Driver for Silicon Laboratories CP2101/CP2102 based serial adapters.

ok dlg@

7 files changed, 493 insertions, 7 deletions

diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile
index 52a073553ab..16b2b4060eb 100644
--- a/share/man/man4/Makefile
+++ b/share/man/man4/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.354 2006/04/26 15:59:26 jason Exp $
+#	$OpenBSD: Makefile,v 1.355 2006/04/29 02:15:06 jsg Exp $
 
 MAN=	aac.4 ac97.4 acphy.4 acpi.4 acpihpet.4 acpitimer.4 \
 	adc.4 addcom.4 admcts.4 admlc.4 admtemp.4 \
@@ -42,8 +42,8 @@ MAN=	aac.4 ac97.4 acphy.4 acpi.4 acpihpet.4 acpitimer.4 \
 	udcf.4 udp.4 udsbr.4 \
 	ueagle.4 uftdi.4 ugen.4 uhci.4 uhid.4 uhidev.4 uipaq.4 uk.4 ukbd.4 \
 	ukphy.4 ulpt.4 umass.4 umct.4 umidi.4 umodem.4 ums.4 umsm.4 \
-	unix.4 upl.4 uplcom.4 urio.4 url.4 urlphy.4 usb.4 \
-	uscanner.4 usscanner.4 uvisor.4 uvscom.4 uyap.4 vga.4 vgafb.4 vge.4 \
+	unix.4 upl.4 uplcom.4 urio.4 url.4 urlphy.4 usb.4 uscanner.4
+	uslcom.4 usscanner.4 uvisor.4 uvscom.4 uyap.4 vga.4 vgafb.4 vge.4 \
 	viaenv.4 viapm.4 viasio.4 vic.4 vlan.4 vnd.4 vr.4 watchdog.4 wb.4 \
 	wbenv.4 wd.4 wdc.4 we.4 wi.4tbl wscons.4 wsdisplay.4 wskbd.4 \
 	wsmouse.4 wsmux.4 xe.4 xf86.4 xl.4 xmphy.4 yds.4 ym.4 zero.4
diff --git a/share/man/man4/usb.4 b/share/man/man4/usb.4
index 3c9a0314d24..df36a75220b 100644
--- a/share/man/man4/usb.4
+++ b/share/man/man4/usb.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: usb.4,v 1.57 2006/04/20 08:09:31 jmc Exp $
+.\"	$OpenBSD: usb.4,v 1.58 2006/04/29 02:15:06 jsg Exp $
 .\"	$NetBSD: usb.4,v 1.15 1999/07/29 14:20:32 augustss Exp $
 .\"
 .\" Copyright (c) 1999 The NetBSD Foundation, Inc.
@@ -173,6 +173,8 @@ Modems.
 Qualcomm MSM EVDO modems.
 .It Xr uplcom 4
 Prolific PL-2303 serial adapters.
+.It Xr uslcom 4
+Silicon Laboratories CP2101/CP2102 serial adapters.
 .It Xr uvscom 4
 SUNTAC Slipper U VS-10U serial adapters.
 .El
diff --git a/share/man/man4/uslcom.4 b/share/man/man4/uslcom.4
new file mode 100644
index 00000000000..efef356d123
--- /dev/null
+++ b/share/man/man4/uslcom.4
@@ -0,0 +1,64 @@
+.\"	$OpenBSD: uslcom.4,v 1.1 2006/04/29 02:15:06 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.
+.\"
+.Dd April 29, 2006
+.Dt USLCOM 4
+.Os
+.Sh NAME
+.Nm uslcom
+.Nd Silicon Laboratories CP2101/CP2102 based serial adapters driver
+.Sh SYNOPSIS
+.Cd "uslcom* at uhub?"
+.Cd "ucom* at uslcom?"
+.Sh DESCRIPTION
+The
+.Nm
+driver supports Silicon Laboratories CP2101/CP2102 based serial adapters.
+.Pp
+The following devices should work with the
+.Nm
+driver:
+.Bd -literal -offset indent
+Burnside Telecom Desktop Mobile
+chip45.com Crumb128 module
+Jablotron PC-60B
+Pololu USB to Serial
+Silicon Laboratories CP2101
+Silicon Laboratories CP2102
+.Ed
+.Pp
+.Sh SEE ALSO
+.Xr tty 4 ,
+.Xr ucom 4 ,
+.Xr uhub 4 ,
+.Xr usb 4 ,
+.Sh HISTORY
+The
+.Nm
+device driver first appeared in
+.Ox 4.0 .
