// SPDX-License-Identifier: GPL-1.0+
/*
 * OHCI HCD (Host Controller Driver) for USB.
 *
 * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
 * (C) Copyright 2000-2004 David Brownell <dbrownell@users.sourceforge.net>
 *
 * This file is licenced under GPL
 */

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

/*
 * OHCI Root Hub ... the nonsharable stuff
 */

#define dbg_port(hc,label,num,value) \
        ohci_dbg (hc, \
                "%s roothub.portstatus [%d] " \
                "= 0x%08x%s%s%s%s%s%s%s%s%s%s%s%s\n", \
                label, num, value, \
                (value & RH_PS_PRSC) ? " PRSC" : "", \
                (value & RH_PS_OCIC) ? " OCIC" : "", \
                (value & RH_PS_PSSC) ? " PSSC" : "", \
                (value & RH_PS_PESC) ? " PESC" : "", \
                (value & RH_PS_CSC) ? " CSC" : "", \
                \
                (value & RH_PS_LSDA) ? " LSDA" : "", \
                (value & RH_PS_PPS) ? " PPS" : "", \
                (value & RH_PS_PRS) ? " PRS" : "", \
                (value & RH_PS_POCI) ? " POCI" : "", \
                (value & RH_PS_PSS) ? " PSS" : "", \
                \
                (value & RH_PS_PES) ? " PES" : "", \
                (value & RH_PS_CCS) ? " CCS" : "" \
                );

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

#define OHCI_SCHED_ENABLES \
        (OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)

static void update_done_list(struct ohci_hcd *);
static void ohci_work(struct ohci_hcd *);

#ifdef  CONFIG_PM
static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
__releases(ohci->lock)
__acquires(ohci->lock)
{
        int                     status = 0;

        ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
        switch (ohci->hc_control & OHCI_CTRL_HCFS) {
        case OHCI_USB_RESUME:
                ohci_dbg (ohci, "resume/suspend?\n");
                ohci->hc_control &= ~OHCI_CTRL_HCFS;
                ohci->hc_control |= OHCI_USB_RESET;
                ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
                (void) ohci_readl (ohci, &ohci->regs->control);
                fallthrough;
        case OHCI_USB_RESET:
                status = -EBUSY;
                ohci_dbg (ohci, "needs reinit!\n");
                goto done;
        case OHCI_USB_SUSPEND:
                if (!ohci->autostop) {
                        ohci_dbg (ohci, "already suspended\n");
                        goto done;
                }
        }
        ohci_dbg (ohci, "%s root hub\n",
                        autostop ? "auto-stop" : "suspend");

        /* First stop any processing */
        if (!autostop && (ohci->hc_control & OHCI_SCHED_ENABLES)) {
                ohci->hc_control &= ~OHCI_SCHED_ENABLES;
                ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
                ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
                ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrstatus);

                /* sched disables take effect on the next frame,
                 * then the last WDH could take 6+ msec
                 */
                ohci_dbg (ohci, "stopping schedules ...\n");
                ohci->autostop = 0;
                spin_unlock_irq (&ohci->lock);
                msleep (8);
                spin_lock_irq (&ohci->lock);
        }
        update_done_list(ohci);
        ohci_work(ohci);

        /*
         * Some controllers don't handle "global" suspend properly if
         * there are unsuspended ports.  For these controllers, put all
         * the enabled ports into suspend before suspending the root hub.
         */
        if (ohci->flags & OHCI_QUIRK_GLOBAL_SUSPEND) {
                __hc32 __iomem  *portstat = ohci->regs->roothub.portstatus;
                int             i;
                unsigned        temp;

                for (i = 0; i < ohci->num_ports; (++i, ++portstat)) {
                        temp = ohci_readl(ohci, portstat);
                        if ((temp & (RH_PS_PES | RH_PS_PSS)) ==
                                        RH_PS_PES)
                                ohci_writel(ohci, RH_PS_PSS, portstat);
                }
        }

        /* maybe resume can wake root hub */
        if (ohci_to_hcd(ohci)->self.root_hub->do_remote_wakeup || autostop) {
                ohci->hc_control |= OHCI_CTRL_RWE;
        } else {
                ohci_writel(ohci, OHCI_INTR_RHSC | OHCI_INTR_RD,
                                &ohci->regs->intrdisable);
                ohci->hc_control &= ~OHCI_CTRL_RWE;
        }

