/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009 Hans Petter Selasky. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * This file contains the driver for the ATMEGA series USB OTG Controller. This
 * driver currently only supports the DCI mode of the USB hardware.
 */

/*
 * NOTE: When the chip detects BUS-reset it will also reset the
 * endpoints, Function-address and more.
 */

#ifdef USB_GLOBAL_INCLUDE_FILE
#include USB_GLOBAL_INCLUDE_FILE
#else
#include <sys/stdint.h>
#include <sys/stddef.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <sys/sx.h>
#include <sys/unistd.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/priv.h>

#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>

#define USB_DEBUG_VAR atmegadci_debug

#include <dev/usb/usb_core.h>
#include <dev/usb/usb_debug.h>
#include <dev/usb/usb_busdma.h>
#include <dev/usb/usb_process.h>
#include <dev/usb/usb_transfer.h>
#include <dev/usb/usb_device.h>
#include <dev/usb/usb_hub.h>
#include <dev/usb/usb_util.h>

#include <dev/usb/usb_controller.h>
#include <dev/usb/usb_bus.h>
#endif                  /* USB_GLOBAL_INCLUDE_FILE */

#include <dev/usb/controller/atmegadci.h>

#define ATMEGA_BUS2SC(bus) \
    __containerof(bus, struct atmegadci_softc, sc_bus)

#define ATMEGA_PC2SC(pc) \
   ATMEGA_BUS2SC(USB_DMATAG_TO_XROOT((pc)->tag_parent)->bus)

#ifdef USB_DEBUG
static int atmegadci_debug = 0;

static SYSCTL_NODE(_hw_usb, OID_AUTO, atmegadci, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "USB ATMEGA DCI");
SYSCTL_INT(_hw_usb_atmegadci, OID_AUTO, debug, CTLFLAG_RWTUN,
    &atmegadci_debug, 0, "ATMEGA DCI debug level");
#endif

#define ATMEGA_INTR_ENDPT 1

/* prototypes */

static const struct usb_bus_methods atmegadci_bus_methods;
static const struct usb_pipe_methods atmegadci_device_non_isoc_methods;
static const struct usb_pipe_methods atmegadci_device_isoc_fs_methods;

static atmegadci_cmd_t atmegadci_setup_rx;
static atmegadci_cmd_t atmegadci_data_rx;
static atmegadci_cmd_t atmegadci_data_tx;
static atmegadci_cmd_t atmegadci_data_tx_sync;
static void atmegadci_device_done(struct usb_xfer *, usb_error_t);
static void atmegadci_do_poll(struct usb_bus *);
static void atmegadci_standard_done(struct usb_xfer *);
static void atmegadci_root_intr(struct atmegadci_softc *sc);

/*
 * Here is a list of what the chip supports:
 */
static const struct usb_hw_ep_profile
        atmegadci_ep_profile[2] = {
        [0] = {
                .max_in_frame_size = 64,
                .max_out_frame_size = 64,
                .is_simplex = 1,
                .support_control = 1,
        },
        [1] = {
                .max_in_frame_size = 64,
                .max_out_frame_size = 64,
                .is_simplex = 1,
                .support_bulk = 1,
                .support_interrupt = 1,
                .support_isochronous = 1,
                .support_in = 1,
                .support_out = 1,
        },
};

static void
atmegadci_get_hw_ep_profile(struct usb_device *udev,
    const struct usb_hw_ep_profile **ppf, uint8_t ep_addr)
{
        if (ep_addr == 0)
                *ppf = atmegadci_ep_profile;
        else if (ep_addr < ATMEGA_EP_MAX)
                *ppf = atmegadci_ep_profile + 1;
        else
                *ppf = NULL;
}

static void
atmegadci_clocks_on(struct atmegadci_softc *sc)
{
        if (sc->sc_flags.clocks_off &&
            sc->sc_flags.port_powered) {
                DPRINTFN(5, "\n");

                /* turn on clocks */
                (sc->sc_clocks_on) (&sc->sc_bus);

                ATMEGA_WRITE_1(sc, ATMEGA_USBCON,
                    ATMEGA_USBCON_USBE |
                    ATMEGA_USBCON_OTGPADE |
                    ATMEGA_USBCON_VBUSTE);

                sc->sc_flags.clocks_off = 0;

                /* enable transceiver ? */
        }
}

static void
atmegadci_clocks_off(struct atmegadci_softc *sc)
{
        if (!sc->sc_flags.clocks_off) {
                DPRINTFN(5, "\n");

                /* disable Transceiver ? */

                ATMEGA_WRITE_1(sc, ATMEGA_USBCON,
                    ATMEGA_USBCON_USBE |
                    ATMEGA_USBCON_OTGPADE |
                    ATMEGA_USBCON_FRZCLK |
                    ATMEGA_USBCON_VBUSTE);

                /* turn clocks off */
                (sc->sc_clocks_off) (&sc->sc_bus);

                sc->sc_flags.clocks_off = 1;
        }
}

static void
atmegadci_pull_up(struct atmegadci_softc *sc)
{
        /* pullup D+, if possible */

        if (!sc->sc_flags.d_pulled_up &&
            sc->sc_flags.port_powered) {
                sc->sc_flags.d_pulled_up = 1;
                ATMEGA_WRITE_1(sc, ATMEGA_UDCON, 0);
        }
}

static void
atmegadci_pull_down(struct atmegadci_softc *sc)
{
        /* pulldown D+, if possible */

        if (sc->sc_flags.d_pulled_up) {
                sc->sc_flags.d_pulled_up = 0;
                ATMEGA_WRITE_1(sc, ATMEGA_UDCON, ATMEGA_UDCON_DETACH);
        }
}

static void
atmegadci_wakeup_peer(struct atmegadci_softc *sc)
{
        uint8_t temp;

        if (!sc->sc_flags.status_suspend) {
                return;
        }

        temp = ATMEGA_READ_1(sc, ATMEGA_UDCON);
        ATMEGA_WRITE_1(sc, ATMEGA_UDCON, temp | ATMEGA_UDCON_RMWKUP);

        /* wait 8 milliseconds */
        /* Wait for reset to complete. */
        usb_pause_mtx(&sc->sc_bus.bus_mtx, hz / 125);

        /* hardware should have cleared RMWKUP bit */
}

static void
atmegadci_set_address(struct atmegadci_softc *sc, uint8_t addr)
{
        DPRINTFN(5, "addr=%d\n", addr);

        addr |= ATMEGA_UDADDR_ADDEN;

        ATMEGA_WRITE_1(sc, ATMEGA_UDADDR, addr);
}

static uint8_t
atmegadci_setup_rx(struct atmegadci_td *td)
{
        struct atmegadci_softc *sc;
        struct usb_device_request req;
        uint16_t count;
        uint8_t temp;

        /* get pointer to softc */
        sc = ATMEGA_PC2SC(td->pc);

        /* select endpoint number */
        ATMEGA_WRITE_1(sc, ATMEGA_UENUM, td->ep_no);

        /* check endpoint status */
        temp = ATMEGA_READ_1(sc, ATMEGA_UEINTX);

        DPRINTFN(5, "UEINTX=0x%02x\n", temp);

        if (!(temp & ATMEGA_UEINTX_RXSTPI)) {
                goto not_complete;
        }
        /* clear did stall */
        td->did_stall = 0;
        /* get the packet byte count */
        count =
            (ATMEGA_READ_1(sc, ATMEGA_UEBCHX) << 8) |
            (ATMEGA_READ_1(sc, ATMEGA_UEBCLX));

        /* mask away undefined bits */
        count &= 0x7FF;

        /* verify data length */
        if (count != td->remainder) {
                DPRINTFN(0, "Invalid SETUP packet "
                    "length, %d bytes\n", count);
                goto not_complete;
        }
        if (count != sizeof(req)) {
                DPRINTFN(0, "Unsupported SETUP packet "
                    "length, %d bytes\n", count);
                goto not_complete;
        }
        /* receive data */
        ATMEGA_READ_MULTI_1(sc, ATMEGA_UEDATX,
            (void *)&req, sizeof(req));

        /* copy data into real buffer */
        usbd_copy_in(td->pc, 0, &req, sizeof(req));

        td->offset = sizeof(req);
        td->remainder = 0;

