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/smp_lock.h>
  62 #include <linux/input.h>
  63 #include <linux/videodev2.h>
  64 #include <media/v4l2-device.h>
  65 #include <media/v4l2-ioctl.h>
  66 #include <linux/usb.h>
  67 #include <linux/version.h>      /* for KERNEL_VERSION MACRO */
  68 #include <linux/mutex.h>
  69
  70 /* driver and module definitions */
  71 #define DRIVER_AUTHOR "Alexey Klimov <klimov.linux@gmail.com>"
  72 #define DRIVER_DESC "AverMedia MR 800 USB FM radio driver"
  73 #define DRIVER_VERSION "0.11"
  74 #define RADIO_VERSION KERNEL_VERSION(0, 1, 1)
  75
  76 MODULE_AUTHOR(DRIVER_AUTHOR);
  77 MODULE_DESCRIPTION(DRIVER_DESC);
  78 MODULE_LICENSE("GPL");
  79
  80 #define USB_AMRADIO_VENDOR 0x07ca
  81 #define USB_AMRADIO_PRODUCT 0xb800
  82
  83 /* dev_warn macro with driver name */
  84 #define MR800_DRIVER_NAME "radio-mr800"
  85 #define amradio_dev_warn(dev, fmt, arg...)                              \
  86                 dev_warn(dev, MR800_DRIVER_NAME " - " fmt, ##arg)
  87
  88 #define amradio_dev_err(dev, fmt, arg...) \
  89                 dev_err(dev, MR800_DRIVER_NAME " - " fmt, ##arg)
  90
  91 /* Probably USB_TIMEOUT should be modified in module parameter */
  92 #define BUFFER_LENGTH 8
  93 #define USB_TIMEOUT 500
  94
  95 /* Frequency limits in MHz -- these are European values.  For Japanese
  96 devices, that would be 76 and 91.  */
  97 #define FREQ_MIN  87.5
  98 #define FREQ_MAX 108.0
  99 #define FREQ_MUL 16000
 100
 101 /*
 102  * Commands that device should understand
 103  * List isnt full and will be updated with implementation of new functions
 104  */
 105 #define AMRADIO_SET_FREQ        0xa4
 106 #define AMRADIO_SET_MUTE        0xab
 107 #define AMRADIO_SET_MONO        0xae
 108
 109 /* Comfortable defines for amradio_set_mute */
 110 #define AMRADIO_START           0x00
 111 #define AMRADIO_STOP            0x01
 112
 113 /* Comfortable defines for amradio_set_stereo */
 114 #define WANT_STEREO             0x00
 115 #define WANT_MONO               0x01
 116
 117 /* module parameter */
 118 static int radio_nr = -1;
 119 module_param(radio_nr, int, 0);
 120 MODULE_PARM_DESC(radio_nr, "Radio Nr");
 121
 122 static int usb_amradio_probe(struct usb_interface *intf,
 123                              const struct usb_device_id *id);
 124 static void usb_amradio_disconnect(struct usb_interface *intf);
 125 static int usb_amradio_open(struct file *file);
 126 static int usb_amradio_close(struct file *file);
 127 static int usb_amradio_suspend(struct usb_interface *intf,
 128                                 pm_message_t message);
 129 static int usb_amradio_resume(struct usb_interface *intf);
 130
 131 /* Data for one (physical) device */
 132 struct amradio_device {
 133         /* reference to USB and video device */
 134         struct usb_device *usbdev;
 135         struct usb_interface *intf;
 136         struct video_device videodev;
 137         struct v4l2_device v4l2_dev;
 138
 139         unsigned char *buffer;
 140         struct mutex lock;      /* buffer locking */
 141         int curfreq;
 142         int stereo;
 143         int muted;
 144         int initialized;
 145 };
 146
 147 #define vdev_to_amradio(r) container_of(r, struct amradio_device, videodev)
 148
 149 /* USB Device ID List */
 150 static struct usb_device_id usb_amradio_device_table[] = {
 151         {USB_DEVICE_AND_INTERFACE_INFO(USB_AMRADIO_VENDOR, USB_AMRADIO_PRODUCT,
 152                                                         USB_CLASS_HID, 0, 0) },
 153         { }                                             /* Terminating entry */
 154 };
 155
 156 MODULE_DEVICE_TABLE(usb, usb_amradio_device_table);
 157
 158 /* USB subsystem interface */
 159 static struct usb_driver usb_amradio_driver = {
 160         .name                   = MR800_DRIVER_NAME,
 161         .probe                  = usb_amradio_probe,
 162         .disconnect             = usb_amradio_disconnect,
 163         .suspend                = usb_amradio_suspend,
