xref: /openbmc/linux/drivers/usb/class/cdc-acm.c (revision e8e0929d)
1 /*
2  * cdc-acm.c
3  *
4  * Copyright (c) 1999 Armin Fuerst	<fuerst@in.tum.de>
5  * Copyright (c) 1999 Pavel Machek	<pavel@suse.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  *
11  * USB Abstract Control Model driver for USB modems and ISDN adapters
12  *
13  * Sponsored by SuSE
14  *
15  * ChangeLog:
16  *	v0.9  - thorough cleaning, URBification, almost a rewrite
17  *	v0.10 - some more cleanups
18  *	v0.11 - fixed flow control, read error doesn't stop reads
19  *	v0.12 - added TIOCM ioctls, added break handling, made struct acm
20  *		kmalloced
21  *	v0.13 - added termios, added hangup
22  *	v0.14 - sized down struct acm
23  *	v0.15 - fixed flow control again - characters could be lost
24  *	v0.16 - added code for modems with swapped data and control interfaces
25  *	v0.17 - added new style probing
26  *	v0.18 - fixed new style probing for devices with more configurations
27  *	v0.19 - fixed CLOCAL handling (thanks to Richard Shih-Ping Chan)
28  *	v0.20 - switched to probing on interface (rather than device) class
29  *	v0.21 - revert to probing on device for devices with multiple configs
30  *	v0.22 - probe only the control interface. if usbcore doesn't choose the
31  *		config we want, sysadmin changes bConfigurationValue in sysfs.
32  *	v0.23 - use softirq for rx processing, as needed by tty layer
33  *	v0.24 - change probe method to evaluate CDC union descriptor
34  *	v0.25 - downstream tasks paralelized to maximize throughput
35  *	v0.26 - multiple write urbs, writesize increased
36  */
37 
38 /*
39  * This program is free software; you can redistribute it and/or modify
40  * it under the terms of the GNU General Public License as published by
41  * the Free Software Foundation; either version 2 of the License, or
42  * (at your option) any later version.
43  *
44  * This program is distributed in the hope that it will be useful,
45  * but WITHOUT ANY WARRANTY; without even the implied warranty of
46  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
47  * GNU General Public License for more details.
48  *
49  * You should have received a copy of the GNU General Public License
50  * along with this program; if not, write to the Free Software
51  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
52  */
53 
54 #undef DEBUG
55 #undef VERBOSE_DEBUG
56 
57 #include <linux/kernel.h>
58 #include <linux/errno.h>
59 #include <linux/init.h>
60 #include <linux/slab.h>
61 #include <linux/tty.h>
62 #include <linux/serial.h>
63 #include <linux/tty_driver.h>
64 #include <linux/tty_flip.h>
65 #include <linux/module.h>
66 #include <linux/mutex.h>
67 #include <linux/uaccess.h>
68 #include <linux/usb.h>
69 #include <linux/usb/cdc.h>
70 #include <asm/byteorder.h>
71 #include <asm/unaligned.h>
72 #include <linux/list.h>
73 
74 #include "cdc-acm.h"
75 
76 
77 #define ACM_CLOSE_TIMEOUT	15	/* seconds to let writes drain */
78 
79 /*
80  * Version Information
81  */
82 #define DRIVER_VERSION "v0.26"
83 #define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek"
84 #define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
85 
86 static struct usb_driver acm_driver;
87 static struct tty_driver *acm_tty_driver;
88 static struct acm *acm_table[ACM_TTY_MINORS];
89 
90 static DEFINE_MUTEX(open_mutex);
91 
92 #define ACM_READY(acm)	(acm && acm->dev && acm->port.count)
93 
94 static const struct tty_port_operations acm_port_ops = {
95 };
96 
97 #ifdef VERBOSE_DEBUG
98 #define verbose	1
99 #else
100 #define verbose	0
101 #endif
102 
103 /*
104  * Functions for ACM control messages.
105  */
106 
107 static int acm_ctrl_msg(struct acm *acm, int request, int value,
108 							void *buf, int len)
109 {
110 	int retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
111 		request, USB_RT_ACM, value,
112 		acm->control->altsetting[0].desc.bInterfaceNumber,
113 		buf, len, 5000);
114 	dbg("acm_control_msg: rq: 0x%02x val: %#x len: %#x result: %d",
115 						request, value, len, retval);
116 	return retval < 0 ? retval : 0;
117 }
118 
119 /* devices aren't required to support these requests.
120  * the cdc acm descriptor tells whether they do...
121  */
122 #define acm_set_control(acm, control) \
123 	acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE, control, NULL, 0)
124 #define acm_set_line(acm, line) \
125 	acm_ctrl_msg(acm, USB_CDC_REQ_SET_LINE_CODING, 0, line, sizeof *(line))
126 #define acm_send_break(acm, ms) \
127 	acm_ctrl_msg(acm, USB_CDC_REQ_SEND_BREAK, ms, NULL, 0)
128 
129 /*
130  * Write buffer management.
131  * All of these assume proper locks taken by the caller.
132  */
133 
134 static int acm_wb_alloc(struct acm *acm)
135 {
136 	int i, wbn;
137 	struct acm_wb *wb;
138 
139 	wbn = 0;
140 	i = 0;
141 	for (;;) {
142 		wb = &acm->wb[wbn];
143 		if (!wb->use) {
144 			wb->use = 1;
145 			return wbn;
146 		}
147 		wbn = (wbn + 1) % ACM_NW;
148 		if (++i >= ACM_NW)
149 			return -1;
150 	}
151 }
152 
153 static int acm_wb_is_avail(struct acm *acm)
154 {
155 	int i, n;
156 	unsigned long flags;
157 
158 	n = ACM_NW;
159 	spin_lock_irqsave(&acm->write_lock, flags);
160 	for (i = 0; i < ACM_NW; i++)
161 		n -= acm->wb[i].use;
162 	spin_unlock_irqrestore(&acm->write_lock, flags);
163 	return n;
164 }
165 
166 /*
167  * Finish write. Caller must hold acm->write_lock
168  */
169 static void acm_write_done(struct acm *acm, struct acm_wb *wb)
170 {
171 	wb->use = 0;
172 	acm->transmitting--;
173 }
174 
175 /*
176  * Poke write.
