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         for (i = 0; i < buf->size && !acm->throttle; i++) {
 339                 /* if we insert more than TTY_FLIPBUF_SIZE characters,
 340                    we drop them. */
 341                 if (tty->flip.count >= TTY_FLIPBUF_SIZE) {
 342                         tty_flip_buffer_push(tty);
 343                 }
 344                 tty_insert_flip_char(tty, buf->base[i], 0);
 345         }
 346         tty_flip_buffer_push(tty);
 347
 348         spin_lock(&acm->throttle_lock);
 349         if (acm->throttle) {
 350                 dbg("Throtteling noticed");
 351                 memmove(buf->base, buf->base + i, buf->size - i);
 352                 buf->size -= i;
 353                 spin_unlock(&acm->throttle_lock);
 354                 spin_lock(&acm->read_lock);
 355                 list_add(&buf->list, &acm->filled_read_bufs);
 356                 spin_unlock(&acm->read_lock);
 357                 return;
 358         }
 359         spin_unlock(&acm->throttle_lock);
 360
 361         spin_lock(&acm->read_lock);
 362         list_add(&buf->list, &acm->spare_read_bufs);
 363         spin_unlock(&acm->read_lock);
 364         goto next_buffer;
 365
 366 urbs:
 367         while (!list_empty(&acm->spare_read_bufs)) {
 368                 spin_lock(&acm->read_lock);
 369                 if (list_empty(&acm->spare_read_urbs)) {
 370                         spin_unlock(&acm->read_lock);
 371                         return;
 372                 }
 373                 rcv = list_entry(acm->spare_read_urbs.next,
 374                                  struct acm_ru, list);
 375                 list_del(&rcv->list);
 376                 spin_unlock(&acm->read_lock);
 377
 378                 buf = list_entry(acm->spare_read_bufs.next,
 379                                  struct acm_rb, list);
 380                 list_del(&buf->list);
 381
 382                 rcv->buffer = buf;
 383
 384                 usb_fill_bulk_urb(rcv->urb, acm->dev,
 385                                   acm->rx_endpoint,
 386                                   buf->base,
 387                                   acm->readsize,
 388                                   acm_read_bulk, rcv);
 389                 rcv->urb->transfer_dma = buf->dma;
 390                 rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 391
 392                 dbg("acm_rx_tasklet: sending urb 0x%p, rcv 0x%p, buf 0x%p\n", rcv->urb, rcv, buf);
 393
 394                 /* This shouldn't kill the driver as unsuccessful URBs are returned to the
 395                    free-urbs-pool and resubmited ASAP */
 396                 if (usb_submit_urb(rcv->urb, GFP_ATOMIC) < 0) {
 397                         list_add(&buf->list, &acm->spare_read_bufs);
 398                         spin_lock(&acm->read_lock);
 399                         list_add(&rcv->list, &acm->spare_read_urbs);
 400                         spin_unlock(&acm->read_lock);
 401                         return;
 402                 }
 403         }
 404 }
 405
 406 /* data interface wrote those outgoing bytes */
 407 static void acm_write_bulk(struct urb *urb, struct pt_regs *regs)
 408 {
 409         struct acm *acm = (struct acm *)urb->context;
 410
 411         dbg("Entering acm_write_bulk with status %d\n", urb->status);
 412
 413         acm_write_done(acm);
 414         acm_write_start(acm);
 415         if (ACM_READY(acm))
 416                 schedule_work(&acm->work);
 417 }
 418
 419 static void acm_softint(void *private)
 420 {
 421         struct acm *acm = private;
 422         dbg("Entering acm_softint.\n");
 423
 424         if (!ACM_READY(acm))
 425                 return;
 426         tty_wakeup(acm->tty);
 427 }
 428
 429 /*
 430  * TTY handlers
 431  */
 432
 433 static int acm_tty_open(struct tty_struct *tty, struct file *filp)
 434 {
 435         struct acm *acm;
 436         int rv = -EINVAL;
 437         int i;
 438         dbg("Entering acm_tty_open.\n");
 439
 440         down(&open_sem);
 441
 442         acm = acm_table[tty->index];
 443         if (!acm || !acm->dev)
 444                 goto err_out;
 445         else
