xref: /freebsd/sys/dev/usb/serial/umct.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 #include <sys/cdefs.h>
2 __FBSDID("$FreeBSD$");
3 
4 /*-
5  * Copyright (c) 2003 Scott Long
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  */
30 
31 /*
32  * Driver for the MCT (Magic Control Technology) USB-RS232 Converter.
33  * Based on the superb documentation from the linux mct_u232 driver by
34  * Wolfgang Grandeggar <wolfgang@cec.ch>.
35  * This device smells a lot like the Belkin F5U103, except that it has
36  * suffered some mild brain-damage.  This driver is based off of the ubsa.c
37  * driver from Alexander Kabaev <kan@FreeBSD.org>.  Merging the two together
38  * might be useful, though the subtle differences might lead to lots of
39  * #ifdef's.
40  */
41 
42 /*
43  * NOTE: all function names beginning like "umct_cfg_" can only
44  * be called from within the config thread function !
45  */
46 
47 #include <sys/stdint.h>
48 #include <sys/stddef.h>
49 #include <sys/param.h>
50 #include <sys/queue.h>
51 #include <sys/types.h>
52 #include <sys/systm.h>
53 #include <sys/kernel.h>
54 #include <sys/bus.h>
55 #include <sys/module.h>
56 #include <sys/lock.h>
57 #include <sys/mutex.h>
58 #include <sys/condvar.h>
59 #include <sys/sysctl.h>
60 #include <sys/sx.h>
61 #include <sys/unistd.h>
62 #include <sys/callout.h>
63 #include <sys/malloc.h>
64 #include <sys/priv.h>
65 
66 #include <dev/usb/usb.h>
67 #include <dev/usb/usbdi.h>
68 #include <dev/usb/usbdi_util.h>
69 #include "usbdevs.h"
70 
71 #define	USB_DEBUG_VAR usb_debug
72 #include <dev/usb/usb_debug.h>
73 #include <dev/usb/usb_process.h>
74 
75 #include <dev/usb/serial/usb_serial.h>
76 
77 /* The UMCT advertises the standard 8250 UART registers */
78 #define	UMCT_GET_MSR		2	/* Get Modem Status Register */
79 #define	UMCT_GET_MSR_SIZE	1
80 #define	UMCT_GET_LCR		6	/* Get Line Control Register */
81 #define	UMCT_GET_LCR_SIZE	1
82 #define	UMCT_SET_BAUD		5	/* Set the Baud Rate Divisor */
83 #define	UMCT_SET_BAUD_SIZE	4
84 #define	UMCT_SET_LCR		7	/* Set Line Control Register */
85 #define	UMCT_SET_LCR_SIZE	1
86 #define	UMCT_SET_MCR		10	/* Set Modem Control Register */
87 #define	UMCT_SET_MCR_SIZE	1
88 
89 #define	UMCT_INTR_INTERVAL	100
90 #define	UMCT_IFACE_INDEX	0
91 #define	UMCT_CONFIG_INDEX	0
92 
93 enum {
94 	UMCT_BULK_DT_WR,
95 	UMCT_BULK_DT_RD,
96 	UMCT_INTR_DT_RD,
97 	UMCT_N_TRANSFER,
98 };
99 
100 struct umct_softc {
101 	struct ucom_super_softc sc_super_ucom;
102 	struct ucom_softc sc_ucom;
103 
104 	struct usb_device *sc_udev;
105 	struct usb_xfer *sc_xfer[UMCT_N_TRANSFER];
106 	struct mtx sc_mtx;
107 
108 	uint32_t sc_unit;
109 
110 	uint16_t sc_obufsize;
111 
