aboutsummaryrefslogtreecommitdiff
path: root/drivers/media/video/cx18/cx18-streams.c
blob: 0c8e7542cf6044ec86fbe8e0c6eb8931240c8e25 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
/*
 *  cx18 init/start/stop/exit stream functions
 *
 *  Derived from ivtv-streams.c
 *
 *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA
 */

#include "cx18-driver.h"
#include "cx18-io.h"
#include "cx18-fileops.h"
#include "cx18-mailbox.h"
#include "cx18-i2c.h"
#include "cx18-queue.h"
#include "cx18-ioctl.h"
#include "cx18-streams.h"
#include "cx18-cards.h"
#include "cx18-scb.h"
#include "cx18-av-core.h"
#include "cx18-dvb.h"

#define CX18_DSP0_INTERRUPT_MASK     	0xd0004C

static struct file_operations cx18_v4l2_enc_fops = {
	.owner = THIS_MODULE,
	.read = cx18_v4l2_read,
	.open = cx18_v4l2_open,
	/* FIXME change to video_ioctl2 if serialization lock can be removed */
	.ioctl = cx18_v4l2_ioctl,
	.compat_ioctl = v4l_compat_ioctl32,
	.release = cx18_v4l2_close,
	.poll = cx18_v4l2_enc_poll,
};

/* offset from 0 to register ts v4l2 minors on */
#define CX18_V4L2_ENC_TS_OFFSET   16
/* offset from 0 to register pcm v4l2 minors on */
#define CX18_V4L2_ENC_PCM_OFFSET  24
/* offset from 0 to register yuv v4l2 minors on */
#define CX18_V4L2_ENC_YUV_OFFSET  32

static struct {
	const char *name;
	int vfl_type;
	int num_offset;
	int dma;
	enum v4l2_buf_type buf_type;
	struct file_operations *fops;
} cx18_stream_info[] = {
	{	/* CX18_ENC_STREAM_TYPE_MPG */
		"encoder MPEG",
		VFL_TYPE_GRABBER, 0,
		PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE,
		&cx18_v4l2_enc_fops
	},
	{	/* CX18_ENC_STREAM_TYPE_TS */
		"TS",
		VFL_TYPE_GRABBER, -1,
		PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE,
		&cx18_v4l2_enc_fops
	},
	{	/* CX18_ENC_STREAM_TYPE_YUV */
		"encoder YUV",
		VFL_TYPE_GRABBER, CX18_V4L2_ENC_YUV_OFFSET,
		PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE,
		&cx18_v4l2_enc_fops
	},
	{	/* CX18_ENC_STREAM_TYPE_VBI */
		"encoder VBI",
		VFL_TYPE_VBI, 0,
		PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VBI_CAPTURE,
		&cx18_v4l2_enc_fops
	},
	{	/* CX18_ENC_STREAM_TYPE_PCM */
		"encoder PCM audio",
		VFL_TYPE_GRABBER, CX18_V4L2_ENC_PCM_OFFSET,
		PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_PRIVATE,
		&cx18_v4l2_enc_fops
	},
	{	/* CX18_ENC_STREAM_TYPE_IDX */
		"encoder IDX",
		VFL_TYPE_GRABBER, -1,
		PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE,
		&cx18_v4l2_enc_fops
	},
	{	/* CX18_ENC_STREAM_TYPE_RAD */
		"encoder radio",
		VFL_TYPE_RADIO, 0,
		PCI_DMA_NONE, V4L2_BUF_TYPE_PRIVATE,
		&cx18_v4l2_enc_fops
	},
};

static void cx18_stream_init(struct cx18 *cx, int type)
{
	struct cx18_stream *s = &cx->streams[type];
	struct video_device *dev = s->v4l2dev;
	u32 max_size = cx->options.megabytes[type] * 1024 * 1024;

	/* we need to keep v4l2dev, so restore it afterwards */
	memset(s, 0, sizeof(*s));
	s->v4l2dev = dev;

