xref: /freebsd/sys/dev/usb/serial/umct.c (revision 3157ba21)
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/linker_set.h>
56 #include <sys/module.h>
57 #include <sys/lock.h>
58 #include <sys/mutex.h>
59 #include <sys/condvar.h>
60 #include <sys/sysctl.h>
61 #include <sys/sx.h>
62 #include <sys/unistd.h>
63 #include <sys/callout.h>
64 #include <sys/malloc.h>
65 #include <sys/priv.h>
66 
67 #include <dev/usb/usb.h>
68 #include <dev/usb/usbdi.h>
69 #include <dev/usb/usbdi_util.h>
70 #include "usbdevs.h"
71 
72 #define	USB_DEBUG_VAR usb_debug
73 #include <dev/usb/usb_debug.h>
74 #include <dev/usb/usb_process.h>
75 
76 #include <dev/usb/serial/usb_serial.h>
77 
78 /* The UMCT advertises the standard 8250 UART registers */
79 #define	UMCT_GET_MSR		2	/* Get Modem Status Register */
80 #define	UMCT_GET_MSR_SIZE	1
81 #define	UMCT_GET_LCR		6	/* Get Line Control Register */
82 #define	UMCT_GET_LCR_SIZE	1
83 #define	UMCT_SET_BAUD		5	/* Set the Baud Rate Divisor */
84 #define	UMCT_SET_BAUD_SIZE	4
85 #define	UMCT_SET_LCR		7	/* Set Line Control Register */
86 #define	UMCT_SET_LCR_SIZE	1
87 #define	UMCT_SET_MCR		10	/* Set Modem Control Register */
88 #define	UMCT_SET_MCR_SIZE	1
89 
90 #define	UMCT_INTR_INTERVAL	100
91 #define	UMCT_IFACE_INDEX	0
92 #define	UMCT_CONFIG_INDEX	0
93 
94 enum {
95 	UMCT_BULK_DT_WR,
96 	UMCT_BULK_DT_RD,
97 	UMCT_INTR_DT_RD,
98 	UMCT_N_TRANSFER,
99 };
100 
101 struct umct_softc {
102 	struct ucom_super_softc sc_super_ucom;
103 	struct ucom_softc sc_ucom;
104 
105 	struct usb_device *sc_udev;
106 	struct usb_xfer *sc_xfer[UMCT_N_TRANSFER];
107 	struct mtx sc_mtx;
108 
109 	uint32_t sc_unit;
110 
111 	uint16_t sc_obufsize;
112 
113 	uint8_t	sc_lsr;
114 	uint8_t	sc_msr;
115 	uint8_t	sc_lcr;
116 	uint8_t	sc_mcr;
117 	uint8_t	sc_iface_no;
118 	uint8_t sc_swap_cb;
119 	uint8_t	sc_name[16];
120 };
121 
122 /* prototypes */
123 
124 static device_probe_t umct_probe;
125 static device_attach_t umct_attach;
126 static device_detach_t umct_detach;
127 
128 static usb_callback_t umct_intr_callback;
129 static usb_callback_t umct_intr_callback_sub;
130 static usb_callback_t umct_read_callback;
131 static usb_callback_t umct_read_callback_sub;
132 static usb_callback_t umct_write_callback;
133 
134 static void	umct_cfg_do_request(struct umct_softc *sc, uint8_t request,
135 		    uint16_t len, uint32_t value);
136 static void	umct_cfg_get_status(struct ucom_softc *, uint8_t *,
137 		    uint8_t *);
138 static void	umct_cfg_set_break(struct ucom_softc *, uint8_t);
139 static void	umct_cfg_set_dtr(struct ucom_softc *, uint8_t);
140 static void	umct_cfg_set_rts(struct ucom_softc *, uint8_t);
141 static uint8_t	umct_calc_baud(uint32_t);
142 static int	umct_pre_param(struct ucom_softc *, struct termios *);
143 static void	umct_cfg_param(struct ucom_softc *, struct termios *);
144 static void	umct_start_read(struct ucom_softc *);
145 static void	umct_stop_read(struct ucom_softc *);
146 static void	umct_start_write(struct ucom_softc *);
147 static void	umct_stop_write(struct ucom_softc *);
148 static void	umct_poll(struct ucom_softc *ucom);
149 
150 static const struct usb_config umct_config[UMCT_N_TRANSFER] = {
151 
152 	[UMCT_BULK_DT_WR] = {
153 		.type = UE_BULK,
154 		.endpoint = UE_ADDR_ANY,
155 		.direction = UE_DIR_OUT,
156 		.bufsize = 0,	/* use wMaxPacketSize */
157 		.flags = {.pipe_bof = 1,.force_short_xfer = 1,},
158 		.callback = &umct_write_callback,
159 	},