 164         .resume                 = usb_amradio_resume,
 165         .reset_resume           = usb_amradio_resume,
 166         .id_table               = usb_amradio_device_table,
 167         .supports_autosuspend   = 1,
 168 };
 169
 170 /* switch on/off the radio. Send 8 bytes to device */
 171 static int amradio_set_mute(struct amradio_device *radio, char argument)
 172 {
 173         int retval;
 174         int size;
 175
 176         BUG_ON(!mutex_is_locked(&radio->lock));
 177
 178         radio->buffer[0] = 0x00;
 179         radio->buffer[1] = 0x55;
 180         radio->buffer[2] = 0xaa;
 181         radio->buffer[3] = 0x00;
 182         radio->buffer[4] = AMRADIO_SET_MUTE;
 183         radio->buffer[5] = argument;
 184         radio->buffer[6] = 0x00;
 185         radio->buffer[7] = 0x00;
 186
 187         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 188                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 189
 190         if (retval < 0 || size != BUFFER_LENGTH) {
 191                 amradio_dev_warn(&radio->videodev.dev, "set mute failed\n");
 192                 return retval;
 193         }
 194
 195         radio->muted = argument;
 196
 197         return retval;
 198 }
 199
 200 /* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
 201 static int amradio_setfreq(struct amradio_device *radio, int freq)
 202 {
 203         int retval;
 204         int size;
 205         unsigned short freq_send = 0x10 + (freq >> 3) / 25;
 206
 207         BUG_ON(!mutex_is_locked(&radio->lock));
 208
 209         radio->buffer[0] = 0x00;
 210         radio->buffer[1] = 0x55;
 211         radio->buffer[2] = 0xaa;
 212         radio->buffer[3] = 0x03;
 213         radio->buffer[4] = AMRADIO_SET_FREQ;
 214         radio->buffer[5] = 0x00;
 215         radio->buffer[6] = 0x00;
 216         radio->buffer[7] = 0x08;
 217
 218         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 219                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 220
 221         if (retval < 0 || size != BUFFER_LENGTH)
 222                 goto out_err;
 223
 224         /* frequency is calculated from freq_send and placed in first 2 bytes */
 225         radio->buffer[0] = (freq_send >> 8) & 0xff;
 226         radio->buffer[1] = freq_send & 0xff;
 227         radio->buffer[2] = 0x01;
 228         radio->buffer[3] = 0x00;
 229         radio->buffer[4] = 0x00;
 230         /* 5 and 6 bytes of buffer already = 0x00 */
 231         radio->buffer[7] = 0x00;
 232
 233         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 234                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 235
 236         if (retval < 0 || size != BUFFER_LENGTH)
 237                 goto out_err;
 238
 239         radio->curfreq = freq;
 240         goto out;
 241
 242 out_err:
 243         amradio_dev_warn(&radio->videodev.dev, "set frequency failed\n");
 244 out:
 245         return retval;
 246 }
 247
 248 static int amradio_set_stereo(struct amradio_device *radio, char argument)
 249 {
 250         int retval;
 251         int size;
 252
 253         BUG_ON(!mutex_is_locked(&radio->lock));
 254
 255         radio->buffer[0] = 0x00;
 256         radio->buffer[1] = 0x55;
 257         radio->buffer[2] = 0xaa;
 258         radio->buffer[3] = 0x00;
 259         radio->buffer[4] = AMRADIO_SET_MONO;
 260         radio->buffer[5] = argument;
 261         radio->buffer[6] = 0x00;
 262         radio->buffer[7] = 0x00;
 263
 264         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 265                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 266
 267         if (retval < 0 || size != BUFFER_LENGTH) {
 268                 amradio_dev_warn(&radio->videodev.dev, "set stereo failed\n");
 269                 return retval;
 270         }
 271
 272         if (argument == WANT_STEREO)
 273                 radio->stereo = 1;
 274         else
 275                 radio->stereo = 0;
 276
 277         return retval;
 278 }
 279
 280 /* Handle unplugging the device.
