m2m-deinterlace.c

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/*
 * V4L2 deinterlacing support.
 *
 * Copyright (c) 2012 Vista Silicon S.L.
 * Javier Martin <[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
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/platform_device.h>

#include <media/v4l2-mem2mem.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/videobuf2-dma-contig.h>

#define MEM2MEM_TEST_MODULE_NAME "mem2mem-deinterlace"

MODULE_DESCRIPTION("mem2mem device which supports deinterlacing using dmaengine");
MODULE_AUTHOR("Javier Martin <[email protected]");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.0.1");

static bool debug = true;
module_param(debug, bool, 0644);

/* Flags that indicate a format can be used for capture/output */
#define MEM2MEM_CAPTURE (1 << 0)
#define MEM2MEM_OUTPUT  (1 << 1)

#define MEM2MEM_NAME        "m2m-deinterlace"

#define dprintk(dev, fmt, arg...) \
    v4l2_dbg(1, debug, &dev->v4l2_dev, "%s: " fmt, __func__, ## arg)

struct deinterlace_fmt {
    char    *name;
    u32 fourcc;
    /* Types the format can be used for */
    u32 types;
};

static struct deinterlace_fmt formats[] = {
    {
        .name   = "YUV 4:2:0 Planar",
        .fourcc = V4L2_PIX_FMT_YUV420,
        .types  = MEM2MEM_CAPTURE | MEM2MEM_OUTPUT,
    },
    {
        .name   = "YUYV 4:2:2",
        .fourcc = V4L2_PIX_FMT_YUYV,
        .types  = MEM2MEM_CAPTURE | MEM2MEM_OUTPUT,
    },
};

#define NUM_FORMATS ARRAY_SIZE(formats)

/* Per-queue, driver-specific private data */
struct deinterlace_q_data {
    unsigned int        width;
    unsigned int        height;
    unsigned int        sizeimage;
    struct deinterlace_fmt  *fmt;
    enum v4l2_field     field;
};

enum {
    V4L2_M2M_SRC = 0,
    V4L2_M2M_DST = 1,
};

enum {
    YUV420_DMA_Y_ODD,
    YUV420_DMA_Y_EVEN,
    YUV420_DMA_U_ODD,
    YUV420_DMA_U_EVEN,
    YUV420_DMA_V_ODD,
    YUV420_DMA_V_EVEN,
    YUV420_DMA_Y_ODD_DOUBLING,
    YUV420_DMA_U_ODD_DOUBLING,
    YUV420_DMA_V_ODD_DOUBLING,
    YUYV_DMA_ODD,
    YUYV_DMA_EVEN,
    YUYV_DMA_EVEN_DOUBLING,
};

/* Source and destination queue data */
static struct deinterlace_q_data q_data[2];

static struct deinterlace_q_data *get_q_data(enum v4l2_buf_type type)
{
    switch (type) {
    case V4L2_BUF_TYPE_VIDEO_OUTPUT:
        return &q_data[V4L2_M2M_SRC];
    case V4L2_BUF_TYPE_VIDEO_CAPTURE:
        return &q_data[V4L2_M2M_DST];
    default:
        BUG();
    }
    return NULL;
}

static struct deinterlace_fmt *find_format(struct v4l2_format *f)
{
    struct deinterlace_fmt *fmt;
    unsigned int k;

    for (k = 0; k < NUM_FORMATS; k++) {
        fmt = &formats[k];
        if ((fmt->types & f->type) &&
            (fmt->fourcc == f->fmt.pix.pixelformat))
            break;
    }

    if (k == NUM_FORMATS)
        return NULL;

    return &formats[k];
}

struct deinterlace_dev {
    struct v4l2_device  v4l2_dev;
    struct video_device *vfd;

    atomic_t        busy;
    struct mutex        dev_mutex;
    spinlock_t      irqlock;

    struct dma_chan     *dma_chan;

    struct v4l2_m2m_dev *m2m_dev;
    struct vb2_alloc_ctx    *alloc_ctx;
};

struct deinterlace_ctx {
    struct deinterlace_dev  *dev;

    /* Abort requested by m2m */
    int         aborting;
    enum v4l2_colorspace    colorspace;
    dma_cookie_t        cookie;
    struct v4l2_m2m_ctx *m2m_ctx;
    struct dma_interleaved_template *xt;
};

