/*
 * Samsung TV Mixer driver
 *
 * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
 *
 * Tomasz Stanislawski, <t.stanislaws@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation. either version 2 of the License,
 * or (at your option) any later version
 */

#define pr_fmt(fmt) "s5p-tv (mixer): " fmt

#include "mixer.h"

#include <media/v4l2-ioctl.h>
#include <linux/videodev2.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/timer.h>
#include <media/videobuf2-dma-contig.h>

static int find_reg_callback(struct device *dev, void *p)
{
        struct v4l2_subdev **sd = p;

        *sd = dev_get_drvdata(dev);
        /* non-zero value stops iteration */
        return 1;
}

static struct v4l2_subdev *find_and_register_subdev(
        struct mxr_device *mdev, char *module_name)
{
        struct device_driver *drv;
        struct v4l2_subdev *sd = NULL;
        int ret;

        /* TODO: add waiting until probe is finished */
        drv = driver_find(module_name, &platform_bus_type);
        if (!drv) {
                mxr_warn(mdev, "module %s is missing\n", module_name);
                return NULL;
        }
        /* driver refcnt is increased, it is safe to iterate over devices */
        ret = driver_for_each_device(drv, NULL, &sd, find_reg_callback);
        /* ret == 0 means that find_reg_callback was never executed */
        if (sd == NULL) {
                mxr_warn(mdev, "module %s provides no subdev!\n", module_name);
                goto done;
        }
        /* v4l2_device_register_subdev detects if sd is NULL */
        ret = v4l2_device_register_subdev(&mdev->v4l2_dev, sd);
        if (ret) {
                mxr_warn(mdev, "failed to register subdev %s\n", sd->name);
                sd = NULL;
        }

done:
        return sd;
}

int mxr_acquire_video(struct mxr_device *mdev,
                      struct mxr_output_conf *output_conf, int output_count)
{
        struct device *dev = mdev->dev;
        struct v4l2_device *v4l2_dev = &mdev->v4l2_dev;
        int i;
        int ret = 0;
        struct v4l2_subdev *sd;

        strlcpy(v4l2_dev->name, dev_name(mdev->dev), sizeof(v4l2_dev->name));
        /* prepare context for V4L2 device */
        ret = v4l2_device_register(dev, v4l2_dev);
        if (ret) {
                mxr_err(mdev, "could not register v4l2 device.\n");
                goto fail;
        }

        mdev->alloc_ctx = vb2_dma_contig_init_ctx(mdev->dev);
        if (IS_ERR(mdev->alloc_ctx)) {
                mxr_err(mdev, "could not acquire vb2 allocator\n");
                ret = PTR_ERR(mdev->alloc_ctx);
                goto fail_v4l2_dev;
        }

        /* registering outputs */
        mdev->output_cnt = 0;
        for (i = 0; i < output_count; ++i) {
                struct mxr_output_conf *conf = &output_conf[i];
                struct mxr_output *out;

                sd = find_and_register_subdev(mdev, conf->module_name);
                /* trying to register next output */
                if (sd == NULL)
                        continue;
                out = kzalloc(sizeof(*out), GFP_KERNEL);
                if (out == NULL) {
                        mxr_err(mdev, "no memory for '%s'\n",
                                conf->output_name);
                        ret = -ENOMEM;
                        /* registered subdevs are removed in fail_v4l2_dev */
                        goto fail_output;
                }
                strlcpy(out->name, conf->output_name, sizeof(out->name));
                out->sd = sd;
                out->cookie = conf->cookie;
                mdev->output[mdev->output_cnt++] = out;
                mxr_info(mdev, "added output '%s' from module '%s'\n",
                        conf->output_name, conf->module_name);
                /* checking if maximal number of outputs is reached */
                if (mdev->output_cnt >= MXR_MAX_OUTPUTS)
                        break;
        }

        if (mdev->output_cnt == 0) {
                mxr_err(mdev, "failed to register any output\n");
                ret = -ENODEV;
                /* skipping fail_output because there is nothing to free */
                goto fail_vb2_allocator;
        }

        return 0;

fail_output:
        /* kfree is NULL-safe */
        for (i = 0; i < mdev->output_cnt; ++i)
                kfree(mdev->output[i]);
        memset(mdev->output, 0, sizeof(mdev->output));

fail_vb2_allocator:
        /* freeing allocator context */
        vb2_dma_contig_cleanup_ctx(mdev->alloc_ctx);

fail_v4l2_dev:
        /* NOTE: automatically unregister all subdevs */
        v4l2_device_unregister(v4l2_dev);

fail:
        return ret;
}

void mxr_release_video(struct mxr_device *mdev)
{
        int i;

