1 /* GemTek radio card driver for Linux (C) 1998 Jonas Munsin <jmunsin@iki.fi>
2  *
3  * GemTek hasn't released any specs on the card, so the protocol had to
4  * be reverse engineered with dosemu.
5  *
6  * Besides the protocol changes, this is mostly a copy of:
7  *
8  *    RadioTrack II driver for Linux radio support (C) 1998 Ben Pfaff
9  *
10  *    Based on RadioTrack I/RadioReveal (C) 1997 M. Kirkwood
11  *    Converted to new API by Alan Cox <alan@lxorguk.ukuu.org.uk>
12  *    Various bugfixes and enhancements by Russell Kroll <rkroll@exploits.org>
13  *
14  * TODO: Allow for more than one of these foolish entities :-)
15  *
16  * Converted to V4L2 API by Mauro Carvalho Chehab <mchehab@infradead.org>
17  */
18 
19 #include <linux/module.h>	/* Modules 			*/
20 #include <linux/init.h>		/* Initdata			*/
21 #include <linux/ioport.h>	/* request_region		*/
22 #include <linux/delay.h>	/* udelay			*/
23 #include <linux/videodev2.h>	/* kernel radio structs		*/
24 #include <linux/version.h>	/* for KERNEL_VERSION MACRO	*/
25 #include <linux/mutex.h>
26 #include <linux/io.h>		/* outb, outb_p			*/
27 #include <media/v4l2-ioctl.h>
28 #include <media/v4l2-device.h>
29 
30 #define RADIO_VERSION KERNEL_VERSION(0, 0, 3)
31 
32 /*
33  * Module info.
34  */
35 
36 MODULE_AUTHOR("Jonas Munsin, Pekka Sepp�nen <pexu@kapsi.fi>");
37 MODULE_DESCRIPTION("A driver for the GemTek Radio card.");
38 MODULE_LICENSE("GPL");
39 
40 /*
41  * Module params.
42  */
43 
44 #ifndef CONFIG_RADIO_GEMTEK_PORT
45 #define CONFIG_RADIO_GEMTEK_PORT -1
46 #endif
47 #ifndef CONFIG_RADIO_GEMTEK_PROBE
48 #define CONFIG_RADIO_GEMTEK_PROBE 1
49 #endif
50 
51 static int io		= CONFIG_RADIO_GEMTEK_PORT;
52 static int probe	= CONFIG_RADIO_GEMTEK_PROBE;
53 static int hardmute;
54 static int shutdown	= 1;
55 static int keepmuted	= 1;
56 static int initmute	= 1;
57 static int radio_nr	= -1;
58 
59 module_param(io, int, 0444);
60 MODULE_PARM_DESC(io, "Force I/O port for the GemTek Radio card if automatic "
61 	 "probing is disabled or fails. The most common I/O ports are: 0x20c "
62 	 "0x30c, 0x24c or 0x34c (0x20c, 0x248 and 0x28c have been reported to "
63 	 "work for the combined sound/radiocard).");
64 
65 module_param(probe, bool, 0444);
66 MODULE_PARM_DESC(probe, "Enable automatic device probing. Note: only the most "
67 	"common I/O ports used by the card are probed.");
68 
69 module_param(hardmute, bool, 0644);
70 MODULE_PARM_DESC(hardmute, "Enable `hard muting' by shutting down PLL, may "
71 	 "reduce static noise.");
72 
73 module_param(shutdown, bool, 0644);
74 MODULE_PARM_DESC(shutdown, "Enable shutting down PLL and muting line when "
75 	 "module is unloaded.");
76 
77 module_param(keepmuted, bool, 0644);
78 MODULE_PARM_DESC(keepmuted, "Keep card muted even when frequency is changed.");
79 
80 module_param(initmute, bool, 0444);
81 MODULE_PARM_DESC(initmute, "Mute card when module is loaded.");
82 
83 module_param(radio_nr, int, 0444);
84 
85 /*
86  * Functions for controlling the card.
87  */
88 #define GEMTEK_LOWFREQ	(87*16000)
89 #define GEMTEK_HIGHFREQ	(108*16000)
90 
91 /*
92  * Frequency calculation constants.  Intermediate frequency 10.52 MHz (nominal
93  * value 10.7 MHz), reference divisor 6.39 kHz (nominal 6.25 kHz).
