Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <8e381fd6-9475-88fc-9159-927f119a8b9c@xs4all.nl>
Date:   Thu, 27 Jul 2023 10:49:03 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.12.0
Subject: Re: [PATCH v7 4/6] media: starfive: camss: Add video driver
Content-Language: en-US
To:     Jack Zhu <jack.zhu@starfivetech.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Robert Foss <rfoss@kernel.org>,
        Todor Tomov <todor.too@gmail.com>, bryan.odonoghue@linaro.org,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Eugen Hristev <eugen.hristev@collabora.com>,
        Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Cc:     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, changhuang.liang@starfivetech.com
References: <20230619112838.19797-1-jack.zhu@starfivetech.com>
 <20230619112838.19797-5-jack.zhu@starfivetech.com>
From:   Hans Verkuil <hverkuil-cisco@xs4all.nl>
In-Reply-To: <20230619112838.19797-5-jack.zhu@starfivetech.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 19/06/2023 13:28, Jack Zhu wrote:
> Add video driver for StarFive Camera Subsystem.
> 
> Signed-off-by: Jack Zhu <jack.zhu@starfivetech.com>
> ---
>  .../media/platform/starfive/camss/Makefile    |   4 +-
>  .../media/platform/starfive/camss/stf_video.c | 724 ++++++++++++++++++
>  .../media/platform/starfive/camss/stf_video.h |  92 +++
>  3 files changed, 819 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/media/platform/starfive/camss/stf_video.c
>  create mode 100644 drivers/media/platform/starfive/camss/stf_video.h
> 
> diff --git a/drivers/media/platform/starfive/camss/Makefile b/drivers/media/platform/starfive/camss/Makefile
> index d56ddd078a71..eb457917a914 100644
> --- a/drivers/media/platform/starfive/camss/Makefile
> +++ b/drivers/media/platform/starfive/camss/Makefile
> @@ -3,6 +3,8 @@
>  # Makefile for StarFive Camera Subsystem driver
>  #
>  
> -starfive-camss-objs += stf_camss.o
> +starfive-camss-objs += \
> +		stf_camss.o \
> +		stf_video.o
>  
>  obj-$(CONFIG_VIDEO_STARFIVE_CAMSS) += starfive-camss.o
> diff --git a/drivers/media/platform/starfive/camss/stf_video.c b/drivers/media/platform/starfive/camss/stf_video.c
> new file mode 100644
> index 000000000000..2e6472fe51c6
> --- /dev/null
> +++ b/drivers/media/platform/starfive/camss/stf_video.c
> @@ -0,0 +1,724 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * stf_video.c
> + *
> + * StarFive Camera Subsystem - V4L2 device node
> + *
> + * Copyright (C) 2021-2023 StarFive Technology Co., Ltd.
> + */
> +
> +#include <linux/pm_runtime.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-event.h>
> +#include <media/v4l2-mc.h>
> +#include <media/videobuf2-dma-contig.h>
> +
> +#include "stf_camss.h"
> +#include "stf_video.h"
> +
> +static const struct stfcamss_format_info formats_pix_wr[] = {
> +	{
> +		.code = MEDIA_BUS_FMT_SRGGB10_1X10,
> +		.pixelformat = V4L2_PIX_FMT_SRGGB10,
> +		.planes = 1,
> +		.vsub = { 1 },
> +		.bpp = 10,
