Re: [PATCH v6] media: imx: add mem2mem device

[Hans Verkuil <hverkuil@xs4all.nl>]

Hi Philipp,

A quick review (just a few small points):

On 1/8/19 4:38 PM, Philipp Zabel wrote:
> Add a single imx-media mem2mem video device that uses the IPU IC PP
> (image converter post processing) task for scaling and colorspace
> conversion.
> On i.MX6Q/DL SoCs with two IPUs currently only the first IPU is used.
> 
> The hardware only supports writing to destination buffers up to
> 1024x1024 pixels in a single pass, arbitrary sizes can be achieved
> by rendering multiple tiles per frame.
> 
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> [slongerbeam@gmail.com: use ipu_image_convert_adjust(), fix
>  device_run() error handling, add missing media-device header,
>  unregister and remove the mem2mem device in error paths in
>  imx_media_probe_complete() and in imx_media_remove()]
> Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
> ---
> Changes since v5 [1]:
>  - Add missing media-device header
>  - Add missing unregister and remove of mem2mem device
>  - Rename file from mem2mem to csc-scaler
>  - Use strscpy instead of strlcpy
>  - Let the core set device_caps
>  - Add vidioc_prepare_buf support
>  - Set payload to sizeimage in mem2mem_buf_prepare
>  - Disable rotation control while cap_q is busy
>  - Remove stray media_entity_cleanup
>  - Drop tvnorms
>  - Add size check to queue_setup for create_bufs case
>  - Use GPL-2.0+ instead of GPL-2.0-or-later as per license-rules.rst
> 
> [1] https://patchwork.linuxtv.org/patch/53263/
> ---
>  drivers/staging/media/imx/Kconfig             |   1 +
>  drivers/staging/media/imx/Makefile            |   1 +
>  .../staging/media/imx/imx-media-csc-scaler.c  | 861 ++++++++++++++++++
>  drivers/staging/media/imx/imx-media-dev.c     |  34 +-
>  drivers/staging/media/imx/imx-media.h         |  10 +
>  5 files changed, 903 insertions(+), 4 deletions(-)
>  create mode 100644 drivers/staging/media/imx/imx-media-csc-scaler.c
> 
> diff --git a/drivers/staging/media/imx/Kconfig b/drivers/staging/media/imx/Kconfig
> index bfc17de56b17..07013cb3cb66 100644
> --- a/drivers/staging/media/imx/Kconfig
> +++ b/drivers/staging/media/imx/Kconfig
> @@ -6,6 +6,7 @@ config VIDEO_IMX_MEDIA
>  	depends on HAS_DMA
>  	select VIDEOBUF2_DMA_CONTIG
>  	select V4L2_FWNODE
> +	select V4L2_MEM2MEM_DEV
>  	---help---
>  	  Say yes here to enable support for video4linux media controller
>  	  driver for the i.MX5/6 SOC.
> diff --git a/drivers/staging/media/imx/Makefile b/drivers/staging/media/imx/Makefile
> index 698a4210316e..8f1ba788000b 100644
> --- a/drivers/staging/media/imx/Makefile
> +++ b/drivers/staging/media/imx/Makefile
> @@ -6,6 +6,7 @@ imx-media-ic-objs := imx-ic-common.o imx-ic-prp.o imx-ic-prpencvf.o
>  obj-$(CONFIG_VIDEO_IMX_MEDIA) += imx-media.o
>  obj-$(CONFIG_VIDEO_IMX_MEDIA) += imx-media-common.o
>  obj-$(CONFIG_VIDEO_IMX_MEDIA) += imx-media-capture.o
> +obj-$(CONFIG_VIDEO_IMX_MEDIA) += imx-media-csc-scaler.o
>  obj-$(CONFIG_VIDEO_IMX_MEDIA) += imx-media-vdic.o
>  obj-$(CONFIG_VIDEO_IMX_MEDIA) += imx-media-ic.o
>  
> diff --git a/drivers/staging/media/imx/imx-media-csc-scaler.c b/drivers/staging/media/imx/imx-media-csc-scaler.c
> new file mode 100644
> index 000000000000..651e4d7764e4
> --- /dev/null
> +++ b/drivers/staging/media/imx/imx-media-csc-scaler.c
> @@ -0,0 +1,861 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * i.MX IPUv3 IC PP mem2mem CSC/Scaler driver
> + *
> + * Copyright (C) 2011 Pengutronix, Sascha Hauer
> + * Copyright (C) 2018 Pengutronix, Philipp Zabel
> + */
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/fs.h>
> +#include <linux/version.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <video/imx-ipu-v3.h>
> +#include <video/imx-ipu-image-convert.h>
> +
> +#include <media/media-device.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-event.h>
