// SPDX-License-Identifier: GPL-2.0
/*
 * Universal Host Controller Interface driver for USB.
 *
 * Maintainer: Alan Stern <stern@rowland.harvard.edu>
 *
 * (C) Copyright 1999 Linus Torvalds
 * (C) Copyright 1999-2002 Johannes Erdfelt, johannes@erdfelt.com
 * (C) Copyright 1999 Randy Dunlap
 * (C) Copyright 1999 Georg Acher, acher@in.tum.de
 * (C) Copyright 1999 Deti Fliegl, deti@fliegl.de
 * (C) Copyright 1999 Thomas Sailer, sailer@ife.ee.ethz.ch
 * (C) Copyright 2004 Alan Stern, stern@rowland.harvard.edu
 */

static const __u8 root_hub_hub_des[] =
{
        0x09,                   /*  __u8  bLength; */
        USB_DT_HUB,             /*  __u8  bDescriptorType; Hub-descriptor */
        0x02,                   /*  __u8  bNbrPorts; */
        HUB_CHAR_NO_LPSM |      /* __u16  wHubCharacteristics; */
                HUB_CHAR_INDV_PORT_OCPM, /* (per-port OC, no power switching) */
        0x00,
        0x01,                   /*  __u8  bPwrOn2pwrGood; 2ms */
        0x00,                   /*  __u8  bHubContrCurrent; 0 mA */
        0x00,                   /*  __u8  DeviceRemovable; *** 7 Ports max */
        0xff                    /*  __u8  PortPwrCtrlMask; *** 7 ports max */
};

#define UHCI_RH_MAXCHILD        7

/* must write as zeroes */
#define WZ_BITS         (USBPORTSC_RES2 | USBPORTSC_RES3 | USBPORTSC_RES4)

/* status change bits:  nonzero writes will clear */
#define RWC_BITS        (USBPORTSC_OCC | USBPORTSC_PEC | USBPORTSC_CSC)

/* suspend/resume bits: port suspended or port resuming */
#define SUSPEND_BITS    (USBPORTSC_SUSP | USBPORTSC_RD)

/* A port that either is connected or has a changed-bit set will prevent
 * us from AUTO_STOPPING.
 */
static int any_ports_active(struct uhci_hcd *uhci)
{
        int port;

        for (port = 0; port < uhci->rh_numports; ++port) {
                if ((uhci_readw(uhci, USBPORTSC1 + port * 2) &
                                (USBPORTSC_CCS | RWC_BITS)) ||
                                test_bit(port, &uhci->port_c_suspend))
                        return 1;
        }
        return 0;
}

static inline int get_hub_status_data(struct uhci_hcd *uhci, char *buf)
{
        int port;
        int mask = RWC_BITS;

        /* Some boards (both VIA and Intel apparently) report bogus
         * overcurrent indications, causing massive log spam unless
         * we completely ignore them.  This doesn't seem to be a problem
         * with the chipset so much as with the way it is connected on
         * the motherboard; if the overcurrent input is left to float
         * then it may constantly register false positives. */
        if (ignore_oc)
                mask &= ~USBPORTSC_OCC;

        *buf = 0;
        for (port = 0; port < uhci->rh_numports; ++port) {
                if ((uhci_readw(uhci, USBPORTSC1 + port * 2) & mask) ||
                                test_bit(port, &uhci->port_c_suspend))
                        *buf |= (1 << (port + 1));
        }
        return !!*buf;
}

#define CLR_RH_PORTSTAT(x) \
        status = uhci_readw(uhci, port_addr);   \
        status &= ~(RWC_BITS|WZ_BITS); \
        status &= ~(x); \
        status |= RWC_BITS & (x); \
        uhci_writew(uhci, status, port_addr)

#define SET_RH_PORTSTAT(x) \
        status = uhci_readw(uhci, port_addr);   \
        status |= (x); \
        status &= ~(RWC_BITS|WZ_BITS); \
        uhci_writew(uhci, status, port_addr)

