ulpt.c

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#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
 
/*      $NetBSD: ulpt.c,v 1.60 2003/10/04 21:19:50 augustss Exp $       */
 
/*-
 * SPDX-License-Identifier: BSD-2-Clause-NetBSD
 *
 * Copyright (c) 1998, 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson (lennart@augustsson.net) at
 * Carlstedt Research & Technology.
 *
 * 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.
 */
 
/*
 * Printer Class spec: http://www.usb.org/developers/data/devclass/usbprint109.PDF
 * Printer Class spec: http://www.usb.org/developers/devclass_docs/usbprint11.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 <sys/syslog.h>
#include <sys/selinfo.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
 
#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
#include <dev/usb/usbhid.h>
#include "usbdevs.h"
 
#define USB_DEBUG_VAR ulpt_debug
#include <dev/usb/usb_debug.h>
#include <dev/usb/usb_process.h>
 
#ifdef USB_DEBUG
static int ulpt_debug = 0;
 
static SYSCTL_NODE(_hw_usb, OID_AUTO, ulpt, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "USB ulpt");
SYSCTL_INT(_hw_usb_ulpt, OID_AUTO, debug, CTLFLAG_RWTUN,
    &ulpt_debug, 0, "Debug level");
#endif
 
#define ULPT_BSIZE              (1<<15) /* bytes */
#define ULPT_IFQ_MAXLEN         2       /* units */
 
#define UR_GET_DEVICE_ID        0x00
#define UR_GET_PORT_STATUS      0x01
#define UR_SOFT_RESET           0x02
 
#define LPS_NERR                0x08    /* printer no error */
#define LPS_SELECT              0x10    /* printer selected */
#define LPS_NOPAPER             0x20    /* printer out of paper */
#define LPS_INVERT      (LPS_SELECT|LPS_NERR)
#define LPS_MASK        (LPS_SELECT|LPS_NERR|LPS_NOPAPER)
 
enum {
        ULPT_BULK_DT_WR,
        ULPT_BULK_DT_RD,
        ULPT_INTR_DT_RD,
        ULPT_N_TRANSFER,
};
 
struct ulpt_softc {
        struct usb_fifo_sc sc_fifo;
        struct usb_fifo_sc sc_fifo_noreset;
        struct mtx sc_mtx;
        struct usb_callout sc_watchdog;
 
        device_t sc_dev;
        struct usb_device *sc_udev;
        struct usb_fifo *sc_fifo_open[2];
        struct usb_xfer *sc_xfer[ULPT_N_TRANSFER];
 
        int     sc_fflags;              /* current open flags, FREAD and
                                         * FWRITE */
        uint8_t sc_iface_no;
        uint8_t sc_last_status;
        uint8_t sc_zlps;                /* number of consequtive zero length
                                         * packets received */
};
 
/* prototypes */
 
static device_probe_t ulpt_probe;
static device_attach_t ulpt_attach;
static device_detach_t ulpt_detach;
 
static usb_callback_t ulpt_write_callback;
static usb_callback_t ulpt_read_callback;
static usb_callback_t ulpt_status_callback;
 
static void     ulpt_reset(struct ulpt_softc *);
static void     ulpt_watchdog(void *);
 
static usb_fifo_close_t ulpt_close;
static usb_fifo_cmd_t ulpt_start_read;
static usb_fifo_cmd_t ulpt_start_write;
static usb_fifo_cmd_t ulpt_stop_read;
static usb_fifo_cmd_t ulpt_stop_write;
static usb_fifo_ioctl_t ulpt_ioctl;
static usb_fifo_open_t ulpt_open;
static usb_fifo_open_t unlpt_open;
 
static struct usb_fifo_methods ulpt_fifo_methods = {
        .f_close = &ulpt_close,
        .f_ioctl = &ulpt_ioctl,
        .f_open = &ulpt_open,
        .f_start_read = &ulpt_start_read,
        .f_start_write = &ulpt_start_write,
        .f_stop_read = &ulpt_stop_read,
        .f_stop_write = &ulpt_stop_write,
        .basename[0] = "ulpt",
};
 
static struct usb_fifo_methods unlpt_fifo_methods = {
        .f_close = &ulpt_close,
        .f_ioctl = &ulpt_ioctl,
        .f_open = &unlpt_open,
        .f_start_read = &ulpt_start_read,
        .f_start_write = &ulpt_start_write,
        .f_stop_read = &ulpt_stop_read,
        .f_stop_write = &ulpt_stop_write,
        .basename[0] = "unlpt",
};
 
static void
ulpt_reset(struct ulpt_softc *sc)
{
        struct usb_device_request req;
 
