blob: 1b921a33609226afb08a569caefc230d8cfe5df9 [file] [log] [blame]
Hans Verkuil1c1e45d2008-04-28 20:24:33 -03001/*
2 * cx18 init/start/stop/exit stream functions
3 *
4 * Derived from ivtv-streams.c
5 *
6 * Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21 * 02111-1307 USA
22 */
23
24#include "cx18-driver.h"
25#include "cx18-fileops.h"
26#include "cx18-mailbox.h"
27#include "cx18-i2c.h"
28#include "cx18-queue.h"
29#include "cx18-ioctl.h"
30#include "cx18-streams.h"
31#include "cx18-cards.h"
32#include "cx18-scb.h"
33#include "cx18-av-core.h"
34#include "cx18-dvb.h"
35
36#define CX18_DSP0_INTERRUPT_MASK 0xd0004C
37
38static struct file_operations cx18_v4l2_enc_fops = {
Hans Verkuildaf20d92008-05-12 11:21:58 -030039 .owner = THIS_MODULE,
40 .read = cx18_v4l2_read,
41 .open = cx18_v4l2_open,
42 .ioctl = cx18_v4l2_ioctl,
43 .compat_ioctl = v4l_compat_ioctl32,
44 .release = cx18_v4l2_close,
45 .poll = cx18_v4l2_enc_poll,
Hans Verkuil1c1e45d2008-04-28 20:24:33 -030046};
47
48/* offset from 0 to register ts v4l2 minors on */
49#define CX18_V4L2_ENC_TS_OFFSET 16
50/* offset from 0 to register pcm v4l2 minors on */
51#define CX18_V4L2_ENC_PCM_OFFSET 24
52/* offset from 0 to register yuv v4l2 minors on */
53#define CX18_V4L2_ENC_YUV_OFFSET 32
54
55static struct {
56 const char *name;
57 int vfl_type;
58 int minor_offset;
59 int dma;
60 enum v4l2_buf_type buf_type;
61 struct file_operations *fops;
62} cx18_stream_info[] = {
63 { /* CX18_ENC_STREAM_TYPE_MPG */
64 "encoder MPEG",
65 VFL_TYPE_GRABBER, 0,
66 PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE,
67 &cx18_v4l2_enc_fops
68 },
69 { /* CX18_ENC_STREAM_TYPE_TS */
70 "TS",
71 VFL_TYPE_GRABBER, -1,
72 PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE,
73 &cx18_v4l2_enc_fops
74 },
75 { /* CX18_ENC_STREAM_TYPE_YUV */
76 "encoder YUV",
77 VFL_TYPE_GRABBER, CX18_V4L2_ENC_YUV_OFFSET,
78 PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE,
79 &cx18_v4l2_enc_fops
80 },
81 { /* CX18_ENC_STREAM_TYPE_VBI */
82 "encoder VBI",
83 VFL_TYPE_VBI, 0,
84 PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VBI_CAPTURE,
85 &cx18_v4l2_enc_fops
86 },
87 { /* CX18_ENC_STREAM_TYPE_PCM */
88 "encoder PCM audio",
89 VFL_TYPE_GRABBER, CX18_V4L2_ENC_PCM_OFFSET,
90 PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_PRIVATE,
91 &cx18_v4l2_enc_fops
92 },
93 { /* CX18_ENC_STREAM_TYPE_IDX */
94 "encoder IDX",
95 VFL_TYPE_GRABBER, -1,
96 PCI_DMA_FROMDEVICE, V4L2_BUF_TYPE_VIDEO_CAPTURE,
97 &cx18_v4l2_enc_fops
98 },
99 { /* CX18_ENC_STREAM_TYPE_RAD */
100 "encoder radio",
101 VFL_TYPE_RADIO, 0,
102 PCI_DMA_NONE, V4L2_BUF_TYPE_PRIVATE,
103 &cx18_v4l2_enc_fops
104 },
105};
106
107static void cx18_stream_init(struct cx18 *cx, int type)
108{
109 struct cx18_stream *s = &cx->streams[type];
110 struct video_device *dev = s->v4l2dev;
111 u32 max_size = cx->options.megabytes[type] * 1024 * 1024;
112
113 /* we need to keep v4l2dev, so restore it afterwards */
114 memset(s, 0, sizeof(*s));
115 s->v4l2dev = dev;
116
117 /* initialize cx18_stream fields */
118 s->cx = cx;
119 s->type = type;
120 s->name = cx18_stream_info[type].name;
121 s->handle = 0xffffffff;
122
123 s->dma = cx18_stream_info[type].dma;
124 s->buf_size = cx->stream_buf_size[type];
125 if (s->buf_size)
