uplcom.c

Go to the documentation of this file.

/*      $NetBSD: uplcom.c,v 1.21 2001/11/13 06:24:56 lukem Exp $        */
 
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
 
/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD AND BSD-2-Clause-NetBSD
 *
 * 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.
 */
 
/*-
 * Copyright (c) 2001 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Ichiro FUKUHARA (ichiro@ichiro.org).
 *
 * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 driver supports several USB-to-RS232 serial adapters driven by
 * Prolific PL-2303, PL-2303X and probably PL-2303HX USB-to-RS232
 * bridge chip.  The adapters are sold under many different brand
 * names.
 *
 * Datasheets are available at Prolific www site at
 * http://www.prolific.com.tw.  The datasheets don't contain full
 * programming information for the chip.
 *
 * PL-2303HX is probably programmed the same as PL-2303X.
 *
 * There are several differences between PL-2303 and PL-2303(H)X.
 * PL-2303(H)X can do higher bitrate in bulk mode, has _probably_
 * different command for controlling CRTSCTS and needs special
 * sequence of commands for initialization which aren't also
 * documented in the datasheet.
 */
 
#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 <dev/usb/usb_cdc.h>
#include "usbdevs.h"
 
#define USB_DEBUG_VAR uplcom_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 uplcom_debug = 0;
 
static SYSCTL_NODE(_hw_usb, OID_AUTO, uplcom, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "USB uplcom");
SYSCTL_INT(_hw_usb_uplcom, OID_AUTO, debug, CTLFLAG_RWTUN,
    &uplcom_debug, 0, "Debug level");
#endif
 
#define UPLCOM_MODVER                   1       /* module version */
 
#define UPLCOM_CONFIG_INDEX             0
#define UPLCOM_IFACE_INDEX              0
#define UPLCOM_SECOND_IFACE_INDEX       1
 
#ifndef UPLCOM_INTR_INTERVAL
#define UPLCOM_INTR_INTERVAL            0       /* default */
#endif
 
#define UPLCOM_BULK_BUF_SIZE 1024       /* bytes */
 
#define UPLCOM_SET_REQUEST              0x01
#define UPLCOM_SET_REQUEST_PL2303HXN    0x80
#define UPLCOM_SET_CRTSCTS              0x41
#define UPLCOM_SET_CRTSCTS_PL2303X      0x61
#define UPLCOM_SET_CRTSCTS_PL2303HXN    0xFA
#define UPLCOM_CLEAR_CRTSCTS_PL2303HXN  0xFF
#define UPLCOM_CRTSCTS_REG_PL2303HXN    0x0A
#define UPLCOM_STATUS_REG_PL2303HX      0x8080
#define RSAQ_STATUS_CTS                 0x80
#define RSAQ_STATUS_OVERRUN_ERROR       0x40
#define RSAQ_STATUS_PARITY_ERROR        0x20 
#define RSAQ_STATUS_FRAME_ERROR 0x10
#define RSAQ_STATUS_RING                0x08
#define RSAQ_STATUS_BREAK_ERROR 0x04
#define RSAQ_STATUS_DSR                 0x02
#define RSAQ_STATUS_DCD                 0x01
 
#define TYPE_PL2303                     0
#define TYPE_PL2303HX                   1
#define TYPE_PL2303HXD                  2
#define TYPE_PL2303HXN                  3
 
#define UPLCOM_STATE_INDEX              8
 
enum {
        UPLCOM_BULK_DT_WR,
        UPLCOM_BULK_DT_RD,
        UPLCOM_INTR_DT_RD,
        UPLCOM_N_TRANSFER,
};
 
struct uplcom_softc {
        struct ucom_super_softc sc_super_ucom;
        struct ucom_softc sc_ucom;
 
        struct usb_xfer *sc_xfer[UPLCOM_N_TRANSFER];
        struct usb_device *sc_udev;
        struct mtx sc_mtx;
 
        uint16_t sc_line;
 
        uint8_t sc_lsr;                 /* local status register */
        uint8_t sc_msr;                 /* uplcom status register */
        uint8_t sc_chiptype;            /* type of chip */
        uint8_t sc_ctrl_iface_no;
        uint8_t sc_data_iface_no;
        uint8_t sc_iface_index[2];
};
 
/* prototypes */
 
static usb_error_t uplcom_reset(struct uplcom_softc *, struct usb_device *);
static usb_error_t uplcom_pl2303_do(struct usb_device *, uint8_t, uint8_t,
                        uint16_t, uint16_t, uint16_t);
static int      uplcom_pl2303_init(struct usb_device *, uint8_t);
static void     uplcom_free(struct ucom_softc *);
static void     uplcom_cfg_set_dtr(struct ucom_softc *, uint8_t);
static void     uplcom_cfg_set_rts(struct ucom_softc *, uint8_t);
static void     uplcom_cfg_set_break(struct ucom_softc *, uint8_t);
static int      uplcom_pre_param(struct ucom_softc *, struct termios *);
static void     uplcom_cfg_param(struct ucom_softc *, struct termios *);
static void     uplcom_start_read(struct ucom_softc *);
static void     uplcom_stop_read(struct ucom_softc *);
static void     uplcom_start_write(struct ucom_softc *);
static void     uplcom_stop_write(struct ucom_softc *);
static void     uplcom_cfg_get_status(struct ucom_softc *, uint8_t *,
                    uint8_t *);
static void     uplcom_poll(struct ucom_softc *ucom);
 