94  */
95 #define FSCALE		8
96 #define IF_OFFSET	((unsigned int)(10.52 * 16000 * (1<<FSCALE)))
97 #define REF_FREQ	((unsigned int)(6.39 * 16 * (1<<FSCALE)))
98 
99 #define GEMTEK_CK		0x01	/* Clock signal			*/
100 #define GEMTEK_DA		0x02	/* Serial data			*/
101 #define GEMTEK_CE		0x04	/* Chip enable			*/
102 #define GEMTEK_NS		0x08	/* No signal			*/
103 #define GEMTEK_MT		0x10	/* Line mute			*/
104 #define GEMTEK_STDF_3_125_KHZ	0x01	/* Standard frequency 3.125 kHz	*/
105 #define GEMTEK_PLL_OFF		0x07	/* PLL off			*/
106 
107 #define BU2614_BUS_SIZE	32	/* BU2614 / BU2614FS bus size		*/
108 
109 #define SHORT_DELAY 5		/* usec */
110 #define LONG_DELAY 75		/* usec */
111 
112 struct gemtek {
113 	struct v4l2_device v4l2_dev;
114 	struct video_device vdev;
115 	struct mutex lock;
116 	unsigned long lastfreq;
117 	int muted;
118 	int verified;
119 	int io;
120 	u32 bu2614data;
121 };
122 
123 static struct gemtek gemtek_card;
124 
125 #define BU2614_FREQ_BITS 	16 /* D0..D15, Frequency data		*/
126 #define BU2614_PORT_BITS	3 /* P0..P2, Output port control data	*/
127 #define BU2614_VOID_BITS	4 /* unused 				*/
128 #define BU2614_FMES_BITS	1 /* CT, Frequency measurement beginning data */
129 #define BU2614_STDF_BITS	3 /* R0..R2, Standard frequency data	*/
130 #define BU2614_SWIN_BITS	1 /* S, Switch between FMIN / AMIN	*/
131 #define BU2614_SWAL_BITS        1 /* PS, Swallow counter division (AMIN only)*/
132 #define BU2614_VOID2_BITS	1 /* unused				*/
133 #define BU2614_FMUN_BITS	1 /* GT, Frequency measurement time & unlock */
134 #define BU2614_TEST_BITS	1 /* TS, Test data is input		*/
135 
136 #define BU2614_FREQ_SHIFT 	0
137 #define BU2614_PORT_SHIFT	(BU2614_FREQ_BITS + BU2614_FREQ_SHIFT)
138 #define BU2614_VOID_SHIFT	(BU2614_PORT_BITS + BU2614_PORT_SHIFT)
139 #define BU2614_FMES_SHIFT	(BU2614_VOID_BITS + BU2614_VOID_SHIFT)
140 #define BU2614_STDF_SHIFT	(BU2614_FMES_BITS + BU2614_FMES_SHIFT)
141 #define BU2614_SWIN_SHIFT	(BU2614_STDF_BITS + BU2614_STDF_SHIFT)
142 #define BU2614_SWAL_SHIFT	(BU2614_SWIN_BITS + BU2614_SWIN_SHIFT)
143 #define BU2614_VOID2_SHIFT	(BU2614_SWAL_BITS + BU2614_SWAL_SHIFT)
144 #define BU2614_FMUN_SHIFT	(BU2614_VOID2_BITS + BU2614_VOID2_SHIFT)
145 #define BU2614_TEST_SHIFT	(BU2614_FMUN_BITS + BU2614_FMUN_SHIFT)
146 
147 #define MKMASK(field)	(((1<<BU2614_##field##_BITS) - 1) << \
148 			BU2614_##field##_SHIFT)
149 #define BU2614_PORT_MASK	MKMASK(PORT)
150 #define BU2614_FREQ_MASK	MKMASK(FREQ)
151 #define BU2614_VOID_MASK	MKMASK(VOID)
152 #define BU2614_FMES_MASK	MKMASK(FMES)
153 #define BU2614_STDF_MASK	MKMASK(STDF)
154 #define BU2614_SWIN_MASK	MKMASK(SWIN)
155 #define BU2614_SWAL_MASK	MKMASK(SWAL)
156 #define BU2614_VOID2_MASK	MKMASK(VOID2)
157 #define BU2614_FMUN_MASK	MKMASK(FMUN)
158 #define BU2614_TEST_MASK	MKMASK(TEST)
159 
160 /*
161  * Set data which will be sent to BU2614FS.