> +	},
> +	{
> +		.code = MEDIA_BUS_FMT_SGRBG10_1X10,
> +		.pixelformat = V4L2_PIX_FMT_SGRBG10,
> +		.planes = 1,
> +		.vsub = { 1 },
> +		.bpp = 10,
> +	},
> +	{
> +		.code = MEDIA_BUS_FMT_SGBRG10_1X10,
> +		.pixelformat = V4L2_PIX_FMT_SGBRG10,
> +		.planes = 1,
> +		.vsub = { 1 },
> +		.bpp = 10,
> +	},
> +	{
> +		.code = MEDIA_BUS_FMT_SBGGR10_1X10,
> +		.pixelformat = V4L2_PIX_FMT_SBGGR10,
> +		.planes = 1,
> +		.vsub = { 1 },
> +		.bpp = 10,
> +	},
> +};
> +
> +static const struct stfcamss_format_info formats_pix_isp[] = {
> +	{
> +		.code = MEDIA_BUS_FMT_Y12_1X12,
> +		.pixelformat = V4L2_PIX_FMT_NV12,
> +		.planes = 2,
> +		.vsub = { 1, 2 },
> +		.bpp = 8,
> +	},
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Helper functions
> + */
> +
> +static int video_find_format(u32 code, u32 pixelformat,
> +			     struct stfcamss_video *video)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < video->nformats; ++i) {
> +		if (video->formats[i].code == code &&
> +		    video->formats[i].pixelformat == pixelformat)
> +			return i;
> +	}
> +
> +	for (i = 0; i < video->nformats; ++i)
> +		if (video->formats[i].code == code)
> +			return i;
> +
> +	for (i = 0; i < video->nformats; ++i)
> +		if (video->formats[i].pixelformat == pixelformat)
> +			return i;
> +
> +	return -EINVAL;
> +}
> +
> +static int __video_try_fmt(struct stfcamss_video *video, struct v4l2_format *f)
> +{
> +	struct v4l2_pix_format *pix;
> +	const struct stfcamss_format_info *fi;
> +	u32 width, height;
> +	u32 bpl;
> +	unsigned int i;
> +
> +	pix = &f->fmt.pix;
> +
> +	for (i = 0; i < video->nformats; i++)
> +		if (pix->pixelformat == video->formats[i].pixelformat)
> +			break;
> +
> +	if (i == video->nformats)
> +		i = 0; /* default format */
> +
> +	fi = &video->formats[i];
> +	width = pix->width;
> +	height = pix->height;
> +
> +	memset(pix, 0, sizeof(*pix));
> +
> +	pix->pixelformat = fi->pixelformat;
> +	pix->width = clamp_t(u32, width, STFCAMSS_FRAME_MIN_WIDTH,
> +			     STFCAMSS_FRAME_MAX_WIDTH);
> +	pix->height = clamp_t(u32, height, STFCAMSS_FRAME_MIN_HEIGHT,
> +			      STFCAMSS_FRAME_MAX_HEIGHT);
> +	bpl = pix->width * fi->bpp / 8;
> +	bpl = ALIGN(bpl, video->bpl_alignment);
> +	pix->bytesperline = bpl;
> +
> +	for (i = 0; i < fi->planes; ++i)
> +		pix->sizeimage += bpl * pix->height / fi->vsub[i];
> +
> +	pix->field = V4L2_FIELD_NONE;
> +	pix->colorspace = V4L2_COLORSPACE_SRGB;
> +	pix->flags = 0;
> +	pix->ycbcr_enc =
> +		V4L2_MAP_YCBCR_ENC_DEFAULT(pix->colorspace);
> +	pix->quantization = V4L2_MAP_QUANTIZATION_DEFAULT(true,
> +							  pix->colorspace,
> +							  pix->ycbcr_enc);
> +	pix->xfer_func = V4L2_MAP_XFER_FUNC_DEFAULT(pix->colorspace);
> +
> +	return 0;
> +}
> +
> +static int stf_video_init_format(struct stfcamss_video *video)
> +{
> +	int ret;
> +	struct v4l2_format format = {
> +		.type = video->type,
> +		.fmt.pix = {
> +			.width = 1920,
> +			.height = 1080,
> +			.pixelformat = V4L2_PIX_FMT_RGB565,