        /* sneak peek the set address */
        if ((req.bmRequestType == UT_WRITE_DEVICE) &&
            (req.bRequest == UR_SET_ADDRESS)) {
                sc->sc_dv_addr = req.wValue[0] & 0x7F;
                /* must write address before ZLP */
                ATMEGA_WRITE_1(sc, ATMEGA_UDADDR, sc->sc_dv_addr);
        } else {
                sc->sc_dv_addr = 0xFF;
        }

        /* Clear SETUP packet interrupt and all other previous interrupts */
        ATMEGA_WRITE_1(sc, ATMEGA_UEINTX, 0);
        return (0);                     /* complete */

not_complete:
        /* abort any ongoing transfer */
        if (!td->did_stall) {
                DPRINTFN(5, "stalling\n");
                ATMEGA_WRITE_1(sc, ATMEGA_UECONX,
                    ATMEGA_UECONX_EPEN |
                    ATMEGA_UECONX_STALLRQ);
                td->did_stall = 1;
        }
        if (temp & ATMEGA_UEINTX_RXSTPI) {
                /* clear SETUP packet interrupt */
                ATMEGA_WRITE_1(sc, ATMEGA_UEINTX, ~ATMEGA_UEINTX_RXSTPI);
        }
        /* we only want to know if there is a SETUP packet */
        ATMEGA_WRITE_1(sc, ATMEGA_UEIENX, ATMEGA_UEIENX_RXSTPE);
        return (1);                     /* not complete */
}

static uint8_t
atmegadci_data_rx(struct atmegadci_td *td)
{
        struct atmegadci_softc *sc;
        struct usb_page_search buf_res;
        uint16_t count;
        uint8_t temp;
        uint8_t to;
        uint8_t got_short;

        to = 3;                         /* don't loop forever! */
        got_short = 0;

        /* get pointer to softc */
        sc = ATMEGA_PC2SC(td->pc);

        /* select endpoint number */
        ATMEGA_WRITE_1(sc, ATMEGA_UENUM, td->ep_no);

repeat:
        /* check if any of the FIFO banks have data */
        /* check endpoint status */
        temp = ATMEGA_READ_1(sc, ATMEGA_UEINTX);

        DPRINTFN(5, "temp=0x%02x rem=%u\n", temp, td->remainder);

        if (temp & ATMEGA_UEINTX_RXSTPI) {
                if (td->remainder == 0) {
                        /*
                         * We are actually complete and have
                         * received the next SETUP
                         */
                        DPRINTFN(5, "faking complete\n");
                        return (0);     /* complete */
                }
                /*
                 * USB Host Aborted the transfer.
                 */
                td->error = 1;
                return (0);             /* complete */
        }
        /* check status */
        if (!(temp & (ATMEGA_UEINTX_FIFOCON |
            ATMEGA_UEINTX_RXOUTI))) {
                /* no data */
                goto not_complete;
        }
        /* get the packet byte count */
        count =
            (ATMEGA_READ_1(sc, ATMEGA_UEBCHX) << 8) |
            (ATMEGA_READ_1(sc, ATMEGA_UEBCLX));

        /* mask away undefined bits */
        count &= 0x7FF;

        /* verify the packet byte count */
        if (count != td->max_packet_size) {
                if (count < td->max_packet_size) {
                        /* we have a short packet */
                        td->short_pkt = 1;
                        got_short = 1;
                } else {
                        /* invalid USB packet */
                        td->error = 1;
                        return (0);     /* we are complete */
                }
        }
        /* verify the packet byte count */
        if (count > td->remainder) {
                /* invalid USB packet */
                td->error = 1;
                return (0);             /* we are complete */
        }
        while (count > 0) {
                usbd_get_page(td->pc, td->offset, &buf_res);

                /* get correct length */
                if (buf_res.length > count) {
                        buf_res.length = count;
                }
                /* receive data */
                ATMEGA_READ_MULTI_1(sc, ATMEGA_UEDATX,
                    buf_res.buffer, buf_res.length);

                /* update counters */
                count -= buf_res.length;
                td->offset += buf_res.length;
                td->remainder -= buf_res.length;
        }

        /* clear OUT packet interrupt */
        ATMEGA_WRITE_1(sc, ATMEGA_UEINTX, ATMEGA_UEINTX_RXOUTI ^ 0xFF);

        /* release FIFO bank */
        ATMEGA_WRITE_1(sc, ATMEGA_UEINTX, ATMEGA_UEINTX_FIFOCON ^ 0xFF);

        /* check if we are complete */
        if ((td->remainder == 0) || got_short) {
                if (td->short_pkt) {
                        /* we are complete */
                        return (0);
                }
                /* else need to receive a zero length packet */
        }
        if (--to) {
                goto repeat;
        }
not_complete:
        /* we only want to know if there is a SETUP packet or OUT packet */
        ATMEGA_WRITE_1(sc, ATMEGA_UEIENX,
            ATMEGA_UEIENX_RXSTPE | ATMEGA_UEIENX_RXOUTE);
        return (1);                     /* not complete */
}

static uint8_t
atmegadci_data_tx(struct atmegadci_td *td)
{
        struct atmegadci_softc *sc;
        struct usb_page_search buf_res;
        uint16_t count;
        uint8_t to;
        uint8_t temp;

        to = 3;                         /* don't loop forever! */

        /* get pointer to softc */
        sc = ATMEGA_PC2SC(td->pc);

        /* select endpoint number */
        ATMEGA_WRITE_1(sc, ATMEGA_UENUM, td->ep_no);

repeat:

        /* check endpoint status */
        temp = ATMEGA_READ_1(sc, ATMEGA_UEINTX);

        DPRINTFN(5, "temp=0x%02x rem=%u\n", temp, td->remainder);

        if (temp & ATMEGA_UEINTX_RXSTPI) {
                /*
                 * The current transfer was aborted
                 * by the USB Host
                 */
                td->error = 1;
                return (0);             /* complete */
        }

        temp = ATMEGA_READ_1(sc, ATMEGA_UESTA0X);
        if (temp & 3) {
                /* cannot write any data - a bank is busy */
                goto not_complete;
        }

        count = td->max_packet_size;
        if (td->remainder < count) {
                /* we have a short packet */
                td->short_pkt = 1;
                count = td->remainder;
        }
        while (count > 0) {
                usbd_get_page(td->pc, td->offset, &buf_res);

                /* get correct length */
                if (buf_res.length > count) {
                        buf_res.length = count;
                }
                /* transmit data */
                ATMEGA_WRITE_MULTI_1(sc, ATMEGA_UEDATX,
                    buf_res.buffer, buf_res.length);

                /* update counters */
                count -= buf_res.length;
                td->offset += buf_res.length;
                td->remainder -= buf_res.length;
        }

        /* clear IN packet interrupt */
        ATMEGA_WRITE_1(sc, ATMEGA_UEINTX, 0xFF ^ ATMEGA_UEINTX_TXINI);

        /* allocate FIFO bank */
        ATMEGA_WRITE_1(sc, ATMEGA_UEINTX, 0xFF ^ ATMEGA_UEINTX_FIFOCON);

        /* check remainder */
        if (td->remainder == 0) {
                if (td->short_pkt) {
                        return (0);     /* complete */
                }
                /* else we need to transmit a short packet */
        }
        if (--to) {
                goto repeat;
        }
not_complete:
        /* we only want to know if there is a SETUP packet or free IN packet */
        ATMEGA_WRITE_1(sc, ATMEGA_UEIENX,
            ATMEGA_UEIENX_RXSTPE | ATMEGA_UEIENX_TXINE);
        return (1);                     /* not complete */
}

static uint8_t
atmegadci_data_tx_sync(struct atmegadci_td *td)
{
        struct atmegadci_softc *sc;
        uint8_t temp;

        /* get pointer to softc */
        sc = ATMEGA_PC2SC(td->pc);

        /* select endpoint number */
        ATMEGA_WRITE_1(sc, ATMEGA_UENUM, td->ep_no);

        /* check endpoint status */
        temp = ATMEGA_READ_1(sc, ATMEGA_UEINTX);