162  */
163 #define gemtek_bu2614_set(dev, field, data) ((dev)->bu2614data = \
164 	((dev)->bu2614data & ~field##_MASK) | ((data) << field##_SHIFT))
165 
166 /*
167  * Transmit settings to BU2614FS over GemTek IC.
168  */
169 static void gemtek_bu2614_transmit(struct gemtek *gt)
170 {
171 	int i, bit, q, mute;
172 
173 	mutex_lock(&gt->lock);
174 
175 	mute = gt->muted ? GEMTEK_MT : 0x00;
176 
177 	outb_p(mute | GEMTEK_DA | GEMTEK_CK, gt->io);
178 	udelay(SHORT_DELAY);
179 	outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, gt->io);
180 	udelay(LONG_DELAY);
181 
182 	for (i = 0, q = gt->bu2614data; i < 32; i++, q >>= 1) {
183 		bit = (q & 1) ? GEMTEK_DA : 0;
184 		outb_p(mute | GEMTEK_CE | bit, gt->io);
185 		udelay(SHORT_DELAY);
186 		outb_p(mute | GEMTEK_CE | bit | GEMTEK_CK, gt->io);
187 		udelay(SHORT_DELAY);
188 	}
189 
190 	outb_p(mute | GEMTEK_DA | GEMTEK_CK, gt->io);
191 	udelay(SHORT_DELAY);
192 	outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, gt->io);
193 	udelay(LONG_DELAY);
194 
195 	mutex_unlock(&gt->lock);
196 }
197 
198 /*
199  * Calculate divisor from FM-frequency for BU2614FS (3.125 KHz STDF expected).
200  */
201 static unsigned long gemtek_convfreq(unsigned long freq)
202 {
203 	return ((freq<<FSCALE) + IF_OFFSET + REF_FREQ/2) / REF_FREQ;
204 }
205 
206 /*
207  * Set FM-frequency.
208  */
209 static void gemtek_setfreq(struct gemtek *gt, unsigned long freq)
210 {
211 	if (keepmuted && hardmute && gt->muted)
212 		return;
213 
214 	freq = clamp_val(freq, GEMTEK_LOWFREQ, GEMTEK_HIGHFREQ);
215 
216 	gt->lastfreq = freq;
217 	gt->muted = 0;
218 
219 	gemtek_bu2614_set(gt, BU2614_PORT, 0);
220 	gemtek_bu2614_set(gt, BU2614_FMES, 0);
221 	gemtek_bu2614_set(gt, BU2614_SWIN, 0);	/* FM-mode	*/
222 	gemtek_bu2614_set(gt, BU2614_SWAL, 0);
223 	gemtek_bu2614_set(gt, BU2614_FMUN, 1);	/* GT bit set	*/
224 	gemtek_bu2614_set(gt, BU2614_TEST, 0);
225 
226 	gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_STDF_3_125_KHZ);
227 	gemtek_bu2614_set(gt, BU2614_FREQ, gemtek_convfreq(freq));
228 
229 	gemtek_bu2614_transmit(gt);
230 }
231 
232 /*
233  * Set mute flag.
234  */
235 static void gemtek_mute(struct gemtek *gt)
236 {
237 	int i;
238 
239 	gt->muted = 1;
240 
241 	if (hardmute) {
242 		/* Turn off PLL, disable data output */
243 		gemtek_bu2614_set(gt, BU2614_PORT, 0);
244 		gemtek_bu2614_set(gt, BU2614_FMES, 0);	/* CT bit off	*/
245 		gemtek_bu2614_set(gt, BU2614_SWIN, 0);	/* FM-mode	*/
246 		gemtek_bu2614_set(gt, BU2614_SWAL, 0);
247 		gemtek_bu2614_set(gt, BU2614_FMUN, 0);	/* GT bit off	*/
248 		gemtek_bu2614_set(gt, BU2614_TEST, 0);
249 		gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_PLL_OFF);
250 		gemtek_bu2614_set(gt, BU2614_FREQ, 0);
251 		gemtek_bu2614_transmit(gt);
252 		return;
253 	}
254 
255 	mutex_lock(&gt->lock);
256 
257 	/* Read bus contents (CE, CK and DA). */
258 	i = inb_p(gt->io);
259 	/* Write it back with mute flag set. */
260 	outb_p((i >> 5) | GEMTEK_MT, gt->io);
261 	udelay(SHORT_DELAY);
262 
263 	mutex_unlock(&gt->lock);
264 }
265 
266 /*
267  * Unset mute flag.
