ispvideo.c

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/*
 * ispvideo.c
 *
 * TI OMAP3 ISP - Generic video node
 *
 * Copyright (C) 2009-2010 Nokia Corporation
 *
 * Contacts: Laurent Pinchart <[email protected]>
 *       Sakari Ailus <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <asm/cacheflush.h>
#include <linux/clk.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-ioctl.h>
#include <plat/iommu.h>
#include <plat/iovmm.h>
#include <plat/omap-pm.h>

#include "ispvideo.h"
#include "isp.h"


/* -----------------------------------------------------------------------------
 * Helper functions
 */

/*
 * NOTE: When adding new media bus codes, always remember to add
 * corresponding in-memory formats to the table below!!!
 */
static struct isp_format_info formats[] = {
    { V4L2_MBUS_FMT_Y8_1X8, V4L2_MBUS_FMT_Y8_1X8,
      V4L2_MBUS_FMT_Y8_1X8, V4L2_MBUS_FMT_Y8_1X8,
      V4L2_PIX_FMT_GREY, 8, 1, },
    { V4L2_MBUS_FMT_Y10_1X10, V4L2_MBUS_FMT_Y10_1X10,
      V4L2_MBUS_FMT_Y10_1X10, V4L2_MBUS_FMT_Y8_1X8,
      V4L2_PIX_FMT_Y10, 10, 2, },
    { V4L2_MBUS_FMT_Y12_1X12, V4L2_MBUS_FMT_Y10_1X10,
      V4L2_MBUS_FMT_Y12_1X12, V4L2_MBUS_FMT_Y8_1X8,
      V4L2_PIX_FMT_Y12, 12, 2, },
    { V4L2_MBUS_FMT_SBGGR8_1X8, V4L2_MBUS_FMT_SBGGR8_1X8,
      V4L2_MBUS_FMT_SBGGR8_1X8, V4L2_MBUS_FMT_SBGGR8_1X8,
      V4L2_PIX_FMT_SBGGR8, 8, 1, },
    { V4L2_MBUS_FMT_SGBRG8_1X8, V4L2_MBUS_FMT_SGBRG8_1X8,
      V4L2_MBUS_FMT_SGBRG8_1X8, V4L2_MBUS_FMT_SGBRG8_1X8,
      V4L2_PIX_FMT_SGBRG8, 8, 1, },
    { V4L2_MBUS_FMT_SGRBG8_1X8, V4L2_MBUS_FMT_SGRBG8_1X8,
      V4L2_MBUS_FMT_SGRBG8_1X8, V4L2_MBUS_FMT_SGRBG8_1X8,
      V4L2_PIX_FMT_SGRBG8, 8, 1, },
    { V4L2_MBUS_FMT_SRGGB8_1X8, V4L2_MBUS_FMT_SRGGB8_1X8,
      V4L2_MBUS_FMT_SRGGB8_1X8, V4L2_MBUS_FMT_SRGGB8_1X8,
      V4L2_PIX_FMT_SRGGB8, 8, 1, },
    { V4L2_MBUS_FMT_SBGGR10_DPCM8_1X8, V4L2_MBUS_FMT_SBGGR10_DPCM8_1X8,
      V4L2_MBUS_FMT_SBGGR10_1X10, 0,
      V4L2_PIX_FMT_SBGGR10DPCM8, 8, 1, },
    { V4L2_MBUS_FMT_SGBRG10_DPCM8_1X8, V4L2_MBUS_FMT_SGBRG10_DPCM8_1X8,
      V4L2_MBUS_FMT_SGBRG10_1X10, 0,
      V4L2_PIX_FMT_SGBRG10DPCM8, 8, 1, },
    { V4L2_MBUS_FMT_SGRBG10_DPCM8_1X8, V4L2_MBUS_FMT_SGRBG10_DPCM8_1X8,
      V4L2_MBUS_FMT_SGRBG10_1X10, 0,
      V4L2_PIX_FMT_SGRBG10DPCM8, 8, 1, },
    { V4L2_MBUS_FMT_SRGGB10_DPCM8_1X8, V4L2_MBUS_FMT_SRGGB10_DPCM8_1X8,
      V4L2_MBUS_FMT_SRGGB10_1X10, 0,
      V4L2_PIX_FMT_SRGGB10DPCM8, 8, 1, },
    { V4L2_MBUS_FMT_SBGGR10_1X10, V4L2_MBUS_FMT_SBGGR10_1X10,
      V4L2_MBUS_FMT_SBGGR10_1X10, V4L2_MBUS_FMT_SBGGR8_1X8,
      V4L2_PIX_FMT_SBGGR10, 10, 2, },
    { V4L2_MBUS_FMT_SGBRG10_1X10, V4L2_MBUS_FMT_SGBRG10_1X10,
      V4L2_MBUS_FMT_SGBRG10_1X10, V4L2_MBUS_FMT_SGBRG8_1X8,
      V4L2_PIX_FMT_SGBRG10, 10, 2, },
    { V4L2_MBUS_FMT_SGRBG10_1X10, V4L2_MBUS_FMT_SGRBG10_1X10,
      V4L2_MBUS_FMT_SGRBG10_1X10, V4L2_MBUS_FMT_SGRBG8_1X8,
      V4L2_PIX_FMT_SGRBG10, 10, 2, },
    { V4L2_MBUS_FMT_SRGGB10_1X10, V4L2_MBUS_FMT_SRGGB10_1X10,
      V4L2_MBUS_FMT_SRGGB10_1X10, V4L2_MBUS_FMT_SRGGB8_1X8,
      V4L2_PIX_FMT_SRGGB10, 10, 2, },
    { V4L2_MBUS_FMT_SBGGR12_1X12, V4L2_MBUS_FMT_SBGGR10_1X10,
      V4L2_MBUS_FMT_SBGGR12_1X12, V4L2_MBUS_FMT_SBGGR8_1X8,
      V4L2_PIX_FMT_SBGGR12, 12, 2, },
    { V4L2_MBUS_FMT_SGBRG12_1X12, V4L2_MBUS_FMT_SGBRG10_1X10,
      V4L2_MBUS_FMT_SGBRG12_1X12, V4L2_MBUS_FMT_SGBRG8_1X8,
      V4L2_PIX_FMT_SGBRG12, 12, 2, },
    { V4L2_MBUS_FMT_SGRBG12_1X12, V4L2_MBUS_FMT_SGRBG10_1X10,
      V4L2_MBUS_FMT_SGRBG12_1X12, V4L2_MBUS_FMT_SGRBG8_1X8,
      V4L2_PIX_FMT_SGRBG12, 12, 2, },
    { V4L2_MBUS_FMT_SRGGB12_1X12, V4L2_MBUS_FMT_SRGGB10_1X10,
      V4L2_MBUS_FMT_SRGGB12_1X12, V4L2_MBUS_FMT_SRGGB8_1X8,
      V4L2_PIX_FMT_SRGGB12, 12, 2, },
    { V4L2_MBUS_FMT_UYVY8_1X16, V4L2_MBUS_FMT_UYVY8_1X16,
      V4L2_MBUS_FMT_UYVY8_1X16, 0,
      V4L2_PIX_FMT_UYVY, 16, 2, },
    { V4L2_MBUS_FMT_YUYV8_1X16, V4L2_MBUS_FMT_YUYV8_1X16,
      V4L2_MBUS_FMT_YUYV8_1X16, 0,
      V4L2_PIX_FMT_YUYV, 16, 2, },
    { V4L2_MBUS_FMT_UYVY8_2X8, V4L2_MBUS_FMT_UYVY8_2X8,
      V4L2_MBUS_FMT_UYVY8_2X8, 0,
      V4L2_PIX_FMT_UYVY, 8, 2, },
    { V4L2_MBUS_FMT_YUYV8_2X8, V4L2_MBUS_FMT_YUYV8_2X8,
      V4L2_MBUS_FMT_YUYV8_2X8, 0,
      V4L2_PIX_FMT_YUYV, 8, 2, },
    /* Empty entry to catch the unsupported pixel code (0) used by the CCDC
     * module and avoid NULL pointer dereferences.
     */
    { 0, }
};

