/*
 *  Driver for the NXP SAA7164 PCIe bridge
 *
 *  Copyright (c) 2010-2015 Steven Toth <stoth@kernellabs.com>
 *
 *  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.
 */

#include "saa7164.h"

/* Take the encoder configuration from the port struct and
 * flush it to the hardware.
 */
static void saa7164_vbi_configure(struct saa7164_port *port)
{
        struct saa7164_dev *dev = port->dev;
        dprintk(DBGLVL_VBI, "%s()\n", __func__);

        port->vbi_params.width = port->enc_port->width;
        port->vbi_params.height = port->enc_port->height;
        port->vbi_params.is_50hz =
                (port->enc_port->encodernorm.id & V4L2_STD_625_50) != 0;

        /* Set up the DIF (enable it) for analog mode by default */
        saa7164_api_initialize_dif(port);
        dprintk(DBGLVL_VBI, "%s() ends\n", __func__);
}

static int saa7164_vbi_buffers_dealloc(struct saa7164_port *port)
{
        struct list_head *c, *n, *p, *q, *l, *v;
        struct saa7164_dev *dev = port->dev;
        struct saa7164_buffer *buf;
        struct saa7164_user_buffer *ubuf;

        /* Remove any allocated buffers */
        mutex_lock(&port->dmaqueue_lock);

        dprintk(DBGLVL_VBI, "%s(port=%d) dmaqueue\n", __func__, port->nr);
        list_for_each_safe(c, n, &port->dmaqueue.list) {
                buf = list_entry(c, struct saa7164_buffer, list);
                list_del(c);
                saa7164_buffer_dealloc(buf);
        }

        dprintk(DBGLVL_VBI, "%s(port=%d) used\n", __func__, port->nr);
        list_for_each_safe(p, q, &port->list_buf_used.list) {
                ubuf = list_entry(p, struct saa7164_user_buffer, list);
                list_del(p);
                saa7164_buffer_dealloc_user(ubuf);
        }

        dprintk(DBGLVL_VBI, "%s(port=%d) free\n", __func__, port->nr);
        list_for_each_safe(l, v, &port->list_buf_free.list) {
                ubuf = list_entry(l, struct saa7164_user_buffer, list);
                list_del(l);
                saa7164_buffer_dealloc_user(ubuf);
        }

        mutex_unlock(&port->dmaqueue_lock);
        dprintk(DBGLVL_VBI, "%s(port=%d) done\n", __func__, port->nr);

        return 0;
}

/* Dynamic buffer switch at vbi start time */
static int saa7164_vbi_buffers_alloc(struct saa7164_port *port)
{
        struct saa7164_dev *dev = port->dev;
        struct saa7164_buffer *buf;
        struct saa7164_user_buffer *ubuf;
        struct tmHWStreamParameters *params = &port->hw_streamingparams;
        int result = -ENODEV, i;
        int len = 0;

        dprintk(DBGLVL_VBI, "%s()\n", __func__);

        /* TODO: NTSC SPECIFIC */
        /* Init and establish defaults */
        params->samplesperline = 1440;
        params->numberoflines = 12;
        params->numberoflines = 18;
        params->pitch = 1600;
        params->pitch = 1440;
        params->numpagetables = 2 +
                ((params->numberoflines * params->pitch) / PAGE_SIZE);
        params->bitspersample = 8;
        params->linethreshold = 0;
        params->pagetablelistvirt = NULL;
        params->pagetablelistphys = NULL;
        params->numpagetableentries = port->hwcfg.buffercount;

        /* Allocate the PCI resources, buffers (hard) */
        for (i = 0; i < port->hwcfg.buffercount; i++) {
                buf = saa7164_buffer_alloc(port,
                        params->numberoflines *
                        params->pitch);

                if (!buf) {
                        printk(KERN_ERR "%s() failed (errno = %d), unable to allocate buffer\n",
                                __func__, result);
                        result = -ENOMEM;
                        goto failed;
                } else {

                        mutex_lock(&port->dmaqueue_lock);
                        list_add_tail(&buf->list, &port->dmaqueue.list);
                        mutex_unlock(&port->dmaqueue_lock);

