Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6] / drivers / usb / class / cdc-acm.c
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  *
10  * USB Abstract Control Model driver for USB modems and ISDN adapters
11  *
12  * Sponsored by SuSE
13  *
14  * ChangeLog:
15  *      v0.9  - thorough cleaning, URBification, almost a rewrite
16  *      v0.10 - some more cleanups
17  *      v0.11 - fixed flow control, read error doesn't stop reads
18  *      v0.12 - added TIOCM ioctls, added break handling, made struct acm kmalloced
19  *      v0.13 - added termios, added hangup
20  *      v0.14 - sized down struct acm
21  *      v0.15 - fixed flow control again - characters could be lost
22  *      v0.16 - added code for modems with swapped data and control interfaces
23  *      v0.17 - added new style probing
24  *      v0.18 - fixed new style probing for devices with more configurations
25  *      v0.19 - fixed CLOCAL handling (thanks to Richard Shih-Ping Chan)
26  *      v0.20 - switched to probing on interface (rather than device) class
27  *      v0.21 - revert to probing on device for devices with multiple configs
28  *      v0.22 - probe only the control interface. if usbcore doesn't choose the
29  *              config we want, sysadmin changes bConfigurationValue in sysfs.
30  *      v0.23 - use softirq for rx processing, as needed by tty layer
31  *      v0.24 - change probe method to evaluate CDC union descriptor
32  */
33
34 /*
35  * This program is free software; you can redistribute it and/or modify
36  * it under the terms of the GNU General Public License as published by
37  * the Free Software Foundation; either version 2 of the License, or
38  * (at your option) any later version.
39  *
40  * This program is distributed in the hope that it will be useful,
41  * but WITHOUT ANY WARRANTY; without even the implied warranty of
42  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
43  * GNU General Public License for more details.
44  *
45  * You should have received a copy of the GNU General Public License
46  * along with this program; if not, write to the Free Software
47  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
48  */
49
50 #undef DEBUG
51
52 #include <linux/kernel.h>
53 #include <linux/errno.h>
54 #include <linux/init.h>
55 #include <linux/slab.h>
56 #include <linux/tty.h>
57 #include <linux/tty_driver.h>
58 #include <linux/tty_flip.h>
59 #include <linux/module.h>
60 #include <linux/smp_lock.h>
61 #include <asm/uaccess.h>
62 #include <linux/usb.h>
63 #include <linux/usb_cdc.h>
64 #include <asm/byteorder.h>
65 #include <asm/unaligned.h>
66
67 #include "cdc-acm.h"
68
69 /*
70  * Version Information
71  */
72 #define DRIVER_VERSION "v0.23"
73 #define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik"
74 #define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
75
76 static struct usb_driver acm_driver;
77 static struct tty_driver *acm_tty_driver;
78 static struct acm *acm_table[ACM_TTY_MINORS];
79
80 static DECLARE_MUTEX(open_sem);
81
82 #define ACM_READY(acm)  (acm && acm->dev && acm->used)
83
84 /*
85  * Functions for ACM control messages.
86  */
87
88 static int acm_ctrl_msg(struct acm *acm, int request, int value, void *buf, int len)
89 {
90         int retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
91                 request, USB_RT_ACM, value,
92                 acm->control->altsetting[0].desc.bInterfaceNumber,
93                 buf, len, 5000);
94         dbg("acm_control_msg: rq: 0x%02x val: %#x len: %#x result: %d", request, value, len, retval);
95         return retval < 0 ? retval : 0;
96 }
97
98 /* devices aren't required to support these requests.
99  * the cdc acm descriptor tells whether they do...
100  */
101 #define acm_set_control(acm, control) \
102         acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE, control, NULL, 0)
103 #define acm_set_line(acm, line) \
104         acm_ctrl_msg(acm, USB_CDC_REQ_SET_LINE_CODING, 0, line, sizeof *(line))
105 #define acm_send_break(acm, ms) \
106         acm_ctrl_msg(acm, USB_CDC_REQ_SEND_BREAK, ms, NULL, 0)
107
108 /*
109  * Write buffer management.
110  * All of these assume proper locks taken by the caller.
111  */
112
113 static int acm_wb_alloc(struct acm *acm)
114 {
115         int i, wbn;
116         struct acm_wb *wb;
117
118         wbn = acm->write_current;
119         i = 0;
120         for (;;) {
121                 wb = &acm->wb[wbn];
122                 if (!wb->use) {
123                         wb->use = 1;
124                         return wbn;
125                 }
126                 wbn = (wbn + 1) % ACM_NWB;
127                 if (++i >= ACM_NWB)
128                         return -1;
129         }
130 }
131
132 static void acm_wb_free(struct acm *acm, int wbn)
133 {
134         acm->wb[wbn].use = 0;
135 }
136
137 static int acm_wb_is_avail(struct acm *acm)
138 {
139         int i, n;
140
141         n = 0;
142         for (i = 0; i < ACM_NWB; i++) {
143                 if (!acm->wb[i].use)
144                         n++;
145         }
146         return n;
147 }
148
149 static inline int acm_wb_is_used(struct acm *acm, int wbn)
150 {
151         return acm->wb[wbn].use;
152 }
153
154 /*
155  * Finish write.
