linux-libre/drivers/usb/host/xhci-hub.c

/*
 * xHCI host controller driver
 *
 * Copyright (C) 2008 Intel Corp.
 *
 * Author: Sarah Sharp
 * Some code borrowed from the Linux EHCI driver.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <linux/slab.h>
#include <asm/unaligned.h>

#include "xhci.h"
#include "xhci-trace.h"

#define	PORT_WAKE_BITS	(PORT_WKOC_E | PORT_WKDISC_E | PORT_WKCONN_E)
#define	PORT_RWC_BITS	(PORT_CSC | PORT_PEC | PORT_WRC | PORT_OCC | \
			 PORT_RC | PORT_PLC | PORT_PE)

/* USB 3 BOS descriptor and a capability descriptors, combined.
 * Fields will be adjusted and added later in xhci_create_usb3_bos_desc()
 */
static u8 usb_bos_descriptor [] = {
	USB_DT_BOS_SIZE,		/*  __u8 bLength, 5 bytes */
	USB_DT_BOS,			/*  __u8 bDescriptorType */
	0x0F, 0x00,			/*  __le16 wTotalLength, 15 bytes */
	0x1,				/*  __u8 bNumDeviceCaps */
	/* First device capability, SuperSpeed */
	USB_DT_USB_SS_CAP_SIZE,		/*  __u8 bLength, 10 bytes */
	USB_DT_DEVICE_CAPABILITY,	/* Device Capability */
	USB_SS_CAP_TYPE,		/* bDevCapabilityType, SUPERSPEED_USB */
	0x00,				/* bmAttributes, LTM off by default */
	USB_5GBPS_OPERATION, 0x00,	/* wSpeedsSupported, 5Gbps only */
	0x03,				/* bFunctionalitySupport,
					   USB 3.0 speed only */
	0x00,				/* bU1DevExitLat, set later. */
	0x00, 0x00,			/* __le16 bU2DevExitLat, set later. */
	/* Second device capability, SuperSpeedPlus */
	0x1c,				/* bLength 28, will be adjusted later */
	USB_DT_DEVICE_CAPABILITY,	/* Device Capability */
	USB_SSP_CAP_TYPE,		/* bDevCapabilityType SUPERSPEED_PLUS */
	0x00,				/* bReserved 0 */
	0x23, 0x00, 0x00, 0x00,		/* bmAttributes, SSAC=3 SSIC=1 */
	0x01, 0x00,			/* wFunctionalitySupport */
	0x00, 0x00,			/* wReserved 0 */
	/* Default Sublink Speed Attributes, overwrite if custom PSI exists */
	0x34, 0x00, 0x05, 0x00,		/* 5Gbps, symmetric, rx, ID = 4 */
	0xb4, 0x00, 0x05, 0x00,		/* 5Gbps, symmetric, tx, ID = 4 */
	0x35, 0x40, 0x0a, 0x00,		/* 10Gbps, SSP, symmetric, rx, ID = 5 */
	0xb5, 0x40, 0x0a, 0x00,		/* 10Gbps, SSP, symmetric, tx, ID = 5 */
};

static int xhci_create_usb3_bos_desc(struct xhci_hcd *xhci, char *buf,
				     u16 wLength)
{
	int i, ssa_count;
	u32 temp;
	u16 desc_size, ssp_cap_size, ssa_size = 0;
	bool usb3_1 = false;

	desc_size = USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE;
	ssp_cap_size = sizeof(usb_bos_descriptor) - desc_size;

	/* does xhci support USB 3.1 Enhanced SuperSpeed */
	if (xhci->usb3_rhub.min_rev >= 0x01) {
		/* does xhci provide a PSI table for SSA speed attributes? */
		if (xhci->usb3_rhub.psi_count) {
			/* two SSA entries for each unique PSI ID, RX and TX */
			ssa_count = xhci->usb3_rhub.psi_uid_count * 2;
			ssa_size = ssa_count * sizeof(u32);
			ssp_cap_size -= 16; /* skip copying the default SSA */
		}
		desc_size += ssp_cap_size;
		usb3_1 = true;
	}
	memcpy(buf, &usb_bos_descriptor, min(desc_size, wLength));

	if (usb3_1) {
		/* modify bos descriptor bNumDeviceCaps and wTotalLength */
		buf[4] += 1;
		put_unaligned_le16(desc_size + ssa_size, &buf[2]);
	}

	if (wLength < USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE)
		return wLength;

	/* Indicate whether the host has LTM support. */
	temp = readl(&xhci->cap_regs->hcc_params);
	if (HCC_LTC(temp))
		buf[8] |= USB_LTM_SUPPORT;

	/* Set the U1 and U2 exit latencies. */
	if ((xhci->quirks & XHCI_LPM_SUPPORT)) {
		temp = readl(&xhci->cap_regs->hcs_params3);
		buf[12] = HCS_U1_LATENCY(temp);
		put_unaligned_le16(HCS_U2_LATENCY(temp), &buf[13]);
	}

	/* If PSI table exists, add the custom speed attributes from it */
	if (usb3_1 && xhci->usb3_rhub.psi_count) {
		u32 ssp_cap_base, bm_attrib, psi, psi_mant, psi_exp;
		int offset;

		ssp_cap_base = USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE;

		if (wLength < desc_size)
			return wLength;
		buf[ssp_cap_base] = ssp_cap_size + ssa_size;

		/* attribute count SSAC bits 4:0 and ID count SSIC bits 8:5 */
		bm_attrib = (ssa_count - 1) & 0x1f;
		bm_attrib |= (xhci->usb3_rhub.psi_uid_count - 1) << 5;
		put_unaligned_le32(bm_attrib, &buf[ssp_cap_base + 4]);

		if (wLength < desc_size + ssa_size)
			return wLength;
		/*
		 * Create the Sublink Speed Attributes (SSA) array.
		 * The xhci PSI field and USB 3.1 SSA fields are very similar,
		 * but link type bits 7:6 differ for values 01b and 10b.
		 * xhci has also only one PSI entry for a symmetric link when
		 * USB 3.1 requires two SSA entries (RX and TX) for every link
		 */
		offset = desc_size;
		for (i = 0; i < xhci->usb3_rhub.psi_count; i++) {
			psi = xhci->usb3_rhub.psi[i];
			psi &= ~USB_SSP_SUBLINK_SPEED_RSVD;
			psi_exp = XHCI_EXT_PORT_PSIE(psi);
			psi_mant = XHCI_EXT_PORT_PSIM(psi);