/* UHCI controllers don't automatically stop resume signalling after 20 msec,
 * so we have to poll and check timeouts in order to take care of it.
 */
static void uhci_finish_suspend(struct uhci_hcd *uhci, int port,
                unsigned long port_addr)
{
        int status;
        int i;

        if (uhci_readw(uhci, port_addr) & SUSPEND_BITS) {
                CLR_RH_PORTSTAT(SUSPEND_BITS);
                if (test_bit(port, &uhci->resuming_ports))
                        set_bit(port, &uhci->port_c_suspend);

                /* The controller won't actually turn off the RD bit until
                 * it has had a chance to send a low-speed EOP sequence,
                 * which is supposed to take 3 bit times (= 2 microseconds).
                 * Experiments show that some controllers take longer, so
                 * we'll poll for completion. */
                for (i = 0; i < 10; ++i) {
                        if (!(uhci_readw(uhci, port_addr) & SUSPEND_BITS))
                                break;
                        udelay(1);
                }
        }
        clear_bit(port, &uhci->resuming_ports);
        usb_hcd_end_port_resume(&uhci_to_hcd(uhci)->self, port);
}

/* Wait for the UHCI controller in HP's iLO2 server management chip.
 * It can take up to 250 us to finish a reset and set the CSC bit.
 */
static void wait_for_HP(struct uhci_hcd *uhci, unsigned long port_addr)
{
        int i;

        for (i = 10; i < 250; i += 10) {
                if (uhci_readw(uhci, port_addr) & USBPORTSC_CSC)
                        return;
                udelay(10);
        }
        /* Log a warning? */
}

static void uhci_check_ports(struct uhci_hcd *uhci)
{
        unsigned int port;
        unsigned long port_addr;
        int status;

        for (port = 0; port < uhci->rh_numports; ++port) {
                port_addr = USBPORTSC1 + 2 * port;
                status = uhci_readw(uhci, port_addr);
                if (unlikely(status & USBPORTSC_PR)) {
                        if (time_after_eq(jiffies, uhci->ports_timeout)) {
                                CLR_RH_PORTSTAT(USBPORTSC_PR);
                                udelay(10);

                                /* HP's server management chip requires
                                 * a longer delay. */
                                if (uhci->wait_for_hp)
                                        wait_for_HP(uhci, port_addr);

                                /* If the port was enabled before, turning
                                 * reset on caused a port enable change.
                                 * Turning reset off causes a port connect
                                 * status change.  Clear these changes. */
                                CLR_RH_PORTSTAT(USBPORTSC_CSC | USBPORTSC_PEC);
                                SET_RH_PORTSTAT(USBPORTSC_PE);
                        }
                }
                if (unlikely(status & USBPORTSC_RD)) {
                        if (!test_bit(port, &uhci->resuming_ports)) {

                                /* Port received a wakeup request */
                                set_bit(port, &uhci->resuming_ports);
                                uhci->ports_timeout = jiffies +
                                        msecs_to_jiffies(USB_RESUME_TIMEOUT);
                                usb_hcd_start_port_resume(
                                                &uhci_to_hcd(uhci)->self, port);

                                /* Make sure we see the port again
                                 * after the resuming period is over. */
                                mod_timer(&uhci_to_hcd(uhci)->rh_timer,
                                                uhci->ports_timeout);
                        } else if (time_after_eq(jiffies,
                                                uhci->ports_timeout)) {
                                uhci_finish_suspend(uhci, port, port_addr);
                        }
                }
        }
}

static int uhci_hub_status_data(struct usb_hcd *hcd, char *buf)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
        unsigned long flags;
        int status = 0;

        spin_lock_irqsave(&uhci->lock, flags);

        uhci_scan_schedule(uhci);
        if (!HCD_HW_ACCESSIBLE(hcd) || uhci->dead)
                goto done;
        uhci_check_ports(uhci);

        status = get_hub_status_data(uhci, buf);

