xref: /openbmc/linux/drivers/usb/class/cdc-acm.c (revision 193b1fc1)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * cdc-acm.c
4  *
5  * Copyright (c) 1999 Armin Fuerst	<fuerst@in.tum.de>
6  * Copyright (c) 1999 Pavel Machek	<pavel@ucw.cz>
7  * Copyright (c) 1999 Johannes Erdfelt	<johannes@erdfelt.com>
8  * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>
9  * Copyright (c) 2004 Oliver Neukum	<oliver@neukum.name>
10  * Copyright (c) 2005 David Kubicek	<dave@awk.cz>
11  * Copyright (c) 2011 Johan Hovold	<jhovold@gmail.com>
12  *
13  * USB Abstract Control Model driver for USB modems and ISDN adapters
14  *
15  * Sponsored by SuSE
16  */
17 
18 #undef DEBUG
19 #undef VERBOSE_DEBUG
20 
21 #include <linux/kernel.h>
22 #include <linux/sched/signal.h>
23 #include <linux/errno.h>
24 #include <linux/init.h>
25 #include <linux/slab.h>
26 #include <linux/log2.h>
27 #include <linux/tty.h>
28 #include <linux/serial.h>
29 #include <linux/tty_driver.h>
30 #include <linux/tty_flip.h>
31 #include <linux/tty_ldisc.h>
32 #include <linux/module.h>
33 #include <linux/mutex.h>
34 #include <linux/uaccess.h>
35 #include <linux/usb.h>
36 #include <linux/usb/cdc.h>
37 #include <asm/byteorder.h>
38 #include <asm/unaligned.h>
39 #include <linux/idr.h>
40 #include <linux/list.h>
41 
42 #include "cdc-acm.h"
43 
44 
45 #define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek, Johan Hovold"
46 #define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
47 
48 static struct usb_driver acm_driver;
49 static struct tty_driver *acm_tty_driver;
50 
51 static DEFINE_IDR(acm_minors);
52 static DEFINE_MUTEX(acm_minors_lock);
53 
54 static void acm_tty_set_termios(struct tty_struct *tty,
55 				const struct ktermios *termios_old);
56 
57 /*
58  * acm_minors accessors
59  */
60 
61 /*
62  * Look up an ACM structure by minor. If found and not disconnected, increment
63  * its refcount and return it with its mutex held.
64  */
65 static struct acm *acm_get_by_minor(unsigned int minor)
66 {
67 	struct acm *acm;
68 
69 	mutex_lock(&acm_minors_lock);
70 	acm = idr_find(&acm_minors, minor);
71 	if (acm) {
72 		mutex_lock(&acm->mutex);
73 		if (acm->disconnected) {
74 			mutex_unlock(&acm->mutex);
75 			acm = NULL;
76 		} else {
77 			tty_port_get(&acm->port);
78 			mutex_unlock(&acm->mutex);
79 		}
80 	}
81 	mutex_unlock(&acm_minors_lock);
82 	return acm;
83 }
84 
85 /*
86  * Try to find an available minor number and if found, associate it with 'acm'.
87  */
88 static int acm_alloc_minor(struct acm *acm)
89 {
90 	int minor;
91 
92 	mutex_lock(&acm_minors_lock);
93 	minor = idr_alloc(&acm_minors, acm, 0, ACM_TTY_MINORS, GFP_KERNEL);
94 	mutex_unlock(&acm_minors_lock);
95 
96 	return minor;
97 }
98 
99 /* Release the minor number associated with 'acm'.  */
100 static void acm_release_minor(struct acm *acm)
101 {
102 	mutex_lock(&acm_minors_lock);
103 	idr_remove(&acm_minors, acm->minor);
104 	mutex_unlock(&acm_minors_lock);
105 }
106 
107 /*
108  * Functions for ACM control messages.
109  */
110 
111 static int acm_ctrl_msg(struct acm *acm, int request, int value,
112 							void *buf, int len)
113 {
114 	int retval;
115 
116 	retval = usb_autopm_get_interface(acm->control);
117 	if (retval)
118 		return retval;
119 
120 	retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
121 		request, USB_RT_ACM, value,
122 		acm->control->altsetting[0].desc.bInterfaceNumber,
123 		buf, len, USB_CTRL_SET_TIMEOUT);
124 
125 	dev_dbg(&acm->control->dev,
126 		"%s - rq 0x%02x, val %#x, len %#x, result %d\n",
127 		__func__, request, value, len, retval);
128 
129 	usb_autopm_put_interface(acm->control);
130 
131 	return retval < 0 ? retval : 0;
132 }
133 
134 /* devices aren't required to support these requests.
135  * the cdc acm descriptor tells whether they do...
136  */
137 static inline int acm_set_control(struct acm *acm, int control)
138 {
139 	if (acm->quirks & QUIRK_CONTROL_LINE_STATE)
140 		return -EOPNOTSUPP;
141 
142 	return acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE,
143 			control, NULL, 0);
144 }
145 
146 #define acm_set_line(acm, line) \
147 	acm_ctrl_msg(acm, USB_CDC_REQ_SET_LINE_CODING, 0, line, sizeof *(line))
148 #define acm_send_break(acm, ms) \
149 	acm_ctrl_msg(acm, USB_CDC_REQ_SEND_BREAK, ms, NULL, 0)
150 
151 static void acm_poison_urbs(struct acm *acm)
152 {
153 	int i;
154 
155 	usb_poison_urb(acm->ctrlurb);
156 	for (i = 0; i < ACM_NW; i++)
157 		usb_poison_urb(acm->wb[i].urb);
158 	for (i = 0; i < acm->rx_buflimit; i++)
159 		usb_poison_urb(acm->read_urbs[i]);
160 }
161 
162 static void acm_unpoison_urbs(struct acm *acm)
163 {
164 	int i;
165 
166 	for (i = 0; i < acm->rx_buflimit; i++)
167 		usb_unpoison_urb(acm->read_urbs[i]);
168 	for (i = 0; i < ACM_NW; i++)
169 		usb_unpoison_urb(acm->wb[i].urb);
170 	usb_unpoison_urb(acm->ctrlurb);
171 }
172 
173 
174 /*
175  * Write buffer management.
176  * All of these assume proper locks taken by the caller.
177  */
178 
179 static int acm_wb_alloc(struct acm *acm)
180 {
181 	int i, wbn;
182 	struct acm_wb *wb;
183 
184 	wbn = 0;
185 	i = 0;
186 	for (;;) {
187 		wb = &acm->wb[wbn];
188 		if (!wb->use) {
189 			wb->use = true;
190 			wb->len = 0;
191 			return wbn;
192 		}
193 		wbn = (wbn + 1) % ACM_NW;
194 		if (++i >= ACM_NW)
195 			return -1;
196 	}
197 }
198 
199 static int acm_wb_is_avail(struct acm *acm)
200 {
201 	int i, n;
202 	unsigned long flags;
203 
204 	n = ACM_NW;
205 	spin_lock_irqsave(&acm->write_lock, flags);
206 	for (i = 0; i < ACM_NW; i++)
207 		if(acm->wb[i].use)
208 			n--;
209 	spin_unlock_irqrestore(&acm->write_lock, flags);
210 	return n;
211 }
212 
213 /*
214  * Finish write. Caller must hold acm->write_lock
215  */
216 static void acm_write_done(struct acm *acm, struct acm_wb *wb)
217 {
218 	wb->use = false;
219 	acm->transmitting--;
220 	usb_autopm_put_interface_async(acm->control);
221 }
222 
223 /*
224  * Poke write.
225  *
226  * the caller is responsible for locking
227  */
228 
229 static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
230 {
231 	int rc;
232 
233 	acm->transmitting++;
234 
235 	wb->urb->transfer_buffer = wb->buf;
236 	wb->urb->transfer_dma = wb->dmah;
237 	wb->urb->transfer_buffer_length = wb->len;
238 	wb->urb->dev = acm->dev;
239 
240 	rc = usb_submit_urb(wb->urb, GFP_ATOMIC);
241 	if (rc < 0) {
242 		if (rc != -EPERM)
243 			dev_err(&acm->data->dev,
244 				"%s - usb_submit_urb(write bulk) failed: %d\n",
245 				__func__, rc);
246 		acm_write_done(acm, wb);
247 	}
248 	return rc;
249 }
250 
251 /*
252  * attributes exported through sysfs
253  */
254 static ssize_t bmCapabilities_show
255 (struct device *dev, struct device_attribute *attr, char *buf)
256 {
257 	struct usb_interface *intf = to_usb_interface(dev);
258 	struct acm *acm = usb_get_intfdata(intf);
259 
260 	return sprintf(buf, "%d", acm->ctrl_caps);
261 }
262 static DEVICE_ATTR_RO(bmCapabilities);
263 
264 static ssize_t wCountryCodes_show
265 (struct device *dev, struct device_attribute *attr, char *buf)
266 {
267 	struct usb_interface *intf = to_usb_interface(dev);
268 	struct acm *acm = usb_get_intfdata(intf);
269 
270 	memcpy(buf, acm->country_codes, acm->country_code_size);
271 	return acm->country_code_size;
272 }
273 
274 static DEVICE_ATTR_RO(wCountryCodes);
275 
276 static ssize_t iCountryCodeRelDate_show
277 (struct device *dev, struct device_attribute *attr, char *buf)
278 {
279 	struct usb_interface *intf = to_usb_interface(dev);
280 	struct acm *acm = usb_get_intfdata(intf);
281 
282 	return sprintf(buf, "%d", acm->country_rel_date);
283 }
284 
285 static DEVICE_ATTR_RO(iCountryCodeRelDate);
286 /*
287  * Interrupt handlers for various ACM device responses
288  */
289 
290 static void acm_process_notification(struct acm *acm, unsigned char *buf)
291 {
292 	int newctrl;
293 	int difference;
294 	unsigned long flags;
295 	struct usb_cdc_notification *dr = (struct usb_cdc_notification *)buf;
296 	unsigned char *data = buf + sizeof(struct usb_cdc_notification);
297 
298 	switch (dr->bNotificationType) {
299 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
300 		dev_dbg(&acm->control->dev,
301 			"%s - network connection: %d\n", __func__, dr->wValue);
302 		break;
303 
304 	case USB_CDC_NOTIFY_SERIAL_STATE:
305 		if (le16_to_cpu(dr->wLength) != 2) {
306 			dev_dbg(&acm->control->dev,
307 				"%s - malformed serial state\n", __func__);
308 			break;
309 		}
310 
311 		newctrl = get_unaligned_le16(data);
312 		dev_dbg(&acm->control->dev,
313 			"%s - serial state: 0x%x\n", __func__, newctrl);
314 
315 		if (!acm->clocal && (acm->ctrlin & ~newctrl & USB_CDC_SERIAL_STATE_DCD)) {
316 			dev_dbg(&acm->control->dev,
317 				"%s - calling hangup\n", __func__);
318 			tty_port_tty_hangup(&acm->port, false);
319 		}
320 
321 		difference = acm->ctrlin ^ newctrl;
322 
323 		if ((difference & USB_CDC_SERIAL_STATE_DCD) && acm->port.tty) {
324 			struct tty_ldisc *ld = tty_ldisc_ref(acm->port.tty);
325 			if (ld) {
326 				if (ld->ops->dcd_change)
327 					ld->ops->dcd_change(acm->port.tty, newctrl & USB_CDC_SERIAL_STATE_DCD);
328 				tty_ldisc_deref(ld);
329 			}
330 		}
331 
332 		spin_lock_irqsave(&acm->read_lock, flags);