156  */
157 static void acm_write_done(struct acm *acm)
158 {
159         unsigned long flags;
160         int wbn;
161
162         spin_lock_irqsave(&acm->write_lock, flags);
163         acm->write_ready = 1;
164         wbn = acm->write_current;
165         acm_wb_free(acm, wbn);
166         acm->write_current = (wbn + 1) % ACM_NWB;
167         spin_unlock_irqrestore(&acm->write_lock, flags);
168 }
169
170 /*
171  * Poke write.
172  */
173 static int acm_write_start(struct acm *acm)
174 {
175         unsigned long flags;
176         int wbn;
177         struct acm_wb *wb;
178         int rc;
179
180         spin_lock_irqsave(&acm->write_lock, flags);
181         if (!acm->dev) {
182                 spin_unlock_irqrestore(&acm->write_lock, flags);
183                 return -ENODEV;
184         }
185
186         if (!acm->write_ready) {
187                 spin_unlock_irqrestore(&acm->write_lock, flags);
188                 return 0;       /* A white lie */
189         }
190
191         wbn = acm->write_current;
192         if (!acm_wb_is_used(acm, wbn)) {
193                 spin_unlock_irqrestore(&acm->write_lock, flags);
194                 return 0;
195         }
196         wb = &acm->wb[wbn];
197
198         acm->write_ready = 0;
199         spin_unlock_irqrestore(&acm->write_lock, flags);
200
201         acm->writeurb->transfer_buffer = wb->buf;
202         acm->writeurb->transfer_dma = wb->dmah;
203         acm->writeurb->transfer_buffer_length = wb->len;
204         acm->writeurb->dev = acm->dev;
205
206         if ((rc = usb_submit_urb(acm->writeurb, GFP_ATOMIC)) < 0) {
207                 dbg("usb_submit_urb(write bulk) failed: %d", rc);
208                 acm_write_done(acm);
209         }
210         return rc;
211 }
212
213 /*
214  * Interrupt handlers for various ACM device responses
215  */
216
217 /* control interface reports status changes with "interrupt" transfers */
218 static void acm_ctrl_irq(struct urb *urb, struct pt_regs *regs)
219 {
220         struct acm *acm = urb->context;
221         struct usb_cdc_notification *dr = urb->transfer_buffer;
222         unsigned char *data;
223         int newctrl;
224         int status;
225
226         switch (urb->status) {
227         case 0:
228                 /* success */
229                 break;
230         case -ECONNRESET:
231         case -ENOENT:
232         case -ESHUTDOWN:
233                 /* this urb is terminated, clean up */
234                 dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
235                 return;
236         default:
237                 dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
238                 goto exit;
239         }
240
241         if (!ACM_READY(acm))
242                 goto exit;
243
244         data = (unsigned char *)(dr + 1);
245         switch (dr->bNotificationType) {
246
247                 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
248
249                         dbg("%s network", dr->wValue ? "connected to" : "disconnected from");
250                         break;
251
252                 case USB_CDC_NOTIFY_SERIAL_STATE:
253
254                         newctrl = le16_to_cpu(get_unaligned((__le16 *) data));
255
256                         if (acm->tty && !acm->clocal && (acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
257                                 dbg("calling hangup");
258                                 tty_hangup(acm->tty);
259                         }
260
261                         acm->ctrlin = newctrl;
262
263                         dbg("input control lines: dcd%c dsr%c break%c ring%c framing%c parity%c overrun%c",
264                                 acm->ctrlin & ACM_CTRL_DCD ? '+' : '-', acm->ctrlin & ACM_CTRL_DSR ? '+' : '-',
265                                 acm->ctrlin & ACM_CTRL_BRK ? '+' : '-', acm->ctrlin & ACM_CTRL_RI  ? '+' : '-',
266                                 acm->ctrlin & ACM_CTRL_FRAMING ? '+' : '-',     acm->ctrlin & ACM_CTRL_PARITY ? '+' : '-',
267                                 acm->ctrlin & ACM_CTRL_OVERRUN ? '+' : '-');
268
269                         break;
270
271                 default:
272                         dbg("unknown notification %d received: index %d len %d data0 %d data1 %d",
273                                 dr->bNotificationType, dr->wIndex,
274                                 dr->wLength, data[0], data[1]);
275                         break;
276         }
277 exit:
278         status = usb_submit_urb (urb, GFP_ATOMIC);
279         if (status)
280                 err ("%s - usb_submit_urb failed with result %d",
281                      __FUNCTION__, status);
282 }
283
284 /* data interface returns incoming bytes, or we got unthrottled */
285 static void acm_read_bulk(struct urb *urb, struct pt_regs *regs)
286 {
287         struct acm *acm = urb->context;
288         dbg("Entering acm_read_bulk with status %d\n", urb->status);
289
290         if (!ACM_READY(acm))
291                 return;
292
293         if (urb->status)
294                 dev_dbg(&acm->data->dev, "bulk rx status %d\n", urb->status);
295
