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 <linux/init.h>
23#include <linux/list.h>
24#include <linux/module.h>
25#include <linux/kernel.h>
26#include <linux/bitmap.h>
27#include <linux/usb.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.h"
39#include "cx231xx-vbi.h"
40
41static inline void print_err_status(struct cx231xx *dev, int packet, int status)
42{
43	char *errmsg = "Unknown";
44
45	switch (status) {
46	case -ENOENT:
47		errmsg = "unlinked synchronuously";
48		break;
49	case -ECONNRESET:
50		errmsg = "unlinked asynchronuously";
51		break;
52	case -ENOSR:
53		errmsg = "Buffer error (overrun)";
54		break;
55	case -EPIPE:
56		errmsg = "Stalled (device not responding)";
57		break;
58	case -EOVERFLOW:
59		errmsg = "Babble (bad cable?)";
60		break;
61	case -EPROTO:
62		errmsg = "Bit-stuff error (bad cable?)";
63		break;
64	case -EILSEQ:
65		errmsg = "CRC/Timeout (could be anything)";
66		break;
67	case -ETIME:
68		errmsg = "Device does not respond";
69		break;
70	}
71	if (packet < 0) {
72		cx231xx_err("URB status %d [%s].\n", status,
73			    errmsg);
74	} else {
75		cx231xx_err("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		cx231xx_err("urb completition error %d.\n",
320			    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		cx231xx_err("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	cx231xx_info("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	cx231xx_info("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		cx231xx_errdev("cannot alloc memory for usb buffers\n");
423		return -ENOMEM;
424	}
425
426	dev->vbi_mode.bulk_ctl.transfer_buffer =
427	    kzalloc(sizeof(void *) * num_bufs, GFP_KERNEL);
428	if (!dev->vbi_mode.bulk_ctl.transfer_buffer) {
429		cx231xx_errdev("cannot allocate memory for usbtransfer\n");
430		kfree(dev->vbi_mode.bulk_ctl.urb);
431		return -ENOMEM;
432	}
433
434	dev->vbi_mode.bulk_ctl.max_pkt_size = max_pkt_size;
435	dev->vbi_mode.bulk_ctl.buf = NULL;
436
437	sb_size = max_packets * dev->vbi_mode.bulk_ctl.max_pkt_size;
438
439	/* allocate urbs and transfer buffers */
440	for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
441
442		urb = usb_alloc_urb(0, GFP_KERNEL);
443		if (!urb) {
444			cx231xx_err("cannot alloc bulk_ctl.urb %i\n", i);
445			cx231xx_uninit_vbi_isoc(dev);
446			return -ENOMEM;
447		}
448		dev->vbi_mode.bulk_ctl.urb[i] = urb;
449		urb->transfer_flags = 0;
450
451		dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
452		    kzalloc(sb_size, GFP_KERNEL);
453		if (!dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {
454			cx231xx_err("unable to allocate %i bytes for transfer"
455				    " buffer %i%s\n", sb_size, i,
456				    in_interrupt() ? " while in int" : "");
457			cx231xx_uninit_vbi_isoc(dev);
458			return -ENOMEM;
459		}
460
461		pipe = usb_rcvbulkpipe(dev->udev, dev->vbi_mode.end_point_addr);
462		usb_fill_bulk_urb(urb, dev->udev, pipe,
463				  dev->vbi_mode.bulk_ctl.transfer_buffer[i],
464				  sb_size, cx231xx_irq_vbi_callback, dma_q);
465	}
466
467	init_waitqueue_head(&dma_q->wq);
468
469	/* submit urbs and enables IRQ */
470	for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
471		rc = usb_submit_urb(dev->vbi_mode.bulk_ctl.urb[i], GFP_ATOMIC);
472		if (rc) {
473			cx231xx_err("submit of urb %i failed (error=%i)\n", i,
474				    rc);
475			cx231xx_uninit_vbi_isoc(dev);
476			return rc;
477		}
478	}
479
480	cx231xx_capture_start(dev, 1, Vbi);
481
482	return 0;
483}
484EXPORT_SYMBOL_GPL(cx231xx_init_vbi_isoc);
485
486u32 cx231xx_get_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
487			 u8 sav_eav, u8 *p_buffer, u32 buffer_size)
488{
489	u32 bytes_copied = 0;
490	int current_field = -1;
491
492	switch (sav_eav) {
493
494	case SAV_VBI_FIELD1:
495		current_field = 1;
496		break;
497
498	case SAV_VBI_FIELD2:
499		current_field = 2;
500		break;
501	default:
502		break;
503	}
504
505	if (current_field < 0)
506		return bytes_copied;
507
508	dma_q->last_sav = sav_eav;
509
510	bytes_copied =
511	    cx231xx_copy_vbi_line(dev, dma_q, p_buffer, buffer_size,
512				  current_field);
513
514	return bytes_copied;
515}
516
517/*
518 * Announces that a buffer were filled and request the next
519 */
520static inline void vbi_buffer_filled(struct cx231xx *dev,
521				     struct cx231xx_dmaqueue *dma_q,
522				     struct cx231xx_buffer *buf)
523{
524	/* Advice that buffer was filled */
525	/* cx231xx_info("[%p/%d] wakeup\n", buf, buf->vb.i); */
526
527	buf->vb.state = VIDEOBUF_DONE;
528	buf->vb.field_count++;
529	v4l2_get_timestamp(&buf->vb.ts);
530
531	dev->vbi_mode.bulk_ctl.buf = NULL;
532
533	list_del(&buf->vb.queue);
534	wake_up(&buf->vb.done);
535}