 446                 rv = 0;
 447
 448         tty->driver_data = acm;
 449         acm->tty = tty;
 450
 451         /* force low_latency on so that our tty_push actually forces the data through,
 452            otherwise it is scheduled, and with high data rates data can get lost. */
 453         tty->low_latency = 1;
 454
 455         if (acm->used++) {
 456                 goto done;
 457         }
 458
 459         acm->ctrlurb->dev = acm->dev;
 460         if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {
 461                 dbg("usb_submit_urb(ctrl irq) failed");
 462                 goto bail_out;
 463         }
 464
 465         if (0 > acm_set_control(acm, acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS))
 466                 goto full_bailout;
 467
 468         INIT_LIST_HEAD(&acm->spare_read_urbs);
 469         INIT_LIST_HEAD(&acm->spare_read_bufs);
 470         INIT_LIST_HEAD(&acm->filled_read_bufs);
 471         for (i = 0; i < ACM_NRU; i++) {
 472                 list_add(&(acm->ru[i].list), &acm->spare_read_urbs);
 473         }
 474         for (i = 0; i < ACM_NRB; i++) {
 475                 list_add(&(acm->rb[i].list), &acm->spare_read_bufs);
 476         }
 477
 478         tasklet_schedule(&acm->urb_task);
 479
 480 done:
 481 err_out:
 482         up(&open_sem);
 483         return rv;
 484
 485 full_bailout:
 486         usb_kill_urb(acm->ctrlurb);
 487 bail_out:
 488         acm->used--;
 489         up(&open_sem);
 490         return -EIO;
 491 }
 492
 493 static void acm_tty_unregister(struct acm *acm)
 494 {
 495         int i;
 496
 497         tty_unregister_device(acm_tty_driver, acm->minor);
 498         usb_put_intf(acm->control);
 499         acm_table[acm->minor] = NULL;
 500         usb_free_urb(acm->ctrlurb);
 501         usb_free_urb(acm->writeurb);
 502         for (i = 0; i < ACM_NRU; i++)
 503                 usb_free_urb(acm->ru[i].urb);
 504         kfree(acm);
 505 }
 506
 507 static void acm_tty_close(struct tty_struct *tty, struct file *filp)
 508 {
 509         struct acm *acm = tty->driver_data;
 510         int i;
 511
 512         if (!acm || !acm->used)
 513                 return;
 514
 515         down(&open_sem);
 516         if (!--acm->used) {
 517                 if (acm->dev) {
 518                         acm_set_control(acm, acm->ctrlout = 0);
 519                         usb_kill_urb(acm->ctrlurb);
 520                         usb_kill_urb(acm->writeurb);
 521                         for (i = 0; i < ACM_NRU; i++)
 522                                 usb_kill_urb(acm->ru[i].urb);
 523                 } else
 524                         acm_tty_unregister(acm);
 525         }
 526         up(&open_sem);
 527 }
 528
 529 static int acm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
 530 {
 531         struct acm *acm = tty->driver_data;
 532         int stat;
 533         unsigned long flags;
 534         int wbn;
 535         struct acm_wb *wb;
 536
 537         dbg("Entering acm_tty_write to write %d bytes,\n", count);
 538
 539         if (!ACM_READY(acm))
 540                 return -EINVAL;
 541         if (!count)
 542                 return 0;
 543
 544         spin_lock_irqsave(&acm->write_lock, flags);
 545         if ((wbn = acm_wb_alloc(acm)) < 0) {
 546                 spin_unlock_irqrestore(&acm->write_lock, flags);
 547                 acm_write_start(acm);
 548                 return 0;
 549         }
 550         wb = &acm->wb[wbn];
 551
 552         count = (count > acm->writesize) ? acm->writesize : count;
 553         dbg("Get %d bytes...", count);
 554         memcpy(wb->buf, buf, count);
 555         wb->len = count;
 556         spin_unlock_irqrestore(&acm->write_lock, flags);
 557
 558         if ((stat = acm_write_start(acm)) < 0)
 559                 return stat;
 560         return count;
 561 }
 562
 563 static int acm_tty_write_room(struct tty_struct *tty)
 564 {
 565         struct acm *acm = tty->driver_data;
 566         if (!ACM_READY(acm))
 567                 return -EINVAL;
 568         /*
 569          * Do not let the line discipline to know that we have a reserve,
 570          * or it might get too enthusiastic.
