mem2mem_testdev.c

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/*
 * A virtual v4l2-mem2mem example device.
 *
 * This is a virtual device driver for testing mem-to-mem videobuf framework.
 * It simulates a device that uses memory buffers for both source and
 * destination, processes the data and issues an "irq" (simulated by a timer).
 * The device is capable of multi-instance, multi-buffer-per-transaction
 * operation (via the mem2mem framework).
 *
 * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
 * Pawel Osciak, <[email protected]>
 * Marek Szyprowski, <[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/delay.h>
#include <linux/fs.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include <linux/platform_device.h>
#include <media/v4l2-mem2mem.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-event.h>
#include <media/videobuf2-vmalloc.h>

#define MEM2MEM_TEST_MODULE_NAME "mem2mem-testdev"

MODULE_DESCRIPTION("Virtual device for mem2mem framework testing");
MODULE_AUTHOR("Pawel Osciak, <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.1.1");

#define MIN_W 32
#define MIN_H 32
#define MAX_W 640
#define MAX_H 480
#define DIM_ALIGN_MASK 7 /* 8-byte alignment for line length */

/* 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-testdev"

/* Per queue */
#define MEM2MEM_DEF_NUM_BUFS    VIDEO_MAX_FRAME
/* In bytes, per queue */
#define MEM2MEM_VID_MEM_LIMIT   (16 * 1024 * 1024)

/* Default transaction time in msec */
#define MEM2MEM_DEF_TRANSTIME   1000
/* Default number of buffers per transaction */
#define MEM2MEM_DEF_TRANSLEN    1
#define MEM2MEM_COLOR_STEP  (0xff >> 4)
#define MEM2MEM_NUM_TILES   8

/* Flags that indicate processing mode */
#define MEM2MEM_HFLIP   (1 << 0)
#define MEM2MEM_VFLIP   (1 << 1)

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


static void m2mtest_dev_release(struct device *dev)
{}

static struct platform_device m2mtest_pdev = {
    .name       = MEM2MEM_NAME,
    .dev.release    = m2mtest_dev_release,
};

struct m2mtest_fmt {
    char    *name;
    u32 fourcc;
    int depth;
    /* Types the format can be used for */
    u32 types;
};

static struct m2mtest_fmt formats[] = {
    {
        .name   = "RGB565 (BE)",
        .fourcc = V4L2_PIX_FMT_RGB565X, /* rrrrrggg gggbbbbb */
        .depth  = 16,
        /* Both capture and output format */
        .types  = MEM2MEM_CAPTURE | MEM2MEM_OUTPUT,
    },
    {
        .name   = "4:2:2, packed, YUYV",
        .fourcc = V4L2_PIX_FMT_YUYV,
        .depth  = 16,
        /* Output-only format */
        .types  = MEM2MEM_OUTPUT,
    },
};

#define NUM_FORMATS ARRAY_SIZE(formats)

/* Per-queue, driver-specific private data */
struct m2mtest_q_data {
    unsigned int        width;
    unsigned int        height;
    unsigned int        sizeimage;
    struct m2mtest_fmt  *fmt;
};

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

#define V4L2_CID_TRANS_TIME_MSEC    (V4L2_CID_USER_BASE + 0x1000)
#define V4L2_CID_TRANS_NUM_BUFS     (V4L2_CID_USER_BASE + 0x1001)

static struct m2mtest_fmt *find_format(struct v4l2_format *f)
{
    struct m2mtest_fmt *fmt;
    unsigned int k;

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

    if (k == NUM_FORMATS)
        return NULL;

    return &formats[k];
}

struct m2mtest_dev {
    struct v4l2_device  v4l2_dev;
    struct video_device *vfd;

    atomic_t        num_inst;
    struct mutex        dev_mutex;
    spinlock_t      irqlock;

    struct timer_list   timer;

    struct v4l2_m2m_dev *m2m_dev;
};

struct m2mtest_ctx {
    struct v4l2_fh      fh;
    struct m2mtest_dev  *dev;

    struct v4l2_ctrl_handler hdl;

    /* Processed buffers in this transaction */
    u8          num_processed;

    /* Transaction length (i.e. how many buffers per transaction) */
    u32         translen;
    /* Transaction time (i.e. simulated processing time) in milliseconds */
    u32         transtime;