			/* Shift to Gbps and set SSP Link BIT(14) if 10Gpbs */
			for (; psi_exp < 3; psi_exp++)
				psi_mant /= 1000;
			if (psi_mant >= 10)
				psi |= BIT(14);

			if ((psi & PLT_MASK) == PLT_SYM) {
			/* Symmetric, create SSA RX and TX from one PSI entry */
				put_unaligned_le32(psi, &buf[offset]);
				psi |= 1 << 7;  /* turn entry to TX */
				offset += 4;
				if (offset >= desc_size + ssa_size)
					return desc_size + ssa_size;
			} else if ((psi & PLT_MASK) == PLT_ASYM_RX) {
				/* Asymetric RX, flip bits 7:6 for SSA */
				psi ^= PLT_MASK;
			}
			put_unaligned_le32(psi, &buf[offset]);
			offset += 4;
			if (offset >= desc_size + ssa_size)
				return desc_size + ssa_size;
		}
	}
	/* ssa_size is 0 for other than usb 3.1 hosts */
	return desc_size + ssa_size;
}

static void xhci_common_hub_descriptor(struct xhci_hcd *xhci,
		struct usb_hub_descriptor *desc, int ports)
{
	u16 temp;

	desc->bPwrOn2PwrGood = 10;	/* xhci section 5.4.9 says 20ms max */
	desc->bHubContrCurrent = 0;

	desc->bNbrPorts = ports;
	temp = 0;
	/* Bits 1:0 - support per-port power switching, or power always on */
	if (HCC_PPC(xhci->hcc_params))
		temp |= HUB_CHAR_INDV_PORT_LPSM;
	else
		temp |= HUB_CHAR_NO_LPSM;
	/* Bit  2 - root hubs are not part of a compound device */
	/* Bits 4:3 - individual port over current protection */
	temp |= HUB_CHAR_INDV_PORT_OCPM;
	/* Bits 6:5 - no TTs in root ports */
	/* Bit  7 - no port indicators */
	desc->wHubCharacteristics = cpu_to_le16(temp);
}

/* Fill in the USB 2.0 roothub descriptor */
static void xhci_usb2_hub_descriptor(struct usb_hcd *hcd, struct xhci_hcd *xhci,
		struct usb_hub_descriptor *desc)
{
	int ports;
	u16 temp;
	__u8 port_removable[(USB_MAXCHILDREN + 1 + 7) / 8];
	u32 portsc;
	unsigned int i;

	ports = xhci->num_usb2_ports;

	xhci_common_hub_descriptor(xhci, desc, ports);
	desc->bDescriptorType = USB_DT_HUB;
	temp = 1 + (ports / 8);
	desc->bDescLength = USB_DT_HUB_NONVAR_SIZE + 2 * temp;

	/* The Device Removable bits are reported on a byte granularity.
	 * If the port doesn't exist within that byte, the bit is set to 0.
	 */
	memset(port_removable, 0, sizeof(port_removable));
	for (i = 0; i < ports; i++) {
		portsc = readl(xhci->usb2_ports[i]);
		/* If a device is removable, PORTSC reports a 0, same as in the
		 * hub descriptor DeviceRemovable bits.
		 */
		if (portsc & PORT_DEV_REMOVE)
			/* This math is hairy because bit 0 of DeviceRemovable
			 * is reserved, and bit 1 is for port 1, etc.
			 */
			port_removable[(i + 1) / 8] |= 1 << ((i + 1) % 8);
	}

	/* ch11.h defines a hub descriptor that has room for USB_MAXCHILDREN
	 * ports on it.  The USB 2.0 specification says that there are two
	 * variable length fields at the end of the hub descriptor:
	 * DeviceRemovable and PortPwrCtrlMask.  But since we can have less than
	 * USB_MAXCHILDREN ports, we may need to use the DeviceRemovable array
	 * to set PortPwrCtrlMask bits.  PortPwrCtrlMask must always be set to
	 * 0xFF, so we initialize the both arrays (DeviceRemovable and
	 * PortPwrCtrlMask) to 0xFF.  Then we set the DeviceRemovable for each
	 * set of ports that actually exist.
	 */
	memset(desc->u.hs.DeviceRemovable, 0xff,
			sizeof(desc->u.hs.DeviceRemovable));
	memset(desc->u.hs.PortPwrCtrlMask, 0xff,
			sizeof(desc->u.hs.PortPwrCtrlMask));

	for (i = 0; i < (ports + 1 + 7) / 8; i++)
		memset(&desc->u.hs.DeviceRemovable[i], port_removable[i],
				sizeof(__u8));
}

/* Fill in the USB 3.0 roothub descriptor */
static void xhci_usb3_hub_descriptor(struct usb_hcd *hcd, struct xhci_hcd *xhci,
		struct usb_hub_descriptor *desc)
{
	int ports;
	u16 port_removable;
	u32 portsc;
	unsigned int i;

	ports = xhci->num_usb3_ports;
	xhci_common_hub_descriptor(xhci, desc, ports);
	desc->bDescriptorType = USB_DT_SS_HUB;
	desc->bDescLength = USB_DT_SS_HUB_SIZE;

	/* header decode latency should be zero for roothubs,
	 * see section 4.23.5.2.
	 */
	desc->u.ss.bHubHdrDecLat = 0;
	desc->u.ss.wHubDelay = 0;

	port_removable = 0;
	/* bit 0 is reserved, bit 1 is for port 1, etc. */
	for (i = 0; i < ports; i++) {
		portsc = readl(xhci->usb3_ports[i]);
		if (portsc & PORT_DEV_REMOVE)
			port_removable |= 1 << (i + 1);
	}

	desc->u.ss.DeviceRemovable = cpu_to_le16(port_removable);
}

static void xhci_hub_descriptor(struct usb_hcd *hcd, struct xhci_hcd *xhci,
		struct usb_hub_descriptor *desc)
{

	if (hcd->speed >= HCD_USB3)
		xhci_usb3_hub_descriptor(hcd, xhci, desc);
	else
		xhci_usb2_hub_descriptor(hcd, xhci, desc);

}

static unsigned int xhci_port_speed(unsigned int port_status)
{
	if (DEV_LOWSPEED(port_status))
		return USB_PORT_STAT_LOW_SPEED;
	if (DEV_HIGHSPEED(port_status))
		return USB_PORT_STAT_HIGH_SPEED;
	/*
	 * FIXME: Yes, we should check for full speed, but the core uses that as
	 * a default in portspeed() in usb/core/hub.c (which is the only place
	 * USB_PORT_STAT_*_SPEED is used).
	 */
	return 0;
}

/*
 * These bits are Read Only (RO) and should be saved and written to the
 * registers: 0, 3, 10:13, 30
 * connect status, over-current status, port speed, and device removable.
 * connect status and port speed are also sticky - meaning they're in
 * the AUX well and they aren't changed by a hot, warm, or cold reset.
 */
#define	XHCI_PORT_RO	((1<<0) | (1<<3) | (0xf<<10) | (1<<30))
/*
 * These bits are RW; writing a 0 clears the bit, writing a 1 sets the bit:
 * bits 5:8, 9, 14:15, 25:27
 * link state, port power, port indicator state, "wake on" enable state
 */
#define XHCI_PORT_RWS	((0xf<<5) | (1<<9) | (0x3<<14) | (0x7<<25))
/*
 * These bits are RW; writing a 1 sets the bit, writing a 0 has no effect:
 * bit 4 (port reset)
 */
#define	XHCI_PORT_RW1S	((1<<4))
/*
 * These bits are RW; writing a 1 clears the bit, writing a 0 has no effect:
 * bits 1, 17, 18, 19, 20, 21, 22, 23
 * port enable/disable, and
 * change bits: connect, PED, warm port reset changed (reserved zero for USB 2.0 ports),
 * over-current, reset, link state, and L1 change
 */
#define XHCI_PORT_RW1CS	((1<<1) | (0x7f<<17))
/*
 * Bit 16 is RW, and writing a '1' to it causes the link state control to be
 * latched in
 */
#define	XHCI_PORT_RW	((1<<16))
/*
 * These bits are Reserved Zero (RsvdZ) and zero should be written to them:
 * bits 2, 24, 28:31
 */
#define	XHCI_PORT_RZ	((1<<2) | (1<<24) | (0xf<<28))

