copyright 1999 Gregory P. Smith]
 *
 *
 * OHCI is the main "non-Intel/VIA" standard for USB 1.1 host controller
 * interfaces (though some non-x86 Intel chips use it).  It supports
 * smarter hardware than UHCI.  A download link for the spec available
 * through the https://www.usb.org website.
 *
 * This file is licenced under the GPL.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/usb.h>
#include <linux/usb/otg.h>
#include <linux/usb/hcd.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/workqueue.h>
#include <linux/debugfs.h>
#include <linux/genalloc.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <asm/unaligned.h>
#include <asm/byteorder.h>


#define DRIVER_AUTHOR "Roman Weissgaerber, David Brownell"
#define DRIVER_DESC "USB 1.1 'Open' Host Controller (OHCI) Driver"

/*-------------------------------------------------------------------------*/

/* For initializing controller (mask in an HCFS mode too) */
#define OHCI_CONTROL_INIT       OHCI_CTRL_CBSR
#define OHCI_INTR_INIT \
                (OHCI_INTR_MIE | OHCI_INTR_RHSC | OHCI_INTR_UE \
                | OHCI_INTR_RD | OHCI_INTR_WDH)

#ifdef __hppa__
/* On PA-RISC, PDC can leave IR set incorrectly; ignore it there. */
#define IR_DISABLE
#endif

#ifdef CONFIG_ARCH_OMAP
/* OMAP doesn't support IR (no SMM; not needed) */
#define IR_DISABLE
#endif

/*-------------------------------------------------------------------------*/

static const char       hcd_name [] = "ohci_hcd";

#define STATECHANGE_DELAY       msecs_to_jiffies(300)
#define IO_WATCHDOG_DELAY       msecs_to_jiffies(275)
#define IO_WATCHDOG_OFF         0xffffff00

#include "ohci.h"
#include "pci-quirks.h"

static void ohci_dump(struct ohci_hcd *ohci);
static void ohci_stop(struct usb_hcd *hcd);
static void io_watchdog_func(struct timer_list *t);

#include "ohci-hub.c"
#include "ohci-dbg.c"
#include "ohci-mem.c"
#include "ohci-q.c"


/*
 * On architectures with edge-triggered interrupts we must never return
 * IRQ_NONE.
 */
#if defined(CONFIG_SA1111)  /* ... or other edge-triggered systems */
#define IRQ_NOTMINE     IRQ_HANDLED
#else
#define IRQ_NOTMINE     IRQ_NONE
#endif


/* Some boards misreport power switching/overcurrent */
static bool distrust_firmware;
module_param (distrust_firmware, bool, 0);
MODULE_PARM_DESC (distrust_firmware,
        "true to distrust firmware power/overcurrent setup");

/* Some boards leave IR set wrongly, since they fail BIOS/SMM handshakes */
static bool no_handshake;
module_param (no_handshake, bool, 0);
MODULE_PARM_DESC (no_handshake, "true (not default) disables BIOS handshake");

/*-------------------------------------------------------------------------*/

static int number_of_tds(struct urb *urb)
{
        int                     len, i, num, this_sg_len;
        struct scatterlist      *sg;

        len = urb->transfer_buffer_length;
        i = urb->num_mapped_sgs;

        if (len > 0 && i > 0) {         /* Scatter-gather transfer */
                num = 0;
                sg = urb->sg;
                for (;;) {
                        this_sg_len = min_t(int, sg_dma_len(sg), len);
                        num += DIV_ROUND_UP(this_sg_len, 4096);
                        len -= this_sg_len;
                        if (--i <= 0 || len <= 0)
                                break;
                        sg = sg_next(sg);
                }

        } else {                        /* Non-SG transfer */
                /* one TD for every 4096 Bytes (could be up to 8K) */
                num = DIV_ROUND_UP(len, 4096);
        }
        return num;
}

/*
 * queue up an urb for anything except the root hub
 */
static int ohci_urb_enqueue (
        struct usb_hcd  *hcd,
        struct urb      *urb,
        gfp_t           mem_flags
) {
        struct ohci_hcd *ohci = hcd_to_ohci (hcd);
        struct ed       *ed;
        urb_priv_t      *urb_priv;
        unsigned int    pipe = urb->pipe;
        int             i, size = 0;
        unsigned long   flags;
        int             retval = 0;

        /* every endpoint has a ed, locate and maybe (re)initialize it */
        ed = ed_get(ohci, urb->ep, urb->dev, pipe, urb->interval);
        if (! ed)
                return -ENOMEM;

        /* for the private part of the URB we need the number of TDs (size) */
        switch (ed->type) {
                case PIPE_CONTROL:
                        /* td_submit_urb() doesn't yet handle these */
                        if (urb->transfer_buffer_length > 4096)
                                return -EMSGSIZE;

                        /* 1 TD for setup, 1 for ACK, plus ... */
                        size = 2;
                        fallthrough;
                // case PIPE_INTERRUPT:
                // case PIPE_BULK:
                default:
                        size += number_of_tds(urb);
                        /* maybe a zero-length packet to wrap it up */
                        if (size == 0)
                                size++;
                        else if ((urb->transfer_flags & URB_ZERO_PACKET) != 0
                                && (urb->transfer_buffer_length
                                        % usb_maxpacket (urb->dev, pipe,
                                                usb_pipeout (pipe))) == 0)
                                size++;
                        break;
                case PIPE_ISOCHRONOUS: /* number of packets from URB */
                        size = urb->number_of_packets;
                        break;
        }

        /* allocate the private part of the URB */
        urb_priv = kzalloc (sizeof (urb_priv_t) + size * sizeof (struct td *),
                        mem_flags);
        if (!urb_priv)
                return -ENOMEM;
        INIT_LIST_HEAD (&urb_priv->pending);
        urb_priv->length = size;
        urb_priv->ed = ed;