126 s->buffers = max_size / s->buf_size;
127 if (s->buffers > 63) {
128 /* Each stream has a maximum of 63 buffers,
129 ensure we do not exceed that. */
130 s->buffers = 63;
131 s->buf_size = (max_size / s->buffers) & ~0xfff;
132 }
133 spin_lock_init(&s->qlock);
134 init_waitqueue_head(&s->waitq);
135 s->id = -1;
136 cx18_queue_init(&s->q_free);
137 cx18_queue_init(&s->q_full);
138 cx18_queue_init(&s->q_io);
139}
140
141static int cx18_prep_dev(struct cx18 *cx, int type)
142{
143 struct cx18_stream *s = &cx->streams[type];
144 u32 cap = cx->v4l2_cap;
145 int minor_offset = cx18_stream_info[type].minor_offset;
146 int minor;
147
148 /* These four fields are always initialized. If v4l2dev == NULL, then
149 this stream is not in use. In that case no other fields but these
150 four can be used. */
151 s->v4l2dev = NULL;
152 s->cx = cx;
153 s->type = type;
154 s->name = cx18_stream_info[type].name;
155
156 /* Check whether the radio is supported */
157 if (type == CX18_ENC_STREAM_TYPE_RAD && !(cap & V4L2_CAP_RADIO))
158 return 0;
159
160 /* Check whether VBI is supported */
161 if (type == CX18_ENC_STREAM_TYPE_VBI &&
162 !(cap & (V4L2_CAP_VBI_CAPTURE | V4L2_CAP_SLICED_VBI_CAPTURE)))
163 return 0;
164
165 /* card number + user defined offset + device offset */
166 minor = cx->num + cx18_first_minor + minor_offset;
167
168 /* User explicitly selected 0 buffers for these streams, so don't
169 create them. */
170 if (cx18_stream_info[type].dma != PCI_DMA_NONE &&
171 cx->options.megabytes[type] == 0) {
172 CX18_INFO("Disabled %s device\n", cx18_stream_info[type].name);
173 return 0;
174 }
175
176 cx18_stream_init(cx, type);
177
178 if (minor_offset == -1)
179 return 0;
180
181 /* allocate and initialize the v4l2 video device structure */
182 s->v4l2dev = video_device_alloc();
183 if (s->v4l2dev == NULL) {
184 CX18_ERR("Couldn't allocate v4l2 video_device for %s\n",
185 s->name);
186 return -ENOMEM;
187 }
188
189 s->v4l2dev->type =
190 VID_TYPE_CAPTURE | VID_TYPE_TUNER | VID_TYPE_TELETEXT |
191 VID_TYPE_CLIPPING | VID_TYPE_SCALES | VID_TYPE_MPEG_ENCODER;
192 snprintf(s->v4l2dev->name, sizeof(s->v4l2dev->name), "cx18%d %s",
193 cx->num, s->name);
194
195 s->v4l2dev->minor = minor;
196 s->v4l2dev->dev = &cx->dev->dev;
197 s->v4l2dev->fops = cx18_stream_info[type].fops;
198 s->v4l2dev->release = video_device_release;
199
200 return 0;
201}
202
203/* Initialize v4l2 variables and register v4l2 devices */
204int cx18_streams_setup(struct cx18 *cx)
205{
206 int type;
207
208 /* Setup V4L2 Devices */
209 for (type = 0; type < CX18_MAX_STREAMS; type++) {
210 /* Prepare device */
211 if (cx18_prep_dev(cx, type))
212 break;
213
214 /* Allocate Stream */
215 if (cx18_stream_alloc(&cx->streams[type]))
216 break;
217 }
218 if (type == CX18_MAX_STREAMS)
219 return 0;
220
221 /* One or more streams could not be initialized. Clean 'em all up. */
Hans Verkuil3f983872008-05-01 10:31:12 -0300222 cx18_streams_cleanup(cx, 0);
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300223 return -ENOMEM;
224}
225
226static int cx18_reg_dev(struct cx18 *cx, int type)
227{
228 struct cx18_stream *s = &cx->streams[type];
229 int vfl_type = cx18_stream_info[type].vfl_type;
230 int minor;
231
232 /* TODO: Shouldn't this be a VFL_TYPE_TRANSPORT or something?