> +#include <media/v4l2-mem2mem.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/videobuf2-dma-contig.h>
> +
> +#include "imx-media.h"
> +
> +#define fh_to_ctx(__fh)	container_of(__fh, struct ipu_csc_scaler_ctx, fh)
> +
> +enum {
> +	V4L2_M2M_SRC = 0,
> +	V4L2_M2M_DST = 1,
> +};
> +
> +struct ipu_csc_scaler_priv {
> +	struct imx_media_video_dev	vdev;
> +
> +	struct v4l2_m2m_dev		*m2m_dev;
> +	struct device			*dev;
> +
> +	struct imx_media_dev		*md;
> +
> +	struct mutex			mutex;	/* mem2mem device mutex */
> +};
> +
> +#define vdev_to_priv(v) container_of(v, struct ipu_csc_scaler_priv, vdev)
> +
> +/* Per-queue, driver-specific private data */
> +struct ipu_csc_scaler_q_data {
> +	struct v4l2_pix_format		cur_fmt;
> +	struct v4l2_rect		rect;
> +};
> +
> +struct ipu_csc_scaler_ctx {
> +	struct ipu_csc_scaler_priv	*priv;
> +
> +	struct v4l2_fh			fh;
> +	struct ipu_csc_scaler_q_data	q_data[2];
> +	struct ipu_image_convert_ctx	*icc;
> +
> +	struct v4l2_ctrl_handler	ctrl_hdlr;
> +	int				rotate;
> +	bool				hflip;
> +	bool				vflip;
> +	enum ipu_rotate_mode		rot_mode;
> +};
> +
> +static struct ipu_csc_scaler_q_data *get_q_data(struct ipu_csc_scaler_ctx *ctx,
> +						enum v4l2_buf_type type)
> +{
> +	if (V4L2_TYPE_IS_OUTPUT(type))
> +		return &ctx->q_data[V4L2_M2M_SRC];
> +	else
> +		return &ctx->q_data[V4L2_M2M_DST];
> +}
> +
> +/*
> + * mem2mem callbacks
> + */
> +
> +static void job_abort(void *_ctx)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = _ctx;
> +
> +	if (ctx->icc)
> +		ipu_image_convert_abort(ctx->icc);
> +}
> +
> +static void ipu_ic_pp_complete(struct ipu_image_convert_run *run, void *_ctx)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = _ctx;
> +	struct ipu_csc_scaler_priv *priv = ctx->priv;
> +	struct vb2_v4l2_buffer *src_buf, *dst_buf;
> +
> +	src_buf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
> +	dst_buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
> +
> +	dst_buf->vb2_buf.timestamp = src_buf->vb2_buf.timestamp;
> +	dst_buf->timecode = src_buf->timecode;
> +
> +	v4l2_m2m_buf_done(src_buf, run->status ? VB2_BUF_STATE_ERROR :
> +						 VB2_BUF_STATE_DONE);
> +	v4l2_m2m_buf_done(dst_buf, run->status ? VB2_BUF_STATE_ERROR :
> +						 VB2_BUF_STATE_DONE);
> +
> +	v4l2_m2m_job_finish(priv->m2m_dev, ctx->fh.m2m_ctx);
> +	kfree(run);
> +}
> +
> +static void device_run(void *_ctx)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = _ctx;
> +	struct ipu_csc_scaler_priv *priv = ctx->priv;
> +	struct vb2_v4l2_buffer *src_buf, *dst_buf;
> +	struct ipu_image_convert_run *run;
> +	int ret;
> +
> +	src_buf = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
> +	dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
> +
> +	run = kzalloc(sizeof(*run), GFP_KERNEL);
> +	if (!run)
> +		goto err;
> +
> +	run->ctx = ctx->icc;
> +	run->in_phys = vb2_dma_contig_plane_dma_addr(&src_buf->vb2_buf, 0);
> +	run->out_phys = vb2_dma_contig_plane_dma_addr(&dst_buf->vb2_buf, 0);
> +
> +	ret = ipu_image_convert_queue(run);
> +	if (ret < 0) {
> +		v4l2_err(ctx->priv->vdev.vfd->v4l2_dev,
> +			 "%s: failed to queue: %d\n", __func__, ret);
> +		goto err;
> +	}
> +
> +	return;
> +
> +err:
> +	v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
> +	v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
> +	v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_ERROR);
> +	v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_ERROR);
> +	v4l2_m2m_job_finish(priv->m2m_dev, ctx->fh.m2m_ctx);
> +}
> +
> +/*
> + * Video ioctls
> + */
> +static int ipu_csc_scaler_querycap(struct file *file, void *priv,
> +				   struct v4l2_capability *cap)
> +{
> +	strscpy(cap->driver, "imx-media-mem2mem", sizeof(cap->driver));
> +	strscpy(cap->card, "imx-media-mem2mem", sizeof(cap->card));
> +	strscpy(cap->bus_info, "platform:imx-media-mem2mem",

Please update the names to imx-media-csc-scaler.