296         /* calling tty_flip_buffer_push() in_irq() isn't allowed */
297         tasklet_schedule(&acm->bh);
298 }
299
300 static void acm_rx_tasklet(unsigned long _acm)
301 {
302         struct acm *acm = (void *)_acm;
303         struct urb *urb = acm->readurb;
304         struct tty_struct *tty = acm->tty;
305         unsigned char *data = urb->transfer_buffer;
306         int i = 0;
307         dbg("Entering acm_rx_tasklet");
308
309         if (urb->actual_length > 0 && !acm->throttle)  {
310                 for (i = 0; i < urb->actual_length && !acm->throttle; i++) {
311                         /* if we insert more than TTY_FLIPBUF_SIZE characters,
312                          * we drop them. */
313                         if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
314                                 tty_flip_buffer_push(tty);
315                         }
316                         tty_insert_flip_char(tty, data[i], 0);
317                 }
318                 dbg("Handed %d bytes to tty layer", i+1);
319                 tty_flip_buffer_push(tty);
320         }
321
322         spin_lock(&acm->throttle_lock);
323         if (acm->throttle) {
324                 dbg("Throtteling noticed");
325                 memmove(data, data + i, urb->actual_length - i);
326                 urb->actual_length -= i;
327                 acm->resubmit_to_unthrottle = 1;
328                 spin_unlock(&acm->throttle_lock);
329                 return;
330         }
331         spin_unlock(&acm->throttle_lock);
332
333         urb->actual_length = 0;
334         urb->dev = acm->dev;
335
336         i = usb_submit_urb(urb, GFP_ATOMIC);
337         if (i)
338                 dev_dbg(&acm->data->dev, "bulk rx resubmit %d\n", i);
339 }
340
341 /* data interface wrote those outgoing bytes */
342 static void acm_write_bulk(struct urb *urb, struct pt_regs *regs)
343 {
344         struct acm *acm = (struct acm *)urb->context;
345
346         dbg("Entering acm_write_bulk with status %d\n", urb->status);
347
348         acm_write_done(acm);
349         acm_write_start(acm);
350         if (ACM_READY(acm))
351                 schedule_work(&acm->work);
352 }
353
354 static void acm_softint(void *private)
355 {
356         struct acm *acm = private;
357         dbg("Entering acm_softint.\n");
358         
359         if (!ACM_READY(acm))
360                 return;
361         tty_wakeup(acm->tty);
362 }
363
364 /*
365  * TTY handlers
366  */
367
368 static int acm_tty_open(struct tty_struct *tty, struct file *filp)
369 {
370         struct acm *acm;
371         int rv = -EINVAL;
372         dbg("Entering acm_tty_open.\n");
373         
374         down(&open_sem);
375
376         acm = acm_table[tty->index];
377         if (!acm || !acm->dev)
378                 goto err_out;
379         else
380                 rv = 0;
381
382         tty->driver_data = acm;
383         acm->tty = tty;
384
385
386
387         if (acm->used++) {
388                 goto done;
389         }
390
391         acm->ctrlurb->dev = acm->dev;
392         if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
393                 dbg("usb_submit_urb(ctrl irq) failed");
394                 goto bail_out;
395         }
396
397         acm->readurb->dev = acm->dev;
398         if (usb_submit_urb(acm->readurb, GFP_KERNEL)) {
399                 dbg("usb_submit_urb(read bulk) failed");
400                 goto bail_out_and_unlink;
401         }
402
403         if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS))
404                 goto full_bailout;
405
406         /* force low_latency on so that our tty_push actually forces the data through, 
407            otherwise it is scheduled, and with high data rates data can get lost. */
408         tty->low_latency = 1;
409
410 done:
411 err_out:
412         up(&open_sem);
413         return rv;
414
415 full_bailout:
416         usb_kill_urb(acm->readurb);
417 bail_out_and_unlink:
418         usb_kill_urb(acm->ctrlurb);
419 bail_out:
420         acm->used--;
421         up(&open_sem);
422         return -EIO;
423 }
424
425 static void acm_tty_unregister(struct acm *acm)
426 {
427         tty_unregister_device(acm_tty_driver, acm->minor);
428         usb_put_intf(acm->control);
429         acm_table[acm->minor] = NULL;
430         usb_free_urb(acm->ctrlurb);
431         usb_free_urb(acm->readurb);
432         usb_free_urb(acm->writeurb);
433         kfree(acm);
434 }
435
436 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
437 {
438         struct acm *acm = tty->driver_data;
439
440         if (!acm || !acm->used)
441                 return;
442
443         down(&open_sem);
444         if (!--acm->used) {
445                 if (acm->dev) {
446                         acm_set_control(acm, acm->ctrlout = 0);
447                         usb_kill_urb(acm->ctrlurb);
448                         usb_kill_urb(acm->writeurb);
449                         usb_kill_urb(acm->readurb);
450                 } else
451                         acm_tty_unregister(acm);
452         }
453         up(&open_sem);
454 }
455
