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  * 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 kmalloced
  20  *      v0.13 - added termios, added hangup
  21  *      v0.14 - sized down struct acm
  22  *      v0.15 - fixed flow control again - characters could be lost
  23  *      v0.16 - added code for modems with swapped data and control interfaces
  24  *      v0.17 - added new style probing
  25  *      v0.18 - fixed new style probing for devices with more configurations
  26  *      v0.19 - fixed CLOCAL handling (thanks to Richard Shih-Ping Chan)
  27  *      v0.20 - switched to probing on interface (rather than device) class
  28  *      v0.21 - revert to probing on device for devices with multiple configs
  29  *      v0.22 - probe only the control interface. if usbcore doesn't choose the
  30  *              config we want, sysadmin changes bConfigurationValue in sysfs.
  31  *      v0.23 - use softirq for rx processing, as needed by tty layer
  32  *      v0.24 - change probe method to evaluate CDC union descriptor
  33  *      v0.25 - downstream tasks paralelized to maximize throughput
  34  */
  35
  36 /*
  37  * This program is free software; you can redistribute it and/or modify
  38  * it under the terms of the GNU General Public License as published by
  39  * the Free Software Foundation; either version 2 of the License, or
  40  * (at your option) any later version.
  41  *
  42  * This program is distributed in the hope that it will be useful,
  43  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  44  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  45  * GNU General Public License for more details.
  46  *
  47  * You should have received a copy of the GNU General Public License
  48  * along with this program; if not, write to the Free Software
  49  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  50  */
  51
  52 #undef DEBUG
  53
  54 #include <linux/kernel.h>
  55 #include <linux/errno.h>
  56 #include <linux/init.h>
  57 #include <linux/slab.h>
  58 #include <linux/tty.h>
  59 #include <linux/tty_driver.h>
  60 #include <linux/tty_flip.h>
  61 #include <linux/module.h>
  62 #include <linux/smp_lock.h>
  63 #include <asm/uaccess.h>
  64 #include <linux/usb.h>
  65 #include <linux/usb_cdc.h>
  66 #include <asm/byteorder.h>
  67 #include <asm/unaligned.h>
  68 #include <linux/list.h>
  69
  70 #include "cdc-acm.h"
  71
  72 /*
  73  * Version Information
  74  */
  75 #define DRIVER_VERSION "v0.25"
  76 #define DRIVER_AUTHOR "Armin Fuerst, Pavel Machek, Johannes Erdfelt, Vojtech Pavlik, David Kubicek"
  77 #define DRIVER_DESC "USB Abstract Control Model driver for USB modems and ISDN adapters"
  78
  79 static struct usb_driver acm_driver;
  80 static struct tty_driver *acm_tty_driver;
  81 static struct acm *acm_table[ACM_TTY_MINORS];
  82
  83 static DECLARE_MUTEX(open_sem);
  84
  85 #define ACM_READY(acm)  (acm && acm->dev && acm->used)
  86
  87 /*
  88  * Functions for ACM control messages.
  89  */
  90
  91 static int acm_ctrl_msg(struct acm *acm, int request, int value, void *buf, int len)
  92 {
  93         int retval = usb_control_msg(acm->dev, usb_sndctrlpipe(acm->dev, 0),
  94                 request, USB_RT_ACM, value,
  95                 acm->control->altsetting[0].desc.bInterfaceNumber,
  96                 buf, len, 5000);
  97         dbg("acm_control_msg: rq: 0x%02x val: %#x len: %#x result: %d", request, value, len, retval);
  98         return retval < 0 ? retval : 0;
  99 }
 100
 101 /* devices aren't required to support these requests.
 102  * the cdc acm descriptor tells whether they do...
 103  */
 104 #define acm_set_control(acm, control) \
 105         acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE, control, NULL, 0)
 106 #define acm_set_line(acm, line) \
 107         acm_ctrl_msg(acm, USB_CDC_REQ_SET_LINE_CODING, 0, line, sizeof *(line))
 108 #define acm_send_break(acm, ms) \
 109         acm_ctrl_msg(acm, USB_CDC_REQ_SEND_BREAK, ms, NULL, 0)
 110
 111 /*
 112  * Write buffer management.
 113  * All of these assume proper locks taken by the caller.
 114  */
 115
 116 static int acm_wb_alloc(struct acm *acm)
 117 {
 118         int i, wbn;
 119         struct acm_wb *wb;
 120
 121         wbn = acm->write_current;
 122         i = 0;
 123         for (;;) {
 124                 wb = &acm->wb[wbn];
 125                 if (!wb->use) {
 126                         wb->use = 1;
 127                         return wbn;
 128                 }
 129                 wbn = (wbn + 1) % ACM_NWB;
 130                 if (++i >= ACM_NWB)
 131                         return -1;
 132         }
 133 }
 134
 135 static void acm_wb_free(struct acm *acm, int wbn)
 136 {
 137         acm->wb[wbn].use = 0;
 138 }
 139
 140 static int acm_wb_is_avail(struct acm *acm)
 141 {
 142         int i, n;
 143
 144         n = 0;
 145         for (i = 0; i < ACM_NWB; i++) {
 146                 if (!acm->wb[i].use)
 147                         n++;
 148         }
 149         return n;
 150 }
 151
 152 static inline int acm_wb_is_used(struct acm *acm, int wbn)
 153 {
 154         return acm->wb[wbn].use;
 155 }
 156
 157 /*
 158  * Finish write.