112 	uint8_t	sc_lsr;
113 	uint8_t	sc_msr;
114 	uint8_t	sc_lcr;
115 	uint8_t	sc_mcr;
116 	uint8_t	sc_iface_no;
117 	uint8_t sc_swap_cb;
118 	uint8_t	sc_name[16];
119 };
120 
121 /* prototypes */
122 
123 static device_probe_t umct_probe;
124 static device_attach_t umct_attach;
125 static device_detach_t umct_detach;
126 
127 static usb_callback_t umct_intr_callback;
128 static usb_callback_t umct_intr_callback_sub;
129 static usb_callback_t umct_read_callback;
130 static usb_callback_t umct_read_callback_sub;
131 static usb_callback_t umct_write_callback;
132 
133 static void	umct_cfg_do_request(struct umct_softc *sc, uint8_t request,
134 		    uint16_t len, uint32_t value);
135 static void	umct_cfg_get_status(struct ucom_softc *, uint8_t *,
136 		    uint8_t *);
137 static void	umct_cfg_set_break(struct ucom_softc *, uint8_t);
138 static void	umct_cfg_set_dtr(struct ucom_softc *, uint8_t);
139 static void	umct_cfg_set_rts(struct ucom_softc *, uint8_t);
140 static uint8_t	umct_calc_baud(uint32_t);
141 static int	umct_pre_param(struct ucom_softc *, struct termios *);
142 static void	umct_cfg_param(struct ucom_softc *, struct termios *);
143 static void	umct_start_read(struct ucom_softc *);
144 static void	umct_stop_read(struct ucom_softc *);
145 static void	umct_start_write(struct ucom_softc *);
146 static void	umct_stop_write(struct ucom_softc *);
147 static void	umct_poll(struct ucom_softc *ucom);
148 
149 static const struct usb_config umct_config[UMCT_N_TRANSFER] = {
150 
151 	[UMCT_BULK_DT_WR] = {
152 		.type = UE_BULK,
153 		.endpoint = UE_ADDR_ANY,
154 		.direction = UE_DIR_OUT,
155 		.bufsize = 0,	/* use wMaxPacketSize */
156 		.flags = {.pipe_bof = 1,.force_short_xfer = 1,},
157 		.callback = &umct_write_callback,
158 	},
159 
160 	[UMCT_BULK_DT_RD] = {
161 		.type = UE_INTERRUPT,
162 		.endpoint = UE_ADDR_ANY,
163 		.direction = UE_DIR_IN,
164 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
165 		.bufsize = 0,	/* use wMaxPacketSize */
166 		.callback = &umct_read_callback,
167 		.ep_index = 0,		/* first interrupt endpoint */
168 	},
169 
170 	[UMCT_INTR_DT_RD] = {
171 		.type = UE_INTERRUPT,
172 		.endpoint = UE_ADDR_ANY,
173 		.direction = UE_DIR_IN,
174 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
175 		.bufsize = 0,	/* use wMaxPacketSize */
176 		.callback = &umct_intr_callback,
177 		.ep_index = 1,		/* second interrupt endpoint */
178 	},
179 };
180 
181 static const struct ucom_callback umct_callback = {
182 	.ucom_cfg_get_status = &umct_cfg_get_status,
183 	.ucom_cfg_set_dtr = &umct_cfg_set_dtr,
184 	.ucom_cfg_set_rts = &umct_cfg_set_rts,
185 	.ucom_cfg_set_break = &umct_cfg_set_break,
186 	.ucom_cfg_param = &umct_cfg_param,
