/*
 * Xilinx Video DMA
 *
 * Copyright (C) 2013-2015 Ideas on Board
 * Copyright (C) 2013-2015 Xilinx, Inc.
 *
 * Contacts: Hyun Kwon <hyun.kwon@xilinx.com>
 *           Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/dma/xilinx_dma.h>
#include <linux/dma/xilinx_frmbuf.h>
#include <linux/lcm.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/xilinx-v4l2-controls.h>

#include <media/v4l2-dev.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-ioctl.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-dma-contig.h>

#include "xilinx-dma.h"
#include "xilinx-vip.h"
#include "xilinx-vipp.h"

#define XVIP_DMA_DEF_FORMAT             V4L2_PIX_FMT_YUYV
#define XVIP_DMA_DEF_WIDTH              1920
#define XVIP_DMA_DEF_HEIGHT             1080

/* Minimum and maximum widths are expressed in bytes */
#define XVIP_DMA_MIN_WIDTH              1U
#define XVIP_DMA_MAX_WIDTH              65535U
#define XVIP_DMA_MIN_HEIGHT             1U
#define XVIP_DMA_MAX_HEIGHT             8191U

struct xventity_list {
        struct list_head list;
        struct media_entity *entity;
};

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

static struct v4l2_subdev *
xvip_dma_remote_subdev(struct media_pad *local, u32 *pad)
{
        struct media_pad *remote;

        remote = media_entity_remote_pad(local);
        if (!remote || !is_media_entity_v4l2_subdev(remote->entity))
                return NULL;

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

        return media_entity_to_v4l2_subdev(remote->entity);
}

static int xvip_dma_verify_format(struct xvip_dma *dma)
{
        struct v4l2_subdev_format fmt;
        struct v4l2_subdev *subdev;
        int ret;
        int width, height;

        subdev = xvip_dma_remote_subdev(&dma->pad, &fmt.pad);
        if (!subdev)
                return -EPIPE;

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

        if (dma->fmtinfo->code != fmt.format.code)
                return -EINVAL;

        if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type)) {
                width = dma->format.fmt.pix_mp.width;
                height = dma->format.fmt.pix_mp.height;
        } else {
                width = dma->format.fmt.pix.width;
                height = dma->format.fmt.pix.height;
        }

        if (width != fmt.format.width || height != fmt.format.height)
                return -EINVAL;

        return 0;
}

/* -----------------------------------------------------------------------------
 * Pipeline Stream Management
 */

static int xvip_entity_start_stop(struct xvip_composite_device *xdev,
                                  struct media_entity *entity, bool start)
{
        struct v4l2_subdev *subdev;
        bool is_streaming;
        int ret = 0;

        dev_dbg(xdev->dev, "%s entity %s\n",
                start ? "Starting" : "Stopping", entity->name);
        subdev = media_entity_to_v4l2_subdev(entity);

        /* This is to maintain list of stream on/off devices */
        is_streaming = xvip_subdev_set_streaming(xdev, subdev, start);

        /*
         * start or stop the subdev only once in case if they are
         * shared between sub-graphs
         */
        if (start && !is_streaming) {
                /* power-on subdevice */
                ret = v4l2_subdev_call(subdev, core, s_power, 1);
                if (ret < 0 && ret != -ENOIOCTLCMD) {
                        dev_err(xdev->dev,
                                "s_power on failed on subdev\n");
                        xvip_subdev_set_streaming(xdev, subdev, 0);
                        return ret;
                }

                /* stream-on subdevice */
                ret = v4l2_subdev_call(subdev, video, s_stream, 1);
                if (ret < 0 && ret != -ENOIOCTLCMD) {
                        dev_err(xdev->dev,
                                "s_stream on failed on subdev\n");
                        v4l2_subdev_call(subdev, core, s_power, 0);
                        xvip_subdev_set_streaming(xdev, subdev, 0);
                }
        } else if (!start && is_streaming) {
                /* stream-off subdevice */
                ret = v4l2_subdev_call(subdev, video, s_stream, 0);
                if (ret < 0 && ret != -ENOIOCTLCMD) {
                        dev_err(xdev->dev,
                                "s_stream off failed on subdev\n");
                        xvip_subdev_set_streaming(xdev, subdev, 1);
                }

                /* power-off subdevice */
                ret = v4l2_subdev_call(subdev, core, s_power, 0);
                if (ret < 0 && ret != -ENOIOCTLCMD)
                        dev_err(xdev->dev,
                                "s_power off failed on subdev\n");
        }

        return ret;
}

/**
 * xvip_pipeline_start_stop - Start ot stop streaming on a pipeline
 * @xdev: Composite video device
 * @dma: xvip dma
 * @start: Start (when true) or stop (when false) the pipeline
 *
 * Walk the entities chain starting @dma and start or stop all of them
 *
 * Return: 0 if successful, or the return value of the failed video::s_stream
 * operation otherwise.
 */
static int xvip_pipeline_start_stop(struct xvip_composite_device *xdev,
                                    struct xvip_dma *dma, bool start)
{
        struct media_graph graph;
        struct media_entity *entity = &dma->video.entity;
        struct media_device *mdev = entity->graph_obj.mdev;
        struct xventity_list *temp, *_temp;
        LIST_HEAD(ent_list);
        int ret = 0;

        mutex_lock(&mdev->graph_mutex);

        /* Walk the graph to locate the subdev nodes */
        ret = media_graph_walk_init(&graph, mdev);
        if (ret)
                goto error;

        media_graph_walk_start(&graph, entity);

        /* get the list of entities */
        while ((entity = media_graph_walk_next(&graph))) {
                struct xventity_list *ele;

                /* We want to stream on/off only subdevs */
                if (!is_media_entity_v4l2_subdev(entity))
                        continue;

