xref: /netbsd-src/sys/dev/usb/u3g.c (revision 7330f729ccf0bd976a06f95fad452fe774fc7fd1)
1 /*	$NetBSD: u3g.c,v 1.37 2019/05/09 02:43:35 mrg Exp $	*/
2 
3 /*-
4  * Copyright (c) 2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 /*
32  * Copyright (c) 2008 AnyWi Technologies
33  *   Author: Andrea Guzzo <aguzzo@anywi.com>
34  *   * based on uark.c 1.1 2006/08/14 08:30:22 jsg *
35  *   * parts from ubsa.c 183348 2008-09-25 12:00:56Z phk *
36  *
37  * Permission to use, copy, modify, and distribute this software for any
38  * purpose with or without fee is hereby granted, provided that the above
39  * copyright notice and this permission notice appear in all copies.
40  *
41  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
42  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
43  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
44  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
45  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
46  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
47  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
48  *
49  * $FreeBSD$
50  */
51 
52 #include <sys/cdefs.h>
53 __KERNEL_RCSID(0, "$NetBSD: u3g.c,v 1.37 2019/05/09 02:43:35 mrg Exp $");
54 
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #include <sys/kernel.h>
58 #include <sys/kmem.h>
59 #include <sys/bus.h>
60 #include <sys/conf.h>
61 #include <sys/tty.h>
62 
63 #include <dev/usb/usb.h>
64 #include <dev/usb/usbdi.h>
65 #include <dev/usb/usbdivar.h>
66 #include <dev/usb/usbdi_util.h>
67 
68 #include <dev/usb/ucomvar.h>
69 
70 #include "usbdevs.h"
71 
72 /*
73  * We read/write data from/to the device in 4KB chunks to maximise
74  * performance.
75  */
76 #define U3G_BUFF_SIZE	4096
77 
78 /*
79  * Some 3G devices (the Huawei E160/E220 springs to mind here) buffer up
80  * data internally even when the USB pipes are closed. So on first open,
81  * we can receive a large chunk of stale data.
82  *
83  * This causes a real problem because the default TTYDEF_LFLAG (applied
84  * on first open) has the ECHO flag set, resulting in all the stale data
85  * being echoed straight back to the device by the tty(4) layer. Some
86  * devices (again, the Huawei E160/E220 for example) react to this spew
87  * by going catatonic.
88  *
89  * All this happens before the application gets a chance to disable ECHO.
90  *
91  * We work around this by ignoring all data received from the device for
92  * a period of two seconds, or until the application starts sending data -
93  * whichever comes first.
94  */
95 #define	U3G_PURGE_SECS	2
96 
97 /*
98  * Define bits for the virtual modem control pins.
99  * The input pin states are reported via the interrupt pipe on some devices.
100  */
101 #define	U3G_OUTPIN_DTR	(1u << 0)
102 #define	U3G_OUTPIN_RTS	(1u << 1)
103 #define	U3G_INPIN_DCD	(1u << 0)
104 #define	U3G_INPIN_DSR	(1u << 1)
105 #define	U3G_INPIN_RI	(1u << 3)
106 
107 /*
108  * USB request to set the output pin status
109  */
110 #define	U3G_SET_PIN	0x22
111 
112 struct u3g_softc {
113 	device_t		sc_dev;
114 	struct usbd_device *	sc_udev;
115 	bool			sc_dying;	/* We're going away */
116 	int			sc_ifaceno;	/* Device interface number */
117 
118 	struct u3g_com {
119 		device_t	c_dev;		/* Child ucom(4) handle */
120 
121 		bool		c_open;		/* Device is in use */
122 		bool		c_purging;	/* Purging stale data */
123 		struct timeval	c_purge_start;	/* Control duration of purge */
124 
125 		u_char		c_msr;		/* Emulated 'msr' */
126 		uint16_t	c_outpins;	/* Output pin state */
127 	} sc_com[10];
128 	size_t			sc_ncom;
129 
130 	struct usbd_pipe *	sc_intr_pipe;	/* Interrupt pipe */
131 	u_char			*sc_intr_buff;	/* Interrupt buffer */
132 	size_t			sc_intr_size;	/* buffer size */
133 };
134 
135 /*
136  * The device driver has two personalities. The first uses the 'usbdevif'
137  * interface attribute so that a match will claim the entire USB device
138  * for itself. This is used for when a device needs to be mode-switched
139  * and ensures any other interfaces present cannot be claimed by other
140  * drivers while the mode-switch is in progress. This is implemented by
141  * the umodeswitch driver.