/*
 * Given a port state, this function returns a value that would result in the
 * port being in the same state, if the value was written to the port status
 * control register.
 * Save Read Only (RO) bits and save read/write bits where
 * writing a 0 clears the bit and writing a 1 sets the bit (RWS).
 * For all other types (RW1S, RW1CS, RW, and RZ), writing a '0' has no effect.
 */
u32 xhci_port_state_to_neutral(u32 state)
{
	/* Save read-only status and port state */
	return (state & XHCI_PORT_RO) | (state & XHCI_PORT_RWS);
}

/*
 * find slot id based on port number.
 * @port: The one-based port number from one of the two split roothubs.
 */
int xhci_find_slot_id_by_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
		u16 port)
{
	int slot_id;
	int i;
	enum usb_device_speed speed;

	slot_id = 0;
	for (i = 0; i < MAX_HC_SLOTS; i++) {
		if (!xhci->devs[i])
			continue;
		speed = xhci->devs[i]->udev->speed;
		if (((speed >= USB_SPEED_SUPER) == (hcd->speed >= HCD_USB3))
				&& xhci->devs[i]->fake_port == port) {
			slot_id = i;
			break;
		}
	}

	return slot_id;
}

/*
 * Stop device
 * It issues stop endpoint command for EP 0 to 30. And wait the last command
 * to complete.
 * suspend will set to 1, if suspend bit need to set in command.
 */
static int xhci_stop_device(struct xhci_hcd *xhci, int slot_id, int suspend)
{
	struct xhci_virt_device *virt_dev;
	struct xhci_command *cmd;
	unsigned long flags;
	int ret;
	int i;

	ret = 0;
	virt_dev = xhci->devs[slot_id];
	if (!virt_dev)
		return -ENODEV;

	cmd = xhci_alloc_command(xhci, false, true, GFP_NOIO);
	if (!cmd) {
		xhci_dbg(xhci, "Couldn't allocate command structure.\n");
		return -ENOMEM;
	}

	spin_lock_irqsave(&xhci->lock, flags);
	for (i = LAST_EP_INDEX; i > 0; i--) {
		if (virt_dev->eps[i].ring && virt_dev->eps[i].ring->dequeue) {
			struct xhci_command *command;
			command = xhci_alloc_command(xhci, false, false,
						     GFP_NOWAIT);
			if (!command) {
				spin_unlock_irqrestore(&xhci->lock, flags);
				ret = -ENOMEM;
				goto cmd_cleanup;
			}

			ret = xhci_queue_stop_endpoint(xhci, command, slot_id,
						       i, suspend);
			if (ret) {
				spin_unlock_irqrestore(&xhci->lock, flags);
				xhci_free_command(xhci, command);
				goto cmd_cleanup;
			}
		}
	}
	ret = xhci_queue_stop_endpoint(xhci, cmd, slot_id, 0, suspend);
	if (ret) {
		spin_unlock_irqrestore(&xhci->lock, flags);
		goto cmd_cleanup;
	}

	xhci_ring_cmd_db(xhci);
	spin_unlock_irqrestore(&xhci->lock, flags);

	/* Wait for last stop endpoint command to finish */
	wait_for_completion(cmd->completion);

	if (cmd->status == COMP_CMD_ABORT || cmd->status == COMP_CMD_STOP) {
		xhci_warn(xhci, "Timeout while waiting for stop endpoint command\n");
		ret = -ETIME;
	}

cmd_cleanup:
	xhci_free_command(xhci, cmd);
	return ret;
}

/*
 * Ring device, it rings the all doorbells unconditionally.
 */
void xhci_ring_device(struct xhci_hcd *xhci, int slot_id)
{
	int i, s;
	struct xhci_virt_ep *ep;

	for (i = 0; i < LAST_EP_INDEX + 1; i++) {
		ep = &xhci->devs[slot_id]->eps[i];

		if (ep->ep_state & EP_HAS_STREAMS) {
			for (s = 1; s < ep->stream_info->num_streams; s++)
				xhci_ring_ep_doorbell(xhci, slot_id, i, s);
		} else if (ep->ring && ep->ring->dequeue) {
			xhci_ring_ep_doorbell(xhci, slot_id, i, 0);
		}
	}

	return;
}

static void xhci_disable_port(struct usb_hcd *hcd, struct xhci_hcd *xhci,
		u16 wIndex, __le32 __iomem *addr, u32 port_status)
{
	/* Don't allow the USB core to disable SuperSpeed ports. */
	if (hcd->speed >= HCD_USB3) {
		xhci_dbg(xhci, "Ignoring request to disable "
				"SuperSpeed port.\n");
		return;
	}

	if (xhci->quirks & XHCI_BROKEN_PORT_PED) {
		xhci_dbg(xhci,
			 "Broken Port Enabled/Disabled, ignoring port disable request.\n");
		return;
	}

	/* Write 1 to disable the port */
	writel(port_status | PORT_PE, addr);
	port_status = readl(addr);
	xhci_dbg(xhci, "disable port, actual port %d status  = 0x%x\n",
			wIndex, port_status);
}

static void xhci_clear_port_change_bit(struct xhci_hcd *xhci, u16 wValue,
		u16 wIndex, __le32 __iomem *addr, u32 port_status)
{
	char *port_change_bit;
	u32 status;

	switch (wValue) {
	case USB_PORT_FEAT_C_RESET:
		status = PORT_RC;
		port_change_bit = "reset";
		break;
	case USB_PORT_FEAT_C_BH_PORT_RESET:
		status = PORT_WRC;
		port_change_bit = "warm(BH) reset";
		break;
	case USB_PORT_FEAT_C_CONNECTION:
		status = PORT_CSC;
		port_change_bit = "connect";
		break;
	case USB_PORT_FEAT_C_OVER_CURRENT:
		status = PORT_OCC;
		port_change_bit = "over-current";
		break;
	case USB_PORT_FEAT_C_ENABLE:
		status = PORT_PEC;
		port_change_bit = "enable/disable";
		break;
	case USB_PORT_FEAT_C_SUSPEND:
		status = PORT_PLC;
		port_change_bit = "suspend/resume";
		break;
	case USB_PORT_FEAT_C_PORT_LINK_STATE:
		status = PORT_PLC;
		port_change_bit = "link state";
		break;
	case USB_PORT_FEAT_C_PORT_CONFIG_ERROR:
		status = PORT_CEC;
		port_change_bit = "config error";
		break;
	default:
		/* Should never happen */
		return;
	}
	/* Change bits are all write 1 to clear */
	writel(port_status | status, addr);
	port_status = readl(addr);
	xhci_dbg(xhci, "clear port %s change, actual port %d status  = 0x%x\n",
			port_change_bit, wIndex, port_status);
}

static int xhci_get_ports(struct usb_hcd *hcd, __le32 __iomem ***port_array)
{
	int max_ports;
	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);