/*
 * mem2mem callbacks
 */
static int deinterlace_job_ready(void *priv)
{
    struct deinterlace_ctx *ctx = priv;
    struct deinterlace_dev *pcdev = ctx->dev;

    if ((v4l2_m2m_num_src_bufs_ready(ctx->m2m_ctx) > 0)
        && (v4l2_m2m_num_dst_bufs_ready(ctx->m2m_ctx) > 0)
        && (atomic_read(&ctx->dev->busy) == 0)) {
        dprintk(pcdev, "Task ready\n");
        return 1;
    }

    dprintk(pcdev, "Task not ready to run\n");

    return 0;
}

static void deinterlace_job_abort(void *priv)
{
    struct deinterlace_ctx *ctx = priv;
    struct deinterlace_dev *pcdev = ctx->dev;

    ctx->aborting = 1;

    dprintk(pcdev, "Aborting task\n");

    v4l2_m2m_job_finish(pcdev->m2m_dev, ctx->m2m_ctx);
}

static void deinterlace_lock(void *priv)
{
    struct deinterlace_ctx *ctx = priv;
    struct deinterlace_dev *pcdev = ctx->dev;
    mutex_lock(&pcdev->dev_mutex);
}

static void deinterlace_unlock(void *priv)
{
    struct deinterlace_ctx *ctx = priv;
    struct deinterlace_dev *pcdev = ctx->dev;
    mutex_unlock(&pcdev->dev_mutex);
}

static void dma_callback(void *data)
{
    struct deinterlace_ctx *curr_ctx = data;
    struct deinterlace_dev *pcdev = curr_ctx->dev;
    struct vb2_buffer *src_vb, *dst_vb;

    atomic_set(&pcdev->busy, 0);

    src_vb = v4l2_m2m_src_buf_remove(curr_ctx->m2m_ctx);
    dst_vb = v4l2_m2m_dst_buf_remove(curr_ctx->m2m_ctx);

    v4l2_m2m_buf_done(src_vb, VB2_BUF_STATE_DONE);
    v4l2_m2m_buf_done(dst_vb, VB2_BUF_STATE_DONE);

    v4l2_m2m_job_finish(pcdev->m2m_dev, curr_ctx->m2m_ctx);

    dprintk(pcdev, "dma transfers completed.\n");
}

static void deinterlace_issue_dma(struct deinterlace_ctx *ctx, int op,
                  int do_callback)
{
    struct deinterlace_q_data *s_q_data, *d_q_data;
    struct vb2_buffer *src_buf, *dst_buf;
    struct deinterlace_dev *pcdev = ctx->dev;
    struct dma_chan *chan = pcdev->dma_chan;
    struct dma_device *dmadev = chan->device;
    struct dma_async_tx_descriptor *tx;
    unsigned int s_width, s_height;
    unsigned int d_width, d_height;
    unsigned int d_size, s_size;
    dma_addr_t p_in, p_out;
    enum dma_ctrl_flags flags;

    src_buf = v4l2_m2m_next_src_buf(ctx->m2m_ctx);
    dst_buf = v4l2_m2m_next_dst_buf(ctx->m2m_ctx);

    s_q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_OUTPUT);
    s_width = s_q_data->width;
    s_height = s_q_data->height;
    s_size = s_width * s_height;

    d_q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_CAPTURE);
    d_width = d_q_data->width;
    d_height = d_q_data->height;
    d_size = d_width * d_height;

    p_in = (dma_addr_t)vb2_dma_contig_plane_dma_addr(src_buf, 0);
    p_out = (dma_addr_t)vb2_dma_contig_plane_dma_addr(dst_buf, 0);
    if (!p_in || !p_out) {
        v4l2_err(&pcdev->v4l2_dev,
             "Acquiring kernel pointers to buffers failed\n");
        return;
    }