static device_probe_t uplcom_probe;
static device_attach_t uplcom_attach;
static device_detach_t uplcom_detach;
static void uplcom_free_softc(struct uplcom_softc *);
 
static usb_callback_t uplcom_intr_callback;
static usb_callback_t uplcom_write_callback;
static usb_callback_t uplcom_read_callback;
 
static const struct usb_config uplcom_config_data[UPLCOM_N_TRANSFER] = {
        [UPLCOM_BULK_DT_WR] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_OUT,
                .bufsize = UPLCOM_BULK_BUF_SIZE,
                .flags = {.pipe_bof = 1,.force_short_xfer = 1,},
                .callback = &uplcom_write_callback,
                .if_index = 0,
        },
 
        [UPLCOM_BULK_DT_RD] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .bufsize = UPLCOM_BULK_BUF_SIZE,
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
                .callback = &uplcom_read_callback,
                .if_index = 0,
        },
 
        [UPLCOM_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 = &uplcom_intr_callback,
                .if_index = 1,
        },
};
 
static struct ucom_callback uplcom_callback = {
        .ucom_cfg_get_status = &uplcom_cfg_get_status,
        .ucom_cfg_set_dtr = &uplcom_cfg_set_dtr,
        .ucom_cfg_set_rts = &uplcom_cfg_set_rts,
        .ucom_cfg_set_break = &uplcom_cfg_set_break,
        .ucom_cfg_param = &uplcom_cfg_param,
        .ucom_pre_param = &uplcom_pre_param,
        .ucom_start_read = &uplcom_start_read,
        .ucom_stop_read = &uplcom_stop_read,
        .ucom_start_write = &uplcom_start_write,
        .ucom_stop_write = &uplcom_stop_write,
        .ucom_poll = &uplcom_poll,
        .ucom_free = &uplcom_free,
};
 