 159  */
 160 static void acm_write_done(struct acm *acm)
 161 {
 162         unsigned long flags;
 163         int wbn;
 164
 165         spin_lock_irqsave(&acm->write_lock, flags);
 166         acm->write_ready = 1;
 167         wbn = acm->write_current;
 168         acm_wb_free(acm, wbn);
 169         acm->write_current = (wbn + 1) % ACM_NWB;
 170         spin_unlock_irqrestore(&acm->write_lock, flags);
 171 }
 172
 173 /*
 174  * Poke write.
 175  */
 176 static int acm_write_start(struct acm *acm)
 177 {
 178         unsigned long flags;
 179         int wbn;
 180         struct acm_wb *wb;
 181         int rc;
 182
 183         spin_lock_irqsave(&acm->write_lock, flags);
 184         if (!acm->dev) {
 185                 spin_unlock_irqrestore(&acm->write_lock, flags);
 186                 return -ENODEV;
 187         }
 188
 189         if (!acm->write_ready) {
 190                 spin_unlock_irqrestore(&acm->write_lock, flags);
 191                 return 0;       /* A white lie */
 192         }
 193
 194         wbn = acm->write_current;
 195         if (!acm_wb_is_used(acm, wbn)) {
 196                 spin_unlock_irqrestore(&acm->write_lock, flags);
 197                 return 0;
 198         }
 199         wb = &acm->wb[wbn];
 200
 201         acm->write_ready = 0;
 202         spin_unlock_irqrestore(&acm->write_lock, flags);
 203
 204         acm->writeurb->transfer_buffer = wb->buf;
 205         acm->writeurb->transfer_dma = wb->dmah;
 206         acm->writeurb->transfer_buffer_length = wb->len;
 207         acm->writeurb->dev = acm->dev;
 208
 209         if ((rc = usb_submit_urb(acm->writeurb, GFP_ATOMIC)) < 0) {
 210                 dbg("usb_submit_urb(write bulk) failed: %d", rc);
 211                 acm_write_done(acm);
 212         }
 213         return rc;
 214 }
 215
 216 /*
 217  * Interrupt handlers for various ACM device responses
 218  */
 219
 220 /* control interface reports status changes with "interrupt" transfers */
 221 static void acm_ctrl_irq(struct urb *urb, struct pt_regs *regs)
 222 {
 223         struct acm *acm = urb->context;
 224         struct usb_cdc_notification *dr = urb->transfer_buffer;
 225         unsigned char *data;
 226         int newctrl;
 227         int status;
 228
 229         switch (urb->status) {
 230         case 0:
 231                 /* success */
 232                 break;
 233         case -ECONNRESET:
 234         case -ENOENT:
 235         case -ESHUTDOWN:
 236                 /* this urb is terminated, clean up */
 237                 dbg("%s - urb shutting down with status: %d", __FUNCTION__, urb->status);
 238                 return;
 239         default:
 240                 dbg("%s - nonzero urb status received: %d", __FUNCTION__, urb->status);
 241                 goto exit;
 242         }
 243
 244         if (!ACM_READY(acm))
 245                 goto exit;
 246
 247         data = (unsigned char *)(dr + 1);
 248         switch (dr->bNotificationType) {
 249
 250                 case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 251
 252                         dbg("%s network", dr->wValue ? "connected to" : "disconnected from");
 253                         break;
 254
 255                 case USB_CDC_NOTIFY_SERIAL_STATE:
 256
 257                         newctrl = le16_to_cpu(get_unaligned((__le16 *) data));
 258
 259                         if (acm->tty && !acm->clocal && (acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
 260                                 dbg("calling hangup");
 261                                 tty_hangup(acm->tty);
 262                         }
 263
 264                         acm->ctrlin = newctrl;
 265
 266                         dbg("input control lines: dcd%c dsr%c break%c ring%c framing%c parity%c overrun%c",
 267                                 acm->ctrlin & ACM_CTRL_DCD ? '+' : '-', acm->ctrlin & ACM_CTRL_DSR ? '+' : '-',
 268                                 acm->ctrlin & ACM_CTRL_BRK ? '+' : '-', acm->ctrlin & ACM_CTRL_RI  ? '+' : '-',
 269                                 acm->ctrlin & ACM_CTRL_FRAMING ? '+' : '-',     acm->ctrlin & ACM_CTRL_PARITY ? '+' : '-',
 270                                 acm->ctrlin & ACM_CTRL_OVERRUN ? '+' : '-');
 271
 272                         break;
 273
 274                 default:
 275                         dbg("unknown notification %d received: index %d len %d data0 %d data1 %d",
 276                                 dr->bNotificationType, dr->wIndex,
 277                                 dr->wLength, data[0], data[1]);
 278                         break;
 279         }
 280 exit:
 281         status = usb_submit_urb (urb, GFP_ATOMIC);
 282         if (status)
 283                 err ("%s - usb_submit_urb failed with result %d",
 284                      __FUNCTION__, status);
 285 }
 286
 287 /* data interface returns incoming bytes, or we got unthrottled */
 288 static void acm_read_bulk(struct urb *urb, struct pt_regs *regs)
 289 {
 290         struct acm_rb *buf;
