1/*
2   cx231xx_vbi.c - driver for Conexant Cx23100/101/102 USB video capture devices
3
4   Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
5	Based on cx88 driver
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 2 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software
19   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include "cx231xx.h"
23#include <linux/init.h>
24#include <linux/list.h>
25#include <linux/module.h>
26#include <linux/kernel.h>
27#include <linux/bitmap.h>
28#include <linux/i2c.h>
29#include <linux/mm.h>
30#include <linux/mutex.h>
31#include <linux/slab.h>
32
33#include <media/v4l2-common.h>
34#include <media/v4l2-ioctl.h>
35#include <media/msp3400.h>
36#include <media/tuner.h>
37
38#include "cx231xx-vbi.h"
39
40static inline void print_err_status(struct cx231xx *dev, int packet, int status)
41{
42	char *errmsg = "Unknown";
43
44	switch (status) {
45	case -ENOENT:
46		errmsg = "unlinked synchronuously";
47		break;
48	case -ECONNRESET:
49		errmsg = "unlinked asynchronuously";
50		break;
51	case -ENOSR:
52		errmsg = "Buffer error (overrun)";
53		break;
54	case -EPIPE:
55		errmsg = "Stalled (device not responding)";
56		break;
57	case -EOVERFLOW:
58		errmsg = "Babble (bad cable?)";
59		break;
60	case -EPROTO:
61		errmsg = "Bit-stuff error (bad cable?)";
62		break;
63	case -EILSEQ:
64		errmsg = "CRC/Timeout (could be anything)";
65		break;
66	case -ETIME:
67		errmsg = "Device does not respond";
68		break;
69	}
70	if (packet < 0) {
71		dev_err(dev->dev,
72			"URB status %d [%s].\n", status, errmsg);
73	} else {
74		dev_err(dev->dev,
75			"URB packet %d, status %d [%s].\n",
76			packet, status, errmsg);
77	}
78}
79
80/*
81 * Controls the isoc copy of each urb packet
82 */
83static inline int cx231xx_isoc_vbi_copy(struct cx231xx *dev, struct urb *urb)
84{
85	struct cx231xx_dmaqueue *dma_q = urb->context;
86	int rc = 1;
87	unsigned char *p_buffer;
88	u32 bytes_parsed = 0, buffer_size = 0;
89	u8 sav_eav = 0;
90
91	if (!dev)
92		return 0;
93
94	if (dev->state & DEV_DISCONNECTED)
95		return 0;
96
97	if (urb->status < 0) {
98		print_err_status(dev, -1, urb->status);
99		if (urb->status == -ENOENT)
100			return 0;
101	}
102
103	/* get buffer pointer and length */
104	p_buffer = urb->transfer_buffer;
105	buffer_size = urb->actual_length;
106
107	if (buffer_size > 0) {
108		bytes_parsed = 0;
109
110		if (dma_q->is_partial_line) {
111			/* Handle the case where we were working on a partial
112			   line */
113			sav_eav = dma_q->last_sav;
114		} else {
115			/* Check for a SAV/EAV overlapping the
116			   buffer boundary */
117
118			sav_eav = cx231xx_find_boundary_SAV_EAV(p_buffer,
119							  dma_q->partial_buf,
120							  &bytes_parsed);
121		}
122
123		sav_eav &= 0xF0;
124		/* Get the first line if we have some portion of an SAV/EAV from
125		   the last buffer or a partial line */
126		if (sav_eav) {
127			bytes_parsed += cx231xx_get_vbi_line(dev, dma_q,
128				sav_eav,		       /* SAV/EAV */
129				p_buffer + bytes_parsed,       /* p_buffer */
130				buffer_size - bytes_parsed);   /* buffer size */
