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 managment 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/version.h>      /* for KERNEL_VERSION MACRO */
  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 "0.11"
  72 #define RADIO_VERSION KERNEL_VERSION(0, 1, 1)
  73
  74 MODULE_AUTHOR(DRIVER_AUTHOR);
  75 MODULE_DESCRIPTION(DRIVER_DESC);
  76 MODULE_LICENSE("GPL");
  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 /* Probably USB_TIMEOUT should be modified in module parameter */
  87 #define BUFFER_LENGTH 8
  88 #define USB_TIMEOUT 500
  89
  90 /* Frequency limits in MHz -- these are European values.  For Japanese
  91 devices, that would be 76 and 91.  */
  92 #define FREQ_MIN  87.5
  93 #define FREQ_MAX 108.0
  94 #define FREQ_MUL 16000
  95
  96 /*
  97  * Commands that device should understand
  98  * List isnt full and will be updated with implementation of new functions
  99  */
 100 #define AMRADIO_SET_FREQ        0xa4
 101 #define AMRADIO_SET_MUTE        0xab
 102 #define AMRADIO_SET_MONO        0xae
 103
 104 /* Comfortable defines for amradio_set_mute */
 105 #define AMRADIO_START           0x00
 106 #define AMRADIO_STOP            0x01
 107
 108 /* Comfortable defines for amradio_set_stereo */
 109 #define WANT_STEREO             0x00
 110 #define WANT_MONO               0x01
 111
 112 /* module parameter */
 113 static int radio_nr = -1;
 114 module_param(radio_nr, int, 0);
 115 MODULE_PARM_DESC(radio_nr, "Radio Nr");
 116
 117 static int usb_amradio_probe(struct usb_interface *intf,
 118                              const struct usb_device_id *id);
 119 static void usb_amradio_disconnect(struct usb_interface *intf);
 120 static int usb_amradio_open(struct file *file);
 121 static int usb_amradio_close(struct file *file);
 122 static int usb_amradio_suspend(struct usb_interface *intf,
 123                                 pm_message_t message);
 124 static int usb_amradio_resume(struct usb_interface *intf);
 125
 126 /* Data for one (physical) device */
 127 struct amradio_device {
 128         /* reference to USB and video device */
 129         struct usb_device *usbdev;
 130         struct video_device *videodev;
 131         struct v4l2_device v4l2_dev;
 132
 133         unsigned char *buffer;
 134         struct mutex lock;      /* buffer locking */
 135         int curfreq;
 136         int stereo;
 137         int users;
 138         int removed;
 139         int muted;
 140 };
 141
 142 /* USB Device ID List */
 143 static struct usb_device_id usb_amradio_device_table[] = {
 144         {USB_DEVICE_AND_INTERFACE_INFO(USB_AMRADIO_VENDOR, USB_AMRADIO_PRODUCT,
 145                                                         USB_CLASS_HID, 0, 0) },
 146         { }                                             /* Terminating entry */
 147 };
 148
 149 MODULE_DEVICE_TABLE(usb, usb_amradio_device_table);
 150
 151 /* USB subsystem interface */
 152 static struct usb_driver usb_amradio_driver = {
 153         .name                   = MR800_DRIVER_NAME,
 154         .probe                  = usb_amradio_probe,
 155         .disconnect             = usb_amradio_disconnect,
 156         .suspend                = usb_amradio_suspend,
 157         .resume                 = usb_amradio_resume,
 158         .reset_resume           = usb_amradio_resume,
 159         .id_table               = usb_amradio_device_table,
 160         .supports_autosuspend   = 0,
 161 };
 162
 163 /* switch on/off the radio. Send 8 bytes to device */
 164 static int amradio_set_mute(struct amradio_device *radio, char argument)
 165 {
 166         int retval;
 167         int size;
 168
 169         /* safety check */
 170         if (radio->removed)