456 static int acm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
457 {
458         struct acm *acm = tty->driver_data;
459         int stat;
460         unsigned long flags;
461         int wbn;
462         struct acm_wb *wb;
463
464         dbg("Entering acm_tty_write to write %d bytes,\n", count);
465
466         if (!ACM_READY(acm))
467                 return -EINVAL;
468         if (!count)
469                 return 0;
470
471         spin_lock_irqsave(&acm->write_lock, flags);
472         if ((wbn = acm_wb_alloc(acm)) < 0) {
473                 spin_unlock_irqrestore(&acm->write_lock, flags);
474                 acm_write_start(acm);
475                 return 0;
476         }
477         wb = &acm->wb[wbn];
478
479         count = (count > acm->writesize) ? acm->writesize : count;
480         dbg("Get %d bytes...", count);
481         memcpy(wb->buf, buf, count);
482         wb->len = count;
483         spin_unlock_irqrestore(&acm->write_lock, flags);
484
485         if ((stat = acm_write_start(acm)) < 0)
486                 return stat;
487         return count;
488 }
489
490 static int acm_tty_write_room(struct tty_struct *tty)
491 {
492         struct acm *acm = tty->driver_data;
493         if (!ACM_READY(acm))
494                 return -EINVAL;
495         /*
496          * Do not let the line discipline to know that we have a reserve,
497          * or it might get too enthusiastic.
498          */
499         return (acm->write_ready && acm_wb_is_avail(acm)) ? acm->writesize : 0;
500 }
501
502 static int acm_tty_chars_in_buffer(struct tty_struct *tty)
503 {
504         struct acm *acm = tty->driver_data;
505         if (!ACM_READY(acm))
506                 return -EINVAL;
507         /*
508          * This is inaccurate (overcounts), but it works.
509          */
510         return (ACM_NWB - acm_wb_is_avail(acm)) * acm->writesize;
511 }
512
513 static void acm_tty_throttle(struct tty_struct *tty)
514 {
515         struct acm *acm = tty->driver_data;
516         if (!ACM_READY(acm))
517                 return;
518         spin_lock_bh(&acm->throttle_lock);
519         acm->throttle = 1;
520         spin_unlock_bh(&acm->throttle_lock);
521 }
522
523 static void acm_tty_unthrottle(struct tty_struct *tty)
524 {
525         struct acm *acm = tty->driver_data;
526         if (!ACM_READY(acm))
527                 return;
528         spin_lock_bh(&acm->throttle_lock);
529         acm->throttle = 0;
530         spin_unlock_bh(&acm->throttle_lock);
531         if (acm->resubmit_to_unthrottle) {
532                 acm->resubmit_to_unthrottle = 0;
533                 acm_read_bulk(acm->readurb, NULL);
534         }
535 }
536
537 static void acm_tty_break_ctl(struct tty_struct *tty, int state)
538 {
539         struct acm *acm = tty->driver_data;
540         if (!ACM_READY(acm))
541                 return;
542         if (acm_send_break(acm, state ? 0xffff : 0))
543                 dbg("send break failed");
544 }
545
546 static int acm_tty_tiocmget(struct tty_struct *tty, struct file *file)
547 {
548         struct acm *acm = tty->driver_data;
549
550         if (!ACM_READY(acm))
551                 return -EINVAL;
552
553         return (acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
554                (acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
555                (acm->ctrlin  & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
556                (acm->ctrlin  & ACM_CTRL_RI  ? TIOCM_RI  : 0) |
557                (acm->ctrlin  & ACM_CTRL_DCD ? TIOCM_CD  : 0) |
558                TIOCM_CTS;
559 }
560
561 static int acm_tty_tiocmset(struct tty_struct *tty, struct file *file,
562                             unsigned int set, unsigned int clear)
563 {
564         struct acm *acm = tty->driver_data;
565         unsigned int newctrl;
566
567         if (!ACM_READY(acm))
568                 return -EINVAL;
569
570         newctrl = acm->ctrlout;
571         set = (set & TIOCM_DTR ? ACM_CTRL_DTR : 0) | (set & TIOCM_RTS ? ACM_CTRL_RTS : 0);
572         clear = (clear & TIOCM_DTR ? ACM_CTRL_DTR : 0) | (clear & TIOCM_RTS ? ACM_CTRL_RTS : 0);
573
574         newctrl = (newctrl & ~clear) | set;
575
576         if (acm->ctrlout == newctrl)
577                 return 0;
578         return acm_set_control(acm, acm->ctrlout = newctrl);
579 }
580
581 static int acm_tty_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
582 {
583         struct acm *acm = tty->driver_data;
584
585         if (!ACM_READY(acm))
586                 return -EINVAL;
587
588         return -ENOIOCTLCMD;
589 }
590
591 static __u32 acm_tty_speed[] = {
592         0, 50, 75, 110, 134, 150, 200, 300, 600,
593         1200, 1800, 2400, 4800, 9600, 19200, 38400,
594         57600, 115200, 230400, 460800, 500000, 576000,
595         921600, 1000000, 1152000, 1500000, 2000000,
596         2500000, 3000000, 3500000, 4000000
597 };
598
599 static __u8 acm_tty_size[] = {
600         5, 6, 7, 8
601 };
602
603 static void acm_tty_set_termios(struct tty_struct *tty, struct termios *termios_old)
604 {
605         struct acm *acm = tty->driver_data;