187 	.ucom_pre_param = &umct_pre_param,
188 	.ucom_start_read = &umct_start_read,
189 	.ucom_stop_read = &umct_stop_read,
190 	.ucom_start_write = &umct_start_write,
191 	.ucom_stop_write = &umct_stop_write,
192 	.ucom_poll = &umct_poll,
193 };
194 
195 static const STRUCT_USB_HOST_ID umct_devs[] = {
196 	{USB_VPI(USB_VENDOR_MCT, USB_PRODUCT_MCT_USB232, 0)},
197 	{USB_VPI(USB_VENDOR_MCT, USB_PRODUCT_MCT_SITECOM_USB232, 0)},
198 	{USB_VPI(USB_VENDOR_MCT, USB_PRODUCT_MCT_DU_H3SP_USB232, 0)},
199 	{USB_VPI(USB_VENDOR_BELKIN, USB_PRODUCT_BELKIN_F5U109, 0)},
200 	{USB_VPI(USB_VENDOR_BELKIN, USB_PRODUCT_BELKIN_F5U409, 0)},
201 };
202 
203 static device_method_t umct_methods[] = {
204 	DEVMETHOD(device_probe, umct_probe),
205 	DEVMETHOD(device_attach, umct_attach),
206 	DEVMETHOD(device_detach, umct_detach),
207 	{0, 0}
208 };
209 
210 static devclass_t umct_devclass;
211 
212 static driver_t umct_driver = {
213 	.name = "umct",
214 	.methods = umct_methods,
215 	.size = sizeof(struct umct_softc),
216 };
217 
218 DRIVER_MODULE(umct, uhub, umct_driver, umct_devclass, NULL, 0);
219 MODULE_DEPEND(umct, ucom, 1, 1, 1);
220 MODULE_DEPEND(umct, usb, 1, 1, 1);
221 MODULE_VERSION(umct, 1);
222 
223 static int
224 umct_probe(device_t dev)
225 {
226 	struct usb_attach_arg *uaa = device_get_ivars(dev);
227 
228 	if (uaa->usb_mode != USB_MODE_HOST) {
229 		return (ENXIO);
230 	}
231 	if (uaa->info.bConfigIndex != UMCT_CONFIG_INDEX) {
232 		return (ENXIO);
233 	}
234 	if (uaa->info.bIfaceIndex != UMCT_IFACE_INDEX) {
235 		return (ENXIO);
236 	}
237 	return (usbd_lookup_id_by_uaa(umct_devs, sizeof(umct_devs), uaa));
238 }
239 
240 static int
241 umct_attach(device_t dev)
242 {
243 	struct usb_attach_arg *uaa = device_get_ivars(dev);
244 	struct umct_softc *sc = device_get_softc(dev);
245 	int32_t error;
246 	uint16_t maxp;
247 	uint8_t iface_index;
248 
249 	sc->sc_udev = uaa->device;
250 	sc->sc_unit = device_get_unit(dev);
251 
252 	device_set_usb_desc(dev);
253 	mtx_init(&sc->sc_mtx, "umct", NULL, MTX_DEF);
254 
255 	snprintf(sc->sc_name, sizeof(sc->sc_name),
256 	    "%s", device_get_nameunit(dev));
257 
258 	sc->sc_iface_no = uaa->info.bIfaceNum;
259 
260 	iface_index = UMCT_IFACE_INDEX;
261 	error = usbd_transfer_setup(uaa->device, &iface_index,
262 	    sc->sc_xfer, umct_config, UMCT_N_TRANSFER, sc, &sc->sc_mtx);
263 
264 	if (error) {
265 		device_printf(dev, "allocating USB "
266 		    "transfers failed\n");
267 		goto detach;
268 	}
269 
270 	/*
271 	 * The real bulk-in endpoint is also marked as an interrupt.
272 	 * The only way to differentiate it from the real interrupt
273 	 * endpoint is to look at the wMaxPacketSize field.