        DPRINTFN(2, "\n");
 
        req.bRequest = UR_SOFT_RESET;
        USETW(req.wValue, 0);
        USETW(req.wIndex, sc->sc_iface_no);
        USETW(req.wLength, 0);
 
        /*
         * There was a mistake in the USB printer 1.0 spec that gave the
         * request type as UT_WRITE_CLASS_OTHER; it should have been
         * UT_WRITE_CLASS_INTERFACE.  Many printers use the old one,
         * so we try both.
         */
 
        mtx_lock(&sc->sc_mtx);
        req.bmRequestType = UT_WRITE_CLASS_OTHER;
        if (usbd_do_request_flags(sc->sc_udev, &sc->sc_mtx,
            &req, NULL, 0, NULL, 2 * USB_MS_HZ)) {      /* 1.0 */
                req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
                if (usbd_do_request_flags(sc->sc_udev, &sc->sc_mtx,
                    &req, NULL, 0, NULL, 2 * USB_MS_HZ)) {      /* 1.1 */
                        /* ignore error */
                }
        }
        mtx_unlock(&sc->sc_mtx);
}
 
static void
ulpt_write_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct ulpt_softc *sc = usbd_xfer_softc(xfer);
        struct usb_fifo *f = sc->sc_fifo_open[USB_FIFO_TX];
        struct usb_page_cache *pc;
        int actlen, max;
 
        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
 
        if (f == NULL) {
                /* should not happen */
                DPRINTF("no FIFO\n");
                return;
        }
        DPRINTF("state=0x%x actlen=%d\n", USB_GET_STATE(xfer), actlen);
 
        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
        case USB_ST_SETUP:
tr_setup:
                pc = usbd_xfer_get_frame(xfer, 0);
                max = usbd_xfer_max_len(xfer);
                if (usb_fifo_get_data(f, pc, 0, max, &actlen, 0)) {
                        usbd_xfer_set_frame_len(xfer, 0, actlen);
                        usbd_transfer_submit(xfer);
                }
                break;
 
        default:                        /* Error */
                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                break;
        }
}
 
static void
ulpt_read_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct ulpt_softc *sc = usbd_xfer_softc(xfer);
        struct usb_fifo *f = sc->sc_fifo_open[USB_FIFO_RX];
        struct usb_page_cache *pc;
        int actlen;
 
        usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
 
        if (f == NULL) {
                /* should not happen */
                DPRINTF("no FIFO\n");
                return;
        }
        DPRINTF("state=0x%x\n", USB_GET_STATE(xfer));
 
        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
 
                if (actlen == 0) {
                        if (sc->sc_zlps == 4) {
                                /* enable BULK throttle */
                                usbd_xfer_set_interval(xfer, 500); /* ms */
                        } else {
                                sc->sc_zlps++;
                        }
                } else {
                        /* disable BULK throttle */
 
                        usbd_xfer_set_interval(xfer, 0);
                        sc->sc_zlps = 0;
                }
 
                pc = usbd_xfer_get_frame(xfer, 0);
                usb_fifo_put_data(f, pc, 0, actlen, 1);
 
        case USB_ST_SETUP:
tr_setup:
                if (usb_fifo_put_bytes_max(f) != 0) {
                        usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
                        usbd_transfer_submit(xfer);
                }
                break;
 
        default:                        /* Error */
                /* disable BULK throttle */
                usbd_xfer_set_interval(xfer, 0);
                sc->sc_zlps = 0;
 
