ivtv-fileops.c

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/*
    file operation functions
    Copyright (C) 2003-2004  Kevin Thayer <nufan_wfk at yahoo.com>
    Copyright (C) 2004  Chris Kennedy <[email protected]>
    Copyright (C) 2005-2007  Hans Verkuil <[email protected]>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "ivtv-driver.h"
#include "ivtv-fileops.h"
#include "ivtv-i2c.h"
#include "ivtv-queue.h"
#include "ivtv-udma.h"
#include "ivtv-irq.h"
#include "ivtv-vbi.h"
#include "ivtv-mailbox.h"
#include "ivtv-routing.h"
#include "ivtv-streams.h"
#include "ivtv-yuv.h"
#include "ivtv-ioctl.h"
#include "ivtv-cards.h"
#include "ivtv-firmware.h"
#include <media/v4l2-event.h>
#include <media/saa7115.h>

/* This function tries to claim the stream for a specific file descriptor.
   If no one else is using this stream then the stream is claimed and
   associated VBI streams are also automatically claimed.
   Possible error returns: -EBUSY if someone else has claimed
   the stream or 0 on success. */
int ivtv_claim_stream(struct ivtv_open_id *id, int type)
{
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[type];
    struct ivtv_stream *s_vbi;
    int vbi_type;

    if (test_and_set_bit(IVTV_F_S_CLAIMED, &s->s_flags)) {
        /* someone already claimed this stream */
        if (s->fh == &id->fh) {
            /* yes, this file descriptor did. So that's OK. */
            return 0;
        }
        if (s->fh == NULL && (type == IVTV_DEC_STREAM_TYPE_VBI ||
                     type == IVTV_ENC_STREAM_TYPE_VBI)) {
            /* VBI is handled already internally, now also assign
               the file descriptor to this stream for external
               reading of the stream. */
            s->fh = &id->fh;
            IVTV_DEBUG_INFO("Start Read VBI\n");
            return 0;
        }
        /* someone else is using this stream already */
        IVTV_DEBUG_INFO("Stream %d is busy\n", type);
        return -EBUSY;
    }
    s->fh = &id->fh;
    if (type == IVTV_DEC_STREAM_TYPE_VBI) {
        /* Enable reinsertion interrupt */
        ivtv_clear_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);
    }

    /* IVTV_DEC_STREAM_TYPE_MPG needs to claim IVTV_DEC_STREAM_TYPE_VBI,
       IVTV_ENC_STREAM_TYPE_MPG needs to claim IVTV_ENC_STREAM_TYPE_VBI
       (provided VBI insertion is on and sliced VBI is selected), for all
       other streams we're done */
    if (type == IVTV_DEC_STREAM_TYPE_MPG) {
        vbi_type = IVTV_DEC_STREAM_TYPE_VBI;
    } else if (type == IVTV_ENC_STREAM_TYPE_MPG &&
           itv->vbi.insert_mpeg && !ivtv_raw_vbi(itv)) {
        vbi_type = IVTV_ENC_STREAM_TYPE_VBI;
    } else {
        return 0;
    }
    s_vbi = &itv->streams[vbi_type];

    if (!test_and_set_bit(IVTV_F_S_CLAIMED, &s_vbi->s_flags)) {
        /* Enable reinsertion interrupt */
        if (vbi_type == IVTV_DEC_STREAM_TYPE_VBI)
            ivtv_clear_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);
    }
    /* mark that it is used internally */
    set_bit(IVTV_F_S_INTERNAL_USE, &s_vbi->s_flags);
    return 0;
}
EXPORT_SYMBOL(ivtv_claim_stream);

/* This function releases a previously claimed stream. It will take into
   account associated VBI streams. */
void ivtv_release_stream(struct ivtv_stream *s)
{
    struct ivtv *itv = s->itv;
    struct ivtv_stream *s_vbi;

    s->fh = NULL;
    if ((s->type == IVTV_DEC_STREAM_TYPE_VBI || s->type == IVTV_ENC_STREAM_TYPE_VBI) &&
        test_bit(IVTV_F_S_INTERNAL_USE, &s->s_flags)) {
        /* this stream is still in use internally */
        return;
    }
    if (!test_and_clear_bit(IVTV_F_S_CLAIMED, &s->s_flags)) {
        IVTV_DEBUG_WARN("Release stream %s not in use!\n", s->name);
        return;
    }

    ivtv_flush_queues(s);

    /* disable reinsertion interrupt */
    if (s->type == IVTV_DEC_STREAM_TYPE_VBI)
        ivtv_set_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);

    /* IVTV_DEC_STREAM_TYPE_MPG needs to release IVTV_DEC_STREAM_TYPE_VBI,
       IVTV_ENC_STREAM_TYPE_MPG needs to release IVTV_ENC_STREAM_TYPE_VBI,
       for all other streams we're done */
    if (s->type == IVTV_DEC_STREAM_TYPE_MPG)
        s_vbi = &itv->streams[IVTV_DEC_STREAM_TYPE_VBI];
    else if (s->type == IVTV_ENC_STREAM_TYPE_MPG)
        s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];
    else
        return;