const struct isp_format_info *
omap3isp_video_format_info(enum v4l2_mbus_pixelcode code)
{
    unsigned int i;

    for (i = 0; i < ARRAY_SIZE(formats); ++i) {
        if (formats[i].code == code)
            return &formats[i];
    }

    return NULL;
}

/*
 * isp_video_mbus_to_pix - Convert v4l2_mbus_framefmt to v4l2_pix_format
 * @video: ISP video instance
 * @mbus: v4l2_mbus_framefmt format (input)
 * @pix: v4l2_pix_format format (output)
 *
 * Fill the output pix structure with information from the input mbus format.
 * The bytesperline and sizeimage fields are computed from the requested bytes
 * per line value in the pix format and information from the video instance.
 *
 * Return the number of padding bytes at end of line.
 */
static unsigned int isp_video_mbus_to_pix(const struct isp_video *video,
                      const struct v4l2_mbus_framefmt *mbus,
                      struct v4l2_pix_format *pix)
{
    unsigned int bpl = pix->bytesperline;
    unsigned int min_bpl;
    unsigned int i;

    memset(pix, 0, sizeof(*pix));
    pix->width = mbus->width;
    pix->height = mbus->height;

    for (i = 0; i < ARRAY_SIZE(formats); ++i) {
        if (formats[i].code == mbus->code)
            break;
    }

    if (WARN_ON(i == ARRAY_SIZE(formats)))
        return 0;

    min_bpl = pix->width * formats[i].bpp;

    /* Clamp the requested bytes per line value. If the maximum bytes per
     * line value is zero, the module doesn't support user configurable line
     * sizes. Override the requested value with the minimum in that case.
     */
    if (video->bpl_max)
        bpl = clamp(bpl, min_bpl, video->bpl_max);
    else
        bpl = min_bpl;

    if (!video->bpl_zero_padding || bpl != min_bpl)
        bpl = ALIGN(bpl, video->bpl_alignment);

    pix->pixelformat = formats[i].pixelformat;
    pix->bytesperline = bpl;
    pix->sizeimage = pix->bytesperline * pix->height;
    pix->colorspace = mbus->colorspace;
    pix->field = mbus->field;

    return bpl - min_bpl;
}

static void isp_video_pix_to_mbus(const struct v4l2_pix_format *pix,
                  struct v4l2_mbus_framefmt *mbus)
{
    unsigned int i;

    memset(mbus, 0, sizeof(*mbus));
    mbus->width = pix->width;
    mbus->height = pix->height;

    /* Skip the last format in the loop so that it will be selected if no
     * match is found.
     */
    for (i = 0; i < ARRAY_SIZE(formats) - 1; ++i) {
        if (formats[i].pixelformat == pix->pixelformat)
            break;
    }

    mbus->code = formats[i].code;
    mbus->colorspace = pix->colorspace;
    mbus->field = pix->field;
}

static struct v4l2_subdev *
isp_video_remote_subdev(struct isp_video *video, u32 *pad)
{
    struct media_pad *remote;

    remote = media_entity_remote_source(&video->pad);

    if (remote == NULL ||
        media_entity_type(remote->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
        return NULL;

    if (pad)
        *pad = remote->index;

    return media_entity_to_v4l2_subdev(remote->entity);
}

/* Return a pointer to the ISP video instance at the far end of the pipeline. */
static int isp_video_get_graph_data(struct isp_video *video,
                    struct isp_pipeline *pipe)
{
    struct media_entity_graph graph;
    struct media_entity *entity = &video->video.entity;
    struct media_device *mdev = entity->parent;
    struct isp_video *far_end = NULL;

    mutex_lock(&mdev->graph_mutex);
    media_entity_graph_walk_start(&graph, entity);

    while ((entity = media_entity_graph_walk_next(&graph))) {
        struct isp_video *__video;

        pipe->entities |= 1 << entity->id;

        if (far_end != NULL)
            continue;

        if (entity == &video->video.entity)
            continue;

        if (media_entity_type(entity) != MEDIA_ENT_T_DEVNODE)
            continue;