> +		sizeof(cap->bus_info));
> +
> +	return 0;
> +}
> +
> +static int ipu_csc_scaler_enum_fmt(struct file *file, void *fh,
> +				   struct v4l2_fmtdesc *f)
> +{
> +	u32 fourcc;
> +	int ret;
> +
> +	ret = imx_media_enum_format(&fourcc, f->index, CS_SEL_ANY);
> +	if (ret)
> +		return ret;
> +
> +	f->pixelformat = fourcc;
> +
> +	return 0;
> +}
> +
> +static int ipu_csc_scaler_g_fmt(struct file *file, void *priv,
> +				struct v4l2_format *f)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = fh_to_ctx(priv);
> +	struct ipu_csc_scaler_q_data *q_data;
> +
> +	q_data = get_q_data(ctx, f->type);
> +
> +	f->fmt.pix = q_data->cur_fmt;
> +
> +	return 0;
> +}
> +
> +static int ipu_csc_scaler_try_fmt(struct file *file, void *priv,
> +				  struct v4l2_format *f)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = fh_to_ctx(priv);
> +	struct ipu_csc_scaler_q_data *q_data = get_q_data(ctx, f->type);
> +	struct ipu_image test_in, test_out;
> +
> +	if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
> +		struct ipu_csc_scaler_q_data *q_data_in =
> +			get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
> +
> +		test_out.pix = f->fmt.pix;
> +		test_in.pix = q_data_in->cur_fmt;
> +	} else {
> +		struct ipu_csc_scaler_q_data *q_data_out =
> +			get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
> +
> +		test_in.pix = f->fmt.pix;
> +		test_out.pix = q_data_out->cur_fmt;
> +	}
> +
> +	ipu_image_convert_adjust(&test_in, &test_out, ctx->rot_mode);
> +
> +	f->fmt.pix = (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) ?
> +		test_out.pix : test_in.pix;
> +
> +	if (f->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
> +		f->fmt.pix.colorspace = q_data->cur_fmt.colorspace;
> +		f->fmt.pix.ycbcr_enc = q_data->cur_fmt.ycbcr_enc;
> +		f->fmt.pix.xfer_func = q_data->cur_fmt.xfer_func;
> +		f->fmt.pix.quantization = q_data->cur_fmt.quantization;
> +	} else if (f->fmt.pix.colorspace == V4L2_COLORSPACE_DEFAULT) {
> +		f->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
> +		f->fmt.pix.ycbcr_enc = V4L2_YCBCR_ENC_DEFAULT;
> +		f->fmt.pix.xfer_func = V4L2_XFER_FUNC_DEFAULT;
> +		f->fmt.pix.quantization = V4L2_QUANTIZATION_DEFAULT;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ipu_csc_scaler_s_fmt(struct file *file, void *priv,
> +				struct v4l2_format *f)
> +{
> +	struct ipu_csc_scaler_q_data *q_data;
> +	struct ipu_csc_scaler_ctx *ctx = fh_to_ctx(priv);
> +	struct vb2_queue *vq;
> +	int ret;
> +
> +	vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
> +	if (vb2_is_busy(vq)) {
> +		v4l2_err(ctx->priv->vdev.vfd->v4l2_dev, "%s queue busy\n",
> +			 __func__);
> +		return -EBUSY;
> +	}
> +
> +	q_data = get_q_data(ctx, f->type);
> +
> +	ret = ipu_csc_scaler_try_fmt(file, priv, f);
> +	if (ret < 0)
> +		return ret;
> +
> +	q_data->cur_fmt.width = f->fmt.pix.width;
> +	q_data->cur_fmt.height = f->fmt.pix.height;
> +	q_data->cur_fmt.pixelformat = f->fmt.pix.pixelformat;
> +	q_data->cur_fmt.field = f->fmt.pix.field;
> +	q_data->cur_fmt.bytesperline = f->fmt.pix.bytesperline;
> +	q_data->cur_fmt.sizeimage = f->fmt.pix.sizeimage;
> +
> +	/* Reset cropping/composing rectangle */
> +	q_data->rect.left = 0;
> +	q_data->rect.top = 0;
> +	q_data->rect.width = q_data->cur_fmt.width;
> +	q_data->rect.height = q_data->cur_fmt.height;
> +
> +	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) {
> +		/* Set colorimetry on the output queue */
> +		q_data->cur_fmt.colorspace = f->fmt.pix.colorspace;
> +		q_data->cur_fmt.ycbcr_enc = f->fmt.pix.ycbcr_enc;
> +		q_data->cur_fmt.xfer_func = f->fmt.pix.xfer_func;
> +		q_data->cur_fmt.quantization = f->fmt.pix.quantization;
> +		/* Propagate colorimetry to the capture queue */
> +		q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
> +		q_data->cur_fmt.colorspace = f->fmt.pix.colorspace;
> +		q_data->cur_fmt.ycbcr_enc = f->fmt.pix.ycbcr_enc;
> +		q_data->cur_fmt.xfer_func = f->fmt.pix.xfer_func;
> +		q_data->cur_fmt.quantization = f->fmt.pix.quantization;
> +	}
> +
> +	/*
> +	 * TODO: Setting colorimetry on the capture queue is currently not
> +	 * supported by the V4L2 API
> +	 */
> +
> +	return 0;
> +}
> +
> +static int ipu_csc_scaler_g_selection(struct file *file, void *priv,
> +				      struct v4l2_selection *s)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = fh_to_ctx(priv);
> +	struct ipu_csc_scaler_q_data *q_data;
> +
> +	switch (s->target) {
> +	case V4L2_SEL_TGT_CROP:
> +	case V4L2_SEL_TGT_CROP_DEFAULT:
> +	case V4L2_SEL_TGT_CROP_BOUNDS:
> +		if (s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
> +			return -EINVAL;
> +		q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
> +		break;
> +	case V4L2_SEL_TGT_COMPOSE:
> +	case V4L2_SEL_TGT_COMPOSE_DEFAULT:
> +	case V4L2_SEL_TGT_COMPOSE_BOUNDS:
> +	case V4L2_SEL_TGT_COMPOSE_PADDED:

I don't think you need to implement COMPOSE_PADDED, unless there
is actual padding going on.