        DPRINTFN(5, "temp=0x%02x\n", temp);

        if (temp & ATMEGA_UEINTX_RXSTPI) {
                DPRINTFN(5, "faking complete\n");
                /* Race condition */
                return (0);             /* complete */
        }
        /*
         * The control endpoint has only got one bank, so if that bank
         * is free the packet has been transferred!
         */
        temp = ATMEGA_READ_1(sc, ATMEGA_UESTA0X);
        if (temp & 3) {
                /* cannot write any data - a bank is busy */
                goto not_complete;
        }
        if (sc->sc_dv_addr != 0xFF) {
                /* set new address */
                atmegadci_set_address(sc, sc->sc_dv_addr);
        }
        return (0);                     /* complete */

not_complete:
        /* we only want to know if there is a SETUP packet or free IN packet */
        ATMEGA_WRITE_1(sc, ATMEGA_UEIENX,
            ATMEGA_UEIENX_RXSTPE | ATMEGA_UEIENX_TXINE);
        return (1);                     /* not complete */
}

static uint8_t
atmegadci_xfer_do_fifo(struct usb_xfer *xfer)
{
        struct atmegadci_td *td;

        DPRINTFN(9, "\n");

        td = xfer->td_transfer_cache;
        while (1) {
                if ((td->func) (td)) {
                        /* operation in progress */
                        break;
                }
                if (((void *)td) == xfer->td_transfer_last) {
                        goto done;
                }
                if (td->error) {
                        goto done;
                } else if (td->remainder > 0) {
                        /*
                         * We had a short transfer. If there is no alternate
                         * next, stop processing !
                         */
                        if (!td->alt_next) {
                                goto done;
                        }
                }
                /*
                 * Fetch the next transfer descriptor and transfer
                 * some flags to the next transfer descriptor
                 */
                td = td->obj_next;
                xfer->td_transfer_cache = td;
        }
        return (1);                     /* not complete */

done:
        /* compute all actual lengths */

        atmegadci_standard_done(xfer);
        return (0);                     /* complete */
}

static void
atmegadci_interrupt_poll(struct atmegadci_softc *sc)
{
        struct usb_xfer *xfer;

repeat:
        TAILQ_FOREACH(xfer, &sc->sc_bus.intr_q.head, wait_entry) {
                if (!atmegadci_xfer_do_fifo(xfer)) {
                        /* queue has been modified */
                        goto repeat;
                }
        }
}

static void
atmegadci_vbus_interrupt(struct atmegadci_softc *sc, uint8_t is_on)
{
        DPRINTFN(5, "vbus = %u\n", is_on);

        if (is_on) {
                if (!sc->sc_flags.status_vbus) {
                        sc->sc_flags.status_vbus = 1;

                        /* complete root HUB interrupt endpoint */

                        atmegadci_root_intr(sc);
                }
        } else {
                if (sc->sc_flags.status_vbus) {
                        sc->sc_flags.status_vbus = 0;
                        sc->sc_flags.status_bus_reset = 0;
                        sc->sc_flags.status_suspend = 0;
                        sc->sc_flags.change_suspend = 0;
                        sc->sc_flags.change_connect = 1;

                        /* complete root HUB interrupt endpoint */

                        atmegadci_root_intr(sc);
                }
        }
}

void
atmegadci_interrupt(struct atmegadci_softc *sc)
{
        uint8_t status;

        USB_BUS_LOCK(&sc->sc_bus);

        /* read interrupt status */
        status = ATMEGA_READ_1(sc, ATMEGA_UDINT);

        /* clear all set interrupts */
        ATMEGA_WRITE_1(sc, ATMEGA_UDINT, (~status) & 0x7D);

        DPRINTFN(14, "UDINT=0x%02x\n", status);

        /* check for any bus state change interrupts */
        if (status & ATMEGA_UDINT_EORSTI) {
                DPRINTFN(5, "end of reset\n");

                /* set correct state */
                sc->sc_flags.status_bus_reset = 1;
                sc->sc_flags.status_suspend = 0;
                sc->sc_flags.change_suspend = 0;
                sc->sc_flags.change_connect = 1;

                /* disable resume interrupt */
                ATMEGA_WRITE_1(sc, ATMEGA_UDIEN,
                    ATMEGA_UDINT_SUSPE |
                    ATMEGA_UDINT_EORSTE);

                /* complete root HUB interrupt endpoint */
                atmegadci_root_intr(sc);
        }
        /*
         * If resume and suspend is set at the same time we interpret
         * that like RESUME. Resume is set when there is at least 3
         * milliseconds of inactivity on the USB BUS.
         */
        if (status & ATMEGA_UDINT_WAKEUPI) {
                DPRINTFN(5, "resume interrupt\n");

                if (sc->sc_flags.status_suspend) {
                        /* update status bits */
                        sc->sc_flags.status_suspend = 0;
                        sc->sc_flags.change_suspend = 1;

                        /* disable resume interrupt */
                        ATMEGA_WRITE_1(sc, ATMEGA_UDIEN,
                            ATMEGA_UDINT_SUSPE |
                            ATMEGA_UDINT_EORSTE);

                        /* complete root HUB interrupt endpoint */
                        atmegadci_root_intr(sc);
                }
        } else if (status & ATMEGA_UDINT_SUSPI) {
                DPRINTFN(5, "suspend interrupt\n");

                if (!sc->sc_flags.status_suspend) {
                        /* update status bits */
                        sc->sc_flags.status_suspend = 1;
                        sc->sc_flags.change_suspend = 1;

                        /* disable suspend interrupt */
                        ATMEGA_WRITE_1(sc, ATMEGA_UDIEN,
                            ATMEGA_UDINT_WAKEUPE |
                            ATMEGA_UDINT_EORSTE);

                        /* complete root HUB interrupt endpoint */
                        atmegadci_root_intr(sc);
                }
        }
        /* check VBUS */
        status = ATMEGA_READ_1(sc, ATMEGA_USBINT);

        /* clear all set interrupts */
        ATMEGA_WRITE_1(sc, ATMEGA_USBINT, (~status) & 0x03);

        if (status & ATMEGA_USBINT_VBUSTI) {
                uint8_t temp;

                DPRINTFN(5, "USBINT=0x%02x\n", status);

                temp = ATMEGA_READ_1(sc, ATMEGA_USBSTA);
                atmegadci_vbus_interrupt(sc, temp & ATMEGA_USBSTA_VBUS);
        }
        /* check for any endpoint interrupts */
        status = ATMEGA_READ_1(sc, ATMEGA_UEINT);
        /* the hardware will clear the UEINT bits automatically */
        if (status) {
                DPRINTFN(5, "real endpoint interrupt UEINT=0x%02x\n", status);

                atmegadci_interrupt_poll(sc);
        }
        USB_BUS_UNLOCK(&sc->sc_bus);
}

static void
atmegadci_setup_standard_chain_sub(struct atmegadci_std_temp *temp)
{
        struct atmegadci_td *td;

        /* get current Transfer Descriptor */
        td = temp->td_next;
        temp->td = td;

        /* prepare for next TD */
        temp->td_next = td->obj_next;

        /* fill out the Transfer Descriptor */
        td->func = temp->func;
        td->pc = temp->pc;
        td->offset = temp->offset;
        td->remainder = temp->len;
        td->error = 0;
        td->did_stall = temp->did_stall;
        td->short_pkt = temp->short_pkt;
        td->alt_next = temp->setup_alt_next;
}

static void
atmegadci_setup_standard_chain(struct usb_xfer *xfer)
{
        struct atmegadci_std_temp temp;
        struct atmegadci_td *td;
        uint32_t x;
        uint8_t need_sync;

        DPRINTFN(9, "addr=%d endpt=%d sumlen=%d speed=%d\n",
            xfer->address, UE_GET_ADDR(xfer->endpointno),
            xfer->sumlen, usbd_get_speed(xfer->xroot->udev));

        temp.max_frame_size = xfer->max_frame_size;

        td = xfer->td_start[0];
        xfer->td_transfer_first = td;
        xfer->td_transfer_cache = td;