131		}
132
133		/* Now parse data that is completely in this buffer */
134		dma_q->is_partial_line = 0;
135
136		while (bytes_parsed < buffer_size) {
137			u32 bytes_used = 0;
138
139			sav_eav = cx231xx_find_next_SAV_EAV(
140				p_buffer + bytes_parsed,	/* p_buffer */
141				buffer_size - bytes_parsed, /* buffer size */
142				&bytes_used);	/* bytes used to get SAV/EAV */
143
144			bytes_parsed += bytes_used;
145
146			sav_eav &= 0xF0;
147			if (sav_eav && (bytes_parsed < buffer_size)) {
148				bytes_parsed += cx231xx_get_vbi_line(dev,
149					dma_q, sav_eav,	/* SAV/EAV */
150					p_buffer+bytes_parsed, /* p_buffer */
151					buffer_size-bytes_parsed);/*buf size*/
152			}
153		}
154
155		/* Save the last four bytes of the buffer so we can
156		check the buffer boundary condition next time */
157		memcpy(dma_q->partial_buf, p_buffer + buffer_size - 4, 4);
158		bytes_parsed = 0;
159	}
160
161	return rc;
162}
163
164/* ------------------------------------------------------------------
165	Vbi buf operations
166   ------------------------------------------------------------------*/
167
168static int
169vbi_buffer_setup(struct videobuf_queue *vq, unsigned int *count,
170		 unsigned int *size)
171{
172	struct cx231xx_fh *fh = vq->priv_data;
173	struct cx231xx *dev = fh->dev;
174	u32 height = 0;
175
176	height = ((dev->norm & V4L2_STD_625_50) ?
177		  PAL_VBI_LINES : NTSC_VBI_LINES);
178
179	*size = (dev->width * height * 2 * 2);
180	if (0 == *count)
181		*count = CX231XX_DEF_VBI_BUF;
182
183	if (*count < CX231XX_MIN_BUF)
184		*count = CX231XX_MIN_BUF;
185
186	return 0;
187}
188
189/* This is called *without* dev->slock held; please keep it that way */
190static void free_buffer(struct videobuf_queue *vq, struct cx231xx_buffer *buf)
191{
192	struct cx231xx_fh *fh = vq->priv_data;
193	struct cx231xx *dev = fh->dev;
194	unsigned long flags = 0;
195	if (in_interrupt())
196		BUG();
197
198	/* We used to wait for the buffer to finish here, but this didn't work
199	   because, as we were keeping the state as VIDEOBUF_QUEUED,
200	   videobuf_queue_cancel marked it as finished for us.
201	   (Also, it could wedge forever if the hardware was misconfigured.)
202
203	   This should be safe; by the time we get here, the buffer isn't
204	   queued anymore. If we ever start marking the buffers as
205	   VIDEOBUF_ACTIVE, it won't be, though.
206	 */
207	spin_lock_irqsave(&dev->vbi_mode.slock, flags);
208	if (dev->vbi_mode.bulk_ctl.buf == buf)
209		dev->vbi_mode.bulk_ctl.buf = NULL;
210	spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);
211
212	videobuf_vmalloc_free(&buf->vb);
213	buf->vb.state = VIDEOBUF_NEEDS_INIT;
214}
215
216static int
217vbi_buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
218		   enum v4l2_field field)
219{
220	struct cx231xx_fh *fh = vq->priv_data;
221	struct cx231xx_buffer *buf =
222	    container_of(vb, struct cx231xx_buffer, vb);
223	struct cx231xx *dev = fh->dev;
224	int rc = 0, urb_init = 0;
225	u32 height = 0;
226
227	height = ((dev->norm & V4L2_STD_625_50) ?
