usb: ehci: add weak-aliased function for PORTSC

[people/ms/u-boot.git] / drivers / usb / host / ehci-hcd.c

/*-
 * Copyright (c) 2007-2008, Juniper Networks, Inc.
 * Copyright (c) 2008, Excito Elektronik i Skåne AB
 * Copyright (c) 2008, Michael Trimarchi <trimarchimichael@yahoo.it>
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2 of
 * the License.
 *
 * 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., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */
#include <common.h>
#include <errno.h>
#include <asm/byteorder.h>
#include <asm/unaligned.h>
#include <usb.h>
#include <asm/io.h>
#include <malloc.h>
#include <watchdog.h>
#include <linux/compiler.h>

#include "ehci.h"

#ifndef CONFIG_USB_MAX_CONTROLLER_COUNT
#define CONFIG_USB_MAX_CONTROLLER_COUNT 1
#endif

static struct ehci_ctrl {
        struct ehci_hccr *hccr; /* R/O registers, not need for volatile */
        struct ehci_hcor *hcor;
        int rootdev;
        uint16_t portreset;
        struct QH qh_list __aligned(USB_DMA_MINALIGN);
        struct QH periodic_queue __aligned(USB_DMA_MINALIGN);
        uint32_t *periodic_list;
        int ntds;
} ehcic[CONFIG_USB_MAX_CONTROLLER_COUNT];

#define ALIGN_END_ADDR(type, ptr, size)                 \
        ((uint32_t)(ptr) + roundup((size) * sizeof(type), USB_DMA_MINALIGN))

static struct descriptor {
        struct usb_hub_descriptor hub;
        struct usb_device_descriptor device;
        struct usb_linux_config_descriptor config;
        struct usb_linux_interface_descriptor interface;
        struct usb_endpoint_descriptor endpoint;
}  __attribute__ ((packed)) descriptor = {
        {
                0x8,            /* bDescLength */
                0x29,           /* bDescriptorType: hub descriptor */
                2,              /* bNrPorts -- runtime modified */
                0,              /* wHubCharacteristics */
                10,             /* bPwrOn2PwrGood */
                0,              /* bHubCntrCurrent */
                {},             /* Device removable */
                {}              /* at most 7 ports! XXX */
        },
        {
                0x12,           /* bLength */
                1,              /* bDescriptorType: UDESC_DEVICE */
                cpu_to_le16(0x0200), /* bcdUSB: v2.0 */
                9,              /* bDeviceClass: UDCLASS_HUB */
                0,              /* bDeviceSubClass: UDSUBCLASS_HUB */
                1,              /* bDeviceProtocol: UDPROTO_HSHUBSTT */
                64,             /* bMaxPacketSize: 64 bytes */
                0x0000,         /* idVendor */
                0x0000,         /* idProduct */
                cpu_to_le16(0x0100), /* bcdDevice */
                1,              /* iManufacturer */
                2,              /* iProduct */
                0,              /* iSerialNumber */
                1               /* bNumConfigurations: 1 */
        },
        {
                0x9,
                2,              /* bDescriptorType: UDESC_CONFIG */
                cpu_to_le16(0x19),
                1,              /* bNumInterface */
                1,              /* bConfigurationValue */
                0,              /* iConfiguration */
                0x40,           /* bmAttributes: UC_SELF_POWER */
                0               /* bMaxPower */
        },
        {
                0x9,            /* bLength */
                4,              /* bDescriptorType: UDESC_INTERFACE */
                0,              /* bInterfaceNumber */
                0,              /* bAlternateSetting */
                1,              /* bNumEndpoints */
                9,              /* bInterfaceClass: UICLASS_HUB */
                0,              /* bInterfaceSubClass: UISUBCLASS_HUB */
                0,              /* bInterfaceProtocol: UIPROTO_HSHUBSTT */
                0               /* iInterface */
        },
        {
                0x7,            /* bLength */
                5,              /* bDescriptorType: UDESC_ENDPOINT */
                0x81,           /* bEndpointAddress:
                                 * UE_DIR_IN | EHCI_INTR_ENDPT
                                 */
                3,              /* bmAttributes: UE_INTERRUPT */
                8,              /* wMaxPacketSize */
                255             /* bInterval */
        },
};

#if defined(CONFIG_EHCI_IS_TDI)
#define ehci_is_TDI()   (1)
#else
#define ehci_is_TDI()   (0)
#endif

int __ehci_get_port_speed(struct ehci_hcor *hcor, uint32_t reg)
{
        return PORTSC_PSPD(reg);
}

int ehci_get_port_speed(struct ehci_hcor *hcor, uint32_t reg)
        __attribute__((weak, alias("__ehci_get_port_speed")));

void __ehci_set_usbmode(int index)
{
        uint32_t tmp;
        uint32_t *reg_ptr;

        reg_ptr = (uint32_t *)((u8 *)&ehcic[index].hcor->or_usbcmd + USBMODE);
        tmp = ehci_readl(reg_ptr);
        tmp |= USBMODE_CM_HC;
#if defined(CONFIG_EHCI_MMIO_BIG_ENDIAN)
        tmp |= USBMODE_BE;
#endif
        ehci_writel(reg_ptr, tmp);
}

void ehci_set_usbmode(int index)
        __attribute__((weak, alias("__ehci_set_usbmode")));

void __ehci_powerup_fixup(uint32_t *status_reg, uint32_t *reg)
{
        mdelay(50);
}

void ehci_powerup_fixup(uint32_t *status_reg, uint32_t *reg)
        __attribute__((weak, alias("__ehci_powerup_fixup")));

static int handshake(uint32_t *ptr, uint32_t mask, uint32_t done, int usec)
{
        uint32_t result;
        do {
                result = ehci_readl(ptr);
                udelay(5);
                if (result == ~(uint32_t)0)
                        return -1;
                result &= mask;
                if (result == done)
                        return 0;
                usec--;
        } while (usec > 0);
        return -1;
}

static int ehci_reset(int index)
{
        uint32_t cmd;
        int ret = 0;

        cmd = ehci_readl(&ehcic[index].hcor->or_usbcmd);
        cmd = (cmd & ~CMD_RUN) | CMD_RESET;
        ehci_writel(&ehcic[index].hcor->or_usbcmd, cmd);
        ret = handshake((uint32_t *)&ehcic[index].hcor->or_usbcmd,
                        CMD_RESET, 0, 250 * 1000);
        if (ret < 0) {
                printf("EHCI fail to reset\n");
                goto out;
        }

        if (ehci_is_TDI())
                ehci_set_usbmode(index);