606         struct termios *termios = tty->termios;
607         struct usb_cdc_line_coding newline;
608         int newctrl = acm->ctrlout;
609
610         if (!ACM_READY(acm))
611                 return;
612
613         newline.dwDTERate = cpu_to_le32p(acm_tty_speed +
614                 (termios->c_cflag & CBAUD & ~CBAUDEX) + (termios->c_cflag & CBAUDEX ? 15 : 0));
615         newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
616         newline.bParityType = termios->c_cflag & PARENB ?
617                 (termios->c_cflag & PARODD ? 1 : 2) + (termios->c_cflag & CMSPAR ? 2 : 0) : 0;
618         newline.bDataBits = acm_tty_size[(termios->c_cflag & CSIZE) >> 4];
619
620         acm->clocal = ((termios->c_cflag & CLOCAL) != 0);
621
622         if (!newline.dwDTERate) {
623                 newline.dwDTERate = acm->line.dwDTERate;
624                 newctrl &= ~ACM_CTRL_DTR;
625         } else  newctrl |=  ACM_CTRL_DTR;
626
627         if (newctrl != acm->ctrlout)
628                 acm_set_control(acm, acm->ctrlout = newctrl);
629
630         if (memcmp(&acm->line, &newline, sizeof newline)) {
631                 memcpy(&acm->line, &newline, sizeof newline);
632                 dbg("set line: %d %d %d %d", le32_to_cpu(newline.dwDTERate),
633                         newline.bCharFormat, newline.bParityType,
634                         newline.bDataBits);
635                 acm_set_line(acm, &acm->line);
636         }
637 }
638
639 /*
640  * USB probe and disconnect routines.
641  */
642
643 /* Little helper: write buffers free */
644 static void acm_write_buffers_free(struct acm *acm)
645 {
646         int i;
647         struct acm_wb *wb;
648
649         for (wb = &acm->wb[0], i = 0; i < ACM_NWB; i++, wb++) {
650                 usb_buffer_free(acm->dev, acm->writesize, wb->buf, wb->dmah);
651         }
652 }
653
654 /* Little helper: write buffers allocate */
655 static int acm_write_buffers_alloc(struct acm *acm)
656 {
657         int i;
658         struct acm_wb *wb;
659
660         for (wb = &acm->wb[0], i = 0; i < ACM_NWB; i++, wb++) {
661                 wb->buf = usb_buffer_alloc(acm->dev, acm->writesize, GFP_KERNEL,
662                     &wb->dmah);
663                 if (!wb->buf) {
664                         while (i != 0) {
665                                 --i;
666                                 --wb;
667                                 usb_buffer_free(acm->dev, acm->writesize,
668                                     wb->buf, wb->dmah);
669                         }
670                         return -ENOMEM;
671                 }
672         }
673         return 0;
674 }
675
676 static int acm_probe (struct usb_interface *intf,
677                       const struct usb_device_id *id)
678 {
679         struct usb_cdc_union_desc *union_header = NULL;
680         char *buffer = intf->altsetting->extra;
681         int buflen = intf->altsetting->extralen;
682         struct usb_interface *control_interface;
683         struct usb_interface *data_interface;
684         struct usb_endpoint_descriptor *epctrl;
685         struct usb_endpoint_descriptor *epread;
686         struct usb_endpoint_descriptor *epwrite;
687         struct usb_device *usb_dev = interface_to_usbdev(intf);
688         struct acm *acm;
689         int minor;
690         int ctrlsize,readsize;
691         u8 *buf;
692         u8 ac_management_function = 0;
693         u8 call_management_function = 0;
694         int call_interface_num = -1;
695         int data_interface_num;
696         unsigned long quirks;
697
698         /* handle quirks deadly to normal probing*/
699         quirks = (unsigned long)id->driver_info;
700         if (quirks == NO_UNION_NORMAL) {
701                 data_interface = usb_ifnum_to_if(usb_dev, 1);
702                 control_interface = usb_ifnum_to_if(usb_dev, 0);
703                 goto skip_normal_probe;
704         }
705         
706         /* normal probing*/
707         if (!buffer) {
708                 err("Wierd descriptor references\n");
709                 return -EINVAL;
710         }
711
712         if (!buflen) {
713                 if (intf->cur_altsetting->endpoint->extralen && intf->cur_altsetting->endpoint->extra) {
714                         dev_dbg(&intf->dev,"Seeking extra descriptors on endpoint\n");
715                         buflen = intf->cur_altsetting->endpoint->extralen;
716                         buffer = intf->cur_altsetting->endpoint->extra;
717                 } else {
718                         err("Zero length descriptor references\n");
719                         return -EINVAL;
720                 }
721         }
722
723         while (buflen > 0) {
724                 if (buffer [1] != USB_DT_CS_INTERFACE) {
725                         err("skipping garbage\n");
726                         goto next_desc;
727                 }
728
729                 switch (buffer [2]) {
730                         case USB_CDC_UNION_TYPE: /* we've found it */
731                                 if (union_header) {
732                                         err("More than one union descriptor, skipping ...");
