linux/drivers/media/video/cx231xx/cx231xx-vbi.c
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   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/v4l2-chip-ident.h>
  36#include <media/msp3400.h>
  37#include <media/tuner.h>
  38
  39#include "cx231xx.h"
  40#include "cx231xx-vbi.h"
  41
  42static inline void print_err_status(struct cx231xx *dev, int packet, int status)
  43{
  44        char *errmsg = "Unknown";
  45
  46        switch (status) {
  47        case -ENOENT:
  48                errmsg = "unlinked synchronuously";
  49                break;
  50        case -ECONNRESET:
  51                errmsg = "unlinked asynchronuously";
  52                break;
  53        case -ENOSR:
  54                errmsg = "Buffer error (overrun)";
  55                break;
  56        case -EPIPE:
  57                errmsg = "Stalled (device not responding)";
  58                break;
  59        case -EOVERFLOW:
  60                errmsg = "Babble (bad cable?)";
  61                break;
  62        case -EPROTO:
  63                errmsg = "Bit-stuff error (bad cable?)";
  64                break;
  65        case -EILSEQ:
  66                errmsg = "CRC/Timeout (could be anything)";
  67                break;
  68        case -ETIME:
  69                errmsg = "Device does not respond";
  70                break;
  71        }
  72        if (packet < 0) {
  73                cx231xx_err(DRIVER_NAME "URB status %d [%s].\n", status,
  74                            errmsg);
  75        } else {
  76                cx231xx_err(DRIVER_NAME "URB packet %d, status %d [%s].\n",
  77                            packet, status, errmsg);
  78        }
  79}
  80
  81/*
  82 * Controls the isoc copy of each urb packet
  83 */
  84static inline int cx231xx_isoc_vbi_copy(struct cx231xx *dev, struct urb *urb)
  85{
  86        struct cx231xx_buffer *buf;
  87        struct cx231xx_dmaqueue *dma_q = urb->context;
  88        int rc = 1;
  89        unsigned char *p_buffer;
  90        u32 bytes_parsed = 0, buffer_size = 0;
  91        u8 sav_eav = 0;
  92
  93        if (!dev)
  94                return 0;
  95
  96        if ((dev->state & DEV_DISCONNECTED) || (dev->state & DEV_MISCONFIGURED))
  97                return 0;
  98
  99        if (urb->status < 0) {
 100                print_err_status(dev, -1, urb->status);
 101                if (urb->status == -ENOENT)
 102                        return 0;
 103        }
 104
 105        buf = dev->vbi_mode.isoc_ctl.buf;
 106
 107        /* get buffer pointer and length */
 108        p_buffer = urb->transfer_buffer;
 109        buffer_size = urb->actual_length;
 110
 111        if (buffer_size > 0) {
 112                bytes_parsed = 0;
 113
 114                if (dma_q->is_partial_line) {
 115                        /* Handle the case where we were working on a partial
 116                           line */
 117                        sav_eav = dma_q->last_sav;
 118                } else {
 119                        /* Check for a SAV/EAV overlapping the
 120                           buffer boundary */
 121
 122                        sav_eav = cx231xx_find_boundary_SAV_EAV(p_buffer,
 123                                                          dma_q->partial_buf,
 124                                                          &bytes_parsed);
 125                }
 126
 127                sav_eav &= 0xF0;
 128                /* Get the first line if we have some portion of an SAV/EAV from
 129                   the last buffer or a partial line */
 130                if (sav_eav) {
 131                        bytes_parsed += cx231xx_get_vbi_line(dev, dma_q,
 132                                sav_eav,                       /* SAV/EAV */
 133                                p_buffer + bytes_parsed,       /* p_buffer */
 134                                buffer_size - bytes_parsed);   /* buffer size */
 135                }
 136
 137                /* Now parse data that is completely in this buffer */
 138                dma_q->is_partial_line = 0;
 139
 140                while (bytes_parsed < buffer_size) {
 141                        u32 bytes_used = 0;
 142
 143                        sav_eav = cx231xx_find_next_SAV_EAV(
 144                                p_buffer + bytes_parsed,        /* p_buffer */
 145                                buffer_size - bytes_parsed, /* buffer size */
 146                                &bytes_used);   /* bytes used to get SAV/EAV */
 147
 148                        bytes_parsed += bytes_used;
 149
 150                        sav_eav &= 0xF0;
 151                        if (sav_eav && (bytes_parsed < buffer_size)) {
 152                                bytes_parsed += cx231xx_get_vbi_line(dev,
 153                                        dma_q, sav_eav, /* SAV/EAV */
 154                                        p_buffer+bytes_parsed, /* p_buffer */
 155                                        buffer_size-bytes_parsed);/*buf size*/
 156                        }
 157                }
 158
 159                /* Save the last four bytes of the buffer so we can
 160                check the buffer boundary condition next time */
 161                memcpy(dma_q->partial_buf, p_buffer + buffer_size - 4, 4);
 162                bytes_parsed = 0;
 163        }
 164
 165        return rc;
 166}
 167
 168/* ------------------------------------------------------------------
 169        Vbi buf operations
 170   ------------------------------------------------------------------*/
 171
 172static int
 173vbi_buffer_setup(struct videobuf_queue *vq, unsigned int *count,
 174                 unsigned int *size)
 175{
 176        struct cx231xx_fh *fh = vq->priv_data;
 177        struct cx231xx *dev = fh->dev;
 178        u32 height = 0;
 179
 180        height = ((dev->norm & V4L2_STD_625_50) ?