    /* Abort requested by m2m */
    int         aborting;

    /* Processing mode */
    int         mode;

    enum v4l2_colorspace    colorspace;

    struct v4l2_m2m_ctx *m2m_ctx;

    /* Source and destination queue data */
    struct m2mtest_q_data   q_data[2];
};

static inline struct m2mtest_ctx *file2ctx(struct file *file)
{
    return container_of(file->private_data, struct m2mtest_ctx, fh);
}

static struct m2mtest_q_data *get_q_data(struct m2mtest_ctx *ctx,
                     enum v4l2_buf_type type)
{
    switch (type) {
    case V4L2_BUF_TYPE_VIDEO_OUTPUT:
        return &ctx->q_data[V4L2_M2M_SRC];
    case V4L2_BUF_TYPE_VIDEO_CAPTURE:
        return &ctx->q_data[V4L2_M2M_DST];
    default:
        BUG();
    }
    return NULL;
}


static int device_process(struct m2mtest_ctx *ctx,
              struct vb2_buffer *in_vb,
              struct vb2_buffer *out_vb)
{
    struct m2mtest_dev *dev = ctx->dev;
    struct m2mtest_q_data *q_data;
    u8 *p_in, *p_out;
    int x, y, t, w;
    int tile_w, bytes_left;
    int width, height, bytesperline;

    q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);

    width   = q_data->width;
    height  = q_data->height;
    bytesperline    = (q_data->width * q_data->fmt->depth) >> 3;

    p_in = vb2_plane_vaddr(in_vb, 0);
    p_out = vb2_plane_vaddr(out_vb, 0);
    if (!p_in || !p_out) {
        v4l2_err(&dev->v4l2_dev,
             "Acquiring kernel pointers to buffers failed\n");
        return -EFAULT;
    }

    if (vb2_plane_size(in_vb, 0) > vb2_plane_size(out_vb, 0)) {
        v4l2_err(&dev->v4l2_dev, "Output buffer is too small\n");
        return -EINVAL;
    }

    tile_w = (width * (q_data[V4L2_M2M_DST].fmt->depth >> 3))
        / MEM2MEM_NUM_TILES;
    bytes_left = bytesperline - tile_w * MEM2MEM_NUM_TILES;
    w = 0;

    switch (ctx->mode) {
    case MEM2MEM_HFLIP | MEM2MEM_VFLIP:
        p_out += bytesperline * height - bytes_left;
        for (y = 0; y < height; ++y) {
            for (t = 0; t < MEM2MEM_NUM_TILES; ++t) {
                if (w & 0x1) {
                    for (x = 0; x < tile_w; ++x)
                        *--p_out = *p_in++ +
                            MEM2MEM_COLOR_STEP;
                } else {
                    for (x = 0; x < tile_w; ++x)
                        *--p_out = *p_in++ -
                            MEM2MEM_COLOR_STEP;
                }
                ++w;
            }
            p_in += bytes_left;
            p_out -= bytes_left;
        }
        break;

    case MEM2MEM_HFLIP:
        for (y = 0; y < height; ++y) {
            p_out += MEM2MEM_NUM_TILES * tile_w;
            for (t = 0; t < MEM2MEM_NUM_TILES; ++t) {
                if (w & 0x01) {
                    for (x = 0; x < tile_w; ++x)
                        *--p_out = *p_in++ +
                            MEM2MEM_COLOR_STEP;
                } else {
                    for (x = 0; x < tile_w; ++x)
                        *--p_out = *p_in++ -
                            MEM2MEM_COLOR_STEP;
                }
                ++w;
            }
            p_in += bytes_left;
            p_out += bytesperline;
        }
        break;

    case MEM2MEM_VFLIP:
        p_out += bytesperline * (height - 1);
        for (y = 0; y < height; ++y) {
            for (t = 0; t < MEM2MEM_NUM_TILES; ++t) {
                if (w & 0x1) {
                    for (x = 0; x < tile_w; ++x)
                        *p_out++ = *p_in++ +
                            MEM2MEM_COLOR_STEP;
                } else {
                    for (x = 0; x < tile_w; ++x)
                        *p_out++ = *p_in++ -
                            MEM2MEM_COLOR_STEP;
                }
                ++w;
            }
            p_in += bytes_left;
            p_out += bytes_left - 2 * bytesperline;
        }
        break;