        /* kfree is NULL-safe */
        for (i = 0; i < mdev->output_cnt; ++i)
                kfree(mdev->output[i]);

        vb2_dma_contig_cleanup_ctx(mdev->alloc_ctx);
        v4l2_device_unregister(&mdev->v4l2_dev);
}

static int mxr_querycap(struct file *file, void *priv,
        struct v4l2_capability *cap)
{
        struct mxr_layer *layer = video_drvdata(file);

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);

        strlcpy(cap->driver, MXR_DRIVER_NAME, sizeof(cap->driver));
        strlcpy(cap->card, layer->vfd.name, sizeof(cap->card));
        sprintf(cap->bus_info, "%d", layer->idx);
        cap->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_VIDEO_OUTPUT_MPLANE;
        cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS;

        return 0;
}

static void mxr_geometry_dump(struct mxr_device *mdev, struct mxr_geometry *geo)
{
        mxr_dbg(mdev, "src.full_size = (%u, %u)\n",
                geo->src.full_width, geo->src.full_height);
        mxr_dbg(mdev, "src.size = (%u, %u)\n",
                geo->src.width, geo->src.height);
        mxr_dbg(mdev, "src.offset = (%u, %u)\n",
                geo->src.x_offset, geo->src.y_offset);
        mxr_dbg(mdev, "dst.full_size = (%u, %u)\n",
                geo->dst.full_width, geo->dst.full_height);
        mxr_dbg(mdev, "dst.size = (%u, %u)\n",
                geo->dst.width, geo->dst.height);
        mxr_dbg(mdev, "dst.offset = (%u, %u)\n",
                geo->dst.x_offset, geo->dst.y_offset);
        mxr_dbg(mdev, "ratio = (%u, %u)\n",
                geo->x_ratio, geo->y_ratio);
}

static void mxr_layer_default_geo(struct mxr_layer *layer)
{
        struct mxr_device *mdev = layer->mdev;
        struct v4l2_mbus_framefmt mbus_fmt;

        memset(&layer->geo, 0, sizeof(layer->geo));

        mxr_get_mbus_fmt(mdev, &mbus_fmt);

        layer->geo.dst.full_width = mbus_fmt.width;
        layer->geo.dst.full_height = mbus_fmt.height;
        layer->geo.dst.width = layer->geo.dst.full_width;
        layer->geo.dst.height = layer->geo.dst.full_height;
        layer->geo.dst.field = mbus_fmt.field;

        layer->geo.src.full_width = mbus_fmt.width;
        layer->geo.src.full_height = mbus_fmt.height;
        layer->geo.src.width = layer->geo.src.full_width;
        layer->geo.src.height = layer->geo.src.full_height;

        mxr_geometry_dump(mdev, &layer->geo);
        layer->ops.fix_geometry(layer, MXR_GEOMETRY_SINK, 0);
        mxr_geometry_dump(mdev, &layer->geo);
}

static void mxr_layer_update_output(struct mxr_layer *layer)
{
        struct mxr_device *mdev = layer->mdev;
        struct v4l2_mbus_framefmt mbus_fmt;

        mxr_get_mbus_fmt(mdev, &mbus_fmt);
        /* checking if update is needed */
        if (layer->geo.dst.full_width == mbus_fmt.width &&
                layer->geo.dst.full_height == mbus_fmt.width)
                return;

        layer->geo.dst.full_width = mbus_fmt.width;
        layer->geo.dst.full_height = mbus_fmt.height;
        layer->geo.dst.field = mbus_fmt.field;
        layer->ops.fix_geometry(layer, MXR_GEOMETRY_SINK, 0);

        mxr_geometry_dump(mdev, &layer->geo);
}

static const struct mxr_format *find_format_by_fourcc(
        struct mxr_layer *layer, unsigned long fourcc);
static const struct mxr_format *find_format_by_index(
        struct mxr_layer *layer, unsigned long index);

static int mxr_enum_fmt(struct file *file, void  *priv,
        struct v4l2_fmtdesc *f)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;
        const struct mxr_format *fmt;

        mxr_dbg(mdev, "%s\n", __func__);
        fmt = find_format_by_index(layer, f->index);
        if (fmt == NULL)
                return -EINVAL;

        strlcpy(f->description, fmt->name, sizeof(f->description));
        f->pixelformat = fmt->fourcc;

        return 0;
}

static unsigned int divup(unsigned int divident, unsigned int divisor)
{
        return (divident + divisor - 1) / divisor;
}

unsigned long mxr_get_plane_size(const struct mxr_block *blk,
        unsigned int width, unsigned int height)
{
        unsigned int bl_width = divup(width, blk->width);
        unsigned int bl_height = divup(height, blk->height);

        return bl_width * bl_height * blk->size;
}

static void mxr_mplane_fill(struct v4l2_plane_pix_format *planes,
        const struct mxr_format *fmt, u32 width, u32 height)
{
        int i;

