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 trough 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 /* Probably USB_TIMEOUT should be modified in module parameter */
  89 #define BUFFER_LENGTH 8
  90 #define USB_TIMEOUT 500
  91
  92 /* Frequency limits in MHz -- these are European values.  For Japanese
  93 devices, that would be 76 and 91.  */
  94 #define FREQ_MIN  87.5
  95 #define FREQ_MAX 108.0
  96 #define FREQ_MUL 16000
  97
  98 /*
  99  * Commands that device should understand
 100  * List isnt full and will be updated with implementation of new functions
 101  */
 102 #define AMRADIO_SET_FREQ        0xa4
 103 #define AMRADIO_SET_MUTE        0xab
 104 #define AMRADIO_SET_MONO        0xae
 105
 106 /* Comfortable defines for amradio_set_mute */
 107 #define AMRADIO_START           0x00
 108 #define AMRADIO_STOP            0x01
 109
 110 /* Comfortable defines for amradio_set_stereo */
 111 #define WANT_STEREO             0x00
 112 #define WANT_MONO               0x01
 113
 114 /* module parameter */
 115 static int radio_nr = -1;
 116 module_param(radio_nr, int, 0);
 117 MODULE_PARM_DESC(radio_nr, "Radio Nr");
 118
 119 static int usb_amradio_probe(struct usb_interface *intf,
 120                              const struct usb_device_id *id);
 121 static void usb_amradio_disconnect(struct usb_interface *intf);
 122 static int usb_amradio_open(struct file *file);
 123 static int usb_amradio_close(struct file *file);
 124 static int usb_amradio_suspend(struct usb_interface *intf,
 125                                 pm_message_t message);
 126 static int usb_amradio_resume(struct usb_interface *intf);
 127
 128 /* Data for one (physical) device */
 129 struct amradio_device {
 130         /* reference to USB and video device */
 131         struct usb_device *usbdev;
 132         struct video_device *videodev;
 133         struct v4l2_device v4l2_dev;
 134
 135         unsigned char *buffer;
 136         struct mutex lock;      /* buffer locking */
 137         int curfreq;
 138         int stereo;
 139         int users;
 140         int removed;
 141         int muted;
 142 };
 143
 144 /* USB Device ID List */
 145 static struct usb_device_id usb_amradio_device_table[] = {
 146         {USB_DEVICE_AND_INTERFACE_INFO(USB_AMRADIO_VENDOR, USB_AMRADIO_PRODUCT,
 147                                                         USB_CLASS_HID, 0, 0) },
 148         { }                                             /* Terminating entry */
 149 };
 150
 151 MODULE_DEVICE_TABLE(usb, usb_amradio_device_table);
 152
 153 /* USB subsystem interface */
 154 static struct usb_driver usb_amradio_driver = {
 155         .name                   = MR800_DRIVER_NAME,
 156         .probe                  = usb_amradio_probe,
 157         .disconnect             = usb_amradio_disconnect,
 158         .suspend                = usb_amradio_suspend,
 159         .resume                 = usb_amradio_resume,
 160         .reset_resume           = usb_amradio_resume,
 161         .id_table               = usb_amradio_device_table,
 162         .supports_autosuspend   = 0,
 163 };
 164
 165 /* switch on/off the radio. Send 8 bytes to device */
 166 static int amradio_set_mute(struct amradio_device *radio, char argument)
 167 {
 168         int retval;
 169         int size;
 170
 171         /* safety check */
 172         if (radio->removed)
 173                 return -EIO;
 174
 175         mutex_lock(&radio->lock);
 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                 mutex_unlock(&radio->lock);
 191                 return retval;
 192         }
 193
 194         radio->muted = argument;
 195
 196         mutex_unlock(&radio->lock);
 197
 198         return retval;
 199 }
 200
 201 /* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */
 202 static int amradio_setfreq(struct amradio_device *radio, int freq)
 203 {
 204         int retval;
 205         int size;
 206         unsigned short freq_send = 0x10 + (freq >> 3) / 25;
 207
 208         /* safety check */
 209         if (radio->removed)
 210                 return -EIO;
 211
 212         mutex_lock(&radio->lock);
 213
 214         radio->buffer[0] = 0x00;
 215         radio->buffer[1] = 0x55;
 216         radio->buffer[2] = 0xaa;
 217         radio->buffer[3] = 0x03;
 218         radio->buffer[4] = AMRADIO_SET_FREQ;
 219         radio->buffer[5] = 0x00;
 220         radio->buffer[6] = 0x00;
 221         radio->buffer[7] = 0x08;
 222
 223         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 224                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 225
