xref: /src/sys/dev/usb/umodem_common.c

/*	$NetBSD: umodem_common.c,v 1.28 2019/05/04 08:04:13 mrg Exp $	*/

/*
 * Copyright (c) 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Lennart Augustsson (lennart (at) 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.
 */

/*
 * Comm Class spec:  http://www.usb.org/developers/devclass_docs/usbccs10.pdf
 *                   http://www.usb.org/developers/devclass_docs/usbcdc11.pdf
 */

/*
 * TODO:
 * - Add error recovery in various places; the big problem is what
 *   to do in a callback if there is an error.
 * - Implement a Call Device for modems without multiplexed commands.
 *
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: umodem_common.c,v 1.28 2019/05/04 08:04:13 mrg Exp $");

#ifdef _KERNEL_OPT
#include "opt_usb.h"
#endif

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/ioctl.h>
#include <sys/conf.h>
#include <sys/tty.h>
#include <sys/file.h>
#include <sys/select.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/device.h>
#include <sys/poll.h>

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

#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
#include <dev/usb/usbdevs.h>
#include <dev/usb/usb_quirks.h>

#include <dev/usb/ucomvar.h>
#include <dev/usb/umodemvar.h>

#ifdef UMODEM_DEBUG
#define DPRINTFN(n, x)	if (umodemdebug > (n)) printf x
int	umodemdebug = 0;
#else
#define DPRINTFN(n, x)
#endif
#define DPRINTF(x) DPRINTFN(0, x)

/*
 * These are the maximum number of bytes transferred per frame.
 * If some really high speed devices should use this driver they
 * may need to be increased, but this is good enough for normal modems.
 *
 * Note: increased from 64/256, to better support EVDO wireless PPP.
 * The sizes should not be increased further, or there
 * will be problems with contiguous storage allocation.
 */
#define UMODEMIBUFSIZE 4096
#define UMODEMOBUFSIZE 4096

static usbd_status umodem_set_comm_feature(struct umodem_softc *,
					   int, int);
static usbd_status umodem_set_line_coding(struct umodem_softc *,
					  usb_cdc_line_state_t *);

static void	umodem_dtr(struct umodem_softc *, int);
static void	umodem_rts(struct umodem_softc *, int);
static void	umodem_break(struct umodem_softc *, int);
static void	umodem_set_line_state(struct umodem_softc *);
static void	umodem_intr(struct usbd_xfer *, void *, usbd_status);

int
umodem_common_attach(device_t self, struct umodem_softc *sc,
    struct usbif_attach_arg *uiaa, struct ucom_attach_args *ucaa)
{
	struct usbd_device *dev = uiaa->uiaa_device;
	usb_interface_descriptor_t *id;
	usb_endpoint_descriptor_t *ed;
	char *devinfop;
	usbd_status err;
	int data_ifcno;
	int i;

	sc->sc_dev = self;
	sc->sc_udev = dev;
	sc->sc_ctl_iface = uiaa->uiaa_iface;
	sc->sc_refcnt = 0;
	sc->sc_dying = false;

	aprint_naive("\n");
	aprint_normal("\n");

	mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_SOFTUSB);
	cv_init(&sc->sc_detach_cv, "umodemdet");

	id = usbd_get_interface_descriptor(sc->sc_ctl_iface);
	devinfop = usbd_devinfo_alloc(uiaa->uiaa_device, 0);
	aprint_normal_dev(self, "%s, iclass %d/%d\n",
	       devinfop, id->bInterfaceClass, id->bInterfaceSubClass);
	usbd_devinfo_free(devinfop);

	sc->sc_ctl_iface_no = id->bInterfaceNumber;

	/* Get the data interface no. */
	sc->sc_data_iface_no = data_ifcno =
	    umodem_get_caps(dev, &sc->sc_cm_cap, &sc->sc_acm_cap, id);

	if (data_ifcno == -1) {
		aprint_error_dev(self, "no pointer to data interface\n");
		goto bad;
	}

	aprint_normal_dev(self,
	    "data interface %d, has %sCM over data, has %sbreak\n",
	    data_ifcno, sc->sc_cm_cap & USB_CDC_CM_OVER_DATA ? "" : "no ",
	    sc->sc_acm_cap & USB_CDC_ACM_HAS_BREAK ? "" : "no ");

	/* Get the data interface too. */
	for (i = 0; i < uiaa->uiaa_nifaces; i++) {
		if (uiaa->uiaa_ifaces[i] != NULL) {
			id = usbd_get_interface_descriptor(uiaa->uiaa_ifaces[i]);
			if (id != NULL && id->bInterfaceNumber == data_ifcno) {
				sc->sc_data_iface = uiaa->uiaa_ifaces[i];
				uiaa->uiaa_ifaces[i] = NULL;
			}
		}
	}
	if (sc->sc_data_iface == NULL) {
		aprint_error_dev(self, "no data interface\n");
		goto bad;
	}

