root/drivers/media/usb/cx231xx/cx231xx-vbi.c

DEFINITIONS

1. print_err_status
2. cx231xx_isoc_vbi_copy
3. vbi_buffer_setup
4. free_buffer
5. vbi_buffer_prepare
6. vbi_buffer_queue
7. vbi_buffer_release
8. cx231xx_irq_vbi_callback
9. cx231xx_uninit_vbi_isoc
10. cx231xx_init_vbi_isoc
11. cx231xx_get_vbi_line
12. vbi_buffer_filled
13. cx231xx_copy_vbi_line
14. get_next_vbi_buf
15. cx231xx_reset_vbi_buffer
16. cx231xx_do_vbi_copy
17. cx231xx_is_vbi_buffer_done

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3    cx231xx_vbi.c - driver for Conexant Cx23100/101/102 USB video capture devices
   4 
   5    Copyright (C) 2008 <srinivasa.deevi at conexant dot com>
   6         Based on cx88 driver
   7 
   8  */
   9 
  10 #include "cx231xx.h"
  11 #include <linux/init.h>
  12 #include <linux/list.h>
  13 #include <linux/module.h>
  14 #include <linux/kernel.h>
  15 #include <linux/bitmap.h>
  16 #include <linux/i2c.h>
  17 #include <linux/mm.h>
  18 #include <linux/mutex.h>
  19 #include <linux/slab.h>
  20 
  21 #include <media/v4l2-common.h>
  22 #include <media/v4l2-ioctl.h>
  23 #include <media/drv-intf/msp3400.h>
  24 #include <media/tuner.h>
  25 
  26 #include "cx231xx-vbi.h"
  27 
  28 static inline void print_err_status(struct cx231xx *dev, int packet, int status)
  29 {
  30         char *errmsg = "Unknown";
  31 
  32         switch (status) {
  33         case -ENOENT:
  34                 errmsg = "unlinked synchronously";
  35                 break;
  36         case -ECONNRESET:
  37                 errmsg = "unlinked asynchronously";
  38                 break;
  39         case -ENOSR:
  40                 errmsg = "Buffer error (overrun)";
  41                 break;
  42         case -EPIPE:
  43                 errmsg = "Stalled (device not responding)";
  44                 break;
  45         case -EOVERFLOW:
  46                 errmsg = "Babble (bad cable?)";
  47                 break;
  48         case -EPROTO:
  49                 errmsg = "Bit-stuff error (bad cable?)";
  50                 break;
  51         case -EILSEQ:
  52                 errmsg = "CRC/Timeout (could be anything)";
  53                 break;
  54         case -ETIME:
  55                 errmsg = "Device does not respond";
  56                 break;
  57         }
  58         if (packet < 0) {
  59                 dev_err(dev->dev,
  60                         "URB status %d [%s].\n", status, errmsg);
  61         } else {
  62                 dev_err(dev->dev,
  63                         "URB packet %d, status %d [%s].\n",
  64                         packet, status, errmsg);
  65         }
  66 }
  67 
  68 /*
  69  * Controls the isoc copy of each urb packet
  70  */
  71 static inline int cx231xx_isoc_vbi_copy(struct cx231xx *dev, struct urb *urb)
  72 {
  73         struct cx231xx_dmaqueue *dma_q = urb->context;
  74         int rc = 1;
  75         unsigned char *p_buffer;
  76         u32 bytes_parsed = 0, buffer_size = 0;
  77         u8 sav_eav = 0;
  78 
  79         if (!dev)
  80                 return 0;
  81 
  82         if (dev->state & DEV_DISCONNECTED)
  83                 return 0;
  84 
  85         if (urb->status < 0) {
  86                 print_err_status(dev, -1, urb->status);
  87                 if (urb->status == -ENOENT)
  88                         return 0;
  89         }
  90 
  91         /* get buffer pointer and length */
  92         p_buffer = urb->transfer_buffer;
  93         buffer_size = urb->actual_length;
  94 
  95         if (buffer_size > 0) {
  96                 bytes_parsed = 0;
  97 
  98                 if (dma_q->is_partial_line) {
  99                         /* Handle the case where we were working on a partial
 100                            line */
 101                         sav_eav = dma_q->last_sav;
 102                 } else {