> +		if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +			return -EINVAL;
> +		q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (s->target == V4L2_SEL_TGT_CROP ||
> +	    s->target == V4L2_SEL_TGT_COMPOSE) {
> +		s->r = q_data->rect;
> +	} else {
> +		s->r.left = 0;
> +		s->r.top = 0;
> +		s->r.width = q_data->cur_fmt.width;
> +		s->r.height = q_data->cur_fmt.height;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ipu_csc_scaler_s_selection(struct file *file, void *priv,
> +				      struct v4l2_selection *s)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = fh_to_ctx(priv);
> +	struct ipu_csc_scaler_q_data *q_data;
> +
> +	switch (s->target) {
> +	case V4L2_SEL_TGT_CROP:
> +		if (s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
> +			return -EINVAL;
> +		break;
> +	case V4L2_SEL_TGT_COMPOSE:
> +		if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
> +			return -EINVAL;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (s->type != V4L2_BUF_TYPE_VIDEO_CAPTURE &&
> +	    s->type != V4L2_BUF_TYPE_VIDEO_OUTPUT)
> +		return -EINVAL;
> +
> +	q_data = get_q_data(ctx, s->type);
> +
> +	/* The input's frame width to the IC must be a multiple of 8 pixels
> +	 * When performing resizing the frame width must be multiple of burst
> +	 * size - 8 or 16 pixels as defined by CB#_BURST_16 parameter.
> +	 */
> +	if (s->flags & V4L2_SEL_FLAG_GE)
> +		s->r.width = round_up(s->r.width, 8);
> +	if (s->flags & V4L2_SEL_FLAG_LE)
> +		s->r.width = round_down(s->r.width, 8);
> +	s->r.width = clamp_t(unsigned int, s->r.width, 8,
> +			     round_down(q_data->cur_fmt.width, 8));
> +	s->r.height = clamp_t(unsigned int, s->r.height, 1,
> +			      q_data->cur_fmt.height);
> +	s->r.left = clamp_t(unsigned int, s->r.left, 0,
> +			    q_data->cur_fmt.width - s->r.width);
> +	s->r.top = clamp_t(unsigned int, s->r.top, 0,
> +			   q_data->cur_fmt.height - s->r.height);
> +
> +	/* V4L2_SEL_FLAG_KEEP_CONFIG is only valid for subdevices */
> +	q_data->rect = s->r;
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_ioctl_ops ipu_csc_scaler_ioctl_ops = {
> +	.vidioc_querycap		= ipu_csc_scaler_querycap,
> +
> +	.vidioc_enum_fmt_vid_cap	= ipu_csc_scaler_enum_fmt,
> +	.vidioc_g_fmt_vid_cap		= ipu_csc_scaler_g_fmt,
> +	.vidioc_try_fmt_vid_cap		= ipu_csc_scaler_try_fmt,
> +	.vidioc_s_fmt_vid_cap		= ipu_csc_scaler_s_fmt,
> +
> +	.vidioc_enum_fmt_vid_out	= ipu_csc_scaler_enum_fmt,
> +	.vidioc_g_fmt_vid_out		= ipu_csc_scaler_g_fmt,
> +	.vidioc_try_fmt_vid_out		= ipu_csc_scaler_try_fmt,
> +	.vidioc_s_fmt_vid_out		= ipu_csc_scaler_s_fmt,
> +
> +	.vidioc_g_selection		= ipu_csc_scaler_g_selection,
> +	.vidioc_s_selection		= ipu_csc_scaler_s_selection,
> +
> +	.vidioc_reqbufs			= v4l2_m2m_ioctl_reqbufs,
> +	.vidioc_querybuf		= v4l2_m2m_ioctl_querybuf,
> +
> +	.vidioc_qbuf			= v4l2_m2m_ioctl_qbuf,
> +	.vidioc_expbuf			= v4l2_m2m_ioctl_expbuf,
> +	.vidioc_dqbuf			= v4l2_m2m_ioctl_dqbuf,
> +	.vidioc_create_bufs		= v4l2_m2m_ioctl_create_bufs,
> +	.vidioc_prepare_buf		= v4l2_m2m_ioctl_prepare_buf,
> +
> +	.vidioc_streamon		= v4l2_m2m_ioctl_streamon,
> +	.vidioc_streamoff		= v4l2_m2m_ioctl_streamoff,
> +
> +	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
> +	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
> +};
> +
> +/*
> + * Queue operations
> + */
> +
> +static int ipu_csc_scaler_queue_setup(struct vb2_queue *vq,
> +				      unsigned int *nbuffers,
> +				      unsigned int *nplanes,
> +				      unsigned int sizes[],
> +				      struct device *alloc_devs[])
> +{
> +	struct ipu_csc_scaler_ctx *ctx = vb2_get_drv_priv(vq);
> +	struct ipu_csc_scaler_q_data *q_data;
> +	unsigned int size, count = *nbuffers;
> +
> +	q_data = get_q_data(ctx, vq->type);
