xref: /linux/drivers/usb/class/cdc-acm.c (revision 17afab1de42236ee2f6235f4383cc6f3f13f8a10)
1 /*
2  * cdc-acm.c
3  *
4  * Copyright (c) 1999 Armin Fuerst	<fuerst@in.tum.de>
5  * Copyright (c) 1999 Pavel Machek	<pavel@ucw.cz>
6  * Copyright (c) 1999 Johannes Erdfelt	<johannes@erdfelt.com>
7  * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>
8  * Copyright (c) 2004 Oliver Neukum	<oliver@neukum.name>
9  * Copyright (c) 2005 David Kubicek	<dave@awk.cz>
10  * Copyright (c) 2011 Johan Hovold	<jhovold@gmail.com>
11  *
12  * USB Abstract Control Model driver for USB modems and ISDN adapters
13  *
14  * Sponsored by SuSE
15  *
16  * This program is free software; you can redistribute it and/or modify
17  * it under the terms of the GNU General Public License as published by
18  * the Free Software Foundation; either version 2 of the License, or
19  * (at your option) any later version.
20  *
21  * This program is distributed in the hope that it will be useful,
22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24  * GNU General Public License for more details.
25  *
26  * You should have received a copy of the GNU General Public License
27  * along with this program; if not, write to the Free Software
28  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29  */
30 
31 #undef DEBUG
32 #undef VERBOSE_DEBUG
33 
34 #include <linux/kernel.h>
35 #include <linux/errno.h>
36 #include <linux/init.h>
37 #include <linux/slab.h>
38 #include <linux/tty.h>
39 #include <linux/serial.h>
40 #include <linux/tty_driver.h>
41 #include <linux/tty_flip.h>
42 #include <linux/module.h>
43 #include <linux/mutex.h>
44 #include <linux/uaccess.h>
45 #include <linux/usb.h>
46 #include <linux/usb/cdc.h>
47 #include <asm/byteorder.h>
48 #include <asm/unaligned.h>
49 #include <linux/list.h>
50 
51 #include "cdc-acm.h"
52 
53 
54 #define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek, Johan Hovold"
55 #define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
56 
57 static struct usb_driver acm_driver;
58 static struct tty_driver *acm_tty_driver;
59 static struct acm *acm_table[ACM_TTY_MINORS];
60 
61 static DEFINE_MUTEX(acm_table_lock);
62 
63 /*
64  * acm_table accessors
65  */
66 
67 /*
68  * Look up an ACM structure by index. If found and not disconnected, increment
69  * its refcount and return it with its mutex held.
70  */
71 static struct acm *acm_get_by_index(unsigned index)
72 {
73 	struct acm *acm;
74 
75 	mutex_lock(&acm_table_lock);
76 	acm = acm_table[index];
77 	if (acm) {
78 		mutex_lock(&acm->mutex);
79 		if (acm->disconnected) {
80 			mutex_unlock(&acm->mutex);
81 			acm = NULL;
82 		} else {
83 			tty_port_get(&acm->port);
84 			mutex_unlock(&acm->mutex);
85 		}
86 	}
87 	mutex_unlock(&acm_table_lock);
88 	return acm;
89 }
90 
91 /*
92  * Try to find an available minor number and if found, associate it with 'acm'.
93  */
94 static int acm_alloc_minor(struct acm *acm)
95 {
96 	int minor;
97 
98 	mutex_lock(&acm_table_lock);
99 	for (minor = 0; minor < ACM_TTY_MINORS; minor++) {
100 		if (!acm_table[minor]) {
101 			acm_table[minor] = acm;
102 			break;
103 		}
104 	}
105 	mutex_unlock(&acm_table_lock);
106 
107 	return minor;
108 }
109 
110 /* Release the minor number associated with 'acm'.  */
111 static void acm_release_minor(struct acm *acm)
112 {
113 	mutex_lock(&acm_table_lock);
114 	acm_table[acm->minor] = NULL;
115 	mutex_unlock(&acm_table_lock);
116 }
117 
118 /*
119  * Functions for ACM control messages.
120  */
121 
122 static int acm_ctrl_msg(struct acm *acm, int request, int value,
123 							void *buf, int len)
124 {
125 	int retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
126 		request, USB_RT_ACM, value,
127 		acm->control->altsetting[0].desc.bInterfaceNumber,
128 		buf, len, 5000);
129 	dev_dbg(&acm->control->dev,
130 			"%s - rq 0x%02x, val %#x, len %#x, result %d\n",
131 			__func__, request, value, len, retval);
132 	return retval < 0 ? retval : 0;
133 }
134 
135 /* devices aren't required to support these requests.
136  * the cdc acm descriptor tells whether they do...
137  */
138 #define acm_set_control(acm, control) \
139 	acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE, control, NULL, 0)
140 #define acm_set_line(acm, line) \
141 	acm_ctrl_msg(acm, USB_CDC_REQ_SET_LINE_CODING, 0, line, sizeof *(line))
142 #define acm_send_break(acm, ms) \
143 	acm_ctrl_msg(acm, USB_CDC_REQ_SEND_BREAK, ms, NULL, 0)
144 
145 /*
146  * Write buffer management.
147  * All of these assume proper locks taken by the caller.
148  */
149 
150 static int acm_wb_alloc(struct acm *acm)
151 {
152 	int i, wbn;
153 	struct acm_wb *wb;
154 
155 	wbn = 0;
156 	i = 0;
157 	for (;;) {
158 		wb = &acm->wb[wbn];
159 		if (!wb->use) {
160 			wb->use = 1;
161 			return wbn;
162 		}
163 		wbn = (wbn + 1) % ACM_NW;
164 		if (++i >= ACM_NW)
165 			return -1;
166 	}
167 }
168 
169 static int acm_wb_is_avail(struct acm *acm)
170 {
171 	int i, n;
172 	unsigned long flags;
173 
174 	n = ACM_NW;
175 	spin_lock_irqsave(&acm->write_lock, flags);
176 	for (i = 0; i < ACM_NW; i++)
177 		n -= acm->wb[i].use;
178 	spin_unlock_irqrestore(&acm->write_lock, flags);
179 	return n;
180 }
181 
182 /*
183  * Finish write. Caller must hold acm->write_lock
184  */
185 static void acm_write_done(struct acm *acm, struct acm_wb *wb)
186 {
187 	wb->use = 0;
188 	acm->transmitting--;
189 	usb_autopm_put_interface_async(acm->control);
190 }
191 
192 /*
193  * Poke write.