 171                 return -EIO;
 172
 173         mutex_lock(&radio->lock);
 174
 175         radio->buffer[0] = 0x00;
 176         radio->buffer[1] = 0x55;
 177         radio->buffer[2] = 0xaa;
 178         radio->buffer[3] = 0x00;
 179         radio->buffer[4] = AMRADIO_SET_MUTE;
 180         radio->buffer[5] = argument;
 181         radio->buffer[6] = 0x00;
 182         radio->buffer[7] = 0x00;
 183
 184         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 185                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 186
 187         if (retval < 0 || size != BUFFER_LENGTH) {
 188                 mutex_unlock(&radio->lock);
 189                 return retval;
 190         }
 191
 192         radio->muted = argument;
 193
 194         mutex_unlock(&radio->lock);
 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         /* safety check */
 207         if (radio->removed)
 208                 return -EIO;
 209
 210         mutex_lock(&radio->lock);
 211
 212         radio->buffer[0] = 0x00;
 213         radio->buffer[1] = 0x55;
 214         radio->buffer[2] = 0xaa;
 215         radio->buffer[3] = 0x03;
 216         radio->buffer[4] = AMRADIO_SET_FREQ;
 217         radio->buffer[5] = 0x00;
 218         radio->buffer[6] = 0x00;
 219         radio->buffer[7] = 0x08;
 220
 221         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 222                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 223
 224         if (retval < 0 || size != BUFFER_LENGTH) {
 225                 mutex_unlock(&radio->lock);
 226                 return retval;
 227         }
 228
 229         /* frequency is calculated from freq_send and placed in first 2 bytes */
 230         radio->buffer[0] = (freq_send >> 8) & 0xff;
 231         radio->buffer[1] = freq_send & 0xff;
 232         radio->buffer[2] = 0x01;
 233         radio->buffer[3] = 0x00;
 234         radio->buffer[4] = 0x00;
 235         /* 5 and 6 bytes of buffer already = 0x00 */
 236         radio->buffer[7] = 0x00;
 237
 238         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 239                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 240
 241         if (retval < 0 || size != BUFFER_LENGTH) {
 242                 mutex_unlock(&radio->lock);
 243                 return retval;
 244         }
 245
 246         mutex_unlock(&radio->lock);
 247
 248         return retval;
 249 }
 250
 251 static int amradio_set_stereo(struct amradio_device *radio, char argument)
 252 {
 253         int retval;
 254         int size;
 255
 256         /* safety check */
 257         if (radio->removed)
 258                 return -EIO;
 259
 260         mutex_lock(&radio->lock);
 261
 262         radio->buffer[0] = 0x00;
 263         radio->buffer[1] = 0x55;
 264         radio->buffer[2] = 0xaa;
 265         radio->buffer[3] = 0x00;
 266         radio->buffer[4] = AMRADIO_SET_MONO;
 267         radio->buffer[5] = argument;
 268         radio->buffer[6] = 0x00;
 269         radio->buffer[7] = 0x00;
 270
 271         retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2),
 272                 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT);
 273
 274         if (retval < 0 || size != BUFFER_LENGTH) {
 275                 radio->stereo = -1;
 276                 mutex_unlock(&radio->lock);
 277                 return retval;
 278         }
 279
 280         radio->stereo = 1;
 281
 282         mutex_unlock(&radio->lock);
 283
 284         return retval;
 285 }
 286
 287 /* Handle unplugging the device.
 288  * We call video_unregister_device in any case.
 289  * The last function called in this procedure is
 290  * usb_amradio_device_release.