 571          */
 572         return (acm->write_ready && acm_wb_is_avail(acm)) ? acm->writesize : 0;
 573 }
 574
 575 static int acm_tty_chars_in_buffer(struct tty_struct *tty)
 576 {
 577         struct acm *acm = tty->driver_data;
 578         if (!ACM_READY(acm))
 579                 return -EINVAL;
 580         /*
 581          * This is inaccurate (overcounts), but it works.
 582          */
 583         return (ACM_NWB - acm_wb_is_avail(acm)) * acm->writesize;
 584 }
 585
 586 static void acm_tty_throttle(struct tty_struct *tty)
 587 {
 588         struct acm *acm = tty->driver_data;
 589         if (!ACM_READY(acm))
 590                 return;
 591         spin_lock_bh(&acm->throttle_lock);
 592         acm->throttle = 1;
 593         spin_unlock_bh(&acm->throttle_lock);
 594 }
 595
 596 static void acm_tty_unthrottle(struct tty_struct *tty)
 597 {
 598         struct acm *acm = tty->driver_data;
 599         if (!ACM_READY(acm))
 600                 return;
 601         spin_lock_bh(&acm->throttle_lock);
 602         acm->throttle = 0;
 603         spin_unlock_bh(&acm->throttle_lock);
 604         tasklet_schedule(&acm->urb_task);
 605 }
 606
 607 static void acm_tty_break_ctl(struct tty_struct *tty, int state)
 608 {
 609         struct acm *acm = tty->driver_data;
 610         if (!ACM_READY(acm))
 611                 return;
 612         if (acm_send_break(acm, state ? 0xffff : 0))
 613                 dbg("send break failed");
 614 }
 615
 616 static int acm_tty_tiocmget(struct tty_struct *tty, struct file *file)
 617 {
 618         struct acm *acm = tty->driver_data;
 619
 620         if (!ACM_READY(acm))
 621                 return -EINVAL;
 622
 623         return (acm->ctrlout & ACM_CTRL_DTR ? TIOCM_DTR : 0) |
 624                (acm->ctrlout & ACM_CTRL_RTS ? TIOCM_RTS : 0) |
 625                (acm->ctrlin  & ACM_CTRL_DSR ? TIOCM_DSR : 0) |
 626                (acm->ctrlin  & ACM_CTRL_RI  ? TIOCM_RI  : 0) |
 627                (acm->ctrlin  & ACM_CTRL_DCD ? TIOCM_CD  : 0) |
 628                TIOCM_CTS;
 629 }
 630
 631 static int acm_tty_tiocmset(struct tty_struct *tty, struct file *file,
 632                             unsigned int set, unsigned int clear)
 633 {
 634         struct acm *acm = tty->driver_data;
 635         unsigned int newctrl;
 636
 637         if (!ACM_READY(acm))
 638                 return -EINVAL;
 639
 640         newctrl = acm->ctrlout;
 641         set = (set & TIOCM_DTR ? ACM_CTRL_DTR : 0) | (set & TIOCM_RTS ? ACM_CTRL_RTS : 0);
 642         clear = (clear & TIOCM_DTR ? ACM_CTRL_DTR : 0) | (clear & TIOCM_RTS ? ACM_CTRL_RTS : 0);
 643
 644         newctrl = (newctrl & ~clear) | set;
 645
 646         if (acm->ctrlout == newctrl)
 647                 return 0;
 648         return acm_set_control(acm, acm->ctrlout = newctrl);
 649 }
 650
 651 static int acm_tty_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
 652 {
 653         struct acm *acm = tty->driver_data;
 654
 655         if (!ACM_READY(acm))
 656                 return -EINVAL;
 657
 658         return -ENOIOCTLCMD;
 659 }
 660
 661 static const __u32 acm_tty_speed[] = {
 662         0, 50, 75, 110, 134, 150, 200, 300, 600,
 663         1200, 1800, 2400, 4800, 9600, 19200, 38400,
 664         57600, 115200, 230400, 460800, 500000, 576000,
 665         921600, 1000000, 1152000, 1500000, 2000000,
 666         2500000, 3000000, 3500000, 4000000
 667 };
 668
 669 static const __u8 acm_tty_size[] = {
 670         5, 6, 7, 8
 671 };
 672
 673 static void acm_tty_set_termios(struct tty_struct *tty, struct termios *termios_old)
 674 {
 675         struct acm *acm = tty->driver_data;
 676         struct termios *termios = tty->termios;
 677         struct usb_cdc_line_coding newline;
 678         int newctrl = acm->ctrlout;
 679
 680         if (!ACM_READY(acm))
 681                 return;
 682
 683         newline.dwDTERate = cpu_to_le32p(acm_tty_speed +
 684                 (termios->c_cflag & CBAUD & ~CBAUDEX) + (termios->c_cflag & CBAUDEX ? 15 : 0));
 685         newline.bCharFormat = termios->c_cflag & CSTOPB ? 2 : 0;
 686         newline.bParityType = termios->c_cflag & PARENB ?