177  *
178  * the caller is responsible for locking
179  */
180 
181 static int acm_start_wb(struct acm *acm, struct acm_wb *wb)
182 {
183 	int rc;
184 
185 	acm->transmitting++;
186 
187 	wb->urb->transfer_buffer = wb->buf;
188 	wb->urb->transfer_dma = wb->dmah;
189 	wb->urb->transfer_buffer_length = wb->len;
190 	wb->urb->dev = acm->dev;
191 
192 	rc = usb_submit_urb(wb->urb, GFP_ATOMIC);
193 	if (rc < 0) {
194 		dbg("usb_submit_urb(write bulk) failed: %d", rc);
195 		acm_write_done(acm, wb);
196 	}
197 	return rc;
198 }
199 
200 static int acm_write_start(struct acm *acm, int wbn)
201 {
202 	unsigned long flags;
203 	struct acm_wb *wb = &acm->wb[wbn];
204 	int rc;
205 
206 	spin_lock_irqsave(&acm->write_lock, flags);
207 	if (!acm->dev) {
208 		wb->use = 0;
209 		spin_unlock_irqrestore(&acm->write_lock, flags);
210 		return -ENODEV;
211 	}
212 
213 	dbg("%s susp_count: %d", __func__, acm->susp_count);
214 	if (acm->susp_count) {
215 		acm->delayed_wb = wb;
216 		schedule_work(&acm->waker);
217 		spin_unlock_irqrestore(&acm->write_lock, flags);
218 		return 0;	/* A white lie */
219 	}
220 	usb_mark_last_busy(acm->dev);
221 
222 	rc = acm_start_wb(acm, wb);
223 	spin_unlock_irqrestore(&acm->write_lock, flags);
224 
225 	return rc;
226 
227 }
228 /*
229  * attributes exported through sysfs
230  */
231 static ssize_t show_caps
232 (struct device *dev, struct device_attribute *attr, char *buf)
233 {
234 	struct usb_interface *intf = to_usb_interface(dev);
235 	struct acm *acm = usb_get_intfdata(intf);
236 
237 	return sprintf(buf, "%d", acm->ctrl_caps);
238 }
239 static DEVICE_ATTR(bmCapabilities, S_IRUGO, show_caps, NULL);
240 
241 static ssize_t show_country_codes
242 (struct device *dev, struct device_attribute *attr, char *buf)
243 {
244 	struct usb_interface *intf = to_usb_interface(dev);
245 	struct acm *acm = usb_get_intfdata(intf);
246 
247 	memcpy(buf, acm->country_codes, acm->country_code_size);
248 	return acm->country_code_size;
249 }
250 
251 static DEVICE_ATTR(wCountryCodes, S_IRUGO, show_country_codes, NULL);
252 
253 static ssize_t show_country_rel_date
254 (struct device *dev, struct device_attribute *attr, char *buf)
255 {
256 	struct usb_interface *intf = to_usb_interface(dev);
257 	struct acm *acm = usb_get_intfdata(intf);
258 
259 	return sprintf(buf, "%d", acm->country_rel_date);
260 }
261 
262 static DEVICE_ATTR(iCountryCodeRelDate, S_IRUGO, show_country_rel_date, NULL);
263 /*
264  * Interrupt handlers for various ACM device responses
265  */
266 
267 /* control interface reports status changes with "interrupt" transfers */
268 static void acm_ctrl_irq(struct urb *urb)
269 {
270 	struct acm *acm = urb->context;
271 	struct usb_cdc_notification *dr = urb->transfer_buffer;
272 	struct tty_struct *tty;
273 	unsigned char *data;
274 	int newctrl;
275 	int retval;
276 	int status = urb->status;
277 
278 	switch (status) {
279 	case 0:
280 		/* success */
281 		break;
282 	case -ECONNRESET:
283 	case -ENOENT:
284 	case -ESHUTDOWN:
285 		/* this urb is terminated, clean up */
286 		dbg("%s - urb shutting down with status: %d", __func__, status);
287 		return;
288 	default:
289 		dbg("%s - nonzero urb status received: %d", __func__, status);
290 		goto exit;
291 	}
292 
293 	if (!ACM_READY(acm))
294 		goto exit;
295 
296 	data = (unsigned char *)(dr + 1);
297 	switch (dr->bNotificationType) {
298 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
299 		dbg("%s network", dr->wValue ?
300 					"connected to" : "disconnected from");
301 		break;
302 
303 	case USB_CDC_NOTIFY_SERIAL_STATE:
304 		tty = tty_port_tty_get(&acm->port);
305 		newctrl = get_unaligned_le16(data);
306 
307 		if (tty) {
308 			if (!acm->clocal &&
309 				(acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
310 				dbg("calling hangup");
311 				tty_hangup(tty);
312 			}
313 			tty_kref_put(tty);
314 		}
315 
316 		acm->ctrlin = newctrl;
317 
318 		dbg("input control lines: dcd%c dsr%c break%c ring%c framing%c parity%c overrun%c",
319 			acm->ctrlin & ACM_CTRL_DCD ? '+' : '-',
320 			acm->ctrlin & ACM_CTRL_DSR ? '+' : '-',
321 			acm->ctrlin & ACM_CTRL_BRK ? '+' : '-',
322 			acm->ctrlin & ACM_CTRL_RI  ? '+' : '-',
323 			acm->ctrlin & ACM_CTRL_FRAMING ? '+' : '-',
324 			acm->ctrlin & ACM_CTRL_PARITY ? '+' : '-',
325 			acm->ctrlin & ACM_CTRL_OVERRUN ? '+' : '-');
326 			break;
327 
328 	default:
329 		dbg("unknown notification %d received: index %d len %d data0 %d data1 %d",
330 			dr->bNotificationType, dr->wIndex,
331 			dr->wLength, data[0], data[1]);
332 		break;
333 	}
334 exit:
335 	usb_mark_last_busy(acm->dev);
336 	retval = usb_submit_urb(urb, GFP_ATOMIC);
337 	if (retval)
338 		dev_err(&urb->dev->dev, "%s - usb_submit_urb failed with "
339 			"result %d", __func__, retval);
340 }
341 
342 /* data interface returns incoming bytes, or we got unthrottled */
343 static void acm_read_bulk(struct urb *urb)
344 {
345 	struct acm_rb *buf;
346 	struct acm_ru *rcv = urb->context;
347 	struct acm *acm = rcv->instance;
348 	int status = urb->status;
349 
350 	dbg("Entering acm_read_bulk with status %d", status);
351 
352 	if (!ACM_READY(acm)) {
353 		dev_dbg(&acm->data->dev, "Aborting, acm not ready");
354 		return;
355 	}
356 	usb_mark_last_busy(acm->dev);
357 
358 	if (status)
359 		dev_dbg(&acm->data->dev, "bulk rx status %d\n", status);
360 
361 	buf = rcv->buffer;
362 	buf->size = urb->actual_length;
363 
364 	if (likely(status == 0)) {
365 		spin_lock(&acm->read_lock);
366 		acm->processing++;
367 		list_add_tail(&rcv->list, &acm->spare_read_urbs);
368 		list_add_tail(&buf->list, &acm->filled_read_bufs);
369 		spin_unlock(&acm->read_lock);
370 	} else {
371 		/* we drop the buffer due to an error */
372 		spin_lock(&acm->read_lock);
373 		list_add_tail(&rcv->list, &acm->spare_read_urbs);
374 		list_add(&buf->list, &acm->spare_read_bufs);
375 		spin_unlock(&acm->read_lock);
376 		/* nevertheless the tasklet must be kicked unconditionally
377 		so the queue cannot dry up */
378 	}
379 	if (likely(!acm->susp_count))
380 		tasklet_schedule(&acm->urb_task);
381 }
382 
383 static void acm_rx_tasklet(unsigned long _acm)
384 {
385 	struct acm *acm = (void *)_acm;
386 	struct acm_rb *buf;
387 	struct tty_struct *tty;
388 	struct acm_ru *rcv;
389 	unsigned long flags;
390 	unsigned char throttled;
391 
392 	dbg("Entering acm_rx_tasklet");
393 
394 	if (!ACM_READY(acm)) {
395 		dbg("acm_rx_tasklet: ACM not ready");
396 		return;
397 	}
398 
399 	spin_lock_irqsave(&acm->throttle_lock, flags);
400 	throttled = acm->throttle;
401 	spin_unlock_irqrestore(&acm->throttle_lock, flags);
402 	if (throttled) {
403 		dbg("acm_rx_tasklet: throttled");
404 		return;
405 	}
406 