 103                         /* Check for a SAV/EAV overlapping the
 104                            buffer boundary */
 105 
 106                         sav_eav = cx231xx_find_boundary_SAV_EAV(p_buffer,
 107                                                           dma_q->partial_buf,
 108                                                           &bytes_parsed);
 109                 }
 110 
 111                 sav_eav &= 0xF0;
 112                 /* Get the first line if we have some portion of an SAV/EAV from
 113                    the last buffer or a partial line */
 114                 if (sav_eav) {
 115                         bytes_parsed += cx231xx_get_vbi_line(dev, dma_q,
 116                                 sav_eav,                       /* SAV/EAV */
 117                                 p_buffer + bytes_parsed,       /* p_buffer */
 118                                 buffer_size - bytes_parsed);   /* buffer size */
 119                 }
 120 
 121                 /* Now parse data that is completely in this buffer */
 122                 dma_q->is_partial_line = 0;
 123 
 124                 while (bytes_parsed < buffer_size) {
 125                         u32 bytes_used = 0;
 126 
 127                         sav_eav = cx231xx_find_next_SAV_EAV(
 128                                 p_buffer + bytes_parsed,        /* p_buffer */
 129                                 buffer_size - bytes_parsed, /* buffer size */
 130                                 &bytes_used);   /* bytes used to get SAV/EAV */
 131 
 132                         bytes_parsed += bytes_used;
 133 
 134                         sav_eav &= 0xF0;
 135                         if (sav_eav && (bytes_parsed < buffer_size)) {
 136                                 bytes_parsed += cx231xx_get_vbi_line(dev,
 137                                         dma_q, sav_eav, /* SAV/EAV */
 138                                         p_buffer+bytes_parsed, /* p_buffer */
 139                                         buffer_size-bytes_parsed);/*buf size*/
 140                         }
 141                 }
 142 
 143                 /* Save the last four bytes of the buffer so we can
 144                 check the buffer boundary condition next time */
 145                 memcpy(dma_q->partial_buf, p_buffer + buffer_size - 4, 4);
 146                 bytes_parsed = 0;
 147         }
 148 
 149         return rc;
 150 }
 151 
 152 /* ------------------------------------------------------------------
 153         Vbi buf operations
 154    ------------------------------------------------------------------*/
 155 
 156 static int
 157 vbi_buffer_setup(struct videobuf_queue *vq, unsigned int *count,
 158                  unsigned int *size)
 159 {
 160         struct cx231xx_fh *fh = vq->priv_data;
 161         struct cx231xx *dev = fh->dev;
 162         u32 height = 0;
 163 
 164         height = ((dev->norm & V4L2_STD_625_50) ?
 165                   PAL_VBI_LINES : NTSC_VBI_LINES);
 166 
 167         *size = (dev->width * height * 2 * 2);
 168         if (0 == *count)
 169                 *count = CX231XX_DEF_VBI_BUF;
 170 
 171         if (*count < CX231XX_MIN_BUF)
 172                 *count = CX231XX_MIN_BUF;
 173 
 174         return 0;
 175 }
 176 
 177 /* This is called *without* dev->slock held; please keep it that way */
 178 static void free_buffer(struct videobuf_queue *vq, struct cx231xx_buffer *buf)
 179 {
 180         struct cx231xx_fh *fh = vq->priv_data;
 181         struct cx231xx *dev = fh->dev;
 182         unsigned long flags = 0;
 183         BUG_ON(in_interrupt());
 184 
 185         /* We used to wait for the buffer to finish here, but this didn't work
 186            because, as we were keeping the state as VIDEOBUF_QUEUED,
 187            videobuf_queue_cancel marked it as finished for us.
 188            (Also, it could wedge forever if the hardware was misconfigured.)
