xref: /linux/drivers/media/radio/radio-gemtek.c (revision f33c596a2f921696391801b637ed50d514634079)
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/mutex.h>
25 #include <linux/io.h>		/* outb, outb_p			*/
26 #include <media/v4l2-ioctl.h>
27 #include <media/v4l2-device.h>
28 
29 /*
30  * Module info.
31  */
32 
33 MODULE_AUTHOR("Jonas Munsin, Pekka Seppänen <pexu@kapsi.fi>");
34 MODULE_DESCRIPTION("A driver for the GemTek Radio card.");
35 MODULE_LICENSE("GPL");
36 MODULE_VERSION("0.0.4");
37 
38 /*
39  * Module params.
40  */
41 
42 #ifndef CONFIG_RADIO_GEMTEK_PORT
43 #define CONFIG_RADIO_GEMTEK_PORT -1
44 #endif
45 #ifndef CONFIG_RADIO_GEMTEK_PROBE
46 #define CONFIG_RADIO_GEMTEK_PROBE 1
47 #endif
48 
49 static int io		= CONFIG_RADIO_GEMTEK_PORT;
50 static int probe	= CONFIG_RADIO_GEMTEK_PROBE;
51 static int hardmute;
52 static int shutdown	= 1;
53 static int keepmuted	= 1;
54 static int initmute	= 1;
55 static int radio_nr	= -1;
56 
57 module_param(io, int, 0444);
58 MODULE_PARM_DESC(io, "Force I/O port for the GemTek Radio card if automatic "
59 	 "probing is disabled or fails. The most common I/O ports are: 0x20c "
60 	 "0x30c, 0x24c or 0x34c (0x20c, 0x248 and 0x28c have been reported to "
61 	 "work for the combined sound/radiocard).");
62 
63 module_param(probe, bool, 0444);
64 MODULE_PARM_DESC(probe, "Enable automatic device probing. Note: only the most "
65 	"common I/O ports used by the card are probed.");
66 
67 module_param(hardmute, bool, 0644);
68 MODULE_PARM_DESC(hardmute, "Enable `hard muting' by shutting down PLL, may "
69 	 "reduce static noise.");
70 
71 module_param(shutdown, bool, 0644);
72 MODULE_PARM_DESC(shutdown, "Enable shutting down PLL and muting line when "
73 	 "module is unloaded.");
74 
75 module_param(keepmuted, bool, 0644);
76 MODULE_PARM_DESC(keepmuted, "Keep card muted even when frequency is changed.");
77 
78 module_param(initmute, bool, 0444);
79 MODULE_PARM_DESC(initmute, "Mute card when module is loaded.");
80 
81 module_param(radio_nr, int, 0444);
82 
83 /*
84  * Functions for controlling the card.
85  */
86 #define GEMTEK_LOWFREQ	(87*16000)
87 #define GEMTEK_HIGHFREQ	(108*16000)
88 
89 /*
90  * Frequency calculation constants.  Intermediate frequency 10.52 MHz (nominal
91  * value 10.7 MHz), reference divisor 6.39 kHz (nominal 6.25 kHz).