407 	tty = tty_port_tty_get(&acm->port);
408 
409 next_buffer:
410 	spin_lock_irqsave(&acm->read_lock, flags);
411 	if (list_empty(&acm->filled_read_bufs)) {
412 		spin_unlock_irqrestore(&acm->read_lock, flags);
413 		goto urbs;
414 	}
415 	buf = list_entry(acm->filled_read_bufs.next,
416 			 struct acm_rb, list);
417 	list_del(&buf->list);
418 	spin_unlock_irqrestore(&acm->read_lock, flags);
419 
420 	dbg("acm_rx_tasklet: procesing buf 0x%p, size = %d", buf, buf->size);
421 
422 	if (tty) {
423 		spin_lock_irqsave(&acm->throttle_lock, flags);
424 		throttled = acm->throttle;
425 		spin_unlock_irqrestore(&acm->throttle_lock, flags);
426 		if (!throttled) {
427 			tty_buffer_request_room(tty, buf->size);
428 			tty_insert_flip_string(tty, buf->base, buf->size);
429 			tty_flip_buffer_push(tty);
430 		} else {
431 			tty_kref_put(tty);
432 			dbg("Throttling noticed");
433 			spin_lock_irqsave(&acm->read_lock, flags);
434 			list_add(&buf->list, &acm->filled_read_bufs);
435 			spin_unlock_irqrestore(&acm->read_lock, flags);
436 			return;
437 		}
438 	}
439 
440 	spin_lock_irqsave(&acm->read_lock, flags);
441 	list_add(&buf->list, &acm->spare_read_bufs);
442 	spin_unlock_irqrestore(&acm->read_lock, flags);
443 	goto next_buffer;
444 
445 urbs:
446 	tty_kref_put(tty);
447 
448 	while (!list_empty(&acm->spare_read_bufs)) {
449 		spin_lock_irqsave(&acm->read_lock, flags);
450 		if (list_empty(&acm->spare_read_urbs)) {
451 			acm->processing = 0;
452 			spin_unlock_irqrestore(&acm->read_lock, flags);
453 			return;
454 		}
455 		rcv = list_entry(acm->spare_read_urbs.next,
456 				 struct acm_ru, list);
457 		list_del(&rcv->list);
458 		spin_unlock_irqrestore(&acm->read_lock, flags);
459 
460 		buf = list_entry(acm->spare_read_bufs.next,
461 				 struct acm_rb, list);
462 		list_del(&buf->list);
463 
464 		rcv->buffer = buf;
465 
466 		if (acm->is_int_ep)
467 			usb_fill_int_urb(rcv->urb, acm->dev,
468 					 acm->rx_endpoint,
469 					 buf->base,
470 					 acm->readsize,
471 					 acm_read_bulk, rcv, acm->bInterval);
472 		else
473 			usb_fill_bulk_urb(rcv->urb, acm->dev,
474 					  acm->rx_endpoint,
475 					  buf->base,
476 					  acm->readsize,
477 					  acm_read_bulk, rcv);
478 		rcv->urb->transfer_dma = buf->dma;
479 		rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
480 
481 		/* This shouldn't kill the driver as unsuccessful URBs are
482 		   returned to the free-urbs-pool and resubmited ASAP */
483 		spin_lock_irqsave(&acm->read_lock, flags);
484 		if (acm->susp_count ||
485 				usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
486 			list_add(&buf->list, &acm->spare_read_bufs);
487 			list_add(&rcv->list, &acm->spare_read_urbs);
488 			acm->processing = 0;
489 			spin_unlock_irqrestore(&acm->read_lock, flags);
490 			return;
491 		} else {
492 			spin_unlock_irqrestore(&acm->read_lock, flags);
493 			dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
494 		}
495 	}
496 	spin_lock_irqsave(&acm->read_lock, flags);
497 	acm->processing = 0;
498 	spin_unlock_irqrestore(&acm->read_lock, flags);
499 }
500 
501 /* data interface wrote those outgoing bytes */
502 static void acm_write_bulk(struct urb *urb)
503 {
504 	struct acm_wb *wb = urb->context;
505 	struct acm *acm = wb->instance;
506 	unsigned long flags;
507 
508 	if (verbose || urb->status
509 			|| (urb->actual_length != urb->transfer_buffer_length))
510 		dev_dbg(&acm->data->dev, "tx %d/%d bytes -- > %d\n",
511 			urb->actual_length,
512 			urb->transfer_buffer_length,
513 			urb->status);
514 
515 	spin_lock_irqsave(&acm->write_lock, flags);
516 	acm_write_done(acm, wb);
517 	spin_unlock_irqrestore(&acm->write_lock, flags);
518 	if (ACM_READY(acm))
519 		schedule_work(&acm->work);
520 	else
521 		wake_up_interruptible(&acm->drain_wait);
522 }
523 
524 static void acm_softint(struct work_struct *work)
525 {
526 	struct acm *acm = container_of(work, struct acm, work);
527 	struct tty_struct *tty;
528 
529 	dev_vdbg(&acm->data->dev, "tx work\n");
530 	if (!ACM_READY(acm))
531 		return;
532 	tty = tty_port_tty_get(&acm->port);
533 	tty_wakeup(tty);
534 	tty_kref_put(tty);
535 }
536 
537 static void acm_waker(struct work_struct *waker)
538 {
539 	struct acm *acm = container_of(waker, struct acm, waker);
540 	int rv;
541 
542 	rv = usb_autopm_get_interface(acm->control);
543 	if (rv < 0) {
544 		dev_err(&acm->dev->dev, "Autopm failure in %s\n", __func__);
545 		return;
546 	}
547 	if (acm->delayed_wb) {
548 		acm_start_wb(acm, acm->delayed_wb);
549 		acm->delayed_wb = NULL;
550 	}
551 	usb_autopm_put_interface(acm->control);
552 }
553 
554 /*
555  * TTY handlers
556  */
557 
558 static int acm_tty_open(struct tty_struct *tty, struct file *filp)
559 {
560 	struct acm *acm;
561 	int rv = -ENODEV;
562 	int i;
563 	dbg("Entering acm_tty_open.");
564 
565 	mutex_lock(&open_mutex);
566 
567 	acm = acm_table[tty->index];
568 	if (!acm || !acm->dev)
569 		goto err_out;
570 	else
571 		rv = 0;
572 
573 	set_bit(TTY_NO_WRITE_SPLIT, &tty->flags);
574 
575 	tty->driver_data = acm;
576 	tty_port_tty_set(&acm->port, tty);
577 
578 	if (usb_autopm_get_interface(acm->control) < 0)
579 		goto early_bail;
580 	else
581 		acm->control->needs_remote_wakeup = 1;
582 
583 	mutex_lock(&acm->mutex);
584 	if (acm->port.count++) {
585 		usb_autopm_put_interface(acm->control);
586 		goto done;
587 	}
588 
589 	acm->ctrlurb->dev = acm->dev;
590 	if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
591 		dbg("usb_submit_urb(ctrl irq) failed");
592 		goto bail_out;
593 	}
594 
595 	if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS) &&
596 	    (acm->ctrl_caps & USB_CDC_CAP_LINE))
597 		goto full_bailout;
598 
599 	usb_autopm_put_interface(acm->control);
600 
601 	INIT_LIST_HEAD(&acm->spare_read_urbs);
602 	INIT_LIST_HEAD(&acm->spare_read_bufs);
603 	INIT_LIST_HEAD(&acm->filled_read_bufs);
604 
605 	for (i = 0; i < acm->rx_buflimit; i++)
606 		list_add(&(acm->ru[i].list), &acm->spare_read_urbs);
607 	for (i = 0; i < acm->rx_buflimit; i++)
608 		list_add(&(acm->rb[i].list), &acm->spare_read_bufs);
609 
610 	acm->throttle = 0;
611 
612 	tasklet_schedule(&acm->urb_task);
613 	set_bit(ASYNCB_INITIALIZED, &acm->port.flags);
614 	rv = tty_port_block_til_ready(&acm->port, tty, filp);
615 done:
616 	mutex_unlock(&acm->mutex);
617 err_out:
618 	mutex_unlock(&open_mutex);
619 	return rv;
620 
621 full_bailout:
622 	usb_kill_urb(acm->ctrlurb);
623 bail_out:
624 	usb_autopm_put_interface(acm->control);
625 	acm->port.count--;
626 	mutex_unlock(&acm->mutex);
627 early_bail:
628 	mutex_unlock(&open_mutex);
629 	tty_port_tty_set(&acm->port, NULL);
630 	return -EIO;
631 }
632 
633 static void acm_tty_unregister(struct acm *acm)
634 {
635 	int i, nr;
636 