                /* Maintain the pipeline sequence in a list */
                ele = kzalloc(sizeof(*ele), GFP_KERNEL);
                if (!ele) {
                        ret = -ENOMEM;
                        goto error;
                }

                ele->entity = entity;
                list_add(&ele->list, &ent_list);
        }

        if (start) {
                list_for_each_entry_safe(temp, _temp, &ent_list, list) {
                        /* Enable all subdevs from sink to source */
                        ret = xvip_entity_start_stop(xdev, temp->entity, start);
                        if (ret < 0) {
                                dev_err(xdev->dev, "ret = %d for entity %s\n",
                                        ret, temp->entity->name);
                                break;
                        }
                }
        } else {
                list_for_each_entry_safe_reverse(temp, _temp, &ent_list, list)
                        /* Enable all subdevs from source to sink */
                        xvip_entity_start_stop(xdev, temp->entity, start);
        }

        list_for_each_entry_safe(temp, _temp, &ent_list, list) {
                list_del(&temp->list);
                kfree(temp);
        }

error:
        mutex_unlock(&mdev->graph_mutex);
        media_graph_walk_cleanup(&graph);
        return ret;
}

/**
 * xvip_pipeline_set_stream - Enable/disable streaming on a pipeline
 * @pipe: The pipeline
 * @on: Turn the stream on when true or off when false
 *
 * The pipeline is shared between all DMA engines connect at its input and
 * output. While the stream state of DMA engines can be controlled
 * independently, pipelines have a shared stream state that enable or disable
 * all entities in the pipeline. For this reason the pipeline uses a streaming
 * counter that tracks the number of DMA engines that have requested the stream
 * to be enabled. This will walk the graph starting from each DMA and enable or
 * disable the entities in the path.
 *
 * When called with the @on argument set to true, this function will increment
 * the pipeline streaming count. If the streaming count reaches the number of
 * DMA engines in the pipeline it will enable all entities that belong to the
 * pipeline.
 *
 * Similarly, when called with the @on argument set to false, this function will
 * decrement the pipeline streaming count and disable all entities in the
 * pipeline when the streaming count reaches zero.
 *
 * Return: 0 if successful, or the return value of the failed video::s_stream
 * operation otherwise. Stopping the pipeline never fails. The pipeline state is
 * not updated when the operation fails.
 */
static int xvip_pipeline_set_stream(struct xvip_pipeline *pipe, bool on)
{
        struct xvip_composite_device *xdev;
        struct xvip_dma *dma;
        int ret = 0;

        mutex_lock(&pipe->lock);
        xdev = pipe->xdev;

        if (on) {
                if (pipe->stream_count == pipe->num_dmas - 1) {
                        /*
                         * This will iterate the DMAs and the stream-on of
                         * subdevs may not be sequential due to multiple
                         * sub-graph path
                         */
                        list_for_each_entry(dma, &xdev->dmas, list) {
                                ret = xvip_pipeline_start_stop(xdev, dma, true);
                                if (ret < 0)
                                        goto done;
                        }
                }
                pipe->stream_count++;
        } else {
                if (--pipe->stream_count == 0)
                        list_for_each_entry(dma, &xdev->dmas, list)
                                xvip_pipeline_start_stop(xdev, dma, false);
        }

done:
        mutex_unlock(&pipe->lock);
        return ret;
}

static int xvip_pipeline_validate(struct xvip_pipeline *pipe,
                                  struct xvip_dma *start)
{
        struct media_graph graph;
        struct media_entity *entity = &start->video.entity;
        struct media_device *mdev = entity->graph_obj.mdev;
        unsigned int num_inputs = 0;
        unsigned int num_outputs = 0;
        int ret;

        mutex_lock(&mdev->graph_mutex);

        /* Walk the graph to locate the video nodes. */
        ret = media_graph_walk_init(&graph, mdev);
        if (ret) {
                mutex_unlock(&mdev->graph_mutex);
                return ret;
        }

        media_graph_walk_start(&graph, entity);

        while ((entity = media_graph_walk_next(&graph))) {
                struct xvip_dma *dma;

                if (entity->function != MEDIA_ENT_F_IO_V4L)
                        continue;

                dma = to_xvip_dma(media_entity_to_video_device(entity));

                if (dma->pad.flags & MEDIA_PAD_FL_SINK)
                        num_outputs++;
                else
                        num_inputs++;
        }

        mutex_unlock(&mdev->graph_mutex);

        media_graph_walk_cleanup(&graph);

        /* We need at least one DMA to proceed */
        if (num_outputs == 0 && num_inputs == 0)
                return -EPIPE;

        pipe->num_dmas = num_inputs + num_outputs;
        pipe->xdev = start->xdev;

        return 0;
}

static void __xvip_pipeline_cleanup(struct xvip_pipeline *pipe)
{
        pipe->num_dmas = 0;
}

/**
 * xvip_pipeline_cleanup - Cleanup the pipeline after streaming
 * @pipe: the pipeline
 *
 * Decrease the pipeline use count and clean it up if we were the last user.
 */
static void xvip_pipeline_cleanup(struct xvip_pipeline *pipe)
{
        mutex_lock(&pipe->lock);

        /* If we're the last user clean up the pipeline. */
        if (--pipe->use_count == 0)
                __xvip_pipeline_cleanup(pipe);

        mutex_unlock(&pipe->lock);
}

/**
 * xvip_pipeline_prepare - Prepare the pipeline for streaming
 * @pipe: the pipeline
 * @dma: DMA engine at one end of the pipeline
 *
 * Validate the pipeline if no user exists yet, otherwise just increase the use
 * count.
 *
 * Return: 0 if successful or -EPIPE if the pipeline is not valid.
 */
static int xvip_pipeline_prepare(struct xvip_pipeline *pipe,
                                 struct xvip_dma *dma)
{
        int ret;

        mutex_lock(&pipe->lock);