 181                  PAL_VBI_LINES : NTSC_VBI_LINES);
 182
 183        *size = (dev->width * height * 2);
 184        if (0 == *count)
 185                *count = CX231XX_DEF_VBI_BUF;
 186
 187        if (*count < CX231XX_MIN_BUF)
 188                *count = CX231XX_MIN_BUF;
 189
 190        return 0;
 191}
 192
 193/* This is called *without* dev->slock held; please keep it that way */
 194static void free_buffer(struct videobuf_queue *vq, struct cx231xx_buffer *buf)
 195{
 196        struct cx231xx_fh *fh = vq->priv_data;
 197        struct cx231xx *dev = fh->dev;
 198        unsigned long flags = 0;
 199        if (in_interrupt())
 200                BUG();
 201
 202        /* We used to wait for the buffer to finish here, but this didn't work
 203           because, as we were keeping the state as VIDEOBUF_QUEUED,
 204           videobuf_queue_cancel marked it as finished for us.
 205           (Also, it could wedge forever if the hardware was misconfigured.)
 206
 207           This should be safe; by the time we get here, the buffer isn't
 208           queued anymore. If we ever start marking the buffers as
 209           VIDEOBUF_ACTIVE, it won't be, though.
 210         */
 211        spin_lock_irqsave(&dev->vbi_mode.slock, flags);
 212        if (dev->vbi_mode.isoc_ctl.buf == buf)
 213                dev->vbi_mode.isoc_ctl.buf = NULL;
 214        spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);
 215
 216        videobuf_vmalloc_free(&buf->vb);
 217        buf->vb.state = VIDEOBUF_NEEDS_INIT;
 218}
 219
 220static int
 221vbi_buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
 222                   enum v4l2_field field)
 223{
 224        struct cx231xx_fh *fh = vq->priv_data;
 225        struct cx231xx_buffer *buf =
 226            container_of(vb, struct cx231xx_buffer, vb);
 227        struct cx231xx *dev = fh->dev;
 228        int rc = 0, urb_init = 0;
 229        u32 height = 0;
 230
 231        height = ((dev->norm & V4L2_STD_625_50) ?