142  *
143  * The second personality uses the 'usbifif' interface attribute so that
144  * it can claim the 3G modem interfaces for itself, leaving others (such
145  * as the mass storage interfaces on some devices) for other drivers.
146  */
147 
148 static int u3g_match(device_t, cfdata_t, void *);
149 static void u3g_attach(device_t, device_t, void *);
150 static int u3g_detach(device_t, int);
151 static void u3g_childdet(device_t, device_t);
152 
153 CFATTACH_DECL2_NEW(u3g, sizeof(struct u3g_softc), u3g_match,
154     u3g_attach, u3g_detach, NULL, NULL, u3g_childdet);
155 
156 
157 static void u3g_intr(struct usbd_xfer *, void *, usbd_status);
158 static void u3g_get_status(void *, int, u_char *, u_char *);
159 static void u3g_set(void *, int, int, int);
160 static int  u3g_open(void *, int);
161 static void u3g_close(void *, int);
162 static void u3g_read(void *, int, u_char **, uint32_t *);
163 static void u3g_write(void *, int, u_char *, u_char *, uint32_t *);
164 
165 struct ucom_methods u3g_methods = {
166 	.ucom_get_status = u3g_get_status,
167 	.ucom_set = u3g_set,
168 	.ucom_open = u3g_open,
169 	.ucom_close = u3g_close,
170 	.ucom_read = u3g_read,
171 	.ucom_write = u3g_write,
172 };
173 
174 /*
175  * Allegedly supported devices
176  */
177 static const struct usb_devno u3g_devs[] = {
178 	{ USB_VENDOR_DELL, USB_PRODUCT_DELL_W5500 },
179 	{ USB_VENDOR_HP, USB_PRODUCT_HP_UN2430 },
180 	/* OEM: Huawei */
181 	{ USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E1750 },
182 	{ USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E1820 },
183 	{ USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E220 },
184 	{ USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_EM770W },
185 	{ USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_K3765 },
186 	{ USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_MOBILE },
187 	{ USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E171 },
188 	{ USB_VENDOR_HUAWEI, USB_PRODUCT_HUAWEI_E353 },
189 	/* LG Electronics */
190 	{ USB_VENDOR_LG, USB_PRODUCT_LG_NTT_DOCOMO_L02C_MODEM },
191 	/* OEM: Merlin */
192 	{ USB_VENDOR_MERLIN, USB_PRODUCT_MERLIN_V620 },
193 	/* OEM: Novatel */
194 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_ES620 },
195 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_EU8X0D },
196 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_MC950D },
197 #if 0
198 	/* These are matched in u3ginit_match() */
199 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_MC950D_DRIVER },
200 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U760_DRIVER },
201 #endif
202 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_MERLINU740 },
203 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_MERLINV620 },
204 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_S720 },
205 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U720 },
206 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U727 },
207 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U740_2 },
208 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U760 },
209 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_U870 },
210 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_V740 },
211 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_X950D },
212 	{ USB_VENDOR_NOVATEL2, USB_PRODUCT_NOVATEL2_XU870 },
213 	/* OEM: Option N.V. */
214 	{ USB_VENDOR_OPTIONNV, USB_PRODUCT_OPTIONNV_QUADPLUSUMTS },
215 	{ USB_VENDOR_OPTIONNV, USB_PRODUCT_OPTIONNV_HSDPA },
216 	{ USB_VENDOR_OPTIONNV, USB_PRODUCT_OPTIONNV_GTMAXHSUPA },
217 
218 	/* OEM: Sierra Wireless: */
219 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC595U },