    /* clear internal use flag */
    if (!test_and_clear_bit(IVTV_F_S_INTERNAL_USE, &s_vbi->s_flags)) {
        /* was already cleared */
        return;
    }
    if (s_vbi->fh) {
        /* VBI stream still claimed by a file descriptor */
        return;
    }
    /* disable reinsertion interrupt */
    if (s_vbi->type == IVTV_DEC_STREAM_TYPE_VBI)
        ivtv_set_irq_mask(itv, IVTV_IRQ_DEC_VBI_RE_INSERT);
    clear_bit(IVTV_F_S_CLAIMED, &s_vbi->s_flags);
    ivtv_flush_queues(s_vbi);
}
EXPORT_SYMBOL(ivtv_release_stream);

static void ivtv_dualwatch(struct ivtv *itv)
{
    struct v4l2_tuner vt;
    u32 new_stereo_mode;
    const u32 dual = 0x02;

    new_stereo_mode = v4l2_ctrl_g_ctrl(itv->cxhdl.audio_mode);
    memset(&vt, 0, sizeof(vt));
    ivtv_call_all(itv, tuner, g_tuner, &vt);
    if (vt.audmode == V4L2_TUNER_MODE_LANG1_LANG2 && (vt.rxsubchans & V4L2_TUNER_SUB_LANG2))
        new_stereo_mode = dual;

    if (new_stereo_mode == itv->dualwatch_stereo_mode)
        return;

    IVTV_DEBUG_INFO("dualwatch: change stereo flag from 0x%x to 0x%x.\n",
               itv->dualwatch_stereo_mode, new_stereo_mode);
    if (v4l2_ctrl_s_ctrl(itv->cxhdl.audio_mode, new_stereo_mode))
        IVTV_DEBUG_INFO("dualwatch: changing stereo flag failed\n");
}

static void ivtv_update_pgm_info(struct ivtv *itv)
{
    u32 wr_idx = (read_enc(itv->pgm_info_offset) - itv->pgm_info_offset - 4) / 24;
    int cnt;
    int i = 0;

    if (wr_idx >= itv->pgm_info_num) {
        IVTV_DEBUG_WARN("Invalid PGM index %d (>= %d)\n", wr_idx, itv->pgm_info_num);
        return;
    }
    cnt = (wr_idx + itv->pgm_info_num - itv->pgm_info_write_idx) % itv->pgm_info_num;
    while (i < cnt) {
        int idx = (itv->pgm_info_write_idx + i) % itv->pgm_info_num;
        struct v4l2_enc_idx_entry *e = itv->pgm_info + idx;
        u32 addr = itv->pgm_info_offset + 4 + idx * 24;
        const int mapping[8] = { -1, V4L2_ENC_IDX_FRAME_I, V4L2_ENC_IDX_FRAME_P, -1,
            V4L2_ENC_IDX_FRAME_B, -1, -1, -1 };
                    // 1=I, 2=P, 4=B

        e->offset = read_enc(addr + 4) + ((u64)read_enc(addr + 8) << 32);
        if (e->offset > itv->mpg_data_received) {
            break;
        }
        e->offset += itv->vbi_data_inserted;
        e->length = read_enc(addr);
        e->pts = read_enc(addr + 16) + ((u64)(read_enc(addr + 20) & 1) << 32);
        e->flags = mapping[read_enc(addr + 12) & 7];
        i++;
    }
    itv->pgm_info_write_idx = (itv->pgm_info_write_idx + i) % itv->pgm_info_num;
}

static struct ivtv_buffer *ivtv_get_buffer(struct ivtv_stream *s, int non_block, int *err)
{
    struct ivtv *itv = s->itv;
    struct ivtv_stream *s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];
    struct ivtv_buffer *buf;
    DEFINE_WAIT(wait);

    *err = 0;
    while (1) {
        if (s->type == IVTV_ENC_STREAM_TYPE_MPG) {
            /* Process pending program info updates and pending VBI data */
            ivtv_update_pgm_info(itv);

            if (time_after(jiffies,
                       itv->dualwatch_jiffies +
                       msecs_to_jiffies(1000))) {
                itv->dualwatch_jiffies = jiffies;
                ivtv_dualwatch(itv);
            }

            if (test_bit(IVTV_F_S_INTERNAL_USE, &s_vbi->s_flags) &&
                !test_bit(IVTV_F_S_APPL_IO, &s_vbi->s_flags)) {
                while ((buf = ivtv_dequeue(s_vbi, &s_vbi->q_full))) {
                    /* byteswap and process VBI data */
                    ivtv_process_vbi_data(itv, buf, s_vbi->dma_pts, s_vbi->type);
                    ivtv_enqueue(s_vbi, buf, &s_vbi->q_free);
                }
            }
            buf = &itv->vbi.sliced_mpeg_buf;
            if (buf->readpos != buf->bytesused) {
                return buf;
            }
        }

        /* do we have leftover data? */
        buf = ivtv_dequeue(s, &s->q_io);
        if (buf)
            return buf;

        /* do we have new data? */
        buf = ivtv_dequeue(s, &s->q_full);
        if (buf) {
            if ((buf->b_flags & IVTV_F_B_NEED_BUF_SWAP) == 0)
                return buf;
            buf->b_flags &= ~IVTV_F_B_NEED_BUF_SWAP;
            if (s->type == IVTV_ENC_STREAM_TYPE_MPG)
                /* byteswap MPG data */
                ivtv_buf_swap(buf);
            else if (s->type != IVTV_DEC_STREAM_TYPE_VBI) {
                /* byteswap and process VBI data */
                ivtv_process_vbi_data(itv, buf, s->dma_pts, s->type);
            }
            return buf;
        }