 281  * We call video_unregister_device in any case.
 282  * The last function called in this procedure is
 283  * usb_amradio_device_release.
 284  */
 285 static void usb_amradio_disconnect(struct usb_interface *intf)
 286 {
 287         struct amradio_device *radio = usb_get_intfdata(intf);
 288
 289         mutex_lock(&radio->lock);
 290         radio->usbdev = NULL;
 291         mutex_unlock(&radio->lock);
 292
 293         usb_set_intfdata(intf, NULL);
 294         v4l2_device_disconnect(&radio->v4l2_dev);
 295         video_unregister_device(&radio->videodev);
 296 }
 297
 298 /* vidioc_querycap - query device capabilities */
 299 static int vidioc_querycap(struct file *file, void *priv,
 300                                         struct v4l2_capability *v)
 301 {
 302         struct amradio_device *radio = file->private_data;
 303
 304         strlcpy(v->driver, "radio-mr800", sizeof(v->driver));
 305         strlcpy(v->card, "AverMedia MR 800 USB FM Radio", sizeof(v->card));
 306         usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
 307         v->version = RADIO_VERSION;
 308         v->capabilities = V4L2_CAP_TUNER;
 309         return 0;
 310 }
 311
 312 /* vidioc_g_tuner - get tuner attributes */
 313 static int vidioc_g_tuner(struct file *file, void *priv,
 314                                 struct v4l2_tuner *v)
 315 {
 316         struct amradio_device *radio = file->private_data;
 317         int retval;
 318
 319         if (v->index > 0)
 320                 return -EINVAL;
 321
 322 /* TODO: Add function which look is signal stereo or not
 323  *      amradio_getstat(radio);
 324  */
 325
 326 /* we call amradio_set_stereo to set radio->stereo
 327  * Honestly, amradio_getstat should cover this in future and
 328  * amradio_set_stereo shouldn't be here
 329  */
 330         retval = amradio_set_stereo(radio, WANT_STEREO);
 331
 332         strcpy(v->name, "FM");
 333         v->type = V4L2_TUNER_RADIO;
 334         v->rangelow = FREQ_MIN * FREQ_MUL;
 335         v->rangehigh = FREQ_MAX * FREQ_MUL;
 336         v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
 337         v->capability = V4L2_TUNER_CAP_LOW;
 338         if (radio->stereo)
 339                 v->audmode = V4L2_TUNER_MODE_STEREO;
 340         else
 341                 v->audmode = V4L2_TUNER_MODE_MONO;
 342         v->signal = 0xffff;     /* Can't get the signal strength, sad.. */
 343         v->afc = 0; /* Don't know what is this */
 344
 345         return retval;
 346 }
 347
 348 /* vidioc_s_tuner - set tuner attributes */
 349 static int vidioc_s_tuner(struct file *file, void *priv,
 350                                 struct v4l2_tuner *v)
 351 {
 352         struct amradio_device *radio = file->private_data;
 353         int retval = -EINVAL;
 354
 355         if (v->index > 0)
 356                 return -EINVAL;
 357
 358         /* mono/stereo selector */
 359         switch (v->audmode) {
 360         case V4L2_TUNER_MODE_MONO:
 361                 retval = amradio_set_stereo(radio, WANT_MONO);
 362                 break;
 363         case V4L2_TUNER_MODE_STEREO:
 364                 retval = amradio_set_stereo(radio, WANT_STEREO);
 365                 break;
 366         }
 367
 368         return retval;
 369 }
 370
 371 /* vidioc_s_frequency - set tuner radio frequency */
 372 static int vidioc_s_frequency(struct file *file, void *priv,
 373                                 struct v4l2_frequency *f)
 374 {
 375         struct amradio_device *radio = file->private_data;
 376
 377         if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
 378                 return -EINVAL;
 379         return amradio_setfreq(radio, f->frequency);
