/*      $OpenBSD: uslcom.c,v 1.17 2007/11/24 10:52:12 jsg Exp $ */

/*
 * Copyright (c) 2006 Jonathan Gray <jsg@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * Driver for Silicon Laboratories CP2101/CP2102/CP2103/CP2104/CP2105
 * USB-Serial adapters.  Based on datasheet AN571, publicly available from
 * http://www.silabs.com/Support%20Documents/TechnicalDocs/AN571.pdf
 */

#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_ioctl.h>
#include "usbdevs.h"

#define USB_DEBUG_VAR uslcom_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 uslcom_debug = 0;

static SYSCTL_NODE(_hw_usb, OID_AUTO, uslcom, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "USB uslcom");
SYSCTL_INT(_hw_usb_uslcom, OID_AUTO, debug, CTLFLAG_RWTUN,
    &uslcom_debug, 0, "Debug level");
#endif

#define USLCOM_BULK_BUF_SIZE    1024
#define USLCOM_CONFIG_INDEX     0

/* Request types */
#define USLCOM_WRITE            0x41
#define USLCOM_READ             0xc1

/* Request codes */
#define USLCOM_IFC_ENABLE       0x00
#define USLCOM_SET_BAUDDIV      0x01
#define USLCOM_SET_LINE_CTL     0x03
#define USLCOM_SET_BREAK        0x05
#define USLCOM_SET_MHS          0x07
#define USLCOM_GET_MDMSTS       0x08
#define USLCOM_SET_FLOW         0x13
#define USLCOM_SET_BAUDRATE     0x1e
#define USLCOM_VENDOR_SPECIFIC  0xff

/* USLCOM_IFC_ENABLE values */
#define USLCOM_IFC_ENABLE_DIS   0x00
#define USLCOM_IFC_ENABLE_EN    0x01

/* USLCOM_SET_MHS/USLCOM_GET_MDMSTS values */
#define USLCOM_MHS_DTR_ON       0x0001
#define USLCOM_MHS_DTR_SET      0x0100
#define USLCOM_MHS_RTS_ON       0x0002
#define USLCOM_MHS_RTS_SET      0x0200
#define USLCOM_MHS_CTS          0x0010
#define USLCOM_MHS_DSR          0x0020
#define USLCOM_MHS_RI           0x0040
#define USLCOM_MHS_DCD          0x0080

/* USLCOM_SET_BAUDDIV values */
#define USLCOM_BAUDDIV_REF      3686400 /* 3.6864 MHz */

/* USLCOM_SET_LINE_CTL values */
#define USLCOM_STOP_BITS_1      0x00
#define USLCOM_STOP_BITS_2      0x02
#define USLCOM_PARITY_NONE      0x00
#define USLCOM_PARITY_ODD       0x10
#define USLCOM_PARITY_EVEN      0x20
#define USLCOM_SET_DATA_BITS(x) ((x) << 8)

/* USLCOM_SET_BREAK values */
#define USLCOM_SET_BREAK_OFF    0x00
#define USLCOM_SET_BREAK_ON     0x01

/* USLCOM_SET_FLOW values - 1st word */
#define USLCOM_FLOW_DTR_ON      0x00000001 /* DTR static active */
#define USLCOM_FLOW_CTS_HS      0x00000008 /* CTS handshake */
/* USLCOM_SET_FLOW values - 2nd word */
#define USLCOM_FLOW_RTS_ON      0x00000040 /* RTS static active */
#define USLCOM_FLOW_RTS_HS      0x00000080 /* RTS handshake */

/* USLCOM_VENDOR_SPECIFIC values */
#define USLCOM_GET_PARTNUM      0x370B
#define USLCOM_WRITE_LATCH      0x37E1
#define USLCOM_READ_LATCH       0x00C2

