/*      $NetBSD: usb/uvscom.c,v 1.1 2002/03/19 15:08:42 augustss Exp $  */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2001-2003, 2005 Shunsuke Akiyama <akiyama@jp.FreeBSD.org>.
 * 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.
 *
 */

/*
 * uvscom: SUNTAC Slipper U VS-10U driver.
 * Slipper U is a PC Card to USB converter for data communication card
 * adapter.  It supports DDI Pocket's Air H" C@rd, C@rd H" 64, NTT's P-in,
 * P-in m@ater and various data communication card adapters.
 */

#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>
#include <dev/usb/usbdi_util.h>
#include "usbdevs.h"

#define USB_DEBUG_VAR uvscom_debug
#include <dev/usb/usb_debug.h>
#include <dev/usb/usb_process.h>

#include <dev/usb/serial/usb_serial.h>

#ifdef USB_DEBUG
static int uvscom_debug = 0;

static SYSCTL_NODE(_hw_usb, OID_AUTO, uvscom, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "USB uvscom");
SYSCTL_INT(_hw_usb_uvscom, OID_AUTO, debug, CTLFLAG_RWTUN,
    &uvscom_debug, 0, "Debug level");
#endif

#define UVSCOM_MODVER           1       /* module version */

#define UVSCOM_CONFIG_INDEX     0
#define UVSCOM_IFACE_INDEX      0

/* Request */
#define UVSCOM_SET_SPEED        0x10
#define UVSCOM_LINE_CTL         0x11
#define UVSCOM_SET_PARAM        0x12
#define UVSCOM_READ_STATUS      0xd0
#define UVSCOM_SHUTDOWN         0xe0

/* UVSCOM_SET_SPEED parameters */
#define UVSCOM_SPEED_150BPS     0x00
#define UVSCOM_SPEED_300BPS     0x01
#define UVSCOM_SPEED_600BPS     0x02
#define UVSCOM_SPEED_1200BPS    0x03
#define UVSCOM_SPEED_2400BPS    0x04
#define UVSCOM_SPEED_4800BPS    0x05
#define UVSCOM_SPEED_9600BPS    0x06
#define UVSCOM_SPEED_19200BPS   0x07
#define UVSCOM_SPEED_38400BPS   0x08
#define UVSCOM_SPEED_57600BPS   0x09
#define UVSCOM_SPEED_115200BPS  0x0a

/* UVSCOM_LINE_CTL parameters */
#define UVSCOM_BREAK            0x40
#define UVSCOM_RTS              0x02
#define UVSCOM_DTR              0x01
#define UVSCOM_LINE_INIT        0x08

/* UVSCOM_SET_PARAM parameters */
#define UVSCOM_DATA_MASK        0x03
#define UVSCOM_DATA_BIT_8       0x03
#define UVSCOM_DATA_BIT_7       0x02
#define UVSCOM_DATA_BIT_6       0x01
#define UVSCOM_DATA_BIT_5       0x00

#define UVSCOM_STOP_MASK        0x04
#define UVSCOM_STOP_BIT_2       0x04
#define UVSCOM_STOP_BIT_1       0x00

#define UVSCOM_PARITY_MASK      0x18
#define UVSCOM_PARITY_EVEN      0x18
#define UVSCOM_PARITY_ODD       0x08
#define UVSCOM_PARITY_NONE      0x00

/* Status bits */
#define UVSCOM_TXRDY            0x04
#define UVSCOM_RXRDY            0x01

#define UVSCOM_DCD              0x08
#define UVSCOM_NOCARD           0x04
#define UVSCOM_DSR              0x02
#define UVSCOM_CTS              0x01
#define UVSCOM_USTAT_MASK       (UVSCOM_NOCARD | UVSCOM_DSR | UVSCOM_CTS)

#define UVSCOM_BULK_BUF_SIZE    1024    /* bytes */

enum {
        UVSCOM_BULK_DT_WR,
        UVSCOM_BULK_DT_RD,
        UVSCOM_INTR_DT_RD,
        UVSCOM_N_TRANSFER,
};

struct uvscom_softc {
        struct ucom_super_softc sc_super_ucom;
        struct ucom_softc sc_ucom;

        struct usb_xfer *sc_xfer[UVSCOM_N_TRANSFER];
        struct usb_device *sc_udev;
        struct mtx sc_mtx;

        uint16_t sc_line;               /* line control register */

        uint8_t sc_iface_no;            /* interface number */
        uint8_t sc_iface_index;         /* interface index */
        uint8_t sc_lsr;                 /* local status register */
        uint8_t sc_msr;                 /* uvscom status register */
        uint8_t sc_unit_status;         /* unit status */
};