	/*
	 * Find the bulk endpoints.
	 * Iterate over all endpoints in the data interface and take note.
	 */
	ucaa->ucaa_bulkin = ucaa->ucaa_bulkout = -1;

	id = usbd_get_interface_descriptor(sc->sc_data_iface);
	for (i = 0; i < id->bNumEndpoints; i++) {
		ed = usbd_interface2endpoint_descriptor(sc->sc_data_iface, i);
		if (ed == NULL) {
			aprint_error_dev(self,
			    "no endpoint descriptor for %d\n)", i);
			goto bad;
		}
		if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
		    (ed->bmAttributes & UE_XFERTYPE) == UE_BULK) {
			ucaa->ucaa_bulkin = ed->bEndpointAddress;
		} else if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_OUT &&
			   (ed->bmAttributes & UE_XFERTYPE) == UE_BULK) {
			ucaa->ucaa_bulkout = ed->bEndpointAddress;
		}
	}

	if (ucaa->ucaa_bulkin == -1) {
		aprint_error_dev(self, "Could not find data bulk in\n");
		goto bad;
	}
	if (ucaa->ucaa_bulkout == -1) {
		aprint_error_dev(self, "Could not find data bulk out\n");
		goto bad;
	}

	if (usbd_get_quirks(sc->sc_udev)->uq_flags & UQ_ASSUME_CM_OVER_DATA) {
		sc->sc_cm_over_data = 1;
	} else {
		if (sc->sc_cm_cap & USB_CDC_CM_OVER_DATA) {
			if (sc->sc_acm_cap & USB_CDC_ACM_HAS_FEATURE)
				err = umodem_set_comm_feature(sc,
				    UCDC_ABSTRACT_STATE, UCDC_DATA_MULTIPLEXED);
			else
				err = 0;
			if (err) {
				aprint_error_dev(self,
				    "could not set data multiplex mode\n");
				goto bad;
			}
			sc->sc_cm_over_data = 1;
		}
	}

	/*
	 * The standard allows for notification messages (to indicate things
	 * like a modem hangup) to come in via an interrupt endpoint
	 * off of the control interface.  Iterate over the endpoints on
	 * the control interface and see if there are any interrupt
	 * endpoints; if there are, then register it.
	 */

	sc->sc_ctl_notify = -1;
	sc->sc_notify_pipe = NULL;

	id = usbd_get_interface_descriptor(sc->sc_ctl_iface);
	for (i = 0; i < id->bNumEndpoints; i++) {
		ed = usbd_interface2endpoint_descriptor(sc->sc_ctl_iface, i);
		if (ed == NULL)
			continue;

		if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
		    (ed->bmAttributes & UE_XFERTYPE) == UE_INTERRUPT) {
			aprint_verbose_dev(self,
			    "status change notification available\n");
			sc->sc_ctl_notify = ed->bEndpointAddress;
		}
	}

	sc->sc_dtr = -1;

	/* ucaa_bulkin, ucaa_bulkout set above */
	ucaa->ucaa_ibufsize = UMODEMIBUFSIZE;
	ucaa->ucaa_obufsize = UMODEMOBUFSIZE;
	ucaa->ucaa_ibufsizepad = UMODEMIBUFSIZE;
	ucaa->ucaa_opkthdrlen = 0;
	ucaa->ucaa_device = sc->sc_udev;
	ucaa->ucaa_iface = sc->sc_data_iface;
	ucaa->ucaa_arg = sc;

	usbd_add_drv_event(USB_EVENT_DRIVER_ATTACH, sc->sc_udev, sc->sc_dev);

	DPRINTF(("umodem_common_attach: sc=%p\n", sc));
	sc->sc_subdev = config_found_sm_loc(self, "ucombus", NULL, ucaa,
					    ucomprint, ucomsubmatch);

	return 0;

 bad:
	sc->sc_dying = true;
	return 1;
}

int
umodem_open(void *addr, int portno)
{
	struct umodem_softc *sc = addr;
	int err;

	mutex_enter(&sc->sc_lock);
	if (sc->sc_dying) {
		mutex_exit(&sc->sc_lock);
		return EIO;
	}

	sc->sc_refcnt++;
	mutex_exit(&sc->sc_lock);