 232                  PAL_VBI_LINES : NTSC_VBI_LINES);
 233        buf->vb.size = ((dev->width << 1) * height);
 234
 235        if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size)
 236                return -EINVAL;
 237
 238        buf->vb.width = dev->width;
 239        buf->vb.height = height;
 240        buf->vb.field = field;
 241        buf->vb.field = V4L2_FIELD_SEQ_TB;
 242
 243        if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
 244                rc = videobuf_iolock(vq, &buf->vb, NULL);
 245                if (rc < 0)
 246                        goto fail;
 247        }
 248
 249        if (!dev->vbi_mode.isoc_ctl.num_bufs)
 250                urb_init = 1;
 251
 252        if (urb_init) {
 253                rc = cx231xx_init_vbi_isoc(dev, CX231XX_NUM_VBI_PACKETS,
 254                                           CX231XX_NUM_VBI_BUFS,
 255                                           dev->vbi_mode.alt_max_pkt_size[0],
 256                                           cx231xx_isoc_vbi_copy);
 257                if (rc < 0)
 258                        goto fail;
 259        }
 260
 261        buf->vb.state = VIDEOBUF_PREPARED;
 262        return 0;
 263
 264fail:
 265        free_buffer(vq, buf);
 266        return rc;
 267}
 268
 269static void
 270vbi_buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
 271{
 272        struct cx231xx_buffer *buf =
 273            container_of(vb, struct cx231xx_buffer, vb);
 274        struct cx231xx_fh *fh = vq->priv_data;
 275        struct cx231xx *dev = fh->dev;
 276        struct cx231xx_dmaqueue *vidq = &dev->vbi_mode.vidq;
 277
 278        buf->vb.state = VIDEOBUF_QUEUED;
 279        list_add_tail(&buf->vb.queue, &vidq->active);
 280
 281}
 282
 283static void vbi_buffer_release(struct videobuf_queue *vq,
 284                               struct videobuf_buffer *vb)
 285{
 286        struct cx231xx_buffer *buf =
 287            container_of(vb, struct cx231xx_buffer, vb);
 288
 289
 290        free_buffer(vq, buf);
 291}
 292
 293struct videobuf_queue_ops cx231xx_vbi_qops = {
 294        .buf_setup   = vbi_buffer_setup,
 295        .buf_prepare = vbi_buffer_prepare,
 296        .buf_queue   = vbi_buffer_queue,
 297        .buf_release = vbi_buffer_release,
 298};
 299
 300/* ------------------------------------------------------------------
 301        URB control
 302   ------------------------------------------------------------------*/
 303
 304/*
 305 * IRQ callback, called by URB callback
 306 */
 307static void cx231xx_irq_vbi_callback(struct urb *urb)
 308{
 309        struct cx231xx_dmaqueue *dma_q = urb->context;
 310        struct cx231xx_video_mode *vmode =
 311            container_of(dma_q, struct cx231xx_video_mode, vidq);
 312        struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
 313        int rc;
 314
 315        switch (urb->status) {
 316        case 0:         /* success */
 317        case -ETIMEDOUT:        /* NAK */
 318                break;
 319        case -ECONNRESET:       /* kill */
 320        case -ENOENT:
 321        case -ESHUTDOWN:
 322                return;
 323        default:                /* error */
 324                cx231xx_err(DRIVER_NAME "urb completition error %d.\n",
 325                            urb->status);
 326                break;
 327        }
 328
 329        /* Copy data from URB */
 330        spin_lock(&dev->vbi_mode.slock);
 331        rc = dev->vbi_mode.isoc_ctl.isoc_copy(dev, urb);
 332        spin_unlock(&dev->vbi_mode.slock);
 333
 334        /* Reset status */
 335        urb->status = 0;
 336
 337        urb->status = usb_submit_urb(urb, GFP_ATOMIC);
 338        if (urb->status) {
 339                cx231xx_err(DRIVER_NAME "urb resubmit failed (error=%i)\n",
 340                            urb->status);
 341        }
 342}
 343
 344/*
 345 * Stop and Deallocate URBs
 346 */
 347void cx231xx_uninit_vbi_isoc(struct cx231xx *dev)
 348{
 349        struct urb *urb;
 350        int i;
 351
 352        cx231xx_info(DRIVER_NAME "cx231xx: called cx231xx_uninit_vbi_isoc\n");
 353
 354        dev->vbi_mode.isoc_ctl.nfields = -1;
 355        for (i = 0; i < dev->vbi_mode.isoc_ctl.num_bufs; i++) {
 356                urb = dev->vbi_mode.isoc_ctl.urb[i];
 357                if (urb) {
 358                        if (!irqs_disabled())
 359                                usb_kill_urb(urb);
 360                        else
 361                                usb_unlink_urb(urb);
 362
 363                        if (dev->vbi_mode.isoc_ctl.transfer_buffer[i]) {
 364
 365                                kfree(dev->vbi_mode.isoc_ctl.