        /* allocate the TDs (deferring hash chain updates) */
        for (i = 0; i < size; i++) {
                urb_priv->td [i] = td_alloc (ohci, mem_flags);
                if (!urb_priv->td [i]) {
                        urb_priv->length = i;
                        urb_free_priv (ohci, urb_priv);
                        return -ENOMEM;
                }
        }

        spin_lock_irqsave (&ohci->lock, flags);

        /* don't submit to a dead HC */
        if (!HCD_HW_ACCESSIBLE(hcd)) {
                retval = -ENODEV;
                goto fail;
        }
        if (ohci->rh_state != OHCI_RH_RUNNING) {
                retval = -ENODEV;
                goto fail;
        }
        retval = usb_hcd_link_urb_to_ep(hcd, urb);
        if (retval)
                goto fail;

        /* schedule the ed if needed */
        if (ed->state == ED_IDLE) {
                retval = ed_schedule (ohci, ed);
                if (retval < 0) {
                        usb_hcd_unlink_urb_from_ep(hcd, urb);
                        goto fail;
                }

                /* Start up the I/O watchdog timer, if it's not running */
                if (ohci->prev_frame_no == IO_WATCHDOG_OFF &&
                                list_empty(&ohci->eds_in_use) &&
                                !(ohci->flags & OHCI_QUIRK_QEMU)) {
                        ohci->prev_frame_no = ohci_frame_no(ohci);
                        mod_timer(&ohci->io_watchdog,
                                        jiffies + IO_WATCHDOG_DELAY);
                }
                list_add(&ed->in_use_list, &ohci->eds_in_use);

                if (ed->type == PIPE_ISOCHRONOUS) {
                        u16     frame = ohci_frame_no(ohci);

                        /* delay a few frames before the first TD */
                        frame += max_t (u16, 8, ed->interval);
                        frame &= ~(ed->interval - 1);
                        frame |= ed->branch;
                        urb->start_frame = frame;
                        ed->last_iso = frame + ed->interval * (size - 1);
                }
        } else if (ed->type == PIPE_ISOCHRONOUS) {
                u16     next = ohci_frame_no(ohci) + 1;
                u16     frame = ed->last_iso + ed->interval;
                u16     length = ed->interval * (size - 1);

                /* Behind the scheduling threshold? */
                if (unlikely(tick_before(frame, next))) {

                        /* URB_ISO_ASAP: Round up to the first available slot */
                        if (urb->transfer_flags & URB_ISO_ASAP) {
                                frame += (next - frame + ed->interval - 1) &
                                                -ed->interval;

                        /*
                         * Not ASAP: Use the next slot in the stream,
                         * no matter what.
                         */
                        } else {
                                /*
                                 * Some OHCI hardware doesn't handle late TDs
                                 * correctly.  After retiring them it proceeds
                                 * to the next ED instead of the next TD.
                                 * Therefore we have to omit the late TDs
                                 * entirely.
                                 */
                                urb_priv->td_cnt = DIV_ROUND_UP(
                                                (u16) (next - frame),
                                                ed->interval);
                                if (urb_priv->td_cnt >= urb_priv->length) {
                                        ++urb_priv->td_cnt;     /* Mark it */
                                        ohci_dbg(ohci, "iso underrun %p (%u+%u < %u)\n",
                                                        urb, frame, length,
                                                        next);
                                }
                        }
                }
                urb->start_frame = frame;
                ed->last_iso = frame + length;
        }

        /* fill the TDs and link them to the ed; and
         * enable that part of the schedule, if needed
         * and update count of queued periodic urbs
         */
        urb->hcpriv = urb_priv;
        td_submit_urb (ohci, urb);

fail:
        if (retval)
                urb_free_priv (ohci, urb_priv);
        spin_unlock_irqrestore (&ohci->lock, flags);
        return retval;
}

/*
 * decouple the URB from the HC queues (TDs, urb_priv).
 * reporting is always done
 * asynchronously, and we might be dealing with an urb that's
 * partially transferred, or an ED with other urbs being unlinked.
 */
static int ohci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        unsigned long           flags;
        int                     rc;
        urb_priv_t              *urb_priv;

        spin_lock_irqsave (&ohci->lock, flags);
        rc = usb_hcd_check_unlink_urb(hcd, urb, status);
        if (rc == 0) {

                /* Unless an IRQ completed the unlink while it was being
                 * handed to us, flag it for unlink and giveback, and force
                 * some upcoming INTR_SF to call finish_unlinks()
                 */
                urb_priv = urb->hcpriv;
                if (urb_priv->ed->state == ED_OPER)
                        start_ed_unlink(ohci, urb_priv->ed);

                if (ohci->rh_state != OHCI_RH_RUNNING) {
                        /* With HC dead, we can clean up right away */
                        ohci_work(ohci);
                }
        }
        spin_unlock_irqrestore (&ohci->lock, flags);
        return rc;
}

/*-------------------------------------------------------------------------*/

/* frees config/altsetting state for endpoints,
 * including ED memory, dummy TD, and bulk/intr data toggle
 */

static void
ohci_endpoint_disable (struct usb_hcd *hcd, struct usb_host_endpoint *ep)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        unsigned long           flags;
        struct ed               *ed = ep->hcpriv;
        unsigned                limit = 1000;