                if (error != USB_ERR_CANCELLED) {
                        /* try to clear stall first */
                        usbd_xfer_set_stall(xfer);
                        goto tr_setup;
                }
                break;
        }
}
 
static void
ulpt_status_callback(struct usb_xfer *xfer, usb_error_t error)
{
        struct ulpt_softc *sc = usbd_xfer_softc(xfer);
        struct usb_device_request req;
        struct usb_page_cache *pc;
        uint8_t cur_status;
        uint8_t new_status;
 
        switch (USB_GET_STATE(xfer)) {
        case USB_ST_TRANSFERRED:
 
                pc = usbd_xfer_get_frame(xfer, 1);
                usbd_copy_out(pc, 0, &cur_status, 1);
 
                cur_status = (cur_status ^ LPS_INVERT) & LPS_MASK;
                new_status = cur_status & ~sc->sc_last_status;
                sc->sc_last_status = cur_status;
 
                if (new_status & LPS_SELECT)
                        log(LOG_NOTICE, "%s: offline\n",
                            device_get_nameunit(sc->sc_dev));
                else if (new_status & LPS_NOPAPER)
                        log(LOG_NOTICE, "%s: out of paper\n",
                            device_get_nameunit(sc->sc_dev));
                else if (new_status & LPS_NERR)
                        log(LOG_NOTICE, "%s: output error\n",
                            device_get_nameunit(sc->sc_dev));
                break;
 
        case USB_ST_SETUP:
                req.bmRequestType = UT_READ_CLASS_INTERFACE;
                req.bRequest = UR_GET_PORT_STATUS;
                USETW(req.wValue, 0);
                req.wIndex[0] = sc->sc_iface_no;
                req.wIndex[1] = 0;
                USETW(req.wLength, 1);
 
                pc = usbd_xfer_get_frame(xfer, 0);
                usbd_copy_in(pc, 0, &req, sizeof(req));
 
                usbd_xfer_set_frame_len(xfer, 0, sizeof(req));
                usbd_xfer_set_frame_len(xfer, 1, 1);
                usbd_xfer_set_frames(xfer, 2);
                usbd_transfer_submit(xfer);
                break;
 
        default:                        /* Error */
                DPRINTF("error=%s\n", usbd_errstr(error));
                if (error != USB_ERR_CANCELLED) {
                        /* wait for next watchdog timeout */
                }
                break;
        }
}
 
static const struct usb_config ulpt_config[ULPT_N_TRANSFER] = {
        [ULPT_BULK_DT_WR] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_OUT,
                .bufsize = ULPT_BSIZE,
                .flags = {.pipe_bof = 1,.proxy_buffer = 1},
                .callback = &ulpt_write_callback,
        },
 
        [ULPT_BULK_DT_RD] = {
                .type = UE_BULK,
                .endpoint = UE_ADDR_ANY,
                .direction = UE_DIR_IN,
                .bufsize = ULPT_BSIZE,
                .flags = {.pipe_bof = 1,.short_xfer_ok = 1,.proxy_buffer = 1},
                .callback = &ulpt_read_callback,
        },
 
        [ULPT_INTR_DT_RD] = {
                .type = UE_CONTROL,
                .endpoint = 0x00,       /* Control pipe */
                .direction = UE_DIR_ANY,
                .bufsize = sizeof(struct usb_device_request) + 1,
                .callback = &ulpt_status_callback,
                .timeout = 1000,        /* 1 second */
        },
};
 
static void
ulpt_start_read(struct usb_fifo *fifo)
{
        struct ulpt_softc *sc = usb_fifo_softc(fifo);
 
        usbd_transfer_start(sc->sc_xfer[ULPT_BULK_DT_RD]);
}
 
static void
ulpt_stop_read(struct usb_fifo *fifo)
{
        struct ulpt_softc *sc = usb_fifo_softc(fifo);
 
        usbd_transfer_stop(sc->sc_xfer[ULPT_BULK_DT_RD]);
}
 
static void
ulpt_start_write(struct usb_fifo *fifo)
{
        struct ulpt_softc *sc = usb_fifo_softc(fifo);
 
        usbd_transfer_start(sc->sc_xfer[ULPT_BULK_DT_WR]);
}
 
static void
ulpt_stop_write(struct usb_fifo *fifo)
{
        struct ulpt_softc *sc = usb_fifo_softc(fifo);
 
        usbd_transfer_stop(sc->sc_xfer[ULPT_BULK_DT_WR]);
}
 
static int
ulpt_open(struct usb_fifo *fifo, int fflags)
{
        struct ulpt_softc *sc = usb_fifo_softc(fifo);
 
