/*
   * Universal Host Controller Interface driver for USB.
   *
   * Maintainer: Alan Stern <stern@rowland.harvard.edu>
   *
   * (C) Copyright 1999 Linus Torvalds
   * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
   * (C) Copyright 1999 Randy Dunlap
   * (C) Copyright 1999 Georg Acher, acher@in.tum.de
   * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
   * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
   * (C) Copyright 2004 Alan Stern, stern@rowland.harvard.edu
   */
  
  static const __u8 root_hub_hub_des[] =
  {
  	0x09,			/*  __u8  bLength; */
  	0x29,			/*  __u8  bDescriptorType; Hub-descriptor */
  	0x02,			/*  __u8  bNbrPorts; */
  	0x0a,			/* __u16  wHubCharacteristics; */
  	0x00,			/*   (per-port OC, no power switching) */
  	0x01,			/*  __u8  bPwrOn2pwrGood; 2ms */
  	0x00,			/*  __u8  bHubContrCurrent; 0 mA */
  	0x00,			/*  __u8  DeviceRemovable; *** 7 Ports max */
  	0xff			/*  __u8  PortPwrCtrlMask; *** 7 ports max */
  };
  
  #define	UHCI_RH_MAXCHILD	7
  
  /* must write as zeroes */
  #define WZ_BITS		(USBPORTSC_RES2 | USBPORTSC_RES3 | USBPORTSC_RES4)
  
  /* status change bits:  nonzero writes will clear */
  #define RWC_BITS	(USBPORTSC_OCC | USBPORTSC_PEC | USBPORTSC_CSC)
  
  /* suspend/resume bits: port suspended or port resuming */
  #define SUSPEND_BITS	(USBPORTSC_SUSP | USBPORTSC_RD)
  
  /* A port that either is connected or has a changed-bit set will prevent
   * us from AUTO_STOPPING.
   */
  static int any_ports_active(struct uhci_hcd *uhci)
  {
  	int port;
  
  	for (port = 0; port < uhci->rh_numports; ++port) {
  		if ((uhci_readw(uhci, USBPORTSC1 + port * 2) &
  				(USBPORTSC_CCS | RWC_BITS)) ||
  				test_bit(port, &uhci->port_c_suspend))
  			return 1;
  	}
  	return 0;
  }
  
  static inline int get_hub_status_data(struct uhci_hcd *uhci, char *buf)
  {
  	int port;
  	int mask = RWC_BITS;
  
  	/* Some boards (both VIA and Intel apparently) report bogus
  	 * overcurrent indications, causing massive log spam unless
  	 * we completely ignore them.  This doesn't seem to be a problem
  	 * with the chipset so much as with the way it is connected on
  	 * the motherboard; if the overcurrent input is left to float
  	 * then it may constantly register false positives. */
  	if (ignore_oc)
  		mask &= ~USBPORTSC_OCC;
  
  	*buf = 0;
  	for (port = 0; port < uhci->rh_numports; ++port) {
  		if ((uhci_readw(uhci, USBPORTSC1 + port * 2) & mask) ||
  				test_bit(port, &uhci->port_c_suspend))
  			*buf |= (1 << (port + 1));
  	}
  	return !!*buf;
  }
  
  #define CLR_RH_PORTSTAT(x) \
  	status = uhci_readw(uhci, port_addr);	\
  	status &= ~(RWC_BITS|WZ_BITS); \
  	status &= ~(x); \
  	status |= RWC_BITS & (x); \
  	uhci_writew(uhci, status, port_addr)
  
  #define SET_RH_PORTSTAT(x) \
  	status = uhci_readw(uhci, port_addr);	\
  	status |= (x); \
  	status &= ~(RWC_BITS|WZ_BITS); \
  	uhci_writew(uhci, status, port_addr)
  