#define UPLCOM_DEV(v,p)                         \
  { USB_VENDOR(USB_VENDOR_##v), USB_PRODUCT(USB_PRODUCT_##v##_##p) }
 
static const STRUCT_USB_HOST_ID uplcom_devs[] = {
        UPLCOM_DEV(ACERP, S81),                 /* BenQ S81 phone */
        UPLCOM_DEV(ADLINK, ND6530),             /* ADLINK ND-6530 USB-Serial */
        UPLCOM_DEV(ALCATEL, OT535),             /* Alcatel One Touch 535/735 */
        UPLCOM_DEV(ALCOR, AU9720),              /* Alcor AU9720 USB 2.0-RS232 */
        UPLCOM_DEV(ANCHOR, SERIAL),             /* Anchor Serial adapter */
        UPLCOM_DEV(ATEN, UC232A),               /* PLANEX USB-RS232 URS-03 */
        UPLCOM_DEV(ATEN, UC232B),               /* Prolific USB-RS232 Controller D */
        UPLCOM_DEV(BELKIN, F5U257),             /* Belkin F5U257 USB to Serial */
        UPLCOM_DEV(COREGA, CGUSBRS232R),        /* Corega CG-USBRS232R */
        UPLCOM_DEV(EPSON, CRESSI_EDY),          /* Cressi Edy diving computer */
        UPLCOM_DEV(EPSON, N2ITION3),            /* Zeagle N2iTion3 diving computer */
        UPLCOM_DEV(ELECOM, UCSGT),              /* ELECOM UC-SGT Serial Adapter */
        UPLCOM_DEV(ELECOM, UCSGT0),             /* ELECOM UC-SGT Serial Adapter */
        UPLCOM_DEV(HAL, IMR001),                /* HAL Corporation Crossam2+USB */
        UPLCOM_DEV(HP, LD220),                  /* HP LD220 POS Display */
        UPLCOM_DEV(IODATA, USBRSAQ),            /* I/O DATA USB-RSAQ */
        UPLCOM_DEV(IODATA, USBRSAQ5),           /* I/O DATA USB-RSAQ5 */
        UPLCOM_DEV(ITEGNO, WM1080A),            /* iTegno WM1080A GSM/GFPRS modem */
        UPLCOM_DEV(ITEGNO, WM2080A),            /* iTegno WM2080A CDMA modem */
        UPLCOM_DEV(LEADTEK, 9531),              /* Leadtek 9531 GPS */
        UPLCOM_DEV(MICROSOFT, 700WX),           /* Microsoft Palm 700WX */
        UPLCOM_DEV(MOBILEACTION, MA620),        /* Mobile Action MA-620 Infrared Adapter */
        UPLCOM_DEV(NETINDEX, WS002IN),          /* Willcom W-S002IN */
        UPLCOM_DEV(NOKIA2, CA42),               /* Nokia CA-42 cable */
        UPLCOM_DEV(OTI, DKU5),                  /* OTI DKU-5 cable */
        UPLCOM_DEV(PANASONIC, TYTP50P6S),       /* Panasonic TY-TP50P6-S flat screen */
        UPLCOM_DEV(PLX, CA42),                  /* PLX CA-42 clone cable */
        UPLCOM_DEV(PROLIFIC, ALLTRONIX_GPRS),   /* Alltronix ACM003U00 modem */
        UPLCOM_DEV(PROLIFIC, ALDIGA_AL11U),     /* AlDiga AL-11U modem */
        UPLCOM_DEV(PROLIFIC, DCU11),            /* DCU-11 Phone Cable */
        UPLCOM_DEV(PROLIFIC, HCR331),           /* HCR331 Card Reader */
        UPLCOM_DEV(PROLIFIC, MICROMAX_610U),    /* Micromax 610U modem */
        UPLCOM_DEV(PROLIFIC, MOTOROLA),         /* Motorola cable */
        UPLCOM_DEV(PROLIFIC, PHAROS),           /* Prolific Pharos */
        UPLCOM_DEV(PROLIFIC, PL2303),           /* Generic adapter */
        UPLCOM_DEV(PROLIFIC, PL2303GC),         /* Generic adapter (PL2303HXN, type GC) */
        UPLCOM_DEV(PROLIFIC, PL2303GB),         /* Generic adapter (PL2303HXN, type GB) */
        UPLCOM_DEV(PROLIFIC, PL2303GT),         /* Generic adapter (PL2303HXN, type GT) */
        UPLCOM_DEV(PROLIFIC, PL2303GL),         /* Generic adapter (PL2303HXN, type GL) */
        UPLCOM_DEV(PROLIFIC, PL2303GE),         /* Generic adapter (PL2303HXN, type GE) */
        UPLCOM_DEV(PROLIFIC, PL2303GS),         /* Generic adapter (PL2303HXN, type GS) */
        UPLCOM_DEV(PROLIFIC, RSAQ2),            /* I/O DATA USB-RSAQ2 */
        UPLCOM_DEV(PROLIFIC, RSAQ3),            /* I/O DATA USB-RSAQ3 */
        UPLCOM_DEV(PROLIFIC, UIC_MSR206),       /* UIC MSR206 Card Reader */
        UPLCOM_DEV(PROLIFIC2, PL2303),          /* Prolific adapter */
        UPLCOM_DEV(RADIOSHACK, USBCABLE),       /* Radio Shack USB Adapter */
        UPLCOM_DEV(RATOC, REXUSB60),            /* RATOC REX-USB60 */
        UPLCOM_DEV(SAGEM, USBSERIAL),           /* Sagem USB-Serial Controller */
        UPLCOM_DEV(SAMSUNG, I330),              /* Samsung I330 phone cradle */
        UPLCOM_DEV(SANWA, KB_USB2),             /* Sanwa KB-USB2 Multimeter cable */
        UPLCOM_DEV(SIEMENS3, EF81),             /* Siemens EF81 */
        UPLCOM_DEV(SIEMENS3, SX1),              /* Siemens SX1 */
        UPLCOM_DEV(SIEMENS3, X65),              /* Siemens X65 */
        UPLCOM_DEV(SIEMENS3, X75),              /* Siemens X75 */
        UPLCOM_DEV(SITECOM, SERIAL),            /* Sitecom USB to Serial */
        UPLCOM_DEV(SMART, PL2303),              /* SMART Technologies USB to Serial */
        UPLCOM_DEV(SONY, QN3),                  /* Sony QN3 phone cable */
        UPLCOM_DEV(SONYERICSSON, DATAPILOT),    /* Sony Ericsson Datapilot */
        UPLCOM_DEV(SONYERICSSON, DCU10),        /* Sony Ericsson DCU-10 Cable */
        UPLCOM_DEV(SOURCENEXT, KEIKAI8),        /* SOURCENEXT KeikaiDenwa 8 */
        UPLCOM_DEV(SOURCENEXT, KEIKAI8_CHG),    /* SOURCENEXT KeikaiDenwa 8 with charger */
        UPLCOM_DEV(SPEEDDRAGON, MS3303H),       /* Speed Dragon USB-Serial */
        UPLCOM_DEV(SYNTECH, CPT8001C),          /* Syntech CPT-8001C Barcode scanner */
        UPLCOM_DEV(TDK, UHA6400),               /* TDK USB-PHS Adapter UHA6400 */
        UPLCOM_DEV(TDK, UPA9664),               /* TDK USB-PHS Adapter UPA9664 */
        UPLCOM_DEV(TRIPPLITE, U209),            /* Tripp-Lite U209-000-R USB to Serial */
        UPLCOM_DEV(YCCABLE, PL2303),            /* YC Cable USB-Serial */
};
#undef UPLCOM_DEV
 
static device_method_t uplcom_methods[] = {
        DEVMETHOD(device_probe, uplcom_probe),
        DEVMETHOD(device_attach, uplcom_attach),
        DEVMETHOD(device_detach, uplcom_detach),
        DEVMETHOD_END
};
 
static devclass_t uplcom_devclass;
 
static driver_t uplcom_driver = {
        .name = "uplcom",
        .methods = uplcom_methods,
        .size = sizeof(struct uplcom_softc),
};
 