        /* checking if nothing to fill */
        if (!planes)
                return;

        memset(planes, 0, sizeof(*planes) * fmt->num_subframes);
        for (i = 0; i < fmt->num_planes; ++i) {
                struct v4l2_plane_pix_format *plane = planes
                        + fmt->plane2subframe[i];
                const struct mxr_block *blk = &fmt->plane[i];
                u32 bl_width = divup(width, blk->width);
                u32 bl_height = divup(height, blk->height);
                u32 sizeimage = bl_width * bl_height * blk->size;
                u32 bytesperline = bl_width * blk->size / blk->height;

                plane->sizeimage += sizeimage;
                plane->bytesperline = max(plane->bytesperline, bytesperline);
        }
}

static int mxr_g_fmt(struct file *file, void *priv,
                             struct v4l2_format *f)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct v4l2_pix_format_mplane *pix = &f->fmt.pix_mp;

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);

        pix->width = layer->geo.src.full_width;
        pix->height = layer->geo.src.full_height;
        pix->field = V4L2_FIELD_NONE;
        pix->pixelformat = layer->fmt->fourcc;
        pix->colorspace = layer->fmt->colorspace;
        mxr_mplane_fill(pix->plane_fmt, layer->fmt, pix->width, pix->height);

        return 0;
}

static int mxr_s_fmt(struct file *file, void *priv,
        struct v4l2_format *f)
{
        struct mxr_layer *layer = video_drvdata(file);
        const struct mxr_format *fmt;
        struct v4l2_pix_format_mplane *pix;
        struct mxr_device *mdev = layer->mdev;
        struct mxr_geometry *geo = &layer->geo;

        mxr_dbg(mdev, "%s:%d\n", __func__, __LINE__);

        pix = &f->fmt.pix_mp;
        fmt = find_format_by_fourcc(layer, pix->pixelformat);
        if (fmt == NULL) {
                mxr_warn(mdev, "not recognized fourcc: %08x\n",
                        pix->pixelformat);
                return -EINVAL;
        }
        layer->fmt = fmt;
        /* set source size to highest accepted value */
        geo->src.full_width = max(geo->dst.full_width, pix->width);
        geo->src.full_height = max(geo->dst.full_height, pix->height);
        layer->ops.fix_geometry(layer, MXR_GEOMETRY_SOURCE, 0);
        mxr_geometry_dump(mdev, &layer->geo);
        /* set cropping to total visible screen */
        geo->src.width = pix->width;
        geo->src.height = pix->height;
        geo->src.x_offset = 0;
        geo->src.y_offset = 0;
        /* assure consistency of geometry */
        layer->ops.fix_geometry(layer, MXR_GEOMETRY_CROP, MXR_NO_OFFSET);
        mxr_geometry_dump(mdev, &layer->geo);
        /* set full size to lowest possible value */
        geo->src.full_width = 0;
        geo->src.full_height = 0;
        layer->ops.fix_geometry(layer, MXR_GEOMETRY_SOURCE, 0);
        mxr_geometry_dump(mdev, &layer->geo);

        /* returning results */
        mxr_g_fmt(file, priv, f);

        return 0;
}

static int mxr_g_selection(struct file *file, void *fh,
        struct v4l2_selection *s)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_geometry *geo = &layer->geo;

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);

        if (s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT &&
                s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
                return -EINVAL;

        switch (s->target) {
        case V4L2_SEL_TGT_CROP:
                s->r.left = geo->src.x_offset;
                s->r.top = geo->src.y_offset;
                s->r.width = geo->src.width;
                s->r.height = geo->src.height;
                break;
        case V4L2_SEL_TGT_CROP_DEFAULT:
        case V4L2_SEL_TGT_CROP_BOUNDS:
                s->r.left = 0;
                s->r.top = 0;
                s->r.width = geo->src.full_width;
                s->r.height = geo->src.full_height;
                break;
        case V4L2_SEL_TGT_COMPOSE:
        case V4L2_SEL_TGT_COMPOSE_PADDED:
                s->r.left = geo->dst.x_offset;
                s->r.top = geo->dst.y_offset;
                s->r.width = geo->dst.width;
                s->r.height = geo->dst.height;
                break;
        case V4L2_SEL_TGT_COMPOSE_DEFAULT:
        case V4L2_SEL_TGT_COMPOSE_BOUNDS:
                s->r.left = 0;
                s->r.top = 0;
                s->r.width = geo->dst.full_width;
                s->r.height = geo->dst.full_height;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