  /* UHCI controllers don't automatically stop resume signalling after 20 msec,
   * so we have to poll and check timeouts in order to take care of it.
   */
  static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
  		unsigned long port_addr)
  {
  	int status;
  	int i;
  
  	if (uhci_readw(uhci, port_addr) & SUSPEND_BITS) {
  		CLR_RH_PORTSTAT(SUSPEND_BITS);
  		if (test_bit(port, &uhci->resuming_ports))
  			set_bit(port, &uhci->port_c_suspend);
  
  		/* The controller won't actually turn off the RD bit until
  		 * it has had a chance to send a low-speed EOP sequence,
  		 * which is supposed to take 3 bit times (= 2 microseconds).
  		 * Experiments show that some controllers take longer, so
  		 * we'll poll for completion. */
  		for (i = 0; i < 10; ++i) {
  			if (!(uhci_readw(uhci, port_addr) & SUSPEND_BITS))
  				break;
  			udelay(1);
  		}
  	}
  	clear_bit(port, &uhci->resuming_ports);
  	usb_hcd_end_port_resume(&uhci_to_hcd(uhci)->self, port);
  }
  
  /* Wait for the UHCI controller in HP's iLO2 server management chip.
   * It can take up to 250 us to finish a reset and set the CSC bit.
   */
  static void wait_for_HP(struct uhci_hcd *uhci, unsigned long port_addr)
  {
  	int i;
  
  	for (i = 10; i < 250; i += 10) {
  		if (uhci_readw(uhci, port_addr) & USBPORTSC_CSC)
  			return;
  		udelay(10);
  	}
  	/* Log a warning? */
  }
  
  static void uhci_check_ports(struct uhci_hcd *uhci)
  {
  	unsigned int port;
  	unsigned long port_addr;
  	int status;
  
  	for (port = 0; port < uhci->rh_numports; ++port) {
  		port_addr = USBPORTSC1 + 2 * port;
  		status = uhci_readw(uhci, port_addr);
  		if (unlikely(status & USBPORTSC_PR)) {
  			if (time_after_eq(jiffies, uhci->ports_timeout)) {
  				CLR_RH_PORTSTAT(USBPORTSC_PR);
  				udelay(10);
  
  				/* HP's server management chip requires
  				 * a longer delay. */
  				if (uhci->wait_for_hp)
  					wait_for_HP(uhci, port_addr);
  
  				/* If the port was enabled before, turning
  				 * reset on caused a port enable change.
  				 * Turning reset off causes a port connect
  				 * status change.  Clear these changes. */
  				CLR_RH_PORTSTAT(USBPORTSC_CSC | USBPORTSC_PEC);
  				SET_RH_PORTSTAT(USBPORTSC_PE);
  			}
  		}
  		if (unlikely(status & USBPORTSC_RD)) {
  			if (!test_bit(port, &uhci->resuming_ports)) {
  
  				/* Port received a wakeup request */
  				set_bit(port, &uhci->resuming_ports);
  				uhci->ports_timeout = jiffies +
  						msecs_to_jiffies(25);
  				usb_hcd_start_port_resume(
  						&uhci_to_hcd(uhci)->self, port);
  
  				/* Make sure we see the port again
  				 * after the resuming period is over. */
  				mod_timer(&uhci_to_hcd(uhci)->rh_timer,
  						uhci->ports_timeout);
  			} else if (time_after_eq(jiffies,
  						uhci->ports_timeout)) {
  				uhci_finish_suspend(uhci, port, port_addr);
  			}
  		}
  	}
  }
  
  static int uhci_hub_status_data(struct usb_hcd *hcd, char *buf)
  {
  	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
  	unsigned long flags;
  	int status = 0;
  
  	spin_lock_irqsave(&uhci->lock, flags);
  
  	uhci_scan_schedule(uhci);
  	if (!HCD_HW_ACCESSIBLE(hcd) || uhci->dead)
  		goto done;
  	uhci_check_ports(uhci);
  
  	status = get_hub_status_data(uhci, buf);
  
  	switch (uhci->rh_state) {
  	    case UHCI_RH_SUSPENDED:
  		/* if port change, ask to be resumed */
  		if (status || uhci->resuming_ports) {
  			status = 1;
  			usb_hcd_resume_root_hub(hcd);
  		}
  		break;
  
