xref: /netbsd-src/sys/dev/usb/umodem_common.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /*	$NetBSD: umodem_common.c,v 1.35 2021/08/07 16:19:17 thorpej Exp $	*/
2 
3 /*
4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Lennart Augustsson (lennart@augustsson.net) at
9  * Carlstedt Research & Technology.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Comm Class spec:  http://www.usb.org/developers/devclass_docs/usbccs10.pdf
35  *                   http://www.usb.org/developers/devclass_docs/usbcdc11.pdf
36  */
37 
38 /*
39  * TODO:
40  * - Add error recovery in various places; the big problem is what
41  *   to do in a callback if there is an error.
42  * - Implement a Call Device for modems without multiplexed commands.
43  *
44  */
45 
46 #include <sys/cdefs.h>
47 __KERNEL_RCSID(0, "$NetBSD: umodem_common.c,v 1.35 2021/08/07 16:19:17 thorpej Exp $");
48 
49 #ifdef _KERNEL_OPT
50 #include "opt_usb.h"
51 #endif
52 
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/kernel.h>
56 #include <sys/ioctl.h>
57 #include <sys/conf.h>
58 #include <sys/tty.h>
59 #include <sys/file.h>
60 #include <sys/select.h>
61 #include <sys/proc.h>
62 #include <sys/vnode.h>
63 #include <sys/device.h>
64 #include <sys/poll.h>
65 
66 #include <dev/usb/usb.h>
67 #include <dev/usb/usbcdc.h>
68 
69 #include <dev/usb/usbdi.h>
70 #include <dev/usb/usbdi_util.h>
71 #include <dev/usb/usbdevs.h>
72 #include <dev/usb/usb_quirks.h>
73 
74 #include <dev/usb/ucomvar.h>
75 #include <dev/usb/umodemvar.h>
76 
77 #ifdef UMODEM_DEBUG
78 #define DPRINTFN(n, x)	if (umodemdebug > (n)) printf x
79 int	umodemdebug = 0;
80 #else
81 #define DPRINTFN(n, x)
82 #endif
83 #define DPRINTF(x) DPRINTFN(0, x)
84 
85 /*
86  * These are the maximum number of bytes transferred per frame.
87  * If some really high speed devices should use this driver they
88  * may need to be increased, but this is good enough for normal modems.
89  *
90  * Note: increased from 64/256, to better support EVDO wireless PPP.
91  * The sizes should not be increased further, or there
92  * will be problems with contiguous storage allocation.
93  */
94 #define UMODEMIBUFSIZE 4096
95 #define UMODEMOBUFSIZE 4096
96 
97 static usbd_status umodem_set_comm_feature(struct umodem_softc *,
98 					   int, int);
99 static usbd_status umodem_set_line_coding(struct umodem_softc *,
100 					  usb_cdc_line_state_t *);
101 
102 static void	umodem_dtr(struct umodem_softc *, int);
103 static void	umodem_rts(struct umodem_softc *, int);
104 static void	umodem_break(struct umodem_softc *, int);
105 static void	umodem_set_line_state(struct umodem_softc *);
106 static void	umodem_intr(struct usbd_xfer *, void *, usbd_status);
107 
108 /*
109  * NOTE: Callers of umodem_common_attach() should initialise their ucaa
110  * to 0 before assigning any fields.  ucaa_ibufsize, ucaa_ibufsize and
111  * ucaa_obufsize may be set by the caller, but if 0 are set to default
112  * umodem values.