#ifdef CONFIG_USB_EHCI_TXFIFO_THRESH
        cmd = ehci_readl(&ehcic[index].hcor->or_txfilltuning);
        cmd &= ~TXFIFO_THRESH_MASK;
        cmd |= TXFIFO_THRESH(CONFIG_USB_EHCI_TXFIFO_THRESH);
        ehci_writel(&ehcic[index].hcor->or_txfilltuning, cmd);
#endif
out:
        return ret;
}

static int ehci_td_buffer(struct qTD *td, void *buf, size_t sz)
{
        uint32_t delta, next;
        uint32_t addr = (uint32_t)buf;
        int idx;

        if (addr != ALIGN(addr, ARCH_DMA_MINALIGN))
                debug("EHCI-HCD: Misaligned buffer address (%p)\n", buf);

        flush_dcache_range(addr, ALIGN(addr + sz, ARCH_DMA_MINALIGN));

        idx = 0;
        while (idx < QT_BUFFER_CNT) {
                td->qt_buffer[idx] = cpu_to_hc32(addr);
                td->qt_buffer_hi[idx] = 0;
                next = (addr + EHCI_PAGE_SIZE) & ~(EHCI_PAGE_SIZE - 1);
                delta = next - addr;
                if (delta >= sz)
                        break;
                sz -= delta;
                addr = next;
                idx++;
        }

        if (idx == QT_BUFFER_CNT) {
                printf("out of buffer pointers (%u bytes left)\n", sz);
                return -1;
        }

        return 0;
}

static inline u8 ehci_encode_speed(enum usb_device_speed speed)
{
        #define QH_HIGH_SPEED   2
        #define QH_FULL_SPEED   0
        #define QH_LOW_SPEED    1
        if (speed == USB_SPEED_HIGH)
                return QH_HIGH_SPEED;
        if (speed == USB_SPEED_LOW)
                return QH_LOW_SPEED;
        return QH_FULL_SPEED;
}

static int
ehci_submit_async(struct usb_device *dev, unsigned long pipe, void *buffer,
                   int length, struct devrequest *req)
{
        ALLOC_ALIGN_BUFFER(struct QH, qh, 1, USB_DMA_MINALIGN);
        struct qTD *qtd;
        int qtd_count = 0;
        int qtd_counter = 0;
        volatile struct qTD *vtd;
        unsigned long ts;
        uint32_t *tdp;
        uint32_t endpt, maxpacket, token, usbsts;
        uint32_t c, toggle;
        uint32_t cmd;
        int timeout;
        int ret = 0;
        struct ehci_ctrl *ctrl = dev->controller;

        debug("dev=%p, pipe=%lx, buffer=%p, length=%d, req=%p\n", dev, pipe,
              buffer, length, req);
        if (req != NULL)
                debug("req=%u (%#x), type=%u (%#x), value=%u (%#x), index=%u\n",
                      req->request, req->request,
                      req->requesttype, req->requesttype,
                      le16_to_cpu(req->value), le16_to_cpu(req->value),
                      le16_to_cpu(req->index));

#define PKT_ALIGN       512
        /*
         * The USB transfer is split into qTD transfers. Eeach qTD transfer is
         * described by a transfer descriptor (the qTD). The qTDs form a linked
         * list with a queue head (QH).
         *
         * Each qTD transfer starts with a new USB packet, i.e. a packet cannot
         * have its beginning in a qTD transfer and its end in the following
         * one, so the qTD transfer lengths have to be chosen accordingly.
         *
         * Each qTD transfer uses up to QT_BUFFER_CNT data buffers, mapped to
         * single pages. The first data buffer can start at any offset within a
         * page (not considering the cache-line alignment issues), while the
         * following buffers must be page-aligned. There is no alignment
         * constraint on the size of a qTD transfer.
         */
        if (req != NULL)
                /* 1 qTD will be needed for SETUP, and 1 for ACK. */
                qtd_count += 1 + 1;
        if (length > 0 || req == NULL) {
                /*
                 * Determine the qTD transfer size that will be used for the
                 * data payload (not considering the first qTD transfer, which
                 * may be longer or shorter, and the final one, which may be
                 * shorter).
                 *
                 * In order to keep each packet within a qTD transfer, the qTD
                 * transfer size is aligned to PKT_ALIGN, which is a multiple of
                 * wMaxPacketSize (except in some cases for interrupt transfers,
                 * see comment in submit_int_msg()).
                 *
                 * By default, i.e. if the input buffer is aligned to PKT_ALIGN,
                 * QT_BUFFER_CNT full pages will be used.
                 */
                int xfr_sz = QT_BUFFER_CNT;
                /*
                 * However, if the input buffer is not aligned to PKT_ALIGN, the
                 * qTD transfer size will be one page shorter, and the first qTD
                 * data buffer of each transfer will be page-unaligned.
                 */
                if ((uint32_t)buffer & (PKT_ALIGN - 1))
                        xfr_sz--;
                /* Convert the qTD transfer size to bytes. */
                xfr_sz *= EHCI_PAGE_SIZE;
                /*
                 * Approximate by excess the number of qTDs that will be
                 * required for the data payload. The exact formula is way more
                 * complicated and saves at most 2 qTDs, i.e. a total of 128
                 * bytes.
                 */
                qtd_count += 2 + length / xfr_sz;
        }
/*
 * Threshold value based on the worst-case total size of the allocated qTDs for
 * a mass-storage transfer of 65535 blocks of 512 bytes.
 */
#if CONFIG_SYS_MALLOC_LEN <= 64 + 128 * 1024
#warning CONFIG_SYS_MALLOC_LEN may be too small for EHCI
#endif
        qtd = memalign(USB_DMA_MINALIGN, qtd_count * sizeof(struct qTD));
        if (qtd == NULL) {
                printf("unable to allocate TDs\n");
                return -1;
        }

        memset(qh, 0, sizeof(struct QH));
        memset(qtd, 0, qtd_count * sizeof(*qtd));

        toggle = usb_gettoggle(dev, usb_pipeendpoint(pipe), usb_pipeout(pipe));