                }
        }

        /* Allocate some kernel buffers for copying
         * to userpsace.
         */
        len = params->numberoflines * params->pitch;

        if (vbi_buffers < 16)
                vbi_buffers = 16;
        if (vbi_buffers > 512)
                vbi_buffers = 512;

        for (i = 0; i < vbi_buffers; i++) {

                ubuf = saa7164_buffer_alloc_user(dev, len);
                if (ubuf) {
                        mutex_lock(&port->dmaqueue_lock);
                        list_add_tail(&ubuf->list, &port->list_buf_free.list);
                        mutex_unlock(&port->dmaqueue_lock);
                }

        }

        result = 0;

failed:
        return result;
}


static int saa7164_vbi_initialize(struct saa7164_port *port)
{
        saa7164_vbi_configure(port);
        return 0;
}

/* -- V4L2 --------------------------------------------------------- */
static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id id)
{
        struct saa7164_vbi_fh *fh = file->private_data;

        return saa7164_s_std(fh->port->enc_port, id);
}

static int vidioc_g_std(struct file *file, void *priv, v4l2_std_id *id)
{
        struct saa7164_encoder_fh *fh = file->private_data;

        return saa7164_g_std(fh->port->enc_port, id);
}

static int vidioc_g_input(struct file *file, void *priv, unsigned int *i)
{
        struct saa7164_vbi_fh *fh = file->private_data;

        return saa7164_g_input(fh->port->enc_port, i);
}

static int vidioc_s_input(struct file *file, void *priv, unsigned int i)
{
        struct saa7164_vbi_fh *fh = file->private_data;

        return saa7164_s_input(fh->port->enc_port, i);
}

static int vidioc_g_frequency(struct file *file, void *priv,
        struct v4l2_frequency *f)
{
        struct saa7164_vbi_fh *fh = file->private_data;

        return saa7164_g_frequency(fh->port->enc_port, f);
}

static int vidioc_s_frequency(struct file *file, void *priv,
        const struct v4l2_frequency *f)
{
        struct saa7164_vbi_fh *fh = file->private_data;
        int ret = saa7164_s_frequency(fh->port->enc_port, f);

        if (ret == 0)
                saa7164_vbi_initialize(fh->port);
        return ret;
}

static int vidioc_querycap(struct file *file, void  *priv,
        struct v4l2_capability *cap)
{
        struct saa7164_vbi_fh *fh = file->private_data;
        struct saa7164_port *port = fh->port;
        struct saa7164_dev *dev = port->dev;

        strcpy(cap->driver, dev->name);
        strlcpy(cap->card, saa7164_boards[dev->board].name,
                sizeof(cap->card));
        sprintf(cap->bus_info, "PCI:%s", pci_name(dev->pci));

        cap->device_caps =
                V4L2_CAP_VBI_CAPTURE |
                V4L2_CAP_READWRITE |
                V4L2_CAP_TUNER;

        cap->capabilities = cap->device_caps |
                V4L2_CAP_VIDEO_CAPTURE |
                V4L2_CAP_DEVICE_CAPS;

        return 0;
}

static int saa7164_vbi_stop_port(struct saa7164_port *port)
{
        struct saa7164_dev *dev = port->dev;
        int ret;

        ret = saa7164_api_transition_port(port, SAA_DMASTATE_STOP);
        if ((ret != SAA_OK) && (ret != SAA_ERR_ALREADY_STOPPED)) {
                printk(KERN_ERR "%s() stop transition failed, ret = 0x%x\n",
                        __func__, ret);
                ret = -EIO;
        } else {
                dprintk(DBGLVL_VBI, "%s()    Stopped\n", __func__);
                ret = 0;
        }

        return ret;
}

static int saa7164_vbi_acquire_port(struct saa7164_port *port)
{
        struct saa7164_dev *dev = port->dev;
        int ret;

        ret = saa7164_api_transition_port(port, SAA_DMASTATE_ACQUIRE);
        if ((ret != SAA_OK) && (ret != SAA_ERR_ALREADY_STOPPED)) {
                printk(KERN_ERR "%s() acquire transition failed, ret = 0x%x\n",
                        __func__, ret);
                ret = -EIO;
        } else {
                dprintk(DBGLVL_VBI, "%s() Acquired\n", __func__);
                ret = 0;
        }

        return ret;
}

static int saa7164_vbi_pause_port(struct saa7164_port *port)
{
        struct saa7164_dev *dev = port->dev;
        int ret;