113  */
114 int
115 umodem_common_attach(device_t self, struct umodem_softc *sc,
116     struct usbif_attach_arg *uiaa, struct ucom_attach_args *ucaa)
117 {
118 	struct usbd_device *dev = uiaa->uiaa_device;
119 	usb_interface_descriptor_t *id;
120 	usb_endpoint_descriptor_t *ed;
121 	char *devinfop;
122 	usbd_status err;
123 	int data_ifcno;
124 	int i;
125 
126 	sc->sc_dev = self;
127 	sc->sc_udev = dev;
128 	sc->sc_ctl_iface = uiaa->uiaa_iface;
129 	sc->sc_dying = false;
130 
131 	aprint_naive("\n");
132 	aprint_normal("\n");
133 
134 	id = usbd_get_interface_descriptor(sc->sc_ctl_iface);
135 	devinfop = usbd_devinfo_alloc(uiaa->uiaa_device, 0);
136 	aprint_normal_dev(self, "%s, iclass %d/%d\n",
137 	       devinfop, id->bInterfaceClass, id->bInterfaceSubClass);
138 	usbd_devinfo_free(devinfop);
139 
140 	sc->sc_ctl_iface_no = id->bInterfaceNumber;
141 
142 	/* Get the data interface no. */
143 	sc->sc_data_iface_no = data_ifcno =
144 	    umodem_get_caps(dev, &sc->sc_cm_cap, &sc->sc_acm_cap, id);
145 
146 	if (data_ifcno == -1) {
147 		aprint_error_dev(self, "no pointer to data interface\n");
148 		goto bad;
149 	}
150 
151 	aprint_normal_dev(self,
152 	    "data interface %d, has %sCM over data, has %sbreak\n",
153 	    data_ifcno, sc->sc_cm_cap & USB_CDC_CM_OVER_DATA ? "" : "no ",
154 	    sc->sc_acm_cap & USB_CDC_ACM_HAS_BREAK ? "" : "no ");
155 
156 	/* Get the data interface too. */
157 	for (i = 0; i < uiaa->uiaa_nifaces; i++) {
158 		if (uiaa->uiaa_ifaces[i] != NULL) {
159 			id = usbd_get_interface_descriptor(uiaa->uiaa_ifaces[i]);
160 			if (id != NULL && id->bInterfaceNumber == data_ifcno) {
161 				sc->sc_data_iface = uiaa->uiaa_ifaces[i];
162 				uiaa->uiaa_ifaces[i] = NULL;
163 			}
164 		}
165 	}
166 	if (sc->sc_data_iface == NULL) {
167 		aprint_error_dev(self, "no data interface\n");
168 		goto bad;
169 	}
170 
171 	/*
172 	 * Find the bulk endpoints.
173 	 * Iterate over all endpoints in the data interface and take note.
174 	 */
175 	ucaa->ucaa_bulkin = ucaa->ucaa_bulkout = -1;
176 
177 	id = usbd_get_interface_descriptor(sc->sc_data_iface);
178 	for (i = 0; i < id->bNumEndpoints; i++) {
179 		ed = usbd_interface2endpoint_descriptor(sc->sc_data_iface, i);
180 		if (ed == NULL) {
181 			aprint_error_dev(self,
182 			    "no endpoint descriptor for %d\n)", i);
183 			goto bad;
184 		}
185 		if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
186 		    (ed->bmAttributes & UE_XFERTYPE) == UE_BULK) {
187 			ucaa->ucaa_bulkin = ed->bEndpointAddress;
188 		} else if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_OUT &&
189 			   (ed->bmAttributes & UE_XFERTYPE) == UE_BULK) {
190 			ucaa->ucaa_bulkout = ed->bEndpointAddress;
191 		}
192 	}
193 
194 	if (ucaa->ucaa_bulkin == -1) {
195 		aprint_error_dev(self, "Could not find data bulk in\n");
196 		goto bad;
197 	}
198 	if (ucaa->ucaa_bulkout == -1) {
199 		aprint_error_dev(self, "Could not find data bulk out\n");
200 		goto bad;
201 	}
202 
203 	if (usbd_get_quirks(sc->sc_udev)->uq_flags & UQ_ASSUME_CM_OVER_DATA) {
204 		sc->sc_cm_over_data = 1;
205 	} else {
206 		if (sc->sc_cm_cap & USB_CDC_CM_OVER_DATA) {
207 			if (sc->sc_acm_cap & USB_CDC_ACM_HAS_FEATURE)
208 				err = umodem_set_comm_feature(sc,
209 				    UCDC_ABSTRACT_STATE, UCDC_DATA_MULTIPLEXED);
210 			else
211 				err = 0;
212 			if (err) {
213 				aprint_error_dev(self,
214 				    "could not set data multiplex mode\n");
215 				goto bad;
216 			}
217 			sc->sc_cm_over_data = 1;
218 		}
219 	}
220 
221 	/*
222 	 * The standard allows for notification messages (to indicate things
223 	 * like a modem hangup) to come in via an interrupt endpoint
224 	 * off of the control interface.  Iterate over the endpoints on
225 	 * the control interface and see if there are any interrupt
226 	 * endpoints; if there are, then register it.