> +		},
> +	};
> +
> +	ret = __video_try_fmt(video, &format);
> +
> +	if (ret < 0)
> +		return ret;
> +
> +	video->active_fmt = format;
> +
> +	return 0;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Video queue operations
> + */
> +
> +static int video_queue_setup(struct vb2_queue *q,
> +			     unsigned int *num_buffers,
> +			     unsigned int *num_planes,
> +			     unsigned int sizes[],
> +			     struct device *alloc_devs[])
> +{
> +	struct stfcamss_video *video = vb2_get_drv_priv(q);
> +	const struct v4l2_pix_format *format = &video->active_fmt.fmt.pix;
> +
> +	if (*num_planes) {
> +		if (*num_planes != 1)
> +			return -EINVAL;
> +
> +		if (sizes[0] < format->sizeimage)
> +			return -EINVAL;
> +	}
> +
> +	*num_planes = 1;
> +	sizes[0] = format->sizeimage;
> +	if (!sizes[0])
> +		dev_err(video->stfcamss->dev,
> +			"%s: error size is zero!!!\n", __func__);
> +
> +	dev_dbg(video->stfcamss->dev, "planes = %d, size = %d\n",
> +		*num_planes, sizes[0]);
> +
> +	return 0;
> +}
> +
> +static int video_buf_init(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +	struct stfcamss_video *video = vb2_get_drv_priv(vb->vb2_queue);
> +	struct stfcamss_buffer *buffer =
> +		container_of(vbuf, struct stfcamss_buffer, vb);
> +	const struct v4l2_pix_format *fmt = &video->active_fmt.fmt.pix;
> +	dma_addr_t *paddr;
> +
> +	paddr = vb2_plane_cookie(vb, 0);
> +	buffer->addr[0] = *paddr;
> +
> +	if (fmt->pixelformat == V4L2_PIX_FMT_NV12 ||
> +	    fmt->pixelformat == V4L2_PIX_FMT_NV21 ||
> +	    fmt->pixelformat == V4L2_PIX_FMT_NV16 ||
> +	    fmt->pixelformat == V4L2_PIX_FMT_NV61)
> +		buffer->addr[1] =
> +			buffer->addr[0] + fmt->bytesperline * fmt->height;
> +
> +	return 0;
> +}
> +
> +static int video_buf_prepare(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +	struct stfcamss_video *video = vb2_get_drv_priv(vb->vb2_queue);
> +	const struct v4l2_pix_format *fmt = &video->active_fmt.fmt.pix;
> +
> +	if (fmt->sizeimage > vb2_plane_size(vb, 0)) {
> +		dev_err(video->stfcamss->dev,
> +			"sizeimage = %d, plane size = %d\n",
> +			fmt->sizeimage, (unsigned int)vb2_plane_size(vb, 0));
> +		return -EINVAL;
> +	}
> +	vb2_set_plane_payload(vb, 0, fmt->sizeimage);
> +
> +	vbuf->field = V4L2_FIELD_NONE;
> +
> +	return 0;
> +}
> +
> +static void video_buf_queue(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +	struct stfcamss_video *video = vb2_get_drv_priv(vb->vb2_queue);
> +	struct stfcamss_buffer *buffer =
> +		container_of(vbuf, struct stfcamss_buffer, vb);
> +
> +	video->ops->queue_buffer(video, buffer);
> +}
> +
> +/*
> + * video_mbus_to_pix - Convert v4l2_mbus_framefmt to v4l2_pix_format
> + * @mbus: v4l2_mbus_framefmt format (input)
> + * @pix: v4l2_pix_format_mplane format (output)
> + * @f: a pointer to formats array element to be used for the conversion
> + * @alignment: bytesperline alignment value
> + *
> + * Fill the output pix structure with information from the input mbus format.