        /* If we're the first user validate and initialize the pipeline. */
        if (pipe->use_count == 0) {
                ret = xvip_pipeline_validate(pipe, dma);
                if (ret < 0) {
                        __xvip_pipeline_cleanup(pipe);
                        goto done;
                }
        }

        pipe->use_count++;
        ret = 0;

done:
        mutex_unlock(&pipe->lock);
        return ret;
}

/* -----------------------------------------------------------------------------
 * videobuf2 queue operations
 */

/**
 * struct xvip_dma_buffer - Video DMA buffer
 * @buf: vb2 buffer base object
 * @queue: buffer list entry in the DMA engine queued buffers list
 * @dma: DMA channel that uses the buffer
 * @desc: Descriptor associated with this structure
 */
struct xvip_dma_buffer {
        struct vb2_v4l2_buffer buf;
        struct list_head queue;
        struct xvip_dma *dma;
        struct dma_async_tx_descriptor *desc;
};

#define to_xvip_dma_buffer(vb)  container_of(vb, struct xvip_dma_buffer, buf)

static void xvip_dma_complete(void *param)
{
        struct xvip_dma_buffer *buf = param;
        struct xvip_dma *dma = buf->dma;
        int i, sizeimage;
        u32 fid;
        int status;

        spin_lock(&dma->queued_lock);
        list_del(&buf->queue);
        spin_unlock(&dma->queued_lock);

        buf->buf.field = V4L2_FIELD_NONE;
        buf->buf.sequence = dma->sequence++;
        buf->buf.vb2_buf.timestamp = ktime_get_ns();

        status = xilinx_xdma_get_fid(dma->dma, buf->desc, &fid);
        if (!status) {
                if (((V4L2_TYPE_IS_MULTIPLANAR(dma->format.type)) &&
                     dma->format.fmt.pix_mp.field == V4L2_FIELD_ALTERNATE) ||
                     dma->format.fmt.pix.field == V4L2_FIELD_ALTERNATE) {
                        /*
                         * fid = 1 is odd field i.e. V4L2_FIELD_TOP.
                         * fid = 0 is even field i.e. V4L2_FIELD_BOTTOM.
                         */
                        buf->buf.field = fid ?
                                         V4L2_FIELD_TOP : V4L2_FIELD_BOTTOM;

                        if (fid == dma->prev_fid)
                                buf->buf.sequence = dma->sequence++;

                        buf->buf.sequence >>= 1;
                        dma->prev_fid = fid;
                }
        }

        if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type)) {
                for (i = 0; i < dma->fmtinfo->buffers; i++) {
                        sizeimage =
                                dma->format.fmt.pix_mp.plane_fmt[i].sizeimage;
                        vb2_set_plane_payload(&buf->buf.vb2_buf, i, sizeimage);
                }
        } else {
                sizeimage = dma->format.fmt.pix.sizeimage;
                vb2_set_plane_payload(&buf->buf.vb2_buf, 0, sizeimage);
        }

        vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE);
}

static int
xvip_dma_queue_setup(struct vb2_queue *vq,
                     unsigned int *nbuffers, unsigned int *nplanes,
                     unsigned int sizes[], struct device *alloc_devs[])
{
        struct xvip_dma *dma = vb2_get_drv_priv(vq);
        u8 i;
        int sizeimage;

        /* Multi planar case: Make sure the image size is large enough */
        if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type)) {
                if (*nplanes) {
                        if (*nplanes != dma->format.fmt.pix_mp.num_planes)
                                return -EINVAL;

                        for (i = 0; i < *nplanes; i++) {
                                sizeimage =
                                  dma->format.fmt.pix_mp.plane_fmt[i].sizeimage;
                                if (sizes[i] < sizeimage)
                                        return -EINVAL;
                        }
                } else {
                        *nplanes = dma->fmtinfo->buffers;
                        for (i = 0; i < dma->fmtinfo->buffers; i++) {
                                sizeimage =
                                  dma->format.fmt.pix_mp.plane_fmt[i].sizeimage;
                                sizes[i] = sizeimage;
                        }
                }
                return 0;
        }

        /* Single planar case: Make sure the image size is large enough */
        sizeimage = dma->format.fmt.pix.sizeimage;
        if (*nplanes == 1)
                return sizes[0] < sizeimage ? -EINVAL : 0;

        *nplanes = 1;
        sizes[0] = sizeimage;

        return 0;
}

static int xvip_dma_buffer_prepare(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct xvip_dma *dma = vb2_get_drv_priv(vb->vb2_queue);
        struct xvip_dma_buffer *buf = to_xvip_dma_buffer(vbuf);

        buf->dma = dma;

        return 0;
}

static void xvip_dma_buffer_queue(struct vb2_buffer *vb)
{
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct xvip_dma *dma = vb2_get_drv_priv(vb->vb2_queue);
        struct xvip_dma_buffer *buf = to_xvip_dma_buffer(vbuf);
        struct dma_async_tx_descriptor *desc;
        dma_addr_t addr = vb2_dma_contig_plane_dma_addr(vb, 0);
        u32 flags;
        u32 luma_size;
        u32 padding_factor_nume, padding_factor_deno, bpl_nume, bpl_deno;
        u32 fid = ~0;

        if (dma->queue.type == V4L2_BUF_TYPE_VIDEO_CAPTURE ||
            dma->queue.type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) {
                flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
                dma->xt.dir = DMA_DEV_TO_MEM;
                dma->xt.src_sgl = false;
                dma->xt.dst_sgl = true;
                dma->xt.dst_start = addr;
        } else if (dma->queue.type == V4L2_BUF_TYPE_VIDEO_OUTPUT ||
                   dma->queue.type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
                flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
                dma->xt.dir = DMA_MEM_TO_DEV;
                dma->xt.src_sgl = true;
                dma->xt.dst_sgl = false;
                dma->xt.src_start = addr;
        }