333 		acm->ctrlin = newctrl;
334 		acm->oldcount = acm->iocount;
335 
336 		if (difference & USB_CDC_SERIAL_STATE_DSR)
337 			acm->iocount.dsr++;
338 		if (difference & USB_CDC_SERIAL_STATE_DCD)
339 			acm->iocount.dcd++;
340 		if (newctrl & USB_CDC_SERIAL_STATE_BREAK) {
341 			acm->iocount.brk++;
342 			tty_insert_flip_char(&acm->port, 0, TTY_BREAK);
343 		}
344 		if (newctrl & USB_CDC_SERIAL_STATE_RING_SIGNAL)
345 			acm->iocount.rng++;
346 		if (newctrl & USB_CDC_SERIAL_STATE_FRAMING)
347 			acm->iocount.frame++;
348 		if (newctrl & USB_CDC_SERIAL_STATE_PARITY)
349 			acm->iocount.parity++;
350 		if (newctrl & USB_CDC_SERIAL_STATE_OVERRUN)
351 			acm->iocount.overrun++;
352 		spin_unlock_irqrestore(&acm->read_lock, flags);
353 
354 		if (newctrl & USB_CDC_SERIAL_STATE_BREAK)
355 			tty_flip_buffer_push(&acm->port);
356 
357 		if (difference)
358 			wake_up_all(&acm->wioctl);
359 
360 		break;
361 
362 	default:
363 		dev_dbg(&acm->control->dev,
364 			"%s - unknown notification %d received: index %d len %d\n",
365 			__func__,
366 			dr->bNotificationType, dr->wIndex, dr->wLength);
367 	}
368 }
369 
370 /* control interface reports status changes with "interrupt" transfers */
371 static void acm_ctrl_irq(struct urb *urb)
372 {
373 	struct acm *acm = urb->context;
374 	struct usb_cdc_notification *dr = urb->transfer_buffer;
375 	unsigned int current_size = urb->actual_length;
376 	unsigned int expected_size, copy_size, alloc_size;
377 	int retval;
378 	int status = urb->status;
379 
380 	switch (status) {
381 	case 0:
382 		/* success */
383 		break;
384 	case -ECONNRESET:
385 	case -ENOENT:
386 	case -ESHUTDOWN:
387 		/* this urb is terminated, clean up */
388 		dev_dbg(&acm->control->dev,
389 			"%s - urb shutting down with status: %d\n",
390 			__func__, status);
391 		return;
392 	default:
393 		dev_dbg(&acm->control->dev,
394 			"%s - nonzero urb status received: %d\n",
395 			__func__, status);
396 		goto exit;
397 	}
398 
399 	usb_mark_last_busy(acm->dev);
400 
401 	if (acm->nb_index)
402 		dr = (struct usb_cdc_notification *)acm->notification_buffer;
403 
404 	/* size = notification-header + (optional) data */
405 	expected_size = sizeof(struct usb_cdc_notification) +
406 					le16_to_cpu(dr->wLength);
407 
408 	if (current_size < expected_size) {
409 		/* notification is transmitted fragmented, reassemble */
410 		if (acm->nb_size < expected_size) {
411 			u8 *new_buffer;
412 			alloc_size = roundup_pow_of_two(expected_size);
413 			/* Final freeing is done on disconnect. */
414 			new_buffer = krealloc(acm->notification_buffer,
415 					      alloc_size, GFP_ATOMIC);
416 			if (!new_buffer) {
417 				acm->nb_index = 0;
418 				goto exit;
419 			}
420 
421 			acm->notification_buffer = new_buffer;
422 			acm->nb_size = alloc_size;
423 			dr = (struct usb_cdc_notification *)acm->notification_buffer;
424 		}
425 
426 		copy_size = min(current_size,
427 				expected_size - acm->nb_index);
428 
429 		memcpy(&acm->notification_buffer[acm->nb_index],
430 		       urb->transfer_buffer, copy_size);
431 		acm->nb_index += copy_size;
432 		current_size = acm->nb_index;
433 	}
434 
435 	if (current_size >= expected_size) {
436 		/* notification complete */
437 		acm_process_notification(acm, (unsigned char *)dr);
438 		acm->nb_index = 0;
439 	}
440 
441 exit:
442 	retval = usb_submit_urb(urb, GFP_ATOMIC);
443 	if (retval && retval != -EPERM && retval != -ENODEV)
444 		dev_err(&acm->control->dev,
445 			"%s - usb_submit_urb failed: %d\n", __func__, retval);
446 	else
447 		dev_vdbg(&acm->control->dev,
448 			"control resubmission terminated %d\n", retval);
449 }
450 
451 static int acm_submit_read_urb(struct acm *acm, int index, gfp_t mem_flags)
452 {
453 	int res;
454 
455 	if (!test_and_clear_bit(index, &acm->read_urbs_free))
456 		return 0;
457 
458 	res = usb_submit_urb(acm->read_urbs[index], mem_flags);
459 	if (res) {
460 		if (res != -EPERM && res != -ENODEV) {
461 			dev_err(&acm->data->dev,
462 				"urb %d failed submission with %d\n",
463 				index, res);
464 		} else {
465 			dev_vdbg(&acm->data->dev, "intended failure %d\n", res);
466 		}
467 		set_bit(index, &acm->read_urbs_free);
468 		return res;
469 	} else {
470 		dev_vdbg(&acm->data->dev, "submitted urb %d\n", index);
471 	}
472 
473 	return 0;
474 }
475 
476 static int acm_submit_read_urbs(struct acm *acm, gfp_t mem_flags)
477 {
478 	int res;
479 	int i;
480 
481 	for (i = 0; i < acm->rx_buflimit; ++i) {
482 		res = acm_submit_read_urb(acm, i, mem_flags);
483 		if (res)
484 			return res;
485 	}
486 
487 	return 0;
488 }
489 
490 static void acm_process_read_urb(struct acm *acm, struct urb *urb)
491 {
492 	unsigned long flags;
493 
494 	if (!urb->actual_length)
495 		return;
496 
497 	spin_lock_irqsave(&acm->read_lock, flags);
498 	tty_insert_flip_string(&acm->port, urb->transfer_buffer,
499 			urb->actual_length);
500 	spin_unlock_irqrestore(&acm->read_lock, flags);
501 
502 	tty_flip_buffer_push(&acm->port);
503 }
504 
505 static void acm_read_bulk_callback(struct urb *urb)
506 {
507 	struct acm_rb *rb = urb->context;
508 	struct acm *acm = rb->instance;
509 	int status = urb->status;
510 	bool stopped = false;
511 	bool stalled = false;
512 	bool cooldown = false;
513 
514 	dev_vdbg(&acm->data->dev, "got urb %d, len %d, status %d\n",
515 		rb->index, urb->actual_length, status);
516 
517 	switch (status) {
518 	case 0:
519 		usb_mark_last_busy(acm->dev);
520 		acm_process_read_urb(acm, urb);
521 		break;
522 	case -EPIPE:
523 		set_bit(EVENT_RX_STALL, &acm->flags);
524 		stalled = true;
525 		break;
526 	case -ENOENT:
527 	case -ECONNRESET:
528 	case -ESHUTDOWN:
529 		dev_dbg(&acm->data->dev,
530 			"%s - urb shutting down with status: %d\n",
531 			__func__, status);
532 		stopped = true;
533 		break;
534 	case -EOVERFLOW:
535 	case -EPROTO:
536 		dev_dbg(&acm->data->dev,
537 			"%s - cooling babbling device\n", __func__);
538 		usb_mark_last_busy(acm->dev);
539 		set_bit(rb->index, &acm->urbs_in_error_delay);
540 		set_bit(ACM_ERROR_DELAY, &acm->flags);
541 		cooldown = true;
542 		break;
543 	default:
544 		dev_dbg(&acm->data->dev,
545 			"%s - nonzero urb status received: %d\n",
546 			__func__, status);
547 		break;
548 	}
549 
550 	/*
551 	 * Make sure URB processing is done before marking as free to avoid
552 	 * racing with unthrottle() on another CPU. Matches the barriers
553 	 * implied by the test_and_clear_bit() in acm_submit_read_urb().
554 	 */
555 	smp_mb__before_atomic();
556 	set_bit(rb->index, &acm->read_urbs_free);
557 	/*
558 	 * Make sure URB is marked as free before checking the throttled flag
559 	 * to avoid racing with unthrottle() on another CPU. Matches the
560 	 * smp_mb() in unthrottle().
561 	 */
562 	smp_mb__after_atomic();
563 
564 	if (stopped || stalled || cooldown) {
565 		if (stalled)
566 			schedule_delayed_work(&acm->dwork, 0);
567 		else if (cooldown)
568 			schedule_delayed_work(&acm->dwork, HZ / 2);
569 		return;
570 	}
571 
572 	if (test_bit(ACM_THROTTLED, &acm->flags))
573 		return;
574 
575 	acm_submit_read_urb(acm, rb->index, GFP_ATOMIC);
576 }
577 
578 /* data interface wrote those outgoing bytes */
579 static void acm_write_bulk(struct urb *urb)
580 {
581 	struct acm_wb *wb = urb->context;
582 	struct acm *acm = wb->instance;
583 	unsigned long flags;
584 	int status = urb->status;
585 
586 	if (status || (urb->actual_length != urb->transfer_buffer_length))
587 		dev_vdbg(&acm->data->dev, "wrote len %d/%d, status %d\n",
588 			urb->actual_length,
589 			urb->transfer_buffer_length,
590 			status);
591 
592 	spin_lock_irqsave(&acm->write_lock, flags);
593 	acm_write_done(acm, wb);
594 	spin_unlock_irqrestore(&acm->write_lock, flags);
595 	set_bit(EVENT_TTY_WAKEUP, &acm->flags);
596 	schedule_delayed_work(&acm->dwork, 0);
597 }
598 
599 static void acm_softint(struct work_struct *work)
600 {
601 	int i;
602 	struct acm *acm = container_of(work, struct acm, dwork.work);
603 
604 	if (test_bit(EVENT_RX_STALL, &acm->flags)) {
605 		smp_mb(); /* against acm_suspend() */
606 		if (!acm->susp_count) {
607 			for (i = 0; i < acm->rx_buflimit; i++)
608 				usb_kill_urb(acm->read_urbs[i]);
609 			usb_clear_halt(acm->dev, acm->in);
610 			acm_submit_read_urbs(acm, GFP_KERNEL);
611 			clear_bit(EVENT_RX_STALL, &acm->flags);
612 		}
613 	}
614 
615 	if (test_and_clear_bit(ACM_ERROR_DELAY, &acm->flags)) {
616 		for (i = 0; i < acm->rx_buflimit; i++)
617 			if (test_and_clear_bit(i, &acm->urbs_in_error_delay))
618 				acm_submit_read_urb(acm, i, GFP_KERNEL);
619 	}
620 
621 	if (test_and_clear_bit(EVENT_TTY_WAKEUP, &acm->flags))
622 		tty_port_tty_wakeup(&acm->port);
623 }
624 
625 /*
626  * TTY handlers
627  */
628 
629 static int acm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
630 {
631 	struct acm *acm;
632 	int retval;
633 
634 	acm = acm_get_by_minor(tty->index);
635 	if (!acm)
636 		return -ENODEV;
637 
638 	retval = tty_standard_install(driver, tty);
639 	if (retval)
640 		goto error_init_termios;
641 
642 	/*
643 	 * Suppress initial echoing for some devices which might send data
644 	 * immediately after acm driver has been installed.