        /* return if end of stream */
        if (s->type != IVTV_DEC_STREAM_TYPE_VBI && !test_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
            IVTV_DEBUG_INFO("EOS %s\n", s->name);
            return NULL;
        }

        /* return if file was opened with O_NONBLOCK */
        if (non_block) {
            *err = -EAGAIN;
            return NULL;
        }

        /* wait for more data to arrive */
        mutex_unlock(&itv->serialize_lock);
        prepare_to_wait(&s->waitq, &wait, TASK_INTERRUPTIBLE);
        /* New buffers might have become available before we were added to the waitqueue */
        if (!s->q_full.buffers)
            schedule();
        finish_wait(&s->waitq, &wait);
        mutex_lock(&itv->serialize_lock);
        if (signal_pending(current)) {
            /* return if a signal was received */
            IVTV_DEBUG_INFO("User stopped %s\n", s->name);
            *err = -EINTR;
            return NULL;
        }
    }
}

static void ivtv_setup_sliced_vbi_buf(struct ivtv *itv)
{
    int idx = itv->vbi.inserted_frame % IVTV_VBI_FRAMES;

    itv->vbi.sliced_mpeg_buf.buf = itv->vbi.sliced_mpeg_data[idx];
    itv->vbi.sliced_mpeg_buf.bytesused = itv->vbi.sliced_mpeg_size[idx];
    itv->vbi.sliced_mpeg_buf.readpos = 0;
}

static size_t ivtv_copy_buf_to_user(struct ivtv_stream *s, struct ivtv_buffer *buf,
        char __user *ubuf, size_t ucount)
{
    struct ivtv *itv = s->itv;
    size_t len = buf->bytesused - buf->readpos;

    if (len > ucount) len = ucount;
    if (itv->vbi.insert_mpeg && s->type == IVTV_ENC_STREAM_TYPE_MPG &&
        !ivtv_raw_vbi(itv) && buf != &itv->vbi.sliced_mpeg_buf) {
        const char *start = buf->buf + buf->readpos;
        const char *p = start + 1;
        const u8 *q;
        u8 ch = itv->search_pack_header ? 0xba : 0xe0;
        int stuffing, i;

        while (start + len > p && (q = memchr(p, 0, start + len - p))) {
            p = q + 1;
            if ((char *)q + 15 >= buf->buf + buf->bytesused ||
                q[1] != 0 || q[2] != 1 || q[3] != ch) {
                continue;
            }
            if (!itv->search_pack_header) {
                if ((q[6] & 0xc0) != 0x80)
                    continue;
                if (((q[7] & 0xc0) == 0x80 && (q[9] & 0xf0) == 0x20) ||
                    ((q[7] & 0xc0) == 0xc0 && (q[9] & 0xf0) == 0x30)) {
                    ch = 0xba;
                    itv->search_pack_header = 1;
                    p = q + 9;
                }
                continue;
            }
            stuffing = q[13] & 7;
            /* all stuffing bytes must be 0xff */
            for (i = 0; i < stuffing; i++)
                if (q[14 + i] != 0xff)
                    break;
            if (i == stuffing && (q[4] & 0xc4) == 0x44 && (q[12] & 3) == 3 &&
                    q[14 + stuffing] == 0 && q[15 + stuffing] == 0 &&
                    q[16 + stuffing] == 1) {
                itv->search_pack_header = 0;
                len = (char *)q - start;
                ivtv_setup_sliced_vbi_buf(itv);
                break;
            }
        }
    }
    if (copy_to_user(ubuf, (u8 *)buf->buf + buf->readpos, len)) {
        IVTV_DEBUG_WARN("copy %zd bytes to user failed for %s\n", len, s->name);
        return -EFAULT;
    }
    /*IVTV_INFO("copied %lld %d %d %d %d %d vbi %d\n", itv->mpg_data_received, len, ucount,
            buf->readpos, buf->bytesused, buf->bytesused - buf->readpos - len,
            buf == &itv->vbi.sliced_mpeg_buf); */
    buf->readpos += len;
    if (s->type == IVTV_ENC_STREAM_TYPE_MPG && buf != &itv->vbi.sliced_mpeg_buf)
        itv->mpg_data_received += len;
    return len;
}

static ssize_t ivtv_read(struct ivtv_stream *s, char __user *ubuf, size_t tot_count, int non_block)
{
    struct ivtv *itv = s->itv;
    size_t tot_written = 0;
    int single_frame = 0;

    if (atomic_read(&itv->capturing) == 0 && s->fh == NULL) {
        /* shouldn't happen */
        IVTV_DEBUG_WARN("Stream %s not initialized before read\n", s->name);
        return -EIO;
    }