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

	if (sc->sc_ctl_notify != -1 && sc->sc_notify_pipe == NULL) {
		err = usbd_open_pipe_intr(sc->sc_ctl_iface, sc->sc_ctl_notify,
		    USBD_SHORT_XFER_OK, &sc->sc_notify_pipe, sc,
		    &sc->sc_notify_buf, sizeof(sc->sc_notify_buf),
		    umodem_intr, USBD_DEFAULT_INTERVAL);

		if (err) {
			DPRINTF(("Failed to establish notify pipe: %s\n",
				usbd_errstr(err)));
			mutex_enter(&sc->sc_lock);
			if (--sc->sc_refcnt < 0)
				cv_broadcast(&sc->sc_detach_cv);
			mutex_exit(&sc->sc_lock);
			return EIO;
		}
	}

	return 0;
}

void
umodem_close(void *addr, int portno)
{
	struct umodem_softc *sc = addr;
	int err;

	mutex_enter(&sc->sc_lock);
	if (sc->sc_dying)
		goto out;
	mutex_exit(&sc->sc_lock);

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

	if (sc->sc_notify_pipe != NULL) {
		err = usbd_abort_pipe(sc->sc_notify_pipe);
		if (err)
			printf("%s: abort notify pipe failed: %s\n",
			    device_xname(sc->sc_dev), usbd_errstr(err));
		err = usbd_close_pipe(sc->sc_notify_pipe);
		if (err)
			printf("%s: close notify pipe failed: %s\n",
			    device_xname(sc->sc_dev), usbd_errstr(err));
		sc->sc_notify_pipe = NULL;
	}

	mutex_enter(&sc->sc_lock);
out:
	if (--sc->sc_refcnt < 0)
		cv_broadcast(&sc->sc_detach_cv);
	mutex_exit(&sc->sc_lock);
}

static void
umodem_intr(struct usbd_xfer *xfer, void *priv,
    usbd_status status)
{
	struct umodem_softc *sc = priv;
	u_char mstatus;

	if (sc->sc_dying)
		return;

	if (status != USBD_NORMAL_COMPLETION) {
		if (status == USBD_NOT_STARTED || status == USBD_CANCELLED)
			return;
		printf("%s: abnormal status: %s\n", device_xname(sc->sc_dev),
		       usbd_errstr(status));
		if (status == USBD_STALLED)
			usbd_clear_endpoint_stall_async(sc->sc_notify_pipe);
		return;
	}

	if (sc->sc_notify_buf.bmRequestType != UCDC_NOTIFICATION) {
		DPRINTF(("%s: unknown message type (%02x) on notify pipe\n",
			 device_xname(sc->sc_dev),
			 sc->sc_notify_buf.bmRequestType));
		return;
	}

	switch (sc->sc_notify_buf.bNotification) {
	case UCDC_N_SERIAL_STATE:
		/*
		 * Set the serial state in ucom driver based on
		 * the bits from the notify message
		 */
		if (UGETW(sc->sc_notify_buf.wLength) != 2) {
			printf("%s: Invalid notification length! (%d)\n",
			       device_xname(sc->sc_dev),
			       UGETW(sc->sc_notify_buf.wLength));
			break;
		}
		DPRINTF(("%s: notify bytes = %02x%02x\n",
			 device_xname(sc->sc_dev),
			 sc->sc_notify_buf.data[0],
			 sc->sc_notify_buf.data[1]));
		/* Currently, lsr is always zero. */
		sc->sc_lsr = sc->sc_msr = 0;
		mstatus = sc->sc_notify_buf.data[0];

		if (ISSET(mstatus, UCDC_N_SERIAL_RI))
			sc->sc_msr |= UMSR_RI;
		if (ISSET(mstatus, UCDC_N_SERIAL_DSR))
			sc->sc_msr |= UMSR_DSR;
		if (ISSET(mstatus, UCDC_N_SERIAL_DCD))
			sc->sc_msr |= UMSR_DCD;
		ucom_status_change(device_private(sc->sc_subdev));
		break;
	default:
		DPRINTF(("%s: unknown notify message: %02x\n",
			 device_xname(sc->sc_dev),
			 sc->sc_notify_buf.bNotification));
		break;
	}
}

int
umodem_get_caps(struct usbd_device *dev, int *cm, int *acm,
		usb_interface_descriptor_t *id)
{
	const usb_cdc_cm_descriptor_t *cmd;
	const usb_cdc_acm_descriptor_t *cad;
	const usb_cdc_union_descriptor_t *cud;
	uint32_t uq_flags;