645 	 */
646 	if (acm->quirks & DISABLE_ECHO)
647 		tty->termios.c_lflag &= ~ECHO;
648 
649 	tty->driver_data = acm;
650 
651 	return 0;
652 
653 error_init_termios:
654 	tty_port_put(&acm->port);
655 	return retval;
656 }
657 
658 static int acm_tty_open(struct tty_struct *tty, struct file *filp)
659 {
660 	struct acm *acm = tty->driver_data;
661 
662 	return tty_port_open(&acm->port, tty, filp);
663 }
664 
665 static void acm_port_dtr_rts(struct tty_port *port, bool active)
666 {
667 	struct acm *acm = container_of(port, struct acm, port);
668 	int val;
669 	int res;
670 
671 	if (active)
672 		val = USB_CDC_CTRL_DTR | USB_CDC_CTRL_RTS;
673 	else
674 		val = 0;
675 
676 	/* FIXME: add missing ctrlout locking throughout driver */
677 	acm->ctrlout = val;
678 
679 	res = acm_set_control(acm, val);
680 	if (res && (acm->ctrl_caps & USB_CDC_CAP_LINE))
681 		/* This is broken in too many devices to spam the logs */
682 		dev_dbg(&acm->control->dev, "failed to set dtr/rts\n");
683 }
684 
685 static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
686 {
687 	struct acm *acm = container_of(port, struct acm, port);
688 	int retval = -ENODEV;
689 	int i;
690 
691 	mutex_lock(&acm->mutex);
692 	if (acm->disconnected)
693 		goto disconnected;
694 
695 	retval = usb_autopm_get_interface(acm->control);
696 	if (retval)
697 		goto error_get_interface;
698 
699 	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
700 	acm->control->needs_remote_wakeup = 1;
701 
702 	acm->ctrlurb->dev = acm->dev;
703 	retval = usb_submit_urb(acm->ctrlurb, GFP_KERNEL);
704 	if (retval) {
705 		dev_err(&acm->control->dev,
706 			"%s - usb_submit_urb(ctrl irq) failed\n", __func__);
707 		goto error_submit_urb;
708 	}
709 
710 	acm_tty_set_termios(tty, NULL);
711 
712 	/*
713 	 * Unthrottle device in case the TTY was closed while throttled.
714 	 */
715 	clear_bit(ACM_THROTTLED, &acm->flags);
716 
717 	retval = acm_submit_read_urbs(acm, GFP_KERNEL);
718 	if (retval)
719 		goto error_submit_read_urbs;
720 
721 	usb_autopm_put_interface(acm->control);
722 
723 	mutex_unlock(&acm->mutex);
724 
725 	return 0;
726 
727 error_submit_read_urbs:
728 	for (i = 0; i < acm->rx_buflimit; i++)
729 		usb_kill_urb(acm->read_urbs[i]);
730 	usb_kill_urb(acm->ctrlurb);
731 error_submit_urb:
732 	usb_autopm_put_interface(acm->control);
733 error_get_interface:
734 disconnected:
735 	mutex_unlock(&acm->mutex);
736 
737 	return usb_translate_errors(retval);
738 }
739 
740 static void acm_port_destruct(struct tty_port *port)
741 {
742 	struct acm *acm = container_of(port, struct acm, port);
743 
744 	if (acm->minor != ACM_MINOR_INVALID)
745 		acm_release_minor(acm);
746 	usb_put_intf(acm->control);
747 	kfree(acm->country_codes);
748 	kfree(acm);
749 }
750 
751 static void acm_port_shutdown(struct tty_port *port)
752 {
753 	struct acm *acm = container_of(port, struct acm, port);
754 	struct urb *urb;
755 	struct acm_wb *wb;
756 
757 	/*
758 	 * Need to grab write_lock to prevent race with resume, but no need to
759 	 * hold it due to the tty-port initialised flag.
760 	 */
761 	acm_poison_urbs(acm);
762 	spin_lock_irq(&acm->write_lock);
763 	spin_unlock_irq(&acm->write_lock);
764 
765 	usb_autopm_get_interface_no_resume(acm->control);
766 	acm->control->needs_remote_wakeup = 0;
767 	usb_autopm_put_interface(acm->control);
768 
769 	for (;;) {
770 		urb = usb_get_from_anchor(&acm->delayed);
771 		if (!urb)
772 			break;
773 		wb = urb->context;
774 		wb->use = false;
775 		usb_autopm_put_interface_async(acm->control);
776 	}
777 
778 	acm_unpoison_urbs(acm);
779 
780 }
781 
782 static void acm_tty_cleanup(struct tty_struct *tty)
783 {
784 	struct acm *acm = tty->driver_data;
785 
786 	tty_port_put(&acm->port);
787 }
788 
789 static void acm_tty_hangup(struct tty_struct *tty)
790 {
791 	struct acm *acm = tty->driver_data;
792 
793 	tty_port_hangup(&acm->port);
794 }
795 
796 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
797 {
798 	struct acm *acm = tty->driver_data;
799 
800 	tty_port_close(&acm->port, tty, filp);
801 }
802 
803 static ssize_t acm_tty_write(struct tty_struct *tty, const u8 *buf,
804 			     size_t count)
805 {
806 	struct acm *acm = tty->driver_data;
807 	int stat;
808 	unsigned long flags;
809 	int wbn;
810 	struct acm_wb *wb;
811 
812 	if (!count)
813 		return 0;
814 
815 	dev_vdbg(&acm->data->dev, "%zu bytes from tty layer\n", count);
816 
817 	spin_lock_irqsave(&acm->write_lock, flags);
818 	wbn = acm_wb_alloc(acm);
819 	if (wbn < 0) {
820 		spin_unlock_irqrestore(&acm->write_lock, flags);
821 		return 0;
822 	}
823 	wb = &acm->wb[wbn];
824 
825 	if (!acm->dev) {
826 		wb->use = false;
827 		spin_unlock_irqrestore(&acm->write_lock, flags);
828 		return -ENODEV;
829 	}
830 
831 	count = (count > acm->writesize) ? acm->writesize : count;
832 	dev_vdbg(&acm->data->dev, "writing %zu bytes\n", count);
833 	memcpy(wb->buf, buf, count);
834 	wb->len = count;
835 
836 	stat = usb_autopm_get_interface_async(acm->control);
837 	if (stat) {
838 		wb->use = false;
839 		spin_unlock_irqrestore(&acm->write_lock, flags);
840 		return stat;
841 	}
842 
843 	if (acm->susp_count) {
844 		usb_anchor_urb(wb->urb, &acm->delayed);
845 		spin_unlock_irqrestore(&acm->write_lock, flags);
846 		return count;
847 	}
848 
849 	stat = acm_start_wb(acm, wb);
850 	spin_unlock_irqrestore(&acm->write_lock, flags);
851 
852 	if (stat < 0)
853 		return stat;
854 	return count;
855 }
856 
857 static unsigned int acm_tty_write_room(struct tty_struct *tty)
858 {
859 	struct acm *acm = tty->driver_data;
860 	/*
861 	 * Do not let the line discipline to know that we have a reserve,
862 	 * or it might get too enthusiastic.
863 	 */
864 	return acm_wb_is_avail(acm) ? acm->writesize : 0;
865 }
866 
867 static void acm_tty_flush_buffer(struct tty_struct *tty)
868 {
869 	struct acm *acm = tty->driver_data;
870 	unsigned long flags;
871 	int i;
872 
873 	spin_lock_irqsave(&acm->write_lock, flags);
874 	for (i = 0; i < ACM_NW; i++)
875 		if (acm->wb[i].use)
876 			usb_unlink_urb(acm->wb[i].urb);
877 	spin_unlock_irqrestore(&acm->write_lock, flags);
878 }
879 
880 static unsigned int acm_tty_chars_in_buffer(struct tty_struct *tty)
881 {
882 	struct acm *acm = tty->driver_data;
883 	/*
884 	 * if the device was unplugged then any remaining characters fell out
885 	 * of the connector ;)
886 	 */
887 	if (acm->disconnected)
888 		return 0;
889 	/*
890 	 * This is inaccurate (overcounts), but it works.