 291  */
 292 static void usb_amradio_disconnect(struct usb_interface *intf)
 293 {
 294         struct amradio_device *radio = usb_get_intfdata(intf);
 295
 296         mutex_lock(&radio->lock);
 297         radio->removed = 1;
 298         mutex_unlock(&radio->lock);
 299
 300         usb_set_intfdata(intf, NULL);
 301         video_unregister_device(radio->videodev);
 302         v4l2_device_disconnect(&radio->v4l2_dev);
 303 }
 304
 305 /* vidioc_querycap - query device capabilities */
 306 static int vidioc_querycap(struct file *file, void *priv,
 307                                         struct v4l2_capability *v)
 308 {
 309         struct amradio_device *radio = video_drvdata(file);
 310
 311         strlcpy(v->driver, "radio-mr800", sizeof(v->driver));
 312         strlcpy(v->card, "AverMedia MR 800 USB FM Radio", sizeof(v->card));
 313         usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info));
 314         v->version = RADIO_VERSION;
 315         v->capabilities = V4L2_CAP_TUNER;
 316         return 0;
 317 }
 318
 319 /* vidioc_g_tuner - get tuner attributes */
 320 static int vidioc_g_tuner(struct file *file, void *priv,
 321                                 struct v4l2_tuner *v)
 322 {
 323         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 324         int retval;
 325
 326         /* safety check */
 327         if (radio->removed)
 328                 return -EIO;
 329
 330         if (v->index > 0)
 331                 return -EINVAL;
 332
 333 /* TODO: Add function which look is signal stereo or not
 334  *      amradio_getstat(radio);
 335  */
 336
 337 /* we call amradio_set_stereo to set radio->stereo
 338  * Honestly, amradio_getstat should cover this in future and
 339  * amradio_set_stereo shouldn't be here
 340  */
 341         retval = amradio_set_stereo(radio, WANT_STEREO);
 342         if (retval < 0)
 343                 amradio_dev_warn(&radio->videodev->dev,
 344                         "set stereo failed\n");
 345
 346         strcpy(v->name, "FM");
 347         v->type = V4L2_TUNER_RADIO;
 348         v->rangelow = FREQ_MIN * FREQ_MUL;
 349         v->rangehigh = FREQ_MAX * FREQ_MUL;
 350         v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO;
 351         v->capability = V4L2_TUNER_CAP_LOW;
 352         if (radio->stereo)
 353                 v->audmode = V4L2_TUNER_MODE_STEREO;
 354         else
 355                 v->audmode = V4L2_TUNER_MODE_MONO;
 356         v->signal = 0xffff;     /* Can't get the signal strength, sad.. */
 357         v->afc = 0; /* Don't know what is this */
 358         return 0;
 359 }
 360
 361 /* vidioc_s_tuner - set tuner attributes */
 362 static int vidioc_s_tuner(struct file *file, void *priv,
 363                                 struct v4l2_tuner *v)
 364 {
 365         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 366         int retval;
 367
 368         /* safety check */
 369         if (radio->removed)
 370                 return -EIO;
 371
 372         if (v->index > 0)
 373                 return -EINVAL;
 374
 375         /* mono/stereo selector */
 376         switch (v->audmode) {
 377         case V4L2_TUNER_MODE_MONO:
 378                 retval = amradio_set_stereo(radio, WANT_MONO);
 379                 if (retval < 0)
 380                         amradio_dev_warn(&radio->videodev->dev,
 381                                 "set mono failed\n");
 382                 break;
 383         case V4L2_TUNER_MODE_STEREO:
 384                 retval = amradio_set_stereo(radio, WANT_STEREO);
 385                 if (retval < 0)
 386                         amradio_dev_warn(&radio->videodev->dev,
 387                                 "set stereo failed\n");
 388                 break;
 389         default:
 390                 return -EINVAL;
 391         }
 392
 393         return 0;
 394 }
 395
 396 /* vidioc_s_frequency - set tuner radio frequency */
 397 static int vidioc_s_frequency(struct file *file, void *priv,