637 	nr = acm->rx_buflimit;
638 	tty_unregister_device(acm_tty_driver, acm->minor);
639 	usb_put_intf(acm->control);
640 	acm_table[acm->minor] = NULL;
641 	usb_free_urb(acm->ctrlurb);
642 	for (i = 0; i < ACM_NW; i++)
643 		usb_free_urb(acm->wb[i].urb);
644 	for (i = 0; i < nr; i++)
645 		usb_free_urb(acm->ru[i].urb);
646 	kfree(acm->country_codes);
647 	kfree(acm);
648 }
649 
650 static int acm_tty_chars_in_buffer(struct tty_struct *tty);
651 
652 static void acm_port_down(struct acm *acm, int drain)
653 {
654 	int i, nr = acm->rx_buflimit;
655 	mutex_lock(&open_mutex);
656 	if (acm->dev) {
657 		usb_autopm_get_interface(acm->control);
658 		acm_set_control(acm, acm->ctrlout = 0);
659 		/* try letting the last writes drain naturally */
660 		if (drain) {
661 			wait_event_interruptible_timeout(acm->drain_wait,
662 				(ACM_NW == acm_wb_is_avail(acm)) || !acm->dev,
663 					ACM_CLOSE_TIMEOUT * HZ);
664 		}
665 		usb_kill_urb(acm->ctrlurb);
666 		for (i = 0; i < ACM_NW; i++)
667 			usb_kill_urb(acm->wb[i].urb);
668 		for (i = 0; i < nr; i++)
669 			usb_kill_urb(acm->ru[i].urb);
670 		acm->control->needs_remote_wakeup = 0;
671 		usb_autopm_put_interface(acm->control);
672 	}
673 	mutex_unlock(&open_mutex);
674 }
675 
676 static void acm_tty_hangup(struct tty_struct *tty)
677 {
678 	struct acm *acm = tty->driver_data;
679 	tty_port_hangup(&acm->port);
680 	acm_port_down(acm, 0);
681 }
682 
683 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
684 {
685 	struct acm *acm = tty->driver_data;
686 
687 	/* Perform the closing process and see if we need to do the hardware
688 	   shutdown */
689 	if (!acm || tty_port_close_start(&acm->port, tty, filp) == 0)
690 		return;
691 	acm_port_down(acm, 0);
692 	tty_port_close_end(&acm->port, tty);
693 	mutex_lock(&open_mutex);
694 	tty_port_tty_set(&acm->port, NULL);
695 	if (!acm->dev)
696 		acm_tty_unregister(acm);
697 	mutex_unlock(&open_mutex);
698 }
699 
700 static int acm_tty_write(struct tty_struct *tty,
701 					const unsigned char *buf, int count)
702 {
703 	struct acm *acm = tty->driver_data;
704 	int stat;
705 	unsigned long flags;
706 	int wbn;
707 	struct acm_wb *wb;
708 
709 	dbg("Entering acm_tty_write to write %d bytes,", count);
710 
711 	if (!ACM_READY(acm))
712 		return -EINVAL;
713 	if (!count)
714 		return 0;
715 
716 	spin_lock_irqsave(&acm->write_lock, flags);
717 	wbn = acm_wb_alloc(acm);
718 	if (wbn < 0) {
719 		spin_unlock_irqrestore(&acm->write_lock, flags);
720 		return 0;
721 	}
722 	wb = &acm->wb[wbn];
723 
724 	count = (count > acm->writesize) ? acm->writesize : count;
725 	dbg("Get %d bytes...", count);
726 	memcpy(wb->buf, buf, count);
727 	wb->len = count;
728 	spin_unlock_irqrestore(&acm->write_lock, flags);
729 
730 	stat = acm_write_start(acm, wbn);
731 	if (stat < 0)
732 		return stat;
733 	return count;
734 }
735 
736 static int acm_tty_write_room(struct tty_struct *tty)
737 {
738 	struct acm *acm = tty->driver_data;
739 	if (!ACM_READY(acm))
740 		return -EINVAL;
741 	/*
742 	 * Do not let the line discipline to know that we have a reserve,
743 	 * or it might get too enthusiastic.
744 	 */
745 	return acm_wb_is_avail(acm) ? acm->writesize : 0;
746 }
747 
748 static int acm_tty_chars_in_buffer(struct tty_struct *tty)
749 {
750 	struct acm *acm = tty->driver_data;
751 	if (!ACM_READY(acm))
752 		return 0;
753 	/*
754 	 * This is inaccurate (overcounts), but it works.
755 	 */
756 	return (ACM_NW - acm_wb_is_avail(acm)) * acm->writesize;
757 }
758 
759 static void acm_tty_throttle(struct tty_struct *tty)
760 {
761 	struct acm *acm = tty->driver_data;
762 	if (!ACM_READY(acm))
763 		return;
764 	spin_lock_bh(&acm->throttle_lock);
765 	acm->throttle = 1;
766 	spin_unlock_bh(&acm->throttle_lock);
767 }
768 
769 static void acm_tty_unthrottle(struct tty_struct *tty)
770 {
771 	struct acm *acm = tty->driver_data;
772 	if (!ACM_READY(acm))
773 		return;
774 	spin_lock_bh(&acm->throttle_lock);
775 	acm->throttle = 0;
776 	spin_unlock_bh(&acm->throttle_lock);
777 	tasklet_schedule(&acm->urb_task);
778 }
779 
780 static int acm_tty_break_ctl(struct tty_struct *tty, int state)
781 {
782 	struct acm *acm = tty->driver_data;
783 	int retval;
784 	if (!ACM_READY(acm))
785 		return -EINVAL;
786 	retval = acm_send_break(acm, state ? 0xffff : 0);
787 	if (retval < 0)
788 		dbg("send break failed");
789 	return retval;
790 }
791 
792 static int acm_tty_tiocmget(struct tty_struct *tty, struct file *file)
793 {
794 	struct acm *acm = tty->driver_data;
795 
796 	if (!ACM_READY(acm))
797 		return -EINVAL;
798 
799 	return (acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
800 	       (acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
801 	       (acm->ctrlin  & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
802 	       (acm->ctrlin  & ACM_CTRL_RI  ? TIOCM_RI  : 0) |
803 	       (acm->ctrlin  & ACM_CTRL_DCD ? TIOCM_CD  : 0) |
804 	       TIOCM_CTS;
805 }
806 
807 static int acm_tty_tiocmset(struct tty_struct *tty, struct file *file,
808 			    unsigned int set, unsigned int clear)
809 {
810 	struct acm *acm = tty->driver_data;
811 	unsigned int newctrl;
812 
813 	if (!ACM_READY(acm))
814 		return -EINVAL;
815 
816 	newctrl = acm->ctrlout;
817 	set = (set & TIOCM_DTR ? ACM_CTRL_DTR : 0) |
818 					(set & TIOCM_RTS ? ACM_CTRL_RTS : 0);
819 	clear = (clear & TIOCM_DTR ? ACM_CTRL_DTR : 0) |
820 					(clear & TIOCM_RTS ? ACM_CTRL_RTS : 0);
821 
822 	newctrl = (newctrl & ~clear) | set;
823 
824 	if (acm->ctrlout == newctrl)
825 		return 0;
826 	return acm_set_control(acm, acm->ctrlout = newctrl);
827 }
828 
829 static int acm_tty_ioctl(struct tty_struct *tty, struct file *file,
830 					unsigned int cmd, unsigned long arg)
831 {
832 	struct acm *acm = tty->driver_data;
833 
834 	if (!ACM_READY(acm))
835 		return -EINVAL;
836 
837 	return -ENOIOCTLCMD;
838 }
839 
840 static const __u32 acm_tty_speed[] = {
841 	0, 50, 75, 110, 134, 150, 200, 300, 600,
842 	1200, 1800, 2400, 4800, 9600, 19200, 38400,
843 	57600, 115200, 230400, 460800, 500000, 576000,
844 	921600, 1000000, 1152000, 1500000, 2000000,
845 	2500000, 3000000, 3500000, 4000000
846 };
847 
848 static const __u8 acm_tty_size[] = {
849 	5, 6, 7, 8
850 };
851 
852 static void acm_tty_set_termios(struct tty_struct *tty,
853 						struct ktermios *termios_old)
854 {
855 	struct acm *acm = tty->driver_data;
856 	struct ktermios *termios = tty->termios;
857 	struct usb_cdc_line_coding newline;
858 	int newctrl = acm->ctrlout;
859 
860 	if (!ACM_READY(acm))
861 		return;
862 
863 	newline.dwDTERate = cpu_to_le32(tty_get_baud_rate(tty));
864 	newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
865 	newline.bParityType = termios->c_cflag & PARENB ?