        /*
         * DMA IP supports only 2 planes, so one datachunk is sufficient
         * to get start address of 2nd plane
         */
        if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type)) {
                struct v4l2_pix_format_mplane *pix_mp;

                pix_mp = &dma->format.fmt.pix_mp;
                xilinx_xdma_v4l2_config(dma->dma, pix_mp->pixelformat);
                xvip_width_padding_factor(pix_mp->pixelformat,
                                          &padding_factor_nume,
                                          &padding_factor_deno);
                xvip_bpl_scaling_factor(pix_mp->pixelformat, &bpl_nume,
                                        &bpl_deno);
                dma->xt.frame_size = dma->fmtinfo->num_planes;
                dma->sgl[0].size = (pix_mp->width * dma->fmtinfo->bpl_factor *
                                    padding_factor_nume * bpl_nume) /
                                    (padding_factor_deno * bpl_deno);
                dma->sgl[0].icg = pix_mp->plane_fmt[0].bytesperline -
                                                        dma->sgl[0].size;
                dma->xt.numf = pix_mp->height;

                /*
                 * dst_icg is the number of bytes to jump after last luma addr
                 * and before first chroma addr
                 */

                /* Handling contiguous data with mplanes */
                if (dma->fmtinfo->buffers == 1) {
                        dma->sgl[0].dst_icg = 0;
                } else {
                        /* Handling non-contiguous data with mplanes */
                        if (dma->fmtinfo->buffers == 2) {
                                dma_addr_t chroma_addr =
                                        vb2_dma_contig_plane_dma_addr(vb, 1);
                                luma_size = pix_mp->plane_fmt[0].bytesperline *
                                            dma->xt.numf;
                                if (chroma_addr > addr)
                                        dma->sgl[0].dst_icg = chroma_addr -
                                                              addr - luma_size;
                                }
                }
        } else {
                struct v4l2_pix_format *pix;

                pix = &dma->format.fmt.pix;
                xilinx_xdma_v4l2_config(dma->dma, pix->pixelformat);
                xvip_width_padding_factor(pix->pixelformat,
                                          &padding_factor_nume,
                                          &padding_factor_deno);
                xvip_bpl_scaling_factor(pix->pixelformat, &bpl_nume,
                                        &bpl_deno);
                dma->xt.frame_size = dma->fmtinfo->num_planes;
                dma->sgl[0].size = (pix->width * dma->fmtinfo->bpl_factor *
                                    padding_factor_nume * bpl_nume) /
                                    (padding_factor_deno * bpl_deno);
                dma->sgl[0].icg = pix->bytesperline - dma->sgl[0].size;
                dma->xt.numf = pix->height;
                dma->sgl[0].dst_icg = 0;
        }

        desc = dmaengine_prep_interleaved_dma(dma->dma, &dma->xt, flags);
        if (!desc) {
                dev_err(dma->xdev->dev, "Failed to prepare DMA transfer\n");
                vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);
                return;
        }
        desc->callback = xvip_dma_complete;
        desc->callback_param = buf;
        buf->desc = desc;

        if (buf->buf.field == V4L2_FIELD_TOP)
                fid = 1;
        else if (buf->buf.field == V4L2_FIELD_BOTTOM)
                fid = 0;
        else if (buf->buf.field == V4L2_FIELD_NONE)
                fid = 0;

        xilinx_xdma_set_fid(dma->dma, desc, fid);

        /* Set low latency capture mode */
        if (dma->earlycb_mode) {
                int ret;

                ret = xilinx_xdma_set_earlycb(dma->dma, desc,
                                              dma->earlycb_mode);
                if (ret < 0) {
                        dev_err(dma->xdev->dev,
                                "Failed enable low latency mode\n");
                }
        }

        spin_lock_irq(&dma->queued_lock);
        list_add_tail(&buf->queue, &dma->queued_bufs);
        spin_unlock_irq(&dma->queued_lock);

        dmaengine_submit(desc);

        if (vb2_is_streaming(&dma->queue))
                dma_async_issue_pending(dma->dma);
}

static int xvip_dma_start_streaming(struct vb2_queue *vq, unsigned int count)
{
        struct xvip_dma *dma = vb2_get_drv_priv(vq);
        struct xvip_dma_buffer *buf, *nbuf;
        struct xvip_pipeline *pipe;
        int ret;

        dma->sequence = 0;
        dma->prev_fid = ~0;

        /*
         * Start streaming on the pipeline. No link touching an entity in the
         * pipeline can be activated or deactivated once streaming is started.
         *
         * Use the pipeline object embedded in the first DMA object that starts
         * streaming.
         */
        mutex_lock(&dma->xdev->lock);
        pipe = dma->video.entity.pipe
             ? to_xvip_pipeline(&dma->video.entity) : &dma->pipe;

        ret = media_pipeline_start(&dma->video.entity, &pipe->pipe);
        mutex_unlock(&dma->xdev->lock);
        if (ret < 0)
                goto error;

        /* Verify that the configured format matches the output of the
         * connected subdev.
         */
        ret = xvip_dma_verify_format(dma);
        if (ret < 0)
                goto error_stop;

        ret = xvip_pipeline_prepare(pipe, dma);
        if (ret < 0)
                goto error_stop;

        /* Start the DMA engine. This must be done before starting the blocks
         * in the pipeline to avoid DMA synchronization issues.
         */
        dma_async_issue_pending(dma->dma);