 398                                 struct v4l2_frequency *f)
 399 {
 400         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 401         int retval;
 402
 403         /* safety check */
 404         if (radio->removed)
 405                 return -EIO;
 406
 407         mutex_lock(&radio->lock);
 408         radio->curfreq = f->frequency;
 409         mutex_unlock(&radio->lock);
 410
 411         retval = amradio_setfreq(radio, radio->curfreq);
 412         if (retval < 0)
 413                 amradio_dev_warn(&radio->videodev->dev,
 414                         "set frequency failed\n");
 415         return 0;
 416 }
 417
 418 /* vidioc_g_frequency - get tuner radio frequency */
 419 static int vidioc_g_frequency(struct file *file, void *priv,
 420                                 struct v4l2_frequency *f)
 421 {
 422         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 423
 424         /* safety check */
 425         if (radio->removed)
 426                 return -EIO;
 427
 428         f->type = V4L2_TUNER_RADIO;
 429         f->frequency = radio->curfreq;
 430         return 0;
 431 }
 432
 433 /* vidioc_queryctrl - enumerate control items */
 434 static int vidioc_queryctrl(struct file *file, void *priv,
 435                                 struct v4l2_queryctrl *qc)
 436 {
 437         switch (qc->id) {
 438         case V4L2_CID_AUDIO_MUTE:
 439                 return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1);
 440         }
 441
 442         return -EINVAL;
 443 }
 444
 445 /* vidioc_g_ctrl - get the value of a control */
 446 static int vidioc_g_ctrl(struct file *file, void *priv,
 447                                 struct v4l2_control *ctrl)
 448 {
 449         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 450
 451         /* safety check */
 452         if (radio->removed)
 453                 return -EIO;
 454
 455         switch (ctrl->id) {
 456         case V4L2_CID_AUDIO_MUTE:
 457                 ctrl->value = radio->muted;
 458                 return 0;
 459         }
 460         return -EINVAL;
 461 }
 462
 463 /* vidioc_s_ctrl - set the value of a control */
 464 static int vidioc_s_ctrl(struct file *file, void *priv,
 465                                 struct v4l2_control *ctrl)
 466 {
 467         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 468         int retval;
 469
 470         /* safety check */
 471         if (radio->removed)
 472                 return -EIO;
 473
 474         switch (ctrl->id) {
 475         case V4L2_CID_AUDIO_MUTE:
 476                 if (ctrl->value) {
 477                         retval = amradio_set_mute(radio, AMRADIO_STOP);
 478                         if (retval < 0) {
 479                                 amradio_dev_warn(&radio->videodev->dev,
 480                                         "amradio_stop failed\n");
 481                                 return -1;
 482                         }
 483                 } else {
 484                         retval = amradio_set_mute(radio, AMRADIO_START);
 485                         if (retval < 0) {
 486                                 amradio_dev_warn(&radio->videodev->dev,
 487                                         "amradio_start failed\n");
 488                                 return -1;
 489                         }
 490                 }
 491                 return 0;
 492         }
 493         return -EINVAL;
 494 }
 495
 496 /* vidioc_g_audio - get audio attributes */
 497 static int vidioc_g_audio(struct file *file, void *priv,
 498                                 struct v4l2_audio *a)
 499 {
 500         if (a->index > 1)
 501                 return -EINVAL;
 502
 503         strcpy(a->name, "Radio");
 504         a->capability = V4L2_AUDCAP_STEREO;
 505         return 0;
 506 }
 507
 508 /* vidioc_s_audio - set audio attributes  */
 509 static int vidioc_s_audio(struct file *file, void *priv,
 510                                         struct v4l2_audio *a)
 511 {
 512         if (a->index != 0)