 189 
 190            This should be safe; by the time we get here, the buffer isn't
 191            queued anymore. If we ever start marking the buffers as
 192            VIDEOBUF_ACTIVE, it won't be, though.
 193          */
 194         spin_lock_irqsave(&dev->vbi_mode.slock, flags);
 195         if (dev->vbi_mode.bulk_ctl.buf == buf)
 196                 dev->vbi_mode.bulk_ctl.buf = NULL;
 197         spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);
 198 
 199         videobuf_vmalloc_free(&buf->vb);
 200         buf->vb.state = VIDEOBUF_NEEDS_INIT;
 201 }
 202 
 203 static int
 204 vbi_buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
 205                    enum v4l2_field field)
 206 {
 207         struct cx231xx_fh *fh = vq->priv_data;
 208         struct cx231xx_buffer *buf =
 209             container_of(vb, struct cx231xx_buffer, vb);
 210         struct cx231xx *dev = fh->dev;
 211         int rc = 0, urb_init = 0;
 212         u32 height = 0;
 213 
 214         height = ((dev->norm & V4L2_STD_625_50) ?
 215                   PAL_VBI_LINES : NTSC_VBI_LINES);
 216         buf->vb.size = ((dev->width << 1) * height * 2);
 217 
 218         if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size)
 219                 return -EINVAL;
 220 
 221         buf->vb.width = dev->width;
 222         buf->vb.height = height;
 223         buf->vb.field = field;
 224         buf->vb.field = V4L2_FIELD_SEQ_TB;
 225 
 226         if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
 227                 rc = videobuf_iolock(vq, &buf->vb, NULL);
 228                 if (rc < 0)
 229                         goto fail;
 230         }
 231 
 232         if (!dev->vbi_mode.bulk_ctl.num_bufs)
 233                 urb_init = 1;
 234 
 235         if (urb_init) {
 236                 rc = cx231xx_init_vbi_isoc(dev, CX231XX_NUM_VBI_PACKETS,
 237                                            CX231XX_NUM_VBI_BUFS,
 238                                            dev->vbi_mode.alt_max_pkt_size[0],
 239                                            cx231xx_isoc_vbi_copy);
 240                 if (rc < 0)
 241                         goto fail;
 242         }
 243 
 244         buf->vb.state = VIDEOBUF_PREPARED;
 245         return 0;
 246 
 247 fail:
 248         free_buffer(vq, buf);
 249         return rc;
 250 }
 251 
 252 static void
 253 vbi_buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
 254 {
 255         struct cx231xx_buffer *buf =
 256             container_of(vb, struct cx231xx_buffer, vb);
 257         struct cx231xx_fh *fh = vq->priv_data;
 258         struct cx231xx *dev = fh->dev;
 259         struct cx231xx_dmaqueue *vidq = &dev->vbi_mode.vidq;
 260 
 261         buf->vb.state = VIDEOBUF_QUEUED;
 262         list_add_tail(&buf->vb.queue, &vidq->active);
 263 
 264 }
 265 
 266 static void vbi_buffer_release(struct videobuf_queue *vq,
 267                                struct videobuf_buffer *vb)
 268 {
 269         struct cx231xx_buffer *buf =
 270             container_of(vb, struct cx231xx_buffer, vb);
 271 
 272 
 273         free_buffer(vq, buf);
 274 }
 275 
 276 const struct videobuf_queue_ops cx231xx_vbi_qops = {
 277         .buf_setup   = vbi_buffer_setup,
 278         .buf_prepare = vbi_buffer_prepare,
 279         .buf_queue   = vbi_buffer_queue,
 280         .buf_release = vbi_buffer_release,
 281 };
 282 
 283 /* ------------------------------------------------------------------
 284         URB control
 285    ------------------------------------------------------------------*/
 286 
 287 /*
 288  * IRQ callback, called by URB callback
 289  */
 290 static void cx231xx_irq_vbi_callback(struct urb *urb)
 291 {
 292         struct cx231xx_dmaqueue *dma_q = urb->context;
 293         struct cx231xx_video_mode *vmode =
 294             container_of(dma_q, struct cx231xx_video_mode, vidq);
 295         struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
 296         unsigned long flags;
