sound/usb/line6/driver.c

   1 /*
   2  * Line 6 Linux USB driver
   3  *
   4  * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at)
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License as
   8  *      published by the Free Software Foundation, version 2.
   9  *
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/export.h>
  15 #include <linux/slab.h>
  16 #include <linux/usb.h>
  17
  18 #include <sound/core.h>
  19 #include <sound/initval.h>
  20 #include <sound/hwdep.h>
  21
  22 #include "capture.h"
  23 #include "driver.h"
  24 #include "midi.h"
  25 #include "playback.h"
  26
  27 #define DRIVER_AUTHOR  "Markus Grabner <grabner@icg.tugraz.at>"
  28 #define DRIVER_DESC    "Line 6 USB Driver"
  29
  30 /*
  31         This is Line 6's MIDI manufacturer ID.
  32 */
  33 const unsigned char line6_midi_id[3] = {
  34         0x00, 0x01, 0x0c
  35 };
  36 EXPORT_SYMBOL_GPL(line6_midi_id);
  37
  38 /*
  39         Code to request version of POD, Variax interface
  40         (and maybe other devices).
  41 */
  42 static const char line6_request_version[] = {
  43         0xf0, 0x7e, 0x7f, 0x06, 0x01, 0xf7
  44 };
  45
  46 /*
  47          Class for asynchronous messages.
  48 */
  49 struct message {
  50         struct usb_line6 *line6;
  51         const char *buffer;
  52         int size;
  53         int done;
  54 };
  55
  56 /*
  57         Forward declarations.
  58 */
  59 static void line6_data_received(struct urb *urb);
  60 static int line6_send_raw_message_async_part(struct message *msg,
  61                                              struct urb *urb);
  62
  63 /*
  64         Start to listen on endpoint.
  65 */
  66 static int line6_start_listen(struct usb_line6 *line6)
  67 {
  68         int err;
  69
  70         if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
  71                 usb_fill_int_urb(line6->urb_listen, line6->usbdev,
  72                         usb_rcvintpipe(line6->usbdev, line6->properties->ep_ctrl_r),
  73                         line6->buffer_listen, LINE6_BUFSIZE_LISTEN,
  74                         line6_data_received, line6, line6->interval);
  75         } else {
  76                 usb_fill_bulk_urb(line6->urb_listen, line6->usbdev,
  77                         usb_rcvbulkpipe(line6->usbdev, line6->properties->ep_ctrl_r),
  78                         line6->buffer_listen, LINE6_BUFSIZE_LISTEN,
  79                         line6_data_received, line6);
  80         }
  81         line6->urb_listen->actual_length = 0;
  82         err = usb_submit_urb(line6->urb_listen, GFP_ATOMIC);
  83         return err;
  84 }
  85
  86 /*
  87         Stop listening on endpoint.
  88 */
  89 static void line6_stop_listen(struct usb_line6 *line6)
  90 {
  91         usb_kill_urb(line6->urb_listen);
  92 }
  93
  94 /*
  95         Send raw message in pieces of wMaxPacketSize bytes.
  96 */
  97 static int line6_send_raw_message(struct usb_line6 *line6, const char *buffer,
  98                                   int size)
  99 {
 100         int i, done = 0;
 101         const struct line6_properties *properties = line6->properties;
 102
 103         for (i = 0; i < size; i += line6->max_packet_size) {
 104                 int partial;
 105                 const char *frag_buf = buffer + i;
 106                 int frag_size = min(line6->max_packet_size, size - i);
 107                 int retval;
 108
 109                 if (properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
 110                         retval = usb_interrupt_msg(line6->usbdev,
 111                                                 usb_sndintpipe(line6->usbdev, properties->ep_ctrl_w),
 112                                                 (char *)frag_buf, frag_size,
 113                                                 &partial, LINE6_TIMEOUT * HZ);
 114                 } else {
 115                         retval = usb_bulk_msg(line6->usbdev,
 116                                                 usb_sndbulkpipe(line6->usbdev, properties->ep_ctrl_w),
 117                                                 (char *)frag_buf, frag_size,
 118                                                 &partial, LINE6_TIMEOUT * HZ);
 119                 }
 120
 121                 if (retval) {
 122                         dev_err(line6->ifcdev,
 123                                 "usb_bulk_msg failed (%d)\n", retval);
 124                         break;
 125                 }
 126
 127                 done += frag_size;
 128         }
 129
 130         return done;