92  */
93 #define FSCALE		8
94 #define IF_OFFSET	((unsigned int)(10.52 * 16000 * (1<<FSCALE)))
95 #define REF_FREQ	((unsigned int)(6.39 * 16 * (1<<FSCALE)))
96 
97 #define GEMTEK_CK		0x01	/* Clock signal			*/
98 #define GEMTEK_DA		0x02	/* Serial data			*/
99 #define GEMTEK_CE		0x04	/* Chip enable			*/
100 #define GEMTEK_NS		0x08	/* No signal			*/
101 #define GEMTEK_MT		0x10	/* Line mute			*/
102 #define GEMTEK_STDF_3_125_KHZ	0x01	/* Standard frequency 3.125 kHz	*/
103 #define GEMTEK_PLL_OFF		0x07	/* PLL off			*/
104 
105 #define BU2614_BUS_SIZE	32	/* BU2614 / BU2614FS bus size		*/
106 
107 #define SHORT_DELAY 5		/* usec */
108 #define LONG_DELAY 75		/* usec */
109 
110 struct gemtek {
111 	struct v4l2_device v4l2_dev;
112 	struct video_device vdev;
113 	struct mutex lock;
114 	unsigned long lastfreq;
115 	int muted;
116 	int verified;
117 	int io;
118 	u32 bu2614data;
119 };
120 
121 static struct gemtek gemtek_card;
122 
123 #define BU2614_FREQ_BITS 	16 /* D0..D15, Frequency data		*/
124 #define BU2614_PORT_BITS	3 /* P0..P2, Output port control data	*/
125 #define BU2614_VOID_BITS	4 /* unused 				*/
126 #define BU2614_FMES_BITS	1 /* CT, Frequency measurement beginning data */
127 #define BU2614_STDF_BITS	3 /* R0..R2, Standard frequency data	*/
128 #define BU2614_SWIN_BITS	1 /* S, Switch between FMIN / AMIN	*/
129 #define BU2614_SWAL_BITS        1 /* PS, Swallow counter division (AMIN only)*/
130 #define BU2614_VOID2_BITS	1 /* unused				*/
131 #define BU2614_FMUN_BITS	1 /* GT, Frequency measurement time & unlock */
132 #define BU2614_TEST_BITS	1 /* TS, Test data is input		*/
133 
134 #define BU2614_FREQ_SHIFT 	0
135 #define BU2614_PORT_SHIFT	(BU2614_FREQ_BITS + BU2614_FREQ_SHIFT)
136 #define BU2614_VOID_SHIFT	(BU2614_PORT_BITS + BU2614_PORT_SHIFT)
137 #define BU2614_FMES_SHIFT	(BU2614_VOID_BITS + BU2614_VOID_SHIFT)
138 #define BU2614_STDF_SHIFT	(BU2614_FMES_BITS + BU2614_FMES_SHIFT)
139 #define BU2614_SWIN_SHIFT	(BU2614_STDF_BITS + BU2614_STDF_SHIFT)
140 #define BU2614_SWAL_SHIFT	(BU2614_SWIN_BITS + BU2614_SWIN_SHIFT)
141 #define BU2614_VOID2_SHIFT	(BU2614_SWAL_BITS + BU2614_SWAL_SHIFT)
142 #define BU2614_FMUN_SHIFT	(BU2614_VOID2_BITS + BU2614_VOID2_SHIFT)
143 #define BU2614_TEST_SHIFT	(BU2614_FMUN_BITS + BU2614_FMUN_SHIFT)
144 
145 #define MKMASK(field)	(((1<<BU2614_##field##_BITS) - 1) << \
146 			BU2614_##field##_SHIFT)
147 #define BU2614_PORT_MASK	MKMASK(PORT)
148 #define BU2614_FREQ_MASK	MKMASK(FREQ)
149 #define BU2614_VOID_MASK	MKMASK(VOID)
150 #define BU2614_FMES_MASK	MKMASK(FMES)
151 #define BU2614_STDF_MASK	MKMASK(STDF)
152 #define BU2614_SWIN_MASK	MKMASK(SWIN)
153 #define BU2614_SWAL_MASK	MKMASK(SWAL)
154 #define BU2614_VOID2_MASK	MKMASK(VOID2)
155 #define BU2614_FMUN_MASK	MKMASK(FMUN)
156 #define BU2614_TEST_MASK	MKMASK(TEST)
157 
158 /*
159  * Set data which will be sent to BU2614FS.
160  */
161 #define gemtek_bu2614_set(dev, field, data) ((dev)->bu2614data = \
162 	((dev)->bu2614data & ~field##_MASK) | ((data) << field##_SHIFT))
163 
164 /*
165  * Transmit settings to BU2614FS over GemTek IC.