        /* ASSERT:  any requests/urbs are being unlinked */
        /* ASSERT:  nobody can be submitting urbs for this any more */

        if (!ed)
                return;

rescan:
        spin_lock_irqsave (&ohci->lock, flags);

        if (ohci->rh_state != OHCI_RH_RUNNING) {
sanitize:
                ed->state = ED_IDLE;
                ohci_work(ohci);
        }

        switch (ed->state) {
        case ED_UNLINK:         /* wait for hw to finish? */
                /* major IRQ delivery trouble loses INTR_SF too... */
                if (limit-- == 0) {
                        ohci_warn(ohci, "ED unlink timeout\n");
                        goto sanitize;
                }
                spin_unlock_irqrestore (&ohci->lock, flags);
                schedule_timeout_uninterruptible(1);
                goto rescan;
        case ED_IDLE:           /* fully unlinked */
                if (list_empty (&ed->td_list)) {
                        td_free (ohci, ed->dummy);
                        ed_free (ohci, ed);
                        break;
                }
                fallthrough;
        default:
                /* caller was supposed to have unlinked any requests;
                 * that's not our job.  can't recover; must leak ed.
                 */
                ohci_err (ohci, "leak ed %p (#%02x) state %d%s\n",
                        ed, ep->desc.bEndpointAddress, ed->state,
                        list_empty (&ed->td_list) ? "" : " (has tds)");
                td_free (ohci, ed->dummy);
                break;
        }
        ep->hcpriv = NULL;
        spin_unlock_irqrestore (&ohci->lock, flags);
}

static int ohci_get_frame (struct usb_hcd *hcd)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);

        return ohci_frame_no(ohci);
}

static void ohci_usb_reset (struct ohci_hcd *ohci)
{
        ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
        ohci->hc_control &= OHCI_CTRL_RWC;
        ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
        ohci->rh_state = OHCI_RH_HALTED;
}

/* ohci_shutdown forcibly disables IRQs and DMA, helping kexec and
 * other cases where the next software may expect clean state from the
 * "firmware".  this is bus-neutral, unlike shutdown() methods.
 */
static void _ohci_shutdown(struct usb_hcd *hcd)
{
        struct ohci_hcd *ohci;

        ohci = hcd_to_ohci (hcd);
        ohci_writel(ohci, (u32) ~0, &ohci->regs->intrdisable);

        /* Software reset, after which the controller goes into SUSPEND */
        ohci_writel(ohci, OHCI_HCR, &ohci->regs->cmdstatus);
        ohci_readl(ohci, &ohci->regs->cmdstatus);       /* flush the writes */
        udelay(10);

        ohci_writel(ohci, ohci->fminterval, &ohci->regs->fminterval);
        ohci->rh_state = OHCI_RH_HALTED;
}

static void ohci_shutdown(struct usb_hcd *hcd)
{
        struct ohci_hcd *ohci = hcd_to_ohci(hcd);
        unsigned long flags;

        spin_lock_irqsave(&ohci->lock, flags);
        _ohci_shutdown(hcd);
        spin_unlock_irqrestore(&ohci->lock, flags);
}

/*-------------------------------------------------------------------------*
 * HC functions
 *-------------------------------------------------------------------------*/

/* init memory, and kick BIOS/SMM off */

static int ohci_init (struct ohci_hcd *ohci)
{
        int ret;
        struct usb_hcd *hcd = ohci_to_hcd(ohci);

        /* Accept arbitrarily long scatter-gather lists */
        if (!hcd->localmem_pool)
                hcd->self.sg_tablesize = ~0;

        if (distrust_firmware)
                ohci->flags |= OHCI_QUIRK_HUB_POWER;

        ohci->rh_state = OHCI_RH_HALTED;
        ohci->regs = hcd->regs;

        /* REVISIT this BIOS handshake is now moved into PCI "quirks", and
         * was never needed for most non-PCI systems ... remove the code?
         */

#ifndef IR_DISABLE
        /* SMM owns the HC?  not for long! */
        if (!no_handshake && ohci_readl (ohci,
                                        &ohci->regs->control) & OHCI_CTRL_IR) {
                u32 temp;

                ohci_dbg (ohci, "USB HC TakeOver from BIOS/SMM\n");

                /* this timeout is arbitrary.  we make it long, so systems
                 * depending on usb keyboards may be usable even if the
                 * BIOS/SMM code seems pretty broken.
                 */
                temp = 500;     /* arbitrary: five seconds */

                ohci_writel (ohci, OHCI_INTR_OC, &ohci->regs->intrenable);
                ohci_writel (ohci, OHCI_OCR, &ohci->regs->cmdstatus);
                while (ohci_readl (ohci, &ohci->regs->control) & OHCI_CTRL_IR) {
                        msleep (10);
                        if (--temp == 0) {
                                ohci_err (ohci, "USB HC takeover failed!"
                                        "  (BIOS/SMM bug)\n");
                                return -EBUSY;
                        }
                }
                ohci_usb_reset (ohci);
        }
#endif

        /* Disable HC interrupts */
        ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);

        /* flush the writes, and save key bits like RWC */
        if (ohci_readl (ohci, &ohci->regs->control) & OHCI_CTRL_RWC)
                ohci->hc_control |= OHCI_CTRL_RWC;

        /* Read the number of ports unless overridden */
        if (ohci->num_ports == 0)
                ohci->num_ports = roothub_a(ohci) & RH_A_NDP;

        if (ohci->hcca)
                return 0;

        timer_setup(&ohci->io_watchdog, io_watchdog_func, 0);
        ohci->prev_frame_no = IO_WATCHDOG_OFF;

        if (hcd->localmem_pool)
                ohci->hcca = gen_pool_dma_alloc_align(hcd->localmem_pool,
                                                sizeof(*ohci->hcca),
                                                &ohci->hcca_dma, 256);
        else
                ohci->hcca = dma_alloc_coherent(hcd->self.controller,
                                                sizeof(*ohci->hcca),
                                                &ohci->hcca_dma,
                                                GFP_KERNEL);
        if (!ohci->hcca)
                return -ENOMEM;

        if ((ret = ohci_mem_init (ohci)) < 0)
                ohci_stop (hcd);
        else {
                create_debug_files (ohci);
        }

        return ret;
}

/*-------------------------------------------------------------------------*/

/* Start an OHCI controller, set the BUS operational
 * resets USB and controller
 * enable interrupts
 */
static int ohci_run (struct ohci_hcd *ohci)
{
        u32                     mask, val;
        int                     first = ohci->fminterval == 0;
        struct usb_hcd          *hcd = ohci_to_hcd(ohci);

        ohci->rh_state = OHCI_RH_HALTED;

