xref: /openbmc/linux/drivers/usb/class/cdc-acm.c (revision 0e6774ec)
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 	mutex_lock(&acm->port.mutex);
966 	ss->close_delay	= jiffies_to_msecs(acm->port.close_delay) / 10;
967 	ss->closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
968 				ASYNC_CLOSING_WAIT_NONE :
969 				jiffies_to_msecs(acm->port.closing_wait) / 10;
970 	mutex_unlock(&acm->port.mutex);
971 	return 0;
972 }
973 
974 static int set_serial_info(struct tty_struct *tty, struct serial_struct *ss)
975 {
976 	struct acm *acm = tty->driver_data;
977 	unsigned int closing_wait, close_delay;
978 	int retval = 0;
979 
980 	close_delay = msecs_to_jiffies(ss->close_delay * 10);
981 	closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
982 			ASYNC_CLOSING_WAIT_NONE :
983 			msecs_to_jiffies(ss->closing_wait * 10);
984 
985 	mutex_lock(&acm->port.mutex);
986 
987 	if (!capable(CAP_SYS_ADMIN)) {
988 		if ((close_delay != acm->port.close_delay) ||
989 		    (closing_wait != acm->port.closing_wait))
990 			retval = -EPERM;
991 	} else {
992 		acm->port.close_delay  = close_delay;
993 		acm->port.closing_wait = closing_wait;
994 	}
995 
996 	mutex_unlock(&acm->port.mutex);
997 	return retval;
998 }
999 
1000 static int wait_serial_change(struct acm *acm, unsigned long arg)
1001 {
1002 	int rv = 0;
1003 	DECLARE_WAITQUEUE(wait, current);
1004 	struct async_icount old, new;
1005 
1006 	do {
1007 		spin_lock_irq(&acm->read_lock);
1008 		old = acm->oldcount;
1009 		new = acm->iocount;
1010 		acm->oldcount = new;
1011 		spin_unlock_irq(&acm->read_lock);
1012 
1013 		if ((arg & TIOCM_DSR) &&
1014 			old.dsr != new.dsr)
1015 			break;
1016 		if ((arg & TIOCM_CD)  &&
1017 			old.dcd != new.dcd)
1018 			break;
1019 		if ((arg & TIOCM_RI) &&
1020 			old.rng != new.rng)
1021 			break;
1022 
1023 		add_wait_queue(&acm->wioctl, &wait);
1024 		set_current_state(TASK_INTERRUPTIBLE);
1025 		schedule();
1026 		remove_wait_queue(&acm->wioctl, &wait);
1027 		if (acm->disconnected) {
1028 			if (arg & TIOCM_CD)
1029 				break;
1030 			else
1031 				rv = -ENODEV;
1032 		} else {
1033 			if (signal_pending(current))
1034 				rv = -ERESTARTSYS;
1035 		}
1036 	} while (!rv);
1037 
1038 
1039 
1040 	return rv;
1041 }
1042 
1043 static int acm_tty_get_icount(struct tty_struct *tty,
1044 					struct serial_icounter_struct *icount)
1045 {
1046 	struct acm *acm = tty->driver_data;
1047 
1048 	icount->dsr = acm->iocount.dsr;
1049 	icount->rng = acm->iocount.rng;
1050 	icount->dcd = acm->iocount.dcd;
1051 	icount->frame = acm->iocount.frame;
1052 	icount->overrun = acm->iocount.overrun;
1053 	icount->parity = acm->iocount.parity;
1054 	icount->brk = acm->iocount.brk;
1055 
1056 	return 0;
1057 }
1058 
1059 static int acm_tty_ioctl(struct tty_struct *tty,
1060 					unsigned int cmd, unsigned long arg)
1061 {
1062 	struct acm *acm = tty->driver_data;
1063 	int rv = -ENOIOCTLCMD;
1064 
1065 	switch (cmd) {
1066 	case TIOCMIWAIT:
1067 		rv = usb_autopm_get_interface(acm->control);
1068 		if (rv < 0) {
1069 			rv = -EIO;
1070 			break;
1071 		}
1072 		rv = wait_serial_change(acm, arg);
1073 		usb_autopm_put_interface(acm->control);
1074 		break;
1075 	}
1076 
1077 	return rv;
1078 }
1079 
1080 static void acm_tty_set_termios(struct tty_struct *tty,
1081 				const struct ktermios *termios_old)
1082 {
1083 	struct acm *acm = tty->driver_data;
1084 	struct ktermios *termios = &tty->termios;
1085 	struct usb_cdc_line_coding newline;
1086 	int newctrl = acm->ctrlout;
1087 
1088 	newline.dwDTERate = cpu_to_le32(tty_get_baud_rate(tty));
1089 	newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
1090 	newline.bParityType = termios->c_cflag & PARENB ?
1091 				(termios->c_cflag & PARODD ? 1 : 2) +
1092 				(termios->c_cflag & CMSPAR ? 2 : 0) : 0;
1093 	newline.bDataBits = tty_get_char_size(termios->c_cflag);
1094 
1095 	/* FIXME: Needs to clear unsupported bits in the termios */
1096 	acm->clocal = ((termios->c_cflag & CLOCAL) != 0);
1097 
1098 	if (C_BAUD(tty) == B0) {
1099 		newline.dwDTERate = acm->line.dwDTERate;
1100 		newctrl &= ~USB_CDC_CTRL_DTR;
1101 	} else if (termios_old && (termios_old->c_cflag & CBAUD) == B0) {
1102 		newctrl |=  USB_CDC_CTRL_DTR;
1103 	}
1104 
1105 	if (newctrl != acm->ctrlout)
1106 		acm_set_control(acm, acm->ctrlout = newctrl);
1107 
1108 	if (memcmp(&acm->line, &newline, sizeof newline)) {
1109 		memcpy(&acm->line, &newline, sizeof newline);
1110 		dev_dbg(&acm->control->dev, "%s - set line: %d %d %d %d\n",
1111 			__func__,
1112 			le32_to_cpu(newline.dwDTERate),
1113 			newline.bCharFormat, newline.bParityType,
1114 			newline.bDataBits);
1115 		acm_set_line(acm, &acm->line);
1116 	}
1117 }
1118 
1119 static const struct tty_port_operations acm_port_ops = {
1120 	.dtr_rts = acm_port_dtr_rts,
1121 	.shutdown = acm_port_shutdown,
1122 	.activate = acm_port_activate,
1123 	.destruct = acm_port_destruct,
1124 };
1125 
1126 /*
1127  * USB probe and disconnect routines.