228		  PAL_VBI_LINES : NTSC_VBI_LINES);
229	buf->vb.size = ((dev->width << 1) * height * 2);
230
231	if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size)
232		return -EINVAL;
233
234	buf->vb.width = dev->width;
235	buf->vb.height = height;
236	buf->vb.field = field;
237	buf->vb.field = V4L2_FIELD_SEQ_TB;
238
239	if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
240		rc = videobuf_iolock(vq, &buf->vb, NULL);
241		if (rc < 0)
242			goto fail;
243	}
244
245	if (!dev->vbi_mode.bulk_ctl.num_bufs)
246		urb_init = 1;
247
248	if (urb_init) {
249		rc = cx231xx_init_vbi_isoc(dev, CX231XX_NUM_VBI_PACKETS,
250					   CX231XX_NUM_VBI_BUFS,
251					   dev->vbi_mode.alt_max_pkt_size[0],
252					   cx231xx_isoc_vbi_copy);
253		if (rc < 0)
254			goto fail;
255	}
256
257	buf->vb.state = VIDEOBUF_PREPARED;
258	return 0;
259
260fail:
261	free_buffer(vq, buf);
262	return rc;
263}
264
265static void
266vbi_buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
267{
268	struct cx231xx_buffer *buf =
269	    container_of(vb, struct cx231xx_buffer, vb);
270	struct cx231xx_fh *fh = vq->priv_data;
271	struct cx231xx *dev = fh->dev;
272	struct cx231xx_dmaqueue *vidq = &dev->vbi_mode.vidq;
273
274	buf->vb.state = VIDEOBUF_QUEUED;
275	list_add_tail(&buf->vb.queue, &vidq->active);
276
277}
278
279static void vbi_buffer_release(struct videobuf_queue *vq,
280			       struct videobuf_buffer *vb)
281{
282	struct cx231xx_buffer *buf =
283	    container_of(vb, struct cx231xx_buffer, vb);
284
285
286	free_buffer(vq, buf);
287}
288
289struct videobuf_queue_ops cx231xx_vbi_qops = {
290	.buf_setup   = vbi_buffer_setup,
291	.buf_prepare = vbi_buffer_prepare,
292	.buf_queue   = vbi_buffer_queue,
293	.buf_release = vbi_buffer_release,
294};
295
296/* ------------------------------------------------------------------
297	URB control
298   ------------------------------------------------------------------*/
299
300/*
301 * IRQ callback, called by URB callback
302 */
303static void cx231xx_irq_vbi_callback(struct urb *urb)
304{
305	struct cx231xx_dmaqueue *dma_q = urb->context;
306	struct cx231xx_video_mode *vmode =
307	    container_of(dma_q, struct cx231xx_video_mode, vidq);
308	struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
309
310	switch (urb->status) {
311	case 0:		/* success */
312	case -ETIMEDOUT:	/* NAK */
313		break;
314	case -ECONNRESET:	/* kill */
315	case -ENOENT:
316	case -ESHUTDOWN:
317		return;
318	default:		/* error */
319		dev_err(dev->dev,
320			"urb completition error %d.\n",	urb->status);
321		break;
322	}
323
324	/* Copy data from URB */
325	spin_lock(&dev->vbi_mode.slock);
326	dev->vbi_mode.bulk_ctl.bulk_copy(dev, urb);
327	spin_unlock(&dev->vbi_mode.slock);
328
329	/* Reset status */
330	urb->status = 0;
331
332	urb->status = usb_submit_urb(urb, GFP_ATOMIC);
333	if (urb->status) {
334		dev_err(dev->dev, "urb resubmit failed (error=%i)\n",
335			urb->status);
336	}
337}
338
339/*
340 * Stop and Deallocate URBs
341 */
342void cx231xx_uninit_vbi_isoc(struct cx231xx *dev)
343{
344	struct urb *urb;
345	int i;
346
347	dev_dbg(dev->dev, "called cx231xx_uninit_vbi_isoc\n");
348
349	dev->vbi_mode.bulk_ctl.nfields = -1;
350	for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
351		urb = dev->vbi_mode.bulk_ctl.urb[i];
352		if (urb) {
353			if (!irqs_disabled())
354				usb_kill_urb(urb);
355			else
356				usb_unlink_urb(urb);
357
358			if (dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {
359
360				kfree(dev->vbi_mode.bulk_ctl.