        /* setup temp */

        temp.pc = NULL;
        temp.td = NULL;
        temp.td_next = xfer->td_start[0];
        temp.offset = 0;
        temp.setup_alt_next = xfer->flags_int.short_frames_ok ||
            xfer->flags_int.isochronous_xfr;
        temp.did_stall = !xfer->flags_int.control_stall;

        /* check if we should prepend a setup message */

        if (xfer->flags_int.control_xfr) {
                if (xfer->flags_int.control_hdr) {
                        temp.func = &atmegadci_setup_rx;
                        temp.len = xfer->frlengths[0];
                        temp.pc = xfer->frbuffers + 0;
                        temp.short_pkt = temp.len ? 1 : 0;
                        /* check for last frame */
                        if (xfer->nframes == 1) {
                                /* no STATUS stage yet, SETUP is last */
                                if (xfer->flags_int.control_act)
                                        temp.setup_alt_next = 0;
                        }

                        atmegadci_setup_standard_chain_sub(&temp);
                }
                x = 1;
        } else {
                x = 0;
        }

        if (x != xfer->nframes) {
                if (xfer->endpointno & UE_DIR_IN) {
                        temp.func = &atmegadci_data_tx;
                        need_sync = 1;
                } else {
                        temp.func = &atmegadci_data_rx;
                        need_sync = 0;
                }

                /* setup "pc" pointer */
                temp.pc = xfer->frbuffers + x;
        } else {
                need_sync = 0;
        }
        while (x != xfer->nframes) {
                /* DATA0 / DATA1 message */

                temp.len = xfer->frlengths[x];

                x++;

                if (x == xfer->nframes) {
                        if (xfer->flags_int.control_xfr) {
                                if (xfer->flags_int.control_act) {
                                        temp.setup_alt_next = 0;
                                }
                        } else {
                                temp.setup_alt_next = 0;
                        }
                }
                if (temp.len == 0) {
                        /* make sure that we send an USB packet */

                        temp.short_pkt = 0;

                } else {
                        /* regular data transfer */

                        temp.short_pkt = (xfer->flags.force_short_xfer) ? 0 : 1;
                }

                atmegadci_setup_standard_chain_sub(&temp);

                if (xfer->flags_int.isochronous_xfr) {
                        temp.offset += temp.len;
                } else {
                        /* get next Page Cache pointer */
                        temp.pc = xfer->frbuffers + x;
                }
        }

        if (xfer->flags_int.control_xfr) {
                /* always setup a valid "pc" pointer for status and sync */
                temp.pc = xfer->frbuffers + 0;
                temp.len = 0;
                temp.short_pkt = 0;
                temp.setup_alt_next = 0;

                /* check if we need to sync */
                if (need_sync) {
                        /* we need a SYNC point after TX */
                        temp.func = &atmegadci_data_tx_sync;
                        atmegadci_setup_standard_chain_sub(&temp);
                }

                /* check if we should append a status stage */
                if (!xfer->flags_int.control_act) {
                        /*
                         * Send a DATA1 message and invert the current
                         * endpoint direction.
                         */
                        if (xfer->endpointno & UE_DIR_IN) {
                                temp.func = &atmegadci_data_rx;
                                need_sync = 0;
                        } else {
                                temp.func = &atmegadci_data_tx;
                                need_sync = 1;
                        }

                        atmegadci_setup_standard_chain_sub(&temp);
                        if (need_sync) {
                                /* we need a SYNC point after TX */
                                temp.func = &atmegadci_data_tx_sync;
                                atmegadci_setup_standard_chain_sub(&temp);
                        }
                }
        }
        /* must have at least one frame! */
        td = temp.td;
        xfer->td_transfer_last = td;
}

static void
atmegadci_timeout(void *arg)
{
        struct usb_xfer *xfer = arg;

        DPRINTF("xfer=%p\n", xfer);

        USB_BUS_LOCK_ASSERT(xfer->xroot->bus, MA_OWNED);

        /* transfer is transferred */
        atmegadci_device_done(xfer, USB_ERR_TIMEOUT);
}

static void
atmegadci_start_standard_chain(struct usb_xfer *xfer)
{
        DPRINTFN(9, "\n");

        /* poll one time - will turn on interrupts */
        if (atmegadci_xfer_do_fifo(xfer)) {
                /* put transfer on interrupt queue */
                usbd_transfer_enqueue(&xfer->xroot->bus->intr_q, xfer);

                /* start timeout, if any */
                if (xfer->timeout != 0) {
                        usbd_transfer_timeout_ms(xfer,
                            &atmegadci_timeout, xfer->timeout);
                }
        }
}

static void
atmegadci_root_intr(struct atmegadci_softc *sc)
{
        DPRINTFN(9, "\n");

        USB_BUS_LOCK_ASSERT(&sc->sc_bus, MA_OWNED);

        /* set port bit */
        sc->sc_hub_idata[0] = 0x02;     /* we only have one port */

        uhub_root_intr(&sc->sc_bus, sc->sc_hub_idata,
            sizeof(sc->sc_hub_idata));
 }

static usb_error_t
atmegadci_standard_done_sub(struct usb_xfer *xfer)
{
        struct atmegadci_td *td;
        uint32_t len;
        uint8_t error;

        DPRINTFN(9, "\n");

        td = xfer->td_transfer_cache;

        do {
                len = td->remainder;

                if (xfer->aframes != xfer->nframes) {
                        /*
                         * Verify the length and subtract
                         * the remainder from "frlengths[]":
                         */
                        if (len > xfer->frlengths[xfer->aframes]) {
                                td->error = 1;
                        } else {
                                xfer->frlengths[xfer->aframes] -= len;
                        }
                }
                /* Check for transfer error */
                if (td->error) {
                        /* the transfer is finished */
                        error = 1;
                        td = NULL;
                        break;
                }
                /* Check for short transfer */
                if (len > 0) {
                        if (xfer->flags_int.short_frames_ok ||
                            xfer->flags_int.isochronous_xfr) {
                                /* follow alt next */
                                if (td->alt_next) {
                                        td = td->obj_next;
                                } else {
                                        td = NULL;
                                }
                        } else {
                                /* the transfer is finished */
                                td = NULL;
                        }
                        error = 0;
                        break;
                }
                td = td->obj_next;

                /* this USB frame is complete */
                error = 0;
                break;

        } while (0);

        /* update transfer cache */

        xfer->td_transfer_cache = td;

        return (error ?
            USB_ERR_STALLED : USB_ERR_NORMAL_COMPLETION);
}

static void
atmegadci_standard_done(struct usb_xfer *xfer)
{
        usb_error_t err = 0;

        DPRINTFN(13, "xfer=%p endpoint=%p transfer done\n",
            xfer, xfer->endpoint);

        /* reset scanner */

        xfer->td_transfer_cache = xfer->td_transfer_first;

        if (xfer->flags_int.control_xfr) {
                if (xfer->flags_int.control_hdr) {
                        err = atmegadci_standard_done_sub(xfer);
                }
                xfer->aframes = 1;

                if (xfer->td_transfer_cache == NULL) {
                        goto done;
                }
        }
        while (xfer->aframes != xfer->nframes) {
                err = atmegadci_standard_done_sub(xfer);
                xfer->aframes++;

                if (xfer->td_transfer_cache == NULL) {
                        goto done;
                }
        }

        if (xfer->flags_int.control_xfr &&
            !xfer->flags_int.control_act) {
                err = atmegadci_standard_done_sub(xfer);
        }
done:
        atmegadci_device_done(xfer, err);
}

/*------------------------------------------------------------------------*
 *      atmegadci_device_done
 *
 * NOTE: this function can be called more than one time on the
 * same USB transfer!
 *------------------------------------------------------------------------*/
static void
atmegadci_device_done(struct usb_xfer *xfer, usb_error_t error)
{
        struct atmegadci_softc *sc = ATMEGA_BUS2SC(xfer->xroot->bus);
        uint8_t ep_no;

        USB_BUS_LOCK_ASSERT(&sc->sc_bus, MA_OWNED);

        DPRINTFN(9, "xfer=%p, endpoint=%p, error=%d\n",
            xfer, xfer->endpoint, error);

        if (xfer->flags_int.usb_mode == USB_MODE_DEVICE) {
                ep_no = (xfer->endpointno & UE_ADDR);