1128  */
1129 
1130 /* Little helpers: write/read buffers free */
1131 static void acm_write_buffers_free(struct acm *acm)
1132 {
1133 	int i;
1134 	struct acm_wb *wb;
1135 
1136 	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++)
1137 		usb_free_coherent(acm->dev, acm->writesize, wb->buf, wb->dmah);
1138 }
1139 
1140 static void acm_read_buffers_free(struct acm *acm)
1141 {
1142 	int i;
1143 
1144 	for (i = 0; i < acm->rx_buflimit; i++)
1145 		usb_free_coherent(acm->dev, acm->readsize,
1146 			  acm->read_buffers[i].base, acm->read_buffers[i].dma);
1147 }
1148 
1149 /* Little helper: write buffers allocate */
1150 static int acm_write_buffers_alloc(struct acm *acm)
1151 {
1152 	int i;
1153 	struct acm_wb *wb;
1154 
1155 	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
1156 		wb->buf = usb_alloc_coherent(acm->dev, acm->writesize, GFP_KERNEL,
1157 		    &wb->dmah);
1158 		if (!wb->buf) {
1159 			while (i != 0) {
1160 				--i;
1161 				--wb;
1162 				usb_free_coherent(acm->dev, acm->writesize,
1163 				    wb->buf, wb->dmah);
1164 			}
1165 			return -ENOMEM;
1166 		}
1167 	}
1168 	return 0;
1169 }
1170 
1171 static int acm_probe(struct usb_interface *intf,
1172 		     const struct usb_device_id *id)
1173 {
1174 	struct usb_cdc_union_desc *union_header = NULL;
1175 	struct usb_cdc_call_mgmt_descriptor *cmgmd = NULL;
1176 	unsigned char *buffer = intf->altsetting->extra;
1177 	int buflen = intf->altsetting->extralen;
1178 	struct usb_interface *control_interface;
1179 	struct usb_interface *data_interface;
1180 	struct usb_endpoint_descriptor *epctrl = NULL;
1181 	struct usb_endpoint_descriptor *epread = NULL;
1182 	struct usb_endpoint_descriptor *epwrite = NULL;
1183 	struct usb_device *usb_dev = interface_to_usbdev(intf);
1184 	struct usb_cdc_parsed_header h;
1185 	struct acm *acm;
1186 	int minor;
1187 	int ctrlsize, readsize;
1188 	u8 *buf;
1189 	int call_intf_num = -1;
1190 	int data_intf_num = -1;
1191 	unsigned long quirks;
1192 	int num_rx_buf;
1193 	int i;
1194 	int combined_interfaces = 0;
1195 	struct device *tty_dev;
1196 	int rv = -ENOMEM;
1197 	int res;
1198 
1199 	/* normal quirks */
1200 	quirks = (unsigned long)id->driver_info;
1201 
1202 	if (quirks == IGNORE_DEVICE)
1203 		return -ENODEV;
1204 
1205 	memset(&h, 0x00, sizeof(struct usb_cdc_parsed_header));
1206 
1207 	num_rx_buf = (quirks == SINGLE_RX_URB) ? 1 : ACM_NR;
1208 
1209 	/* handle quirks deadly to normal probing*/
1210 	if (quirks == NO_UNION_NORMAL) {
1211 		data_interface = usb_ifnum_to_if(usb_dev, 1);
1212 		control_interface = usb_ifnum_to_if(usb_dev, 0);
1213 		/* we would crash */
1214 		if (!data_interface || !control_interface)
1215 			return -ENODEV;
1216 		goto skip_normal_probe;
1217 	}
1218 
1219 	/* normal probing*/
1220 	if (!buffer) {
1221 		dev_err(&intf->dev, "Weird descriptor references\n");
1222 		return -EINVAL;
1223 	}
1224 
1225 	if (!buflen) {
1226 		if (intf->cur_altsetting->endpoint &&
1227 				intf->cur_altsetting->endpoint->extralen &&
1228 				intf->cur_altsetting->endpoint->extra) {
1229 			dev_dbg(&intf->dev,
1230 				"Seeking extra descriptors on endpoint\n");
1231 			buflen = intf->cur_altsetting->endpoint->extralen;
1232 			buffer = intf->cur_altsetting->endpoint->extra;
1233 		} else {
1234 			dev_err(&intf->dev,
1235 				"Zero length descriptor references\n");
1236 			return -EINVAL;
1237 		}
1238 	}
1239 
1240 	cdc_parse_cdc_header(&h, intf, buffer, buflen);
1241 	union_header = h.usb_cdc_union_desc;
1242 	cmgmd = h.usb_cdc_call_mgmt_descriptor;
1243 	if (cmgmd)
1244 		call_intf_num = cmgmd->bDataInterface;
1245 
1246 	if (!union_header) {
1247 		if (intf->cur_altsetting->desc.bNumEndpoints == 3) {
1248 			dev_dbg(&intf->dev, "No union descriptor, assuming single interface\n");
1249 			combined_interfaces = 1;
1250 			control_interface = data_interface = intf;
1251 			goto look_for_collapsed_interface;
1252 		} else if (call_intf_num > 0) {
1253 			dev_dbg(&intf->dev, "No union descriptor, using call management descriptor\n");
1254 			data_intf_num = call_intf_num;
1255 			data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
1256 			control_interface = intf;
1257 		} else {
1258 			dev_dbg(&intf->dev, "No union descriptor, giving up\n");
1259 			return -ENODEV;
1260 		}
1261 	} else {
1262 		int class = -1;
1263 
1264 		data_intf_num = union_header->bSlaveInterface0;
1265 		control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
1266 		data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
1267 
1268 		if (control_interface)
1269 			class = control_interface->cur_altsetting->desc.bInterfaceClass;
1270 
1271 		if (class != USB_CLASS_COMM && class != USB_CLASS_CDC_DATA) {
1272 			dev_dbg(&intf->dev, "Broken union descriptor, assuming single interface\n");
1273 			combined_interfaces = 1;
1274 			control_interface = data_interface = intf;
1275 			goto look_for_collapsed_interface;
1276 		}
1277 	}
1278 
1279 	if (!control_interface || !data_interface) {
1280 		dev_dbg(&intf->dev, "no interfaces\n");
1281 		return -ENODEV;
1282 	}
1283 
1284 	if (data_intf_num != call_intf_num)
1285 		dev_dbg(&intf->dev, "Separate call control interface. That is not fully supported.\n");
1286 
1287 	if (control_interface == data_interface) {
1288 		/* some broken devices designed for windows work this way */
1289 		dev_warn(&intf->dev,"Control and data interfaces are not separated!\n");