 291         struct acm_ru *rcv = urb->context;
 292         struct acm *acm = rcv->instance;
 293         dbg("Entering acm_read_bulk with status %d\n", urb->status);
 294
 295         if (!ACM_READY(acm))
 296                 return;
 297
 298         if (urb->status)
 299                 dev_dbg(&acm->data->dev, "bulk rx status %d\n", urb->status);
 300
 301         buf = rcv->buffer;
 302         buf->size = urb->actual_length;
 303
 304         spin_lock(&acm->read_lock);
 305         list_add_tail(&rcv->list, &acm->spare_read_urbs);
 306         list_add_tail(&buf->list, &acm->filled_read_bufs);
 307         spin_unlock(&acm->read_lock);
 308
 309         tasklet_schedule(&acm->urb_task);
 310 }
 311
 312 static void acm_rx_tasklet(unsigned long _acm)
 313 {
 314         struct acm *acm = (void *)_acm;
 315         struct acm_rb *buf;
 316         struct tty_struct *tty = acm->tty;
 317         struct acm_ru *rcv;
 318         //unsigned long flags;
 319         int i = 0;
 320         dbg("Entering acm_rx_tasklet");
 321
 322         if (!ACM_READY(acm) || acm->throttle)
 323                 return;
 324
 325 next_buffer:
 326         spin_lock(&acm->read_lock);
 327         if (list_empty(&acm->filled_read_bufs)) {
 328                 spin_unlock(&acm->read_lock);
 329                 goto urbs;
 330         }
 331         buf = list_entry(acm->filled_read_bufs.next,
 332                          struct acm_rb, list);
 333         list_del(&buf->list);
 334         spin_unlock(&acm->read_lock);
 335
 336         dbg("acm_rx_tasklet: procesing buf 0x%p, size = %d\n", buf, buf->size);
 337
 338         tty_buffer_request_room(tty, buf->size);
 339         if (!acm->throttle)
 340                 tty_insert_flip_string(tty, buf->base, buf->size);
 341         tty_flip_buffer_push(tty);
 342
 343         spin_lock(&acm->throttle_lock);
 344         if (acm->throttle) {
 345                 dbg("Throtteling noticed");
 346                 memmove(buf->base, buf->base + i, buf->size - i);
 347                 buf->size -= i;
 348                 spin_unlock(&acm->throttle_lock);
 349                 spin_lock(&acm->read_lock);
 350                 list_add(&buf->list, &acm->filled_read_bufs);
 351                 spin_unlock(&acm->read_lock);
 352                 return;
 353         }
 354         spin_unlock(&acm->throttle_lock);
 355
 356         spin_lock(&acm->read_lock);
 357         list_add(&buf->list, &acm->spare_read_bufs);
 358         spin_unlock(&acm->read_lock);
 359         goto next_buffer;
 360
 361 urbs:
 362         while (!list_empty(&acm->spare_read_bufs)) {
 363                 spin_lock(&acm->read_lock);
 364                 if (list_empty(&acm->spare_read_urbs)) {
 365                         spin_unlock(&acm->read_lock);
 366                         return;
 367                 }
 368                 rcv = list_entry(acm->spare_read_urbs.next,
 369                                  struct acm_ru, list);
 370                 list_del(&rcv->list);
 371                 spin_unlock(&acm->read_lock);
 372
 373                 buf = list_entry(acm->spare_read_bufs.next,
 374                                  struct acm_rb, list);
 375                 list_del(&buf->list);
 376
 377                 rcv->buffer = buf;
 378
 379                 usb_fill_bulk_urb(rcv->urb, acm->dev,
 380                                   acm->rx_endpoint,
 381                                   buf->base,
 382                                   acm->readsize,
 383                                   acm_read_bulk, rcv);
 384                 rcv->urb->transfer_dma = buf->dma;
 385                 rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 386
 387                 dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p\n", rcv->urb, rcv, buf);
 388
 389                 /* This shouldn't kill the driver as unsuccessful URBs are returned to the
 390                    free-urbs-pool and resubmited ASAP */
 391                 if (usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
 392                         list_add(&buf->list, &acm->spare_read_bufs);
 393                         spin_lock(&acm->read_lock);
 394                         list_add(&rcv->list, &acm->spare_read_urbs);
 395                         spin_unlock(&acm->read_lock);
 396                         return;
 397                 }
 398         }
 399 }
 400
 401 /* data interface wrote those outgoing bytes */
 402 static void acm_write_bulk(struct urb *urb, struct pt_regs *regs)
 403 {
 404         struct acm *acm = (struct acm *)urb->context;
 405
 406         dbg("Entering acm_write_bulk with status %d\n", urb->status);
 407
 408         acm_write_done(acm);
 409         acm_write_start(acm);
 410         if (ACM_READY(acm))
 411                 schedule_work(&acm->work);
 412 }
 413
 414 static void acm_softint(void *private)
 415 {
 416         struct acm *acm = private;
 417         dbg("Entering acm_softint.\n");
 418
 419         if (!ACM_READY(acm))