  	    case UHCI_RH_AUTO_STOPPED:
  		/* if port change, auto start */
  		if (status)
  			wakeup_rh(uhci);
  		break;
  
  	    case UHCI_RH_RUNNING:
  		/* are any devices attached? */
  		if (!any_ports_active(uhci)) {
  			uhci->rh_state = UHCI_RH_RUNNING_NODEVS;
  			uhci->auto_stop_time = jiffies + HZ;
  		}
  		break;
  
  	    case UHCI_RH_RUNNING_NODEVS:
  		/* auto-stop if nothing connected for 1 second */
  		if (any_ports_active(uhci))
  			uhci->rh_state = UHCI_RH_RUNNING;
  		else if (time_after_eq(jiffies, uhci->auto_stop_time) &&
  				!uhci->wait_for_hp)
  			suspend_rh(uhci, UHCI_RH_AUTO_STOPPED);
  		break;
  
  	    default:
  		break;
  	}
  
  done:
  	spin_unlock_irqrestore(&uhci->lock, flags);
  	return status;
  }
  
  /* size of returned buffer is part of USB spec */
  static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
  			u16 wIndex, char *buf, u16 wLength)
  {
  	struct uhci_hcd *uhci = hcd_to_uhci(hcd);
  	int status, lstatus, retval = 0;
  	unsigned int port = wIndex - 1;
  	unsigned long port_addr = USBPORTSC1 + 2 * port;
  	u16 wPortChange, wPortStatus;
  	unsigned long flags;
  
  	if (!HCD_HW_ACCESSIBLE(hcd) || uhci->dead)
  		return -ETIMEDOUT;
  
  	spin_lock_irqsave(&uhci->lock, flags);
  	switch (typeReq) {
  
  	case GetHubStatus:
  		*(__le32 *)buf = cpu_to_le32(0);
  		retval = 4; /* hub power */
  		break;
  	case GetPortStatus:
  		if (port >= uhci->rh_numports)
  			goto err;
  
  		uhci_check_ports(uhci);
  		status = uhci_readw(uhci, port_addr);
  
  		/* Intel controllers report the OverCurrent bit active on.
  		 * VIA controllers report it active off, so we'll adjust the
  		 * bit value.  (It's not standardized in the UHCI spec.)
  		 */
  		if (uhci->oc_low)
  			status ^= USBPORTSC_OC;
  
  		/* UHCI doesn't support C_RESET (always false) */
  		wPortChange = lstatus = 0;
  		if (status & USBPORTSC_CSC)
  			wPortChange |= USB_PORT_STAT_C_CONNECTION;
  		if (status & USBPORTSC_PEC)
  			wPortChange |= USB_PORT_STAT_C_ENABLE;
  		if ((status & USBPORTSC_OCC) && !ignore_oc)
  			wPortChange |= USB_PORT_STAT_C_OVERCURRENT;
  
  		if (test_bit(port, &uhci->port_c_suspend)) {
  			wPortChange |= USB_PORT_STAT_C_SUSPEND;
  			lstatus |= 1;
  		}
  		if (test_bit(port, &uhci->resuming_ports))
  			lstatus |= 4;
  
  		/* UHCI has no power switching (always on) */
  		wPortStatus = USB_PORT_STAT_POWER;
  		if (status & USBPORTSC_CCS)
  			wPortStatus |= USB_PORT_STAT_CONNECTION;
  		if (status & USBPORTSC_PE) {
  			wPortStatus |= USB_PORT_STAT_ENABLE;
  			if (status & SUSPEND_BITS)
  				wPortStatus |= USB_PORT_STAT_SUSPEND;
  		}
  		if (status & USBPORTSC_OC)
  			wPortStatus |= USB_PORT_STAT_OVERCURRENT;
  		if (status & USBPORTSC_PR)
  			wPortStatus |= USB_PORT_STAT_RESET;
  		if (status & USBPORTSC_LSDA)
  			wPortStatus |= USB_PORT_STAT_LOW_SPEED;
  
  		if (wPortChange)
  			dev_dbg(uhci_dev(uhci), "port %d portsc %04x,%02x
  ",
  					wIndex, status, lstatus);
  