 687                 (termios->c_cflag & PARODD ? 1 : 2) + (termios->c_cflag & CMSPAR ? 2 : 0) : 0;
 688         newline.bDataBits = acm_tty_size[(termios->c_cflag & CSIZE) >> 4];
 689
 690         acm->clocal = ((termios->c_cflag & CLOCAL) != 0);
 691
 692         if (!newline.dwDTERate) {
 693                 newline.dwDTERate = acm->line.dwDTERate;
 694                 newctrl &= ~ACM_CTRL_DTR;
 695         } else  newctrl |=  ACM_CTRL_DTR;
 696
 697         if (newctrl != acm->ctrlout)
 698                 acm_set_control(acm, acm->ctrlout = newctrl);
 699
 700         if (memcmp(&acm->line, &newline, sizeof newline)) {
 701                 memcpy(&acm->line, &newline, sizeof newline);
 702                 dbg("set line: %d %d %d %d", le32_to_cpu(newline.dwDTERate),
 703                         newline.bCharFormat, newline.bParityType,
 704                         newline.bDataBits);
 705                 acm_set_line(acm, &acm->line);
 706         }
 707 }
 708
 709 /*
 710  * USB probe and disconnect routines.
 711  */
 712
 713 /* Little helper: write buffers free */
 714 static void acm_write_buffers_free(struct acm *acm)
 715 {
 716         int i;
 717         struct acm_wb *wb;
 718
 719         for (wb = &acm->wb[0], i = 0; i < ACM_NWB; i++, wb++) {
 720                 usb_buffer_free(acm->dev, acm->writesize, wb->buf, wb->dmah);
 721         }
 722 }
 723
 724 /* Little helper: write buffers allocate */
 725 static int acm_write_buffers_alloc(struct acm *acm)
 726 {
 727         int i;
 728         struct acm_wb *wb;
 729
 730         for (wb = &acm->wb[0], i = 0; i < ACM_NWB; i++, wb++) {
 731                 wb->buf = usb_buffer_alloc(acm->dev, acm->writesize, GFP_KERNEL,
 732                     &wb->dmah);
 733                 if (!wb->buf) {
 734                         while (i != 0) {
 735                                 --i;
 736                                 --wb;
 737                                 usb_buffer_free(acm->dev, acm->writesize,
 738                                     wb->buf, wb->dmah);
 739                         }
 740                         return -ENOMEM;
 741                 }
 742         }
 743         return 0;
 744 }
 745
 746 static int acm_probe (struct usb_interface *intf,
 747                       const struct usb_device_id *id)
 748 {
 749         struct usb_cdc_union_desc *union_header = NULL;
 750         char *buffer = intf->altsetting->extra;
 751         int buflen = intf->altsetting->extralen;
 752         struct usb_interface *control_interface;
 753         struct usb_interface *data_interface;
 754         struct usb_endpoint_descriptor *epctrl;
 755         struct usb_endpoint_descriptor *epread;
 756         struct usb_endpoint_descriptor *epwrite;
 757         struct usb_device *usb_dev = interface_to_usbdev(intf);
 758         struct acm *acm;
 759         int minor;
 760         int ctrlsize,readsize;
 761         u8 *buf;
 762         u8 ac_management_function = 0;
 763         u8 call_management_function = 0;
 764         int call_interface_num = -1;
 765         int data_interface_num;
 766         unsigned long quirks;
 767         int i;
 768
 769         /* handle quirks deadly to normal probing*/
 770         quirks = (unsigned long)id->driver_info;
 771         if (quirks == NO_UNION_NORMAL) {
 772                 data_interface = usb_ifnum_to_if(usb_dev, 1);
 773                 control_interface = usb_ifnum_to_if(usb_dev, 0);
 774                 goto skip_normal_probe;
 775         }
 776
 777         /* normal probing*/
 778         if (!buffer) {
 779                 err("Wierd descriptor references\n");
 780                 return -EINVAL;
 781         }
 782
 783         if (!buflen) {
 784                 if (intf->cur_altsetting->endpoint->extralen && intf->cur_altsetting->endpoint->extra) {
 785                         dev_dbg(&intf->dev,"Seeking extra descriptors on endpoint\n");