 380 }
 381
 382 /* vidioc_g_frequency - get tuner radio frequency */
 383 static int vidioc_g_frequency(struct file *file, void *priv,
 384                                 struct v4l2_frequency *f)
 385 {
 386         struct amradio_device *radio = file->private_data;
 387
 388         if (f->tuner != 0)
 389                 return -EINVAL;
 390         f->type = V4L2_TUNER_RADIO;
 391         f->frequency = radio->curfreq;
 392
 393         return 0;
 394 }
 395
 396 /* vidioc_queryctrl - enumerate control items */
 397 static int vidioc_queryctrl(struct file *file, void *priv,
 398                                 struct v4l2_queryctrl *qc)
 399 {
 400         switch (qc->id) {
 401         case V4L2_CID_AUDIO_MUTE:
 402                 return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1);
 403         }
 404
 405         return -EINVAL;
 406 }
 407
 408 /* vidioc_g_ctrl - get the value of a control */
 409 static int vidioc_g_ctrl(struct file *file, void *priv,
 410                                 struct v4l2_control *ctrl)
 411 {
 412         struct amradio_device *radio = file->private_data;
 413
 414         switch (ctrl->id) {
 415         case V4L2_CID_AUDIO_MUTE:
 416                 ctrl->value = radio->muted;
 417                 return 0;
 418         }
 419
 420         return -EINVAL;
 421 }
 422
 423 /* vidioc_s_ctrl - set the value of a control */
 424 static int vidioc_s_ctrl(struct file *file, void *priv,
 425                                 struct v4l2_control *ctrl)
 426 {
 427         struct amradio_device *radio = file->private_data;
 428         int retval = -EINVAL;
 429
 430         switch (ctrl->id) {
 431         case V4L2_CID_AUDIO_MUTE:
 432                 if (ctrl->value)
 433                         retval = amradio_set_mute(radio, AMRADIO_STOP);
 434                 else
 435                         retval = amradio_set_mute(radio, AMRADIO_START);
 436
 437                 break;
 438         }
 439
 440         return retval;
 441 }
 442
 443 /* vidioc_g_audio - get audio attributes */
 444 static int vidioc_g_audio(struct file *file, void *priv,
 445                                 struct v4l2_audio *a)
 446 {
 447         if (a->index > 1)
 448                 return -EINVAL;
 449
 450         strcpy(a->name, "Radio");
 451         a->capability = V4L2_AUDCAP_STEREO;
 452         return 0;
 453 }
 454
 455 /* vidioc_s_audio - set audio attributes  */
 456 static int vidioc_s_audio(struct file *file, void *priv,
 457                                         struct v4l2_audio *a)
 458 {
 459         if (a->index != 0)
 460                 return -EINVAL;
 461         return 0;
 462 }
 463
 464 /* vidioc_g_input - get input */
 465 static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
 466 {
 467         *i = 0;
 468         return 0;
 469 }
 470
 471 /* vidioc_s_input - set input */
 472 static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
 473 {
 474         if (i != 0)
 475                 return -EINVAL;
 476         return 0;
 477 }
 478
 479 static int usb_amradio_init(struct amradio_device *radio)
 480 {
 481         int retval;
 482
 483         retval = amradio_set_mute(radio, AMRADIO_STOP);
 484         if (retval)
 485                 goto out_err;
 486
 487         retval = amradio_set_stereo(radio, WANT_STEREO);
 488         if (retval)
 489                 goto out_err;
 490
 491         radio->initialized = 1;
 492         goto out;
 493
 494 out_err:
 495         amradio_dev_err(&radio->videodev.dev, "initialization failed\n");
 496 out:
 497         return retval;
 498 }
 499
 500 /* open device - amradio_start() and amradio_setfreq() */
 501 static int usb_amradio_open(struct file *file)