        __video = to_isp_video(media_entity_to_video_device(entity));
        if (__video->type != video->type)
            far_end = __video;
    }

    mutex_unlock(&mdev->graph_mutex);

    if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
        pipe->input = far_end;
        pipe->output = video;
    } else {
        if (far_end == NULL)
            return -EPIPE;

        pipe->input = video;
        pipe->output = far_end;
    }

    return 0;
}

/*
 * Validate a pipeline by checking both ends of all links for format
 * discrepancies.
 *
 * Compute the minimum time per frame value as the maximum of time per frame
 * limits reported by every block in the pipeline.
 *
 * Return 0 if all formats match, or -EPIPE if at least one link is found with
 * different formats on its two ends or if the pipeline doesn't start with a
 * video source (either a subdev with no input pad, or a non-subdev entity).
 */
static int isp_video_validate_pipeline(struct isp_pipeline *pipe)
{
    struct isp_device *isp = pipe->output->isp;
    struct media_pad *pad;
    struct v4l2_subdev *subdev;

    subdev = isp_video_remote_subdev(pipe->output, NULL);
    if (subdev == NULL)
        return -EPIPE;

    while (1) {
        /* Retrieve the sink format */
        pad = &subdev->entity.pads[0];
        if (!(pad->flags & MEDIA_PAD_FL_SINK))
            break;

        /* Update the maximum frame rate */
        if (subdev == &isp->isp_res.subdev)
            omap3isp_resizer_max_rate(&isp->isp_res,
                          &pipe->max_rate);

        /* Retrieve the source format. Return an error if no source
         * entity can be found, and stop checking the pipeline if the
         * source entity isn't a subdev.
         */
        pad = media_entity_remote_source(pad);
        if (pad == NULL)
            return -EPIPE;

        if (media_entity_type(pad->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
            break;

        subdev = media_entity_to_v4l2_subdev(pad->entity);
    }

    return 0;
}

static int
__isp_video_get_format(struct isp_video *video, struct v4l2_format *format)
{
    struct v4l2_subdev_format fmt;
    struct v4l2_subdev *subdev;
    u32 pad;
    int ret;

    subdev = isp_video_remote_subdev(video, &pad);
    if (subdev == NULL)
        return -EINVAL;

    mutex_lock(&video->mutex);

    fmt.pad = pad;
    fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
    ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
    if (ret == -ENOIOCTLCMD)
        ret = -EINVAL;

    mutex_unlock(&video->mutex);

    if (ret)
        return ret;

    format->type = video->type;
    return isp_video_mbus_to_pix(video, &fmt.format, &format->fmt.pix);
}

static int
isp_video_check_format(struct isp_video *video, struct isp_video_fh *vfh)
{
    struct v4l2_format format;
    int ret;

    memcpy(&format, &vfh->format, sizeof(format));
    ret = __isp_video_get_format(video, &format);
    if (ret < 0)
        return ret;

    if (vfh->format.fmt.pix.pixelformat != format.fmt.pix.pixelformat ||
        vfh->format.fmt.pix.height != format.fmt.pix.height ||
        vfh->format.fmt.pix.width != format.fmt.pix.width ||
        vfh->format.fmt.pix.bytesperline != format.fmt.pix.bytesperline ||
        vfh->format.fmt.pix.sizeimage != format.fmt.pix.sizeimage)
        return -EINVAL;

    return ret;
}

/* -----------------------------------------------------------------------------
 * IOMMU management
 */

#define IOMMU_FLAG  (IOVMF_ENDIAN_LITTLE | IOVMF_ELSZ_8)

/*
 * ispmmu_vmap - Wrapper for Virtual memory mapping of a scatter gather list
 * @dev: Device pointer specific to the OMAP3 ISP.
 * @sglist: Pointer to source Scatter gather list to allocate.
 * @sglen: Number of elements of the scatter-gatter list.
 *
 * Returns a resulting mapped device address by the ISP MMU, or -ENOMEM if
 * we ran out of memory.
 */
static dma_addr_t
ispmmu_vmap(struct isp_device *isp, const struct scatterlist *sglist, int sglen)
{
    struct sg_table *sgt;
    u32 da;

    sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
    if (sgt == NULL)
        return -ENOMEM;

    sgt->sgl = (struct scatterlist *)sglist;
    sgt->nents = sglen;
    sgt->orig_nents = sglen;

    da = omap_iommu_vmap(isp->domain, isp->dev, 0, sgt, IOMMU_FLAG);
    if (IS_ERR_VALUE(da))
        kfree(sgt);

    return da;
}

/*
 * ispmmu_vunmap - Unmap a device address from the ISP MMU
 * @dev: Device pointer specific to the OMAP3 ISP.
 * @da: Device address generated from a ispmmu_vmap call.
 */
static void ispmmu_vunmap(struct isp_device *isp, dma_addr_t da)
{
    struct sg_table *sgt;

    sgt = omap_iommu_vunmap(isp->domain, isp->dev, (u32)da);
    kfree(sgt);
}

/* -----------------------------------------------------------------------------
 * Video queue operations
 */

static void isp_video_queue_prepare(struct isp_video_queue *queue,
                    unsigned int *nbuffers, unsigned int *size)
{
    struct isp_video_fh *vfh =
        container_of(queue, struct isp_video_fh, queue);
    struct isp_video *video = vfh->video;

    *size = vfh->format.fmt.pix.sizeimage;
    if (*size == 0)
        return;

    *nbuffers = min(*nbuffers, video->capture_mem / PAGE_ALIGN(*size));
}

static void isp_video_buffer_cleanup(struct isp_video_buffer *buf)
{
    struct isp_video_fh *vfh = isp_video_queue_to_isp_video_fh(buf->queue);
    struct isp_buffer *buffer = to_isp_buffer(buf);
    struct isp_video *video = vfh->video;

    if (buffer->isp_addr) {
        ispmmu_vunmap(video->isp, buffer->isp_addr);
        buffer->isp_addr = 0;
    }
}

static int isp_video_buffer_prepare(struct isp_video_buffer *buf)
{
    struct isp_video_fh *vfh = isp_video_queue_to_isp_video_fh(buf->queue);
    struct isp_buffer *buffer = to_isp_buffer(buf);
    struct isp_video *video = vfh->video;
    unsigned long addr;

    addr = ispmmu_vmap(video->isp, buf->sglist, buf->sglen);
    if (IS_ERR_VALUE(addr))
        return -EIO;

    if (!IS_ALIGNED(addr, 32)) {
        dev_dbg(video->isp->dev, "Buffer address must be "
            "aligned to 32 bytes boundary.\n");
        ispmmu_vunmap(video->isp, buffer->isp_addr);
        return -EINVAL;
    }

    buf->vbuf.bytesused = vfh->format.fmt.pix.sizeimage;
    buffer->isp_addr = addr;
    return 0;
}