        /* boot firmware should have set this up (5.1.1.3.1) */
        if (first) {

                val = ohci_readl (ohci, &ohci->regs->fminterval);
                ohci->fminterval = val & 0x3fff;
                if (ohci->fminterval != FI)
                        ohci_dbg (ohci, "fminterval delta %d\n",
                                ohci->fminterval - FI);
                ohci->fminterval |= FSMP (ohci->fminterval) << 16;
                /* also: power/overcurrent flags in roothub.a */
        }

        /* Reset USB nearly "by the book".  RemoteWakeupConnected has
         * to be checked in case boot firmware (BIOS/SMM/...) has set up
         * wakeup in a way the bus isn't aware of (e.g., legacy PCI PM).
         * If the bus glue detected wakeup capability then it should
         * already be enabled; if so we'll just enable it again.
         */
        if ((ohci->hc_control & OHCI_CTRL_RWC) != 0)
                device_set_wakeup_capable(hcd->self.controller, 1);

        switch (ohci->hc_control & OHCI_CTRL_HCFS) {
        case OHCI_USB_OPER:
                val = 0;
                break;
        case OHCI_USB_SUSPEND:
        case OHCI_USB_RESUME:
                ohci->hc_control &= OHCI_CTRL_RWC;
                ohci->hc_control |= OHCI_USB_RESUME;
                val = 10 /* msec wait */;
                break;
        // case OHCI_USB_RESET:
        default:
                ohci->hc_control &= OHCI_CTRL_RWC;
                ohci->hc_control |= OHCI_USB_RESET;
                val = 50 /* msec wait */;
                break;
        }
        ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
        // flush the writes
        (void) ohci_readl (ohci, &ohci->regs->control);
        msleep(val);

        memset (ohci->hcca, 0, sizeof (struct ohci_hcca));

        /* 2msec timelimit here means no irqs/preempt */
        spin_lock_irq (&ohci->lock);

retry:
        /* HC Reset requires max 10 us delay */
        ohci_writel (ohci, OHCI_HCR,  &ohci->regs->cmdstatus);
        val = 30;       /* ... allow extra time */
        while ((ohci_readl (ohci, &ohci->regs->cmdstatus) & OHCI_HCR) != 0) {
                if (--val == 0) {
                        spin_unlock_irq (&ohci->lock);
                        ohci_err (ohci, "USB HC reset timed out!\n");
                        return -1;
                }
                udelay (1);
        }

        /* now we're in the SUSPEND state ... must go OPERATIONAL
         * within 2msec else HC enters RESUME
         *
         * ... but some hardware won't init fmInterval "by the book"
         * (SiS, OPTi ...), so reset again instead.  SiS doesn't need
         * this if we write fmInterval after we're OPERATIONAL.
         * Unclear about ALi, ServerWorks, and others ... this could
         * easily be a longstanding bug in chip init on Linux.
         */
        if (ohci->flags & OHCI_QUIRK_INITRESET) {
                ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
                // flush those writes
                (void) ohci_readl (ohci, &ohci->regs->control);
        }

        /* Tell the controller where the control and bulk lists are
         * The lists are empty now. */
        ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
        ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);

        /* a reset clears this */
        ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);

        periodic_reinit (ohci);

        /* some OHCI implementations are finicky about how they init.
         * bogus values here mean not even enumeration could work.
         */
        if ((ohci_readl (ohci, &ohci->regs->fminterval) & 0x3fff0000) == 0
                        || !ohci_readl (ohci, &ohci->regs->periodicstart)) {
                if (!(ohci->flags & OHCI_QUIRK_INITRESET)) {
                        ohci->flags |= OHCI_QUIRK_INITRESET;
                        ohci_dbg (ohci, "enabling initreset quirk\n");
                        goto retry;
                }
                spin_unlock_irq (&ohci->lock);
                ohci_err (ohci, "init err (%08x %04x)\n",
                        ohci_readl (ohci, &ohci->regs->fminterval),
                        ohci_readl (ohci, &ohci->regs->periodicstart));
                return -EOVERFLOW;
        }

        /* use rhsc irqs after hub_wq is allocated */
        set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
        hcd->uses_new_polling = 1;

        /* start controller operations */
        ohci->hc_control &= OHCI_CTRL_RWC;
        ohci->hc_control |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
        ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
        ohci->rh_state = OHCI_RH_RUNNING;

        /* wake on ConnectStatusChange, matching external hubs */
        ohci_writel (ohci, RH_HS_DRWE, &ohci->regs->roothub.status);

        /* Choose the interrupts we care about now, others later on demand */
        mask = OHCI_INTR_INIT;
        ohci_writel (ohci, ~0, &ohci->regs->intrstatus);
        ohci_writel (ohci, mask, &ohci->regs->intrenable);

        /* handle root hub init quirks ... */
        val = roothub_a (ohci);
        /* Configure for per-port over-current protection by default */
        val &= ~RH_A_NOCP;
        val |= RH_A_OCPM;
        if (ohci->flags & OHCI_QUIRK_SUPERIO) {
                /* NSC 87560 and maybe others.
                 * Ganged power switching, no over-current protection.
                 */
                val |= RH_A_NOCP;
                val &= ~(RH_A_POTPGT | RH_A_NPS | RH_A_PSM | RH_A_OCPM);
        } else if ((ohci->flags & OHCI_QUIRK_AMD756) ||
                        (ohci->flags & OHCI_QUIRK_HUB_POWER)) {
                /* hub power always on; required for AMD-756 and some
                 * Mac platforms.
                 */
                val |= RH_A_NPS;
        }
        ohci_writel(ohci, val, &ohci->regs->roothub.a);

        ohci_writel (ohci, RH_HS_LPSC, &ohci->regs->roothub.status);
        ohci_writel (ohci, (val & RH_A_NPS) ? 0 : RH_B_PPCM,
                                                &ohci->regs->roothub.b);
        // flush those writes
        (void) ohci_readl (ohci, &ohci->regs->control);

        ohci->next_statechange = jiffies + STATECHANGE_DELAY;
        spin_unlock_irq (&ohci->lock);