	if (hcd->speed >= HCD_USB3) {
		max_ports = xhci->num_usb3_ports;
		*port_array = xhci->usb3_ports;
	} else {
		max_ports = xhci->num_usb2_ports;
		*port_array = xhci->usb2_ports;
	}

	return max_ports;
}

void xhci_set_link_state(struct xhci_hcd *xhci, __le32 __iomem **port_array,
				int port_id, u32 link_state)
{
	u32 temp;

	temp = readl(port_array[port_id]);
	temp = xhci_port_state_to_neutral(temp);
	temp &= ~PORT_PLS_MASK;
	temp |= PORT_LINK_STROBE | link_state;
	writel(temp, port_array[port_id]);
}

static void xhci_set_remote_wake_mask(struct xhci_hcd *xhci,
		__le32 __iomem **port_array, int port_id, u16 wake_mask)
{
	u32 temp;

	temp = readl(port_array[port_id]);
	temp = xhci_port_state_to_neutral(temp);

	if (wake_mask & USB_PORT_FEAT_REMOTE_WAKE_CONNECT)
		temp |= PORT_WKCONN_E;
	else
		temp &= ~PORT_WKCONN_E;

	if (wake_mask & USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT)
		temp |= PORT_WKDISC_E;
	else
		temp &= ~PORT_WKDISC_E;

	if (wake_mask & USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT)
		temp |= PORT_WKOC_E;
	else
		temp &= ~PORT_WKOC_E;

	writel(temp, port_array[port_id]);
}

/* Test and clear port RWC bit */
void xhci_test_and_clear_bit(struct xhci_hcd *xhci, __le32 __iomem **port_array,
				int port_id, u32 port_bit)
{
	u32 temp;

	temp = readl(port_array[port_id]);
	if (temp & port_bit) {
		temp = xhci_port_state_to_neutral(temp);
		temp |= port_bit;
		writel(temp, port_array[port_id]);
	}
}

/* Updates Link Status for USB 2.1 port */
static void xhci_hub_report_usb2_link_state(u32 *status, u32 status_reg)
{
	if ((status_reg & PORT_PLS_MASK) == XDEV_U2)
		*status |= USB_PORT_STAT_L1;
}

/* Updates Link Status for super Speed port */
static void xhci_hub_report_usb3_link_state(struct xhci_hcd *xhci,
		u32 *status, u32 status_reg)
{
	u32 pls = status_reg & PORT_PLS_MASK;

	/* resume state is a xHCI internal state.
	 * Do not report it to usb core, instead, pretend to be U3,
	 * thus usb core knows it's not ready for transfer
	 */
	if (pls == XDEV_RESUME) {
		*status |= USB_SS_PORT_LS_U3;
		return;
	}

	/* When the CAS bit is set then warm reset
	 * should be performed on port
	 */
	if (status_reg & PORT_CAS) {
		/* The CAS bit can be set while the port is
		 * in any link state.
		 * Only roothubs have CAS bit, so we
		 * pretend to be in compliance mode
		 * unless we're already in compliance
		 * or the inactive state.
		 */
		if (pls != USB_SS_PORT_LS_COMP_MOD &&
		    pls != USB_SS_PORT_LS_SS_INACTIVE) {
			pls = USB_SS_PORT_LS_COMP_MOD;
		}
		/* Return also connection bit -
		 * hub state machine resets port
		 * when this bit is set.
		 */
		pls |= USB_PORT_STAT_CONNECTION;
	} else {
		/*
		 * If CAS bit isn't set but the Port is already at
		 * Compliance Mode, fake a connection so the USB core
		 * notices the Compliance state and resets the port.
		 * This resolves an issue generated by the SN65LVPE502CP
		 * in which sometimes the port enters compliance mode
		 * caused by a delay on the host-device negotiation.
		 */
		if ((xhci->quirks & XHCI_COMP_MODE_QUIRK) &&
				(pls == USB_SS_PORT_LS_COMP_MOD))
			pls |= USB_PORT_STAT_CONNECTION;
	}

	/* update status field */
	*status |= pls;
}

/*
 * Function for Compliance Mode Quirk.
 *
 * This Function verifies if all xhc USB3 ports have entered U0, if so,
 * the compliance mode timer is deleted. A port won't enter
 * compliance mode if it has previously entered U0.
 */
static void xhci_del_comp_mod_timer(struct xhci_hcd *xhci, u32 status,
				    u16 wIndex)
{
	u32 all_ports_seen_u0 = ((1 << xhci->num_usb3_ports)-1);
	bool port_in_u0 = ((status & PORT_PLS_MASK) == XDEV_U0);

	if (!(xhci->quirks & XHCI_COMP_MODE_QUIRK))
		return;

	if ((xhci->port_status_u0 != all_ports_seen_u0) && port_in_u0) {
		xhci->port_status_u0 |= 1 << wIndex;
		if (xhci->port_status_u0 == all_ports_seen_u0) {
			del_timer_sync(&xhci->comp_mode_recovery_timer);
			xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
				"All USB3 ports have entered U0 already!");
			xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
				"Compliance Mode Recovery Timer Deleted.");
		}
	}
}

static u32 xhci_get_ext_port_status(u32 raw_port_status, u32 port_li)
{
	u32 ext_stat = 0;
	int speed_id;

	/* only support rx and tx lane counts of 1 in usb3.1 spec */
	speed_id = DEV_PORT_SPEED(raw_port_status);
	ext_stat |= speed_id;		/* bits 3:0, RX speed id */
	ext_stat |= speed_id << 4;	/* bits 7:4, TX speed id */

	ext_stat |= PORT_RX_LANES(port_li) << 8;  /* bits 11:8 Rx lane count */
	ext_stat |= PORT_TX_LANES(port_li) << 12; /* bits 15:12 Tx lane count */

	return ext_stat;
}

/*
 * Converts a raw xHCI port status into the format that external USB 2.0 or USB
 * 3.0 hubs use.
 *
 * Possible side effects:
 *  - Mark a port as being done with device resume,
 *    and ring the endpoint doorbells.
 *  - Stop the Synopsys redriver Compliance Mode polling.
 *  - Drop and reacquire the xHCI lock, in order to wait for port resume.
 */
static u32 xhci_get_port_status(struct usb_hcd *hcd,
		struct xhci_bus_state *bus_state,
		__le32 __iomem **port_array,
		u16 wIndex, u32 raw_port_status,
		unsigned long flags)
	__releases(&xhci->lock)
	__acquires(&xhci->lock)
{
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	u32 status = 0;
	int slot_id;