    default:
        for (y = 0; y < height; ++y) {
            for (t = 0; t < MEM2MEM_NUM_TILES; ++t) {
                if (w & 0x1) {
                    for (x = 0; x < tile_w; ++x)
                        *p_out++ = *p_in++ +
                            MEM2MEM_COLOR_STEP;
                } else {
                    for (x = 0; x < tile_w; ++x)
                        *p_out++ = *p_in++ -
                            MEM2MEM_COLOR_STEP;
                }
                ++w;
            }
            p_in += bytes_left;
            p_out += bytes_left;
        }
    }

    return 0;
}

static void schedule_irq(struct m2mtest_dev *dev, int msec_timeout)
{
    dprintk(dev, "Scheduling a simulated irq\n");
    mod_timer(&dev->timer, jiffies + msecs_to_jiffies(msec_timeout));
}

/*
 * mem2mem callbacks
 */

static int job_ready(void *priv)
{
    struct m2mtest_ctx *ctx = priv;

    if (v4l2_m2m_num_src_bufs_ready(ctx->m2m_ctx) < ctx->translen
        || v4l2_m2m_num_dst_bufs_ready(ctx->m2m_ctx) < ctx->translen) {
        dprintk(ctx->dev, "Not enough buffers available\n");
        return 0;
    }

    return 1;
}

static void job_abort(void *priv)
{
    struct m2mtest_ctx *ctx = priv;

    /* Will cancel the transaction in the next interrupt handler */
    ctx->aborting = 1;
}

static void m2mtest_lock(void *priv)
{
    struct m2mtest_ctx *ctx = priv;
    struct m2mtest_dev *dev = ctx->dev;
    mutex_lock(&dev->dev_mutex);
}

static void m2mtest_unlock(void *priv)
{
    struct m2mtest_ctx *ctx = priv;
    struct m2mtest_dev *dev = ctx->dev;
    mutex_unlock(&dev->dev_mutex);
}


/* device_run() - prepares and starts the device
 *
 * This simulates all the immediate preparations required before starting
 * a device. This will be called by the framework when it decides to schedule
 * a particular instance.
 */
static void device_run(void *priv)
{
    struct m2mtest_ctx *ctx = priv;
    struct m2mtest_dev *dev = ctx->dev;
    struct vb2_buffer *src_buf, *dst_buf;

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

    device_process(ctx, src_buf, dst_buf);

    /* Run a timer, which simulates a hardware irq  */
    schedule_irq(dev, ctx->transtime);
}

static void device_isr(unsigned long priv)
{
    struct m2mtest_dev *m2mtest_dev = (struct m2mtest_dev *)priv;
    struct m2mtest_ctx *curr_ctx;
    struct vb2_buffer *src_vb, *dst_vb;
    unsigned long flags;

    curr_ctx = v4l2_m2m_get_curr_priv(m2mtest_dev->m2m_dev);

    if (NULL == curr_ctx) {
        pr_err("Instance released before the end of transaction\n");
        return;
    }

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

    curr_ctx->num_processed++;

    spin_lock_irqsave(&m2mtest_dev->irqlock, flags);
    v4l2_m2m_buf_done(src_vb, VB2_BUF_STATE_DONE);
    v4l2_m2m_buf_done(dst_vb, VB2_BUF_STATE_DONE);
    spin_unlock_irqrestore(&m2mtest_dev->irqlock, flags);

    if (curr_ctx->num_processed == curr_ctx->translen
        || curr_ctx->aborting) {
        dprintk(curr_ctx->dev, "Finishing transaction\n");
        curr_ctx->num_processed = 0;
        v4l2_m2m_job_finish(m2mtest_dev->m2m_dev, curr_ctx->m2m_ctx);
    } else {
        device_run(curr_ctx);
    }
}