/* prototypes */

static device_probe_t uvscom_probe;
static device_attach_t uvscom_attach;
static device_detach_t uvscom_detach;
static void uvscom_free_softc(struct uvscom_softc *);

static usb_callback_t uvscom_write_callback;
static usb_callback_t uvscom_read_callback;
static usb_callback_t uvscom_intr_callback;

static void     uvscom_free(struct ucom_softc *);
static void     uvscom_cfg_set_dtr(struct ucom_softc *, uint8_t);
static void     uvscom_cfg_set_rts(struct ucom_softc *, uint8_t);
static void     uvscom_cfg_set_break(struct ucom_softc *, uint8_t);
static int      uvscom_pre_param(struct ucom_softc *, struct termios *);
static void     uvscom_cfg_param(struct ucom_softc *, struct termios *);
static int      uvscom_pre_open(struct ucom_softc *);
static void     uvscom_cfg_open(struct ucom_softc *);
static void     uvscom_cfg_close(struct ucom_softc *);
static void     uvscom_start_read(struct ucom_softc *);
static void     uvscom_stop_read(struct ucom_softc *);
static void     uvscom_start_write(struct ucom_softc *);
static void     uvscom_stop_write(struct ucom_softc *);
static void     uvscom_cfg_get_status(struct ucom_softc *, uint8_t *,
                    uint8_t *);
static void     uvscom_cfg_write(struct uvscom_softc *, uint8_t, uint16_t);
static uint16_t uvscom_cfg_read_status(struct uvscom_softc *);
static void     uvscom_poll(struct ucom_softc *ucom);

static const struct usb_config uvscom_config[UVSCOM_N_TRANSFER] = {
        [UVSCOM_BULK_DT_WR] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_OUT,
                .bufsize = UVSCOM_BULK_BUF_SIZE,
                .flags = {.pipe_bof = 1,.force_short_xfer = 1,},
                .callback = &uvscom_write_callback,
        },

        [UVSCOM_BULK_DT_RD] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .bufsize = UVSCOM_BULK_BUF_SIZE,
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
                .callback = &uvscom_read_callback,
        },

        [UVSCOM_INTR_DT_RD] = {
                .type = UE_INTERRUPT,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
                .bufsize = 0,   /* use wMaxPacketSize */
                .callback = &uvscom_intr_callback,
        },
};

static const struct ucom_callback uvscom_callback = {
        .ucom_cfg_get_status = &uvscom_cfg_get_status,
        .ucom_cfg_set_dtr = &uvscom_cfg_set_dtr,
        .ucom_cfg_set_rts = &uvscom_cfg_set_rts,
        .ucom_cfg_set_break = &uvscom_cfg_set_break,
        .ucom_cfg_param = &uvscom_cfg_param,
        .ucom_cfg_open = &uvscom_cfg_open,
        .ucom_cfg_close = &uvscom_cfg_close,
        .ucom_pre_open = &uvscom_pre_open,
        .ucom_pre_param = &uvscom_pre_param,
        .ucom_start_read = &uvscom_start_read,
        .ucom_stop_read = &uvscom_stop_read,
        .ucom_start_write = &uvscom_start_write,
        .ucom_stop_write = &uvscom_stop_write,
        .ucom_poll = &uvscom_poll,
        .ucom_free = &uvscom_free,
};

static const STRUCT_USB_HOST_ID uvscom_devs[] = {
        /* SUNTAC U-Cable type A4 */
        {USB_VPI(USB_VENDOR_SUNTAC, USB_PRODUCT_SUNTAC_AS144L4, 0)},
        /* SUNTAC U-Cable type D2 */
        {USB_VPI(USB_VENDOR_SUNTAC, USB_PRODUCT_SUNTAC_DS96L, 0)},
        /* SUNTAC Ir-Trinity */
        {USB_VPI(USB_VENDOR_SUNTAC, USB_PRODUCT_SUNTAC_IS96U, 0)},
        /* SUNTAC U-Cable type P1 */
        {USB_VPI(USB_VENDOR_SUNTAC, USB_PRODUCT_SUNTAC_PS64P1, 0)},
        /* SUNTAC Slipper U */
        {USB_VPI(USB_VENDOR_SUNTAC, USB_PRODUCT_SUNTAC_VS10U, 0)},
};

static device_method_t uvscom_methods[] = {
        DEVMETHOD(device_probe, uvscom_probe),
        DEVMETHOD(device_attach, uvscom_attach),
        DEVMETHOD(device_detach, uvscom_detach),
        DEVMETHOD_END
};

static driver_t uvscom_driver = {
        .name = "uvscom",
        .methods = uvscom_methods,
        .size = sizeof(struct uvscom_softc),
};