DRIVER_MODULE(uplcom, uhub, uplcom_driver, uplcom_devclass, NULL, 0);
MODULE_DEPEND(uplcom, ucom, 1, 1, 1);
MODULE_DEPEND(uplcom, usb, 1, 1, 1);
MODULE_VERSION(uplcom, UPLCOM_MODVER);
USB_PNP_HOST_INFO(uplcom_devs);
 
static int
uplcom_probe(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);
 
        DPRINTFN(11, "\n");
 
        if (uaa->usb_mode != USB_MODE_HOST) {
                return (ENXIO);
        }
        if (uaa->info.bConfigIndex != UPLCOM_CONFIG_INDEX) {
                return (ENXIO);
        }
        if (uaa->info.bIfaceIndex != UPLCOM_IFACE_INDEX) {
                return (ENXIO);
        }
        return (usbd_lookup_id_by_uaa(uplcom_devs, sizeof(uplcom_devs), uaa));
}
 
static int
uplcom_attach(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        struct uplcom_softc *sc = device_get_softc(dev);
        struct usb_interface *iface;
        struct usb_interface_descriptor *id;
        struct usb_device_descriptor *dd;
        int error;
 
        struct usb_device_request req;
        usb_error_t err;
        uint8_t buf[4];
 
        DPRINTFN(11, "\n");
 
        device_set_usb_desc(dev);
        mtx_init(&sc->sc_mtx, "uplcom", NULL, MTX_DEF);
        ucom_ref(&sc->sc_super_ucom);
 
        DPRINTF("sc = %p\n", sc);
 
        sc->sc_udev = uaa->device;
 
        dd = usbd_get_device_descriptor(sc->sc_udev);
 
        switch (UGETW(dd->bcdDevice)) {
        case 0x0300:
                sc->sc_chiptype = TYPE_PL2303HX;
                /* or TA, that is HX with external crystal */
                break;
        case 0x0400:
                sc->sc_chiptype = TYPE_PL2303HXD;
                /* or EA, that is HXD with ESD protection */
                /* or RA, that has internal voltage level converter that works only up to 1Mbaud (!) */
                break;
        case 0x0500:
                sc->sc_chiptype = TYPE_PL2303HXD;
                /* in fact it's TB, that is HXD with external crystal */
                break;
        default:
                /* NOTE: I have no info about the bcdDevice for the base PL2303 (up to 1.2Mbaud,
                   only fixed rates) and for PL2303SA (8-pin chip, up to 115200 baud */
                /* Determine the chip type.  This algorithm is taken from Linux. */
                if (dd->bDeviceClass == 0x02)
                        sc->sc_chiptype = TYPE_PL2303;
                else if (dd->bMaxPacketSize == 0x40)
                        sc->sc_chiptype = TYPE_PL2303HX;
                else
                        sc->sc_chiptype = TYPE_PL2303;
                break;
        }
 
        /*
         * The new chip revision PL2303HXN is only compatible with the new
         * UPLCOM_SET_REQUEST_PL2303HXN command. Issuing the old command
         * UPLCOM_SET_REQUEST to the new chip raises an error. Thus, PL2303HX
         * and PL2303HXN can be distinguished by issuing an old-style request
         * (on a status register) to the new chip and checking the error.
         */
        if (sc->sc_chiptype == TYPE_PL2303HX) {
                req.bmRequestType = UT_READ_VENDOR_DEVICE;
                req.bRequest = UPLCOM_SET_REQUEST;
                USETW(req.wValue, UPLCOM_STATUS_REG_PL2303HX);
                req.wIndex[0] = sc->sc_data_iface_no;
                req.wIndex[1] = 0;
                USETW(req.wLength, 1);
                err = usbd_do_request(sc->sc_udev, NULL, &req, buf);
                if (err)
                        sc->sc_chiptype = TYPE_PL2303HXN;
        }
 
        switch (sc->sc_chiptype) {
        case TYPE_PL2303:
                DPRINTF("chiptype: 2303\n");
                break;
        case TYPE_PL2303HX:
                DPRINTF("chiptype: 2303HX/TA\n");
                break;
        case TYPE_PL2303HXN:
                DPRINTF("chiptype: 2303HXN\n");
                break;
        case TYPE_PL2303HXD:
                DPRINTF("chiptype: 2303HXD/TB/RA/EA\n");
                break;
        default:
                DPRINTF("chiptype: unknown %d\n", sc->sc_chiptype);
                break;
        }
 
        /*
         * USB-RSAQ1 has two interface
         *
         *  USB-RSAQ1       | USB-RSAQ2
         * -----------------+-----------------
         * Interface 0      |Interface 0
         *  Interrupt(0x81) | Interrupt(0x81)
         * -----------------+ BulkIN(0x02)
         * Interface 1      | BulkOUT(0x83)
         *   BulkIN(0x02)   |
         *   BulkOUT(0x83)  |
         */
 
        sc->sc_ctrl_iface_no = uaa->info.bIfaceNum;
        sc->sc_iface_index[1] = UPLCOM_IFACE_INDEX;
 