> +
> +	size = q_data->cur_fmt.sizeimage;
> +
> +	*nbuffers = count;
> +
> +	if (*nplanes)
> +		return sizes[0] < size ? -EINVAL : 0;
> +
> +	*nplanes = 1;
> +	sizes[0] = size;
> +
> +	dev_dbg(ctx->priv->dev, "get %d buffer(s) of size %d each.\n",
> +		count, size);
> +
> +	return 0;
> +}
> +
> +static int ipu_csc_scaler_buf_prepare(struct vb2_buffer *vb)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
> +	struct ipu_csc_scaler_q_data *q_data;
> +	unsigned long size;
> +
> +	dev_dbg(ctx->priv->dev, "type: %d\n", vb->vb2_queue->type);
> +
> +	q_data = get_q_data(ctx, vb->vb2_queue->type);
> +	size = q_data->cur_fmt.sizeimage;
> +
> +	if (vb2_plane_size(vb, 0) < size) {
> +		dev_dbg(ctx->priv->dev,
> +			"%s data will not fit into plane (%lu < %lu)\n",
> +			__func__, vb2_plane_size(vb, 0), size);
> +		return -EINVAL;
> +	}
> +
> +	vb2_set_plane_payload(vb, 0, size);
> +
> +	return 0;
> +}
> +
> +static void ipu_csc_scaler_buf_queue(struct vb2_buffer *vb)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
> +
> +	v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, to_vb2_v4l2_buffer(vb));
> +}
> +
> +static void ipu_image_from_q_data(struct ipu_image *im,
> +				  struct ipu_csc_scaler_q_data *q_data)
> +{
> +	im->pix.width = q_data->cur_fmt.width;
> +	im->pix.height = q_data->cur_fmt.height;
> +	im->pix.bytesperline = q_data->cur_fmt.bytesperline;
> +	im->pix.pixelformat = q_data->cur_fmt.pixelformat;
> +	im->rect = q_data->rect;
> +}
> +
> +static int ipu_csc_scaler_start_streaming(struct vb2_queue *q,
> +					  unsigned int count)
> +{
> +	const enum ipu_ic_task ic_task = IC_TASK_POST_PROCESSOR;
> +	struct ipu_csc_scaler_ctx *ctx = vb2_get_drv_priv(q);
> +	struct ipu_csc_scaler_priv *priv = ctx->priv;
> +	struct ipu_soc *ipu = priv->md->ipu[0];
> +	struct ipu_csc_scaler_q_data *q_data;
> +	struct vb2_queue *other_q;
> +	struct ipu_image in, out;
> +
> +	other_q = v4l2_m2m_get_vq(ctx->fh.m2m_ctx,
> +				  (q->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) ?
> +				  V4L2_BUF_TYPE_VIDEO_OUTPUT :
> +				  V4L2_BUF_TYPE_VIDEO_CAPTURE);
> +	if (!vb2_is_streaming(other_q))
> +		return 0;
> +
> +	if (ctx->icc) {
> +		v4l2_warn(ctx->priv->vdev.vfd->v4l2_dev, "removing old ICC\n");
> +		ipu_image_convert_unprepare(ctx->icc);
> +	}
> +
> +	q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
> +	ipu_image_from_q_data(&in, q_data);
> +
> +	q_data = get_q_data(ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
> +	ipu_image_from_q_data(&out, q_data);
> +
> +	ctx->icc = ipu_image_convert_prepare(ipu, ic_task, &in, &out,
> +					     ctx->rot_mode,
> +					     ipu_ic_pp_complete, ctx);
> +	if (IS_ERR(ctx->icc)) {
> +		struct vb2_v4l2_buffer *buf;
> +		int ret = PTR_ERR(ctx->icc);
> +
> +		ctx->icc = NULL;
> +		v4l2_err(ctx->priv->vdev.vfd->v4l2_dev, "%s: error %d\n",
> +			 __func__, ret);
> +		while ((buf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx)))
> +			v4l2_m2m_buf_done(buf, VB2_BUF_STATE_QUEUED);
> +		while ((buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx)))
> +			v4l2_m2m_buf_done(buf, VB2_BUF_STATE_QUEUED);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static void ipu_csc_scaler_stop_streaming(struct vb2_queue *q)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = vb2_get_drv_priv(q);
> +	struct vb2_v4l2_buffer *buf;
> +
> +	if (ctx->icc) {
> +		ipu_image_convert_unprepare(ctx->icc);
> +		ctx->icc = NULL;
> +	}
> +
> +	if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) {
> +		while ((buf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx)))
> +			v4l2_m2m_buf_done(buf, VB2_BUF_STATE_ERROR);
> +	} else {
> +		while ((buf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx)))