 297 
 298         switch (urb->status) {
 299         case 0:         /* success */
 300         case -ETIMEDOUT:        /* NAK */
 301                 break;
 302         case -ECONNRESET:       /* kill */
 303         case -ENOENT:
 304         case -ESHUTDOWN:
 305                 return;
 306         default:                /* error */
 307                 dev_err(dev->dev,
 308                         "urb completion error %d.\n", urb->status);
 309                 break;
 310         }
 311 
 312         /* Copy data from URB */
 313         spin_lock_irqsave(&dev->vbi_mode.slock, flags);
 314         dev->vbi_mode.bulk_ctl.bulk_copy(dev, urb);
 315         spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);
 316 
 317         /* Reset status */
 318         urb->status = 0;
 319 
 320         urb->status = usb_submit_urb(urb, GFP_ATOMIC);
 321         if (urb->status) {
 322                 dev_err(dev->dev, "urb resubmit failed (error=%i)\n",
 323                         urb->status);
 324         }
 325 }
 326 
 327 /*
 328  * Stop and Deallocate URBs
 329  */
 330 void cx231xx_uninit_vbi_isoc(struct cx231xx *dev)
 331 {
 332         struct urb *urb;
 333         int i;
 334 
 335         dev_dbg(dev->dev, "called cx231xx_uninit_vbi_isoc\n");
 336 
 337         dev->vbi_mode.bulk_ctl.nfields = -1;
 338         for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
 339                 urb = dev->vbi_mode.bulk_ctl.urb[i];
 340                 if (urb) {
 341                         if (!irqs_disabled())
 342                                 usb_kill_urb(urb);
 343                         else
 344                                 usb_unlink_urb(urb);
 345 
 346                         if (dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {
 347 
 348                                 kfree(dev->vbi_mode.bulk_ctl.
 349                                       transfer_buffer[i]);
 350                                 dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
 351                                     NULL;
 352                         }
 353                         usb_free_urb(urb);
 354                         dev->vbi_mode.bulk_ctl.urb[i] = NULL;
 355                 }
 356                 dev->vbi_mode.bulk_ctl.transfer_buffer[i] = NULL;
 357         }
 358 
 359         kfree(dev->vbi_mode.bulk_ctl.urb);
 360         kfree(dev->vbi_mode.bulk_ctl.transfer_buffer);
 361 
 362         dev->vbi_mode.bulk_ctl.urb = NULL;
 363         dev->vbi_mode.bulk_ctl.transfer_buffer = NULL;
 364         dev->vbi_mode.bulk_ctl.num_bufs = 0;
 365 
 366         cx231xx_capture_start(dev, 0, Vbi);
 367 }
 368 EXPORT_SYMBOL_GPL(cx231xx_uninit_vbi_isoc);
 369 
 370 /*
 371  * Allocate URBs and start IRQ
 372  */
 373 int cx231xx_init_vbi_isoc(struct cx231xx *dev, int max_packets,
 374                           int num_bufs, int max_pkt_size,
 375                           int (*bulk_copy) (struct cx231xx *dev,
 376                                             struct urb *urb))
 377 {
 378         struct cx231xx_dmaqueue *dma_q = &dev->vbi_mode.vidq;
 379         int i;
 380         int sb_size, pipe;
 381         struct urb *urb;
 382         int rc;
 383 
 384         dev_dbg(dev->dev, "called cx231xx_vbi_isoc\n");
 385 
 386         /* De-allocates all pending stuff */
 387         cx231xx_uninit_vbi_isoc(dev);
 388 
 389         /* clear if any halt */
 390         usb_clear_halt(dev->udev,
 391                        usb_rcvbulkpipe(dev->udev,
 392                                        dev->vbi_mode.end_point_addr));
 393 
 394         dev->vbi_mode.bulk_ctl.bulk_copy = bulk_copy;
 395         dev->vbi_mode.bulk_ctl.num_bufs = num_bufs;
 396         dma_q->pos = 0;
 397         dma_q->is_partial_line = 0;
 398         dma_q->last_sav = 0;
 399         dma_q->current_field = -1;
 400         dma_q->bytes_left_in_line = dev->width << 1;
 401         dma_q->lines_per_field = ((dev->norm & V4L2_STD_625_50) ?
