radio-mr800.c revision af901ca181d92aac3a7dc265144a9081a86d8f39 
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
76MODULE_AUTHOR(DRIVER_AUTHOR);
77MODULE_DESCRIPTION(DRIVER_DESC);
78MODULE_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
93devices, 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 */
115static int radio_nr = -1;
116module_param(radio_nr, int, 0);
117MODULE_PARM_DESC(radio_nr, "Radio Nr");
118
119static int usb_amradio_probe(struct usb_interface *intf,
120			     const struct usb_device_id *id);
121static void usb_amradio_disconnect(struct usb_interface *intf);
122static int usb_amradio_open(struct file *file);
123static int usb_amradio_close(struct file *file);
124static int usb_amradio_suspend(struct usb_interface *intf,
125				pm_message_t message);
126static int usb_amradio_resume(struct usb_interface *intf);
127
128/* Data for one (physical) device */
129struct 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 */
145static 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
151MODULE_DEVICE_TABLE(usb, usb_amradio_device_table);
152
153/* USB subsystem interface */
154static 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 */
166static 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 */
202static 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
253static 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 */
294static 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 */
308static 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 */
322static 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 */
364static 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 */
399static 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 */
421static 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 */
436static 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 */
448static 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 */
466static 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 */
499static 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  */
511static 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 */
520static 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 */
527static 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() */
535static 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 */
569static 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 */
592static 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 */
607static 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 */
622static 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
629static 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
644static 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 */
659static 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
729static 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
743static void __exit amradio_exit(void)
744{
745	usb_deregister(&usb_amradio_driver);
746}
747
748module_init(amradio_init);
749module_exit(amradio_exit);
750
751