LXR linux/drivers/media/usb/cx231xx/cx231xx-vbi.c

   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
  28static 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 */
  71static 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
 156static int vbi_queue_setup(struct vb2_queue *vq,
 157                           unsigned int *nbuffers, unsigned int *nplanes,
 158                           unsigned int sizes[], struct device *alloc_devs[])
 159{
 160        struct cx231xx *dev = vb2_get_drv_priv(vq);
 161        u32 height = 0;
 162
 163        height = ((dev->norm & V4L2_STD_625_50) ?
 164                  PAL_VBI_LINES : NTSC_VBI_LINES);
 165
 166        *nplanes = 1;
 167        sizes[0] = (dev->width * height * 2 * 2);
 168        return 0;
 169}
 170
 171/* This is called *without* dev->slock held; please keep it that way */
 172static int vbi_buf_prepare(struct vb2_buffer *vb)
 173{
 174        struct cx231xx *dev = vb2_get_drv_priv(vb->vb2_queue);
 175        u32 height = 0;
 176        u32 size;
 177
 178        height = ((dev->norm & V4L2_STD_625_50) ?
 179                  PAL_VBI_LINES : NTSC_VBI_LINES);
 180        size = ((dev->width << 1) * height * 2);
 181
 182        if (vb2_plane_size(vb, 0) < size)
 183                return -EINVAL;
 184        vb2_set_plane_payload(vb, 0, size);
 185        return 0;
 186}
 187
 188static void vbi_buf_queue(struct vb2_buffer *vb)
 189{
 190        struct cx231xx *dev = vb2_get_drv_priv(vb->vb2_queue);
 191        struct cx231xx_buffer *buf =
 192            container_of(vb, struct cx231xx_buffer, vb.vb2_buf);
 193        struct cx231xx_dmaqueue *vidq = &dev->vbi_mode.vidq;
 194        unsigned long flags;
 195
 196        spin_lock_irqsave(&dev->vbi_mode.slock, flags);
 197        list_add_tail(&buf->list, &vidq->active);
 198        spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);
 199}
 200
 201static void return_all_buffers(struct cx231xx *dev,
 202                               enum vb2_buffer_state state)
 203{
 204        struct cx231xx_dmaqueue *vidq = &dev->vbi_mode.vidq;
 205        struct cx231xx_buffer *buf, *node;
 206        unsigned long flags;
 207
 208        spin_lock_irqsave(&dev->vbi_mode.slock, flags);
 209        dev->vbi_mode.bulk_ctl.buf = NULL;
 210        list_for_each_entry_safe(buf, node, &vidq->active, list) {
 211                list_del(&buf->list);
 212                vb2_buffer_done(&buf->vb.vb2_buf, state);
 213        }
 214        spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);
 215}
 216
 217static int vbi_start_streaming(struct vb2_queue *vq, unsigned int count)
 218{
 219        struct cx231xx *dev = vb2_get_drv_priv(vq);
 220        struct cx231xx_dmaqueue *vidq = &dev->vbi_mode.vidq;
 221        int ret;
 222
 223        vidq->sequence = 0;
 224        ret = cx231xx_init_vbi_isoc(dev, CX231XX_NUM_VBI_PACKETS,
 225                                    CX231XX_NUM_VBI_BUFS,
 226                                    dev->vbi_mode.alt_max_pkt_size[0],
 227                                    cx231xx_isoc_vbi_copy);
 228        if (ret)
 229                return_all_buffers(dev, VB2_BUF_STATE_QUEUED);
 230        return ret;
 231}
 232
 233static void vbi_stop_streaming(struct vb2_queue *vq)
 234{
 235        struct cx231xx *dev = vb2_get_drv_priv(vq);
 236
 237        return_all_buffers(dev, VB2_BUF_STATE_ERROR);
 238}
 239
 240struct vb2_ops cx231xx_vbi_qops = {
 241        .queue_setup = vbi_queue_setup,
 242        .buf_prepare = vbi_buf_prepare,
 243        .buf_queue = vbi_buf_queue,
 244        .start_streaming = vbi_start_streaming,
 245        .stop_streaming = vbi_stop_streaming,
 246        .wait_prepare = vb2_ops_wait_prepare,
 247        .wait_finish = vb2_ops_wait_finish,
 248};
 249
 250/* ------------------------------------------------------------------
 251        URB control
 252   ------------------------------------------------------------------*/
 253
 254/*
 255 * IRQ callback, called by URB callback
 256 */
 257static void cx231xx_irq_vbi_callback(struct urb *urb)
 258{
 259        struct cx231xx_dmaqueue *dma_q = urb->context;