        /*
         * Setup QH (3.6 in ehci-r10.pdf)
         *
         *   qh_link ................. 03-00 H
         *   qh_endpt1 ............... 07-04 H
         *   qh_endpt2 ............... 0B-08 H
         * - qh_curtd
         *   qh_overlay.qt_next ...... 13-10 H
         * - qh_overlay.qt_altnext
         */
        qh->qh_link = cpu_to_hc32((uint32_t)&ctrl->qh_list | QH_LINK_TYPE_QH);
        c = (dev->speed != USB_SPEED_HIGH) && !usb_pipeendpoint(pipe);
        maxpacket = usb_maxpacket(dev, pipe);
        endpt = QH_ENDPT1_RL(8) | QH_ENDPT1_C(c) |
                QH_ENDPT1_MAXPKTLEN(maxpacket) | QH_ENDPT1_H(0) |
                QH_ENDPT1_DTC(QH_ENDPT1_DTC_DT_FROM_QTD) |
                QH_ENDPT1_EPS(ehci_encode_speed(dev->speed)) |
                QH_ENDPT1_ENDPT(usb_pipeendpoint(pipe)) | QH_ENDPT1_I(0) |
                QH_ENDPT1_DEVADDR(usb_pipedevice(pipe));
        qh->qh_endpt1 = cpu_to_hc32(endpt);
        endpt = QH_ENDPT2_MULT(1) | QH_ENDPT2_PORTNUM(dev->portnr) |
                QH_ENDPT2_HUBADDR(dev->parent->devnum) |
                QH_ENDPT2_UFCMASK(0) | QH_ENDPT2_UFSMASK(0);
        qh->qh_endpt2 = cpu_to_hc32(endpt);
        qh->qh_overlay.qt_next = cpu_to_hc32(QT_NEXT_TERMINATE);

        tdp = &qh->qh_overlay.qt_next;

        if (req != NULL) {
                /*
                 * Setup request qTD (3.5 in ehci-r10.pdf)
                 *
                 *   qt_next ................ 03-00 H
                 *   qt_altnext ............. 07-04 H
                 *   qt_token ............... 0B-08 H
                 *
                 *   [ buffer, buffer_hi ] loaded with "req".
                 */
                qtd[qtd_counter].qt_next = cpu_to_hc32(QT_NEXT_TERMINATE);
                qtd[qtd_counter].qt_altnext = cpu_to_hc32(QT_NEXT_TERMINATE);
                token = QT_TOKEN_DT(0) | QT_TOKEN_TOTALBYTES(sizeof(*req)) |
                        QT_TOKEN_IOC(0) | QT_TOKEN_CPAGE(0) | QT_TOKEN_CERR(3) |
                        QT_TOKEN_PID(QT_TOKEN_PID_SETUP) |
                        QT_TOKEN_STATUS(QT_TOKEN_STATUS_ACTIVE);
                qtd[qtd_counter].qt_token = cpu_to_hc32(token);
                if (ehci_td_buffer(&qtd[qtd_counter], req, sizeof(*req))) {
                        printf("unable to construct SETUP TD\n");
                        goto fail;
                }
                /* Update previous qTD! */
                *tdp = cpu_to_hc32((uint32_t)&qtd[qtd_counter]);
                tdp = &qtd[qtd_counter++].qt_next;
                toggle = 1;
        }

        if (length > 0 || req == NULL) {
                uint8_t *buf_ptr = buffer;
                int left_length = length;

                do {
                        /*
                         * Determine the size of this qTD transfer. By default,
                         * QT_BUFFER_CNT full pages can be used.
                         */
                        int xfr_bytes = QT_BUFFER_CNT * EHCI_PAGE_SIZE;
                        /*
                         * However, if the input buffer is not page-aligned, the
                         * portion of the first page before the buffer start
                         * offset within that page is unusable.
                         */
                        xfr_bytes -= (uint32_t)buf_ptr & (EHCI_PAGE_SIZE - 1);
                        /*
                         * In order to keep each packet within a qTD transfer,
                         * align the qTD transfer size to PKT_ALIGN.
                         */
                        xfr_bytes &= ~(PKT_ALIGN - 1);
                        /*
                         * This transfer may be shorter than the available qTD
                         * transfer size that has just been computed.
                         */
                        xfr_bytes = min(xfr_bytes, left_length);

                        /*
                         * Setup request qTD (3.5 in ehci-r10.pdf)
                         *
                         *   qt_next ................ 03-00 H
                         *   qt_altnext ............. 07-04 H
                         *   qt_token ............... 0B-08 H
                         *
                         *   [ buffer, buffer_hi ] loaded with "buffer".
                         */
                        qtd[qtd_counter].qt_next =
                                        cpu_to_hc32(QT_NEXT_TERMINATE);
                        qtd[qtd_counter].qt_altnext =
                                        cpu_to_hc32(QT_NEXT_TERMINATE);
                        token = QT_TOKEN_DT(toggle) |
                                QT_TOKEN_TOTALBYTES(xfr_bytes) |
                                QT_TOKEN_IOC(req == NULL) | QT_TOKEN_CPAGE(0) |
                                QT_TOKEN_CERR(3) |
                                QT_TOKEN_PID(usb_pipein(pipe) ?
                                        QT_TOKEN_PID_IN : QT_TOKEN_PID_OUT) |
                                QT_TOKEN_STATUS(QT_TOKEN_STATUS_ACTIVE);
                        qtd[qtd_counter].qt_token = cpu_to_hc32(token);
                        if (ehci_td_buffer(&qtd[qtd_counter], buf_ptr,
                                                xfr_bytes)) {
                                printf("unable to construct DATA TD\n");
                                goto fail;
                        }
                        /* Update previous qTD! */
                        *tdp = cpu_to_hc32((uint32_t)&qtd[qtd_counter]);
                        tdp = &qtd[qtd_counter++].qt_next;
                        /*
                         * Data toggle has to be adjusted since the qTD transfer
                         * size is not always an even multiple of
                         * wMaxPacketSize.
                         */
                        if ((xfr_bytes / maxpacket) & 1)
                                toggle ^= 1;
                        buf_ptr += xfr_bytes;
                        left_length -= xfr_bytes;
                } while (left_length > 0);
        }

        if (req != NULL) {
                /*
                 * Setup request qTD (3.5 in ehci-r10.pdf)
                 *
                 *   qt_next ................ 03-00 H
                 *   qt_altnext ............. 07-04 H
                 *   qt_token ............... 0B-08 H
                 */
                qtd[qtd_counter].qt_next = cpu_to_hc32(QT_NEXT_TERMINATE);
                qtd[qtd_counter].qt_altnext = cpu_to_hc32(QT_NEXT_TERMINATE);
                token = QT_TOKEN_DT(1) | QT_TOKEN_TOTALBYTES(0) |
                        QT_TOKEN_IOC(1) | QT_TOKEN_CPAGE(0) | QT_TOKEN_CERR(3) |
                        QT_TOKEN_PID(usb_pipein(pipe) ?
                                QT_TOKEN_PID_OUT : QT_TOKEN_PID_IN) |
                        QT_TOKEN_STATUS(QT_TOKEN_STATUS_ACTIVE);
                qtd[qtd_counter].qt_token = cpu_to_hc32(token);
                /* Update previous qTD! */
                *tdp = cpu_to_hc32((uint32_t)&qtd[qtd_counter]);
                tdp = &qtd[qtd_counter++].qt_next;
        }

        ctrl->qh_list.qh_link = cpu_to_hc32((uint32_t)qh | QH_LINK_TYPE_QH);

