Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / media / platform / xilinx / xilinx-dma.c
diff --git a/kernel/drivers/media/platform/xilinx/xilinx-dma.c b/kernel/drivers/media/platform/xilinx/xilinx-dma.c
new file mode 100644 (file)
index 0000000..efde88a
--- /dev/null
@@ -0,0 +1,766 @@
+/*
+ * 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/lcm.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#include <media/v4l2-dev.h>
+#include <media/v4l2-fh.h>
+#include <media/v4l2-ioctl.h>
+#include <media/videobuf2-core.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
+
+/* -----------------------------------------------------------------------------
+ * 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 == NULL ||
+           media_entity_type(remote->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
+               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;
+
+       subdev = xvip_dma_remote_subdev(&dma->pad, &fmt.pad);
+       if (subdev == NULL)
+               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 ||
+           dma->format.height != fmt.format.height ||
+           dma->format.width != fmt.format.width ||
+           dma->format.colorspace != fmt.format.colorspace)
+               return -EINVAL;
+
+       return 0;
+}
+
+/* -----------------------------------------------------------------------------
+ * Pipeline Stream Management
+ */
+
+/**
+ * xvip_pipeline_start_stop - Start ot stop streaming on a pipeline
+ * @pipe: The pipeline
+ * @start: Start (when true) or stop (when false) the pipeline
+ *
+ * Walk the entities chain starting at the pipeline output video node 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_pipeline *pipe, bool start)
+{
+       struct xvip_dma *dma = pipe->output;
+       struct media_entity *entity;
+       struct media_pad *pad;
+       struct v4l2_subdev *subdev;
+       int ret;
+
+       entity = &dma->video.entity;
+       while (1) {
+               pad = &entity->pads[0];
+               if (!(pad->flags & MEDIA_PAD_FL_SINK))
+                       break;
+
+               pad = media_entity_remote_pad(pad);
+               if (pad == NULL ||
+                   media_entity_type(pad->entity) != MEDIA_ENT_T_V4L2_SUBDEV)
+                       break;
+
+               entity = pad->entity;
+               subdev = media_entity_to_v4l2_subdev(entity);
+
+               ret = v4l2_subdev_call(subdev, video, s_stream, start);
+               if (start && ret < 0 && ret != -ENOIOCTLCMD)
+                       return ret;
+       }
+
+       return 0;
+}
+
+/**
+ * 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.
+ *
+ * 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)
+{
+       int ret = 0;
+
+       mutex_lock(&pipe->lock);
+
+       if (on) {
+               if (pipe->stream_count == pipe->num_dmas - 1) {
+                       ret = xvip_pipeline_start_stop(pipe, true);
+                       if (ret < 0)
+                               goto done;
+               }
+               pipe->stream_count++;
+       } else {
+               if (--pipe->stream_count == 0)
+                       xvip_pipeline_start_stop(pipe, false);
+       }
+
+done:
+       mutex_unlock(&pipe->lock);
+       return ret;
+}
+
+static int xvip_pipeline_validate(struct xvip_pipeline *pipe,
+                                 struct xvip_dma *start)
+{
+       struct media_entity_graph graph;
+       struct media_entity *entity = &start->video.entity;
+       struct media_device *mdev = entity->parent;
+       unsigned int num_inputs = 0;
+       unsigned int num_outputs = 0;
+
+       mutex_lock(&mdev->graph_mutex);
+
+       /* Walk the graph to locate the video nodes. */
+       media_entity_graph_walk_start(&graph, entity);
+
+       while ((entity = media_entity_graph_walk_next(&graph))) {
+               struct xvip_dma *dma;
+
+               if (entity->type != MEDIA_ENT_T_DEVNODE_V4L)
+                       continue;
+
+               dma = to_xvip_dma(media_entity_to_video_device(entity));
+
+               if (dma->pad.flags & MEDIA_PAD_FL_SINK) {
+                       pipe->output = dma;
+                       num_outputs++;
+               } else {
+                       num_inputs++;
+               }
+       }
+
+       mutex_unlock(&mdev->graph_mutex);
+
+       /* We need exactly one output and zero or one input. */
+       if (num_outputs != 1 || num_inputs > 1)
+               return -EPIPE;
+
+       pipe->num_dmas = num_inputs + num_outputs;
+