 786                         buflen = intf->cur_altsetting->endpoint->extralen;
 787                         buffer = intf->cur_altsetting->endpoint->extra;
 788                 } else {
 789                         err("Zero length descriptor references\n");
 790                         return -EINVAL;
 791                 }
 792         }
 793
 794         while (buflen > 0) {
 795                 if (buffer [1] != USB_DT_CS_INTERFACE) {
 796                         err("skipping garbage\n");
 797                         goto next_desc;
 798                 }
 799
 800                 switch (buffer [2]) {
 801                         case USB_CDC_UNION_TYPE: /* we've found it */
 802                                 if (union_header) {
 803                                         err("More than one union descriptor, skipping ...");
 804                                         goto next_desc;
 805                                 }
 806                                 union_header = (struct usb_cdc_union_desc *)
 807                                                         buffer;
 808                                 break;
 809                         case USB_CDC_COUNTRY_TYPE: /* maybe somehow export */
 810                                 break; /* for now we ignore it */
 811                         case USB_CDC_HEADER_TYPE: /* maybe check version */
 812                                 break; /* for now we ignore it */
 813                         case USB_CDC_ACM_TYPE:
 814                                 ac_management_function = buffer[3];
 815                                 break;
 816                         case USB_CDC_CALL_MANAGEMENT_TYPE:
 817                                 call_management_function = buffer[3];
 818                                 call_interface_num = buffer[4];
 819                                 if ((call_management_function & 3) != 3)
 820                                         err("This device cannot do calls on its own. It is no modem.");
 821                                 break;
 822
 823                         default:
 824                                 err("Ignoring extra header, type %d, length %d", buffer[2], buffer[0]);
 825                                 break;
 826                         }
 827 next_desc:
 828                 buflen -= buffer[0];
 829                 buffer += buffer[0];
 830         }
 831
 832         if (!union_header) {
 833                 if (call_interface_num > 0) {
 834                         dev_dbg(&intf->dev,"No union descriptor, using call management descriptor\n");
 835                         data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));
 836                         control_interface = intf;
 837                 } else {
 838                         dev_dbg(&intf->dev,"No union descriptor, giving up\n");
 839                         return -ENODEV;
 840                 }
 841         } else {
 842                 control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
 843                 data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = union_header->bSlaveInterface0));
 844                 if (!control_interface || !data_interface) {
 845                         dev_dbg(&intf->dev,"no interfaces\n");
 846                         return -ENODEV;
 847                 }
 848         }
 849
 850         if (data_interface_num != call_interface_num)
 851                 dev_dbg(&intf->dev,"Seperate call control interface. That is not fully supported.\n");
 852
 853 skip_normal_probe:
 854
 855         /*workaround for switched interfaces */
 856         if (data_interface->cur_altsetting->desc.bInterfaceClass != CDC_DATA_INTERFACE_TYPE) {
 857                 if (control_interface->cur_altsetting->desc.bInterfaceClass == CDC_DATA_INTERFACE_TYPE) {
 858                         struct usb_interface *t;
 859                         dev_dbg(&intf->dev,"Your device has switched interfaces.\n");
 860