        switch (uhci->rh_state) {
            case UHCI_RH_SUSPENDED:
                /* if port change, ask to be resumed */
                if (status || uhci->resuming_ports) {
                        status = 1;
                        usb_hcd_resume_root_hub(hcd);
                }
                break;

            case UHCI_RH_AUTO_STOPPED:
                /* if port change, auto start */
                if (status)
                        wakeup_rh(uhci);
                break;

            case UHCI_RH_RUNNING:
                /* are any devices attached? */
                if (!any_ports_active(uhci)) {
                        uhci->rh_state = UHCI_RH_RUNNING_NODEVS;
                        uhci->auto_stop_time = jiffies + HZ;
                }
                break;

            case UHCI_RH_RUNNING_NODEVS:
                /* auto-stop if nothing connected for 1 second */
                if (any_ports_active(uhci))
                        uhci->rh_state = UHCI_RH_RUNNING;
                else if (time_after_eq(jiffies, uhci->auto_stop_time) &&
                                !uhci->wait_for_hp)
                        suspend_rh(uhci, UHCI_RH_AUTO_STOPPED);
                break;

            default:
                break;
        }

done:
        spin_unlock_irqrestore(&uhci->lock, flags);
        return status;
}

/* size of returned buffer is part of USB spec */
static int uhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                        u16 wIndex, char *buf, u16 wLength)
{
        struct uhci_hcd *uhci = hcd_to_uhci(hcd);
        int status, lstatus, retval = 0;
        unsigned int port = wIndex - 1;
        unsigned long port_addr = USBPORTSC1 + 2 * port;
        u16 wPortChange, wPortStatus;
        unsigned long flags;

        if (!HCD_HW_ACCESSIBLE(hcd) || uhci->dead)
                return -ETIMEDOUT;

        spin_lock_irqsave(&uhci->lock, flags);
        switch (typeReq) {

        case GetHubStatus:
                *(__le32 *)buf = cpu_to_le32(0);
                retval = 4; /* hub power */
                break;
        case GetPortStatus:
                if (port >= uhci->rh_numports)
                        goto err;

                uhci_check_ports(uhci);
                status = uhci_readw(uhci, port_addr);

                /* Intel controllers report the OverCurrent bit active on.
                 * VIA controllers report it active off, so we'll adjust the
                 * bit value.  (It's not standardized in the UHCI spec.)
                 */
                if (uhci->oc_low)
                        status ^= USBPORTSC_OC;

                /* UHCI doesn't support C_RESET (always false) */
                wPortChange = lstatus = 0;
                if (status & USBPORTSC_CSC)
                        wPortChange |= USB_PORT_STAT_C_CONNECTION;
                if (status & USBPORTSC_PEC)
                        wPortChange |= USB_PORT_STAT_C_ENABLE;
                if ((status & USBPORTSC_OCC) && !ignore_oc)
                        wPortChange |= USB_PORT_STAT_C_OVERCURRENT;

                if (test_bit(port, &uhci->port_c_suspend)) {
                        wPortChange |= USB_PORT_STAT_C_SUSPEND;
                        lstatus |= 1;
                }
                if (test_bit(port, &uhci->resuming_ports))
                        lstatus |= 4;

                /* UHCI has no power switching (always on) */
                wPortStatus = USB_PORT_STAT_POWER;
                if (status & USBPORTSC_CCS)
                        wPortStatus |= USB_PORT_STAT_CONNECTION;
                if (status & USBPORTSC_PE) {
                        wPortStatus |= USB_PORT_STAT_ENABLE;
                        if (status & SUSPEND_BITS)
                                wPortStatus |= USB_PORT_STAT_SUSPEND;
                }
                if (status & USBPORTSC_OC)
                        wPortStatus |= USB_PORT_STAT_OVERCURRENT;
                if (status & USBPORTSC_PR)
                        wPortStatus |= USB_PORT_STAT_RESET;
                if (status & USBPORTSC_LSDA)
                        wPortStatus |= USB_PORT_STAT_LOW_SPEED;

                if (wPortChange)
                        dev_dbg(uhci_dev(uhci), "port %d portsc %04x,%02x\n",
                                        wIndex, status, lstatus);