DRIVER_MODULE(uvscom, uhub, uvscom_driver, NULL, NULL);
MODULE_DEPEND(uvscom, ucom, 1, 1, 1);
MODULE_DEPEND(uvscom, usb, 1, 1, 1);
MODULE_VERSION(uvscom, UVSCOM_MODVER);
USB_PNP_HOST_INFO(uvscom_devs);

static int
uvscom_probe(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);

        if (uaa->usb_mode != USB_MODE_HOST) {
                return (ENXIO);
        }
        if (uaa->info.bConfigIndex != UVSCOM_CONFIG_INDEX) {
                return (ENXIO);
        }
        if (uaa->info.bIfaceIndex != UVSCOM_IFACE_INDEX) {
                return (ENXIO);
        }
        return (usbd_lookup_id_by_uaa(uvscom_devs, sizeof(uvscom_devs), uaa));
}

static int
uvscom_attach(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        struct uvscom_softc *sc = device_get_softc(dev);
        int error;

        device_set_usb_desc(dev);
        mtx_init(&sc->sc_mtx, "uvscom", NULL, MTX_DEF);
        ucom_ref(&sc->sc_super_ucom);

        sc->sc_udev = uaa->device;

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

        sc->sc_iface_no = uaa->info.bIfaceNum;
        sc->sc_iface_index = UVSCOM_IFACE_INDEX;

        error = usbd_transfer_setup(uaa->device, &sc->sc_iface_index,
            sc->sc_xfer, uvscom_config, UVSCOM_N_TRANSFER, sc, &sc->sc_mtx);

        if (error) {
                DPRINTF("could not allocate all USB transfers!\n");
                goto detach;
        }
        sc->sc_line = UVSCOM_LINE_INIT;

        /* clear stall at first run */
        mtx_lock(&sc->sc_mtx);
        usbd_xfer_set_stall(sc->sc_xfer[UVSCOM_BULK_DT_WR]);
        usbd_xfer_set_stall(sc->sc_xfer[UVSCOM_BULK_DT_RD]);
        mtx_unlock(&sc->sc_mtx);

        error = ucom_attach(&sc->sc_super_ucom, &sc->sc_ucom, 1, sc,
            &uvscom_callback, &sc->sc_mtx);
        if (error) {
                goto detach;
        }
        ucom_set_pnpinfo_usb(&sc->sc_super_ucom, dev);

        /* start interrupt pipe */
        mtx_lock(&sc->sc_mtx);
        usbd_transfer_start(sc->sc_xfer[UVSCOM_INTR_DT_RD]);
        mtx_unlock(&sc->sc_mtx);

        return (0);

detach:
        uvscom_detach(dev);
        return (ENXIO);
}

static int
uvscom_detach(device_t dev)
{
        struct uvscom_softc *sc = device_get_softc(dev);

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

        /* stop interrupt pipe */

        if (sc->sc_xfer[UVSCOM_INTR_DT_RD])
                usbd_transfer_stop(sc->sc_xfer[UVSCOM_INTR_DT_RD]);

        ucom_detach(&sc->sc_super_ucom, &sc->sc_ucom);
        usbd_transfer_unsetup(sc->sc_xfer, UVSCOM_N_TRANSFER);

        device_claim_softc(dev);

        uvscom_free_softc(sc);

        return (0);
}

UCOM_UNLOAD_DRAIN(uvscom);

static void
uvscom_free_softc(struct uvscom_softc *sc)
{
        if (ucom_unref(&sc->sc_super_ucom)) {
                mtx_destroy(&sc->sc_mtx);
                device_free_softc(sc);
        }
}

static void
uvscom_free(struct ucom_softc *ucom)
{
        uvscom_free_softc(ucom->sc_parent);
}

static void
uvscom_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct uvscom_softc *sc = usbd_xfer_softc(xfer);
        struct usb_page_cache *pc;
        uint32_t actlen;

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_SETUP:
        case USB_ST_TRANSFERRED:
tr_setup:
                pc = usbd_xfer_get_frame(xfer, 0);
                if (ucom_get_data(&sc->sc_ucom, pc, 0,
                    UVSCOM_BULK_BUF_SIZE, &actlen)) {
                        usbd_xfer_set_frame_len(xfer, 0, actlen);
                        usbd_transfer_submit(xfer);
                }
                return;

        default:                        /* Error */
                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                return;
        }
}

static void
uvscom_read_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct uvscom_softc *sc = usbd_xfer_softc(xfer);
        struct usb_page_cache *pc;
        int actlen;