233 * We need a VFL_TYPE_TS defined.
234 */
235 if (strcmp("TS", s->name) == 0) {
236 /* just return if no DVB is supported */
237 if ((cx->card->hw_all & CX18_HW_DVB) == 0)
238 return 0;
239 if (cx18_dvb_register(s) < 0) {
240 CX18_ERR("DVB failed to register\n");
241 return -EINVAL;
242 }
243 }
244
245 if (s->v4l2dev == NULL)
246 return 0;
247
248 minor = s->v4l2dev->minor;
249
250 /* Register device. First try the desired minor, then any free one. */
251 if (video_register_device(s->v4l2dev, vfl_type, minor) &&
252 video_register_device(s->v4l2dev, vfl_type, -1)) {
253 CX18_ERR("Couldn't register v4l2 device for %s minor %d\n",
254 s->name, minor);
255 video_device_release(s->v4l2dev);
256 s->v4l2dev = NULL;
257 return -ENOMEM;
258 }
259 minor = s->v4l2dev->minor;
260
261 switch (vfl_type) {
262 case VFL_TYPE_GRABBER:
263 CX18_INFO("Registered device video%d for %s (%d MB)\n",
264 minor, s->name, cx->options.megabytes[type]);
265 break;
266
267 case VFL_TYPE_RADIO:
268 CX18_INFO("Registered device radio%d for %s\n",
269 minor - MINOR_VFL_TYPE_RADIO_MIN, s->name);
270 break;
271
272 case VFL_TYPE_VBI:
273 if (cx->options.megabytes[type])
274 CX18_INFO("Registered device vbi%d for %s (%d MB)\n",
275 minor - MINOR_VFL_TYPE_VBI_MIN,
276 s->name, cx->options.megabytes[type]);
277 else
278 CX18_INFO("Registered device vbi%d for %s\n",
279 minor - MINOR_VFL_TYPE_VBI_MIN, s->name);
280 break;
281 }
282
283 return 0;
284}
285
286/* Register v4l2 devices */
287int cx18_streams_register(struct cx18 *cx)
288{
289 int type;
290 int err = 0;
291
292 /* Register V4L2 devices */
293 for (type = 0; type < CX18_MAX_STREAMS; type++)
294 err |= cx18_reg_dev(cx, type);
295
296 if (err == 0)
297 return 0;
298
299 /* One or more streams could not be initialized. Clean 'em all up. */
Hans Verkuil3f983872008-05-01 10:31:12 -0300300 cx18_streams_cleanup(cx, 1);
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300301 return -ENOMEM;
302}
303
304/* Unregister v4l2 devices */
Hans Verkuil3f983872008-05-01 10:31:12 -0300305void cx18_streams_cleanup(struct cx18 *cx, int unregister)
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300306{
307 struct video_device *vdev;
308 int type;
309
310 /* Teardown all streams */
311 for (type = 0; type < CX18_MAX_STREAMS; type++) {
312 if (cx->streams[type].dvb.enabled)
313 cx18_dvb_unregister(&cx->streams[type]);
314
315 vdev = cx->streams[type].v4l2dev;
316
317 cx->streams[type].v4l2dev = NULL;
318 if (vdev == NULL)
319 continue;
320
321 cx18_stream_free(&cx->streams[type]);
322
Hans Verkuil3f983872008-05-01 10:31:12 -0300323 /* Unregister or release device */
324 if (unregister)
325 video_unregister_device(vdev);
326 else
327 video_device_release(vdev);
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300328 }