        /* we assume that open is a serial process */
 
        if (sc->sc_fflags == 0) {
                /* reset USB parallel port */
 
                ulpt_reset(sc);
        }
        return (unlpt_open(fifo, fflags));
}
 
static int
unlpt_open(struct usb_fifo *fifo, int fflags)
{
        struct ulpt_softc *sc = usb_fifo_softc(fifo);
 
        if (sc->sc_fflags & fflags) {
                return (EBUSY);
        }
        if (fflags & FREAD) {
                /* clear stall first */
                mtx_lock(&sc->sc_mtx);
                usbd_xfer_set_stall(sc->sc_xfer[ULPT_BULK_DT_RD]);
                mtx_unlock(&sc->sc_mtx);
                if (usb_fifo_alloc_buffer(fifo,
                    usbd_xfer_max_len(sc->sc_xfer[ULPT_BULK_DT_RD]),
                    ULPT_IFQ_MAXLEN)) {
                        return (ENOMEM);
                }
                /* set which FIFO is opened */
                sc->sc_fifo_open[USB_FIFO_RX] = fifo;
        }
        if (fflags & FWRITE) {
                /* clear stall first */
                mtx_lock(&sc->sc_mtx);
                usbd_xfer_set_stall(sc->sc_xfer[ULPT_BULK_DT_WR]);
                mtx_unlock(&sc->sc_mtx);
                if (usb_fifo_alloc_buffer(fifo,
                    usbd_xfer_max_len(sc->sc_xfer[ULPT_BULK_DT_WR]),
                    ULPT_IFQ_MAXLEN)) {
                        return (ENOMEM);
                }
                /* set which FIFO is opened */
                sc->sc_fifo_open[USB_FIFO_TX] = fifo;
        }
        sc->sc_fflags |= fflags & (FREAD | FWRITE);
        return (0);
}
 
static void
ulpt_close(struct usb_fifo *fifo, int fflags)
{
        struct ulpt_softc *sc = usb_fifo_softc(fifo);
 
        sc->sc_fflags &= ~(fflags & (FREAD | FWRITE));
 
        if (fflags & (FREAD | FWRITE)) {
                usb_fifo_free_buffer(fifo);
        }
}
 
static int
ulpt_ioctl(struct usb_fifo *fifo, u_long cmd, void *data,
    int fflags)
{
        return (ENODEV);
}
 
static const STRUCT_USB_HOST_ID ulpt_devs[] = {
        /* Uni-directional USB printer */
        {USB_IFACE_CLASS(UICLASS_PRINTER),
         USB_IFACE_SUBCLASS(UISUBCLASS_PRINTER),
         USB_IFACE_PROTOCOL(UIPROTO_PRINTER_UNI)},
 
        /* Bi-directional USB printer */
        {USB_IFACE_CLASS(UICLASS_PRINTER),
         USB_IFACE_SUBCLASS(UISUBCLASS_PRINTER),
         USB_IFACE_PROTOCOL(UIPROTO_PRINTER_BI)},
 
        /* 1284 USB printer */
        {USB_IFACE_CLASS(UICLASS_PRINTER),
         USB_IFACE_SUBCLASS(UISUBCLASS_PRINTER),
         USB_IFACE_PROTOCOL(UIPROTO_PRINTER_1284)},
};
 
static int
ulpt_probe(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        int error;
 