/* USLCOM_GET_PARTNUM values from hardware */
#define USLCOM_PARTNUM_CP2101   1
#define USLCOM_PARTNUM_CP2102   2
#define USLCOM_PARTNUM_CP2103   3
#define USLCOM_PARTNUM_CP2104   4
#define USLCOM_PARTNUM_CP2105   5

enum {
        USLCOM_BULK_DT_WR,
        USLCOM_BULK_DT_RD,
        USLCOM_CTRL_DT_RD,
        USLCOM_N_TRANSFER,
};

struct uslcom_softc {
        struct ucom_super_softc sc_super_ucom;
        struct ucom_softc sc_ucom;
        struct usb_callout sc_watchdog;

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

        uint8_t sc_msr;
        uint8_t sc_lsr;
        uint8_t sc_iface_no;
        uint8_t sc_partnum;
};

static device_probe_t uslcom_probe;
static device_attach_t uslcom_attach;
static device_detach_t uslcom_detach;
static void uslcom_free_softc(struct uslcom_softc *);

static usb_callback_t uslcom_write_callback;
static usb_callback_t uslcom_read_callback;
static usb_callback_t uslcom_control_callback;

static void uslcom_free(struct ucom_softc *);
static uint8_t uslcom_get_partnum(struct uslcom_softc *);
static void uslcom_cfg_open(struct ucom_softc *);
static void uslcom_cfg_close(struct ucom_softc *);
static void uslcom_cfg_set_dtr(struct ucom_softc *, uint8_t);
static void uslcom_cfg_set_rts(struct ucom_softc *, uint8_t);
static void uslcom_cfg_set_break(struct ucom_softc *, uint8_t);
static void uslcom_cfg_param(struct ucom_softc *, struct termios *);
static void uslcom_cfg_get_status(struct ucom_softc *, uint8_t *, uint8_t *);
static int uslcom_ioctl(struct ucom_softc *, uint32_t, caddr_t, int,
    struct thread *);
static int uslcom_pre_param(struct ucom_softc *, struct termios *);
static void uslcom_start_read(struct ucom_softc *);
static void uslcom_stop_read(struct ucom_softc *);
static void uslcom_start_write(struct ucom_softc *);
static void uslcom_stop_write(struct ucom_softc *);
static void uslcom_poll(struct ucom_softc *ucom);

static const struct usb_config uslcom_config[USLCOM_N_TRANSFER] = {
        [USLCOM_BULK_DT_WR] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_OUT,
                .bufsize = USLCOM_BULK_BUF_SIZE,
               .flags = {.pipe_bof = 1,},
                .callback = &uslcom_write_callback,
        },

        [USLCOM_BULK_DT_RD] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .bufsize = USLCOM_BULK_BUF_SIZE,
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
                .callback = &uslcom_read_callback,
        },
        [USLCOM_CTRL_DT_RD] = {
                .type = UE_CONTROL,
                .endpoint = 0x00,
                .direction = UE_DIR_ANY,
                .bufsize = sizeof(struct usb_device_request) + 8,
                .flags = {.pipe_bof = 1,},
                .callback = &uslcom_control_callback,
                .timeout = 1000,        /* 1 second timeout */
        },
};

static struct ucom_callback uslcom_callback = {
        .ucom_cfg_get_status = &uslcom_cfg_get_status,
        .ucom_cfg_set_dtr = &uslcom_cfg_set_dtr,
        .ucom_cfg_set_rts = &uslcom_cfg_set_rts,
        .ucom_cfg_set_break = &uslcom_cfg_set_break,
        .ucom_cfg_open = &uslcom_cfg_open,
        .ucom_cfg_close = &uslcom_cfg_close,
        .ucom_cfg_param = &uslcom_cfg_param,
        .ucom_pre_param = &uslcom_pre_param,
        .ucom_ioctl = &uslcom_ioctl,
        .ucom_start_read = &uslcom_start_read,
        .ucom_stop_read = &uslcom_stop_read,
        .ucom_start_write = &uslcom_start_write,
        .ucom_stop_write = &uslcom_stop_write,
        .ucom_poll = &uslcom_poll,
        .ucom_free = &uslcom_free,
};

