drivers/media/radio/radio-mr800.c

   1 /*
   2  * A driver for the AverMedia MR 800 USB FM radio. This device plugs
   3  * into both the USB and an analog audio input, so this thing
   4  * only deals with initialization and frequency setting, the
   5  * audio data has to be handled by a sound driver.
   6  *
   7  * Copyright (c) 2008 Alexey Klimov <klimov.linux@gmail.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 /*
  25  * Big thanks to authors and contributors of dsbr100.c and radio-si470x.c
  26  *
  27  * When work was looked pretty good, i discover this:
  28  * http://av-usbradio.sourceforge.net/index.php
  29  * http://sourceforge.net/projects/av-usbradio/
  30  * Latest release of theirs project was in 2005.
  31  * Probably, this driver could be improved through using their
  32  * achievements (specifications given).
  33  * Also, Faidon Liambotis <paravoid@debian.org> wrote nice driver for this radio
  34  * in 2007. He allowed to use his driver to improve current mr800 radio driver.
  35  * http://kerneltrap.org/mailarchive/linux-usb-devel/2007/10/11/342492
  36  *
  37  * Version 0.01:        First working version.
  38  *                      It's required to blacklist AverMedia USB Radio
  39  *                      in usbhid/hid-quirks.c
  40  * Version 0.10:        A lot of cleanups and fixes: unpluging the device,
  41  *                      few mutex locks were added, codinstyle issues, etc.
  42  *                      Added stereo support. Thanks to
  43  *                      Douglas Schilling Landgraf <dougsland@gmail.com> and
  44  *                      David Ellingsworth <david@identd.dyndns.org>
  45  *                      for discussion, help and support.
  46  * Version 0.11:        Converted to v4l2_device.
  47  *
  48  * Many things to do:
  49  *      - Correct power management of device (suspend & resume)
  50  *      - Add code for scanning and smooth tuning
  51  *      - Add code for sensitivity value
  52  *      - Correct mistakes
  53  *      - In Japan another FREQ_MIN and FREQ_MAX
  54  */
  55
  56 /* kernel includes */
  57 #include <linux/kernel.h>
  58 #include <linux/module.h>
  59 #include <linux/init.h>
  60 #include <linux/slab.h>
  61 #include <linux/input.h>
  62 #include <linux/videodev2.h>
  63 #include <media/v4l2-device.h>
  64 #include <media/v4l2-ioctl.h>
  65 #include <linux/usb.h>
  66 #include <linux/mutex.h>
  67
  68 /* driver and module definitions */
  69 #define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@gmail.com>"
  70 #define DRIVER_DESC "AverMedia MR 800 USB FM radio driver"
  71 #define DRIVER_VERSION "0.1.2"
  72
  73 MODULE_AUTHOR(DRIVER_AUTHOR);
  74 MODULE_DESCRIPTION(DRIVER_DESC);
  75 MODULE_LICENSE("GPL");
  76 MODULE_VERSION(DRIVER_VERSION);
  77
  78 #define USB_AMRADIO_VENDOR 0x07ca
  79 #define USB_AMRADIO_PRODUCT 0xb800
  80
  81 /* dev_warn macro with driver name */
  82 #define MR800_DRIVER_NAME "radio-mr800"
  83 #define amradio_dev_warn(dev, fmt, arg...)                              \
  84                 dev_warn(dev, MR800_DRIVER_NAME " - " fmt, ##arg)
  85
  86 #define amradio_dev_err(dev, fmt, arg...) \
  87                 dev_err(dev, MR800_DRIVER_NAME " - " fmt, ##arg)
  88
  89 /* Probably USB_TIMEOUT should be modified in module parameter */
  90 #define BUFFER_LENGTH 8
  91 #define USB_TIMEOUT 500
  92
  93 /* Frequency limits in MHz -- these are European values.  For Japanese
  94 devices, that would be 76 and 91.  */
  95 #define FREQ_MIN  87.5
  96 #define FREQ_MAX 108.0
  97 #define FREQ_MUL 16000
  98
  99 /*
 100  * Commands that device should understand
 101  * List isn't full and will be updated with implementation of new functions
 102  */
 103 #define AMRADIO_SET_FREQ        0xa4
 104 #define AMRADIO_SET_MUTE        0xab
 105 #define AMRADIO_SET_MONO        0xae
 106
 107 /* Comfortable defines for amradio_set_mute */