 502 {
 503         struct amradio_device *radio = vdev_to_amradio(video_devdata(file));
 504         int retval = 0;
 505
 506         mutex_lock(&radio->lock);
 507
 508         if (!radio->usbdev) {
 509                 retval = -EIO;
 510                 goto unlock;
 511         }
 512
 513         file->private_data = radio;
 514         retval = usb_autopm_get_interface(radio->intf);
 515         if (retval)
 516                 goto unlock;
 517
 518         if (unlikely(!radio->initialized)) {
 519                 retval = usb_amradio_init(radio);
 520                 if (retval)
 521                         usb_autopm_put_interface(radio->intf);
 522         }
 523
 524 unlock:
 525         mutex_unlock(&radio->lock);
 526         return retval;
 527 }
 528
 529 /*close device */
 530 static int usb_amradio_close(struct file *file)
 531 {
 532         struct amradio_device *radio = file->private_data;
 533         int retval = 0;
 534
 535         mutex_lock(&radio->lock);
 536
 537         if (!radio->usbdev)
 538                 retval = -EIO;
 539         else
 540                 usb_autopm_put_interface(radio->intf);
 541
 542         mutex_unlock(&radio->lock);
 543         return retval;
 544 }
 545
 546 static long usb_amradio_ioctl(struct file *file, unsigned int cmd,
 547                                 unsigned long arg)
 548 {
 549         struct amradio_device *radio = file->private_data;
 550         long retval = 0;
 551
 552         mutex_lock(&radio->lock);
 553
 554         if (!radio->usbdev) {
 555                 retval = -EIO;
 556                 goto unlock;
 557         }
 558
 559         retval = video_ioctl2(file, cmd, arg);
 560
 561 unlock:
 562         mutex_unlock(&radio->lock);
 563         return retval;
 564 }
 565
 566 /* Suspend device - stop device. Need to be checked and fixed */
 567 static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message)
 568 {
 569         struct amradio_device *radio = usb_get_intfdata(intf);
 570
 571         mutex_lock(&radio->lock);
 572
 573         if (!radio->muted && radio->initialized) {
 574                 amradio_set_mute(radio, AMRADIO_STOP);
 575                 radio->muted = 0;
 576         }
 577
 578         dev_info(&intf->dev, "going into suspend..\n");
 579
 580         mutex_unlock(&radio->lock);
 581         return 0;
 582 }
 583
 584 /* Resume device - start device. Need to be checked and fixed */
 585 static int usb_amradio_resume(struct usb_interface *intf)
 586 {
 587         struct amradio_device *radio = usb_get_intfdata(intf);
 588
 589         mutex_lock(&radio->lock);
 590
 591         if (unlikely(!radio->initialized))
 592                 goto unlock;
 593
 594         if (radio->stereo)
 595                 amradio_set_stereo(radio, WANT_STEREO);
 596         else
 597                 amradio_set_stereo(radio, WANT_MONO);
 598
 599         amradio_setfreq(radio, radio->curfreq);
 600
 601         if (!radio->muted)
 602                 amradio_set_mute(radio, AMRADIO_START);
 603
 604 unlock:
 605         dev_info(&intf->dev, "coming out of suspend..\n");
 606
 607         mutex_unlock(&radio->lock);
 608         return 0;
 609 }
 610
 611 /* File system interface */
 612 static const struct v4l2_file_operations usb_amradio_fops = {
 613         .owner          = THIS_MODULE,
 614         .open           = usb_amradio_open,
 615         .release        = usb_amradio_close,
 616         .ioctl          = usb_amradio_ioctl,
 617 };
 618
 619 static const struct v4l2_ioctl_ops usb_amradio_ioctl_ops = {
 620         .vidioc_querycap    = vidioc_querycap,
 621         .vidioc_g_tuner     = vidioc_g_tuner,
 622         .vidioc_s_tuner     = vidioc_s_tuner,