329}
330
331static void cx18_vbi_setup(struct cx18_stream *s)
332{
333 struct cx18 *cx = s->cx;
334 int raw = cx->vbi.sliced_in->service_set == 0;
335 u32 data[CX2341X_MBOX_MAX_DATA];
336 int lines;
337
338 if (cx->is_60hz) {
339 cx->vbi.count = 12;
340 cx->vbi.start[0] = 10;
341 cx->vbi.start[1] = 273;
342 } else { /* PAL/SECAM */
343 cx->vbi.count = 18;
344 cx->vbi.start[0] = 6;
345 cx->vbi.start[1] = 318;
346 }
347
348 /* setup VBI registers */
349 cx18_av_cmd(cx, VIDIOC_S_FMT, &cx->vbi.in);
350
351 /* determine number of lines and total number of VBI bytes.
352 A raw line takes 1443 bytes: 2 * 720 + 4 byte frame header - 1
353 The '- 1' byte is probably an unused U or V byte. Or something...
354 A sliced line takes 51 bytes: 4 byte frame header, 4 byte internal
355 header, 42 data bytes + checksum (to be confirmed) */
356 if (raw) {
357 lines = cx->vbi.count * 2;
358 } else {
359 lines = cx->is_60hz ? 24 : 38;
360 if (cx->is_60hz)
361 lines += 2;
362 }
363
364 cx->vbi.enc_size = lines *
365 (raw ? cx->vbi.raw_size : cx->vbi.sliced_size);
366
367 data[0] = s->handle;
368 /* Lines per field */
369 data[1] = (lines / 2) | ((lines / 2) << 16);
370 /* bytes per line */
371 data[2] = (raw ? cx->vbi.raw_size : cx->vbi.sliced_size);
372 /* Every X number of frames a VBI interrupt arrives
373 (frames as in 25 or 30 fps) */
374 data[3] = 1;
375 /* Setup VBI for the cx25840 digitizer */
376 if (raw) {
377 data[4] = 0x20602060;
378 data[5] = 0x30703070;
379 } else {
380 data[4] = 0xB0F0B0F0;
381 data[5] = 0xA0E0A0E0;
382 }
383
384 CX18_DEBUG_INFO("Setup VBI h: %d lines %x bpl %d fr %d %x %x\n",
385 data[0], data[1], data[2], data[3], data[4], data[5]);
386
387 if (s->type == CX18_ENC_STREAM_TYPE_VBI)
388 cx18_api(cx, CX18_CPU_SET_RAW_VBI_PARAM, 6, data);
389}
390
391int cx18_start_v4l2_encode_stream(struct cx18_stream *s)
392{
393 u32 data[MAX_MB_ARGUMENTS];
394 struct cx18 *cx = s->cx;
395 struct list_head *p;
396 int ts = 0;
397 int captype = 0;
398
399 if (s->v4l2dev == NULL && s->dvb.enabled == 0)
400 return -EINVAL;
401
402 CX18_DEBUG_INFO("Start encoder stream %s\n", s->name);
403
404 switch (s->type) {
405 case CX18_ENC_STREAM_TYPE_MPG:
406 captype = CAPTURE_CHANNEL_TYPE_MPEG;
407 cx->mpg_data_received = cx->vbi_data_inserted = 0;
408 cx->dualwatch_jiffies = jiffies;
409 cx->dualwatch_stereo_mode = cx->params.audio_properties & 0x300;
410 cx->search_pack_header = 0;
411 break;
412
413 case CX18_ENC_STREAM_TYPE_TS:
414 captype = CAPTURE_CHANNEL_TYPE_TS;
415 ts = 1;
416 break;
417 case CX18_ENC_STREAM_TYPE_YUV:
418 captype = CAPTURE_CHANNEL_TYPE_YUV;
419 break;
420 case CX18_ENC_STREAM_TYPE_PCM:
421 captype = CAPTURE_CHANNEL_TYPE_PCM;
422 break;
423 case CX18_ENC_STREAM_TYPE_VBI:
424 captype = cx->vbi.sliced_in->service_set ?