        /* Suspend hub ... this is the "global (to this bus) suspend" mode,
         * which doesn't imply ports will first be individually suspended.
         */
        ohci->hc_control &= ~OHCI_CTRL_HCFS;
        ohci->hc_control |= OHCI_USB_SUSPEND;
        ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
        (void) ohci_readl (ohci, &ohci->regs->control);

        /* no resumes until devices finish suspending */
        if (!autostop) {
                ohci->next_statechange = jiffies + msecs_to_jiffies (5);
                ohci->autostop = 0;
                ohci->rh_state = OHCI_RH_SUSPENDED;
        }

done:
        return status;
}

static inline struct ed *find_head (struct ed *ed)
{
        /* for bulk and control lists */
        while (ed->ed_prev)
                ed = ed->ed_prev;
        return ed;
}

/* caller has locked the root hub */
static int ohci_rh_resume (struct ohci_hcd *ohci)
__releases(ohci->lock)
__acquires(ohci->lock)
{
        struct usb_hcd          *hcd = ohci_to_hcd (ohci);
        u32                     temp, enables;
        int                     status = -EINPROGRESS;
        int                     autostopped = ohci->autostop;

        ohci->autostop = 0;
        ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);

        if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
                /* this can happen after resuming a swsusp snapshot */
                if (ohci->rh_state != OHCI_RH_RUNNING) {
                        ohci_dbg (ohci, "BIOS/SMM active, control %03x\n",
                                        ohci->hc_control);
                        status = -EBUSY;
                /* this happens when pmcore resumes HC then root */
                } else {
                        ohci_dbg (ohci, "duplicate resume\n");
                        status = 0;
                }
        } else switch (ohci->hc_control & OHCI_CTRL_HCFS) {
        case OHCI_USB_SUSPEND:
                ohci->hc_control &= ~(OHCI_CTRL_HCFS|OHCI_SCHED_ENABLES);
                ohci->hc_control |= OHCI_USB_RESUME;
                ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
                (void) ohci_readl (ohci, &ohci->regs->control);
                ohci_dbg (ohci, "%s root hub\n",
                                autostopped ? "auto-start" : "resume");
                break;
        case OHCI_USB_RESUME:
                /* HCFS changes sometime after INTR_RD */
                ohci_dbg(ohci, "%swakeup root hub\n",
                                autostopped ? "auto-" : "");
                break;
        case OHCI_USB_OPER:
                /* this can happen after resuming a swsusp snapshot */
                ohci_dbg (ohci, "snapshot resume? reinit\n");
                status = -EBUSY;
                break;
        default:                /* RESET, we lost power */
                ohci_dbg (ohci, "lost power\n");
                status = -EBUSY;
        }
        if (status == -EBUSY) {
                if (!autostopped) {
                        spin_unlock_irq (&ohci->lock);
                        status = ohci_restart (ohci);

                        usb_root_hub_lost_power(hcd->self.root_hub);

                        spin_lock_irq (&ohci->lock);
                }
                return status;
        }
        if (status != -EINPROGRESS)
                return status;
        if (autostopped)
                goto skip_resume;
        spin_unlock_irq (&ohci->lock);

        /* Some controllers (lucent erratum) need extra-long delays */
        msleep (20 /* usb 11.5.1.10 */ + 12 /* 32 msec counter */ + 1);

        temp = ohci_readl (ohci, &ohci->regs->control);
        temp &= OHCI_CTRL_HCFS;
        if (temp != OHCI_USB_RESUME) {
                ohci_err (ohci, "controller won't resume\n");
                spin_lock_irq(&ohci->lock);
                return -EBUSY;
        }

        /* disable old schedule state, reinit from scratch */
        ohci_writel (ohci, 0, &ohci->regs->ed_controlhead);
        ohci_writel (ohci, 0, &ohci->regs->ed_controlcurrent);
        ohci_writel (ohci, 0, &ohci->regs->ed_bulkhead);
        ohci_writel (ohci, 0, &ohci->regs->ed_bulkcurrent);
        ohci_writel (ohci, 0, &ohci->regs->ed_periodcurrent);
        ohci_writel (ohci, (u32) ohci->hcca_dma, &ohci->regs->hcca);

        /* Sometimes PCI D3 suspend trashes frame timings ... */
        periodic_reinit (ohci);

        /*
         * The following code is executed with ohci->lock held and
         * irqs disabled if and only if autostopped is true.  This
         * will cause sparse to warn about a "context imbalance".
         */
skip_resume:
        /* interrupts might have been disabled */
        ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
        if (ohci->ed_rm_list)
                ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);