> + *
> + * Return 0 on success or a negative error code otherwise
> + */
> +static int video_mbus_to_pix(const struct v4l2_mbus_framefmt *mbus,
> +			     struct v4l2_pix_format *pix,
> +			     const struct stfcamss_format_info *f,
> +			     unsigned int alignment)
> +{
> +	u32 bytesperline;
> +	unsigned int i;
> +
> +	memset(pix, 0, sizeof(*pix));
> +	v4l2_fill_pix_format(pix, mbus);
> +	pix->pixelformat = f->pixelformat;
> +	bytesperline = pix->width * f->bpp / 8;
> +	bytesperline = ALIGN(bytesperline, alignment);
> +	pix->bytesperline = bytesperline;
> +
> +	for (i = 0; i < f->planes; ++i)
> +		pix->sizeimage += bytesperline * pix->height / f->vsub[i];
> +
> +	return 0;
> +}
> +
> +static struct v4l2_subdev *video_remote_subdev(struct stfcamss_video *video,
> +					       u32 *pad)
> +{
> +	struct media_pad *remote;
> +
> +	remote = media_pad_remote_pad_first(&video->pad);
> +
> +	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 video_get_subdev_format(struct stfcamss_video *video,
> +				   struct v4l2_format *format)
> +{
> +	struct v4l2_pix_format *pix = &video->active_fmt.fmt.pix;
> +	struct v4l2_subdev_format fmt;
> +	struct v4l2_subdev *subdev;
> +	u32 pixelformat;
> +	u32 pad;
> +	int ret;
> +
> +	subdev = video_remote_subdev(video, &pad);
> +	if (!subdev)
> +		return -EPIPE;
> +
> +	fmt.pad = pad;
> +	fmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> +
> +	ret = v4l2_subdev_call(subdev, pad, get_fmt, NULL, &fmt);
> +	if (ret)
> +		return ret;
> +
> +	pixelformat = pix->pixelformat;
> +	ret = video_find_format(fmt.format.code, pixelformat, video);
> +	if (ret < 0)
> +		return ret;
> +
> +	format->type = video->type;
> +
> +	return video_mbus_to_pix(&fmt.format, &format->fmt.pix,
> +				 &video->formats[ret], video->bpl_alignment);
> +}
> +
> +static int video_check_format(struct stfcamss_video *video)
> +{
> +	struct v4l2_pix_format *pix = &video->active_fmt.fmt.pix;
> +	struct v4l2_format format;
> +	struct v4l2_pix_format *sd_pix = &format.fmt.pix;
> +	int ret;
> +
> +	sd_pix->pixelformat = pix->pixelformat;
> +	ret = video_get_subdev_format(video, &format);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (pix->pixelformat != sd_pix->pixelformat ||
> +	    pix->height != sd_pix->height ||
> +	    pix->width != sd_pix->width ||
> +	    pix->field != format.fmt.pix.field) {
> +		dev_err(video->stfcamss->dev,
> +			"not match:\n"
> +			"pixelformat: 0x%x <-> 0x%x\n"
> +			"height: %d <-> %d\n"
> +			"field: %d <-> %d\n",
> +			pix->pixelformat, sd_pix->pixelformat,
> +			pix->height, sd_pix->height,
> +			pix->field, format.fmt.pix.field);
> +		return -EPIPE;
> +	}
> +
> +	return 0;
> +}
> +
> +static int video_start_streaming(struct vb2_queue *q, unsigned int count)
> +{
> +	struct stfcamss_video *video = vb2_get_drv_priv(q);
> +	struct video_device *vdev = &video->vdev;
> +	struct media_entity *entity;
> +	struct media_pad *pad;
> +	struct v4l2_subdev *subdev;
> +	int ret;
> +
> +	ret = video_device_pipeline_start(vdev, &video->stfcamss->pipe);
> +	if (ret < 0) {
> +		dev_err(video->stfcamss->dev,
> +			"Failed to media_pipeline_start: %d\n", ret);

This doesn't call flush_buffers to return the buffers back to the QUEUED state.

You do that correctly elsewhere in this function, but you missed this case.