361				      transfer_buffer[i]);
362				dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
363				    NULL;
364			}
365			usb_free_urb(urb);
366			dev->vbi_mode.bulk_ctl.urb[i] = NULL;
367		}
368		dev->vbi_mode.bulk_ctl.transfer_buffer[i] = NULL;
369	}
370
371	kfree(dev->vbi_mode.bulk_ctl.urb);
372	kfree(dev->vbi_mode.bulk_ctl.transfer_buffer);
373
374	dev->vbi_mode.bulk_ctl.urb = NULL;
375	dev->vbi_mode.bulk_ctl.transfer_buffer = NULL;
376	dev->vbi_mode.bulk_ctl.num_bufs = 0;
377
378	cx231xx_capture_start(dev, 0, Vbi);
379}
380EXPORT_SYMBOL_GPL(cx231xx_uninit_vbi_isoc);
381
382/*
383 * Allocate URBs and start IRQ
384 */
385int cx231xx_init_vbi_isoc(struct cx231xx *dev, int max_packets,
386			  int num_bufs, int max_pkt_size,
387			  int (*bulk_copy) (struct cx231xx *dev,
388					    struct urb *urb))
389{
390	struct cx231xx_dmaqueue *dma_q = &dev->vbi_mode.vidq;
391	int i;
392	int sb_size, pipe;
393	struct urb *urb;
394	int rc;
395
396	dev_dbg(dev->dev, "called cx231xx_vbi_isoc\n");
397
398	/* De-allocates all pending stuff */
399	cx231xx_uninit_vbi_isoc(dev);
400
401	/* clear if any halt */
402	usb_clear_halt(dev->udev,
403		       usb_rcvbulkpipe(dev->udev,
404				       dev->vbi_mode.end_point_addr));
405
406	dev->vbi_mode.bulk_ctl.bulk_copy = bulk_copy;
407	dev->vbi_mode.bulk_ctl.num_bufs = num_bufs;
408	dma_q->pos = 0;
409	dma_q->is_partial_line = 0;
410	dma_q->last_sav = 0;
411	dma_q->current_field = -1;
412	dma_q->bytes_left_in_line = dev->width << 1;
413	dma_q->lines_per_field = ((dev->norm & V4L2_STD_625_50) ?
414				  PAL_VBI_LINES : NTSC_VBI_LINES);
415	dma_q->lines_completed = 0;
416	for (i = 0; i < 8; i++)
417		dma_q->partial_buf[i] = 0;
418
419	dev->vbi_mode.bulk_ctl.urb = kzalloc(sizeof(void *) * num_bufs,
420					     GFP_KERNEL);
421	if (!dev->vbi_mode.bulk_ctl.urb) {
422		dev_err(dev->dev,
423			"cannot alloc memory for usb buffers\n");
424		return -ENOMEM;
425	}
426
427	dev->vbi_mode.bulk_ctl.transfer_buffer =
428	    kzalloc(sizeof(void *) * num_bufs, GFP_KERNEL);
429	if (!dev->vbi_mode.bulk_ctl.transfer_buffer) {
430		dev_err(dev->dev,
431			"cannot allocate memory for usbtransfer\n");
432		kfree(dev->vbi_mode.bulk_ctl.urb);
433		return -ENOMEM;
434	}
435
436	dev->vbi_mode.bulk_ctl.max_pkt_size = max_pkt_size;
437	dev->vbi_mode.bulk_ctl.buf = NULL;
438
439	sb_size = max_packets * dev->vbi_mode.bulk_ctl.max_pkt_size;
440
441	/* allocate urbs and transfer buffers */
442	for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
443
444		urb = usb_alloc_urb(0, GFP_KERNEL);
445		if (!urb) {
446			dev_err(dev->dev,
447				"cannot alloc bulk_ctl.urb %i\n", i);
448			cx231xx_uninit_vbi_isoc(dev);
449			return -ENOMEM;
450		}
451		dev->vbi_mode.bulk_ctl.urb[i] = urb;
452		urb->transfer_flags = 0;
453
454		dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
455		    kzalloc(sb_size, GFP_KERNEL);
456		if (!dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {
457			dev_err(dev->dev,
458				"unable to allocate %i bytes for transfer buffer %i%s\n",
459				sb_size, i,
460				in_interrupt() ? " while in int" : "");
461			cx231xx_uninit_vbi_isoc(dev);
462			return -ENOMEM;
463		}
464
465		pipe = usb_rcvbulkpipe(dev->udev, dev->vbi_mode.end_point_addr);