1290 		combined_interfaces = 1;
1291 		/* a popular other OS doesn't use it */
1292 		quirks |= NO_CAP_LINE;
1293 		if (data_interface->cur_altsetting->desc.bNumEndpoints != 3) {
1294 			dev_err(&intf->dev, "This needs exactly 3 endpoints\n");
1295 			return -EINVAL;
1296 		}
1297 look_for_collapsed_interface:
1298 		res = usb_find_common_endpoints(data_interface->cur_altsetting,
1299 				&epread, &epwrite, &epctrl, NULL);
1300 		if (res)
1301 			return res;
1302 
1303 		goto made_compressed_probe;
1304 	}
1305 
1306 skip_normal_probe:
1307 
1308 	/*workaround for switched interfaces */
1309 	if (data_interface->cur_altsetting->desc.bInterfaceClass != USB_CLASS_CDC_DATA) {
1310 		if (control_interface->cur_altsetting->desc.bInterfaceClass == USB_CLASS_CDC_DATA) {
1311 			dev_dbg(&intf->dev,
1312 				"Your device has switched interfaces.\n");
1313 			swap(control_interface, data_interface);
1314 		} else {
1315 			return -EINVAL;
1316 		}
1317 	}
1318 
1319 	/* Accept probe requests only for the control interface */
1320 	if (!combined_interfaces && intf != control_interface)
1321 		return -ENODEV;
1322 
1323 	if (data_interface->cur_altsetting->desc.bNumEndpoints < 2 ||
1324 	    control_interface->cur_altsetting->desc.bNumEndpoints == 0)
1325 		return -EINVAL;
1326 
1327 	epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
1328 	epread = &data_interface->cur_altsetting->endpoint[0].desc;
1329 	epwrite = &data_interface->cur_altsetting->endpoint[1].desc;
1330 
1331 
1332 	/* workaround for switched endpoints */
1333 	if (!usb_endpoint_dir_in(epread)) {
1334 		/* descriptors are swapped */
1335 		dev_dbg(&intf->dev,
1336 			"The data interface has switched endpoints\n");
1337 		swap(epread, epwrite);
1338 	}
1339 made_compressed_probe:
1340 	dev_dbg(&intf->dev, "interfaces are valid\n");
1341 
1342 	acm = kzalloc(sizeof(struct acm), GFP_KERNEL);
1343 	if (!acm)
1344 		return -ENOMEM;
1345 
1346 	tty_port_init(&acm->port);
1347 	acm->port.ops = &acm_port_ops;
1348 
1349 	ctrlsize = usb_endpoint_maxp(epctrl);
1350 	readsize = usb_endpoint_maxp(epread) *
1351 				(quirks == SINGLE_RX_URB ? 1 : 2);
1352 	acm->combined_interfaces = combined_interfaces;
1353 	acm->writesize = usb_endpoint_maxp(epwrite) * 20;
1354 	acm->control = control_interface;
1355 	acm->data = data_interface;
1356 
1357 	usb_get_intf(acm->control); /* undone in destruct() */
1358 
1359 	minor = acm_alloc_minor(acm);
1360 	if (minor < 0) {
1361 		acm->minor = ACM_MINOR_INVALID;
1362 		goto err_put_port;
1363 	}
1364 
1365 	acm->minor = minor;
1366 	acm->dev = usb_dev;
1367 	if (h.usb_cdc_acm_descriptor)
1368 		acm->ctrl_caps = h.usb_cdc_acm_descriptor->bmCapabilities;
1369 	if (quirks & NO_CAP_LINE)
1370 		acm->ctrl_caps &= ~USB_CDC_CAP_LINE;
1371 	acm->ctrlsize = ctrlsize;
1372 	acm->readsize = readsize;
1373 	acm->rx_buflimit = num_rx_buf;
1374 	INIT_DELAYED_WORK(&acm->dwork, acm_softint);
1375 	init_waitqueue_head(&acm->wioctl);
1376 	spin_lock_init(&acm->write_lock);
1377 	spin_lock_init(&acm->read_lock);
1378 	mutex_init(&acm->mutex);
1379 	if (usb_endpoint_xfer_int(epread)) {
1380 		acm->bInterval = epread->bInterval;
1381 		acm->in = usb_rcvintpipe(usb_dev, epread->bEndpointAddress);
1382 	} else {
1383 		acm->in = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
1384 	}
1385 	if (usb_endpoint_xfer_int(epwrite))
1386 		acm->out = usb_sndintpipe(usb_dev, epwrite->bEndpointAddress);
1387 	else
1388 		acm->out = usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress);
1389 	init_usb_anchor(&acm->delayed);
1390 	acm->quirks = quirks;
1391 
1392 	buf = usb_alloc_coherent(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
1393 	if (!buf)
1394 		goto err_put_port;
1395 	acm->ctrl_buffer = buf;
1396 
1397 	if (acm_write_buffers_alloc(acm) < 0)
1398 		goto err_free_ctrl_buffer;
1399 
1400 	acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
1401 	if (!acm->ctrlurb)
1402 		goto err_free_write_buffers;
1403 
1404 	for (i = 0; i < num_rx_buf; i++) {
1405 		struct acm_rb *rb = &(acm->read_buffers[i]);
1406 		struct urb *urb;
1407 
1408 		rb->base = usb_alloc_coherent(acm->dev, readsize, GFP_KERNEL,
1409 								&rb->dma);
1410 		if (!rb->base)
1411 			goto err_free_read_urbs;
1412 		rb->index = i;
1413 		rb->instance = acm;
1414 
1415 		urb = usb_alloc_urb(0, GFP_KERNEL);
1416 		if (!urb)
1417 			goto err_free_read_urbs;
1418 
1419 		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1420 		urb->transfer_dma = rb->dma;
1421 		if (usb_endpoint_xfer_int(epread))
1422 			usb_fill_int_urb(urb, acm->dev, acm->in, rb->base,
1423 					 acm->readsize,
1424 					 acm_read_bulk_callback, rb,
1425 					 acm->bInterval);
1426 		else
1427 			usb_fill_bulk_urb(urb, acm->dev, acm->in, rb->base,
1428 					  acm->readsize,
1429 					  acm_read_bulk_callback, rb);
1430 
1431 		acm->read_urbs[i] = urb;
1432 		__set_bit(i, &acm->read_urbs_free);
1433 	}
1434 	for (i = 0; i < ACM_NW; i++) {
1435 		struct acm_wb *snd = &(acm->wb[i]);
1436 
1437 		snd->urb = usb_alloc_urb(0, GFP_KERNEL);
1438 		if (!snd->urb)
1439 			goto err_free_write_urbs;
1440 
1441 		if (usb_endpoint_xfer_int(epwrite))
1442 			usb_fill_int_urb(snd->urb, usb_dev, acm->out,
1443 				NULL, acm->writesize, acm_write_bulk, snd, epwrite->bInterval);
1444 		else
1445 			usb_fill_bulk_urb(snd->urb, usb_dev, acm->out,
1446 				NULL, acm->writesize, acm_write_bulk, snd);
