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 static inline struct amradio_device *to_amradio_dev(struct v4l2_device *v4l2_dev) 148 { 149 return container_of(v4l2_dev, struct amradio_device, v4l2_dev); 150 } 151 152 /* USB Device ID List */ 153 static struct usb_device_id usb_amradio_device_table[] = { 154 {USB_DEVICE_AND_INTERFACE_INFO(USB_AMRADIO_VENDOR, USB_AMRADIO_PRODUCT, 155 USB_CLASS_HID, 0, 0) }, 156 { } /* Terminating entry */ 157 }; 158 159 MODULE_DEVICE_TABLE(usb, usb_amradio_device_table); 160 161 /* USB subsystem interface */ 162 static struct usb_driver usb_amradio_driver = { 163 .name = MR800_DRIVER_NAME, 164 .probe = usb_amradio_probe, 165 .disconnect = usb_amradio_disconnect, 166 .suspend = usb_amradio_suspend, 167 .resume = usb_amradio_resume, 168 .reset_resume = usb_amradio_resume, 169 .id_table = usb_amradio_device_table, 170 .supports_autosuspend = 1, 171 }; 172 173 /* switch on/off the radio. Send 8 bytes to device */ 174 static int amradio_set_mute(struct amradio_device *radio, char argument) 175 { 176 int retval; 177 int size; 178 179 BUG_ON(!mutex_is_locked(&radio->lock)); 180 181 radio->buffer[0] = 0x00; 182 radio->buffer[1] = 0x55; 183 radio->buffer[2] = 0xaa; 184 radio->buffer[3] = 0x00; 185 radio->buffer[4] = AMRADIO_SET_MUTE; 186 radio->buffer[5] = argument; 187 radio->buffer[6] = 0x00; 188 radio->buffer[7] = 0x00; 189 190 retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2), 191 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT); 192 193 if (retval < 0 || size != BUFFER_LENGTH) { 194 amradio_dev_warn(&radio->videodev.dev, "set mute failed\n"); 195 return retval; 196 } 197 198 radio->muted = argument; 199 200 return retval; 201 } 202 203 /* set a frequency, freq is defined by v4l's TUNER_LOW, i.e. 1/16th kHz */ 204 static int amradio_setfreq(struct amradio_device *radio, int freq) 205 { 206 int retval; 207 int size; 208 unsigned short freq_send = 0x10 + (freq >> 3) / 25; 209 210 BUG_ON(!mutex_is_locked(&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 goto out_err; 226 227 /* frequency is calculated from freq_send and placed in first 2 bytes */ 228 radio->buffer[0] = (freq_send >> 8) & 0xff; 229 radio->buffer[1] = freq_send & 0xff; 230 radio->buffer[2] = 0x01; 231 radio->buffer[3] = 0x00; 232 radio->buffer[4] = 0x00; 233 /* 5 and 6 bytes of buffer already = 0x00 */ 234 radio->buffer[7] = 0x00; 235 236 retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2), 237 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT); 238 239 if (retval < 0 || size != BUFFER_LENGTH) 240 goto out_err; 241 242 radio->curfreq = freq; 243 goto out; 244 245 out_err: 246 amradio_dev_warn(&radio->videodev.dev, "set frequency failed\n"); 247 out: 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 BUG_ON(!mutex_is_locked(&radio->lock)); 257 258 radio->buffer[0] = 0x00; 259 radio->buffer[1] = 0x55; 260 radio->buffer[2] = 0xaa; 261 radio->buffer[3] = 0x00; 262 radio->buffer[4] = AMRADIO_SET_MONO; 263 radio->buffer[5] = argument; 264 radio->buffer[6] = 0x00; 265 radio->buffer[7] = 0x00; 266 267 retval = usb_bulk_msg(radio->usbdev, usb_sndintpipe(radio->usbdev, 2), 268 (void *) (radio->buffer), BUFFER_LENGTH, &size, USB_TIMEOUT); 269 270 if (retval < 0 || size != BUFFER_LENGTH) { 271 amradio_dev_warn(&radio->videodev.dev, "set stereo failed\n"); 272 return retval; 273 } 274 275 if (argument == WANT_STEREO) 276 radio->stereo = 1; 277 else 278 radio->stereo = 0; 279 280 return retval; 281 } 282 283 /* Handle unplugging the device. 