166  */
167 static void gemtek_bu2614_transmit(struct gemtek *gt)
168 {
169 	int i, bit, q, mute;
170 
171 	mutex_lock(&gt->lock);
172 
173 	mute = gt->muted ? GEMTEK_MT : 0x00;
174 
175 	outb_p(mute | GEMTEK_DA | GEMTEK_CK, gt->io);
176 	udelay(SHORT_DELAY);
177 	outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, gt->io);
178 	udelay(LONG_DELAY);
179 
180 	for (i = 0, q = gt->bu2614data; i < 32; i++, q >>= 1) {
181 		bit = (q & 1) ? GEMTEK_DA : 0;
182 		outb_p(mute | GEMTEK_CE | bit, gt->io);
183 		udelay(SHORT_DELAY);
184 		outb_p(mute | GEMTEK_CE | bit | GEMTEK_CK, gt->io);
185 		udelay(SHORT_DELAY);
186 	}
187 
188 	outb_p(mute | GEMTEK_DA | GEMTEK_CK, gt->io);
189 	udelay(SHORT_DELAY);
190 	outb_p(mute | GEMTEK_CE | GEMTEK_DA | GEMTEK_CK, gt->io);
191 	udelay(LONG_DELAY);
192 
193 	mutex_unlock(&gt->lock);
194 }
195 
196 /*
197  * Calculate divisor from FM-frequency for BU2614FS (3.125 KHz STDF expected).
198  */
199 static unsigned long gemtek_convfreq(unsigned long freq)
200 {
201 	return ((freq<<FSCALE) + IF_OFFSET + REF_FREQ/2) / REF_FREQ;
202 }
203 
204 /*
205  * Set FM-frequency.
206  */
207 static void gemtek_setfreq(struct gemtek *gt, unsigned long freq)
208 {
209 	if (keepmuted && hardmute && gt->muted)
210 		return;
211 
212 	freq = clamp_val(freq, GEMTEK_LOWFREQ, GEMTEK_HIGHFREQ);
213 
214 	gt->lastfreq = freq;
215 	gt->muted = 0;
216 
217 	gemtek_bu2614_set(gt, BU2614_PORT, 0);
218 	gemtek_bu2614_set(gt, BU2614_FMES, 0);
219 	gemtek_bu2614_set(gt, BU2614_SWIN, 0);	/* FM-mode	*/
220 	gemtek_bu2614_set(gt, BU2614_SWAL, 0);
221 	gemtek_bu2614_set(gt, BU2614_FMUN, 1);	/* GT bit set	*/
222 	gemtek_bu2614_set(gt, BU2614_TEST, 0);
223 
224 	gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_STDF_3_125_KHZ);
225 	gemtek_bu2614_set(gt, BU2614_FREQ, gemtek_convfreq(freq));
226 
227 	gemtek_bu2614_transmit(gt);
228 }
229 
230 /*
231  * Set mute flag.
232  */
233 static void gemtek_mute(struct gemtek *gt)
234 {
235 	int i;
236 
237 	gt->muted = 1;
238 
239 	if (hardmute) {
240 		/* Turn off PLL, disable data output */
241 		gemtek_bu2614_set(gt, BU2614_PORT, 0);
242 		gemtek_bu2614_set(gt, BU2614_FMES, 0);	/* CT bit off	*/
243 		gemtek_bu2614_set(gt, BU2614_SWIN, 0);	/* FM-mode	*/
244 		gemtek_bu2614_set(gt, BU2614_SWAL, 0);
245 		gemtek_bu2614_set(gt, BU2614_FMUN, 0);	/* GT bit off	*/
246 		gemtek_bu2614_set(gt, BU2614_TEST, 0);
247 		gemtek_bu2614_set(gt, BU2614_STDF, GEMTEK_PLL_OFF);
248 		gemtek_bu2614_set(gt, BU2614_FREQ, 0);
249 		gemtek_bu2614_transmit(gt);
250 		return;
251 	}
252 
253 	mutex_lock(&gt->lock);
254 
255 	/* Read bus contents (CE, CK and DA). */
256 	i = inb_p(gt->io);
257 	/* Write it back with mute flag set. */
258 	outb_p((i >> 5) | GEMTEK_MT, gt->io);
259 	udelay(SHORT_DELAY);
260 
261 	mutex_unlock(&gt->lock);
262 }
263 
264 /*
265  * Unset mute flag.