268  */
269 static void gemtek_unmute(struct gemtek *gt)
270 {
271 	int i;
272 
273 	gt->muted = 0;
274 	if (hardmute) {
275 		/* Turn PLL back on. */
276 		gemtek_setfreq(gt, gt->lastfreq);
277 		return;
278 	}
279 	mutex_lock(&gt->lock);
280 
281 	i = inb_p(gt->io);
282 	outb_p(i >> 5, gt->io);
283 	udelay(SHORT_DELAY);
284 
285 	mutex_unlock(&gt->lock);
286 }
287 
288 /*
289  * Get signal strength (= stereo status).
290  */
291 static inline int gemtek_getsigstr(struct gemtek *gt)
292 {
293 	int sig;
294 
295 	mutex_lock(&gt->lock);
296 	sig = inb_p(gt->io) & GEMTEK_NS ? 0 : 1;
297 	mutex_unlock(&gt->lock);
298 	return sig;
299 }
300 
301 /*
302  * Check if requested card acts like GemTek Radio card.
303  */
304 static int gemtek_verify(struct gemtek *gt, int port)
305 {
306 	int i, q;
307 
308 	if (gt->verified == port)
309 		return 1;
310 
311 	mutex_lock(&gt->lock);
312 
313 	q = inb_p(port);	/* Read bus contents before probing. */
314 	/* Try to turn on CE, CK and DA respectively and check if card responds
315 	   properly. */
316 	for (i = 0; i < 3; ++i) {
317 		outb_p(1 << i, port);
318 		udelay(SHORT_DELAY);
319 
320 		if ((inb_p(port) & (~GEMTEK_NS)) != (0x17 | (1 << (i + 5)))) {
321 			mutex_unlock(&gt->lock);
322 			return 0;
323 		}
324 	}
325 	outb_p(q >> 5, port);	/* Write bus contents back. */
326 	udelay(SHORT_DELAY);
327 
328 	mutex_unlock(&gt->lock);
329 	gt->verified = port;
330 
331 	return 1;
332 }
333 
334 /*
335  * Automatic probing for card.
336  */
337 static int gemtek_probe(struct gemtek *gt)
338 {
339 	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
340 	int ioports[] = { 0x20c, 0x30c, 0x24c, 0x34c, 0x248, 0x28c };
341 	int i;
342 
343 	if (!probe) {
344 		v4l2_info(v4l2_dev, "Automatic device probing disabled.\n");
345 		return -1;
346 	}
347 
348 	v4l2_info(v4l2_dev, "Automatic device probing enabled.\n");
349 
350 	for (i = 0; i < ARRAY_SIZE(ioports); ++i) {
351 		v4l2_info(v4l2_dev, "Trying I/O port 0x%x...\n", ioports[i]);
352 
353 		if (!request_region(ioports[i], 1, "gemtek-probe")) {
354 			v4l2_warn(v4l2_dev, "I/O port 0x%x busy!\n",
355 			       ioports[i]);
356 			continue;
357 		}
358 
359 		if (gemtek_verify(gt, ioports[i])) {
360 			v4l2_info(v4l2_dev, "Card found from I/O port "
361 			       "0x%x!\n", ioports[i]);
362 
363 			release_region(ioports[i], 1);
364 			gt->io = ioports[i];
365 			return gt->io;
366 		}
367 
368 		release_region(ioports[i], 1);
369 	}
370 
371 	v4l2_err(v4l2_dev, "Automatic probing failed!\n");
372 	return -1;
373 }
374 
375 /*
376  * Video 4 Linux stuff.