static const STRUCT_USB_HOST_ID uslcom_devs[] = {
#define USLCOM_DEV(v,p)  { USB_VP(USB_VENDOR_##v, USB_PRODUCT_##v##_##p) }
    USLCOM_DEV(BALTECH, CARDREADER),
    USLCOM_DEV(CLIPSAL, 5000CT2),
    USLCOM_DEV(CLIPSAL, 5500PACA),
    USLCOM_DEV(CLIPSAL, 5500PCU),
    USLCOM_DEV(CLIPSAL, 560884),
    USLCOM_DEV(CLIPSAL, 5800PC),
    USLCOM_DEV(CLIPSAL, C5000CT2),
    USLCOM_DEV(CLIPSAL, L51xx),
    USLCOM_DEV(DATAAPEX, MULTICOM),
    USLCOM_DEV(DELL, DW700),
    USLCOM_DEV(DIGIANSWER, ZIGBEE802154),
    USLCOM_DEV(DYNASTREAM, ANTDEVBOARD),
    USLCOM_DEV(DYNASTREAM, ANTDEVBOARD2),
    USLCOM_DEV(DYNASTREAM, ANT2USB),
    USLCOM_DEV(ELV, USBI2C),
    USLCOM_DEV(FESTO, CMSP),
    USLCOM_DEV(FESTO, CPX_USB),
    USLCOM_DEV(FOXCONN, PIRELLI_DP_L10),
    USLCOM_DEV(FOXCONN, TCOM_TC_300),
    USLCOM_DEV(GEMALTO, PROXPU),
    USLCOM_DEV(JABLOTRON, PC60B),
    USLCOM_DEV(KAMSTRUP, OPTICALEYE),
    USLCOM_DEV(KAMSTRUP, MBUS_250D),
    USLCOM_DEV(LAKESHORE, 121),
    USLCOM_DEV(LAKESHORE, 218A),
    USLCOM_DEV(LAKESHORE, 219),
    USLCOM_DEV(LAKESHORE, 233),
    USLCOM_DEV(LAKESHORE, 235),
    USLCOM_DEV(LAKESHORE, 335),
    USLCOM_DEV(LAKESHORE, 336),
    USLCOM_DEV(LAKESHORE, 350),
    USLCOM_DEV(LAKESHORE, 371),
    USLCOM_DEV(LAKESHORE, 411),
    USLCOM_DEV(LAKESHORE, 425),
    USLCOM_DEV(LAKESHORE, 455A),
    USLCOM_DEV(LAKESHORE, 465),
    USLCOM_DEV(LAKESHORE, 475A),
    USLCOM_DEV(LAKESHORE, 625A),
    USLCOM_DEV(LAKESHORE, 642A),
    USLCOM_DEV(LAKESHORE, 648),
    USLCOM_DEV(LAKESHORE, 737),
    USLCOM_DEV(LAKESHORE, 776),
    USLCOM_DEV(LINKINSTRUMENTS, MSO19),
    USLCOM_DEV(LINKINSTRUMENTS, MSO28),
    USLCOM_DEV(LINKINSTRUMENTS, MSO28_2),
    USLCOM_DEV(MEI, CASHFLOW_SC),
    USLCOM_DEV(MEI, S2000),
    USLCOM_DEV(NETGEAR, M4100),
    USLCOM_DEV(OWEN, AC4),
    USLCOM_DEV(OWL, CM_160),
    USLCOM_DEV(PHILIPS, ACE1001),
    USLCOM_DEV(PLX, CA42),
    USLCOM_DEV(RENESAS, RX610),
    USLCOM_DEV(SEL, C662),
    USLCOM_DEV(SILABS, AC_SERV_CAN),
    USLCOM_DEV(SILABS, AC_SERV_CIS),
    USLCOM_DEV(SILABS, AC_SERV_IBUS),
    USLCOM_DEV(SILABS, AC_SERV_OBD),
    USLCOM_DEV(SILABS, AEROCOMM),
    USLCOM_DEV(SILABS, AMBER_AMB2560),
    USLCOM_DEV(SILABS, ARGUSISP),
    USLCOM_DEV(SILABS, ARKHAM_DS101_A),
    USLCOM_DEV(SILABS, ARKHAM_DS101_M),
    USLCOM_DEV(SILABS, ARYGON_MIFARE),
    USLCOM_DEV(SILABS, AVIT_USB_TTL),
    USLCOM_DEV(SILABS, B_G_H3000),
    USLCOM_DEV(SILABS, BALLUFF_RFID),