	/* initialize cx18_stream fields */
	s->cx = cx;
	s->type = type;
	s->name = cx18_stream_info[type].name;
	s->handle = CX18_INVALID_TASK_HANDLE;

	s->dma = cx18_stream_info[type].dma;
	s->buf_size = cx->stream_buf_size[type];
	if (s->buf_size)
		s->buffers = max_size / s->buf_size;
	if (s->buffers > 63) {
		/* Each stream has a maximum of 63 buffers,
		   ensure we do not exceed that. */
		s->buffers = 63;
		s->buf_size = (max_size / s->buffers) & ~0xfff;
	}
	spin_lock_init(&s->qlock);
	init_waitqueue_head(&s->waitq);
	s->id = -1;
	cx18_queue_init(&s->q_free);
	cx18_queue_init(&s->q_full);
	cx18_queue_init(&s->q_io);
}

static int cx18_prep_dev(struct cx18 *cx, int type)
{
	struct cx18_stream *s = &cx->streams[type];
	u32 cap = cx->v4l2_cap;
	int num_offset = cx18_stream_info[type].num_offset;
	int num = cx->num + cx18_first_minor + num_offset;

	/* These four fields are always initialized. If v4l2dev == NULL, then
	   this stream is not in use. In that case no other fields but these
	   four can be used. */
	s->v4l2dev = NULL;
	s->cx = cx;
	s->type = type;
	s->name = cx18_stream_info[type].name;

	/* Check whether the radio is supported */
	if (type == CX18_ENC_STREAM_TYPE_RAD && !(cap & V4L2_CAP_RADIO))
		return 0;

	/* Check whether VBI is supported */
	if (type == CX18_ENC_STREAM_TYPE_VBI &&
	    !(cap & (V4L2_CAP_VBI_CAPTURE | V4L2_CAP_SLICED_VBI_CAPTURE)))
		return 0;

	/* User explicitly selected 0 buffers for these streams, so don't
	   create them. */
	if (cx18_stream_info[type].dma != PCI_DMA_NONE &&
	    cx->options.megabytes[type] == 0) {
		CX18_INFO("Disabled %s device\n", cx18_stream_info[type].name);
		return 0;
	}

	cx18_stream_init(cx, type);

	if (num_offset == -1)
		return 0;

	/* allocate and initialize the v4l2 video device structure */
	s->v4l2dev = video_device_alloc();
	if (s->v4l2dev == NULL) {
		CX18_ERR("Couldn't allocate v4l2 video_device for %s\n",
				s->name);
		return -ENOMEM;
	}

	snprintf(s->v4l2dev->name, sizeof(s->v4l2dev->name), "cx18-%d",
			cx->num);

	s->v4l2dev->num = num;
	s->v4l2dev->parent = &cx->dev->dev;
	s->v4l2dev->fops = cx18_stream_info[type].fops;
	s->v4l2dev->release = video_device_release;
	s->v4l2dev->tvnorms = V4L2_STD_ALL;
	cx18_set_funcs(s->v4l2dev);
	return 0;
}

/* Initialize v4l2 variables and register v4l2 devices */
int cx18_streams_setup(struct cx18 *cx)
{
	int type;

	/* Setup V4L2 Devices */
	for (type = 0; type < CX18_MAX_STREAMS; type++) {
		/* Prepare device */
		if (cx18_prep_dev(cx, type))
			break;

		/* Allocate Stream */
		if (cx18_stream_alloc(&cx->streams[type]))
			break;
	}
	if (type == CX18_MAX_STREAMS)
		return 0;

	/* One or more streams could not be initialized. Clean 'em all up. */
	cx18_streams_cleanup(cx, 0);
	return -ENOMEM;
}

static int cx18_reg_dev(struct cx18 *cx, int type)
{
	struct cx18_stream *s = &cx->streams[type];
	int vfl_type = cx18_stream_info[type].vfl_type;
	int num;

	/* TODO: Shouldn't this be a VFL_TYPE_TRANSPORT or something?
	 * We need a VFL_TYPE_TS defined.
	 */
	if (strcmp("TS", s->name) == 0) {
		/* just return if no DVB is supported */
		if ((cx->card->hw_all & CX18_HW_DVB) == 0)
			return 0;
		if (cx18_dvb_register(s) < 0) {
			CX18_ERR("DVB failed to register\n");
			return -EINVAL;
		}
	}

	if (s->v4l2dev == NULL)
		return 0;

	num = s->v4l2dev->num;
	/* card number + user defined offset + device offset */
	if (type != CX18_ENC_STREAM_TYPE_MPG) {
		struct cx18_stream *s_mpg = &cx->streams[CX18_ENC_STREAM_TYPE_MPG];

		if (s_mpg->v4l2dev)
			num = s_mpg->v4l2dev->num + cx18_stream_info[type].num_offset;
	}