    /* Each VBI buffer is one frame, the v4l2 API says that for VBI the frames should
       arrive one-by-one, so make sure we never output more than one VBI frame at a time */
    if (s->type == IVTV_DEC_STREAM_TYPE_VBI ||
        (s->type == IVTV_ENC_STREAM_TYPE_VBI && !ivtv_raw_vbi(itv)))
        single_frame = 1;

    for (;;) {
        struct ivtv_buffer *buf;
        int rc;

        buf = ivtv_get_buffer(s, non_block, &rc);
        /* if there is no data available... */
        if (buf == NULL) {
            /* if we got data, then return that regardless */
            if (tot_written)
                break;
            /* EOS condition */
            if (rc == 0) {
                clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
                clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
                ivtv_release_stream(s);
            }
            /* set errno */
            return rc;
        }
        rc = ivtv_copy_buf_to_user(s, buf, ubuf + tot_written, tot_count - tot_written);
        if (buf != &itv->vbi.sliced_mpeg_buf) {
            ivtv_enqueue(s, buf, (buf->readpos == buf->bytesused) ? &s->q_free : &s->q_io);
        }
        else if (buf->readpos == buf->bytesused) {
            int idx = itv->vbi.inserted_frame % IVTV_VBI_FRAMES;
            itv->vbi.sliced_mpeg_size[idx] = 0;
            itv->vbi.inserted_frame++;
            itv->vbi_data_inserted += buf->bytesused;
        }
        if (rc < 0)
            return rc;
        tot_written += rc;

        if (tot_written == tot_count || single_frame)
            break;
    }
    return tot_written;
}

static ssize_t ivtv_read_pos(struct ivtv_stream *s, char __user *ubuf, size_t count,
            loff_t *pos, int non_block)
{
    ssize_t rc = count ? ivtv_read(s, ubuf, count, non_block) : 0;
    struct ivtv *itv = s->itv;

    IVTV_DEBUG_HI_FILE("read %zd from %s, got %zd\n", count, s->name, rc);
    if (rc > 0)
        pos += rc;
    return rc;
}

int ivtv_start_capture(struct ivtv_open_id *id)
{
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[id->type];
    struct ivtv_stream *s_vbi;

    if (s->type == IVTV_ENC_STREAM_TYPE_RAD ||
        s->type == IVTV_DEC_STREAM_TYPE_MPG ||
        s->type == IVTV_DEC_STREAM_TYPE_YUV ||
        s->type == IVTV_DEC_STREAM_TYPE_VOUT) {
        /* you cannot read from these stream types. */
        return -EINVAL;
    }

    /* Try to claim this stream. */
    if (ivtv_claim_stream(id, s->type))
        return -EBUSY;

    /* This stream does not need to start capturing */
    if (s->type == IVTV_DEC_STREAM_TYPE_VBI) {
        set_bit(IVTV_F_S_APPL_IO, &s->s_flags);
        return 0;
    }

    /* If capture is already in progress, then we also have to
       do nothing extra. */
    if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) || test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
        set_bit(IVTV_F_S_APPL_IO, &s->s_flags);
        return 0;
    }

    /* Start VBI capture if required */
    s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];
    if (s->type == IVTV_ENC_STREAM_TYPE_MPG &&
        test_bit(IVTV_F_S_INTERNAL_USE, &s_vbi->s_flags) &&
        !test_and_set_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags)) {
        /* Note: the IVTV_ENC_STREAM_TYPE_VBI is claimed
           automatically when the MPG stream is claimed.
           We only need to start the VBI capturing. */
        if (ivtv_start_v4l2_encode_stream(s_vbi)) {
            IVTV_DEBUG_WARN("VBI capture start failed\n");

            /* Failure, clean up and return an error */
            clear_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags);
            clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
            /* also releases the associated VBI stream */
            ivtv_release_stream(s);
            return -EIO;
        }
        IVTV_DEBUG_INFO("VBI insertion started\n");
    }

    /* Tell the card to start capturing */
    if (!ivtv_start_v4l2_encode_stream(s)) {
        /* We're done */
        set_bit(IVTV_F_S_APPL_IO, &s->s_flags);
        /* Resume a possibly paused encoder */
        if (test_and_clear_bit(IVTV_F_I_ENC_PAUSED, &itv->i_flags))
            ivtv_vapi(itv, CX2341X_ENC_PAUSE_ENCODER, 1, 1);
        return 0;
    }

    /* failure, clean up */
    IVTV_DEBUG_WARN("Failed to start capturing for stream %s\n", s->name);

    /* Note: the IVTV_ENC_STREAM_TYPE_VBI is released
       automatically when the MPG stream is released.
       We only need to stop the VBI capturing. */
    if (s->type == IVTV_ENC_STREAM_TYPE_MPG &&
        test_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags)) {
        ivtv_stop_v4l2_encode_stream(s_vbi, 0);
        clear_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags);
    }
    clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
    ivtv_release_stream(s);
    return -EIO;
}

ssize_t ivtv_v4l2_read(struct file * filp, char __user *buf, size_t count, loff_t * pos)
{
    struct ivtv_open_id *id = fh2id(filp->private_data);
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[id->type];
    ssize_t rc;