    USLCOM_DEV(SILABS, BEI_VCP),
    USLCOM_DEV(SILABS, BSM7DUSB),
    USLCOM_DEV(SILABS, BURNSIDE),
    USLCOM_DEV(SILABS, C2_EDGE_MODEM),
    USLCOM_DEV(SILABS, CP2102),
    USLCOM_DEV(SILABS, CP210X_2),
    USLCOM_DEV(SILABS, CP210X_3),
    USLCOM_DEV(SILABS, CP210X_4),
    USLCOM_DEV(SILABS, CRUMB128),
    USLCOM_DEV(SILABS, CYGNAL),
    USLCOM_DEV(SILABS, CYGNAL_DEBUG),
    USLCOM_DEV(SILABS, CYGNAL_GPS),
    USLCOM_DEV(SILABS, DEGREE),
    USLCOM_DEV(SILABS, DEKTEK_DTAPLUS),
    USLCOM_DEV(SILABS, EMS_C1007),
    USLCOM_DEV(SILABS, HAMLINKUSB),
    USLCOM_DEV(SILABS, HELICOM),
    USLCOM_DEV(SILABS, HUBZ),
    USLCOM_DEV(SILABS, BV_AV2010_10),
    USLCOM_DEV(SILABS, IMS_USB_RS422),
    USLCOM_DEV(SILABS, INFINITY_MIC),
    USLCOM_DEV(SILABS, INGENI_ZIGBEE),
    USLCOM_DEV(SILABS, INSYS_MODEM),
    USLCOM_DEV(SILABS, IRZ_SG10),
    USLCOM_DEV(SILABS, KYOCERA_GPS),
    USLCOM_DEV(SILABS, LIPOWSKY_HARP),
    USLCOM_DEV(SILABS, LIPOWSKY_JTAG),
    USLCOM_DEV(SILABS, LIPOWSKY_LIN),
    USLCOM_DEV(SILABS, MC35PU),
    USLCOM_DEV(SILABS, MMB_ZIGBEE),
    USLCOM_DEV(SILABS, MJS_TOSLINK),
    USLCOM_DEV(SILABS, MSD_DASHHAWK),
    USLCOM_DEV(SILABS, MULTIPLEX_RC),
    USLCOM_DEV(SILABS, OPTRIS_MSPRO),
    USLCOM_DEV(SILABS, POLOLU),
    USLCOM_DEV(SILABS, PROCYON_AVS),
    USLCOM_DEV(SILABS, SB_PARAMOUNT_ME),
    USLCOM_DEV(SILABS, SUUNTO),
    USLCOM_DEV(SILABS, TAMSMASTER),
    USLCOM_DEV(SILABS, TELEGESIS_ETRX2),
    USLCOM_DEV(SILABS, TRACIENT),
    USLCOM_DEV(SILABS, TRAQMATE),
    USLCOM_DEV(SILABS, USBCOUNT50),
    USLCOM_DEV(SILABS, USBPULSE100),
    USLCOM_DEV(SILABS, USBSCOPE50),
    USLCOM_DEV(SILABS, USBWAVE12),
    USLCOM_DEV(SILABS, V_PREON32),
    USLCOM_DEV(SILABS, VSTABI),
    USLCOM_DEV(SILABS, WAVIT),
    USLCOM_DEV(SILABS, WMRBATT),
    USLCOM_DEV(SILABS, WMRRIGBLASTER),
    USLCOM_DEV(SILABS, WMRRIGTALK),
    USLCOM_DEV(SILABS, ZEPHYR_BIO),
    USLCOM_DEV(SILABS2, DCU11CLONE),
    USLCOM_DEV(SILABS3, GPRS_MODEM),
    USLCOM_DEV(SILABS4, 100EU_MODEM),
    USLCOM_DEV(SYNTECH, CYPHERLAB100),
    USLCOM_DEV(USI, MC60),
    USLCOM_DEV(VAISALA, CABLE),
    USLCOM_DEV(WAGO, SERVICECABLE),
    USLCOM_DEV(WAVESENSE, JAZZ),
    USLCOM_DEV(WESTMOUNTAIN, RIGBLASTER_ADVANTAGE),
    USLCOM_DEV(WIENERPLEINBAUS, PL512),
    USLCOM_DEV(WIENERPLEINBAUS, RCM),
    USLCOM_DEV(WIENERPLEINBAUS, MPOD),
    USLCOM_DEV(WIENERPLEINBAUS, CML),
#undef USLCOM_DEV
};