                /* select endpoint number */
                ATMEGA_WRITE_1(sc, ATMEGA_UENUM, ep_no);

                /* disable endpoint interrupt */
                ATMEGA_WRITE_1(sc, ATMEGA_UEIENX, 0);

                DPRINTFN(15, "disabled interrupts!\n");
        }
        /* dequeue transfer and start next transfer */
        usbd_transfer_done(xfer, error);
}

static void
atmegadci_xfer_stall(struct usb_xfer *xfer)
{
        atmegadci_device_done(xfer, USB_ERR_STALLED);
}

static void
atmegadci_set_stall(struct usb_device *udev,
    struct usb_endpoint *ep, uint8_t *did_stall)
{
        struct atmegadci_softc *sc;
        uint8_t ep_no;

        USB_BUS_LOCK_ASSERT(udev->bus, MA_OWNED);

        DPRINTFN(5, "endpoint=%p\n", ep);

        sc = ATMEGA_BUS2SC(udev->bus);
        /* get endpoint number */
        ep_no = (ep->edesc->bEndpointAddress & UE_ADDR);
        /* select endpoint number */
        ATMEGA_WRITE_1(sc, ATMEGA_UENUM, ep_no);
        /* set stall */
        ATMEGA_WRITE_1(sc, ATMEGA_UECONX,
            ATMEGA_UECONX_EPEN |
            ATMEGA_UECONX_STALLRQ);
}

static void
atmegadci_clear_stall_sub(struct atmegadci_softc *sc, uint8_t ep_no,
    uint8_t ep_type, uint8_t ep_dir)
{
        uint8_t temp;

        if (ep_type == UE_CONTROL) {
                /* clearing stall is not needed */
                return;
        }
        /* select endpoint number */
        ATMEGA_WRITE_1(sc, ATMEGA_UENUM, ep_no);

        /* set endpoint reset */
        ATMEGA_WRITE_1(sc, ATMEGA_UERST, ATMEGA_UERST_MASK(ep_no));

        /* clear endpoint reset */
        ATMEGA_WRITE_1(sc, ATMEGA_UERST, 0);

        /* set stall */
        ATMEGA_WRITE_1(sc, ATMEGA_UECONX,
            ATMEGA_UECONX_EPEN |
            ATMEGA_UECONX_STALLRQ);

        /* reset data toggle */
        ATMEGA_WRITE_1(sc, ATMEGA_UECONX,
            ATMEGA_UECONX_EPEN |
            ATMEGA_UECONX_RSTDT);

        /* clear stall */
        ATMEGA_WRITE_1(sc, ATMEGA_UECONX,
            ATMEGA_UECONX_EPEN |
            ATMEGA_UECONX_STALLRQC);

        do {
                if (ep_type == UE_BULK) {
                        temp = ATMEGA_UECFG0X_EPTYPE2;
                } else if (ep_type == UE_INTERRUPT) {
                        temp = ATMEGA_UECFG0X_EPTYPE3;
                } else {
                        temp = ATMEGA_UECFG0X_EPTYPE1;
                }
                if (ep_dir & UE_DIR_IN) {
                        temp |= ATMEGA_UECFG0X_EPDIR;
                }
                /* two banks, 64-bytes wMaxPacket */
                ATMEGA_WRITE_1(sc, ATMEGA_UECFG0X, temp);
                ATMEGA_WRITE_1(sc, ATMEGA_UECFG1X,
                    ATMEGA_UECFG1X_ALLOC |
                    ATMEGA_UECFG1X_EPBK0 |      /* one bank */
                    ATMEGA_UECFG1X_EPSIZE(3));

                temp = ATMEGA_READ_1(sc, ATMEGA_UESTA0X);
                if (!(temp & ATMEGA_UESTA0X_CFGOK)) {
                        device_printf(sc->sc_bus.bdev,
                            "Chip rejected configuration\n");
                }
        } while (0);
}

static void
atmegadci_clear_stall(struct usb_device *udev, struct usb_endpoint *ep)
{
        struct atmegadci_softc *sc;
        struct usb_endpoint_descriptor *ed;

        DPRINTFN(5, "endpoint=%p\n", ep);

        USB_BUS_LOCK_ASSERT(udev->bus, MA_OWNED);

        /* check mode */
        if (udev->flags.usb_mode != USB_MODE_DEVICE) {
                /* not supported */
                return;
        }
        /* get softc */
        sc = ATMEGA_BUS2SC(udev->bus);

        /* get endpoint descriptor */
        ed = ep->edesc;

        /* reset endpoint */
        atmegadci_clear_stall_sub(sc,
            (ed->bEndpointAddress & UE_ADDR),
            (ed->bmAttributes & UE_XFERTYPE),
            (ed->bEndpointAddress & (UE_DIR_IN | UE_DIR_OUT)));
}

usb_error_t
atmegadci_init(struct atmegadci_softc *sc)
{
        uint8_t n;

        DPRINTF("start\n");

        /* set up the bus structure */
        sc->sc_bus.usbrev = USB_REV_1_1;
        sc->sc_bus.methods = &atmegadci_bus_methods;

        USB_BUS_LOCK(&sc->sc_bus);

        /* make sure USB is enabled */
        ATMEGA_WRITE_1(sc, ATMEGA_USBCON,
            ATMEGA_USBCON_USBE |
            ATMEGA_USBCON_FRZCLK);

        /* enable USB PAD regulator */
        ATMEGA_WRITE_1(sc, ATMEGA_UHWCON,
            ATMEGA_UHWCON_UVREGE |
            ATMEGA_UHWCON_UIMOD);

        /* the following register sets up the USB PLL, assuming 16MHz X-tal */
        ATMEGA_WRITE_1(sc, 0x49 /* PLLCSR */, 0x14 | 0x02);

        /* wait for PLL to lock */
        for (n = 0; n != 20; n++) {
                if (ATMEGA_READ_1(sc, 0x49) & 0x01)
                        break;
                /* wait a little bit for PLL to start */
                usb_pause_mtx(&sc->sc_bus.bus_mtx, hz / 100);
        }

        /* make sure USB is enabled */
        ATMEGA_WRITE_1(sc, ATMEGA_USBCON,
            ATMEGA_USBCON_USBE |
            ATMEGA_USBCON_OTGPADE |
            ATMEGA_USBCON_VBUSTE);

        /* turn on clocks */
        (sc->sc_clocks_on) (&sc->sc_bus);

        /* make sure device is re-enumerated */
        ATMEGA_WRITE_1(sc, ATMEGA_UDCON, ATMEGA_UDCON_DETACH);

        /* wait a little for things to stabilise */
        usb_pause_mtx(&sc->sc_bus.bus_mtx, hz / 20);

        /* enable interrupts */
        ATMEGA_WRITE_1(sc, ATMEGA_UDIEN,
            ATMEGA_UDINT_SUSPE |
            ATMEGA_UDINT_EORSTE);

        /* reset all endpoints */
        ATMEGA_WRITE_1(sc, ATMEGA_UERST,
            (1 << ATMEGA_EP_MAX) - 1);

        /* disable reset */
        ATMEGA_WRITE_1(sc, ATMEGA_UERST, 0);

        /* disable all endpoints */
        for (n = 0; n != ATMEGA_EP_MAX; n++) {
                /* select endpoint */
                ATMEGA_WRITE_1(sc, ATMEGA_UENUM, n);

                /* disable endpoint interrupt */
                ATMEGA_WRITE_1(sc, ATMEGA_UEIENX, 0);

                /* disable endpoint */
                ATMEGA_WRITE_1(sc, ATMEGA_UECONX, 0);
        }

        /* turn off clocks */

        atmegadci_clocks_off(sc);

        /* read initial VBUS state */

        n = ATMEGA_READ_1(sc, ATMEGA_USBSTA);
        atmegadci_vbus_interrupt(sc, n & ATMEGA_USBSTA_VBUS);

        USB_BUS_UNLOCK(&sc->sc_bus);

        /* catch any lost interrupts */

        atmegadci_do_poll(&sc->sc_bus);

        return (0);                     /* success */
}

void
atmegadci_uninit(struct atmegadci_softc *sc)
{
        USB_BUS_LOCK(&sc->sc_bus);