> +		return ret;
> +	}
> +
> +	ret = video_check_format(video);
> +	if (ret < 0)
> +		goto error;
> +
> +	ret = pm_runtime_resume_and_get(video->stfcamss->dev);
> +	if (ret < 0) {
> +		dev_err(video->stfcamss->dev, "power up failed %d\n", ret);
> +		goto error;
> +	}
> +
> +	entity = &vdev->entity;
> +	while (1) {
> +		pad = &entity->pads[0];
> +		if (!(pad->flags & MEDIA_PAD_FL_SINK))
> +			break;
> +
> +		pad = media_pad_remote_pad_first(pad);
> +		if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
> +			break;
> +
> +		entity = pad->entity;
> +		subdev = media_entity_to_v4l2_subdev(entity);
> +
> +		ret = v4l2_subdev_call(subdev, video, s_stream, 1);
> +		if (ret < 0 && ret != -ENOIOCTLCMD)
> +			goto err_pm_put;
> +	}
> +	return 0;
> +
> +err_pm_put:
> +	pm_runtime_put(video->stfcamss->dev);
> +error:
> +	video_device_pipeline_stop(vdev);
> +	video->ops->flush_buffers(video, VB2_BUF_STATE_QUEUED);
> +	return ret;
> +}
> +
> +static void video_stop_streaming(struct vb2_queue *q)
> +{
> +	struct stfcamss_video *video = vb2_get_drv_priv(q);
> +	struct video_device *vdev = &video->vdev;
> +	struct media_entity *entity;
> +	struct media_pad *pad;
> +	struct v4l2_subdev *subdev;
> +	int ret;
> +
> +	entity = &vdev->entity;
> +	while (1) {
> +		pad = &entity->pads[0];
> +		if (!(pad->flags & MEDIA_PAD_FL_SINK))
> +			break;
> +
> +		pad = media_pad_remote_pad_first(pad);
> +		if (!pad || !is_media_entity_v4l2_subdev(pad->entity))
> +			break;
> +
> +		entity = pad->entity;
> +		subdev = media_entity_to_v4l2_subdev(entity);
> +
> +		v4l2_subdev_call(subdev, video, s_stream, 0);
> +	}
> +
> +	ret = pm_runtime_put(video->stfcamss->dev);
> +	if (ret < 0)
> +		dev_err(video->stfcamss->dev, "power down failed:%d\n", ret);
> +
> +	video_device_pipeline_stop(vdev);
> +	video->ops->flush_buffers(video, VB2_BUF_STATE_ERROR);
> +}
> +
> +static const struct vb2_ops stf_video_vb2_q_ops = {
> +	.queue_setup     = video_queue_setup,
> +	.wait_prepare    = vb2_ops_wait_prepare,
> +	.wait_finish     = vb2_ops_wait_finish,
> +	.buf_init        = video_buf_init,
> +	.buf_prepare     = video_buf_prepare,
> +	.buf_queue       = video_buf_queue,
> +	.start_streaming = video_start_streaming,
> +	.stop_streaming  = video_stop_streaming,
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * V4L2 ioctls
> + */
> +
> +static int video_querycap(struct file *file, void *fh,
> +			  struct v4l2_capability *cap)
> +{
> +	strscpy(cap->driver, "stf camss", sizeof(cap->driver));
> +	strscpy(cap->card, "Starfive Camera Subsystem", sizeof(cap->card));
> +
> +	return 0;
> +}
> +
> +static int video_get_pfmt_by_index(struct stfcamss_video *video, int ndx)
> +{
> +	int i, j, k;
> +
> +	/* find index "i" of "k"th unique pixelformat in formats array */
> +	k = -1;
> +	for (i = 0; i < video->nformats; i++) {
> +		for (j = 0; j < i; j++) {
> +			if (video->formats[i].pixelformat ==
> +			    video->formats[j].pixelformat)
> +				break;
> +		}
> +
> +		if (j == i)
> +			k++;
> +
> +		if (k == ndx)
> +			return i;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int video_get_pfmt_by_mcode(struct stfcamss_video *video, u32 mcode)
> +{
> +	int i;
> +
> +	for (i = 0; i < video->nformats; i++) {
> +		if (video->formats[i].code == mcode)
> +			return i;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int video_enum_fmt(struct file *file, void *fh, struct v4l2_fmtdesc *f)
> +{
> +	struct stfcamss_video *video = video_drvdata(file);
> +	int i;
> +
> +	if (f->type != video->type)
> +		return -EINVAL;
> +	if (f->index >= video->nformats)