    switch (op) {
    case YUV420_DMA_Y_ODD:
        ctx->xt->numf = s_height / 2;
        ctx->xt->sgl[0].size = s_width;
        ctx->xt->sgl[0].icg = s_width;
        ctx->xt->src_start = p_in;
        ctx->xt->dst_start = p_out;
        break;
    case YUV420_DMA_Y_EVEN:
        ctx->xt->numf = s_height / 2;
        ctx->xt->sgl[0].size = s_width;
        ctx->xt->sgl[0].icg = s_width;
        ctx->xt->src_start = p_in + s_size / 2;
        ctx->xt->dst_start = p_out + s_width;
        break;
    case YUV420_DMA_U_ODD:
        ctx->xt->numf = s_height / 4;
        ctx->xt->sgl[0].size = s_width / 2;
        ctx->xt->sgl[0].icg = s_width / 2;
        ctx->xt->src_start = p_in + s_size;
        ctx->xt->dst_start = p_out + s_size;
        break;
    case YUV420_DMA_U_EVEN:
        ctx->xt->numf = s_height / 4;
        ctx->xt->sgl[0].size = s_width / 2;
        ctx->xt->sgl[0].icg = s_width / 2;
        ctx->xt->src_start = p_in + (9 * s_size) / 8;
        ctx->xt->dst_start = p_out + s_size + s_width / 2;
        break;
    case YUV420_DMA_V_ODD:
        ctx->xt->numf = s_height / 4;
        ctx->xt->sgl[0].size = s_width / 2;
        ctx->xt->sgl[0].icg = s_width / 2;
        ctx->xt->src_start = p_in + (5 * s_size) / 4;
        ctx->xt->dst_start = p_out + (5 * s_size) / 4;
        break;
    case YUV420_DMA_V_EVEN:
        ctx->xt->numf = s_height / 4;
        ctx->xt->sgl[0].size = s_width / 2;
        ctx->xt->sgl[0].icg = s_width / 2;
        ctx->xt->src_start = p_in + (11 * s_size) / 8;
        ctx->xt->dst_start = p_out + (5 * s_size) / 4 + s_width / 2;
        break;
    case YUV420_DMA_Y_ODD_DOUBLING:
        ctx->xt->numf = s_height / 2;
        ctx->xt->sgl[0].size = s_width;
        ctx->xt->sgl[0].icg = s_width;
        ctx->xt->src_start = p_in;
        ctx->xt->dst_start = p_out + s_width;
        break;
    case YUV420_DMA_U_ODD_DOUBLING:
        ctx->xt->numf = s_height / 4;
        ctx->xt->sgl[0].size = s_width / 2;
        ctx->xt->sgl[0].icg = s_width / 2;
        ctx->xt->src_start = p_in + s_size;
        ctx->xt->dst_start = p_out + s_size + s_width / 2;
        break;
    case YUV420_DMA_V_ODD_DOUBLING:
        ctx->xt->numf = s_height / 4;
        ctx->xt->sgl[0].size = s_width / 2;
        ctx->xt->sgl[0].icg = s_width / 2;
        ctx->xt->src_start = p_in + (5 * s_size) / 4;
        ctx->xt->dst_start = p_out + (5 * s_size) / 4 + s_width / 2;
        break;
    case YUYV_DMA_ODD:
        ctx->xt->numf = s_height / 2;
        ctx->xt->sgl[0].size = s_width * 2;
        ctx->xt->sgl[0].icg = s_width * 2;
        ctx->xt->src_start = p_in;
        ctx->xt->dst_start = p_out;
        break;
    case YUYV_DMA_EVEN:
        ctx->xt->numf = s_height / 2;
        ctx->xt->sgl[0].size = s_width * 2;
        ctx->xt->sgl[0].icg = s_width * 2;
        ctx->xt->src_start = p_in + s_size;
        ctx->xt->dst_start = p_out + s_width * 2;
        break;
    case YUYV_DMA_EVEN_DOUBLING:
    default:
        ctx->xt->numf = s_height / 2;
        ctx->xt->sgl[0].size = s_width * 2;
        ctx->xt->sgl[0].icg = s_width * 2;
        ctx->xt->src_start = p_in;
        ctx->xt->dst_start = p_out + s_width * 2;
        break;
    }

    /* Common parameters for al transfers */
    ctx->xt->frame_size = 1;
    ctx->xt->dir = DMA_MEM_TO_MEM;
    ctx->xt->src_sgl = false;
    ctx->xt->dst_sgl = true;
    flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT |
        DMA_COMPL_SKIP_DEST_UNMAP | DMA_COMPL_SKIP_SRC_UNMAP;

    tx = dmadev->device_prep_interleaved_dma(chan, ctx->xt, flags);
    if (tx == NULL) {
        v4l2_warn(&pcdev->v4l2_dev, "DMA interleaved prep error\n");
        return;
    }

    if (do_callback) {
        tx->callback = dma_callback;
        tx->callback_param = ctx;
    }

    ctx->cookie = dmaengine_submit(tx);
    if (dma_submit_error(ctx->cookie)) {
        v4l2_warn(&pcdev->v4l2_dev,
              "DMA submit error %d with src=0x%x dst=0x%x len=0x%x\n",
              ctx->cookie, (unsigned)p_in, (unsigned)p_out,
              s_size * 3/2);
        return;
    }

    dma_async_issue_pending(chan);
}

static void deinterlace_device_run(void *priv)
{
    struct deinterlace_ctx *ctx = priv;
    struct deinterlace_q_data *dst_q_data;

    atomic_set(&ctx->dev->busy, 1);

    dprintk(ctx->dev, "%s: DMA try issue.\n", __func__);

    dst_q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_CAPTURE);