        /* turn on clocks */
        (sc->sc_clocks_on) (&sc->sc_bus);

        /* disable interrupts */
        ATMEGA_WRITE_1(sc, ATMEGA_UDIEN, 0);

        /* reset all endpoints */
        ATMEGA_WRITE_1(sc, ATMEGA_UERST,
            (1 << ATMEGA_EP_MAX) - 1);

        /* disable reset */
        ATMEGA_WRITE_1(sc, ATMEGA_UERST, 0);

        sc->sc_flags.port_powered = 0;
        sc->sc_flags.status_vbus = 0;
        sc->sc_flags.status_bus_reset = 0;
        sc->sc_flags.status_suspend = 0;
        sc->sc_flags.change_suspend = 0;
        sc->sc_flags.change_connect = 1;

        atmegadci_pull_down(sc);
        atmegadci_clocks_off(sc);

        /* disable USB PAD regulator */
        ATMEGA_WRITE_1(sc, ATMEGA_UHWCON, 0);

        USB_BUS_UNLOCK(&sc->sc_bus);
}

static void
atmegadci_suspend(struct atmegadci_softc *sc)
{
        /* TODO */
}

static void
atmegadci_resume(struct atmegadci_softc *sc)
{
        /* TODO */
}

static void
atmegadci_do_poll(struct usb_bus *bus)
{
        struct atmegadci_softc *sc = ATMEGA_BUS2SC(bus);

        USB_BUS_LOCK(&sc->sc_bus);
        atmegadci_interrupt_poll(sc);
        USB_BUS_UNLOCK(&sc->sc_bus);
}

/*------------------------------------------------------------------------*
 * atmegadci bulk support
 * atmegadci control support
 * atmegadci interrupt support
 *------------------------------------------------------------------------*/
static void
atmegadci_device_non_isoc_open(struct usb_xfer *xfer)
{
        return;
}

static void
atmegadci_device_non_isoc_close(struct usb_xfer *xfer)
{
        atmegadci_device_done(xfer, USB_ERR_CANCELLED);
}

static void
atmegadci_device_non_isoc_enter(struct usb_xfer *xfer)
{
        return;
}

static void
atmegadci_device_non_isoc_start(struct usb_xfer *xfer)
{
        /* setup TDs */
        atmegadci_setup_standard_chain(xfer);
        atmegadci_start_standard_chain(xfer);
}

static const struct usb_pipe_methods atmegadci_device_non_isoc_methods =
{
        .open = atmegadci_device_non_isoc_open,
        .close = atmegadci_device_non_isoc_close,
        .enter = atmegadci_device_non_isoc_enter,
        .start = atmegadci_device_non_isoc_start,
};

/*------------------------------------------------------------------------*
 * atmegadci full speed isochronous support
 *------------------------------------------------------------------------*/
static void
atmegadci_device_isoc_fs_open(struct usb_xfer *xfer)
{
        return;
}

static void
atmegadci_device_isoc_fs_close(struct usb_xfer *xfer)
{
        atmegadci_device_done(xfer, USB_ERR_CANCELLED);
}

static void
atmegadci_device_isoc_fs_enter(struct usb_xfer *xfer)
{
        struct atmegadci_softc *sc = ATMEGA_BUS2SC(xfer->xroot->bus);
        uint32_t nframes;

        DPRINTFN(6, "xfer=%p next=%d nframes=%d\n",
            xfer, xfer->endpoint->isoc_next, xfer->nframes);

        /* get the current frame index */

        nframes =
            (ATMEGA_READ_1(sc, ATMEGA_UDFNUMH) << 8) |
            (ATMEGA_READ_1(sc, ATMEGA_UDFNUML));

        if (usbd_xfer_get_isochronous_start_frame(
            xfer, nframes, 0, 1, ATMEGA_FRAME_MASK, NULL))
                DPRINTFN(3, "start next=%d\n", xfer->endpoint->isoc_next);

        /* setup TDs */
        atmegadci_setup_standard_chain(xfer);
}

static void
atmegadci_device_isoc_fs_start(struct usb_xfer *xfer)
{
        /* start TD chain */
        atmegadci_start_standard_chain(xfer);
}

static const struct usb_pipe_methods atmegadci_device_isoc_fs_methods =
{
        .open = atmegadci_device_isoc_fs_open,
        .close = atmegadci_device_isoc_fs_close,
        .enter = atmegadci_device_isoc_fs_enter,
        .start = atmegadci_device_isoc_fs_start,
};

/*------------------------------------------------------------------------*
 * atmegadci root control support
 *------------------------------------------------------------------------*
 * Simulate a hardware HUB by handling all the necessary requests.
 *------------------------------------------------------------------------*/

static const struct usb_device_descriptor atmegadci_devd = {
        .bLength = sizeof(struct usb_device_descriptor),
        .bDescriptorType = UDESC_DEVICE,
        .bcdUSB = {0x00, 0x02},
        .bDeviceClass = UDCLASS_HUB,
        .bDeviceSubClass = UDSUBCLASS_HUB,
        .bDeviceProtocol = UDPROTO_FSHUB,
        .bMaxPacketSize = 64,
        .bcdDevice = {0x00, 0x01},
        .iManufacturer = 1,
        .iProduct = 2,
        .bNumConfigurations = 1,
};

static const struct atmegadci_config_desc atmegadci_confd = {
        .confd = {
                .bLength = sizeof(struct usb_config_descriptor),
                .bDescriptorType = UDESC_CONFIG,
                .wTotalLength[0] = sizeof(atmegadci_confd),
                .bNumInterface = 1,
                .bConfigurationValue = 1,
                .iConfiguration = 0,
                .bmAttributes = UC_SELF_POWERED,
                .bMaxPower = 0,
        },
        .ifcd = {
                .bLength = sizeof(struct usb_interface_descriptor),
                .bDescriptorType = UDESC_INTERFACE,
                .bNumEndpoints = 1,
                .bInterfaceClass = UICLASS_HUB,
                .bInterfaceSubClass = UISUBCLASS_HUB,
                .bInterfaceProtocol = 0,
        },
        .endpd = {
                .bLength = sizeof(struct usb_endpoint_descriptor),
                .bDescriptorType = UDESC_ENDPOINT,
                .bEndpointAddress = (UE_DIR_IN | ATMEGA_INTR_ENDPT),
                .bmAttributes = UE_INTERRUPT,
                .wMaxPacketSize[0] = 8,
                .bInterval = 255,
        },
};
#define HSETW(ptr, val) ptr = { (uint8_t)(val), (uint8_t)((val) >> 8) }

static const struct usb_hub_descriptor_min atmegadci_hubd = {
        .bDescLength = sizeof(atmegadci_hubd),
        .bDescriptorType = UDESC_HUB,
        .bNbrPorts = 1,
        HSETW(.wHubCharacteristics, (UHD_PWR_NO_SWITCH | UHD_OC_INDIVIDUAL)),
        .bPwrOn2PwrGood = 50,
        .bHubContrCurrent = 0,
        .DeviceRemovable = {0},         /* port is removable */
};

#define STRING_VENDOR \
  "A\0T\0M\0E\0G\0A"

#define STRING_PRODUCT \
  "D\0C\0I\0 \0R\0o\0o\0t\0 \0H\0U\0B"

USB_MAKE_STRING_DESC(STRING_VENDOR, atmegadci_vendor);
USB_MAKE_STRING_DESC(STRING_PRODUCT, atmegadci_product);

static usb_error_t
atmegadci_roothub_exec(struct usb_device *udev,
    struct usb_device_request *req, const void **pptr, uint16_t *plength)
{
        struct atmegadci_softc *sc = ATMEGA_BUS2SC(udev->bus);
        const void *ptr;
        uint16_t len;
        uint16_t value;
        uint16_t index;
        uint8_t temp;
        usb_error_t err;

        USB_BUS_LOCK_ASSERT(&sc->sc_bus, MA_OWNED);

        /* buffer reset */
        ptr = (const void *)&sc->sc_hub_temp;
        len = 0;
        err = 0;

        value = UGETW(req->wValue);
        index = UGETW(req->wIndex);