 131 }
 132
 133 /*
 134         Notification of completion of asynchronous request transmission.
 135 */
 136 static void line6_async_request_sent(struct urb *urb)
 137 {
 138         struct message *msg = (struct message *)urb->context;
 139
 140         if (msg->done >= msg->size) {
 141                 usb_free_urb(urb);
 142                 kfree(msg);
 143         } else
 144                 line6_send_raw_message_async_part(msg, urb);
 145 }
 146
 147 /*
 148         Asynchronously send part of a raw message.
 149 */
 150 static int line6_send_raw_message_async_part(struct message *msg,
 151                                              struct urb *urb)
 152 {
 153         int retval;
 154         struct usb_line6 *line6 = msg->line6;
 155         int done = msg->done;
 156         int bytes = min(msg->size - done, line6->max_packet_size);
 157
 158         if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
 159                 usb_fill_int_urb(urb, line6->usbdev,
 160                         usb_sndintpipe(line6->usbdev, line6->properties->ep_ctrl_w),
 161                         (char *)msg->buffer + done, bytes,
 162                         line6_async_request_sent, msg, line6->interval);
 163         } else {
 164                 usb_fill_bulk_urb(urb, line6->usbdev,
 165                         usb_sndbulkpipe(line6->usbdev, line6->properties->ep_ctrl_w),
 166                         (char *)msg->buffer + done, bytes,
 167                         line6_async_request_sent, msg);
 168         }
 169
 170         msg->done += bytes;
 171         retval = usb_submit_urb(urb, GFP_ATOMIC);
 172
 173         if (retval < 0) {
 174                 dev_err(line6->ifcdev, "%s: usb_submit_urb failed (%d)\n",
 175                         __func__, retval);
 176                 usb_free_urb(urb);
 177                 kfree(msg);
 178                 return retval;
 179         }
 180
 181         return 0;
 182 }
 183
 184 /*
 185         Setup and start timer.
 186 */
 187 void line6_start_timer(struct timer_list *timer, unsigned long msecs,
 188                        void (*function)(unsigned long), unsigned long data)
 189 {
 190         setup_timer(timer, function, data);
 191         mod_timer(timer, jiffies + msecs_to_jiffies(msecs));
 192 }
 193 EXPORT_SYMBOL_GPL(line6_start_timer);
 194
 195 /*
 196         Asynchronously send raw message.
 197 */
 198 int line6_send_raw_message_async(struct usb_line6 *line6, const char *buffer,
 199                                  int size)
 200 {
 201         struct message *msg;
 202         struct urb *urb;
 203
 204         /* create message: */
 205         msg = kmalloc(sizeof(struct message), GFP_ATOMIC);
 206         if (msg == NULL)
 207                 return -ENOMEM;
 208
 209         /* create URB: */
 210         urb = usb_alloc_urb(0, GFP_ATOMIC);
 211
 212         if (urb == NULL) {
 213                 kfree(msg);
 214                 return -ENOMEM;
 215         }
 216
 217         /* set message data: */
 218         msg->line6 = line6;
 219         msg->buffer = buffer;
 220         msg->size = size;
 221         msg->done = 0;
 222
 223         /* start sending: */
 224         return line6_send_raw_message_async_part(msg, urb);
 225 }
 226 EXPORT_SYMBOL_GPL(line6_send_raw_message_async);
 227
 228 /*
 229         Send asynchronous device version request.
 230 */
 231 int line6_version_request_async(struct usb_line6 *line6)
 232 {
 233         char *buffer;
 234         int retval;
 235
 236         buffer = kmemdup(line6_request_version,
 237                         sizeof(line6_request_version), GFP_ATOMIC);
 238         if (buffer == NULL)
 239                 return -ENOMEM;
 240
 241         retval = line6_send_raw_message_async(line6, buffer,
 242                                               sizeof(line6_request_version));
 243         kfree(buffer);
 244         return retval;
 245 }
 246 EXPORT_SYMBOL_GPL(line6_version_request_async);
 247
 248 /*
 249         Send sysex message in pieces of wMaxPacketSize bytes.
 250 */
 251 int line6_send_sysex_message(struct usb_line6 *line6, const char *buffer,
 252                              int size)