 420                 return;
 421         tty_wakeup(acm->tty);
 422 }
 423
 424 /*
 425  * TTY handlers
 426  */
 427
 428 static int acm_tty_open(struct tty_struct *tty, struct file *filp)
 429 {
 430         struct acm *acm;
 431         int rv = -EINVAL;
 432         int i;
 433         dbg("Entering acm_tty_open.\n");
 434
 435         down(&open_sem);
 436
 437         acm = acm_table[tty->index];
 438         if (!acm || !acm->dev)
 439                 goto err_out;
 440         else
 441                 rv = 0;
 442
 443         tty->driver_data = acm;
 444         acm->tty = tty;
 445
 446         /* force low_latency on so that our tty_push actually forces the data through,
 447            otherwise it is scheduled, and with high data rates data can get lost. */
 448         tty->low_latency = 1;
 449
 450         if (acm->used++) {
 451                 goto done;
 452         }
 453
 454         acm->ctrlurb->dev = acm->dev;
 455         if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
 456                 dbg("usb_submit_urb(ctrl irq) failed");
 457                 goto bail_out;
 458         }
 459
 460         if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS))
 461                 goto full_bailout;
 462
 463         INIT_LIST_HEAD(&acm->spare_read_urbs);
 464         INIT_LIST_HEAD(&acm->spare_read_bufs);
 465         INIT_LIST_HEAD(&acm->filled_read_bufs);
 466         for (i = 0; i < ACM_NRU; i++) {
 467                 list_add(&(acm->ru[i].list), &acm->spare_read_urbs);
 468         }
 469         for (i = 0; i < ACM_NRB; i++) {
 470                 list_add(&(acm->rb[i].list), &acm->spare_read_bufs);
 471         }
 472
 473         tasklet_schedule(&acm->urb_task);
 474
 475 done:
 476 err_out:
 477         up(&open_sem);
 478         return rv;
 479
 480 full_bailout:
 481         usb_kill_urb(acm->ctrlurb);
 482 bail_out:
 483         acm->used--;
 484         up(&open_sem);
 485         return -EIO;
 486 }
 487
 488 static void acm_tty_unregister(struct acm *acm)
 489 {
 490         int i;
 491
 492         tty_unregister_device(acm_tty_driver, acm->minor);
 493         usb_put_intf(acm->control);
 494         acm_table[acm->minor] = NULL;
 495         usb_free_urb(acm->ctrlurb);
 496         usb_free_urb(acm->writeurb);
 497         for (i = 0; i < ACM_NRU; i++)
 498                 usb_free_urb(acm->ru[i].urb);
 499         kfree(acm);
 500 }
 501
 502 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 503 {
 504         struct acm *acm = tty->driver_data;
 505         int i;
 506
 507         if (!acm || !acm->used)
 508                 return;
 509
 510         down(&open_sem);
 511         if (!--acm->used) {
 512                 if (acm->dev) {
 513                         acm_set_control(acm, acm->ctrlout = 0);
 514                         usb_kill_urb(acm->ctrlurb);
 515                         usb_kill_urb(acm->writeurb);
 516                         for (i = 0; i < ACM_NRU; i++)
 517                                 usb_kill_urb(acm->ru[i].urb);
 518                 } else
 519                         acm_tty_unregister(acm);
 520         }
 521         up(&open_sem);
 522 }
 523
 524 static int acm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
 525 {
 526         struct acm *acm = tty->driver_data;
 527         int stat;
 528         unsigned long flags;
 529         int wbn;
 530         struct acm_wb *wb;
 531
 532         dbg("Entering acm_tty_write to write %d bytes,\n", count);
 533
 534         if (!ACM_READY(acm))
 535                 return -EINVAL;
 536         if (!count)
 537                 return 0;
 538
 539         spin_lock_irqsave(&acm->write_lock, flags);
 540         if ((wbn = acm_wb_alloc(acm)) < 0) {
 541                 spin_unlock_irqrestore(&acm->write_lock, flags);
 542                 acm_write_start(acm);
 543                 return 0;
 544         }
 545         wb = &acm->wb[wbn];
 546
 547         count = (count > acm->writesize) ? acm->writesize : count;
 548         dbg("Get %d bytes...", count);
 549         memcpy(wb->buf, buf, count);
 550         wb->len = count;
 551         spin_unlock_irqrestore(&acm->write_lock, flags);
 552
 553         if ((stat = acm_write_start(acm)) < 0)
 554                 return stat;
 555         return count;
 556 }
 557
 558 static int acm_tty_write_room(struct tty_struct *tty)
 559 {
 560         struct acm *acm = tty->driver_data;
 561         if (!ACM_READY(acm))
 562                 return -EINVAL;
 563         /*
 564          * Do not let the line discipline to know that we have a reserve,
 565          * or it might get too enthusiastic.
 566          */
 567         return (acm->write_ready && acm_wb_is_avail(acm)) ? acm->writesize : 0;
 568 }
 569
 570 static int acm_tty_chars_in_buffer(struct tty_struct *tty)
 571 {
 572         struct acm *acm = tty->driver_data;
 573         if (!ACM_READY(acm))
 574                 return -EINVAL;
 575         /*
 576          * This is inaccurate (overcounts), but it works.