/* returns 1 if rectangle 'a' is inside 'b' */
static int mxr_is_rect_inside(struct v4l2_rect *a, struct v4l2_rect *b)
{
        if (a->left < b->left)
                return 0;
        if (a->top < b->top)
                return 0;
        if (a->left + a->width > b->left + b->width)
                return 0;
        if (a->top + a->height > b->top + b->height)
                return 0;
        return 1;
}

static int mxr_s_selection(struct file *file, void *fh,
        struct v4l2_selection *s)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_geometry *geo = &layer->geo;
        struct mxr_crop *target = NULL;
        enum mxr_geometry_stage stage;
        struct mxr_geometry tmp;
        struct v4l2_rect res;

        memset(&res, 0, sizeof(res));

        mxr_dbg(layer->mdev, "%s: rect: %dx%d@%d,%d\n", __func__,
                s->r.width, s->r.height, s->r.left, s->r.top);

        if (s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT &&
                s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE)
                return -EINVAL;

        switch (s->target) {
        /* ignore read-only targets */
        case V4L2_SEL_TGT_CROP_DEFAULT:
        case V4L2_SEL_TGT_CROP_BOUNDS:
                res.width = geo->src.full_width;
                res.height = geo->src.full_height;
                break;

        /* ignore read-only targets */
        case V4L2_SEL_TGT_COMPOSE_DEFAULT:
        case V4L2_SEL_TGT_COMPOSE_BOUNDS:
                res.width = geo->dst.full_width;
                res.height = geo->dst.full_height;
                break;

        case V4L2_SEL_TGT_CROP:
                target = &geo->src;
                stage = MXR_GEOMETRY_CROP;
                break;
        case V4L2_SEL_TGT_COMPOSE:
        case V4L2_SEL_TGT_COMPOSE_PADDED:
                target = &geo->dst;
                stage = MXR_GEOMETRY_COMPOSE;
                break;
        default:
                return -EINVAL;
        }
        /* apply change and update geometry if needed */
        if (target) {
                /* backup current geometry if setup fails */
                memcpy(&tmp, geo, sizeof(tmp));

                /* apply requested selection */
                target->x_offset = s->r.left;
                target->y_offset = s->r.top;
                target->width = s->r.width;
                target->height = s->r.height;

                layer->ops.fix_geometry(layer, stage, s->flags);

                /* retrieve update selection rectangle */
                res.left = target->x_offset;
                res.top = target->y_offset;
                res.width = target->width;
                res.height = target->height;

                mxr_geometry_dump(layer->mdev, &layer->geo);
        }

        /* checking if the rectangle satisfies constraints */
        if ((s->flags & V4L2_SEL_FLAG_LE) && !mxr_is_rect_inside(&res, &s->r))
                goto fail;
        if ((s->flags & V4L2_SEL_FLAG_GE) && !mxr_is_rect_inside(&s->r, &res))
                goto fail;

        /* return result rectangle */
        s->r = res;

        return 0;
fail:
        /* restore old geometry, which is not touched if target is NULL */
        if (target)
                memcpy(geo, &tmp, sizeof(tmp));
        return -ERANGE;
}

static int mxr_enum_dv_timings(struct file *file, void *fh,
        struct v4l2_enum_dv_timings *timings)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;
        int ret;

        timings->pad = 0;

        /* lock protects from changing sd_out */
        mutex_lock(&mdev->mutex);
        ret = v4l2_subdev_call(to_outsd(mdev), pad, enum_dv_timings, timings);
        mutex_unlock(&mdev->mutex);

        return ret ? -EINVAL : 0;
}

static int mxr_s_dv_timings(struct file *file, void *fh,
        struct v4l2_dv_timings *timings)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;
        int ret;

        /* lock protects from changing sd_out */
        mutex_lock(&mdev->mutex);

        /* timings change cannot be done while there is an entity
         * dependent on output configuration
         */
        if (mdev->n_output > 0) {
                mutex_unlock(&mdev->mutex);
                return -EBUSY;
        }

        ret = v4l2_subdev_call(to_outsd(mdev), video, s_dv_timings, timings);

        mutex_unlock(&mdev->mutex);

        mxr_layer_update_output(layer);