 253 {
 254         return line6_send_raw_message(line6, buffer,
 255                                       size + SYSEX_EXTRA_SIZE) -
 256             SYSEX_EXTRA_SIZE;
 257 }
 258 EXPORT_SYMBOL_GPL(line6_send_sysex_message);
 259
 260 /*
 261         Allocate buffer for sysex message and prepare header.
 262         @param code sysex message code
 263         @param size number of bytes between code and sysex end
 264 */
 265 char *line6_alloc_sysex_buffer(struct usb_line6 *line6, int code1, int code2,
 266                                int size)
 267 {
 268         char *buffer = kmalloc(size + SYSEX_EXTRA_SIZE, GFP_ATOMIC);
 269
 270         if (!buffer)
 271                 return NULL;
 272
 273         buffer[0] = LINE6_SYSEX_BEGIN;
 274         memcpy(buffer + 1, line6_midi_id, sizeof(line6_midi_id));
 275         buffer[sizeof(line6_midi_id) + 1] = code1;
 276         buffer[sizeof(line6_midi_id) + 2] = code2;
 277         buffer[sizeof(line6_midi_id) + 3 + size] = LINE6_SYSEX_END;
 278         return buffer;
 279 }
 280 EXPORT_SYMBOL_GPL(line6_alloc_sysex_buffer);
 281
 282 /*
 283         Notification of data received from the Line 6 device.
 284 */
 285 static void line6_data_received(struct urb *urb)
 286 {
 287         struct usb_line6 *line6 = (struct usb_line6 *)urb->context;
 288         struct midi_buffer *mb = &line6->line6midi->midibuf_in;
 289         int done;
 290
 291         if (urb->status == -ESHUTDOWN)
 292                 return;
 293
 294         if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
 295                 done =
 296                         line6_midibuf_write(mb, urb->transfer_buffer, urb->actual_length);
 297
 298                 if (done < urb->actual_length) {
 299                         line6_midibuf_ignore(mb, done);
 300                         dev_dbg(line6->ifcdev, "%d %d buffer overflow - message skipped\n",
 301                                 done, urb->actual_length);
 302                 }
 303
 304                 for (;;) {
 305                         done =
 306                                 line6_midibuf_read(mb, line6->buffer_message,
 307                                                 LINE6_MIDI_MESSAGE_MAXLEN);
 308
 309                         if (done == 0)
 310                                 break;
 311
 312                         line6->message_length = done;
 313                         line6_midi_receive(line6, line6->buffer_message, done);
 314
 315                         if (line6->process_message)
 316                                 line6->process_message(line6);
 317                 }
 318         } else {
 319                 line6->buffer_message = urb->transfer_buffer;
 320                 line6->message_length = urb->actual_length;
 321                 if (line6->process_message)
 322                         line6->process_message(line6);
 323                 line6->buffer_message = NULL;
 324         }
 325
 326         line6_start_listen(line6);
 327 }
 328
 329 #define LINE6_READ_WRITE_STATUS_DELAY 2  /* milliseconds */
 330 #define LINE6_READ_WRITE_MAX_RETRIES 50
 331
 332 /*
 333         Read data from device.
 334 */
 335 int line6_read_data(struct usb_line6 *line6, unsigned address, void *data,
 336                     unsigned datalen)
 337 {
 338         struct usb_device *usbdev = line6->usbdev;
 339         int ret;
 340         unsigned char len;
 341         unsigned count;
 342
 343         if (address > 0xffff || datalen > 0xff)
 344                 return -EINVAL;
 345
 346         /* query the serial number: */
 347         ret = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x67,
 348                               USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
 349                               (datalen << 8) | 0x21, address,
 350                               NULL, 0, LINE6_TIMEOUT * HZ);
 351
 352         if (ret < 0) {
 353                 dev_err(line6->ifcdev, "read request failed (error %d)\n", ret);
 354                 return ret;
 355         }
 356
 357         /* Wait for data length. We'll get 0xff until length arrives. */
 358         for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
 359                 mdelay(LINE6_READ_WRITE_STATUS_DELAY);
 360
 361                 ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0), 0x67,
 362                                       USB_TYPE_VENDOR | USB_RECIP_DEVICE |
 363                                       USB_DIR_IN,
 364                                       0x0012, 0x0000, &len, 1,
 365                                       LINE6_TIMEOUT * HZ);
 366                 if (ret < 0) {
 367                         dev_err(line6->ifcdev,
 368                                 "receive length failed (error %d)\n", ret);
 369                         return ret;
 370                 }
 371
 372                 if (len != 0xff)
 373                         break;
 374         }
 375
 376         if (len == 0xff) {
 377                 dev_err(line6->ifcdev, "read failed after %d retries\n",
 378                         count);
 379                 return -EIO;
 380         } else if (len != datalen) {
 381                 /* should be equal or something went wrong */
 382                 dev_err(line6->ifcdev,
 383                         "length mismatch (expected %d, got %d)\n",
 384                         (int)datalen, (int)len);
 385                 return -EIO;
 386         }
 387
 388         /* receive the result: */
 389         ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0), 0x67,
 390                               USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
 391                               0x0013, 0x0000, data, datalen,
 392                               LINE6_TIMEOUT * HZ);
 393
 394         if (ret < 0) {
 395                 dev_err(line6->ifcdev, "read failed (error %d)\n", ret);
 396                 return ret;
 397         }
 398
 399         return 0;