        /* Start the pipeline. */
        ret = xvip_pipeline_set_stream(pipe, true);
        if (ret < 0)
                goto error_stop;

        return 0;

error_stop:
        media_pipeline_stop(&dma->video.entity);

error:
        dmaengine_terminate_all(dma->dma);
        /* Give back all queued buffers to videobuf2. */
        spin_lock_irq(&dma->queued_lock);
        list_for_each_entry_safe(buf, nbuf, &dma->queued_bufs, queue) {
                vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_QUEUED);
                list_del(&buf->queue);
        }
        spin_unlock_irq(&dma->queued_lock);

        return ret;
}

static void xvip_dma_stop_streaming(struct vb2_queue *vq)
{
        struct xvip_dma *dma = vb2_get_drv_priv(vq);
        struct xvip_pipeline *pipe = to_xvip_pipeline(&dma->video.entity);
        struct xvip_dma_buffer *buf, *nbuf;

        /* Stop the pipeline. */
        xvip_pipeline_set_stream(pipe, false);

        /* Stop and reset the DMA engine. */
        dmaengine_terminate_all(dma->dma);

        /* Cleanup the pipeline and mark it as being stopped. */
        xvip_pipeline_cleanup(pipe);
        media_pipeline_stop(&dma->video.entity);

        /* Give back all queued buffers to videobuf2. */
        spin_lock_irq(&dma->queued_lock);
        list_for_each_entry_safe(buf, nbuf, &dma->queued_bufs, queue) {
                vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_ERROR);
                list_del(&buf->queue);
        }
        spin_unlock_irq(&dma->queued_lock);
}

static const struct vb2_ops xvip_dma_queue_qops = {
        .queue_setup = xvip_dma_queue_setup,
        .buf_prepare = xvip_dma_buffer_prepare,
        .buf_queue = xvip_dma_buffer_queue,
        .wait_prepare = vb2_ops_wait_prepare,
        .wait_finish = vb2_ops_wait_finish,
        .start_streaming = xvip_dma_start_streaming,
        .stop_streaming = xvip_dma_stop_streaming,
};

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

static int
xvip_dma_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
{
        struct v4l2_fh *vfh = file->private_data;
        struct xvip_dma *dma = to_xvip_dma(vfh->vdev);

        cap->device_caps = V4L2_CAP_STREAMING;

        switch (dma->queue.type) {
        case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
                cap->device_caps |= V4L2_CAP_VIDEO_CAPTURE_MPLANE;
                break;
        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
                cap->device_caps |= V4L2_CAP_VIDEO_CAPTURE;
                break;
        case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE:
                cap->device_caps |= V4L2_CAP_VIDEO_OUTPUT_MPLANE;
                break;
        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
                cap->device_caps |= V4L2_CAP_VIDEO_OUTPUT;
                break;
        }

        cap->capabilities = cap->device_caps | V4L2_CAP_DEVICE_CAPS
                          | dma->xdev->v4l2_caps;

        strlcpy(cap->driver, "xilinx-vipp", sizeof(cap->driver));
        strlcpy(cap->card, dma->video.name, sizeof(cap->card));
        snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:%s:%u",
                 dma->xdev->dev->of_node->name, dma->port);

        return 0;
}

static int xvip_xdma_enum_fmt(struct xvip_dma *dma, struct v4l2_fmtdesc *f,
                              struct v4l2_subdev_format *v4l_fmt)
{
        const struct xvip_video_format *fmt;
        int ret;
        u32 i, fmt_cnt, *fmts;

        ret = xilinx_xdma_get_v4l2_vid_fmts(dma->dma, &fmt_cnt, &fmts);
        if (ret)
                return ret;

        /* Has media pad value changed? */
        if (v4l_fmt->format.code != dma->remote_subdev_med_bus ||
            !dma->remote_subdev_med_bus) {
                /* Re-generate legal list of fourcc codes */
                dma->poss_v4l2_fmt_cnt = 0;
                dma->remote_subdev_med_bus = v4l_fmt->format.code;

                if (!dma->poss_v4l2_fmts) {
                        dma->poss_v4l2_fmts =
                                devm_kzalloc(&dma->video.dev,
                                             sizeof(u32) * fmt_cnt,
                                             GFP_KERNEL);
                        if (!dma->poss_v4l2_fmts)
                                return -ENOMEM;
                }

                for (i = 0; i < fmt_cnt; i++) {
                        fmt = xvip_get_format_by_fourcc(fmts[i]);
                        if (IS_ERR(fmt))
                                return PTR_ERR(fmt);

                        if (fmt->code != dma->remote_subdev_med_bus)
                                continue;

                        dma->poss_v4l2_fmts[dma->poss_v4l2_fmt_cnt++] = fmts[i];
                }
        }

        /* Return err if index is greater than count of legal values */
        if (f->index >= dma->poss_v4l2_fmt_cnt)
                return -EINVAL;

        /* Else return pix format in table */
        fmt = xvip_get_format_by_fourcc(dma->poss_v4l2_fmts[f->index]);
        if (IS_ERR(fmt))
                return PTR_ERR(fmt);

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

        return 0;
}

/* FIXME: without this callback function, some applications are not configured
 * with correct formats, and it results in frames in wrong format. Whether this
 * callback needs to be required is not clearly defined, so it should be
 * clarified through the mailing list.
 */
static int
xvip_dma_enum_format(struct file *file, void *fh, struct v4l2_fmtdesc *f)
{
        struct v4l2_fh *vfh = file->private_data;
        struct xvip_dma *dma = to_xvip_dma(vfh->vdev);
        struct v4l2_subdev *subdev;
        struct v4l2_subdev_format v4l_fmt;
        const struct xvip_video_format *fmt;
        int err, ret;

        /* Establish media pad format */
        subdev = xvip_dma_remote_subdev(&dma->pad, &v4l_fmt.pad);
        if (!subdev)
                return -EPIPE;

        v4l_fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
        ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &v4l_fmt);
        if (ret < 0)
                return ret == -ENOIOCTLCMD ? -EINVAL : ret;

        /*
         * In case of frmbuf DMA, this will invoke frambuf driver specific APIs
         * to enumerate formats otherwise return the pix format corresponding
         * to subdev's media bus format. This kind of separation would be
         * helpful for clean up and upstreaming.
         */
        err = xvip_xdma_enum_fmt(dma, f, &v4l_fmt);
        if (!err)
                return err;