160 
161 	[UMCT_BULK_DT_RD] = {
162 		.type = UE_INTERRUPT,
163 		.endpoint = UE_ADDR_ANY,
164 		.direction = UE_DIR_IN,
165 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
166 		.bufsize = 0,	/* use wMaxPacketSize */
167 		.callback = &umct_read_callback,
168 		.ep_index = 0,		/* first interrupt endpoint */
169 	},
170 
171 	[UMCT_INTR_DT_RD] = {
172 		.type = UE_INTERRUPT,
173 		.endpoint = UE_ADDR_ANY,
174 		.direction = UE_DIR_IN,
175 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
176 		.bufsize = 0,	/* use wMaxPacketSize */
177 		.callback = &umct_intr_callback,
178 		.ep_index = 1,		/* second interrupt endpoint */
179 	},
180 };
181 
182 static const struct ucom_callback umct_callback = {
183 	.ucom_cfg_get_status = &umct_cfg_get_status,
184 	.ucom_cfg_set_dtr = &umct_cfg_set_dtr,
185 	.ucom_cfg_set_rts = &umct_cfg_set_rts,
186 	.ucom_cfg_set_break = &umct_cfg_set_break,
187 	.ucom_cfg_param = &umct_cfg_param,
188 	.ucom_pre_param = &umct_pre_param,
189 	.ucom_start_read = &umct_start_read,
190 	.ucom_stop_read = &umct_stop_read,
191 	.ucom_start_write = &umct_start_write,
192 	.ucom_stop_write = &umct_stop_write,
193 	.ucom_poll = &umct_poll,
194 };
195 
196 static const struct usb_device_id umct_devs[] = {
197 	{USB_VPI(USB_VENDOR_MCT, USB_PRODUCT_MCT_USB232, 0)},
198 	{USB_VPI(USB_VENDOR_MCT, USB_PRODUCT_MCT_SITECOM_USB232, 0)},
199 	{USB_VPI(USB_VENDOR_MCT, USB_PRODUCT_MCT_DU_H3SP_USB232, 0)},
200 	{USB_VPI(USB_VENDOR_BELKIN, USB_PRODUCT_BELKIN_F5U109, 0)},
201 	{USB_VPI(USB_VENDOR_BELKIN, USB_PRODUCT_BELKIN_F5U409, 0)},
202 };
203 
204 static device_method_t umct_methods[] = {
205 	DEVMETHOD(device_probe, umct_probe),
206 	DEVMETHOD(device_attach, umct_attach),
207 	DEVMETHOD(device_detach, umct_detach),
208 	{0, 0}
209 };
210 
211 static devclass_t umct_devclass;
212 
213 static driver_t umct_driver = {
214 	.name = "umct",
215 	.methods = umct_methods,
216 	.size = sizeof(struct umct_softc),
217 };
218 
219 DRIVER_MODULE(umct, uhub, umct_driver, umct_devclass, NULL, 0);
220 MODULE_DEPEND(umct, ucom, 1, 1, 1);
221 MODULE_DEPEND(umct, usb, 1, 1, 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 	return (0);			/* success */
300 
301 detach:
302 	umct_detach(dev);
303 	return (ENXIO);			/* failure */
304 }
305 
306 static int
307 umct_detach(device_t dev)
308 {
309 	struct umct_softc *sc = device_get_softc(dev);
310 
311 	ucom_detach(&sc->sc_super_ucom, &sc->sc_ucom, 1);
312 	usbd_transfer_unsetup(sc->sc_xfer, UMCT_N_TRANSFER);
313 	mtx_destroy(&sc->sc_mtx);
314 
315 	return (0);
316 }
317 
318 static void
319 umct_cfg_do_request(struct umct_softc *sc, uint8_t request,
320     uint16_t len, uint32_t value)
321 {
322 	struct usb_device_request req;
323 	usb_error_t err;
324 	uint8_t temp[4];
325 
326 	if (len > 4)
327 		len = 4;
328 	req.bmRequestType = UT_WRITE_VENDOR_DEVICE;
329 	req.bRequest = request;
330 	USETW(req.wValue, 0);
331 	req.wIndex[0] = sc->sc_iface_no;
332 	req.wIndex[1] = 0;
333 	USETW(req.wLength, len);
334 	USETDW(temp, value);
335 
336 	err = ucom_cfg_do_request(sc->sc_udev, &sc->sc_ucom,
337 	    &req, temp, 0, 1000);
338 	if (err) {
339 		DPRINTFN(0, "device request failed, err=%s "
340 		    "(ignored)\n", usbd_errstr(err));
341 	}
342 	return;
343 }
344 
345 static void
346 umct_intr_callback_sub(struct usb_xfer *xfer, usb_error_t error)
347 {
348 	struct umct_softc *sc = usbd_xfer_softc(xfer);
349 	struct usb_page_cache *pc;