        /* demultiplex the control request */

        switch (req->bmRequestType) {
        case UT_READ_DEVICE:
                switch (req->bRequest) {
                case UR_GET_DESCRIPTOR:
                        goto tr_handle_get_descriptor;
                case UR_GET_CONFIG:
                        goto tr_handle_get_config;
                case UR_GET_STATUS:
                        goto tr_handle_get_status;
                default:
                        goto tr_stalled;
                }
                break;

        case UT_WRITE_DEVICE:
                switch (req->bRequest) {
                case UR_SET_ADDRESS:
                        goto tr_handle_set_address;
                case UR_SET_CONFIG:
                        goto tr_handle_set_config;
                case UR_CLEAR_FEATURE:
                        goto tr_valid;  /* nop */
                case UR_SET_DESCRIPTOR:
                        goto tr_valid;  /* nop */
                case UR_SET_FEATURE:
                default:
                        goto tr_stalled;
                }
                break;

        case UT_WRITE_ENDPOINT:
                switch (req->bRequest) {
                case UR_CLEAR_FEATURE:
                        switch (UGETW(req->wValue)) {
                        case UF_ENDPOINT_HALT:
                                goto tr_handle_clear_halt;
                        case UF_DEVICE_REMOTE_WAKEUP:
                                goto tr_handle_clear_wakeup;
                        default:
                                goto tr_stalled;
                        }
                        break;
                case UR_SET_FEATURE:
                        switch (UGETW(req->wValue)) {
                        case UF_ENDPOINT_HALT:
                                goto tr_handle_set_halt;
                        case UF_DEVICE_REMOTE_WAKEUP:
                                goto tr_handle_set_wakeup;
                        default:
                                goto tr_stalled;
                        }
                        break;
                case UR_SYNCH_FRAME:
                        goto tr_valid;  /* nop */
                default:
                        goto tr_stalled;
                }
                break;

        case UT_READ_ENDPOINT:
                switch (req->bRequest) {
                case UR_GET_STATUS:
                        goto tr_handle_get_ep_status;
                default:
                        goto tr_stalled;
                }
                break;

        case UT_WRITE_INTERFACE:
                switch (req->bRequest) {
                case UR_SET_INTERFACE:
                        goto tr_handle_set_interface;
                case UR_CLEAR_FEATURE:
                        goto tr_valid;  /* nop */
                case UR_SET_FEATURE:
                default:
                        goto tr_stalled;
                }
                break;

        case UT_READ_INTERFACE:
                switch (req->bRequest) {
                case UR_GET_INTERFACE:
                        goto tr_handle_get_interface;
                case UR_GET_STATUS:
                        goto tr_handle_get_iface_status;
                default:
                        goto tr_stalled;
                }
                break;

        case UT_WRITE_CLASS_INTERFACE:
        case UT_WRITE_VENDOR_INTERFACE:
                /* XXX forward */
                break;

        case UT_READ_CLASS_INTERFACE:
        case UT_READ_VENDOR_INTERFACE:
                /* XXX forward */
                break;

        case UT_WRITE_CLASS_DEVICE:
                switch (req->bRequest) {
                case UR_CLEAR_FEATURE:
                        goto tr_valid;
                case UR_SET_DESCRIPTOR:
                case UR_SET_FEATURE:
                        break;
                default:
                        goto tr_stalled;
                }
                break;

        case UT_WRITE_CLASS_OTHER:
                switch (req->bRequest) {
                case UR_CLEAR_FEATURE:
                        goto tr_handle_clear_port_feature;
                case UR_SET_FEATURE:
                        goto tr_handle_set_port_feature;
                case UR_CLEAR_TT_BUFFER:
                case UR_RESET_TT:
                case UR_STOP_TT:
                        goto tr_valid;

                default:
                        goto tr_stalled;
                }
                break;

        case UT_READ_CLASS_OTHER:
                switch (req->bRequest) {
                case UR_GET_TT_STATE:
                        goto tr_handle_get_tt_state;
                case UR_GET_STATUS:
                        goto tr_handle_get_port_status;
                default:
                        goto tr_stalled;
                }
                break;

        case UT_READ_CLASS_DEVICE:
                switch (req->bRequest) {
                case UR_GET_DESCRIPTOR:
                        goto tr_handle_get_class_descriptor;
                case UR_GET_STATUS:
                        goto tr_handle_get_class_status;

                default:
                        goto tr_stalled;
                }
                break;
        default:
                goto tr_stalled;
        }
        goto tr_valid;

tr_handle_get_descriptor:
        switch (value >> 8) {
        case UDESC_DEVICE:
                if (value & 0xff) {
                        goto tr_stalled;
                }
                len = sizeof(atmegadci_devd);
                ptr = (const void *)&atmegadci_devd;
                goto tr_valid;
        case UDESC_CONFIG:
                if (value & 0xff) {
                        goto tr_stalled;
                }
                len = sizeof(atmegadci_confd);
                ptr = (const void *)&atmegadci_confd;
                goto tr_valid;
        case UDESC_STRING:
                switch (value & 0xff) {
                case 0:         /* Language table */
                        len = sizeof(usb_string_lang_en);
                        ptr = (const void *)&usb_string_lang_en;
                        goto tr_valid;

                case 1:         /* Vendor */
                        len = sizeof(atmegadci_vendor);
                        ptr = (const void *)&atmegadci_vendor;
                        goto tr_valid;

                case 2:         /* Product */
                        len = sizeof(atmegadci_product);
                        ptr = (const void *)&atmegadci_product;
                        goto tr_valid;
                default:
                        break;
                }
                break;
        default:
                goto tr_stalled;
        }
        goto tr_stalled;

tr_handle_get_config:
        len = 1;
        sc->sc_hub_temp.wValue[0] = sc->sc_conf;
        goto tr_valid;

tr_handle_get_status:
        len = 2;
        USETW(sc->sc_hub_temp.wValue, UDS_SELF_POWERED);
        goto tr_valid;

tr_handle_set_address:
        if (value & 0xFF00) {
                goto tr_stalled;
        }
        sc->sc_rt_addr = value;
        goto tr_valid;

tr_handle_set_config:
        if (value >= 2) {
                goto tr_stalled;
        }
        sc->sc_conf = value;
        goto tr_valid;

tr_handle_get_interface:
        len = 1;
        sc->sc_hub_temp.wValue[0] = 0;
        goto tr_valid;

tr_handle_get_tt_state:
tr_handle_get_class_status:
tr_handle_get_iface_status:
tr_handle_get_ep_status:
        len = 2;
        USETW(sc->sc_hub_temp.wValue, 0);
        goto tr_valid;

tr_handle_set_halt:
tr_handle_set_interface:
tr_handle_set_wakeup:
tr_handle_clear_wakeup:
tr_handle_clear_halt:
        goto tr_valid;

tr_handle_clear_port_feature:
        if (index != 1) {
                goto tr_stalled;
        }
        DPRINTFN(9, "UR_CLEAR_PORT_FEATURE on port %d\n", index);

        switch (value) {
        case UHF_PORT_SUSPEND:
                atmegadci_wakeup_peer(sc);
                break;

        case UHF_PORT_ENABLE:
                sc->sc_flags.port_enabled = 0;
                break;

        case UHF_PORT_TEST:
        case UHF_PORT_INDICATOR:
        case UHF_C_PORT_ENABLE:
        case UHF_C_PORT_OVER_CURRENT:
        case UHF_C_PORT_RESET:
                /* nops */
                break;
        case UHF_PORT_POWER:
                sc->sc_flags.port_powered = 0;
                atmegadci_pull_down(sc);
                atmegadci_clocks_off(sc);
                break;
        case UHF_C_PORT_CONNECTION:
                /* clear connect change flag */
                sc->sc_flags.change_connect = 0;

                if (!sc->sc_flags.status_bus_reset) {
                        /* we are not connected */
                        break;
                }

                /* configure the control endpoint */

                /* select endpoint number */
                ATMEGA_WRITE_1(sc, ATMEGA_UENUM, 0);

                /* set endpoint reset */
                ATMEGA_WRITE_1(sc, ATMEGA_UERST, ATMEGA_UERST_MASK(0));

                /* clear endpoint reset */
                ATMEGA_WRITE_1(sc, ATMEGA_UERST, 0);

