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