> +			v4l2_m2m_buf_done(buf, VB2_BUF_STATE_ERROR);
> +	}
> +}
> +
> +static const struct vb2_ops ipu_csc_scaler_qops = {
> +	.queue_setup		= ipu_csc_scaler_queue_setup,
> +	.buf_prepare		= ipu_csc_scaler_buf_prepare,
> +	.buf_queue		= ipu_csc_scaler_buf_queue,
> +	.wait_prepare		= vb2_ops_wait_prepare,
> +	.wait_finish		= vb2_ops_wait_finish,
> +	.start_streaming	= ipu_csc_scaler_start_streaming,
> +	.stop_streaming		= ipu_csc_scaler_stop_streaming,
> +};
> +
> +static int ipu_csc_scaler_queue_init(void *priv, struct vb2_queue *src_vq,
> +				     struct vb2_queue *dst_vq)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = priv;
> +	int ret;
> +
> +	memset(src_vq, 0, sizeof(*src_vq));
> +	src_vq->type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
> +	src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> +	src_vq->drv_priv = ctx;
> +	src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
> +	src_vq->ops = &ipu_csc_scaler_qops;
> +	src_vq->mem_ops = &vb2_dma_contig_memops;
> +	src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> +	src_vq->lock = &ctx->priv->mutex;
> +	src_vq->dev = ctx->priv->dev;
> +
> +	ret = vb2_queue_init(src_vq);
> +	if (ret)
> +		return ret;
> +
> +	memset(dst_vq, 0, sizeof(*dst_vq));
> +	dst_vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> +	dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> +	dst_vq->drv_priv = ctx;
> +	dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
> +	dst_vq->ops = &ipu_csc_scaler_qops;
> +	dst_vq->mem_ops = &vb2_dma_contig_memops;
> +	dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> +	dst_vq->lock = &ctx->priv->mutex;
> +	dst_vq->dev = ctx->priv->dev;
> +
> +	return vb2_queue_init(dst_vq);
> +}
> +
> +static int ipu_csc_scaler_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct ipu_csc_scaler_ctx *ctx = container_of(ctrl->handler,
> +						      struct ipu_csc_scaler_ctx,
> +						      ctrl_hdlr);
> +	enum ipu_rotate_mode rot_mode;
> +	int rotate;
> +	bool hflip, vflip;
> +	int ret = 0;
> +
> +	rotate = ctx->rotate;
> +	hflip = ctx->hflip;
> +	vflip = ctx->vflip;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_HFLIP:
> +		hflip = ctrl->val;
> +		break;
> +	case V4L2_CID_VFLIP:
> +		vflip = ctrl->val;
> +		break;
> +	case V4L2_CID_ROTATE:
> +		rotate = ctrl->val;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	ret = ipu_degrees_to_rot_mode(&rot_mode, rotate, hflip, vflip);
> +	if (ret)
> +		return ret;
> +
> +	if (rot_mode != ctx->rot_mode) {
> +		struct vb2_queue *cap_q;
> +
> +		cap_q = v4l2_m2m_get_vq(ctx->fh.m2m_ctx,
> +					V4L2_BUF_TYPE_VIDEO_CAPTURE);
> +		if (vb2_is_busy(cap_q))
> +			return -EBUSY;
> +
> +		ctx->rot_mode = rot_mode;
> +		ctx->rotate = rotate;
> +		ctx->hflip = hflip;
> +		ctx->vflip = vflip;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_ctrl_ops ipu_csc_scaler_ctrl_ops = {
> +	.s_ctrl = ipu_csc_scaler_s_ctrl,
> +};
> +
> +static int ipu_csc_scaler_init_controls(struct ipu_csc_scaler_ctx *ctx)
> +{
> +	struct v4l2_ctrl_handler *hdlr = &ctx->ctrl_hdlr;
> +	int ret;
> +
> +	v4l2_ctrl_handler_init(hdlr, 3);
> +
> +	v4l2_ctrl_new_std(hdlr, &ipu_csc_scaler_ctrl_ops, V4L2_CID_HFLIP,
> +			  0, 1, 1, 0);
> +	v4l2_ctrl_new_std(hdlr, &ipu_csc_scaler_ctrl_ops, V4L2_CID_VFLIP,
> +			  0, 1, 1, 0);
> +	v4l2_ctrl_new_std(hdlr, &ipu_csc_scaler_ctrl_ops, V4L2_CID_ROTATE,
> +			  0, 270, 90, 0);
> +
> +	if (hdlr->error) {
> +		ret = hdlr->error;
> +		goto out_free;
> +	}
> +
> +	v4l2_ctrl_handler_setup(hdlr);
> +	return 0;
> +
> +out_free:
> +	v4l2_ctrl_handler_free(hdlr);
> +	return ret;

You don't really need a goto here, just replace the 'goto' with these last two lines.