425 CAPTURE_CHANNEL_TYPE_SLICED_VBI : CAPTURE_CHANNEL_TYPE_VBI;
426 cx->vbi.frame = 0;
427 cx->vbi.inserted_frame = 0;
428 memset(cx->vbi.sliced_mpeg_size,
429 0, sizeof(cx->vbi.sliced_mpeg_size));
430 break;
431 default:
432 return -EINVAL;
433 }
434 s->buffers_stolen = 0;
435
436 /* mute/unmute video */
437 cx18_vapi(cx, CX18_CPU_SET_VIDEO_MUTE, 2,
438 s->handle, !!test_bit(CX18_F_I_RADIO_USER, &cx->i_flags));
439
440 /* Clear Streamoff flags in case left from last capture */
441 clear_bit(CX18_F_S_STREAMOFF, &s->s_flags);
442
443 cx18_vapi_result(cx, data, CX18_CREATE_TASK, 1, CPU_CMD_MASK_CAPTURE);
444 s->handle = data[0];
445 cx18_vapi(cx, CX18_CPU_SET_CHANNEL_TYPE, 2, s->handle, captype);
446
Hans Verkuil31554ae2008-05-25 11:21:27 -0300447 if (atomic_read(&cx->ana_capturing) == 0 && !ts) {
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300448 /* Stuff from Windows, we don't know what it is */
449 cx18_vapi(cx, CX18_CPU_SET_VER_CROP_LINE, 2, s->handle, 0);
450 cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 3, 1);
451 cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 8, 0);
452 cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 3, s->handle, 4, 1);
453 cx18_vapi(cx, CX18_CPU_SET_MISC_PARAMETERS, 2, s->handle, 12);
454
455 cx18_vapi(cx, CX18_CPU_SET_CAPTURE_LINE_NO, 3,
456 s->handle, cx->digitizer, cx->digitizer);
457
458 /* Setup VBI */
459 if (cx->v4l2_cap & V4L2_CAP_VBI_CAPTURE)
460 cx18_vbi_setup(s);
461
462 /* assign program index info.