 226         if (retval < 0 || size != BUFFER_LENGTH) {
 227                 mutex_unlock(&radio->lock);
 228                 return retval;
 229         }
 230
 231         /* frequency is calculated from freq_send and placed in first 2 bytes */
 232         radio->buffer[0] = (freq_send >> 8) & 0xff;
 233         radio->buffer[1] = freq_send & 0xff;
 234         radio->buffer[2] = 0x01;
 235         radio->buffer[3] = 0x00;
 236         radio->buffer[4] = 0x00;
 237         /* 5 and 6 bytes of buffer already = 0x00 */
 238         radio->buffer[7] = 0x00;
 239
 240         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 241                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 242
 243         if (retval < 0 || size != BUFFER_LENGTH) {
 244                 mutex_unlock(&radio->lock);
 245                 return retval;
 246         }
 247
 248         mutex_unlock(&radio->lock);
 249
 250         return retval;
 251 }
 252
 253 static int amradio_set_stereo(struct amradio_device *radio, char argument)
 254 {
 255         int retval;
 256         int size;
 257
 258         /* safety check */
 259         if (radio->removed)
 260                 return -EIO;
 261
 262         mutex_lock(&radio->lock);
 263
 264         radio->buffer[0] = 0x00;
 265         radio->buffer[1] = 0x55;
 266         radio->buffer[2] = 0xaa;
 267         radio->buffer[3] = 0x00;
 268         radio->buffer[4] = AMRADIO_SET_MONO;
 269         radio->buffer[5] = argument;
 270         radio->buffer[6] = 0x00;
 271         radio->buffer[7] = 0x00;
 272
 273         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 274                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 275
 276         if (retval < 0 || size != BUFFER_LENGTH) {
 277                 radio->stereo = -1;
 278                 mutex_unlock(&radio->lock);
 279                 return retval;
 280         }
 281
 282         radio->stereo = 1;
 283
 284         mutex_unlock(&radio->lock);
 285
 286         return retval;
 287 }
 288
 289 /* Handle unplugging the device.
 290  * We call video_unregister_device in any case.
 291  * The last function called in this procedure is
 292  * usb_amradio_device_release.
 293  */
 294 static void usb_amradio_disconnect(struct usb_interface *intf)
 295 {
 296         struct amradio_device *radio = usb_get_intfdata(intf);
 297
 298         mutex_lock(&radio->lock);
 299         radio->removed = 1;
 300         mutex_unlock(&radio->lock);
 301
 302         usb_set_intfdata(intf, NULL);
 303         video_unregister_device(radio->videodev);
 304         v4l2_device_disconnect(&radio->v4l2_dev);
 305 }
 306
 307 /* vidioc_querycap - query device capabilities */
 308 static int vidioc_querycap(struct file *file, void *priv,
 309                                         struct v4l2_capability *v)
 310 {
 311         struct amradio_device *radio = video_drvdata(file);
 312
 313         strlcpy(v->driver, "radio-mr800", sizeof(v->driver));
 314         strlcpy(v->card, "AverMedia MR 800 USB FM Radio", sizeof(v->card));
 315         usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
 316         v->version = RADIO_VERSION;
 317         v->capabilities = V4L2_CAP_TUNER;
 318         return 0;
 319 }
 320
 321 /* vidioc_g_tuner - get tuner attributes */
 322 static int vidioc_g_tuner(struct file *file, void *priv,
 323                                 struct v4l2_tuner *v)
 324 {
 325         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 326         int retval;
 327
 328         /* safety check */
 329         if (radio->removed)
 330                 return -EIO;
 331
 332         if (v->index > 0)
 333                 return -EINVAL;
 334
 335 /* TODO: Add function which look is signal stereo or not
 336  *      amradio_getstat(radio);
 337  */
 338
 339 /* we call amradio_set_stereo to set radio->stereo
 340  * Honestly, amradio_getstat should cover this in future and
 341  * amradio_set_stereo shouldn't be here
 342  */
 343         retval = amradio_set_stereo(radio, WANT_STEREO);
 344         if (retval < 0)
 345                 amradio_dev_warn(&radio->videodev->dev,
 346                         "set stereo failed\n");
 347
 348         strcpy(v->name, "FM");
 349         v->type = V4L2_TUNER_RADIO;
 350         v->rangelow = FREQ_MIN * FREQ_MUL;
 351         v->rangehigh = FREQ_MAX * FREQ_MUL;
 352         v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
 353         v->capability = V4L2_TUNER_CAP_LOW;
 354         if (radio->stereo)