    /*
     * 4 possible field conversions are possible at the moment:
     *  V4L2_FIELD_SEQ_TB --> V4L2_FIELD_INTERLACED_TB:
     *  two separate fields in the same input buffer are interlaced
     *  in the output buffer using weaving. Top field comes first.
     *  V4L2_FIELD_SEQ_TB --> V4L2_FIELD_NONE:
     *  top field from the input buffer is copied to the output buffer
     *  using line doubling. Bottom field from the input buffer is discarded.
     * V4L2_FIELD_SEQ_BT --> V4L2_FIELD_INTERLACED_BT:
     *  two separate fields in the same input buffer are interlaced
     *  in the output buffer using weaving. Bottom field comes first.
     * V4L2_FIELD_SEQ_BT --> V4L2_FIELD_NONE:
     *  bottom field from the input buffer is copied to the output buffer
     *  using line doubling. Top field from the input buffer is discarded.
     */
    switch (dst_q_data->fmt->fourcc) {
    case V4L2_PIX_FMT_YUV420:
        switch (dst_q_data->field) {
        case V4L2_FIELD_INTERLACED_TB:
        case V4L2_FIELD_INTERLACED_BT:
            dprintk(ctx->dev, "%s: yuv420 interlaced tb.\n",
                __func__);
            deinterlace_issue_dma(ctx, YUV420_DMA_Y_ODD, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_Y_EVEN, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_U_ODD, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_U_EVEN, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_V_ODD, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_V_EVEN, 1);
            break;
        case V4L2_FIELD_NONE:
        default:
            dprintk(ctx->dev, "%s: yuv420 interlaced line doubling.\n",
                __func__);
            deinterlace_issue_dma(ctx, YUV420_DMA_Y_ODD, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_Y_ODD_DOUBLING, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_U_ODD, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_U_ODD_DOUBLING, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_V_ODD, 0);
            deinterlace_issue_dma(ctx, YUV420_DMA_V_ODD_DOUBLING, 1);
            break;
        }
        break;
    case V4L2_PIX_FMT_YUYV:
    default:
        switch (dst_q_data->field) {
        case V4L2_FIELD_INTERLACED_TB:
        case V4L2_FIELD_INTERLACED_BT:
            dprintk(ctx->dev, "%s: yuyv interlaced_tb.\n",
                __func__);
            deinterlace_issue_dma(ctx, YUYV_DMA_ODD, 0);
            deinterlace_issue_dma(ctx, YUYV_DMA_EVEN, 1);
            break;
        case V4L2_FIELD_NONE:
        default:
            dprintk(ctx->dev, "%s: yuyv interlaced line doubling.\n",
                __func__);
            deinterlace_issue_dma(ctx, YUYV_DMA_ODD, 0);
            deinterlace_issue_dma(ctx, YUYV_DMA_EVEN_DOUBLING, 1);
            break;
        }
        break;
    }

    dprintk(ctx->dev, "%s: DMA issue done.\n", __func__);
}

/*
 * video ioctls
 */
static int vidioc_querycap(struct file *file, void *priv,
               struct v4l2_capability *cap)
{
    strlcpy(cap->driver, MEM2MEM_NAME, sizeof(cap->driver));
    strlcpy(cap->card, MEM2MEM_NAME, sizeof(cap->card));
    strlcpy(cap->bus_info, MEM2MEM_NAME, sizeof(cap->card));
    /*
     * This is only a mem-to-mem video device. The capture and output
     * device capability flags are left only for backward compatibility
     * and are scheduled for removal.
     */
    cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OUTPUT |
               V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING;
    cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;

    return 0;
}

static int enum_fmt(struct v4l2_fmtdesc *f, u32 type)
{
    int i, num;
    struct deinterlace_fmt *fmt;

    num = 0;

    for (i = 0; i < NUM_FORMATS; ++i) {
        if (formats[i].types & type) {
            /* index-th format of type type found ? */
            if (num == f->index)
                break;
            /* Correct type but haven't reached our index yet,
             * just increment per-type index */
            ++num;
        }
    }

    if (i < NUM_FORMATS) {
        /* Format found */
        fmt = &formats[i];
        strlcpy(f->description, fmt->name, sizeof(f->description));
        f->pixelformat = fmt->fourcc;
        return 0;
    }

    /* Format not found */
    return -EINVAL;
}

static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
                   struct v4l2_fmtdesc *f)
{
    return enum_fmt(f, MEM2MEM_CAPTURE);
}

static int vidioc_enum_fmt_vid_out(struct file *file, void *priv,
                   struct v4l2_fmtdesc *f)
{
    return enum_fmt(f, MEM2MEM_OUTPUT);
}

static int vidioc_g_fmt(struct deinterlace_ctx *ctx, struct v4l2_format *f)
{
    struct vb2_queue *vq;
    struct deinterlace_q_data *q_data;

    vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
    if (!vq)
        return -EINVAL;

    q_data = get_q_data(f->type);

    f->fmt.pix.width    = q_data->width;
    f->fmt.pix.height   = q_data->height;
    f->fmt.pix.field    = q_data->field;
    f->fmt.pix.pixelformat  = q_data->fmt->fourcc;

    switch (q_data->fmt->fourcc) {
    case V4L2_PIX_FMT_YUV420:
        f->fmt.pix.bytesperline = q_data->width * 3 / 2;
        break;
    case V4L2_PIX_FMT_YUYV:
    default:
        f->fmt.pix.bytesperline = q_data->width * 2;
    }

    f->fmt.pix.sizeimage    = q_data->sizeimage;
    f->fmt.pix.colorspace   = ctx->colorspace;

    return 0;
}

static int vidioc_g_fmt_vid_out(struct file *file, void *priv,
                struct v4l2_format *f)
{
    return vidioc_g_fmt(priv, f);
}

static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
                struct v4l2_format *f)
{
    return vidioc_g_fmt(priv, f);
}