733                                         goto next_desc;
734                                 }
735                                 union_header = (struct usb_cdc_union_desc *)
736                                                         buffer;
737                                 break;
738                         case USB_CDC_COUNTRY_TYPE: /* maybe somehow export */
739                                 break; /* for now we ignore it */
740                         case USB_CDC_HEADER_TYPE: /* maybe check version */ 
741                                 break; /* for now we ignore it */ 
742                         case USB_CDC_ACM_TYPE:
743                                 ac_management_function = buffer[3];
744                                 break;
745                         case USB_CDC_CALL_MANAGEMENT_TYPE:
746                                 call_management_function = buffer[3];
747                                 call_interface_num = buffer[4];
748                                 if ((call_management_function & 3) != 3)
749                                         err("This device cannot do calls on its own. It is no modem.");
750                                 break;
751                                 
752                         default:
753                                 err("Ignoring extra header, type %d, length %d", buffer[2], buffer[0]);
754                                 break;
755                         }
756 next_desc:
757                 buflen -= buffer[0];
758                 buffer += buffer[0];
759         }
760
761         if (!union_header) {
762                 if (call_interface_num > 0) {
763                         dev_dbg(&intf->dev,"No union descriptor, using call management descriptor\n");
764                         data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
765                         control_interface = intf;
766                 } else {
767                         dev_dbg(&intf->dev,"No union descriptor, giving up\n");
768                         return -ENODEV;
769                 }
770         } else {
771                 control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
772                 data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
773                 if (!control_interface || !data_interface) {
774                         dev_dbg(&intf->dev,"no interfaces\n");
775                         return -ENODEV;
776                 }
777         }
778         
779         if (data_interface_num != call_interface_num)
780                 dev_dbg(&intf->dev,"Seperate call control interface. That is not fully supported.\n");
781
782 skip_normal_probe:
783
784         /*workaround for switched interfaces */
785         if (data_interface->cur_altsetting->desc.bInterfaceClass != CDC_DATA_INTERFACE_TYPE) {
786                 if (control_interface->cur_altsetting->desc.bInterfaceClass == CDC_DATA_INTERFACE_TYPE) {
787                         struct usb_interface *t;
788                         dev_dbg(&intf->dev,"Your device has switched interfaces.\n");
789
790                         t = control_interface;
791                         control_interface = data_interface;
792                         data_interface = t;
793                 } else {
794                         return -EINVAL;
795                 }
796         }
797         
798         if (usb_interface_claimed(data_interface)) { /* valid in this context */
799                 dev_dbg(&intf->dev,"The data interface isn't available\n");
800                 return -EBUSY;
801         }
802
803
804         if (data_interface->cur_altsetting->desc.bNumEndpoints < 2)
805                 return -EINVAL;
806
807         epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
808         epread = &data_interface->cur_altsetting->endpoint[0].desc;
809         epwrite = &data_interface->cur_altsetting->endpoint[1].desc;
810
811
812         /* workaround for switched endpoints */
813         if ((epread->bEndpointAddress & USB_DIR_IN) != USB_DIR_IN) {
814                 /* descriptors are swapped */
815                 struct usb_endpoint_descriptor *t;
816                 dev_dbg(&intf->dev,"The data interface has switched endpoints\n");
817                 
818                 t = epread;
819                 epread = epwrite;
820                 epwrite = t;
821         }
822         dbg("interfaces are valid");
823         for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);
824
825         if (minor == ACM_TTY_MINORS) {
826                 err("no more free acm devices");
827                 return -ENODEV;
828         }
829
830         if (!(acm = kzalloc(sizeof(struct acm), GFP_KERNEL))) {
831                 dev_dbg(&intf->dev, "out of memory (acm kzalloc)\n");
832                 goto alloc_fail;
833         }
834
835         ctrlsize = le16_to_cpu(epctrl->wMaxPacketSize);
836         readsize = le16_to_cpu(epread->wMaxPacketSize);
837         acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize);
838         acm->control = control_interface;
839         acm->data = data_interface;