 577          */
 578         return (ACM_NWB - acm_wb_is_avail(acm)) * acm->writesize;
 579 }
 580
 581 static void acm_tty_throttle(struct tty_struct *tty)
 582 {
 583         struct acm *acm = tty->driver_data;
 584         if (!ACM_READY(acm))
 585                 return;
 586         spin_lock_bh(&acm->throttle_lock);
 587         acm->throttle = 1;
 588         spin_unlock_bh(&acm->throttle_lock);
 589 }
 590
 591 static void acm_tty_unthrottle(struct tty_struct *tty)
 592 {
 593         struct acm *acm = tty->driver_data;
 594         if (!ACM_READY(acm))
 595                 return;
 596         spin_lock_bh(&acm->throttle_lock);
 597         acm->throttle = 0;
 598         spin_unlock_bh(&acm->throttle_lock);
 599         tasklet_schedule(&acm->urb_task);
 600 }
 601
 602 static void acm_tty_break_ctl(struct tty_struct *tty, int state)
 603 {
 604         struct acm *acm = tty->driver_data;
 605         if (!ACM_READY(acm))
 606                 return;
 607         if (acm_send_break(acm, state ? 0xffff : 0))
 608                 dbg("send break failed");
 609 }
 610
 611 static int acm_tty_tiocmget(struct tty_struct *tty, struct file *file)
 612 {
 613         struct acm *acm = tty->driver_data;
 614
 615         if (!ACM_READY(acm))
 616                 return -EINVAL;
 617
 618         return (acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
 619                (acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
 620                (acm->ctrlin  & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
 621                (acm->ctrlin  & ACM_CTRL_RI  ? TIOCM_RI  : 0) |
 622                (acm->ctrlin  & ACM_CTRL_DCD ? TIOCM_CD  : 0) |
 623                TIOCM_CTS;
 624 }
 625
 626 static int acm_tty_tiocmset(struct tty_struct *tty, struct file *file,
 627                             unsigned int set, unsigned int clear)
 628 {
 629         struct acm *acm = tty->driver_data;
 630         unsigned int newctrl;
 631
 632         if (!ACM_READY(acm))
 633                 return -EINVAL;
 634
 635         newctrl = acm->ctrlout;
 636         set = (set & TIOCM_DTR ? ACM_CTRL_DTR : 0) | (set & TIOCM_RTS ? ACM_CTRL_RTS : 0);
 637         clear = (clear & TIOCM_DTR ? ACM_CTRL_DTR : 0) | (clear & TIOCM_RTS ? ACM_CTRL_RTS : 0);
 638
 639         newctrl = (newctrl & ~clear) | set;
 640
 641         if (acm->ctrlout == newctrl)
 642                 return 0;
 643         return acm_set_control(acm, acm->ctrlout = newctrl);
 644 }
 645
 646 static int acm_tty_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
 647 {
 648         struct acm *acm = tty->driver_data;
 649
 650         if (!ACM_READY(acm))
 651                 return -EINVAL;
 652
 653         return -ENOIOCTLCMD;
 654 }
 655
 656 static const __u32 acm_tty_speed[] = {
 657         0, 50, 75, 110, 134, 150, 200, 300, 600,
 658         1200, 1800, 2400, 4800, 9600, 19200, 38400,
 659         57600, 115200, 230400, 460800, 500000, 576000,
 660         921600, 1000000, 1152000, 1500000, 2000000,
 661         2500000, 3000000, 3500000, 4000000
 662 };
 663
 664 static const __u8 acm_tty_size[] = {
 665         5, 6, 7, 8
 666 };
 667
 668 static void acm_tty_set_termios(struct tty_struct *tty, struct termios *termios_old)
 669 {
 670         struct acm *acm = tty->driver_data;
 671         struct termios *termios = tty->termios;
 672         struct usb_cdc_line_coding newline;
 673         int newctrl = acm->ctrlout;
 674
 675         if (!ACM_READY(acm))
 676                 return;
 677
 678         newline.dwDTERate = cpu_to_le32p(acm_tty_speed +
 679                 (termios->c_cflag & CBAUD & ~CBAUDEX) + (termios->c_cflag & CBAUDEX ? 15 : 0));
 680         newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
 681         newline.bParityType = termios->c_cflag & PARENB ?
 682                 (termios->c_cflag & PARODD ? 1 : 2) + (termios->c_cflag & CMSPAR ? 2 : 0) : 0;
 683         newline.bDataBits = acm_tty_size[(termios->c_cflag & CSIZE) >> 4];
 684
 685         acm->clocal = ((termios->c_cflag & CLOCAL) != 0);
 686
 687         if (!newline.dwDTERate) {
 688                 newline.dwDTERate = acm->line.dwDTERate;
 689                 newctrl &= ~ACM_CTRL_DTR;
 690         } else  newctrl |=  ACM_CTRL_DTR;
 691
 692         if (newctrl != acm->ctrlout)
 693                 acm_set_control(acm, acm->ctrlout = newctrl);
 694
 695         if (memcmp(&acm->line, &newline, sizeof newline)) {
 696                 memcpy(&acm->line, &newline, sizeof newline);
 697                 dbg("set line: %d %d %d %d", le32_to_cpu(newline.dwDTERate),
 698                         newline.bCharFormat, newline.bParityType,
 699                         newline.bDataBits);
 700                 acm_set_line(acm, &acm->line);
 701         }
 702 }
 703
 704 /*
 705  * USB probe and disconnect routines.