 402                                   PAL_VBI_LINES : NTSC_VBI_LINES);
 403         dma_q->lines_completed = 0;
 404         for (i = 0; i < 8; i++)
 405                 dma_q->partial_buf[i] = 0;
 406 
 407         dev->vbi_mode.bulk_ctl.urb = kcalloc(num_bufs, sizeof(void *),
 408                                              GFP_KERNEL);
 409         if (!dev->vbi_mode.bulk_ctl.urb) {
 410                 dev_err(dev->dev,
 411                         "cannot alloc memory for usb buffers\n");
 412                 return -ENOMEM;
 413         }
 414 
 415         dev->vbi_mode.bulk_ctl.transfer_buffer =
 416             kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
 417         if (!dev->vbi_mode.bulk_ctl.transfer_buffer) {
 418                 dev_err(dev->dev,
 419                         "cannot allocate memory for usbtransfer\n");
 420                 kfree(dev->vbi_mode.bulk_ctl.urb);
 421                 return -ENOMEM;
 422         }
 423 
 424         dev->vbi_mode.bulk_ctl.max_pkt_size = max_pkt_size;
 425         dev->vbi_mode.bulk_ctl.buf = NULL;
 426 
 427         sb_size = max_packets * dev->vbi_mode.bulk_ctl.max_pkt_size;
 428 
 429         /* allocate urbs and transfer buffers */
 430         for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
 431 
 432                 urb = usb_alloc_urb(0, GFP_KERNEL);
 433                 if (!urb) {
 434                         cx231xx_uninit_vbi_isoc(dev);
 435                         return -ENOMEM;
 436                 }
 437                 dev->vbi_mode.bulk_ctl.urb[i] = urb;
 438                 urb->transfer_flags = 0;
 439 
 440                 dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
 441                     kzalloc(sb_size, GFP_KERNEL);
 442                 if (!dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {
 443                         dev_err(dev->dev,
 444                                 "unable to allocate %i bytes for transfer buffer %i%s\n",
 445                                 sb_size, i,
 446                                 in_interrupt() ? " while in int" : "");
 447                         cx231xx_uninit_vbi_isoc(dev);
 448                         return -ENOMEM;
 449                 }
 450 
 451                 pipe = usb_rcvbulkpipe(dev->udev, dev->vbi_mode.end_point_addr);
 452                 usb_fill_bulk_urb(urb, dev->udev, pipe,
 453                                   dev->vbi_mode.bulk_ctl.transfer_buffer[i],
 454                                   sb_size, cx231xx_irq_vbi_callback, dma_q);
 455         }
 456 
 457         init_waitqueue_head(&dma_q->wq);
 458 
 459         /* submit urbs and enables IRQ */
 460         for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
 461                 rc = usb_submit_urb(dev->vbi_mode.bulk_ctl.urb[i], GFP_ATOMIC);
 462                 if (rc) {
 463                         dev_err(dev->dev,
 464                                 "submit of urb %i failed (error=%i)\n", i, rc);
 465                         cx231xx_uninit_vbi_isoc(dev);
 466                         return rc;
 467                 }
 468         }
 469 
 470         cx231xx_capture_start(dev, 1, Vbi);
 471 
 472         return 0;
 473 }
 474 EXPORT_SYMBOL_GPL(cx231xx_init_vbi_isoc);
 475 
 476 u32 cx231xx_get_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
 477                          u8 sav_eav, u8 *p_buffer, u32 buffer_size)
 478 {
 479         u32 bytes_copied = 0;
 480         int current_field = -1;
 481 
 482         switch (sav_eav) {
 483 
 484         case SAV_VBI_FIELD1:
 485                 current_field = 1;
 486                 break;
 487 
