/*
 * 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/gfp.h>
#include <asm/unaligned.h>

#include "xhci.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 3.0 BOS descriptor and a capability descriptor, combined */
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 */
        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. */
};


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 = xhci_readl(xhci, 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 = xhci_readl(xhci, 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 timeleft;
        int ret;
        int i;

        ret = 0;
        virt_dev = xhci->devs[slot_id];
        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)
                        xhci_queue_stop_endpoint(xhci, slot_id, i, suspend);
        }
        cmd->command_trb = xhci->cmd_ring->enqueue;
        list_add_tail(&cmd->cmd_list, &virt_dev->cmd_list);
        xhci_queue_stop_endpoint(xhci, slot_id, 0, suspend);
        xhci_ring_cmd_db(xhci);
        spin_unlock_irqrestore(&xhci->lock, flags);

        /* Wait for last stop endpoint command to finish */
        timeleft = wait_for_completion_interruptible_timeout(
                        cmd->completion,
                        USB_CTRL_SET_TIMEOUT);
        if (timeleft <= 0) {
                xhci_warn(xhci, "%s while waiting for stop endpoint command\n",
                                timeleft == 0 ? "Timeout" : "Signal");
                spin_lock_irqsave(&xhci->lock, flags);
                /* The timeout might have raced with the event ring handler, so
                 * only delete from the list if the item isn't poisoned.
                 */
                if (cmd->cmd_list.next != LIST_POISON1)
                        list_del(&cmd->cmd_list);
                spin_unlock_irqrestore(&xhci->lock, flags);
                ret = -ETIME;
                goto command_cleanup;
        }

command_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;

        for (i = 0; i < LAST_EP_INDEX + 1; i++)
                if (xhci->devs[slot_id]->eps[i].ring &&
                    xhci->devs[slot_id]->eps[i].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;
        }

        /* Write 1 to disable the port */
        xhci_writel(xhci, port_status | PORT_PE, addr);
        port_status = xhci_readl(xhci, 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;
        default:
                /* Should never happen */
                return;
        }
        /* Change bits are all write 1 to clear */
        xhci_writel(xhci, port_status | status, addr);
        port_status = xhci_readl(xhci, 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 = xhci_readl(xhci, port_array[port_id]);
        temp = xhci_port_state_to_neutral(temp);
        temp &= ~PORT_PLS_MASK;
        temp |= PORT_LINK_STROBE | link_state;
        xhci_writel(xhci, 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 = xhci_readl(xhci, 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;

        xhci_writel(xhci, 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 = xhci_readl(xhci, port_array[port_id]);
        if (temp & port_bit) {
                temp = xhci_port_state_to_neutral(temp);
                temp |= port_bit;
                xhci_writel(xhci, temp, port_array[port_id]);
        }
}

/* Updates Link Status for super Speed port */
static void xhci_hub_report_link_state(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.
         */
        if (pls == XDEV_RESUME)
                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 (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.
 */
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(xhci, "All USB3 ports have entered U0 already!\n");
                        xhci_dbg(xhci, "Compliance Mode Recovery Timer Deleted.\n");
                }
        }
}

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;

                /* Set the U1 and U2 exit latencies. */
                memcpy(buf, &usb_bos_descriptor,
                                USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE);
                temp = xhci_readl(xhci, &xhci->cap_regs->hcs_params3);
                buf[12] = HCS_U1_LATENCY(temp);
                put_unaligned_le16(HCS_U2_LATENCY(temp), &buf[13]);

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

                spin_unlock_irqrestore(&xhci->lock, flags);
                return USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE;
        case GetPortStatus:
                if (!wIndex || wIndex > max_ports)
                        goto error;
                wIndex--;
                status = 0;
                temp = xhci_readl(xhci, port_array[wIndex]);
                if (temp == 0xffffffff) {
                        retval = -ENODEV;
                        break;
                }
                xhci_dbg(xhci, "get port status, actual port %d status  = 0x%x\n", wIndex, temp);