227 	 */
228 
229 	sc->sc_ctl_notify = -1;
230 	sc->sc_notify_pipe = NULL;
231 
232 	id = usbd_get_interface_descriptor(sc->sc_ctl_iface);
233 	for (i = 0; i < id->bNumEndpoints; i++) {
234 		ed = usbd_interface2endpoint_descriptor(sc->sc_ctl_iface, i);
235 		if (ed == NULL)
236 			continue;
237 
238 		if (UE_GET_DIR(ed->bEndpointAddress) == UE_DIR_IN &&
239 		    (ed->bmAttributes & UE_XFERTYPE) == UE_INTERRUPT) {
240 			aprint_verbose_dev(self,
241 			    "status change notification available\n");
242 			sc->sc_ctl_notify = ed->bEndpointAddress;
243 		}
244 	}
245 
246 	sc->sc_dtr = -1;
247 
248 	/*
249 	 * ucaa_bulkin, ucaa_bulkout set above.  ucaa_ibufsize,
250 	 * ucaa_ibufsize, ucaa_obufsize may be initialised by caller
251 	 */
252 	if (ucaa->ucaa_ibufsize == 0)
253 		ucaa->ucaa_ibufsize = UMODEMIBUFSIZE;
254 	if (ucaa->ucaa_obufsize == 0)
255 		ucaa->ucaa_obufsize = UMODEMOBUFSIZE;
256 	if (ucaa->ucaa_ibufsizepad == 0)
257 		ucaa->ucaa_ibufsizepad = UMODEMIBUFSIZE;
258 	ucaa->ucaa_opkthdrlen = 0;
259 	ucaa->ucaa_device = sc->sc_udev;
260 	ucaa->ucaa_iface = sc->sc_data_iface;
261 	ucaa->ucaa_arg = sc;
262 
263 	usbd_add_drv_event(USB_EVENT_DRIVER_ATTACH, sc->sc_udev, sc->sc_dev);
264 
265 	DPRINTF(("umodem_common_attach: sc=%p\n", sc));
266 	sc->sc_subdev = config_found(self, ucaa, ucomprint,
267 	    CFARGS(.submatch = ucomsubmatch));
268 
269 	return 0;
270 
271  bad:
272 	sc->sc_dying = true;
273 	return 1;
274 }
275 
276 int
277 umodem_open(void *addr, int portno)
278 {
279 	struct umodem_softc *sc = addr;
280 	int err;
281 
282 	if (sc->sc_dying)
283 		return EIO;
284 
285 	DPRINTF(("umodem_open: sc=%p\n", sc));
286 
287 	if (sc->sc_ctl_notify != -1 && sc->sc_notify_pipe == NULL) {
288 		err = usbd_open_pipe_intr(sc->sc_ctl_iface, sc->sc_ctl_notify,
289 		    USBD_SHORT_XFER_OK, &sc->sc_notify_pipe, sc,
290 		    &sc->sc_notify_buf, sizeof(sc->sc_notify_buf),
291 		    umodem_intr, USBD_DEFAULT_INTERVAL);
292 
293 		if (err) {
294 			DPRINTF(("Failed to establish notify pipe: %s\n",
295 				usbd_errstr(err)));
296 			return EIO;
297 		}
298 	}
299 
300 	return 0;
301 }
302 
303 static void
304 umodem_close_pipe(struct umodem_softc *sc)
305 {
306 
307 	if (sc->sc_notify_pipe != NULL) {
308 		usbd_abort_pipe(sc->sc_notify_pipe);
309 		usbd_close_pipe(sc->sc_notify_pipe);
310 		sc->sc_notify_pipe = NULL;
311 	}
312 }
313 
314 void
315 umodem_close(void *addr, int portno)
316 {
317 	struct umodem_softc *sc = addr;
318 
319 	DPRINTF(("umodem_close: sc=%p\n", sc));
320 
321 	if (sc->sc_dying)
322 		return;
323 
324 	umodem_close_pipe(sc);
325 }
326 
327 static void
328 umodem_intr(struct usbd_xfer *xfer, void *priv,
329     usbd_status status)
330 {
331 	struct umodem_softc *sc = priv;
332 	u_char mstatus;
333 
334 	if (sc->sc_dying)
335 		return;
336 
337 	if (status != USBD_NORMAL_COMPLETION) {
338 		if (status == USBD_NOT_STARTED || status == USBD_CANCELLED)
339 			return;
340 		printf("%s: abnormal status: %s\n", device_xname(sc->sc_dev),
341 		       usbd_errstr(status));
342 		if (status == USBD_STALLED)