 366                                      transfer_buffer[i]);
 367                                dev->vbi_mode.isoc_ctl.transfer_buffer[i] =
 368                                    NULL;
 369                        }
 370                        usb_free_urb(urb);
 371                        dev->vbi_mode.isoc_ctl.urb[i] = NULL;
 372                }
 373                dev->vbi_mode.isoc_ctl.transfer_buffer[i] = NULL;
 374        }
 375
 376        kfree(dev->vbi_mode.isoc_ctl.urb);
 377        kfree(dev->vbi_mode.isoc_ctl.transfer_buffer);
 378
 379        dev->vbi_mode.isoc_ctl.urb = NULL;
 380        dev->vbi_mode.isoc_ctl.transfer_buffer = NULL;
 381        dev->vbi_mode.isoc_ctl.num_bufs = 0;
 382
 383        cx231xx_capture_start(dev, 0, Vbi);
 384}
 385EXPORT_SYMBOL_GPL(cx231xx_uninit_vbi_isoc);
 386
 387/*
 388 * Allocate URBs and start IRQ
 389 */
 390int cx231xx_init_vbi_isoc(struct cx231xx *dev, int max_packets,
 391                          int num_bufs, int max_pkt_size,
 392                          int (*isoc_copy) (struct cx231xx *dev,
 393                                            struct urb *urb))
 394{
 395        struct cx231xx_dmaqueue *dma_q = &dev->vbi_mode.vidq;
 396        int i;
 397        int sb_size, pipe;
 398        struct urb *urb;
 399        int rc;
 400
 401        cx231xx_info(DRIVER_NAME "cx231xx: called cx231xx_prepare_isoc\n");
 402
 403        /* De-allocates all pending stuff */
 404        cx231xx_uninit_vbi_isoc(dev);
 405
 406        /* clear if any halt */
 407        usb_clear_halt(dev->udev,
 408                       usb_rcvbulkpipe(dev->udev,
 409                                       dev->vbi_mode.end_point_addr));
 410
 411        dev->vbi_mode.isoc_ctl.isoc_copy = isoc_copy;
 412        dev->vbi_mode.isoc_ctl.num_bufs = num_bufs;
 413        dma_q->pos = 0;
 414        dma_q->is_partial_line = 0;
 415        dma_q->last_sav = 0;
 416        dma_q->current_field = -1;
 417        dma_q->bytes_left_in_line = dev->width << 1;
 418        dma_q->lines_per_field = ((dev->norm & V4L2_STD_625_50) ?
 419                                  PAL_VBI_LINES : NTSC_VBI_LINES);
 420        dma_q->lines_completed = 0;
 421        for (i = 0; i < 8; i++)
 422                dma_q->partial_buf[i] = 0;
 423
 424        dev->vbi_mode.isoc_ctl.urb = kzalloc(sizeof(void *) * num_bufs,
 425                                             GFP_KERNEL);
 426        if (!dev->vbi_mode.isoc_ctl.urb) {
 427                cx231xx_errdev("cannot alloc memory for usb buffers\n");
 428                return -ENOMEM;
 429        }
 430
 431        dev->vbi_mode.isoc_ctl.transfer_buffer =
 432            kzalloc(sizeof(void *) * num_bufs, GFP_KERNEL);
 433        if (!dev->vbi_mode.isoc_ctl.transfer_buffer) {
 434                cx231xx_errdev("cannot allocate memory for usbtransfer\n");
 435                kfree(dev->vbi_mode.isoc_ctl.urb);
 436                return -ENOMEM;
 437        }
 438
 439        dev->vbi_mode.isoc_ctl.max_pkt_size = max_pkt_size;
 440        dev->vbi_mode.isoc_ctl.buf = NULL;
 441
 442        sb_size = max_packets * dev->vbi_mode.isoc_ctl.max_pkt_size;
 443
 444        /* allocate urbs and transfer buffers */
 445        for (i = 0; i < dev->vbi_mode.isoc_ctl.num_bufs; i++) {
 446
 447                urb = usb_alloc_urb(0, GFP_KERNEL);
 448                if (!urb) {
 449                        cx231xx_err(DRIVER_NAME
 450                                    ": cannot alloc isoc_ctl.urb %i\n", i);
 451                        cx231xx_uninit_vbi_isoc(dev);
 452                        return -ENOMEM;
 453                }
 454                dev->vbi_mode.isoc_ctl.urb[i] = urb;
 455                urb->transfer_flags = 0;
 456
 457                dev->vbi_mode.isoc_ctl.transfer_buffer[i] =
 458                    kzalloc(sb_size, GFP_KERNEL);
 459                if (!dev->vbi_mode.isoc_ctl.transfer_buffer[i]) {
 460                        cx231xx_err(DRIVER_NAME
 461                                    ": unable to allocate %i bytes for transfer"
 462                                    " buffer %i%s\n", sb_size, i,