        /* Flush dcache */
        flush_dcache_range((uint32_t)&ctrl->qh_list,
                ALIGN_END_ADDR(struct QH, &ctrl->qh_list, 1));
        flush_dcache_range((uint32_t)qh, ALIGN_END_ADDR(struct QH, qh, 1));
        flush_dcache_range((uint32_t)qtd,
                           ALIGN_END_ADDR(struct qTD, qtd, qtd_count));

        /* Set async. queue head pointer. */
        ehci_writel(&ctrl->hcor->or_asynclistaddr, (uint32_t)&ctrl->qh_list);

        usbsts = ehci_readl(&ctrl->hcor->or_usbsts);
        ehci_writel(&ctrl->hcor->or_usbsts, (usbsts & 0x3f));

        /* Enable async. schedule. */
        cmd = ehci_readl(&ctrl->hcor->or_usbcmd);
        cmd |= CMD_ASE;
        ehci_writel(&ctrl->hcor->or_usbcmd, cmd);

        ret = handshake((uint32_t *)&ctrl->hcor->or_usbsts, STS_ASS, STS_ASS,
                        100 * 1000);
        if (ret < 0) {
                printf("EHCI fail timeout STS_ASS set\n");
                goto fail;
        }

        /* Wait for TDs to be processed. */
        ts = get_timer(0);
        vtd = &qtd[qtd_counter - 1];
        timeout = USB_TIMEOUT_MS(pipe);
        do {
                /* Invalidate dcache */
                invalidate_dcache_range((uint32_t)&ctrl->qh_list,
                        ALIGN_END_ADDR(struct QH, &ctrl->qh_list, 1));
                invalidate_dcache_range((uint32_t)qh,
                        ALIGN_END_ADDR(struct QH, qh, 1));
                invalidate_dcache_range((uint32_t)qtd,
                        ALIGN_END_ADDR(struct qTD, qtd, qtd_count));

                token = hc32_to_cpu(vtd->qt_token);
                if (!(QT_TOKEN_GET_STATUS(token) & QT_TOKEN_STATUS_ACTIVE))
                        break;
                WATCHDOG_RESET();
        } while (get_timer(ts) < timeout);

        /*
         * Invalidate the memory area occupied by buffer
         * Don't try to fix the buffer alignment, if it isn't properly
         * aligned it's upper layer's fault so let invalidate_dcache_range()
         * vow about it. But we have to fix the length as it's actual
         * transfer length and can be unaligned. This is potentially
         * dangerous operation, it's responsibility of the calling
         * code to make sure enough space is reserved.
         */
        invalidate_dcache_range((uint32_t)buffer,
                ALIGN((uint32_t)buffer + length, ARCH_DMA_MINALIGN));

        /* Check that the TD processing happened */
        if (QT_TOKEN_GET_STATUS(token) & QT_TOKEN_STATUS_ACTIVE)
                printf("EHCI timed out on TD - token=%#x\n", token);

        /* Disable async schedule. */
        cmd = ehci_readl(&ctrl->hcor->or_usbcmd);
        cmd &= ~CMD_ASE;
        ehci_writel(&ctrl->hcor->or_usbcmd, cmd);

        ret = handshake((uint32_t *)&ctrl->hcor->or_usbsts, STS_ASS, 0,
                        100 * 1000);
        if (ret < 0) {
                printf("EHCI fail timeout STS_ASS reset\n");
                goto fail;
        }

        token = hc32_to_cpu(qh->qh_overlay.qt_token);
        if (!(QT_TOKEN_GET_STATUS(token) & QT_TOKEN_STATUS_ACTIVE)) {
                debug("TOKEN=%#x\n", token);
                switch (QT_TOKEN_GET_STATUS(token) &
                        ~(QT_TOKEN_STATUS_SPLITXSTATE | QT_TOKEN_STATUS_PERR)) {
                case 0:
                        toggle = QT_TOKEN_GET_DT(token);
                        usb_settoggle(dev, usb_pipeendpoint(pipe),
                                       usb_pipeout(pipe), toggle);
                        dev->status = 0;
                        break;
                case QT_TOKEN_STATUS_HALTED:
                        dev->status = USB_ST_STALLED;
                        break;
                case QT_TOKEN_STATUS_ACTIVE | QT_TOKEN_STATUS_DATBUFERR:
                case QT_TOKEN_STATUS_DATBUFERR:
                        dev->status = USB_ST_BUF_ERR;
                        break;
                case QT_TOKEN_STATUS_HALTED | QT_TOKEN_STATUS_BABBLEDET:
                case QT_TOKEN_STATUS_BABBLEDET:
                        dev->status = USB_ST_BABBLE_DET;
                        break;
                default:
                        dev->status = USB_ST_CRC_ERR;
                        if (QT_TOKEN_GET_STATUS(token) & QT_TOKEN_STATUS_HALTED)
                                dev->status |= USB_ST_STALLED;
                        break;
                }
                dev->act_len = length - QT_TOKEN_GET_TOTALBYTES(token);
        } else {
                dev->act_len = 0;
                debug("dev=%u, usbsts=%#x, p[1]=%#x, p[2]=%#x\n",
                      dev->devnum, ehci_readl(&ctrl->hcor->or_usbsts),
                      ehci_readl(&ctrl->hcor->or_portsc[0]),
                      ehci_readl(&ctrl->hcor->or_portsc[1]));
        }

        free(qtd);
        return (dev->status != USB_ST_NOT_PROC) ? 0 : -1;

fail:
        free(qtd);
        return -1;
}

__weak uint32_t *ehci_get_portsc_register(struct ehci_hcor *hcor, int port)
{
        if (port < 0 || port >= CONFIG_SYS_USB_EHCI_MAX_ROOT_PORTS) {
                /* Printing the message would cause a scan failure! */
                debug("The request port(%u) is not configured\n", port);
                return NULL;
        }