+.Sh AUTHORS
+.An -nosplit
+The
+.Nm
+driver was written by
+.An Jonathan Gray
+.Aq jsg@openbsd.org .
+.Sh CAVEATS
+Setting hardware flow control is not currently supported.
+.Pp
+Silicon Laboratories don't release any programming information
+on their products.
diff --git a/sys/arch/amd64/conf/GENERIC b/sys/arch/amd64/conf/GENERIC
index d6dacc6e921..5a384319bd7 100644
--- a/sys/arch/amd64/conf/GENERIC
+++ b/sys/arch/amd64/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.122 2006/03/30 21:12:50 wilfried Exp $
+#	$OpenBSD: GENERIC,v 1.123 2006/04/29 02:15:06 jsg Exp $
 #
 # For further information on compiling OpenBSD kernels, see the config(8)
 # man page.
@@ -147,6 +147,8 @@ uplcom* at uhub?		# I/O DATA USB-RSAQ2 serial adapter
 ucom*	at uplcom?
 umct*	at uhub?		# MCT USB-RS232 serial adapter
 ucom*	at umct?
+uslcom*	at uhub?		# Silicon Laboratories CP210x serial
+ucom*	at uslcom?
 uipaq*	at uhub?		# iPAQ serial adapter
 ucom*	at uipaq?
 umsm*	at uhub?		# Qualcomm MSM EVDO
diff --git a/sys/arch/i386/conf/GENERIC b/sys/arch/i386/conf/GENERIC
index 9a2401c3c0b..c29e733965e 100644
--- a/sys/arch/i386/conf/GENERIC
+++ b/sys/arch/i386/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.485 2006/04/25 16:27:46 deraadt Exp $
+#	$OpenBSD: GENERIC,v 1.486 2006/04/29 02:15:06 jsg Exp $
 #
 # For further information on compiling OpenBSD kernels, see the config(8)
 # man page.
@@ -195,6 +195,8 @@ uplcom* at uhub?		# I/O DATA USB-RSAQ2 serial adapter
 ucom*	at uplcom?
 umct*	at uhub?		# MCT USB-RS232 serial adapter
 ucom*	at umct?
+uslcom*	at uhub?		# Silicon Laboratories CP210x serial
+ucom*	at uslcom?
 uipaq*	at uhub?		# iPAQ serial adapter
 ucom*	at uipaq?