        /* Then re-enable operations */
        ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
        (void) ohci_readl (ohci, &ohci->regs->control);
        if (!autostopped)
                msleep (3);

        temp = ohci->hc_control;
        temp &= OHCI_CTRL_RWC;
        temp |= OHCI_CONTROL_INIT | OHCI_USB_OPER;
        ohci->hc_control = temp;
        ohci_writel (ohci, temp, &ohci->regs->control);
        (void) ohci_readl (ohci, &ohci->regs->control);

        /* TRSMRCY */
        if (!autostopped) {
                msleep (10);
                spin_lock_irq (&ohci->lock);
        }
        /* now ohci->lock is always held and irqs are always disabled */

        /* keep it alive for more than ~5x suspend + resume costs */
        ohci->next_statechange = jiffies + STATECHANGE_DELAY;

        /* maybe turn schedules back on */
        enables = 0;
        temp = 0;
        if (!ohci->ed_rm_list) {
                if (ohci->ed_controltail) {
                        ohci_writel (ohci,
                                        find_head (ohci->ed_controltail)->dma,
                                        &ohci->regs->ed_controlhead);
                        enables |= OHCI_CTRL_CLE;
                        temp |= OHCI_CLF;
                }
                if (ohci->ed_bulktail) {
                        ohci_writel (ohci, find_head (ohci->ed_bulktail)->dma,
                                &ohci->regs->ed_bulkhead);
                        enables |= OHCI_CTRL_BLE;
                        temp |= OHCI_BLF;
                }
        }
        if (hcd->self.bandwidth_isoc_reqs || hcd->self.bandwidth_int_reqs)
                enables |= OHCI_CTRL_PLE|OHCI_CTRL_IE;
        if (enables) {
                ohci_dbg (ohci, "restarting schedules ... %08x\n", enables);
                ohci->hc_control |= enables;
                ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
                if (temp)
                        ohci_writel (ohci, temp, &ohci->regs->cmdstatus);
                (void) ohci_readl (ohci, &ohci->regs->control);
        }

        ohci->rh_state = OHCI_RH_RUNNING;
        return 0;
}

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

        spin_lock_irq (&ohci->lock);

        if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
                rc = -ESHUTDOWN;
        else
                rc = ohci_rh_suspend (ohci, 0);
        spin_unlock_irq (&ohci->lock);

        if (rc == 0) {
                del_timer_sync(&ohci->io_watchdog);
                ohci->prev_frame_no = IO_WATCHDOG_OFF;
        }
        return rc;
}

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

        if (time_before (jiffies, ohci->next_statechange))
                msleep(5);

        spin_lock_irq (&ohci->lock);

        if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
                rc = -ESHUTDOWN;
        else
                rc = ohci_rh_resume (ohci);
        spin_unlock_irq (&ohci->lock);

        /* poll until we know a device is connected or we autostop */
        if (rc == 0)
                usb_hcd_poll_rh_status(hcd);
        return rc;
}

/* Carry out polling-, autostop-, and autoresume-related state changes */
static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
                int any_connected, int rhsc_status)
{
        int     poll_rh = 1;
        int     rhsc_enable;

        /* Some broken controllers never turn off RHSC in the interrupt
         * status register.  For their sake we won't re-enable RHSC
         * interrupts if the interrupt bit is already active.
         */
        rhsc_enable = ohci_readl(ohci, &ohci->regs->intrenable) &
                        OHCI_INTR_RHSC;

        switch (ohci->hc_control & OHCI_CTRL_HCFS) {
        case OHCI_USB_OPER:
                /* If no status changes are pending, enable RHSC interrupts. */
                if (!rhsc_enable && !rhsc_status && !changed) {
                        rhsc_enable = OHCI_INTR_RHSC;
                        ohci_writel(ohci, rhsc_enable, &ohci->regs->intrenable);
                }

                /* Keep on polling until we know a device is connected
                 * and RHSC is enabled, or until we autostop.
                 */
                if (!ohci->autostop) {
                        if (any_connected ||
                                        !device_may_wakeup(&ohci_to_hcd(ohci)
                                                ->self.root_hub->dev)) {
                                if (rhsc_enable)
                                        poll_rh = 0;
                        } else {
                                ohci->autostop = 1;
                                ohci->next_statechange = jiffies + HZ;
                        }