static device_method_t uslcom_methods[] = {
        DEVMETHOD(device_probe, uslcom_probe),
        DEVMETHOD(device_attach, uslcom_attach),
        DEVMETHOD(device_detach, uslcom_detach),
        DEVMETHOD_END
};

static driver_t uslcom_driver = {
        .name = "uslcom",
        .methods = uslcom_methods,
        .size = sizeof(struct uslcom_softc),
};

DRIVER_MODULE(uslcom, uhub, uslcom_driver, NULL, NULL);
MODULE_DEPEND(uslcom, ucom, 1, 1, 1);
MODULE_DEPEND(uslcom, usb, 1, 1, 1);
MODULE_VERSION(uslcom, 1);
USB_PNP_HOST_INFO(uslcom_devs);

static void
uslcom_watchdog(void *arg)
{
        struct uslcom_softc *sc = arg;

        mtx_assert(&sc->sc_mtx, MA_OWNED);

        usbd_transfer_start(sc->sc_xfer[USLCOM_CTRL_DT_RD]);

        usb_callout_reset(&sc->sc_watchdog,
            hz / 4, &uslcom_watchdog, sc);
}

static int
uslcom_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 != USLCOM_CONFIG_INDEX) {
                return (ENXIO);
        }
        return (usbd_lookup_id_by_uaa(uslcom_devs, sizeof(uslcom_devs), uaa));
}

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

        DPRINTFN(11, "\n");

        device_set_usb_desc(dev);
        mtx_init(&sc->sc_mtx, "uslcom", NULL, MTX_DEF);
        ucom_ref(&sc->sc_super_ucom);
        usb_callout_init_mtx(&sc->sc_watchdog, &sc->sc_mtx, 0);

        sc->sc_udev = uaa->device;
        /* use the interface number from the USB interface descriptor */
        sc->sc_iface_no = uaa->info.bIfaceNum;

        error = usbd_transfer_setup(uaa->device,
            &uaa->info.bIfaceIndex, sc->sc_xfer, uslcom_config,
            USLCOM_N_TRANSFER, sc, &sc->sc_mtx);
        if (error) {
                DPRINTF("one or more missing USB endpoints, "
                    "error=%s\n", usbd_errstr(error));
                goto detach;
        }
        sc->sc_partnum = uslcom_get_partnum(sc);

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

        return (0);

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

static int
uslcom_detach(device_t dev)
{
        struct uslcom_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, USLCOM_N_TRANSFER);

        usb_callout_drain(&sc->sc_watchdog);

        device_claim_softc(dev);

        uslcom_free_softc(sc);

        return (0);
}

UCOM_UNLOAD_DRAIN(uslcom);

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

static void
uslcom_free(struct ucom_softc *ucom)
{
        uslcom_free_softc(ucom->sc_parent);
}

static void
uslcom_cfg_open(struct ucom_softc *ucom)
{
        struct uslcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;

        req.bmRequestType = USLCOM_WRITE;
        req.bRequest = USLCOM_IFC_ENABLE;
        USETW(req.wValue, USLCOM_IFC_ENABLE_EN);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, 0);

        if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
            &req, NULL, 0, 1000)) {
                DPRINTF("UART enable failed (ignored)\n");
        }