536
537u32 cx231xx_copy_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
538			  u8 *p_line, u32 length, int field_number)
539{
540	u32 bytes_to_copy;
541	struct cx231xx_buffer *buf;
542	u32 _line_size = dev->width * 2;
543
544	if (dma_q->current_field == -1) {
545		/* Just starting up */
546		cx231xx_reset_vbi_buffer(dev, dma_q);
547	}
548
549	if (dma_q->current_field != field_number)
550		dma_q->lines_completed = 0;
551
552	/* get the buffer pointer */
553	buf = dev->vbi_mode.bulk_ctl.buf;
554
555	/* Remember the field number for next time */
556	dma_q->current_field = field_number;
557
558	bytes_to_copy = dma_q->bytes_left_in_line;
559	if (bytes_to_copy > length)
560		bytes_to_copy = length;
561
562	if (dma_q->lines_completed >= dma_q->lines_per_field) {
563		dma_q->bytes_left_in_line -= bytes_to_copy;
564		dma_q->is_partial_line =
565		    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
566		return 0;
567	}
568
569	dma_q->is_partial_line = 1;
570
571	/* If we don't have a buffer, just return the number of bytes we would
572	   have copied if we had a buffer. */
573	if (!buf) {
574		dma_q->bytes_left_in_line -= bytes_to_copy;
575		dma_q->is_partial_line =
576		    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
577		return bytes_to_copy;
578	}
579
580	/* copy the data to video buffer */
581	cx231xx_do_vbi_copy(dev, dma_q, p_line, bytes_to_copy);
582
583	dma_q->pos += bytes_to_copy;
584	dma_q->bytes_left_in_line -= bytes_to_copy;
585
586	if (dma_q->bytes_left_in_line == 0) {
587
588		dma_q->bytes_left_in_line = _line_size;
589		dma_q->lines_completed++;
590		dma_q->is_partial_line = 0;
591
592		if (cx231xx_is_vbi_buffer_done(dev, dma_q) && buf) {
593
594			vbi_buffer_filled(dev, dma_q, buf);
595
596			dma_q->pos = 0;
597			dma_q->lines_completed = 0;
598			cx231xx_reset_vbi_buffer(dev, dma_q);
599		}
600	}
601
602	return bytes_to_copy;
603}
604
605/*
606 * video-buf generic routine to get the next available buffer
607 */
608static inline void get_next_vbi_buf(struct cx231xx_dmaqueue *dma_q,
609				    struct cx231xx_buffer **buf)
610{
611	struct cx231xx_video_mode *vmode =
612	    container_of(dma_q, struct cx231xx_video_mode, vidq);
613	struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
614	char *outp;
615
616	if (list_empty(&dma_q->active)) {
617		cx231xx_err("No active queue to serve\n");
618		dev->vbi_mode.bulk_ctl.buf = NULL;
619		*buf = NULL;
620		return;
621	}
622
623	/* Get the next buffer */
624	*buf = list_entry(dma_q->active.next, struct cx231xx_buffer, vb.queue);
625
626	/* Cleans up buffer - Useful for testing for frame/URB loss */
627	outp = videobuf_to_vmalloc(&(*buf)->vb);
628	memset(outp, 0, (*buf)->vb.size);
629
630	dev->vbi_mode.bulk_ctl.buf = *buf;
631
632	return;
633}
634
635void cx231xx_reset_vbi_buffer(struct cx231xx *dev,
636			      struct cx231xx_dmaqueue *dma_q)
637{
638	struct cx231xx_buffer *buf;
639
640	buf = dev->vbi_mode.bulk_ctl.buf;
641
642	if (buf == NULL) {
643		/* first try to get the buffer */
644		get_next_vbi_buf(dma_q, &buf);
645
646		dma_q->pos = 0;
647		dma_q->current_field = -1;
648	}
649
650	dma_q->bytes_left_in_line = dev->width << 1;
651	dma_q->lines_completed = 0;
652}
653
654int cx231xx_do_vbi_copy(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
655			u8 *p_buffer, u32 bytes_to_copy)
656{
657	u8 *p_out_buffer = NULL;
658	u32 current_line_bytes_copied = 0;
659	struct cx231xx_buffer *buf;
660	u32 _line_size = dev->width << 1;
661	void *startwrite;
662	int offset, lencopy;
663
664	buf = dev->vbi_mode.bulk_ctl.buf;
665
666	if (buf == NULL)
667		return -EINVAL;
668
669	p_out_buffer = videobuf_to_vmalloc(&buf->vb);
670
671	if (dma_q->bytes_left_in_line != _line_size) {
672		current_line_bytes_copied =
673		    _line_size - dma_q->bytes_left_in_line;
674	}
675
676	offset = (dma_q->lines_completed * _line_size) +
677		 current_line_bytes_copied;
678
679	if (dma_q->current_field == 2) {
680		/* Populate the second half of the frame */
681		offset += (dev->width * 2 * dma_q->lines_per_field);
682	}
683
684	/* prepare destination address */
685	startwrite = p_out_buffer + offset;
686
687	lencopy = dma_q->bytes_left_in_line > bytes_to_copy ?
688		  bytes_to_copy : dma_q->bytes_left_in_line;
689
690	memcpy(startwrite, p_buffer, lencopy);
691
692	return 0;
693}
694
695u8 cx231xx_is_vbi_buffer_done(struct cx231xx *dev,
696			      struct cx231xx_dmaqueue *dma_q)
697{
698	u32 height = 0;
699
700	height = ((dev->norm & V4L2_STD_625_50) ?
701		  PAL_VBI_LINES : NTSC_VBI_LINES);
702	if (dma_q->lines_completed == height && dma_q->current_field == 2)
703		return 1;
704	else
705		return 0;
706}
707