	/* wPortChange bits */
	if (raw_port_status & PORT_CSC)
		status |= USB_PORT_STAT_C_CONNECTION << 16;
	if (raw_port_status & PORT_PEC)
		status |= USB_PORT_STAT_C_ENABLE << 16;
	if ((raw_port_status & PORT_OCC))
		status |= USB_PORT_STAT_C_OVERCURRENT << 16;
	if ((raw_port_status & PORT_RC))
		status |= USB_PORT_STAT_C_RESET << 16;
	/* USB3.0 only */
	if (hcd->speed >= HCD_USB3) {
		/* Port link change with port in resume state should not be
		 * reported to usbcore, as this is an internal state to be
		 * handled by xhci driver. Reporting PLC to usbcore may
		 * cause usbcore clearing PLC first and port change event
		 * irq won't be generated.
		 */
		if ((raw_port_status & PORT_PLC) &&
			(raw_port_status & PORT_PLS_MASK) != XDEV_RESUME)
			status |= USB_PORT_STAT_C_LINK_STATE << 16;
		if ((raw_port_status & PORT_WRC))
			status |= USB_PORT_STAT_C_BH_RESET << 16;
		if ((raw_port_status & PORT_CEC))
			status |= USB_PORT_STAT_C_CONFIG_ERROR << 16;
	}

	if (hcd->speed < HCD_USB3) {
		if ((raw_port_status & PORT_PLS_MASK) == XDEV_U3
				&& (raw_port_status & PORT_POWER))
			status |= USB_PORT_STAT_SUSPEND;
	}
	if ((raw_port_status & PORT_PLS_MASK) == XDEV_RESUME &&
		!DEV_SUPERSPEED_ANY(raw_port_status)) {
		if ((raw_port_status & PORT_RESET) ||
				!(raw_port_status & PORT_PE))
			return 0xffffffff;
		/* did port event handler already start resume timing? */
		if (!bus_state->resume_done[wIndex]) {
			/* If not, maybe we are in a host initated resume? */
			if (test_bit(wIndex, &bus_state->resuming_ports)) {
				/* Host initated resume doesn't time the resume
				 * signalling using resume_done[].
				 * It manually sets RESUME state, sleeps 20ms
				 * and sets U0 state. This should probably be
				 * changed, but not right now.
				 */
			} else {
				/* port resume was discovered now and here,
				 * start resume timing
				 */
				unsigned long timeout = jiffies +
					msecs_to_jiffies(USB_RESUME_TIMEOUT);

				set_bit(wIndex, &bus_state->resuming_ports);
				bus_state->resume_done[wIndex] = timeout;
				mod_timer(&hcd->rh_timer, timeout);
			}
		/* Has resume been signalled for USB_RESUME_TIME yet? */
		} else if (time_after_eq(jiffies,
					 bus_state->resume_done[wIndex])) {
			int time_left;

			xhci_dbg(xhci, "Resume USB2 port %d\n",
					wIndex + 1);
			bus_state->resume_done[wIndex] = 0;
			clear_bit(wIndex, &bus_state->resuming_ports);

			set_bit(wIndex, &bus_state->rexit_ports);

			xhci_test_and_clear_bit(xhci, port_array, wIndex,
						PORT_PLC);
			xhci_set_link_state(xhci, port_array, wIndex,
					XDEV_U0);

			spin_unlock_irqrestore(&xhci->lock, flags);
			time_left = wait_for_completion_timeout(
					&bus_state->rexit_done[wIndex],
					msecs_to_jiffies(
						XHCI_MAX_REXIT_TIMEOUT));
			spin_lock_irqsave(&xhci->lock, flags);

			if (time_left) {
				slot_id = xhci_find_slot_id_by_port(hcd,
						xhci, wIndex + 1);
				if (!slot_id) {
					xhci_dbg(xhci, "slot_id is zero\n");
					return 0xffffffff;
				}
				xhci_ring_device(xhci, slot_id);
			} else {
				int port_status = readl(port_array[wIndex]);
				xhci_warn(xhci, "Port resume took longer than %i msec, port status = 0x%x\n",
						XHCI_MAX_REXIT_TIMEOUT,
						port_status);
				status |= USB_PORT_STAT_SUSPEND;
				clear_bit(wIndex, &bus_state->rexit_ports);
			}

			bus_state->port_c_suspend |= 1 << wIndex;
			bus_state->suspended_ports &= ~(1 << wIndex);
		} else {
			/*
			 * The resume has been signaling for less than
			 * USB_RESUME_TIME. Report the port status as SUSPEND,
			 * let the usbcore check port status again and clear
			 * resume signaling later.
			 */
			status |= USB_PORT_STAT_SUSPEND;
		}
	}
	/*
	 * Clear stale usb2 resume signalling variables in case port changed
	 * state during resume signalling. For example on error
	 */
	if ((bus_state->resume_done[wIndex] ||
	     test_bit(wIndex, &bus_state->resuming_ports)) &&
	    (raw_port_status & PORT_PLS_MASK) != XDEV_U3 &&
	    (raw_port_status & PORT_PLS_MASK) != XDEV_RESUME) {
		bus_state->resume_done[wIndex] = 0;
		clear_bit(wIndex, &bus_state->resuming_ports);
	}


	if ((raw_port_status & PORT_PLS_MASK) == XDEV_U0 &&
	    (raw_port_status & PORT_POWER)) {
		if (bus_state->suspended_ports & (1 << wIndex)) {
			bus_state->suspended_ports &= ~(1 << wIndex);
			if (hcd->speed < HCD_USB3)
				bus_state->port_c_suspend |= 1 << wIndex;
		}
		bus_state->resume_done[wIndex] = 0;
		clear_bit(wIndex, &bus_state->resuming_ports);
	}
	if (raw_port_status & PORT_CONNECT) {
		status |= USB_PORT_STAT_CONNECTION;
		status |= xhci_port_speed(raw_port_status);
	}
	if (raw_port_status & PORT_PE)
		status |= USB_PORT_STAT_ENABLE;
	if (raw_port_status & PORT_OC)
		status |= USB_PORT_STAT_OVERCURRENT;
	if (raw_port_status & PORT_RESET)
		status |= USB_PORT_STAT_RESET;
	if (raw_port_status & PORT_POWER) {
		if (hcd->speed >= HCD_USB3)
			status |= USB_SS_PORT_STAT_POWER;
		else
			status |= USB_PORT_STAT_POWER;
	}
	/* Update Port Link State */
	if (hcd->speed >= HCD_USB3) {
		xhci_hub_report_usb3_link_state(xhci, &status, raw_port_status);
		/*
		 * Verify if all USB3 Ports Have entered U0 already.
		 * Delete Compliance Mode Timer if so.
		 */
		xhci_del_comp_mod_timer(xhci, raw_port_status, wIndex);
	} else {
		xhci_hub_report_usb2_link_state(&status, raw_port_status);
	}
	if (bus_state->port_c_suspend & (1 << wIndex))
		status |= USB_PORT_STAT_C_SUSPEND << 16;

	return status;
}

int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
		u16 wIndex, char *buf, u16 wLength)
{
	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
	int max_ports;
	unsigned long flags;
	u32 temp, status;
	int retval = 0;
	__le32 __iomem **port_array;
	int slot_id;
	struct xhci_bus_state *bus_state;
	u16 link_state = 0;
	u16 wake_mask = 0;
	u16 timeout = 0;

	max_ports = xhci_get_ports(hcd, &port_array);
	bus_state = &xhci->bus_state[hcd_index(hcd)];

	spin_lock_irqsave(&xhci->lock, flags);
	switch (typeReq) {
	case GetHubStatus:
		/* No power source, over-current reported per port */
		memset(buf, 0, 4);
		break;
	case GetHubDescriptor:
		/* Check to make sure userspace is asking for the USB 3.0 hub
		 * descriptor for the USB 3.0 roothub.  If not, we stall the
		 * endpoint, like external hubs do.
		 */
		if (hcd->speed >= HCD_USB3 &&
				(wLength < USB_DT_SS_HUB_SIZE ||
				 wValue != (USB_DT_SS_HUB << 8))) {
			xhci_dbg(xhci, "Wrong hub descriptor type for "
					"USB 3.0 roothub.\n");
			goto error;
		}
		xhci_hub_descriptor(hcd, xhci,
				(struct usb_hub_descriptor *) buf);
		break;
	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
		if ((wValue & 0xff00) != (USB_DT_BOS << 8))
			goto error;