194  *
195  * the caller is responsible for locking
196  */
197 
198 static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
199 {
200 	int rc;
201 
202 	acm->transmitting++;
203 
204 	wb->urb->transfer_buffer = wb->buf;
205 	wb->urb->transfer_dma = wb->dmah;
206 	wb->urb->transfer_buffer_length = wb->len;
207 	wb->urb->dev = acm->dev;
208 
209 	rc = usb_submit_urb(wb->urb, GFP_ATOMIC);
210 	if (rc < 0) {
211 		dev_err(&acm->data->dev,
212 			"%s - usb_submit_urb(write bulk) failed: %d\n",
213 			__func__, rc);
214 		acm_write_done(acm, wb);
215 	}
216 	return rc;
217 }
218 
219 static int acm_write_start(struct acm *acm, int wbn)
220 {
221 	unsigned long flags;
222 	struct acm_wb *wb = &acm->wb[wbn];
223 	int rc;
224 
225 	spin_lock_irqsave(&acm->write_lock, flags);
226 	if (!acm->dev) {
227 		wb->use = 0;
228 		spin_unlock_irqrestore(&acm->write_lock, flags);
229 		return -ENODEV;
230 	}
231 
232 	dev_vdbg(&acm->data->dev, "%s - susp_count %d\n", __func__,
233 							acm->susp_count);
234 	usb_autopm_get_interface_async(acm->control);
235 	if (acm->susp_count) {
236 		if (!acm->delayed_wb)
237 			acm->delayed_wb = wb;
238 		else
239 			usb_autopm_put_interface_async(acm->control);
240 		spin_unlock_irqrestore(&acm->write_lock, flags);
241 		return 0;	/* A white lie */
242 	}
243 	usb_mark_last_busy(acm->dev);
244 
245 	rc = acm_start_wb(acm, wb);
246 	spin_unlock_irqrestore(&acm->write_lock, flags);
247 
248 	return rc;
249 
250 }
251 /*
252  * attributes exported through sysfs
253  */
254 static ssize_t show_caps
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(bmCapabilities, S_IRUGO, show_caps, NULL);
263 
264 static ssize_t show_country_codes
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(wCountryCodes, S_IRUGO, show_country_codes, NULL);
275 
276 static ssize_t show_country_rel_date
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(iCountryCodeRelDate, S_IRUGO, show_country_rel_date, NULL);
286 /*
287  * Interrupt handlers for various ACM device responses
288  */
289 
290 /* control interface reports status changes with "interrupt" transfers */
291 static void acm_ctrl_irq(struct urb *urb)
292 {
293 	struct acm *acm = urb->context;
294 	struct usb_cdc_notification *dr = urb->transfer_buffer;
295 	unsigned char *data;
296 	int newctrl;
297 	int retval;
298 	int status = urb->status;
299 
300 	switch (status) {
301 	case 0:
302 		/* success */
303 		break;
304 	case -ECONNRESET:
305 	case -ENOENT:
306 	case -ESHUTDOWN:
307 		/* this urb is terminated, clean up */
308 		dev_dbg(&acm->control->dev,
309 				"%s - urb shutting down with status: %d\n",
310 				__func__, status);
311 		return;
312 	default:
313 		dev_dbg(&acm->control->dev,
314 				"%s - nonzero urb status received: %d\n",
315 				__func__, status);
316 		goto exit;
317 	}
318 
319 	usb_mark_last_busy(acm->dev);
320 
321 	data = (unsigned char *)(dr + 1);
322 	switch (dr->bNotificationType) {
323 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
324 		dev_dbg(&acm->control->dev, "%s - network connection: %d\n",
325 							__func__, dr->wValue);
326 		break;
327 
328 	case USB_CDC_NOTIFY_SERIAL_STATE:
329 		newctrl = get_unaligned_le16(data);
330 
331 		if (!acm->clocal && (acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
332 			dev_dbg(&acm->control->dev, "%s - calling hangup\n",
333 					__func__);
334 			tty_port_tty_hangup(&acm->port, false);
335 		}
336 
337 		acm->ctrlin = newctrl;
338 
339 		dev_dbg(&acm->control->dev,
340 			"%s - input control lines: dcd%c dsr%c break%c "
341 			"ring%c framing%c parity%c overrun%c\n",
342 			__func__,
343 			acm->ctrlin & ACM_CTRL_DCD ? '+' : '-',
344 			acm->ctrlin & ACM_CTRL_DSR ? '+' : '-',
345 			acm->ctrlin & ACM_CTRL_BRK ? '+' : '-',
346 			acm->ctrlin & ACM_CTRL_RI  ? '+' : '-',
347 			acm->ctrlin & ACM_CTRL_FRAMING ? '+' : '-',
348 			acm->ctrlin & ACM_CTRL_PARITY ? '+' : '-',
349 			acm->ctrlin & ACM_CTRL_OVERRUN ? '+' : '-');
350 			break;
351 
352 	default:
353 		dev_dbg(&acm->control->dev,
354 			"%s - unknown notification %d received: index %d "
355 			"len %d data0 %d data1 %d\n",
356 			__func__,
357 			dr->bNotificationType, dr->wIndex,
358 			dr->wLength, data[0], data[1]);
359 		break;
360 	}
361 exit:
362 	retval = usb_submit_urb(urb, GFP_ATOMIC);
363 	if (retval)
364 		dev_err(&acm->control->dev, "%s - usb_submit_urb failed: %d\n",
365 							__func__, retval);
366 }
367 
368 static int acm_submit_read_urb(struct acm *acm, int index, gfp_t mem_flags)
369 {
370 	int res;
371 
372 	if (!test_and_clear_bit(index, &acm->read_urbs_free))
373 		return 0;
374 
375 	dev_vdbg(&acm->data->dev, "%s - urb %d\n", __func__, index);
376 
377 	res = usb_submit_urb(acm->read_urbs[index], mem_flags);
378 	if (res) {
379 		if (res != -EPERM) {
380 			dev_err(&acm->data->dev,
381 					"%s - usb_submit_urb failed: %d\n",
382 					__func__, res);
383 		}
384 		set_bit(index, &acm->read_urbs_free);
385 		return res;
386 	}
387 
388 	return 0;
389 }
390 
391 static int acm_submit_read_urbs(struct acm *acm, gfp_t mem_flags)
392 {
393 	int res;
394 	int i;
395 
396 	for (i = 0; i < acm->rx_buflimit; ++i) {
397 		res = acm_submit_read_urb(acm, i, mem_flags);
398 		if (res)
399 			return res;
400 	}
401 
402 	return 0;
403 }
404 
405 static void acm_process_read_urb(struct acm *acm, struct urb *urb)
406 {
407 	if (!urb->actual_length)
408 		return;
409 
410 	tty_insert_flip_string(&acm->port, urb->transfer_buffer,
411 			urb->actual_length);
412 	tty_flip_buffer_push(&acm->port);
413 }
414 
415 static void acm_read_bulk_callback(struct urb *urb)
416 {
417 	struct acm_rb *rb = urb->context;
418 	struct acm *acm = rb->instance;
419 	unsigned long flags;
420 
421 	dev_vdbg(&acm->data->dev, "%s - urb %d, len %d\n", __func__,
422 					rb->index, urb->actual_length);
423 	set_bit(rb->index, &acm->read_urbs_free);
424 
425 	if (!acm->dev) {
426 		dev_dbg(&acm->data->dev, "%s - disconnected\n", __func__);
427 		return;
428 	}
429 	usb_mark_last_busy(acm->dev);
430 
431 	if (urb->status) {
432 		dev_dbg(&acm->data->dev, "%s - non-zero urb status: %d\n",
433 							__func__, urb->status);
434 		return;
435 	}
436 	acm_process_read_urb(acm, urb);
437 
438 	/* throttle device if requested by tty */
439 	spin_lock_irqsave(&acm->read_lock, flags);
440 	acm->throttled = acm->throttle_req;
441 	if (!acm->throttled && !acm->susp_count) {
442 		spin_unlock_irqrestore(&acm->read_lock, flags);
443 		acm_submit_read_urb(acm, rb->index, GFP_ATOMIC);
444 	} else {
445 		spin_unlock_irqrestore(&acm->read_lock, flags);
446 	}
447 }
448 
449 /* data interface wrote those outgoing bytes */
450 static void acm_write_bulk(struct urb *urb)
451 {
452 	struct acm_wb *wb = urb->context;
453 	struct acm *acm = wb->instance;
454 	unsigned long flags;
455 
456 	if (urb->status	|| (urb->actual_length != urb->transfer_buffer_length))
457 		dev_vdbg(&acm->data->dev, "%s - len %d/%d, status %d\n",
458 			__func__,
459 			urb->actual_length,
460 			urb->transfer_buffer_length,
461 			urb->status);
462 
463 	spin_lock_irqsave(&acm->write_lock, flags);
464 	acm_write_done(acm, wb);
465 	spin_unlock_irqrestore(&acm->write_lock, flags);
466 	schedule_work(&acm->work);
467 }
468 
469 static void acm_softint(struct work_struct *work)
470 {
471 	struct acm *acm = container_of(work, struct acm, work);
472 
473 	dev_vdbg(&acm->data->dev, "%s\n", __func__);
474 
475 	tty_port_tty_wakeup(&acm->port);
476 }
477 
478 /*
479  * TTY handlers
480  */
481 
482 static int acm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
483 {
484 	struct acm *acm;
485 	int retval;
486 
487 	dev_dbg(tty->dev, "%s\n", __func__);
488 
489 	acm = acm_get_by_index(tty->index);
490 	if (!acm)
491 		return -ENODEV;
492 
493 	retval = tty_standard_install(driver, tty);
494 	if (retval)
495 		goto error_init_termios;
496 
497 	tty->driver_data = acm;
498 
499 	return 0;
500 
501 error_init_termios:
502 	tty_port_put(&acm->port);
503 	return retval;
504 }
505 
506 static int acm_tty_open(struct tty_struct *tty, struct file *filp)
507 {
508 	struct acm *acm = tty->driver_data;
509 
510 	dev_dbg(tty->dev, "%s\n", __func__);
511 
512 	return tty_port_open(&acm->port, tty, filp);
513 }
514 
515 static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
516 {
517 	struct acm *acm = container_of(port, struct acm, port);
518 	int retval = -ENODEV;
519 
520 	dev_dbg(&acm->control->dev, "%s\n", __func__);
521 
522 	mutex_lock(&acm->mutex);
523 	if (acm->disconnected)
524 		goto disconnected;
525 
526 	retval = usb_autopm_get_interface(acm->control);
527 	if (retval)
528 		goto error_get_interface;
529 
530 	/*
531 	 * FIXME: Why do we need this? Allocating 64K of physically contiguous
532 	 * memory is really nasty...
533 	 */
534 	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
535 	acm->control->needs_remote_wakeup = 1;
536 
537 	acm->ctrlurb->dev = acm->dev;
538 	if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
539 		dev_err(&acm->control->dev,
540 			"%s - usb_submit_urb(ctrl irq) failed\n", __func__);
541 		goto error_submit_urb;
542 	}
543 
544 	acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS;
545 	if (acm_set_control(acm, acm->ctrlout) < 0 &&
546 	    (acm->ctrl_caps & USB_CDC_CAP_LINE))
547 		goto error_set_control;
548 
549 	usb_autopm_put_interface(acm->control);
550 
551 	/*
552 	 * Unthrottle device in case the TTY was closed while throttled.