 260        struct cx231xx_video_mode *vmode =
 261            container_of(dma_q, struct cx231xx_video_mode, vidq);
 262        struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
 263        unsigned long flags;
 264
 265        switch (urb->status) {
 266        case 0:         /* success */
 267        case -ETIMEDOUT:        /* NAK */
 268                break;
 269        case -ECONNRESET:       /* kill */
 270        case -ENOENT:
 271        case -ESHUTDOWN:
 272                return;
 273        default:                /* error */
 274                dev_err(dev->dev,
 275                        "urb completion error %d.\n", urb->status);
 276                break;
 277        }
 278
 279        /* Copy data from URB */
 280        spin_lock_irqsave(&dev->vbi_mode.slock, flags);
 281        dev->vbi_mode.bulk_ctl.bulk_copy(dev, urb);
 282        spin_unlock_irqrestore(&dev->vbi_mode.slock, flags);
 283
 284        /* Reset status */
 285        urb->status = 0;
 286
 287        urb->status = usb_submit_urb(urb, GFP_ATOMIC);
 288        if (urb->status) {
 289                dev_err(dev->dev, "urb resubmit failed (error=%i)\n",
 290                        urb->status);
 291        }
 292}
 293
 294/*
 295 * Stop and Deallocate URBs
 296 */
 297void cx231xx_uninit_vbi_isoc(struct cx231xx *dev)
 298{
 299        struct urb *urb;
 300        int i;
 301
 302        dev_dbg(dev->dev, "called cx231xx_uninit_vbi_isoc\n");
 303
 304        dev->vbi_mode.bulk_ctl.nfields = -1;
 305        for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
 306                urb = dev->vbi_mode.bulk_ctl.urb[i];
 307                if (urb) {
 308                        if (!irqs_disabled())
 309                                usb_kill_urb(urb);
 310                        else
 311                                usb_unlink_urb(urb);
 312
 313                        if (dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {
 314
 315                                kfree(dev->vbi_mode.bulk_ctl.
 316                                      transfer_buffer[i]);
 317                                dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
 318                                    NULL;
 319                        }
 320                        usb_free_urb(urb);
 321                        dev->vbi_mode.bulk_ctl.urb[i] = NULL;
 322                }
 323                dev->vbi_mode.bulk_ctl.transfer_buffer[i] = NULL;
 324        }
 325
 326        kfree(dev->vbi_mode.bulk_ctl.urb);
 327        kfree(dev->vbi_mode.bulk_ctl.transfer_buffer);
 328
 329        dev->vbi_mode.bulk_ctl.urb = NULL;
 330        dev->vbi_mode.bulk_ctl.transfer_buffer = NULL;
 331        dev->vbi_mode.bulk_ctl.num_bufs = 0;
 332
 333        cx231xx_capture_start(dev, 0, Vbi);
 334}
 335EXPORT_SYMBOL_GPL(cx231xx_uninit_vbi_isoc);
 336
 337/*
 338 * Allocate URBs and start IRQ
 339 */
 340int cx231xx_init_vbi_isoc(struct cx231xx *dev, int max_packets,
 341                          int num_bufs, int max_pkt_size,
 342                          int (*bulk_copy) (struct cx231xx *dev,
 343                                            struct urb *urb))
 344{
 345        struct cx231xx_dmaqueue *dma_q = &dev->vbi_mode.vidq;
 346        int i;
 347        int sb_size, pipe;
 348        struct urb *urb;
 349        int rc;
 350
 351        dev_dbg(dev->dev, "called cx231xx_vbi_isoc\n");
 352
 353        /* De-allocates all pending stuff */
 354        cx231xx_uninit_vbi_isoc(dev);
 355
 356        /* clear if any halt */
 357        usb_clear_halt(dev->udev,
 358                       usb_rcvbulkpipe(dev->udev,
 359                                       dev->vbi_mode.end_point_addr));
 360
 361        dev->vbi_mode.bulk_ctl.bulk_copy = bulk_copy;
 362        dev->vbi_mode.bulk_ctl.num_bufs = num_bufs;
 363        dma_q->pos = 0;
 364        dma_q->is_partial_line = 0;
 365        dma_q->last_sav = 0;
 366        dma_q->current_field = -1;
 367        dma_q->bytes_left_in_line = dev->width << 1;
 368        dma_q->lines_per_field = ((dev->norm & V4L2_STD_625_50) ?