        ret = saa7164_api_transition_port(port, SAA_DMASTATE_PAUSE);
        if ((ret != SAA_OK) && (ret != SAA_ERR_ALREADY_STOPPED)) {
                printk(KERN_ERR "%s() pause transition failed, ret = 0x%x\n",
                        __func__, ret);
                ret = -EIO;
        } else {
                dprintk(DBGLVL_VBI, "%s()   Paused\n", __func__);
                ret = 0;
        }

        return ret;
}

/* Firmware is very windows centric, meaning you have to transition
 * the part through AVStream / KS Windows stages, forwards or backwards.
 * States are: stopped, acquired (h/w), paused, started.
 * We have to leave here will all of the soft buffers on the free list,
 * else the cfg_post() func won't have soft buffers to correctly configure.
 */
static int saa7164_vbi_stop_streaming(struct saa7164_port *port)
{
        struct saa7164_dev *dev = port->dev;
        struct saa7164_buffer *buf;
        struct saa7164_user_buffer *ubuf;
        struct list_head *c, *n;
        int ret;

        dprintk(DBGLVL_VBI, "%s(port=%d)\n", __func__, port->nr);

        ret = saa7164_vbi_pause_port(port);
        ret = saa7164_vbi_acquire_port(port);
        ret = saa7164_vbi_stop_port(port);

        dprintk(DBGLVL_VBI, "%s(port=%d) Hardware stopped\n", __func__,
                port->nr);

        /* Reset the state of any allocated buffer resources */
        mutex_lock(&port->dmaqueue_lock);

        /* Reset the hard and soft buffer state */
        list_for_each_safe(c, n, &port->dmaqueue.list) {
                buf = list_entry(c, struct saa7164_buffer, list);
                buf->flags = SAA7164_BUFFER_FREE;
                buf->pos = 0;
        }

        list_for_each_safe(c, n, &port->list_buf_used.list) {
                ubuf = list_entry(c, struct saa7164_user_buffer, list);
                ubuf->pos = 0;
                list_move_tail(&ubuf->list, &port->list_buf_free.list);
        }

        mutex_unlock(&port->dmaqueue_lock);

        /* Free any allocated resources */
        saa7164_vbi_buffers_dealloc(port);

        dprintk(DBGLVL_VBI, "%s(port=%d) Released\n", __func__, port->nr);

        return ret;
}

static int saa7164_vbi_start_streaming(struct saa7164_port *port)
{
        struct saa7164_dev *dev = port->dev;
        int result, ret = 0;

        dprintk(DBGLVL_VBI, "%s(port=%d)\n", __func__, port->nr);

        port->done_first_interrupt = 0;

        /* allocate all of the PCIe DMA buffer resources on the fly,
         * allowing switching between TS and PS payloads without
         * requiring a complete driver reload.
         */
        saa7164_vbi_buffers_alloc(port);

        /* Configure the encoder with any cache values */
#if 0
        saa7164_api_set_encoder(port);
        saa7164_api_get_encoder(port);
#endif

        /* Place the empty buffers on the hardware */
        saa7164_buffer_cfg_port(port);

        /* Negotiate format */
        if (saa7164_api_set_vbi_format(port) != SAA_OK) {
                printk(KERN_ERR "%s() No supported VBI format\n", __func__);
                ret = -EIO;
                goto out;
        }

        /* Acquire the hardware */
        result = saa7164_api_transition_port(port, SAA_DMASTATE_ACQUIRE);
        if ((result != SAA_OK) && (result != SAA_ERR_ALREADY_STOPPED)) {
                printk(KERN_ERR "%s() acquire transition failed, res = 0x%x\n",
                        __func__, result);

                ret = -EIO;
                goto out;
        } else
                dprintk(DBGLVL_VBI, "%s()   Acquired\n", __func__);

        /* Pause the hardware */
        result = saa7164_api_transition_port(port, SAA_DMASTATE_PAUSE);
        if ((result != SAA_OK) && (result != SAA_ERR_ALREADY_STOPPED)) {
                printk(KERN_ERR "%s() pause transition failed, res = 0x%x\n",
                                __func__, result);

                /* Stop the hardware, regardless */
                result = saa7164_vbi_stop_port(port);
                if (result != SAA_OK) {
                        printk(KERN_ERR "%s() pause/forced stop transition failed, res = 0x%x\n",
                               __func__, result);
                }

                ret = -EIO;
                goto out;
        } else
                dprintk(DBGLVL_VBI, "%s()   Paused\n", __func__);