891 	 */
892 	return (ACM_NW - acm_wb_is_avail(acm)) * acm->writesize;
893 }
894 
895 static void acm_tty_throttle(struct tty_struct *tty)
896 {
897 	struct acm *acm = tty->driver_data;
898 
899 	set_bit(ACM_THROTTLED, &acm->flags);
900 }
901 
902 static void acm_tty_unthrottle(struct tty_struct *tty)
903 {
904 	struct acm *acm = tty->driver_data;
905 
906 	clear_bit(ACM_THROTTLED, &acm->flags);
907 
908 	/* Matches the smp_mb__after_atomic() in acm_read_bulk_callback(). */
909 	smp_mb();
910 
911 	acm_submit_read_urbs(acm, GFP_KERNEL);
912 }
913 
914 static int acm_tty_break_ctl(struct tty_struct *tty, int state)
915 {
916 	struct acm *acm = tty->driver_data;
917 	int retval;
918 
919 	if (!(acm->ctrl_caps & USB_CDC_CAP_BRK))
920 		return -EOPNOTSUPP;
921 
922 	retval = acm_send_break(acm, state ? 0xffff : 0);
923 	if (retval < 0)
924 		dev_dbg(&acm->control->dev,
925 			"%s - send break failed\n", __func__);
926 	return retval;
927 }
928 
929 static int acm_tty_tiocmget(struct tty_struct *tty)
930 {
931 	struct acm *acm = tty->driver_data;
932 
933 	return (acm->ctrlout & USB_CDC_CTRL_DTR ? TIOCM_DTR : 0) |
934 	       (acm->ctrlout & USB_CDC_CTRL_RTS ? TIOCM_RTS : 0) |
935 	       (acm->ctrlin  & USB_CDC_SERIAL_STATE_DSR ? TIOCM_DSR : 0) |
936 	       (acm->ctrlin  & USB_CDC_SERIAL_STATE_RING_SIGNAL ? TIOCM_RI : 0) |
937 	       (acm->ctrlin  & USB_CDC_SERIAL_STATE_DCD ? TIOCM_CD : 0) |
938 	       TIOCM_CTS;
939 }
940 
941 static int acm_tty_tiocmset(struct tty_struct *tty,
942 			    unsigned int set, unsigned int clear)
943 {
944 	struct acm *acm = tty->driver_data;
945 	unsigned int newctrl;
946 
947 	newctrl = acm->ctrlout;
948 	set = (set & TIOCM_DTR ? USB_CDC_CTRL_DTR : 0) |
949 	      (set & TIOCM_RTS ? USB_CDC_CTRL_RTS : 0);
950 	clear = (clear & TIOCM_DTR ? USB_CDC_CTRL_DTR : 0) |
951 		(clear & TIOCM_RTS ? USB_CDC_CTRL_RTS : 0);
952 
953 	newctrl = (newctrl & ~clear) | set;
954 
955 	if (acm->ctrlout == newctrl)
956 		return 0;
957 	return acm_set_control(acm, acm->ctrlout = newctrl);
958 }
959 
960 static int get_serial_info(struct tty_struct *tty, struct serial_struct *ss)
961 {
962 	struct acm *acm = tty->driver_data;
963 
964 	ss->line = acm->minor;
965 	ss->close_delay	= jiffies_to_msecs(acm->port.close_delay) / 10;
966 	ss->closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
967 				ASYNC_CLOSING_WAIT_NONE :
968 				jiffies_to_msecs(acm->port.closing_wait) / 10;
969 	return 0;
970 }
971 
972 static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
973 {
974 	struct acm *acm = tty->driver_data;
975 	unsigned int closing_wait, close_delay;
976 	int retval = 0;
977 
978 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
979 	closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
980 			ASYNC_CLOSING_WAIT_NONE :
981 			msecs_to_jiffies(ss->closing_wait * 10);
982 
983 	mutex_lock(&acm->port.mutex);
984 
985 	if (!capable(CAP_SYS_ADMIN)) {
986 		if ((close_delay != acm->port.close_delay) ||
987 		    (closing_wait != acm->port.closing_wait))
988 			retval = -EPERM;
989 	} else {
990 		acm->port.close_delay  = close_delay;
991 		acm->port.closing_wait = closing_wait;
992 	}
993 
994 	mutex_unlock(&acm->port.mutex);
995 	return retval;
996 }
997 
998 static int wait_serial_change(struct acm *acm, unsigned long arg)
999 {
1000 	int rv = 0;
1001 	DECLARE_WAITQUEUE(wait, current);
1002 	struct async_icount old, new;
1003 
1004 	do {
1005 		spin_lock_irq(&acm->read_lock);
1006 		old = acm->oldcount;
1007 		new = acm->iocount;
1008 		acm->oldcount = new;
1009 		spin_unlock_irq(&acm->read_lock);
1010 
1011 		if ((arg & TIOCM_DSR) &&
1012 			old.dsr != new.dsr)
1013 			break;
1014 		if ((arg & TIOCM_CD)  &&
1015 			old.dcd != new.dcd)
1016 			break;
1017 		if ((arg & TIOCM_RI) &&
1018 			old.rng != new.rng)
1019 			break;
1020 
1021 		add_wait_queue(&acm->wioctl, &wait);
1022 		set_current_state(TASK_INTERRUPTIBLE);
1023 		schedule();
1024 		remove_wait_queue(&acm->wioctl, &wait);
1025 		if (acm->disconnected) {
1026 			if (arg & TIOCM_CD)
1027 				break;
1028 			else
1029 				rv = -ENODEV;
1030 		} else {
1031 			if (signal_pending(current))
1032 				rv = -ERESTARTSYS;
1033 		}
1034 	} while (!rv);
1035 
1036 
1037 
1038 	return rv;
1039 }
1040 
1041 static int acm_tty_get_icount(struct tty_struct *tty,
1042 					struct serial_icounter_struct *icount)
1043 {
1044 	struct acm *acm = tty->driver_data;
1045 
1046 	icount->dsr = acm->iocount.dsr;
1047 	icount->rng = acm->iocount.rng;
1048 	icount->dcd = acm->iocount.dcd;
1049 	icount->frame = acm->iocount.frame;
1050 	icount->overrun = acm->iocount.overrun;
1051 	icount->parity = acm->iocount.parity;
1052 	icount->brk = acm->iocount.brk;
1053 
1054 	return 0;
1055 }
1056 
1057 static int acm_tty_ioctl(struct tty_struct *tty,
1058 					unsigned int cmd, unsigned long arg)
1059 {
1060 	struct acm *acm = tty->driver_data;
1061 	int rv = -ENOIOCTLCMD;
1062 
1063 	switch (cmd) {
1064 	case TIOCMIWAIT:
1065 		rv = usb_autopm_get_interface(acm->control);
1066 		if (rv < 0) {
1067 			rv = -EIO;
1068 			break;
1069 		}
1070 		rv = wait_serial_change(acm, arg);
1071 		usb_autopm_put_interface(acm->control);
1072 		break;
1073 	}
1074 
1075 	return rv;
1076 }
1077 
1078 static void acm_tty_set_termios(struct tty_struct *tty,
1079 				const struct ktermios *termios_old)
1080 {
1081 	struct acm *acm = tty->driver_data;
1082 	struct ktermios *termios = &tty->termios;
1083 	struct usb_cdc_line_coding newline;
1084 	int newctrl = acm->ctrlout;
1085 
1086 	newline.dwDTERate = cpu_to_le32(tty_get_baud_rate(tty));
1087 	newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
1088 	newline.bParityType = termios->c_cflag & PARENB ?
1089 				(termios->c_cflag & PARODD ? 1 : 2) +
1090 				(termios->c_cflag & CMSPAR ? 2 : 0) : 0;
1091 	newline.bDataBits = tty_get_char_size(termios->c_cflag);
1092 
1093 	/* FIXME: Needs to clear unsupported bits in the termios */
1094 	acm->clocal = ((termios->c_cflag & CLOCAL) != 0);
1095 
1096 	if (C_BAUD(tty) == B0) {
1097 		newline.dwDTERate = acm->line.dwDTERate;
1098 		newctrl &= ~USB_CDC_CTRL_DTR;
1099 	} else if (termios_old && (termios_old->c_cflag & CBAUD) == B0) {
1100 		newctrl |=  USB_CDC_CTRL_DTR;
1101 	}
1102 
1103 	if (newctrl != acm->ctrlout)
1104 		acm_set_control(acm, acm->ctrlout = newctrl);
1105 
1106 	if (memcmp(&acm->line, &newline, sizeof newline)) {
1107 		memcpy(&acm->line, &newline, sizeof newline);
1108 		dev_dbg(&acm->control->dev, "%s - set line: %d %d %d %d\n",
1109 			__func__,
1110 			le32_to_cpu(newline.dwDTERate),
1111 			newline.bCharFormat, newline.bParityType,
1112 			newline.bDataBits);
1113 		acm_set_line(acm, &acm->line);
1114 	}
1115 }
1116 
1117 static const struct tty_port_operations acm_port_ops = {
1118 	.dtr_rts = acm_port_dtr_rts,
1119 	.shutdown = acm_port_shutdown,
1120 	.activate = acm_port_activate,
1121 	.destruct = acm_port_destruct,
1122 };
1123 
1124 /*
1125  * USB probe and disconnect routines.
1126  */
1127 
1128 /* Little helpers: write/read buffers free */
1129 static void acm_write_buffers_free(struct acm *acm)
1130 {
1131 	int i;
1132 	struct acm_wb *wb;
1133 
1134 	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++)
1135 		usb_free_coherent(acm->dev, acm->writesize, wb->buf, wb->dmah);
1136 }
1137 
1138 static void acm_read_buffers_free(struct acm *acm)
1139 {
1140 	int i;
1141 
1142 	for (i = 0; i < acm->rx_buflimit; i++)
1143 		usb_free_coherent(acm->dev, acm->readsize,
1144 			  acm->read_buffers[i].base, acm->read_buffers[i].dma);
1145 }
1146 
1147 /* Little helper: write buffers allocate */
1148 static int acm_write_buffers_alloc(struct acm *acm)
1149 {
1150 	int i;
1151 	struct acm_wb *wb;
1152 
1153 	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
1154 		wb->buf = usb_alloc_coherent(acm->dev, acm->writesize, GFP_KERNEL,
1155 		    &wb->dmah);
1156 		if (!wb->buf) {
1157 			while (i != 0) {
1158 				--i;
1159 				--wb;
1160 				usb_free_coherent(acm->dev, acm->writesize,
1161 				    wb->buf, wb->dmah);
1162 			}
1163 			return -ENOMEM;
1164 		}
1165 	}
1166 	return 0;
1167 }
1168 
1169 static int acm_probe(struct usb_interface *intf,
1170 		     const struct usb_device_id *id)
1171 {
1172 	struct usb_cdc_union_desc *union_header = NULL;
1173 	struct usb_cdc_call_mgmt_descriptor *cmgmd = NULL;
1174 	unsigned char *buffer = intf->altsetting->extra;
1175 	int buflen = intf->altsetting->extralen;
1176 	struct usb_interface *control_interface;
1177 	struct usb_interface *data_interface;
1178 	struct usb_endpoint_descriptor *epctrl = NULL;
1179 	struct usb_endpoint_descriptor *epread = NULL;