		if (hcd->speed < HCD_USB3)
			goto error;

		retval = xhci_create_usb3_bos_desc(xhci, buf, wLength);
		spin_unlock_irqrestore(&xhci->lock, flags);
		return retval;
	case GetPortStatus:
		if (!wIndex || wIndex > max_ports)
			goto error;
		wIndex--;
		temp = readl(port_array[wIndex]);
		if (temp == 0xffffffff) {
			retval = -ENODEV;
			break;
		}
		status = xhci_get_port_status(hcd, bus_state, port_array,
				wIndex, temp, flags);
		if (status == 0xffffffff)
			goto error;

		xhci_dbg(xhci, "get port status, actual port %d status  = 0x%x\n",
				wIndex, temp);
		xhci_dbg(xhci, "Get port status returned 0x%x\n", status);

		put_unaligned(cpu_to_le32(status), (__le32 *) buf);
		/* if USB 3.1 extended port status return additional 4 bytes */
		if (wValue == 0x02) {
			u32 port_li;

			if (hcd->speed < HCD_USB31 || wLength != 8) {
				xhci_err(xhci, "get ext port status invalid parameter\n");
				retval = -EINVAL;
				break;
			}
			port_li = readl(port_array[wIndex] + PORTLI);
			status = xhci_get_ext_port_status(temp, port_li);
			put_unaligned_le32(cpu_to_le32(status), &buf[4]);
		}
		break;
	case SetPortFeature:
		if (wValue == USB_PORT_FEAT_LINK_STATE)
			link_state = (wIndex & 0xff00) >> 3;
		if (wValue == USB_PORT_FEAT_REMOTE_WAKE_MASK)
			wake_mask = wIndex & 0xff00;
		/* The MSB of wIndex is the U1/U2 timeout */
		timeout = (wIndex & 0xff00) >> 8;
		wIndex &= 0xff;
		if (!wIndex || wIndex > max_ports)
			goto error;
		wIndex--;
		temp = readl(port_array[wIndex]);
		if (temp == 0xffffffff) {
			retval = -ENODEV;
			break;
		}
		temp = xhci_port_state_to_neutral(temp);
		/* FIXME: What new port features do we need to support? */
		switch (wValue) {
		case USB_PORT_FEAT_SUSPEND:
			temp = readl(port_array[wIndex]);
			if ((temp & PORT_PLS_MASK) != XDEV_U0) {
				/* Resume the port to U0 first */
				xhci_set_link_state(xhci, port_array, wIndex,
							XDEV_U0);
				spin_unlock_irqrestore(&xhci->lock, flags);
				msleep(10);
				spin_lock_irqsave(&xhci->lock, flags);
			}
			/* In spec software should not attempt to suspend
			 * a port unless the port reports that it is in the
			 * enabled (PED = ‘1’,PLS < ‘3’) state.
			 */
			temp = readl(port_array[wIndex]);
			if ((temp & PORT_PE) == 0 || (temp & PORT_RESET)
				|| (temp & PORT_PLS_MASK) >= XDEV_U3) {
				xhci_warn(xhci, "USB core suspending device "
					  "not in U0/U1/U2.\n");
				goto error;
			}

			slot_id = xhci_find_slot_id_by_port(hcd, xhci,
					wIndex + 1);
			if (!slot_id) {
				xhci_warn(xhci, "slot_id is zero\n");
				goto error;
			}
			/* unlock to execute stop endpoint commands */
			spin_unlock_irqrestore(&xhci->lock, flags);
			xhci_stop_device(xhci, slot_id, 1);
			spin_lock_irqsave(&xhci->lock, flags);

			xhci_set_link_state(xhci, port_array, wIndex, XDEV_U3);

			spin_unlock_irqrestore(&xhci->lock, flags);
			msleep(10); /* wait device to enter */
			spin_lock_irqsave(&xhci->lock, flags);

			temp = readl(port_array[wIndex]);
			bus_state->suspended_ports |= 1 << wIndex;
			break;
		case USB_PORT_FEAT_LINK_STATE:
			temp = readl(port_array[wIndex]);

			/* Disable port */
			if (link_state == USB_SS_PORT_LS_SS_DISABLED) {
				xhci_dbg(xhci, "Disable port %d\n", wIndex);
				temp = xhci_port_state_to_neutral(temp);
				/*
				 * Clear all change bits, so that we get a new
				 * connection event.
				 */
				temp |= PORT_CSC | PORT_PEC | PORT_WRC |
					PORT_OCC | PORT_RC | PORT_PLC |
					PORT_CEC;
				writel(temp | PORT_PE, port_array[wIndex]);
				temp = readl(port_array[wIndex]);
				break;
			}

			/* Put link in RxDetect (enable port) */
			if (link_state == USB_SS_PORT_LS_RX_DETECT) {
				xhci_dbg(xhci, "Enable port %d\n", wIndex);
				xhci_set_link_state(xhci, port_array, wIndex,
						link_state);
				temp = readl(port_array[wIndex]);
				break;
			}

			/* Software should not attempt to set
			 * port link state above '3' (U3) and the port
			 * must be enabled.
			 */
			if ((temp & PORT_PE) == 0 ||
				(link_state > USB_SS_PORT_LS_U3)) {
				xhci_warn(xhci, "Cannot set link state.\n");
				goto error;
			}

			if (link_state == USB_SS_PORT_LS_U3) {
				slot_id = xhci_find_slot_id_by_port(hcd, xhci,
						wIndex + 1);
				if (slot_id) {
					/* unlock to execute stop endpoint
					 * commands */
					spin_unlock_irqrestore(&xhci->lock,
								flags);
					xhci_stop_device(xhci, slot_id, 1);
					spin_lock_irqsave(&xhci->lock, flags);
				}
			}

			xhci_set_link_state(xhci, port_array, wIndex,
						link_state);

			spin_unlock_irqrestore(&xhci->lock, flags);
			msleep(20); /* wait device to enter */
			spin_lock_irqsave(&xhci->lock, flags);

			temp = readl(port_array[wIndex]);
			if (link_state == USB_SS_PORT_LS_U3)
				bus_state->suspended_ports |= 1 << wIndex;
			break;
		case USB_PORT_FEAT_POWER:
			/*
			 * Turn on ports, even if there isn't per-port switching.
			 * HC will report connect events even before this is set.
			 * However, hub_wq will ignore the roothub events until
			 * the roothub is registered.
			 */
			writel(temp | PORT_POWER, port_array[wIndex]);

			temp = readl(port_array[wIndex]);
			xhci_dbg(xhci, "set port power, actual port %d status  = 0x%x\n", wIndex, temp);

			spin_unlock_irqrestore(&xhci->lock, flags);
			temp = usb_acpi_power_manageable(hcd->self.root_hub,
					wIndex);
			if (temp)
				usb_acpi_set_power_state(hcd->self.root_hub,
						wIndex, true);
			spin_lock_irqsave(&xhci->lock, flags);
			break;
		case USB_PORT_FEAT_RESET:
			temp = (temp | PORT_RESET);
			writel(temp, port_array[wIndex]);