274 	 */
275 	maxp = usbd_xfer_max_framelen(sc->sc_xfer[UMCT_BULK_DT_RD]);
276 	if (maxp == 0x2) {
277 
278 		/* guessed wrong - switch around endpoints */
279 
280 		struct usb_xfer *temp = sc->sc_xfer[UMCT_INTR_DT_RD];
281 
282 		sc->sc_xfer[UMCT_INTR_DT_RD] = sc->sc_xfer[UMCT_BULK_DT_RD];
283 		sc->sc_xfer[UMCT_BULK_DT_RD] = temp;
284 		sc->sc_swap_cb = 1;
285 	}
286 
287 	sc->sc_obufsize = usbd_xfer_max_len(sc->sc_xfer[UMCT_BULK_DT_WR]);
288 
289 	if (uaa->info.idProduct == USB_PRODUCT_MCT_SITECOM_USB232) {
290 		if (sc->sc_obufsize > 16) {
291 			sc->sc_obufsize = 16;
292 		}
293 	}
294 	error = ucom_attach(&sc->sc_super_ucom, &sc->sc_ucom, 1, sc,
295 	    &umct_callback, &sc->sc_mtx);
296 	if (error) {
297 		goto detach;
298 	}
299 	ucom_set_pnpinfo_usb(&sc->sc_super_ucom, dev);
300 
301 	return (0);			/* success */
302 
303 detach:
304 	umct_detach(dev);
305 	return (ENXIO);			/* failure */
306 }
307 
308 static int
309 umct_detach(device_t dev)
310 {
311 	struct umct_softc *sc = device_get_softc(dev);
312 
313 	ucom_detach(&sc->sc_super_ucom, &sc->sc_ucom);
314 	usbd_transfer_unsetup(sc->sc_xfer, UMCT_N_TRANSFER);
315 	mtx_destroy(&sc->sc_mtx);
316 
317 	return (0);
318 }
319 
320 static void
321 umct_cfg_do_request(struct umct_softc *sc, uint8_t request,
322     uint16_t len, uint32_t value)
323 {
324 	struct usb_device_request req;
325 	usb_error_t err;
326 	uint8_t temp[4];
327 
328 	if (len > 4)
329 		len = 4;
330 	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
331 	req.bRequest = request;
332 	USETW(req.wValue, 0);
333 	req.wIndex[0] = sc->sc_iface_no;
334 	req.wIndex[1] = 0;
335 	USETW(req.wLength, len);
336 	USETDW(temp, value);
337 
338 	err = ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
339 	    &req, temp, 0, 1000);
340 	if (err) {
341 		DPRINTFN(0, "device request failed, err=%s "
342 		    "(ignored)\n", usbd_errstr(err));
343 	}
344 	return;
345 }
346 
347 static void
348 umct_intr_callback_sub(struct usb_xfer *xfer, usb_error_t error)
349 {
350 	struct umct_softc *sc = usbd_xfer_softc(xfer);
351 	struct usb_page_cache *pc;
352 	uint8_t buf[2];
353 	int actlen;
354 
355 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
356 
357 	switch (USB_GET_STATE(xfer)) {
358 	case USB_ST_TRANSFERRED:
359 		if (actlen < 2) {
360 			DPRINTF("too short message\n");
361 			goto tr_setup;
362 		}
363 		pc = usbd_xfer_get_frame(xfer, 0);
364 		usbd_copy_out(pc, 0, buf, sizeof(buf));
365 
366 		sc->sc_msr = buf[0];
367 		sc->sc_lsr = buf[1];
368 
369 		ucom_status_change(&sc->sc_ucom);
370 
371 	case USB_ST_SETUP:
372 tr_setup:
373 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
374 		usbd_transfer_submit(xfer);
375 		return;
376 
377 	default:			/* Error */
378 		if (error != USB_ERR_CANCELLED) {