1180 	struct usb_endpoint_descriptor *epwrite = NULL;
1181 	struct usb_device *usb_dev = interface_to_usbdev(intf);
1182 	struct usb_cdc_parsed_header h;
1183 	struct acm *acm;
1184 	int minor;
1185 	int ctrlsize, readsize;
1186 	u8 *buf;
1187 	int call_intf_num = -1;
1188 	int data_intf_num = -1;
1189 	unsigned long quirks;
1190 	int num_rx_buf;
1191 	int i;
1192 	int combined_interfaces = 0;
1193 	struct device *tty_dev;
1194 	int rv = -ENOMEM;
1195 	int res;
1196 
1197 	/* normal quirks */
1198 	quirks = (unsigned long)id->driver_info;
1199 
1200 	if (quirks == IGNORE_DEVICE)
1201 		return -ENODEV;
1202 
1203 	memset(&h, 0x00, sizeof(struct usb_cdc_parsed_header));
1204 
1205 	num_rx_buf = (quirks == SINGLE_RX_URB) ? 1 : ACM_NR;
1206 
1207 	/* handle quirks deadly to normal probing*/
1208 	if (quirks == NO_UNION_NORMAL) {
1209 		data_interface = usb_ifnum_to_if(usb_dev, 1);
1210 		control_interface = usb_ifnum_to_if(usb_dev, 0);
1211 		/* we would crash */
1212 		if (!data_interface || !control_interface)
1213 			return -ENODEV;
1214 		goto skip_normal_probe;
1215 	}
1216 
1217 	/* normal probing*/
1218 	if (!buffer) {
1219 		dev_err(&intf->dev, "Weird descriptor references\n");
1220 		return -EINVAL;
1221 	}
1222 
1223 	if (!buflen) {
1224 		if (intf->cur_altsetting->endpoint &&
1225 				intf->cur_altsetting->endpoint->extralen &&
1226 				intf->cur_altsetting->endpoint->extra) {
1227 			dev_dbg(&intf->dev,
1228 				"Seeking extra descriptors on endpoint\n");
1229 			buflen = intf->cur_altsetting->endpoint->extralen;
1230 			buffer = intf->cur_altsetting->endpoint->extra;
1231 		} else {
1232 			dev_err(&intf->dev,
1233 				"Zero length descriptor references\n");
1234 			return -EINVAL;
1235 		}
1236 	}
1237 
1238 	cdc_parse_cdc_header(&h, intf, buffer, buflen);
1239 	union_header = h.usb_cdc_union_desc;
1240 	cmgmd = h.usb_cdc_call_mgmt_descriptor;
1241 	if (cmgmd)
1242 		call_intf_num = cmgmd->bDataInterface;
1243 
1244 	if (!union_header) {
1245 		if (intf->cur_altsetting->desc.bNumEndpoints == 3) {
1246 			dev_dbg(&intf->dev, "No union descriptor, assuming single interface\n");
1247 			combined_interfaces = 1;
1248 			control_interface = data_interface = intf;
1249 			goto look_for_collapsed_interface;
1250 		} else if (call_intf_num > 0) {
1251 			dev_dbg(&intf->dev, "No union descriptor, using call management descriptor\n");
1252 			data_intf_num = call_intf_num;
1253 			data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
1254 			control_interface = intf;
1255 		} else {
1256 			dev_dbg(&intf->dev, "No union descriptor, giving up\n");
1257 			return -ENODEV;
1258 		}
1259 	} else {
1260 		int class = -1;
1261 
1262 		data_intf_num = union_header->bSlaveInterface0;
1263 		control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
1264 		data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
1265 
1266 		if (control_interface)
1267 			class = control_interface->cur_altsetting->desc.bInterfaceClass;
1268 
1269 		if (class != USB_CLASS_COMM && class != USB_CLASS_CDC_DATA) {
1270 			dev_dbg(&intf->dev, "Broken union descriptor, assuming single interface\n");
1271 			combined_interfaces = 1;
1272 			control_interface = data_interface = intf;
1273 			goto look_for_collapsed_interface;
1274 		}
1275 	}
1276 
1277 	if (!control_interface || !data_interface) {
1278 		dev_dbg(&intf->dev, "no interfaces\n");
1279 		return -ENODEV;
1280 	}
1281 
1282 	if (data_intf_num != call_intf_num)
1283 		dev_dbg(&intf->dev, "Separate call control interface. That is not fully supported.\n");
1284 
1285 	if (control_interface == data_interface) {
1286 		/* some broken devices designed for windows work this way */
1287 		dev_warn(&intf->dev,"Control and data interfaces are not separated!\n");
1288 		combined_interfaces = 1;
1289 		/* a popular other OS doesn't use it */
1290 		quirks |= NO_CAP_LINE;
1291 		if (data_interface->cur_altsetting->desc.bNumEndpoints != 3) {
1292 			dev_err(&intf->dev, "This needs exactly 3 endpoints\n");
1293 			return -EINVAL;
1294 		}
1295 look_for_collapsed_interface:
1296 		res = usb_find_common_endpoints(data_interface->cur_altsetting,
1297 				&epread, &epwrite, &epctrl, NULL);
1298 		if (res)
1299 			return res;
1300 
1301 		goto made_compressed_probe;
1302 	}
1303 
1304 skip_normal_probe:
1305 
1306 	/*workaround for switched interfaces */
1307 	if (data_interface->cur_altsetting->desc.bInterfaceClass != USB_CLASS_CDC_DATA) {
1308 		if (control_interface->cur_altsetting->desc.bInterfaceClass == USB_CLASS_CDC_DATA) {
1309 			dev_dbg(&intf->dev,
1310 				"Your device has switched interfaces.\n");
1311 			swap(control_interface, data_interface);
1312 		} else {
1313 			return -EINVAL;
1314 		}
1315 	}
1316 
1317 	/* Accept probe requests only for the control interface */
1318 	if (!combined_interfaces && intf != control_interface)
1319 		return -ENODEV;
1320 
1321 	if (data_interface->cur_altsetting->desc.bNumEndpoints < 2 ||
1322 	    control_interface->cur_altsetting->desc.bNumEndpoints == 0)
1323 		return -EINVAL;
1324 
1325 	epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
1326 	epread = &data_interface->cur_altsetting->endpoint[0].desc;
1327 	epwrite = &data_interface->cur_altsetting->endpoint[1].desc;
1328 
1329 
1330 	/* workaround for switched endpoints */
1331 	if (!usb_endpoint_dir_in(epread)) {
1332 		/* descriptors are swapped */
1333 		dev_dbg(&intf->dev,
1334 			"The data interface has switched endpoints\n");
1335 		swap(epread, epwrite);
1336 	}
1337 made_compressed_probe:
1338 	dev_dbg(&intf->dev, "interfaces are valid\n");
1339 
1340 	acm = kzalloc(sizeof(struct acm), GFP_KERNEL);
1341 	if (!acm)
1342 		return -ENOMEM;
1343 
1344 	tty_port_init(&acm->port);
1345 	acm->port.ops = &acm_port_ops;
1346 
1347 	ctrlsize = usb_endpoint_maxp(epctrl);
1348 	readsize = usb_endpoint_maxp(epread) *
1349 				(quirks == SINGLE_RX_URB ? 1 : 2);
1350 	acm->combined_interfaces = combined_interfaces;
1351 	acm->writesize = usb_endpoint_maxp(epwrite) * 20;
1352 	acm->control = control_interface;
1353 	acm->data = data_interface;
1354 
1355 	usb_get_intf(acm->control); /* undone in destruct() */
1356 
1357 	minor = acm_alloc_minor(acm);
1358 	if (minor < 0) {
1359 		acm->minor = ACM_MINOR_INVALID;
1360 		goto err_put_port;
1361 	}
1362 
1363 	acm->minor = minor;
1364 	acm->dev = usb_dev;
1365 	if (h.usb_cdc_acm_descriptor)
1366 		acm->ctrl_caps = h.usb_cdc_acm_descriptor->bmCapabilities;
1367 	if (quirks & NO_CAP_LINE)
1368 		acm->ctrl_caps &= ~USB_CDC_CAP_LINE;
1369 	acm->ctrlsize = ctrlsize;
1370 	acm->readsize = readsize;
1371 	acm->rx_buflimit = num_rx_buf;
1372 	INIT_DELAYED_WORK(&acm->dwork, acm_softint);
1373 	init_waitqueue_head(&acm->wioctl);
1374 	spin_lock_init(&acm->write_lock);
1375 	spin_lock_init(&acm->read_lock);
1376 	mutex_init(&acm->mutex);
1377 	if (usb_endpoint_xfer_int(epread)) {
1378 		acm->bInterval = epread->bInterval;
1379 		acm->in = usb_rcvintpipe(usb_dev, epread->bEndpointAddress);
1380 	} else {
1381 		acm->in = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
1382 	}
1383 	if (usb_endpoint_xfer_int(epwrite))
1384 		acm->out = usb_sndintpipe(usb_dev, epwrite->bEndpointAddress);
1385 	else
1386 		acm->out = usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress);
1387 	init_usb_anchor(&acm->delayed);
1388 	acm->quirks = quirks;
1389 
1390 	buf = usb_alloc_coherent(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
1391 	if (!buf)
1392 		goto err_put_port;
1393 	acm->ctrl_buffer = buf;
1394 
1395 	if (acm_write_buffers_alloc(acm) < 0)
1396 		goto err_free_ctrl_buffer;
1397 
1398 	acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
1399 	if (!acm->ctrlurb)
1400 		goto err_free_write_buffers;
1401 
1402 	for (i = 0; i < num_rx_buf; i++) {
1403 		struct acm_rb *rb = &(acm->read_buffers[i]);
1404 		struct urb *urb;
1405 
1406 		rb->base = usb_alloc_coherent(acm->dev, readsize, GFP_KERNEL,
1407 								&rb->dma);
1408 		if (!rb->base)
1409 			goto err_free_read_urbs;
1410 		rb->index = i;
1411 		rb->instance = acm;
1412 
1413 		urb = usb_alloc_urb(0, GFP_KERNEL);
1414 		if (!urb)
1415 			goto err_free_read_urbs;
1416 
1417 		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1418 		urb->transfer_dma = rb->dma;
1419 		if (usb_endpoint_xfer_int(epread))
1420 			usb_fill_int_urb(urb, acm->dev, acm->in, rb->base,
1421 					 acm->readsize,
1422 					 acm_read_bulk_callback, rb,
1423 					 acm->bInterval);
1424 		else
1425 			usb_fill_bulk_urb(urb, acm->dev, acm->in, rb->base,
1426 					  acm->readsize,
1427 					  acm_read_bulk_callback, rb);
1428 