266  */
267 static void gemtek_unmute(struct gemtek *gt)
268 {
269 	int i;
270 
271 	gt->muted = 0;
272 	if (hardmute) {
273 		/* Turn PLL back on. */
274 		gemtek_setfreq(gt, gt->lastfreq);
275 		return;
276 	}
277 	mutex_lock(&gt->lock);
278 
279 	i = inb_p(gt->io);
280 	outb_p(i >> 5, gt->io);
281 	udelay(SHORT_DELAY);
282 
283 	mutex_unlock(&gt->lock);
284 }
285 
286 /*
287  * Get signal strength (= stereo status).
288  */
289 static inline int gemtek_getsigstr(struct gemtek *gt)
290 {
291 	int sig;
292 
293 	mutex_lock(&gt->lock);
294 	sig = inb_p(gt->io) & GEMTEK_NS ? 0 : 1;
295 	mutex_unlock(&gt->lock);
296 	return sig;
297 }
298 
299 /*
300  * Check if requested card acts like GemTek Radio card.
301  */
302 static int gemtek_verify(struct gemtek *gt, int port)
303 {
304 	int i, q;
305 
306 	if (gt->verified == port)
307 		return 1;
308 
309 	mutex_lock(&gt->lock);
310 
311 	q = inb_p(port);	/* Read bus contents before probing. */
312 	/* Try to turn on CE, CK and DA respectively and check if card responds
313 	   properly. */
314 	for (i = 0; i < 3; ++i) {
315 		outb_p(1 << i, port);
316 		udelay(SHORT_DELAY);
317 
318 		if ((inb_p(port) & (~GEMTEK_NS)) != (0x17 | (1 << (i + 5)))) {
319 			mutex_unlock(&gt->lock);
320 			return 0;
321 		}
322 	}
323 	outb_p(q >> 5, port);	/* Write bus contents back. */
324 	udelay(SHORT_DELAY);
325 
326 	mutex_unlock(&gt->lock);
327 	gt->verified = port;
328 
329 	return 1;
330 }
331 
332 /*
333  * Automatic probing for card.
334  */
335 static int gemtek_probe(struct gemtek *gt)
336 {
337 	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
338 	int ioports[] = { 0x20c, 0x30c, 0x24c, 0x34c, 0x248, 0x28c };
339 	int i;
340 
341 	if (!probe) {
342 		v4l2_info(v4l2_dev, "Automatic device probing disabled.\n");
343 		return -1;
344 	}
345 
346 	v4l2_info(v4l2_dev, "Automatic device probing enabled.\n");
347 
348 	for (i = 0; i < ARRAY_SIZE(ioports); ++i) {
349 		v4l2_info(v4l2_dev, "Trying I/O port 0x%x...\n", ioports[i]);
350 
351 		if (!request_region(ioports[i], 1, "gemtek-probe")) {
352 			v4l2_warn(v4l2_dev, "I/O port 0x%x busy!\n",
353 			       ioports[i]);
354 			continue;
355 		}
356 
357 		if (gemtek_verify(gt, ioports[i])) {
358 			v4l2_info(v4l2_dev, "Card found from I/O port "
359 			       "0x%x!\n", ioports[i]);
360 
361 			release_region(ioports[i], 1);
362 			gt->io = ioports[i];
363 			return gt->io;
364 		}
365 
366 		release_region(ioports[i], 1);
367 	}
368 
369 	v4l2_err(v4l2_dev, "Automatic probing failed!\n");
370 	return -1;
371 }
372 
373 /*
374  * Video 4 Linux stuff.