220 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC597E },
221 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC875U },
222 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC880 },
223 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC880E },
224 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC880U },
225 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC881 },
226 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC881E },
227 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AC881U },
228 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AIRCARD580 },
229 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AIRCARD595 },
230 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_AIRCARD875 },
231 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_C597 },
232 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_EM5625 },
233 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC5720 },
234 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC5720_2 },
235 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC5725 },
236 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8755 },
237 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8755_2 },
238 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8755_3 },
239 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8765 },
240 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8775_2 },
241 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8780 },
242 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MC8781 },
243 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_MINI5725 },
244 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_USB305 },
245 	{ USB_VENDOR_SIERRA, USB_PRODUCT_SIERRA_250U },
246 	/* Toshiba */
247 	{ USB_VENDOR_TOSHIBA, USB_PRODUCT_TOSHIBA_HSDPA_MODEM_EU870DT1 },
248 
249 	/* ZTE */
250 	{ USB_VENDOR_ZTE, USB_PRODUCT_ZTE_MF622 },
251 	{ USB_VENDOR_ZTE, USB_PRODUCT_ZTE_MF626 },
252 	{ USB_VENDOR_ZTE, USB_PRODUCT_ZTE_MF628 },
253 	{ USB_VENDOR_ZTE, USB_PRODUCT_ZTE_MF820D },
254 
255 	/* 4G Systems */
256 	{ USB_VENDOR_LONGCHEER, USB_PRODUCT_LONGCHEER_XSSTICK_P14 },
257 	{ USB_VENDOR_LONGCHEER, USB_PRODUCT_LONGCHEER_XSSTICK_W14 },
258 };
259 
260 /*
261  * Second personality:
262  *
263  * Claim only those interfaces required for 3G modem operation.
264  */
265 
266 static int
267 u3g_match(device_t parent, cfdata_t match, void *aux)
268 {
269 	struct usbif_attach_arg *uiaa = aux;
270 	struct usbd_interface *iface;
271 	usb_interface_descriptor_t *id;
272 	usbd_status error;
273 
274 	if (!usb_lookup(u3g_devs, uiaa->uiaa_vendor, uiaa->uiaa_product))
275 		return UMATCH_NONE;
276 
277 	error = usbd_device2interface_handle(uiaa->uiaa_device,
278 	    uiaa->uiaa_ifaceno, &iface);
279 	if (error) {
280 		printf("u3g_match: failed to get interface, err=%s\n",
281 		    usbd_errstr(error));
282 		return UMATCH_NONE;
283 	}
284 
285 	id = usbd_get_interface_descriptor(iface);
286 	if (id == NULL) {
287 		printf("u3g_match: failed to get interface descriptor\n");
288 		return UMATCH_NONE;
289 	}
290 
291 	/*
292 	 * Huawei modems use the vendor-specific class for all interfaces,
293 	 * both tty and CDC NCM, which we should avoid attaching to.
294 	 */
295 	if (uiaa->uiaa_vendor == USB_VENDOR_HUAWEI &&
296 	    id->bInterfaceSubClass == 2 &&
297 	    (id->bInterfaceProtocol & 0xf) == 6)	/* 0x16, 0x46, 0x76 */
298 		return UMATCH_NONE;
299 
300 	/*
301 	 * 3G modems generally report vendor-specific class
302 	 *
303 	 * XXX: this may be too generalised.
304 	 */
305 	return id->bInterfaceClass == UICLASS_VENDOR ?