840         acm->minor = minor;
841         acm->dev = usb_dev;
842         acm->ctrl_caps = ac_management_function;
843         acm->ctrlsize = ctrlsize;
844         acm->readsize = readsize;
845         acm->bh.func = acm_rx_tasklet;
846         acm->bh.data = (unsigned long) acm;
847         INIT_WORK(&acm->work, acm_softint, acm);
848         spin_lock_init(&acm->throttle_lock);
849         spin_lock_init(&acm->write_lock);
850         acm->write_ready = 1;
851
852         buf = usb_buffer_alloc(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
853         if (!buf) {
854                 dev_dbg(&intf->dev, "out of memory (ctrl buffer alloc)\n");
855                 goto alloc_fail2;
856         }
857         acm->ctrl_buffer = buf;
858
859         buf = usb_buffer_alloc(usb_dev, readsize, GFP_KERNEL, &acm->read_dma);
860         if (!buf) {
861                 dev_dbg(&intf->dev, "out of memory (read buffer alloc)\n");
862                 goto alloc_fail3;
863         }
864         acm->read_buffer = buf;
865
866         if (acm_write_buffers_alloc(acm) < 0) {
867                 dev_dbg(&intf->dev, "out of memory (write buffer alloc)\n");
868                 goto alloc_fail4;
869         }
870
871         acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
872         if (!acm->ctrlurb) {
873                 dev_dbg(&intf->dev, "out of memory (ctrlurb kmalloc)\n");
874                 goto alloc_fail5;
875         }
876         acm->readurb = usb_alloc_urb(0, GFP_KERNEL);
877         if (!acm->readurb) {
878                 dev_dbg(&intf->dev, "out of memory (readurb kmalloc)\n");
879                 goto alloc_fail6;
880         }
881         acm->writeurb = usb_alloc_urb(0, GFP_KERNEL);
882         if (!acm->writeurb) {
883                 dev_dbg(&intf->dev, "out of memory (writeurb kmalloc)\n");
884                 goto alloc_fail7;
885         }
886
887         usb_fill_int_urb(acm->ctrlurb, usb_dev, usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
888                          acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm, epctrl->bInterval);
889         acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
890         acm->ctrlurb->transfer_dma = acm->ctrl_dma;
891
892         usb_fill_bulk_urb(acm->readurb, usb_dev, usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress),
893                           acm->read_buffer, readsize, acm_read_bulk, acm);
894         acm->readurb->transfer_flags |= URB_NO_FSBR | URB_NO_TRANSFER_DMA_MAP;
895         acm->readurb->transfer_dma = acm->read_dma;
896
897         usb_fill_bulk_urb(acm->writeurb, usb_dev, usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
898                           NULL, acm->writesize, acm_write_bulk, acm);
899         acm->writeurb->transfer_flags |= URB_NO_FSBR | URB_NO_TRANSFER_DMA_MAP;
900         /* acm->writeurb->transfer_dma = 0; */
901
902         dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
903
904         acm_set_control(acm, acm->ctrlout);
905
906         acm->line.dwDTERate = cpu_to_le32(9600);
907         acm->line.bDataBits = 8;
908         acm_set_line(acm, &acm->line);
909
910         usb_driver_claim_interface(&acm_driver, data_interface, acm);
911
912         usb_get_intf(control_interface);
913         tty_register_device(acm_tty_driver, minor, &control_interface->dev);
914
915         acm_table[minor] = acm;
916         usb_set_intfdata (intf, acm);
917         return 0;
918
919 alloc_fail7:
920         usb_free_urb(acm->readurb);
921 alloc_fail6:
922         usb_free_urb(acm->ctrlurb);
923 alloc_fail5:
924         acm_write_buffers_free(acm);
925 alloc_fail4:
926         usb_buffer_free(usb_dev, readsize, acm->read_buffer, acm->read_dma);
927 alloc_fail3:
928         usb_buffer_free(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
929 alloc_fail2:
930         kfree(acm);
931 alloc_fail:
932         return -ENOMEM;
933 }
934
935 static void acm_disconnect(struct usb_interface *intf)
936 {
937         struct acm *acm = usb_get_intfdata (intf);
938         struct usb_device *usb_dev = interface_to_usbdev(intf);
939
940         if (!acm || !acm->dev) {
941                 dbg("disconnect on nonexisting interface");
942                 return;
943         }
944
945         down(&open_sem);
946         acm->dev = NULL;
947         usb_set_intfdata (intf, NULL);
948
949         usb_kill_urb(acm->ctrlurb);
950         usb_kill_urb(acm->readurb);
951         usb_kill_urb(acm->writeurb);
952
953         flush_scheduled_work(); /* wait for acm_softint */
954
955         acm_write_buffers_free(acm);
956         usb_buffer_free(usb_dev, acm->readsize, acm->read_buffer, acm->read_dma);
957         usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
958
959         usb_driver_release_interface(&acm_driver, acm->data);
960
961         if (!acm->used) {
962                 acm_tty_unregister(acm);
963                 up(&open_sem);
964                 return;
965         }
966
967         up(&open_sem);
968
969         if (acm->tty)
970                 tty_hangup(acm->tty);
971 }
972
973 /*
974  * USB driver structure.
