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/drv-intf/msp3400.h>
36 #include <media/tuner.h>
37 
38 #include "cx231xx-vbi.h"
39 
40 static 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 synchronously";
47 		break;
48 	case -ECONNRESET:
49 		errmsg = "unlinked asynchronously";
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  */
83 static 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 
168 static int
169 vbi_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 */
190 static 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 	BUG_ON(in_interrupt());
196 
197 	/* We used to wait for the buffer to finish here, but this didn't work
198 	   because, as we were keeping the state as VIDEOBUF_QUEUED,
199 	   videobuf_queue_cancel marked it as finished for us.
200 	   (Also, it could wedge forever if the hardware was misconfigured.)
201 
202 	   This should be safe; by the time we get here, the buffer isn't
203 	   queued anymore. If we ever start marking the buffers as
204 	   VIDEOBUF_ACTIVE, it won't be, though.
205 	 */
206 	spin_lock_irqsave(&dev->vbi_mode.slock, flags);
207 	if (dev->vbi_mode.bulk_ctl.buf == buf)
208 		dev->vbi_mode.bulk_ctl.buf = NULL;
209 	spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);
210 
211 	videobuf_vmalloc_free(&buf->vb);
212 	buf->vb.state = VIDEOBUF_NEEDS_INIT;
213 }
214 
215 static int
216 vbi_buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
217 		   enum v4l2_field field)
218 {
219 	struct cx231xx_fh *fh = vq->priv_data;
220 	struct cx231xx_buffer *buf =
221 	    container_of(vb, struct cx231xx_buffer, vb);
222 	struct cx231xx *dev = fh->dev;
223 	int rc = 0, urb_init = 0;
224 	u32 height = 0;
225 
226 	height = ((dev->norm & V4L2_STD_625_50) ?
227 		  PAL_VBI_LINES : NTSC_VBI_LINES);
228 	buf->vb.size = ((dev->width << 1) * height * 2);
229 
230 	if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size)
231 		return -EINVAL;
232 
233 	buf->vb.width = dev->width;
234 	buf->vb.height = height;
235 	buf->vb.field = field;
236 	buf->vb.field = V4L2_FIELD_SEQ_TB;
237 
238 	if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
239 		rc = videobuf_iolock(vq, &buf->vb, NULL);
240 		if (rc < 0)
241 			goto fail;
242 	}
243 
244 	if (!dev->vbi_mode.bulk_ctl.num_bufs)
245 		urb_init = 1;
246 
247 	if (urb_init) {
248 		rc = cx231xx_init_vbi_isoc(dev, CX231XX_NUM_VBI_PACKETS,
249 					   CX231XX_NUM_VBI_BUFS,
250 					   dev->vbi_mode.alt_max_pkt_size[0],
251 					   cx231xx_isoc_vbi_copy);
252 		if (rc < 0)
253 			goto fail;
254 	}
255 
256 	buf->vb.state = VIDEOBUF_PREPARED;
257 	return 0;
258 
259 fail:
260 	free_buffer(vq, buf);
261 	return rc;
262 }
263 
264 static void
265 vbi_buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
266 {
267 	struct cx231xx_buffer *buf =
268 	    container_of(vb, struct cx231xx_buffer, vb);
269 	struct cx231xx_fh *fh = vq->priv_data;
270 	struct cx231xx *dev = fh->dev;
271 	struct cx231xx_dmaqueue *vidq = &dev->vbi_mode.vidq;
272 
273 	buf->vb.state = VIDEOBUF_QUEUED;
274 	list_add_tail(&buf->vb.queue, &vidq->active);
275 
276 }
277 
278 static void vbi_buffer_release(struct videobuf_queue *vq,
279 			       struct videobuf_buffer *vb)
280 {
281 	struct cx231xx_buffer *buf =
282 	    container_of(vb, struct cx231xx_buffer, vb);
283 
284 
285 	free_buffer(vq, buf);
286 }
287 
288 const struct videobuf_queue_ops cx231xx_vbi_qops = {
289 	.buf_setup   = vbi_buffer_setup,
290 	.buf_prepare = vbi_buffer_prepare,
291 	.buf_queue   = vbi_buffer_queue,
292 	.buf_release = vbi_buffer_release,
293 };
294 
295 /* ------------------------------------------------------------------
296 	URB control
297    ------------------------------------------------------------------*/
298 
299 /*
300  * IRQ callback, called by URB callback
301  */
302 static void cx231xx_irq_vbi_callback(struct urb *urb)
303 {
304 	struct cx231xx_dmaqueue *dma_q = urb->context;
305 	struct cx231xx_video_mode *vmode =
306 	    container_of(dma_q, struct cx231xx_video_mode, vidq);
307 	struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