        /* any failure should return EINVAL according to V4L2 doc */
        return ret ? -EINVAL : 0;
}

static int mxr_g_dv_timings(struct file *file, void *fh,
        struct v4l2_dv_timings *timings)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;
        int ret;

        /* lock protects from changing sd_out */
        mutex_lock(&mdev->mutex);
        ret = v4l2_subdev_call(to_outsd(mdev), video, g_dv_timings, timings);
        mutex_unlock(&mdev->mutex);

        return ret ? -EINVAL : 0;
}

static int mxr_dv_timings_cap(struct file *file, void *fh,
        struct v4l2_dv_timings_cap *cap)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;
        int ret;

        cap->pad = 0;

        /* lock protects from changing sd_out */
        mutex_lock(&mdev->mutex);
        ret = v4l2_subdev_call(to_outsd(mdev), pad, dv_timings_cap, cap);
        mutex_unlock(&mdev->mutex);

        return ret ? -EINVAL : 0;
}

static int mxr_s_std(struct file *file, void *fh, v4l2_std_id norm)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;
        int ret;

        /* lock protects from changing sd_out */
        mutex_lock(&mdev->mutex);

        /* standard change cannot be done while there is an entity
         * dependent on output configuration
         */
        if (mdev->n_output > 0) {
                mutex_unlock(&mdev->mutex);
                return -EBUSY;
        }

        ret = v4l2_subdev_call(to_outsd(mdev), video, s_std_output, norm);

        mutex_unlock(&mdev->mutex);

        mxr_layer_update_output(layer);

        return ret ? -EINVAL : 0;
}

static int mxr_g_std(struct file *file, void *fh, v4l2_std_id *norm)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;
        int ret;

        /* lock protects from changing sd_out */
        mutex_lock(&mdev->mutex);
        ret = v4l2_subdev_call(to_outsd(mdev), video, g_std_output, norm);
        mutex_unlock(&mdev->mutex);

        return ret ? -EINVAL : 0;
}

static int mxr_enum_output(struct file *file, void *fh, struct v4l2_output *a)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;
        struct mxr_output *out;
        struct v4l2_subdev *sd;

        if (a->index >= mdev->output_cnt)
                return -EINVAL;
        out = mdev->output[a->index];
        BUG_ON(out == NULL);
        sd = out->sd;
        strlcpy(a->name, out->name, sizeof(a->name));

        /* try to obtain supported tv norms */
        v4l2_subdev_call(sd, video, g_tvnorms_output, &a->std);
        a->capabilities = 0;
        if (sd->ops->video && sd->ops->video->s_dv_timings)
                a->capabilities |= V4L2_OUT_CAP_DV_TIMINGS;
        if (sd->ops->video && sd->ops->video->s_std_output)
                a->capabilities |= V4L2_OUT_CAP_STD;
        a->type = V4L2_OUTPUT_TYPE_ANALOG;

        return 0;
}

static int mxr_s_output(struct file *file, void *fh, unsigned int i)
{
        struct video_device *vfd = video_devdata(file);
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;

        if (i >= mdev->output_cnt || mdev->output[i] == NULL)
                return -EINVAL;

        mutex_lock(&mdev->mutex);
        if (mdev->n_output > 0) {
                mutex_unlock(&mdev->mutex);
                return -EBUSY;
        }
        mdev->current_output = i;
        vfd->tvnorms = 0;
        v4l2_subdev_call(to_outsd(mdev), video, g_tvnorms_output,
                &vfd->tvnorms);
        mutex_unlock(&mdev->mutex);

        /* update layers geometry */
        mxr_layer_update_output(layer);

        mxr_dbg(mdev, "tvnorms = %08llx\n", vfd->tvnorms);

        return 0;
}

static int mxr_g_output(struct file *file, void *fh, unsigned int *p)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;

        mutex_lock(&mdev->mutex);
        *p = mdev->current_output;
        mutex_unlock(&mdev->mutex);

        return 0;
}

static int mxr_reqbufs(struct file *file, void *priv,
                          struct v4l2_requestbuffers *p)
{
        struct mxr_layer *layer = video_drvdata(file);

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);
        return vb2_reqbufs(&layer->vb_queue, p);
}

static int mxr_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
        struct mxr_layer *layer = video_drvdata(file);

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);
        return vb2_querybuf(&layer->vb_queue, p);
}

static int mxr_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
        struct mxr_layer *layer = video_drvdata(file);

        mxr_dbg(layer->mdev, "%s:%d(%d)\n", __func__, __LINE__, p->index);
        return vb2_qbuf(&layer->vb_queue, p);
}

static int mxr_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
        struct mxr_layer *layer = video_drvdata(file);