1447 		snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1448 		if (quirks & SEND_ZERO_PACKET)
1449 			snd->urb->transfer_flags |= URB_ZERO_PACKET;
1450 		snd->instance = acm;
1451 	}
1452 
1453 	usb_set_intfdata(intf, acm);
1454 
1455 	i = device_create_file(&intf->dev, &dev_attr_bmCapabilities);
1456 	if (i < 0)
1457 		goto err_free_write_urbs;
1458 
1459 	if (h.usb_cdc_country_functional_desc) { /* export the country data */
1460 		struct usb_cdc_country_functional_desc * cfd =
1461 					h.usb_cdc_country_functional_desc;
1462 
1463 		acm->country_codes = kmalloc(cfd->bLength - 4, GFP_KERNEL);
1464 		if (!acm->country_codes)
1465 			goto skip_countries;
1466 		acm->country_code_size = cfd->bLength - 4;
1467 		memcpy(acm->country_codes, (u8 *)&cfd->wCountyCode0,
1468 							cfd->bLength - 4);
1469 		acm->country_rel_date = cfd->iCountryCodeRelDate;
1470 
1471 		i = device_create_file(&intf->dev, &dev_attr_wCountryCodes);
1472 		if (i < 0) {
1473 			kfree(acm->country_codes);
1474 			acm->country_codes = NULL;
1475 			acm->country_code_size = 0;
1476 			goto skip_countries;
1477 		}
1478 
1479 		i = device_create_file(&intf->dev,
1480 						&dev_attr_iCountryCodeRelDate);
1481 		if (i < 0) {
1482 			device_remove_file(&intf->dev, &dev_attr_wCountryCodes);
1483 			kfree(acm->country_codes);
1484 			acm->country_codes = NULL;
1485 			acm->country_code_size = 0;
1486 			goto skip_countries;
1487 		}
1488 	}
1489 
1490 skip_countries:
1491 	usb_fill_int_urb(acm->ctrlurb, usb_dev,
1492 			 usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
1493 			 acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm,
1494 			 /* works around buggy devices */
1495 			 epctrl->bInterval ? epctrl->bInterval : 16);
1496 	acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1497 	acm->ctrlurb->transfer_dma = acm->ctrl_dma;
1498 	acm->notification_buffer = NULL;
1499 	acm->nb_index = 0;
1500 	acm->nb_size = 0;
1501 
1502 	acm->line.dwDTERate = cpu_to_le32(9600);
1503 	acm->line.bDataBits = 8;
1504 	acm_set_line(acm, &acm->line);
1505 
1506 	if (!acm->combined_interfaces) {
1507 		rv = usb_driver_claim_interface(&acm_driver, data_interface, acm);
1508 		if (rv)
1509 			goto err_remove_files;
1510 	}
1511 
1512 	tty_dev = tty_port_register_device(&acm->port, acm_tty_driver, minor,
1513 			&control_interface->dev);
1514 	if (IS_ERR(tty_dev)) {
1515 		rv = PTR_ERR(tty_dev);
1516 		goto err_release_data_interface;
1517 	}
1518 
1519 	if (quirks & CLEAR_HALT_CONDITIONS) {
1520 		usb_clear_halt(usb_dev, acm->in);
1521 		usb_clear_halt(usb_dev, acm->out);
1522 	}
1523 
1524 	dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
1525 
1526 	return 0;
1527 
1528 err_release_data_interface:
1529 	if (!acm->combined_interfaces) {
1530 		/* Clear driver data so that disconnect() returns early. */
1531 		usb_set_intfdata(data_interface, NULL);
1532 		usb_driver_release_interface(&acm_driver, data_interface);
1533 	}
1534 err_remove_files:
1535 	if (acm->country_codes) {
1536 		device_remove_file(&acm->control->dev,
1537 				&dev_attr_wCountryCodes);
1538 		device_remove_file(&acm->control->dev,
1539 				&dev_attr_iCountryCodeRelDate);
1540 	}
1541 	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
1542 err_free_write_urbs:
1543 	for (i = 0; i < ACM_NW; i++)
1544 		usb_free_urb(acm->wb[i].urb);
1545 err_free_read_urbs:
1546 	for (i = 0; i < num_rx_buf; i++)
1547 		usb_free_urb(acm->read_urbs[i]);
1548 	acm_read_buffers_free(acm);
1549 	usb_free_urb(acm->ctrlurb);
1550 err_free_write_buffers:
1551 	acm_write_buffers_free(acm);
1552 err_free_ctrl_buffer:
1553 	usb_free_coherent(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1554 err_put_port:
1555 	tty_port_put(&acm->port);
1556 
1557 	return rv;
1558 }
1559 
1560 static void acm_disconnect(struct usb_interface *intf)
1561 {
1562 	struct acm *acm = usb_get_intfdata(intf);
1563 	struct tty_struct *tty;
1564 	int i;
1565 
1566 	/* sibling interface is already cleaning up */
1567 	if (!acm)
1568 		return;
1569 
1570 	acm->disconnected = true;
1571 	/*
1572 	 * there is a circular dependency. acm_softint() can resubmit
1573 	 * the URBs in error handling so we need to block any
1574 	 * submission right away
1575 	 */
1576 	acm_poison_urbs(acm);
1577 	mutex_lock(&acm->mutex);
1578 	if (acm->country_codes) {
1579 		device_remove_file(&acm->control->dev,
1580 				&dev_attr_wCountryCodes);
1581 		device_remove_file(&acm->control->dev,
1582 				&dev_attr_iCountryCodeRelDate);
1583 	}
1584 	wake_up_all(&acm->wioctl);
1585 	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
1586 	usb_set_intfdata(acm->control, NULL);
1587 	usb_set_intfdata(acm->data, NULL);
1588 	mutex_unlock(&acm->mutex);
1589 
1590 	tty = tty_port_tty_get(&acm->port);
1591 	if (tty) {
1592 		tty_vhangup(tty);
1593 		tty_kref_put(tty);
1594 	}
1595 
1596 	cancel_delayed_work_sync(&acm->dwork);
1597 
1598 	tty_unregister_device(acm_tty_driver, acm->minor);
1599 
1600 	usb_free_urb(acm->ctrlurb);
1601 	for (i = 0; i < ACM_NW; i++)
1602 		usb_free_urb(acm->wb[i].urb);
1603 	for (i = 0; i < acm->rx_buflimit; i++)
1604 		usb_free_urb(acm->read_urbs[i]);
1605 	acm_write_buffers_free(acm);
1606 	usb_free_coherent(acm->dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1607 	acm_read_buffers_free(acm);
1608 
1609 	kfree(acm->notification_buffer);
1610 
1611 	if (!acm->combined_interfaces)
1612 		usb_driver_release_interface(&acm_driver, intf == acm->control ?