 108 #define AMRADIO_START           0x00
 109 #define AMRADIO_STOP            0x01
 110
 111 /* Comfortable defines for amradio_set_stereo */
 112 #define WANT_STEREO             0x00
 113 #define WANT_MONO               0x01
 114
 115 /* module parameter */
 116 static int radio_nr = -1;
 117 module_param(radio_nr, int, 0);
 118 MODULE_PARM_DESC(radio_nr, "Radio Nr");
 119
 120 static int usb_amradio_probe(struct usb_interface *intf,
 121                              const struct usb_device_id *id);
 122 static void usb_amradio_disconnect(struct usb_interface *intf);
 123 static int usb_amradio_open(struct file *file);
 124 static int usb_amradio_close(struct file *file);
 125 static int usb_amradio_suspend(struct usb_interface *intf,
 126                                 pm_message_t message);
 127 static int usb_amradio_resume(struct usb_interface *intf);
 128
 129 /* Data for one (physical) device */
 130 struct amradio_device {
 131         /* reference to USB and video device */
 132         struct usb_device *usbdev;
 133         struct usb_interface *intf;
 134         struct video_device videodev;
 135         struct v4l2_device v4l2_dev;
 136
 137         unsigned char *buffer;
 138         struct mutex lock;      /* buffer locking */
 139         int curfreq;
 140         int stereo;
 141         int muted;
 142         int initialized;
 143 };
 144
 145 static inline struct amradio_device *to_amradio_dev(struct v4l2_device *v4l2_dev)
 146 {
 147         return container_of(v4l2_dev, struct amradio_device, v4l2_dev);
 148 }
 149
 150 /* USB Device ID List */
 151 static struct usb_device_id usb_amradio_device_table[] = {
 152         {USB_DEVICE_AND_INTERFACE_INFO(USB_AMRADIO_VENDOR, USB_AMRADIO_PRODUCT,
 153                                                         USB_CLASS_HID, 0, 0) },
 154         { }                                             /* Terminating entry */
 155 };
 156
 157 MODULE_DEVICE_TABLE(usb, usb_amradio_device_table);
 158
 159 /* USB subsystem interface */
 160 static struct usb_driver usb_amradio_driver = {
 161         .name                   = MR800_DRIVER_NAME,
 162         .probe                  = usb_amradio_probe,
 163         .disconnect             = usb_amradio_disconnect,
 164         .suspend                = usb_amradio_suspend,
 165         .resume                 = usb_amradio_resume,
 166         .reset_resume           = usb_amradio_resume,
 167         .id_table               = usb_amradio_device_table,
 168         .supports_autosuspend   = 1,
 169 };
 170
 171 /* switch on/off the radio. Send 8 bytes to device */
 172 static int amradio_set_mute(struct amradio_device *radio, char argument)
 173 {
 174         int retval;
 175         int size;
 176
 177         radio->buffer[0] = 0x00;
 178         radio->buffer[1] = 0x55;
 179         radio->buffer[2] = 0xaa;
 180         radio->buffer[3] = 0x00;
 181         radio->buffer[4] = AMRADIO_SET_MUTE;
 182         radio->buffer[5] = argument;
 183         radio->buffer[6] = 0x00;
 184         radio->buffer[7] = 0x00;
 185
 186         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 187                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 188
 189         if (retval < 0 || size != BUFFER_LENGTH) {
 190                 amradio_dev_warn(&radio->videodev.dev, "set mute failed\n");
 191                 return retval;
 192         }
 193
 194         radio->muted = argument;
 195
 196         return retval;
 197 }
 198
 199 /* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
 200 static int amradio_setfreq(struct amradio_device *radio, int freq)
 201 {
 202         int retval;
 203         int size;
 204         unsigned short freq_send = 0x10 + (freq >> 3) / 25;
 205
 206         radio->buffer[0] = 0x00;
 207         radio->buffer[1] = 0x55;
 208         radio->buffer[2] = 0xaa;
 209         radio->buffer[3] = 0x03;