553 	 */
554 	spin_lock_irq(&acm->read_lock);
555 	acm->throttled = 0;
556 	acm->throttle_req = 0;
557 	spin_unlock_irq(&acm->read_lock);
558 
559 	if (acm_submit_read_urbs(acm, GFP_KERNEL))
560 		goto error_submit_read_urbs;
561 
562 	mutex_unlock(&acm->mutex);
563 
564 	return 0;
565 
566 error_submit_read_urbs:
567 	acm->ctrlout = 0;
568 	acm_set_control(acm, acm->ctrlout);
569 error_set_control:
570 	usb_kill_urb(acm->ctrlurb);
571 error_submit_urb:
572 	usb_autopm_put_interface(acm->control);
573 error_get_interface:
574 disconnected:
575 	mutex_unlock(&acm->mutex);
576 	return retval;
577 }
578 
579 static void acm_port_destruct(struct tty_port *port)
580 {
581 	struct acm *acm = container_of(port, struct acm, port);
582 
583 	dev_dbg(&acm->control->dev, "%s\n", __func__);
584 
585 	acm_release_minor(acm);
586 	usb_put_intf(acm->control);
587 	kfree(acm->country_codes);
588 	kfree(acm);
589 }
590 
591 static void acm_port_shutdown(struct tty_port *port)
592 {
593 	struct acm *acm = container_of(port, struct acm, port);
594 	int i;
595 
596 	dev_dbg(&acm->control->dev, "%s\n", __func__);
597 
598 	mutex_lock(&acm->mutex);
599 	if (!acm->disconnected) {
600 		usb_autopm_get_interface(acm->control);
601 		acm_set_control(acm, acm->ctrlout = 0);
602 		usb_kill_urb(acm->ctrlurb);
603 		for (i = 0; i < ACM_NW; i++)
604 			usb_kill_urb(acm->wb[i].urb);
605 		for (i = 0; i < acm->rx_buflimit; i++)
606 			usb_kill_urb(acm->read_urbs[i]);
607 		acm->control->needs_remote_wakeup = 0;
608 		usb_autopm_put_interface(acm->control);
609 	}
610 	mutex_unlock(&acm->mutex);
611 }
612 
613 static void acm_tty_cleanup(struct tty_struct *tty)
614 {
615 	struct acm *acm = tty->driver_data;
616 	dev_dbg(&acm->control->dev, "%s\n", __func__);
617 	tty_port_put(&acm->port);
618 }
619 
620 static void acm_tty_hangup(struct tty_struct *tty)
621 {
622 	struct acm *acm = tty->driver_data;
623 	dev_dbg(&acm->control->dev, "%s\n", __func__);
624 	tty_port_hangup(&acm->port);
625 }
626 
627 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
628 {
629 	struct acm *acm = tty->driver_data;
630 	dev_dbg(&acm->control->dev, "%s\n", __func__);
631 	tty_port_close(&acm->port, tty, filp);
632 }
633 
634 static int acm_tty_write(struct tty_struct *tty,
635 					const unsigned char *buf, int count)
636 {
637 	struct acm *acm = tty->driver_data;
638 	int stat;
639 	unsigned long flags;
640 	int wbn;
641 	struct acm_wb *wb;
642 
643 	if (!count)
644 		return 0;
645 
646 	dev_vdbg(&acm->data->dev, "%s - count %d\n", __func__, count);
647 
648 	spin_lock_irqsave(&acm->write_lock, flags);
649 	wbn = acm_wb_alloc(acm);
650 	if (wbn < 0) {
651 		spin_unlock_irqrestore(&acm->write_lock, flags);
652 		return 0;
653 	}
654 	wb = &acm->wb[wbn];
655 
656 	count = (count > acm->writesize) ? acm->writesize : count;
657 	dev_vdbg(&acm->data->dev, "%s - write %d\n", __func__, count);
658 	memcpy(wb->buf, buf, count);
659 	wb->len = count;
660 	spin_unlock_irqrestore(&acm->write_lock, flags);
661 
662 	stat = acm_write_start(acm, wbn);
663 	if (stat < 0)
664 		return stat;
665 	return count;
666 }
667 
668 static int acm_tty_write_room(struct tty_struct *tty)
669 {
670 	struct acm *acm = tty->driver_data;
671 	/*
672 	 * Do not let the line discipline to know that we have a reserve,
673 	 * or it might get too enthusiastic.
674 	 */
675 	return acm_wb_is_avail(acm) ? acm->writesize : 0;
676 }
677 
678 static int acm_tty_chars_in_buffer(struct tty_struct *tty)
679 {
680 	struct acm *acm = tty->driver_data;
681 	/*
682 	 * if the device was unplugged then any remaining characters fell out
683 	 * of the connector ;)
684 	 */
685 	if (acm->disconnected)
686 		return 0;
687 	/*
688 	 * This is inaccurate (overcounts), but it works.
689 	 */
690 	return (ACM_NW - acm_wb_is_avail(acm)) * acm->writesize;
691 }
692 
693 static void acm_tty_throttle(struct tty_struct *tty)
694 {
695 	struct acm *acm = tty->driver_data;
696 
697 	spin_lock_irq(&acm->read_lock);
698 	acm->throttle_req = 1;
699 	spin_unlock_irq(&acm->read_lock);
700 }
701 
702 static void acm_tty_unthrottle(struct tty_struct *tty)
703 {
704 	struct acm *acm = tty->driver_data;
705 	unsigned int was_throttled;
706 
707 	spin_lock_irq(&acm->read_lock);
708 	was_throttled = acm->throttled;
709 	acm->throttled = 0;
710 	acm->throttle_req = 0;
711 	spin_unlock_irq(&acm->read_lock);
712 
713 	if (was_throttled)
714 		acm_submit_read_urbs(acm, GFP_KERNEL);
715 }
716 
717 static int acm_tty_break_ctl(struct tty_struct *tty, int state)
718 {
719 	struct acm *acm = tty->driver_data;
720 	int retval;
721 
722 	retval = acm_send_break(acm, state ? 0xffff : 0);
723 	if (retval < 0)
724 		dev_dbg(&acm->control->dev, "%s - send break failed\n",
725 								__func__);
726 	return retval;
727 }
728 
729 static int acm_tty_tiocmget(struct tty_struct *tty)
730 {
731 	struct acm *acm = tty->driver_data;
732 
733 	return (acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
734 	       (acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
735 	       (acm->ctrlin  & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
736 	       (acm->ctrlin  & ACM_CTRL_RI  ? TIOCM_RI  : 0) |
737 	       (acm->ctrlin  & ACM_CTRL_DCD ? TIOCM_CD  : 0) |
738 	       TIOCM_CTS;
739 }
740 
741 static int acm_tty_tiocmset(struct tty_struct *tty,
742 			    unsigned int set, unsigned int clear)
743 {
744 	struct acm *acm = tty->driver_data;
745 	unsigned int newctrl;
746 
747 	newctrl = acm->ctrlout;
748 	set = (set & TIOCM_DTR ? ACM_CTRL_DTR : 0) |
749 					(set & TIOCM_RTS ? ACM_CTRL_RTS : 0);
750 	clear = (clear & TIOCM_DTR ? ACM_CTRL_DTR : 0) |
751 					(clear & TIOCM_RTS ? ACM_CTRL_RTS : 0);
752 
753 	newctrl = (newctrl & ~clear) | set;
754 
755 	if (acm->ctrlout == newctrl)
756 		return 0;
757 	return acm_set_control(acm, acm->ctrlout = newctrl);
758 }
759 
760 static int get_serial_info(struct acm *acm, struct serial_struct __user *info)
761 {
762 	struct serial_struct tmp;
763 
764 	if (!info)
765 		return -EINVAL;
766 
767 	memset(&tmp, 0, sizeof(tmp));
768 	tmp.flags = ASYNC_LOW_LATENCY;
769 	tmp.xmit_fifo_size = acm->writesize;
770 	tmp.baud_base = le32_to_cpu(acm->line.dwDTERate);
771 	tmp.close_delay	= acm->port.close_delay / 10;
772 	tmp.closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
773 				ASYNC_CLOSING_WAIT_NONE :
774 				acm->port.closing_wait / 10;
775 
776 	if (copy_to_user(info, &tmp, sizeof(tmp)))
777 		return -EFAULT;
778 	else
779 		return 0;
780 }
781 
782 static int set_serial_info(struct acm *acm,
783 				struct serial_struct __user *newinfo)
784 {
785 	struct serial_struct new_serial;
786 	unsigned int closing_wait, close_delay;
787 	int retval = 0;
788 
789 	if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
790 		return -EFAULT;
791 
792 	close_delay = new_serial.close_delay * 10;
793 	closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
794 			ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
795 
796 	mutex_lock(&acm->port.mutex);
797 
798 	if (!capable(CAP_SYS_ADMIN)) {
799 		if ((close_delay != acm->port.close_delay) ||
800 		    (closing_wait != acm->port.closing_wait))
801 			retval = -EPERM;
802 		else
803 			retval = -EOPNOTSUPP;
804 	} else {
805 		acm->port.close_delay  = close_delay;
806 		acm->port.closing_wait = closing_wait;
807 	}
808 
809 	mutex_unlock(&acm->port.mutex);
810 	return retval;
811 }
812 
813 static int acm_tty_ioctl(struct tty_struct *tty,
814 					unsigned int cmd, unsigned long arg)
815 {
816 	struct acm *acm = tty->driver_data;
817 	int rv = -ENOIOCTLCMD;
818 
819 	switch (cmd) {
820 	case TIOCGSERIAL: /* gets serial port data */
821 		rv = get_serial_info(acm, (struct serial_struct __user *) arg);
822 		break;
823 	case TIOCSSERIAL:
824 		rv = set_serial_info(acm, (struct serial_struct __user *) arg);
825 		break;
826 	}
827 
828 	return rv;
829 }
830 
831 static void acm_tty_set_termios(struct tty_struct *tty,
832 						struct ktermios *termios_old)
833 {
834 	struct acm *acm = tty->driver_data;
835 	struct ktermios *termios = &tty->termios;
836 	struct usb_cdc_line_coding newline;
837 	int newctrl = acm->ctrlout;
838 
839 	newline.dwDTERate = cpu_to_le32(tty_get_baud_rate(tty));
840 	newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
841 	newline.bParityType = termios->c_cflag & PARENB ?