	/* Register device. First try the desired minor, then any free one. */
	if (video_register_device(s->v4l2dev, vfl_type, num)) {
		CX18_ERR("Couldn't register v4l2 device for %s kernel number %d\n",
			s->name, num);
		video_device_release(s->v4l2dev);
		s->v4l2dev = NULL;
		return -ENOMEM;
	}
	num = s->v4l2dev->num;

	switch (vfl_type) {
	case VFL_TYPE_GRABBER:
		CX18_INFO("Registered device video%d for %s (%d MB)\n",
			num, s->name, cx->options.megabytes[type]);
		break;

	case VFL_TYPE_RADIO:
		CX18_INFO("Registered device radio%d for %s\n",
			num, s->name);
		break;

	case VFL_TYPE_VBI:
		if (cx->options.megabytes[type])
			CX18_INFO("Registered device vbi%d for %s (%d MB)\n",
				num,
				s->name, cx->options.megabytes[type]);
		else
			CX18_INFO("Registered device vbi%d for %s\n",
				num, s->name);
		break;
	}

	return 0;
}

/* Register v4l2 devices */
int cx18_streams_register(struct cx18 *cx)
{
	int type;
	int err = 0;

	/* Register V4L2 devices */
	for (type = 0; type < CX18_MAX_STREAMS; type++)
		err |= cx18_reg_dev(cx, type);

	if (err == 0)
		return 0;

	/* One or more streams could not be initialized. Clean 'em all up. */
	cx18_streams_cleanup(cx, 1);
	return -ENOMEM;
}

/* Unregister v4l2 devices */
void cx18_streams_cleanup(struct cx18 *cx, int unregister)
{
	struct video_device *vdev;
	int type;

	/* Teardown all streams */
	for (type = 0; type < CX18_MAX_STREAMS; type++) {
		if (cx->streams[type].dvb.enabled) {
			cx18_dvb_unregister(&cx->streams[type]);
			cx->streams[type].dvb.enabled = false;
		}

		vdev = cx->streams[type].v4l2dev;

		cx->streams[type].v4l2dev = NULL;
		if (vdev == NULL)
			continue;

		cx18_stream_free(&cx->streams[type]);

		/* Unregister or release device */
		if (unregister)
			video_unregister_device(vdev);
		else
			video_device_release(vdev);
	}
}

static void cx18_vbi_setup(struct cx18_stream *s)
{
	struct cx18 *cx = s->cx;
	int raw = cx->vbi.sliced_in->service_set == 0;
	u32 data[CX2341X_MBOX_MAX_DATA];
	int lines;

	if (cx->is_60hz) {
		cx->vbi.count = 12;
		cx->vbi.start[0] = 10;
		cx->vbi.start[1] = 273;
	} else {        /* PAL/SECAM */
		cx->vbi.count = 18;
		cx->vbi.start[0] = 6;
		cx->vbi.start[1] = 318;
	}

	/* setup VBI registers */
	cx18_av_cmd(cx, VIDIOC_S_FMT, &cx->vbi.in);

	/* determine number of lines and total number of VBI bytes.
	   A raw line takes 1443 bytes: 2 * 720 + 4 byte frame header - 1
	   The '- 1' byte is probably an unused U or V byte. Or something...
	   A sliced line takes 51 bytes: 4 byte frame header, 4 byte internal
	   header, 42 data bytes + checksum (to be confirmed) */
	if (raw) {
		lines = cx->vbi.count * 2;
	} else {
		lines = cx->is_60hz ? 24 : 38;
		if (cx->is_60hz)
			lines += 2;
	}

	cx->vbi.enc_size = lines *
		(raw ? cx->vbi.raw_size : cx->vbi.sliced_size);

	data[0] = s->handle;
	/* Lines per field */
	data[1] = (lines / 2) | ((lines / 2) << 16);
	/* bytes per line */
	data[2] = (raw ? cx->vbi.raw_size : cx->vbi.sliced_size);
	/* Every X number of frames a VBI interrupt arrives
	   (frames as in 25 or 30 fps) */
	data[3] = 1;
	/* Setup VBI for the cx25840 digitizer */
	if (raw) {
		data[4] = 0x20602060;
		data[5] = 0x30703070;
	} else {
		data[4] = 0xB0F0B0F0;
		data[5] = 0xA0E0A0E0;
	}