377  */
378 
379 static const struct v4l2_file_operations gemtek_fops = {
380 	.owner		= THIS_MODULE,
381 	.unlocked_ioctl	= video_ioctl2,
382 };
383 
384 static int vidioc_querycap(struct file *file, void *priv,
385 			   struct v4l2_capability *v)
386 {
387 	strlcpy(v->driver, "radio-gemtek", sizeof(v->driver));
388 	strlcpy(v->card, "GemTek", sizeof(v->card));
389 	strlcpy(v->bus_info, "ISA", sizeof(v->bus_info));
390 	v->version = RADIO_VERSION;
391 	v->capabilities = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
392 	return 0;
393 }
394 
395 static int vidioc_g_tuner(struct file *file, void *priv, struct v4l2_tuner *v)
396 {
397 	struct gemtek *gt = video_drvdata(file);
398 
399 	if (v->index > 0)
400 		return -EINVAL;
401 
402 	strlcpy(v->name, "FM", sizeof(v->name));
403 	v->type = V4L2_TUNER_RADIO;
404 	v->rangelow = GEMTEK_LOWFREQ;
405 	v->rangehigh = GEMTEK_HIGHFREQ;
406 	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
407 	v->signal = 0xffff * gemtek_getsigstr(gt);
408 	if (v->signal) {
409 		v->audmode = V4L2_TUNER_MODE_STEREO;
410 		v->rxsubchans = V4L2_TUNER_SUB_STEREO;
411 	} else {
412 		v->audmode = V4L2_TUNER_MODE_MONO;
413 		v->rxsubchans = V4L2_TUNER_SUB_MONO;
414 	}
415 	return 0;
416 }
417 
418 static int vidioc_s_tuner(struct file *file, void *priv, struct v4l2_tuner *v)
419 {
420 	return (v->index != 0) ? -EINVAL : 0;
421 }
422 
423 static int vidioc_g_frequency(struct file *file, void *priv,
424 			      struct v4l2_frequency *f)
425 {
426 	struct gemtek *gt = video_drvdata(file);
427 
428 	if (f->tuner != 0)
429 		return -EINVAL;
430 	f->type = V4L2_TUNER_RADIO;
431 	f->frequency = gt->lastfreq;
432 	return 0;
433 }
434 
435 static int vidioc_s_frequency(struct file *file, void *priv,
436 			      struct v4l2_frequency *f)
437 {
438 	struct gemtek *gt = video_drvdata(file);
439 
440 	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
441 		return -EINVAL;
442 	gemtek_setfreq(gt, f->frequency);
443 	return 0;
444 }
445 
446 static int vidioc_queryctrl(struct file *file, void *priv,
447 			    struct v4l2_queryctrl *qc)
448 {
449 	switch (qc->id) {
450 	case V4L2_CID_AUDIO_MUTE:
451 		return v4l2_ctrl_query_fill(qc, 0, 1, 1, 0);
452 	default:
453 		return -EINVAL;
454 	}
455 }
456 
457 static int vidioc_g_ctrl(struct file *file, void *priv,
458 			 struct v4l2_control *ctrl)
459 {
460 	struct gemtek *gt = video_drvdata(file);
461 
462 	switch (ctrl->id) {
463 	case V4L2_CID_AUDIO_MUTE:
464 		ctrl->value = gt->muted;
465 		return 0;
466 	}
467 	return -EINVAL;
468 }
469 
470 static int vidioc_s_ctrl(struct file *file, void *priv,
471 			 struct v4l2_control *ctrl)
472 {
473 	struct gemtek *gt = video_drvdata(file);
474 
475 	switch (ctrl->id) {
476 	case V4L2_CID_AUDIO_MUTE:
477 		if (ctrl->value)
478 			gemtek_mute(gt);
479 		else
480 			gemtek_unmute(gt);
481 		return 0;
482 	}
483 	return -EINVAL;
484 }
485 
486 static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
487 {
488 	*i = 0;
489 	return 0;
490 }
491 
492 static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
493 {
494 	return (i != 0) ? -EINVAL : 0;
495 }
496 
497 static int vidioc_g_audio(struct file *file, void *priv, struct v4l2_audio *a)
498 {
499 	a->index = 0;
500 	strlcpy(a->name, "Radio", sizeof(a->name));
501 	a->capability = V4L2_AUDCAP_STEREO;
502 	return 0;
503 }
504 
505 static int vidioc_s_audio(struct file *file, void *priv, struct v4l2_audio *a)
506 {
507 	return (a->index != 0) ? -EINVAL : 0;
508 }
509 
510 static const struct v4l2_ioctl_ops gemtek_ioctl_ops = {
511 	.vidioc_querycap	= vidioc_querycap,
512 	.vidioc_g_tuner		= vidioc_g_tuner,
513 	.vidioc_s_tuner		= vidioc_s_tuner,
514 	.vidioc_g_audio		= vidioc_g_audio,
515 	.vidioc_s_audio		= vidioc_s_audio,
516 	.vidioc_g_input		= vidioc_g_input,
517 	.vidioc_s_input		= vidioc_s_input,
518 	.vidioc_g_frequency	= vidioc_g_frequency,
519 	.vidioc_s_frequency	= vidioc_s_frequency,
520 	.vidioc_queryctrl	= vidioc_queryctrl,
521 	.vidioc_g_ctrl		= vidioc_g_ctrl,
522 	.vidioc_s_ctrl		= vidioc_s_ctrl
523 };
524 
525 /*
526  * Initialization / cleanup related stuff.