        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                pc = usbd_xfer_get_frame(xfer, 0);
                ucom_put_data(&sc->sc_ucom, pc, 0, actlen);

        case USB_ST_SETUP:
tr_setup:
                usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
                usbd_transfer_submit(xfer);
                return;

        default:                        /* Error */
                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                return;
        }
}

static void
uvscom_intr_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct uvscom_softc *sc = usbd_xfer_softc(xfer);
        struct usb_page_cache *pc;
        uint8_t buf[2];
        int actlen;

        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                if (actlen >= 2) {
                        pc = usbd_xfer_get_frame(xfer, 0);
                        usbd_copy_out(pc, 0, buf, sizeof(buf));

                        sc->sc_lsr = 0;
                        sc->sc_msr = 0;
                        sc->sc_unit_status = buf[1];

                        if (buf[0] & UVSCOM_TXRDY) {
                                sc->sc_lsr |= ULSR_TXRDY;
                        }
                        if (buf[0] & UVSCOM_RXRDY) {
                                sc->sc_lsr |= ULSR_RXRDY;
                        }
                        if (buf[1] & UVSCOM_CTS) {
                                sc->sc_msr |= SER_CTS;
                        }
                        if (buf[1] & UVSCOM_DSR) {
                                sc->sc_msr |= SER_DSR;
                        }
                        if (buf[1] & UVSCOM_DCD) {
                                sc->sc_msr |= SER_DCD;
                        }
                        /*
                         * the UCOM layer will ignore this call if the TTY
                         * device is closed!
                         */
                        ucom_status_change(&sc->sc_ucom);
                }
        case USB_ST_SETUP:
tr_setup:
                usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
                usbd_transfer_submit(xfer);
                return;

        default:                        /* Error */
                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                return;
        }
}

static void
uvscom_cfg_set_dtr(struct ucom_softc *ucom, uint8_t onoff)
{
        struct uvscom_softc *sc = ucom->sc_parent;

        DPRINTF("onoff = %d\n", onoff);

        if (onoff)
                sc->sc_line |= UVSCOM_DTR;
        else
                sc->sc_line &= ~UVSCOM_DTR;

        uvscom_cfg_write(sc, UVSCOM_LINE_CTL, sc->sc_line);
}

static void
uvscom_cfg_set_rts(struct ucom_softc *ucom, uint8_t onoff)
{
        struct uvscom_softc *sc = ucom->sc_parent;

        DPRINTF("onoff = %d\n", onoff);

        if (onoff)
                sc->sc_line |= UVSCOM_RTS;
        else
                sc->sc_line &= ~UVSCOM_RTS;

        uvscom_cfg_write(sc, UVSCOM_LINE_CTL, sc->sc_line);
}

static void
uvscom_cfg_set_break(struct ucom_softc *ucom, uint8_t onoff)
{
        struct uvscom_softc *sc = ucom->sc_parent;

        DPRINTF("onoff = %d\n", onoff);

        if (onoff)
                sc->sc_line |= UVSCOM_BREAK;
        else
                sc->sc_line &= ~UVSCOM_BREAK;

        uvscom_cfg_write(sc, UVSCOM_LINE_CTL, sc->sc_line);
}

static int
uvscom_pre_param(struct ucom_softc *ucom, struct termios *t)
{
        switch (t->c_ospeed) {
                case B150:
                case B300:
                case B600:
                case B1200:
                case B2400:
                case B4800:
                case B9600:
                case B19200:
                case B38400:
                case B57600:
                case B115200:
                default:
                return (EINVAL);
        }
        return (0);
}

static void
uvscom_cfg_param(struct ucom_softc *ucom, struct termios *t)
{
        struct uvscom_softc *sc = ucom->sc_parent;
        uint16_t value;

        DPRINTF("\n");

        switch (t->c_ospeed) {
        case B150:
                value = UVSCOM_SPEED_150BPS;
                break;
        case B300:
                value = UVSCOM_SPEED_300BPS;
                break;
        case B600:
                value = UVSCOM_SPEED_600BPS;
                break;
        case B1200:
                value = UVSCOM_SPEED_1200BPS;
                break;
        case B2400:
                value = UVSCOM_SPEED_2400BPS;
                break;
        case B4800:
                value = UVSCOM_SPEED_4800BPS;
                break;
        case B9600:
                value = UVSCOM_SPEED_9600BPS;
                break;
        case B19200:
                value = UVSCOM_SPEED_19200BPS;
                break;
        case B38400:
                value = UVSCOM_SPEED_38400BPS;
                break;
        case B57600:
                value = UVSCOM_SPEED_57600BPS;
                break;
        case B115200:
                value = UVSCOM_SPEED_115200BPS;
                break;
        default:
                return;
        }