        /*
         * This logic will just return one pix format based on subdev's
         * media bus format
         */
        if (f->index > 0)
                return -EINVAL;

        fmt = xvip_get_format_by_code(v4l_fmt.format.code);
        if (IS_ERR(fmt))
                return PTR_ERR(fmt);

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

        return 0;
}

static int
xvip_dma_get_format(struct file *file, void *fh, struct v4l2_format *format)
{
        struct v4l2_fh *vfh = file->private_data;
        struct xvip_dma *dma = to_xvip_dma(vfh->vdev);

        if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type))
                format->fmt.pix_mp = dma->format.fmt.pix_mp;
        else
                format->fmt.pix = dma->format.fmt.pix;

        return 0;
}

static void
__xvip_dma_try_format(struct xvip_dma *dma,
                      struct v4l2_format *format,
                      const struct xvip_video_format **fmtinfo)
{
        const struct xvip_video_format *info;
        unsigned int min_width;
        unsigned int max_width;
        unsigned int min_bpl;
        unsigned int max_bpl;
        unsigned int width;
        unsigned int align;
        unsigned int bpl;
        unsigned int i, hsub, vsub, plane_width, plane_height;
        unsigned int fourcc;
        unsigned int padding_factor_nume, padding_factor_deno;
        unsigned int bpl_nume, bpl_deno;
        struct v4l2_subdev_format fmt;
        struct v4l2_subdev *subdev;
        int ret;

        subdev = xvip_dma_remote_subdev(&dma->pad, &fmt.pad);
        if (!subdev)
                return;

        fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
        ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
        if (ret < 0)
                return;

        if (fmt.format.field == V4L2_FIELD_ALTERNATE) {
                if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type))
                        dma->format.fmt.pix_mp.field = V4L2_FIELD_ALTERNATE;
                else
                        dma->format.fmt.pix.field = V4L2_FIELD_ALTERNATE;
        } else {
                if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type))
                        dma->format.fmt.pix_mp.field = V4L2_FIELD_NONE;
                else
                        dma->format.fmt.pix.field = V4L2_FIELD_NONE;
        }

        /* Retrieve format information and select the default format if the
         * requested format isn't supported.
         */
        if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type))
                fourcc = format->fmt.pix_mp.pixelformat;
        else
                fourcc = format->fmt.pix.pixelformat;

        info = xvip_get_format_by_fourcc(fourcc);

        if (IS_ERR(info))
                info = xvip_get_format_by_fourcc(XVIP_DMA_DEF_FORMAT);

        xvip_width_padding_factor(info->fourcc, &padding_factor_nume,
                                  &padding_factor_deno);
        xvip_bpl_scaling_factor(info->fourcc, &bpl_nume, &bpl_deno);

        /* The transfer alignment requirements are expressed in bytes. Compute
         * the minimum and maximum values, clamp the requested width and convert
         * it back to pixels.
         */
        align = lcm(dma->align, info->bpp >> 3);
        min_width = roundup(XVIP_DMA_MIN_WIDTH, align);
        max_width = rounddown(XVIP_DMA_MAX_WIDTH, align);

        if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type)) {
                struct v4l2_pix_format_mplane *pix_mp;
                struct v4l2_plane_pix_format *plane_fmt;

                pix_mp = &format->fmt.pix_mp;
                plane_fmt = pix_mp->plane_fmt;
                pix_mp->field = dma->format.fmt.pix_mp.field;
                width = rounddown(pix_mp->width * info->bpl_factor, align);
                pix_mp->width = clamp(width, min_width, max_width) /
                                info->bpl_factor;
                pix_mp->height = clamp(pix_mp->height, XVIP_DMA_MIN_HEIGHT,
                                       XVIP_DMA_MAX_HEIGHT);

                /*
                 * Clamp the requested bytes per line value. If the maximum
                 * bytes per line value is zero, the module doesn't support
                 * user configurable line sizes. Override the requested value
                 * with the minimum in that case.
                 */

                max_bpl = rounddown(XVIP_DMA_MAX_WIDTH, dma->align);

                /* Handling contiguous data with mplanes */
                if (info->buffers == 1) {
                        min_bpl = (pix_mp->width * info->bpl_factor *
                                   padding_factor_nume * bpl_nume) /
                                   (padding_factor_deno * bpl_deno);
                        min_bpl = roundup(min_bpl, dma->align);
                        bpl = roundup(plane_fmt[0].bytesperline, dma->align);
                        plane_fmt[0].bytesperline = clamp(bpl, min_bpl,
                                                          max_bpl);

                        if (info->num_planes == 1) {
                                /* Single plane formats */
                                plane_fmt[0].sizeimage =
                                                plane_fmt[0].bytesperline *
                                                pix_mp->height;
                        } else {
                                /* Multi plane formats */
                                plane_fmt[0].sizeimage =
                                        DIV_ROUND_UP(plane_fmt[0].bytesperline *
                                                     pix_mp->height *
                                                     info->bpp, 8);
                        }
                } else {
                        /* Handling non-contiguous data with mplanes */
                        hsub = info->hsub;
                        vsub = info->vsub;
                        for (i = 0; i < info->num_planes; i++) {
                                plane_width = pix_mp->width / (i ? hsub : 1);
                                plane_height = pix_mp->height / (i ? vsub : 1);
                                min_bpl = (plane_width * info->bpl_factor *
                                           padding_factor_nume * bpl_nume) /
                                           (padding_factor_deno * bpl_deno);
                                min_bpl = roundup(min_bpl, dma->align);
                                bpl = rounddown(plane_fmt[i].bytesperline,
                                                dma->align);
                                plane_fmt[i].bytesperline =
                                                clamp(bpl, min_bpl, max_bpl);
                                plane_fmt[i].sizeimage =
                                                plane_fmt[i].bytesperline *
                                                plane_height;
                        }
                }
        } else {
                struct v4l2_pix_format *pix;

