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