284 * We call video_unregister_device in any case. 285 * The last function called in this procedure is 286 * usb_amradio_device_release. 287 */ 288 static void usb_amradio_disconnect(struct usb_interface *intf) 289 { 290 struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf)); 291 292 mutex_lock(&radio->lock); 293 radio->usbdev = NULL; 294 mutex_unlock(&radio->lock); 295 296 v4l2_device_disconnect(&radio->v4l2_dev); 297 video_unregister_device(&radio->videodev); 298 } 299 300 /* vidioc_querycap - query device capabilities */ 301 static int vidioc_querycap(struct file *file, void *priv, 302 struct v4l2_capability *v) 303 { 304 struct amradio_device *radio = file->private_data; 305 306 strlcpy(v->driver, "radio-mr800", sizeof(v->driver)); 307 strlcpy(v->card, "AverMedia MR 800 USB FM Radio", sizeof(v->card)); 308 usb_make_path(radio->usbdev, v->bus_info, sizeof(v->bus_info)); 309 v->version = RADIO_VERSION; 310 v->capabilities = V4L2_CAP_TUNER; 311 return 0; 312 } 313 314 /* vidioc_g_tuner - get tuner attributes */ 315 static int vidioc_g_tuner(struct file *file, void *priv, 316 struct v4l2_tuner *v) 317 { 318 struct amradio_device *radio = file->private_data; 319 int retval; 320 321 if (v->index > 0) 322 return -EINVAL; 323 324 /* TODO: Add function which look is signal stereo or not 325 * amradio_getstat(radio); 326 */ 327 328 /* we call amradio_set_stereo to set radio->stereo 329 * Honestly, amradio_getstat should cover this in future and 330 * amradio_set_stereo shouldn't be here 331 */ 332 retval = amradio_set_stereo(radio, WANT_STEREO); 333 334 strcpy(v->name, "FM"); 335 v->type = V4L2_TUNER_RADIO; 336 v->rangelow = FREQ_MIN * FREQ_MUL; 337 v->rangehigh = FREQ_MAX * FREQ_MUL; 338 v->rxsubchans = V4L2_TUNER_SUB_MONO | V4L2_TUNER_SUB_STEREO; 339 v->capability = V4L2_TUNER_CAP_LOW; 340 if (radio->stereo) 341 v->audmode = V4L2_TUNER_MODE_STEREO; 342 else 343 v->audmode = V4L2_TUNER_MODE_MONO; 344 v->signal = 0xffff; /* Can't get the signal strength, sad.. */ 345 v->afc = 0; /* Don't know what is this */ 346 347 return retval; 348 } 349 350 /* vidioc_s_tuner - set tuner attributes */ 351 static int vidioc_s_tuner(struct file *file, void *priv, 352 struct v4l2_tuner *v) 353 { 354 struct amradio_device *radio = file->private_data; 355 int retval = -EINVAL; 356 357 if (v->index > 0) 358 return -EINVAL; 359 360 /* mono/stereo selector */ 361 switch (v->audmode) { 362 case V4L2_TUNER_MODE_MONO: 363 retval = amradio_set_stereo(radio, WANT_MONO); 364 break; 365 case V4L2_TUNER_MODE_STEREO: 366 retval = amradio_set_stereo(radio, WANT_STEREO); 367 break; 368 } 369 370 return retval; 371 } 372 373 /* vidioc_s_frequency - set tuner radio frequency */ 374 static int vidioc_s_frequency(struct file *file, void *priv, 375 struct v4l2_frequency *f) 376 { 377 struct amradio_device *radio = file->private_data; 378 379 if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO) 380 return -EINVAL; 381 return amradio_setfreq(radio, f->frequency); 382 } 383 384 /* vidioc_g_frequency - get tuner radio frequency */ 385 static int vidioc_g_frequency(struct file *file, void *priv, 386 struct v4l2_frequency *f) 387 { 388 struct amradio_device *radio = file->private_data; 389 390 if (f->tuner != 0) 391 return -EINVAL; 392 f->type = V4L2_TUNER_RADIO; 393 f->frequency = radio->curfreq; 394 395 return 0; 396 } 397 398 /* vidioc_queryctrl - enumerate control items */ 399 static int vidioc_queryctrl(struct file *file, void *priv, 400 struct v4l2_queryctrl *qc) 401 { 402 switch (qc->id) { 403 case V4L2_CID_AUDIO_MUTE: 404 return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1); 405 } 406 407 return -EINVAL; 408 } 409 410 /* vidioc_g_ctrl - get the value of a control */ 411 static int vidioc_g_ctrl(struct file *file, void *priv, 412 struct v4l2_control *ctrl) 413 { 414 struct amradio_device *radio = file->private_data; 415 416 switch (ctrl->id) { 417 case V4L2_CID_AUDIO_MUTE: 418 ctrl->value = radio->muted; 419 return 0; 420 } 421 422 return -EINVAL; 423 } 424 425 /* vidioc_s_ctrl - set the value of a control */ 426 static int vidioc_s_ctrl(struct file *file, void *priv, 427 struct v4l2_control *ctrl) 428 { 429 struct amradio_device *radio = file->private_data; 430 int retval = -EINVAL; 431 432 switch (ctrl->id) { 433 case V4L2_CID_AUDIO_MUTE: 434 if (ctrl->value) 435 retval = amradio_set_mute(radio, AMRADIO_STOP); 436 else 437 retval = amradio_set_mute(radio, AMRADIO_START); 438 439 break; 440 } 441 442 return retval; 443 } 444 445 /* vidioc_g_audio - get audio attributes */ 446 static int vidioc_g_audio(struct file *file, void *priv, 447 struct v4l2_audio *a) 448 { 449 if (a->index > 1) 450 return -EINVAL; 451 452 strcpy(a->name, "Radio"); 453 a->capability = V4L2_AUDCAP_STEREO; 454 return 0; 455 } 456 457 /* vidioc_s_audio - set audio attributes */ 458 static int vidioc_s_audio(struct file *file, void *priv, 459 struct v4l2_audio *a) 460 { 461 if (a->index != 0) 462 return -EINVAL; 463 return 0; 464 } 465 466 /* vidioc_g_input - get input */ 467 static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i) 468 { 469 *i = 0; 470 return 0; 471 } 472 473 /* vidioc_s_input - set input */ 474 static int vidioc_s_input(struct file *filp, void *priv, unsigned int i) 475 { 476 if (i != 0) 477 return -EINVAL; 478 return 0; 479 } 480 481 static int usb_amradio_init(struct amradio_device *radio) 482 { 483 int retval; 484 485 retval = amradio_set_mute(radio, AMRADIO_STOP); 486 if (retval) 487 goto out_err; 488 489 retval = amradio_set_stereo(radio, WANT_STEREO); 490 if (retval) 491 goto out_err; 492 493 radio->initialized = 1; 494 goto out; 495 496 out_err: 497 amradio_dev_err(&radio->videodev.dev, "initialization failed\n"); 498 out: 499 return retval; 500 } 501 502 /* open device - amradio_start() and amradio_setfreq() */ 503 static int usb_amradio_open(struct file *file) 504 { 505 struct amradio_device *radio = video_drvdata(file); 506 int retval = 0; 507 508 mutex_lock(&radio->lock); 509 510 if (!radio->usbdev) { 511 retval = -EIO; 512 goto unlock; 513 } 514 515 file->private_data = radio; 516 retval = usb_autopm_get_interface(radio->intf); 517 if (retval) 518 goto unlock; 519 520 if (unlikely(!radio->initialized)) { 521 retval = usb_amradio_init(radio); 522 if (retval) 523 usb_autopm_put_interface(radio->intf); 524 } 525 526 unlock: 527 mutex_unlock(&radio->lock); 528 return retval; 529 } 530 531 /*close device */ 532 static int usb_amradio_close(struct file *file) 533 { 534 struct amradio_device *radio = file->private_data; 535 int retval = 0; 536 537 mutex_lock(&radio->lock); 538 539 if (!radio->usbdev) 