842 				(termios->c_cflag & PARODD ? 1 : 2) +
843 				(termios->c_cflag & CMSPAR ? 2 : 0) : 0;
844 	switch (termios->c_cflag & CSIZE) {
845 	case CS5:
846 		newline.bDataBits = 5;
847 		break;
848 	case CS6:
849 		newline.bDataBits = 6;
850 		break;
851 	case CS7:
852 		newline.bDataBits = 7;
853 		break;
854 	case CS8:
855 	default:
856 		newline.bDataBits = 8;
857 		break;
858 	}
859 	/* FIXME: Needs to clear unsupported bits in the termios */
860 	acm->clocal = ((termios->c_cflag & CLOCAL) != 0);
861 
862 	if (!newline.dwDTERate) {
863 		newline.dwDTERate = acm->line.dwDTERate;
864 		newctrl &= ~ACM_CTRL_DTR;
865 	} else
866 		newctrl |=  ACM_CTRL_DTR;
867 
868 	if (newctrl != acm->ctrlout)
869 		acm_set_control(acm, acm->ctrlout = newctrl);
870 
871 	if (memcmp(&acm->line, &newline, sizeof newline)) {
872 		memcpy(&acm->line, &newline, sizeof newline);
873 		dev_dbg(&acm->control->dev, "%s - set line: %d %d %d %d\n",
874 			__func__,
875 			le32_to_cpu(newline.dwDTERate),
876 			newline.bCharFormat, newline.bParityType,
877 			newline.bDataBits);
878 		acm_set_line(acm, &acm->line);
879 	}
880 }
881 
882 static const struct tty_port_operations acm_port_ops = {
883 	.shutdown = acm_port_shutdown,
884 	.activate = acm_port_activate,
885 	.destruct = acm_port_destruct,
886 };
887 
888 /*
889  * USB probe and disconnect routines.
890  */
891 
892 /* Little helpers: write/read buffers free */
893 static void acm_write_buffers_free(struct acm *acm)
894 {
895 	int i;
896 	struct acm_wb *wb;
897 	struct usb_device *usb_dev = interface_to_usbdev(acm->control);
898 
899 	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++)
900 		usb_free_coherent(usb_dev, acm->writesize, wb->buf, wb->dmah);
901 }
902 
903 static void acm_read_buffers_free(struct acm *acm)
904 {
905 	struct usb_device *usb_dev = interface_to_usbdev(acm->control);
906 	int i;
907 
908 	for (i = 0; i < acm->rx_buflimit; i++)
909 		usb_free_coherent(usb_dev, acm->readsize,
910 			  acm->read_buffers[i].base, acm->read_buffers[i].dma);
911 }
912 
913 /* Little helper: write buffers allocate */
914 static int acm_write_buffers_alloc(struct acm *acm)
915 {
916 	int i;
917 	struct acm_wb *wb;
918 
919 	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
920 		wb->buf = usb_alloc_coherent(acm->dev, acm->writesize, GFP_KERNEL,
921 		    &wb->dmah);
922 		if (!wb->buf) {
923 			while (i != 0) {
924 				--i;
925 				--wb;
926 				usb_free_coherent(acm->dev, acm->writesize,
927 				    wb->buf, wb->dmah);
928 			}
929 			return -ENOMEM;
930 		}
931 	}
932 	return 0;
933 }
934 
935 static int acm_probe(struct usb_interface *intf,
936 		     const struct usb_device_id *id)
937 {
938 	struct usb_cdc_union_desc *union_header = NULL;
939 	struct usb_cdc_country_functional_desc *cfd = NULL;
940 	unsigned char *buffer = intf->altsetting->extra;
941 	int buflen = intf->altsetting->extralen;
942 	struct usb_interface *control_interface;
943 	struct usb_interface *data_interface;
944 	struct usb_endpoint_descriptor *epctrl = NULL;
945 	struct usb_endpoint_descriptor *epread = NULL;
946 	struct usb_endpoint_descriptor *epwrite = NULL;
947 	struct usb_device *usb_dev = interface_to_usbdev(intf);
948 	struct acm *acm;
949 	int minor;
950 	int ctrlsize, readsize;
951 	u8 *buf;
952 	u8 ac_management_function = 0;
953 	u8 call_management_function = 0;
954 	int call_interface_num = -1;
955 	int data_interface_num = -1;
956 	unsigned long quirks;
957 	int num_rx_buf;
958 	int i;
959 	int combined_interfaces = 0;
960 	struct device *tty_dev;
961 	int rv = -ENOMEM;
962 
963 	/* normal quirks */
964 	quirks = (unsigned long)id->driver_info;
965 	num_rx_buf = (quirks == SINGLE_RX_URB) ? 1 : ACM_NR;
966 
967 	/* handle quirks deadly to normal probing*/
968 	if (quirks == NO_UNION_NORMAL) {
969 		data_interface = usb_ifnum_to_if(usb_dev, 1);
970 		control_interface = usb_ifnum_to_if(usb_dev, 0);
971 		goto skip_normal_probe;
972 	}
973 
974 	/* normal probing*/
975 	if (!buffer) {
976 		dev_err(&intf->dev, "Weird descriptor references\n");
977 		return -EINVAL;
978 	}
979 
980 	if (!buflen) {
981 		if (intf->cur_altsetting->endpoint &&
982 				intf->cur_altsetting->endpoint->extralen &&
983 				intf->cur_altsetting->endpoint->extra) {
984 			dev_dbg(&intf->dev,
985 				"Seeking extra descriptors on endpoint\n");
986 			buflen = intf->cur_altsetting->endpoint->extralen;
987 			buffer = intf->cur_altsetting->endpoint->extra;
988 		} else {
989 			dev_err(&intf->dev,
990 				"Zero length descriptor references\n");
991 			return -EINVAL;
992 		}
993 	}
994 
995 	while (buflen > 0) {
996 		if (buffer[1] != USB_DT_CS_INTERFACE) {
997 			dev_err(&intf->dev, "skipping garbage\n");
998 			goto next_desc;
999 		}
1000 
1001 		switch (buffer[2]) {
1002 		case USB_CDC_UNION_TYPE: /* we've found it */
1003 			if (union_header) {
1004 				dev_err(&intf->dev, "More than one "
1005 					"union descriptor, skipping ...\n");
1006 				goto next_desc;
1007 			}
1008 			union_header = (struct usb_cdc_union_desc *)buffer;
1009 			break;
1010 		case USB_CDC_COUNTRY_TYPE: /* export through sysfs*/
1011 			cfd = (struct usb_cdc_country_functional_desc *)buffer;
1012 			break;
1013 		case USB_CDC_HEADER_TYPE: /* maybe check version */
1014 			break; /* for now we ignore it */
1015 		case USB_CDC_ACM_TYPE:
1016 			ac_management_function = buffer[3];
1017 			break;
1018 		case USB_CDC_CALL_MANAGEMENT_TYPE:
1019 			call_management_function = buffer[3];
1020 			call_interface_num = buffer[4];
1021 			if ((quirks & NOT_A_MODEM) == 0 && (call_management_function & 3) != 3)
1022 				dev_err(&intf->dev, "This device cannot do calls on its own. It is not a modem.\n");
1023 			break;
1024 		default:
1025 			/* there are LOTS more CDC descriptors that
1026 			 * could legitimately be found here.