 umsm*	at uhub?		# Qualcomm MSM EVDO
diff --git a/sys/dev/usb/files.usb b/sys/dev/usb/files.usb
index 9102a1a11ab..2391dce449c 100644
--- a/sys/dev/usb/files.usb
+++ b/sys/dev/usb/files.usb
@@ -1,4 +1,4 @@
-#	$OpenBSD: files.usb,v 1.56 2006/04/24 02:35:26 deraadt Exp $
+#	$OpenBSD: files.usb,v 1.57 2006/04/29 02:15:06 jsg Exp $
 #	$NetBSD: files.usb,v 1.16 2000/02/14 20:29:54 augustss Exp $
 #
 # Config file and device description for machine-independent USB code.
@@ -196,6 +196,11 @@ device	ubsa: ucombus
 attach	ubsa at uhub
 file	dev/usb/ubsa.c			ubsa
 
+# Silicon Laboratories CP210x serial
+device	uslcom: ucombus
+attach	uslcom at uhub
+file	dev/usb/uslcom.c		uslcom
+
 # iPAQ PDAs
 # Generic ipaq support
 device	uipaq: ucombus
diff --git a/sys/dev/usb/uslcom.c b/sys/dev/usb/uslcom.c
new file mode 100644
index 00000000000..c7e65679db6
--- /dev/null
+++ b/sys/dev/usb/uslcom.c
@@ -0,0 +1,411 @@
+/*	$OpenBSD: uslcom.c,v 1.1 2006/04/29 02:15:06 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.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/conf.h>
+#include <sys/tty.h>
+#include <sys/device.h>
+
+#include <dev/usb/usb.h>
+#include <dev/usb/usbdi.h>
+#include <dev/usb/usbdi_util.h>
+#include <dev/usb/usbdevs.h>
+
+#include <dev/usb/usbdevs.h>
+#include <dev/usb/ucomvar.h>
+
+#ifdef USLCOM_DEBUG
+#define DPRINTFN(n, x)  do { if (uslcomdebug > (n)) logprintf x; } while (0)
+int	uslcomdebug = 0;
+#else
+#define DPRINTFN(n, x)
+#endif
+#define DPRINTF(x) DPRINTFN(0, x)
+
+#define USLCOMBUFSZ		256
+#define USLCOM_CONFIG_NO	0
+#define USLCOM_IFACE_NO		0
+
+#define USLCOM_SET_DATA_BITS(x)	(x << 8)
+
+#define USLCOM_WRITE		0x41
+#define USLCOM_READ		0xc1
+
+#define USLCOM_UART		0x00
+#define USLCOM_BAUD_RATE	0x01	
+#define USLCOM_DATA		0x03
+#define USLCOM_BREAK		0x05
+#define USLCOM_CTRL		0x07
+
+#define USLCOM_UART_DISABLE	0x00
+#define USLCOM_UART_ENABLE	0x01
+
+#define USLCOM_CTRL_DTR_ON	0x0001	
+#define USLCOM_CTRL_DTR_SET	0x0100
+#define USLCOM_CTRL_RTS_ON	0x0002
+#define USLCOM_CTRL_RTS_SET	0x0200
+#define USLCOM_CTRL_CTS		0x0010
+#define USLCOM_CTRL_DSR		0x0020
+#define USLCOM_CTRL_DCD		0x0080
+
+
+#define USLCOM_BAUD_REF		0x384000
+
+#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_BREAK_OFF	0x00
+#define USLCOM_BREAK_ON		0x01
+
+
+struct uslcom_softc {
+	USBBASEDEVICE		sc_dev;
+	usbd_device_handle	sc_udev;
+	usbd_interface_handle	sc_iface;
+	device_ptr_t		sc_subdev;
+
+	u_char			sc_msr;
+	u_char			sc_lsr;
+
+	u_char			sc_dying;
+};
+
+Static void	uslcom_get_status(void *, int portno, u_char *lsr, u_char *msr);
+Static void	uslcom_set(void *, int, int, int);
+Static int	uslcom_param(void *, int, struct termios *);
+Static int	uslcom_open(void *sc, int portno);
+Static void	uslcom_break(void *sc, int portno, int onoff);
+
+struct ucom_methods uslcom_methods = {
+	uslcom_get_status,
+	uslcom_set,
+	uslcom_param,
+	NULL,
+	uslcom_open,
+	NULL,
+	NULL,
+	NULL,
+};
+
+static const struct usb_devno uslcom_devs[] = {
+	{ USB_VENDOR_DYNASTREAM,	USB_PRODUCT_DYNASTREAM_ANTDEVBOARD },
+	{ USB_VENDOR_JABLOTRON,		USB_PRODUCT_JABLOTRON_PC60B },
+	{ USB_VENDOR_SILABS,		USB_PRODUCT_SILABS_CRUMB128 },
+	{ USB_VENDOR_SILABS,		USB_PRODUCT_SILABS_DEGREECONT },
+	{ USB_VENDOR_SILABS,		USB_PRODUCT_SILABS_DESKTOPMOBILE },
+	{ USB_VENDOR_SILABS,		USB_PRODUCT_SILABS_IPLINK1220 },
+	{ USB_VENDOR_SILABS,		USB_PRODUCT_SILABS_POLOLU },
+	{ USB_VENDOR_SILABS,		USB_PRODUCT_SILABS_CP210X },
+	{ USB_VENDOR_SILABS,		USB_PRODUCT_SILABS_SUNNTO },
+	{ USB_VENDOR_SILABS2,		USB_PRODUCT_SILABS2_DCU11CLONE },
+	{ USB_VENDOR_USI,		USB_PRODUCT_USI_MC60 }
+};
+
+USB_DECLARE_DRIVER(uslcom);
+
+USB_MATCH(uslcom)
+{
+	USB_MATCH_START(uslcom, uaa);
+
+	if (uaa->iface != NULL)
+		return UMATCH_NONE;
+
+	return (usb_lookup(uslcom_devs, uaa->vendor, uaa->product) != NULL) ?