 210         radio->buffer[4] = AMRADIO_SET_FREQ;
 211         radio->buffer[5] = 0x00;
 212         radio->buffer[6] = 0x00;
 213         radio->buffer[7] = 0x08;
 214
 215         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 216                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 217
 218         if (retval < 0 || size != BUFFER_LENGTH)
 219                 goto out_err;
 220
 221         /* frequency is calculated from freq_send and placed in first 2 bytes */
 222         radio->buffer[0] = (freq_send >> 8) & 0xff;
 223         radio->buffer[1] = freq_send & 0xff;
 224         radio->buffer[2] = 0x01;
 225         radio->buffer[3] = 0x00;
 226         radio->buffer[4] = 0x00;
 227         /* 5 and 6 bytes of buffer already = 0x00 */
 228         radio->buffer[7] = 0x00;
 229
 230         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 231                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 232
 233         if (retval < 0 || size != BUFFER_LENGTH)
 234                 goto out_err;
 235
 236         radio->curfreq = freq;
 237         goto out;
 238
 239 out_err:
 240         amradio_dev_warn(&radio->videodev.dev, "set frequency failed\n");
 241 out:
 242         return retval;
 243 }
 244
 245 static int amradio_set_stereo(struct amradio_device *radio, char argument)
 246 {
 247         int retval;
 248         int size;
 249
 250         radio->buffer[0] = 0x00;
 251         radio->buffer[1] = 0x55;
 252         radio->buffer[2] = 0xaa;
 253         radio->buffer[3] = 0x00;
 254         radio->buffer[4] = AMRADIO_SET_MONO;
 255         radio->buffer[5] = argument;
 256         radio->buffer[6] = 0x00;
 257         radio->buffer[7] = 0x00;
 258
 259         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 260                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 261
 262         if (retval < 0 || size != BUFFER_LENGTH) {
 263                 amradio_dev_warn(&radio->videodev.dev, "set stereo failed\n");
 264                 return retval;
 265         }
 266
 267         if (argument == WANT_STEREO)
 268                 radio->stereo = 1;
 269         else
 270                 radio->stereo = 0;
 271
 272         return retval;
 273 }
 274
 275 /* Handle unplugging the device.
 276  * We call video_unregister_device in any case.
 277  * The last function called in this procedure is
 278  * usb_amradio_device_release.
 279  */
 280 static void usb_amradio_disconnect(struct usb_interface *intf)
 281 {
 282         struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));
 283
 284         mutex_lock(&radio->lock);
 285         /* increase the device node's refcount */
 286         get_device(&radio->videodev.dev);
 287         v4l2_device_disconnect(&radio->v4l2_dev);
 288         video_unregister_device(&radio->videodev);
 289         mutex_unlock(&radio->lock);
 290         /* decrease the device node's refcount, allowing it to be released */
 291         put_device(&radio->videodev.dev);
 292 }
 293
 294 /* vidioc_querycap - query device capabilities */
 295 static int vidioc_querycap(struct file *file, void *priv,
 296                                         struct v4l2_capability *v)
 297 {
 298         struct amradio_device *radio = file->private_data;
 299
 300         strlcpy(v->driver, "radio-mr800", sizeof(v->driver));
 301         strlcpy(v->card, "AverMedia MR 800 USB FM Radio", sizeof(v->card));
 302         usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
 303         v->capabilities = V4L2_CAP_TUNER;
 304         return 0;
 305 }
 306
 307 /* vidioc_g_tuner - get tuner attributes */
 308 static int vidioc_g_tuner(struct file *file, void *priv,
 309                                 struct v4l2_tuner *v)
 310 {
 311         struct amradio_device *radio = file->private_data;
 312         int retval;
 313
 314         if (v->index > 0)
 315                 return -EINVAL;
 316