/*
 * video ioctls
 */
static int vidioc_querycap(struct file *file, void *priv,
               struct v4l2_capability *cap)
{
    strncpy(cap->driver, MEM2MEM_NAME, sizeof(cap->driver) - 1);
    strncpy(cap->card, MEM2MEM_NAME, sizeof(cap->card) - 1);
    snprintf(cap->bus_info, sizeof(cap->bus_info),
            "platform:%s", MEM2MEM_NAME);
    cap->device_caps = 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 m2mtest_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];
        strncpy(f->description, fmt->name, sizeof(f->description) - 1);
        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 m2mtest_ctx *ctx, struct v4l2_format *f)
{
    struct vb2_queue *vq;
    struct m2mtest_q_data *q_data;

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

    q_data = get_q_data(ctx, f->type);

    f->fmt.pix.width    = q_data->width;
    f->fmt.pix.height   = q_data->height;
    f->fmt.pix.field    = V4L2_FIELD_NONE;
    f->fmt.pix.pixelformat  = q_data->fmt->fourcc;
    f->fmt.pix.bytesperline = (q_data->width * q_data->fmt->depth) >> 3;
    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(file2ctx(file), f);
}

static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,
                struct v4l2_format *f)
{
    return vidioc_g_fmt(file2ctx(file), f);
}

static int vidioc_try_fmt(struct v4l2_format *f, struct m2mtest_fmt *fmt)
{
    enum v4l2_field field;

    field = f->fmt.pix.field;

    if (field == V4L2_FIELD_ANY)
        field = V4L2_FIELD_NONE;
    else if (V4L2_FIELD_NONE != field)
        return -EINVAL;

    /* V4L2 specification suggests the driver corrects the format struct
     * if any of the dimensions is unsupported */
    f->fmt.pix.field = field;

    if (f->fmt.pix.height < MIN_H)
        f->fmt.pix.height = MIN_H;
    else if (f->fmt.pix.height > MAX_H)
        f->fmt.pix.height = MAX_H;

    if (f->fmt.pix.width < MIN_W)
        f->fmt.pix.width = MIN_W;
    else if (f->fmt.pix.width > MAX_W)
        f->fmt.pix.width = MAX_W;

    f->fmt.pix.width &= ~DIM_ALIGN_MASK;
    f->fmt.pix.bytesperline = (f->fmt.pix.width * fmt->depth) >> 3;
    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 m2mtest_fmt *fmt;
    struct m2mtest_ctx *ctx = file2ctx(file);

    fmt = find_format(f);
    if (!fmt || !(fmt->types & MEM2MEM_CAPTURE)) {
        v4l2_err(&ctx->dev->v4l2_dev,
             "Fourcc format (0x%08x) invalid.\n",
             f->fmt.pix.pixelformat);
        return -EINVAL;
    }
    f->fmt.pix.colorspace = ctx->colorspace;

    return vidioc_try_fmt(f, fmt);
}

static int vidioc_try_fmt_vid_out(struct file *file, void *priv,
                  struct v4l2_format *f)
{
    struct m2mtest_fmt *fmt;
    struct m2mtest_ctx *ctx = file2ctx(file);

    fmt = find_format(f);
    if (!fmt || !(fmt->types & MEM2MEM_OUTPUT)) {
        v4l2_err(&ctx->dev->v4l2_dev,
             "Fourcc format (0x%08x) invalid.\n",
             f->fmt.pix.pixelformat);
        return -EINVAL;
    }
    if (!f->fmt.pix.colorspace)
        f->fmt.pix.colorspace = V4L2_COLORSPACE_REC709;

    return vidioc_try_fmt(f, fmt);
}

static int vidioc_s_fmt(struct m2mtest_ctx *ctx, struct v4l2_format *f)
{
    struct m2mtest_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(ctx, 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);
    q_data->width       = f->fmt.pix.width;
    q_data->height      = f->fmt.pix.height;
    q_data->sizeimage   = q_data->width * q_data->height
                * q_data->fmt->depth >> 3;

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

    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(file2ctx(file), f);
}

static int vidioc_s_fmt_vid_out(struct file *file, void *priv,
                struct v4l2_format *f)
{
    struct m2mtest_ctx *ctx = file2ctx(file);
    int ret;

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

    ret = vidioc_s_fmt(file2ctx(file), 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 m2mtest_ctx *ctx = file2ctx(file);

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

static int vidioc_querybuf(struct file *file, void *priv,
               struct v4l2_buffer *buf)
{
    struct m2mtest_ctx *ctx = file2ctx(file);