        return (uint32_t *)&hcor->or_portsc[port];
}

int
ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
                 int length, struct devrequest *req)
{
        uint8_t tmpbuf[4];
        u16 typeReq;
        void *srcptr = NULL;
        int len, srclen;
        uint32_t reg;
        uint32_t *status_reg;
        int port = le16_to_cpu(req->index) & 0xff;
        struct ehci_ctrl *ctrl = dev->controller;

        srclen = 0;

        debug("req=%u (%#x), type=%u (%#x), value=%u, index=%u\n",
              req->request, req->request,
              req->requesttype, req->requesttype,
              le16_to_cpu(req->value), le16_to_cpu(req->index));

        typeReq = req->request | req->requesttype << 8;

        switch (typeReq) {
        case USB_REQ_GET_STATUS | ((USB_RT_PORT | USB_DIR_IN) << 8):
        case USB_REQ_SET_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
        case USB_REQ_CLEAR_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
                status_reg = ehci_get_portsc_register(ctrl->hcor, port - 1);
                if (!status_reg)
                        return -1;
                break;
        default:
                status_reg = NULL;
                break;
        }

        switch (typeReq) {
        case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
                switch (le16_to_cpu(req->value) >> 8) {
                case USB_DT_DEVICE:
                        debug("USB_DT_DEVICE request\n");
                        srcptr = &descriptor.device;
                        srclen = descriptor.device.bLength;
                        break;
                case USB_DT_CONFIG:
                        debug("USB_DT_CONFIG config\n");
                        srcptr = &descriptor.config;
                        srclen = descriptor.config.bLength +
                                        descriptor.interface.bLength +
                                        descriptor.endpoint.bLength;
                        break;
                case USB_DT_STRING:
                        debug("USB_DT_STRING config\n");
                        switch (le16_to_cpu(req->value) & 0xff) {
                        case 0: /* Language */
                                srcptr = "\4\3\1\0";
                                srclen = 4;
                                break;
                        case 1: /* Vendor */
                                srcptr = "\16\3u\0-\0b\0o\0o\0t\0";
                                srclen = 14;
                                break;
                        case 2: /* Product */
                                srcptr = "\52\3E\0H\0C\0I\0 "
                                         "\0H\0o\0s\0t\0 "
                                         "\0C\0o\0n\0t\0r\0o\0l\0l\0e\0r\0";
                                srclen = 42;
                                break;
                        default:
                                debug("unknown value DT_STRING %x\n",
                                        le16_to_cpu(req->value));
                                goto unknown;
                        }
                        break;
                default:
                        debug("unknown value %x\n", le16_to_cpu(req->value));
                        goto unknown;
                }
                break;
        case USB_REQ_GET_DESCRIPTOR | ((USB_DIR_IN | USB_RT_HUB) << 8):
                switch (le16_to_cpu(req->value) >> 8) {
                case USB_DT_HUB:
                        debug("USB_DT_HUB config\n");
                        srcptr = &descriptor.hub;
                        srclen = descriptor.hub.bLength;
                        break;
                default:
                        debug("unknown value %x\n", le16_to_cpu(req->value));
                        goto unknown;
                }
                break;
        case USB_REQ_SET_ADDRESS | (USB_RECIP_DEVICE << 8):
                debug("USB_REQ_SET_ADDRESS\n");
                ctrl->rootdev = le16_to_cpu(req->value);
                break;
        case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
                debug("USB_REQ_SET_CONFIGURATION\n");
                /* Nothing to do */
                break;
        case USB_REQ_GET_STATUS | ((USB_DIR_IN | USB_RT_HUB) << 8):
                tmpbuf[0] = 1;  /* USB_STATUS_SELFPOWERED */
                tmpbuf[1] = 0;
                srcptr = tmpbuf;
                srclen = 2;
                break;
        case USB_REQ_GET_STATUS | ((USB_RT_PORT | USB_DIR_IN) << 8):
                memset(tmpbuf, 0, 4);
                reg = ehci_readl(status_reg);
                if (reg & EHCI_PS_CS)
                        tmpbuf[0] |= USB_PORT_STAT_CONNECTION;
                if (reg & EHCI_PS_PE)
                        tmpbuf[0] |= USB_PORT_STAT_ENABLE;
                if (reg & EHCI_PS_SUSP)
                        tmpbuf[0] |= USB_PORT_STAT_SUSPEND;
                if (reg & EHCI_PS_OCA)
                        tmpbuf[0] |= USB_PORT_STAT_OVERCURRENT;
                if (reg & EHCI_PS_PR)
                        tmpbuf[0] |= USB_PORT_STAT_RESET;
                if (reg & EHCI_PS_PP)
                        tmpbuf[1] |= USB_PORT_STAT_POWER >> 8;

                if (ehci_is_TDI()) {
                        switch (ehci_get_port_speed(ctrl->hcor, reg)) {
                        case PORTSC_PSPD_FS:
                                break;
                        case PORTSC_PSPD_LS:
                                tmpbuf[1] |= USB_PORT_STAT_LOW_SPEED >> 8;
                                break;
                        case PORTSC_PSPD_HS:
                        default:
                                tmpbuf[1] |= USB_PORT_STAT_HIGH_SPEED >> 8;
                                break;
                        }
                } else {
                        tmpbuf[1] |= USB_PORT_STAT_HIGH_SPEED >> 8;
                }

                if (reg & EHCI_PS_CSC)
                        tmpbuf[2] |= USB_PORT_STAT_C_CONNECTION;
                if (reg & EHCI_PS_PEC)
                        tmpbuf[2] |= USB_PORT_STAT_C_ENABLE;
                if (reg & EHCI_PS_OCC)
                        tmpbuf[2] |= USB_PORT_STAT_C_OVERCURRENT;
                if (ctrl->portreset & (1 << port))
                        tmpbuf[2] |= USB_PORT_STAT_C_RESET;

                srcptr = tmpbuf;
                srclen = 4;
                break;
        case USB_REQ_SET_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
                reg = ehci_readl(status_reg);
                reg &= ~EHCI_PS_CLEAR;
                switch (le16_to_cpu(req->value)) {
                case USB_PORT_FEAT_ENABLE:
                        reg |= EHCI_PS_PE;
                        ehci_writel(status_reg, reg);
                        break;
                case USB_PORT_FEAT_POWER:
                        if (HCS_PPC(ehci_readl(&ctrl->hccr->cr_hcsparams))) {
                                reg |= EHCI_PS_PP;
                                ehci_writel(status_reg, reg);
                        }
                        break;
                case USB_PORT_FEAT_RESET:
                        if ((reg & (EHCI_PS_PE | EHCI_PS_CS)) == EHCI_PS_CS &&
                            !ehci_is_TDI() &&
                            EHCI_PS_IS_LOWSPEED(reg)) {
                                /* Low speed device, give up ownership. */
                                debug("port %d low speed --> companion\n",
                                      port - 1);
                                reg |= EHCI_PS_PO;
                                ehci_writel(status_reg, reg);
                                break;
                        } else {
                                int ret;