866 				(termios->c_cflag & PARODD ? 1 : 2) +
867 				(termios->c_cflag & CMSPAR ? 2 : 0) : 0;
868 	newline.bDataBits = acm_tty_size[(termios->c_cflag & CSIZE) >> 4];
869 	/* FIXME: Needs to clear unsupported bits in the termios */
870 	acm->clocal = ((termios->c_cflag & CLOCAL) != 0);
871 
872 	if (!newline.dwDTERate) {
873 		newline.dwDTERate = acm->line.dwDTERate;
874 		newctrl &= ~ACM_CTRL_DTR;
875 	} else
876 		newctrl |=  ACM_CTRL_DTR;
877 
878 	if (newctrl != acm->ctrlout)
879 		acm_set_control(acm, acm->ctrlout = newctrl);
880 
881 	if (memcmp(&acm->line, &newline, sizeof newline)) {
882 		memcpy(&acm->line, &newline, sizeof newline);
883 		dbg("set line: %d %d %d %d", le32_to_cpu(newline.dwDTERate),
884 			newline.bCharFormat, newline.bParityType,
885 			newline.bDataBits);
886 		acm_set_line(acm, &acm->line);
887 	}
888 }
889 
890 /*
891  * USB probe and disconnect routines.
892  */
893 
894 /* Little helpers: write/read buffers free */
895 static void acm_write_buffers_free(struct acm *acm)
896 {
897 	int i;
898 	struct acm_wb *wb;
899 	struct usb_device *usb_dev = interface_to_usbdev(acm->control);
900 
901 	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++)
902 		usb_buffer_free(usb_dev, acm->writesize, wb->buf, wb->dmah);
903 }
904 
905 static void acm_read_buffers_free(struct acm *acm)
906 {
907 	struct usb_device *usb_dev = interface_to_usbdev(acm->control);
908 	int i, n = acm->rx_buflimit;
909 
910 	for (i = 0; i < n; i++)
911 		usb_buffer_free(usb_dev, acm->readsize,
912 					acm->rb[i].base, acm->rb[i].dma);
913 }
914 
915 /* Little helper: write buffers allocate */
916 static int acm_write_buffers_alloc(struct acm *acm)
917 {
918 	int i;
919 	struct acm_wb *wb;
920 
921 	for (wb = &acm->wb[0], i = 0; i < ACM_NW; i++, wb++) {
922 		wb->buf = usb_buffer_alloc(acm->dev, acm->writesize, GFP_KERNEL,
923 		    &wb->dmah);
924 		if (!wb->buf) {
925 			while (i != 0) {
926 				--i;
927 				--wb;
928 				usb_buffer_free(acm->dev, acm->writesize,
929 				    wb->buf, wb->dmah);
930 			}
931 			return -ENOMEM;
932 		}
933 	}
934 	return 0;
935 }
936 
937 static int acm_probe(struct usb_interface *intf,
938 		     const struct usb_device_id *id)
939 {
940 	struct usb_cdc_union_desc *union_header = NULL;
941 	struct usb_cdc_country_functional_desc *cfd = NULL;
942 	unsigned char *buffer = intf->altsetting->extra;
943 	int buflen = intf->altsetting->extralen;
944 	struct usb_interface *control_interface;
945 	struct usb_interface *data_interface;
946 	struct usb_endpoint_descriptor *epctrl = NULL;
947 	struct usb_endpoint_descriptor *epread = NULL;
948 	struct usb_endpoint_descriptor *epwrite = NULL;
949 	struct usb_device *usb_dev = interface_to_usbdev(intf);
950 	struct acm *acm;
951 	int minor;
952 	int ctrlsize, readsize;
953 	u8 *buf;
954 	u8 ac_management_function = 0;
955 	u8 call_management_function = 0;
956 	int call_interface_num = -1;
957 	int data_interface_num;
958 	unsigned long quirks;
959 	int num_rx_buf;
960 	int i;
961 	int combined_interfaces = 0;
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->extralen &&
982 				intf->cur_altsetting->endpoint->extra) {
983 			dev_dbg(&intf->dev,
984 				"Seeking extra descriptors on endpoint\n");
985 			buflen = intf->cur_altsetting->endpoint->extralen;
986 			buffer = intf->cur_altsetting->endpoint->extra;
987 		} else {
988 			dev_err(&intf->dev,
989 				"Zero length descriptor references\n");
990 			return -EINVAL;
991 		}
992 	}
993 
994 	while (buflen > 0) {
995 		if (buffer[1] != USB_DT_CS_INTERFACE) {
996 			dev_err(&intf->dev, "skipping garbage\n");
997 			goto next_desc;
998 		}
999 
1000 		switch (buffer[2]) {
1001 		case USB_CDC_UNION_TYPE: /* we've found it */
1002 			if (union_header) {
1003 				dev_err(&intf->dev, "More than one "
1004 					"union descriptor, skipping ...\n");
1005 				goto next_desc;
1006 			}
1007 			union_header = (struct usb_cdc_union_desc *)buffer;
1008 			break;
1009 		case USB_CDC_COUNTRY_TYPE: /* export through sysfs*/
1010 			cfd = (struct usb_cdc_country_functional_desc *)buffer;
1011 			break;
1012 		case USB_CDC_HEADER_TYPE: /* maybe check version */
1013 			break; /* for now we ignore it */
1014 		case USB_CDC_ACM_TYPE:
1015 			ac_management_function = buffer[3];
1016 			break;
1017 		case USB_CDC_CALL_MANAGEMENT_TYPE:
1018 			call_management_function = buffer[3];
1019 			call_interface_num = buffer[4];
1020 			if ((call_management_function & 3) != 3)
1021 				dev_err(&intf->dev, "This device cannot do calls on its own. It is not a modem.\n");
1022 			break;
1023 		default:
1024 			/* there are LOTS more CDC descriptors that
1025 			 * could legitimately be found here.