        // POTPGT delay is bits 24-31, in 2 ms units.
        mdelay ((val >> 23) & 0x1fe);

        ohci_dump(ohci);

        return 0;
}

/* ohci_setup routine for generic controller initialization */

int ohci_setup(struct usb_hcd *hcd)
{
        struct ohci_hcd         *ohci = hcd_to_ohci(hcd);

        ohci_hcd_init(ohci);
        
        return ohci_init(ohci);
}
EXPORT_SYMBOL_GPL(ohci_setup);

/* ohci_start routine for generic controller start of all OHCI bus glue */
static int ohci_start(struct usb_hcd *hcd)
{
        struct ohci_hcd         *ohci = hcd_to_ohci(hcd);
        int     ret;

        ret = ohci_run(ohci);
        if (ret < 0) {
                ohci_err(ohci, "can't start\n");
                ohci_stop(hcd);
        }
        return ret;
}

/*-------------------------------------------------------------------------*/

/*
 * Some OHCI controllers are known to lose track of completed TDs.  They
 * don't add the TDs to the hardware done queue, which means we never see
 * them as being completed.
 *
 * This watchdog routine checks for such problems.  Without some way to
 * tell when those TDs have completed, we would never take their EDs off
 * the unlink list.  As a result, URBs could never be dequeued and
 * endpoints could never be released.
 */
static void io_watchdog_func(struct timer_list *t)
{
        struct ohci_hcd *ohci = from_timer(ohci, t, io_watchdog);
        bool            takeback_all_pending = false;
        u32             status;
        u32             head;
        struct ed       *ed;
        struct td       *td, *td_start, *td_next;
        unsigned        frame_no, prev_frame_no = IO_WATCHDOG_OFF;
        unsigned long   flags;

        spin_lock_irqsave(&ohci->lock, flags);

        /*
         * One way to lose track of completed TDs is if the controller
         * never writes back the done queue head.  If it hasn't been
         * written back since the last time this function ran and if it
         * was non-empty at that time, something is badly wrong with the
         * hardware.
         */
        status = ohci_readl(ohci, &ohci->regs->intrstatus);
        if (!(status & OHCI_INTR_WDH) && ohci->wdh_cnt == ohci->prev_wdh_cnt) {
                if (ohci->prev_donehead) {
                        ohci_err(ohci, "HcDoneHead not written back; disabled\n");
 died:
                        usb_hc_died(ohci_to_hcd(ohci));
                        ohci_dump(ohci);
                        _ohci_shutdown(ohci_to_hcd(ohci));
                        goto done;
                } else {
                        /* No write back because the done queue was empty */
                        takeback_all_pending = true;
                }
        }

        /* Check every ED which might have pending TDs */
        list_for_each_entry(ed, &ohci->eds_in_use, in_use_list) {
                if (ed->pending_td) {
                        if (takeback_all_pending ||
                                        OKAY_TO_TAKEBACK(ohci, ed)) {
                                unsigned tmp = hc32_to_cpu(ohci, ed->hwINFO);

                                ohci_dbg(ohci, "takeback pending TD for dev %d ep 0x%x\n",
                                                0x007f & tmp,
                                                (0x000f & (tmp >> 7)) +
                                                        ((tmp & ED_IN) >> 5));
                                add_to_done_list(ohci, ed->pending_td);
                        }
                }

                /* Starting from the latest pending TD, */
                td = ed->pending_td;

                /* or the last TD on the done list, */
                if (!td) {
                        list_for_each_entry(td_next, &ed->td_list, td_list) {
                                if (!td_next->next_dl_td)
                                        break;
                                td = td_next;
                        }
                }

                /* find the last TD processed by the controller. */
                head = hc32_to_cpu(ohci, READ_ONCE(ed->hwHeadP)) & TD_MASK;
                td_start = td;
                td_next = list_prepare_entry(td, &ed->td_list, td_list);
                list_for_each_entry_continue(td_next, &ed->td_list, td_list) {
                        if (head == (u32) td_next->td_dma)
                                break;
                        td = td_next;   /* head pointer has passed this TD */
                }
                if (td != td_start) {
                        /*
                         * In case a WDH cycle is in progress, we will wait
                         * for the next two cycles to complete before assuming
                         * this TD will never get on the done queue.
                         */
                        ed->takeback_wdh_cnt = ohci->wdh_cnt + 2;
                        ed->pending_td = td;
                }
        }

        ohci_work(ohci);

        if (ohci->rh_state == OHCI_RH_RUNNING) {

                /*
                 * Sometimes a controller just stops working.  We can tell
                 * by checking that the frame counter has advanced since
                 * the last time we ran.
                 *
                 * But be careful: Some controllers violate the spec by
                 * stopping their frame counter when no ports are active.
                 */
                frame_no = ohci_frame_no(ohci);
                if (frame_no == ohci->prev_frame_no) {
                        int             active_cnt = 0;
                        int             i;
                        unsigned        tmp;

                        for (i = 0; i < ohci->num_ports; ++i) {
                                tmp = roothub_portstatus(ohci, i);
                                /* Enabled and not suspended? */
                                if ((tmp & RH_PS_PES) && !(tmp & RH_PS_PSS))
                                        ++active_cnt;
                        }