1027 			 */
1028 			dev_dbg(&intf->dev, "Ignoring descriptor: "
1029 					"type %02x, length %d\n",
1030 					buffer[2], buffer[0]);
1031 			break;
1032 		}
1033 next_desc:
1034 		buflen -= buffer[0];
1035 		buffer += buffer[0];
1036 	}
1037 
1038 	if (!union_header) {
1039 		if (call_interface_num > 0) {
1040 			dev_dbg(&intf->dev, "No union descriptor, using call management descriptor\n");
1041 			/* quirks for Droids MuIn LCD */
1042 			if (quirks & NO_DATA_INTERFACE)
1043 				data_interface = usb_ifnum_to_if(usb_dev, 0);
1044 			else
1045 				data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
1046 			control_interface = intf;
1047 		} else {
1048 			if (intf->cur_altsetting->desc.bNumEndpoints != 3) {
1049 				dev_dbg(&intf->dev,"No union descriptor, giving up\n");
1050 				return -ENODEV;
1051 			} else {
1052 				dev_warn(&intf->dev,"No union descriptor, testing for castrated device\n");
1053 				combined_interfaces = 1;
1054 				control_interface = data_interface = intf;
1055 				goto look_for_collapsed_interface;
1056 			}
1057 		}
1058 	} else {
1059 		control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
1060 		data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
1061 		if (!control_interface || !data_interface) {
1062 			dev_dbg(&intf->dev, "no interfaces\n");
1063 			return -ENODEV;
1064 		}
1065 	}
1066 
1067 	if (data_interface_num != call_interface_num)
1068 		dev_dbg(&intf->dev, "Separate call control interface. That is not fully supported.\n");
1069 
1070 	if (control_interface == data_interface) {
1071 		/* some broken devices designed for windows work this way */
1072 		dev_warn(&intf->dev,"Control and data interfaces are not separated!\n");
1073 		combined_interfaces = 1;
1074 		/* a popular other OS doesn't use it */
1075 		quirks |= NO_CAP_LINE;
1076 		if (data_interface->cur_altsetting->desc.bNumEndpoints != 3) {
1077 			dev_err(&intf->dev, "This needs exactly 3 endpoints\n");
1078 			return -EINVAL;
1079 		}
1080 look_for_collapsed_interface:
1081 		for (i = 0; i < 3; i++) {
1082 			struct usb_endpoint_descriptor *ep;
1083 			ep = &data_interface->cur_altsetting->endpoint[i].desc;
1084 
1085 			if (usb_endpoint_is_int_in(ep))
1086 				epctrl = ep;
1087 			else if (usb_endpoint_is_bulk_out(ep))
1088 				epwrite = ep;
1089 			else if (usb_endpoint_is_bulk_in(ep))
1090 				epread = ep;
1091 			else
1092 				return -EINVAL;
1093 		}
1094 		if (!epctrl || !epread || !epwrite)
1095 			return -ENODEV;
1096 		else
1097 			goto made_compressed_probe;
1098 	}
1099 
1100 skip_normal_probe:
1101 
1102 	/*workaround for switched interfaces */
1103 	if (data_interface->cur_altsetting->desc.bInterfaceClass
1104 						!= CDC_DATA_INTERFACE_TYPE) {
1105 		if (control_interface->cur_altsetting->desc.bInterfaceClass
1106 						== CDC_DATA_INTERFACE_TYPE) {
1107 			struct usb_interface *t;
1108 			dev_dbg(&intf->dev,
1109 				"Your device has switched interfaces.\n");
1110 			t = control_interface;
1111 			control_interface = data_interface;
1112 			data_interface = t;
1113 		} else {
1114 			return -EINVAL;
1115 		}
1116 	}
1117 
1118 	/* Accept probe requests only for the control interface */
1119 	if (!combined_interfaces && intf != control_interface)
1120 		return -ENODEV;
1121 
1122 	if (!combined_interfaces && usb_interface_claimed(data_interface)) {
1123 		/* valid in this context */
1124 		dev_dbg(&intf->dev, "The data interface isn't available\n");
1125 		return -EBUSY;
1126 	}
1127 
1128 
1129 	if (data_interface->cur_altsetting->desc.bNumEndpoints < 2 ||
1130 	    control_interface->cur_altsetting->desc.bNumEndpoints == 0)
1131 		return -EINVAL;
1132 
1133 	epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
1134 	epread = &data_interface->cur_altsetting->endpoint[0].desc;
1135 	epwrite = &data_interface->cur_altsetting->endpoint[1].desc;
1136 
1137 
1138 	/* workaround for switched endpoints */
1139 	if (!usb_endpoint_dir_in(epread)) {
1140 		/* descriptors are swapped */
1141 		struct usb_endpoint_descriptor *t;
1142 		dev_dbg(&intf->dev,
1143 			"The data interface has switched endpoints\n");
1144 		t = epread;
1145 		epread = epwrite;
1146 		epwrite = t;
1147 	}
1148 made_compressed_probe:
1149 	dev_dbg(&intf->dev, "interfaces are valid\n");
1150 
1151 	acm = kzalloc(sizeof(struct acm), GFP_KERNEL);
1152 	if (acm == NULL) {
1153 		dev_err(&intf->dev, "out of memory (acm kzalloc)\n");
1154 		goto alloc_fail;
1155 	}
1156 
1157 	minor = acm_alloc_minor(acm);
1158 	if (minor == ACM_TTY_MINORS) {
1159 		dev_err(&intf->dev, "no more free acm devices\n");
1160 		kfree(acm);
1161 		return -ENODEV;
1162 	}
1163 
1164 	ctrlsize = usb_endpoint_maxp(epctrl);
1165 	readsize = usb_endpoint_maxp(epread) *
1166 				(quirks == SINGLE_RX_URB ? 1 : 2);
1167 	acm->combined_interfaces = combined_interfaces;
1168 	acm->writesize = usb_endpoint_maxp(epwrite) * 20;
1169 	acm->control = control_interface;
1170 	acm->data = data_interface;
1171 	acm->minor = minor;
1172 	acm->dev = usb_dev;
1173 	acm->ctrl_caps = ac_management_function;
1174 	if (quirks & NO_CAP_LINE)
1175 		acm->ctrl_caps &= ~USB_CDC_CAP_LINE;
1176 	acm->ctrlsize = ctrlsize;
1177 	acm->readsize = readsize;
1178 	acm->rx_buflimit = num_rx_buf;
1179 	INIT_WORK(&acm->work, acm_softint);
1180 	spin_lock_init(&acm->write_lock);
1181 	spin_lock_init(&acm->read_lock);
1182 	mutex_init(&acm->mutex);
1183 	acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
1184 	acm->is_int_ep = usb_endpoint_xfer_int(epread);
1185 	if (acm->is_int_ep)
1186 		acm->bInterval = epread->bInterval;
1187 	tty_port_init(&acm->port);
1188 	acm->port.ops = &acm_port_ops;
1189 
1190 	buf = usb_alloc_coherent(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
1191 	if (!buf) {
1192 		dev_err(&intf->dev, "out of memory (ctrl buffer alloc)\n");
1193 		goto alloc_fail2;
1194 	}
1195 	acm->ctrl_buffer = buf;
1196 
1197 	if (acm_write_buffers_alloc(acm) < 0) {
1198 		dev_err(&intf->dev, "out of memory (write buffer alloc)\n");
1199 		goto alloc_fail4;
1200 	}
1201 
1202 	acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
1203 	if (!acm->ctrlurb) {
1204 		dev_err(&intf->dev, "out of memory (ctrlurb kmalloc)\n");
1205 		goto alloc_fail5;
1206 	}
1207 	for (i = 0; i < num_rx_buf; i++) {
1208 		struct acm_rb *rb = &(acm->read_buffers[i]);
1209 		struct urb *urb;
1210 
1211 		rb->base = usb_alloc_coherent(acm->dev, readsize, GFP_KERNEL,
1212 								&rb->dma);
1213 		if (!rb->base) {
1214 			dev_err(&intf->dev, "out of memory "