                *(__le16 *)buf = cpu_to_le16(wPortStatus);
                *(__le16 *)(buf + 2) = cpu_to_le16(wPortChange);
                retval = 4;
                break;
        case SetHubFeature:             /* We don't implement these */
        case ClearHubFeature:
                switch (wValue) {
                case C_HUB_OVER_CURRENT:
                case C_HUB_LOCAL_POWER:
                        break;
                default:
                        goto err;
                }
                break;
        case SetPortFeature:
                if (port >= uhci->rh_numports)
                        goto err;

                switch (wValue) {
                case USB_PORT_FEAT_SUSPEND:
                        SET_RH_PORTSTAT(USBPORTSC_SUSP);
                        break;
                case USB_PORT_FEAT_RESET:
                        SET_RH_PORTSTAT(USBPORTSC_PR);

                        /* Reset terminates Resume signalling */
                        uhci_finish_suspend(uhci, port, port_addr);

                        /* USB v2.0 7.1.7.5 */
                        uhci->ports_timeout = jiffies +
                                msecs_to_jiffies(USB_RESUME_TIMEOUT);
                        break;
                case USB_PORT_FEAT_POWER:
                        /* UHCI has no power switching */
                        break;
                default:
                        goto err;
                }
                break;
        case ClearPortFeature:
                if (port >= uhci->rh_numports)
                        goto err;

                switch (wValue) {
                case USB_PORT_FEAT_ENABLE:
                        CLR_RH_PORTSTAT(USBPORTSC_PE);

                        /* Disable terminates Resume signalling */
                        uhci_finish_suspend(uhci, port, port_addr);
                        break;
                case USB_PORT_FEAT_C_ENABLE:
                        CLR_RH_PORTSTAT(USBPORTSC_PEC);
                        break;
                case USB_PORT_FEAT_SUSPEND:
                        if (!(uhci_readw(uhci, port_addr) & USBPORTSC_SUSP)) {

                                /* Make certain the port isn't suspended */
                                uhci_finish_suspend(uhci, port, port_addr);
                        } else if (!test_and_set_bit(port,
                                                &uhci->resuming_ports)) {
                                SET_RH_PORTSTAT(USBPORTSC_RD);

                                /* The controller won't allow RD to be set
                                 * if the port is disabled.  When this happens
                                 * just skip the Resume signalling.
                                 */
                                if (!(uhci_readw(uhci, port_addr) &
                                                USBPORTSC_RD))
                                        uhci_finish_suspend(uhci, port,
                                                        port_addr);
                                else
                                        /* USB v2.0 7.1.7.7 */
                                        uhci->ports_timeout = jiffies +
                                                msecs_to_jiffies(20);
                        }
                        break;
                case USB_PORT_FEAT_C_SUSPEND:
                        clear_bit(port, &uhci->port_c_suspend);
                        break;
                case USB_PORT_FEAT_POWER:
                        /* UHCI has no power switching */
                        goto err;
                case USB_PORT_FEAT_C_CONNECTION:
                        CLR_RH_PORTSTAT(USBPORTSC_CSC);
                        break;
                case USB_PORT_FEAT_C_OVER_CURRENT:
                        CLR_RH_PORTSTAT(USBPORTSC_OCC);
                        break;
                case USB_PORT_FEAT_C_RESET:
                        /* this driver won't report these */
                        break;
                default:
                        goto err;
                }
                break;
        case GetHubDescriptor:
                retval = min_t(unsigned int, sizeof(root_hub_hub_des), wLength);
                memcpy(buf, root_hub_hub_des, retval);
                if (retval > 2)
                        buf[2] = uhci->rh_numports;
                break;
        default:
err:
                retval = -EPIPE;
        }
        spin_unlock_irqrestore(&uhci->lock, flags);

        return retval;
}