 317 /* TODO: Add function which look is signal stereo or not
 318  *      amradio_getstat(radio);
 319  */
 320
 321 /* we call amradio_set_stereo to set radio->stereo
 322  * Honestly, amradio_getstat should cover this in future and
 323  * amradio_set_stereo shouldn't be here
 324  */
 325         retval = amradio_set_stereo(radio, WANT_STEREO);
 326
 327         strcpy(v->name, "FM");
 328         v->type = V4L2_TUNER_RADIO;
 329         v->rangelow = FREQ_MIN * FREQ_MUL;
 330         v->rangehigh = FREQ_MAX * FREQ_MUL;
 331         v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
 332         v->capability = V4L2_TUNER_CAP_LOW;
 333         if (radio->stereo)
 334                 v->audmode = V4L2_TUNER_MODE_STEREO;
 335         else
 336                 v->audmode = V4L2_TUNER_MODE_MONO;
 337         v->signal = 0xffff;     /* Can't get the signal strength, sad.. */
 338         v->afc = 0; /* Don't know what is this */
 339
 340         return retval;
 341 }
 342
 343 /* vidioc_s_tuner - set tuner attributes */
 344 static int vidioc_s_tuner(struct file *file, void *priv,
 345                                 struct v4l2_tuner *v)
 346 {
 347         struct amradio_device *radio = file->private_data;
 348         int retval = -EINVAL;
 349
 350         if (v->index > 0)
 351                 return -EINVAL;
 352
 353         /* mono/stereo selector */
 354         switch (v->audmode) {
 355         case V4L2_TUNER_MODE_MONO:
 356                 retval = amradio_set_stereo(radio, WANT_MONO);
 357                 break;
 358         case V4L2_TUNER_MODE_STEREO:
 359                 retval = amradio_set_stereo(radio, WANT_STEREO);
 360                 break;
 361         }
 362
 363         return retval;
 364 }
 365
 366 /* vidioc_s_frequency - set tuner radio frequency */
 367 static int vidioc_s_frequency(struct file *file, void *priv,
 368                                 struct v4l2_frequency *f)
 369 {
 370         struct amradio_device *radio = file->private_data;
 371
 372         if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
 373                 return -EINVAL;
 374         return amradio_setfreq(radio, f->frequency);
 375 }
 376
 377 /* vidioc_g_frequency - get tuner radio frequency */
 378 static int vidioc_g_frequency(struct file *file, void *priv,
 379                                 struct v4l2_frequency *f)
 380 {
 381         struct amradio_device *radio = file->private_data;
 382
 383         if (f->tuner != 0)
 384                 return -EINVAL;
 385         f->type = V4L2_TUNER_RADIO;
 386         f->frequency = radio->curfreq;
 387
 388         return 0;
 389 }
 390
 391 /* vidioc_queryctrl - enumerate control items */
 392 static int vidioc_queryctrl(struct file *file, void *priv,
 393                                 struct v4l2_queryctrl *qc)
 394 {
 395         switch (qc->id) {
 396         case V4L2_CID_AUDIO_MUTE:
 397                 return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1);
 398         }
 399
 400         return -EINVAL;
 401 }
 402
 403 /* vidioc_g_ctrl - get the value of a control */
 404 static int vidioc_g_ctrl(struct file *file, void *priv,
 405                                 struct v4l2_control *ctrl)
 406 {
 407         struct amradio_device *radio = file->private_data;
 408
 409         switch (ctrl->id) {
 410         case V4L2_CID_AUDIO_MUTE:
 411                 ctrl->value = radio->muted;
 412                 return 0;
 413         }
 414
 415         return -EINVAL;
 416 }
 417
 418 /* vidioc_s_ctrl - set the value of a control */
 419 static int vidioc_s_ctrl(struct file *file, void *priv,
 420                                 struct v4l2_control *ctrl)
 421 {
 422         struct amradio_device *radio = file->private_data;
 423         int retval = -EINVAL;
 424
 425         switch (ctrl->id) {
 426         case V4L2_CID_AUDIO_MUTE:
 427                 if (ctrl->value)