 400 }
 401 EXPORT_SYMBOL_GPL(line6_read_data);
 402
 403 /*
 404         Write data to device.
 405 */
 406 int line6_write_data(struct usb_line6 *line6, unsigned address, void *data,
 407                      unsigned datalen)
 408 {
 409         struct usb_device *usbdev = line6->usbdev;
 410         int ret;
 411         unsigned char status;
 412         int count;
 413
 414         if (address > 0xffff || datalen > 0xffff)
 415                 return -EINVAL;
 416
 417         ret = usb_control_msg(usbdev, usb_sndctrlpipe(usbdev, 0), 0x67,
 418                               USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
 419                               0x0022, address, data, datalen,
 420                               LINE6_TIMEOUT * HZ);
 421
 422         if (ret < 0) {
 423                 dev_err(line6->ifcdev,
 424                         "write request failed (error %d)\n", ret);
 425                 return ret;
 426         }
 427
 428         for (count = 0; count < LINE6_READ_WRITE_MAX_RETRIES; count++) {
 429                 mdelay(LINE6_READ_WRITE_STATUS_DELAY);
 430
 431                 ret = usb_control_msg(usbdev, usb_rcvctrlpipe(usbdev, 0),
 432                                       0x67,
 433                                       USB_TYPE_VENDOR | USB_RECIP_DEVICE |
 434                                       USB_DIR_IN,
 435                                       0x0012, 0x0000,
 436                                       &status, 1, LINE6_TIMEOUT * HZ);
 437
 438                 if (ret < 0) {
 439                         dev_err(line6->ifcdev,
 440                                 "receiving status failed (error %d)\n", ret);
 441                         return ret;
 442                 }
 443
 444                 if (status != 0xff)
 445                         break;
 446         }
 447
 448         if (status == 0xff) {
 449                 dev_err(line6->ifcdev, "write failed after %d retries\n",
 450                         count);
 451                 return -EIO;
 452         } else if (status != 0) {
 453                 dev_err(line6->ifcdev, "write failed (error %d)\n", ret);
 454                 return -EIO;
 455         }
 456
 457         return 0;
 458 }
 459 EXPORT_SYMBOL_GPL(line6_write_data);
 460
 461 /*
 462         Read Line 6 device serial number.
 463         (POD, TonePort, GuitarPort)
 464 */
 465 int line6_read_serial_number(struct usb_line6 *line6, u32 *serial_number)
 466 {
 467         return line6_read_data(line6, 0x80d0, serial_number,
 468                                sizeof(*serial_number));