540 retval = -EIO; 541 else 542 usb_autopm_put_interface(radio->intf); 543 544 mutex_unlock(&radio->lock); 545 return retval; 546 } 547 548 static long usb_amradio_ioctl(struct file *file, unsigned int cmd, 549 unsigned long arg) 550 { 551 struct amradio_device *radio = file->private_data; 552 long retval = 0; 553 554 mutex_lock(&radio->lock); 555 556 if (!radio->usbdev) { 557 retval = -EIO; 558 goto unlock; 559 } 560 561 retval = video_ioctl2(file, cmd, arg); 562 563 unlock: 564 mutex_unlock(&radio->lock); 565 return retval; 566 } 567 568 /* Suspend device - stop device. Need to be checked and fixed */ 569 static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message) 570 { 571 struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf)); 572 573 mutex_lock(&radio->lock); 574 575 if (!radio->muted && radio->initialized) { 576 amradio_set_mute(radio, AMRADIO_STOP); 577 radio->muted = 0; 578 } 579 580 dev_info(&intf->dev, "going into suspend..\n"); 581 582 mutex_unlock(&radio->lock); 583 return 0; 584 } 585 586 /* Resume device - start device. Need to be checked and fixed */ 587 static int usb_amradio_resume(struct usb_interface *intf) 588 { 589 struct amradio_device *radio = to_amradio_dev(usb_get_intfdata(intf)); 590 591 mutex_lock(&radio->lock); 592 593 if (unlikely(!radio->initialized)) 594 goto unlock; 595 596 if (radio->stereo) 597 amradio_set_stereo(radio, WANT_STEREO); 598 else 599 amradio_set_stereo(radio, WANT_MONO); 600 601 amradio_setfreq(radio, radio->curfreq); 602 603 if (!radio->muted) 604 amradio_set_mute(radio, AMRADIO_START); 605 606 unlock: 607 dev_info(&intf->dev, "coming out of suspend..\n"); 608 609 mutex_unlock(&radio->lock); 610 return 0; 611 } 612 613 /* File system interface */ 614 static const struct v4l2_file_operations usb_amradio_fops = { 615 .owner = THIS_MODULE, 616 .open = usb_amradio_open, 617 .release = usb_amradio_close, 618 .ioctl = usb_amradio_ioctl, 619 }; 620 621 static const struct v4l2_ioctl_ops usb_amradio_ioctl_ops = { 622 .vidioc_querycap = vidioc_querycap, 623 .vidioc_g_tuner = vidioc_g_tuner, 624 .vidioc_s_tuner = vidioc_s_tuner, 625 .vidioc_g_frequency = vidioc_g_frequency, 626 .vidioc_s_frequency = vidioc_s_frequency, 627 .vidioc_queryctrl = vidioc_queryctrl, 628 .vidioc_g_ctrl = vidioc_g_ctrl, 629 .vidioc_s_ctrl = vidioc_s_ctrl, 630 .vidioc_g_audio = vidioc_g_audio, 631 .vidioc_s_audio = vidioc_s_audio, 632 .vidioc_g_input = vidioc_g_input, 633 .vidioc_s_input = vidioc_s_input, 634 }; 635 636 static void usb_amradio_video_device_release(struct video_device *videodev) 637 { 638 struct amradio_device *radio = video_get_drvdata(videodev); 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 return 0; 697 698 err_vdev: 699 v4l2_device_unregister(&radio->v4l2_dev); 700 err_v4l2: 701 kfree(radio->buffer); 702 err_nobuf: 703 kfree(radio); 704 err: 705 return retval; 706 } 707 708 static int __init amradio_init(void) 709 { 710 int retval = usb_register(&usb_amradio_driver); 711 712 pr_info(KBUILD_MODNAME 713 ": version " DRIVER_VERSION " " DRIVER_DESC "\n"); 714 715 if (retval) 716 pr_err(KBUILD_MODNAME 717 ": usb_register failed. Error number %d\n", retval); 718 719 return retval; 720 } 721 722 static void __exit amradio_exit(void) 723 { 724 usb_deregister(&usb_amradio_driver); 725 } 726 727 module_init(amradio_init); 728 module_exit(amradio_exit); 729 730