/* * OHCI HCD (Host Controller Driver) for USB. * * (C) Copyright 1999 Roman Weissgaerber * (C) Copyright 2000-2004 David Brownell * * 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, temp, \ (temp & RH_PS_PRSC) ? " PRSC" : "", \ (temp & RH_PS_OCIC) ? " OCIC" : "", \ (temp & RH_PS_PSSC) ? " PSSC" : "", \ (temp & RH_PS_PESC) ? " PESC" : "", \ (temp & RH_PS_CSC) ? " CSC" : "", \ \ (temp & RH_PS_LSDA) ? " LSDA" : "", \ (temp & RH_PS_PPS) ? " PPS" : "", \ (temp & RH_PS_PRS) ? " PRS" : "", \ (temp & RH_PS_POCI) ? " POCI" : "", \ (temp & RH_PS_PSS) ? " PSS" : "", \ \ (temp & RH_PS_PES) ? " PES" : "", \ (temp & RH_PS_CCS) ? " CCS" : "" \ ); /*-------------------------------------------------------------------------*/ #define OHCI_SCHED_ENABLES \ (OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE) static void dl_done_list (struct ohci_hcd *); static void finish_unlinks (struct ohci_hcd *, u16); #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); /* FALL THROUGH */ 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); } dl_done_list (ohci); finish_unlinks (ohci, ohci_frame_no(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); 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 = 0x29; 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 = 0; if (rh & RH_A_NPS) /* no power switching? */ temp |= 0x0002; if (rh & RH_A_PSM) /* per-port power switching? */ temp |= 0x0001; if (rh & RH_A_NOCP) /* no overcurrent reporting? */ temp |= 0x0010; else if (rh & RH_A_OCPM) /* per-port overcurrent reporting? */ temp |= 0x0008; 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; /* khubd 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 */ #define tick_before(t1,t2) ((s16)(((s16)(t1))-((s16)(t2))) < 0) /* called from some task, normally khubd */ 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);