1429 		acm->read_urbs[i] = urb;
1430 		__set_bit(i, &acm->read_urbs_free);
1431 	}
1432 	for (i = 0; i < ACM_NW; i++) {
1433 		struct acm_wb *snd = &(acm->wb[i]);
1434 
1435 		snd->urb = usb_alloc_urb(0, GFP_KERNEL);
1436 		if (!snd->urb)
1437 			goto err_free_write_urbs;
1438 
1439 		if (usb_endpoint_xfer_int(epwrite))
1440 			usb_fill_int_urb(snd->urb, usb_dev, acm->out,
1441 				NULL, acm->writesize, acm_write_bulk, snd, epwrite->bInterval);
1442 		else
1443 			usb_fill_bulk_urb(snd->urb, usb_dev, acm->out,
1444 				NULL, acm->writesize, acm_write_bulk, snd);
1445 		snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1446 		if (quirks & SEND_ZERO_PACKET)
1447 			snd->urb->transfer_flags |= URB_ZERO_PACKET;
1448 		snd->instance = acm;
1449 	}
1450 
1451 	usb_set_intfdata(intf, acm);
1452 
1453 	i = device_create_file(&intf->dev, &dev_attr_bmCapabilities);
1454 	if (i < 0)
1455 		goto err_free_write_urbs;
1456 
1457 	if (h.usb_cdc_country_functional_desc) { /* export the country data */
1458 		struct usb_cdc_country_functional_desc * cfd =
1459 					h.usb_cdc_country_functional_desc;
1460 
1461 		acm->country_codes = kmalloc(cfd->bLength - 4, GFP_KERNEL);
1462 		if (!acm->country_codes)
1463 			goto skip_countries;
1464 		acm->country_code_size = cfd->bLength - 4;
1465 		memcpy(acm->country_codes, (u8 *)&cfd->wCountyCode0,
1466 							cfd->bLength - 4);
1467 		acm->country_rel_date = cfd->iCountryCodeRelDate;
1468 
1469 		i = device_create_file(&intf->dev, &dev_attr_wCountryCodes);
1470 		if (i < 0) {
1471 			kfree(acm->country_codes);
1472 			acm->country_codes = NULL;
1473 			acm->country_code_size = 0;
1474 			goto skip_countries;
1475 		}
1476 
1477 		i = device_create_file(&intf->dev,
1478 						&dev_attr_iCountryCodeRelDate);
1479 		if (i < 0) {
1480 			device_remove_file(&intf->dev, &dev_attr_wCountryCodes);
1481 			kfree(acm->country_codes);
1482 			acm->country_codes = NULL;
1483 			acm->country_code_size = 0;
1484 			goto skip_countries;
1485 		}
1486 	}
1487 
1488 skip_countries:
1489 	usb_fill_int_urb(acm->ctrlurb, usb_dev,
1490 			 usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
1491 			 acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm,
1492 			 /* works around buggy devices */
1493 			 epctrl->bInterval ? epctrl->bInterval : 16);
1494 	acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1495 	acm->ctrlurb->transfer_dma = acm->ctrl_dma;
1496 	acm->notification_buffer = NULL;
1497 	acm->nb_index = 0;
1498 	acm->nb_size = 0;
1499 
1500 	acm->line.dwDTERate = cpu_to_le32(9600);
1501 	acm->line.bDataBits = 8;
1502 	acm_set_line(acm, &acm->line);
1503 
1504 	if (!acm->combined_interfaces) {
1505 		rv = usb_driver_claim_interface(&acm_driver, data_interface, acm);
1506 		if (rv)
1507 			goto err_remove_files;
1508 	}
1509 
1510 	tty_dev = tty_port_register_device(&acm->port, acm_tty_driver, minor,
1511 			&control_interface->dev);
1512 	if (IS_ERR(tty_dev)) {
1513 		rv = PTR_ERR(tty_dev);
1514 		goto err_release_data_interface;
1515 	}
1516 
1517 	if (quirks & CLEAR_HALT_CONDITIONS) {
1518 		usb_clear_halt(usb_dev, acm->in);
1519 		usb_clear_halt(usb_dev, acm->out);
1520 	}
1521 
1522 	dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
1523 
1524 	return 0;
1525 
1526 err_release_data_interface:
1527 	if (!acm->combined_interfaces) {
1528 		/* Clear driver data so that disconnect() returns early. */
1529 		usb_set_intfdata(data_interface, NULL);
1530 		usb_driver_release_interface(&acm_driver, data_interface);
1531 	}
1532 err_remove_files:
1533 	if (acm->country_codes) {
1534 		device_remove_file(&acm->control->dev,
1535 				&dev_attr_wCountryCodes);
1536 		device_remove_file(&acm->control->dev,
1537 				&dev_attr_iCountryCodeRelDate);
1538 	}
1539 	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
1540 err_free_write_urbs:
1541 	for (i = 0; i < ACM_NW; i++)
1542 		usb_free_urb(acm->wb[i].urb);
1543 err_free_read_urbs:
1544 	for (i = 0; i < num_rx_buf; i++)
1545 		usb_free_urb(acm->read_urbs[i]);
1546 	acm_read_buffers_free(acm);
1547 	usb_free_urb(acm->ctrlurb);
1548 err_free_write_buffers:
1549 	acm_write_buffers_free(acm);
1550 err_free_ctrl_buffer:
1551 	usb_free_coherent(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1552 err_put_port:
1553 	tty_port_put(&acm->port);
1554 
1555 	return rv;
1556 }
1557 
1558 static void acm_disconnect(struct usb_interface *intf)
1559 {
1560 	struct acm *acm = usb_get_intfdata(intf);
1561 	struct tty_struct *tty;
1562 	int i;
1563 
1564 	/* sibling interface is already cleaning up */
1565 	if (!acm)
1566 		return;
1567 
1568 	acm->disconnected = true;
1569 	/*
1570 	 * there is a circular dependency. acm_softint() can resubmit
1571 	 * the URBs in error handling so we need to block any
1572 	 * submission right away
1573 	 */
1574 	acm_poison_urbs(acm);
1575 	mutex_lock(&acm->mutex);
1576 	if (acm->country_codes) {
1577 		device_remove_file(&acm->control->dev,
1578 				&dev_attr_wCountryCodes);
1579 		device_remove_file(&acm->control->dev,
1580 				&dev_attr_iCountryCodeRelDate);
1581 	}
1582 	wake_up_all(&acm->wioctl);
1583 	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
1584 	usb_set_intfdata(acm->control, NULL);
1585 	usb_set_intfdata(acm->data, NULL);
1586 	mutex_unlock(&acm->mutex);
1587 
1588 	tty = tty_port_tty_get(&acm->port);
1589 	if (tty) {
1590 		tty_vhangup(tty);
1591 		tty_kref_put(tty);
1592 	}
1593 
1594 	cancel_delayed_work_sync(&acm->dwork);
1595 
1596 	tty_unregister_device(acm_tty_driver, acm->minor);
1597 
1598 	usb_free_urb(acm->ctrlurb);
1599 	for (i = 0; i < ACM_NW; i++)
1600 		usb_free_urb(acm->wb[i].urb);
1601 	for (i = 0; i < acm->rx_buflimit; i++)
1602 		usb_free_urb(acm->read_urbs[i]);
1603 	acm_write_buffers_free(acm);
1604 	usb_free_coherent(acm->dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1605 	acm_read_buffers_free(acm);
1606 
1607 	kfree(acm->notification_buffer);
1608 
1609 	if (!acm->combined_interfaces)
1610 		usb_driver_release_interface(&acm_driver, intf == acm->control ?
1611 					acm->data : acm->control);
1612 
1613 	tty_port_put(&acm->port);
1614 }
1615 
1616 #ifdef CONFIG_PM
1617 static int acm_suspend(struct usb_interface *intf, pm_message_t message)
1618 {
1619 	struct acm *acm = usb_get_intfdata(intf);
1620 	int cnt;
1621 
1622 	spin_lock_irq(&acm->write_lock);
1623 	if (PMSG_IS_AUTO(message)) {
1624 		if (acm->transmitting) {
1625 			spin_unlock_irq(&acm->write_lock);
1626 			return -EBUSY;
1627 		}
1628 	}
1629 	cnt = acm->susp_count++;
1630 	spin_unlock_irq(&acm->write_lock);
1631 
1632 	if (cnt)
1633 		return 0;
1634 
1635 	acm_poison_urbs(acm);
1636 	cancel_delayed_work_sync(&acm->dwork);
1637 	acm->urbs_in_error_delay = 0;
1638 
1639 	return 0;
1640 }
1641 
1642 static int acm_resume(struct usb_interface *intf)
1643 {
1644 	struct acm *acm = usb_get_intfdata(intf);
1645 	struct urb *urb;
1646 	int rv = 0;
1647 
1648 	spin_lock_irq(&acm->write_lock);
1649 
1650 	if (--acm->susp_count)
1651 		goto out;
1652 
1653 	acm_unpoison_urbs(acm);
1654 
1655 	if (tty_port_initialized(&acm->port)) {
1656 		rv = usb_submit_urb(acm->ctrlurb, GFP_ATOMIC);
1657 
1658 		for (;;) {
1659 			urb = usb_get_from_anchor(&acm->delayed);
1660 			if (!urb)
1661 				break;
1662 
1663 			acm_start_wb(acm, urb->context);
1664 		}
1665 
1666 		/*
1667 		 * delayed error checking because we must
1668 		 * do the write path at all cost
1669 		 */
1670 		if (rv < 0)
1671 			goto out;
1672 
1673 		rv = acm_submit_read_urbs(acm, GFP_ATOMIC);
1674 	}
1675 out:
1676 	spin_unlock_irq(&acm->write_lock);
1677 
1678 	return rv;
1679 }
1680 
1681 static int acm_reset_resume(struct usb_interface *intf)
1682 {
1683 	struct acm *acm = usb_get_intfdata(intf);
1684 
1685 	if (tty_port_initialized(&acm->port))
1686 		tty_port_tty_hangup(&acm->port, false);
1687 
1688 	return acm_resume(intf);
1689 }
1690 
1691 #endif /* CONFIG_PM */
1692 
1693 static int acm_pre_reset(struct usb_interface *intf)
1694 {
1695 	struct acm *acm = usb_get_intfdata(intf);
1696 
1697 	clear_bit(EVENT_RX_STALL, &acm->flags);
1698 	acm->nb_index = 0; /* pending control transfers are lost */
1699 
1700 	return 0;
1701 }
1702 
1703 #define NOKIA_PCSUITE_ACM_INFO(x) \
1704 		USB_DEVICE_AND_INTERFACE_INFO(0x0421, x, \
1705 		USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM, \
1706 		USB_CDC_ACM_PROTO_VENDOR)
1707 
1708 #define SAMSUNG_PCSUITE_ACM_INFO(x) \
1709 		USB_DEVICE_AND_INTERFACE_INFO(0x04e7, x, \
1710 		USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM, \
1711 		USB_CDC_ACM_PROTO_VENDOR)
1712 
1713 /*
1714  * USB driver structure.