	CX18_DEBUG_INFO("Setup VBI h: %d lines %x bpl %d fr %d %x %x\n",
			data[0], data[1], data[2], data[3], data[4], data[5]);

	if (s->type == CX18_ENC_STREAM_TYPE_VBI)
		cx18_api(cx, CX18_CPU_SET_RAW_VBI_PARAM, 6, data);
}

int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
{
	u32 data[MAX_MB_ARGUMENTS];
	struct cx18 *cx = s->cx;
	struct list_head *p;
	int ts = 0;
	int captype = 0;

	if (s->v4l2dev == NULL && s->dvb.enabled == 0)
		return -EINVAL;

	CX18_DEBUG_INFO("Start encoder stream %s\n", s->name);

	switch (s->type) {
	case CX18_ENC_STREAM_TYPE_MPG:
		captype = CAPTURE_CHANNEL_TYPE_MPEG;
		cx->mpg_data_received = cx->vbi_data_inserted = 0;
		cx->dualwatch_jiffies = jiffies;
		cx->dualwatch_stereo_mode = cx->params.audio_properties & 0x300;
		cx->search_pack_header = 0;
		break;

	case CX18_ENC_STREAM_TYPE_TS:
		captype = CAPTURE_CHANNEL_TYPE_TS;
		ts = 1;
		break;
	case CX18_ENC_STREAM_TYPE_YUV:
		captype = CAPTURE_CHANNEL_TYPE_YUV;
		break;
	case CX18_ENC_STREAM_TYPE_PCM:
		captype = CAPTURE_CHANNEL_TYPE_PCM;
		break;
	case CX18_ENC_STREAM_TYPE_VBI:
		captype = cx->vbi.sliced_in->service_set ?
		    CAPTURE_CHANNEL_TYPE_SLICED_VBI : CAPTURE_CHANNEL_TYPE_VBI;
		cx->vbi.frame = 0;
		cx->vbi.inserted_frame = 0;
		memset(cx->vbi.sliced_mpeg_size,
			0, sizeof(cx->vbi.sliced_mpeg_size));
		break;
	default:
		return -EINVAL;
	}

	/* mute/unmute video */
	cx18_vapi(cx, CX18_CPU_SET_VIDEO_MUTE, 2,
		  s->handle, !!test_bit(CX18_F_I_RADIO_USER, &cx->i_flags));

	/* Clear Streamoff flags in case left from last capture */
	clear_bit(CX18_F_S_STREAMOFF, &s->s_flags);

	cx18_vapi_result(cx, data, CX18_CREATE_TASK, 1, CPU_CMD_MASK_CAPTURE);
	s->handle = data[0];
	cx18_vapi(cx, CX18_CPU_SET_CHANNEL_TYPE, 2, s->handle, captype);

	if (atomic_read(&cx->ana_capturing) == 0 && !ts) {
		/* Stuff from Windows, we don't know what it is */
		cx18_vapi(cx, CX18_CPU_SET_VER_CROP_LINE, 2, s->handle, 0);
		cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 3, 1);
		cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 8, 0);
		cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 4, 1);
		cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 2, s->handle, 12);

		cx18_vapi(cx, CX18_CPU_SET_CAPTURE_LINE_NO, 3,
			       s->handle, cx->digitizer, cx->digitizer);

		/* Setup VBI */
		if (cx->v4l2_cap & V4L2_CAP_VBI_CAPTURE)
			cx18_vbi_setup(s);

		/* assign program index info.
		   Mask 7: select I/P/B, Num_req: 400 max */
		cx18_vapi_result(cx, data, CX18_CPU_SET_INDEXTABLE, 1, 0);