1215 					"(read bufs usb_alloc_coherent)\n");
1216 			goto alloc_fail6;
1217 		}
1218 		rb->index = i;
1219 		rb->instance = acm;
1220 
1221 		urb = usb_alloc_urb(0, GFP_KERNEL);
1222 		if (!urb) {
1223 			dev_err(&intf->dev,
1224 				"out of memory (read urbs usb_alloc_urb)\n");
1225 			goto alloc_fail6;
1226 		}
1227 		urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1228 		urb->transfer_dma = rb->dma;
1229 		if (acm->is_int_ep) {
1230 			usb_fill_int_urb(urb, acm->dev,
1231 					 acm->rx_endpoint,
1232 					 rb->base,
1233 					 acm->readsize,
1234 					 acm_read_bulk_callback, rb,
1235 					 acm->bInterval);
1236 		} else {
1237 			usb_fill_bulk_urb(urb, acm->dev,
1238 					  acm->rx_endpoint,
1239 					  rb->base,
1240 					  acm->readsize,
1241 					  acm_read_bulk_callback, rb);
1242 		}
1243 
1244 		acm->read_urbs[i] = urb;
1245 		__set_bit(i, &acm->read_urbs_free);
1246 	}
1247 	for (i = 0; i < ACM_NW; i++) {
1248 		struct acm_wb *snd = &(acm->wb[i]);
1249 
1250 		snd->urb = usb_alloc_urb(0, GFP_KERNEL);
1251 		if (snd->urb == NULL) {
1252 			dev_err(&intf->dev,
1253 				"out of memory (write urbs usb_alloc_urb)\n");
1254 			goto alloc_fail7;
1255 		}
1256 
1257 		if (usb_endpoint_xfer_int(epwrite))
1258 			usb_fill_int_urb(snd->urb, usb_dev,
1259 				usb_sndintpipe(usb_dev, epwrite->bEndpointAddress),
1260 				NULL, acm->writesize, acm_write_bulk, snd, epwrite->bInterval);
1261 		else
1262 			usb_fill_bulk_urb(snd->urb, usb_dev,
1263 				usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
1264 				NULL, acm->writesize, acm_write_bulk, snd);
1265 		snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1266 		snd->instance = acm;
1267 	}
1268 
1269 	usb_set_intfdata(intf, acm);
1270 
1271 	i = device_create_file(&intf->dev, &dev_attr_bmCapabilities);
1272 	if (i < 0)
1273 		goto alloc_fail7;
1274 
1275 	if (cfd) { /* export the country data */
1276 		acm->country_codes = kmalloc(cfd->bLength - 4, GFP_KERNEL);
1277 		if (!acm->country_codes)
1278 			goto skip_countries;
1279 		acm->country_code_size = cfd->bLength - 4;
1280 		memcpy(acm->country_codes, (u8 *)&cfd->wCountyCode0,
1281 							cfd->bLength - 4);
1282 		acm->country_rel_date = cfd->iCountryCodeRelDate;
1283 
1284 		i = device_create_file(&intf->dev, &dev_attr_wCountryCodes);
1285 		if (i < 0) {
1286 			kfree(acm->country_codes);
1287 			acm->country_codes = NULL;
1288 			acm->country_code_size = 0;
1289 			goto skip_countries;
1290 		}
1291 
1292 		i = device_create_file(&intf->dev,
1293 						&dev_attr_iCountryCodeRelDate);
1294 		if (i < 0) {
1295 			device_remove_file(&intf->dev, &dev_attr_wCountryCodes);
1296 			kfree(acm->country_codes);
1297 			acm->country_codes = NULL;
1298 			acm->country_code_size = 0;
1299 			goto skip_countries;
1300 		}
1301 	}
1302 
1303 skip_countries:
1304 	usb_fill_int_urb(acm->ctrlurb, usb_dev,
1305 			 usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
1306 			 acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm,
1307 			 /* works around buggy devices */
1308 			 epctrl->bInterval ? epctrl->bInterval : 0xff);
1309 	acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1310 	acm->ctrlurb->transfer_dma = acm->ctrl_dma;
1311 
1312 	dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
1313 
1314 	acm_set_control(acm, acm->ctrlout);
1315 
1316 	acm->line.dwDTERate = cpu_to_le32(9600);
1317 	acm->line.bDataBits = 8;
1318 	acm_set_line(acm, &acm->line);
1319 
1320 	usb_driver_claim_interface(&acm_driver, data_interface, acm);
1321 	usb_set_intfdata(data_interface, acm);
1322 
1323 	usb_get_intf(control_interface);
1324 	tty_dev = tty_port_register_device(&acm->port, acm_tty_driver, minor,
1325 			&control_interface->dev);
1326 	if (IS_ERR(tty_dev)) {
1327 		rv = PTR_ERR(tty_dev);
1328 		goto alloc_fail8;
1329 	}
1330 
1331 	return 0;
1332 alloc_fail8:
1333 	if (acm->country_codes) {
1334 		device_remove_file(&acm->control->dev,
1335 				&dev_attr_wCountryCodes);
1336 		device_remove_file(&acm->control->dev,
1337 				&dev_attr_iCountryCodeRelDate);
1338 	}
1339 	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
1340 alloc_fail7:
1341 	usb_set_intfdata(intf, NULL);
1342 	for (i = 0; i < ACM_NW; i++)
1343 		usb_free_urb(acm->wb[i].urb);
1344 alloc_fail6:
1345 	for (i = 0; i < num_rx_buf; i++)
1346 		usb_free_urb(acm->read_urbs[i]);
1347 	acm_read_buffers_free(acm);
1348 	usb_free_urb(acm->ctrlurb);
1349 alloc_fail5:
1350 	acm_write_buffers_free(acm);
1351 alloc_fail4:
1352 	usb_free_coherent(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1353 alloc_fail2:
1354 	acm_release_minor(acm);
1355 	kfree(acm);
1356 alloc_fail:
1357 	return rv;
1358 }
1359 
1360 static void stop_data_traffic(struct acm *acm)
1361 {
1362 	int i;
1363 
1364 	dev_dbg(&acm->control->dev, "%s\n", __func__);
1365 
1366 	usb_kill_urb(acm->ctrlurb);
1367 	for (i = 0; i < ACM_NW; i++)
1368 		usb_kill_urb(acm->wb[i].urb);
1369 	for (i = 0; i < acm->rx_buflimit; i++)
1370 		usb_kill_urb(acm->read_urbs[i]);
1371 
1372 	cancel_work_sync(&acm->work);
1373 }
1374 
1375 static void acm_disconnect(struct usb_interface *intf)
1376 {
1377 	struct acm *acm = usb_get_intfdata(intf);
1378 	struct usb_device *usb_dev = interface_to_usbdev(intf);
1379 	struct tty_struct *tty;
1380 	int i;
1381 
1382 	dev_dbg(&intf->dev, "%s\n", __func__);
1383 
1384 	/* sibling interface is already cleaning up */
1385 	if (!acm)
1386 		return;
1387 
1388 	mutex_lock(&acm->mutex);
1389 	acm->disconnected = true;
1390 	if (acm->country_codes) {
1391 		device_remove_file(&acm->control->dev,
1392 				&dev_attr_wCountryCodes);
1393 		device_remove_file(&acm->control->dev,
1394 				&dev_attr_iCountryCodeRelDate);
1395 	}
1396 	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
1397 	usb_set_intfdata(acm->control, NULL);
1398 	usb_set_intfdata(acm->data, NULL);
1399 	mutex_unlock(&acm->mutex);
1400 
1401 	tty = tty_port_tty_get(&acm->port);
1402 	if (tty) {
1403 		tty_vhangup(tty);
1404 		tty_kref_put(tty);
1405 	}
1406 
1407 	stop_data_traffic(acm);
1408 
1409 	tty_unregister_device(acm_tty_driver, acm->minor);
1410 
1411 	usb_free_urb(acm->ctrlurb);
1412 	for (i = 0; i < ACM_NW; i++)
1413 		usb_free_urb(acm->wb[i].urb);
1414 	for (i = 0; i < acm->rx_buflimit; i++)
1415 		usb_free_urb(acm->read_urbs[i]);
1416 	acm_write_buffers_free(acm);
1417 	usb_free_coherent(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1418 	acm_read_buffers_free(acm);
1419 
1420 	if (!acm->combined_interfaces)
1421 		usb_driver_release_interface(&acm_driver, intf == acm->control ?