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);
        return vb2_dqbuf(&layer->vb_queue, p, file->f_flags & O_NONBLOCK);
}

static int mxr_expbuf(struct file *file, void *priv,
        struct v4l2_exportbuffer *eb)
{
        struct mxr_layer *layer = video_drvdata(file);

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);
        return vb2_expbuf(&layer->vb_queue, eb);
}

static int mxr_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
{
        struct mxr_layer *layer = video_drvdata(file);

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);
        return vb2_streamon(&layer->vb_queue, i);
}

static int mxr_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
{
        struct mxr_layer *layer = video_drvdata(file);

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);
        return vb2_streamoff(&layer->vb_queue, i);
}

static const struct v4l2_ioctl_ops mxr_ioctl_ops = {
        .vidioc_querycap = mxr_querycap,
        /* format handling */
        .vidioc_enum_fmt_vid_out_mplane = mxr_enum_fmt,
        .vidioc_s_fmt_vid_out_mplane = mxr_s_fmt,
        .vidioc_g_fmt_vid_out_mplane = mxr_g_fmt,
        /* buffer control */
        .vidioc_reqbufs = mxr_reqbufs,
        .vidioc_querybuf = mxr_querybuf,
        .vidioc_qbuf = mxr_qbuf,
        .vidioc_dqbuf = mxr_dqbuf,
        .vidioc_expbuf = mxr_expbuf,
        /* Streaming control */
        .vidioc_streamon = mxr_streamon,
        .vidioc_streamoff = mxr_streamoff,
        /* DV Timings functions */
        .vidioc_enum_dv_timings = mxr_enum_dv_timings,
        .vidioc_s_dv_timings = mxr_s_dv_timings,
        .vidioc_g_dv_timings = mxr_g_dv_timings,
        .vidioc_dv_timings_cap = mxr_dv_timings_cap,
        /* analog TV standard functions */
        .vidioc_s_std = mxr_s_std,
        .vidioc_g_std = mxr_g_std,
        /* Output handling */
        .vidioc_enum_output = mxr_enum_output,
        .vidioc_s_output = mxr_s_output,
        .vidioc_g_output = mxr_g_output,
        /* selection ioctls */
        .vidioc_g_selection = mxr_g_selection,
        .vidioc_s_selection = mxr_s_selection,
};

static int mxr_video_open(struct file *file)
{
        struct mxr_layer *layer = video_drvdata(file);
        struct mxr_device *mdev = layer->mdev;
        int ret = 0;

        mxr_dbg(mdev, "%s:%d\n", __func__, __LINE__);
        if (mutex_lock_interruptible(&layer->mutex))
                return -ERESTARTSYS;
        /* assure device probe is finished */
        wait_for_device_probe();
        /* creating context for file descriptor */
        ret = v4l2_fh_open(file);
        if (ret) {
                mxr_err(mdev, "v4l2_fh_open failed\n");
                goto unlock;
        }

        /* leaving if layer is already initialized */
        if (!v4l2_fh_is_singular_file(file))
                goto unlock;

        /* FIXME: should power be enabled on open? */
        ret = mxr_power_get(mdev);
        if (ret) {
                mxr_err(mdev, "power on failed\n");
                goto fail_fh_open;
        }

        ret = vb2_queue_init(&layer->vb_queue);
        if (ret != 0) {
                mxr_err(mdev, "failed to initialize vb2 queue\n");
                goto fail_power;
        }
        /* set default format, first on the list */
        layer->fmt = layer->fmt_array[0];
        /* setup default geometry */
        mxr_layer_default_geo(layer);
        mutex_unlock(&layer->mutex);

        return 0;

fail_power:
        mxr_power_put(mdev);

fail_fh_open:
        v4l2_fh_release(file);

unlock:
        mutex_unlock(&layer->mutex);

        return ret;
}

static unsigned int
mxr_video_poll(struct file *file, struct poll_table_struct *wait)
{
        struct mxr_layer *layer = video_drvdata(file);
        unsigned int res;

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);

        mutex_lock(&layer->mutex);
        res = vb2_poll(&layer->vb_queue, file, wait);
        mutex_unlock(&layer->mutex);
        return res;
}

static int mxr_video_mmap(struct file *file, struct vm_area_struct *vma)
{
        struct mxr_layer *layer = video_drvdata(file);
        int ret;