527  */
528 
529 static int __init gemtek_init(void)
530 {
531 	struct gemtek *gt = &gemtek_card;
532 	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
533 	int res;
534 
535 	strlcpy(v4l2_dev->name, "gemtek", sizeof(v4l2_dev->name));
536 
537 	v4l2_info(v4l2_dev, "GemTek Radio card driver: v0.0.3\n");
538 
539 	mutex_init(&gt->lock);
540 
541 	gt->verified = -1;
542 	gt->io = io;
543 	gemtek_probe(gt);
544 	if (gt->io) {
545 		if (!request_region(gt->io, 1, "gemtek")) {
546 			v4l2_err(v4l2_dev, "I/O port 0x%x already in use.\n", gt->io);
547 			return -EBUSY;
548 		}
549 
550 		if (!gemtek_verify(gt, gt->io))
551 			v4l2_warn(v4l2_dev, "Card at I/O port 0x%x does not "
552 			       "respond properly, check your "
553 			       "configuration.\n", gt->io);
554 		else
555 			v4l2_info(v4l2_dev, "Using I/O port 0x%x.\n", gt->io);
556 	} else if (probe) {
557 		v4l2_err(v4l2_dev, "Automatic probing failed and no "
558 		       "fixed I/O port defined.\n");
559 		return -ENODEV;
560 	} else {
561 		v4l2_err(v4l2_dev, "Automatic probing disabled but no fixed "
562 		       "I/O port defined.");
563 		return -EINVAL;
564 	}
565 
566 	res = v4l2_device_register(NULL, v4l2_dev);
567 	if (res < 0) {
568 		v4l2_err(v4l2_dev, "Could not register v4l2_device\n");
569 		release_region(gt->io, 1);
570 		return res;
571 	}
572 
573 	strlcpy(gt->vdev.name, v4l2_dev->name, sizeof(gt->vdev.name));
574 	gt->vdev.v4l2_dev = v4l2_dev;
575 	gt->vdev.fops = &gemtek_fops;
576 	gt->vdev.ioctl_ops = &gemtek_ioctl_ops;
577 	gt->vdev.release = video_device_release_empty;
578 	video_set_drvdata(&gt->vdev, gt);
579 
580 	/* Set defaults */
581 	gt->lastfreq = GEMTEK_LOWFREQ;
582 	gt->bu2614data = 0;
583 
584 	if (initmute)
585 		gemtek_mute(gt);
586 
587 	if (video_register_device(&gt->vdev, VFL_TYPE_RADIO, radio_nr) < 0) {
588 		v4l2_device_unregister(v4l2_dev);
589 		release_region(gt->io, 1);
590 		return -EBUSY;
591 	}
592 
593 	return 0;
594 }
595 
596 /*
597  * Module cleanup
598  */
599 static void __exit gemtek_exit(void)
600 {
601 	struct gemtek *gt = &gemtek_card;
602 	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
603 
604 	if (shutdown) {
605 		hardmute = 1;	/* Turn off PLL */
606 		gemtek_mute(gt);
607 	} else {
608 		v4l2_info(v4l2_dev, "Module unloaded but card not muted!\n");
609 	}
610 
611 	video_unregister_device(&gt->vdev);
612 	v4l2_device_unregister(&gt->v4l2_dev);
613 	release_region(gt->io, 1);
614 }
615 
616 module_init(gemtek_init);
617 module_exit(gemtek_exit);
618