 355                 v->audmode = V4L2_TUNER_MODE_STEREO;
 356         else
 357                 v->audmode = V4L2_TUNER_MODE_MONO;
 358         v->signal = 0xffff;     /* Can't get the signal strength, sad.. */
 359         v->afc = 0; /* Don't know what is this */
 360         return 0;
 361 }
 362
 363 /* vidioc_s_tuner - set tuner attributes */
 364 static int vidioc_s_tuner(struct file *file, void *priv,
 365                                 struct v4l2_tuner *v)
 366 {
 367         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 368         int retval;
 369
 370         /* safety check */
 371         if (radio->removed)
 372                 return -EIO;
 373
 374         if (v->index > 0)
 375                 return -EINVAL;
 376
 377         /* mono/stereo selector */
 378         switch (v->audmode) {
 379         case V4L2_TUNER_MODE_MONO:
 380                 retval = amradio_set_stereo(radio, WANT_MONO);
 381                 if (retval < 0)
 382                         amradio_dev_warn(&radio->videodev->dev,
 383                                 "set mono failed\n");
 384                 break;
 385         case V4L2_TUNER_MODE_STEREO:
 386                 retval = amradio_set_stereo(radio, WANT_STEREO);
 387                 if (retval < 0)
 388                         amradio_dev_warn(&radio->videodev->dev,
 389                                 "set stereo failed\n");
 390                 break;
 391         default:
 392                 return -EINVAL;
 393         }
 394
 395         return 0;
 396 }
 397
 398 /* vidioc_s_frequency - set tuner radio frequency */
 399 static int vidioc_s_frequency(struct file *file, void *priv,
 400                                 struct v4l2_frequency *f)
 401 {
 402         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 403         int retval;
 404
 405         /* safety check */
 406         if (radio->removed)
 407                 return -EIO;
 408
 409         mutex_lock(&radio->lock);
 410         radio->curfreq = f->frequency;
 411         mutex_unlock(&radio->lock);
 412
 413         retval = amradio_setfreq(radio, radio->curfreq);
 414         if (retval < 0)
 415                 amradio_dev_warn(&radio->videodev->dev,
 416                         "set frequency failed\n");
 417         return 0;
 418 }
 419
 420 /* vidioc_g_frequency - get tuner radio frequency */
 421 static int vidioc_g_frequency(struct file *file, void *priv,
 422                                 struct v4l2_frequency *f)
 423 {
 424         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 425
 426         /* safety check */
 427         if (radio->removed)
 428                 return -EIO;
 429
 430         f->type = V4L2_TUNER_RADIO;
 431         f->frequency = radio->curfreq;
 432         return 0;
 433 }
 434
 435 /* vidioc_queryctrl - enumerate control items */
 436 static int vidioc_queryctrl(struct file *file, void *priv,
 437                                 struct v4l2_queryctrl *qc)
 438 {
 439         switch (qc->id) {
 440         case V4L2_CID_AUDIO_MUTE:
 441                 return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1);
 442         }
 443
 444         return -EINVAL;
 445 }
 446
 447 /* vidioc_g_ctrl - get the value of a control */
 448 static int vidioc_g_ctrl(struct file *file, void *priv,
 449                                 struct v4l2_control *ctrl)
 450 {
 451         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 452
 453         /* safety check */
 454         if (radio->removed)
 455                 return -EIO;
 456
 457         switch (ctrl->id) {
 458         case V4L2_CID_AUDIO_MUTE:
 459                 ctrl->value = radio->muted;
 460                 return 0;
 461         }
 462         return -EINVAL;
 463 }
 464
 465 /* vidioc_s_ctrl - set the value of a control */
 466 static int vidioc_s_ctrl(struct file *file, void *priv,
 467                                 struct v4l2_control *ctrl)
 468 {
 469         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 470         int retval;
 471
 472         /* safety check */
 473         if (radio->removed)
 474                 return -EIO;
 475
 476         switch (ctrl->id) {
 477         case V4L2_CID_AUDIO_MUTE:
 478                 if (ctrl->value) {
 479                         retval = amradio_set_mute(radio, AMRADIO_STOP);
 480                         if (retval < 0) {
 481                                 amradio_dev_warn(&radio->videodev->dev,
 482                                         "amradio_stop failed\n");
 483                                 return -1;