  		*(__le16 *)buf = cpu_to_le16(wPortStatus);
  		*(__le16 *)(buf + 2) = cpu_to_le16(wPortChange);
  		retval = 4;
  		break;
  	case SetHubFeature:		/* We don't implement these */
  	case ClearHubFeature:
  		switch (wValue) {
  		case C_HUB_OVER_CURRENT:
  		case C_HUB_LOCAL_POWER:
  			break;
  		default:
  			goto err;
  		}
  		break;
  	case SetPortFeature:
  		if (port >= uhci->rh_numports)
  			goto err;
  
  		switch (wValue) {
  		case USB_PORT_FEAT_SUSPEND:
  			SET_RH_PORTSTAT(USBPORTSC_SUSP);
  			break;
  		case USB_PORT_FEAT_RESET:
  			SET_RH_PORTSTAT(USBPORTSC_PR);
  
  			/* Reset terminates Resume signalling */
  			uhci_finish_suspend(uhci, port, port_addr);
  
  			/* USB v2.0 7.1.7.5 */
  			uhci->ports_timeout = jiffies + msecs_to_jiffies(50);
  			break;
  		case USB_PORT_FEAT_POWER:
  			/* UHCI has no power switching */
  			break;
  		default:
  			goto err;
  		}
  		break;
  	case ClearPortFeature:
  		if (port >= uhci->rh_numports)
  			goto err;
  
  		switch (wValue) {
  		case USB_PORT_FEAT_ENABLE:
  			CLR_RH_PORTSTAT(USBPORTSC_PE);
  
  			/* Disable terminates Resume signalling */
  			uhci_finish_suspend(uhci, port, port_addr);
  			break;
  		case USB_PORT_FEAT_C_ENABLE:
  			CLR_RH_PORTSTAT(USBPORTSC_PEC);
  			break;
  		case USB_PORT_FEAT_SUSPEND:
  			if (!(uhci_readw(uhci, port_addr) & USBPORTSC_SUSP)) {
  
  				/* Make certain the port isn't suspended */
  				uhci_finish_suspend(uhci, port, port_addr);
  			} else if (!test_and_set_bit(port,
  						&uhci->resuming_ports)) {
  				SET_RH_PORTSTAT(USBPORTSC_RD);
  
  				/* The controller won't allow RD to be set
  				 * if the port is disabled.  When this happens
  				 * just skip the Resume signalling.
  				 */
  				if (!(uhci_readw(uhci, port_addr) &
  						USBPORTSC_RD))
  					uhci_finish_suspend(uhci, port,
  							port_addr);
  				else
  					/* USB v2.0 7.1.7.7 */
  					uhci->ports_timeout = jiffies +
  						msecs_to_jiffies(20);
  			}
  			break;
  		case USB_PORT_FEAT_C_SUSPEND:
  			clear_bit(port, &uhci->port_c_suspend);
  			break;
  		case USB_PORT_FEAT_POWER:
  			/* UHCI has no power switching */
  			goto err;
  		case USB_PORT_FEAT_C_CONNECTION:
  			CLR_RH_PORTSTAT(USBPORTSC_CSC);
  			break;
  		case USB_PORT_FEAT_C_OVER_CURRENT:
  			CLR_RH_PORTSTAT(USBPORTSC_OCC);
  			break;
  		case USB_PORT_FEAT_C_RESET:
  			/* this driver won't report these */
  			break;
  		default:
  			goto err;
  		}
  		break;
  	case GetHubDescriptor:
  		retval = min_t(unsigned int, sizeof(root_hub_hub_des), wLength);
  		memcpy(buf, root_hub_hub_des, retval);
  		if (retval > 2)
  			buf[2] = uhci->rh_numports;
  		break;
  	default:
  err:
  		retval = -EPIPE;
  	}
  	spin_unlock_irqrestore(&uhci->lock, flags);
  
  	return retval;
  }