343 			usbd_clear_endpoint_stall_async(sc->sc_notify_pipe);
344 		return;
345 	}
346 
347 	if (sc->sc_notify_buf.bmRequestType != UCDC_NOTIFICATION) {
348 		DPRINTF(("%s: unknown message type (%02x) on notify pipe\n",
349 			 device_xname(sc->sc_dev),
350 			 sc->sc_notify_buf.bmRequestType));
351 		return;
352 	}
353 
354 	switch (sc->sc_notify_buf.bNotification) {
355 	case UCDC_N_SERIAL_STATE:
356 		/*
357 		 * Set the serial state in ucom driver based on
358 		 * the bits from the notify message
359 		 */
360 		if (UGETW(sc->sc_notify_buf.wLength) != 2) {
361 			printf("%s: Invalid notification length! (%d)\n",
362 			       device_xname(sc->sc_dev),
363 			       UGETW(sc->sc_notify_buf.wLength));
364 			break;
365 		}
366 		DPRINTF(("%s: notify bytes = %02x%02x\n",
367 			 device_xname(sc->sc_dev),
368 			 sc->sc_notify_buf.data[0],
369 			 sc->sc_notify_buf.data[1]));
370 		/* Currently, lsr is always zero. */
371 	 	sc->sc_lsr = sc->sc_msr = 0;
372 		mstatus = sc->sc_notify_buf.data[0];
373 
374 		if (ISSET(mstatus, UCDC_N_SERIAL_RI))
375 			sc->sc_msr |= UMSR_RI;
376 		if (ISSET(mstatus, UCDC_N_SERIAL_DSR))
377 			sc->sc_msr |= UMSR_DSR;
378 		if (ISSET(mstatus, UCDC_N_SERIAL_DCD))
379 			sc->sc_msr |= UMSR_DCD;
380 		ucom_status_change(device_private(sc->sc_subdev));
381 		break;
382 	default:
383 		DPRINTF(("%s: unknown notify message: %02x\n",
384 			 device_xname(sc->sc_dev),
385 			 sc->sc_notify_buf.bNotification));
386 		break;
387 	}
388 }
389 
390 int
391 umodem_get_caps(struct usbd_device *dev, int *cm, int *acm,
392 		usb_interface_descriptor_t *id)
393 {
394 	const usb_cdc_cm_descriptor_t *cmd;
395 	const usb_cdc_acm_descriptor_t *cad;
396 	const usb_cdc_union_descriptor_t *cud;
397 	uint32_t uq_flags;
398 
399 	*cm = *acm = 0;
400 	uq_flags = usbd_get_quirks(dev)->uq_flags;
401 
402 	if (uq_flags & UQ_NO_UNION_NRM) {
403 		DPRINTF(("umodem_get_caps: NO_UNION_NRM quirk - returning 0\n"));
404 		return 0;
405 	}
406 
407 	if (uq_flags & UQ_LOST_CS_DESC)
408 		id = NULL;
409 
410 	cmd = (const usb_cdc_cm_descriptor_t *)usb_find_desc_if(dev,
411 							  UDESC_CS_INTERFACE,
412 							  UDESCSUB_CDC_CM, id);
413 	if (cmd == NULL) {
414 		DPRINTF(("umodem_get_caps: no CM desc\n"));
415 	} else {
416 		*cm = cmd->bmCapabilities;
417 	}
418 
419 	cad = (const usb_cdc_acm_descriptor_t *)usb_find_desc_if(dev,
420 							   UDESC_CS_INTERFACE,
421 							   UDESCSUB_CDC_ACM,
422 							   id);
423 	if (cad == NULL) {
424 		DPRINTF(("umodem_get_caps: no ACM desc\n"));
425 	} else {
426 		*acm = cad->bmCapabilities;
427 	}
428 
429 	cud = (const usb_cdc_union_descriptor_t *)usb_find_desc_if(dev,
430 							     UDESC_CS_INTERFACE,
431 							     UDESCSUB_CDC_UNION,
432 							     id);
433 	if (cud == NULL) {
434 		DPRINTF(("umodem_get_caps: no UNION desc\n"));
435 	}
436 
437 	return cmd ? cmd->bDataInterface : cud ? cud->bSlaveInterface[0] : -1;
438 }
439 
440 void
441 umodem_get_status(void *addr, int portno, u_char *lsr, u_char *msr)
442 {
443 	struct umodem_softc *sc = addr;
444 
445 	DPRINTF(("umodem_get_status:\n"));
446 
447 	*lsr = sc->sc_lsr;