        /* clear stall */
        usbd_xfer_set_stall(sc->sc_xfer[USLCOM_BULK_DT_WR]);
        usbd_xfer_set_stall(sc->sc_xfer[USLCOM_BULK_DT_RD]);

        /* start polling status */
        uslcom_watchdog(sc);
}

static void
uslcom_cfg_close(struct ucom_softc *ucom)
{
        struct uslcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;

        /* stop polling status */
        usb_callout_stop(&sc->sc_watchdog);

        req.bmRequestType = USLCOM_WRITE;
        req.bRequest = USLCOM_IFC_ENABLE;
        USETW(req.wValue, USLCOM_IFC_ENABLE_DIS);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, 0);

        if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
            &req, NULL, 0, 1000)) {
                DPRINTF("UART disable failed (ignored)\n");
        }
}

static uint8_t
uslcom_get_partnum(struct uslcom_softc *sc)
{
        struct usb_device_request req;
        uint8_t partnum;

        /* Find specific chip type */
        partnum = 0;
        req.bmRequestType = USLCOM_READ;
        req.bRequest = USLCOM_VENDOR_SPECIFIC;
        USETW(req.wValue, USLCOM_GET_PARTNUM);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, sizeof(partnum));

        if (usbd_do_request_flags(sc->sc_udev, NULL,
            &req, &partnum, 0, NULL, 1000)) {
                DPRINTF("GET_PARTNUM failed\n");
        }

        return(partnum);
}

static void
uslcom_cfg_set_dtr(struct ucom_softc *ucom, uint8_t onoff)
{
        struct uslcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;
        uint16_t ctl;

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

        ctl = onoff ? USLCOM_MHS_DTR_ON : 0;
        ctl |= USLCOM_MHS_DTR_SET;

        req.bmRequestType = USLCOM_WRITE;
        req.bRequest = USLCOM_SET_MHS;
        USETW(req.wValue, ctl);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, 0);

        if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
            &req, NULL, 0, 1000)) {
                DPRINTF("Setting DTR failed (ignored)\n");
        }
}

static void
uslcom_cfg_set_rts(struct ucom_softc *ucom, uint8_t onoff)
{
        struct uslcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;
        uint16_t ctl;

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

        ctl = onoff ? USLCOM_MHS_RTS_ON : 0;
        ctl |= USLCOM_MHS_RTS_SET;

        req.bmRequestType = USLCOM_WRITE;
        req.bRequest = USLCOM_SET_MHS;
        USETW(req.wValue, ctl);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, 0);

        if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
            &req, NULL, 0, 1000)) {
                DPRINTF("Setting DTR failed (ignored)\n");
        }
}

static int
uslcom_pre_param(struct ucom_softc *ucom, struct termios *t)
{
        struct uslcom_softc *sc = ucom->sc_parent;
        uint32_t maxspeed;

        switch (sc->sc_partnum) {
        case USLCOM_PARTNUM_CP2104:
        case USLCOM_PARTNUM_CP2105:
                maxspeed = 2000000;
                break;
        case USLCOM_PARTNUM_CP2101:
        case USLCOM_PARTNUM_CP2102:
        case USLCOM_PARTNUM_CP2103:
        default:
                /*
                 * Datasheet for cp2102 says 921600 max.  Testing shows that
                 * 1228800 and 1843200 work fine.
                 */
                maxspeed = 1843200;
                break;
        }
        if (t->c_ospeed <= 0 || t->c_ospeed > maxspeed)
                return (EINVAL);
        return (0);
}

static void
uslcom_cfg_param(struct ucom_softc *ucom, struct termios *t)
{
        struct uslcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;
        uint32_t baudrate, flowctrl[4];
        uint16_t data;