                        if (active_cnt > 0) {
                                ohci_err(ohci, "frame counter not updating; disabled\n");
                                goto died;
                        }
                }
                if (!list_empty(&ohci->eds_in_use)) {
                        prev_frame_no = frame_no;
                        ohci->prev_wdh_cnt = ohci->wdh_cnt;
                        ohci->prev_donehead = ohci_readl(ohci,
                                        &ohci->regs->donehead);
                        mod_timer(&ohci->io_watchdog,
                                        jiffies + IO_WATCHDOG_DELAY);
                }
        }

 done:
        ohci->prev_frame_no = prev_frame_no;
        spin_unlock_irqrestore(&ohci->lock, flags);
}

/* an interrupt happens */

static irqreturn_t ohci_irq (struct usb_hcd *hcd)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
        struct ohci_regs __iomem *regs = ohci->regs;
        int                     ints;

        /* Read interrupt status (and flush pending writes).  We ignore the
         * optimization of checking the LSB of hcca->done_head; it doesn't
         * work on all systems (edge triggering for OHCI can be a factor).
         */
        ints = ohci_readl(ohci, &regs->intrstatus);

        /* Check for an all 1's result which is a typical consequence
         * of dead, unclocked, or unplugged (CardBus...) devices
         */
        if (ints == ~(u32)0) {
                ohci->rh_state = OHCI_RH_HALTED;
                ohci_dbg (ohci, "device removed!\n");
                usb_hc_died(hcd);
                return IRQ_HANDLED;
        }

        /* We only care about interrupts that are enabled */
        ints &= ohci_readl(ohci, &regs->intrenable);

        /* interrupt for some other device? */
        if (ints == 0 || unlikely(ohci->rh_state == OHCI_RH_HALTED))
                return IRQ_NOTMINE;

        if (ints & OHCI_INTR_UE) {
                // e.g. due to PCI Master/Target Abort
                if (quirk_nec(ohci)) {
                        /* Workaround for a silicon bug in some NEC chips used
                         * in Apple's PowerBooks. Adapted from Darwin code.
                         */
                        ohci_err (ohci, "OHCI Unrecoverable Error, scheduling NEC chip restart\n");

                        ohci_writel (ohci, OHCI_INTR_UE, &regs->intrdisable);

                        schedule_work (&ohci->nec_work);
                } else {
                        ohci_err (ohci, "OHCI Unrecoverable Error, disabled\n");
                        ohci->rh_state = OHCI_RH_HALTED;
                        usb_hc_died(hcd);
                }

                ohci_dump(ohci);
                ohci_usb_reset (ohci);
        }

        if (ints & OHCI_INTR_RHSC) {
                ohci_dbg(ohci, "rhsc\n");
                ohci->next_statechange = jiffies + STATECHANGE_DELAY;
                ohci_writel(ohci, OHCI_INTR_RD | OHCI_INTR_RHSC,
                                &regs->intrstatus);

                /* NOTE: Vendors didn't always make the same implementation
                 * choices for RHSC.  Many followed the spec; RHSC triggers
                 * on an edge, like setting and maybe clearing a port status
                 * change bit.  With others it's level-triggered, active
                 * until hub_wq clears all the port status change bits.  We'll
                 * always disable it here and rely on polling until hub_wq
                 * re-enables it.
                 */
                ohci_writel(ohci, OHCI_INTR_RHSC, &regs->intrdisable);
                usb_hcd_poll_rh_status(hcd);
        }

        /* For connect and disconnect events, we expect the controller
         * to turn on RHSC along with RD.  But for remote wakeup events
         * this might not happen.
         */
        else if (ints & OHCI_INTR_RD) {
                ohci_dbg(ohci, "resume detect\n");
                ohci_writel(ohci, OHCI_INTR_RD, &regs->intrstatus);
                set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
                if (ohci->autostop) {
                        spin_lock (&ohci->lock);
                        ohci_rh_resume (ohci);
                        spin_unlock (&ohci->lock);
                } else
                        usb_hcd_resume_root_hub(hcd);
        }

        spin_lock(&ohci->lock);
        if (ints & OHCI_INTR_WDH)
                update_done_list(ohci);

        /* could track INTR_SO to reduce available PCI/... bandwidth */

        /* handle any pending URB/ED unlinks, leaving INTR_SF enabled
         * when there's still unlinking to be done (next frame).
         */
        ohci_work(ohci);
        if ((ints & OHCI_INTR_SF) != 0 && !ohci->ed_rm_list
                        && ohci->rh_state == OHCI_RH_RUNNING)
                ohci_writel (ohci, OHCI_INTR_SF, &regs->intrdisable);

        if (ohci->rh_state == OHCI_RH_RUNNING) {
                ohci_writel (ohci, ints, &regs->intrstatus);
                if (ints & OHCI_INTR_WDH)
                        ++ohci->wdh_cnt;

                ohci_writel (ohci, OHCI_INTR_MIE, &regs->intrenable);
                // flush those writes
                (void) ohci_readl (ohci, &ohci->regs->control);
        }
        spin_unlock(&ohci->lock);

        return IRQ_HANDLED;
}

/*-------------------------------------------------------------------------*/

static void ohci_stop (struct usb_hcd *hcd)
{
        struct ohci_hcd         *ohci = hcd_to_ohci (hcd);

        ohci_dump(ohci);

        if (quirk_nec(ohci))
                flush_work(&ohci->nec_work);
        del_timer_sync(&ohci->io_watchdog);

        ohci->prev_frame_no = IO_WATCHDOG_OFF;

        ohci_writel (ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
        ohci_usb_reset(ohci);
        free_irq(hcd->irq, hcd);
        hcd->irq = 0;

        if (quirk_amdiso(ohci))
                usb_amd_dev_put();

        remove_debug_files (ohci);
        ohci_mem_cleanup (ohci);
        if (ohci->hcca) {
                if (hcd->localmem_pool)
                        gen_pool_free(hcd->localmem_pool,
                                      (unsigned long)ohci->hcca,
                                      sizeof(*ohci->hcca));
                else
                        dma_free_coherent(hcd->self.controller,
                                          sizeof(*ohci->hcca),
                                          ohci->hcca, ohci->hcca_dma);
                ohci->hcca = NULL;
                ohci->hcca_dma = 0;
        }
}