/*
 * isp_video_buffer_queue - Add buffer to streaming queue
 * @buf: Video buffer
 *
 * In memory-to-memory mode, start streaming on the pipeline if buffers are
 * queued on both the input and the output, if the pipeline isn't already busy.
 * If the pipeline is busy, it will be restarted in the output module interrupt
 * handler.
 */
static void isp_video_buffer_queue(struct isp_video_buffer *buf)
{
    struct isp_video_fh *vfh = isp_video_queue_to_isp_video_fh(buf->queue);
    struct isp_buffer *buffer = to_isp_buffer(buf);
    struct isp_video *video = vfh->video;
    struct isp_pipeline *pipe = to_isp_pipeline(&video->video.entity);
    enum isp_pipeline_state state;
    unsigned long flags;
    unsigned int empty;
    unsigned int start;

    empty = list_empty(&video->dmaqueue);
    list_add_tail(&buffer->buffer.irqlist, &video->dmaqueue);

    if (empty) {
        if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
            state = ISP_PIPELINE_QUEUE_OUTPUT;
        else
            state = ISP_PIPELINE_QUEUE_INPUT;

        spin_lock_irqsave(&pipe->lock, flags);
        pipe->state |= state;
        video->ops->queue(video, buffer);
        video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_QUEUED;

        start = isp_pipeline_ready(pipe);
        if (start)
            pipe->state |= ISP_PIPELINE_STREAM;
        spin_unlock_irqrestore(&pipe->lock, flags);

        if (start)
            omap3isp_pipeline_set_stream(pipe,
                        ISP_PIPELINE_STREAM_SINGLESHOT);
    }
}

static const struct isp_video_queue_operations isp_video_queue_ops = {
    .queue_prepare = &isp_video_queue_prepare,
    .buffer_prepare = &isp_video_buffer_prepare,
    .buffer_queue = &isp_video_buffer_queue,
    .buffer_cleanup = &isp_video_buffer_cleanup,
};

/*
 * omap3isp_video_buffer_next - Complete the current buffer and return the next
 * @video: ISP video object
 *
 * Remove the current video buffer from the DMA queue and fill its timestamp,
 * field count and state fields before waking up its completion handler.
 *
 * For capture video nodes the buffer state is set to ISP_BUF_STATE_DONE if no
 * error has been flagged in the pipeline, or to ISP_BUF_STATE_ERROR otherwise.
 * For video output nodes the buffer state is always set to ISP_BUF_STATE_DONE.
 *
 * The DMA queue is expected to contain at least one buffer.
 *
 * Return a pointer to the next buffer in the DMA queue, or NULL if the queue is
 * empty.
 */
struct isp_buffer *omap3isp_video_buffer_next(struct isp_video *video)
{
    struct isp_pipeline *pipe = to_isp_pipeline(&video->video.entity);
    struct isp_video_queue *queue = video->queue;
    enum isp_pipeline_state state;
    struct isp_video_buffer *buf;
    unsigned long flags;
    struct timespec ts;

    spin_lock_irqsave(&queue->irqlock, flags);
    if (WARN_ON(list_empty(&video->dmaqueue))) {
        spin_unlock_irqrestore(&queue->irqlock, flags);
        return NULL;
    }

    buf = list_first_entry(&video->dmaqueue, struct isp_video_buffer,
                   irqlist);
    list_del(&buf->irqlist);
    spin_unlock_irqrestore(&queue->irqlock, flags);

    ktime_get_ts(&ts);
    buf->vbuf.timestamp.tv_sec = ts.tv_sec;
    buf->vbuf.timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC;

    /* Do frame number propagation only if this is the output video node.
     * Frame number either comes from the CSI receivers or it gets
     * incremented here if H3A is not active.
     * Note: There is no guarantee that the output buffer will finish
     * first, so the input number might lag behind by 1 in some cases.
     */
    if (video == pipe->output && !pipe->do_propagation)
        buf->vbuf.sequence = atomic_inc_return(&pipe->frame_number);
    else
        buf->vbuf.sequence = atomic_read(&pipe->frame_number);

    /* Report pipeline errors to userspace on the capture device side. */
    if (queue->type == V4L2_BUF_TYPE_VIDEO_CAPTURE && pipe->error) {
        buf->state = ISP_BUF_STATE_ERROR;
        pipe->error = false;
    } else {
        buf->state = ISP_BUF_STATE_DONE;
    }

    wake_up(&buf->wait);

    if (list_empty(&video->dmaqueue)) {
        if (queue->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
            state = ISP_PIPELINE_QUEUE_OUTPUT
                  | ISP_PIPELINE_STREAM;
        else
            state = ISP_PIPELINE_QUEUE_INPUT
                  | ISP_PIPELINE_STREAM;

        spin_lock_irqsave(&pipe->lock, flags);
        pipe->state &= ~state;
        if (video->pipe.stream_state == ISP_PIPELINE_STREAM_CONTINUOUS)
            video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_UNDERRUN;
        spin_unlock_irqrestore(&pipe->lock, flags);
        return NULL;
    }

    if (queue->type == V4L2_BUF_TYPE_VIDEO_CAPTURE && pipe->input != NULL) {
        spin_lock_irqsave(&pipe->lock, flags);
        pipe->state &= ~ISP_PIPELINE_STREAM;
        spin_unlock_irqrestore(&pipe->lock, flags);
    }

    buf = list_first_entry(&video->dmaqueue, struct isp_video_buffer,
                   irqlist);
    buf->state = ISP_BUF_STATE_ACTIVE;
    return to_isp_buffer(buf);
}