 706  */
 707
 708 /* Little helper: write buffers free */
 709 static void acm_write_buffers_free(struct acm *acm)
 710 {
 711         int i;
 712         struct acm_wb *wb;
 713
 714         for (wb = &acm->wb[0], i = 0; i < ACM_NWB; i++, wb++) {
 715                 usb_buffer_free(acm->dev, acm->writesize, wb->buf, wb->dmah);
 716         }
 717 }
 718
 719 /* Little helper: write buffers allocate */
 720 static int acm_write_buffers_alloc(struct acm *acm)
 721 {
 722         int i;
 723         struct acm_wb *wb;
 724
 725         for (wb = &acm->wb[0], i = 0; i < ACM_NWB; i++, wb++) {
 726                 wb->buf = usb_buffer_alloc(acm->dev, acm->writesize, GFP_KERNEL,
 727                     &wb->dmah);
 728                 if (!wb->buf) {
 729                         while (i != 0) {
 730                                 --i;
 731                                 --wb;
 732                                 usb_buffer_free(acm->dev, acm->writesize,
 733                                     wb->buf, wb->dmah);
 734                         }
 735                         return -ENOMEM;
 736                 }
 737         }
 738         return 0;
 739 }
 740
 741 static int acm_probe (struct usb_interface *intf,
 742                       const struct usb_device_id *id)
 743 {
 744         struct usb_cdc_union_desc *union_header = NULL;
 745         char *buffer = intf->altsetting->extra;
 746         int buflen = intf->altsetting->extralen;
 747         struct usb_interface *control_interface;
 748         struct usb_interface *data_interface;
 749         struct usb_endpoint_descriptor *epctrl;
 750         struct usb_endpoint_descriptor *epread;
 751         struct usb_endpoint_descriptor *epwrite;
 752         struct usb_device *usb_dev = interface_to_usbdev(intf);
 753         struct acm *acm;
 754         int minor;
 755         int ctrlsize,readsize;
 756         u8 *buf;
 757         u8 ac_management_function = 0;
 758         u8 call_management_function = 0;
 759         int call_interface_num = -1;
 760         int data_interface_num;
 761         unsigned long quirks;
 762         int i;
 763
 764         /* handle quirks deadly to normal probing*/
 765         quirks = (unsigned long)id->driver_info;
 766         if (quirks == NO_UNION_NORMAL) {
 767                 data_interface = usb_ifnum_to_if(usb_dev, 1);
 768                 control_interface = usb_ifnum_to_if(usb_dev, 0);
 769                 goto skip_normal_probe;
 770         }
 771
 772         /* normal probing*/
 773         if (!buffer) {
 774                 err("Wierd descriptor references\n");
 775                 return -EINVAL;
 776         }
 777
 778         if (!buflen) {
 779                 if (intf->cur_altsetting->endpoint->extralen && intf->cur_altsetting->endpoint->extra) {
 780                         dev_dbg(&intf->dev,"Seeking extra descriptors on endpoint\n");
 781                         buflen = intf->cur_altsetting->endpoint->extralen;
 782                         buffer = intf->cur_altsetting->endpoint->extra;
 783                 } else {
 784                         err("Zero length descriptor references\n");
 785                         return -EINVAL;
 786                 }
 787         }
 788
 789         while (buflen > 0) {
 790                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 791                         err("skipping garbage\n");
 792                         goto next_desc;
 793                 }
 794
 795                 switch (buffer [2]) {
 796                         case USB_CDC_UNION_TYPE: /* we've found it */
 797                                 if (union_header) {
 798                                         err("More than one union descriptor, skipping ...");
 799                                         goto next_desc;
 800                                 }
 801                                 union_header = (struct usb_cdc_union_desc *)
 802                                                         buffer;
 803                                 break;
 804                         case USB_CDC_COUNTRY_TYPE: /* maybe somehow export */
 805                                 break; /* for now we ignore it */
 806                         case USB_CDC_HEADER_TYPE: /* maybe check version */
 807                                 break; /* for now we ignore it */
 808                         case USB_CDC_ACM_TYPE:
 809                                 ac_management_function = buffer[3];
 810                                 break;
 811                         case USB_CDC_CALL_MANAGEMENT_TYPE:
 812                                 call_management_function = buffer[3];
 813                                 call_interface_num = buffer[4];
 814                                 if ((call_management_function & 3) != 3)
 815                                         err("This device cannot do calls on its own. It is no modem.");
 816                                 break;
 817
 818                         default:
 819                                 err("Ignoring extra header, type %d, length %d", buffer[2], buffer[0]);
 820                                 break;
 821                         }
 822 next_desc:
 823                 buflen -= buffer[0];
 824                 buffer += buffer[0];
 825         }
 826
 827         if (!union_header) {
 828                 if (call_interface_num > 0) {
 829                         dev_dbg(&intf->dev,"No union descriptor, using call management descriptor\n");
 830                         data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
 831                         control_interface = intf;
 832                 } else {
 833                         dev_dbg(&intf->dev,"No union descriptor, giving up\n");
 834                         return -ENODEV;
 835                 }
 836         } else {
 837                 control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
 838                 data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
 839                 if (!control_interface || !data_interface) {
 840                         dev_dbg(&intf->dev,"no interfaces\n");
 841                         return -ENODEV;
 842                 }
 843         }
 844
 845         if (data_interface_num != call_interface_num)
 846                 dev_dbg(&intf->dev,"Seperate call control interface. That is not fully supported.\n");
 847
 848 skip_normal_probe:
 849
 850         /*workaround for switched interfaces */
 851         if (data_interface->cur_altsetting->desc.bInterfaceClass != CDC_DATA_INTERFACE_TYPE) {
 852                 if (control_interface->cur_altsetting->desc.bInterfaceClass == CDC_DATA_INTERFACE_TYPE) {
 853                         struct usb_interface *t;
 854                         dev_dbg(&intf->dev,"Your device has switched interfaces.\n");
 855
 856                         t = control_interface;
 857                         control_interface = data_interface;
 858                         data_interface = t;
 859                 } else {
 860                         return -EINVAL;
 861                 }
 862         }
 863
 864         if (usb_interface_claimed(data_interface)) { /* valid in this context */
 865                 dev_dbg(&intf->dev,"The data interface isn't available\n");
 866                 return -EBUSY;
 867         }
 868
 869