308 	unsigned long flags;
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 completion error %d.\n", urb->status);
321 		break;
322 	}
323 
324 	/* Copy data from URB */
325 	spin_lock_irqsave(&dev->vbi_mode.slock, flags);
326 	dev->vbi_mode.bulk_ctl.bulk_copy(dev, urb);
327 	spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);
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  */
342 void 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 }
380 EXPORT_SYMBOL_GPL(cx231xx_uninit_vbi_isoc);
381 
382 /*
383  * Allocate URBs and start IRQ
384  */
385 int 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 = kcalloc(num_bufs, sizeof(void *),
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 	    kcalloc(num_bufs, sizeof(void *), 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 			cx231xx_uninit_vbi_isoc(dev);
447 			return -ENOMEM;
448 		}
449 		dev->vbi_mode.bulk_ctl.urb[i] = urb;
450 		urb->transfer_flags = 0;
451 
452 		dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
453 		    kzalloc(sb_size, GFP_KERNEL);
454 		if (!dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {
455 			dev_err(dev->dev,
456 				"unable to allocate %i bytes for transfer buffer %i%s\n",
457 				sb_size, i,
458 				in_interrupt() ? " while in int" : "");
459 			cx231xx_uninit_vbi_isoc(dev);
460 			return -ENOMEM;
461 		}
462 
463 		pipe = usb_rcvbulkpipe(dev->udev, dev->vbi_mode.end_point_addr);
464 		usb_fill_bulk_urb(urb, dev->udev, pipe,
465 				  dev->vbi_mode.bulk_ctl.transfer_buffer[i],
466 				  sb_size, cx231xx_irq_vbi_callback, dma_q);
467 	}
468 
469 	init_waitqueue_head(&dma_q->wq);
470 
471 	/* submit urbs and enables IRQ */
472 	for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
473 		rc = usb_submit_urb(dev->vbi_mode.bulk_ctl.urb[i], GFP_ATOMIC);
474 		if (rc) {
475 			dev_err(dev->dev,
476 				"submit of urb %i failed (error=%i)\n", i, rc);
477 			cx231xx_uninit_vbi_isoc(dev);
478 			return rc;
479 		}
480 	}
481 
482 	cx231xx_capture_start(dev, 1, Vbi);
483 
484 	return 0;
485 }
486 EXPORT_SYMBOL_GPL(cx231xx_init_vbi_isoc);
487 
488 u32 cx231xx_get_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
489 			 u8 sav_eav, u8 *p_buffer, u32 buffer_size)
490 {
491 	u32 bytes_copied = 0;
492 	int current_field = -1;
493 
494 	switch (sav_eav) {
495 
496 	case SAV_VBI_FIELD1:
497 		current_field = 1;
498 		break;
499 
500 	case SAV_VBI_FIELD2:
501 		current_field = 2;
502 		break;
503 	default:
504 		break;
505 	}
506 
507 	if (current_field < 0)
508 		return bytes_copied;
509 
510 	dma_q->last_sav = sav_eav;
511 
512 	bytes_copied =
513 	    cx231xx_copy_vbi_line(dev, dma_q, p_buffer, buffer_size,
514 				  current_field);
515 
516 	return bytes_copied;
517 }
518 
519 /*
520  * Announces that a buffer were filled and request the next
521  */
522 static inline void vbi_buffer_filled(struct cx231xx *dev,
523 				     struct cx231xx_dmaqueue *dma_q,
524 				     struct cx231xx_buffer *buf)
525 {
526 	/* Advice that buffer was filled */
527 	/* dev_dbg(dev->dev, "[%p/%d] wakeup\n", buf, buf->vb.i); */
528 
529 	buf->vb.state = VIDEOBUF_DONE;
530 	buf->vb.field_count++;
531 	buf->vb.ts = ktime_get_ns();
532 
533 	dev->vbi_mode.bulk_ctl.buf = NULL;
534 
535 	list_del(&buf->vb.queue);
536 	wake_up(&buf->vb.done);
537 }
538 
539 u32 cx231xx_copy_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
540 			  u8 *p_line, u32 length, int field_number)
541 {
542 	u32 bytes_to_copy;
543 	struct cx231xx_buffer *buf;
544 	u32 _line_size = dev->width * 2;
545 
546 	if (dma_q->current_field == -1) {
547 		/* Just starting up */
548 		cx231xx_reset_vbi_buffer(dev, dma_q);
549 	}
550 
551 	if (dma_q->current_field != field_number)
552 		dma_q->lines_completed = 0;
553 
554 	/* get the buffer pointer */
555 	buf = dev->vbi_mode.bulk_ctl.buf;
556 
557 	/* Remember the field number for next time */
558 	dma_q->current_field = field_number;
559 
560 	bytes_to_copy = dma_q->bytes_left_in_line;
561 	if (bytes_to_copy > length)
562 		bytes_to_copy = length;
563 