 469 }
 470 EXPORT_SYMBOL_GPL(line6_read_serial_number);
 471
 472 /*
 473         Card destructor.
 474 */
 475 static void line6_destruct(struct snd_card *card)
 476 {
 477         struct usb_line6 *line6 = card->private_data;
 478         struct usb_device *usbdev = line6->usbdev;
 479
 480         /* Free buffer memory first. We cannot depend on the existence of private
 481          * data from the (podhd) module, it may be gone already during this call
 482          */
 483         kfree(line6->buffer_message);
 484
 485         kfree(line6->buffer_listen);
 486
 487         /* then free URBs: */
 488         usb_free_urb(line6->urb_listen);
 489         line6->urb_listen = NULL;
 490
 491         /* decrement reference counters: */
 492         usb_put_dev(usbdev);
 493 }
 494
 495 /* get data from endpoint descriptor (see usb_maxpacket): */
 496 static void line6_get_interval(struct usb_line6 *line6)
 497 {
 498         struct usb_device *usbdev = line6->usbdev;
 499         const struct line6_properties *properties = line6->properties;
 500         int pipe;
 501         struct usb_host_endpoint *ep;
 502
 503         if (properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
 504                 pipe =
 505                         usb_rcvintpipe(line6->usbdev, line6->properties->ep_ctrl_r);
 506         } else {
 507                 pipe =
 508                         usb_rcvbulkpipe(line6->usbdev, line6->properties->ep_ctrl_r);
 509         }
 510         ep = usbdev->ep_in[usb_pipeendpoint(pipe)];
 511
 512         if (ep) {
 513                 line6->interval = ep->desc.bInterval;
 514                 if (usbdev->speed == USB_SPEED_LOW) {
 515                         line6->intervals_per_second = USB_LOW_INTERVALS_PER_SECOND;
 516                         line6->iso_buffers = USB_LOW_ISO_BUFFERS;
 517                 } else {
 518                         line6->intervals_per_second = USB_HIGH_INTERVALS_PER_SECOND;
 519                         line6->iso_buffers = USB_HIGH_ISO_BUFFERS;
 520                 }
 521
 522                 line6->max_packet_size = le16_to_cpu(ep->desc.wMaxPacketSize);
 523         } else {
 524                 dev_err(line6->ifcdev,
 525                         "endpoint not available, using fallback values");
 526                 line6->interval = LINE6_FALLBACK_INTERVAL;
 527                 line6->max_packet_size = LINE6_FALLBACK_MAXPACKETSIZE;
 528         }
 529 }
 530
 531
 532 /* Enable buffering of incoming messages, flush the buffer */
 533 static int line6_hwdep_open(struct snd_hwdep *hw, struct file *file)
 534 {
 535         struct usb_line6 *line6 = hw->private_data;
 536
 537         /* NOTE: hwdep layer provides atomicity here */
 538
 539         line6->messages.active = 1;
 540
 541         return 0;
 542 }
 543
 544 /* Stop buffering */
 545 static int line6_hwdep_release(struct snd_hwdep *hw, struct file *file)
 546 {
 547         struct usb_line6 *line6 = hw->private_data;
 548
 549         line6->messages.active = 0;
 550
 551         return 0;
 552 }
 553
 554 /* Read from circular buffer, return to user */
 555 static long
 556 line6_hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
 557                                         loff_t *offset)
 558 {
 559         struct usb_line6 *line6 = hwdep->private_data;
 560         long rv = 0;
 561         unsigned int out_count;
 562
 563         if (mutex_lock_interruptible(&line6->messages.read_lock))
 564                 return -ERESTARTSYS;
 565
 566         while (kfifo_len(&line6->messages.fifo) == 0) {
 567                 mutex_unlock(&line6->messages.read_lock);
 568
 569                 rv = wait_event_interruptible(
 570                         line6->messages.wait_queue,
 571                         kfifo_len(&line6->messages.fifo) != 0);
 572                 if (rv < 0)
 573                         return rv;
 574
 575                 if (mutex_lock_interruptible(&line6->messages.read_lock))
 576                         return -ERESTARTSYS;
 577         }
 578
 579         if (kfifo_peek_len(&line6->messages.fifo) > count) {
 580                 /* Buffer too small; allow re-read of the current item... */
 581                 rv = -EINVAL;
 582         } else {
 583                 rv = kfifo_to_user(&line6->messages.fifo, buf, count, &out_count);
 584                 if (rv == 0)
 585                         rv = out_count;
 586         }
 587
 588         mutex_unlock(&line6->messages.read_lock);
 589         return rv;
 590 }
 591
 592 /* Write directly (no buffering) to device by user*/
 593 static long