    IVTV_DEBUG_HI_FILE("read %zd bytes from %s\n", count, s->name);

    if (mutex_lock_interruptible(&itv->serialize_lock))
        return -ERESTARTSYS;
    rc = ivtv_start_capture(id);
    if (!rc)
        rc = ivtv_read_pos(s, buf, count, pos, filp->f_flags & O_NONBLOCK);
    mutex_unlock(&itv->serialize_lock);
    return rc;
}

int ivtv_start_decoding(struct ivtv_open_id *id, int speed)
{
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[id->type];
    int rc;

    if (atomic_read(&itv->decoding) == 0) {
        if (ivtv_claim_stream(id, s->type)) {
            /* someone else is using this stream already */
            IVTV_DEBUG_WARN("start decode, stream already claimed\n");
            return -EBUSY;
        }
        rc = ivtv_start_v4l2_decode_stream(s, 0);
        if (rc < 0) {
            if (rc == -EAGAIN)
                rc = ivtv_start_v4l2_decode_stream(s, 0);
            if (rc < 0)
                return rc;
        }
    }
    if (s->type == IVTV_DEC_STREAM_TYPE_MPG)
        return ivtv_set_speed(itv, speed);
    return 0;
}

static ssize_t ivtv_write(struct file *filp, const char __user *user_buf, size_t count, loff_t *pos)
{
    struct ivtv_open_id *id = fh2id(filp->private_data);
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[id->type];
    struct yuv_playback_info *yi = &itv->yuv_info;
    struct ivtv_buffer *buf;
    struct ivtv_queue q;
    int bytes_written = 0;
    int mode;
    int rc;
    DEFINE_WAIT(wait);

    IVTV_DEBUG_HI_FILE("write %zd bytes to %s\n", count, s->name);

    if (s->type != IVTV_DEC_STREAM_TYPE_MPG &&
        s->type != IVTV_DEC_STREAM_TYPE_YUV &&
        s->type != IVTV_DEC_STREAM_TYPE_VOUT)
        /* not decoder streams */
        return -EINVAL;

    /* Try to claim this stream */
    if (ivtv_claim_stream(id, s->type))
        return -EBUSY;

    /* This stream does not need to start any decoding */
    if (s->type == IVTV_DEC_STREAM_TYPE_VOUT) {
        int elems = count / sizeof(struct v4l2_sliced_vbi_data);

        set_bit(IVTV_F_S_APPL_IO, &s->s_flags);
        return ivtv_write_vbi_from_user(itv,
           (const struct v4l2_sliced_vbi_data __user *)user_buf, elems);
    }

    mode = s->type == IVTV_DEC_STREAM_TYPE_MPG ? OUT_MPG : OUT_YUV;

    if (ivtv_set_output_mode(itv, mode) != mode) {
        ivtv_release_stream(s);
        return -EBUSY;
    }
    ivtv_queue_init(&q);
    set_bit(IVTV_F_S_APPL_IO, &s->s_flags);

    /* Start decoder (returns 0 if already started) */
    rc = ivtv_start_decoding(id, itv->speed);
    if (rc) {
        IVTV_DEBUG_WARN("Failed start decode stream %s\n", s->name);

        /* failure, clean up */
        clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
        clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
        return rc;
    }

retry:
    /* If possible, just DMA the entire frame - Check the data transfer size
    since we may get here before the stream has been fully set-up */
    if (mode == OUT_YUV && s->q_full.length == 0 && itv->dma_data_req_size) {
        while (count >= itv->dma_data_req_size) {
            rc = ivtv_yuv_udma_stream_frame(itv, (void __user *)user_buf);

            if (rc < 0)
                return rc;

            bytes_written += itv->dma_data_req_size;
            user_buf += itv->dma_data_req_size;
            count -= itv->dma_data_req_size;
        }
        if (count == 0) {
            IVTV_DEBUG_HI_FILE("Wrote %d bytes to %s (%d)\n", bytes_written, s->name, s->q_full.bytesused);
            return bytes_written;
        }
    }

    for (;;) {
        /* Gather buffers */
        while (q.length - q.bytesused < count && (buf = ivtv_dequeue(s, &s->q_io)))
            ivtv_enqueue(s, buf, &q);
        while (q.length - q.bytesused < count && (buf = ivtv_dequeue(s, &s->q_free))) {
            ivtv_enqueue(s, buf, &q);
        }
        if (q.buffers)
            break;
        if (filp->f_flags & O_NONBLOCK)
            return -EAGAIN;
        mutex_unlock(&itv->serialize_lock);
        prepare_to_wait(&s->waitq, &wait, TASK_INTERRUPTIBLE);
        /* New buffers might have become free before we were added to the waitqueue */
        if (!s->q_free.buffers)
            schedule();
        finish_wait(&s->waitq, &wait);
        mutex_lock(&itv->serialize_lock);
        if (signal_pending(current)) {
            IVTV_DEBUG_INFO("User stopped %s\n", s->name);
            return -EINTR;
        }
    }

    /* copy user data into buffers */
    while ((buf = ivtv_dequeue(s, &q))) {
        /* yuv is a pain. Don't copy more data than needed for a single
           frame, otherwise we lose sync with the incoming stream */
        if (s->type == IVTV_DEC_STREAM_TYPE_YUV &&
            yi->stream_size + count > itv->dma_data_req_size)
            rc  = ivtv_buf_copy_from_user(s, buf, user_buf,
                itv->dma_data_req_size - yi->stream_size);
        else
            rc = ivtv_buf_copy_from_user(s, buf, user_buf, count);