1422 					acm->data : acm->control);
1423 
1424 	tty_port_put(&acm->port);
1425 }
1426 
1427 #ifdef CONFIG_PM
1428 static int acm_suspend(struct usb_interface *intf, pm_message_t message)
1429 {
1430 	struct acm *acm = usb_get_intfdata(intf);
1431 	int cnt;
1432 
1433 	if (PMSG_IS_AUTO(message)) {
1434 		int b;
1435 
1436 		spin_lock_irq(&acm->write_lock);
1437 		b = acm->transmitting;
1438 		spin_unlock_irq(&acm->write_lock);
1439 		if (b)
1440 			return -EBUSY;
1441 	}
1442 
1443 	spin_lock_irq(&acm->read_lock);
1444 	spin_lock(&acm->write_lock);
1445 	cnt = acm->susp_count++;
1446 	spin_unlock(&acm->write_lock);
1447 	spin_unlock_irq(&acm->read_lock);
1448 
1449 	if (cnt)
1450 		return 0;
1451 
1452 	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags))
1453 		stop_data_traffic(acm);
1454 
1455 	return 0;
1456 }
1457 
1458 static int acm_resume(struct usb_interface *intf)
1459 {
1460 	struct acm *acm = usb_get_intfdata(intf);
1461 	struct acm_wb *wb;
1462 	int rv = 0;
1463 	int cnt;
1464 
1465 	spin_lock_irq(&acm->read_lock);
1466 	acm->susp_count -= 1;
1467 	cnt = acm->susp_count;
1468 	spin_unlock_irq(&acm->read_lock);
1469 
1470 	if (cnt)
1471 		return 0;
1472 
1473 	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags)) {
1474 		rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
1475 
1476 		spin_lock_irq(&acm->write_lock);
1477 		if (acm->delayed_wb) {
1478 			wb = acm->delayed_wb;
1479 			acm->delayed_wb = NULL;
1480 			spin_unlock_irq(&acm->write_lock);
1481 			acm_start_wb(acm, wb);
1482 		} else {
1483 			spin_unlock_irq(&acm->write_lock);
1484 		}
1485 
1486 		/*
1487 		 * delayed error checking because we must
1488 		 * do the write path at all cost
1489 		 */
1490 		if (rv < 0)
1491 			goto err_out;
1492 
1493 		rv = acm_submit_read_urbs(acm, GFP_NOIO);
1494 	}
1495 
1496 err_out:
1497 	return rv;
1498 }
1499 
1500 static int acm_reset_resume(struct usb_interface *intf)
1501 {
1502 	struct acm *acm = usb_get_intfdata(intf);
1503 
1504 	if (test_bit(ASYNCB_INITIALIZED, &acm->port.flags))
1505 		tty_port_tty_hangup(&acm->port, false);
1506 
1507 	return acm_resume(intf);
1508 }
1509 
1510 #endif /* CONFIG_PM */
1511 
1512 #define NOKIA_PCSUITE_ACM_INFO(x) \
1513 		USB_DEVICE_AND_INTERFACE_INFO(0x0421, x, \
1514 		USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM, \
1515 		USB_CDC_ACM_PROTO_VENDOR)
1516 
1517 #define SAMSUNG_PCSUITE_ACM_INFO(x) \
1518 		USB_DEVICE_AND_INTERFACE_INFO(0x04e7, x, \
1519 		USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM, \
1520 		USB_CDC_ACM_PROTO_VENDOR)
1521 
1522 /*
1523  * USB driver structure.
1524  */
1525 
1526 static const struct usb_device_id acm_ids[] = {
1527 	/* quirky and broken devices */
1528 	{ USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
1529 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1530 	},
1531 	{ USB_DEVICE(0x0e8d, 0x0003), /* FIREFLY, MediaTek Inc; andrey.arapov@gmail.com */
1532 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1533 	},
1534 	{ USB_DEVICE(0x0e8d, 0x3329), /* MediaTek Inc GPS */
1535 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1536 	},
1537 	{ USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
1538 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1539 	},
1540 	{ USB_DEVICE(0x079b, 0x000f), /* BT On-Air USB MODEM */
1541 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1542 	},
1543 	{ USB_DEVICE(0x0ace, 0x1602), /* ZyDAS 56K USB MODEM */
1544 	.driver_info = SINGLE_RX_URB,
1545 	},
1546 	{ USB_DEVICE(0x0ace, 0x1608), /* ZyDAS 56K USB MODEM */
1547 	.driver_info = SINGLE_RX_URB, /* firmware bug */
1548 	},
1549 	{ USB_DEVICE(0x0ace, 0x1611), /* ZyDAS 56K USB MODEM - new version */
1550 	.driver_info = SINGLE_RX_URB, /* firmware bug */
1551 	},
1552 	{ USB_DEVICE(0x22b8, 0x7000), /* Motorola Q Phone */
1553 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1554 	},
1555 	{ USB_DEVICE(0x0803, 0x3095), /* Zoom Telephonics Model 3095F USB MODEM */
1556 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1557 	},
1558 	{ USB_DEVICE(0x0572, 0x1321), /* Conexant USB MODEM CX93010 */
1559 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1560 	},
1561 	{ USB_DEVICE(0x0572, 0x1324), /* Conexant USB MODEM RD02-D400 */
1562 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1563 	},
1564 	{ USB_DEVICE(0x0572, 0x1328), /* Shiro / Aztech USB MODEM UM-3100 */
1565 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1566 	},
1567 	{ USB_DEVICE(0x22b8, 0x6425), /* Motorola MOTOMAGX phones */
1568 	},
1569 	/* Motorola H24 HSPA module: */
1570 	{ USB_DEVICE(0x22b8, 0x2d91) }, /* modem                                */
1571 	{ USB_DEVICE(0x22b8, 0x2d92) }, /* modem           + diagnostics        */
1572 	{ USB_DEVICE(0x22b8, 0x2d93) }, /* modem + AT port                      */
1573 	{ USB_DEVICE(0x22b8, 0x2d95) }, /* modem + AT port + diagnostics        */
1574 	{ USB_DEVICE(0x22b8, 0x2d96) }, /* modem                         + NMEA */
1575 	{ USB_DEVICE(0x22b8, 0x2d97) }, /* modem           + diagnostics + NMEA */
1576 	{ USB_DEVICE(0x22b8, 0x2d99) }, /* modem + AT port               + NMEA */
1577 	{ USB_DEVICE(0x22b8, 0x2d9a) }, /* modem + AT port + diagnostics + NMEA */
1578 
1579 	{ USB_DEVICE(0x0572, 0x1329), /* Hummingbird huc56s (Conexant) */
1580 	.driver_info = NO_UNION_NORMAL, /* union descriptor misplaced on
1581 					   data interface instead of
1582 					   communications interface.
1583 					   Maybe we should define a new
1584 					   quirk for this. */
1585 	},
1586 	{ USB_DEVICE(0x0572, 0x1340), /* Conexant CX93010-2x UCMxx */
1587 	.driver_info = NO_UNION_NORMAL,
1588 	},
1589 	{ USB_DEVICE(0x05f9, 0x4002), /* PSC Scanning, Magellan 800i */
1590 	.driver_info = NO_UNION_NORMAL,
1591 	},
1592 	{ USB_DEVICE(0x1bbb, 0x0003), /* Alcatel OT-I650 */
1593 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1594 	},
1595 	{ USB_DEVICE(0x1576, 0x03b1), /* Maretron USB100 */
1596 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1597 	},
1598 
1599 	/* Nokia S60 phones expose two ACM channels. The first is
1600 	 * a modem and is picked up by the standard AT-command
1601 	 * information below. The second is 'vendor-specific' but
1602 	 * is treated as a serial device at the S60 end, so we want
1603 	 * to expose it on Linux too. */
1604 	{ NOKIA_PCSUITE_ACM_INFO(0x042D), }, /* Nokia 3250 */
1605 	{ NOKIA_PCSUITE_ACM_INFO(0x04D8), }, /* Nokia 5500 Sport */
1606 	{ NOKIA_PCSUITE_ACM_INFO(0x04C9), }, /* Nokia E50 */
1607 	{ NOKIA_PCSUITE_ACM_INFO(0x0419), }, /* Nokia E60 */
1608 	{ NOKIA_PCSUITE_ACM_INFO(0x044D), }, /* Nokia E61 */
1609 	{ NOKIA_PCSUITE_ACM_INFO(0x0001), }, /* Nokia E61i */
1610 	{ NOKIA_PCSUITE_ACM_INFO(0x0475), }, /* Nokia E62 */
1611 	{ NOKIA_PCSUITE_ACM_INFO(0x0508), }, /* Nokia E65 */
1612 	{ NOKIA_PCSUITE_ACM_INFO(0x0418), }, /* Nokia E70 */
1613 	{ NOKIA_PCSUITE_ACM_INFO(0x0425), }, /* Nokia N71 */
1614 	{ NOKIA_PCSUITE_ACM_INFO(0x0486), }, /* Nokia N73 */
1615 	{ NOKIA_PCSUITE_ACM_INFO(0x04DF), }, /* Nokia N75 */