                                reg |= EHCI_PS_PR;
                                reg &= ~EHCI_PS_PE;
                                ehci_writel(status_reg, reg);
                                /*
                                 * caller must wait, then call GetPortStatus
                                 * usb 2.0 specification say 50 ms resets on
                                 * root
                                 */
                                ehci_powerup_fixup(status_reg, &reg);

                                ehci_writel(status_reg, reg & ~EHCI_PS_PR);
                                /*
                                 * A host controller must terminate the reset
                                 * and stabilize the state of the port within
                                 * 2 milliseconds
                                 */
                                ret = handshake(status_reg, EHCI_PS_PR, 0,
                                                2 * 1000);
                                if (!ret)
                                        ctrl->portreset |= 1 << port;
                                else
                                        printf("port(%d) reset error\n",
                                               port - 1);
                        }
                        break;
                case USB_PORT_FEAT_TEST:
                        reg &= ~(0xf << 16);
                        reg |= ((le16_to_cpu(req->index) >> 8) & 0xf) << 16;
                        ehci_writel(status_reg, reg);
                        break;
                default:
                        debug("unknown feature %x\n", le16_to_cpu(req->value));
                        goto unknown;
                }
                /* unblock posted writes */
                (void) ehci_readl(&ctrl->hcor->or_usbcmd);
                break;
        case USB_REQ_CLEAR_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
                reg = ehci_readl(status_reg);
                reg &= ~EHCI_PS_CLEAR;
                switch (le16_to_cpu(req->value)) {
                case USB_PORT_FEAT_ENABLE:
                        reg &= ~EHCI_PS_PE;
                        break;
                case USB_PORT_FEAT_C_ENABLE:
                        reg |= EHCI_PS_PE;
                        break;
                case USB_PORT_FEAT_POWER:
                        if (HCS_PPC(ehci_readl(&ctrl->hccr->cr_hcsparams)))
                                reg &= ~EHCI_PS_PP;
                        break;
                case USB_PORT_FEAT_C_CONNECTION:
                        reg |= EHCI_PS_CSC;
                        break;
                case USB_PORT_FEAT_OVER_CURRENT:
                        reg |= EHCI_PS_OCC;
                        break;
                case USB_PORT_FEAT_C_RESET:
                        ctrl->portreset &= ~(1 << port);
                        break;
                default:
                        debug("unknown feature %x\n", le16_to_cpu(req->value));
                        goto unknown;
                }
                ehci_writel(status_reg, reg);
                /* unblock posted write */
                (void) ehci_readl(&ctrl->hcor->or_usbcmd);
                break;
        default:
                debug("Unknown request\n");
                goto unknown;
        }

        mdelay(1);
        len = min3(srclen, le16_to_cpu(req->length), length);
        if (srcptr != NULL && len > 0)
                memcpy(buffer, srcptr, len);
        else
                debug("Len is 0\n");

        dev->act_len = len;
        dev->status = 0;
        return 0;

unknown:
        debug("requesttype=%x, request=%x, value=%x, index=%x, length=%x\n",
              req->requesttype, req->request, le16_to_cpu(req->value),
              le16_to_cpu(req->index), le16_to_cpu(req->length));

        dev->act_len = 0;
        dev->status = USB_ST_STALLED;
        return -1;
}

int usb_lowlevel_stop(int index)
{
        return ehci_hcd_stop(index);
}

int usb_lowlevel_init(int index, void **controller)
{
        uint32_t reg;
        uint32_t cmd;
        struct QH *qh_list;
        struct QH *periodic;
        int i;

        if (ehci_hcd_init(index, &ehcic[index].hccr, &ehcic[index].hcor))
                return -1;

        /* EHCI spec section 4.1 */
        if (ehci_reset(index))
                return -1;

#if defined(CONFIG_EHCI_HCD_INIT_AFTER_RESET)
        if (ehci_hcd_init(index, &ehcic[index].hccr, &ehcic[index].hcor))
                return -1;
#endif
        /* Set the high address word (aka segment) for 64-bit controller */
        if (ehci_readl(&ehcic[index].hccr->cr_hccparams) & 1)
                ehci_writel(ehcic[index].hcor->or_ctrldssegment, 0);

        qh_list = &ehcic[index].qh_list;

        /* Set head of reclaim list */
        memset(qh_list, 0, sizeof(*qh_list));
        qh_list->qh_link = cpu_to_hc32((uint32_t)qh_list | QH_LINK_TYPE_QH);
        qh_list->qh_endpt1 = cpu_to_hc32(QH_ENDPT1_H(1) |
                                                QH_ENDPT1_EPS(USB_SPEED_HIGH));
        qh_list->qh_curtd = cpu_to_hc32(QT_NEXT_TERMINATE);
        qh_list->qh_overlay.qt_next = cpu_to_hc32(QT_NEXT_TERMINATE);
        qh_list->qh_overlay.qt_altnext = cpu_to_hc32(QT_NEXT_TERMINATE);
        qh_list->qh_overlay.qt_token =
                        cpu_to_hc32(QT_TOKEN_STATUS(QT_TOKEN_STATUS_HALTED));

        /* Set async. queue head pointer. */
        ehci_writel(&ehcic[index].hcor->or_asynclistaddr, (uint32_t)qh_list);

        /*
         * Set up periodic list
         * Step 1: Parent QH for all periodic transfers.
         */
        periodic = &ehcic[index].periodic_queue;
        memset(periodic, 0, sizeof(*periodic));
        periodic->qh_link = cpu_to_hc32(QH_LINK_TERMINATE);
        periodic->qh_overlay.qt_next = cpu_to_hc32(QT_NEXT_TERMINATE);
        periodic->qh_overlay.qt_altnext = cpu_to_hc32(QT_NEXT_TERMINATE);

        /*
         * Step 2: Setup frame-list: Every microframe, USB tries the same list.
         *         In particular, device specifications on polling frequency
         *         are disregarded. Keyboards seem to send NAK/NYet reliably
         *         when polled with an empty buffer.
         *
         *         Split Transactions will be spread across microframes using
         *         S-mask and C-mask.
         */
        ehcic[index].periodic_list = memalign(4096, 1024*4);
        if (!ehcic[index].periodic_list)
                return -ENOMEM;
        for (i = 0; i < 1024; i++) {
                ehcic[index].periodic_list[i] = (uint32_t)periodic
                                                | QH_LINK_TYPE_QH;
        }