+       return 0;
+}
+
+static void __xvip_pipeline_cleanup(struct xvip_pipeline *pipe)
+{
+       pipe->num_dmas = 0;
+       pipe->output = NULL;
+}
+
+/**
+ * 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
+ */
+struct xvip_dma_buffer {
+       struct vb2_buffer buf;
+       struct list_head queue;
+       struct xvip_dma *dma;
+};
+
+#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;
+
+       spin_lock(&dma->queued_lock);
+       list_del(&buf->queue);
+       spin_unlock(&dma->queued_lock);
+
+       buf->buf.v4l2_buf.field = V4L2_FIELD_NONE;
+       buf->buf.v4l2_buf.sequence = dma->sequence++;
+       v4l2_get_timestamp(&buf->buf.v4l2_buf.timestamp);
+       vb2_set_plane_payload(&buf->buf, 0, dma->format.sizeimage);
+       vb2_buffer_done(&buf->buf, VB2_BUF_STATE_DONE);
+}
+
+static int
+xvip_dma_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
+                    unsigned int *nbuffers, unsigned int *nplanes,
+                    unsigned int sizes[], void *alloc_ctxs[])
+{
+       struct xvip_dma *dma = vb2_get_drv_priv(vq);
+
+       /* Make sure the image size is large enough. */
+       if (fmt && fmt->fmt.pix.sizeimage < dma->format.sizeimage)
+               return -EINVAL;
+
+       *nplanes = 1;
+
+       sizes[0] = fmt ? fmt->fmt.pix.sizeimage : dma->format.sizeimage;
+       alloc_ctxs[0] = dma->alloc_ctx;
+
+       return 0;
+}
+
+static int xvip_dma_buffer_prepare(struct vb2_buffer *vb)
+{
+       struct xvip_dma *dma = vb2_get_drv_priv(vb->vb2_queue);
+       struct xvip_dma_buffer *buf = to_xvip_dma_buffer(vb);
+
+       buf->dma = dma;
+
+       return 0;
+}
+
+static void xvip_dma_buffer_queue(struct vb2_buffer *vb)
+{
+       struct xvip_dma *dma = vb2_get_drv_priv(vb->vb2_queue);
+       struct xvip_dma_buffer *buf = to_xvip_dma_buffer(vb);
+       struct dma_async_tx_descriptor *desc;
+       dma_addr_t addr = vb2_dma_contig_plane_dma_addr(vb, 0);
+       u32 flags;
+
+       if (dma->queue.type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
+               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 {
+               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->xt.frame_size = 1;
+       dma->sgl[0].size = dma->format.width * dma->fmtinfo->bpp;
+       dma->sgl[0].icg = dma->format.bytesperline - dma->sgl[0].size;
+       dma->xt.numf = dma->format.height;
+
+       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_STATE_ERROR);
+               return;
+       }
+       desc->callback = xvip_dma_complete;
+       desc->callback_param = buf;
+
+       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;
+
+       /*
+        * 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.
+        */
+       pipe = dma->video.entity.pipe
+            ? to_xvip_pipeline(&dma->video.entity) : &dma->pipe;
+
+       ret = media_entity_pipeline_start(&dma->video.entity, &pipe->pipe);
+       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. */
+       xvip_pipeline_set_stream(pipe, true);
+
+       return 0;
+
+error_stop:
+       media_entity_pipeline_stop(&dma->video.entity);
+
+error:
+       /* 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_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_entity_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_STATE_ERROR);
+               list_del(&buf->queue);
+       }
+       spin_unlock_irq(&dma->queued_lock);
+}
+
+static 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->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
+                         | dma->xdev->v4l2_caps;
+
+       if (dma->queue.type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
+               cap->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
+       else
+               cap->device_caps = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_STREAMING;
+
+       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;
+}
+
+/* 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);
+
+       if (f->index > 0)
+               return -EINVAL;
+
+       f->pixelformat = dma->format.pixelformat;
+       strlcpy(f->description, dma->fmtinfo->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);
+
+       format->fmt.pix = dma->format;
+
+       return 0;
+}
+
+static void
+__xvip_dma_try_format(struct xvip_dma *dma, struct v4l2_pix_format *pix,
+                     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;
+
+       /* Retrieve format information and select the default format if the
+        * requested format isn't supported.