			temp = readl(port_array[wIndex]);
			xhci_dbg(xhci, "set port reset, actual port %d status  = 0x%x\n", wIndex, temp);
			break;
		case USB_PORT_FEAT_REMOTE_WAKE_MASK:
			xhci_set_remote_wake_mask(xhci, port_array,
					wIndex, wake_mask);
			temp = readl(port_array[wIndex]);
			xhci_dbg(xhci, "set port remote wake mask, "
					"actual port %d status  = 0x%x\n",
					wIndex, temp);
			break;
		case USB_PORT_FEAT_BH_PORT_RESET:
			temp |= PORT_WR;
			writel(temp, port_array[wIndex]);

			temp = readl(port_array[wIndex]);
			break;
		case USB_PORT_FEAT_U1_TIMEOUT:
			if (hcd->speed < HCD_USB3)
				goto error;
			temp = readl(port_array[wIndex] + PORTPMSC);
			temp &= ~PORT_U1_TIMEOUT_MASK;
			temp |= PORT_U1_TIMEOUT(timeout);
			writel(temp, port_array[wIndex] + PORTPMSC);
			break;
		case USB_PORT_FEAT_U2_TIMEOUT:
			if (hcd->speed < HCD_USB3)
				goto error;
			temp = readl(port_array[wIndex] + PORTPMSC);
			temp &= ~PORT_U2_TIMEOUT_MASK;
			temp |= PORT_U2_TIMEOUT(timeout);
			writel(temp, port_array[wIndex] + PORTPMSC);
			break;
		default:
			goto error;
		}
		/* unblock any posted writes */
		temp = readl(port_array[wIndex]);
		break;
	case ClearPortFeature:
		if (!wIndex || wIndex > max_ports)
			goto error;
		wIndex--;
		temp = readl(port_array[wIndex]);
		if (temp == 0xffffffff) {
			retval = -ENODEV;
			break;
		}
		/* FIXME: What new port features do we need to support? */
		temp = xhci_port_state_to_neutral(temp);
		switch (wValue) {
		case USB_PORT_FEAT_SUSPEND:
			temp = readl(port_array[wIndex]);
			xhci_dbg(xhci, "clear USB_PORT_FEAT_SUSPEND\n");
			xhci_dbg(xhci, "PORTSC %04x\n", temp);
			if (temp & PORT_RESET)
				goto error;
			if ((temp & PORT_PLS_MASK) == XDEV_U3) {
				if ((temp & PORT_PE) == 0)
					goto error;

				set_bit(wIndex, &bus_state->resuming_ports);
				xhci_set_link_state(xhci, port_array, wIndex,
							XDEV_RESUME);
				spin_unlock_irqrestore(&xhci->lock, flags);
				msleep(USB_RESUME_TIMEOUT);
				spin_lock_irqsave(&xhci->lock, flags);
				xhci_set_link_state(xhci, port_array, wIndex,
							XDEV_U0);
				clear_bit(wIndex, &bus_state->resuming_ports);
			}
			bus_state->port_c_suspend |= 1 << wIndex;

			slot_id = xhci_find_slot_id_by_port(hcd, xhci,
					wIndex + 1);
			if (!slot_id) {
				xhci_dbg(xhci, "slot_id is zero\n");
				goto error;
			}
			xhci_ring_device(xhci, slot_id);
			break;
		case USB_PORT_FEAT_C_SUSPEND:
			bus_state->port_c_suspend &= ~(1 << wIndex);
		case USB_PORT_FEAT_C_RESET:
		case USB_PORT_FEAT_C_BH_PORT_RESET:
		case USB_PORT_FEAT_C_CONNECTION:
		case USB_PORT_FEAT_C_OVER_CURRENT:
		case USB_PORT_FEAT_C_ENABLE:
		case USB_PORT_FEAT_C_PORT_LINK_STATE:
		case USB_PORT_FEAT_C_PORT_CONFIG_ERROR:
			xhci_clear_port_change_bit(xhci, wValue, wIndex,
					port_array[wIndex], temp);
			break;
		case USB_PORT_FEAT_ENABLE:
			xhci_disable_port(hcd, xhci, wIndex,
					port_array[wIndex], temp);
			break;
		case USB_PORT_FEAT_POWER:
			writel(temp & ~PORT_POWER, port_array[wIndex]);

			spin_unlock_irqrestore(&xhci->lock, flags);
			temp = usb_acpi_power_manageable(hcd->self.root_hub,
					wIndex);
			if (temp)
				usb_acpi_set_power_state(hcd->self.root_hub,
						wIndex, false);
			spin_lock_irqsave(&xhci->lock, flags);
			break;
		default:
			goto error;
		}
		break;
	default:
error:
		/* "stall" on error */
		retval = -EPIPE;
	}
	spin_unlock_irqrestore(&xhci->lock, flags);
	return retval;
}

/*
 * Returns 0 if the status hasn't changed, or the number of bytes in buf.
 * Ports are 0-indexed from the HCD point of view,
 * and 1-indexed from the USB core pointer of view.
 *
 * Note that the status change bits will be cleared as soon as a port status
 * change event is generated, so we use the saved status from that event.
 */
int xhci_hub_status_data(struct usb_hcd *hcd, char *buf)
{
	unsigned long flags;
	u32 temp, status;
	u32 mask;
	int i, retval;
	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
	int max_ports;
	__le32 __iomem **port_array;
	struct xhci_bus_state *bus_state;
	bool reset_change = false;

	max_ports = xhci_get_ports(hcd, &port_array);
	bus_state = &xhci->bus_state[hcd_index(hcd)];

	/* Initial status is no changes */
	retval = (max_ports + 8) / 8;
	memset(buf, 0, retval);

	/*
	 * Inform the usbcore about resume-in-progress by returning
	 * a non-zero value even if there are no status changes.
	 */
	status = bus_state->resuming_ports;

	mask = PORT_CSC | PORT_PEC | PORT_OCC | PORT_PLC | PORT_WRC | PORT_CEC;

	spin_lock_irqsave(&xhci->lock, flags);
	/* For each port, did anything change?  If so, set that bit in buf. */
	for (i = 0; i < max_ports; i++) {
		temp = readl(port_array[i]);
		if (temp == 0xffffffff) {
			retval = -ENODEV;
			break;
		}
		if ((temp & mask) != 0 ||
			(bus_state->port_c_suspend & 1 << i) ||
			(bus_state->resume_done[i] && time_after_eq(
			    jiffies, bus_state->resume_done[i]))) {
			buf[(i + 1) / 8] |= 1 << (i + 1) % 8;
			status = 1;
		}
		if ((temp & PORT_RC))
			reset_change = true;
	}
	if (!status && !reset_change) {
		xhci_dbg(xhci, "%s: stopping port polling.\n", __func__);
		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
	}
	spin_unlock_irqrestore(&xhci->lock, flags);
	return status ? retval : 0;
}