		/* Setup API for Stream */
		cx2341x_update(cx, cx18_api_func, NULL, &cx->params);
	}

	if (atomic_read(&cx->tot_capturing) == 0) {
		clear_bit(CX18_F_I_EOS, &cx->i_flags);
		cx18_write_reg(cx, 7, CX18_DSP0_INTERRUPT_MASK);
	}

	cx18_vapi(cx, CX18_CPU_DE_SET_MDL_ACK, 3, s->handle,
		(void __iomem *)&cx->scb->cpu_mdl_ack[s->type][0] - cx->enc_mem,
		(void __iomem *)&cx->scb->cpu_mdl_ack[s->type][1] - cx->enc_mem);

	list_for_each(p, &s->q_free.list) {
		struct cx18_buffer *buf = list_entry(p, struct cx18_buffer, list);

		cx18_writel(cx, buf->dma_handle,
					&cx->scb->cpu_mdl[buf->id].paddr);
		cx18_writel(cx, s->buf_size, &cx->scb->cpu_mdl[buf->id].length);
		cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5, s->handle,
			(void __iomem *)&cx->scb->cpu_mdl[buf->id] - cx->enc_mem,
			1, buf->id, s->buf_size);
	}
	/* begin_capture */
	if (cx18_vapi(cx, CX18_CPU_CAPTURE_START, 1, s->handle)) {
		CX18_DEBUG_WARN("Error starting capture!\n");
		/* Ensure we're really not capturing before releasing MDLs */
		if (s->type == CX18_ENC_STREAM_TYPE_MPG)
			cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, 1);
		else
			cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 1, s->handle);
		cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle);
		cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
		/* FIXME - clean-up DSP0_INT mask, i_flags, s_flags, etc. */
		return -EINVAL;
	}

	/* you're live! sit back and await interrupts :) */
	if (!ts)
		atomic_inc(&cx->ana_capturing);
	atomic_inc(&cx->tot_capturing);
	return 0;
}

void cx18_stop_all_captures(struct cx18 *cx)
{
	int i;

	for (i = CX18_MAX_STREAMS - 1; i >= 0; i--) {
		struct cx18_stream *s = &cx->streams[i];

		if (s->v4l2dev == NULL && s->dvb.enabled == 0)
			continue;
		if (test_bit(CX18_F_S_STREAMING, &s->s_flags))
			cx18_stop_v4l2_encode_stream(s, 0);
	}
}

int cx18_stop_v4l2_encode_stream(struct cx18_stream *s, int gop_end)
{
	struct cx18 *cx = s->cx;
	unsigned long then;

	if (s->v4l2dev == NULL && s->dvb.enabled == 0)
		return -EINVAL;

	/* This function assumes that you are allowed to stop the capture
	   and that we are actually capturing */

	CX18_DEBUG_INFO("Stop Capture\n");

	if (atomic_read(&cx->tot_capturing) == 0)
		return 0;

	if (s->type == CX18_ENC_STREAM_TYPE_MPG)
		cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, !gop_end);
	else
		cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 1, s->handle);

	then = jiffies;

	if (s->type == CX18_ENC_STREAM_TYPE_MPG && gop_end) {
		CX18_INFO("ignoring gop_end: not (yet?) supported by the firmware\n");
	}

	/* Tell the CX23418 it can't use our buffers anymore */
	cx18_vapi(cx, CX18_CPU_DE_RELEASE_MDL, 1, s->handle);

	if (s->type != CX18_ENC_STREAM_TYPE_TS)
		atomic_dec(&cx->ana_capturing);
	atomic_dec(&cx->tot_capturing);

	/* Clear capture and no-read bits */
	clear_bit(CX18_F_S_STREAMING, &s->s_flags);

	cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
	s->handle = CX18_INVALID_TASK_HANDLE;

	if (atomic_read(&cx->tot_capturing) > 0)
		return 0;

	cx18_write_reg(cx, 5, CX18_DSP0_INTERRUPT_MASK);
	wake_up(&s->waitq);

	return 0;
}

u32 cx18_find_handle(struct cx18 *cx)
{
	int i;

	/* find first available handle to be used for global settings */
	for (i = 0; i < CX18_MAX_STREAMS; i++) {
		struct cx18_stream *s = &cx->streams[i];

		if (s->v4l2dev && (s->handle != CX18_INVALID_TASK_HANDLE))
			return s->handle;
	}
	return CX18_INVALID_TASK_HANDLE;
}