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 
41 static 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  */
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 	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 
216 static int
217 vbi_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 
260 fail:
261 	free_buffer(vq, buf);
262 	return rc;
263 }
264 
265 static void
266 vbi_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 
279 static 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 
289 struct 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  */
303 static 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  */
342 void 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 }
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 	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 }
484 EXPORT_SYMBOL_GPL(cx231xx_init_vbi_isoc);
485 
486 u32 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  */
520 static 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 
537 u32 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  */
608 static 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 
635 void 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 
654 int 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 
695 u8 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