 594 line6_hwdep_write(struct snd_hwdep *hwdep, const char __user *data, long count,
 595                                         loff_t *offset)
 596 {
 597         struct usb_line6 *line6 = hwdep->private_data;
 598         int rv;
 599         char *data_copy;
 600
 601         if (count > line6->max_packet_size * LINE6_RAW_MESSAGES_MAXCOUNT) {
 602                 /* This is an arbitrary limit - still better than nothing... */
 603                 return -EINVAL;
 604         }
 605
 606         data_copy = memdup_user(data, count);
 607         if (IS_ERR(data_copy))
 608                 return PTR_ERR(data_copy);
 609
 610         rv = line6_send_raw_message(line6, data_copy, count);
 611
 612         kfree(data_copy);
 613         return rv;
 614 }
 615
 616 static const struct snd_hwdep_ops hwdep_ops = {
 617         .open    = line6_hwdep_open,
 618         .release = line6_hwdep_release,
 619         .read    = line6_hwdep_read,
 620         .write   = line6_hwdep_write,
 621 };
 622
 623 /* Insert into circular buffer */
 624 static void line6_hwdep_push_message(struct usb_line6 *line6)
 625 {
 626         if (!line6->messages.active)
 627                 return;
 628
 629         if (kfifo_avail(&line6->messages.fifo) >= line6->message_length) {
 630                 /* No race condition here, there's only one writer */
 631                 kfifo_in(&line6->messages.fifo,
 632                         line6->buffer_message, line6->message_length);
 633         } /* else TODO: signal overflow */
 634
 635         wake_up_interruptible(&line6->messages.wait_queue);
 636 }
 637
 638 static int line6_hwdep_init(struct usb_line6 *line6)
 639 {
 640         int err;
 641         struct snd_hwdep *hwdep;
 642
 643         /* TODO: usb_driver_claim_interface(); */
 644         line6->process_message = line6_hwdep_push_message;
 645         line6->messages.active = 0;
 646         init_waitqueue_head(&line6->messages.wait_queue);
 647         mutex_init(&line6->messages.read_lock);
 648         INIT_KFIFO(line6->messages.fifo);
 649
 650         err = snd_hwdep_new(line6->card, "config", 0, &hwdep);
 651         if (err < 0)
 652                 goto end;
 653         strcpy(hwdep->name, "config");
 654         hwdep->iface = SNDRV_HWDEP_IFACE_LINE6;
 655         hwdep->ops = hwdep_ops;
 656         hwdep->private_data = line6;
 657         hwdep->exclusive = true;
 658
 659 end:
 660         return err;
 661 }
 662
 663 static int line6_init_cap_control(struct usb_line6 *line6)
 664 {
 665         int ret;
 666
 667         /* initialize USB buffers: */
 668         line6->buffer_listen = kmalloc(LINE6_BUFSIZE_LISTEN, GFP_KERNEL);
 669         if (!line6->buffer_listen)
 670                 return -ENOMEM;
 671
 672         line6->urb_listen = usb_alloc_urb(0, GFP_KERNEL);
 673         if (!line6->urb_listen)
 674                 return -ENOMEM;
 675
 676         if (line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI) {
 677                 line6->buffer_message = kmalloc(LINE6_MIDI_MESSAGE_MAXLEN, GFP_KERNEL);
 678                 if (!line6->buffer_message)
 679                         return -ENOMEM;
 680         } else {
 681                 ret = line6_hwdep_init(line6);
 682                 if (ret < 0)
 683                         return ret;
 684         }
 685
 686         ret = line6_start_listen(line6);
 687         if (ret < 0) {
 688                 dev_err(line6->ifcdev, "cannot start listening: %d\n", ret);
 689                 return ret;
 690         }
 691
 692         return 0;
 693 }
 694
 695 /*
 696         Probe USB device.
 697 */
 698 int line6_probe(struct usb_interface *interface,
 699                 const struct usb_device_id *id,
 700                 const char *driver_name,
 701                 const struct line6_properties *properties,
 702                 int (*private_init)(struct usb_line6 *, const struct usb_device_id *id),
 703                 size_t data_size)
 704 {
 705         struct usb_device *usbdev = interface_to_usbdev(interface);
 706         struct snd_card *card;
 707         struct usb_line6 *line6;
 708         int interface_number;
 709         int ret;
 710
 711         if (WARN_ON(data_size < sizeof(*line6)))
 712                 return -EINVAL;
 713
 714         /* we don't handle multiple configurations */
 715         if (usbdev->descriptor.bNumConfigurations != 1)
 716                 return -ENODEV;
 717
 718         ret = snd_card_new(&interface->dev,
 719                            SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
 720                            THIS_MODULE, data_size, &card);
 721         if (ret < 0)