	*cm = *acm = 0;
	uq_flags = usbd_get_quirks(dev)->uq_flags;

	if (uq_flags & UQ_NO_UNION_NRM) {
		DPRINTF(("umodem_get_caps: NO_UNION_NRM quirk - returning 0\n"));
		return 0;
	}

	if (uq_flags & UQ_LOST_CS_DESC)
		id = NULL;

	cmd = (const usb_cdc_cm_descriptor_t *)usb_find_desc_if(dev,
							  UDESC_CS_INTERFACE,
							  UDESCSUB_CDC_CM, id);
	if (cmd == NULL) {
		DPRINTF(("umodem_get_caps: no CM desc\n"));
	} else {
		*cm = cmd->bmCapabilities;
	}

	cad = (const usb_cdc_acm_descriptor_t *)usb_find_desc_if(dev,
							   UDESC_CS_INTERFACE,
							   UDESCSUB_CDC_ACM,
							   id);
	if (cad == NULL) {
		DPRINTF(("umodem_get_caps: no ACM desc\n"));
	} else {
		*acm = cad->bmCapabilities;
	}

	cud = (const usb_cdc_union_descriptor_t *)usb_find_desc_if(dev,
							     UDESC_CS_INTERFACE,
							     UDESCSUB_CDC_UNION,
							     id);
	if (cud == NULL) {
		DPRINTF(("umodem_get_caps: no UNION desc\n"));
	}

	return cmd ? cmd->bDataInterface : cud ? cud->bSlaveInterface[0] : -1;
}

void
umodem_get_status(void *addr, int portno, u_char *lsr, u_char *msr)
{
	struct umodem_softc *sc = addr;

	DPRINTF(("umodem_get_status:\n"));

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

int
umodem_param(void *addr, int portno, struct termios *t)
{
	struct umodem_softc *sc = addr;
	usbd_status err;
	usb_cdc_line_state_t ls;

	mutex_enter(&sc->sc_lock);
	if (sc->sc_dying)
		return EIO;
	mutex_exit(&sc->sc_lock);

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

	USETDW(ls.dwDTERate, t->c_ospeed);
	if (ISSET(t->c_cflag, CSTOPB))
		ls.bCharFormat = UCDC_STOP_BIT_2;
	else
		ls.bCharFormat = UCDC_STOP_BIT_1;
	if (ISSET(t->c_cflag, PARENB)) {
		if (ISSET(t->c_cflag, PARODD))
			ls.bParityType = UCDC_PARITY_ODD;
		else
			ls.bParityType = UCDC_PARITY_EVEN;
	} else
		ls.bParityType = UCDC_PARITY_NONE;
	switch (ISSET(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;
	}

	err = umodem_set_line_coding(sc, &ls);
	if (err) {
		DPRINTF(("umodem_param: err=%s\n", usbd_errstr(err)));
		return EPASSTHROUGH;
	}
	return 0;
}

int
umodem_ioctl(void *addr, int portno, u_long cmd, void *data,
    int flag, proc_t *p)
{
	struct umodem_softc *sc = addr;
	int error = 0;

	mutex_enter(&sc->sc_lock);
	if (sc->sc_dying)
		return EIO;
	mutex_exit(&sc->sc_lock);

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

	switch (cmd) {
	case USB_GET_CM_OVER_DATA:
		*(int *)data = sc->sc_cm_over_data;
		break;

	case USB_SET_CM_OVER_DATA:
		if (*(int *)data != sc->sc_cm_over_data) {
			/* XXX change it */
		}
		break;

	default:
		DPRINTF(("umodem_ioctl: unknown\n"));
		error = EPASSTHROUGH;
		break;
	}

	return error;
}

static void
umodem_dtr(struct umodem_softc *sc, int onoff)
{
	DPRINTF(("umodem_dtr: onoff=%d\n", onoff));

	if (sc->sc_dtr == onoff)
		return;
	sc->sc_dtr = onoff;

	umodem_set_line_state(sc);
}

static void
umodem_rts(struct umodem_softc *sc, int onoff)
{
	DPRINTF(("umodem_rts: onoff=%d\n", onoff));

	if (sc->sc_rts == onoff)
		return;
	sc->sc_rts = onoff;

	umodem_set_line_state(sc);
}

static void
umodem_set_line_state(struct umodem_softc *sc)
{
	usb_device_request_t req;
	int ls;

	ls = (sc->sc_dtr ? UCDC_LINE_DTR : 0) |
	     (sc->sc_rts ? UCDC_LINE_RTS : 0);
	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
	req.bRequest = UCDC_SET_CONTROL_LINE_STATE;
	USETW(req.wValue, ls);
	USETW(req.wIndex, sc->sc_ctl_iface_no);
	USETW(req.wLength, 0);

	(void)usbd_do_request(sc->sc_udev, &req, 0);