static int vidioc_try_fmt(struct v4l2_format *f, struct deinterlace_fmt *fmt)
{
    switch (f->fmt.pix.pixelformat) {
    case V4L2_PIX_FMT_YUV420:
        f->fmt.pix.bytesperline = f->fmt.pix.width * 3 / 2;
        break;
    case V4L2_PIX_FMT_YUYV:
    default:
        f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
    }
    f->fmt.pix.sizeimage = f->fmt.pix.height * f->fmt.pix.bytesperline;

    return 0;
}

static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
                  struct v4l2_format *f)
{
    struct deinterlace_fmt *fmt;
    struct deinterlace_ctx *ctx = priv;

    fmt = find_format(f);
    if (!fmt || !(fmt->types & MEM2MEM_CAPTURE))
        f->fmt.pix.pixelformat = V4L2_PIX_FMT_YUV420;

    f->fmt.pix.colorspace = ctx->colorspace;

    if (f->fmt.pix.field != V4L2_FIELD_INTERLACED_TB &&
        f->fmt.pix.field != V4L2_FIELD_INTERLACED_BT &&
        f->fmt.pix.field != V4L2_FIELD_NONE)
        f->fmt.pix.field = V4L2_FIELD_INTERLACED_TB;

    return vidioc_try_fmt(f, fmt);
}

static int vidioc_try_fmt_vid_out(struct file *file, void *priv,
                  struct v4l2_format *f)
{
    struct deinterlace_fmt *fmt;

    fmt = find_format(f);
    if (!fmt || !(fmt->types & MEM2MEM_OUTPUT))
        f->fmt.pix.pixelformat = V4L2_PIX_FMT_YUV420;

    if (!f->fmt.pix.colorspace)
        f->fmt.pix.colorspace = V4L2_COLORSPACE_REC709;

    if (f->fmt.pix.field != V4L2_FIELD_SEQ_TB &&
        f->fmt.pix.field != V4L2_FIELD_SEQ_BT)
        f->fmt.pix.field = V4L2_FIELD_SEQ_TB;

    return vidioc_try_fmt(f, fmt);
}

static int vidioc_s_fmt(struct deinterlace_ctx *ctx, struct v4l2_format *f)
{
    struct deinterlace_q_data *q_data;
    struct vb2_queue *vq;

    vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
    if (!vq)
        return -EINVAL;

    q_data = get_q_data(f->type);
    if (!q_data)
        return -EINVAL;

    if (vb2_is_busy(vq)) {
        v4l2_err(&ctx->dev->v4l2_dev, "%s queue busy\n", __func__);
        return -EBUSY;
    }

    q_data->fmt = find_format(f);
    if (!q_data->fmt) {
        v4l2_err(&ctx->dev->v4l2_dev,
             "Couldn't set format type %d, wxh: %dx%d. fmt: %d, field: %d\n",
            f->type, f->fmt.pix.width, f->fmt.pix.height,
            f->fmt.pix.pixelformat, f->fmt.pix.field);
        return -EINVAL;
    }

    q_data->width       = f->fmt.pix.width;
    q_data->height      = f->fmt.pix.height;
    q_data->field       = f->fmt.pix.field;

    switch (f->fmt.pix.pixelformat) {
    case V4L2_PIX_FMT_YUV420:
        f->fmt.pix.bytesperline = f->fmt.pix.width * 3 / 2;
        q_data->sizeimage = (q_data->width * q_data->height * 3) / 2;
        break;
    case V4L2_PIX_FMT_YUYV:
    default:
        f->fmt.pix.bytesperline = f->fmt.pix.width * 2;
        q_data->sizeimage = q_data->width * q_data->height * 2;
    }

    dprintk(ctx->dev,
        "Setting format for type %d, wxh: %dx%d, fmt: %d, field: %d\n",
        f->type, q_data->width, q_data->height, q_data->fmt->fourcc,
        q_data->field);

    return 0;
}

static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
                struct v4l2_format *f)
{
    int ret;

    ret = vidioc_try_fmt_vid_cap(file, priv, f);
    if (ret)
        return ret;
    return vidioc_s_fmt(priv, f);
}

static int vidioc_s_fmt_vid_out(struct file *file, void *priv,
                struct v4l2_format *f)
{
    struct deinterlace_ctx *ctx = priv;
    int ret;

    ret = vidioc_try_fmt_vid_out(file, priv, f);
    if (ret)
        return ret;

    ret = vidioc_s_fmt(priv, f);
    if (!ret)
        ctx->colorspace = f->fmt.pix.colorspace;

    return ret;
}

static int vidioc_reqbufs(struct file *file, void *priv,
              struct v4l2_requestbuffers *reqbufs)
{
    struct deinterlace_ctx *ctx = priv;

    return v4l2_m2m_reqbufs(file, ctx->m2m_ctx, reqbufs);
}

static int vidioc_querybuf(struct file *file, void *priv,
               struct v4l2_buffer *buf)
{
    struct deinterlace_ctx *ctx = priv;

    return v4l2_m2m_querybuf(file, ctx->m2m_ctx, buf);
}

static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
    struct deinterlace_ctx *ctx = priv;

    return v4l2_m2m_qbuf(file, ctx->m2m_ctx, buf);
}

static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
    struct deinterlace_ctx *ctx = priv;

    return v4l2_m2m_dqbuf(file, ctx->m2m_ctx, buf);
}

static int vidioc_streamon(struct file *file, void *priv,
               enum v4l2_buf_type type)
{
    struct deinterlace_q_data *s_q_data, *d_q_data;
    struct deinterlace_ctx *ctx = priv;

    s_q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_OUTPUT);
    d_q_data = get_q_data(V4L2_BUF_TYPE_VIDEO_CAPTURE);