        /* Start the hardware */
        result = saa7164_api_transition_port(port, SAA_DMASTATE_RUN);
        if ((result != SAA_OK) && (result != SAA_ERR_ALREADY_STOPPED)) {
                printk(KERN_ERR "%s() run transition failed, result = 0x%x\n",
                                __func__, result);

                /* Stop the hardware, regardless */
                result = saa7164_vbi_acquire_port(port);
                result = saa7164_vbi_stop_port(port);
                if (result != SAA_OK) {
                        printk(KERN_ERR "%s() run/forced stop transition failed, res = 0x%x\n",
                               __func__, result);
                }

                ret = -EIO;
        } else
                dprintk(DBGLVL_VBI, "%s()   Running\n", __func__);

out:
        return ret;
}

static int saa7164_vbi_fmt(struct file *file, void *priv,
                           struct v4l2_format *f)
{
        /* ntsc */
        f->fmt.vbi.samples_per_line = 1440;
        f->fmt.vbi.sampling_rate = 27000000;
        f->fmt.vbi.sample_format = V4L2_PIX_FMT_GREY;
        f->fmt.vbi.offset = 0;
        f->fmt.vbi.flags = 0;
        f->fmt.vbi.start[0] = 10;
        f->fmt.vbi.count[0] = 18;
        f->fmt.vbi.start[1] = 263 + 10 + 1;
        f->fmt.vbi.count[1] = 18;
        memset(f->fmt.vbi.reserved, 0, sizeof(f->fmt.vbi.reserved));
        return 0;
}

static int fops_open(struct file *file)
{
        struct saa7164_dev *dev;
        struct saa7164_port *port;
        struct saa7164_vbi_fh *fh;

        port = (struct saa7164_port *)video_get_drvdata(video_devdata(file));
        if (!port)
                return -ENODEV;

        dev = port->dev;

        dprintk(DBGLVL_VBI, "%s()\n", __func__);

        /* allocate + initialize per filehandle data */
        fh = kzalloc(sizeof(*fh), GFP_KERNEL);
        if (NULL == fh)
                return -ENOMEM;

        fh->port = port;
        v4l2_fh_init(&fh->fh, video_devdata(file));
        v4l2_fh_add(&fh->fh);
        file->private_data = fh;

        return 0;
}

static int fops_release(struct file *file)
{
        struct saa7164_vbi_fh *fh = file->private_data;
        struct saa7164_port *port = fh->port;
        struct saa7164_dev *dev = port->dev;

        dprintk(DBGLVL_VBI, "%s()\n", __func__);

        /* Shut device down on last close */
        if (atomic_cmpxchg(&fh->v4l_reading, 1, 0) == 1) {
                if (atomic_dec_return(&port->v4l_reader_count) == 0) {
                        /* stop vbi capture then cancel buffers */
                        saa7164_vbi_stop_streaming(port);
                }
        }

        v4l2_fh_del(&fh->fh);
        v4l2_fh_exit(&fh->fh);
        kfree(fh);

        return 0;
}

static struct
saa7164_user_buffer *saa7164_vbi_next_buf(struct saa7164_port *port)
{
        struct saa7164_user_buffer *ubuf = NULL;
        struct saa7164_dev *dev = port->dev;
        u32 crc;

        mutex_lock(&port->dmaqueue_lock);
        if (!list_empty(&port->list_buf_used.list)) {
                ubuf = list_first_entry(&port->list_buf_used.list,
                        struct saa7164_user_buffer, list);

                if (crc_checking) {
                        crc = crc32(0, ubuf->data, ubuf->actual_size);
                        if (crc != ubuf->crc) {
                                printk(KERN_ERR "%s() ubuf %p crc became invalid, was 0x%x became 0x%x\n",
                                        __func__,
                                        ubuf, ubuf->crc, crc);
                        }
                }

        }
        mutex_unlock(&port->dmaqueue_lock);

        dprintk(DBGLVL_VBI, "%s() returns %p\n", __func__, ubuf);

        return ubuf;
}

static ssize_t fops_read(struct file *file, char __user *buffer,
        size_t count, loff_t *pos)
{
        struct saa7164_vbi_fh *fh = file->private_data;
        struct saa7164_port *port = fh->port;
        struct saa7164_user_buffer *ubuf = NULL;
        struct saa7164_dev *dev = port->dev;
        int ret = 0;
        int rem, cnt;
        u8 *p;

        port->last_read_msecs_diff = port->last_read_msecs;
        port->last_read_msecs = jiffies_to_msecs(jiffies);
        port->last_read_msecs_diff = port->last_read_msecs -
                port->last_read_msecs_diff;

        saa7164_histogram_update(&port->read_interval,
                port->last_read_msecs_diff);

        if (*pos) {
                printk(KERN_ERR "%s() ESPIPE\n", __func__);
                return -ESPIPE;
        }

        if (atomic_cmpxchg(&fh->v4l_reading, 0, 1) == 0) {
                if (atomic_inc_return(&port->v4l_reader_count) == 1) {