 861                         t = control_interface;
 862                         control_interface = data_interface;
 863                         data_interface = t;
 864                 } else {
 865                         return -EINVAL;
 866                 }
 867         }
 868
 869         if (usb_interface_claimed(data_interface)) { /* valid in this context */
 870                 dev_dbg(&intf->dev,"The data interface isn't available\n");
 871                 return -EBUSY;
 872         }
 873
 874
 875         if (data_interface->cur_altsetting->desc.bNumEndpoints < 2)
 876                 return -EINVAL;
 877
 878         epctrl = &control_interface->cur_altsetting->endpoint[0].desc;
 879         epread = &data_interface->cur_altsetting->endpoint[0].desc;
 880         epwrite = &data_interface->cur_altsetting->endpoint[1].desc;
 881
 882
 883         /* workaround for switched endpoints */
 884         if ((epread->bEndpointAddress & USB_DIR_IN) != USB_DIR_IN) {
 885                 /* descriptors are swapped */
 886                 struct usb_endpoint_descriptor *t;
 887                 dev_dbg(&intf->dev,"The data interface has switched endpoints\n");
 888
 889                 t = epread;
 890                 epread = epwrite;
 891                 epwrite = t;
 892         }
 893         dbg("interfaces are valid");
 894         for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);
 895
 896         if (minor == ACM_TTY_MINORS) {
 897                 err("no more free acm devices");
 898                 return -ENODEV;
 899         }
 900
 901         if (!(acm = kzalloc(sizeof(struct acm), GFP_KERNEL))) {
 902                 dev_dbg(&intf->dev, "out of memory (acm kzalloc)\n");
 903                 goto alloc_fail;
 904         }
 905
 906         ctrlsize = le16_to_cpu(epctrl->wMaxPacketSize);
 907         readsize = le16_to_cpu(epread->wMaxPacketSize)*2;
 908         acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize);
 909         acm->control = control_interface;
 910         acm->data = data_interface;
 911         acm->minor = minor;
 912         acm->dev = usb_dev;
 913         acm->ctrl_caps = ac_management_function;
 914         acm->ctrlsize = ctrlsize;
 915         acm->readsize = readsize;
 916         acm->urb_task.func = acm_rx_tasklet;
 917         acm->urb_task.data = (unsigned long) acm;
 918         INIT_WORK(&acm->work, acm_softint, acm);
 919         spin_lock_init(&acm->throttle_lock);
 920         spin_lock_init(&acm->write_lock);
 921         spin_lock_init(&acm->read_lock);
 922         acm->write_ready = 1;
 923         acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
 924
 925         buf = usb_buffer_alloc(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
 926         if (!buf) {
 927                 dev_dbg(&intf->dev, "out of memory (ctrl buffer alloc)\n");
 928                 goto alloc_fail2;
 929         }
 930         acm->ctrl_buffer = buf;
 931
 932         if (acm_write_buffers_alloc(acm) < 0) {
 933                 dev_dbg(&intf->dev, "out of memory (write buffer alloc)\n");
 934                 goto alloc_fail4;
 935         }
 936
 937         acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
 938         if (!acm->ctrlurb) {
 939                 dev_dbg(&intf->dev, "out of memory (ctrlurb kmalloc)\n");
 940                 goto alloc_fail5;
 941         }
 942         for (i = 0; i < ACM_NRU; i++) {
 943                 struct acm_ru *rcv = &(acm->ru[i]);
 944
 945                 if (!(rcv->urb = usb_alloc_urb(0, GFP_KERNEL))) {
 946                         dev_dbg(&intf->dev, "out of memory (read urbs usb_alloc_urb)\n");
 947                         goto alloc_fail7;
 948                 }
 949
 950                 rcv->urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 951                 rcv->instance = acm;
 952         }
 953         for (i = 0; i < ACM_NRB; i++) {
