// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * V4L2 deinterlacing support.
 *
 * Copyright (c) 2012 Vista Silicon S.L.
 * Javier Martin <javier.martin@vista-silicon.com>
 */

#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 <javier.martin@vista-silicon.com");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.0.1");

static bool debug;
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 {
        u32     fourcc;
        /* Types the format can be used for */
        u32     types;
};

static struct deinterlace_fmt formats[] = {
        {
                .fourcc = V4L2_PIX_FMT_YUV420,
                .types  = MEM2MEM_CAPTURE | MEM2MEM_OUTPUT,
        },
        {
                .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 deinterlace_ctx {
        struct v4l2_fh          fh;
        struct deinterlace_dev  *dev;

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

static inline struct deinterlace_ctx *file_to_ctx(struct file *filp)
{
        return container_of(file_to_v4l2_fh(filp), struct deinterlace_ctx, fh);
}

/*
 * 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->fh.m2m_ctx) > 0 &&
            v4l2_m2m_num_dst_bufs_ready(ctx->fh.m2m_ctx) > 0 &&
            !atomic_read(&ctx->dev->busy)) {
                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->fh.m2m_ctx);
}

static void dma_callback(void *data)
{
        struct deinterlace_ctx *curr_ctx = data;
        struct deinterlace_dev *pcdev = curr_ctx->dev;
        struct vb2_v4l2_buffer *src_vb, *dst_vb;

        atomic_set(&pcdev->busy, 0);

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

        dst_vb->vb2_buf.timestamp = src_vb->vb2_buf.timestamp;
        dst_vb->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
        dst_vb->flags |=
                src_vb->flags & V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
        dst_vb->timecode = src_vb->timecode;

        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->fh.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;
        struct vb2_v4l2_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 s_size;
        dma_addr_t p_in, p_out;
        enum dma_ctrl_flags flags;

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

        p_in = (dma_addr_t)vb2_dma_contig_plane_dma_addr(&src_buf->vb2_buf, 0);
        p_out = (dma_addr_t)vb2_dma_contig_plane_dma_addr(&dst_buf->vb2_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;

        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)
{
        strscpy(cap->driver, MEM2MEM_NAME, sizeof(cap->driver));
        strscpy(cap->card, MEM2MEM_NAME, sizeof(cap->card));
        strscpy(cap->bus_info, MEM2MEM_NAME, sizeof(cap->bus_info));
        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];
                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 deinterlace_q_data *q_data;

        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(file_to_ctx(file), f);
}

static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
                                struct v4l2_format *f)
{
        return vidioc_g_fmt(file_to_ctx(file), 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_ctx *ctx = file_to_ctx(file);
        struct deinterlace_fmt *fmt;

        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->fh.m2m_ctx, f->type);

        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(file_to_ctx(file), f);
}

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

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

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

        return ret;
}

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

        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->fh.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         = v4l2_m2m_ioctl_reqbufs,
        .vidioc_querybuf        = v4l2_m2m_ioctl_querybuf,
        .vidioc_qbuf            = v4l2_m2m_ioctl_qbuf,
        .vidioc_dqbuf           = v4l2_m2m_ioctl_dqbuf,
        .vidioc_prepare_buf     = v4l2_m2m_ioctl_prepare_buf,
        .vidioc_expbuf          = v4l2_m2m_ioctl_expbuf,

        .vidioc_streamon        = vidioc_streamon,
        .vidioc_streamoff       = v4l2_m2m_ioctl_streamoff,
};


/*
 * Queue operations
 */
static int deinterlace_queue_setup(struct vb2_queue *vq,
                                unsigned int *nbuffers, unsigned int *nplanes,
                                unsigned int sizes[], struct device *alloc_devs[])
{
        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;

        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 vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct deinterlace_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);

        v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf);
}

static const 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 | VB2_DMABUF;
        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;
        src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
        src_vq->dev = ctx->dev->v4l2_dev.dev;
        src_vq->lock = &ctx->dev->dev_mutex;
        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 | VB2_DMABUF;
        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;
        dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
        dst_vq->dev = ctx->dev->v4l2_dev.dev;
        dst_vq->lock = &ctx->dev->dev_mutex;
        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_obj(*ctx);
        if (!ctx)
                return -ENOMEM;

        v4l2_fh_init(&ctx->fh, video_devdata(file));
        ctx->dev = pcdev;

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

                kfree(ctx);
                return ret;
        }

        ctx->xt = kzalloc(sizeof(struct dma_interleaved_template) +
                                sizeof(struct data_chunk), GFP_KERNEL);
        if (!ctx->xt) {
                kfree(ctx);
                return -ENOMEM;
        }

        ctx->colorspace = V4L2_COLORSPACE_REC709;
        v4l2_fh_add(&ctx->fh, file);

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

        return 0;
}

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

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

        v4l2_fh_del(&ctx->fh, file);
        v4l2_fh_exit(&ctx->fh);
        v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
        kfree(ctx->xt);
        kfree(ctx);

        return 0;
}

static const struct v4l2_file_operations deinterlace_fops = {
        .owner          = THIS_MODULE,
        .open           = deinterlace_open,
        .release        = deinterlace_release,
        .poll           = v4l2_m2m_fop_poll,
        .unlocked_ioctl = video_ioctl2,
        .mmap           = v4l2_m2m_fop_mmap,
};

static const struct video_device deinterlace_videodev = {
        .name           = MEM2MEM_NAME,
        .fops           = &deinterlace_fops,
        .ioctl_ops      = &deinterlace_ioctl_ops,
        .minor          = -1,
        .release        = video_device_release_empty,
        .vfl_dir        = VFL_DIR_M2M,
        .device_caps    = V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING,
};

static const struct v4l2_m2m_ops m2m_ops = {
        .device_run     = deinterlace_device_run,
        .job_ready      = deinterlace_job_ready,
        .job_abort      = deinterlace_job_abort,
};

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 = devm_kzalloc(&pdev->dev, 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)
                return -ENODEV;

        if (!dma_has_cap(DMA_INTERLEAVE, pcdev->dma_chan->device->cap_mask)) {
                dev_err(&pdev->dev, "DMA does not support INTERLEAVE\n");
                ret = -ENODEV;
                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 = &pcdev->vfd;
        *vfd = deinterlace_videodev;
        vfd->lock = &pcdev->dev_mutex;
        vfd->v4l2_dev = &pcdev->v4l2_dev;

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

        video_set_drvdata(vfd, pcdev);
        v4l2_info(&pcdev->v4l2_dev, MEM2MEM_TEST_MODULE_NAME
                        " Device registered as /dev/video%d\n", vfd->num);

        platform_set_drvdata(pdev, pcdev);

        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;

err_m2m:
        video_unregister_device(&pcdev->vfd);
unreg_dev:
        v4l2_device_unregister(&pcdev->v4l2_dev);
rel_dma:
        dma_release_channel(pcdev->dma_chan);

        return ret;
}

static void deinterlace_remove(struct platform_device *pdev)
{
        struct deinterlace_dev *pcdev = 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);
        dma_release_channel(pcdev->dma_chan);
}

static struct platform_driver deinterlace_pdrv = {
        .probe          = deinterlace_probe,
        .remove         = deinterlace_remove,
        .driver         = {
                .name   = MEM2MEM_NAME,
        },
};
module_platform_driver(deinterlace_pdrv);