564 	if (dma_q->lines_completed >= dma_q->lines_per_field) {
565 		dma_q->bytes_left_in_line -= bytes_to_copy;
566 		dma_q->is_partial_line =
567 		    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
568 		return 0;
569 	}
570 
571 	dma_q->is_partial_line = 1;
572 
573 	/* If we don't have a buffer, just return the number of bytes we would
574 	   have copied if we had a buffer. */
575 	if (!buf) {
576 		dma_q->bytes_left_in_line -= bytes_to_copy;
577 		dma_q->is_partial_line =
578 		    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
579 		return bytes_to_copy;
580 	}
581 
582 	/* copy the data to video buffer */
583 	cx231xx_do_vbi_copy(dev, dma_q, p_line, bytes_to_copy);
584 
585 	dma_q->pos += bytes_to_copy;
586 	dma_q->bytes_left_in_line -= bytes_to_copy;
587 
588 	if (dma_q->bytes_left_in_line == 0) {
589 
590 		dma_q->bytes_left_in_line = _line_size;
591 		dma_q->lines_completed++;
592 		dma_q->is_partial_line = 0;
593 
594 		if (cx231xx_is_vbi_buffer_done(dev, dma_q) && buf) {
595 
596 			vbi_buffer_filled(dev, dma_q, buf);
597 
598 			dma_q->pos = 0;
599 			dma_q->lines_completed = 0;
600 			cx231xx_reset_vbi_buffer(dev, dma_q);
601 		}
602 	}
603 
604 	return bytes_to_copy;
605 }
606 
607 /*
608  * video-buf generic routine to get the next available buffer
609  */
610 static inline void get_next_vbi_buf(struct cx231xx_dmaqueue *dma_q,
611 				    struct cx231xx_buffer **buf)
612 {
613 	struct cx231xx_video_mode *vmode =
614 	    container_of(dma_q, struct cx231xx_video_mode, vidq);
615 	struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
616 	char *outp;
617 
618 	if (list_empty(&dma_q->active)) {
619 		dev_err(dev->dev, "No active queue to serve\n");
620 		dev->vbi_mode.bulk_ctl.buf = NULL;
621 		*buf = NULL;
622 		return;
623 	}
624 
625 	/* Get the next buffer */
626 	*buf = list_entry(dma_q->active.next, struct cx231xx_buffer, vb.queue);
627 
628 	/* Cleans up buffer - Useful for testing for frame/URB loss */
629 	outp = videobuf_to_vmalloc(&(*buf)->vb);
630 	memset(outp, 0, (*buf)->vb.size);
631 
632 	dev->vbi_mode.bulk_ctl.buf = *buf;
633 
634 	return;
635 }
636 
637 void cx231xx_reset_vbi_buffer(struct cx231xx *dev,
638 			      struct cx231xx_dmaqueue *dma_q)
639 {
640 	struct cx231xx_buffer *buf;
641 
642 	buf = dev->vbi_mode.bulk_ctl.buf;
643 
644 	if (buf == NULL) {
645 		/* first try to get the buffer */
646 		get_next_vbi_buf(dma_q, &buf);
647 
648 		dma_q->pos = 0;
649 		dma_q->current_field = -1;
650 	}
651 
652 	dma_q->bytes_left_in_line = dev->width << 1;
653 	dma_q->lines_completed = 0;
654 }
655 
656 int cx231xx_do_vbi_copy(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
657 			u8 *p_buffer, u32 bytes_to_copy)
658 {
659 	u8 *p_out_buffer = NULL;
660 	u32 current_line_bytes_copied = 0;
661 	struct cx231xx_buffer *buf;
662 	u32 _line_size = dev->width << 1;
663 	void *startwrite;
664 	int offset, lencopy;
665 
666 	buf = dev->vbi_mode.bulk_ctl.buf;
667 
668 	if (buf == NULL)
669 		return -EINVAL;
670 
671 	p_out_buffer = videobuf_to_vmalloc(&buf->vb);
672 
673 	if (dma_q->bytes_left_in_line != _line_size) {
674 		current_line_bytes_copied =
675 		    _line_size - dma_q->bytes_left_in_line;
676 	}
677 
678 	offset = (dma_q->lines_completed * _line_size) +
679 		 current_line_bytes_copied;
680 
681 	if (dma_q->current_field == 2) {
682 		/* Populate the second half of the frame */
683 		offset += (dev->width * 2 * dma_q->lines_per_field);
684 	}
685 
686 	/* prepare destination address */
687 	startwrite = p_out_buffer + offset;
688 
689 	lencopy = dma_q->bytes_left_in_line > bytes_to_copy ?
690 		  bytes_to_copy : dma_q->bytes_left_in_line;
691 
692 	memcpy(startwrite, p_buffer, lencopy);
693 
694 	return 0;
695 }
696 
697 u8 cx231xx_is_vbi_buffer_done(struct cx231xx *dev,
698 			      struct cx231xx_dmaqueue *dma_q)
699 {
700 	u32 height = 0;
701 
702 	height = ((dev->norm & V4L2_STD_625_50) ?
703 		  PAL_VBI_LINES : NTSC_VBI_LINES);
704 	if (dma_q->lines_completed == height && dma_q->current_field == 2)
705 		return 1;
706 	else
707 		return 0;
708 }
709