 513                 return -EINVAL;
 514         return 0;
 515 }
 516
 517 /* vidioc_g_input - get input */
 518 static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
 519 {
 520         *i = 0;
 521         return 0;
 522 }
 523
 524 /* vidioc_s_input - set input */
 525 static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
 526 {
 527         if (i != 0)
 528                 return -EINVAL;
 529         return 0;
 530 }
 531
 532 /* open device - amradio_start() and amradio_setfreq() */
 533 static int usb_amradio_open(struct file *file)
 534 {
 535         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 536         int retval;
 537
 538         lock_kernel();
 539
 540         radio->users = 1;
 541         radio->muted = 1;
 542
 543         retval = amradio_set_mute(radio, AMRADIO_START);
 544         if (retval < 0) {
 545                 amradio_dev_warn(&radio->videodev->dev,
 546                         "radio did not start up properly\n");
 547                 radio->users = 0;
 548                 unlock_kernel();
 549                 return -EIO;
 550         }
 551
 552         retval = amradio_set_stereo(radio, WANT_STEREO);
 553         if (retval < 0)
 554                 amradio_dev_warn(&radio->videodev->dev,
 555                         "set stereo failed\n");
 556
 557         retval = amradio_setfreq(radio, radio->curfreq);
 558         if (retval < 0)
 559                 amradio_dev_warn(&radio->videodev->dev,
 560                         "set frequency failed\n");
 561
 562         unlock_kernel();
 563         return 0;
 564 }
 565
 566 /*close device */
 567 static int usb_amradio_close(struct file *file)
 568 {
 569         struct amradio_device *radio = video_get_drvdata(video_devdata(file));
 570         int retval;
 571
 572         if (!radio)
 573                 return -ENODEV;
 574
 575         mutex_lock(&radio->lock);
 576         radio->users = 0;
 577         mutex_unlock(&radio->lock);
 578
 579         if (!radio->removed) {
 580                 retval = amradio_set_mute(radio, AMRADIO_STOP);
 581                 if (retval < 0)
 582                         amradio_dev_warn(&radio->videodev->dev,
 583                                 "amradio_stop failed\n");
 584         }
 585
 586         return 0;
 587 }
 588
 589 /* Suspend device - stop device. Need to be checked and fixed */
 590 static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message)
 591 {
 592         struct amradio_device *radio = usb_get_intfdata(intf);
 593         int retval;
 594
 595         retval = amradio_set_mute(radio, AMRADIO_STOP);
 596         if (retval < 0)
 597                 dev_warn(&intf->dev, "amradio_stop failed\n");
 598
 599         dev_info(&intf->dev, "going into suspend..\n");
 600
 601         return 0;
 602 }
 603
 604 /* Resume device - start device. Need to be checked and fixed */
 605 static int usb_amradio_resume(struct usb_interface *intf)
 606 {
 607         struct amradio_device *radio = usb_get_intfdata(intf);
 608         int retval;
 609
 610         retval = amradio_set_mute(radio, AMRADIO_START);
 611         if (retval < 0)
 612                 dev_warn(&intf->dev, "amradio_start failed\n");
 613
 614         dev_info(&intf->dev, "coming out of suspend..\n");
 615
 616         return 0;
 617 }
 618
 619 /* File system interface */
 620 static const struct v4l2_file_operations usb_amradio_fops = {
 621         .owner          = THIS_MODULE,
 622         .open           = usb_amradio_open,
 623         .release        = usb_amradio_close,
 624         .ioctl          = video_ioctl2,
 625 };
 626
 627 static const struct v4l2_ioctl_ops usb_amradio_ioctl_ops = {
 628         .vidioc_querycap    = vidioc_querycap,
 629         .vidioc_g_tuner     = vidioc_g_tuner,
 630         .vidioc_s_tuner     = vidioc_s_tuner,
 631         .vidioc_g_frequency = vidioc_g_frequency,
 632         .vidioc_s_frequency = vidioc_s_frequency,
 633         .vidioc_queryctrl   = vidioc_queryctrl,
 634         .vidioc_g_ctrl      = vidioc_g_ctrl,