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

static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
    struct m2mtest_ctx *ctx = file2ctx(file);

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

static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
    struct m2mtest_ctx *ctx = file2ctx(file);

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

static int vidioc_streamon(struct file *file, void *priv,
               enum v4l2_buf_type type)
{
    struct m2mtest_ctx *ctx = file2ctx(file);

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

static int vidioc_streamoff(struct file *file, void *priv,
                enum v4l2_buf_type type)
{
    struct m2mtest_ctx *ctx = file2ctx(file);

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

static int m2mtest_s_ctrl(struct v4l2_ctrl *ctrl)
{
    struct m2mtest_ctx *ctx =
        container_of(ctrl->handler, struct m2mtest_ctx, hdl);

    switch (ctrl->id) {
    case V4L2_CID_HFLIP:
        if (ctrl->val)
            ctx->mode |= MEM2MEM_HFLIP;
        else
            ctx->mode &= ~MEM2MEM_HFLIP;
        break;

    case V4L2_CID_VFLIP:
        if (ctrl->val)
            ctx->mode |= MEM2MEM_VFLIP;
        else
            ctx->mode &= ~MEM2MEM_VFLIP;
        break;

    case V4L2_CID_TRANS_TIME_MSEC:
        ctx->transtime = ctrl->val;
        break;

    case V4L2_CID_TRANS_NUM_BUFS:
        ctx->translen = ctrl->val;
        break;

    default:
        v4l2_err(&ctx->dev->v4l2_dev, "Invalid control\n");
        return -EINVAL;
    }

    return 0;
}

static const struct v4l2_ctrl_ops m2mtest_ctrl_ops = {
    .s_ctrl = m2mtest_s_ctrl,
};


static const struct v4l2_ioctl_ops m2mtest_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,
    .vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
    .vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};


/*
 * Queue operations
 */

static int m2mtest_queue_setup(struct vb2_queue *vq,
                const struct v4l2_format *fmt,
                unsigned int *nbuffers, unsigned int *nplanes,
                unsigned int sizes[], void *alloc_ctxs[])
{
    struct m2mtest_ctx *ctx = vb2_get_drv_priv(vq);
    struct m2mtest_q_data *q_data;
    unsigned int size, count = *nbuffers;

    q_data = get_q_data(ctx, vq->type);

    size = q_data->width * q_data->height * q_data->fmt->depth >> 3;

    while (size * count > MEM2MEM_VID_MEM_LIMIT)
        (count)--;

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

    /*
     * videobuf2-vmalloc allocator is context-less so no need to set
     * alloc_ctxs array.
     */

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

    return 0;
}

static int m2mtest_buf_prepare(struct vb2_buffer *vb)
{
    struct m2mtest_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
    struct m2mtest_q_data *q_data;

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

    q_data = get_q_data(ctx, 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 m2mtest_buf_queue(struct vb2_buffer *vb)
{
    struct m2mtest_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
    v4l2_m2m_buf_queue(ctx->m2m_ctx, vb);
}

static void m2mtest_wait_prepare(struct vb2_queue *q)
{
    struct m2mtest_ctx *ctx = vb2_get_drv_priv(q);
    m2mtest_unlock(ctx);
}

static void m2mtest_wait_finish(struct vb2_queue *q)
{
    struct m2mtest_ctx *ctx = vb2_get_drv_priv(q);
    m2mtest_lock(ctx);
}

static struct vb2_ops m2mtest_qops = {
    .queue_setup     = m2mtest_queue_setup,
    .buf_prepare     = m2mtest_buf_prepare,
    .buf_queue   = m2mtest_buf_queue,
    .wait_prepare    = m2mtest_wait_prepare,
    .wait_finish     = m2mtest_wait_finish,
};

static int queue_init(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq)
{
    struct m2mtest_ctx *ctx = priv;
    int ret;

    src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
    src_vq->io_modes = VB2_MMAP;
    src_vq->drv_priv = ctx;
    src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
    src_vq->ops = &m2mtest_qops;
    src_vq->mem_ops = &vb2_vmalloc_memops;