        DPRINTFN(11, "\n");
 
        if (uaa->usb_mode != USB_MODE_HOST)
                return (ENXIO);
 
        error = usbd_lookup_id_by_uaa(ulpt_devs, sizeof(ulpt_devs), uaa);
        if (error)
                return (error);
 
        return (BUS_PROBE_GENERIC);
}
 
static int
ulpt_attach(device_t dev)
{
        struct usb_attach_arg *uaa = device_get_ivars(dev);
        struct ulpt_softc *sc = device_get_softc(dev);
        struct usb_interface_descriptor *id;
        int unit = device_get_unit(dev);
        int error;
        uint8_t iface_index = uaa->info.bIfaceIndex;
        uint8_t alt_index;
 
        DPRINTFN(11, "sc=%p\n", sc);
 
        sc->sc_dev = dev;
        sc->sc_udev = uaa->device;
 
        device_set_usb_desc(dev);
 
        mtx_init(&sc->sc_mtx, "ulpt lock", NULL, MTX_DEF | MTX_RECURSE);
 
        usb_callout_init_mtx(&sc->sc_watchdog, &sc->sc_mtx, 0);
 
        /* search through all the descriptors looking for bidir mode */
 
        id = usbd_get_interface_descriptor(uaa->iface);
        alt_index = 0xFF;
        while (1) {
                if (id == NULL) {
                        break;
                }
                if ((id->bDescriptorType == UDESC_INTERFACE) &&
                    (id->bLength >= sizeof(*id))) {
                        if (id->bInterfaceNumber != uaa->info.bIfaceNum) {
                                break;
                        } else {
                                alt_index++;
                                if ((id->bInterfaceClass == UICLASS_PRINTER) &&
                                    (id->bInterfaceSubClass == UISUBCLASS_PRINTER) &&
                                    (id->bInterfaceProtocol == UIPROTO_PRINTER_BI)) {
                                        goto found;
                                }
                        }
                }
                id = (void *)usb_desc_foreach(
                    usbd_get_config_descriptor(uaa->device), (void *)id);
        }
        goto detach;
 
found:
 
        DPRINTF("setting alternate "
            "config number: %d\n", alt_index);
 
        if (alt_index) {
                error = usbd_set_alt_interface_index
                    (uaa->device, iface_index, alt_index);
 
                if (error) {
                        DPRINTF("could not set alternate "
                            "config, error=%s\n", usbd_errstr(error));
                        goto detach;
                }
        }
        sc->sc_iface_no = id->bInterfaceNumber;
 
        error = usbd_transfer_setup(uaa->device, &iface_index,
            sc->sc_xfer, ulpt_config, ULPT_N_TRANSFER,
            sc, &sc->sc_mtx);
        if (error) {
                DPRINTF("error=%s\n", usbd_errstr(error));
                goto detach;
        }
        device_printf(sc->sc_dev, "using bi-directional mode\n");
 
#if 0
/*
 * This code is disabled because for some mysterious reason it causes
 * printing not to work.  But only sometimes, and mostly with
 * UHCI and less often with OHCI.  *sigh*
 */
        {
                struct usb_config_descriptor *cd = usbd_get_config_descriptor(dev);
                struct usb_device_request req;
                int len, alen;
 
                req.bmRequestType = UT_READ_CLASS_INTERFACE;
                req.bRequest = UR_GET_DEVICE_ID;
                USETW(req.wValue, cd->bConfigurationValue);
                USETW2(req.wIndex, id->bInterfaceNumber, id->bAlternateSetting);
                USETW(req.wLength, sizeof devinfo - 1);
                error = usbd_do_request_flags(dev, &req, devinfo, USB_SHORT_XFER_OK,
                    &alen, USB_DEFAULT_TIMEOUT);
                if (error) {
                        device_printf(sc->sc_dev, "cannot get device id\n");
                } else if (alen <= 2) {
                        device_printf(sc->sc_dev, "empty device id, no "
                            "printer connected?\n");
                } else {
                        /* devinfo now contains an IEEE-1284 device ID */
                        len = ((devinfo[0] & 0xff) << 8) | (devinfo[1] & 0xff);
                        if (len > sizeof devinfo - 3)
                                len = sizeof devinfo - 3;
                        devinfo[len] = 0;
                        printf("%s: device id <", device_get_nameunit(sc->sc_dev));
                        ieee1284_print_id(devinfo + 2);
                        printf(">\n");
                }
        }
#endif
 