 463                                    in_interrupt() ? " while in int" : "");
 464                        cx231xx_uninit_vbi_isoc(dev);
 465                        return -ENOMEM;
 466                }
 467
 468                pipe = usb_rcvbulkpipe(dev->udev, dev->vbi_mode.end_point_addr);
 469                usb_fill_bulk_urb(urb, dev->udev, pipe,
 470                                  dev->vbi_mode.isoc_ctl.transfer_buffer[i],
 471                                  sb_size, cx231xx_irq_vbi_callback, dma_q);
 472        }
 473
 474        init_waitqueue_head(&dma_q->wq);
 475
 476        /* submit urbs and enables IRQ */
 477        for (i = 0; i < dev->vbi_mode.isoc_ctl.num_bufs; i++) {
 478                rc = usb_submit_urb(dev->vbi_mode.isoc_ctl.urb[i], GFP_ATOMIC);
 479                if (rc) {
 480                        cx231xx_err(DRIVER_NAME
 481                                    ": submit of urb %i failed (error=%i)\n", i,
 482                                    rc);
 483                        cx231xx_uninit_vbi_isoc(dev);
 484                        return rc;
 485                }
 486        }
 487
 488        cx231xx_capture_start(dev, 1, Vbi);
 489
 490        return 0;
 491}
 492EXPORT_SYMBOL_GPL(cx231xx_init_vbi_isoc);
 493
 494u32 cx231xx_get_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
 495                         u8 sav_eav, u8 *p_buffer, u32 buffer_size)
 496{
 497        u32 bytes_copied = 0;
 498        int current_field = -1;
 499
 500        switch (sav_eav) {
 501
 502        case SAV_VBI_FIELD1:
 503                current_field = 1;
 504                break;
 505
 506        case SAV_VBI_FIELD2:
 507                current_field = 2;
 508                break;
 509        default:
 510                break;
 511        }
 512
 513        if (current_field < 0)
 514                return bytes_copied;
 515
 516        dma_q->last_sav = sav_eav;
 517
 518        bytes_copied =
 519            cx231xx_copy_vbi_line(dev, dma_q, p_buffer, buffer_size,
 520                                  current_field);
 521
 522        return bytes_copied;
 523}
 524
 525/*
 526 * Announces that a buffer were filled and request the next
 527 */
 528static inline void vbi_buffer_filled(struct cx231xx *dev,
 529                                     struct cx231xx_dmaqueue *dma_q,
 530                                     struct cx231xx_buffer *buf)
 531{
 532        /* Advice that buffer was filled */
 533        /* cx231xx_info(DRIVER_NAME "[%p/%d] wakeup\n", buf, buf->vb.i); */
 534
 535        buf->vb.state = VIDEOBUF_DONE;
 536        buf->vb.field_count++;
 537        do_gettimeofday(&buf->vb.ts);
 538
 539        dev->vbi_mode.isoc_ctl.buf = NULL;
 540
 541        list_del(&buf->vb.queue);
 542        wake_up(&buf->vb.done);
 543}
 544
 545u32 cx231xx_copy_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
 546                          u8 *p_line, u32 length, int field_number)
 547{
 548        u32 bytes_to_copy;
 549        struct cx231xx_buffer *buf;
 550        u32 _line_size = dev->width * 2;
 551
 552        if (dma_q->current_field != field_number)
 553                cx231xx_reset_vbi_buffer(dev, dma_q);
 554
 555        /* get the buffer pointer */
 556        buf = dev->vbi_mode.isoc_ctl.buf;
 557
 558        /* Remember the field number for next time */
 559        dma_q->current_field = field_number;
 560
 561        bytes_to_copy = dma_q->bytes_left_in_line;
 562        if (bytes_to_copy > length)
 563                bytes_to_copy = length;
 564
 565        if (dma_q->lines_completed >= dma_q->lines_per_field) {
 566                dma_q->bytes_left_in_line -= bytes_to_copy;
 567                dma_q->is_partial_line =
 568                    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
 569                return 0;
 570        }
 571
 572        dma_q->is_partial_line = 1;
 573
 574        /* If we don't have a buffer, just return the number of bytes we would
 575           have copied if we had a buffer. */
 576        if (!buf) {
 577                dma_q->bytes_left_in_line -= bytes_to_copy;
 578                dma_q->is_partial_line =