        /* Make sure we really got all the user data */
        if (rc < 0) {
            ivtv_queue_move(s, &q, NULL, &s->q_free, 0);
            return rc;
        }
        user_buf += rc;
        count -= rc;
        bytes_written += rc;

        if (s->type == IVTV_DEC_STREAM_TYPE_YUV) {
            yi->stream_size += rc;
            /* If we have a complete yuv frame, break loop now */
            if (yi->stream_size == itv->dma_data_req_size) {
                ivtv_enqueue(s, buf, &s->q_full);
                yi->stream_size = 0;
                break;
            }
        }

        if (buf->bytesused != s->buf_size) {
            /* incomplete, leave in q_io for next time */
            ivtv_enqueue(s, buf, &s->q_io);
            break;
        }
        /* Byteswap MPEG buffer */
        if (s->type == IVTV_DEC_STREAM_TYPE_MPG)
            ivtv_buf_swap(buf);
        ivtv_enqueue(s, buf, &s->q_full);
    }

    if (test_bit(IVTV_F_S_NEEDS_DATA, &s->s_flags)) {
        if (s->q_full.length >= itv->dma_data_req_size) {
            int got_sig;

            if (mode == OUT_YUV)
                ivtv_yuv_setup_stream_frame(itv);

            mutex_unlock(&itv->serialize_lock);
            prepare_to_wait(&itv->dma_waitq, &wait, TASK_INTERRUPTIBLE);
            while (!(got_sig = signal_pending(current)) &&
                    test_bit(IVTV_F_S_DMA_PENDING, &s->s_flags)) {
                schedule();
            }
            finish_wait(&itv->dma_waitq, &wait);
            mutex_lock(&itv->serialize_lock);
            if (got_sig) {
                IVTV_DEBUG_INFO("User interrupted %s\n", s->name);
                return -EINTR;
            }

            clear_bit(IVTV_F_S_NEEDS_DATA, &s->s_flags);
            ivtv_queue_move(s, &s->q_full, NULL, &s->q_predma, itv->dma_data_req_size);
            ivtv_dma_stream_dec_prepare(s, itv->dma_data_req_offset + IVTV_DECODER_OFFSET, 1);
        }
    }
    /* more user data is available, wait until buffers become free
       to transfer the rest. */
    if (count && !(filp->f_flags & O_NONBLOCK))
        goto retry;
    IVTV_DEBUG_HI_FILE("Wrote %d bytes to %s (%d)\n", bytes_written, s->name, s->q_full.bytesused);
    return bytes_written;
}

ssize_t ivtv_v4l2_write(struct file *filp, const char __user *user_buf, size_t count, loff_t *pos)
{
    struct ivtv_open_id *id = fh2id(filp->private_data);
    struct ivtv *itv = id->itv;
    ssize_t res;

    if (mutex_lock_interruptible(&itv->serialize_lock))
        return -ERESTARTSYS;
    res = ivtv_write(filp, user_buf, count, pos);
    mutex_unlock(&itv->serialize_lock);
    return res;
}

unsigned int ivtv_v4l2_dec_poll(struct file *filp, poll_table *wait)
{
    struct ivtv_open_id *id = fh2id(filp->private_data);
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[id->type];
    int res = 0;

    /* add stream's waitq to the poll list */
    IVTV_DEBUG_HI_FILE("Decoder poll\n");

    /* If there are subscribed events, then only use the new event
       API instead of the old video.h based API. */
    if (!list_empty(&id->fh.subscribed)) {
        poll_wait(filp, &id->fh.wait, wait);
        /* Turn off the old-style vsync events */
        clear_bit(IVTV_F_I_EV_VSYNC_ENABLED, &itv->i_flags);
        if (v4l2_event_pending(&id->fh))
            res = POLLPRI;
    } else {
        /* This is the old-style API which is here only for backwards
           compatibility. */
        poll_wait(filp, &s->waitq, wait);
        set_bit(IVTV_F_I_EV_VSYNC_ENABLED, &itv->i_flags);
        if (test_bit(IVTV_F_I_EV_VSYNC, &itv->i_flags) ||
            test_bit(IVTV_F_I_EV_DEC_STOPPED, &itv->i_flags))
            res = POLLPRI;
    }

    /* Allow write if buffers are available for writing */
    if (s->q_free.buffers)
        res |= POLLOUT | POLLWRNORM;
    return res;
}

unsigned int ivtv_v4l2_enc_poll(struct file *filp, poll_table *wait)
{
    unsigned long req_events = poll_requested_events(wait);
    struct ivtv_open_id *id = fh2id(filp->private_data);
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[id->type];
    int eof = test_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
    unsigned res = 0;

    /* Start a capture if there is none */
    if (!eof && !test_bit(IVTV_F_S_STREAMING, &s->s_flags) &&
            s->type != IVTV_ENC_STREAM_TYPE_RAD &&
            (req_events & (POLLIN | POLLRDNORM))) {
        int rc;

        mutex_lock(&itv->serialize_lock);
        rc = ivtv_start_capture(id);
        mutex_unlock(&itv->serialize_lock);
        if (rc) {
            IVTV_DEBUG_INFO("Could not start capture for %s (%d)\n",
                    s->name, rc);
            return POLLERR;
        }
        IVTV_DEBUG_FILE("Encoder poll started capture\n");
    }

    /* add stream's waitq to the poll list */
    IVTV_DEBUG_HI_FILE("Encoder poll\n");
    poll_wait(filp, &s->waitq, wait);
    if (v4l2_event_pending(&id->fh))
        res |= POLLPRI;
    else
        poll_wait(filp, &id->fh.wait, wait);

    if (s->q_full.length || s->q_io.length)
        return res | POLLIN | POLLRDNORM;
    if (eof)
        return res | POLLHUP;
    return res;
}

void ivtv_stop_capture(struct ivtv_open_id *id, int gop_end)
{
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[id->type];