 369                                  PAL_VBI_LINES : NTSC_VBI_LINES);
 370        dma_q->lines_completed = 0;
 371        for (i = 0; i < 8; i++)
 372                dma_q->partial_buf[i] = 0;
 373
 374        dev->vbi_mode.bulk_ctl.urb = kcalloc(num_bufs, sizeof(void *),
 375                                             GFP_KERNEL);
 376        if (!dev->vbi_mode.bulk_ctl.urb) {
 377                dev_err(dev->dev,
 378                        "cannot alloc memory for usb buffers\n");
 379                return -ENOMEM;
 380        }
 381
 382        dev->vbi_mode.bulk_ctl.transfer_buffer =
 383            kcalloc(num_bufs, sizeof(void *), GFP_KERNEL);
 384        if (!dev->vbi_mode.bulk_ctl.transfer_buffer) {
 385                dev_err(dev->dev,
 386                        "cannot allocate memory for usbtransfer\n");
 387                kfree(dev->vbi_mode.bulk_ctl.urb);
 388                return -ENOMEM;
 389        }
 390
 391        dev->vbi_mode.bulk_ctl.max_pkt_size = max_pkt_size;
 392        dev->vbi_mode.bulk_ctl.buf = NULL;
 393
 394        sb_size = max_packets * dev->vbi_mode.bulk_ctl.max_pkt_size;
 395
 396        /* allocate urbs and transfer buffers */
 397        for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
 398
 399                urb = usb_alloc_urb(0, GFP_KERNEL);
 400                if (!urb) {
 401                        cx231xx_uninit_vbi_isoc(dev);
 402                        return -ENOMEM;
 403                }
 404                dev->vbi_mode.bulk_ctl.urb[i] = urb;
 405                urb->transfer_flags = 0;
 406
 407                dev->vbi_mode.bulk_ctl.transfer_buffer[i] =
 408                    kzalloc(sb_size, GFP_KERNEL);
 409                if (!dev->vbi_mode.bulk_ctl.transfer_buffer[i]) {
 410                        dev_err(dev->dev,
 411                                "unable to allocate %i bytes for transfer buffer %i\n",
 412                                sb_size, i);
 413                        cx231xx_uninit_vbi_isoc(dev);
 414                        return -ENOMEM;
 415                }
 416
 417                pipe = usb_rcvbulkpipe(dev->udev, dev->vbi_mode.end_point_addr);
 418                usb_fill_bulk_urb(urb, dev->udev, pipe,
 419                                  dev->vbi_mode.bulk_ctl.transfer_buffer[i],
 420                                  sb_size, cx231xx_irq_vbi_callback, dma_q);
 421        }
 422
 423        init_waitqueue_head(&dma_q->wq);
 424
 425        /* submit urbs and enables IRQ */
 426        for (i = 0; i < dev->vbi_mode.bulk_ctl.num_bufs; i++) {
 427                rc = usb_submit_urb(dev->vbi_mode.bulk_ctl.urb[i], GFP_ATOMIC);
 428                if (rc) {
 429                        dev_err(dev->dev,
 430                                "submit of urb %i failed (error=%i)\n", i, rc);
 431                        cx231xx_uninit_vbi_isoc(dev);
 432                        return rc;
 433                }
 434        }
 435
 436        cx231xx_capture_start(dev, 1, Vbi);
 437
 438        return 0;
 439}
 440EXPORT_SYMBOL_GPL(cx231xx_init_vbi_isoc);
 441
 442u32 cx231xx_get_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
 443                         u8 sav_eav, u8 *p_buffer, u32 buffer_size)
 444{
 445        u32 bytes_copied = 0;
 446        int current_field = -1;
 447
 448        switch (sav_eav) {
 449
 450        case SAV_VBI_FIELD1:
 451                current_field = 1;
 452                break;
 453
 454        case SAV_VBI_FIELD2:
 455                current_field = 2;
 456                break;