        DPRINTF("\n");

        baudrate = t->c_ospeed;
        req.bmRequestType = USLCOM_WRITE;
        req.bRequest = USLCOM_SET_BAUDRATE;
        USETW(req.wValue, 0);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, sizeof(baudrate));

        if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
            &req, &baudrate, 0, 1000)) {
                printf("Set baudrate failed (ignored)\n");
        }

        if (t->c_cflag & CSTOPB)
                data = USLCOM_STOP_BITS_2;
        else
                data = USLCOM_STOP_BITS_1;
        if (t->c_cflag & PARENB) {
                if (t->c_cflag & PARODD)
                        data |= USLCOM_PARITY_ODD;
                else
                        data |= USLCOM_PARITY_EVEN;
        } else
                data |= USLCOM_PARITY_NONE;
        switch (t->c_cflag & CSIZE) {
        case CS5:
                data |= USLCOM_SET_DATA_BITS(5);
                break;
        case CS6:
                data |= USLCOM_SET_DATA_BITS(6);
                break;
        case CS7:
                data |= USLCOM_SET_DATA_BITS(7);
                break;
        case CS8:
                data |= USLCOM_SET_DATA_BITS(8);
                break;
        }

        req.bmRequestType = USLCOM_WRITE;
        req.bRequest = USLCOM_SET_LINE_CTL;
        USETW(req.wValue, data);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, 0);

        if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
            &req, NULL, 0, 1000)) {
                DPRINTF("Set format failed (ignored)\n");
        }

        if (t->c_cflag & CRTSCTS) {
                flowctrl[0] = htole32(USLCOM_FLOW_DTR_ON | USLCOM_FLOW_CTS_HS);
                flowctrl[1] = htole32(USLCOM_FLOW_RTS_HS);
        } else {
                flowctrl[0] = htole32(USLCOM_FLOW_DTR_ON);
                flowctrl[1] = htole32(USLCOM_FLOW_RTS_ON);
        }
        flowctrl[2] = 0;
        flowctrl[3] = 0;
        req.bmRequestType = USLCOM_WRITE;
        req.bRequest = USLCOM_SET_FLOW;
        USETW(req.wValue, 0);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, sizeof(flowctrl));

        if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
            &req, flowctrl, 0, 1000)) {
                DPRINTF("Set flowcontrol failed (ignored)\n");
        }
}

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

        DPRINTF("\n");

        /* XXX Note: sc_lsr is always zero */
        *lsr = sc->sc_lsr;
        *msr = sc->sc_msr;
}

static void
uslcom_cfg_set_break(struct ucom_softc *ucom, uint8_t onoff)
{
        struct uslcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;
        uint16_t brk = onoff ? USLCOM_SET_BREAK_ON : USLCOM_SET_BREAK_OFF;

        req.bmRequestType = USLCOM_WRITE;
        req.bRequest = USLCOM_SET_BREAK;
        USETW(req.wValue, brk);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, 0);

        if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
            &req, NULL, 0, 1000)) {
                DPRINTF("Set BREAK failed (ignored)\n");
        }
}

static int
uslcom_ioctl(struct ucom_softc *ucom, uint32_t cmd, caddr_t data,
    int flag, struct thread *td)
{
        struct uslcom_softc *sc = ucom->sc_parent;
        struct usb_device_request req;
        int error = 0;
        uint8_t latch;

        DPRINTF("cmd=0x%08x\n", cmd);

        switch (cmd) {
        case USB_GET_GPIO:
                if (sc->sc_partnum < USLCOM_PARTNUM_CP2103) {
                        error = ENODEV;
                        break;
                }
                req.bmRequestType = USLCOM_READ;
                req.bRequest = USLCOM_VENDOR_SPECIFIC;
                USETW(req.wValue, USLCOM_READ_LATCH);
                USETW(req.wIndex, sc->sc_iface_no);
                USETW(req.wLength, sizeof(latch));

                if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
                    &req, &latch, 0, 1000)) {
                        DPRINTF("Get LATCH failed\n");
                        error = EIO;
                }
                *(int *)data = latch;
                break;