 954                 struct acm_rb *buf = &(acm->rb[i]);
 955
 956                 // Using usb_buffer_alloc instead of kmalloc as Oliver suggested
 957                 if (!(buf->base = usb_buffer_alloc(acm->dev, readsize, GFP_KERNEL, &buf->dma))) {
 958                         dev_dbg(&intf->dev, "out of memory (read bufs usb_buffer_alloc)\n");
 959                         goto alloc_fail7;
 960                 }
 961         }
 962         acm->writeurb = usb_alloc_urb(0, GFP_KERNEL);
 963         if (!acm->writeurb) {
 964                 dev_dbg(&intf->dev, "out of memory (writeurb kmalloc)\n");
 965                 goto alloc_fail7;
 966         }
 967
 968         usb_fill_int_urb(acm->ctrlurb, usb_dev, usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
 969                          acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm, epctrl->bInterval);
 970         acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 971         acm->ctrlurb->transfer_dma = acm->ctrl_dma;
 972
 973         usb_fill_bulk_urb(acm->writeurb, usb_dev, usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress),
 974                           NULL, acm->writesize, acm_write_bulk, acm);
 975         acm->writeurb->transfer_flags |= URB_NO_FSBR | URB_NO_TRANSFER_DMA_MAP;
 976
 977         dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);
 978
 979         acm_set_control(acm, acm->ctrlout);
 980
 981         acm->line.dwDTERate = cpu_to_le32(9600);
 982         acm->line.bDataBits = 8;
 983         acm_set_line(acm, &acm->line);
 984
 985         usb_driver_claim_interface(&acm_driver, data_interface, acm);
 986
 987         usb_get_intf(control_interface);
 988         tty_register_device(acm_tty_driver, minor, &control_interface->dev);
 989
 990         acm_table[minor] = acm;
 991         usb_set_intfdata (intf, acm);
 992         return 0;
 993
 994 alloc_fail7:
 995         for (i = 0; i < ACM_NRB; i++)
 996                 usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
 997         for (i = 0; i < ACM_NRU; i++)
 998                 usb_free_urb(acm->ru[i].urb);
 999         usb_free_urb(acm->ctrlurb);
1000 alloc_fail5:
1001         acm_write_buffers_free(acm);
1002 alloc_fail4:
1003         usb_buffer_free(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1004 alloc_fail2:
1005         kfree(acm);
1006 alloc_fail:
1007         return -ENOMEM;
1008 }
1009
1010 static void acm_disconnect(struct usb_interface *intf)
1011 {
1012         struct acm *acm = usb_get_intfdata (intf);
1013         struct usb_device *usb_dev = interface_to_usbdev(intf);
1014         int i;
1015
1016         if (!acm || !acm->dev) {
1017                 dbg("disconnect on nonexisting interface");
1018                 return;
1019         }
1020
1021         down(&open_sem);
1022         acm->dev = NULL;
1023         usb_set_intfdata (intf, NULL);
1024
1025         tasklet_disable(&acm->urb_task);
1026
1027         usb_kill_urb(acm->ctrlurb);
1028         usb_kill_urb(acm->writeurb);
1029         for (i = 0; i < ACM_NRU; i++)
1030                 usb_kill_urb(acm->ru[i].urb);
1031
1032         INIT_LIST_HEAD(&acm->filled_read_bufs);
1033         INIT_LIST_HEAD(&acm->spare_read_bufs);
1034
1035         tasklet_enable(&acm->urb_task);
1036
1037         flush_scheduled_work(); /* wait for acm_softint */
1038
1039         acm_write_buffers_free(acm);
1040         usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
1041         for (i = 0; i < ACM_NRB; i++)
1042                 usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
1043
1044         usb_driver_release_interface(&acm_driver, acm->data);
1045
1046         if (!acm->used) {
1047                 acm_tty_unregister(acm);
1048                 up(&open_sem);
1049                 return;
1050         }
1051
1052         up(&open_sem);
1053
1054         if (acm->tty)
1055                 tty_hangup(acm->tty);
1056 }
1057
1058 /*
1059  * USB driver structure.