 870         if (data_interface->cur_altsetting->desc.bNumEndpoints < 2)
 871                 return -EINVAL;
 872
 873         epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
 874         epread = &data_interface->cur_altsetting->endpoint[0].desc;
 875         epwrite = &data_interface->cur_altsetting->endpoint[1].desc;
 876
 877
 878         /* workaround for switched endpoints */
 879         if ((epread->bEndpointAddress & USB_DIR_IN) != USB_DIR_IN) {
 880                 /* descriptors are swapped */
 881                 struct usb_endpoint_descriptor *t;
 882                 dev_dbg(&intf->dev,"The data interface has switched endpoints\n");
 883
 884                 t = epread;
 885                 epread = epwrite;
 886                 epwrite = t;
 887         }
 888         dbg("interfaces are valid");
 889         for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);
 890
 891         if (minor == ACM_TTY_MINORS) {
 892                 err("no more free acm devices");
 893                 return -ENODEV;
 894         }
 895
 896         if (!(acm = kzalloc(sizeof(struct acm), GFP_KERNEL))) {
 897                 dev_dbg(&intf->dev, "out of memory (acm kzalloc)\n");
 898                 goto alloc_fail;
 899         }
 900
 901         ctrlsize = le16_to_cpu(epctrl->wMaxPacketSize);
 902         readsize = le16_to_cpu(epread->wMaxPacketSize)*2;
 903         acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize);
 904         acm->control = control_interface;
 905         acm->data = data_interface;
 906         acm->minor = minor;
 907         acm->dev = usb_dev;
 908         acm->ctrl_caps = ac_management_function;
 909         acm->ctrlsize = ctrlsize;
 910         acm->readsize = readsize;
 911         acm->urb_task.func = acm_rx_tasklet;
 912         acm->urb_task.data = (unsigned long) acm;
 913         INIT_WORK(&acm->work, acm_softint, acm);
 914         spin_lock_init(&acm->throttle_lock);
 915         spin_lock_init(&acm->write_lock);
 916         spin_lock_init(&acm->read_lock);
 917         acm->write_ready = 1;
 918         acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
 919
 920         buf = usb_buffer_alloc(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
 921         if (!buf) {
 922                 dev_dbg(&intf->dev, "out of memory (ctrl buffer alloc)\n");
 923                 goto alloc_fail2;
 924         }
 925         acm->ctrl_buffer = buf;
 926
 927         if (acm_write_buffers_alloc(acm) < 0) {
 928                 dev_dbg(&intf->dev, "out of memory (write buffer alloc)\n");
 929                 goto alloc_fail4;
 930         }
 931
 932         acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
 933         if (!acm->ctrlurb) {
 934                 dev_dbg(&intf->dev, "out of memory (ctrlurb kmalloc)\n");
 935                 goto alloc_fail5;
 936         }
 937         for (i = 0; i < ACM_NRU; i++) {
 938                 struct acm_ru *rcv = &(acm->ru[i]);
 939
 940                 if (!(rcv->urb = usb_alloc_urb(0, GFP_KERNEL))) {
 941                         dev_dbg(&intf->dev, "out of memory (read urbs usb_alloc_urb)\n");
 942                         goto alloc_fail7;
 943                 }
 944
 945                 rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 946                 rcv->instance = acm;
 947         }
 948         for (i = 0; i < ACM_NRB; i++) {
 949                 struct acm_rb *buf = &(acm->rb[i]);
 950
 951                 // Using usb_buffer_alloc instead of kmalloc as Oliver suggested
 952                 if (!(buf->base = usb_buffer_alloc(acm->dev, readsize, GFP_KERNEL, &buf->dma))) {
 953                         dev_dbg(&intf->dev, "out of memory (read bufs usb_buffer_alloc)\n");
 954                         goto alloc_fail7;
 955                 }
 956         }
 957         acm->writeurb = usb_alloc_urb(0, GFP_KERNEL);
 958         if (!acm->writeurb) {
 959                 dev_dbg(&intf->dev, "out of memory (writeurb kmalloc)\n");
 960                 goto alloc_fail7;
 961         }
 962
 963         usb_fill_int_urb(acm->ctrlurb, usb_dev, usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
 964                          acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm, epctrl->bInterval);
 965         acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 966         acm->ctrlurb->transfer_dma = acm->ctrl_dma;
 967
 968         usb_fill_bulk_urb(acm->writeurb, usb_dev, usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
 969                           NULL, acm->writesize, acm_write_bulk, acm);
 970         acm->writeurb->transfer_flags |= URB_NO_FSBR | URB_NO_TRANSFER_DMA_MAP;
 971
 972         dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
 973
 974         acm_set_control(acm, acm->ctrlout);
 975
 976         acm->line.dwDTERate = cpu_to_le32(9600);
 977         acm->line.bDataBits = 8;
 978         acm_set_line(acm, &acm->line);
 979
 980         usb_driver_claim_interface(&acm_driver, data_interface, acm);
 981
 982         usb_get_intf(control_interface);
 983         tty_register_device(acm_tty_driver, minor, &control_interface->dev);
 984
 985         acm_table[minor] = acm;
 986         usb_set_intfdata (intf, acm);
 987         return 0;
 988
 989 alloc_fail7:
 990         for (i = 0; i < ACM_NRB; i++)
 991                 usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
 992         for (i = 0; i < ACM_NRU; i++)
 993                 usb_free_urb(acm->ru[i].urb);
 994         usb_free_urb(acm->ctrlurb);
 995 alloc_fail5:
 996         acm_write_buffers_free(acm);
 997 alloc_fail4:
 998         usb_buffer_free(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
 999 alloc_fail2:
1000         kfree(acm);
1001 alloc_fail:
1002         return -ENOMEM;
1003 }
1004
1005 static void acm_disconnect(struct usb_interface *intf)
1006 {
1007         struct acm *acm = usb_get_intfdata (intf);
1008         struct usb_device *usb_dev = interface_to_usbdev(intf);
1009         int i;
1010
1011         if (!acm || !acm->dev) {
1012                 dbg("disconnect on nonexisting interface");
1013                 return;
1014         }
1015
1016         down(&open_sem);
1017         acm->dev = NULL;
1018         usb_set_intfdata (intf, NULL);
1019
1020         tasklet_disable(&acm->urb_task);
1021
1022         usb_kill_urb(acm->ctrlurb);
1023         usb_kill_urb(acm->writeurb);
1024         for (i = 0; i < ACM_NRU; i++)
1025                 usb_kill_urb(acm->ru[i].urb);
1026
1027         INIT_LIST_HEAD(&acm->filled_read_bufs);
1028         INIT_LIST_HEAD(&acm->spare_read_bufs);
1029
1030         tasklet_enable(&acm->urb_task);
1031
1032         flush_scheduled_work(); /* wait for acm_softint */
1033
1034         acm_write_buffers_free(acm);
1035         usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1036         for (i = 0; i < ACM_NRB; i++)
1037                 usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
1038
1039         usb_driver_release_interface(&acm_driver, acm->data);
1040
1041         if (!acm->used) {
1042                 acm_tty_unregister(acm);
1043                 up(&open_sem);
1044                 return;
1045         }
1046
1047         up(&open_sem);
1048
1049         if (acm->tty)
1050                 tty_hangup(acm->tty);
1051 }
1052
1053 /*
1054  * USB driver structure.