 428                         retval = amradio_set_mute(radio, AMRADIO_STOP);
 429                 else
 430                         retval = amradio_set_mute(radio, AMRADIO_START);
 431
 432                 break;
 433         }
 434
 435         return retval;
 436 }
 437
 438 /* vidioc_g_audio - get audio attributes */
 439 static int vidioc_g_audio(struct file *file, void *priv,
 440                                 struct v4l2_audio *a)
 441 {
 442         if (a->index > 1)
 443                 return -EINVAL;
 444
 445         strcpy(a->name, "Radio");
 446         a->capability = V4L2_AUDCAP_STEREO;
 447         return 0;
 448 }
 449
 450 /* vidioc_s_audio - set audio attributes  */
 451 static int vidioc_s_audio(struct file *file, void *priv,
 452                                         struct v4l2_audio *a)
 453 {
 454         if (a->index != 0)
 455                 return -EINVAL;
 456         return 0;
 457 }
 458
 459 /* vidioc_g_input - get input */
 460 static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
 461 {
 462         *i = 0;
 463         return 0;
 464 }
 465
 466 /* vidioc_s_input - set input */
 467 static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
 468 {
 469         if (i != 0)
 470                 return -EINVAL;
 471         return 0;
 472 }
 473
 474 static int usb_amradio_init(struct amradio_device *radio)
 475 {
 476         int retval;
 477
 478         retval = amradio_set_mute(radio, AMRADIO_STOP);
 479         if (retval)
 480                 goto out_err;
 481
 482         retval = amradio_set_stereo(radio, WANT_STEREO);
 483         if (retval)
 484                 goto out_err;
 485
 486         radio->initialized = 1;
 487         goto out;
 488
 489 out_err:
 490         amradio_dev_err(&radio->videodev.dev, "initialization failed\n");
 491 out:
 492         return retval;
 493 }
 494
 495 /* open device - amradio_start() and amradio_setfreq() */
 496 static int usb_amradio_open(struct file *file)
 497 {
 498         struct amradio_device *radio = video_drvdata(file);
 499         int retval;
 500
 501         file->private_data = radio;
 502         retval = usb_autopm_get_interface(radio->intf);
 503         if (retval)
 504                 return retval;
 505
 506         if (unlikely(!radio->initialized)) {
 507                 retval = usb_amradio_init(radio);
 508                 if (retval)
 509                         usb_autopm_put_interface(radio->intf);
 510         }
 511         return retval;
 512 }
 513
 514 /*close device */
 515 static int usb_amradio_close(struct file *file)
 516 {
 517         struct amradio_device *radio = file->private_data;
 518
 519         if (video_is_registered(&radio->videodev))
 520                 usb_autopm_put_interface(radio->intf);
 521         return 0;
 522 }
 523
 524 /* Suspend device - stop device. Need to be checked and fixed */
 525 static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message)
 526 {
 527         struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));
 528
 529         mutex_lock(&radio->lock);
 530         if (!radio->muted && radio->initialized) {
 531                 amradio_set_mute(radio, AMRADIO_STOP);
 532                 radio->muted = 0;
 533         }
 534         mutex_unlock(&radio->lock);
 535
 536         dev_info(&intf->dev, "going into suspend..\n");
 537         return 0;
 538 }
 539
 540 /* Resume device - start device. Need to be checked and fixed */
 541 static int usb_amradio_resume(struct usb_interface *intf)
 542 {
 543         struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf));
 544
 545         mutex_lock(&radio->lock);
 546         if (unlikely(!radio->initialized))
 547                 goto unlock;
 548
 549         if (radio->stereo)
 550                 amradio_set_stereo(radio, WANT_STEREO);
 551         else
 552                 amradio_set_stereo(radio, WANT_MONO);
 553