 484                         }
 485                 } else {
 486                         retval = amradio_set_mute(radio, AMRADIO_START);
 487                         if (retval < 0) {
 488                                 amradio_dev_warn(&radio->videodev->dev,
 489                                         "amradio_start failed\n");
 490                                 return -1;
 491                         }
 492                 }
 493                 return 0;
 494         }
 495         return -EINVAL;
 496 }
 497
 498 /* vidioc_g_audio - get audio attributes */
 499 static int vidioc_g_audio(struct file *file, void *priv,
 500                                 struct v4l2_audio *a)
 501 {
 502         if (a->index > 1)
 503                 return -EINVAL;
 504
 505         strcpy(a->name, "Radio");
 506         a->capability = V4L2_AUDCAP_STEREO;
 507         return 0;
 508 }
 509
 510 /* vidioc_s_audio - set audio attributes  */
 511 static int vidioc_s_audio(struct file *file, void *priv,
 512                                         struct v4l2_audio *a)
 513 {
 514         if (a->index != 0)
 515                 return -EINVAL;
 516         return 0;
 517 }
 518
 519 /* vidioc_g_input - get input */
 520 static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
 521 {
 522         *i = 0;
 523         return 0;
 524 }
 525
 526 /* vidioc_s_input - set input */
 527 static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
 528 {
 529         if (i != 0)
 530                 return -EINVAL;
 531         return 0;
 532 }
 533
 534 /* open device - amradio_start() and amradio_setfreq() */
 535 static int usb_amradio_open(struct file *file)
 536 {
 537         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 538         int retval;
 539
 540         lock_kernel();
 541
 542         radio->users = 1;
 543         radio->muted = 1;
 544
 545         retval = amradio_set_mute(radio, AMRADIO_START);
 546         if (retval < 0) {
 547                 amradio_dev_warn(&radio->videodev->dev,
 548                         "radio did not start up properly\n");
 549                 radio->users = 0;
 550                 unlock_kernel();
 551                 return -EIO;
 552         }
 553
 554         retval = amradio_set_stereo(radio, WANT_STEREO);
 555         if (retval < 0)
 556                 amradio_dev_warn(&radio->videodev->dev,
 557                         "set stereo failed\n");
 558
 559         retval = amradio_setfreq(radio, radio->curfreq);
 560         if (retval < 0)
 561                 amradio_dev_warn(&radio->videodev->dev,
 562                         "set frequency failed\n");
 563
 564         unlock_kernel();
 565         return 0;
 566 }
 567
 568 /*close device */
 569 static int usb_amradio_close(struct file *file)
 570 {
 571         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 572         int retval;
 573
 574         if (!radio)
 575                 return -ENODEV;
 576
 577         mutex_lock(&radio->lock);
 578         radio->users = 0;
 579         mutex_unlock(&radio->lock);
 580
 581         if (!radio->removed) {
 582                 retval = amradio_set_mute(radio, AMRADIO_STOP);
 583                 if (retval < 0)
 584                         amradio_dev_warn(&radio->videodev->dev,
 585                                 "amradio_stop failed\n");
 586         }
 587
 588         return 0;
 589 }
 590
 591 /* Suspend device - stop device. Need to be checked and fixed */
 592 static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message)
 593 {
 594         struct amradio_device *radio = usb_get_intfdata(intf);
 595         int retval;
 596
 597         retval = amradio_set_mute(radio, AMRADIO_STOP);
 598         if (retval < 0)
 599                 dev_warn(&intf->dev, "amradio_stop failed\n");
 600
 601         dev_info(&intf->dev, "going into suspend..\n");
 602
 603         return 0;
 604 }
 605
 606 /* Resume device - start device. Need to be checked and fixed */
 607 static int usb_amradio_resume(struct usb_interface *intf)
 608 {
 609         struct amradio_device *radio = usb_get_intfdata(intf);
 610         int retval;
 611
 612         retval = amradio_set_mute(radio, AMRADIO_START);
 613         if (retval < 0)
 614                 dev_warn(&intf->dev, "amradio_start failed\n");
 615
 616         dev_info(&intf->dev, "coming out of suspend..\n");
 617
 618         return 0;
 619 }
 620
 621 /* File system interface */
 622 static const struct v4l2_file_operations usb_amradio_fops = {
 623         .owner          = THIS_MODULE,