+	    UMATCH_VENDOR_PRODUCT : UMATCH_NONE;
+}
+
+USB_ATTACH(uslcom)
+{
+	USB_ATTACH_START(uslcom, sc, uaa);
+	struct ucom_attach_args uca;
+	usb_interface_descriptor_t *id;
+	usb_endpoint_descriptor_t *ed;
+	usbd_status error;
+	char *devinfop;
+	int i;
+
+	bzero(&uca, sizeof(uca));
+	sc->sc_udev = uaa->device;
+	devinfop = usbd_devinfo_alloc(uaa->device, 0);
+	USB_ATTACH_SETUP;
+	printf("%s: %s\n", USBDEVNAME(sc->sc_dev), devinfop);
+	usbd_devinfo_free(devinfop);
+
+	if (usbd_set_config_index(sc->sc_udev, USLCOM_CONFIG_NO, 1) != 0) {
+		printf("%s: could not set configuration no\n",
+		    USBDEVNAME(sc->sc_dev));
+		sc->sc_dying = 1;
+		USB_ATTACH_ERROR_RETURN;
+	}
+
+	/* get the first interface handle */
+	error = usbd_device2interface_handle(sc->sc_udev, USLCOM_IFACE_NO,
+	    &sc->sc_iface);
+	if (error != 0) {
+		printf("%s: could not get interface handle\n",
+		    USBDEVNAME(sc->sc_dev));
+		sc->sc_dying = 1;
+		USB_ATTACH_ERROR_RETURN;
+	}
+
+	id = usbd_get_interface_descriptor(sc->sc_iface);
+
+	uca.bulkin = uca.bulkout = -1;
+	for (i = 0; i < id->bNumEndpoints; i++) {
+		ed = usbd_interface2endpoint_descriptor(sc->sc_iface, i);
+		if (ed == NULL) {
+			printf("%s: no endpoint descriptor found for %d\n",
+			    USBDEVNAME(sc->sc_dev), i);
+			sc->sc_dying = 1;
+			USB_ATTACH_ERROR_RETURN;
+		}
+
+		if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
+		    UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK)
+			uca.bulkin = ed->bEndpointAddress;
+		else if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_OUT &&
+		    UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK)
+			uca.bulkout = ed->bEndpointAddress;
+	}
+
+	if (uca.bulkin == -1 || uca.bulkout == -1) {
+		printf("%s: missing endpoint\n", USBDEVNAME(sc->sc_dev));
+		sc->sc_dying = 1;
+		USB_ATTACH_ERROR_RETURN;
+	}
+
+	uca.ibufsize = USLCOMBUFSZ;
+	uca.obufsize = USLCOMBUFSZ;
+	uca.ibufsizepad = USLCOMBUFSZ;
+	uca.opkthdrlen = 0;
+	uca.device = sc->sc_udev;
+	uca.iface = sc->sc_iface;
+	uca.methods = &uslcom_methods;
+	uca.arg = sc;
+	uca.info = NULL;
+
+	usbd_add_drv_event(USB_EVENT_DRIVER_ATTACH, sc->sc_udev,
+	    USBDEV(sc->sc_dev));
+	
+	sc->sc_subdev = config_found_sm(self, &uca, ucomprint, ucomsubmatch);
+
+	USB_ATTACH_SUCCESS_RETURN;
+}
+
+USB_DETACH(uslcom)
+{
+	USB_DETACH_START(uslcom, sc);
+	int rv = 0;
+
+	sc->sc_dying = 1;
+	if (sc->sc_subdev != NULL) {
+		rv = config_detach(sc->sc_subdev, flags);
+		sc->sc_subdev = NULL;
+	}
+
+	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH, sc->sc_udev,
+			   USBDEV(sc->sc_dev));
+
+	return (rv);
+}
+
+int
+uslcom_activate(device_ptr_t self, enum devact act)
+{
+	struct uslcom_softc *sc = (struct uslcom_softc *)self;
+	int rv = 0;
+
+	switch (act) {
+	case DVACT_ACTIVATE:
+		return (EOPNOTSUPP);
+
+	case DVACT_DEACTIVATE:
+		if (sc->sc_subdev != NULL)
+			rv = config_deactivate(sc->sc_subdev);
+		sc->sc_dying = 1;
+		break;
+	}
+	return (rv);
+}
+
+Static int
+uslcom_open(void *vsc, int portno)
+{
+	struct uslcom_softc *sc = vsc;