1055  */
1056
1057 static struct usb_device_id acm_ids[] = {
1058         /* quirky and broken devices */
1059         { USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
1060         .driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1061         },
1062         { USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
1063         .driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1064         },
1065         /* control interfaces with various AT-command sets */
1066         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1067                 USB_CDC_ACM_PROTO_AT_V25TER) },
1068         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1069                 USB_CDC_ACM_PROTO_AT_PCCA101) },
1070         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1071                 USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
1072         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1073                 USB_CDC_ACM_PROTO_AT_GSM) },
1074         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1075                 USB_CDC_ACM_PROTO_AT_3G ) },
1076         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1077                 USB_CDC_ACM_PROTO_AT_CDMA) },
1078
1079         /* NOTE:  COMM/ACM/0xff is likely MSFT RNDIS ... NOT a modem!! */
1080         { }
1081 };
1082
1083 MODULE_DEVICE_TABLE (usb, acm_ids);
1084
1085 static struct usb_driver acm_driver = {
1086         .name =         "cdc_acm",
1087         .probe =        acm_probe,
1088         .disconnect =   acm_disconnect,
1089         .id_table =     acm_ids,
1090 };
1091
1092 /*
1093  * TTY driver structures.
1094  */
1095
1096 static struct tty_operations acm_ops = {
1097         .open =                 acm_tty_open,
1098         .close =                acm_tty_close,
1099         .write =                acm_tty_write,
1100         .write_room =           acm_tty_write_room,
1101         .ioctl =                acm_tty_ioctl,
1102         .throttle =             acm_tty_throttle,
1103         .unthrottle =           acm_tty_unthrottle,
1104         .chars_in_buffer =      acm_tty_chars_in_buffer,
1105         .break_ctl =            acm_tty_break_ctl,
1106         .set_termios =          acm_tty_set_termios,
1107         .tiocmget =             acm_tty_tiocmget,
1108         .tiocmset =             acm_tty_tiocmset,
1109 };
1110
1111 /*
1112  * Init / exit.
1113  */
1114
1115 static int __init acm_init(void)
1116 {
1117         int retval;
1118         acm_tty_driver = alloc_tty_driver(ACM_TTY_MINORS);
1119         if (!acm_tty_driver)
1120                 return -ENOMEM;
1121         acm_tty_driver->owner = THIS_MODULE,
1122         acm_tty_driver->driver_name = "acm",
1123         acm_tty_driver->name = "ttyACM",
1124         acm_tty_driver->devfs_name = "usb/acm/",
1125         acm_tty_driver->major = ACM_TTY_MAJOR,
1126         acm_tty_driver->minor_start = 0,
1127         acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
1128         acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
1129         acm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS,
1130         acm_tty_driver->init_termios = tty_std_termios;
1131         acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1132         tty_set_operations(acm_tty_driver, &acm_ops);
1133
1134         retval = tty_register_driver(acm_tty_driver);
1135         if (retval) {
1136                 put_tty_driver(acm_tty_driver);
1137                 return retval;
1138         }
1139
1140         retval = usb_register(&acm_driver);
1141         if (retval) {
1142                 tty_unregister_driver(acm_tty_driver);
1143                 put_tty_driver(acm_tty_driver);
1144                 return retval;
1145         }
1146
1147         info(DRIVER_VERSION ":" DRIVER_DESC);
1148
1149         return 0;
1150 }
1151
1152 static void __exit acm_exit(void)
1153 {
1154         usb_deregister(&acm_driver);
1155         tty_unregister_driver(acm_tty_driver);
1156         put_tty_driver(acm_tty_driver);
1157 }
1158
1159 module_init(acm_init);
1160 module_exit(acm_exit);
1161
1162 MODULE_AUTHOR( DRIVER_AUTHOR );
1163 MODULE_DESCRIPTION( DRIVER_DESC );
1164 MODULE_LICENSE("GPL");
1165