1715  */
1716 
1717 static const struct usb_device_id acm_ids[] = {
1718 	/* quirky and broken devices */
1719 	{ USB_DEVICE(0x0424, 0x274e), /* Microchip Technology, Inc. (formerly SMSC) */
1720 	  .driver_info = DISABLE_ECHO, }, /* DISABLE ECHO in termios flag */
1721 	{ USB_DEVICE(0x076d, 0x0006), /* Denso Cradle CU-321 */
1722 	.driver_info = NO_UNION_NORMAL, },/* has no union descriptor */
1723 	{ USB_DEVICE(0x17ef, 0x7000), /* Lenovo USB modem */
1724 	.driver_info = NO_UNION_NORMAL, },/* has no union descriptor */
1725 	{ USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
1726 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1727 	},
1728 	{ USB_DEVICE(0x045b, 0x023c),	/* Renesas USB Download mode */
1729 	.driver_info = DISABLE_ECHO,	/* Don't echo banner */
1730 	},
1731 	{ USB_DEVICE(0x045b, 0x0248),	/* Renesas USB Download mode */
1732 	.driver_info = DISABLE_ECHO,	/* Don't echo banner */
1733 	},
1734 	{ USB_DEVICE(0x045b, 0x024D),	/* Renesas USB Download mode */
1735 	.driver_info = DISABLE_ECHO,	/* Don't echo banner */
1736 	},
1737 	{ USB_DEVICE(0x0e8d, 0x0003), /* FIREFLY, MediaTek Inc; andrey.arapov@gmail.com */
1738 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1739 	},
1740 	{ USB_DEVICE(0x0e8d, 0x2000), /* MediaTek Inc Preloader */
1741 	.driver_info = DISABLE_ECHO, /* DISABLE ECHO in termios flag */
1742 	},
1743 	{ USB_DEVICE(0x0e8d, 0x3329), /* MediaTek Inc GPS */
1744 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1745 	},
1746 	{ USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
1747 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1748 	},
1749 	{ USB_DEVICE(0x079b, 0x000f), /* BT On-Air USB MODEM */
1750 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1751 	},
1752 	{ USB_DEVICE(0x0ace, 0x1602), /* ZyDAS 56K USB MODEM */
1753 	.driver_info = SINGLE_RX_URB,
1754 	},
1755 	{ USB_DEVICE(0x0ace, 0x1608), /* ZyDAS 56K USB MODEM */
1756 	.driver_info = SINGLE_RX_URB, /* firmware bug */
1757 	},
1758 	{ USB_DEVICE(0x0ace, 0x1611), /* ZyDAS 56K USB MODEM - new version */
1759 	.driver_info = SINGLE_RX_URB, /* firmware bug */
1760 	},
1761 	{ USB_DEVICE(0x11ca, 0x0201), /* VeriFone Mx870 Gadget Serial */
1762 	.driver_info = SINGLE_RX_URB,
1763 	},
1764 	{ USB_DEVICE(0x1901, 0x0006), /* GE Healthcare Patient Monitor UI Controller */
1765 	.driver_info = DISABLE_ECHO, /* DISABLE ECHO in termios flag */
1766 	},
1767 	{ USB_DEVICE(0x1965, 0x0018), /* Uniden UBC125XLT */
1768 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1769 	},
1770 	{ USB_DEVICE(0x22b8, 0x7000), /* Motorola Q Phone */
1771 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1772 	},
1773 	{ USB_DEVICE(0x0803, 0x3095), /* Zoom Telephonics Model 3095F USB MODEM */
1774 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1775 	},
1776 	{ USB_DEVICE(0x0572, 0x1321), /* Conexant USB MODEM CX93010 */
1777 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1778 	},
1779 	{ USB_DEVICE(0x0572, 0x1324), /* Conexant USB MODEM RD02-D400 */
1780 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1781 	},
1782 	{ USB_DEVICE(0x0572, 0x1328), /* Shiro / Aztech USB MODEM UM-3100 */
1783 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1784 	},
1785 	{ USB_DEVICE(0x0572, 0x1349), /* Hiro (Conexant) USB MODEM H50228 */
1786 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1787 	},
1788 	{ USB_DEVICE(0x20df, 0x0001), /* Simtec Electronics Entropy Key */
1789 	.driver_info = QUIRK_CONTROL_LINE_STATE, },
1790 	{ USB_DEVICE(0x2184, 0x001c) },	/* GW Instek AFG-2225 */
1791 	{ USB_DEVICE(0x2184, 0x0036) },	/* GW Instek AFG-125 */
1792 	{ USB_DEVICE(0x22b8, 0x6425), /* Motorola MOTOMAGX phones */
1793 	},
1794 	/* Motorola H24 HSPA module: */
1795 	{ USB_DEVICE(0x22b8, 0x2d91) }, /* modem                                */
1796 	{ USB_DEVICE(0x22b8, 0x2d92),   /* modem           + diagnostics        */
1797 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1798 	},
1799 	{ USB_DEVICE(0x22b8, 0x2d93),   /* modem + AT port                      */
1800 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1801 	},
1802 	{ USB_DEVICE(0x22b8, 0x2d95),   /* modem + AT port + diagnostics        */
1803 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1804 	},
1805 	{ USB_DEVICE(0x22b8, 0x2d96),   /* modem                         + NMEA */
1806 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1807 	},
1808 	{ USB_DEVICE(0x22b8, 0x2d97),   /* modem           + diagnostics + NMEA */
1809 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1810 	},
1811 	{ USB_DEVICE(0x22b8, 0x2d99),   /* modem + AT port               + NMEA */
1812 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1813 	},
1814 	{ USB_DEVICE(0x22b8, 0x2d9a),   /* modem + AT port + diagnostics + NMEA */
1815 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1816 	},
1817 
1818 	{ USB_DEVICE(0x0572, 0x1329), /* Hummingbird huc56s (Conexant) */
1819 	.driver_info = NO_UNION_NORMAL, /* union descriptor misplaced on
1820 					   data interface instead of
1821 					   communications interface.
1822 					   Maybe we should define a new
1823 					   quirk for this. */
1824 	},
1825 	{ USB_DEVICE(0x0572, 0x1340), /* Conexant CX93010-2x UCMxx */
1826 	.driver_info = NO_UNION_NORMAL,
1827 	},
1828 	{ USB_DEVICE(0x05f9, 0x4002), /* PSC Scanning, Magellan 800i */
1829 	.driver_info = NO_UNION_NORMAL,
1830 	},
1831 	{ USB_DEVICE(0x1bbb, 0x0003), /* Alcatel OT-I650 */
1832 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1833 	},
1834 	{ USB_DEVICE(0x1576, 0x03b1), /* Maretron USB100 */
1835 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1836 	},
1837 	{ USB_DEVICE(0xfff0, 0x0100), /* DATECS FP-2000 */
1838 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1839 	},
1840 	{ USB_DEVICE(0x09d8, 0x0320), /* Elatec GmbH TWN3 */
1841 	.driver_info = NO_UNION_NORMAL, /* has misplaced union descriptor */
1842 	},
1843 	{ USB_DEVICE(0x0c26, 0x0020), /* Icom ICF3400 Serie */
1844 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1845 	},
1846 	{ USB_DEVICE(0x0ca6, 0xa050), /* Castles VEGA3000 */
1847 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1848 	},
1849 
1850 	{ USB_DEVICE(0x2912, 0x0001), /* ATOL FPrint */
1851 	.driver_info = CLEAR_HALT_CONDITIONS,
1852 	},
1853 
1854 	/* Nokia S60 phones expose two ACM channels. The first is
1855 	 * a modem and is picked up by the standard AT-command
1856 	 * information below. The second is 'vendor-specific' but
1857 	 * is treated as a serial device at the S60 end, so we want
1858 	 * to expose it on Linux too. */
1859 	{ NOKIA_PCSUITE_ACM_INFO(0x042D), }, /* Nokia 3250 */
1860 	{ NOKIA_PCSUITE_ACM_INFO(0x04D8), }, /* Nokia 5500 Sport */
1861 	{ NOKIA_PCSUITE_ACM_INFO(0x04C9), }, /* Nokia E50 */
1862 	{ NOKIA_PCSUITE_ACM_INFO(0x0419), }, /* Nokia E60 */
1863 	{ NOKIA_PCSUITE_ACM_INFO(0x044D), }, /* Nokia E61 */
1864 	{ NOKIA_PCSUITE_ACM_INFO(0x0001), }, /* Nokia E61i */
1865 	{ NOKIA_PCSUITE_ACM_INFO(0x0475), }, /* Nokia E62 */
1866 	{ NOKIA_PCSUITE_ACM_INFO(0x0508), }, /* Nokia E65 */
1867 	{ NOKIA_PCSUITE_ACM_INFO(0x0418), }, /* Nokia E70 */
1868 	{ NOKIA_PCSUITE_ACM_INFO(0x0425), }, /* Nokia N71 */
1869 	{ NOKIA_PCSUITE_ACM_INFO(0x0486), }, /* Nokia N73 */
1870 	{ NOKIA_PCSUITE_ACM_INFO(0x04DF), }, /* Nokia N75 */
1871 	{ NOKIA_PCSUITE_ACM_INFO(0x000e), }, /* Nokia N77 */
1872 	{ NOKIA_PCSUITE_ACM_INFO(0x0445), }, /* Nokia N80 */
1873 	{ NOKIA_PCSUITE_ACM_INFO(0x042F), }, /* Nokia N91 & N91 8GB */
1874 	{ NOKIA_PCSUITE_ACM_INFO(0x048E), }, /* Nokia N92 */
1875 	{ NOKIA_PCSUITE_ACM_INFO(0x0420), }, /* Nokia N93 */
1876 	{ NOKIA_PCSUITE_ACM_INFO(0x04E6), }, /* Nokia N93i  */
1877 	{ NOKIA_PCSUITE_ACM_INFO(0x04B2), }, /* Nokia 5700 XpressMusic */
1878 	{ NOKIA_PCSUITE_ACM_INFO(0x0134), }, /* Nokia 6110 Navigator (China) */
1879 	{ NOKIA_PCSUITE_ACM_INFO(0x046E), }, /* Nokia 6110 Navigator */
1880 	{ NOKIA_PCSUITE_ACM_INFO(0x002f), }, /* Nokia 6120 classic &  */
1881 	{ NOKIA_PCSUITE_ACM_INFO(0x0088), }, /* Nokia 6121 classic */
1882 	{ NOKIA_PCSUITE_ACM_INFO(0x00fc), }, /* Nokia 6124 classic */
1883 	{ NOKIA_PCSUITE_ACM_INFO(0x0042), }, /* Nokia E51 */
1884 	{ NOKIA_PCSUITE_ACM_INFO(0x00b0), }, /* Nokia E66 */
1885 	{ NOKIA_PCSUITE_ACM_INFO(0x00ab), }, /* Nokia E71 */
1886 	{ NOKIA_PCSUITE_ACM_INFO(0x0481), }, /* Nokia N76 */
1887 	{ NOKIA_PCSUITE_ACM_INFO(0x0007), }, /* Nokia N81 & N81 8GB */