                /* wPortChange bits */
                if (temp & PORT_CSC)
                        status |= USB_PORT_STAT_C_CONNECTION << 16;
                if (temp & PORT_PEC)
                        status |= USB_PORT_STAT_C_ENABLE << 16;
                if ((temp & PORT_OCC))
                        status |= USB_PORT_STAT_C_OVERCURRENT << 16;
                if ((temp & PORT_RC))
                        status |= USB_PORT_STAT_C_RESET << 16;
                /* USB3.0 only */
                if (hcd->speed == HCD_USB3) {
                        if ((temp & PORT_PLC))
                                status |= USB_PORT_STAT_C_LINK_STATE << 16;
                        if ((temp & PORT_WRC))
                                status |= USB_PORT_STAT_C_BH_RESET << 16;
                }

                if (hcd->speed != HCD_USB3) {
                        if ((temp & PORT_PLS_MASK) == XDEV_U3
                                        && (temp & PORT_POWER))
                                status |= USB_PORT_STAT_SUSPEND;
                }
                if ((temp & PORT_PLS_MASK) == XDEV_RESUME &&
                                !DEV_SUPERSPEED(temp)) {
                        if ((temp & PORT_RESET) || !(temp & PORT_PE))
                                goto error;
                        if (time_after_eq(jiffies,
                                        bus_state->resume_done[wIndex])) {
                                xhci_dbg(xhci, "Resume USB2 port %d\n",
                                        wIndex + 1);
                                bus_state->resume_done[wIndex] = 0;
                                clear_bit(wIndex, &bus_state->resuming_ports);
                                xhci_set_link_state(xhci, port_array, wIndex,
                                                        XDEV_U0);
                                xhci_dbg(xhci, "set port %d resume\n",
                                        wIndex + 1);
                                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);
                                bus_state->port_c_suspend |= 1 << wIndex;
                                bus_state->suspended_ports &= ~(1 << wIndex);
                        } else {
                                /*
                                 * The resume has been signaling for less than
                                 * 20ms. Report the port status as SUSPEND,
                                 * let the usbcore check port status again
                                 * and clear resume signaling later.
                                 */
                                status |= USB_PORT_STAT_SUSPEND;
                        }
                }
                if ((temp & PORT_PLS_MASK) == XDEV_U0
                        && (temp & PORT_POWER)
                        && (bus_state->suspended_ports & (1 << wIndex))) {
                        bus_state->suspended_ports &= ~(1 << wIndex);
                        if (hcd->speed != HCD_USB3)
                                bus_state->port_c_suspend |= 1 << wIndex;
                }
                if (temp & PORT_CONNECT) {
                        status |= USB_PORT_STAT_CONNECTION;
                        status |= xhci_port_speed(temp);
                }
                if (temp & PORT_PE)
                        status |= USB_PORT_STAT_ENABLE;
                if (temp & PORT_OC)
                        status |= USB_PORT_STAT_OVERCURRENT;
                if (temp & PORT_RESET)
                        status |= USB_PORT_STAT_RESET;
                if (temp & PORT_POWER) {
                        if (hcd->speed == HCD_USB3)
                                status |= USB_SS_PORT_STAT_POWER;
                        else
                                status |= USB_PORT_STAT_POWER;
                }
                /* Update Port Link State for super speed ports*/
                if (hcd->speed == HCD_USB3) {
                        xhci_hub_report_link_state(&status, temp);
                        /*
                         * Verify if all USB3 Ports Have entered U0 already.
                         * Delete Compliance Mode Timer if so.
                         */
                        xhci_del_comp_mod_timer(xhci, temp, wIndex);
                }
                if (bus_state->port_c_suspend & (1 << wIndex))
                        status |= 1 << USB_PORT_FEAT_C_SUSPEND;
                xhci_dbg(xhci, "Get port status returned 0x%x\n", status);
                put_unaligned(cpu_to_le32(status), (__le32 *) buf);
                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 = xhci_readl(xhci, 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 = xhci_readl(xhci, 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 = xhci_readl(xhci, 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 = xhci_readl(xhci, port_array[wIndex]);
                        bus_state->suspended_ports |= 1 << wIndex;
                        break;
                case USB_PORT_FEAT_LINK_STATE:
                        temp = xhci_readl(xhci, port_array[wIndex]);
                        /* Software should not attempt to set
                         * port link state above '5' (Rx.Detect) and the port
                         * must be enabled.
                         */
                        if ((temp & PORT_PE) == 0 ||
                                (link_state > USB_SS_PORT_LS_RX_DETECT)) {
                                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 = xhci_readl(xhci, 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, khubd will ignore the roothub events until
                         * the roothub is registered.
                         */
                        xhci_writel(xhci, temp | PORT_POWER,
                                        port_array[wIndex]);

                        temp = xhci_readl(xhci, 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);
                        xhci_writel(xhci, temp, port_array[wIndex]);