 457        default:
 458                break;
 459        }
 460
 461        if (current_field < 0)
 462                return bytes_copied;
 463
 464        dma_q->last_sav = sav_eav;
 465
 466        bytes_copied =
 467            cx231xx_copy_vbi_line(dev, dma_q, p_buffer, buffer_size,
 468                                  current_field);
 469
 470        return bytes_copied;
 471}
 472
 473/*
 474 * Announces that a buffer were filled and request the next
 475 */
 476static inline void vbi_buffer_filled(struct cx231xx *dev,
 477                                     struct cx231xx_dmaqueue *dma_q,
 478                                     struct cx231xx_buffer *buf)
 479{
 480        /* Advice that buffer was filled */
 481        /* dev_dbg(dev->dev, "[%p/%d] wakeup\n", buf, buf->vb.index); */
 482
 483        buf->vb.sequence = dma_q->sequence++;
 484        buf->vb.vb2_buf.timestamp = ktime_get_ns();
 485
 486        dev->vbi_mode.bulk_ctl.buf = NULL;
 487
 488        list_del(&buf->list);
 489        vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_DONE);
 490}
 491
 492u32 cx231xx_copy_vbi_line(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
 493                          u8 *p_line, u32 length, int field_number)
 494{
 495        u32 bytes_to_copy;
 496        struct cx231xx_buffer *buf;
 497        u32 _line_size = dev->width * 2;
 498
 499        if (dma_q->current_field == -1) {
 500                /* Just starting up */
 501                cx231xx_reset_vbi_buffer(dev, dma_q);
 502        }
 503
 504        if (dma_q->current_field != field_number)
 505                dma_q->lines_completed = 0;
 506
 507        /* get the buffer pointer */
 508        buf = dev->vbi_mode.bulk_ctl.buf;
 509
 510        /* Remember the field number for next time */
 511        dma_q->current_field = field_number;
 512
 513        bytes_to_copy = dma_q->bytes_left_in_line;
 514        if (bytes_to_copy > length)
 515                bytes_to_copy = length;
 516
 517        if (dma_q->lines_completed >= dma_q->lines_per_field) {
 518                dma_q->bytes_left_in_line -= bytes_to_copy;
 519                dma_q->is_partial_line =
 520                    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
 521                return 0;
 522        }
 523
 524        dma_q->is_partial_line = 1;
 525
 526        /* If we don't have a buffer, just return the number of bytes we would
 527           have copied if we had a buffer. */
 528        if (!buf) {
 529                dma_q->bytes_left_in_line -= bytes_to_copy;
 530                dma_q->is_partial_line =
 531                    (dma_q->bytes_left_in_line == 0) ? 0 : 1;
 532                return bytes_to_copy;
 533        }
 534
 535        /* copy the data to video buffer */
 536        cx231xx_do_vbi_copy(dev, dma_q, p_line, bytes_to_copy);
 537
 538        dma_q->pos += bytes_to_copy;
 539        dma_q->bytes_left_in_line -= bytes_to_copy;
 540
 541        if (dma_q->bytes_left_in_line == 0) {
 542
 543                dma_q->bytes_left_in_line = _line_size;
 544                dma_q->lines_completed++;
 545                dma_q->is_partial_line = 0;
 546
 547                if (cx231xx_is_vbi_buffer_done(dev, dma_q) && buf) {
 548
 549                        vbi_buffer_filled(dev, dma_q, buf);
 550
 551                        dma_q->pos = 0;
 552                        dma_q->lines_completed = 0;
 553                        cx231xx_reset_vbi_buffer(dev, dma_q);
 554                }
 555        }
 556
 557        return bytes_to_copy;