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);

        if (mutex_lock_interruptible(&layer->mutex))
                return -ERESTARTSYS;
        ret = vb2_mmap(&layer->vb_queue, vma);
        mutex_unlock(&layer->mutex);
        return ret;
}

static int mxr_video_release(struct file *file)
{
        struct mxr_layer *layer = video_drvdata(file);

        mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__);
        mutex_lock(&layer->mutex);
        if (v4l2_fh_is_singular_file(file)) {
                vb2_queue_release(&layer->vb_queue);
                mxr_power_put(layer->mdev);
        }
        v4l2_fh_release(file);
        mutex_unlock(&layer->mutex);
        return 0;
}

static const struct v4l2_file_operations mxr_fops = {
        .owner = THIS_MODULE,
        .open = mxr_video_open,
        .poll = mxr_video_poll,
        .mmap = mxr_video_mmap,
        .release = mxr_video_release,
        .unlocked_ioctl = video_ioctl2,
};

static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *pfmt,
        unsigned int *nbuffers, unsigned int *nplanes, unsigned int sizes[],
        void *alloc_ctxs[])
{
        struct mxr_layer *layer = vb2_get_drv_priv(vq);
        const struct mxr_format *fmt = layer->fmt;
        int i;
        struct mxr_device *mdev = layer->mdev;
        struct v4l2_plane_pix_format planes[3];

        mxr_dbg(mdev, "%s\n", __func__);
        /* checking if format was configured */
        if (fmt == NULL)
                return -EINVAL;
        mxr_dbg(mdev, "fmt = %s\n", fmt->name);
        mxr_mplane_fill(planes, fmt, layer->geo.src.full_width,
                layer->geo.src.full_height);

        *nplanes = fmt->num_subframes;
        for (i = 0; i < fmt->num_subframes; ++i) {
                alloc_ctxs[i] = layer->mdev->alloc_ctx;
                sizes[i] = planes[i].sizeimage;
                mxr_dbg(mdev, "size[%d] = %08x\n", i, sizes[i]);
        }

        if (*nbuffers == 0)
                *nbuffers = 1;

        return 0;
}

static void buf_queue(struct vb2_buffer *vb)
{
        struct mxr_buffer *buffer = container_of(vb, struct mxr_buffer, vb);
        struct mxr_layer *layer = vb2_get_drv_priv(vb->vb2_queue);
        struct mxr_device *mdev = layer->mdev;
        unsigned long flags;

        spin_lock_irqsave(&layer->enq_slock, flags);
        list_add_tail(&buffer->list, &layer->enq_list);
        spin_unlock_irqrestore(&layer->enq_slock, flags);

        mxr_dbg(mdev, "queuing buffer\n");
}

static int start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct mxr_layer *layer = vb2_get_drv_priv(vq);
        struct mxr_device *mdev = layer->mdev;
        unsigned long flags;

        mxr_dbg(mdev, "%s\n", __func__);

        /* block any changes in output configuration */
        mxr_output_get(mdev);

        mxr_layer_update_output(layer);
        layer->ops.format_set(layer);
        /* enabling layer in hardware */
        spin_lock_irqsave(&layer->enq_slock, flags);
        layer->state = MXR_LAYER_STREAMING;
        spin_unlock_irqrestore(&layer->enq_slock, flags);

        layer->ops.stream_set(layer, MXR_ENABLE);
        mxr_streamer_get(mdev);

        return 0;
}

static void mxr_watchdog(unsigned long arg)
{
        struct mxr_layer *layer = (struct mxr_layer *) arg;
        struct mxr_device *mdev = layer->mdev;
        unsigned long flags;

        mxr_err(mdev, "watchdog fired for layer %s\n", layer->vfd.name);

        spin_lock_irqsave(&layer->enq_slock, flags);

        if (layer->update_buf == layer->shadow_buf)
                layer->update_buf = NULL;
        if (layer->update_buf) {
                vb2_buffer_done(&layer->update_buf->vb, VB2_BUF_STATE_ERROR);
                layer->update_buf = NULL;
        }
        if (layer->shadow_buf) {
                vb2_buffer_done(&layer->shadow_buf->vb, VB2_BUF_STATE_ERROR);
                layer->shadow_buf = NULL;
        }
        spin_unlock_irqrestore(&layer->enq_slock, flags);
}

static void stop_streaming(struct vb2_queue *vq)
{
        struct mxr_layer *layer = vb2_get_drv_priv(vq);
        struct mxr_device *mdev = layer->mdev;
        unsigned long flags;
        struct timer_list watchdog;
        struct mxr_buffer *buf, *buf_tmp;

        mxr_dbg(mdev, "%s\n", __func__);

        spin_lock_irqsave(&layer->enq_slock, flags);

        /* reset list */
        layer->state = MXR_LAYER_STREAMING_FINISH;