        iface = usbd_get_iface(uaa->device, UPLCOM_SECOND_IFACE_INDEX);
        if (iface) {
                id = usbd_get_interface_descriptor(iface);
                if (id == NULL) {
                        device_printf(dev, "no interface descriptor (2)\n");
                        goto detach;
                }
                sc->sc_data_iface_no = id->bInterfaceNumber;
                sc->sc_iface_index[0] = UPLCOM_SECOND_IFACE_INDEX;
                usbd_set_parent_iface(uaa->device,
                    UPLCOM_SECOND_IFACE_INDEX, uaa->info.bIfaceIndex);
        } else {
                sc->sc_data_iface_no = sc->sc_ctrl_iface_no;
                sc->sc_iface_index[0] = UPLCOM_IFACE_INDEX;
        }
 
        error = usbd_transfer_setup(uaa->device,
            sc->sc_iface_index, sc->sc_xfer, uplcom_config_data,
            UPLCOM_N_TRANSFER, sc, &sc->sc_mtx);
        if (error) {
                DPRINTF("one or more missing USB endpoints, "
                    "error=%s\n", usbd_errstr(error));
                goto detach;
        }
        error = uplcom_reset(sc, uaa->device);
        if (error) {
                device_printf(dev, "reset failed, error=%s\n",
                    usbd_errstr(error));
                goto detach;
        }
 
        if (sc->sc_chiptype == TYPE_PL2303) {
                /* HX variants seem to lock up after a clear stall request. */
                mtx_lock(&sc->sc_mtx);
                usbd_xfer_set_stall(sc->sc_xfer[UPLCOM_BULK_DT_WR]);
                usbd_xfer_set_stall(sc->sc_xfer[UPLCOM_BULK_DT_RD]);
                mtx_unlock(&sc->sc_mtx);
        } else if (sc->sc_chiptype == TYPE_PL2303HX ||
                   sc->sc_chiptype == TYPE_PL2303HXD) {
                /* reset upstream data pipes */
                if (uplcom_pl2303_do(sc->sc_udev, UT_WRITE_VENDOR_DEVICE,
                    UPLCOM_SET_REQUEST, 8, 0, 0) ||
                    uplcom_pl2303_do(sc->sc_udev, UT_WRITE_VENDOR_DEVICE,
                    UPLCOM_SET_REQUEST, 9, 0, 0)) {
                        goto detach;
                }
        } else if (sc->sc_chiptype == TYPE_PL2303HXN) {
                /* reset upstream data pipes */
                if (uplcom_pl2303_do(sc->sc_udev, UT_WRITE_VENDOR_DEVICE,
                    UPLCOM_SET_REQUEST_PL2303HXN, 0x07, 0x03, 0)) {
                        goto detach;
                }
        }
 
        error = ucom_attach(&sc->sc_super_ucom, &sc->sc_ucom, 1, sc,
            &uplcom_callback, &sc->sc_mtx);
        if (error) {
                goto detach;
        }
        /*
         * do the initialization during attach so that the system does not
         * sleep during open:
         */
        if (uplcom_pl2303_init(uaa->device, sc->sc_chiptype)) {
                device_printf(dev, "init failed\n");
                goto detach;
        }
        ucom_set_pnpinfo_usb(&sc->sc_super_ucom, dev);
 
        return (0);
 
detach:
        uplcom_detach(dev);
        return (ENXIO);
}
 
static int
uplcom_detach(device_t dev)
{
        struct uplcom_softc *sc = device_get_softc(dev);
 
        DPRINTF("sc=%p\n", sc);
 
        ucom_detach(&sc->sc_super_ucom, &sc->sc_ucom);
        usbd_transfer_unsetup(sc->sc_xfer, UPLCOM_N_TRANSFER);
 
        device_claim_softc(dev);
 
        uplcom_free_softc(sc);
 
        return (0);
}
 
UCOM_UNLOAD_DRAIN(uplcom);
 
static void
uplcom_free_softc(struct uplcom_softc *sc)
{
        if (ucom_unref(&sc->sc_super_ucom)) {
                mtx_destroy(&sc->sc_mtx);
                device_free_softc(sc);
        }
}
 
static void
uplcom_free(struct ucom_softc *ucom)
{
        uplcom_free_softc(ucom->sc_parent);
}
 
static usb_error_t
uplcom_reset(struct uplcom_softc *sc, struct usb_device *udev)
{
        struct usb_device_request req;
 
        if (sc->sc_chiptype == TYPE_PL2303HXN) {
                /* PL2303HXN doesn't need this reset sequence */
                return (0);
        }
 
        req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
        req.bRequest = UPLCOM_SET_REQUEST;
        USETW(req.wValue, 0);
        req.wIndex[0] = sc->sc_data_iface_no;
        req.wIndex[1] = 0;
        USETW(req.wLength, 0);
 
        return (usbd_do_request(udev, NULL, &req, NULL));
}
 
static usb_error_t
uplcom_pl2303_do(struct usb_device *udev, uint8_t req_type, uint8_t request,
    uint16_t value, uint16_t index, uint16_t length)
{
        struct usb_device_request req;
        usb_error_t err;
        uint8_t buf[4];
 
        req.bmRequestType = req_type;
        req.bRequest = request;
        USETW(req.wValue, value);
        USETW(req.wIndex, index);
        USETW(req.wLength, length);
 
        err = usbd_do_request(udev, NULL, &req, buf);
        if (err) {
                DPRINTF("error=%s\n", usbd_errstr(err));
                return (1);
        }
        return (0);
}
 