448 	*msr = sc->sc_msr;
449 }
450 
451 int
452 umodem_param(void *addr, int portno, struct termios *t)
453 {
454 	struct umodem_softc *sc = addr;
455 	usbd_status err;
456 	usb_cdc_line_state_t ls;
457 
458 	DPRINTF(("umodem_param: sc=%p\n", sc));
459 
460 	if (sc->sc_dying)
461 		return EIO;
462 
463 	USETDW(ls.dwDTERate, t->c_ospeed);
464 	if (ISSET(t->c_cflag, CSTOPB))
465 		ls.bCharFormat = UCDC_STOP_BIT_2;
466 	else
467 		ls.bCharFormat = UCDC_STOP_BIT_1;
468 	if (ISSET(t->c_cflag, PARENB)) {
469 		if (ISSET(t->c_cflag, PARODD))
470 			ls.bParityType = UCDC_PARITY_ODD;
471 		else
472 			ls.bParityType = UCDC_PARITY_EVEN;
473 	} else
474 		ls.bParityType = UCDC_PARITY_NONE;
475 	switch (ISSET(t->c_cflag, CSIZE)) {
476 	case CS5:
477 		ls.bDataBits = 5;
478 		break;
479 	case CS6:
480 		ls.bDataBits = 6;
481 		break;
482 	case CS7:
483 		ls.bDataBits = 7;
484 		break;
485 	case CS8:
486 		ls.bDataBits = 8;
487 		break;
488 	}
489 
490 	err = umodem_set_line_coding(sc, &ls);
491 	if (err) {
492 		DPRINTF(("umodem_param: err=%s\n", usbd_errstr(err)));
493 		return EPASSTHROUGH;
494 	}
495 	return 0;
496 }
497 
498 int
499 umodem_ioctl(void *addr, int portno, u_long cmd, void *data,
500     int flag, proc_t *p)
501 {
502 	struct umodem_softc *sc = addr;
503 	int error = 0;
504 
505 	DPRINTF(("umodem_ioctl: cmd=0x%08lx\n", cmd));
506 
507 	if (sc->sc_dying)
508 		return EIO;
509 
510 	switch (cmd) {
511 	case USB_GET_CM_OVER_DATA:
512 		*(int *)data = sc->sc_cm_over_data;
513 		break;
514 
515 	case USB_SET_CM_OVER_DATA:
516 		if (*(int *)data != sc->sc_cm_over_data) {
517 			/* XXX change it */
518 		}
519 		break;
520 
521 	default:
522 		DPRINTF(("umodem_ioctl: unknown\n"));
523 		error = EPASSTHROUGH;
524 		break;
525 	}
526 
527 	return error;
528 }
529 
530 static void
531 umodem_dtr(struct umodem_softc *sc, int onoff)
532 {
533 	DPRINTF(("umodem_dtr: onoff=%d\n", onoff));
534 
535 	if (sc->sc_dtr == onoff)
536 		return;
537 	sc->sc_dtr = onoff;
538 
539 	umodem_set_line_state(sc);
540 }
541 
542 static void
543 umodem_rts(struct umodem_softc *sc, int onoff)
544 {
545 	DPRINTF(("umodem_rts: onoff=%d\n", onoff));
546 
547 	if (sc->sc_rts == onoff)
548 		return;
549 	sc->sc_rts = onoff;
550 
551 	umodem_set_line_state(sc);
552 }
553 
554 static void
555 umodem_set_line_state(struct umodem_softc *sc)
556 {
557 	usb_device_request_t req;
558 	int ls;
559 
560 	ls = (sc->sc_dtr ? UCDC_LINE_DTR : 0) |
561 	     (sc->sc_rts ? UCDC_LINE_RTS : 0);
562 	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
563 	req.bRequest = UCDC_SET_CONTROL_LINE_STATE;
564 	USETW(req.wValue, ls);
565 	USETW(req.wIndex, sc->sc_ctl_iface_no);
566 	USETW(req.wLength, 0);
567 
568 	(void)usbd_do_request(sc->sc_udev, &req, 0);
569 
570 }
571 
572 static void
573 umodem_break(struct umodem_softc *sc, int onoff)
574 {
575 	usb_device_request_t req;
576 
577 	DPRINTF(("umodem_break: onoff=%d\n", onoff));
578 
579 	if (!(sc->sc_acm_cap & USB_CDC_ACM_HAS_BREAK))
580 		return;
581 
582 	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
583 	req.bRequest = UCDC_SEND_BREAK;