 554         amradio_setfreq(radio, radio->curfreq);
 555
 556         if (!radio->muted)
 557                 amradio_set_mute(radio, AMRADIO_START);
 558
 559 unlock:
 560         mutex_unlock(&radio->lock);
 561
 562         dev_info(&intf->dev, "coming out of suspend..\n");
 563         return 0;
 564 }
 565
 566 /* File system interface */
 567 static const struct v4l2_file_operations usb_amradio_fops = {
 568         .owner          = THIS_MODULE,
 569         .open           = usb_amradio_open,
 570         .release        = usb_amradio_close,
 571         .unlocked_ioctl = video_ioctl2,
 572 };
 573
 574 static const struct v4l2_ioctl_ops usb_amradio_ioctl_ops = {
 575         .vidioc_querycap    = vidioc_querycap,
 576         .vidioc_g_tuner     = vidioc_g_tuner,
 577         .vidioc_s_tuner     = vidioc_s_tuner,
 578         .vidioc_g_frequency = vidioc_g_frequency,
 579         .vidioc_s_frequency = vidioc_s_frequency,
 580         .vidioc_queryctrl   = vidioc_queryctrl,
 581         .vidioc_g_ctrl      = vidioc_g_ctrl,
 582         .vidioc_s_ctrl      = vidioc_s_ctrl,
 583         .vidioc_g_audio     = vidioc_g_audio,
 584         .vidioc_s_audio     = vidioc_s_audio,
 585         .vidioc_g_input     = vidioc_g_input,
 586         .vidioc_s_input     = vidioc_s_input,
 587 };
 588
 589 static void usb_amradio_video_device_release(struct video_device *videodev)
 590 {
 591         struct amradio_device *radio = video_get_drvdata(videodev);
 592
 593         /* free rest memory */
 594         kfree(radio->buffer);
 595         kfree(radio);
 596 }
 597
 598 /* check if the device is present and register with v4l and usb if it is */
 599 static int usb_amradio_probe(struct usb_interface *intf,
 600                                 const struct usb_device_id *id)
 601 {
 602         struct amradio_device *radio;
 603         int retval = 0;
 604
 605         radio = kzalloc(sizeof(struct amradio_device), GFP_KERNEL);
 606
 607         if (!radio) {
 608                 dev_err(&intf->dev, "kmalloc for amradio_device failed\n");
 609                 retval = -ENOMEM;
 610                 goto err;
 611         }
 612
 613         radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
 614
 615         if (!radio->buffer) {
 616                 dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
 617                 retval = -ENOMEM;
 618                 goto err_nobuf;
 619         }
 620
 621         retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
 622         if (retval < 0) {
 623                 dev_err(&intf->dev, "couldn't register v4l2_device\n");
 624                 goto err_v4l2;
 625         }
 626
 627         mutex_init(&radio->lock);
 628
 629         strlcpy(radio->videodev.name, radio->v4l2_dev.name,
 630                 sizeof(radio->videodev.name));
 631         radio->videodev.v4l2_dev = &radio->v4l2_dev;
 632         radio->videodev.fops = &usb_amradio_fops;
 633         radio->videodev.ioctl_ops = &usb_amradio_ioctl_ops;
 634         radio->videodev.release = usb_amradio_video_device_release;
 635         radio->videodev.lock = &radio->lock;
 636
 637         radio->usbdev = interface_to_usbdev(intf);
 638         radio->intf = intf;
 639         radio->curfreq = 95.16 * FREQ_MUL;
 640
 641         video_set_drvdata(&radio->videodev, radio);
 642
 643         retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
 644                                         radio_nr);
 645         if (retval < 0) {
 646                 dev_err(&intf->dev, "could not register video device\n");
 647                 goto err_vdev;
 648         }
 649
 650         return 0;
 651
 652 err_vdev:
 653         v4l2_device_unregister(&radio->v4l2_dev);
 654 err_v4l2:
 655         kfree(radio->buffer);
 656 err_nobuf:
 657         kfree(radio);
 658 err:
 659         return retval;
 660 }
 661
 662 module_usb_driver(usb_amradio_driver);