 623         .vidioc_g_frequency = vidioc_g_frequency,
 624         .vidioc_s_frequency = vidioc_s_frequency,
 625         .vidioc_queryctrl   = vidioc_queryctrl,
 626         .vidioc_g_ctrl      = vidioc_g_ctrl,
 627         .vidioc_s_ctrl      = vidioc_s_ctrl,
 628         .vidioc_g_audio     = vidioc_g_audio,
 629         .vidioc_s_audio     = vidioc_s_audio,
 630         .vidioc_g_input     = vidioc_g_input,
 631         .vidioc_s_input     = vidioc_s_input,
 632 };
 633
 634 static void usb_amradio_video_device_release(struct video_device *videodev)
 635 {
 636         struct amradio_device *radio = vdev_to_amradio(videodev);
 637
 638         v4l2_device_unregister(&radio->v4l2_dev);
 639
 640         /* free rest memory */
 641         kfree(radio->buffer);
 642         kfree(radio);
 643 }
 644
 645 /* check if the device is present and register with v4l and usb if it is */
 646 static int usb_amradio_probe(struct usb_interface *intf,
 647                                 const struct usb_device_id *id)
 648 {
 649         struct amradio_device *radio;
 650         int retval = 0;
 651
 652         radio = kzalloc(sizeof(struct amradio_device), GFP_KERNEL);
 653
 654         if (!radio) {
 655                 dev_err(&intf->dev, "kmalloc for amradio_device failed\n");
 656                 retval = -ENOMEM;
 657                 goto err;
 658         }
 659
 660         radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
 661
 662         if (!radio->buffer) {
 663                 dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
 664                 retval = -ENOMEM;
 665                 goto err_nobuf;
 666         }
 667
 668         retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev);
 669         if (retval < 0) {
 670                 dev_err(&intf->dev, "couldn't register v4l2_device\n");
 671                 goto err_v4l2;
 672         }
 673
 674         strlcpy(radio->videodev.name, radio->v4l2_dev.name,
 675                 sizeof(radio->videodev.name));
 676         radio->videodev.v4l2_dev = &radio->v4l2_dev;
 677         radio->videodev.fops = &usb_amradio_fops;
 678         radio->videodev.ioctl_ops = &usb_amradio_ioctl_ops;
 679         radio->videodev.release = usb_amradio_video_device_release;
 680
 681         radio->usbdev = interface_to_usbdev(intf);
 682         radio->intf = intf;
 683         radio->curfreq = 95.16 * FREQ_MUL;
 684
 685         mutex_init(&radio->lock);
 686
 687         video_set_drvdata(&radio->videodev, radio);
 688
 689         retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO,
 690                                         radio_nr);
 691         if (retval < 0) {
 692                 dev_err(&intf->dev, "could not register video device\n");
 693                 goto err_vdev;
 694         }
 695
 696         usb_set_intfdata(intf, radio);
 697         return 0;
 698
 699 err_vdev:
 700         v4l2_device_unregister(&radio->v4l2_dev);
 701 err_v4l2:
 702         kfree(radio->buffer);
 703 err_nobuf:
 704         kfree(radio);
 705 err:
 706         return retval;
 707 }
 708
 709 static int __init amradio_init(void)
 710 {
 711         int retval = usb_register(&usb_amradio_driver);
 712
 713         pr_info(KBUILD_MODNAME
 714                 ": version " DRIVER_VERSION " " DRIVER_DESC "\n");
 715
 716         if (retval)
 717                 pr_err(KBUILD_MODNAME
 718                         ": usb_register failed. Error number %d\n", retval);
 719
 720         return retval;
 721 }
 722
 723 static void __exit amradio_exit(void)
 724 {
 725         usb_deregister(&usb_amradio_driver);
 726 }
 727
 728 module_init(amradio_init);
 729 module_exit(amradio_exit);
 730