> +}
> +
> +#define DEFAULT_WIDTH	720
> +#define DEFAULT_HEIGHT	576
> +static const struct ipu_csc_scaler_q_data ipu_csc_scaler_q_data_default = {
> +	.cur_fmt = {
> +		.width = DEFAULT_WIDTH,
> +		.height = DEFAULT_HEIGHT,
> +		.pixelformat = V4L2_PIX_FMT_YUV420,
> +		.field = V4L2_FIELD_NONE,
> +		.bytesperline = DEFAULT_WIDTH,
> +		.sizeimage = DEFAULT_WIDTH * DEFAULT_HEIGHT * 3 / 2,
> +		.colorspace = V4L2_COLORSPACE_SRGB,
> +	},
> +	.rect = {
> +		.width = DEFAULT_WIDTH,
> +		.height = DEFAULT_HEIGHT,
> +	},
> +};
> +
> +/*
> + * File operations
> + */
> +static int ipu_csc_scaler_open(struct file *file)
> +{
> +	struct ipu_csc_scaler_priv *priv = video_drvdata(file);
> +	struct ipu_csc_scaler_ctx *ctx = NULL;
> +	int ret;
> +
> +	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	ctx->rot_mode = IPU_ROTATE_NONE;
> +
> +	v4l2_fh_init(&ctx->fh, video_devdata(file));
> +	file->private_data = &ctx->fh;
> +	v4l2_fh_add(&ctx->fh);
> +	ctx->priv = priv;
> +
> +	ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(priv->m2m_dev, ctx,
> +					    &ipu_csc_scaler_queue_init);
> +	if (IS_ERR(ctx->fh.m2m_ctx)) {
> +		ret = PTR_ERR(ctx->fh.m2m_ctx);
> +		goto err_ctx;
> +	}
> +
> +	ret = ipu_csc_scaler_init_controls(ctx);
> +	if (ret)
> +		goto err_ctrls;
> +
> +	ctx->fh.ctrl_handler = &ctx->ctrl_hdlr;
> +
> +	ctx->q_data[V4L2_M2M_SRC] = ipu_csc_scaler_q_data_default;
> +	ctx->q_data[V4L2_M2M_DST] = ipu_csc_scaler_q_data_default;
> +
> +	dev_dbg(priv->dev, "Created instance %p, m2m_ctx: %p\n", ctx,
> +		ctx->fh.m2m_ctx);
> +
> +	return 0;
> +
> +err_ctrls:
> +	v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
> +err_ctx:
> +	v4l2_fh_del(&ctx->fh);
> +	v4l2_fh_exit(&ctx->fh);
> +	kfree(ctx);
> +	return ret;
> +}
> +
> +static int ipu_csc_scaler_release(struct file *file)
> +{
> +	struct ipu_csc_scaler_priv *priv = video_drvdata(file);
> +	struct ipu_csc_scaler_ctx *ctx = fh_to_ctx(file->private_data);
> +
> +	dev_dbg(priv->dev, "Releasing instance %p\n", ctx);
> +
> +	v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
> +	v4l2_fh_del(&ctx->fh);
> +	v4l2_fh_exit(&ctx->fh);
> +	kfree(ctx);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_file_operations ipu_csc_scaler_fops = {
> +	.owner		= THIS_MODULE,
> +	.open		= ipu_csc_scaler_open,
> +	.release	= ipu_csc_scaler_release,
> +	.poll		= v4l2_m2m_fop_poll,
> +	.unlocked_ioctl	= video_ioctl2,
> +	.mmap		= v4l2_m2m_fop_mmap,
> +};
> +
> +static struct v4l2_m2m_ops m2m_ops = {
> +	.device_run	= device_run,
> +	.job_abort	= job_abort,
> +};
> +
> +static const struct video_device ipu_csc_scaler_videodev_template = {
> +	.name		= "ipu0_ic_pp mem2mem",
> +	.fops		= &ipu_csc_scaler_fops,
> +	.ioctl_ops	= &ipu_csc_scaler_ioctl_ops,
> +	.minor		= -1,
> +	.release	= video_device_release,
> +	.vfl_dir	= VFL_DIR_M2M,
> +	.device_caps	= V4L2_CAP_VIDEO_M2M | V4L2_CAP_STREAMING,
> +};
> +
> +int imx_media_csc_scaler_device_register(struct imx_media_video_dev *vdev)
> +{
> +	struct ipu_csc_scaler_priv *priv = vdev_to_priv(vdev);
> +	struct video_device *vfd = vdev->vfd;
> +	int ret;
> +
> +	vfd->v4l2_dev = &priv->md->v4l2_dev;
> +
> +	ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
> +	if (ret) {
> +		v4l2_err(vfd->v4l2_dev, "Failed to register video device\n");
> +		return ret;
> +	}
> +
> +	v4l2_info(vfd->v4l2_dev, "Registered %s as /dev/%s\n", vfd->name,
> +		  video_device_node_name(vfd));
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(imx_media_csc_scaler_device_register);
> +
> +void imx_media_csc_scaler_device_unregister(struct imx_media_video_dev *vdev)
> +{
> +	struct ipu_csc_scaler_priv *priv = vdev_to_priv(vdev);
> +	struct video_device *vfd = priv->vdev.vfd;
> +
> +	mutex_lock(&priv->mutex);
> +
> +	if (video_is_registered(vfd))
> +		video_unregister_device(vfd);
> +
> +	mutex_unlock(&priv->mutex);
> +}
> +EXPORT_SYMBOL_GPL(imx_media_csc_scaler_device_unregister);
> +
> +struct imx_media_video_dev *
> +imx_media_csc_scaler_device_init(struct imx_media_dev *md)
> +{
> +	struct ipu_csc_scaler_priv *priv;
> +	struct video_device *vfd;
> +	int ret;
> +