/*
 * omap3isp_video_resume - Perform resume operation on the buffers
 * @video: ISP video object
 * @continuous: Pipeline is in single shot mode if 0 or continuous mode otherwise
 *
 * This function is intended to be used on suspend/resume scenario. It
 * requests video queue layer to discard buffers marked as DONE if it's in
 * continuous mode and requests ISP modules to queue again the ACTIVE buffer
 * if there's any.
 */
void omap3isp_video_resume(struct isp_video *video, int continuous)
{
    struct isp_buffer *buf = NULL;

    if (continuous && video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
        omap3isp_video_queue_discard_done(video->queue);

    if (!list_empty(&video->dmaqueue)) {
        buf = list_first_entry(&video->dmaqueue,
                       struct isp_buffer, buffer.irqlist);
        video->ops->queue(video, buf);
        video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_QUEUED;
    } else {
        if (continuous)
            video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_UNDERRUN;
    }
}

/* -----------------------------------------------------------------------------
 * V4L2 ioctls
 */

static int
isp_video_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
{
    struct isp_video *video = video_drvdata(file);

    strlcpy(cap->driver, ISP_VIDEO_DRIVER_NAME, sizeof(cap->driver));
    strlcpy(cap->card, video->video.name, sizeof(cap->card));
    strlcpy(cap->bus_info, "media", sizeof(cap->bus_info));

    if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
        cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
    else
        cap->capabilities = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_STREAMING;

    return 0;
}

static int
isp_video_get_format(struct file *file, void *fh, struct v4l2_format *format)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);
    struct isp_video *video = video_drvdata(file);

    if (format->type != video->type)
        return -EINVAL;

    mutex_lock(&video->mutex);
    *format = vfh->format;
    mutex_unlock(&video->mutex);

    return 0;
}

static int
isp_video_set_format(struct file *file, void *fh, struct v4l2_format *format)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);
    struct isp_video *video = video_drvdata(file);
    struct v4l2_mbus_framefmt fmt;

    if (format->type != video->type)
        return -EINVAL;

    mutex_lock(&video->mutex);

    /* Fill the bytesperline and sizeimage fields by converting to media bus
     * format and back to pixel format.
     */
    isp_video_pix_to_mbus(&format->fmt.pix, &fmt);
    isp_video_mbus_to_pix(video, &fmt, &format->fmt.pix);

    vfh->format = *format;

    mutex_unlock(&video->mutex);
    return 0;
}

static int
isp_video_try_format(struct file *file, void *fh, struct v4l2_format *format)
{
    struct isp_video *video = video_drvdata(file);
    struct v4l2_subdev_format fmt;
    struct v4l2_subdev *subdev;
    u32 pad;
    int ret;

    if (format->type != video->type)
        return -EINVAL;

    subdev = isp_video_remote_subdev(video, &pad);
    if (subdev == NULL)
        return -EINVAL;

    isp_video_pix_to_mbus(&format->fmt.pix, &fmt.format);

    fmt.pad = pad;
    fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
    ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
    if (ret)
        return ret == -ENOIOCTLCMD ? -ENOTTY : ret;

    isp_video_mbus_to_pix(video, &fmt.format, &format->fmt.pix);
    return 0;
}

static int
isp_video_cropcap(struct file *file, void *fh, struct v4l2_cropcap *cropcap)
{
    struct isp_video *video = video_drvdata(file);
    struct v4l2_subdev *subdev;
    int ret;

    subdev = isp_video_remote_subdev(video, NULL);
    if (subdev == NULL)
        return -EINVAL;

    mutex_lock(&video->mutex);
    ret = v4l2_subdev_call(subdev, video, cropcap, cropcap);
    mutex_unlock(&video->mutex);

    return ret == -ENOIOCTLCMD ? -ENOTTY : ret;
}

static int
isp_video_get_crop(struct file *file, void *fh, struct v4l2_crop *crop)
{
    struct isp_video *video = video_drvdata(file);
    struct v4l2_subdev_format format;
    struct v4l2_subdev *subdev;
    u32 pad;
    int ret;

    subdev = isp_video_remote_subdev(video, &pad);
    if (subdev == NULL)
        return -EINVAL;

    /* Try the get crop operation first and fallback to get format if not
     * implemented.
     */
    ret = v4l2_subdev_call(subdev, video, g_crop, crop);
    if (ret != -ENOIOCTLCMD)
        return ret;

    format.pad = pad;
    format.which = V4L2_SUBDEV_FORMAT_ACTIVE;
    ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &format);
    if (ret < 0)
        return ret == -ENOIOCTLCMD ? -ENOTTY : ret;

    crop->c.left = 0;
    crop->c.top = 0;
    crop->c.width = format.format.width;
    crop->c.height = format.format.height;

    return 0;
}

static int
isp_video_set_crop(struct file *file, void *fh, const struct v4l2_crop *crop)
{
    struct isp_video *video = video_drvdata(file);
    struct v4l2_subdev *subdev;
    int ret;

    subdev = isp_video_remote_subdev(video, NULL);
    if (subdev == NULL)
        return -EINVAL;

    mutex_lock(&video->mutex);
    ret = v4l2_subdev_call(subdev, video, s_crop, crop);
    mutex_unlock(&video->mutex);

    return ret == -ENOIOCTLCMD ? -ENOTTY : ret;
}

static int
isp_video_get_param(struct file *file, void *fh, struct v4l2_streamparm *a)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);
    struct isp_video *video = video_drvdata(file);

    if (video->type != V4L2_BUF_TYPE_VIDEO_OUTPUT ||
        video->type != a->type)
        return -EINVAL;

    memset(a, 0, sizeof(*a));
    a->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
    a->parm.output.capability = V4L2_CAP_TIMEPERFRAME;
    a->parm.output.timeperframe = vfh->timeperframe;

    return 0;
}

static int
isp_video_set_param(struct file *file, void *fh, struct v4l2_streamparm *a)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);
    struct isp_video *video = video_drvdata(file);

    if (video->type != V4L2_BUF_TYPE_VIDEO_OUTPUT ||
        video->type != a->type)
        return -EINVAL;