 558}
 559
 560/*
 561 * video-buf generic routine to get the next available buffer
 562 */
 563static inline void get_next_vbi_buf(struct cx231xx_dmaqueue *dma_q,
 564                                    struct cx231xx_buffer **buf)
 565{
 566        struct cx231xx_video_mode *vmode =
 567            container_of(dma_q, struct cx231xx_video_mode, vidq);
 568        struct cx231xx *dev = container_of(vmode, struct cx231xx, vbi_mode);
 569        char *outp;
 570
 571        if (list_empty(&dma_q->active)) {
 572                dev_err(dev->dev, "No active queue to serve\n");
 573                dev->vbi_mode.bulk_ctl.buf = NULL;
 574                *buf = NULL;
 575                return;
 576        }
 577
 578        /* Get the next buffer */
 579        *buf = list_entry(dma_q->active.next, struct cx231xx_buffer, list);
 580
 581        /* Cleans up buffer - Useful for testing for frame/URB loss */
 582        outp = vb2_plane_vaddr(&(*buf)->vb.vb2_buf, 0);
 583        memset(outp, 0, vb2_plane_size(&(*buf)->vb.vb2_buf, 0));
 584
 585        dev->vbi_mode.bulk_ctl.buf = *buf;
 586
 587        return;
 588}
 589
 590void cx231xx_reset_vbi_buffer(struct cx231xx *dev,
 591                              struct cx231xx_dmaqueue *dma_q)
 592{
 593        struct cx231xx_buffer *buf;
 594
 595        buf = dev->vbi_mode.bulk_ctl.buf;
 596
 597        if (buf == NULL) {
 598                /* first try to get the buffer */
 599                get_next_vbi_buf(dma_q, &buf);
 600
 601                dma_q->pos = 0;
 602                dma_q->current_field = -1;
 603        }
 604
 605        dma_q->bytes_left_in_line = dev->width << 1;
 606        dma_q->lines_completed = 0;
 607}
 608
 609int cx231xx_do_vbi_copy(struct cx231xx *dev, struct cx231xx_dmaqueue *dma_q,
 610                        u8 *p_buffer, u32 bytes_to_copy)
 611{
 612        u8 *p_out_buffer = NULL;
 613        u32 current_line_bytes_copied = 0;
 614        struct cx231xx_buffer *buf;
 615        u32 _line_size = dev->width << 1;
 616        void *startwrite;
 617        int offset, lencopy;
 618
 619        buf = dev->vbi_mode.bulk_ctl.buf;
 620
 621        if (buf == NULL)
 622                return -EINVAL;
 623
 624        p_out_buffer = vb2_plane_vaddr(&buf->vb.vb2_buf, 0);
 625
 626        if (dma_q->bytes_left_in_line != _line_size) {
 627                current_line_bytes_copied =
 628                    _line_size - dma_q->bytes_left_in_line;
 629        }
 630
 631        offset = (dma_q->lines_completed * _line_size) +
 632                 current_line_bytes_copied;
 633
 634        if (dma_q->current_field == 2) {
 635                /* Populate the second half of the frame */
 636                offset += (dev->width * 2 * dma_q->lines_per_field);
 637        }
 638
 639        /* prepare destination address */
 640        startwrite = p_out_buffer + offset;
 641
 642        lencopy = dma_q->bytes_left_in_line > bytes_to_copy ?
 643                  bytes_to_copy : dma_q->bytes_left_in_line;
 644
 645        memcpy(startwrite, p_buffer, lencopy);
 646
 647        return 0;
 648}
 649
 650u8 cx231xx_is_vbi_buffer_done(struct cx231xx *dev,
 651                              struct cx231xx_dmaqueue *dma_q)
 652{
 653        u32 height = 0;
 654
 655        height = ((dev->norm & V4L2_STD_625_50) ?
 656                  PAL_VBI_LINES : NTSC_VBI_LINES);
 657        if (dma_q->lines_completed == height && dma_q->current_field == 2)
 658                return 1;
 659        else
 660                return 0;
 661}
 662