350 	uint8_t buf[2];
351 	int actlen;
352 
353 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
354 
355 	switch (USB_GET_STATE(xfer)) {
356 	case USB_ST_TRANSFERRED:
357 		if (actlen < 2) {
358 			DPRINTF("too short message\n");
359 			goto tr_setup;
360 		}
361 		pc = usbd_xfer_get_frame(xfer, 0);
362 		usbd_copy_out(pc, 0, buf, sizeof(buf));
363 
364 		sc->sc_msr = buf[0];
365 		sc->sc_lsr = buf[1];
366 
367 		ucom_status_change(&sc->sc_ucom);
368 
369 	case USB_ST_SETUP:
370 tr_setup:
371 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
372 		usbd_transfer_submit(xfer);
373 		return;
374 
375 	default:			/* Error */
376 		if (error != USB_ERR_CANCELLED) {
377 			/* try to clear stall first */
378 			usbd_xfer_set_stall(xfer);
379 			goto tr_setup;
380 		}
381 		return;
382 	}
383 }
384 
385 static void
386 umct_cfg_get_status(struct ucom_softc *ucom, uint8_t *lsr, uint8_t *msr)
387 {
388 	struct umct_softc *sc = ucom->sc_parent;
389 
390 	*lsr = sc->sc_lsr;
391 	*msr = sc->sc_msr;
392 }
393 
394 static void
395 umct_cfg_set_break(struct ucom_softc *ucom, uint8_t onoff)
396 {
397 	struct umct_softc *sc = ucom->sc_parent;
398 
399 	if (onoff)
400 		sc->sc_lcr |= 0x40;
401 	else
402 		sc->sc_lcr &= ~0x40;
403 
404 	umct_cfg_do_request(sc, UMCT_SET_LCR, UMCT_SET_LCR_SIZE, sc->sc_lcr);
405 }
406 
407 static void
408 umct_cfg_set_dtr(struct ucom_softc *ucom, uint8_t onoff)
409 {
410 	struct umct_softc *sc = ucom->sc_parent;
411 
412 	if (onoff)
413 		sc->sc_mcr |= 0x01;
414 	else
415 		sc->sc_mcr &= ~0x01;
416 
417 	umct_cfg_do_request(sc, UMCT_SET_MCR, UMCT_SET_MCR_SIZE, sc->sc_mcr);
418 }
419 
420 static void
421 umct_cfg_set_rts(struct ucom_softc *ucom, uint8_t onoff)
422 {
423 	struct umct_softc *sc = ucom->sc_parent;
424 
425 	if (onoff)
426 		sc->sc_mcr |= 0x02;
427 	else
428 		sc->sc_mcr &= ~0x02;
429 
430 	umct_cfg_do_request(sc, UMCT_SET_MCR, UMCT_SET_MCR_SIZE, sc->sc_mcr);
431 }
432 
433 static uint8_t
434 umct_calc_baud(uint32_t baud)
435 {
436 	switch (baud) {
437 		case B300:return (0x1);
438 	case B600:
439 		return (0x2);
440 	case B1200:
441 		return (0x3);
442 	case B2400:
443 		return (0x4);
444 	case B4800:
445 		return (0x6);
446 	case B9600:
447 		return (0x8);
448 	case B19200:
449 		return (0x9);
450 	case B38400:
451 		return (0xa);
452 	case B57600:
453 		return (0xb);
454 	case 115200:
455 		return (0xc);
456 	case B0:
457 	default:
458 		break;
459 	}
460 	return (0x0);
461 }
462 
463 static int
464 umct_pre_param(struct ucom_softc *ucom, struct termios *t)
465 {
466 	return (0);			/* we accept anything */
467 }
468 
469 static void
470 umct_cfg_param(struct ucom_softc *ucom, struct termios *t)
471 {
472 	struct umct_softc *sc = ucom->sc_parent;
473 	uint32_t value;
474 
475 	value = umct_calc_baud(t->c_ospeed);
476 	umct_cfg_do_request(sc, UMCT_SET_BAUD, UMCT_SET_BAUD_SIZE, value);
477 
478 	value = (sc->sc_lcr & 0x40);
479 
480 	switch (t->c_cflag & CSIZE) {
481 	case CS5:
482 		value |= 0x0;
483 		break;
484 	case CS6:
485 		value |= 0x1;
486 		break;
487 	case CS7:
488 		value |= 0x2;
489 		break;
490 	default:
491 	case CS8:
492 		value |= 0x3;
493 		break;
494 	}
495 
496 	value |= (t->c_cflag & CSTOPB) ? 0x4 : 0;
497 	if (t->c_cflag & PARENB) {
498 		value |= 0x8;
499 		value |= (t->c_cflag & PARODD) ? 0x0 : 0x10;
500 	}
501 	/*
502 	 * XXX There doesn't seem to be a way to tell the device
503 	 * to use flow control.