 488         case SAV_VBI_FIELD2:
 489                 current_field = 2;
 490                 break;
 491         default:
 492                 break;
 493         }
 494 
 495         if (current_field < 0)
 496                 return bytes_copied;
 497 
 498         dma_q->last_sav = sav_eav;
 499 
 500         bytes_copied =
 501             cx231xx_copy_vbi_line(dev, dma_q, p_buffer, buffer_size,
 502                                   current_field);
 503 
 504         return bytes_copied;
 505 }
 506 
 507 /*
 508  * Announces that a buffer were filled and request the next
 509  */
 510 static inline void vbi_buffer_filled(struct cx231xx *dev,
 511                                      struct cx231xx_dmaqueue *dma_q,
 512                                      struct cx231xx_buffer *buf)
 513 {
 514         /* Advice that buffer was filled */
 515         /* dev_dbg(dev->dev, "[%p/%d] wakeup\n", buf, buf->vb.i); */
 516 
 517         buf->vb.state = VIDEOBUF_DONE;
 518         buf->vb.field_count++;
 519         buf->vb.ts = ktime_get_ns();
 520 
 521         dev->vbi_mode.bulk_ctl.buf = NULL;
 522 
 523         list_del(&buf->vb.queue);
 524         wake_up(&buf->vb.done);
 525 }
 526 
 527 u32 cx231xx_copy_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
 528                           u8 *p_line, u32 length, int field_number)
 529 {
 530         u32 bytes_to_copy;
 531         struct cx231xx_buffer *buf;
 532         u32 _line_size = dev->width * 2;
 533 
 534         if (dma_q->current_field == -1) {
 535                 /* Just starting up */
 536                 cx231xx_reset_vbi_buffer(dev, dma_q);
 537         }
 538 
 539         if (dma_q->current_field != field_number)
 540                 dma_q->lines_completed = 0;
 541 
 542         /* get the buffer pointer */
 543         buf = dev->vbi_mode.bulk_ctl.buf;
 544 
 545         /* Remember the field number for next time */
 546         dma_q->current_field = field_number;
 547 
 548         bytes_to_copy = dma_q->bytes_left_in_line;
 549         if (bytes_to_copy > length)
 550                 bytes_to_copy = length;
 551 
 552         if (dma_q->lines_completed >= dma_q->lines_per_field) {
 553                 dma_q->bytes_left_in_line -= bytes_to_copy;
 554                 dma_q->is_partial_line =
 555                     (dma_q->bytes_left_in_line == 0) ? 0 : 1;
 556                 return 0;
 557         }
 558 
 559         dma_q->is_partial_line = 1;
 560 
 561         /* If we don't have a buffer, just return the number of bytes we would
 562            have copied if we had a buffer. */
 563         if (!buf) {
 564                 dma_q->bytes_left_in_line -= bytes_to_copy;
 565                 dma_q->is_partial_line =
 566                     (dma_q->bytes_left_in_line == 0) ? 0 : 1;
 567                 return bytes_to_copy;
 568         }
 569 
 570         /* copy the data to video buffer */
 571         cx231xx_do_vbi_copy(dev, dma_q, p_line, bytes_to_copy);
 572 
 573         dma_q->pos += bytes_to_copy;
 574         dma_q->bytes_left_in_line -= bytes_to_copy;
 575 
 576         if (dma_q->bytes_left_in_line == 0) {
 577 
 578                 dma_q->bytes_left_in_line = _line_size;
 579                 dma_q->lines_completed++;
 580                 dma_q->is_partial_line = 0;
 581 
 582                 if (cx231xx_is_vbi_buffer_done(dev, dma_q) && buf) {
 583 
 584                         vbi_buffer_filled(dev, dma_q, buf);
 585 
 586                         dma_q->pos = 0;
 587                         dma_q->lines_completed = 0;
 588                         cx231xx_reset_vbi_buffer(dev, dma_q);
 589                 }