1026 			 */
1027 			dev_dbg(&intf->dev, "Ignoring descriptor: "
1028 					"type %02x, length %d\n",
1029 					buffer[2], buffer[0]);
1030 			break;
1031 		}
1032 next_desc:
1033 		buflen -= buffer[0];
1034 		buffer += buffer[0];
1035 	}
1036 
1037 	if (!union_header) {
1038 		if (call_interface_num > 0) {
1039 			dev_dbg(&intf->dev, "No union descriptor, using call management descriptor\n");
1040 			data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
1041 			control_interface = intf;
1042 		} else {
1043 			if (intf->cur_altsetting->desc.bNumEndpoints != 3) {
1044 				dev_dbg(&intf->dev,"No union descriptor, giving up\n");
1045 				return -ENODEV;
1046 			} else {
1047 				dev_warn(&intf->dev,"No union descriptor, testing for castrated device\n");
1048 				combined_interfaces = 1;
1049 				control_interface = data_interface = intf;
1050 				goto look_for_collapsed_interface;
1051 			}
1052 		}
1053 	} else {
1054 		control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
1055 		data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
1056 		if (!control_interface || !data_interface) {
1057 			dev_dbg(&intf->dev, "no interfaces\n");
1058 			return -ENODEV;
1059 		}
1060 	}
1061 
1062 	if (data_interface_num != call_interface_num)
1063 		dev_dbg(&intf->dev, "Separate call control interface. That is not fully supported.\n");
1064 
1065 	if (control_interface == data_interface) {
1066 		/* some broken devices designed for windows work this way */
1067 		dev_warn(&intf->dev,"Control and data interfaces are not separated!\n");
1068 		combined_interfaces = 1;
1069 		/* a popular other OS doesn't use it */
1070 		quirks |= NO_CAP_LINE;
1071 		if (data_interface->cur_altsetting->desc.bNumEndpoints != 3) {
1072 			dev_err(&intf->dev, "This needs exactly 3 endpoints\n");
1073 			return -EINVAL;
1074 		}
1075 look_for_collapsed_interface:
1076 		for (i = 0; i < 3; i++) {
1077 			struct usb_endpoint_descriptor *ep;
1078 			ep = &data_interface->cur_altsetting->endpoint[i].desc;
1079 
1080 			if (usb_endpoint_is_int_in(ep))
1081 				epctrl = ep;
1082 			else if (usb_endpoint_is_bulk_out(ep))
1083 				epwrite = ep;
1084 			else if (usb_endpoint_is_bulk_in(ep))
1085 				epread = ep;
1086 			else
1087 				return -EINVAL;
1088 		}
1089 		if (!epctrl || !epread || !epwrite)
1090 			return -ENODEV;
1091 		else
1092 			goto made_compressed_probe;
1093 	}
1094 
1095 skip_normal_probe:
1096 
1097 	/*workaround for switched interfaces */
1098 	if (data_interface->cur_altsetting->desc.bInterfaceClass
1099 						!= CDC_DATA_INTERFACE_TYPE) {
1100 		if (control_interface->cur_altsetting->desc.bInterfaceClass
1101 						== CDC_DATA_INTERFACE_TYPE) {
1102 			struct usb_interface *t;
1103 			dev_dbg(&intf->dev,
1104 				"Your device has switched interfaces.\n");
1105 			t = control_interface;
1106 			control_interface = data_interface;
1107 			data_interface = t;
1108 		} else {
1109 			return -EINVAL;
1110 		}
1111 	}
1112 
1113 	/* Accept probe requests only for the control interface */
1114 	if (!combined_interfaces && intf != control_interface)
1115 		return -ENODEV;
1116 
1117 	if (!combined_interfaces && usb_interface_claimed(data_interface)) {
1118 		/* valid in this context */
1119 		dev_dbg(&intf->dev, "The data interface isn't available\n");
1120 		return -EBUSY;
1121 	}
1122 
1123 
1124 	if (data_interface->cur_altsetting->desc.bNumEndpoints < 2)
1125 		return -EINVAL;
1126 
1127 	epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
1128 	epread = &data_interface->cur_altsetting->endpoint[0].desc;
1129 	epwrite = &data_interface->cur_altsetting->endpoint[1].desc;
1130 
1131 
1132 	/* workaround for switched endpoints */
1133 	if (!usb_endpoint_dir_in(epread)) {
1134 		/* descriptors are swapped */
1135 		struct usb_endpoint_descriptor *t;
1136 		dev_dbg(&intf->dev,
1137 			"The data interface has switched endpoints\n");
1138 		t = epread;
1139 		epread = epwrite;
1140 		epwrite = t;
1141 	}
1142 made_compressed_probe:
1143 	dbg("interfaces are valid");
1144 	for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);
1145 
1146 	if (minor == ACM_TTY_MINORS) {
1147 		dev_err(&intf->dev, "no more free acm devices\n");
1148 		return -ENODEV;
1149 	}
1150 
1151 	acm = kzalloc(sizeof(struct acm), GFP_KERNEL);
1152 	if (acm == NULL) {
1153 		dev_dbg(&intf->dev, "out of memory (acm kzalloc)\n");
1154 		goto alloc_fail;
1155 	}
1156 
1157 	ctrlsize = le16_to_cpu(epctrl->wMaxPacketSize);
1158 	readsize = le16_to_cpu(epread->wMaxPacketSize) *
1159 				(quirks == SINGLE_RX_URB ? 1 : 2);
1160 	acm->combined_interfaces = combined_interfaces;
1161 	acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize) * 20;
1162 	acm->control = control_interface;
1163 	acm->data = data_interface;
1164 	acm->minor = minor;
1165 	acm->dev = usb_dev;
1166 	acm->ctrl_caps = ac_management_function;
1167 	if (quirks & NO_CAP_LINE)
1168 		acm->ctrl_caps &= ~USB_CDC_CAP_LINE;
1169 	acm->ctrlsize = ctrlsize;
1170 	acm->readsize = readsize;
1171 	acm->rx_buflimit = num_rx_buf;
1172 	acm->urb_task.func = acm_rx_tasklet;
1173 	acm->urb_task.data = (unsigned long) acm;
1174 	INIT_WORK(&acm->work, acm_softint);
1175 	INIT_WORK(&acm->waker, acm_waker);
1176 	init_waitqueue_head(&acm->drain_wait);
1177 	spin_lock_init(&acm->throttle_lock);
1178 	spin_lock_init(&acm->write_lock);
1179 	spin_lock_init(&acm->read_lock);
1180 	mutex_init(&acm->mutex);
1181 	acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
1182 	acm->is_int_ep = usb_endpoint_xfer_int(epread);
1183 	if (acm->is_int_ep)
1184 		acm->bInterval = epread->bInterval;
1185 	tty_port_init(&acm->port);
1186 	acm->port.ops = &acm_port_ops;
1187 
1188 	buf = usb_buffer_alloc(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
1189 	if (!buf) {
1190 		dev_dbg(&intf->dev, "out of memory (ctrl buffer alloc)\n");
1191 		goto alloc_fail2;
1192 	}
1193 	acm->ctrl_buffer = buf;
1194 
1195 	if (acm_write_buffers_alloc(acm) < 0) {
1196 		dev_dbg(&intf->dev, "out of memory (write buffer alloc)\n");
1197 		goto alloc_fail4;
1198 	}
1199 
1200 	acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
1201 	if (!acm->ctrlurb) {
1202 		dev_dbg(&intf->dev, "out of memory (ctrlurb kmalloc)\n");
1203 		goto alloc_fail5;
1204 	}
1205 	for (i = 0; i < num_rx_buf; i++) {
1206 		struct acm_ru *rcv = &(acm->ru[i]);
1207 
1208 		rcv->urb = usb_alloc_urb(0, GFP_KERNEL);
1209 		if (rcv->urb == NULL) {
1210 			dev_dbg(&intf->dev,
1211 				"out of memory (read urbs usb_alloc_urb)\n");
1212 			goto alloc_fail7;
1213 		}
1214 
1215 		rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1216 		rcv->instance = acm;
1217 	}
1218 	for (i = 0; i < num_rx_buf; i++) {
1219 		struct acm_rb *rb = &(acm->rb[i]);
1220 
1221 		rb->base = usb_buffer_alloc(acm->dev, readsize,
1222 				GFP_KERNEL, &rb->dma);