static int
uplcom_pl2303_init(struct usb_device *udev, uint8_t chiptype)
{
        int err;
 
        if (chiptype == TYPE_PL2303HXN) {
                /* PL2303HXN doesn't need this initialization sequence */
                return (0);
        }
 
        if (uplcom_pl2303_do(udev, UT_READ_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0x8484, 0, 1)
            || uplcom_pl2303_do(udev, UT_WRITE_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0x0404, 0, 0)
            || uplcom_pl2303_do(udev, UT_READ_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0x8484, 0, 1)
            || uplcom_pl2303_do(udev, UT_READ_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0x8383, 0, 1)
            || uplcom_pl2303_do(udev, UT_READ_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0x8484, 0, 1)
            || uplcom_pl2303_do(udev, UT_WRITE_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0x0404, 1, 0)
            || uplcom_pl2303_do(udev, UT_READ_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0x8484, 0, 1)
            || uplcom_pl2303_do(udev, UT_READ_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0x8383, 0, 1)
            || uplcom_pl2303_do(udev, UT_WRITE_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 0, 1, 0)
            || uplcom_pl2303_do(udev, UT_WRITE_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 1, 0, 0))
                return (EIO);
 
        if (chiptype != TYPE_PL2303)
                err = uplcom_pl2303_do(udev, UT_WRITE_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 2, 0x44, 0);
        else
                err = uplcom_pl2303_do(udev, UT_WRITE_VENDOR_DEVICE, UPLCOM_SET_REQUEST, 2, 0x24, 0);
        if (err)
                return (EIO);
 
        return (0);
}
 
static void
uplcom_cfg_set_dtr(struct ucom_softc *ucom, uint8_t onoff)
{
        struct uplcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;
 
        DPRINTF("onoff = %d\n", onoff);
 
        if (onoff)
                sc->sc_line |= UCDC_LINE_DTR;
        else
                sc->sc_line &= ~UCDC_LINE_DTR;
 
        req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
        req.bRequest = UCDC_SET_CONTROL_LINE_STATE;
        USETW(req.wValue, sc->sc_line);
        req.wIndex[0] = sc->sc_data_iface_no;
        req.wIndex[1] = 0;
        USETW(req.wLength, 0);
 
        ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom, 
            &req, NULL, 0, 1000);
}
 
static void
uplcom_cfg_set_rts(struct ucom_softc *ucom, uint8_t onoff)
{
        struct uplcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;
 
        DPRINTF("onoff = %d\n", onoff);
 
        if (onoff)
                sc->sc_line |= UCDC_LINE_RTS;
        else
                sc->sc_line &= ~UCDC_LINE_RTS;
 
        req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
        req.bRequest = UCDC_SET_CONTROL_LINE_STATE;
        USETW(req.wValue, sc->sc_line);
        req.wIndex[0] = sc->sc_data_iface_no;
        req.wIndex[1] = 0;
        USETW(req.wLength, 0);
 
        ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom, 
            &req, NULL, 0, 1000);
}
 
static void
uplcom_cfg_set_break(struct ucom_softc *ucom, uint8_t onoff)
{
        struct uplcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;
        uint16_t temp;
 
        DPRINTF("onoff = %d\n", onoff);
 
        temp = (onoff ? UCDC_BREAK_ON : UCDC_BREAK_OFF);
 
        req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
        req.bRequest = UCDC_SEND_BREAK;
        USETW(req.wValue, temp);
        req.wIndex[0] = sc->sc_data_iface_no;
        req.wIndex[1] = 0;
        USETW(req.wLength, 0);
 
        ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom, 
            &req, NULL, 0, 1000);
}
 
/*
 * NOTE: These baud rates are officially supported, they can be written
 * directly into dwDTERate register.
 *
 * Free baudrate setting is not supported by the base PL2303, and on
 * other models it requires writing a divisor value to dwDTERate instead
 * of the raw baudrate. The formula for divisor calculation is not published
 * by the vendor, so it is speculative, though the official product homepage
 * refers to the Linux module source as a reference implementation.
 */
static const uint32_t uplcom_rates[] = {
        /*
         * Basic 'standard' speed rates, supported by all models
         * NOTE: 900 and 56000 actually works as well
         */
        75, 150, 300, 600, 900, 1200, 1800, 2400, 3600, 4800, 7200, 9600, 14400,
        19200, 28800, 38400, 56000, 57600, 115200,
        /*
         * Advanced speed rates up to 6Mbs, supported by HX/TA and HXD/TB/EA/RA
     * NOTE: regardless of the spec, 256000 does not work
         */
        128000, 134400, 161280, 201600, 230400, 268800, 403200, 460800, 614400,
        806400, 921600, 1228800, 2457600, 3000000, 6000000,
        /*
         * Advanced speed rates up to 12, supported by HXD/TB/EA/RA
         */
        12000000
};
 
#define N_UPLCOM_RATES  nitems(uplcom_rates)
 
static int
uplcom_baud_supported(unsigned int speed)
{
        int i;
        for (i = 0; i < N_UPLCOM_RATES; i++) {
                if (uplcom_rates[i] == speed)
                        return 1;
        }
        return 0;
}
 
static int
uplcom_pre_param(struct ucom_softc *ucom, struct termios *t)
{
        struct uplcom_softc *sc = ucom->sc_parent;
 