                /* if no devices have been attached for one second, autostop */
                } else {
                        if (changed || any_connected) {
                                ohci->autostop = 0;
                                ohci->next_statechange = jiffies +
                                                STATECHANGE_DELAY;
                        } else if (time_after_eq(jiffies,
                                                ohci->next_statechange)
                                        && !ohci->ed_rm_list
                                        && !(ohci->hc_control &
                                                OHCI_SCHED_ENABLES)) {
                                ohci_rh_suspend(ohci, 1);
                                if (rhsc_enable)
                                        poll_rh = 0;
                        }
                }
                break;

        case OHCI_USB_SUSPEND:
        case OHCI_USB_RESUME:
                /* if there is a port change, autostart or ask to be resumed */
                if (changed) {
                        if (ohci->autostop)
                                ohci_rh_resume(ohci);
                        else
                                usb_hcd_resume_root_hub(ohci_to_hcd(ohci));

                /* If remote wakeup is disabled, stop polling */
                } else if (!ohci->autostop &&
                                !ohci_to_hcd(ohci)->self.root_hub->
                                        do_remote_wakeup) {
                        poll_rh = 0;

                } else {
                        /* If no status changes are pending,
                         * enable RHSC interrupts
                         */
                        if (!rhsc_enable && !rhsc_status) {
                                rhsc_enable = OHCI_INTR_RHSC;
                                ohci_writel(ohci, rhsc_enable,
                                                &ohci->regs->intrenable);
                        }
                        /* Keep polling until RHSC is enabled */
                        if (rhsc_enable)
                                poll_rh = 0;
                }
                break;
        }
        return poll_rh;
}

#else   /* CONFIG_PM */

static inline int ohci_rh_resume(struct ohci_hcd *ohci)
{
        return 0;
}

/* Carry out polling-related state changes.
 * autostop isn't used when CONFIG_PM is turned off.
 */
static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
                int any_connected, int rhsc_status)
{
        /* If RHSC is enabled, don't poll */
        if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
                return 0;

        /* If status changes are pending, continue polling.
         * Conversely, if no status changes are pending but the RHSC
         * status bit was set, then RHSC may be broken so continue polling.
         */
        if (changed || rhsc_status)
                return 1;

        /* It's safe to re-enable RHSC interrupts */
        ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
        return 0;
}

#endif  /* CONFIG_PM */

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

/* build "status change" packet (one or two bytes) from HC registers */

int ohci_hub_status_data(struct usb_hcd *hcd, char *buf)
{
        struct ohci_hcd *ohci = hcd_to_ohci (hcd);
        int             i, changed = 0, length = 1;
        int             any_connected = 0;
        int             rhsc_status;
        unsigned long   flags;

        spin_lock_irqsave (&ohci->lock, flags);
        if (!HCD_HW_ACCESSIBLE(hcd))
                goto done;

        /* undocumented erratum seen on at least rev D */
        if ((ohci->flags & OHCI_QUIRK_AMD756)
                        && (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
                ohci_warn (ohci, "bogus NDP, rereads as NDP=%d\n",
                          ohci_readl (ohci, &ohci->regs->roothub.a) & RH_A_NDP);
                /* retry later; "should not happen" */
                goto done;
        }

        /* init status */
        if (roothub_status (ohci) & (RH_HS_LPSC | RH_HS_OCIC))
                buf [0] = changed = 1;
        else
                buf [0] = 0;
        if (ohci->num_ports > 7) {
                buf [1] = 0;
                length++;
        }

        /* Clear the RHSC status flag before reading the port statuses */
        ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrstatus);
        rhsc_status = ohci_readl(ohci, &ohci->regs->intrstatus) &
                        OHCI_INTR_RHSC;

        /* look at each port */
        for (i = 0; i < ohci->num_ports; i++) {
                u32     status = roothub_portstatus (ohci, i);

                /* can't autostop if ports are connected */
                any_connected |= (status & RH_PS_CCS);

                if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
                                | RH_PS_OCIC | RH_PS_PRSC)) {
                        changed = 1;
                        if (i < 7)
                            buf [0] |= 1 << (i + 1);
                        else
                            buf [1] |= 1 << (i - 7);
                }
        }

        if (ohci_root_hub_state_changes(ohci, changed,
                        any_connected, rhsc_status))
                set_bit(HCD_FLAG_POLL_RH, &hcd->flags);
        else
                clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);


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

        return changed ? length : 0;
}
EXPORT_SYMBOL_GPL(ohci_hub_status_data);