    IVTV_DEBUG_FILE("close() of %s\n", s->name);

    /* 'Unclaim' this stream */

    /* Stop capturing */
    if (test_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
        struct ivtv_stream *s_vbi = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];

        IVTV_DEBUG_INFO("close stopping capture\n");
        /* Special case: a running VBI capture for VBI insertion
           in the mpeg stream. Need to stop that too. */
        if (id->type == IVTV_ENC_STREAM_TYPE_MPG &&
            test_bit(IVTV_F_S_STREAMING, &s_vbi->s_flags) &&
            !test_bit(IVTV_F_S_APPL_IO, &s_vbi->s_flags)) {
            IVTV_DEBUG_INFO("close stopping embedded VBI capture\n");
            ivtv_stop_v4l2_encode_stream(s_vbi, 0);
        }
        if ((id->type == IVTV_DEC_STREAM_TYPE_VBI ||
             id->type == IVTV_ENC_STREAM_TYPE_VBI) &&
            test_bit(IVTV_F_S_INTERNAL_USE, &s->s_flags)) {
            /* Also used internally, don't stop capturing */
            s->fh = NULL;
        }
        else {
            ivtv_stop_v4l2_encode_stream(s, gop_end);
        }
    }
    if (!gop_end) {
        clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
        clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
        ivtv_release_stream(s);
    }
}

static void ivtv_stop_decoding(struct ivtv_open_id *id, int flags, u64 pts)
{
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[id->type];

    IVTV_DEBUG_FILE("close() of %s\n", s->name);

    if (id->type == IVTV_DEC_STREAM_TYPE_YUV &&
        test_bit(IVTV_F_I_DECODING_YUV, &itv->i_flags)) {
        /* Restore registers we've changed & clean up any mess */
        ivtv_yuv_close(itv);
    }

    /* Stop decoding */
    if (test_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
        IVTV_DEBUG_INFO("close stopping decode\n");

        ivtv_stop_v4l2_decode_stream(s, flags, pts);
        itv->output_mode = OUT_NONE;
    }
    clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
    clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);

    if (itv->output_mode == OUT_UDMA_YUV && id->yuv_frames)
        itv->output_mode = OUT_NONE;

    itv->speed = 0;
    clear_bit(IVTV_F_I_DEC_PAUSED, &itv->i_flags);
    ivtv_release_stream(s);
}

int ivtv_v4l2_close(struct file *filp)
{
    struct v4l2_fh *fh = filp->private_data;
    struct ivtv_open_id *id = fh2id(fh);
    struct ivtv *itv = id->itv;
    struct ivtv_stream *s = &itv->streams[id->type];

    IVTV_DEBUG_FILE("close %s\n", s->name);

    mutex_lock(&itv->serialize_lock);

    /* Stop radio */
    if (id->type == IVTV_ENC_STREAM_TYPE_RAD &&
            v4l2_fh_is_singular_file(filp)) {
        /* Closing radio device, return to TV mode */
        ivtv_mute(itv);
        /* Mark that the radio is no longer in use */
        clear_bit(IVTV_F_I_RADIO_USER, &itv->i_flags);
        /* Switch tuner to TV */
        ivtv_call_all(itv, core, s_std, itv->std);
        /* Select correct audio input (i.e. TV tuner or Line in) */
        ivtv_audio_set_io(itv);
        if (itv->hw_flags & IVTV_HW_SAA711X) {
            ivtv_call_hw(itv, IVTV_HW_SAA711X, video, s_crystal_freq,
                    SAA7115_FREQ_32_11_MHZ, 0);
        }
        if (atomic_read(&itv->capturing) > 0) {
            /* Undo video mute */
            ivtv_vapi(itv, CX2341X_ENC_MUTE_VIDEO, 1,
                    v4l2_ctrl_g_ctrl(itv->cxhdl.video_mute) |
                    (v4l2_ctrl_g_ctrl(itv->cxhdl.video_mute_yuv) << 8));
        }
        /* Done! Unmute and continue. */
        ivtv_unmute(itv);
    }

    v4l2_fh_del(fh);
    v4l2_fh_exit(fh);

    /* Easy case first: this stream was never claimed by us */
    if (s->fh != &id->fh)
        goto close_done;

    /* 'Unclaim' this stream */

    if (s->type >= IVTV_DEC_STREAM_TYPE_MPG) {
        struct ivtv_stream *s_vout = &itv->streams[IVTV_DEC_STREAM_TYPE_VOUT];

        ivtv_stop_decoding(id, V4L2_DEC_CMD_STOP_TO_BLACK | V4L2_DEC_CMD_STOP_IMMEDIATELY, 0);

        /* If all output streams are closed, and if the user doesn't have
           IVTV_DEC_STREAM_TYPE_VOUT open, then disable CC on TV-out. */
        if (itv->output_mode == OUT_NONE && !test_bit(IVTV_F_S_APPL_IO, &s_vout->s_flags)) {
            /* disable CC on TV-out */
            ivtv_disable_cc(itv);
        }
    } else {
        ivtv_stop_capture(id, 0);
    }
close_done:
    kfree(id);
    mutex_unlock(&itv->serialize_lock);
    return 0;
}

static int ivtv_open(struct file *filp)
{
    struct video_device *vdev = video_devdata(filp);
    struct ivtv_stream *s = video_get_drvdata(vdev);
    struct ivtv *itv = s->itv;
    struct ivtv_open_id *item;
    int res = 0;

