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 #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 return amradio_setfreq(radio, f->frequency); 378 } 379 380 /* vidioc_g_frequency - get tuner radio frequency */ 381 static int vidioc_g_frequency(struct file *file, void *priv, 382 struct v4l2_frequency *f) 383 { 384 struct amradio_device *radio = file->private_data; 385 386 f->type = V4L2_TUNER_RADIO; 387 f->frequency = radio->curfreq; 388 389 return 0; 390 } 391 392 /* vidioc_queryctrl - enumerate control items */ 393 static int vidioc_queryctrl(struct file *file, void *priv, 394 struct v4l2_queryctrl *qc) 395 { 396 switch (qc->id) { 397 case V4L2_CID_AUDIO_MUTE: 398 return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1); 399 } 400 401 return -EINVAL; 402 } 403 404 /* vidioc_g_ctrl - get the value of a control */ 405 static int vidioc_g_ctrl(struct file *file, void *priv, 406 struct v4l2_control *ctrl) 407 { 408 struct amradio_device *radio = file->private_data; 409 410 switch (ctrl->id) { 411 case V4L2_CID_AUDIO_MUTE: 412 ctrl->value = radio->muted; 413 return 0; 414 } 415 416 return -EINVAL; 417 } 418 419 /* vidioc_s_ctrl - set the value of a control */ 420 static int vidioc_s_ctrl(struct file *file, void *priv, 421 struct v4l2_control *ctrl) 422 { 423 struct amradio_device *radio = file->private_data; 424 int retval = -EINVAL; 425 426 switch (ctrl->id) { 427 case V4L2_CID_AUDIO_MUTE: 428 if (ctrl->value) 429 retval = amradio_set_mute(radio, AMRADIO_STOP); 430 else 431 retval = amradio_set_mute(radio, AMRADIO_START); 432 433 break; 434 } 435 436 return retval; 437 } 438 439 /* vidioc_g_audio - get audio attributes */ 440 static int vidioc_g_audio(struct file *file, void *priv, 441 struct v4l2_audio *a) 442 { 443 if (a->index > 1) 444 return -EINVAL; 445 446 strcpy(a->name, "Radio"); 447 a->capability = V4L2_AUDCAP_STEREO; 448 return 0; 449 } 450 451 /* vidioc_s_audio - set audio attributes */ 452 static int vidioc_s_audio(struct file *file, void *priv, 453 struct v4l2_audio *a) 454 { 455 if (a->index != 0) 456 return -EINVAL; 457 return 0; 458 } 459 460 /* vidioc_g_input - get input */ 461 static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i) 462 { 463 *i = 0; 464 return 0; 465 } 466 467 /* vidioc_s_input - set input */ 468 static int vidioc_s_input(struct file *filp, void *priv, unsigned int i) 469 { 470 if (i != 0) 471 return -EINVAL; 472 return 0; 473 } 474 475 static int usb_amradio_init(struct amradio_device *radio) 476 { 477 int retval; 478 479 retval = amradio_set_mute(radio, AMRADIO_STOP); 480 if (retval) 481 goto out_err; 482 483 retval = amradio_set_stereo(radio, WANT_STEREO); 484 if (retval) 485 goto out_err; 486 487 radio->initialized = 1; 488 goto out; 489 490 out_err: 491 amradio_dev_err(&radio->videodev.dev, "initialization failed\n"); 492 out: 493 return retval; 494 } 495 496 /* open device - amradio_start() and amradio_setfreq() */ 497 static int usb_amradio_open(struct file *file) 498 { 499 struct amradio_device *radio = vdev_to_amradio(video_devdata(file)); 500 int retval = 0; 501 502 mutex_lock(&radio->lock); 503 504 if (!radio->usbdev) { 505 retval = -EIO; 506 goto unlock; 507 } 508 509 file->private_data = radio; 510 retval = usb_autopm_get_interface(radio->intf); 511 if (retval) 512 goto unlock; 513 514 if (unlikely(!radio->initialized)) { 515 retval = usb_amradio_init(radio); 516 if (retval) 517 usb_autopm_put_interface(radio->intf); 518 } 519 520 unlock: 521 mutex_unlock(&radio->lock); 522 return retval; 523 } 524 525 /*close device */ 526 static int usb_amradio_close(struct file *file) 527 { 528 struct amradio_device *radio = file->private_data; 529 int retval = 0; 530 531 mutex_lock(&radio->lock); 532 533 if (!radio->usbdev) 534 retval = -EIO; 535 else 536 usb_autopm_put_interface(radio->intf); 537 538 mutex_unlock(&radio->lock); 539 return retval; 540 } 541 542 static long usb_amradio_ioctl(struct file *file, unsigned int cmd, 543 unsigned long arg) 544 { 545 struct amradio_device *radio = file->private_data; 546 long retval = 0; 547 548 mutex_lock(&radio->lock); 549 550 if (!radio->usbdev) { 551 retval = -EIO; 552 goto unlock; 553 } 554 555 retval = video_ioctl2(file, cmd, arg); 556 557 unlock: 558 mutex_unlock(&radio->lock); 559 return retval; 560 } 561 562 /* Suspend device - stop device. Need to be checked and fixed */ 563 static int usb_amradio_suspend(struct usb_interface *intf, pm_message_t message) 564 { 565 struct amradio_device *radio = usb_get_intfdata(intf); 566 567 mutex_lock(&radio->lock); 568 569 if (!radio->muted && radio->initialized) { 570 amradio_set_mute(radio, AMRADIO_STOP); 571 radio->muted = 0; 572 } 573 574 dev_info(&intf->dev, "going into suspend..