+        */
+       info = xvip_get_format_by_fourcc(pix->pixelformat);
+       if (IS_ERR(info))
+               info = xvip_get_format_by_fourcc(XVIP_DMA_DEF_FORMAT);
+
+       pix->pixelformat = info->fourcc;
+       pix->field = V4L2_FIELD_NONE;
+
+       /* 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);
+       min_width = roundup(XVIP_DMA_MIN_WIDTH, align);
+       max_width = rounddown(XVIP_DMA_MAX_WIDTH, align);
+       width = rounddown(pix->width * info->bpp, align);
+
+       pix->width = clamp(width, min_width, max_width) / info->bpp;
+       pix->height = clamp(pix->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.
+        */
+       min_bpl = pix->width * info->bpp;
+       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->bytesperline * pix->height;
+
+       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->fmt.pix, 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->fmt.pix, &info);
+
+       if (vb2_is_busy(&dma->queue))
+               return -EBUSY;
+
+       dma->format = format->fmt.pix;
+       dma->fmtinfo = info;
+
+       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_g_fmt_vid_cap           = xvip_dma_get_format,
+       .vidioc_g_fmt_vid_out           = xvip_dma_get_format,
+       .vidioc_s_fmt_vid_cap           = xvip_dma_set_format,
+       .vidioc_s_fmt_vid_out           = xvip_dma_set_format,
+       .vidioc_try_fmt_vid_cap         = xvip_dma_try_format,
+       .vidioc_try_fmt_vid_out         = 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[14];
+       int ret;
+
+       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.pixelformat = dma->fmtinfo->fourcc;
+       dma->format.colorspace = V4L2_COLORSPACE_SRGB;
+       dma->format.field = V4L2_FIELD_NONE;
+       dma->format.width = XVIP_DMA_DEF_WIDTH;
+       dma->format.height = XVIP_DMA_DEF_HEIGHT;
+       dma->format.bytesperline = dma->format.width * dma->fmtinfo->bpp;
+       dma->format.sizeimage = dma->format.bytesperline * dma->format.height;
+
+       /* Initialize the media entity... */
+       dma->pad.flags = type == V4L2_BUF_TYPE_VIDEO_CAPTURE
+                      ? MEDIA_PAD_FL_SINK : MEDIA_PAD_FL_SOURCE;
+
+       ret = media_entity_init(&dma->video.entity, 1, &dma->pad, 0);
+       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 ? "output" : "input",
+                port);
+       dma->video.vfl_type = VFL_TYPE_GRABBER;
+       dma->video.vfl_dir = type == V4L2_BUF_TYPE_VIDEO_CAPTURE
+                          ? VFL_DIR_RX : 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... */
+       dma->alloc_ctx = vb2_dma_contig_init_ctx(dma->xdev->dev);
+       if (IS_ERR(dma->alloc_ctx))
+               goto error;
+
+       /* 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;
+       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. */
+       sprintf(name, "port%u", port);
+       dma->dma = dma_request_slave_channel(dma->xdev->dev, name);
+       if (dma->dma == NULL) {
+               dev_err(dma->xdev->dev, "no VDMA channel found\n");
+               ret = -ENODEV;
+               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 (dma->dma)
+               dma_release_channel(dma->dma);
+
+       if (!IS_ERR_OR_NULL(dma->alloc_ctx))
+               vb2_dma_contig_cleanup_ctx(dma->alloc_ctx);
+
+       media_entity_cleanup(&dma->video.entity);
+
+       mutex_destroy(&dma->lock);
+       mutex_destroy(&dma->pipe.lock);
+}