    IVTV_DEBUG_FILE("open %s\n", s->name);

    if (ivtv_init_on_first_open(itv)) {
        IVTV_ERR("Failed to initialize on device %s\n",
             video_device_node_name(vdev));
        return -ENXIO;
    }

#ifdef CONFIG_VIDEO_ADV_DEBUG
    /* Unless ivtv_fw_debug is set, error out if firmware dead. */
    if (ivtv_fw_debug) {
        IVTV_WARN("Opening %s with dead firmware lockout disabled\n",
              video_device_node_name(vdev));
        IVTV_WARN("Selected firmware errors will be ignored\n");
    } else {
#else
    if (1) {
#endif
        res = ivtv_firmware_check(itv, "ivtv_serialized_open");
        if (res == -EAGAIN)
            res = ivtv_firmware_check(itv, "ivtv_serialized_open");
        if (res < 0)
            return -EIO;
    }

    if (s->type == IVTV_DEC_STREAM_TYPE_MPG &&
        test_bit(IVTV_F_S_CLAIMED, &itv->streams[IVTV_DEC_STREAM_TYPE_YUV].s_flags))
        return -EBUSY;

    if (s->type == IVTV_DEC_STREAM_TYPE_YUV &&
        test_bit(IVTV_F_S_CLAIMED, &itv->streams[IVTV_DEC_STREAM_TYPE_MPG].s_flags))
        return -EBUSY;

    if (s->type == IVTV_DEC_STREAM_TYPE_YUV) {
        if (read_reg(0x82c) == 0) {
            IVTV_ERR("Tried to open YUV output device but need to send data to mpeg decoder before it can be used\n");
            /* return -ENODEV; */
        }
        ivtv_udma_alloc(itv);
    }

    /* Allocate memory */
    item = kzalloc(sizeof(struct ivtv_open_id), GFP_KERNEL);
    if (NULL == item) {
        IVTV_DEBUG_WARN("nomem on v4l2 open\n");
        return -ENOMEM;
    }
    v4l2_fh_init(&item->fh, s->vdev);
    item->itv = itv;
    item->type = s->type;

    filp->private_data = &item->fh;
    v4l2_fh_add(&item->fh);

    if (item->type == IVTV_ENC_STREAM_TYPE_RAD &&
            v4l2_fh_is_singular_file(filp)) {
        if (!test_bit(IVTV_F_I_RADIO_USER, &itv->i_flags)) {
            if (atomic_read(&itv->capturing) > 0) {
                /* switching to radio while capture is
                   in progress is not polite */
                v4l2_fh_del(&item->fh);
                v4l2_fh_exit(&item->fh);
                kfree(item);
                return -EBUSY;
            }
        }
        /* Mark that the radio is being used. */
        set_bit(IVTV_F_I_RADIO_USER, &itv->i_flags);
        /* We have the radio */
        ivtv_mute(itv);
        /* Switch tuner to radio */
        ivtv_call_all(itv, tuner, s_radio);
        /* Select the correct audio input (i.e. radio tuner) */
        ivtv_audio_set_io(itv);
        if (itv->hw_flags & IVTV_HW_SAA711X) {
            ivtv_call_hw(itv, IVTV_HW_SAA711X, video, s_crystal_freq,
                SAA7115_FREQ_32_11_MHZ, SAA7115_FREQ_FL_APLL);
        }
        /* Done! Unmute and continue. */
        ivtv_unmute(itv);
    }

    /* YUV or MPG Decoding Mode? */
    if (s->type == IVTV_DEC_STREAM_TYPE_MPG) {
        clear_bit(IVTV_F_I_DEC_YUV, &itv->i_flags);
    } else if (s->type == IVTV_DEC_STREAM_TYPE_YUV) {
        set_bit(IVTV_F_I_DEC_YUV, &itv->i_flags);
        /* For yuv, we need to know the dma size before we start */
        itv->dma_data_req_size =
                1080 * ((itv->yuv_info.v4l2_src_h + 31) & ~31);
        itv->yuv_info.stream_size = 0;
    }
    return 0;
}

int ivtv_v4l2_open(struct file *filp)
{
    struct video_device *vdev = video_devdata(filp);
    int res;

    if (mutex_lock_interruptible(vdev->lock))
        return -ERESTARTSYS;
    res = ivtv_open(filp);
    mutex_unlock(vdev->lock);
    return res;
}

void ivtv_mute(struct ivtv *itv)
{
    if (atomic_read(&itv->capturing))
        ivtv_vapi(itv, CX2341X_ENC_MUTE_AUDIO, 1, 1);
    IVTV_DEBUG_INFO("Mute\n");
}

void ivtv_unmute(struct ivtv *itv)
{
    if (atomic_read(&itv->capturing)) {
        ivtv_msleep_timeout(100, 0);
        ivtv_vapi(itv, CX2341X_ENC_MISC, 1, 12);
        ivtv_vapi(itv, CX2341X_ENC_MUTE_AUDIO, 1, 0);
    }
    IVTV_DEBUG_INFO("Unmute\n");
}