379 			/* try to clear stall first */
380 			usbd_xfer_set_stall(xfer);
381 			goto tr_setup;
382 		}
383 		return;
384 	}
385 }
386 
387 static void
388 umct_cfg_get_status(struct ucom_softc *ucom, uint8_t *lsr, uint8_t *msr)
389 {
390 	struct umct_softc *sc = ucom->sc_parent;
391 
392 	*lsr = sc->sc_lsr;
393 	*msr = sc->sc_msr;
394 }
395 
396 static void
397 umct_cfg_set_break(struct ucom_softc *ucom, uint8_t onoff)
398 {
399 	struct umct_softc *sc = ucom->sc_parent;
400 
401 	if (onoff)
402 		sc->sc_lcr |= 0x40;
403 	else
404 		sc->sc_lcr &= ~0x40;
405 
406 	umct_cfg_do_request(sc, UMCT_SET_LCR, UMCT_SET_LCR_SIZE, sc->sc_lcr);
407 }
408 
409 static void
410 umct_cfg_set_dtr(struct ucom_softc *ucom, uint8_t onoff)
411 {
412 	struct umct_softc *sc = ucom->sc_parent;
413 
414 	if (onoff)
415 		sc->sc_mcr |= 0x01;
416 	else
417 		sc->sc_mcr &= ~0x01;
418 
419 	umct_cfg_do_request(sc, UMCT_SET_MCR, UMCT_SET_MCR_SIZE, sc->sc_mcr);
420 }
421 
422 static void
423 umct_cfg_set_rts(struct ucom_softc *ucom, uint8_t onoff)
424 {
425 	struct umct_softc *sc = ucom->sc_parent;
426 
427 	if (onoff)
428 		sc->sc_mcr |= 0x02;
429 	else
430 		sc->sc_mcr &= ~0x02;
431 
432 	umct_cfg_do_request(sc, UMCT_SET_MCR, UMCT_SET_MCR_SIZE, sc->sc_mcr);
433 }
434 
435 static uint8_t
436 umct_calc_baud(uint32_t baud)
437 {
438 	switch (baud) {
439 		case B300:return (0x1);
440 	case B600:
441 		return (0x2);
442 	case B1200:
443 		return (0x3);
444 	case B2400:
445 		return (0x4);
446 	case B4800:
447 		return (0x6);
448 	case B9600:
449 		return (0x8);
450 	case B19200:
451 		return (0x9);
452 	case B38400:
453 		return (0xa);
454 	case B57600:
455 		return (0xb);
456 	case 115200:
457 		return (0xc);
458 	case B0:
459 	default:
460 		break;
461 	}
462 	return (0x0);
463 }
464 
465 static int
466 umct_pre_param(struct ucom_softc *ucom, struct termios *t)
467 {
468 	return (0);			/* we accept anything */
469 }
470 
471 static void
472 umct_cfg_param(struct ucom_softc *ucom, struct termios *t)
473 {
474 	struct umct_softc *sc = ucom->sc_parent;
475 	uint32_t value;
476 
477 	value = umct_calc_baud(t->c_ospeed);
478 	umct_cfg_do_request(sc, UMCT_SET_BAUD, UMCT_SET_BAUD_SIZE, value);
479 
480 	value = (sc->sc_lcr & 0x40);
481 
482 	switch (t->c_cflag & CSIZE) {
483 	case CS5:
484 		value |= 0x0;
485 		break;
486 	case CS6:
487 		value |= 0x1;
488 		break;
489 	case CS7:
490 		value |= 0x2;
491 		break;
492 	default:
493 	case CS8:
494 		value |= 0x3;
495 		break;
496 	}
497 
498 	value |= (t->c_cflag & CSTOPB) ? 0x4 : 0;
499 	if (t->c_cflag & PARENB) {
500 		value |= 0x8;
501 		value |= (t->c_cflag & PARODD) ? 0x0 : 0x10;
502 	}
503 	/*
504 	 * XXX There doesn't seem to be a way to tell the device
505 	 * to use flow control.