                        if (saa7164_vbi_initialize(port) < 0) {
                                printk(KERN_ERR "%s() EINVAL\n", __func__);
                                return -EINVAL;
                        }

                        saa7164_vbi_start_streaming(port);
                        msleep(200);
                }
        }

        /* blocking wait for buffer */
        if ((file->f_flags & O_NONBLOCK) == 0) {
                if (wait_event_interruptible(port->wait_read,
                        saa7164_vbi_next_buf(port))) {
                                printk(KERN_ERR "%s() ERESTARTSYS\n", __func__);
                                return -ERESTARTSYS;
                }
        }

        /* Pull the first buffer from the used list */
        ubuf = saa7164_vbi_next_buf(port);

        while ((count > 0) && ubuf) {

                /* set remaining bytes to copy */
                rem = ubuf->actual_size - ubuf->pos;
                cnt = rem > count ? count : rem;

                p = ubuf->data + ubuf->pos;

                dprintk(DBGLVL_VBI,
                        "%s() count=%d cnt=%d rem=%d buf=%p buf->pos=%d\n",
                        __func__, (int)count, cnt, rem, ubuf, ubuf->pos);

                if (copy_to_user(buffer, p, cnt)) {
                        printk(KERN_ERR "%s() copy_to_user failed\n", __func__);
                        if (!ret) {
                                printk(KERN_ERR "%s() EFAULT\n", __func__);
                                ret = -EFAULT;
                        }
                        goto err;
                }

                ubuf->pos += cnt;
                count -= cnt;
                buffer += cnt;
                ret += cnt;

                if (ubuf->pos > ubuf->actual_size)
                        printk(KERN_ERR "read() pos > actual, huh?\n");

                if (ubuf->pos == ubuf->actual_size) {

                        /* finished with current buffer, take next buffer */

                        /* Requeue the buffer on the free list */
                        ubuf->pos = 0;

                        mutex_lock(&port->dmaqueue_lock);
                        list_move_tail(&ubuf->list, &port->list_buf_free.list);
                        mutex_unlock(&port->dmaqueue_lock);

                        /* Dequeue next */
                        if ((file->f_flags & O_NONBLOCK) == 0) {
                                if (wait_event_interruptible(port->wait_read,
                                        saa7164_vbi_next_buf(port))) {
                                                break;
                                }
                        }
                        ubuf = saa7164_vbi_next_buf(port);
                }
        }
err:
        if (!ret && !ubuf) {
                printk(KERN_ERR "%s() EAGAIN\n", __func__);
                ret = -EAGAIN;
        }

        return ret;
}

static unsigned int fops_poll(struct file *file, poll_table *wait)
{
        struct saa7164_vbi_fh *fh = (struct saa7164_vbi_fh *)file->private_data;
        struct saa7164_port *port = fh->port;
        unsigned int mask = 0;

        port->last_poll_msecs_diff = port->last_poll_msecs;
        port->last_poll_msecs = jiffies_to_msecs(jiffies);
        port->last_poll_msecs_diff = port->last_poll_msecs -
                port->last_poll_msecs_diff;

        saa7164_histogram_update(&port->poll_interval,
                port->last_poll_msecs_diff);

        if (!video_is_registered(port->v4l_device))
                return -EIO;

        if (atomic_cmpxchg(&fh->v4l_reading, 0, 1) == 0) {
                if (atomic_inc_return(&port->v4l_reader_count) == 1) {
                        if (saa7164_vbi_initialize(port) < 0)
                                return -EINVAL;
                        saa7164_vbi_start_streaming(port);
                        msleep(200);
                }
        }

        /* blocking wait for buffer */
        if ((file->f_flags & O_NONBLOCK) == 0) {
                if (wait_event_interruptible(port->wait_read,
                        saa7164_vbi_next_buf(port))) {
                                return -ERESTARTSYS;
                }
        }