306 	    UMATCH_VENDOR_PRODUCT : UMATCH_NONE;
307 }
308 
309 static void
310 u3g_attach(device_t parent, device_t self, void *aux)
311 {
312 	struct u3g_softc *sc = device_private(self);
313 	struct usbif_attach_arg *uiaa = aux;
314 	struct usbd_device *dev = uiaa->uiaa_device;
315 	struct usbd_interface *iface;
316 	usb_interface_descriptor_t *id;
317 	usb_endpoint_descriptor_t *ed;
318 	struct ucom_attach_args ucaa;
319 	usbd_status error;
320 	int n, intr_address, intr_size;
321 
322 	aprint_naive("\n");
323 	aprint_normal("\n");
324 
325 	sc->sc_dev = self;
326 	sc->sc_dying = false;
327 	sc->sc_udev = dev;
328 
329 	error = usbd_device2interface_handle(dev, uiaa->uiaa_ifaceno, &iface);
330 	if (error) {
331 		aprint_error_dev(self, "failed to get interface, err=%s\n",
332 		    usbd_errstr(error));
333 		return;
334 	}
335 
336 	id = usbd_get_interface_descriptor(iface);
337 
338 	ucaa.ucaa_info = "3G Modem";
339 	ucaa.ucaa_ibufsize = U3G_BUFF_SIZE;
340 	ucaa.ucaa_obufsize = U3G_BUFF_SIZE;
341 	ucaa.ucaa_ibufsizepad = U3G_BUFF_SIZE;
342 	ucaa.ucaa_opkthdrlen = 0;
343 	ucaa.ucaa_device = dev;
344 	ucaa.ucaa_iface = iface;
345 	ucaa.ucaa_methods = &u3g_methods;
346 	ucaa.ucaa_arg = sc;
347 	ucaa.ucaa_portno = -1;
348 	ucaa.ucaa_bulkin = ucaa.ucaa_bulkout = -1;
349 
350 	sc->sc_ifaceno = uiaa->uiaa_ifaceno;
351 	intr_address = -1;
352 	intr_size = 0;
353 
354 	for (n = 0; n < id->bNumEndpoints; n++) {
355 		ed = usbd_interface2endpoint_descriptor(iface, n);
356 		if (ed == NULL) {
357 			aprint_error_dev(self, "no endpoint descriptor "
358 			    "for %d (interface: %d)\n", n, sc->sc_ifaceno);
359 			sc->sc_dying = true;
360 			return;
361 		}
362 
363 		if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
364 		    UE_GET_XFERTYPE(ed->bmAttributes) == UE_INTERRUPT) {
365 			intr_address = ed->bEndpointAddress;
366 			intr_size = UGETW(ed->wMaxPacketSize);
367 		} else
368 		if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
369 		    UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK) {
370 			ucaa.ucaa_bulkin = ed->bEndpointAddress;
371 		} else
372 		if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_OUT &&
373 		    UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK) {
374 			ucaa.ucaa_bulkout = ed->bEndpointAddress;
375 		}
376 		if (ucaa.ucaa_bulkin != -1 && ucaa.ucaa_bulkout != -1) {
377 			struct u3g_com *com;
378 			if (sc->sc_ncom == __arraycount(sc->sc_com)) {
379 				aprint_error_dev(self, "Need to configure "
380 				    "more than %zu ttys", sc->sc_ncom);
381 				continue;
382 			}
383 			ucaa.ucaa_portno = sc->sc_ncom++;
384 			com = &sc->sc_com[ucaa.ucaa_portno];
385 			com->c_outpins = 0;
386 			com->c_msr = UMSR_DSR | UMSR_CTS | UMSR_DCD;
387 			com->c_open = false;
388 			com->c_purging = false;
389 			com->c_dev = config_found_sm_loc(self, "ucombus",
390 				NULL, &ucaa, ucomprint, ucomsubmatch);
391 			ucaa.ucaa_bulkin = -1;
392 			ucaa.ucaa_bulkout = -1;
393 		}
394 	}
395 
396 	if (sc->sc_ncom == 0) {
397 		aprint_error_dev(self, "Missing bulk in/out for interface %d\n",
398 		    sc->sc_ifaceno);
399 		sc->sc_dying = true;
400 		return;
401 	}
402 
403 	/*
404 	 * If the interface has an interrupt pipe, open it immediately so
405 	 * that we can track input pin state changes regardless of whether
406 	 * the tty(4) device is open or not.