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

static void
ohci_hub_descriptor (
        struct ohci_hcd                 *ohci,
        struct usb_hub_descriptor       *desc
) {
        u32             rh = roothub_a (ohci);
        u16             temp;

        desc->bDescriptorType = USB_DT_HUB;
        desc->bPwrOn2PwrGood = (rh & RH_A_POTPGT) >> 24;
        desc->bHubContrCurrent = 0;

        desc->bNbrPorts = ohci->num_ports;
        temp = 1 + (ohci->num_ports / 8);
        desc->bDescLength = 7 + 2 * temp;

        temp = HUB_CHAR_COMMON_LPSM | HUB_CHAR_COMMON_OCPM;
        if (rh & RH_A_NPS)              /* no power switching? */
                temp |= HUB_CHAR_NO_LPSM;
        if (rh & RH_A_PSM)              /* per-port power switching? */
                temp |= HUB_CHAR_INDV_PORT_LPSM;
        if (rh & RH_A_NOCP)             /* no overcurrent reporting? */
                temp |= HUB_CHAR_NO_OCPM;
        else if (rh & RH_A_OCPM)        /* per-port overcurrent reporting? */
                temp |= HUB_CHAR_INDV_PORT_OCPM;
        desc->wHubCharacteristics = cpu_to_le16(temp);

        /* ports removable, and usb 1.0 legacy PortPwrCtrlMask */
        rh = roothub_b (ohci);
        memset(desc->u.hs.DeviceRemovable, 0xff,
                        sizeof(desc->u.hs.DeviceRemovable));
        desc->u.hs.DeviceRemovable[0] = rh & RH_B_DR;
        if (ohci->num_ports > 7) {
                desc->u.hs.DeviceRemovable[1] = (rh & RH_B_DR) >> 8;
                desc->u.hs.DeviceRemovable[2] = 0xff;
        } else
                desc->u.hs.DeviceRemovable[1] = 0xff;
}

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

#ifdef  CONFIG_USB_OTG

static int ohci_start_port_reset (struct usb_hcd *hcd, unsigned port)
{
        struct ohci_hcd *ohci = hcd_to_ohci (hcd);
        u32                     status;

        if (!port)
                return -EINVAL;
        port--;

        /* start port reset before HNP protocol times out */
        status = ohci_readl(ohci, &ohci->regs->roothub.portstatus [port]);
        if (!(status & RH_PS_CCS))
                return -ENODEV;

        /* hub_wq will finish the reset later */
        ohci_writel(ohci, RH_PS_PRS, &ohci->regs->roothub.portstatus [port]);
        return 0;
}

#else

#define ohci_start_port_reset           NULL

#endif

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


/* See usb 7.1.7.5:  root hubs must issue at least 50 msec reset signaling,
 * not necessarily continuous ... to guard against resume signaling.
 */
#define PORT_RESET_MSEC         50

/* this timer value might be vendor-specific ... */
#define PORT_RESET_HW_MSEC      10

/* wrap-aware logic morphed from <linux/jiffies.h> */
#define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0)

/* called from some task, normally hub_wq */
static inline int root_port_reset (struct ohci_hcd *ohci, unsigned port)
{
        __hc32 __iomem *portstat = &ohci->regs->roothub.portstatus [port];
        u32     temp = 0;
        u16     now = ohci_readl(ohci, &ohci->regs->fmnumber);
        u16     reset_done = now + PORT_RESET_MSEC;
        int     limit_1 = DIV_ROUND_UP(PORT_RESET_MSEC, PORT_RESET_HW_MSEC);

        /* build a "continuous enough" reset signal, with up to
         * 3msec gap between pulses.  scheduler HZ==100 must work;
         * this might need to be deadline-scheduled.
         */
        do {
                int limit_2;

                /* spin until any current reset finishes */
                limit_2 = PORT_RESET_HW_MSEC * 2;
                while (--limit_2 >= 0) {
                        temp = ohci_readl (ohci, portstat);
                        /* handle e.g. CardBus eject */
                        if (temp == ~(u32)0)
                                return -ESHUTDOWN;
                        if (!(temp & RH_PS_PRS))
                                break;
                        udelay (500);
                }

                /* timeout (a hardware error) has been observed when
                 * EHCI sets CF while this driver is resetting a port;
                 * presumably other disconnect paths might do it too.
                 */
                if (limit_2 < 0) {
                        ohci_dbg(ohci,
                                "port[%d] reset timeout, stat %08x\n",
                                port, temp);
                        break;
                }

                if (!(temp & RH_PS_CCS))
                        break;
                if (temp & RH_PS_PRSC)
                        ohci_writel (ohci, RH_PS_PRSC, portstat);