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

    dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
    dst_vq->io_modes = VB2_MMAP;
    dst_vq->drv_priv = ctx;
    dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
    dst_vq->ops = &m2mtest_qops;
    dst_vq->mem_ops = &vb2_vmalloc_memops;

    return vb2_queue_init(dst_vq);
}

static const struct v4l2_ctrl_config m2mtest_ctrl_trans_time_msec = {
    .ops = &m2mtest_ctrl_ops,
    .id = V4L2_CID_TRANS_TIME_MSEC,
    .name = "Transaction Time (msec)",
    .type = V4L2_CTRL_TYPE_INTEGER,
    .def = 1001,
    .min = 1,
    .max = 10001,
    .step = 100,
};

static const struct v4l2_ctrl_config m2mtest_ctrl_trans_num_bufs = {
    .ops = &m2mtest_ctrl_ops,
    .id = V4L2_CID_TRANS_NUM_BUFS,
    .name = "Buffers Per Transaction",
    .type = V4L2_CTRL_TYPE_INTEGER,
    .def = 1,
    .min = 1,
    .max = MEM2MEM_DEF_NUM_BUFS,
    .step = 1,
};

/*
 * File operations
 */
static int m2mtest_open(struct file *file)
{
    struct m2mtest_dev *dev = video_drvdata(file);
    struct m2mtest_ctx *ctx = NULL;
    struct v4l2_ctrl_handler *hdl;
    int rc = 0;

    if (mutex_lock_interruptible(&dev->dev_mutex))
        return -ERESTARTSYS;
    ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
    if (!ctx) {
        rc = -ENOMEM;
        goto open_unlock;
    }

    v4l2_fh_init(&ctx->fh, video_devdata(file));
    file->private_data = &ctx->fh;
    ctx->dev = dev;
    hdl = &ctx->hdl;
    v4l2_ctrl_handler_init(hdl, 4);
    v4l2_ctrl_new_std(hdl, &m2mtest_ctrl_ops, V4L2_CID_HFLIP, 0, 1, 1, 0);
    v4l2_ctrl_new_std(hdl, &m2mtest_ctrl_ops, V4L2_CID_VFLIP, 0, 1, 1, 0);
    v4l2_ctrl_new_custom(hdl, &m2mtest_ctrl_trans_time_msec, NULL);
    v4l2_ctrl_new_custom(hdl, &m2mtest_ctrl_trans_num_bufs, NULL);
    if (hdl->error) {
        rc = hdl->error;
        v4l2_ctrl_handler_free(hdl);
        goto open_unlock;
    }
    ctx->fh.ctrl_handler = hdl;
    v4l2_ctrl_handler_setup(hdl);

    ctx->q_data[V4L2_M2M_SRC].fmt = &formats[0];
    ctx->q_data[V4L2_M2M_SRC].width = 640;
    ctx->q_data[V4L2_M2M_SRC].height = 480;
    ctx->q_data[V4L2_M2M_SRC].sizeimage =
        ctx->q_data[V4L2_M2M_SRC].width *
        ctx->q_data[V4L2_M2M_SRC].height *
        (ctx->q_data[V4L2_M2M_SRC].fmt->depth >> 3);
    ctx->q_data[V4L2_M2M_DST] = ctx->q_data[V4L2_M2M_SRC];
    ctx->colorspace = V4L2_COLORSPACE_REC709;

    ctx->m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx, &queue_init);

    if (IS_ERR(ctx->m2m_ctx)) {
        rc = PTR_ERR(ctx->m2m_ctx);

        v4l2_ctrl_handler_free(hdl);
        kfree(ctx);
        goto open_unlock;
    }

    v4l2_fh_add(&ctx->fh);
    atomic_inc(&dev->num_inst);

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

open_unlock:
    mutex_unlock(&dev->dev_mutex);
    return rc;
}

static int m2mtest_release(struct file *file)
{
    struct m2mtest_dev *dev = video_drvdata(file);
    struct m2mtest_ctx *ctx = file2ctx(file);