/*-------------------------------------------------------------------------*/

#if defined(CONFIG_PM) || defined(CONFIG_USB_PCI)

/* must not be called from interrupt context */
int ohci_restart(struct ohci_hcd *ohci)
{
        int temp;
        int i;
        struct urb_priv *priv;

        ohci_init(ohci);
        spin_lock_irq(&ohci->lock);
        ohci->rh_state = OHCI_RH_HALTED;

        /* Recycle any "live" eds/tds (and urbs). */
        if (!list_empty (&ohci->pending))
                ohci_dbg(ohci, "abort schedule...\n");
        list_for_each_entry (priv, &ohci->pending, pending) {
                struct urb      *urb = priv->td[0]->urb;
                struct ed       *ed = priv->ed;

                switch (ed->state) {
                case ED_OPER:
                        ed->state = ED_UNLINK;
                        ed->hwINFO |= cpu_to_hc32(ohci, ED_DEQUEUE);
                        ed_deschedule (ohci, ed);

                        ed->ed_next = ohci->ed_rm_list;
                        ed->ed_prev = NULL;
                        ohci->ed_rm_list = ed;
                        fallthrough;
                case ED_UNLINK:
                        break;
                default:
                        ohci_dbg(ohci, "bogus ed %p state %d\n",
                                        ed, ed->state);
                }

                if (!urb->unlinked)
                        urb->unlinked = -ESHUTDOWN;
        }
        ohci_work(ohci);
        spin_unlock_irq(&ohci->lock);

        /* paranoia, in case that didn't work: */

        /* empty the interrupt branches */
        for (i = 0; i < NUM_INTS; i++) ohci->load [i] = 0;
        for (i = 0; i < NUM_INTS; i++) ohci->hcca->int_table [i] = 0;

        /* no EDs to remove */
        ohci->ed_rm_list = NULL;

        /* empty control and bulk lists */
        ohci->ed_controltail = NULL;
        ohci->ed_bulktail    = NULL;

        if ((temp = ohci_run (ohci)) < 0) {
                ohci_err (ohci, "can't restart, %d\n", temp);
                return temp;
        }
        ohci_dbg(ohci, "restart complete\n");
        return 0;
}
EXPORT_SYMBOL_GPL(ohci_restart);

#endif

#ifdef CONFIG_PM

int ohci_suspend(struct usb_hcd *hcd, bool do_wakeup)
{
        struct ohci_hcd *ohci = hcd_to_ohci (hcd);
        unsigned long   flags;
        int             rc = 0;

        /* Disable irq emission and mark HW unaccessible. Use
         * the spinlock to properly synchronize with possible pending
         * RH suspend or resume activity.
         */
        spin_lock_irqsave (&ohci->lock, flags);
        ohci_writel(ohci, OHCI_INTR_MIE, &ohci->regs->intrdisable);
        (void)ohci_readl(ohci, &ohci->regs->intrdisable);

        clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
        spin_unlock_irqrestore (&ohci->lock, flags);

        synchronize_irq(hcd->irq);

        if (do_wakeup && HCD_WAKEUP_PENDING(hcd)) {
                ohci_resume(hcd, false);
                rc = -EBUSY;
        }
        return rc;
}
EXPORT_SYMBOL_GPL(ohci_suspend);


int ohci_resume(struct usb_hcd *hcd, bool hibernated)
{
        struct ohci_hcd         *ohci = hcd_to_ohci(hcd);
        int                     port;
        bool                    need_reinit = false;

        set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);

        /* Make sure resume from hibernation re-enumerates everything */
        if (hibernated)
                ohci_usb_reset(ohci);

        /* See if the controller is already running or has been reset */
        ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
        if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
                need_reinit = true;
        } else {
                switch (ohci->hc_control & OHCI_CTRL_HCFS) {
                case OHCI_USB_OPER:
                case OHCI_USB_RESET:
                        need_reinit = true;
                }
        }

        /* If needed, reinitialize and suspend the root hub */
        if (need_reinit) {
                spin_lock_irq(&ohci->lock);
                ohci_rh_resume(ohci);
                ohci_rh_suspend(ohci, 0);
                spin_unlock_irq(&ohci->lock);
        }

        /* Normally just turn on port power and enable interrupts */
        else {
                ohci_dbg(ohci, "powerup ports\n");
                for (port = 0; port < ohci->num_ports; port++)
                        ohci_writel(ohci, RH_PS_PPS,
                                        &ohci->regs->roothub.portstatus[port]);

                ohci_writel(ohci, OHCI_INTR_MIE, &ohci->regs->intrenable);
                ohci_readl(ohci, &ohci->regs->intrenable);
                msleep(20);
        }

        usb_hcd_resume_root_hub(hcd);

        return 0;
}
EXPORT_SYMBOL_GPL(ohci_resume);

#endif

/*-------------------------------------------------------------------------*/

/*
 * Generic structure: This gets copied for platform drivers so that
 * individual entries can be overridden as needed.
 */

static const struct hc_driver ohci_hc_driver = {
        .description =          hcd_name,
        .product_desc =         "OHCI Host Controller",
        .hcd_priv_size =        sizeof(struct ohci_hcd),

        /*
         * generic hardware linkage
        */
        .irq =                  ohci_irq,
        .flags =                HCD_MEMORY | HCD_DMA | HCD_USB11,