                /* start the next reset, sleep till it's probably done */
                ohci_writel (ohci, RH_PS_PRS, portstat);
                msleep(PORT_RESET_HW_MSEC);
                now = ohci_readl(ohci, &ohci->regs->fmnumber);
        } while (tick_before(now, reset_done) && --limit_1 >= 0);

        /* caller synchronizes using PRSC ... and handles PRS
         * still being set when this returns.
         */

        return 0;
}

int ohci_hub_control(
        struct usb_hcd  *hcd,
        u16             typeReq,
        u16             wValue,
        u16             wIndex,
        char            *buf,
        u16             wLength
) {
        struct ohci_hcd *ohci = hcd_to_ohci (hcd);
        int             ports = ohci->num_ports;
        u32             temp;
        int             retval = 0;

        if (unlikely(!HCD_HW_ACCESSIBLE(hcd)))
                return -ESHUTDOWN;

        switch (typeReq) {
        case ClearHubFeature:
                switch (wValue) {
                case C_HUB_OVER_CURRENT:
                        ohci_writel (ohci, RH_HS_OCIC,
                                        &ohci->regs->roothub.status);
                case C_HUB_LOCAL_POWER:
                        break;
                default:
                        goto error;
                }
                break;
        case ClearPortFeature:
                if (!wIndex || wIndex > ports)
                        goto error;
                wIndex--;

                switch (wValue) {
                case USB_PORT_FEAT_ENABLE:
                        temp = RH_PS_CCS;
                        break;
                case USB_PORT_FEAT_C_ENABLE:
                        temp = RH_PS_PESC;
                        break;
                case USB_PORT_FEAT_SUSPEND:
                        temp = RH_PS_POCI;
                        break;
                case USB_PORT_FEAT_C_SUSPEND:
                        temp = RH_PS_PSSC;
                        break;
                case USB_PORT_FEAT_POWER:
                        temp = RH_PS_LSDA;
                        break;
                case USB_PORT_FEAT_C_CONNECTION:
                        temp = RH_PS_CSC;
                        break;
                case USB_PORT_FEAT_C_OVER_CURRENT:
                        temp = RH_PS_OCIC;
                        break;
                case USB_PORT_FEAT_C_RESET:
                        temp = RH_PS_PRSC;
                        break;
                default:
                        goto error;
                }
                ohci_writel (ohci, temp,
                                &ohci->regs->roothub.portstatus [wIndex]);
                // ohci_readl (ohci, &ohci->regs->roothub.portstatus [wIndex]);
                break;
        case GetHubDescriptor:
                ohci_hub_descriptor (ohci, (struct usb_hub_descriptor *) buf);
                break;
        case GetHubStatus:
                temp = roothub_status (ohci) & ~(RH_HS_CRWE | RH_HS_DRWE);
                put_unaligned_le32(temp, buf);
                break;
        case GetPortStatus:
                if (!wIndex || wIndex > ports)
                        goto error;
                wIndex--;
                temp = roothub_portstatus (ohci, wIndex);
                put_unaligned_le32(temp, buf);

                if (*(u16*)(buf+2))     /* only if wPortChange is interesting */
                        dbg_port(ohci, "GetStatus", wIndex, temp);
                break;
        case SetHubFeature:
                switch (wValue) {
                case C_HUB_OVER_CURRENT:
                        // FIXME:  this can be cleared, yes?
                case C_HUB_LOCAL_POWER:
                        break;
                default:
                        goto error;
                }
                break;
        case SetPortFeature:
                if (!wIndex || wIndex > ports)
                        goto error;
                wIndex--;
                switch (wValue) {
                case USB_PORT_FEAT_SUSPEND:
#ifdef  CONFIG_USB_OTG
                        if (hcd->self.otg_port == (wIndex + 1)
                                        && hcd->self.b_hnp_enable)
                                ohci->start_hnp(ohci);
                        else
#endif
                        ohci_writel (ohci, RH_PS_PSS,
                                &ohci->regs->roothub.portstatus [wIndex]);
                        break;
                case USB_PORT_FEAT_POWER:
                        ohci_writel (ohci, RH_PS_PPS,
                                &ohci->regs->roothub.portstatus [wIndex]);
                        break;
                case USB_PORT_FEAT_RESET:
                        retval = root_port_reset (ohci, wIndex);
                        break;
                default:
                        goto error;
                }
                break;

        default:
error:
                /* "protocol stall" on error */
                retval = -EPIPE;
        }
        return retval;
}
EXPORT_SYMBOL_GPL(ohci_hub_control);