 579                    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
 580                return bytes_to_copy;
 581        }
 582
 583        /* copy the data to video buffer */
 584        cx231xx_do_vbi_copy(dev, dma_q, p_line, bytes_to_copy);
 585
 586        dma_q->pos += bytes_to_copy;
 587        dma_q->bytes_left_in_line -= bytes_to_copy;
 588
 589        if (dma_q->bytes_left_in_line == 0) {
 590
 591                dma_q->bytes_left_in_line = _line_size;
 592                dma_q->lines_completed++;
 593                dma_q->is_partial_line = 0;
 594
 595                if (cx231xx_is_vbi_buffer_done(dev, dma_q) && buf) {
 596
 597                        vbi_buffer_filled(dev, dma_q, buf);
 598
 599                        dma_q->pos = 0;
 600                        buf = NULL;
 601                        dma_q->lines_completed = 0;
 602                }
 603        }
 604
 605        return bytes_to_copy;
 606}
 607
 608/*
 609 * video-buf generic routine to get the next available buffer
 610 */
 611static inline void get_next_vbi_buf(struct cx231xx_dmaqueue *dma_q,
 612                                    struct cx231xx_buffer **buf)
 613{
 614        struct cx231xx_video_mode *vmode =
 615            container_of(dma_q, struct cx231xx_video_mode, vidq);
 616        struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
 617        char *outp;
 618
 619        if (list_empty(&dma_q->active)) {
 620                cx231xx_err(DRIVER_NAME ": No active queue to serve\n");
 621                dev->vbi_mode.isoc_ctl.buf = NULL;
 622                *buf = NULL;
 623                return;
 624        }
 625
 626        /* Get the next buffer */
 627        *buf = list_entry(dma_q->active.next, struct cx231xx_buffer, vb.queue);
 628
 629        /* Cleans up buffer - Usefull for testing for frame/URB loss */
 630        outp = videobuf_to_vmalloc(&(*buf)->vb);
 631        memset(outp, 0, (*buf)->vb.size);
 632
 633        dev->vbi_mode.isoc_ctl.buf = *buf;
 634
 635        return;
 636}
 637
 638void cx231xx_reset_vbi_buffer(struct cx231xx *dev,
 639                              struct cx231xx_dmaqueue *dma_q)
 640{
 641        struct cx231xx_buffer *buf;
 642
 643        buf = dev->vbi_mode.isoc_ctl.buf;
 644
 645        if (buf == NULL) {
 646                /* first try to get the buffer */
 647                get_next_vbi_buf(dma_q, &buf);
 648
 649                dma_q->pos = 0;
 650                dma_q->current_field = -1;
 651        }
 652
 653        dma_q->bytes_left_in_line = dev->width << 1;
 654        dma_q->lines_completed = 0;
 655}
 656
 657int cx231xx_do_vbi_copy(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
 658                        u8 *p_buffer, u32 bytes_to_copy)
 659{
 660        u8 *p_out_buffer = NULL;
 661        u32 current_line_bytes_copied = 0;
 662        struct cx231xx_buffer *buf;
 663        u32 _line_size = dev->width << 1;
 664        void *startwrite;
 665        int offset, lencopy;
 666
 667        buf = dev->vbi_mode.isoc_ctl.buf;
 668
 669        if (buf == NULL)
 670                return -EINVAL;
 671
 672        p_out_buffer = videobuf_to_vmalloc(&buf->vb);
 673
 674        if (dma_q->bytes_left_in_line != _line_size) {
 675                current_line_bytes_copied =
 676                    _line_size - dma_q->bytes_left_in_line;
 677        }
 678
 679        offset = (dma_q->lines_completed * _line_size) +
 680                 current_line_bytes_copied;
 681
 682        /* prepare destination address */
 683        startwrite = p_out_buffer + offset;
 684
 685        lencopy = dma_q->bytes_left_in_line > bytes_to_copy ?
 686                  bytes_to_copy : dma_q->bytes_left_in_line;
 687
 688        memcpy(startwrite, p_buffer, lencopy);
 689
 690        return 0;
 691}
 692
 693u8 cx231xx_is_vbi_buffer_done(struct cx231xx *dev,
 694                              struct cx231xx_dmaqueue *dma_q)
 695{
 696        u32 height = 0;
 697
 698        height = ((dev->norm & V4L2_STD_625_50) ?
 699                  PAL_VBI_LINES : NTSC_VBI_LINES);
 700        return (dma_q->lines_completed == height) ? 1 : 0;
 701}
 702