463 Mask 7: select I/P/B, Num_req: 400 max */
464 cx18_vapi_result(cx, data, CX18_CPU_SET_INDEXTABLE, 1, 0);
465
466 /* Setup API for Stream */
467 cx2341x_update(cx, cx18_api_func, NULL, &cx->params);
468 }
469
Hans Verkuil31554ae2008-05-25 11:21:27 -0300470 if (atomic_read(&cx->tot_capturing) == 0) {
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300471 clear_bit(CX18_F_I_EOS, &cx->i_flags);
472 write_reg(7, CX18_DSP0_INTERRUPT_MASK);
473 }
474
475 cx18_vapi(cx, CX18_CPU_DE_SET_MDL_ACK, 3, s->handle,
Al Viro990c81c2008-05-21 00:32:01 -0300476 (void __iomem *)&cx->scb->cpu_mdl_ack[s->type][0] - cx->enc_mem,
477 (void __iomem *)&cx->scb->cpu_mdl_ack[s->type][1] - cx->enc_mem);
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300478
479 list_for_each(p, &s->q_free.list) {
480 struct cx18_buffer *buf = list_entry(p, struct cx18_buffer, list);
481
482 writel(buf->dma_handle, &cx->scb->cpu_mdl[buf->id].paddr);
483 writel(s->buf_size, &cx->scb->cpu_mdl[buf->id].length);
484 cx18_vapi(cx, CX18_CPU_DE_SET_MDL, 5, s->handle,
Al Viro990c81c2008-05-21 00:32:01 -0300485 (void __iomem *)&cx->scb->cpu_mdl[buf->id] - cx->enc_mem,
486 1, buf->id, s->buf_size);
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300487 }
488 /* begin_capture */
489 if (cx18_vapi(cx, CX18_CPU_CAPTURE_START, 1, s->handle)) {
490 CX18_DEBUG_WARN("Error starting capture!\n");
491 cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
492 return -EINVAL;
493 }
494
495 /* you're live! sit back and await interrupts :) */
Hans Verkuil31554ae2008-05-25 11:21:27 -0300496 if (!ts)
497 atomic_inc(&cx->ana_capturing);
498 atomic_inc(&cx->tot_capturing);
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300499 return 0;
500}
501
502void cx18_stop_all_captures(struct cx18 *cx)
503{
504 int i;
505
506 for (i = CX18_MAX_STREAMS - 1; i >= 0; i--) {
507 struct cx18_stream *s = &cx->streams[i];
508
509 if (s->v4l2dev == NULL && s->dvb.enabled == 0)
510 continue;
511 if (test_bit(CX18_F_S_STREAMING, &s->s_flags))
512 cx18_stop_v4l2_encode_stream(s, 0);
513 }
514}
515
516int cx18_stop_v4l2_encode_stream(struct cx18_stream *s, int gop_end)
517{
518 struct cx18 *cx = s->cx;
519 unsigned long then;
520
521 if (s->v4l2dev == NULL && s->dvb.enabled == 0)
522 return -EINVAL;
523
524 /* This function assumes that you are allowed to stop the capture
525 and that we are actually capturing */
526
527 CX18_DEBUG_INFO("Stop Capture\n");
528
Hans Verkuil31554ae2008-05-25 11:21:27 -0300529 if (atomic_read(&cx->tot_capturing) == 0)
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300530 return 0;
531
532 if (s->type == CX18_ENC_STREAM_TYPE_MPG)
533 cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 2, s->handle, !gop_end);
534 else
535 cx18_vapi(cx, CX18_CPU_CAPTURE_STOP, 1, s->handle);
536
537 then = jiffies;
538
539 if (s->type == CX18_ENC_STREAM_TYPE_MPG && gop_end) {
540 CX18_INFO("ignoring gop_end: not (yet?) supported by the firmware\n");
541 }
542
Hans Verkuil31554ae2008-05-25 11:21:27 -0300543 if (s->type != CX18_ENC_STREAM_TYPE_TS)
544 atomic_dec(&cx->ana_capturing);
545 atomic_dec(&cx->tot_capturing);
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300546
547 /* Clear capture and no-read bits */
548 clear_bit(CX18_F_S_STREAMING, &s->s_flags);
549
550 cx18_vapi(cx, CX18_DESTROY_TASK, 1, s->handle);
551 s->handle = 0xffffffff;
552
Hans Verkuil31554ae2008-05-25 11:21:27 -0300553 if (atomic_read(&cx->tot_capturing) > 0)
Hans Verkuil1c1e45d2008-04-28 20:24:33 -0300554 return 0;
555
556 write_reg(5, CX18_DSP0_INTERRUPT_MASK);
557 wake_up(&s->waitq);
558
559 return 0;
560}
561
562u32 cx18_find_handle(struct cx18 *cx)
563{
564 int i;
565
566 /* find first available handle to be used for global settings */
567 for (i = 0; i < CX18_MAX_STREAMS; i++) {
568 struct cx18_stream *s = &cx->streams[i];
569
570 if (s->v4l2dev && s->handle)
571 return s->handle;
572 }
573 return 0;
574}