        /* Pull the first buffer from the used list */
        if (!list_empty(&port->list_buf_used.list))
                mask |= POLLIN | POLLRDNORM;

        return mask;
}
static const struct v4l2_file_operations vbi_fops = {
        .owner          = THIS_MODULE,
        .open           = fops_open,
        .release        = fops_release,
        .read           = fops_read,
        .poll           = fops_poll,
        .unlocked_ioctl = video_ioctl2,
};

static const struct v4l2_ioctl_ops vbi_ioctl_ops = {
        .vidioc_s_std            = vidioc_s_std,
        .vidioc_g_std            = vidioc_g_std,
        .vidioc_enum_input       = saa7164_enum_input,
        .vidioc_g_input          = vidioc_g_input,
        .vidioc_s_input          = vidioc_s_input,
        .vidioc_g_tuner          = saa7164_g_tuner,
        .vidioc_s_tuner          = saa7164_s_tuner,
        .vidioc_g_frequency      = vidioc_g_frequency,
        .vidioc_s_frequency      = vidioc_s_frequency,
        .vidioc_querycap         = vidioc_querycap,
        .vidioc_g_fmt_vbi_cap    = saa7164_vbi_fmt,
        .vidioc_try_fmt_vbi_cap  = saa7164_vbi_fmt,
        .vidioc_s_fmt_vbi_cap    = saa7164_vbi_fmt,
};

static struct video_device saa7164_vbi_template = {
        .name          = "saa7164",
        .fops          = &vbi_fops,
        .ioctl_ops     = &vbi_ioctl_ops,
        .minor         = -1,
        .tvnorms       = SAA7164_NORMS,
};

static struct video_device *saa7164_vbi_alloc(
        struct saa7164_port *port,
        struct pci_dev *pci,
        struct video_device *template,
        char *type)
{
        struct video_device *vfd;
        struct saa7164_dev *dev = port->dev;

        dprintk(DBGLVL_VBI, "%s()\n", __func__);

        vfd = video_device_alloc();
        if (NULL == vfd)
                return NULL;

        *vfd = *template;
        snprintf(vfd->name, sizeof(vfd->name), "%s %s (%s)", dev->name,
                type, saa7164_boards[dev->board].name);

        vfd->v4l2_dev  = &dev->v4l2_dev;
        vfd->release = video_device_release;
        return vfd;
}

int saa7164_vbi_register(struct saa7164_port *port)
{
        struct saa7164_dev *dev = port->dev;
        int result = -ENODEV;

        dprintk(DBGLVL_VBI, "%s()\n", __func__);

        if (port->type != SAA7164_MPEG_VBI)
                BUG();

        /* Sanity check that the PCI configuration space is active */
        if (port->hwcfg.BARLocation == 0) {
                printk(KERN_ERR "%s() failed (errno = %d), NO PCI configuration\n",
                        __func__, result);
                result = -ENOMEM;
                goto failed;
        }

        /* Establish VBI defaults here */

        /* Allocate and register the video device node */
        port->v4l_device = saa7164_vbi_alloc(port,
                dev->pci, &saa7164_vbi_template, "vbi");

        if (!port->v4l_device) {
                printk(KERN_INFO "%s: can't allocate vbi device\n",
                        dev->name);
                result = -ENOMEM;
                goto failed;
        }

        port->enc_port = &dev->ports[port->nr - 2];
        video_set_drvdata(port->v4l_device, port);
        result = video_register_device(port->v4l_device,
                VFL_TYPE_VBI, -1);
        if (result < 0) {
                printk(KERN_INFO "%s: can't register vbi device\n",
                        dev->name);
                /* TODO: We're going to leak here if we don't dealloc
                 The buffers above. The unreg function can't deal wit it.
                */
                goto failed;
        }

        printk(KERN_INFO "%s: registered device vbi%d [vbi]\n",
                dev->name, port->v4l_device->num);

        /* Configure the hardware defaults */

        result = 0;
failed:
        return result;
}

void saa7164_vbi_unregister(struct saa7164_port *port)
{
        struct saa7164_dev *dev = port->dev;

        dprintk(DBGLVL_VBI, "%s(port=%d)\n", __func__, port->nr);

        if (port->type != SAA7164_MPEG_VBI)
                BUG();

        if (port->v4l_device) {
                if (port->v4l_device->minor != -1)
                        video_unregister_device(port->v4l_device);
                else
                        video_device_release(port->v4l_device);

                port->v4l_device = NULL;
        }

}