407 	 */
408 	if (intr_address != -1) {
409 		sc->sc_intr_size = intr_size;
410 		sc->sc_intr_buff = kmem_alloc(intr_size, KM_SLEEP);
411 		error = usbd_open_pipe_intr(iface, intr_address,
412 		    USBD_SHORT_XFER_OK, &sc->sc_intr_pipe, sc, sc->sc_intr_buff,
413 		    intr_size, u3g_intr, 100);
414 		if (error) {
415 			aprint_error_dev(self, "cannot open interrupt pipe "
416 			    "(addr %d)\n", intr_address);
417 			return;
418 		}
419 	} else {
420 		sc->sc_intr_pipe = NULL;
421 		sc->sc_intr_buff = NULL;
422 	}
423 
424 	if (!pmf_device_register(self, NULL, NULL))
425 		aprint_error_dev(self, "couldn't establish power handler\n");
426 }
427 
428 static int
429 u3g_detach(device_t self, int flags)
430 {
431 	struct u3g_softc *sc = device_private(self);
432 	int rv = 0;
433 
434 	sc->sc_dying = true;
435 
436 	if (sc->sc_intr_pipe != NULL) {
437 		usbd_abort_pipe(sc->sc_intr_pipe);
438 		usbd_close_pipe(sc->sc_intr_pipe);
439 		sc->sc_intr_pipe = NULL;
440 	}
441 	if (sc->sc_intr_buff != NULL) {
442 		kmem_free(sc->sc_intr_buff, sc->sc_intr_size);
443 		sc->sc_intr_buff = NULL;
444 	}
445 
446 	for (size_t i = 0; i < sc->sc_ncom; i++)
447 		if (sc->sc_com[i].c_dev != NULL) {
448 			int port_rv;
449 
450 			port_rv = config_detach(sc->sc_com[i].c_dev, flags);
451 			if (port_rv != 0) {
452 				aprint_verbose_dev(self, "Can't deallocate "
453 				    "port (%d)", port_rv);
454 			}
455 			rv |= port_rv;
456 			sc->sc_com[i].c_dev = NULL;
457 		}
458 
459 	pmf_device_deregister(self);
460 
461 	return rv;
462 }
463 
464 static void
465 u3g_childdet(device_t self, device_t child)
466 {
467 	struct u3g_softc *sc = device_private(self);
468 
469 	for (size_t i = 0; i < sc->sc_ncom; i++)
470 		    if (sc->sc_com[i].c_dev == child)
471 			    sc->sc_com[i].c_dev = NULL;
472 }
473 
474 static void
475 u3g_intr(struct usbd_xfer *xfer, void *priv, usbd_status status)
476 {
477 	struct u3g_softc *sc = (struct u3g_softc *)priv;
478 	u_char *buf;
479 	int portno = 0;	/* XXX */
480 	struct u3g_com *com = &sc->sc_com[portno];
481 
482 	if (sc->sc_dying)
483 		return;
484 
485 	if (status != USBD_NORMAL_COMPLETION) {
486 		if (status == USBD_NOT_STARTED || status == USBD_CANCELLED)
487 			return;
488 		usbd_clear_endpoint_stall_async(sc->sc_intr_pipe);
489 		return;
490 	}
491 
492 	buf = sc->sc_intr_buff;
493 	if (buf[0] == 0xa1 && buf[1] == 0x20) {
494 		u_char msr;
495 
496 		msr = com->c_msr & ~(UMSR_DCD | UMSR_DSR | UMSR_RI);
497 
498 		if (buf[8] & U3G_INPIN_DCD)
499 			msr |= UMSR_DCD;
500 
501 		if (buf[8] & U3G_INPIN_DSR)
502 			msr |= UMSR_DSR;
503 
504 		if (buf[8] & U3G_INPIN_RI)
505 			msr |= UMSR_RI;
506 
507 		if (msr != com->c_msr) {
508 			com->c_msr = msr;
509 			if (com->c_open)
510 				ucom_status_change(device_private(com->c_dev));
511 		}
512 	}
513 }
514 
515 /*ARGSUSED*/
516 static void
517 u3g_get_status(void *arg, int portno, u_char *lsr, u_char *msr)
518 {
519 	struct u3g_softc *sc = arg;
520 
521 	*lsr = 0;	/* LSR isn't supported */
522 	*msr = sc->sc_com[portno].c_msr;
523 }
524 
525 /*ARGSUSED*/
526 static void
527 u3g_set(void *arg, int portno, int reg, int onoff)
528 {
529 	struct u3g_softc *sc = arg;
530 	usb_device_request_t req;
531 	uint16_t mask, new_state;
532 	usbd_status err;
533 	struct u3g_com *com = &sc->sc_com[portno];
534 
535 	if (sc->sc_dying)
536 		return;
537 