1223 		if (!rb->base) {
1224 			dev_dbg(&intf->dev,
1225 				"out of memory (read bufs usb_buffer_alloc)\n");
1226 			goto alloc_fail7;
1227 		}
1228 	}
1229 	for (i = 0; i < ACM_NW; i++) {
1230 		struct acm_wb *snd = &(acm->wb[i]);
1231 
1232 		snd->urb = usb_alloc_urb(0, GFP_KERNEL);
1233 		if (snd->urb == NULL) {
1234 			dev_dbg(&intf->dev,
1235 				"out of memory (write urbs usb_alloc_urb)");
1236 			goto alloc_fail7;
1237 		}
1238 
1239 		if (usb_endpoint_xfer_int(epwrite))
1240 			usb_fill_int_urb(snd->urb, usb_dev,
1241 				usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
1242 				NULL, acm->writesize, acm_write_bulk, snd, epwrite->bInterval);
1243 		else
1244 			usb_fill_bulk_urb(snd->urb, usb_dev,
1245 				usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
1246 				NULL, acm->writesize, acm_write_bulk, snd);
1247 		snd->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1248 		snd->instance = acm;
1249 	}
1250 
1251 	usb_set_intfdata(intf, acm);
1252 
1253 	i = device_create_file(&intf->dev, &dev_attr_bmCapabilities);
1254 	if (i < 0)
1255 		goto alloc_fail8;
1256 
1257 	if (cfd) { /* export the country data */
1258 		acm->country_codes = kmalloc(cfd->bLength - 4, GFP_KERNEL);
1259 		if (!acm->country_codes)
1260 			goto skip_countries;
1261 		acm->country_code_size = cfd->bLength - 4;
1262 		memcpy(acm->country_codes, (u8 *)&cfd->wCountyCode0,
1263 							cfd->bLength - 4);
1264 		acm->country_rel_date = cfd->iCountryCodeRelDate;
1265 
1266 		i = device_create_file(&intf->dev, &dev_attr_wCountryCodes);
1267 		if (i < 0) {
1268 			kfree(acm->country_codes);
1269 			goto skip_countries;
1270 		}
1271 
1272 		i = device_create_file(&intf->dev,
1273 						&dev_attr_iCountryCodeRelDate);
1274 		if (i < 0) {
1275 			kfree(acm->country_codes);
1276 			goto skip_countries;
1277 		}
1278 	}
1279 
1280 skip_countries:
1281 	usb_fill_int_urb(acm->ctrlurb, usb_dev,
1282 			 usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
1283 			 acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm,
1284 			 /* works around buggy devices */
1285 			 epctrl->bInterval ? epctrl->bInterval : 0xff);
1286 	acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
1287 	acm->ctrlurb->transfer_dma = acm->ctrl_dma;
1288 
1289 	dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
1290 
1291 	acm_set_control(acm, acm->ctrlout);
1292 
1293 	acm->line.dwDTERate = cpu_to_le32(9600);
1294 	acm->line.bDataBits = 8;
1295 	acm_set_line(acm, &acm->line);
1296 
1297 	usb_driver_claim_interface(&acm_driver, data_interface, acm);
1298 	usb_set_intfdata(data_interface, acm);
1299 
1300 	usb_get_intf(control_interface);
1301 	tty_register_device(acm_tty_driver, minor, &control_interface->dev);
1302 
1303 	acm_table[minor] = acm;
1304 
1305 	return 0;
1306 alloc_fail8:
1307 	for (i = 0; i < ACM_NW; i++)
1308 		usb_free_urb(acm->wb[i].urb);
1309 alloc_fail7:
1310 	acm_read_buffers_free(acm);
1311 	for (i = 0; i < num_rx_buf; i++)
1312 		usb_free_urb(acm->ru[i].urb);
1313 	usb_free_urb(acm->ctrlurb);
1314 alloc_fail5:
1315 	acm_write_buffers_free(acm);
1316 alloc_fail4:
1317 	usb_buffer_free(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1318 alloc_fail2:
1319 	kfree(acm);
1320 alloc_fail:
1321 	return -ENOMEM;
1322 }
1323 
1324 static void stop_data_traffic(struct acm *acm)
1325 {
1326 	int i;
1327 	dbg("Entering stop_data_traffic");
1328 
1329 	tasklet_disable(&acm->urb_task);
1330 
1331 	usb_kill_urb(acm->ctrlurb);
1332 	for (i = 0; i < ACM_NW; i++)
1333 		usb_kill_urb(acm->wb[i].urb);
1334 	for (i = 0; i < acm->rx_buflimit; i++)
1335 		usb_kill_urb(acm->ru[i].urb);
1336 
1337 	tasklet_enable(&acm->urb_task);
1338 
1339 	cancel_work_sync(&acm->work);
1340 	cancel_work_sync(&acm->waker);
1341 }
1342 
1343 static void acm_disconnect(struct usb_interface *intf)
1344 {
1345 	struct acm *acm = usb_get_intfdata(intf);
1346 	struct usb_device *usb_dev = interface_to_usbdev(intf);
1347 	struct tty_struct *tty;
1348 
1349 	/* sibling interface is already cleaning up */
1350 	if (!acm)
1351 		return;
1352 
1353 	mutex_lock(&open_mutex);
1354 	if (acm->country_codes) {
1355 		device_remove_file(&acm->control->dev,
1356 				&dev_attr_wCountryCodes);
1357 		device_remove_file(&acm->control->dev,
1358 				&dev_attr_iCountryCodeRelDate);
1359 	}
1360 	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
1361 	acm->dev = NULL;
1362 	usb_set_intfdata(acm->control, NULL);
1363 	usb_set_intfdata(acm->data, NULL);
1364 
1365 	stop_data_traffic(acm);
1366 
1367 	acm_write_buffers_free(acm);
1368 	usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer,
1369 								acm->ctrl_dma);
1370 	acm_read_buffers_free(acm);
1371 
1372 	if (!acm->combined_interfaces)
1373 		usb_driver_release_interface(&acm_driver, intf == acm->control ?
1374 					acm->data : acm->control);
1375 
1376 	if (acm->port.count == 0) {
1377 		acm_tty_unregister(acm);
1378 		mutex_unlock(&open_mutex);
1379 		return;
1380 	}
1381 
1382 	mutex_unlock(&open_mutex);
1383 	tty = tty_port_tty_get(&acm->port);
1384 	if (tty) {
1385 		tty_hangup(tty);
1386 		tty_kref_put(tty);
1387 	}
1388 }
1389 
1390 #ifdef CONFIG_PM
1391 static int acm_suspend(struct usb_interface *intf, pm_message_t message)
1392 {
1393 	struct acm *acm = usb_get_intfdata(intf);
1394 	int cnt;
1395 
1396 	if (message.event & PM_EVENT_AUTO) {
1397 		int b;
1398 
1399 		spin_lock_irq(&acm->read_lock);
1400 		spin_lock(&acm->write_lock);
1401 		b = acm->processing + acm->transmitting;
1402 		spin_unlock(&acm->write_lock);
1403 		spin_unlock_irq(&acm->read_lock);
1404 		if (b)
1405 			return -EBUSY;
1406 	}
1407 
1408 	spin_lock_irq(&acm->read_lock);
1409 	spin_lock(&acm->write_lock);
1410 	cnt = acm->susp_count++;
1411 	spin_unlock(&acm->write_lock);
1412 	spin_unlock_irq(&acm->read_lock);
1413 
1414 	if (cnt)
1415 		return 0;
1416 	/*
1417 	we treat opened interfaces differently,
1418 	we must guard against open
1419 	*/
1420 	mutex_lock(&acm->mutex);
1421 
1422 	if (acm->port.count)
1423 		stop_data_traffic(acm);
1424 
1425 	mutex_unlock(&acm->mutex);
1426 	return 0;
1427 }
1428 
1429 static int acm_resume(struct usb_interface *intf)
1430 {
1431 	struct acm *acm = usb_get_intfdata(intf);
1432 	int rv = 0;
1433 	int cnt;
1434 
1435 	spin_lock_irq(&acm->read_lock);
1436 	acm->susp_count -= 1;
1437 	cnt = acm->susp_count;
1438 	spin_unlock_irq(&acm->read_lock);
1439 
1440 	if (cnt)
1441 		return 0;
1442 
1443 	mutex_lock(&acm->mutex);
1444 	if (acm->port.count) {
1445 		rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);
1446 		if (rv < 0)
1447 			goto err_out;
1448 
1449 		tasklet_schedule(&acm->urb_task);
1450 	}
1451 
1452 err_out:
1453 	mutex_unlock(&acm->mutex);
1454 	return rv;
1455 }
1456 
1457 #endif /* CONFIG_PM */
1458 /*
1459  * USB driver structure.