    /* Check that src and dst queues have the same pix format */
    if (s_q_data->fmt->fourcc != d_q_data->fmt->fourcc) {
        v4l2_err(&ctx->dev->v4l2_dev,
             "src and dst formats don't match.\n");
        return -EINVAL;
    }

    /* Check that input and output deinterlacing types are compatible */
    switch (s_q_data->field) {
    case V4L2_FIELD_SEQ_BT:
        if (d_q_data->field != V4L2_FIELD_NONE &&
            d_q_data->field != V4L2_FIELD_INTERLACED_BT) {
            v4l2_err(&ctx->dev->v4l2_dev,
             "src and dst field conversion [(%d)->(%d)] not supported.\n",
                s_q_data->field, d_q_data->field);
            return -EINVAL;
        }
        break;
    case V4L2_FIELD_SEQ_TB:
        if (d_q_data->field != V4L2_FIELD_NONE &&
            d_q_data->field != V4L2_FIELD_INTERLACED_TB) {
            v4l2_err(&ctx->dev->v4l2_dev,
             "src and dst field conversion [(%d)->(%d)] not supported.\n",
                s_q_data->field, d_q_data->field);
            return -EINVAL;
        }
        break;
    default:
        return -EINVAL;
    }

    return v4l2_m2m_streamon(file, ctx->m2m_ctx, type);
}

static int vidioc_streamoff(struct file *file, void *priv,
                enum v4l2_buf_type type)
{
    struct deinterlace_ctx *ctx = priv;

    return v4l2_m2m_streamoff(file, ctx->m2m_ctx, type);
}

static const struct v4l2_ioctl_ops deinterlace_ioctl_ops = {
    .vidioc_querycap    = vidioc_querycap,

    .vidioc_enum_fmt_vid_cap = vidioc_enum_fmt_vid_cap,
    .vidioc_g_fmt_vid_cap   = vidioc_g_fmt_vid_cap,
    .vidioc_try_fmt_vid_cap = vidioc_try_fmt_vid_cap,
    .vidioc_s_fmt_vid_cap   = vidioc_s_fmt_vid_cap,

    .vidioc_enum_fmt_vid_out = vidioc_enum_fmt_vid_out,
    .vidioc_g_fmt_vid_out   = vidioc_g_fmt_vid_out,
    .vidioc_try_fmt_vid_out = vidioc_try_fmt_vid_out,
    .vidioc_s_fmt_vid_out   = vidioc_s_fmt_vid_out,

    .vidioc_reqbufs     = vidioc_reqbufs,
    .vidioc_querybuf    = vidioc_querybuf,

    .vidioc_qbuf        = vidioc_qbuf,
    .vidioc_dqbuf       = vidioc_dqbuf,

    .vidioc_streamon    = vidioc_streamon,
    .vidioc_streamoff   = vidioc_streamoff,
};


/*
 * Queue operations
 */
struct vb2_dc_conf {
    struct device           *dev;
};

static int deinterlace_queue_setup(struct vb2_queue *vq,
                const struct v4l2_format *fmt,
                unsigned int *nbuffers, unsigned int *nplanes,
                unsigned int sizes[], void *alloc_ctxs[])
{
    struct deinterlace_ctx *ctx = vb2_get_drv_priv(vq);
    struct deinterlace_q_data *q_data;
    unsigned int size, count = *nbuffers;

    q_data = get_q_data(vq->type);

    switch (q_data->fmt->fourcc) {
    case V4L2_PIX_FMT_YUV420:
        size = q_data->width * q_data->height * 3 / 2;
        break;
    case V4L2_PIX_FMT_YUYV:
    default:
        size = q_data->width * q_data->height * 2;
    }