    if (a->parm.output.timeperframe.denominator == 0)
        a->parm.output.timeperframe.denominator = 1;

    vfh->timeperframe = a->parm.output.timeperframe;

    return 0;
}

static int
isp_video_reqbufs(struct file *file, void *fh, struct v4l2_requestbuffers *rb)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);

    return omap3isp_video_queue_reqbufs(&vfh->queue, rb);
}

static int
isp_video_querybuf(struct file *file, void *fh, struct v4l2_buffer *b)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);

    return omap3isp_video_queue_querybuf(&vfh->queue, b);
}

static int
isp_video_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);

    return omap3isp_video_queue_qbuf(&vfh->queue, b);
}

static int
isp_video_dqbuf(struct file *file, void *fh, struct v4l2_buffer *b)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);

    return omap3isp_video_queue_dqbuf(&vfh->queue, b,
                      file->f_flags & O_NONBLOCK);
}

static int isp_video_check_external_subdevs(struct isp_video *video,
                        struct isp_pipeline *pipe)
{
    struct isp_device *isp = video->isp;
    struct media_entity *ents[] = {
        &isp->isp_csi2a.subdev.entity,
        &isp->isp_csi2c.subdev.entity,
        &isp->isp_ccp2.subdev.entity,
        &isp->isp_ccdc.subdev.entity
    };
    struct media_pad *source_pad;
    struct media_entity *source = NULL;
    struct media_entity *sink;
    struct v4l2_subdev_format fmt;
    struct v4l2_ext_controls ctrls;
    struct v4l2_ext_control ctrl;
    unsigned int i;
    int ret = 0;

    for (i = 0; i < ARRAY_SIZE(ents); i++) {
        /* Is the entity part of the pipeline? */
        if (!(pipe->entities & (1 << ents[i]->id)))
            continue;

        /* ISP entities have always sink pad == 0. Find source. */
        source_pad = media_entity_remote_source(&ents[i]->pads[0]);
        if (source_pad == NULL)
            continue;

        source = source_pad->entity;
        sink = ents[i];
        break;
    }

    if (!source) {
        dev_warn(isp->dev, "can't find source, failing now\n");
        return ret;
    }

    if (media_entity_type(source) != MEDIA_ENT_T_V4L2_SUBDEV)
        return 0;

    pipe->external = media_entity_to_v4l2_subdev(source);

    fmt.pad = source_pad->index;
    fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
    ret = v4l2_subdev_call(media_entity_to_v4l2_subdev(sink),
                   pad, get_fmt, NULL, &fmt);
    if (unlikely(ret < 0)) {
        dev_warn(isp->dev, "get_fmt returned null!\n");
        return ret;
    }

    pipe->external_width =
        omap3isp_video_format_info(fmt.format.code)->width;

    memset(&ctrls, 0, sizeof(ctrls));
    memset(&ctrl, 0, sizeof(ctrl));

    ctrl.id = V4L2_CID_PIXEL_RATE;

    ctrls.count = 1;
    ctrls.controls = &ctrl;

    ret = v4l2_g_ext_ctrls(pipe->external->ctrl_handler, &ctrls);
    if (ret < 0) {
        dev_warn(isp->dev, "no pixel rate control in subdev %s\n",
             pipe->external->name);
        return ret;
    }

    pipe->external_rate = ctrl.value64;

    if (pipe->entities & (1 << isp->isp_ccdc.subdev.entity.id)) {
        unsigned int rate = UINT_MAX;
        /*
         * Check that maximum allowed CCDC pixel rate isn't
         * exceeded by the pixel rate.
         */
        omap3isp_ccdc_max_rate(&isp->isp_ccdc, &rate);
        if (pipe->external_rate > rate)
            return -ENOSPC;
    }

    return 0;
}

/*
 * Stream management
 *
 * Every ISP pipeline has a single input and a single output. The input can be
 * either a sensor or a video node. The output is always a video node.
 *
 * As every pipeline has an output video node, the ISP video objects at the
 * pipeline output stores the pipeline state. It tracks the streaming state of
 * both the input and output, as well as the availability of buffers.
 *
 * In sensor-to-memory mode, frames are always available at the pipeline input.
 * Starting the sensor usually requires I2C transfers and must be done in
 * interruptible context. The pipeline is started and stopped synchronously
 * to the stream on/off commands. All modules in the pipeline will get their
 * subdev set stream handler called. The module at the end of the pipeline must
 * delay starting the hardware until buffers are available at its output.
 *
 * In memory-to-memory mode, starting/stopping the stream requires
 * synchronization between the input and output. ISP modules can't be stopped
 * in the middle of a frame, and at least some of the modules seem to become
 * busy as soon as they're started, even if they don't receive a frame start
 * event. For that reason frames need to be processed in single-shot mode. The
 * driver needs to wait until a frame is completely processed and written to
 * memory before restarting the pipeline for the next frame. Pipelined
 * processing might be possible but requires more testing.
 *
 * Stream start must be delayed until buffers are available at both the input
 * and output. The pipeline must be started in the videobuf queue callback with
 * the buffers queue spinlock held. The modules subdev set stream operation must
 * not sleep.
 */
static int
isp_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);
    struct isp_video *video = video_drvdata(file);
    enum isp_pipeline_state state;
    struct isp_pipeline *pipe;
    unsigned long flags;
    int ret;

    if (type != video->type)
        return -EINVAL;

    mutex_lock(&video->stream_lock);

    if (video->streaming) {
        mutex_unlock(&video->stream_lock);
        return -EBUSY;
    }

    /* Start streaming on the pipeline. No link touching an entity in the
     * pipeline can be activated or deactivated once streaming is started.
     */
    pipe = video->video.entity.pipe
         ? to_isp_pipeline(&video->video.entity) : &video->pipe;

    pipe->entities = 0;

    if (video->isp->pdata->set_constraints)
        video->isp->pdata->set_constraints(video->isp, true);
    pipe->l3_ick = clk_get_rate(video->isp->clock[ISP_CLK_L3_ICK]);
    pipe->max_rate = pipe->l3_ick;

    ret = media_entity_pipeline_start(&video->video.entity, &pipe->pipe);
    if (ret < 0)
        goto err_pipeline_start;