        error = usb_fifo_attach(uaa->device, sc, &sc->sc_mtx,
            &ulpt_fifo_methods, &sc->sc_fifo,
            unit, -1, uaa->info.bIfaceIndex,
            UID_ROOT, GID_OPERATOR, 0644);
        if (error) {
                goto detach;
        }
        error = usb_fifo_attach(uaa->device, sc, &sc->sc_mtx,
            &unlpt_fifo_methods, &sc->sc_fifo_noreset,
            unit, -1, uaa->info.bIfaceIndex,
            UID_ROOT, GID_OPERATOR, 0644);
        if (error) {
                goto detach;
        }
        /* start reading of status */
 
        mtx_lock(&sc->sc_mtx);
        ulpt_watchdog(sc);
        mtx_unlock(&sc->sc_mtx);
        return (0);
 
detach:
        ulpt_detach(dev);
        return (ENOMEM);
}
 
static int
ulpt_detach(device_t dev)
{
        struct ulpt_softc *sc = device_get_softc(dev);
 
        DPRINTF("sc=%p\n", sc);
 
        usb_fifo_detach(&sc->sc_fifo);
        usb_fifo_detach(&sc->sc_fifo_noreset);
 
        mtx_lock(&sc->sc_mtx);
        usb_callout_stop(&sc->sc_watchdog);
        mtx_unlock(&sc->sc_mtx);
 
        usbd_transfer_unsetup(sc->sc_xfer, ULPT_N_TRANSFER);
        usb_callout_drain(&sc->sc_watchdog);
        mtx_destroy(&sc->sc_mtx);
 
        return (0);
}
 
#if 0
/* XXX This does not belong here. */
 
/*
 * Compare two strings until the second ends.
 */
 
static uint8_t
ieee1284_compare(const char *a, const char *b)
{
        while (1) {
                if (*b == 0) {
                        break;
                }
                if (*a != *b) {
                        return 1;
                }
                b++;
                a++;
        }
        return 0;
}
 
/*
 * Print select parts of an IEEE 1284 device ID.
 */
void
ieee1284_print_id(char *str)
{
        char *p, *q;
 
        for (p = str - 1; p; p = strchr(p, ';')) {
                p++;                    /* skip ';' */
                if (ieee1284_compare(p, "MFG:") == 0 ||
                    ieee1284_compare(p, "MANUFACTURER:") == 0 ||
                    ieee1284_compare(p, "MDL:") == 0 ||
                    ieee1284_compare(p, "MODEL:") == 0) {
                        q = strchr(p, ';');
                        if (q)
                                printf("%.*s", (int)(q - p + 1), p);
                }
        }
}
 
#endif
 
static void
ulpt_watchdog(void *arg)
{
        struct ulpt_softc *sc = arg;
 
        mtx_assert(&sc->sc_mtx, MA_OWNED);
 
        /* 
         * Only read status while the device is not opened, due to
         * possible hardware or firmware bug in some printers.
         */
        if (sc->sc_fflags == 0)
                usbd_transfer_start(sc->sc_xfer[ULPT_INTR_DT_RD]);
 
        usb_callout_reset(&sc->sc_watchdog,
            hz, &ulpt_watchdog, sc);
}
 
static devclass_t ulpt_devclass;
 
static device_method_t ulpt_methods[] = {
        DEVMETHOD(device_probe, ulpt_probe),
        DEVMETHOD(device_attach, ulpt_attach),
        DEVMETHOD(device_detach, ulpt_detach),
        DEVMETHOD_END
};
 
static driver_t ulpt_driver = {
        .name = "ulpt",
        .methods = ulpt_methods,
        .size = sizeof(struct ulpt_softc),
};
 
DRIVER_MODULE(ulpt, uhub, ulpt_driver, ulpt_devclass, NULL, 0);
MODULE_DEPEND(ulpt, usb, 1, 1, 1);
MODULE_VERSION(ulpt, 1);
USB_PNP_HOST_INFO(ulpt_devs);