538 	switch (reg) {
539 	case UCOM_SET_DTR:
540 		mask = U3G_OUTPIN_DTR;
541 		break;
542 	case UCOM_SET_RTS:
543 		mask = U3G_OUTPIN_RTS;
544 		break;
545 	default:
546 		return;
547 	}
548 
549 	new_state = com->c_outpins & ~mask;
550 	if (onoff)
551 		new_state |= mask;
552 
553 	if (new_state == com->c_outpins)
554 		return;
555 
556 	com->c_outpins = new_state;
557 
558 	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
559 	req.bRequest = U3G_SET_PIN;
560 	USETW(req.wValue, new_state);
561 	USETW(req.wIndex, sc->sc_ifaceno);
562 	USETW(req.wLength, 0);
563 
564 	err = usbd_do_request(sc->sc_udev, &req, 0);
565 	if (err == USBD_STALLED)
566 		usbd_clear_endpoint_stall(sc->sc_udev->ud_pipe0);
567 }
568 
569 /*ARGSUSED*/
570 static int
571 u3g_open(void *arg, int portno)
572 {
573 	struct u3g_softc *sc = arg;
574 	usb_device_request_t req;
575 	usb_endpoint_descriptor_t *ed;
576 	usb_interface_descriptor_t *id;
577 	struct usbd_interface *ih;
578 	usbd_status err;
579 	struct u3g_com *com = &sc->sc_com[portno];
580 	int i, nin;
581 
582 	if (sc->sc_dying)
583  		return EIO;
584 
585 	err = usbd_device2interface_handle(sc->sc_udev, sc->sc_ifaceno, &ih);
586 	if (err)
587 		return EIO;
588 
589 	id = usbd_get_interface_descriptor(ih);
590 
591 	for (nin = i = 0; i < id->bNumEndpoints; i++) {
592 		ed = usbd_interface2endpoint_descriptor(ih, i);
593 		if (ed == NULL)
594 			return EIO;
595 
596 		if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
597 		    UE_GET_XFERTYPE(ed->bmAttributes) == UE_BULK &&
598 		    nin++ == portno) {
599 			/* Issue ENDPOINT_HALT request */
600 			req.bmRequestType = UT_WRITE_ENDPOINT;
601 			req.bRequest = UR_CLEAR_FEATURE;
602 			USETW(req.wValue, UF_ENDPOINT_HALT);
603 			USETW(req.wIndex, ed->bEndpointAddress);
604 			USETW(req.wLength, 0);
605 			err = usbd_do_request(sc->sc_udev, &req, 0);
606 			if (err)
607 				return EIO;
608 		}
609 	}
610 
611 	com->c_open = true;
612 	com->c_purging = true;
613 	getmicrotime(&com->c_purge_start);
614 
615 	return 0;
616 }
617 
618 /*ARGSUSED*/
619 static void
620 u3g_close(void *arg, int portno)
621 {
622 	struct u3g_softc *sc = arg;
623 	struct u3g_com *com = &sc->sc_com[portno];
624 
625 	com->c_open = false;
626 }
627 
628 /*ARGSUSED*/
629 static void
630 u3g_read(void *arg, int portno, u_char **cpp, uint32_t *ccp)
631 {
632 	struct u3g_softc *sc = arg;
633 	struct timeval curr_tv, diff_tv;
634 	struct u3g_com *com = &sc->sc_com[portno];
635 
636 	/*
637 	 * If we're not purging input data following first open, do nothing.
638 	 */
639 	if (com->c_purging == false)
640 		return;
641 
642 	/*
643 	 * Otherwise check if the purge timeout has expired
644 	 */
645 	getmicrotime(&curr_tv);
646 	timersub(&curr_tv, &com->c_purge_start, &diff_tv);
647 
648 	if (diff_tv.tv_sec >= U3G_PURGE_SECS) {
649 		/* Timeout expired. */
650 		com->c_purging = false;
651 	} else {
652 		/* Still purging. Adjust the caller's byte count. */
653 		*ccp = 0;
654 	}
655 }
656 
657 /*ARGSUSED*/
658 static void
659 u3g_write(void *arg, int portno, u_char *to, u_char *from, uint32_t *count)
660 {
661 	struct u3g_softc *sc = arg;
662 	struct u3g_com *com = &sc->sc_com[portno];
663 
664 	/*
665 	 * Stop purging as soon as the first data is written to the device.
666 	 */
667 	com->c_purging = false;
668 	memcpy(to, from, *count);
669 }
670