    /* Verify that the currently configured format matches the output of
     * the connected subdev.
     */
    ret = isp_video_check_format(video, vfh);
    if (ret < 0)
        goto err_check_format;

    video->bpl_padding = ret;
    video->bpl_value = vfh->format.fmt.pix.bytesperline;

    ret = isp_video_get_graph_data(video, pipe);
    if (ret < 0)
        goto err_check_format;

    if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
        state = ISP_PIPELINE_STREAM_OUTPUT | ISP_PIPELINE_IDLE_OUTPUT;
    else
        state = ISP_PIPELINE_STREAM_INPUT | ISP_PIPELINE_IDLE_INPUT;

    ret = isp_video_check_external_subdevs(video, pipe);
    if (ret < 0)
        goto err_check_format;

    /* Validate the pipeline and update its state. */
    ret = isp_video_validate_pipeline(pipe);
    if (ret < 0)
        goto err_check_format;

    pipe->error = false;

    spin_lock_irqsave(&pipe->lock, flags);
    pipe->state &= ~ISP_PIPELINE_STREAM;
    pipe->state |= state;
    spin_unlock_irqrestore(&pipe->lock, flags);

    /* Set the maximum time per frame as the value requested by userspace.
     * This is a soft limit that can be overridden if the hardware doesn't
     * support the request limit.
     */
    if (video->type == V4L2_BUF_TYPE_VIDEO_OUTPUT)
        pipe->max_timeperframe = vfh->timeperframe;

    video->queue = &vfh->queue;
    INIT_LIST_HEAD(&video->dmaqueue);
    atomic_set(&pipe->frame_number, -1);

    ret = omap3isp_video_queue_streamon(&vfh->queue);
    if (ret < 0)
        goto err_check_format;

    /* In sensor-to-memory mode, the stream can be started synchronously
     * to the stream on command. In memory-to-memory mode, it will be
     * started when buffers are queued on both the input and output.
     */
    if (pipe->input == NULL) {
        ret = omap3isp_pipeline_set_stream(pipe,
                          ISP_PIPELINE_STREAM_CONTINUOUS);
        if (ret < 0)
            goto err_set_stream;
        spin_lock_irqsave(&video->queue->irqlock, flags);
        if (list_empty(&video->dmaqueue))
            video->dmaqueue_flags |= ISP_VIDEO_DMAQUEUE_UNDERRUN;
        spin_unlock_irqrestore(&video->queue->irqlock, flags);
    }

    video->streaming = 1;

    mutex_unlock(&video->stream_lock);
    return 0;

err_set_stream:
    omap3isp_video_queue_streamoff(&vfh->queue);
err_check_format:
    media_entity_pipeline_stop(&video->video.entity);
err_pipeline_start:
    if (video->isp->pdata->set_constraints)
        video->isp->pdata->set_constraints(video->isp, false);
    /* The DMA queue must be emptied here, otherwise CCDC interrupts that
     * will get triggered the next time the CCDC is powered up will try to
     * access buffers that might have been freed but still present in the
     * DMA queue. This can easily get triggered if the above
     * omap3isp_pipeline_set_stream() call fails on a system with a
     * free-running sensor.
     */
    INIT_LIST_HEAD(&video->dmaqueue);
    video->queue = NULL;

    mutex_unlock(&video->stream_lock);
    return ret;
}

static int
isp_video_streamoff(struct file *file, void *fh, enum v4l2_buf_type type)
{
    struct isp_video_fh *vfh = to_isp_video_fh(fh);
    struct isp_video *video = video_drvdata(file);
    struct isp_pipeline *pipe = to_isp_pipeline(&video->video.entity);
    enum isp_pipeline_state state;
    unsigned int streaming;
    unsigned long flags;

    if (type != video->type)
        return -EINVAL;

    mutex_lock(&video->stream_lock);

    /* Make sure we're not streaming yet. */
    mutex_lock(&vfh->queue.lock);
    streaming = vfh->queue.streaming;
    mutex_unlock(&vfh->queue.lock);

    if (!streaming)
        goto done;

    /* Update the pipeline state. */
    if (video->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
        state = ISP_PIPELINE_STREAM_OUTPUT
              | ISP_PIPELINE_QUEUE_OUTPUT;
    else
        state = ISP_PIPELINE_STREAM_INPUT
              | ISP_PIPELINE_QUEUE_INPUT;

    spin_lock_irqsave(&pipe->lock, flags);
    pipe->state &= ~state;
    spin_unlock_irqrestore(&pipe->lock, flags);

    /* Stop the stream. */
    omap3isp_pipeline_set_stream(pipe, ISP_PIPELINE_STREAM_STOPPED);
    omap3isp_video_queue_streamoff(&vfh->queue);
    video->queue = NULL;
    video->streaming = 0;

    if (video->isp->pdata->set_constraints)
        video->isp->pdata->set_constraints(video->isp, false);
    media_entity_pipeline_stop(&video->video.entity);

done:
    mutex_unlock(&video->stream_lock);
    return 0;
}

static int
isp_video_enum_input(struct file *file, void *fh, struct v4l2_input *input)
{
    if (input->index > 0)
        return -EINVAL;

    strlcpy(input->name, "camera", sizeof(input->name));
    input->type = V4L2_INPUT_TYPE_CAMERA;

    return 0;
}

static int
isp_video_g_input(struct file *file, void *fh, unsigned int *input)
{
    *input = 0;

    return 0;
}

static int
isp_video_s_input(struct file *file, void *fh, unsigned int input)
{
    return input == 0 ? 0 : -EINVAL;
}