466		usb_fill_bulk_urb(urb, dev->udev, pipe,
467				  dev->vbi_mode.bulk_ctl.transfer_buffer[i],
468				  sb_size, cx231xx_irq_vbi_callback, dma_q);
469	}
470
471	init_waitqueue_head(&dma_q->wq);
472
473	/* submit urbs and enables IRQ */
474	for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
475		rc = usb_submit_urb(dev->vbi_mode.bulk_ctl.urb[i], GFP_ATOMIC);
476		if (rc) {
477			dev_err(dev->dev,
478				"submit of urb %i failed (error=%i)\n", i, rc);
479			cx231xx_uninit_vbi_isoc(dev);
480			return rc;
481		}
482	}
483
484	cx231xx_capture_start(dev, 1, Vbi);
485
486	return 0;
487}
488EXPORT_SYMBOL_GPL(cx231xx_init_vbi_isoc);
489
490u32 cx231xx_get_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
491			 u8 sav_eav, u8 *p_buffer, u32 buffer_size)
492{
493	u32 bytes_copied = 0;
494	int current_field = -1;
495
496	switch (sav_eav) {
497
498	case SAV_VBI_FIELD1:
499		current_field = 1;
500		break;
501
502	case SAV_VBI_FIELD2:
503		current_field = 2;
504		break;
505	default:
506		break;
507	}
508
509	if (current_field < 0)
510		return bytes_copied;
511
512	dma_q->last_sav = sav_eav;
513
514	bytes_copied =
515	    cx231xx_copy_vbi_line(dev, dma_q, p_buffer, buffer_size,
516				  current_field);
517
518	return bytes_copied;
519}
520
521/*
522 * Announces that a buffer were filled and request the next
523 */
524static inline void vbi_buffer_filled(struct cx231xx *dev,
525				     struct cx231xx_dmaqueue *dma_q,
526				     struct cx231xx_buffer *buf)
527{
528	/* Advice that buffer was filled */
529	/* dev_dbg(dev->dev, "[%p/%d] wakeup\n", buf, buf->vb.i); */
530
531	buf->vb.state = VIDEOBUF_DONE;
532	buf->vb.field_count++;
533	v4l2_get_timestamp(&buf->vb.ts);
534
535	dev->vbi_mode.bulk_ctl.buf = NULL;
536
537	list_del(&buf->vb.queue);
538	wake_up(&buf->vb.done);
539}
540
541u32 cx231xx_copy_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
542			  u8 *p_line, u32 length, int field_number)
543{
544	u32 bytes_to_copy;
545	struct cx231xx_buffer *buf;
546	u32 _line_size = dev->width * 2;
547
548	if (dma_q->current_field == -1) {
549		/* Just starting up */
550		cx231xx_reset_vbi_buffer(dev, dma_q);
551	}
552
553	if (dma_q->current_field != field_number)
554		dma_q->lines_completed = 0;
555
556	/* get the buffer pointer */
557	buf = dev->vbi_mode.bulk_ctl.buf;
558
559	/* Remember the field number for next time */
560	dma_q->current_field = field_number;
561
562	bytes_to_copy = dma_q->bytes_left_in_line;
563	if (bytes_to_copy > length)
564		bytes_to_copy = length;
565
566	if (dma_q->lines_completed >= dma_q->lines_per_field) {
567		dma_q->bytes_left_in_line -= bytes_to_copy;
568		dma_q->is_partial_line =
569		    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
570		return 0;
571	}
572
573	dma_q->is_partial_line = 1;
574
575	/* If we don't have a buffer, just return the number of bytes we would
576	   have copied if we had a buffer. */
577	if (!buf) {
578		dma_q->bytes_left_in_line -= bytes_to_copy;
579		dma_q->is_partial_line =
580		    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
581		return bytes_to_copy;
582	}
583
584	/* copy the data to video buffer */
585	cx231xx_do_vbi_copy(dev, dma_q, p_line, bytes_to_copy);
586
587	dma_q->pos += bytes_to_copy;