 590         }
 591 
 592         return bytes_to_copy;
 593 }
 594 
 595 /*
 596  * video-buf generic routine to get the next available buffer
 597  */
 598 static inline void get_next_vbi_buf(struct cx231xx_dmaqueue *dma_q,
 599                                     struct cx231xx_buffer **buf)
 600 {
 601         struct cx231xx_video_mode *vmode =
 602             container_of(dma_q, struct cx231xx_video_mode, vidq);
 603         struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
 604         char *outp;
 605 
 606         if (list_empty(&dma_q->active)) {
 607                 dev_err(dev->dev, "No active queue to serve\n");
 608                 dev->vbi_mode.bulk_ctl.buf = NULL;
 609                 *buf = NULL;
 610                 return;
 611         }
 612 
 613         /* Get the next buffer */
 614         *buf = list_entry(dma_q->active.next, struct cx231xx_buffer, vb.queue);
 615 
 616         /* Cleans up buffer - Useful for testing for frame/URB loss */
 617         outp = videobuf_to_vmalloc(&(*buf)->vb);
 618         memset(outp, 0, (*buf)->vb.size);
 619 
 620         dev->vbi_mode.bulk_ctl.buf = *buf;
 621 
 622         return;
 623 }
 624 
 625 void cx231xx_reset_vbi_buffer(struct cx231xx *dev,
 626                               struct cx231xx_dmaqueue *dma_q)
 627 {
 628         struct cx231xx_buffer *buf;
 629 
 630         buf = dev->vbi_mode.bulk_ctl.buf;
 631 
 632         if (buf == NULL) {
 633                 /* first try to get the buffer */
 634                 get_next_vbi_buf(dma_q, &buf);
 635 
 636                 dma_q->pos = 0;
 637                 dma_q->current_field = -1;
 638         }
 639 
 640         dma_q->bytes_left_in_line = dev->width << 1;
 641         dma_q->lines_completed = 0;
 642 }
 643 
 644 int cx231xx_do_vbi_copy(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
 645                         u8 *p_buffer, u32 bytes_to_copy)
 646 {
 647         u8 *p_out_buffer = NULL;
 648         u32 current_line_bytes_copied = 0;
 649         struct cx231xx_buffer *buf;
 650         u32 _line_size = dev->width << 1;
 651         void *startwrite;
 652         int offset, lencopy;
 653 
 654         buf = dev->vbi_mode.bulk_ctl.buf;
 655 
 656         if (buf == NULL)
 657                 return -EINVAL;
 658 
 659         p_out_buffer = videobuf_to_vmalloc(&buf->vb);
 660 
 661         if (dma_q->bytes_left_in_line != _line_size) {
 662                 current_line_bytes_copied =
 663                     _line_size - dma_q->bytes_left_in_line;
 664         }
 665 
 666         offset = (dma_q->lines_completed * _line_size) +
 667                  current_line_bytes_copied;
 668 
 669         if (dma_q->current_field == 2) {
 670                 /* Populate the second half of the frame */
 671                 offset += (dev->width * 2 * dma_q->lines_per_field);
 672         }
 673 
 674         /* prepare destination address */
 675         startwrite = p_out_buffer + offset;
 676 
 677         lencopy = dma_q->bytes_left_in_line > bytes_to_copy ?
 678                   bytes_to_copy : dma_q->bytes_left_in_line;
 679 
 680         memcpy(startwrite, p_buffer, lencopy);
 681 
 682         return 0;
 683 }
 684 
 685 u8 cx231xx_is_vbi_buffer_done(struct cx231xx *dev,
 686                               struct cx231xx_dmaqueue *dma_q)
 687 {
 688         u32 height = 0;
 689 
 690         height = ((dev->norm & V4L2_STD_625_50) ?
 691                   PAL_VBI_LINES : NTSC_VBI_LINES);
 692         if (dma_q->lines_completed == height && dma_q->current_field == 2)
 693                 return 1;
 694         else
 695                 return 0;
 696 }