506 	 */
507 
508 	sc->sc_lcr = value;
509 	umct_cfg_do_request(sc, UMCT_SET_LCR, UMCT_SET_LCR_SIZE, value);
510 }
511 
512 static void
513 umct_start_read(struct ucom_softc *ucom)
514 {
515 	struct umct_softc *sc = ucom->sc_parent;
516 
517 	/* start interrupt endpoint */
518 	usbd_transfer_start(sc->sc_xfer[UMCT_INTR_DT_RD]);
519 
520 	/* start read endpoint */
521 	usbd_transfer_start(sc->sc_xfer[UMCT_BULK_DT_RD]);
522 }
523 
524 static void
525 umct_stop_read(struct ucom_softc *ucom)
526 {
527 	struct umct_softc *sc = ucom->sc_parent;
528 
529 	/* stop interrupt endpoint */
530 	usbd_transfer_stop(sc->sc_xfer[UMCT_INTR_DT_RD]);
531 
532 	/* stop read endpoint */
533 	usbd_transfer_stop(sc->sc_xfer[UMCT_BULK_DT_RD]);
534 }
535 
536 static void
537 umct_start_write(struct ucom_softc *ucom)
538 {
539 	struct umct_softc *sc = ucom->sc_parent;
540 
541 	usbd_transfer_start(sc->sc_xfer[UMCT_BULK_DT_WR]);
542 }
543 
544 static void
545 umct_stop_write(struct ucom_softc *ucom)
546 {
547 	struct umct_softc *sc = ucom->sc_parent;
548 
549 	usbd_transfer_stop(sc->sc_xfer[UMCT_BULK_DT_WR]);
550 }
551 
552 static void
553 umct_read_callback(struct usb_xfer *xfer, usb_error_t error)
554 {
555 	struct umct_softc *sc = usbd_xfer_softc(xfer);
556 
557 	if (sc->sc_swap_cb)
558 		umct_intr_callback_sub(xfer, error);
559 	else
560 		umct_read_callback_sub(xfer, error);
561 }
562 
563 static void
564 umct_intr_callback(struct usb_xfer *xfer, usb_error_t error)
565 {
566 	struct umct_softc *sc = usbd_xfer_softc(xfer);
567 
568 	if (sc->sc_swap_cb)
569 		umct_read_callback_sub(xfer, error);
570 	else
571 		umct_intr_callback_sub(xfer, error);
572 }
573 
574 static void
575 umct_write_callback(struct usb_xfer *xfer, usb_error_t error)
576 {
577 	struct umct_softc *sc = usbd_xfer_softc(xfer);
578 	struct usb_page_cache *pc;
579 	uint32_t actlen;
580 
581 	switch (USB_GET_STATE(xfer)) {
582 	case USB_ST_SETUP:
583 	case USB_ST_TRANSFERRED:
584 tr_setup:
585 		pc = usbd_xfer_get_frame(xfer, 0);
586 		if (ucom_get_data(&sc->sc_ucom, pc, 0,
587 		    sc->sc_obufsize, &actlen)) {
588 
589 			usbd_xfer_set_frame_len(xfer, 0, actlen);
590 			usbd_transfer_submit(xfer);
591 		}
592 		return;
593 
594 	default:			/* Error */
595 		if (error != USB_ERR_CANCELLED) {
596 			/* try to clear stall first */
597 			usbd_xfer_set_stall(xfer);
598 			goto tr_setup;
599 		}
600 		return;
601 	}
602 }
603 
604 static void
605 umct_read_callback_sub(struct usb_xfer *xfer, usb_error_t error)
606 {
607 	struct umct_softc *sc = usbd_xfer_softc(xfer);
608 	struct usb_page_cache *pc;
609 	int actlen;
610 
611 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
612 
613 	switch (USB_GET_STATE(xfer)) {
614 	case USB_ST_TRANSFERRED:
615 		pc = usbd_xfer_get_frame(xfer, 0);
616 		ucom_put_data(&sc->sc_ucom, pc, 0, actlen);
617 
618 	case USB_ST_SETUP:
619 tr_setup:
620 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
621 		usbd_transfer_submit(xfer);
622 		return;
623 
624 	default:			/* Error */
625 		if (error != USB_ERR_CANCELLED) {
626 			/* try to clear stall first */
627 			usbd_xfer_set_stall(xfer);
628 			goto tr_setup;
629 		}
630 		return;
631 	}
632 }
633 
634 static void
635 umct_poll(struct ucom_softc *ucom)
636 {
637 	struct umct_softc *sc = ucom->sc_parent;
638 	usbd_transfer_poll(sc->sc_xfer, UMCT_N_TRANSFER);
639 }
640