                pix = &format->fmt.pix;
                pix->field = dma->format.fmt.pix.field;
                width = rounddown(pix->width * info->bpl_factor, align);
                pix->width = clamp(width, min_width, max_width) /
                             info->bpl_factor;
                pix->height = clamp(pix->height, XVIP_DMA_MIN_HEIGHT,
                                    XVIP_DMA_MAX_HEIGHT);

                min_bpl = (pix->width * info->bpl_factor *
                          padding_factor_nume * bpl_nume) /
                          (padding_factor_deno * bpl_deno);
                min_bpl = roundup(min_bpl, dma->align);
                max_bpl = rounddown(XVIP_DMA_MAX_WIDTH, dma->align);
                bpl = rounddown(pix->bytesperline, dma->align);
                pix->bytesperline = clamp(bpl, min_bpl, max_bpl);
                pix->sizeimage = pix->width * pix->height * info->bpp / 8;
        }

        if (fmtinfo)
                *fmtinfo = info;
}

static int
xvip_dma_try_format(struct file *file, void *fh, struct v4l2_format *format)
{
        struct v4l2_fh *vfh = file->private_data;
        struct xvip_dma *dma = to_xvip_dma(vfh->vdev);

        __xvip_dma_try_format(dma, format, NULL);
        return 0;
}

static int
xvip_dma_set_format(struct file *file, void *fh, struct v4l2_format *format)
{
        struct v4l2_fh *vfh = file->private_data;
        struct xvip_dma *dma = to_xvip_dma(vfh->vdev);
        const struct xvip_video_format *info;

        __xvip_dma_try_format(dma, format, &info);

        if (vb2_is_busy(&dma->queue))
                return -EBUSY;

        if (V4L2_TYPE_IS_MULTIPLANAR(dma->format.type))
                dma->format.fmt.pix_mp = format->fmt.pix_mp;
        else
                dma->format.fmt.pix = format->fmt.pix;

        dma->fmtinfo = info;

        return 0;
}

static int
xvip_dma_set_ctrl(struct file *file, void *fh, struct v4l2_control *ctl)
{
        struct v4l2_fh *vfh = file->private_data;
        struct xvip_dma *dma = to_xvip_dma(vfh->vdev);

        if (vb2_is_busy(&dma->queue))
                return -EBUSY;

        if (ctl->id == V4L2_CID_XILINX_LOW_LATENCY) {
                if (ctl->value)
                        dma->earlycb_mode = EARLY_CALLBACK_LOW_LATENCY;
                else
                        dma->earlycb_mode = 0;
        }

        return 0;
}

static const struct v4l2_ioctl_ops xvip_dma_ioctl_ops = {
        .vidioc_querycap                = xvip_dma_querycap,
        .vidioc_enum_fmt_vid_cap        = xvip_dma_enum_format,
        .vidioc_enum_fmt_vid_cap_mplane = xvip_dma_enum_format,
        .vidioc_enum_fmt_vid_out        = xvip_dma_enum_format,
        .vidioc_enum_fmt_vid_out_mplane = xvip_dma_enum_format,
        .vidioc_g_fmt_vid_cap           = xvip_dma_get_format,
        .vidioc_g_fmt_vid_cap_mplane    = xvip_dma_get_format,
        .vidioc_g_fmt_vid_out           = xvip_dma_get_format,
        .vidioc_g_fmt_vid_out_mplane    = xvip_dma_get_format,
        .vidioc_s_fmt_vid_cap           = xvip_dma_set_format,
        .vidioc_s_fmt_vid_cap_mplane    = xvip_dma_set_format,
        .vidioc_s_fmt_vid_out           = xvip_dma_set_format,
        .vidioc_s_fmt_vid_out_mplane    = xvip_dma_set_format,
        .vidioc_s_ctrl                  = xvip_dma_set_ctrl,
        .vidioc_try_fmt_vid_cap         = xvip_dma_try_format,
        .vidioc_try_fmt_vid_cap_mplane  = xvip_dma_try_format,
        .vidioc_try_fmt_vid_out         = xvip_dma_try_format,
        .vidioc_try_fmt_vid_out_mplane  = xvip_dma_try_format,
        .vidioc_reqbufs                 = vb2_ioctl_reqbufs,
        .vidioc_querybuf                = vb2_ioctl_querybuf,
        .vidioc_qbuf                    = vb2_ioctl_qbuf,
        .vidioc_dqbuf                   = vb2_ioctl_dqbuf,
        .vidioc_create_bufs             = vb2_ioctl_create_bufs,
        .vidioc_expbuf                  = vb2_ioctl_expbuf,
        .vidioc_streamon                = vb2_ioctl_streamon,
        .vidioc_streamoff               = vb2_ioctl_streamoff,
};

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

static const struct v4l2_file_operations xvip_dma_fops = {
        .owner          = THIS_MODULE,
        .unlocked_ioctl = video_ioctl2,
        .open           = v4l2_fh_open,
        .release        = vb2_fop_release,
        .poll           = vb2_fop_poll,
        .mmap           = vb2_fop_mmap,
};