                /* enable and stall endpoint */
                ATMEGA_WRITE_1(sc, ATMEGA_UECONX,
                    ATMEGA_UECONX_EPEN |
                    ATMEGA_UECONX_STALLRQ);

                /* one bank, 64-bytes wMaxPacket */
                ATMEGA_WRITE_1(sc, ATMEGA_UECFG0X,
                    ATMEGA_UECFG0X_EPTYPE0);
                ATMEGA_WRITE_1(sc, ATMEGA_UECFG1X,
                    ATMEGA_UECFG1X_ALLOC |
                    ATMEGA_UECFG1X_EPBK0 |
                    ATMEGA_UECFG1X_EPSIZE(3));

                /* check valid config */
                temp = ATMEGA_READ_1(sc, ATMEGA_UESTA0X);
                if (!(temp & ATMEGA_UESTA0X_CFGOK)) {
                        device_printf(sc->sc_bus.bdev,
                            "Chip rejected EP0 configuration\n");
                }
                break;
        case UHF_C_PORT_SUSPEND:
                sc->sc_flags.change_suspend = 0;
                break;
        default:
                err = USB_ERR_IOERROR;
                goto done;
        }
        goto tr_valid;

tr_handle_set_port_feature:
        if (index != 1) {
                goto tr_stalled;
        }
        DPRINTFN(9, "UR_SET_PORT_FEATURE\n");

        switch (value) {
        case UHF_PORT_ENABLE:
                sc->sc_flags.port_enabled = 1;
                break;
        case UHF_PORT_SUSPEND:
        case UHF_PORT_RESET:
        case UHF_PORT_TEST:
        case UHF_PORT_INDICATOR:
                /* nops */
                break;
        case UHF_PORT_POWER:
                sc->sc_flags.port_powered = 1;
                break;
        default:
                err = USB_ERR_IOERROR;
                goto done;
        }
        goto tr_valid;

tr_handle_get_port_status:

        DPRINTFN(9, "UR_GET_PORT_STATUS\n");

        if (index != 1) {
                goto tr_stalled;
        }
        if (sc->sc_flags.status_vbus) {
                atmegadci_clocks_on(sc);
                atmegadci_pull_up(sc);
        } else {
                atmegadci_pull_down(sc);
                atmegadci_clocks_off(sc);
        }

        /* Select FULL-speed and Device Side Mode */

        value = UPS_PORT_MODE_DEVICE;

        if (sc->sc_flags.port_powered) {
                value |= UPS_PORT_POWER;
        }
        if (sc->sc_flags.port_enabled) {
                value |= UPS_PORT_ENABLED;
        }
        if (sc->sc_flags.status_vbus &&
            sc->sc_flags.status_bus_reset) {
                value |= UPS_CURRENT_CONNECT_STATUS;
        }
        if (sc->sc_flags.status_suspend) {
                value |= UPS_SUSPEND;
        }
        USETW(sc->sc_hub_temp.ps.wPortStatus, value);

        value = 0;

        if (sc->sc_flags.change_connect) {
                value |= UPS_C_CONNECT_STATUS;
        }
        if (sc->sc_flags.change_suspend) {
                value |= UPS_C_SUSPEND;
        }
        USETW(sc->sc_hub_temp.ps.wPortChange, value);
        len = sizeof(sc->sc_hub_temp.ps);
        goto tr_valid;

tr_handle_get_class_descriptor:
        if (value & 0xFF) {
                goto tr_stalled;
        }
        ptr = (const void *)&atmegadci_hubd;
        len = sizeof(atmegadci_hubd);
        goto tr_valid;

tr_stalled:
        err = USB_ERR_STALLED;
tr_valid:
done:
        *plength = len;
        *pptr = ptr;
        return (err);
}

static void
atmegadci_xfer_setup(struct usb_setup_params *parm)
{
        const struct usb_hw_ep_profile *pf;
        struct usb_xfer *xfer;
        void *last_obj;
        uint32_t ntd;
        uint32_t n;
        uint8_t ep_no;

        xfer = parm->curr_xfer;

        /*
         * NOTE: This driver does not use any of the parameters that
         * are computed from the following values. Just set some
         * reasonable dummies:
         */
        parm->hc_max_packet_size = 0x500;
        parm->hc_max_packet_count = 1;
        parm->hc_max_frame_size = 0x500;

        usbd_transfer_setup_sub(parm);

        /*
         * compute maximum number of TDs
         */
        if ((xfer->endpoint->edesc->bmAttributes & UE_XFERTYPE) == UE_CONTROL) {
                ntd = xfer->nframes + 1 /* STATUS */ + 1 /* SYNC 1 */
                    + 1 /* SYNC 2 */ ;
        } else {
                ntd = xfer->nframes + 1 /* SYNC */ ;
        }

        /*
         * check if "usbd_transfer_setup_sub" set an error
         */
        if (parm->err)
                return;

        /*
         * allocate transfer descriptors
         */
        last_obj = NULL;

        /*
         * get profile stuff
         */
        ep_no = xfer->endpointno & UE_ADDR;
        atmegadci_get_hw_ep_profile(parm->udev, &pf, ep_no);

        if (pf == NULL) {
                /* should not happen */
                parm->err = USB_ERR_INVAL;
                return;
        }

        /* align data */
        parm->size[0] += ((-parm->size[0]) & (USB_HOST_ALIGN - 1));

        for (n = 0; n != ntd; n++) {
                struct atmegadci_td *td;

                if (parm->buf) {
                        td = USB_ADD_BYTES(parm->buf, parm->size[0]);

                        /* init TD */
                        td->max_packet_size = xfer->max_packet_size;
                        td->ep_no = ep_no;
                        if (pf->support_multi_buffer) {
                                td->support_multi_buffer = 1;
                        }
                        td->obj_next = last_obj;

                        last_obj = td;
                }
                parm->size[0] += sizeof(*td);
        }

        xfer->td_start[0] = last_obj;
}

static void
atmegadci_xfer_unsetup(struct usb_xfer *xfer)
{
        return;
}

static void
atmegadci_ep_init(struct usb_device *udev, struct usb_endpoint_descriptor *edesc,
    struct usb_endpoint *ep)
{
        struct atmegadci_softc *sc = ATMEGA_BUS2SC(udev->bus);

        DPRINTFN(2, "endpoint=%p, addr=%d, endpt=%d, mode=%d (%d,%d)\n",
            ep, udev->address,
            edesc->bEndpointAddress, udev->flags.usb_mode,
            sc->sc_rt_addr, udev->device_index);

        if (udev->device_index != sc->sc_rt_addr) {
                if (udev->speed != USB_SPEED_FULL) {
                        /* not supported */
                        return;
                }
                if ((edesc->bmAttributes & UE_XFERTYPE) == UE_ISOCHRONOUS)
                        ep->methods = &atmegadci_device_isoc_fs_methods;
                else
                        ep->methods = &atmegadci_device_non_isoc_methods;
        }
}

static void
atmegadci_set_hw_power_sleep(struct usb_bus *bus, uint32_t state)
{
        struct atmegadci_softc *sc = ATMEGA_BUS2SC(bus);

        switch (state) {
        case USB_HW_POWER_SUSPEND:
                atmegadci_suspend(sc);
                break;
        case USB_HW_POWER_SHUTDOWN:
                atmegadci_uninit(sc);
                break;
        case USB_HW_POWER_RESUME:
                atmegadci_resume(sc);
                break;
        default:
                break;
        }
}

static const struct usb_bus_methods atmegadci_bus_methods =
{
        .endpoint_init = &atmegadci_ep_init,
        .xfer_setup = &atmegadci_xfer_setup,
        .xfer_unsetup = &atmegadci_xfer_unsetup,
        .get_hw_ep_profile = &atmegadci_get_hw_ep_profile,
        .xfer_stall = &atmegadci_xfer_stall,
        .set_stall = &atmegadci_set_stall,
        .clear_stall = &atmegadci_clear_stall,
        .roothub_exec = &atmegadci_roothub_exec,
        .xfer_poll = &atmegadci_do_poll,
        .set_hw_power_sleep = &atmegadci_set_hw_power_sleep,
};