        /*
        * basic lifecycle operations
        */
        .reset =                ohci_setup,
        .start =                ohci_start,
        .stop =                 ohci_stop,
        .shutdown =             ohci_shutdown,

        /*
         * managing i/o requests and associated device resources
        */
        .urb_enqueue =          ohci_urb_enqueue,
        .urb_dequeue =          ohci_urb_dequeue,
        .endpoint_disable =     ohci_endpoint_disable,

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

        /*
        * root hub support
        */
        .hub_status_data =      ohci_hub_status_data,
        .hub_control =          ohci_hub_control,
#ifdef CONFIG_PM
        .bus_suspend =          ohci_bus_suspend,
        .bus_resume =           ohci_bus_resume,
#endif
        .start_port_reset =     ohci_start_port_reset,
};

void ohci_init_driver(struct hc_driver *drv,
                const struct ohci_driver_overrides *over)
{
        /* Copy the generic table to drv and then apply the overrides */
        *drv = ohci_hc_driver;

        if (over) {
                drv->product_desc = over->product_desc;
                drv->hcd_priv_size += over->extra_priv_size;
                if (over->reset)
                        drv->reset = over->reset;
        }
}
EXPORT_SYMBOL_GPL(ohci_init_driver);

/*-------------------------------------------------------------------------*/

MODULE_AUTHOR (DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE ("GPL");

#if defined(CONFIG_ARCH_SA1100) && defined(CONFIG_SA1111)
#include "ohci-sa1111.c"
#define SA1111_DRIVER           ohci_hcd_sa1111_driver
#endif

#ifdef CONFIG_USB_OHCI_HCD_PPC_OF
#include "ohci-ppc-of.c"
#define OF_PLATFORM_DRIVER      ohci_hcd_ppc_of_driver
#endif

#ifdef CONFIG_PPC_PS3
#include "ohci-ps3.c"
#define PS3_SYSTEM_BUS_DRIVER   ps3_ohci_driver
#endif

#ifdef CONFIG_MFD_SM501
#include "ohci-sm501.c"
#define SM501_OHCI_DRIVER       ohci_hcd_sm501_driver
#endif

#ifdef CONFIG_MFD_TC6393XB
#include "ohci-tmio.c"
#define TMIO_OHCI_DRIVER        ohci_hcd_tmio_driver
#endif

static int __init ohci_hcd_mod_init(void)
{
        int retval = 0;

        if (usb_disabled())
                return -ENODEV;

        printk(KERN_INFO "%s: " DRIVER_DESC "\n", hcd_name);
        pr_debug ("%s: block sizes: ed %zd td %zd\n", hcd_name,
                sizeof (struct ed), sizeof (struct td));
        set_bit(USB_OHCI_LOADED, &usb_hcds_loaded);

        ohci_debug_root = debugfs_create_dir("ohci", usb_debug_root);

#ifdef PS3_SYSTEM_BUS_DRIVER
        retval = ps3_ohci_driver_register(&PS3_SYSTEM_BUS_DRIVER);
        if (retval < 0)
                goto error_ps3;
#endif

#ifdef OF_PLATFORM_DRIVER
        retval = platform_driver_register(&OF_PLATFORM_DRIVER);
        if (retval < 0)
                goto error_of_platform;
#endif

#ifdef SA1111_DRIVER
        retval = sa1111_driver_register(&SA1111_DRIVER);
        if (retval < 0)
                goto error_sa1111;
#endif

#ifdef SM501_OHCI_DRIVER
        retval = platform_driver_register(&SM501_OHCI_DRIVER);
        if (retval < 0)
                goto error_sm501;
#endif

#ifdef TMIO_OHCI_DRIVER
        retval = platform_driver_register(&TMIO_OHCI_DRIVER);
        if (retval < 0)
                goto error_tmio;
#endif

        return retval;

        /* Error path */
#ifdef TMIO_OHCI_DRIVER
        platform_driver_unregister(&TMIO_OHCI_DRIVER);
 error_tmio:
#endif
#ifdef SM501_OHCI_DRIVER
        platform_driver_unregister(&SM501_OHCI_DRIVER);
 error_sm501:
#endif
#ifdef SA1111_DRIVER
        sa1111_driver_unregister(&SA1111_DRIVER);
 error_sa1111:
#endif
#ifdef OF_PLATFORM_DRIVER
        platform_driver_unregister(&OF_PLATFORM_DRIVER);
 error_of_platform:
#endif
#ifdef PS3_SYSTEM_BUS_DRIVER
        ps3_ohci_driver_unregister(&PS3_SYSTEM_BUS_DRIVER);
 error_ps3:
#endif
        debugfs_remove(ohci_debug_root);
        ohci_debug_root = NULL;

        clear_bit(USB_OHCI_LOADED, &usb_hcds_loaded);
        return retval;
}
module_init(ohci_hcd_mod_init);

static void __exit ohci_hcd_mod_exit(void)
{
#ifdef TMIO_OHCI_DRIVER
        platform_driver_unregister(&TMIO_OHCI_DRIVER);
#endif
#ifdef SM501_OHCI_DRIVER
        platform_driver_unregister(&SM501_OHCI_DRIVER);
#endif
#ifdef SA1111_DRIVER
        sa1111_driver_unregister(&SA1111_DRIVER);
#endif
#ifdef OF_PLATFORM_DRIVER
        platform_driver_unregister(&OF_PLATFORM_DRIVER);
#endif
#ifdef PS3_SYSTEM_BUS_DRIVER
        ps3_ohci_driver_unregister(&PS3_SYSTEM_BUS_DRIVER);
#endif
        debugfs_remove(ohci_debug_root);
        clear_bit(USB_OHCI_LOADED, &usb_hcds_loaded);
}
module_exit(ohci_hcd_mod_exit);