1613 					acm->data : acm->control);
1614 
1615 	tty_port_put(&acm->port);
1616 }
1617 
1618 #ifdef CONFIG_PM
1619 static int acm_suspend(struct usb_interface *intf, pm_message_t message)
1620 {
1621 	struct acm *acm = usb_get_intfdata(intf);
1622 	int cnt;
1623 
1624 	spin_lock_irq(&acm->write_lock);
1625 	if (PMSG_IS_AUTO(message)) {
1626 		if (acm->transmitting) {
1627 			spin_unlock_irq(&acm->write_lock);
1628 			return -EBUSY;
1629 		}
1630 	}
1631 	cnt = acm->susp_count++;
1632 	spin_unlock_irq(&acm->write_lock);
1633 
1634 	if (cnt)
1635 		return 0;
1636 
1637 	acm_poison_urbs(acm);
1638 	cancel_delayed_work_sync(&acm->dwork);
1639 	acm->urbs_in_error_delay = 0;
1640 
1641 	return 0;
1642 }
1643 
1644 static int acm_resume(struct usb_interface *intf)
1645 {
1646 	struct acm *acm = usb_get_intfdata(intf);
1647 	struct urb *urb;
1648 	int rv = 0;
1649 
1650 	spin_lock_irq(&acm->write_lock);
1651 
1652 	if (--acm->susp_count)
1653 		goto out;
1654 
1655 	acm_unpoison_urbs(acm);
1656 
1657 	if (tty_port_initialized(&acm->port)) {
1658 		rv = usb_submit_urb(acm->ctrlurb, GFP_ATOMIC);
1659 
1660 		for (;;) {
1661 			urb = usb_get_from_anchor(&acm->delayed);
1662 			if (!urb)
1663 				break;
1664 
1665 			acm_start_wb(acm, urb->context);
1666 		}
1667 
1668 		/*
1669 		 * delayed error checking because we must
1670 		 * do the write path at all cost
1671 		 */
1672 		if (rv < 0)
1673 			goto out;
1674 
1675 		rv = acm_submit_read_urbs(acm, GFP_ATOMIC);
1676 	}
1677 out:
1678 	spin_unlock_irq(&acm->write_lock);
1679 
1680 	return rv;
1681 }
1682 
1683 static int acm_reset_resume(struct usb_interface *intf)
1684 {
1685 	struct acm *acm = usb_get_intfdata(intf);
1686 
1687 	if (tty_port_initialized(&acm->port))
1688 		tty_port_tty_hangup(&acm->port, false);
1689 
1690 	return acm_resume(intf);
1691 }
1692 
1693 #endif /* CONFIG_PM */
1694 
1695 static int acm_pre_reset(struct usb_interface *intf)
1696 {
1697 	struct acm *acm = usb_get_intfdata(intf);
1698 
1699 	clear_bit(EVENT_RX_STALL, &acm->flags);
1700 	acm->nb_index = 0; /* pending control transfers are lost */
1701 
1702 	return 0;
1703 }
1704 
1705 #define NOKIA_PCSUITE_ACM_INFO(x) \
1706 		USB_DEVICE_AND_INTERFACE_INFO(0x0421, x, \
1707 		USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM, \
1708 		USB_CDC_ACM_PROTO_VENDOR)
1709 
1710 #define SAMSUNG_PCSUITE_ACM_INFO(x) \
1711 		USB_DEVICE_AND_INTERFACE_INFO(0x04e7, x, \
1712 		USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM, \
1713 		USB_CDC_ACM_PROTO_VENDOR)
1714 
1715 /*
1716  * USB driver structure.
1717  */
1718 
1719 static const struct usb_device_id acm_ids[] = {
1720 	/* quirky and broken devices */
1721 	{ USB_DEVICE(0x0424, 0x274e), /* Microchip Technology, Inc. (formerly SMSC) */
1722 	  .driver_info = DISABLE_ECHO, }, /* DISABLE ECHO in termios flag */
1723 	{ USB_DEVICE(0x076d, 0x0006), /* Denso Cradle CU-321 */
1724 	.driver_info = NO_UNION_NORMAL, },/* has no union descriptor */
1725 	{ USB_DEVICE(0x17ef, 0x7000), /* Lenovo USB modem */
1726 	.driver_info = NO_UNION_NORMAL, },/* has no union descriptor */
1727 	{ USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
1728 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1729 	},
1730 	{ USB_DEVICE(0x045b, 0x023c),	/* Renesas USB Download mode */
1731 	.driver_info = DISABLE_ECHO,	/* Don't echo banner */
1732 	},
1733 	{ USB_DEVICE(0x045b, 0x0248),	/* Renesas USB Download mode */
1734 	.driver_info = DISABLE_ECHO,	/* Don't echo banner */
1735 	},
1736 	{ USB_DEVICE(0x045b, 0x024D),	/* Renesas USB Download mode */
1737 	.driver_info = DISABLE_ECHO,	/* Don't echo banner */
1738 	},
1739 	{ USB_DEVICE(0x0e8d, 0x0003), /* FIREFLY, MediaTek Inc; andrey.arapov@gmail.com */
1740 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1741 	},
1742 	{ USB_DEVICE(0x0e8d, 0x2000), /* MediaTek Inc Preloader */
1743 	.driver_info = DISABLE_ECHO, /* DISABLE ECHO in termios flag */
1744 	},
1745 	{ USB_DEVICE(0x0e8d, 0x3329), /* MediaTek Inc GPS */
1746 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1747 	},
1748 	{ USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
1749 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1750 	},
1751 	{ USB_DEVICE(0x079b, 0x000f), /* BT On-Air USB MODEM */
1752 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1753 	},
1754 	{ USB_DEVICE(0x0ace, 0x1602), /* ZyDAS 56K USB MODEM */
1755 	.driver_info = SINGLE_RX_URB,
1756 	},
1757 	{ USB_DEVICE(0x0ace, 0x1608), /* ZyDAS 56K USB MODEM */
1758 	.driver_info = SINGLE_RX_URB, /* firmware bug */
1759 	},
1760 	{ USB_DEVICE(0x0ace, 0x1611), /* ZyDAS 56K USB MODEM - new version */
1761 	.driver_info = SINGLE_RX_URB, /* firmware bug */
1762 	},
1763 	{ USB_DEVICE(0x11ca, 0x0201), /* VeriFone Mx870 Gadget Serial */
1764 	.driver_info = SINGLE_RX_URB,
1765 	},