1460  */
1461 
1462 static struct usb_device_id acm_ids[] = {
1463 	/* quirky and broken devices */
1464 	{ USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
1465 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1466 	},
1467 	{ USB_DEVICE(0x0e8d, 0x0003), /* FIREFLY, MediaTek Inc; andrey.arapov@gmail.com */
1468 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1469 	},
1470 	{ USB_DEVICE(0x0e8d, 0x3329), /* MediaTek Inc GPS */
1471 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1472 	},
1473 	{ USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
1474 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1475 	},
1476 	{ USB_DEVICE(0x079b, 0x000f), /* BT On-Air USB MODEM */
1477 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1478 	},
1479 	{ USB_DEVICE(0x0ace, 0x1602), /* ZyDAS 56K USB MODEM */
1480 	.driver_info = SINGLE_RX_URB,
1481 	},
1482 	{ USB_DEVICE(0x0ace, 0x1608), /* ZyDAS 56K USB MODEM */
1483 	.driver_info = SINGLE_RX_URB, /* firmware bug */
1484 	},
1485 	{ USB_DEVICE(0x0ace, 0x1611), /* ZyDAS 56K USB MODEM - new version */
1486 	.driver_info = SINGLE_RX_URB, /* firmware bug */
1487 	},
1488 	{ USB_DEVICE(0x22b8, 0x7000), /* Motorola Q Phone */
1489 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1490 	},
1491 	{ USB_DEVICE(0x0803, 0x3095), /* Zoom Telephonics Model 3095F USB MODEM */
1492 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1493 	},
1494 	{ USB_DEVICE(0x0572, 0x1321), /* Conexant USB MODEM CX93010 */
1495 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1496 	},
1497 	{ USB_DEVICE(0x0572, 0x1324), /* Conexant USB MODEM RD02-D400 */
1498 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1499 	},
1500 	{ USB_DEVICE(0x0572, 0x1328), /* Shiro / Aztech USB MODEM UM-3100 */
1501 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1502 	},
1503 	{ USB_DEVICE(0x22b8, 0x6425), /* Motorola MOTOMAGX phones */
1504 	},
1505 	{ USB_DEVICE(0x0572, 0x1329), /* Hummingbird huc56s (Conexant) */
1506 	.driver_info = NO_UNION_NORMAL, /* union descriptor misplaced on
1507 					   data interface instead of
1508 					   communications interface.
1509 					   Maybe we should define a new
1510 					   quirk for this. */
1511 	},
1512 	{ USB_DEVICE(0x1bbb, 0x0003), /* Alcatel OT-I650 */
1513 	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
1514 	},
1515 
1516 	/* control interfaces with various AT-command sets */
1517 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1518 		USB_CDC_ACM_PROTO_AT_V25TER) },
1519 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1520 		USB_CDC_ACM_PROTO_AT_PCCA101) },
1521 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1522 		USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
1523 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1524 		USB_CDC_ACM_PROTO_AT_GSM) },
1525 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1526 		USB_CDC_ACM_PROTO_AT_3G) },
1527 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1528 		USB_CDC_ACM_PROTO_AT_CDMA) },
1529 
1530 	/* NOTE:  COMM/ACM/0xff is likely MSFT RNDIS ... NOT a modem!! */
1531 	{ }
1532 };
1533 
1534 MODULE_DEVICE_TABLE(usb, acm_ids);
1535 
1536 static struct usb_driver acm_driver = {
1537 	.name =		"cdc_acm",
1538 	.probe =	acm_probe,
1539 	.disconnect =	acm_disconnect,
1540 #ifdef CONFIG_PM
1541 	.suspend =	acm_suspend,
1542 	.resume =	acm_resume,
1543 #endif
1544 	.id_table =	acm_ids,
1545 #ifdef CONFIG_PM
1546 	.supports_autosuspend = 1,
1547 #endif
1548 };
1549 
1550 /*
1551  * TTY driver structures.
1552  */
1553 
1554 static const struct tty_operations acm_ops = {
1555 	.open =			acm_tty_open,
1556 	.close =		acm_tty_close,
1557 	.hangup =		acm_tty_hangup,
1558 	.write =		acm_tty_write,
1559 	.write_room =		acm_tty_write_room,
1560 	.ioctl =		acm_tty_ioctl,
1561 	.throttle =		acm_tty_throttle,
1562 	.unthrottle =		acm_tty_unthrottle,
1563 	.chars_in_buffer =	acm_tty_chars_in_buffer,
1564 	.break_ctl =		acm_tty_break_ctl,
1565 	.set_termios =		acm_tty_set_termios,
1566 	.tiocmget =		acm_tty_tiocmget,
1567 	.tiocmset =		acm_tty_tiocmset,
1568 };
1569 
1570 /*
1571  * Init / exit.
1572  */
1573 
1574 static int __init acm_init(void)
1575 {
1576 	int retval;
1577 	acm_tty_driver = alloc_tty_driver(ACM_TTY_MINORS);
1578 	if (!acm_tty_driver)
1579 		return -ENOMEM;
1580 	acm_tty_driver->owner = THIS_MODULE,
1581 	acm_tty_driver->driver_name = "acm",
1582 	acm_tty_driver->name = "ttyACM",
1583 	acm_tty_driver->major = ACM_TTY_MAJOR,
1584 	acm_tty_driver->minor_start = 0,
1585 	acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
1586 	acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
1587 	acm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
1588 	acm_tty_driver->init_termios = tty_std_termios;
1589 	acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD |
1590 								HUPCL | CLOCAL;
1591 	tty_set_operations(acm_tty_driver, &acm_ops);
1592 
1593 	retval = tty_register_driver(acm_tty_driver);
1594 	if (retval) {
1595 		put_tty_driver(acm_tty_driver);
1596 		return retval;
1597 	}
1598 
1599 	retval = usb_register(&acm_driver);
1600 	if (retval) {
1601 		tty_unregister_driver(acm_tty_driver);
1602 		put_tty_driver(acm_tty_driver);
1603 		return retval;
1604 	}
1605 
1606 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
1607 	       DRIVER_DESC "\n");
1608 
1609 	return 0;
1610 }
1611 
1612 static void __exit acm_exit(void)
1613 {
1614 	usb_deregister(&acm_driver);
1615 	tty_unregister_driver(acm_tty_driver);
1616 	put_tty_driver(acm_tty_driver);
1617 }
1618 
1619 module_init(acm_init);
1620 module_exit(acm_exit);
1621 
1622 MODULE_AUTHOR(DRIVER_AUTHOR);
1623 MODULE_DESCRIPTION(DRIVER_DESC);
1624 MODULE_LICENSE("GPL");
1625 MODULE_ALIAS_CHARDEV_MAJOR(ACM_TTY_MAJOR);
1626