+	usb_device_request_t req;
+	usbd_status err;
+
+	if (sc->sc_dying)
+		return (EIO);
+
+	req.bmRequestType = USLCOM_WRITE;
+	req.bRequest = USLCOM_UART;
+	USETW(req.wValue, USLCOM_UART_ENABLE);
+	USETW(req.wIndex, portno);
+	USETW(req.wLength, 0);
+	err = usbd_do_request(sc->sc_udev, &req, NULL);
+	if (err)
+		return (EIO);
+
+	return (0);
+}
+
+Static void
+uslcom_set(void *vsc, int portno, int reg, int onoff)
+{
+	struct uslcom_softc *sc = vsc;
+	usb_device_request_t req;
+	int ctl;
+
+	switch (reg) {
+	case UCOM_SET_DTR:
+		ctl = onoff ? USLCOM_CTRL_DTR_ON : 0;
+		ctl |= USLCOM_CTRL_DTR_SET;
+		break;
+	case UCOM_SET_RTS:
+		ctl = onoff ? USLCOM_CTRL_RTS_ON : 0;
+		ctl |= USLCOM_CTRL_RTS_SET;
+		break;
+	case UCOM_SET_BREAK:
+		uslcom_break(sc, portno, onoff);
+		return;
+	default:
+		return;
+	}
+	req.bmRequestType = USLCOM_WRITE;
+	req.bRequest = USLCOM_CTRL;
+	USETW(req.wValue, ctl);
+	USETW(req.wIndex, portno);
+	USETW(req.wLength, 0);
+	usbd_do_request(sc->sc_udev, &req, NULL);
+}
+
+Static int
+uslcom_param(void *vsc, int portno, struct termios *t)
+{
+	struct uslcom_softc *sc = (struct uslcom_softc *)vsc;
+	usbd_status err;
+	usb_device_request_t req;
+	int data;
+
+	switch (t->c_ospeed) {
+	case 600:
+	case 1200:
+	case 1800:
+	case 2400:
+	case 4800:
+	case 9600:
+	case 19200:
+	case 38400:
+	case 57600:
+	case 115200:
+	case 460800:
+	case 921600:
+		req.bmRequestType = USLCOM_WRITE;
+		req.bRequest = USLCOM_BAUD_RATE;
+		USETW(req.wValue, USLCOM_BAUD_REF / t->c_ospeed);
+		USETW(req.wIndex, portno);
+		USETW(req.wLength, 0);
+		err = usbd_do_request(sc->sc_udev, &req, NULL);
+		if (err)
+			return (EIO);
+		break;
+	default:
+		return (EINVAL);
+	}
+
+	if (ISSET(t->c_cflag, CSTOPB))
+		data = USLCOM_STOP_BITS_2;
+	else
+		data = USLCOM_STOP_BITS_1;
+	if (ISSET(t->c_cflag, PARENB)) {
+		if (ISSET(t->c_cflag, PARODD))
+			data |= USLCOM_PARITY_ODD;
+		else
+			data |= USLCOM_PARITY_EVEN;
+	} else
+		data |= USLCOM_PARITY_NONE;
+	switch (ISSET(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_DATA;
+	USETW(req.wValue, data);
+	USETW(req.wIndex, portno);
+	USETW(req.wLength, 0);
+	err = usbd_do_request(sc->sc_udev, &req, NULL);
+	if (err)
+		return (EIO);
+
+#if 0
+	/* XXX flow control */
+	if (ISSET(t->c_cflag, CRTSCTS))
+		/*  rts/cts flow ctl */
+	} else if (ISSET(t->c_iflag, IXON|IXOFF)) {
+		/*  xon/xoff flow ctl */
+	} else {
+		/* disable flow ctl */
+	}
+#endif
+
+	return (0);
+}
+
+void
+uslcom_get_status(void *vsc, int portno, u_char *lsr, u_char *msr)
+{
+	struct uslcom_softc *sc = vsc;
+	
+	if (msr != NULL)
+		*msr = sc->sc_msr;
+	if (lsr != NULL)
+		*lsr = sc->sc_lsr;
+}
+
+void
+uslcom_break(void *vsc, int portno, int onoff)
+{
+	struct uslcom_softc *sc = vsc;
+	usb_device_request_t req;
+	int brk = onoff ? USLCOM_BREAK_ON : USLCOM_BREAK_OFF;	
+
+	req.bmRequestType = USLCOM_WRITE;
+	req.bRequest = USLCOM_BREAK;
+	USETW(req.wValue, brk);
+	USETW(req.wIndex, portno);
+	USETW(req.wLength, 0);
+	usbd_do_request(sc->sc_udev, &req, NULL);
+}