1060  */
1061
1062 static struct usb_device_id acm_ids[] = {
1063         /* quirky and broken devices */
1064         { USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
1065         .driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1066         },
1067         { USB_DEVICE(0x0482, 0x0203), /* KYOCERA AH-K3001V */
1068         .driver_info = NO_UNION_NORMAL, /* has no union descriptor */
1069         },
1070         /* control interfaces with various AT-command sets */
1071         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1072                 USB_CDC_ACM_PROTO_AT_V25TER) },
1073         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1074                 USB_CDC_ACM_PROTO_AT_PCCA101) },
1075         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1076                 USB_CDC_ACM_PROTO_AT_PCCA101_WAKE) },
1077         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1078                 USB_CDC_ACM_PROTO_AT_GSM) },
1079         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1080                 USB_CDC_ACM_PROTO_AT_3G ) },
1081         { USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
1082                 USB_CDC_ACM_PROTO_AT_CDMA) },
1083
1084         /* NOTE:  COMM/ACM/0xff is likely MSFT RNDIS ... NOT a modem!! */
1085         { }
1086 };
1087
1088 MODULE_DEVICE_TABLE (usb, acm_ids);
1089
1090 static struct usb_driver acm_driver = {
1091         .name =         "cdc_acm",
1092         .probe =        acm_probe,
1093         .disconnect =   acm_disconnect,
1094         .id_table =     acm_ids,
1095 };
1096
1097 /*
1098  * TTY driver structures.
1099  */
1100
1101 static struct tty_operations acm_ops = {
1102         .open =                 acm_tty_open,
1103         .close =                acm_tty_close,
1104         .write =                acm_tty_write,
1105         .write_room =           acm_tty_write_room,
1106         .ioctl =                acm_tty_ioctl,
1107         .throttle =             acm_tty_throttle,
1108         .unthrottle =           acm_tty_unthrottle,
1109         .chars_in_buffer =      acm_tty_chars_in_buffer,
1110         .break_ctl =            acm_tty_break_ctl,
1111         .set_termios =          acm_tty_set_termios,
1112         .tiocmget =             acm_tty_tiocmget,
1113         .tiocmset =             acm_tty_tiocmset,
1114 };
1115
1116 /*
1117  * Init / exit.
1118  */
1119
1120 static int __init acm_init(void)
1121 {
1122         int retval;
1123         acm_tty_driver = alloc_tty_driver(ACM_TTY_MINORS);
1124         if (!acm_tty_driver)
1125                 return -ENOMEM;
1126         acm_tty_driver->owner = THIS_MODULE,
1127         acm_tty_driver->driver_name = "acm",
1128         acm_tty_driver->name = "ttyACM",
1129         acm_tty_driver->devfs_name = "usb/acm/",
1130         acm_tty_driver->major = ACM_TTY_MAJOR,
1131         acm_tty_driver->minor_start = 0,
1132         acm_tty_driver->type = TTY_DRIVER_TYPE_SERIAL,
1133         acm_tty_driver->subtype = SERIAL_TYPE_NORMAL,
1134         acm_tty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS,
1135         acm_tty_driver->init_termios = tty_std_termios;
1136         acm_tty_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
1137         tty_set_operations(acm_tty_driver, &acm_ops);
1138
1139         retval = tty_register_driver(acm_tty_driver);
1140         if (retval) {
1141                 put_tty_driver(acm_tty_driver);
1142                 return retval;
1143         }
1144
1145         retval = usb_register(&acm_driver);
1146         if (retval) {
1147                 tty_unregister_driver(acm_tty_driver);
1148                 put_tty_driver(acm_tty_driver);
1149                 return retval;
1150         }
1151
1152         info(DRIVER_VERSION ":" DRIVER_DESC);
1153
1154         return 0;
1155 }
1156
1157 static void __exit acm_exit(void)
1158 {
1159         usb_deregister(&acm_driver);
1160         tty_unregister_driver(acm_tty_driver);
1161         put_tty_driver(acm_tty_driver);
1162 }
1163
1164 module_init(acm_init);
1165 module_exit(acm_exit);
1166
1167 MODULE_AUTHOR( DRIVER_AUTHOR );
1168 MODULE_DESCRIPTION( DRIVER_DESC );
1169 MODULE_LICENSE("GPL");
1170