        /* Set periodic list base address */
        ehci_writel(&ehcic[index].hcor->or_periodiclistbase,
                (uint32_t)ehcic[index].periodic_list);

        reg = ehci_readl(&ehcic[index].hccr->cr_hcsparams);
        descriptor.hub.bNbrPorts = HCS_N_PORTS(reg);
        debug("Register %x NbrPorts %d\n", reg, descriptor.hub.bNbrPorts);
        /* Port Indicators */
        if (HCS_INDICATOR(reg))
                put_unaligned(get_unaligned(&descriptor.hub.wHubCharacteristics)
                                | 0x80, &descriptor.hub.wHubCharacteristics);
        /* Port Power Control */
        if (HCS_PPC(reg))
                put_unaligned(get_unaligned(&descriptor.hub.wHubCharacteristics)
                                | 0x01, &descriptor.hub.wHubCharacteristics);

        /* Start the host controller. */
        cmd = ehci_readl(&ehcic[index].hcor->or_usbcmd);
        /*
         * Philips, Intel, and maybe others need CMD_RUN before the
         * root hub will detect new devices (why?); NEC doesn't
         */
        cmd &= ~(CMD_LRESET|CMD_IAAD|CMD_PSE|CMD_ASE|CMD_RESET);
        cmd |= CMD_RUN;
        ehci_writel(&ehcic[index].hcor->or_usbcmd, cmd);

        /* take control over the ports */
        cmd = ehci_readl(&ehcic[index].hcor->or_configflag);
        cmd |= FLAG_CF;
        ehci_writel(&ehcic[index].hcor->or_configflag, cmd);
        /* unblock posted write */
        cmd = ehci_readl(&ehcic[index].hcor->or_usbcmd);
        mdelay(5);
        reg = HC_VERSION(ehci_readl(&ehcic[index].hccr->cr_capbase));
        printf("USB EHCI %x.%02x\n", reg >> 8, reg & 0xff);

        ehcic[index].rootdev = 0;

        *controller = &ehcic[index];
        return 0;
}

int
submit_bulk_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
                int length)
{

        if (usb_pipetype(pipe) != PIPE_BULK) {
                debug("non-bulk pipe (type=%lu)", usb_pipetype(pipe));
                return -1;
        }
        return ehci_submit_async(dev, pipe, buffer, length, NULL);
}

int
submit_control_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
                   int length, struct devrequest *setup)
{
        struct ehci_ctrl *ctrl = dev->controller;

        if (usb_pipetype(pipe) != PIPE_CONTROL) {
                debug("non-control pipe (type=%lu)", usb_pipetype(pipe));
                return -1;
        }

        if (usb_pipedevice(pipe) == ctrl->rootdev) {
                if (!ctrl->rootdev)
                        dev->speed = USB_SPEED_HIGH;
                return ehci_submit_root(dev, pipe, buffer, length, setup);
        }
        return ehci_submit_async(dev, pipe, buffer, length, setup);
}

struct int_queue {
        struct QH *first;
        struct QH *current;
        struct QH *last;
        struct qTD *tds;
};

#define NEXT_QH(qh) (struct QH *)((qh)->qh_link & ~0x1f)

static int
enable_periodic(struct ehci_ctrl *ctrl)
{
        uint32_t cmd;
        struct ehci_hcor *hcor = ctrl->hcor;
        int ret;

        cmd = ehci_readl(&hcor->or_usbcmd);
        cmd |= CMD_PSE;
        ehci_writel(&hcor->or_usbcmd, cmd);

        ret = handshake((uint32_t *)&hcor->or_usbsts,
                        STS_PSS, STS_PSS, 100 * 1000);
        if (ret < 0) {
                printf("EHCI failed: timeout when enabling periodic list\n");
                return -ETIMEDOUT;
        }
        udelay(1000);
        return 0;
}

static int
disable_periodic(struct ehci_ctrl *ctrl)
{
        uint32_t cmd;
        struct ehci_hcor *hcor = ctrl->hcor;
        int ret;

        cmd = ehci_readl(&hcor->or_usbcmd);
        cmd &= ~CMD_PSE;
        ehci_writel(&hcor->or_usbcmd, cmd);

        ret = handshake((uint32_t *)&hcor->or_usbsts,
                        STS_PSS, 0, 100 * 1000);
        if (ret < 0) {
                printf("EHCI failed: timeout when disabling periodic list\n");
                return -ETIMEDOUT;
        }
        return 0;
}

static int periodic_schedules;

struct int_queue *
create_int_queue(struct usb_device *dev, unsigned long pipe, int queuesize,
                 int elementsize, void *buffer)
{
        struct ehci_ctrl *ctrl = dev->controller;
        struct int_queue *result = NULL;
        int i;

        debug("Enter create_int_queue\n");
        if (usb_pipetype(pipe) != PIPE_INTERRUPT) {
                debug("non-interrupt pipe (type=%lu)", usb_pipetype(pipe));
                return NULL;
        }

        /* limit to 4 full pages worth of data -
         * we can safely fit them in a single TD,
         * no matter the alignment
         */
        if (elementsize >= 16384) {
                debug("too large elements for interrupt transfers\n");
                return NULL;
        }

        result = malloc(sizeof(*result));
        if (!result) {
                debug("ehci intr queue: out of memory\n");
                goto fail1;
        }
        result->first = memalign(32, sizeof(struct QH) * queuesize);
        if (!result->first) {
                debug("ehci intr queue: out of memory\n");
                goto fail2;
        }
        result->current = result->first;
        result->last = result->first + queuesize - 1;
        result->tds = memalign(32, sizeof(struct qTD) * queuesize);
        if (!result->tds) {
                debug("ehci intr queue: out of memory\n");
                goto fail3;
        }
        memset(result->first, 0, sizeof(struct QH) * queuesize);
        memset(result->tds, 0, sizeof(struct qTD) * queuesize);

        for (i = 0; i < queuesize; i++) {
                struct QH *qh = result->first + i;
                struct qTD *td = result->tds + i;
                void **buf = &qh->buffer;

                qh->qh_link = (uint32_t)(qh+1) | QH_LINK_TYPE_QH;
                if (i == queuesize - 1)
                        qh->qh_link = QH_LINK_TERMINATE;