    *nplanes = 1;
    *nbuffers = count;
    sizes[0] = size;

    alloc_ctxs[0] = ctx->dev->alloc_ctx;

    dprintk(ctx->dev, "get %d buffer(s) of size %d each.\n", count, size);

    return 0;
}

static int deinterlace_buf_prepare(struct vb2_buffer *vb)
{
    struct deinterlace_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
    struct deinterlace_q_data *q_data;

    dprintk(ctx->dev, "type: %d\n", vb->vb2_queue->type);

    q_data = get_q_data(vb->vb2_queue->type);

    if (vb2_plane_size(vb, 0) < q_data->sizeimage) {
        dprintk(ctx->dev, "%s data will not fit into plane (%lu < %lu)\n",
            __func__, vb2_plane_size(vb, 0), (long)q_data->sizeimage);
        return -EINVAL;
    }

    vb2_set_plane_payload(vb, 0, q_data->sizeimage);

    return 0;
}

static void deinterlace_buf_queue(struct vb2_buffer *vb)
{
    struct deinterlace_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
    v4l2_m2m_buf_queue(ctx->m2m_ctx, vb);
}

static struct vb2_ops deinterlace_qops = {
    .queue_setup     = deinterlace_queue_setup,
    .buf_prepare     = deinterlace_buf_prepare,
    .buf_queue   = deinterlace_buf_queue,
};

static int queue_init(void *priv, struct vb2_queue *src_vq,
              struct vb2_queue *dst_vq)
{
    struct deinterlace_ctx *ctx = priv;
    int ret;

    src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
    src_vq->io_modes = VB2_MMAP | VB2_USERPTR;
    src_vq->drv_priv = ctx;
    src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
    src_vq->ops = &deinterlace_qops;
    src_vq->mem_ops = &vb2_dma_contig_memops;
    q_data[V4L2_M2M_SRC].fmt = &formats[0];
    q_data[V4L2_M2M_SRC].width = 640;
    q_data[V4L2_M2M_SRC].height = 480;
    q_data[V4L2_M2M_SRC].sizeimage = (640 * 480 * 3) / 2;
    q_data[V4L2_M2M_SRC].field = V4L2_FIELD_SEQ_TB;

    ret = vb2_queue_init(src_vq);
    if (ret)
        return ret;

    dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    dst_vq->io_modes = VB2_MMAP | VB2_USERPTR;
    dst_vq->drv_priv = ctx;
    dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
    dst_vq->ops = &deinterlace_qops;
    dst_vq->mem_ops = &vb2_dma_contig_memops;
    q_data[V4L2_M2M_DST].fmt = &formats[0];
    q_data[V4L2_M2M_DST].width = 640;
    q_data[V4L2_M2M_DST].height = 480;
    q_data[V4L2_M2M_DST].sizeimage = (640 * 480 * 3) / 2;
    q_data[V4L2_M2M_SRC].field = V4L2_FIELD_INTERLACED_TB;

    return vb2_queue_init(dst_vq);
}

/*
 * File operations
 */
static int deinterlace_open(struct file *file)
{
    struct deinterlace_dev *pcdev = video_drvdata(file);
    struct deinterlace_ctx *ctx = NULL;

    ctx = kzalloc(sizeof *ctx, GFP_KERNEL);
    if (!ctx)
        return -ENOMEM;

    file->private_data = ctx;
    ctx->dev = pcdev;

    ctx->m2m_ctx = v4l2_m2m_ctx_init(pcdev->m2m_dev, ctx, &queue_init);
    if (IS_ERR(ctx->m2m_ctx)) {
        int ret = PTR_ERR(ctx->m2m_ctx);

        kfree(ctx);
        return ret;
    }

    ctx->xt = kzalloc(sizeof(struct dma_async_tx_descriptor) +
                sizeof(struct data_chunk), GFP_KERNEL);
    if (!ctx->xt) {
        int ret = PTR_ERR(ctx->xt);

        kfree(ctx);
        return ret;
    }

    ctx->colorspace = V4L2_COLORSPACE_REC709;

    dprintk(pcdev, "Created instance %p, m2m_ctx: %p\n", ctx, ctx->m2m_ctx);

    return 0;
}

static int deinterlace_release(struct file *file)
{
    struct deinterlace_dev *pcdev = video_drvdata(file);
    struct deinterlace_ctx *ctx = file->private_data;

    dprintk(pcdev, "Releasing instance %p\n", ctx);

    v4l2_m2m_ctx_release(ctx->m2m_ctx);
    kfree(ctx->xt);
    kfree(ctx);

    return 0;
}

static unsigned int deinterlace_poll(struct file *file,
                 struct poll_table_struct *wait)
{
    struct deinterlace_ctx *ctx = file->private_data;
    int ret;

    deinterlace_lock(ctx);
    ret = v4l2_m2m_poll(file, ctx->m2m_ctx, wait);
    deinterlace_unlock(ctx);

    return ret;
}

static int deinterlace_mmap(struct file *file, struct vm_area_struct *vma)
{
    struct deinterlace_ctx *ctx = file->private_data;

    return v4l2_m2m_mmap(file, ctx->m2m_ctx, vma);
}

static const struct v4l2_file_operations deinterlace_fops = {
    .owner      = THIS_MODULE,
    .open       = deinterlace_open,
    .release    = deinterlace_release,
    .poll       = deinterlace_poll,
    .unlocked_ioctl = video_ioctl2,
    .mmap       = deinterlace_mmap,
};