        case USB_SET_GPIO:
                if (sc->sc_partnum < USLCOM_PARTNUM_CP2103)
                        error = ENODEV;
                else if ((sc->sc_partnum == USLCOM_PARTNUM_CP2103) ||
                    (sc->sc_partnum == USLCOM_PARTNUM_CP2104)) {
                        req.bmRequestType = USLCOM_WRITE;
                        req.bRequest = USLCOM_VENDOR_SPECIFIC;
                        USETW(req.wValue, USLCOM_WRITE_LATCH);
                        USETW(req.wIndex, (*(int *)data));
                        USETW(req.wLength, 0);

                        if (ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
                            &req, NULL, 0, 1000)) {
                                DPRINTF("Set LATCH failed\n");
                                error = EIO;
                        }
                } else
                        error = ENODEV; /* Not yet */
                break;

        default:
                DPRINTF("Unknown IOCTL\n");
                error = ENOIOCTL;
                break;
        }
        return (error);
}

static void
uslcom_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct uslcom_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,
                    USLCOM_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
uslcom_read_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct uslcom_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
uslcom_control_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct uslcom_softc *sc = usbd_xfer_softc(xfer);
        struct usb_page_cache *pc;
        struct usb_device_request req;
        uint8_t msr = 0;
        uint8_t buf;

        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
                pc = usbd_xfer_get_frame(xfer, 1);
                usbd_copy_out(pc, 0, &buf, sizeof(buf));
                if (buf & USLCOM_MHS_CTS)
                        msr |= SER_CTS;
                if (buf & USLCOM_MHS_DSR)
                        msr |= SER_DSR;
                if (buf & USLCOM_MHS_RI)
                        msr |= SER_RI;
                if (buf & USLCOM_MHS_DCD)
                        msr |= SER_DCD;

                if (msr != sc->sc_msr) {
                        DPRINTF("status change msr=0x%02x "
                            "(was 0x%02x)\n", msr, sc->sc_msr);
                        sc->sc_msr = msr;
                        ucom_status_change(&sc->sc_ucom);
                }
                break;

        case USB_ST_SETUP:
                req.bmRequestType = USLCOM_READ;
                req.bRequest = USLCOM_GET_MDMSTS;
                USETW(req.wValue, 0);
                USETW(req.wIndex, sc->sc_iface_no);
                USETW(req.wLength, sizeof(buf));

                usbd_xfer_set_frames(xfer, 2);
                usbd_xfer_set_frame_len(xfer, 0, sizeof(req));
                usbd_xfer_set_frame_len(xfer, 1, sizeof(buf));

                pc = usbd_xfer_get_frame(xfer, 0);
                usbd_copy_in(pc, 0, &req, sizeof(req));
                usbd_transfer_submit(xfer);
                break;

        default:                /* error */
                if (error != USB_ERR_CANCELLED)
                        DPRINTF("error=%s\n", usbd_errstr(error));
                break;
        }
}

static void
uslcom_start_read(struct ucom_softc *ucom)
{
        struct uslcom_softc *sc = ucom->sc_parent;

        /* start read endpoint */
        usbd_transfer_start(sc->sc_xfer[USLCOM_BULK_DT_RD]);
}

static void
uslcom_stop_read(struct ucom_softc *ucom)
{
        struct uslcom_softc *sc = ucom->sc_parent;

        /* stop read endpoint */
        usbd_transfer_stop(sc->sc_xfer[USLCOM_BULK_DT_RD]);
}

static void
uslcom_start_write(struct ucom_softc *ucom)
{
        struct uslcom_softc *sc = ucom->sc_parent;

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

static void
uslcom_stop_write(struct ucom_softc *ucom)
{
        struct uslcom_softc *sc = ucom->sc_parent;

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

static void
uslcom_poll(struct ucom_softc *ucom)
{
        struct uslcom_softc *sc = ucom->sc_parent;
        usbd_transfer_poll(sc->sc_xfer, USLCOM_N_TRANSFER);
}