1766 	{ USB_DEVICE(0x1901, 0x0006), /* GE Healthcare Patient Monitor UI Controller */
1767 	.driver_info = DISABLE_ECHO, /* DISABLE ECHO in termios flag */
1768 	},
1769 	{ USB_DEVICE(0x1965, 0x0018), /* Uniden UBC125XLT */
1770 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1771 	},
1772 	{ USB_DEVICE(0x22b8, 0x7000), /* Motorola Q Phone */
1773 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1774 	},
1775 	{ USB_DEVICE(0x0803, 0x3095), /* Zoom Telephonics Model 3095F USB MODEM */
1776 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1777 	},
1778 	{ USB_DEVICE(0x0572, 0x1321), /* Conexant USB MODEM CX93010 */
1779 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1780 	},
1781 	{ USB_DEVICE(0x0572, 0x1324), /* Conexant USB MODEM RD02-D400 */
1782 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1783 	},
1784 	{ USB_DEVICE(0x0572, 0x1328), /* Shiro / Aztech USB MODEM UM-3100 */
1785 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1786 	},
1787 	{ USB_DEVICE(0x0572, 0x1349), /* Hiro (Conexant) USB MODEM H50228 */
1788 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1789 	},
1790 	{ USB_DEVICE(0x20df, 0x0001), /* Simtec Electronics Entropy Key */
1791 	.driver_info = QUIRK_CONTROL_LINE_STATE, },
1792 	{ USB_DEVICE(0x2184, 0x001c) },	/* GW Instek AFG-2225 */
1793 	{ USB_DEVICE(0x2184, 0x0036) },	/* GW Instek AFG-125 */
1794 	{ USB_DEVICE(0x22b8, 0x6425), /* Motorola MOTOMAGX phones */
1795 	},
1796 	/* Motorola H24 HSPA module: */
1797 	{ USB_DEVICE(0x22b8, 0x2d91) }, /* modem                                */
1798 	{ USB_DEVICE(0x22b8, 0x2d92),   /* modem           + diagnostics        */
1799 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1800 	},
1801 	{ USB_DEVICE(0x22b8, 0x2d93),   /* modem + AT port                      */
1802 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1803 	},
1804 	{ USB_DEVICE(0x22b8, 0x2d95),   /* modem + AT port + diagnostics        */
1805 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1806 	},
1807 	{ USB_DEVICE(0x22b8, 0x2d96),   /* modem                         + NMEA */
1808 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1809 	},
1810 	{ USB_DEVICE(0x22b8, 0x2d97),   /* modem           + diagnostics + NMEA */
1811 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1812 	},
1813 	{ USB_DEVICE(0x22b8, 0x2d99),   /* modem + AT port               + NMEA */
1814 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1815 	},
1816 	{ USB_DEVICE(0x22b8, 0x2d9a),   /* modem + AT port + diagnostics + NMEA */
1817 	.driver_info = NO_UNION_NORMAL, /* handle only modem interface          */
1818 	},
1819 
1820 	{ USB_DEVICE(0x0572, 0x1329), /* Hummingbird huc56s (Conexant) */
1821 	.driver_info = NO_UNION_NORMAL, /* union descriptor misplaced on
1822 					   data interface instead of
1823 					   communications interface.
1824 					   Maybe we should define a new
1825 					   quirk for this. */
1826 	},
1827 	{ USB_DEVICE(0x0572, 0x1340), /* Conexant CX93010-2x UCMxx */
1828 	.driver_info = NO_UNION_NORMAL,
1829 	},
1830 	{ USB_DEVICE(0x05f9, 0x4002), /* PSC Scanning, Magellan 800i */
1831 	.driver_info = NO_UNION_NORMAL,
1832 	},
1833 	{ USB_DEVICE(0x1bbb, 0x0003), /* Alcatel OT-I650 */
1834 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1835 	},
1836 	{ USB_DEVICE(0x1576, 0x03b1), /* Maretron USB100 */
1837 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1838 	},
1839 	{ USB_DEVICE(0xfff0, 0x0100), /* DATECS FP-2000 */
1840 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1841 	},
1842 	{ USB_DEVICE(0x09d8, 0x0320), /* Elatec GmbH TWN3 */
1843 	.driver_info = NO_UNION_NORMAL, /* has misplaced union descriptor */
1844 	},
1845 	{ USB_DEVICE(0x0c26, 0x0020), /* Icom ICF3400 Serie */
1846 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1847 	},
1848 	{ USB_DEVICE(0x0ca6, 0xa050), /* Castles VEGA3000 */
1849 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1850 	},
1851 
1852 	{ USB_DEVICE(0x2912, 0x0001), /* ATOL FPrint */
1853 	.driver_info = CLEAR_HALT_CONDITIONS,
1854 	},
1855 
1856 	/* Nokia S60 phones expose two ACM channels. The first is
1857 	 * a modem and is picked up by the standard AT-command
1858 	 * information below. The second is 'vendor-specific' but
1859 	 * is treated as a serial device at the S60 end, so we want
1860 	 * to expose it on Linux too. */
1861 	{ NOKIA_PCSUITE_ACM_INFO(0x042D), }, /* Nokia 3250 */
1862 	{ NOKIA_PCSUITE_ACM_INFO(0x04D8), }, /* Nokia 5500 Sport */
1863 	{ NOKIA_PCSUITE_ACM_INFO(0x04C9), }, /* Nokia E50 */
1864 	{ NOKIA_PCSUITE_ACM_INFO(0x0419), }, /* Nokia E60 */
1865 	{ NOKIA_PCSUITE_ACM_INFO(0x044D), }, /* Nokia E61 */
1866 	{ NOKIA_PCSUITE_ACM_INFO(0x0001), }, /* Nokia E61i */
1867 	{ NOKIA_PCSUITE_ACM_INFO(0x0475), }, /* Nokia E62 */
1868 	{ NOKIA_PCSUITE_ACM_INFO(0x0508), }, /* Nokia E65 */