975  */
976
977 static struct usb_device_id acm_ids[] = {
978         /* quirky and broken devices */
979         { USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
980         .driver_info = NO_UNION_NORMAL, /* has no union descriptor */
981         },
982         { USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
983         .driver_info = NO_UNION_NORMAL, /* has no union descriptor */
984         },
985         /* control interfaces with various AT-command sets */
986         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
987                 USB_CDC_ACM_PROTO_AT_V25TER) },
988         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
989                 USB_CDC_ACM_PROTO_AT_PCCA101) },
990         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
991                 USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
992         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
993                 USB_CDC_ACM_PROTO_AT_GSM) },
994         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
995                 USB_CDC_ACM_PROTO_AT_3G ) },
996         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
997                 USB_CDC_ACM_PROTO_AT_CDMA) },
998
999         /* NOTE:  COMM/ACM/0xff is likely MSFT RNDIS ... NOT a modem!! */
1000         { }
1001 };
1002
1003 MODULE_DEVICE_TABLE (usb, acm_ids);
1004
1005 static struct usb_driver acm_driver = {
1006         .owner =        THIS_MODULE,
1007         .name =         "cdc_acm",
1008         .probe =        acm_probe,
1009         .disconnect =   acm_disconnect,
1010         .id_table =     acm_ids,
1011 };
1012
1013 /*
1014  * TTY driver structures.
1015  */
1016
1017 static struct tty_operations acm_ops = {
1018         .open =                 acm_tty_open,
1019         .close =                acm_tty_close,
1020         .write =                acm_tty_write,
1021         .write_room =           acm_tty_write_room,
1022         .ioctl =                acm_tty_ioctl,
1023         .throttle =             acm_tty_throttle,
1024         .unthrottle =           acm_tty_unthrottle,
1025         .chars_in_buffer =      acm_tty_chars_in_buffer,
1026         .break_ctl =            acm_tty_break_ctl,
1027         .set_termios =          acm_tty_set_termios,
1028         .tiocmget =             acm_tty_tiocmget,
1029         .tiocmset =             acm_tty_tiocmset,
1030 };
1031
1032 /*
1033  * Init / exit.
1034  */
1035
1036 static int __init acm_init(void)
1037 {
1038         int retval;
1039         acm_tty_driver = alloc_tty_driver(ACM_TTY_MINORS);
1040         if (!acm_tty_driver)
1041                 return -ENOMEM;
1042         acm_tty_driver->owner = THIS_MODULE,
1043         acm_tty_driver->driver_name = "acm",
1044         acm_tty_driver->name = "ttyACM",
1045         acm_tty_driver->devfs_name = "usb/acm/",
1046         acm_tty_driver->major = ACM_TTY_MAJOR,
1047         acm_tty_driver->minor_start = 0,
1048         acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
1049         acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
1050         acm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS,
1051         acm_tty_driver->init_termios = tty_std_termios;
1052         acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1053         tty_set_operations(acm_tty_driver, &acm_ops);
1054
1055         retval = tty_register_driver(acm_tty_driver);
1056         if (retval) {
1057                 put_tty_driver(acm_tty_driver);
1058                 return retval;
1059         }
1060
1061         retval = usb_register(&acm_driver);
1062         if (retval) {
1063                 tty_unregister_driver(acm_tty_driver);
1064                 put_tty_driver(acm_tty_driver);
1065                 return retval;
1066         }
1067
1068         info(DRIVER_VERSION ":" DRIVER_DESC);
1069
1070         return 0;
1071 }
1072
1073 static void __exit acm_exit(void)
1074 {
1075         usb_deregister(&acm_driver);
1076         tty_unregister_driver(acm_tty_driver);
1077         put_tty_driver(acm_tty_driver);
1078 }
1079
1080 module_init(acm_init);
1081 module_exit(acm_exit);
1082
1083 MODULE_AUTHOR( DRIVER_AUTHOR );
1084 MODULE_DESCRIPTION( DRIVER_DESC );
1085 MODULE_LICENSE("GPL");
1086