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

    v4l2_fh_del(&ctx->fh);
    v4l2_fh_exit(&ctx->fh);
    v4l2_ctrl_handler_free(&ctx->hdl);
    mutex_lock(&dev->dev_mutex);
    v4l2_m2m_ctx_release(ctx->m2m_ctx);
    mutex_unlock(&dev->dev_mutex);
    kfree(ctx);

    atomic_dec(&dev->num_inst);

    return 0;
}

static unsigned int m2mtest_poll(struct file *file,
                 struct poll_table_struct *wait)
{
    struct m2mtest_ctx *ctx = file2ctx(file);

    return v4l2_m2m_poll(file, ctx->m2m_ctx, wait);
}

static int m2mtest_mmap(struct file *file, struct vm_area_struct *vma)
{
    struct m2mtest_dev *dev = video_drvdata(file);
    struct m2mtest_ctx *ctx = file2ctx(file);
    int res;

    if (mutex_lock_interruptible(&dev->dev_mutex))
        return -ERESTARTSYS;
    res = v4l2_m2m_mmap(file, ctx->m2m_ctx, vma);
    mutex_unlock(&dev->dev_mutex);
    return res;
}

static const struct v4l2_file_operations m2mtest_fops = {
    .owner      = THIS_MODULE,
    .open       = m2mtest_open,
    .release    = m2mtest_release,
    .poll       = m2mtest_poll,
    .unlocked_ioctl = video_ioctl2,
    .mmap       = m2mtest_mmap,
};

static struct video_device m2mtest_videodev = {
    .name       = MEM2MEM_NAME,
    .vfl_dir    = VFL_DIR_M2M,
    .fops       = &m2mtest_fops,
    .ioctl_ops  = &m2mtest_ioctl_ops,
    .minor      = -1,
    .release    = video_device_release,
};

static struct v4l2_m2m_ops m2m_ops = {
    .device_run = device_run,
    .job_ready  = job_ready,
    .job_abort  = job_abort,
    .lock       = m2mtest_lock,
    .unlock     = m2mtest_unlock,
};

static int m2mtest_probe(struct platform_device *pdev)
{
    struct m2mtest_dev *dev;
    struct video_device *vfd;
    int ret;

    dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
    if (!dev)
        return -ENOMEM;

    spin_lock_init(&dev->irqlock);

    ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
    if (ret)
        return ret;

    atomic_set(&dev->num_inst, 0);
    mutex_init(&dev->dev_mutex);

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

    *vfd = m2mtest_videodev;
    vfd->lock = &dev->dev_mutex;

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

    video_set_drvdata(vfd, dev);
    snprintf(vfd->name, sizeof(vfd->name), "%s", m2mtest_videodev.name);
    dev->vfd = vfd;
    v4l2_info(&dev->v4l2_dev, MEM2MEM_TEST_MODULE_NAME
            "Device registered as /dev/video%d\n", vfd->num);

    setup_timer(&dev->timer, device_isr, (long)dev);
    platform_set_drvdata(pdev, dev);

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

    return 0;

err_m2m:
    v4l2_m2m_release(dev->m2m_dev);
    video_unregister_device(dev->vfd);
rel_vdev:
    video_device_release(vfd);
unreg_dev:
    v4l2_device_unregister(&dev->v4l2_dev);

    return ret;
}

static int m2mtest_remove(struct platform_device *pdev)
{
    struct m2mtest_dev *dev =
        (struct m2mtest_dev *)platform_get_drvdata(pdev);

    v4l2_info(&dev->v4l2_dev, "Removing " MEM2MEM_TEST_MODULE_NAME);
    v4l2_m2m_release(dev->m2m_dev);
    del_timer_sync(&dev->timer);
    video_unregister_device(dev->vfd);
    v4l2_device_unregister(&dev->v4l2_dev);

    return 0;
}

static struct platform_driver m2mtest_pdrv = {
    .probe      = m2mtest_probe,
    .remove     = m2mtest_remove,
    .driver     = {
        .name   = MEM2MEM_NAME,
        .owner  = THIS_MODULE,
    },
};

static void __exit m2mtest_exit(void)
{
    platform_driver_unregister(&m2mtest_pdrv);
    platform_device_unregister(&m2mtest_pdev);
}

static int __init m2mtest_init(void)
{
    int ret;

    ret = platform_device_register(&m2mtest_pdev);
    if (ret)
        return ret;

    ret = platform_driver_register(&m2mtest_pdrv);
    if (ret)
        platform_device_unregister(&m2mtest_pdev);

    return 0;
}

module_init(m2mtest_init);
module_exit(m2mtest_exit);