        uvscom_cfg_write(sc, UVSCOM_SET_SPEED, value);

        value = 0;

        if (t->c_cflag & CSTOPB) {
                value |= UVSCOM_STOP_BIT_2;
        }
        if (t->c_cflag & PARENB) {
                if (t->c_cflag & PARODD) {
                        value |= UVSCOM_PARITY_ODD;
                } else {
                        value |= UVSCOM_PARITY_EVEN;
                }
        } else {
                value |= UVSCOM_PARITY_NONE;
        }

        switch (t->c_cflag & CSIZE) {
        case CS5:
                value |= UVSCOM_DATA_BIT_5;
                break;
        case CS6:
                value |= UVSCOM_DATA_BIT_6;
                break;
        case CS7:
                value |= UVSCOM_DATA_BIT_7;
                break;
        default:
        case CS8:
                value |= UVSCOM_DATA_BIT_8;
                break;
        }

        uvscom_cfg_write(sc, UVSCOM_SET_PARAM, value);
}

static int
uvscom_pre_open(struct ucom_softc *ucom)
{
        struct uvscom_softc *sc = ucom->sc_parent;

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

        /* check if PC card was inserted */

        if (sc->sc_unit_status & UVSCOM_NOCARD) {
                DPRINTF("no PC card!\n");
                return (ENXIO);
        }
        return (0);
}

static void
uvscom_cfg_open(struct ucom_softc *ucom)
{
        struct uvscom_softc *sc = ucom->sc_parent;

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

        uvscom_cfg_read_status(sc);
}

static void
uvscom_cfg_close(struct ucom_softc *ucom)
{
        struct uvscom_softc *sc = ucom->sc_parent;

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

        uvscom_cfg_write(sc, UVSCOM_SHUTDOWN, 0);
}

static void
uvscom_start_read(struct ucom_softc *ucom)
{
        struct uvscom_softc *sc = ucom->sc_parent;

        usbd_transfer_start(sc->sc_xfer[UVSCOM_BULK_DT_RD]);
}

static void
uvscom_stop_read(struct ucom_softc *ucom)
{
        struct uvscom_softc *sc = ucom->sc_parent;

        usbd_transfer_stop(sc->sc_xfer[UVSCOM_BULK_DT_RD]);
}

static void
uvscom_start_write(struct ucom_softc *ucom)
{
        struct uvscom_softc *sc = ucom->sc_parent;

        usbd_transfer_start(sc->sc_xfer[UVSCOM_BULK_DT_WR]);
}

static void
uvscom_stop_write(struct ucom_softc *ucom)
{
        struct uvscom_softc *sc = ucom->sc_parent;

        usbd_transfer_stop(sc->sc_xfer[UVSCOM_BULK_DT_WR]);
}

static void
uvscom_cfg_get_status(struct ucom_softc *ucom, uint8_t *lsr, uint8_t *msr)
{
        struct uvscom_softc *sc = ucom->sc_parent;

        *lsr = sc->sc_lsr;
        *msr = sc->sc_msr;
}

static void
uvscom_cfg_write(struct uvscom_softc *sc, uint8_t index, uint16_t value)
{
        struct usb_device_request req;
        usb_error_t err;

        req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
        req.bRequest = index;
        USETW(req.wValue, value);
        USETW(req.wIndex, 0);
        USETW(req.wLength, 0);

        err = ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom, 
            &req, NULL, 0, 1000);
        if (err) {
                DPRINTFN(0, "device request failed, err=%s "
                    "(ignored)\n", usbd_errstr(err));
        }
}

static uint16_t
uvscom_cfg_read_status(struct uvscom_softc *sc)
{
        struct usb_device_request req;
        usb_error_t err;
        uint8_t data[2];

        req.bmRequestType = UT_READ_VENDOR_DEVICE;
        req.bRequest = UVSCOM_READ_STATUS;
        USETW(req.wValue, 0);
        USETW(req.wIndex, 0);
        USETW(req.wLength, 2);

        err = ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom, 
            &req, data, 0, 1000);
        if (err) {
                DPRINTFN(0, "device request failed, err=%s "
                    "(ignored)\n", usbd_errstr(err));
        }
        return (data[0] | (data[1] << 8));
}

static void
uvscom_poll(struct ucom_softc *ucom)
{
        struct uvscom_softc *sc = ucom->sc_parent;
        usbd_transfer_poll(sc->sc_xfer, UVSCOM_N_TRANSFER);
}