375  */
376 
377 static const struct v4l2_file_operations gemtek_fops = {
378 	.owner		= THIS_MODULE,
379 	.unlocked_ioctl	= video_ioctl2,
380 };
381 
382 static int vidioc_querycap(struct file *file, void *priv,
383 			   struct v4l2_capability *v)
384 {
385 	strlcpy(v->driver, "radio-gemtek", sizeof(v->driver));
386 	strlcpy(v->card, "GemTek", sizeof(v->card));
387 	strlcpy(v->bus_info, "ISA", sizeof(v->bus_info));
388 	v->capabilities = V4L2_CAP_TUNER | V4L2_CAP_RADIO;
389 	return 0;
390 }
391 
392 static int vidioc_g_tuner(struct file *file, void *priv, struct v4l2_tuner *v)
393 {
394 	struct gemtek *gt = video_drvdata(file);
395 
396 	if (v->index > 0)
397 		return -EINVAL;
398 
399 	strlcpy(v->name, "FM", sizeof(v->name));
400 	v->type = V4L2_TUNER_RADIO;
401 	v->rangelow = GEMTEK_LOWFREQ;
402 	v->rangehigh = GEMTEK_HIGHFREQ;
403 	v->capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_STEREO;
404 	v->signal = 0xffff * gemtek_getsigstr(gt);
405 	if (v->signal) {
406 		v->audmode = V4L2_TUNER_MODE_STEREO;
407 		v->rxsubchans = V4L2_TUNER_SUB_STEREO;
408 	} else {
409 		v->audmode = V4L2_TUNER_MODE_MONO;
410 		v->rxsubchans = V4L2_TUNER_SUB_MONO;
411 	}
412 	return 0;
413 }
414 
415 static int vidioc_s_tuner(struct file *file, void *priv, struct v4l2_tuner *v)
416 {
417 	return (v->index != 0) ? -EINVAL : 0;
418 }
419 
420 static int vidioc_g_frequency(struct file *file, void *priv,
421 			      struct v4l2_frequency *f)
422 {
423 	struct gemtek *gt = video_drvdata(file);
424 
425 	if (f->tuner != 0)
426 		return -EINVAL;
427 	f->type = V4L2_TUNER_RADIO;
428 	f->frequency = gt->lastfreq;
429 	return 0;
430 }
431 
432 static int vidioc_s_frequency(struct file *file, void *priv,
433 			      struct v4l2_frequency *f)
434 {
435 	struct gemtek *gt = video_drvdata(file);
436 
437 	if (f->tuner != 0 || f->type != V4L2_TUNER_RADIO)
438 		return -EINVAL;
439 	gemtek_setfreq(gt, f->frequency);
440 	return 0;
441 }
442 
443 static int vidioc_queryctrl(struct file *file, void *priv,
444 			    struct v4l2_queryctrl *qc)
445 {
446 	switch (qc->id) {
447 	case V4L2_CID_AUDIO_MUTE:
448 		return v4l2_ctrl_query_fill(qc, 0, 1, 1, 0);
449 	default:
450 		return -EINVAL;
451 	}
452 }
453 
454 static int vidioc_g_ctrl(struct file *file, void *priv,
455 			 struct v4l2_control *ctrl)
456 {
457 	struct gemtek *gt = video_drvdata(file);
458 
459 	switch (ctrl->id) {
460 	case V4L2_CID_AUDIO_MUTE:
461 		ctrl->value = gt->muted;
462 		return 0;
463 	}
464 	return -EINVAL;
465 }
466 
467 static int vidioc_s_ctrl(struct file *file, void *priv,
468 			 struct v4l2_control *ctrl)
469 {
470 	struct gemtek *gt = video_drvdata(file);
471 
472 	switch (ctrl->id) {
473 	case V4L2_CID_AUDIO_MUTE:
474 		if (ctrl->value)
475 			gemtek_mute(gt);
476 		else
477 			gemtek_unmute(gt);
478 		return 0;
479 	}
480 	return -EINVAL;
481 }
482 
483 static int vidioc_g_input(struct file *filp, void *priv, unsigned int *i)
484 {
485 	*i = 0;
486 	return 0;
487 }
488 
489 static int vidioc_s_input(struct file *filp, void *priv, unsigned int i)
490 {
491 	return (i != 0) ? -EINVAL : 0;
492 }
493 
494 static int vidioc_g_audio(struct file *file, void *priv, struct v4l2_audio *a)
495 {
496 	a->index = 0;
497 	strlcpy(a->name, "Radio", sizeof(a->name));
498 	a->capability = V4L2_AUDCAP_STEREO;
499 	return 0;
500 }
501 
502 static int vidioc_s_audio(struct file *file, void *priv, struct v4l2_audio *a)
503 {
504 	return (a->index != 0) ? -EINVAL : 0;
505 }
506 
507 static const struct v4l2_ioctl_ops gemtek_ioctl_ops = {
508 	.vidioc_querycap	= vidioc_querycap,
509 	.vidioc_g_tuner		= vidioc_g_tuner,
510 	.vidioc_s_tuner		= vidioc_s_tuner,
511 	.vidioc_g_audio		= vidioc_g_audio,
512 	.vidioc_s_audio		= vidioc_s_audio,
513 	.vidioc_g_input		= vidioc_g_input,
514 	.vidioc_s_input		= vidioc_s_input,
515 	.vidioc_g_frequency	= vidioc_g_frequency,
516 	.vidioc_s_frequency	= vidioc_s_frequency,
517 	.vidioc_queryctrl	= vidioc_queryctrl,
518 	.vidioc_g_ctrl		= vidioc_g_ctrl,
519 	.vidioc_s_ctrl		= vidioc_s_ctrl
520 };
521 
522 /*
523  * Initialization / cleanup related stuff.