        /* set all buffer to be done */
        list_for_each_entry_safe(buf, buf_tmp, &layer->enq_list, list) {
                list_del(&buf->list);
                vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
        }

        spin_unlock_irqrestore(&layer->enq_slock, flags);

        /* give 1 seconds to complete to complete last buffers */
        setup_timer_on_stack(&watchdog, mxr_watchdog,

                (unsigned long)layer);
        mod_timer(&watchdog, jiffies + msecs_to_jiffies(1000));

        /* wait until all buffers are goes to done state */
        vb2_wait_for_all_buffers(vq);

        /* stop timer if all synchronization is done */
        del_timer_sync(&watchdog);
        destroy_timer_on_stack(&watchdog);

        /* stopping hardware */
        spin_lock_irqsave(&layer->enq_slock, flags);
        layer->state = MXR_LAYER_IDLE;
        spin_unlock_irqrestore(&layer->enq_slock, flags);

        /* disabling layer in hardware */
        layer->ops.stream_set(layer, MXR_DISABLE);
        /* remove one streamer */
        mxr_streamer_put(mdev);
        /* allow changes in output configuration */
        mxr_output_put(mdev);
}

static struct vb2_ops mxr_video_qops = {
        .queue_setup = queue_setup,
        .buf_queue = buf_queue,
        .wait_prepare = vb2_ops_wait_prepare,
        .wait_finish = vb2_ops_wait_finish,
        .start_streaming = start_streaming,
        .stop_streaming = stop_streaming,
};

/* FIXME: try to put this functions to mxr_base_layer_create */
int mxr_base_layer_register(struct mxr_layer *layer)
{
        struct mxr_device *mdev = layer->mdev;
        int ret;

        ret = video_register_device(&layer->vfd, VFL_TYPE_GRABBER, -1);
        if (ret)
                mxr_err(mdev, "failed to register video device\n");
        else
                mxr_info(mdev, "registered layer %s as /dev/video%d\n",
                        layer->vfd.name, layer->vfd.num);
        return ret;
}

void mxr_base_layer_unregister(struct mxr_layer *layer)
{
        video_unregister_device(&layer->vfd);
}

void mxr_layer_release(struct mxr_layer *layer)
{
        if (layer->ops.release)
                layer->ops.release(layer);
}

void mxr_base_layer_release(struct mxr_layer *layer)
{
        kfree(layer);
}

static void mxr_vfd_release(struct video_device *vdev)
{
        pr_info("video device release\n");
}

struct mxr_layer *mxr_base_layer_create(struct mxr_device *mdev,
        int idx, char *name, struct mxr_layer_ops *ops)
{
        struct mxr_layer *layer;

        layer = kzalloc(sizeof(*layer), GFP_KERNEL);
        if (layer == NULL) {
                mxr_err(mdev, "not enough memory for layer.\n");
                goto fail;
        }

        layer->mdev = mdev;
        layer->idx = idx;
        layer->ops = *ops;

        spin_lock_init(&layer->enq_slock);
        INIT_LIST_HEAD(&layer->enq_list);
        mutex_init(&layer->mutex);

        layer->vfd = (struct video_device) {
                .minor = -1,
                .release = mxr_vfd_release,
                .fops = &mxr_fops,
                .vfl_dir = VFL_DIR_TX,
                .ioctl_ops = &mxr_ioctl_ops,
        };
        strlcpy(layer->vfd.name, name, sizeof(layer->vfd.name));

        video_set_drvdata(&layer->vfd, layer);
        layer->vfd.lock = &layer->mutex;
        layer->vfd.v4l2_dev = &mdev->v4l2_dev;

        layer->vb_queue = (struct vb2_queue) {
                .type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE,
                .io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF,
                .drv_priv = layer,
                .buf_struct_size = sizeof(struct mxr_buffer),
                .ops = &mxr_video_qops,
                .min_buffers_needed = 1,
                .mem_ops = &vb2_dma_contig_memops,
                .lock = &layer->mutex,
        };

        return layer;

fail:
        return NULL;
}

static const struct mxr_format *find_format_by_fourcc(
        struct mxr_layer *layer, unsigned long fourcc)
{
        int i;

        for (i = 0; i < layer->fmt_array_size; ++i)
                if (layer->fmt_array[i]->fourcc == fourcc)
                        return layer->fmt_array[i];
        return NULL;
}

static const struct mxr_format *find_format_by_index(
        struct mxr_layer *layer, unsigned long index)
{
        if (index >= layer->fmt_array_size)
                return NULL;
        return layer->fmt_array[index];
}