1616 	{ NOKIA_PCSUITE_ACM_INFO(0x000e), }, /* Nokia N77 */
1617 	{ NOKIA_PCSUITE_ACM_INFO(0x0445), }, /* Nokia N80 */
1618 	{ NOKIA_PCSUITE_ACM_INFO(0x042F), }, /* Nokia N91 & N91 8GB */
1619 	{ NOKIA_PCSUITE_ACM_INFO(0x048E), }, /* Nokia N92 */
1620 	{ NOKIA_PCSUITE_ACM_INFO(0x0420), }, /* Nokia N93 */
1621 	{ NOKIA_PCSUITE_ACM_INFO(0x04E6), }, /* Nokia N93i  */
1622 	{ NOKIA_PCSUITE_ACM_INFO(0x04B2), }, /* Nokia 5700 XpressMusic */
1623 	{ NOKIA_PCSUITE_ACM_INFO(0x0134), }, /* Nokia 6110 Navigator (China) */
1624 	{ NOKIA_PCSUITE_ACM_INFO(0x046E), }, /* Nokia 6110 Navigator */
1625 	{ NOKIA_PCSUITE_ACM_INFO(0x002f), }, /* Nokia 6120 classic &  */
1626 	{ NOKIA_PCSUITE_ACM_INFO(0x0088), }, /* Nokia 6121 classic */
1627 	{ NOKIA_PCSUITE_ACM_INFO(0x00fc), }, /* Nokia 6124 classic */
1628 	{ NOKIA_PCSUITE_ACM_INFO(0x0042), }, /* Nokia E51 */
1629 	{ NOKIA_PCSUITE_ACM_INFO(0x00b0), }, /* Nokia E66 */
1630 	{ NOKIA_PCSUITE_ACM_INFO(0x00ab), }, /* Nokia E71 */
1631 	{ NOKIA_PCSUITE_ACM_INFO(0x0481), }, /* Nokia N76 */
1632 	{ NOKIA_PCSUITE_ACM_INFO(0x0007), }, /* Nokia N81 & N81 8GB */
1633 	{ NOKIA_PCSUITE_ACM_INFO(0x0071), }, /* Nokia N82 */
1634 	{ NOKIA_PCSUITE_ACM_INFO(0x04F0), }, /* Nokia N95 & N95-3 NAM */
1635 	{ NOKIA_PCSUITE_ACM_INFO(0x0070), }, /* Nokia N95 8GB  */
1636 	{ NOKIA_PCSUITE_ACM_INFO(0x00e9), }, /* Nokia 5320 XpressMusic */
1637 	{ NOKIA_PCSUITE_ACM_INFO(0x0099), }, /* Nokia 6210 Navigator, RM-367 */
1638 	{ NOKIA_PCSUITE_ACM_INFO(0x0128), }, /* Nokia 6210 Navigator, RM-419 */
1639 	{ NOKIA_PCSUITE_ACM_INFO(0x008f), }, /* Nokia 6220 Classic */
1640 	{ NOKIA_PCSUITE_ACM_INFO(0x00a0), }, /* Nokia 6650 */
1641 	{ NOKIA_PCSUITE_ACM_INFO(0x007b), }, /* Nokia N78 */
1642 	{ NOKIA_PCSUITE_ACM_INFO(0x0094), }, /* Nokia N85 */
1643 	{ NOKIA_PCSUITE_ACM_INFO(0x003a), }, /* Nokia N96 & N96-3  */
1644 	{ NOKIA_PCSUITE_ACM_INFO(0x00e9), }, /* Nokia 5320 XpressMusic */
1645 	{ NOKIA_PCSUITE_ACM_INFO(0x0108), }, /* Nokia 5320 XpressMusic 2G */
1646 	{ NOKIA_PCSUITE_ACM_INFO(0x01f5), }, /* Nokia N97, RM-505 */
1647 	{ NOKIA_PCSUITE_ACM_INFO(0x02e3), }, /* Nokia 5230, RM-588 */
1648 	{ NOKIA_PCSUITE_ACM_INFO(0x0178), }, /* Nokia E63 */
1649 	{ NOKIA_PCSUITE_ACM_INFO(0x010e), }, /* Nokia E75 */
1650 	{ NOKIA_PCSUITE_ACM_INFO(0x02d9), }, /* Nokia 6760 Slide */
1651 	{ NOKIA_PCSUITE_ACM_INFO(0x01d0), }, /* Nokia E52 */
1652 	{ NOKIA_PCSUITE_ACM_INFO(0x0223), }, /* Nokia E72 */
1653 	{ NOKIA_PCSUITE_ACM_INFO(0x0275), }, /* Nokia X6 */
1654 	{ NOKIA_PCSUITE_ACM_INFO(0x026c), }, /* Nokia N97 Mini */
1655 	{ NOKIA_PCSUITE_ACM_INFO(0x0154), }, /* Nokia 5800 XpressMusic */
1656 	{ NOKIA_PCSUITE_ACM_INFO(0x04ce), }, /* Nokia E90 */
1657 	{ NOKIA_PCSUITE_ACM_INFO(0x01d4), }, /* Nokia E55 */
1658 	{ NOKIA_PCSUITE_ACM_INFO(0x0302), }, /* Nokia N8 */
1659 	{ NOKIA_PCSUITE_ACM_INFO(0x0335), }, /* Nokia E7 */
1660 	{ NOKIA_PCSUITE_ACM_INFO(0x03cd), }, /* Nokia C7 */
1661 	{ SAMSUNG_PCSUITE_ACM_INFO(0x6651), }, /* Samsung GTi8510 (INNOV8) */
1662 
1663 	/* Support for Owen devices */
1664 	{ USB_DEVICE(0x03eb, 0x0030), }, /* Owen SI30 */
1665 
1666 	/* NOTE: non-Nokia COMM/ACM/0xff is likely MSFT RNDIS... NOT a modem! */
1667 
1668 	/* Support Lego NXT using pbLua firmware */
1669 	{ USB_DEVICE(0x0694, 0xff00),
1670 	.driver_info = NOT_A_MODEM,
1671 	},
1672 
1673 	/* Support for Droids MuIn LCD */
1674 	{ USB_DEVICE(0x04d8, 0x000b),
1675 	.driver_info = NO_DATA_INTERFACE,
1676 	},
1677 
1678 	/* control interfaces without any protocol set */
1679 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1680 		USB_CDC_PROTO_NONE) },
1681 
1682 	/* control interfaces with various AT-command sets */
1683 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1684 		USB_CDC_ACM_PROTO_AT_V25TER) },
1685 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1686 		USB_CDC_ACM_PROTO_AT_PCCA101) },
1687 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1688 		USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
1689 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1690 		USB_CDC_ACM_PROTO_AT_GSM) },
1691 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1692 		USB_CDC_ACM_PROTO_AT_3G) },
1693 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1694 		USB_CDC_ACM_PROTO_AT_CDMA) },
1695 
1696 	{ }
1697 };
1698 
1699 MODULE_DEVICE_TABLE(usb, acm_ids);
1700 
1701 static struct usb_driver acm_driver = {
1702 	.name =		"cdc_acm",
1703 	.probe =	acm_probe,
1704 	.disconnect =	acm_disconnect,
1705 #ifdef CONFIG_PM
1706 	.suspend =	acm_suspend,
1707 	.resume =	acm_resume,
1708 	.reset_resume =	acm_reset_resume,
1709 #endif
1710 	.id_table =	acm_ids,
1711 #ifdef CONFIG_PM
1712 	.supports_autosuspend = 1,
1713 #endif
1714 	.disable_hub_initiated_lpm = 1,
1715 };
1716 
1717 /*
1718  * TTY driver structures.
1719  */
1720 
1721 static const struct tty_operations acm_ops = {
1722 	.install =		acm_tty_install,
1723 	.open =			acm_tty_open,
1724 	.close =		acm_tty_close,
1725 	.cleanup =		acm_tty_cleanup,
1726 	.hangup =		acm_tty_hangup,
1727 	.write =		acm_tty_write,
1728 	.write_room =		acm_tty_write_room,
1729 	.ioctl =		acm_tty_ioctl,
1730 	.throttle =		acm_tty_throttle,
1731 	.unthrottle =		acm_tty_unthrottle,
1732 	.chars_in_buffer =	acm_tty_chars_in_buffer,
1733 	.break_ctl =		acm_tty_break_ctl,
1734 	.set_termios =		acm_tty_set_termios,
1735 	.tiocmget =		acm_tty_tiocmget,
1736 	.tiocmset =		acm_tty_tiocmset,
1737 };
1738 
1739 /*
1740  * Init / exit.
1741  */
1742 
1743 static int __init acm_init(void)
1744 {
1745 	int retval;
1746 	acm_tty_driver = alloc_tty_driver(ACM_TTY_MINORS);
1747 	if (!acm_tty_driver)
1748 		return -ENOMEM;
1749 	acm_tty_driver->driver_name = "acm",
1750 	acm_tty_driver->name = "ttyACM",
1751 	acm_tty_driver->major = ACM_TTY_MAJOR,
1752 	acm_tty_driver->minor_start = 0,
1753 	acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
1754 	acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
1755 	acm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1756 	acm_tty_driver->init_termios = tty_std_termios;
1757 	acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD |
1758 								HUPCL | CLOCAL;
1759 	tty_set_operations(acm_tty_driver, &acm_ops);
1760 
1761 	retval = tty_register_driver(acm_tty_driver);
1762 	if (retval) {
1763 		put_tty_driver(acm_tty_driver);
1764 		return retval;
1765 	}
1766 
1767 	retval = usb_register(&acm_driver);
1768 	if (retval) {
1769 		tty_unregister_driver(acm_tty_driver);
1770 		put_tty_driver(acm_tty_driver);
1771 		return retval;
1772 	}
1773 
1774 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_DESC "\n");
1775 
1776 	return 0;
1777 }
1778 
1779 static void __exit acm_exit(void)
1780 {
1781 	usb_deregister(&acm_driver);
1782 	tty_unregister_driver(acm_tty_driver);
1783 	put_tty_driver(acm_tty_driver);
1784 }
1785 
1786 module_init(acm_init);
1787 module_exit(acm_exit);
1788 
1789 MODULE_AUTHOR(DRIVER_AUTHOR);
1790 MODULE_DESCRIPTION(DRIVER_DESC);
1791 MODULE_LICENSE("GPL");
1792 MODULE_ALIAS_CHARDEV_MAJOR(ACM_TTY_MAJOR);
1793