524  */
525 
526 static int __init gemtek_init(void)
527 {
528 	struct gemtek *gt = &gemtek_card;
529 	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
530 	int res;
531 
532 	strlcpy(v4l2_dev->name, "gemtek", sizeof(v4l2_dev->name));
533 
534 	v4l2_info(v4l2_dev, "GemTek Radio card driver: v0.0.3\n");
535 
536 	mutex_init(&gt->lock);
537 
538 	gt->verified = -1;
539 	gt->io = io;
540 	gemtek_probe(gt);
541 	if (gt->io) {
542 		if (!request_region(gt->io, 1, "gemtek")) {
543 			v4l2_err(v4l2_dev, "I/O port 0x%x already in use.\n", gt->io);
544 			return -EBUSY;
545 		}
546 
547 		if (!gemtek_verify(gt, gt->io))
548 			v4l2_warn(v4l2_dev, "Card at I/O port 0x%x does not "
549 			       "respond properly, check your "
550 			       "configuration.\n", gt->io);
551 		else
552 			v4l2_info(v4l2_dev, "Using I/O port 0x%x.\n", gt->io);
553 	} else if (probe) {
554 		v4l2_err(v4l2_dev, "Automatic probing failed and no "
555 		       "fixed I/O port defined.\n");
556 		return -ENODEV;
557 	} else {
558 		v4l2_err(v4l2_dev, "Automatic probing disabled but no fixed "
559 		       "I/O port defined.");
560 		return -EINVAL;
561 	}
562 
563 	res = v4l2_device_register(NULL, v4l2_dev);
564 	if (res < 0) {
565 		v4l2_err(v4l2_dev, "Could not register v4l2_device\n");
566 		release_region(gt->io, 1);
567 		return res;
568 	}
569 
570 	strlcpy(gt->vdev.name, v4l2_dev->name, sizeof(gt->vdev.name));
571 	gt->vdev.v4l2_dev = v4l2_dev;
572 	gt->vdev.fops = &gemtek_fops;
573 	gt->vdev.ioctl_ops = &gemtek_ioctl_ops;
574 	gt->vdev.release = video_device_release_empty;
575 	video_set_drvdata(&gt->vdev, gt);
576 
577 	/* Set defaults */
578 	gt->lastfreq = GEMTEK_LOWFREQ;
579 	gt->bu2614data = 0;
580 
581 	if (initmute)
582 		gemtek_mute(gt);
583 
584 	if (video_register_device(&gt->vdev, VFL_TYPE_RADIO, radio_nr) < 0) {
585 		v4l2_device_unregister(v4l2_dev);
586 		release_region(gt->io, 1);
587 		return -EBUSY;
588 	}
589 
590 	return 0;
591 }
592 
593 /*
594  * Module cleanup
595  */
596 static void __exit gemtek_exit(void)
597 {
598 	struct gemtek *gt = &gemtek_card;
599 	struct v4l2_device *v4l2_dev = &gt->v4l2_dev;
600 
601 	if (shutdown) {
602 		hardmute = 1;	/* Turn off PLL */
603 		gemtek_mute(gt);
604 	} else {
605 		v4l2_info(v4l2_dev, "Module unloaded but card not muted!\n");
606 	}
607 
608 	video_unregister_device(&gt->vdev);
609 	v4l2_device_unregister(&gt->v4l2_dev);
610 	release_region(gt->io, 1);
611 }
612 
613 module_init(gemtek_init);
614 module_exit(gemtek_exit);
615