}

static void
umodem_break(struct umodem_softc *sc, int onoff)
{
	usb_device_request_t req;

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

	if (!(sc->sc_acm_cap & USB_CDC_ACM_HAS_BREAK))
		return;

	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
	req.bRequest = UCDC_SEND_BREAK;
	USETW(req.wValue, onoff ? UCDC_BREAK_ON : UCDC_BREAK_OFF);
	USETW(req.wIndex, sc->sc_ctl_iface_no);
	USETW(req.wLength, 0);

	(void)usbd_do_request(sc->sc_udev, &req, 0);
}

void
umodem_set(void *addr, int portno, int reg, int onoff)
{
	struct umodem_softc *sc = addr;

	mutex_enter(&sc->sc_lock);
	if (sc->sc_dying)
		return;
	mutex_exit(&sc->sc_lock);

	switch (reg) {
	case UCOM_SET_DTR:
		umodem_dtr(sc, onoff);
		break;
	case UCOM_SET_RTS:
		umodem_rts(sc, onoff);
		break;
	case UCOM_SET_BREAK:
		umodem_break(sc, onoff);
		break;
	default:
		break;
	}
}

static usbd_status
umodem_set_line_coding(struct umodem_softc *sc, usb_cdc_line_state_t *state)
{
	usb_device_request_t req;
	usbd_status err;

	DPRINTF(("umodem_set_line_coding: rate=%d fmt=%d parity=%d bits=%d\n",
		 UGETDW(state->dwDTERate), state->bCharFormat,
		 state->bParityType, state->bDataBits));

	if (memcmp(state, &sc->sc_line_state, UCDC_LINE_STATE_LENGTH) == 0) {
		DPRINTF(("umodem_set_line_coding: already set\n"));
		return USBD_NORMAL_COMPLETION;
	}

	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
	req.bRequest = UCDC_SET_LINE_CODING;
	USETW(req.wValue, 0);
	USETW(req.wIndex, sc->sc_ctl_iface_no);
	USETW(req.wLength, UCDC_LINE_STATE_LENGTH);

	err = usbd_do_request(sc->sc_udev, &req, state);
	if (err) {
		DPRINTF(("umodem_set_line_coding: failed, err=%s\n",
			 usbd_errstr(err)));
		return err;
	}

	sc->sc_line_state = *state;

	return USBD_NORMAL_COMPLETION;
}

static usbd_status
umodem_set_comm_feature(struct umodem_softc *sc, int feature, int state)
{
	usb_device_request_t req;
	usbd_status err;
	usb_cdc_abstract_state_t ast;

	DPRINTF(("umodem_set_comm_feature: feature=%d state=%d\n", feature,
		 state));

	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
	req.bRequest = UCDC_SET_COMM_FEATURE;
	USETW(req.wValue, feature);
	USETW(req.wIndex, sc->sc_ctl_iface_no);
	USETW(req.wLength, UCDC_ABSTRACT_STATE_LENGTH);
	USETW(ast.wState, state);

	err = usbd_do_request(sc->sc_udev, &req, &ast);
	if (err) {
		DPRINTF(("umodem_set_comm_feature: feature=%d, err=%s\n",
			 feature, usbd_errstr(err)));
		return err;
	}

	return USBD_NORMAL_COMPLETION;
}

int
umodem_common_activate(struct umodem_softc *sc, enum devact act)
{
	switch (act) {
	case DVACT_DEACTIVATE:
		mutex_enter(&sc->sc_lock);
		sc->sc_dying = true;
		mutex_exit(&sc->sc_lock);
		return 0;
	default:
		return EOPNOTSUPP;
	}
}

void
umodem_common_childdet(struct umodem_softc *sc, device_t child)
{
	KASSERT(sc->sc_subdev == child);
	sc->sc_subdev = NULL;
}

int
umodem_common_detach(struct umodem_softc *sc, int flags)
{
	int rv = 0;

	DPRINTF(("umodem_common_detach: sc=%p flags=%d\n", sc, flags));

	mutex_enter(&sc->sc_lock);
	sc->sc_dying = true;

	sc->sc_refcnt--;
	while (sc->sc_refcnt > 0) {
		if (cv_timedwait(&sc->sc_detach_cv, &sc->sc_lock, hz * 60))
			aprint_error_dev(sc->sc_dev, ": didn't detach\n");
	}
	mutex_exit(&sc->sc_lock);

	if (sc->sc_subdev != NULL)
		rv = config_detach(sc->sc_subdev, flags);

	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH, sc->sc_udev, sc->sc_dev);

	mutex_destroy(&sc->sc_lock);
	cv_destroy(&sc->sc_detach_cv);

	return rv;
}