584 	USETW(req.wValue, onoff ? UCDC_BREAK_ON : UCDC_BREAK_OFF);
585 	USETW(req.wIndex, sc->sc_ctl_iface_no);
586 	USETW(req.wLength, 0);
587 
588 	(void)usbd_do_request(sc->sc_udev, &req, 0);
589 }
590 
591 void
592 umodem_set(void *addr, int portno, int reg, int onoff)
593 {
594 	struct umodem_softc *sc = addr;
595 
596 	if (sc->sc_dying)
597 		return;
598 
599 	switch (reg) {
600 	case UCOM_SET_DTR:
601 		umodem_dtr(sc, onoff);
602 		break;
603 	case UCOM_SET_RTS:
604 		umodem_rts(sc, onoff);
605 		break;
606 	case UCOM_SET_BREAK:
607 		umodem_break(sc, onoff);
608 		break;
609 	default:
610 		break;
611 	}
612 }
613 
614 static usbd_status
615 umodem_set_line_coding(struct umodem_softc *sc, usb_cdc_line_state_t *state)
616 {
617 	usb_device_request_t req;
618 	usbd_status err;
619 
620 	DPRINTF(("umodem_set_line_coding: rate=%d fmt=%d parity=%d bits=%d\n",
621 		 UGETDW(state->dwDTERate), state->bCharFormat,
622 		 state->bParityType, state->bDataBits));
623 
624 	if (memcmp(state, &sc->sc_line_state, UCDC_LINE_STATE_LENGTH) == 0) {
625 		DPRINTF(("umodem_set_line_coding: already set\n"));
626 		return USBD_NORMAL_COMPLETION;
627 	}
628 
629 	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
630 	req.bRequest = UCDC_SET_LINE_CODING;
631 	USETW(req.wValue, 0);
632 	USETW(req.wIndex, sc->sc_ctl_iface_no);
633 	USETW(req.wLength, UCDC_LINE_STATE_LENGTH);
634 
635 	err = usbd_do_request(sc->sc_udev, &req, state);
636 	if (err) {
637 		DPRINTF(("umodem_set_line_coding: failed, err=%s\n",
638 			 usbd_errstr(err)));
639 		return err;
640 	}
641 
642 	sc->sc_line_state = *state;
643 
644 	return USBD_NORMAL_COMPLETION;
645 }
646 
647 static usbd_status
648 umodem_set_comm_feature(struct umodem_softc *sc, int feature, int state)
649 {
650 	usb_device_request_t req;
651 	usbd_status err;
652 	usb_cdc_abstract_state_t ast;
653 
654 	DPRINTF(("umodem_set_comm_feature: feature=%d state=%d\n", feature,
655 		 state));
656 
657 	req.bmRequestType = UT_WRITE_CLASS_INTERFACE;
658 	req.bRequest = UCDC_SET_COMM_FEATURE;
659 	USETW(req.wValue, feature);
660 	USETW(req.wIndex, sc->sc_ctl_iface_no);
661 	USETW(req.wLength, UCDC_ABSTRACT_STATE_LENGTH);
662 	USETW(ast.wState, state);
663 
664 	err = usbd_do_request(sc->sc_udev, &req, &ast);
665 	if (err) {
666 		DPRINTF(("umodem_set_comm_feature: feature=%d, err=%s\n",
667 			 feature, usbd_errstr(err)));
668 		return err;
669 	}
670 
671 	return USBD_NORMAL_COMPLETION;
672 }
673 
674 void
675 umodem_common_childdet(struct umodem_softc *sc, device_t child)
676 {
677 	KASSERT(sc->sc_subdev == child);
678 	sc->sc_subdev = NULL;
679 }
680 
681 int
682 umodem_common_detach(struct umodem_softc *sc, int flags)
683 {
684 	int rv = 0;
685 
686 	DPRINTF(("umodem_common_detach: sc=%p flags=%d\n", sc, flags));
687 
688 	sc->sc_dying = true;
689 
690 	umodem_close_pipe(sc);
691 
692 	if (sc->sc_subdev != NULL) {
693 		rv = config_detach(sc->sc_subdev, flags);
694 		sc->sc_subdev = NULL;
695 	}
696 
697 	usbd_add_drv_event(USB_EVENT_DRIVER_DETACH, sc->sc_udev, sc->sc_dev);
698 
699 	return rv;
700 }
701