> +	priv = devm_kzalloc(md->md.dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return ERR_PTR(-ENOMEM);
> +
> +	priv->md = md;
> +	priv->dev = md->md.dev;
> +
> +	mutex_init(&priv->mutex);
> +
> +	vfd = video_device_alloc();
> +	if (!vfd)
> +		return ERR_PTR(-ENOMEM);
> +
> +	*vfd = ipu_csc_scaler_videodev_template;
> +	snprintf(vfd->name, sizeof(vfd->name), "ipu_ic_pp mem2mem");
> +	vfd->lock = &priv->mutex;
> +	priv->vdev.vfd = vfd;
> +
> +	INIT_LIST_HEAD(&priv->vdev.list);
> +
> +	video_set_drvdata(vfd, priv);
> +
> +	priv->m2m_dev = v4l2_m2m_init(&m2m_ops);
> +	if (IS_ERR(priv->m2m_dev)) {
> +		ret = PTR_ERR(priv->m2m_dev);
> +		v4l2_err(&md->v4l2_dev, "Failed to init mem2mem device: %d\n",
> +			 ret);
> +		return ERR_PTR(ret);
> +	}
> +
> +	return &priv->vdev;
> +}
> +EXPORT_SYMBOL_GPL(imx_media_csc_scaler_device_init);
> +
> +void imx_media_csc_scaler_device_remove(struct imx_media_video_dev *vdev)
> +{
> +	struct ipu_csc_scaler_priv *priv = vdev_to_priv(vdev);
> +
> +	v4l2_m2m_release(priv->m2m_dev);
> +}
> +EXPORT_SYMBOL_GPL(imx_media_csc_scaler_device_remove);
> +
> +MODULE_DESCRIPTION("i.MX IPUv3 mem2mem scaler/CSC driver");
> +MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c
> index 4b344a4a3706..fee2ece0a6f8 100644
> --- a/drivers/staging/media/imx/imx-media-dev.c
> +++ b/drivers/staging/media/imx/imx-media-dev.c
> @@ -318,12 +318,36 @@ static int imx_media_probe_complete(struct v4l2_async_notifier *notifier)
>  		goto unlock;
>  
>  	ret = v4l2_device_register_subdev_nodes(&imxmd->v4l2_dev);
> -unlock:
> -	mutex_unlock(&imxmd->mutex);
>  	if (ret)
> -		return ret;
> +		goto unlock;
> +
> +	imxmd->m2m_vdev = imx_media_csc_scaler_device_init(imxmd);
> +	if (IS_ERR(imxmd->m2m_vdev)) {
> +		ret = PTR_ERR(imxmd->m2m_vdev);
> +		goto unlock;
> +	}
>  
> -	return media_device_register(&imxmd->md);
> +	ret = imx_media_csc_scaler_device_register(imxmd->m2m_vdev);
> +	if (ret)
> +		goto m2m_remove;
> +
> +	mutex_unlock(&imxmd->mutex);
> +
> +	ret = media_device_register(&imxmd->md);
> +	if (ret) {
> +		mutex_lock(&imxmd->mutex);
> +		goto m2m_unreg;
> +	}
> +
> +	return 0;
> +
> +m2m_unreg:
> +	imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev);
> +m2m_remove:
> +	imx_media_csc_scaler_device_remove(imxmd->m2m_vdev);
> +unlock:
> +	mutex_unlock(&imxmd->mutex);
> +	return ret;
>  }
>  
>  static const struct v4l2_async_notifier_operations imx_media_subdev_ops = {
> @@ -532,6 +556,8 @@ static int imx_media_remove(struct platform_device *pdev)
>  	v4l2_async_notifier_unregister(&imxmd->notifier);
>  	imx_media_remove_internal_subdevs(imxmd);
>  	v4l2_async_notifier_cleanup(&imxmd->notifier);
> +	imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev);
> +	imx_media_csc_scaler_device_remove(imxmd->m2m_vdev);
>  	v4l2_device_unregister(&imxmd->v4l2_dev);
>  	media_device_unregister(&imxmd->md);
>  	media_device_cleanup(&imxmd->md);
> diff --git a/drivers/staging/media/imx/imx-media.h b/drivers/staging/media/imx/imx-media.h
> index bc7feb81937c..d1c4df4445cf 100644
> --- a/drivers/staging/media/imx/imx-media.h
> +++ b/drivers/staging/media/imx/imx-media.h
> @@ -149,6 +149,9 @@ struct imx_media_dev {
>  
>  	/* for async subdev registration */
>  	struct v4l2_async_notifier notifier;
> +
> +	/* IC scaler/CSC mem2mem video device */
> +	struct imx_media_video_dev *m2m_vdev;
>  };
>  
>  enum codespace_sel {
> @@ -262,6 +265,13 @@ void imx_media_capture_device_set_format(struct imx_media_video_dev *vdev,
>  					 struct v4l2_pix_format *pix);
>  void imx_media_capture_device_error(struct imx_media_video_dev *vdev);
>  
> +/* imx-media-mem2mem.c */
> +struct imx_media_video_dev *
> +imx_media_csc_scaler_device_init(struct imx_media_dev *dev);
> +void imx_media_csc_scaler_device_remove(struct imx_media_video_dev *vdev);
> +int imx_media_csc_scaler_device_register(struct imx_media_video_dev *vdev);
> +void imx_media_csc_scaler_device_unregister(struct imx_media_video_dev *vdev);
> +
>  /* subdev group ids */
>  #define IMX_MEDIA_GRP_ID_CSI2      BIT(8)
>  #define IMX_MEDIA_GRP_ID_CSI_BIT   9
> 

Regards,

	Hans