                        temp = xhci_readl(xhci, 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 = xhci_readl(xhci, 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;
                        xhci_writel(xhci, temp, port_array[wIndex]);

                        temp = xhci_readl(xhci, port_array[wIndex]);
                        break;
                case USB_PORT_FEAT_U1_TIMEOUT:
                        if (hcd->speed != HCD_USB3)
                                goto error;
                        temp = xhci_readl(xhci, port_array[wIndex] + 1);
                        temp &= ~PORT_U1_TIMEOUT_MASK;
                        temp |= PORT_U1_TIMEOUT(timeout);
                        xhci_writel(xhci, temp, port_array[wIndex] + 1);
                        break;
                case USB_PORT_FEAT_U2_TIMEOUT:
                        if (hcd->speed != HCD_USB3)
                                goto error;
                        temp = xhci_readl(xhci, port_array[wIndex] + 1);
                        temp &= ~PORT_U2_TIMEOUT_MASK;
                        temp |= PORT_U2_TIMEOUT(timeout);
                        xhci_writel(xhci, temp, port_array[wIndex] + 1);
                        break;
                default:
                        goto error;
                }
                /* unblock any posted writes */
                temp = xhci_readl(xhci, port_array[wIndex]);
                break;
        case ClearPortFeature:
                if (!wIndex || wIndex > max_ports)
                        goto error;
                wIndex--;
                temp = xhci_readl(xhci, 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 = xhci_readl(xhci, 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;

                                xhci_set_link_state(xhci, port_array, wIndex,
                                                        XDEV_RESUME);
                                spin_unlock_irqrestore(&xhci->lock, flags);
                                msleep(20);
                                spin_lock_irqsave(&xhci->lock, flags);
                                xhci_set_link_state(xhci, port_array, wIndex,
                                                        XDEV_U0);
                        }
                        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:
                        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:
                        xhci_writel(xhci, 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;

        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;

        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 = xhci_readl(xhci, 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;
                }
        }
        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) {
                        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 = xhci_readl(xhci, 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_USB_SUSPEND
                 * 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)
                        xhci_writel(xhci, t2, port_array[port_index]);

                if (hcd->speed != HCD_USB3) {
                        /* enable remote wake up for USB 2.0 */
                        __le32 __iomem *addr;
                        u32 tmp;

                        /* Add one to the port status register address to get
                         * the port power control register address.
                         */
                        addr = port_array[port_index] + 1;
                        tmp = xhci_readl(xhci, addr);
                        tmp |= PORT_RWE;
                        xhci_writel(xhci, tmp, addr);
                }
        }
        hcd->state = HC_STATE_SUSPENDED;
        bus_state->next_statechange = jiffies + msecs_to_jiffies(10);
        spin_unlock_irqrestore(&xhci->lock, flags);
        return 0;
}

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;

        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 = xhci_readl(xhci, &xhci->op_regs->command);
        temp &= ~CMD_EIE;
        xhci_writel(xhci, 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;
                int slot_id;

                temp = xhci_readl(xhci, port_array[port_index]);
                if (DEV_SUPERSPEED(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)) {
                        if (DEV_SUPERSPEED(temp)) {
                                xhci_set_link_state(xhci, port_array,
                                                        port_index, XDEV_U0);
                        } else {
                                xhci_set_link_state(xhci, port_array,
                                                port_index, XDEV_RESUME);

                                spin_unlock_irqrestore(&xhci->lock, flags);
                                msleep(20);
                                spin_lock_irqsave(&xhci->lock, flags);

                                xhci_set_link_state(xhci, port_array,
                                                        port_index, XDEV_U0);
                        }
                        /* wait for the port to enter U0 and report port link
                         * state change.
                         */
                        spin_unlock_irqrestore(&xhci->lock, flags);
                        msleep(20);
                        spin_lock_irqsave(&xhci->lock, flags);

                        /* Clear PLC */
                        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);
                } else
                        xhci_writel(xhci, temp, port_array[port_index]);

                if (hcd->speed != HCD_USB3) {
                        /* disable remote wake up for USB 2.0 */
                        __le32 __iomem *addr;
                        u32 tmp;

                        /* Add one to the port status register address to get
                         * the port power control register address.
                         */
                        addr = port_array[port_index] + 1;
                        tmp = xhci_readl(xhci, addr);
                        tmp &= ~PORT_RWE;
                        xhci_writel(xhci, tmp, addr);
                }
        }

        (void) xhci_readl(xhci, &xhci->op_regs->command);

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

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

#endif  /* CONFIG_PM */