 624         .open           = usb_amradio_open,
 625         .release        = usb_amradio_close,
 626         .ioctl          = video_ioctl2,
 627 };
 628
 629 static const struct v4l2_ioctl_ops usb_amradio_ioctl_ops = {
 630         .vidioc_querycap    = vidioc_querycap,
 631         .vidioc_g_tuner     = vidioc_g_tuner,
 632         .vidioc_s_tuner     = vidioc_s_tuner,
 633         .vidioc_g_frequency = vidioc_g_frequency,
 634         .vidioc_s_frequency = vidioc_s_frequency,
 635         .vidioc_queryctrl   = vidioc_queryctrl,
 636         .vidioc_g_ctrl      = vidioc_g_ctrl,
 637         .vidioc_s_ctrl      = vidioc_s_ctrl,
 638         .vidioc_g_audio     = vidioc_g_audio,
 639         .vidioc_s_audio     = vidioc_s_audio,
 640         .vidioc_g_input     = vidioc_g_input,
 641         .vidioc_s_input     = vidioc_s_input,
 642 };
 643
 644 static void usb_amradio_video_device_release(struct video_device *videodev)
 645 {
 646         struct amradio_device *radio = video_get_drvdata(videodev);
 647
 648         /* we call v4l to free radio->videodev */
 649         video_device_release(videodev);
 650
 651         v4l2_device_unregister(&radio->v4l2_dev);
 652
 653         /* free rest memory */
 654         kfree(radio->buffer);
 655         kfree(radio);
 656 }
 657
 658 /* check if the device is present and register with v4l and usb if it is */
 659 static int usb_amradio_probe(struct usb_interface *intf,
 660                                 const struct usb_device_id *id)
 661 {
 662         struct amradio_device *radio;
 663         struct v4l2_device *v4l2_dev;
 664         int retval;
 665
 666         radio = kzalloc(sizeof(struct amradio_device), GFP_KERNEL);
 667
 668         if (!radio) {
 669                 dev_err(&intf->dev, "kmalloc for amradio_device failed\n");
 670                 return -ENOMEM;
 671         }
 672
 673         radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
 674
 675         if (!radio->buffer) {
 676                 dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
 677                 kfree(radio);
 678                 return -ENOMEM;
 679         }
 680
 681         v4l2_dev = &radio->v4l2_dev;
 682         retval = v4l2_device_register(&intf->dev, v4l2_dev);
 683         if (retval < 0) {
 684                 dev_err(&intf->dev, "couldn't register v4l2_device\n");
 685                 kfree(radio->buffer);
 686                 kfree(radio);
 687                 return retval;
 688         }
 689
 690         radio->videodev = video_device_alloc();
 691
 692         if (!radio->videodev) {
 693                 dev_err(&intf->dev, "video_device_alloc failed\n");
 694                 kfree(radio->buffer);
 695                 kfree(radio);
 696                 return -ENOMEM;
 697         }
 698
 699         strlcpy(radio->videodev->name, v4l2_dev->name, sizeof(radio->videodev->name));
 700         radio->videodev->v4l2_dev = v4l2_dev;
 701         radio->videodev->fops = &usb_amradio_fops;
 702         radio->videodev->ioctl_ops = &usb_amradio_ioctl_ops;
 703         radio->videodev->release = usb_amradio_video_device_release;
 704
 705         radio->removed = 0;
 706         radio->users = 0;
 707         radio->usbdev = interface_to_usbdev(intf);
 708         radio->curfreq = 95.16 * FREQ_MUL;
 709         radio->stereo = -1;
 710
 711         mutex_init(&radio->lock);
 712
 713         video_set_drvdata(radio->videodev, radio);
 714
 715         retval = video_register_device(radio->videodev, VFL_TYPE_RADIO, radio_nr);
 716         if (retval < 0) {
 717                 dev_err(&intf->dev, "could not register video device\n");
 718                 video_device_release(radio->videodev);
 719                 v4l2_device_unregister(v4l2_dev);
 720                 kfree(radio->buffer);
 721                 kfree(radio);
 722                 return -EIO;
 723         }
 724
 725         usb_set_intfdata(intf, radio);
 726         return 0;
 727 }
 728
 729 static int __init amradio_init(void)
 730 {
 731         int retval = usb_register(&usb_amradio_driver);
 732
 733         pr_info(KBUILD_MODNAME
 734                 ": version " DRIVER_VERSION " " DRIVER_DESC "\n");
 735
 736         if (retval)
 737                 pr_err(KBUILD_MODNAME
 738                         ": usb_register failed. Error number %d\n", retval);
 739
 740         return retval;
 741 }
 742
 743 static void __exit amradio_exit(void)
 744 {
 745         usb_deregister(&usb_amradio_driver);
 746 }
 747
 748 module_init(amradio_init);
 749 module_exit(amradio_exit);
 750