static struct video_device deinterlace_videodev = {
    .name       = MEM2MEM_NAME,
    .fops       = &deinterlace_fops,
    .ioctl_ops  = &deinterlace_ioctl_ops,
    .minor      = -1,
    .release    = video_device_release,
    .vfl_dir    = VFL_DIR_M2M,
};

static struct v4l2_m2m_ops m2m_ops = {
    .device_run = deinterlace_device_run,
    .job_ready  = deinterlace_job_ready,
    .job_abort  = deinterlace_job_abort,
    .lock       = deinterlace_lock,
    .unlock     = deinterlace_unlock,
};

static int deinterlace_probe(struct platform_device *pdev)
{
    struct deinterlace_dev *pcdev;
    struct video_device *vfd;
    dma_cap_mask_t mask;
    int ret = 0;

    pcdev = kzalloc(sizeof *pcdev, GFP_KERNEL);
    if (!pcdev)
        return -ENOMEM;

    spin_lock_init(&pcdev->irqlock);

    dma_cap_zero(mask);
    dma_cap_set(DMA_INTERLEAVE, mask);
    pcdev->dma_chan = dma_request_channel(mask, NULL, pcdev);
    if (!pcdev->dma_chan)
        goto free_dev;

    if (!dma_has_cap(DMA_INTERLEAVE, pcdev->dma_chan->device->cap_mask)) {
        v4l2_err(&pcdev->v4l2_dev, "DMA does not support INTERLEAVE\n");
        goto rel_dma;
    }

    ret = v4l2_device_register(&pdev->dev, &pcdev->v4l2_dev);
    if (ret)
        goto rel_dma;

    atomic_set(&pcdev->busy, 0);
    mutex_init(&pcdev->dev_mutex);

    vfd = video_device_alloc();
    if (!vfd) {
        v4l2_err(&pcdev->v4l2_dev, "Failed to allocate video device\n");
        ret = -ENOMEM;
        goto unreg_dev;
    }

    *vfd = deinterlace_videodev;
    vfd->lock = &pcdev->dev_mutex;

    ret = video_register_device(vfd, VFL_TYPE_GRABBER, 0);
    if (ret) {
        v4l2_err(&pcdev->v4l2_dev, "Failed to register video device\n");
        goto rel_vdev;
    }

    video_set_drvdata(vfd, pcdev);
    snprintf(vfd->name, sizeof(vfd->name), "%s", deinterlace_videodev.name);
    pcdev->vfd = vfd;
    v4l2_info(&pcdev->v4l2_dev, MEM2MEM_TEST_MODULE_NAME
            " Device registered as /dev/video%d\n", vfd->num);

    platform_set_drvdata(pdev, pcdev);

    pcdev->alloc_ctx = vb2_dma_contig_init_ctx(&pdev->dev);
    if (IS_ERR(pcdev->alloc_ctx)) {
        v4l2_err(&pcdev->v4l2_dev, "Failed to alloc vb2 context\n");
        ret = PTR_ERR(pcdev->alloc_ctx);
        goto err_ctx;
    }

    pcdev->m2m_dev = v4l2_m2m_init(&m2m_ops);
    if (IS_ERR(pcdev->m2m_dev)) {
        v4l2_err(&pcdev->v4l2_dev, "Failed to init mem2mem device\n");
        ret = PTR_ERR(pcdev->m2m_dev);
        goto err_m2m;
    }

    return 0;

    v4l2_m2m_release(pcdev->m2m_dev);
err_m2m:
    video_unregister_device(pcdev->vfd);
err_ctx:
    vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
rel_vdev:
    video_device_release(vfd);
unreg_dev:
    v4l2_device_unregister(&pcdev->v4l2_dev);
rel_dma:
    dma_release_channel(pcdev->dma_chan);
free_dev:
    kfree(pcdev);

    return ret;
}

static int deinterlace_remove(struct platform_device *pdev)
{
    struct deinterlace_dev *pcdev =
        (struct deinterlace_dev *)platform_get_drvdata(pdev);

    v4l2_info(&pcdev->v4l2_dev, "Removing " MEM2MEM_TEST_MODULE_NAME);
    v4l2_m2m_release(pcdev->m2m_dev);
    video_unregister_device(pcdev->vfd);
    v4l2_device_unregister(&pcdev->v4l2_dev);
    vb2_dma_contig_cleanup_ctx(pcdev->alloc_ctx);
    dma_release_channel(pcdev->dma_chan);
    kfree(pcdev);

    return 0;
}

static struct platform_driver deinterlace_pdrv = {
    .probe      = deinterlace_probe,
    .remove     = deinterlace_remove,
    .driver     = {
        .name   = MEM2MEM_NAME,
        .owner  = THIS_MODULE,
    },
};

static void __exit deinterlace_exit(void)
{
    platform_driver_unregister(&deinterlace_pdrv);
}

static int __init deinterlace_init(void)
{
    return platform_driver_register(&deinterlace_pdrv);
}

module_init(deinterlace_init);
module_exit(deinterlace_exit);