                qh->qh_overlay.qt_next = (uint32_t)td;
                qh->qh_endpt1 = (0 << 28) | /* No NAK reload (ehci 4.9) */
                        (usb_maxpacket(dev, pipe) << 16) | /* MPS */
                        (1 << 14) |
                        QH_ENDPT1_EPS(ehci_encode_speed(dev->speed)) |
                        (usb_pipeendpoint(pipe) << 8) | /* Endpoint Number */
                        (usb_pipedevice(pipe) << 0);
                qh->qh_endpt2 = (1 << 30) | /* 1 Tx per mframe */
                        (1 << 0); /* S-mask: microframe 0 */
                if (dev->speed == USB_SPEED_LOW ||
                                dev->speed == USB_SPEED_FULL) {
                        debug("TT: port: %d, hub address: %d\n",
                                dev->portnr, dev->parent->devnum);
                        qh->qh_endpt2 |= (dev->portnr << 23) |
                                (dev->parent->devnum << 16) |
                                (0x1c << 8); /* C-mask: microframes 2-4 */
                }

                td->qt_next = QT_NEXT_TERMINATE;
                td->qt_altnext = QT_NEXT_TERMINATE;
                debug("communication direction is '%s'\n",
                      usb_pipein(pipe) ? "in" : "out");
                td->qt_token = (elementsize << 16) |
                        ((usb_pipein(pipe) ? 1 : 0) << 8) | /* IN/OUT token */
                        0x80; /* active */
                td->qt_buffer[0] = (uint32_t)buffer + i * elementsize;
                td->qt_buffer[1] = (td->qt_buffer[0] + 0x1000) & ~0xfff;
                td->qt_buffer[2] = (td->qt_buffer[0] + 0x2000) & ~0xfff;
                td->qt_buffer[3] = (td->qt_buffer[0] + 0x3000) & ~0xfff;
                td->qt_buffer[4] = (td->qt_buffer[0] + 0x4000) & ~0xfff;

                *buf = buffer + i * elementsize;
        }

        if (disable_periodic(ctrl) < 0) {
                debug("FATAL: periodic should never fail, but did");
                goto fail3;
        }

        /* hook up to periodic list */
        struct QH *list = &ctrl->periodic_queue;
        result->last->qh_link = list->qh_link;
        list->qh_link = (uint32_t)result->first | QH_LINK_TYPE_QH;

        if (enable_periodic(ctrl) < 0) {
                debug("FATAL: periodic should never fail, but did");
                goto fail3;
        }
        periodic_schedules++;

        debug("Exit create_int_queue\n");
        return result;
fail3:
        if (result->tds)
                free(result->tds);
fail2:
        if (result->first)
                free(result->first);
        if (result)
                free(result);
fail1:
        return NULL;
}

void *poll_int_queue(struct usb_device *dev, struct int_queue *queue)
{
        struct QH *cur = queue->current;

        /* depleted queue */
        if (cur == NULL) {
                debug("Exit poll_int_queue with completed queue\n");
                return NULL;
        }
        /* still active */
        if (cur->qh_overlay.qt_token & 0x80) {
                debug("Exit poll_int_queue with no completed intr transfer. "
                      "token is %x\n", cur->qh_overlay.qt_token);
                return NULL;
        }
        if (!(cur->qh_link & QH_LINK_TERMINATE))
                queue->current++;
        else
                queue->current = NULL;
        debug("Exit poll_int_queue with completed intr transfer. "
              "token is %x at %p (first at %p)\n", cur->qh_overlay.qt_token,
              &cur->qh_overlay.qt_token, queue->first);
        return cur->buffer;
}

/* Do not free buffers associated with QHs, they're owned by someone else */
int
destroy_int_queue(struct usb_device *dev, struct int_queue *queue)
{
        struct ehci_ctrl *ctrl = dev->controller;
        int result = -1;
        unsigned long timeout;

        if (disable_periodic(ctrl) < 0) {
                debug("FATAL: periodic should never fail, but did");
                goto out;
        }
        periodic_schedules--;

        struct QH *cur = &ctrl->periodic_queue;
        timeout = get_timer(0) + 500; /* abort after 500ms */
        while (!(cur->qh_link & QH_LINK_TERMINATE)) {
                debug("considering %p, with qh_link %x\n", cur, cur->qh_link);
                if (NEXT_QH(cur) == queue->first) {
                        debug("found candidate. removing from chain\n");
                        cur->qh_link = queue->last->qh_link;
                        result = 0;
                        break;
                }
                cur = NEXT_QH(cur);
                if (get_timer(0) > timeout) {
                        printf("Timeout destroying interrupt endpoint queue\n");
                        result = -1;
                        goto out;
                }
        }

        if (periodic_schedules > 0) {
                result = enable_periodic(ctrl);
                if (result < 0)
                        debug("FATAL: periodic should never fail, but did");
        }

out:
        free(queue->tds);
        free(queue->first);
        free(queue);

        return result;
}

int
submit_int_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
               int length, int interval)
{
        void *backbuffer;
        struct int_queue *queue;
        unsigned long timeout;
        int result = 0, ret;

        debug("dev=%p, pipe=%lu, buffer=%p, length=%d, interval=%d",
              dev, pipe, buffer, length, interval);

        /*
         * Interrupt transfers requiring several transactions are not supported
         * because bInterval is ignored.
         *
         * Also, ehci_submit_async() relies on wMaxPacketSize being a power of 2
         * <= PKT_ALIGN if several qTDs are required, while the USB
         * specification does not constrain this for interrupt transfers. That
         * means that ehci_submit_async() would support interrupt transfers
         * requiring several transactions only as long as the transfer size does
         * not require more than a single qTD.
         */
        if (length > usb_maxpacket(dev, pipe)) {
                printf("%s: Interrupt transfers requiring several "
                        "transactions are not supported.\n", __func__);
                return -1;
        }

        queue = create_int_queue(dev, pipe, 1, length, buffer);

        timeout = get_timer(0) + USB_TIMEOUT_MS(pipe);
        while ((backbuffer = poll_int_queue(dev, queue)) == NULL)
                if (get_timer(0) > timeout) {
                        printf("Timeout poll on interrupt endpoint\n");
                        result = -ETIMEDOUT;
                        break;
                }

        if (backbuffer != buffer) {
                debug("got wrong buffer back (%x instead of %x)\n",
                      (uint32_t)backbuffer, (uint32_t)buffer);
                return -EINVAL;
        }

        ret = destroy_int_queue(dev, queue);
        if (ret < 0)
                return ret;

        /* everything worked out fine */
        return result;
}