1869 	{ NOKIA_PCSUITE_ACM_INFO(0x0418), }, /* Nokia E70 */
1870 	{ NOKIA_PCSUITE_ACM_INFO(0x0425), }, /* Nokia N71 */
1871 	{ NOKIA_PCSUITE_ACM_INFO(0x0486), }, /* Nokia N73 */
1872 	{ NOKIA_PCSUITE_ACM_INFO(0x04DF), }, /* Nokia N75 */
1873 	{ NOKIA_PCSUITE_ACM_INFO(0x000e), }, /* Nokia N77 */
1874 	{ NOKIA_PCSUITE_ACM_INFO(0x0445), }, /* Nokia N80 */
1875 	{ NOKIA_PCSUITE_ACM_INFO(0x042F), }, /* Nokia N91 & N91 8GB */
1876 	{ NOKIA_PCSUITE_ACM_INFO(0x048E), }, /* Nokia N92 */
1877 	{ NOKIA_PCSUITE_ACM_INFO(0x0420), }, /* Nokia N93 */
1878 	{ NOKIA_PCSUITE_ACM_INFO(0x04E6), }, /* Nokia N93i  */
1879 	{ NOKIA_PCSUITE_ACM_INFO(0x04B2), }, /* Nokia 5700 XpressMusic */
1880 	{ NOKIA_PCSUITE_ACM_INFO(0x0134), }, /* Nokia 6110 Navigator (China) */
1881 	{ NOKIA_PCSUITE_ACM_INFO(0x046E), }, /* Nokia 6110 Navigator */
1882 	{ NOKIA_PCSUITE_ACM_INFO(0x002f), }, /* Nokia 6120 classic &  */
1883 	{ NOKIA_PCSUITE_ACM_INFO(0x0088), }, /* Nokia 6121 classic */
1884 	{ NOKIA_PCSUITE_ACM_INFO(0x00fc), }, /* Nokia 6124 classic */
1885 	{ NOKIA_PCSUITE_ACM_INFO(0x0042), }, /* Nokia E51 */
1886 	{ NOKIA_PCSUITE_ACM_INFO(0x00b0), }, /* Nokia E66 */
1887 	{ NOKIA_PCSUITE_ACM_INFO(0x00ab), }, /* Nokia E71 */
1888 	{ NOKIA_PCSUITE_ACM_INFO(0x0481), }, /* Nokia N76 */
1889 	{ NOKIA_PCSUITE_ACM_INFO(0x0007), }, /* Nokia N81 & N81 8GB */
1890 	{ NOKIA_PCSUITE_ACM_INFO(0x0071), }, /* Nokia N82 */
1891 	{ NOKIA_PCSUITE_ACM_INFO(0x04F0), }, /* Nokia N95 & N95-3 NAM */
1892 	{ NOKIA_PCSUITE_ACM_INFO(0x0070), }, /* Nokia N95 8GB  */
1893 	{ NOKIA_PCSUITE_ACM_INFO(0x0099), }, /* Nokia 6210 Navigator, RM-367 */
1894 	{ NOKIA_PCSUITE_ACM_INFO(0x0128), }, /* Nokia 6210 Navigator, RM-419 */
1895 	{ NOKIA_PCSUITE_ACM_INFO(0x008f), }, /* Nokia 6220 Classic */
1896 	{ NOKIA_PCSUITE_ACM_INFO(0x00a0), }, /* Nokia 6650 */
1897 	{ NOKIA_PCSUITE_ACM_INFO(0x007b), }, /* Nokia N78 */
1898 	{ NOKIA_PCSUITE_ACM_INFO(0x0094), }, /* Nokia N85 */
1899 	{ NOKIA_PCSUITE_ACM_INFO(0x003a), }, /* Nokia N96 & N96-3  */
1900 	{ NOKIA_PCSUITE_ACM_INFO(0x00e9), }, /* Nokia 5320 XpressMusic */
1901 	{ NOKIA_PCSUITE_ACM_INFO(0x0108), }, /* Nokia 5320 XpressMusic 2G */
1902 	{ NOKIA_PCSUITE_ACM_INFO(0x01f5), }, /* Nokia N97, RM-505 */
1903 	{ NOKIA_PCSUITE_ACM_INFO(0x02e3), }, /* Nokia 5230, RM-588 */
1904 	{ NOKIA_PCSUITE_ACM_INFO(0x0178), }, /* Nokia E63 */
1905 	{ NOKIA_PCSUITE_ACM_INFO(0x010e), }, /* Nokia E75 */
1906 	{ NOKIA_PCSUITE_ACM_INFO(0x02d9), }, /* Nokia 6760 Slide */
1907 	{ NOKIA_PCSUITE_ACM_INFO(0x01d0), }, /* Nokia E52 */
1908 	{ NOKIA_PCSUITE_ACM_INFO(0x0223), }, /* Nokia E72 */
1909 	{ NOKIA_PCSUITE_ACM_INFO(0x0275), }, /* Nokia X6 */
1910 	{ NOKIA_PCSUITE_ACM_INFO(0x026c), }, /* Nokia N97 Mini */
1911 	{ NOKIA_PCSUITE_ACM_INFO(0x0154), }, /* Nokia 5800 XpressMusic */
1912 	{ NOKIA_PCSUITE_ACM_INFO(0x04ce), }, /* Nokia E90 */
1913 	{ NOKIA_PCSUITE_ACM_INFO(0x01d4), }, /* Nokia E55 */
1914 	{ NOKIA_PCSUITE_ACM_INFO(0x0302), }, /* Nokia N8 */
1915 	{ NOKIA_PCSUITE_ACM_INFO(0x0335), }, /* Nokia E7 */
1916 	{ NOKIA_PCSUITE_ACM_INFO(0x03cd), }, /* Nokia C7 */
1917 	{ SAMSUNG_PCSUITE_ACM_INFO(0x6651), }, /* Samsung GTi8510 (INNOV8) */
1918 
1919 	/* Support for Owen devices */
1920 	{ USB_DEVICE(0x03eb, 0x0030), }, /* Owen SI30 */
1921 
1922 	/* NOTE: non-Nokia COMM/ACM/0xff is likely MSFT RNDIS... NOT a modem! */
1923 
1924 #if IS_ENABLED(CONFIG_INPUT_IMS_PCU)
1925 	{ USB_DEVICE(0x04d8, 0x0082),	/* Application mode */
1926 	.driver_info = IGNORE_DEVICE,
1927 	},
1928 	{ USB_DEVICE(0x04d8, 0x0083),	/* Bootloader mode */
1929 	.driver_info = IGNORE_DEVICE,
1930 	},
1931 #endif
1932 
1933 #if IS_ENABLED(CONFIG_IR_TOY)
1934 	{ USB_DEVICE(0x04d8, 0xfd08),
1935 	.driver_info = IGNORE_DEVICE,
1936 	},
1937 
1938 	{ USB_DEVICE(0x04d8, 0xf58b),
1939 	.driver_info = IGNORE_DEVICE,
1940 	},
1941 #endif
1942 
1943 #if IS_ENABLED(CONFIG_USB_SERIAL_XR)
1944 	{ USB_DEVICE(0x04e2, 0x1400), .driver_info = IGNORE_DEVICE },
1945 	{ USB_DEVICE(0x04e2, 0x1401), .driver_info = IGNORE_DEVICE },
1946 	{ USB_DEVICE(0x04e2, 0x1402), .driver_info = IGNORE_DEVICE },
1947 	{ USB_DEVICE(0x04e2, 0x1403), .driver_info = IGNORE_DEVICE },
1948 	{ USB_DEVICE(0x04e2, 0x1410), .driver_info = IGNORE_DEVICE },
1949 	{ USB_DEVICE(0x04e2, 0x1411), .driver_info = IGNORE_DEVICE },
1950 	{ USB_DEVICE(0x04e2, 0x1412), .driver_info = IGNORE_DEVICE },
1951 	{ USB_DEVICE(0x04e2, 0x1414), .driver_info = IGNORE_DEVICE },
1952 	{ USB_DEVICE(0x04e2, 0x1420), .driver_info = IGNORE_DEVICE },
1953 	{ USB_DEVICE(0x04e2, 0x1422), .driver_info = IGNORE_DEVICE },
1954 	{ USB_DEVICE(0x04e2, 0x1424), .driver_info = IGNORE_DEVICE },
1955 #endif
1956 
1957 	/*Samsung phone in firmware update mode */
1958 	{ USB_DEVICE(0x04e8, 0x685d),
1959 	.driver_info = IGNORE_DEVICE,
1960 	},
1961 
1962 	/* Exclude Infineon Flash Loader utility */
1963 	{ USB_DEVICE(0x058b, 0x0041),