1888 	{ NOKIA_PCSUITE_ACM_INFO(0x0071), }, /* Nokia N82 */
1889 	{ NOKIA_PCSUITE_ACM_INFO(0x04F0), }, /* Nokia N95 & N95-3 NAM */
1890 	{ NOKIA_PCSUITE_ACM_INFO(0x0070), }, /* Nokia N95 8GB  */
1891 	{ NOKIA_PCSUITE_ACM_INFO(0x0099), }, /* Nokia 6210 Navigator, RM-367 */
1892 	{ NOKIA_PCSUITE_ACM_INFO(0x0128), }, /* Nokia 6210 Navigator, RM-419 */
1893 	{ NOKIA_PCSUITE_ACM_INFO(0x008f), }, /* Nokia 6220 Classic */
1894 	{ NOKIA_PCSUITE_ACM_INFO(0x00a0), }, /* Nokia 6650 */
1895 	{ NOKIA_PCSUITE_ACM_INFO(0x007b), }, /* Nokia N78 */
1896 	{ NOKIA_PCSUITE_ACM_INFO(0x0094), }, /* Nokia N85 */
1897 	{ NOKIA_PCSUITE_ACM_INFO(0x003a), }, /* Nokia N96 & N96-3  */
1898 	{ NOKIA_PCSUITE_ACM_INFO(0x00e9), }, /* Nokia 5320 XpressMusic */
1899 	{ NOKIA_PCSUITE_ACM_INFO(0x0108), }, /* Nokia 5320 XpressMusic 2G */
1900 	{ NOKIA_PCSUITE_ACM_INFO(0x01f5), }, /* Nokia N97, RM-505 */
1901 	{ NOKIA_PCSUITE_ACM_INFO(0x02e3), }, /* Nokia 5230, RM-588 */
1902 	{ NOKIA_PCSUITE_ACM_INFO(0x0178), }, /* Nokia E63 */
1903 	{ NOKIA_PCSUITE_ACM_INFO(0x010e), }, /* Nokia E75 */
1904 	{ NOKIA_PCSUITE_ACM_INFO(0x02d9), }, /* Nokia 6760 Slide */
1905 	{ NOKIA_PCSUITE_ACM_INFO(0x01d0), }, /* Nokia E52 */
1906 	{ NOKIA_PCSUITE_ACM_INFO(0x0223), }, /* Nokia E72 */
1907 	{ NOKIA_PCSUITE_ACM_INFO(0x0275), }, /* Nokia X6 */
1908 	{ NOKIA_PCSUITE_ACM_INFO(0x026c), }, /* Nokia N97 Mini */
1909 	{ NOKIA_PCSUITE_ACM_INFO(0x0154), }, /* Nokia 5800 XpressMusic */
1910 	{ NOKIA_PCSUITE_ACM_INFO(0x04ce), }, /* Nokia E90 */
1911 	{ NOKIA_PCSUITE_ACM_INFO(0x01d4), }, /* Nokia E55 */
1912 	{ NOKIA_PCSUITE_ACM_INFO(0x0302), }, /* Nokia N8 */
1913 	{ NOKIA_PCSUITE_ACM_INFO(0x0335), }, /* Nokia E7 */
1914 	{ NOKIA_PCSUITE_ACM_INFO(0x03cd), }, /* Nokia C7 */
1915 	{ SAMSUNG_PCSUITE_ACM_INFO(0x6651), }, /* Samsung GTi8510 (INNOV8) */
1916 
1917 	/* Support for Owen devices */
1918 	{ USB_DEVICE(0x03eb, 0x0030), }, /* Owen SI30 */
1919 
1920 	/* NOTE: non-Nokia COMM/ACM/0xff is likely MSFT RNDIS... NOT a modem! */
1921 
1922 #if IS_ENABLED(CONFIG_INPUT_IMS_PCU)
1923 	{ USB_DEVICE(0x04d8, 0x0082),	/* Application mode */
1924 	.driver_info = IGNORE_DEVICE,
1925 	},
1926 	{ USB_DEVICE(0x04d8, 0x0083),	/* Bootloader mode */
1927 	.driver_info = IGNORE_DEVICE,
1928 	},
1929 #endif
1930 
1931 #if IS_ENABLED(CONFIG_IR_TOY)
1932 	{ USB_DEVICE(0x04d8, 0xfd08),
1933 	.driver_info = IGNORE_DEVICE,
1934 	},
1935 
1936 	{ USB_DEVICE(0x04d8, 0xf58b),
1937 	.driver_info = IGNORE_DEVICE,
1938 	},
1939 #endif
1940 
1941 #if IS_ENABLED(CONFIG_USB_SERIAL_XR)
1942 	{ USB_DEVICE(0x04e2, 0x1400), .driver_info = IGNORE_DEVICE },
1943 	{ USB_DEVICE(0x04e2, 0x1401), .driver_info = IGNORE_DEVICE },
1944 	{ USB_DEVICE(0x04e2, 0x1402), .driver_info = IGNORE_DEVICE },
1945 	{ USB_DEVICE(0x04e2, 0x1403), .driver_info = IGNORE_DEVICE },
1946 	{ USB_DEVICE(0x04e2, 0x1410), .driver_info = IGNORE_DEVICE },
1947 	{ USB_DEVICE(0x04e2, 0x1411), .driver_info = IGNORE_DEVICE },
1948 	{ USB_DEVICE(0x04e2, 0x1412), .driver_info = IGNORE_DEVICE },
1949 	{ USB_DEVICE(0x04e2, 0x1414), .driver_info = IGNORE_DEVICE },
1950 	{ USB_DEVICE(0x04e2, 0x1420), .driver_info = IGNORE_DEVICE },
1951 	{ USB_DEVICE(0x04e2, 0x1422), .driver_info = IGNORE_DEVICE },
1952 	{ USB_DEVICE(0x04e2, 0x1424), .driver_info = IGNORE_DEVICE },
1953 #endif
1954 
1955 	/*Samsung phone in firmware update mode */
1956 	{ USB_DEVICE(0x04e8, 0x685d),
1957 	.driver_info = IGNORE_DEVICE,
1958 	},
1959 
1960 	/* Exclude Infineon Flash Loader utility */
1961 	{ USB_DEVICE(0x058b, 0x0041),
1962 	.driver_info = IGNORE_DEVICE,
1963 	},
1964 
1965 	/* Exclude ETAS ES58x */
1966 	{ USB_DEVICE(0x108c, 0x0159), /* ES581.4 */
1967 	.driver_info = IGNORE_DEVICE,
1968 	},
1969 	{ USB_DEVICE(0x108c, 0x0168), /* ES582.1 */
1970 	.driver_info = IGNORE_DEVICE,
1971 	},
1972 	{ USB_DEVICE(0x108c, 0x0169), /* ES584.1 */
1973 	.driver_info = IGNORE_DEVICE,
1974 	},
1975 
1976 	{ USB_DEVICE(0x1bc7, 0x0021), /* Telit 3G ACM only composition */
1977 	.driver_info = SEND_ZERO_PACKET,
1978 	},
1979 	{ USB_DEVICE(0x1bc7, 0x0023), /* Telit 3G ACM + ECM composition */
1980 	.driver_info = SEND_ZERO_PACKET,
1981 	},
1982 
1983 	/* Exclude Goodix Fingerprint Reader */
1984 	{ USB_DEVICE(0x27c6, 0x5395),
1985 	.driver_info = IGNORE_DEVICE,
1986 	},
1987 
1988 	/* Exclude Heimann Sensor GmbH USB appset demo */
1989 	{ USB_DEVICE(0x32a7, 0x0000),
1990 	.driver_info = IGNORE_DEVICE,
1991 	},
1992 
1993 	/* control interfaces without any protocol set */
1994 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1995 		USB_CDC_PROTO_NONE) },
1996 
1997 	/* control interfaces with various AT-command sets */
1998 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1999 		USB_CDC_ACM_PROTO_AT_V25TER) },
2000 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2001 		USB_CDC_ACM_PROTO_AT_PCCA101) },
2002 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2003 		USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
2004 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2005 		USB_CDC_ACM_PROTO_AT_GSM) },
2006 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2007 		USB_CDC_ACM_PROTO_AT_3G) },
2008 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2009 		USB_CDC_ACM_PROTO_AT_CDMA) },
2010 
2011 	{ USB_DEVICE(0x1519, 0x0452), /* Intel 7260 modem */
2012 	.driver_info = SEND_ZERO_PACKET,
2013 	},
2014 
2015 	{ }
2016 };
2017 
2018 MODULE_DEVICE_TABLE(usb, acm_ids);
2019 
2020 static struct usb_driver acm_driver = {
2021 	.name =		"cdc_acm",
2022 	.probe =	acm_probe,
2023 	.disconnect =	acm_disconnect,
2024 #ifdef CONFIG_PM
2025 	.suspend =	acm_suspend,
2026 	.resume =	acm_resume,
2027 	.reset_resume =	acm_reset_resume,
2028 #endif
2029 	.pre_reset =	acm_pre_reset,
2030 	.id_table =	acm_ids,
2031 #ifdef CONFIG_PM
2032 	.supports_autosuspend = 1,
2033 #endif
2034 	.disable_hub_initiated_lpm = 1,
2035 };
2036 
2037 /*
2038  * TTY driver structures.
2039  */
2040 
2041 static const struct tty_operations acm_ops = {
2042 	.install =		acm_tty_install,
2043 	.open =			acm_tty_open,
2044 	.close =		acm_tty_close,
2045 	.cleanup =		acm_tty_cleanup,
2046 	.hangup =		acm_tty_hangup,
2047 	.write =		acm_tty_write,
2048 	.write_room =		acm_tty_write_room,
2049 	.flush_buffer =		acm_tty_flush_buffer,
2050 	.ioctl =		acm_tty_ioctl,
2051 	.throttle =		acm_tty_throttle,
2052 	.unthrottle =		acm_tty_unthrottle,
2053 	.chars_in_buffer =	acm_tty_chars_in_buffer,
2054 	.break_ctl =		acm_tty_break_ctl,
2055 	.set_termios =		acm_tty_set_termios,
2056 	.tiocmget =		acm_tty_tiocmget,
2057 	.tiocmset =		acm_tty_tiocmset,
2058 	.get_serial =		get_serial_info,
2059 	.set_serial =		set_serial_info,
2060 	.get_icount =		acm_tty_get_icount,
2061 };
2062 
2063 /*
2064  * Init / exit.
2065  */
2066 
2067 static int __init acm_init(void)
2068 {
2069 	int retval;
2070 	acm_tty_driver = tty_alloc_driver(ACM_TTY_MINORS, TTY_DRIVER_REAL_RAW |
2071 			TTY_DRIVER_DYNAMIC_DEV);
2072 	if (IS_ERR(acm_tty_driver))
2073 		return PTR_ERR(acm_tty_driver);
2074 	acm_tty_driver->driver_name = "acm",
2075 	acm_tty_driver->name = "ttyACM",
2076 	acm_tty_driver->major = ACM_TTY_MAJOR,
2077 	acm_tty_driver->minor_start = 0,
2078 	acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
2079 	acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
2080 	acm_tty_driver->init_termios = tty_std_termios;
2081 	acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD |
2082 								HUPCL | CLOCAL;
2083 	tty_set_operations(acm_tty_driver, &acm_ops);
2084 
2085 	retval = tty_register_driver(acm_tty_driver);
2086 	if (retval) {
2087 		tty_driver_kref_put(acm_tty_driver);
2088 		return retval;
2089 	}
2090 
2091 	retval = usb_register(&acm_driver);
2092 	if (retval) {
2093 		tty_unregister_driver(acm_tty_driver);
2094 		tty_driver_kref_put(acm_tty_driver);
2095 		return retval;
2096 	}
2097 
2098 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");
2099 
2100 	return 0;
2101 }
2102 
2103 static void __exit acm_exit(void)
2104 {
2105 	usb_deregister(&acm_driver);
2106 	tty_unregister_driver(acm_tty_driver);
2107 	tty_driver_kref_put(acm_tty_driver);
2108 	idr_destroy(&acm_minors);
2109 }
2110 
2111 module_init(acm_init);
2112 module_exit(acm_exit);
2113 
2114 MODULE_AUTHOR(DRIVER_AUTHOR);
2115 MODULE_DESCRIPTION(DRIVER_DESC);
2116 MODULE_LICENSE("GPL");
2117 MODULE_ALIAS_CHARDEV_MAJOR(ACM_TTY_MAJOR);
2118