504 	 */
505 
506 	sc->sc_lcr = value;
507 	umct_cfg_do_request(sc, UMCT_SET_LCR, UMCT_SET_LCR_SIZE, value);
508 }
509 
510 static void
511 umct_start_read(struct ucom_softc *ucom)
512 {
513 	struct umct_softc *sc = ucom->sc_parent;
514 
515 	/* start interrupt endpoint */
516 	usbd_transfer_start(sc->sc_xfer[UMCT_INTR_DT_RD]);
517 
518 	/* start read endpoint */
519 	usbd_transfer_start(sc->sc_xfer[UMCT_BULK_DT_RD]);
520 }
521 
522 static void
523 umct_stop_read(struct ucom_softc *ucom)
524 {
525 	struct umct_softc *sc = ucom->sc_parent;
526 
527 	/* stop interrupt endpoint */
528 	usbd_transfer_stop(sc->sc_xfer[UMCT_INTR_DT_RD]);
529 
530 	/* stop read endpoint */
531 	usbd_transfer_stop(sc->sc_xfer[UMCT_BULK_DT_RD]);
532 }
533 
534 static void
535 umct_start_write(struct ucom_softc *ucom)
536 {
537 	struct umct_softc *sc = ucom->sc_parent;
538 
539 	usbd_transfer_start(sc->sc_xfer[UMCT_BULK_DT_WR]);
540 }
541 
542 static void
543 umct_stop_write(struct ucom_softc *ucom)
544 {
545 	struct umct_softc *sc = ucom->sc_parent;
546 
547 	usbd_transfer_stop(sc->sc_xfer[UMCT_BULK_DT_WR]);
548 }
549 
550 static void
551 umct_read_callback(struct usb_xfer *xfer, usb_error_t error)
552 {
553 	struct umct_softc *sc = usbd_xfer_softc(xfer);
554 
555 	if (sc->sc_swap_cb)
556 		umct_intr_callback_sub(xfer, error);
557 	else
558 		umct_read_callback_sub(xfer, error);
559 }
560 
561 static void
562 umct_intr_callback(struct usb_xfer *xfer, usb_error_t error)
563 {
564 	struct umct_softc *sc = usbd_xfer_softc(xfer);
565 
566 	if (sc->sc_swap_cb)
567 		umct_read_callback_sub(xfer, error);
568 	else
569 		umct_intr_callback_sub(xfer, error);
570 }
571 
572 static void
573 umct_write_callback(struct usb_xfer *xfer, usb_error_t error)
574 {
575 	struct umct_softc *sc = usbd_xfer_softc(xfer);
576 	struct usb_page_cache *pc;
577 	uint32_t actlen;
578 
579 	switch (USB_GET_STATE(xfer)) {
580 	case USB_ST_SETUP:
581 	case USB_ST_TRANSFERRED:
582 tr_setup:
583 		pc = usbd_xfer_get_frame(xfer, 0);
584 		if (ucom_get_data(&sc->sc_ucom, pc, 0,
585 		    sc->sc_obufsize, &actlen)) {
586 
587 			usbd_xfer_set_frame_len(xfer, 0, actlen);
588 			usbd_transfer_submit(xfer);
589 		}
590 		return;
591 
592 	default:			/* Error */
593 		if (error != USB_ERR_CANCELLED) {
594 			/* try to clear stall first */
595 			usbd_xfer_set_stall(xfer);
596 			goto tr_setup;
597 		}
598 		return;
599 	}
600 }
601 
602 static void
603 umct_read_callback_sub(struct usb_xfer *xfer, usb_error_t error)
604 {
605 	struct umct_softc *sc = usbd_xfer_softc(xfer);
606 	struct usb_page_cache *pc;
607 	int actlen;
608 
609 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
610 
611 	switch (USB_GET_STATE(xfer)) {
612 	case USB_ST_TRANSFERRED:
613 		pc = usbd_xfer_get_frame(xfer, 0);
614 		ucom_put_data(&sc->sc_ucom, pc, 0, actlen);
615 
616 	case USB_ST_SETUP:
617 tr_setup:
618 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
619 		usbd_transfer_submit(xfer);
620 		return;
621 
622 	default:			/* Error */
623 		if (error != USB_ERR_CANCELLED) {
624 			/* try to clear stall first */
625 			usbd_xfer_set_stall(xfer);
626 			goto tr_setup;
627 		}
628 		return;
629 	}
630 }
631 
632 static void
633 umct_poll(struct ucom_softc *ucom)
634 {
635 	struct umct_softc *sc = ucom->sc_parent;
636 	usbd_transfer_poll(sc->sc_xfer, UMCT_N_TRANSFER);
637 }
638