        DPRINTF("\n");
 
        /* accept raw divisor data, if someone wants to do the math in user domain */
        if (t->c_ospeed & 0x80000000)
                return 0;
        switch (sc->sc_chiptype) {
                case TYPE_PL2303HXN:
                        if (t->c_ospeed <= 12000000)
                                return (0);
                        break;
                case TYPE_PL2303HXD:
                        if (t->c_ospeed <= 12000000)
                                return (0);
                        break;
                case TYPE_PL2303HX:
                        if (t->c_ospeed <= 6000000)
                                return (0);
                        break;
                default:
                        if (uplcom_baud_supported(t->c_ospeed))
                                return (0);
                        break;
        }
 
        DPRINTF("uplcom_param: bad baud rate (%d)\n", t->c_ospeed);
        return (EIO);
}
 
static unsigned int
uplcom_encode_baud_rate_divisor(uint8_t *buf, unsigned int baud)
{
        unsigned int baseline, mantissa, exponent;
 
        /* Determine the baud rate divisor. This algorithm is taken from Linux. */
        /*
         * Apparently the formula is:
         *   baudrate = baseline / (mantissa * 4^exponent)
         * where
         *   mantissa = buf[8:0]
         *   exponent = buf[11:9]
         */
        if (baud == 0)
                baud = 1;
        baseline = 383385600;
        mantissa = baseline / baud;
        if (mantissa == 0)
                mantissa = 1;
        exponent = 0;
        while (mantissa >= 512) {
                if (exponent < 7) {
                        mantissa >>= 2; /* divide by 4 */
                        exponent++;
                } else {
                        /* Exponent is maxed. Trim mantissa and leave. This gives approx. 45.8 baud */
                        mantissa = 511;
                        break;
                }
        }
 
        buf[3] = 0x80;
        buf[2] = 0;
        buf[1] = exponent << 1 | mantissa >> 8;
        buf[0] = mantissa & 0xff;
 
        /* Calculate and return the exact baud rate. */
        baud = (baseline / mantissa) >> (exponent << 1);
        DPRINTF("real baud rate will be %u\n", baud);
 
        return baud;
}
static void
uplcom_cfg_param(struct ucom_softc *ucom, struct termios *t)
{
        struct uplcom_softc *sc = ucom->sc_parent;
        struct usb_cdc_line_state ls;
        struct usb_device_request req;
 
        DPRINTF("sc = %p\n", sc);
 
        memset(&ls, 0, sizeof(ls));
 
        /*
         * NOTE: If unsupported baud rates are set directly, the PL2303* uses 9600 baud.
         */
        if ((t->c_ospeed & 0x80000000) || uplcom_baud_supported(t->c_ospeed))
                USETDW(ls.dwDTERate, t->c_ospeed);
        else
                t->c_ospeed = uplcom_encode_baud_rate_divisor((uint8_t*)&ls.dwDTERate, t->c_ospeed);
 
        if (t->c_cflag & CSTOPB) {
                if ((t->c_cflag & CSIZE) == CS5) {
                        /*
                         * NOTE: Comply with "real" UARTs / RS232:
                         *       use 1.5 instead of 2 stop bits with 5 data bits
                         */
                        ls.bCharFormat = UCDC_STOP_BIT_1_5;
                } else {
                        ls.bCharFormat = UCDC_STOP_BIT_2;
                }
        } else {
                ls.bCharFormat = UCDC_STOP_BIT_1;
        }
 
        if (t->c_cflag & PARENB) {
                if (t->c_cflag & PARODD) {
                        ls.bParityType = UCDC_PARITY_ODD;
                } else {
                        ls.bParityType = UCDC_PARITY_EVEN;
                }
        } else {
                ls.bParityType = UCDC_PARITY_NONE;
        }
 
        switch (t->c_cflag & CSIZE) {
        case CS5:
                ls.bDataBits = 5;
                break;
        case CS6:
                ls.bDataBits = 6;
                break;
        case CS7:
                ls.bDataBits = 7;
                break;
        case CS8:
                ls.bDataBits = 8;
                break;
        }
 
        DPRINTF("rate=0x%08x fmt=%d parity=%d bits=%d\n",
            UGETDW(ls.dwDTERate), ls.bCharFormat,
            ls.bParityType, ls.bDataBits);
 
        req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
        req.bRequest = UCDC_SET_LINE_CODING;
        USETW(req.wValue, 0);
        req.wIndex[0] = sc->sc_data_iface_no;
        req.wIndex[1] = 0;
        USETW(req.wLength, UCDC_LINE_STATE_LENGTH);
 
        ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom, 
            &req, &ls, 0, 1000);
 
        if (t->c_cflag & CRTSCTS) {
                DPRINTF("crtscts = on\n");
 
                req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
                if (sc->sc_chiptype == TYPE_PL2303HXN) {
                        req.bRequest = UPLCOM_SET_REQUEST_PL2303HXN;
                        USETW(req.wValue, UPLCOM_CRTSCTS_REG_PL2303HXN);
                        USETW(req.wIndex, UPLCOM_SET_CRTSCTS_PL2303HXN);
                } else {
                        req.bRequest = UPLCOM_SET_REQUEST;
                        USETW(req.wValue, 0);
                        if (sc->sc_chiptype != TYPE_PL2303)
                                USETW(req.wIndex, UPLCOM_SET_CRTSCTS_PL2303X);
                        else
                                USETW(req.wIndex, UPLCOM_SET_CRTSCTS);
                }
                USETW(req.wLength, 0);
 
                ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom, 
                    &req, NULL, 0, 1000);
        } else {
                req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
                if (sc->sc_chiptype == TYPE_PL2303HXN) {
                        req.bRequest = UPLCOM_SET_REQUEST_PL2303HXN;
                        USETW(req.wValue, UPLCOM_CRTSCTS_REG_PL2303HXN);
                        USETW(req.wIndex, UPLCOM_CLEAR_CRTSCTS_PL2303HXN);
                }
                else {
                        req.bRequest = UPLCOM_SET_REQUEST;
                        USETW(req.wValue, 0);
                        USETW(req.wIndex, 0);
                }
                USETW(req.wLength, 0);
                ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom, 
                    &req, NULL, 0, 1000);
        }
}
 
static void
uplcom_start_read(struct ucom_softc *ucom)
{
        struct uplcom_softc *sc = ucom->sc_parent;
 
        /* start interrupt endpoint */
        usbd_transfer_start(sc->sc_xfer[UPLCOM_INTR_DT_RD]);
 
        /* start read endpoint */
        usbd_transfer_start(sc->sc_xfer[UPLCOM_BULK_DT_RD]);
}
 
static void
uplcom_stop_read(struct ucom_softc *ucom)
{
        struct uplcom_softc *sc = ucom->sc_parent;
 
        /* stop interrupt endpoint */
        usbd_transfer_stop(sc->sc_xfer[UPLCOM_INTR_DT_RD]);
 
        /* stop read endpoint */
        usbd_transfer_stop(sc->sc_xfer[UPLCOM_BULK_DT_RD]);
}
 
static void
uplcom_start_write(struct ucom_softc *ucom)
{
        struct uplcom_softc *sc = ucom->sc_parent;
 
        usbd_transfer_start(sc->sc_xfer[UPLCOM_BULK_DT_WR]);
}
 
static void
uplcom_stop_write(struct ucom_softc *ucom)
{
        struct uplcom_softc *sc = ucom->sc_parent;
 
        usbd_transfer_stop(sc->sc_xfer[UPLCOM_BULK_DT_WR]);
}
 
static void
uplcom_cfg_get_status(struct ucom_softc *ucom, uint8_t *lsr, uint8_t *msr)
{
        struct uplcom_softc *sc = ucom->sc_parent;
 
        DPRINTF("\n");
 
        *lsr = sc->sc_lsr;
        *msr = sc->sc_msr;
}
 
static void
uplcom_intr_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct uplcom_softc *sc = usbd_xfer_softc(xfer);
        struct usb_page_cache *pc;
        uint8_t buf[9];
        int actlen;
 
        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
 
        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
 
                DPRINTF("actlen = %u\n", actlen);
 
                if (actlen >= 9) {
                        pc = usbd_xfer_get_frame(xfer, 0);
                        usbd_copy_out(pc, 0, buf, sizeof(buf));
 
                        DPRINTF("status = 0x%02x\n", buf[UPLCOM_STATE_INDEX]);
 
                        sc->sc_lsr = 0;
                        sc->sc_msr = 0;
 
                        if (buf[UPLCOM_STATE_INDEX] & RSAQ_STATUS_CTS) {
                                sc->sc_msr |= SER_CTS;
                        }
                        if (buf[UPLCOM_STATE_INDEX] & RSAQ_STATUS_OVERRUN_ERROR) {
                                sc->sc_lsr |= ULSR_OE;
                        }
                        if (buf[UPLCOM_STATE_INDEX] & RSAQ_STATUS_PARITY_ERROR) {
                                sc->sc_lsr |= ULSR_PE;
                        }
                        if (buf[UPLCOM_STATE_INDEX] & RSAQ_STATUS_FRAME_ERROR) {
                                sc->sc_lsr |= ULSR_FE;
                        }
                        if (buf[UPLCOM_STATE_INDEX] & RSAQ_STATUS_RING) {
                                sc->sc_msr |= SER_RI;
                        }
                        if (buf[UPLCOM_STATE_INDEX] & RSAQ_STATUS_BREAK_ERROR) {
                                sc->sc_lsr |= ULSR_BI;
                        }
                        if (buf[UPLCOM_STATE_INDEX] & RSAQ_STATUS_DSR) {
                                sc->sc_msr |= SER_DSR;
                        }
                        if (buf[UPLCOM_STATE_INDEX] & RSAQ_STATUS_DCD) {
                                sc->sc_msr |= SER_DCD;
                        }
                        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
uplcom_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct uplcom_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,
                    UPLCOM_BULK_BUF_SIZE, &actlen)) {
                        DPRINTF("actlen = %d\n", 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
uplcom_read_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct uplcom_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
uplcom_poll(struct ucom_softc *ucom)
{
        struct uplcom_softc *sc = ucom->sc_parent;
        usbd_transfer_poll(sc->sc_xfer, UPLCOM_N_TRANSFER);
}