 722                 return ret;
 723
 724         /* store basic data: */
 725         line6 = card->private_data;
 726         line6->card = card;
 727         line6->properties = properties;
 728         line6->usbdev = usbdev;
 729         line6->ifcdev = &interface->dev;
 730
 731         strcpy(card->id, properties->id);
 732         strcpy(card->driver, driver_name);
 733         strcpy(card->shortname, properties->name);
 734         sprintf(card->longname, "Line 6 %s at USB %s", properties->name,
 735                 dev_name(line6->ifcdev));
 736         card->private_free = line6_destruct;
 737
 738         usb_set_intfdata(interface, line6);
 739
 740         /* increment reference counters: */
 741         usb_get_dev(usbdev);
 742
 743         /* initialize device info: */
 744         dev_info(&interface->dev, "Line 6 %s found\n", properties->name);
 745
 746         /* query interface number */
 747         interface_number = interface->cur_altsetting->desc.bInterfaceNumber;
 748
 749         /* TODO reserves the bus bandwidth even without actual transfer */
 750         ret = usb_set_interface(usbdev, interface_number,
 751                                 properties->altsetting);
 752         if (ret < 0) {
 753                 dev_err(&interface->dev, "set_interface failed\n");
 754                 goto error;
 755         }
 756
 757         if (properties->capabilities & LINE6_CAP_CONTROL) {
 758                 line6_get_interval(line6);
 759                 ret = line6_init_cap_control(line6);
 760                 if (ret < 0)
 761                         goto error;
 762         }
 763
 764         /* initialize device data based on device: */
 765         ret = private_init(line6, id);
 766         if (ret < 0)
 767                 goto error;
 768
 769         /* creation of additional special files should go here */
 770
 771         dev_info(&interface->dev, "Line 6 %s now attached\n",
 772                  properties->name);
 773
 774         return 0;
 775
 776  error:
 777         if (line6->disconnect)
 778                 line6->disconnect(line6);
 779         snd_card_free(card);
 780         return ret;
 781 }
 782 EXPORT_SYMBOL_GPL(line6_probe);
 783
 784 /*
 785         Line 6 device disconnected.
 786 */
 787 void line6_disconnect(struct usb_interface *interface)
 788 {
 789         struct usb_line6 *line6 = usb_get_intfdata(interface);
 790         struct usb_device *usbdev = interface_to_usbdev(interface);
 791
 792         if (!line6)
 793                 return;
 794
 795         if (WARN_ON(usbdev != line6->usbdev))
 796                 return;
 797
 798         if (line6->urb_listen != NULL)
 799                 line6_stop_listen(line6);
 800
 801         snd_card_disconnect(line6->card);
 802         if (line6->line6pcm)
 803                 line6_pcm_disconnect(line6->line6pcm);
 804         if (line6->disconnect)
 805                 line6->disconnect(line6);
 806
 807         dev_info(&interface->dev, "Line 6 %s now disconnected\n",
 808                  line6->properties->name);
 809
 810         /* make sure the device isn't destructed twice: */
 811         usb_set_intfdata(interface, NULL);
 812
 813         snd_card_free_when_closed(line6->card);
 814 }
 815 EXPORT_SYMBOL_GPL(line6_disconnect);
 816
 817 #ifdef CONFIG_PM
 818
 819 /*
 820         Suspend Line 6 device.
 821 */
 822 int line6_suspend(struct usb_interface *interface, pm_message_t message)
 823 {
 824         struct usb_line6 *line6 = usb_get_intfdata(interface);
 825         struct snd_line6_pcm *line6pcm = line6->line6pcm;
 826
 827         snd_power_change_state(line6->card, SNDRV_CTL_POWER_D3hot);
 828
 829         if (line6->properties->capabilities & LINE6_CAP_CONTROL)
 830                 line6_stop_listen(line6);
 831
 832         if (line6pcm != NULL) {
 833                 snd_pcm_suspend_all(line6pcm->pcm);
 834                 line6pcm->flags = 0;
 835         }
 836
 837         return 0;
 838 }
 839 EXPORT_SYMBOL_GPL(line6_suspend);
 840
 841 /*
 842         Resume Line 6 device.
 843 */
 844 int line6_resume(struct usb_interface *interface)
 845 {
 846         struct usb_line6 *line6 = usb_get_intfdata(interface);
 847
 848         if (line6->properties->capabilities & LINE6_CAP_CONTROL)
 849                 line6_start_listen(line6);
 850
 851         snd_power_change_state(line6->card, SNDRV_CTL_POWER_D0);
 852         return 0;
 853 }
 854 EXPORT_SYMBOL_GPL(line6_resume);
 855
 856 #endif /* CONFIG_PM */
 857
 858 MODULE_AUTHOR(DRIVER_AUTHOR);
 859 MODULE_DESCRIPTION(DRIVER_DESC);
 860 MODULE_LICENSE("GPL");
 861