/* -----------------------------------------------------------------------------
 * Xilinx Video DMA Core
 */

int xvip_dma_init(struct xvip_composite_device *xdev, struct xvip_dma *dma,
                  enum v4l2_buf_type type, unsigned int port)
{
        char name[16];
        int ret;
        u32 i, hsub, vsub, width, height;

        dma->xdev = xdev;
        dma->port = port;
        mutex_init(&dma->lock);
        mutex_init(&dma->pipe.lock);
        INIT_LIST_HEAD(&dma->queued_bufs);
        spin_lock_init(&dma->queued_lock);

        dma->fmtinfo = xvip_get_format_by_fourcc(XVIP_DMA_DEF_FORMAT);
        dma->format.type = type;

        if (V4L2_TYPE_IS_MULTIPLANAR(type)) {
                struct v4l2_pix_format_mplane *pix_mp;

                pix_mp = &dma->format.fmt.pix_mp;
                pix_mp->pixelformat = dma->fmtinfo->fourcc;
                pix_mp->colorspace = V4L2_COLORSPACE_SRGB;
                pix_mp->field = V4L2_FIELD_NONE;
                pix_mp->width = XVIP_DMA_DEF_WIDTH;

                /* Handling contiguous data with mplanes */
                if (dma->fmtinfo->buffers == 1) {
                        pix_mp->plane_fmt[0].bytesperline =
                                pix_mp->width * dma->fmtinfo->bpl_factor;
                        pix_mp->plane_fmt[0].sizeimage =
                                        pix_mp->width * pix_mp->height *
                                        dma->fmtinfo->bpp / 8;
                } else {
                    /* Handling non-contiguous data with mplanes */
                        hsub = dma->fmtinfo->hsub;
                        vsub = dma->fmtinfo->vsub;
                        for (i = 0; i < dma->fmtinfo->buffers; i++) {
                                width = pix_mp->width / (i ? hsub : 1);
                                height = pix_mp->height / (i ? vsub : 1);
                                pix_mp->plane_fmt[i].bytesperline =
                                        width * dma->fmtinfo->bpl_factor;
                                pix_mp->plane_fmt[i].sizeimage = width * height;
                        }
                }
        } else {
                struct v4l2_pix_format *pix;

                pix = &dma->format.fmt.pix;
                pix->pixelformat = dma->fmtinfo->fourcc;
                pix->colorspace = V4L2_COLORSPACE_SRGB;
                pix->field = V4L2_FIELD_NONE;
                pix->width = XVIP_DMA_DEF_WIDTH;
                pix->height = XVIP_DMA_DEF_HEIGHT;
                pix->bytesperline = pix->width * dma->fmtinfo->bpl_factor;
                pix->sizeimage =
                        pix->width * pix->height * dma->fmtinfo->bpp / 8;
        }

        /* Initialize the media entity... */
        if (type == V4L2_BUF_TYPE_VIDEO_CAPTURE ||
            type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
                dma->pad.flags = MEDIA_PAD_FL_SINK;
        else
                dma->pad.flags = MEDIA_PAD_FL_SOURCE;

        ret = media_entity_pads_init(&dma->video.entity, 1, &dma->pad);
        if (ret < 0)
                goto error;

        /* ... and the video node... */
        dma->video.fops = &xvip_dma_fops;
        dma->video.v4l2_dev = &xdev->v4l2_dev;
        dma->video.queue = &dma->queue;
        snprintf(dma->video.name, sizeof(dma->video.name), "%s %s %u",
                 xdev->dev->of_node->name,
                 (type == V4L2_BUF_TYPE_VIDEO_CAPTURE ||
                  type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
                                        ? "output" : "input",
                 port);

        dma->video.vfl_type = VFL_TYPE_GRABBER;
        if (type == V4L2_BUF_TYPE_VIDEO_CAPTURE ||
            type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
                dma->video.vfl_dir = VFL_DIR_RX;
        else
                dma->video.vfl_dir = VFL_DIR_TX;

        dma->video.release = video_device_release_empty;
        dma->video.ioctl_ops = &xvip_dma_ioctl_ops;
        dma->video.lock = &dma->lock;

        video_set_drvdata(&dma->video, dma);

        /* ... and the buffers queue... */
        /* Don't enable VB2_READ and VB2_WRITE, as using the read() and write()
         * V4L2 APIs would be inefficient. Testing on the command line with a
         * 'cat /dev/video?' thus won't be possible, but given that the driver
         * anyway requires a test tool to setup the pipeline before any video
         * stream can be started, requiring a specific V4L2 test tool as well
         * instead of 'cat' isn't really a drawback.
         */
        dma->queue.type = type;
        dma->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
        dma->queue.lock = &dma->lock;
        dma->queue.drv_priv = dma;
        dma->queue.buf_struct_size = sizeof(struct xvip_dma_buffer);
        dma->queue.ops = &xvip_dma_queue_qops;
        dma->queue.mem_ops = &vb2_dma_contig_memops;
        dma->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
                                   | V4L2_BUF_FLAG_TSTAMP_SRC_EOF;
        dma->queue.dev = dma->xdev->dev;
        ret = vb2_queue_init(&dma->queue);
        if (ret < 0) {
                dev_err(dma->xdev->dev, "failed to initialize VB2 queue\n");
                goto error;
        }

        /* ... and the DMA channel. */
        snprintf(name, sizeof(name), "port%u", port);
        dma->dma = dma_request_chan(dma->xdev->dev, name);
        if (IS_ERR(dma->dma)) {
                ret = PTR_ERR(dma->dma);
                if (ret != -EPROBE_DEFER)
                        dev_err(dma->xdev->dev,
                                "No Video DMA channel found");
                goto error;
        }

        dma->align = 1 << dma->dma->device->copy_align;

        ret = video_register_device(&dma->video, VFL_TYPE_GRABBER, -1);
        if (ret < 0) {
                dev_err(dma->xdev->dev, "failed to register video device\n");
                goto error;
        }

        return 0;

error:
        xvip_dma_cleanup(dma);
        return ret;
}

void xvip_dma_cleanup(struct xvip_dma *dma)
{
        if (video_is_registered(&dma->video))
                video_unregister_device(&dma->video);

        if (!IS_ERR(dma->dma))
                dma_release_channel(dma->dma);

        media_entity_cleanup(&dma->video.entity);

        mutex_destroy(&dma->lock);
        mutex_destroy(&dma->pipe.lock);
}