static const struct v4l2_ioctl_ops isp_video_ioctl_ops = {
    .vidioc_querycap        = isp_video_querycap,
    .vidioc_g_fmt_vid_cap       = isp_video_get_format,
    .vidioc_s_fmt_vid_cap       = isp_video_set_format,
    .vidioc_try_fmt_vid_cap     = isp_video_try_format,
    .vidioc_g_fmt_vid_out       = isp_video_get_format,
    .vidioc_s_fmt_vid_out       = isp_video_set_format,
    .vidioc_try_fmt_vid_out     = isp_video_try_format,
    .vidioc_cropcap         = isp_video_cropcap,
    .vidioc_g_crop          = isp_video_get_crop,
    .vidioc_s_crop          = isp_video_set_crop,
    .vidioc_g_parm          = isp_video_get_param,
    .vidioc_s_parm          = isp_video_set_param,
    .vidioc_reqbufs         = isp_video_reqbufs,
    .vidioc_querybuf        = isp_video_querybuf,
    .vidioc_qbuf            = isp_video_qbuf,
    .vidioc_dqbuf           = isp_video_dqbuf,
    .vidioc_streamon        = isp_video_streamon,
    .vidioc_streamoff       = isp_video_streamoff,
    .vidioc_enum_input      = isp_video_enum_input,
    .vidioc_g_input         = isp_video_g_input,
    .vidioc_s_input         = isp_video_s_input,
};

/* -----------------------------------------------------------------------------
 * V4L2 file operations
 */

static int isp_video_open(struct file *file)
{
    struct isp_video *video = video_drvdata(file);
    struct isp_video_fh *handle;
    int ret = 0;

    handle = kzalloc(sizeof(*handle), GFP_KERNEL);
    if (handle == NULL)
        return -ENOMEM;

    v4l2_fh_init(&handle->vfh, &video->video);
    v4l2_fh_add(&handle->vfh);

    /* If this is the first user, initialise the pipeline. */
    if (omap3isp_get(video->isp) == NULL) {
        ret = -EBUSY;
        goto done;
    }

    ret = omap3isp_pipeline_pm_use(&video->video.entity, 1);
    if (ret < 0) {
        omap3isp_put(video->isp);
        goto done;
    }

    omap3isp_video_queue_init(&handle->queue, video->type,
                  &isp_video_queue_ops, video->isp->dev,
                  sizeof(struct isp_buffer));

    memset(&handle->format, 0, sizeof(handle->format));
    handle->format.type = video->type;
    handle->timeperframe.denominator = 1;

    handle->video = video;
    file->private_data = &handle->vfh;

done:
    if (ret < 0) {
        v4l2_fh_del(&handle->vfh);
        kfree(handle);
    }

    return ret;
}

static int isp_video_release(struct file *file)
{
    struct isp_video *video = video_drvdata(file);
    struct v4l2_fh *vfh = file->private_data;
    struct isp_video_fh *handle = to_isp_video_fh(vfh);

    /* Disable streaming and free the buffers queue resources. */
    isp_video_streamoff(file, vfh, video->type);

    mutex_lock(&handle->queue.lock);
    omap3isp_video_queue_cleanup(&handle->queue);
    mutex_unlock(&handle->queue.lock);

    omap3isp_pipeline_pm_use(&video->video.entity, 0);

    /* Release the file handle. */
    v4l2_fh_del(vfh);
    kfree(handle);
    file->private_data = NULL;

    omap3isp_put(video->isp);

    return 0;
}

static unsigned int isp_video_poll(struct file *file, poll_table *wait)
{
    struct isp_video_fh *vfh = to_isp_video_fh(file->private_data);
    struct isp_video_queue *queue = &vfh->queue;

    return omap3isp_video_queue_poll(queue, file, wait);
}

static int isp_video_mmap(struct file *file, struct vm_area_struct *vma)
{
    struct isp_video_fh *vfh = to_isp_video_fh(file->private_data);

    return omap3isp_video_queue_mmap(&vfh->queue, vma);
}

static struct v4l2_file_operations isp_video_fops = {
    .owner = THIS_MODULE,
    .unlocked_ioctl = video_ioctl2,
    .open = isp_video_open,
    .release = isp_video_release,
    .poll = isp_video_poll,
    .mmap = isp_video_mmap,
};

/* -----------------------------------------------------------------------------
 * ISP video core
 */

static const struct isp_video_operations isp_video_dummy_ops = {
};

int omap3isp_video_init(struct isp_video *video, const char *name)
{
    const char *direction;
    int ret;

    switch (video->type) {
    case V4L2_BUF_TYPE_VIDEO_CAPTURE:
        direction = "output";
        video->pad.flags = MEDIA_PAD_FL_SINK;
        break;
    case V4L2_BUF_TYPE_VIDEO_OUTPUT:
        direction = "input";
        video->pad.flags = MEDIA_PAD_FL_SOURCE;
        video->video.vfl_dir = VFL_DIR_TX;
        break;

    default:
        return -EINVAL;
    }

    ret = media_entity_init(&video->video.entity, 1, &video->pad, 0);
    if (ret < 0)
        return ret;

    mutex_init(&video->mutex);
    atomic_set(&video->active, 0);

    spin_lock_init(&video->pipe.lock);
    mutex_init(&video->stream_lock);

    /* Initialize the video device. */
    if (video->ops == NULL)
        video->ops = &isp_video_dummy_ops;

    video->video.fops = &isp_video_fops;
    snprintf(video->video.name, sizeof(video->video.name),
         "OMAP3 ISP %s %s", name, direction);
    video->video.vfl_type = VFL_TYPE_GRABBER;
    video->video.release = video_device_release_empty;
    video->video.ioctl_ops = &isp_video_ioctl_ops;
    video->pipe.stream_state = ISP_PIPELINE_STREAM_STOPPED;

    video_set_drvdata(&video->video, video);

    return 0;
}

void omap3isp_video_cleanup(struct isp_video *video)
{
    media_entity_cleanup(&video->video.entity);
    mutex_destroy(&video->stream_lock);
    mutex_destroy(&video->mutex);
}

int omap3isp_video_register(struct isp_video *video, struct v4l2_device *vdev)
{
    int ret;

    video->video.v4l2_dev = vdev;

    ret = video_register_device(&video->video, VFL_TYPE_GRABBER, -1);
    if (ret < 0)
        printk(KERN_ERR "%s: could not register video device (%d)\n",
            __func__, ret);

    return ret;
}

void omap3isp_video_unregister(struct isp_video *video)
{
    if (video_is_registered(&video->video))
        video_unregister_device(&video->video);
}