 635         .vidioc_s_ctrl      = vidioc_s_ctrl,
 636         .vidioc_g_audio     = vidioc_g_audio,
 637         .vidioc_s_audio     = vidioc_s_audio,
 638         .vidioc_g_input     = vidioc_g_input,
 639         .vidioc_s_input     = vidioc_s_input,
 640 };
 641
 642 static void usb_amradio_video_device_release(struct video_device *videodev)
 643 {
 644         struct amradio_device *radio = video_get_drvdata(videodev);
 645
 646         /* we call v4l to free radio->videodev */
 647         video_device_release(videodev);
 648
 649         v4l2_device_unregister(&radio->v4l2_dev);
 650
 651         /* free rest memory */
 652         kfree(radio->buffer);
 653         kfree(radio);
 654 }
 655
 656 /* check if the device is present and register with v4l and usb if it is */
 657 static int usb_amradio_probe(struct usb_interface *intf,
 658                                 const struct usb_device_id *id)
 659 {
 660         struct amradio_device *radio;
 661         struct v4l2_device *v4l2_dev;
 662         int retval;
 663
 664         radio = kzalloc(sizeof(struct amradio_device), GFP_KERNEL);
 665
 666         if (!radio) {
 667                 dev_err(&intf->dev, "kmalloc for amradio_device failed\n");
 668                 return -ENOMEM;
 669         }
 670
 671         radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL);
 672
 673         if (!radio->buffer) {
 674                 dev_err(&intf->dev, "kmalloc for radio->buffer failed\n");
 675                 kfree(radio);
 676                 return -ENOMEM;
 677         }
 678
 679         v4l2_dev = &radio->v4l2_dev;
 680         retval = v4l2_device_register(&intf->dev, v4l2_dev);
 681         if (retval < 0) {
 682                 dev_err(&intf->dev, "couldn't register v4l2_device\n");
 683                 kfree(radio->buffer);
 684                 kfree(radio);
 685                 return retval;
 686         }
 687
 688         radio->videodev = video_device_alloc();
 689
 690         if (!radio->videodev) {
 691                 dev_err(&intf->dev, "video_device_alloc failed\n");
 692                 kfree(radio->buffer);
 693                 kfree(radio);
 694                 return -ENOMEM;
 695         }
 696
 697         strlcpy(radio->videodev->name, v4l2_dev->name, sizeof(radio->videodev->name));
 698         radio->videodev->v4l2_dev = v4l2_dev;
 699         radio->videodev->fops = &usb_amradio_fops;
 700         radio->videodev->ioctl_ops = &usb_amradio_ioctl_ops;
 701         radio->videodev->release = usb_amradio_video_device_release;
 702
 703         radio->removed = 0;
 704         radio->users = 0;
 705         radio->usbdev = interface_to_usbdev(intf);
 706         radio->curfreq = 95.16 * FREQ_MUL;
 707         radio->stereo = -1;
 708
 709         mutex_init(&radio->lock);
 710
 711         video_set_drvdata(radio->videodev, radio);
 712
 713         retval = video_register_device(radio->videodev, VFL_TYPE_RADIO, radio_nr);
 714         if (retval < 0) {
 715                 dev_err(&intf->dev, "could not register video device\n");
 716                 video_device_release(radio->videodev);
 717                 v4l2_device_unregister(v4l2_dev);
 718                 kfree(radio->buffer);
 719                 kfree(radio);
 720                 return -EIO;
 721         }
 722
 723         usb_set_intfdata(intf, radio);
 724         return 0;
 725 }
 726
 727 static int __init amradio_init(void)
 728 {
 729         int retval = usb_register(&usb_amradio_driver);
 730
 731         pr_info(KBUILD_MODNAME
 732                 ": version " DRIVER_VERSION " " DRIVER_DESC "\n");
 733
 734         if (retval)
 735                 pr_err(KBUILD_MODNAME
 736                         ": usb_register failed. Error number %d\n", retval);
 737
 738         return retval;
 739 }
 740
 741 static void __exit amradio_exit(void)
 742 {
 743         usb_deregister(&usb_amradio_driver);
 744 }
 745
 746 module_init(amradio_init);
 747 module_exit(amradio_exit);
 748