\n"); 575 576 mutex_unlock(&radio->lock); 577 return 0; 578 } 579 580 /* Resume device - start device. Need to be checked and fixed */ 581 static int usb_amradio_resume(struct usb_interface *intf) 582 { 583 struct amradio_device *radio = usb_get_intfdata(intf); 584 585 mutex_lock(&radio->lock); 586 587 if (unlikely(!radio->initialized)) 588 goto unlock; 589 590 if (radio->stereo) 591 amradio_set_stereo(radio, WANT_STEREO); 592 else 593 amradio_set_stereo(radio, WANT_MONO); 594 595 amradio_setfreq(radio, radio->curfreq); 596 597 if (!radio->muted) 598 amradio_set_mute(radio, AMRADIO_START); 599 600 unlock: 601 dev_info(&intf->dev, "coming out of suspend..\n"); 602 603 mutex_unlock(&radio->lock); 604 return 0; 605 } 606 607 /* File system interface */ 608 static const struct v4l2_file_operations usb_amradio_fops = { 609 .owner = THIS_MODULE, 610 .open = usb_amradio_open, 611 .release = usb_amradio_close, 612 .ioctl = usb_amradio_ioctl, 613 }; 614 615 static const struct v4l2_ioctl_ops usb_amradio_ioctl_ops = { 616 .vidioc_querycap = vidioc_querycap, 617 .vidioc_g_tuner = vidioc_g_tuner, 618 .vidioc_s_tuner = vidioc_s_tuner, 619 .vidioc_g_frequency = vidioc_g_frequency, 620 .vidioc_s_frequency = vidioc_s_frequency, 621 .vidioc_queryctrl = vidioc_queryctrl, 622 .vidioc_g_ctrl = vidioc_g_ctrl, 623 .vidioc_s_ctrl = vidioc_s_ctrl, 624 .vidioc_g_audio = vidioc_g_audio, 625 .vidioc_s_audio = vidioc_s_audio, 626 .vidioc_g_input = vidioc_g_input, 627 .vidioc_s_input = vidioc_s_input, 628 }; 629 630 static void usb_amradio_video_device_release(struct video_device *videodev) 631 { 632 struct amradio_device *radio = vdev_to_amradio(videodev); 633 634 v4l2_device_unregister(&radio->v4l2_dev); 635 636 /* free rest memory */ 637 kfree(radio->buffer); 638 kfree(radio); 639 } 640 641 /* check if the device is present and register with v4l and usb if it is */ 642 static int usb_amradio_probe(struct usb_interface *intf, 643 const struct usb_device_id *id) 644 { 645 struct amradio_device *radio; 646 int retval = 0; 647 648 radio = kzalloc(sizeof(struct amradio_device), GFP_KERNEL); 649 650 if (!radio) { 651 dev_err(&intf->dev, "kmalloc for amradio_device failed\n"); 652 retval = -ENOMEM; 653 goto err; 654 } 655 656 radio->buffer = kmalloc(BUFFER_LENGTH, GFP_KERNEL); 657 658 if (!radio->buffer) { 659 dev_err(&intf->dev, "kmalloc for radio->buffer failed\n"); 660 retval = -ENOMEM; 661 goto err_nobuf; 662 } 663 664 retval = v4l2_device_register(&intf->dev, &radio->v4l2_dev); 665 if (retval < 0) { 666 dev_err(&intf->dev, "couldn't register v4l2_device\n"); 667 goto err_v4l2; 668 } 669 670 strlcpy(radio->videodev.name, radio->v4l2_dev.name, 671 sizeof(radio->videodev.name)); 672 radio->videodev.v4l2_dev = &radio->v4l2_dev; 673 radio->videodev.fops = &usb_amradio_fops; 674 radio->videodev.ioctl_ops = &usb_amradio_ioctl_ops; 675 radio->videodev.release = usb_amradio_video_device_release; 676 677 radio->usbdev = interface_to_usbdev(intf); 678 radio->intf = intf; 679 radio->curfreq = 95.16 * FREQ_MUL; 680 681 mutex_init(&radio->lock); 682 683 video_set_drvdata(&radio->videodev, radio); 684 685 retval = video_register_device(&radio->videodev, VFL_TYPE_RADIO, 686 radio_nr); 687 if (retval < 0) { 688 dev_err(&intf->dev, "could not register video device\n"); 689 goto err_vdev; 690 } 691 692 usb_set_intfdata(intf, radio); 693 return 0; 694 695 err_vdev: 696 v4l2_device_unregister(&radio->v4l2_dev); 697 err_v4l2: 698 kfree(radio->buffer); 699 err_nobuf: 700 kfree(radio); 701 err: 702 return retval; 703 } 704 705 static int __init amradio_init(void) 706 { 707 int retval = usb_register(&usb_amradio_driver); 708 709 pr_info(KBUILD_MODNAME 710 ": version " DRIVER_VERSION " " DRIVER_DESC "\n"); 711 712 if (retval) 713 pr_err(KBUILD_MODNAME 714 ": usb_register failed. Error number %d\n", retval); 715 716 return retval; 717 } 718 719 static void __exit amradio_exit(void) 720 { 721 usb_deregister(&usb_amradio_driver); 722 } 723 724 module_init(amradio_init); 725 module_exit(amradio_exit); 726 727