#ifdef CONFIG_PM

int xhci_bus_suspend(struct usb_hcd *hcd)
{
	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
	int max_ports, port_index;
	__le32 __iomem **port_array;
	struct xhci_bus_state *bus_state;
	unsigned long flags;

	max_ports = xhci_get_ports(hcd, &port_array);
	bus_state = &xhci->bus_state[hcd_index(hcd)];

	spin_lock_irqsave(&xhci->lock, flags);

	if (hcd->self.root_hub->do_remote_wakeup) {
		if (bus_state->resuming_ports ||	/* USB2 */
		    bus_state->port_remote_wakeup) {	/* USB3 */
			spin_unlock_irqrestore(&xhci->lock, flags);
			xhci_dbg(xhci, "suspend failed because a port is resuming\n");
			return -EBUSY;
		}
	}

	port_index = max_ports;
	bus_state->bus_suspended = 0;
	while (port_index--) {
		/* suspend the port if the port is not suspended */
		u32 t1, t2;
		int slot_id;

		t1 = readl(port_array[port_index]);
		t2 = xhci_port_state_to_neutral(t1);

		if ((t1 & PORT_PE) && !(t1 & PORT_PLS_MASK)) {
			xhci_dbg(xhci, "port %d not suspended\n", port_index);
			slot_id = xhci_find_slot_id_by_port(hcd, xhci,
					port_index + 1);
			if (slot_id) {
				spin_unlock_irqrestore(&xhci->lock, flags);
				xhci_stop_device(xhci, slot_id, 1);
				spin_lock_irqsave(&xhci->lock, flags);
			}
			t2 &= ~PORT_PLS_MASK;
			t2 |= PORT_LINK_STROBE | XDEV_U3;
			set_bit(port_index, &bus_state->bus_suspended);
		}
		/* USB core sets remote wake mask for USB 3.0 hubs,
		 * including the USB 3.0 roothub, but only if CONFIG_PM
		 * is enabled, so also enable remote wake here.
		 */
		if (hcd->self.root_hub->do_remote_wakeup) {
			if (t1 & PORT_CONNECT) {
				t2 |= PORT_WKOC_E | PORT_WKDISC_E;
				t2 &= ~PORT_WKCONN_E;
			} else {
				t2 |= PORT_WKOC_E | PORT_WKCONN_E;
				t2 &= ~PORT_WKDISC_E;
			}
		} else
			t2 &= ~PORT_WAKE_BITS;

		t1 = xhci_port_state_to_neutral(t1);
		if (t1 != t2)
			writel(t2, port_array[port_index]);
	}
	hcd->state = HC_STATE_SUSPENDED;
	bus_state->next_statechange = jiffies + msecs_to_jiffies(10);
	spin_unlock_irqrestore(&xhci->lock, flags);
	return 0;
}

/*
 * Workaround for missing Cold Attach Status (CAS) if device re-plugged in S3.
 * warm reset a USB3 device stuck in polling or compliance mode after resume.
 * See Intel 100/c230 series PCH specification update Doc #332692-006 Errata #8
 */
static bool xhci_port_missing_cas_quirk(int port_index,
					     __le32 __iomem **port_array)
{
	u32 portsc;

	portsc = readl(port_array[port_index]);

	/* if any of these are set we are not stuck */
	if (portsc & (PORT_CONNECT | PORT_CAS))
		return false;

	if (((portsc & PORT_PLS_MASK) != XDEV_POLLING) &&
	    ((portsc & PORT_PLS_MASK) != XDEV_COMP_MODE))
		return false;

	/* clear wakeup/change bits, and do a warm port reset */
	portsc &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS);
	portsc |= PORT_WR;
	writel(portsc, port_array[port_index]);
	/* flush write */
	readl(port_array[port_index]);
	return true;
}

int xhci_bus_resume(struct usb_hcd *hcd)
{
	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
	int max_ports, port_index;
	__le32 __iomem **port_array;
	struct xhci_bus_state *bus_state;
	u32 temp;
	unsigned long flags;
	unsigned long port_was_suspended = 0;
	bool need_usb2_u3_exit = false;
	int slot_id;
	int sret;

	max_ports = xhci_get_ports(hcd, &port_array);
	bus_state = &xhci->bus_state[hcd_index(hcd)];

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

	spin_lock_irqsave(&xhci->lock, flags);
	if (!HCD_HW_ACCESSIBLE(hcd)) {
		spin_unlock_irqrestore(&xhci->lock, flags);
		return -ESHUTDOWN;
	}

	/* delay the irqs */
	temp = readl(&xhci->op_regs->command);
	temp &= ~CMD_EIE;
	writel(temp, &xhci->op_regs->command);

	port_index = max_ports;
	while (port_index--) {
		/* Check whether need resume ports. If needed
		   resume port and disable remote wakeup */
		u32 temp;

		temp = readl(port_array[port_index]);

		/* warm reset CAS limited ports stuck in polling/compliance */
		if ((xhci->quirks & XHCI_MISSING_CAS) &&
		    (hcd->speed >= HCD_USB3) &&
		    xhci_port_missing_cas_quirk(port_index, port_array)) {
			xhci_dbg(xhci, "reset stuck port %d\n", port_index);
			continue;
		}
		if (DEV_SUPERSPEED_ANY(temp))
			temp &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS);
		else
			temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
		if (test_bit(port_index, &bus_state->bus_suspended) &&
		    (temp & PORT_PLS_MASK)) {
			set_bit(port_index, &port_was_suspended);
			if (!DEV_SUPERSPEED_ANY(temp)) {
				xhci_set_link_state(xhci, port_array,
						port_index, XDEV_RESUME);
				need_usb2_u3_exit = true;
			}
		} else
			writel(temp, port_array[port_index]);
	}

	if (need_usb2_u3_exit) {
		spin_unlock_irqrestore(&xhci->lock, flags);
		msleep(USB_RESUME_TIMEOUT);
		spin_lock_irqsave(&xhci->lock, flags);
	}

	port_index = max_ports;
	while (port_index--) {
		if (!(port_was_suspended & BIT(port_index)))
			continue;
		/* Clear PLC to poll it later after XDEV_U0 */
		xhci_test_and_clear_bit(xhci, port_array, port_index, PORT_PLC);
		xhci_set_link_state(xhci, port_array, port_index, XDEV_U0);
	}

	port_index = max_ports;
	while (port_index--) {
		if (!(port_was_suspended & BIT(port_index)))
			continue;
		/* Poll and Clear PLC */
		sret = xhci_handshake(port_array[port_index], PORT_PLC,
				      PORT_PLC, 10 * 1000);
		if (sret)
			xhci_warn(xhci, "port %d resume PLC timeout\n",
				  port_index);
		xhci_test_and_clear_bit(xhci, port_array, port_index, PORT_PLC);
		slot_id = xhci_find_slot_id_by_port(hcd, xhci, port_index + 1);
		if (slot_id)
			xhci_ring_device(xhci, slot_id);
	}

	(void) readl(&xhci->op_regs->command);

	bus_state->next_statechange = jiffies + msecs_to_jiffies(5);
	/* re-enable irqs */
	temp = readl(&xhci->op_regs->command);
	temp |= CMD_EIE;
	writel(temp, &xhci->op_regs->command);
	temp = readl(&xhci->op_regs->command);

	spin_unlock_irqrestore(&xhci->lock, flags);
	return 0;
}

#endif	/* CONFIG_PM */