text: /*
   * 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, 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));
  
  	/* 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;
  	}
  
  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 (hcd->state == HC_STATE_RESUMING) {
  			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);
  			(void) ohci_init (ohci);
  			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
  	 */
  
  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);
  	}
  
  	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 the final steps of resuming the controller device */
  static void ohci_finish_controller_resume(struct usb_hcd *hcd)
  {
  	struct ohci_hcd		*ohci = hcd_to_ohci(hcd);
  	int			port;
  	bool			need_reinit = false;
  
  	/* 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);
  		hcd->state = HC_STATE_RESUMING;
  		ohci_rh_resume(ohci);
  		hcd->state = HC_STATE_QUIESCING;
  		ohci_rh_suspend(ohci, 0);
  		hcd->state = HC_STATE_SUSPENDED;
  		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);
  	}
  
  	/* Does the root hub have a port wakeup pending? */
  	if (ohci_readl(ohci, &ohci->regs->intrstatus) &
  			(OHCI_INTR_RD | OHCI_INTR_RHSC))
  		usb_hcd_resume_root_hub(hcd);
  }
  
  /* 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 */
  
  static 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;
  }
  
  /*-------------------------------------------------------------------------*/
  
  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 = (__force __u16)cpu_to_hc16(ohci, temp);
  
  	/* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
  	rh = roothub_b (ohci);
  	memset(desc->bitmap, 0xff, sizeof(desc->bitmap));
  	desc->bitmap [0] = rh & RH_B_DR;
  	if (ohci->num_ports > 7) {
  		desc->bitmap [1] = (rh & RH_B_DR) >> 8;
  		desc->bitmap [2] = 0xff;
  	} else
  		desc->bitmap [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.
   * The short timeout is safe for non-root hubs, and is backward-compatible
   * with earlier Linux hosts.
   */
  #ifdef	CONFIG_USB_SUSPEND
  #define	PORT_RESET_MSEC		50
  #else
  #define	PORT_RESET_MSEC		10
  #endif
  
  /* 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 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;
  }
  
  static 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);
  
  #ifndef	OHCI_VERBOSE_DEBUG
  	if (*(u16*)(buf+2))	/* only if wPortChange is interesting */
  #endif
  		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;
  }
  
  