588	dma_q->bytes_left_in_line -= bytes_to_copy;
589
590	if (dma_q->bytes_left_in_line == 0) {
591
592		dma_q->bytes_left_in_line = _line_size;
593		dma_q->lines_completed++;
594		dma_q->is_partial_line = 0;
595
596		if (cx231xx_is_vbi_buffer_done(dev, dma_q) && buf) {
597
598			vbi_buffer_filled(dev, dma_q, buf);
599
600			dma_q->pos = 0;
601			dma_q->lines_completed = 0;
602			cx231xx_reset_vbi_buffer(dev, dma_q);
603		}
604	}
605
606	return bytes_to_copy;
607}
608
609/*
610 * video-buf generic routine to get the next available buffer
611 */
612static inline void get_next_vbi_buf(struct cx231xx_dmaqueue *dma_q,
613				    struct cx231xx_buffer **buf)
614{
615	struct cx231xx_video_mode *vmode =
616	    container_of(dma_q, struct cx231xx_video_mode, vidq);
617	struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
618	char *outp;
619
620	if (list_empty(&dma_q->active)) {
621		dev_err(dev->dev, "No active queue to serve\n");
622		dev->vbi_mode.bulk_ctl.buf = NULL;
623		*buf = NULL;
624		return;
625	}
626
627	/* Get the next buffer */
628	*buf = list_entry(dma_q->active.next, struct cx231xx_buffer, vb.queue);
629
630	/* Cleans up buffer - Useful for testing for frame/URB loss */
631	outp = videobuf_to_vmalloc(&(*buf)->vb);
632	memset(outp, 0, (*buf)->vb.size);
633
634	dev->vbi_mode.bulk_ctl.buf = *buf;
635
636	return;
637}
638
639void cx231xx_reset_vbi_buffer(struct cx231xx *dev,
640			      struct cx231xx_dmaqueue *dma_q)
641{
642	struct cx231xx_buffer *buf;
643
644	buf = dev->vbi_mode.bulk_ctl.buf;
645
646	if (buf == NULL) {
647		/* first try to get the buffer */
648		get_next_vbi_buf(dma_q, &buf);
649
650		dma_q->pos = 0;
651		dma_q->current_field = -1;
652	}
653
654	dma_q->bytes_left_in_line = dev->width << 1;
655	dma_q->lines_completed = 0;
656}
657
658int cx231xx_do_vbi_copy(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
659			u8 *p_buffer, u32 bytes_to_copy)
660{
661	u8 *p_out_buffer = NULL;
662	u32 current_line_bytes_copied = 0;
663	struct cx231xx_buffer *buf;
664	u32 _line_size = dev->width << 1;
665	void *startwrite;
666	int offset, lencopy;
667
668	buf = dev->vbi_mode.bulk_ctl.buf;
669
670	if (buf == NULL)
671		return -EINVAL;
672
673	p_out_buffer = videobuf_to_vmalloc(&buf->vb);
674
675	if (dma_q->bytes_left_in_line != _line_size) {
676		current_line_bytes_copied =
677		    _line_size - dma_q->bytes_left_in_line;
678	}
679
680	offset = (dma_q->lines_completed * _line_size) +
681		 current_line_bytes_copied;
682
683	if (dma_q->current_field == 2) {
684		/* Populate the second half of the frame */
685		offset += (dev->width * 2 * dma_q->lines_per_field);
686	}
687
688	/* prepare destination address */
689	startwrite = p_out_buffer + offset;
690
691	lencopy = dma_q->bytes_left_in_line > bytes_to_copy ?
692		  bytes_to_copy : dma_q->bytes_left_in_line;
693
694	memcpy(startwrite, p_buffer, lencopy);
695
696	return 0;
697}
698
699u8 cx231xx_is_vbi_buffer_done(struct cx231xx *dev,
700			      struct cx231xx_dmaqueue *dma_q)
701{
702	u32 height = 0;
703
704	height = ((dev->norm & V4L2_STD_625_50) ?
705		  PAL_VBI_LINES : NTSC_VBI_LINES);
706	if (dma_q->lines_completed == height && dma_q->current_field == 2)
707		return 1;
708	else
709		return 0;
710}
711