1964 	.driver_info = IGNORE_DEVICE,
1965 	},
1966 
1967 	/* Exclude ETAS ES58x */
1968 	{ USB_DEVICE(0x108c, 0x0159), /* ES581.4 */
1969 	.driver_info = IGNORE_DEVICE,
1970 	},
1971 	{ USB_DEVICE(0x108c, 0x0168), /* ES582.1 */
1972 	.driver_info = IGNORE_DEVICE,
1973 	},
1974 	{ USB_DEVICE(0x108c, 0x0169), /* ES584.1 */
1975 	.driver_info = IGNORE_DEVICE,
1976 	},
1977 
1978 	{ USB_DEVICE(0x1bc7, 0x0021), /* Telit 3G ACM only composition */
1979 	.driver_info = SEND_ZERO_PACKET,
1980 	},
1981 	{ USB_DEVICE(0x1bc7, 0x0023), /* Telit 3G ACM + ECM composition */
1982 	.driver_info = SEND_ZERO_PACKET,
1983 	},
1984 
1985 	/* Exclude Goodix Fingerprint Reader */
1986 	{ USB_DEVICE(0x27c6, 0x5395),
1987 	.driver_info = IGNORE_DEVICE,
1988 	},
1989 
1990 	/* Exclude Heimann Sensor GmbH USB appset demo */
1991 	{ USB_DEVICE(0x32a7, 0x0000),
1992 	.driver_info = IGNORE_DEVICE,
1993 	},
1994 
1995 	/* control interfaces without any protocol set */
1996 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1997 		USB_CDC_PROTO_NONE) },
1998 
1999 	/* control interfaces with various AT-command sets */
2000 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2001 		USB_CDC_ACM_PROTO_AT_V25TER) },
2002 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2003 		USB_CDC_ACM_PROTO_AT_PCCA101) },
2004 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2005 		USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
2006 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2007 		USB_CDC_ACM_PROTO_AT_GSM) },
2008 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2009 		USB_CDC_ACM_PROTO_AT_3G) },
2010 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
2011 		USB_CDC_ACM_PROTO_AT_CDMA) },
2012 
2013 	{ USB_DEVICE(0x1519, 0x0452), /* Intel 7260 modem */
2014 	.driver_info = SEND_ZERO_PACKET,
2015 	},
2016 
2017 	{ }
2018 };
2019 
2020 MODULE_DEVICE_TABLE(usb, acm_ids);
2021 
2022 static struct usb_driver acm_driver = {
2023 	.name =		"cdc_acm",
2024 	.probe =	acm_probe,
2025 	.disconnect =	acm_disconnect,
2026 #ifdef CONFIG_PM
2027 	.suspend =	acm_suspend,
2028 	.resume =	acm_resume,
2029 	.reset_resume =	acm_reset_resume,
2030 #endif
2031 	.pre_reset =	acm_pre_reset,
2032 	.id_table =	acm_ids,
2033 #ifdef CONFIG_PM
2034 	.supports_autosuspend = 1,
2035 #endif
2036 	.disable_hub_initiated_lpm = 1,
2037 };
2038 
2039 /*
2040  * TTY driver structures.
2041  */
2042 
2043 static const struct tty_operations acm_ops = {
2044 	.install =		acm_tty_install,
2045 	.open =			acm_tty_open,
2046 	.close =		acm_tty_close,
2047 	.cleanup =		acm_tty_cleanup,
2048 	.hangup =		acm_tty_hangup,
2049 	.write =		acm_tty_write,
2050 	.write_room =		acm_tty_write_room,
2051 	.flush_buffer =		acm_tty_flush_buffer,
2052 	.ioctl =		acm_tty_ioctl,
2053 	.throttle =		acm_tty_throttle,
2054 	.unthrottle =		acm_tty_unthrottle,
2055 	.chars_in_buffer =	acm_tty_chars_in_buffer,
2056 	.break_ctl =		acm_tty_break_ctl,
2057 	.set_termios =		acm_tty_set_termios,
2058 	.tiocmget =		acm_tty_tiocmget,
2059 	.tiocmset =		acm_tty_tiocmset,
2060 	.get_serial =		get_serial_info,
2061 	.set_serial =		set_serial_info,
2062 	.get_icount =		acm_tty_get_icount,
2063 };
2064 
2065 /*
2066  * Init / exit.
2067  */
2068 
2069 static int __init acm_init(void)
2070 {
2071 	int retval;
2072 	acm_tty_driver = tty_alloc_driver(ACM_TTY_MINORS, TTY_DRIVER_REAL_RAW |
2073 			TTY_DRIVER_DYNAMIC_DEV);
2074 	if (IS_ERR(acm_tty_driver))
2075 		return PTR_ERR(acm_tty_driver);
2076 	acm_tty_driver->driver_name = "acm",
2077 	acm_tty_driver->name = "ttyACM",
2078 	acm_tty_driver->major = ACM_TTY_MAJOR,
2079 	acm_tty_driver->minor_start = 0,
2080 	acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
2081 	acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
2082 	acm_tty_driver->init_termios = tty_std_termios;
2083 	acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD |
2084 								HUPCL | CLOCAL;
2085 	tty_set_operations(acm_tty_driver, &acm_ops);
2086 
2087 	retval = tty_register_driver(acm_tty_driver);
2088 	if (retval) {
2089 		tty_driver_kref_put(acm_tty_driver);
2090 		return retval;
2091 	}
2092 
2093 	retval = usb_register(&acm_driver);
2094 	if (retval) {
2095 		tty_unregister_driver(acm_tty_driver);
2096 		tty_driver_kref_put(acm_tty_driver);
2097 		return retval;
2098 	}
2099 
2100 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");
2101 
2102 	return 0;
2103 }
2104 
2105 static void __exit acm_exit(void)
2106 {
2107 	usb_deregister(&acm_driver);
2108 	tty_unregister_driver(acm_tty_driver);
2109 	tty_driver_kref_put(acm_tty_driver);
2110 	idr_destroy(&acm_minors);
2111 }
2112 
2113 module_init(acm_init);
2114 module_exit(acm_exit);
2115 
2116 MODULE_AUTHOR(DRIVER_AUTHOR);
2117 MODULE_DESCRIPTION(DRIVER_DESC);
2118 MODULE_LICENSE("GPL");
2119 MODULE_ALIAS_CHARDEV_MAJOR(ACM_TTY_MAJOR);
2120