> +		return -EINVAL;
> +
> +	if (f->mbus_code) {
> +		/* Each entry in formats[] table has unique mbus_code */
> +		if (f->index > 0)
> +			return -EINVAL;
> +
> +		i = video_get_pfmt_by_mcode(video, f->mbus_code);
> +	} else {
> +		i = video_get_pfmt_by_index(video, f->index);
> +	}
> +
> +	if (i < 0)
> +		return -EINVAL;
> +
> +	f->pixelformat = video->formats[i].pixelformat;
> +
> +	return 0;
> +}
> +
> +static int video_enum_framesizes(struct file *file, void *fh,
> +				 struct v4l2_frmsizeenum *fsize)
> +{
> +	struct stfcamss_video *video = video_drvdata(file);
> +	int i;
> +
> +	if (fsize->index)
> +		return -EINVAL;
> +
> +	for (i = 0; i < video->nformats; i++) {
> +		if (video->formats[i].pixelformat == fsize->pixel_format)
> +			break;
> +	}
> +
> +	if (i == video->nformats)
> +		return -EINVAL;
> +
> +	fsize->type = V4L2_FRMSIZE_TYPE_CONTINUOUS;
> +	fsize->stepwise.min_width = STFCAMSS_FRAME_MIN_WIDTH;
> +	fsize->stepwise.max_width = STFCAMSS_FRAME_MAX_WIDTH;
> +	fsize->stepwise.min_height = STFCAMSS_FRAME_MIN_HEIGHT;
> +	fsize->stepwise.max_height = STFCAMSS_FRAME_MAX_HEIGHT;
> +	fsize->stepwise.step_width = 1;
> +	fsize->stepwise.step_height = 1;
> +
> +	return 0;
> +}
> +
> +static int video_g_fmt(struct file *file, void *fh, struct v4l2_format *f)
> +{
> +	struct stfcamss_video *video = video_drvdata(file);
> +
> +	*f = video->active_fmt;
> +
> +	return 0;
> +}
> +
> +static int video_s_fmt(struct file *file, void *fh, struct v4l2_format *f)
> +{
> +	struct stfcamss_video *video = video_drvdata(file);
> +	int ret;
> +
> +	if (vb2_is_busy(&video->vb2_q))
> +		return -EBUSY;
> +
> +	ret = __video_try_fmt(video, f);
> +	if (ret < 0)
> +		return ret;
> +
> +	video->active_fmt = *f;
> +
> +	return 0;
> +}
> +
> +static int video_try_fmt(struct file *file, void *fh, struct v4l2_format *f)
> +{
> +	struct stfcamss_video *video = video_drvdata(file);
> +
> +	return __video_try_fmt(video, f);
> +}
> +
> +static const struct v4l2_ioctl_ops stf_vid_ioctl_ops = {
> +	.vidioc_querycap                = video_querycap,
> +	.vidioc_enum_fmt_vid_cap        = video_enum_fmt,
> +	.vidioc_enum_fmt_vid_out        = video_enum_fmt,
> +	.vidioc_enum_framesizes         = video_enum_framesizes,
> +	.vidioc_g_fmt_vid_cap           = video_g_fmt,
> +	.vidioc_s_fmt_vid_cap           = video_s_fmt,
> +	.vidioc_try_fmt_vid_cap         = video_try_fmt,
> +	.vidioc_g_fmt_vid_out           = video_g_fmt,
> +	.vidioc_s_fmt_vid_out           = video_s_fmt,
> +	.vidioc_try_fmt_vid_out         = video_try_fmt,
> +	.vidioc_reqbufs                 = vb2_ioctl_reqbufs,
> +	.vidioc_querybuf                = vb2_ioctl_querybuf,
> +	.vidioc_qbuf                    = vb2_ioctl_qbuf,
> +	.vidioc_expbuf                  = vb2_ioctl_expbuf,
> +	.vidioc_dqbuf                   = vb2_ioctl_dqbuf,
> +	.vidioc_create_bufs             = vb2_ioctl_create_bufs,
> +	.vidioc_prepare_buf             = vb2_ioctl_prepare_buf,
> +	.vidioc_streamon                = vb2_ioctl_streamon,
> +	.vidioc_streamoff               = vb2_ioctl_streamoff,
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * V4L2 file operations
> + */
> +
> +static const struct v4l2_file_operations stf_vid_fops = {
> +	.owner          = THIS_MODULE,
> +	.unlocked_ioctl = video_ioctl2,
> +	.open           = v4l2_fh_open,
> +	.release        = vb2_fop_release,
> +	.poll           = vb2_fop_poll,
> +	.mmap           = vb2_fop_mmap,
> +	.read           = vb2_fop_read,
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * STFCAMSS video core
> + */
> +
> +static void stf_video_release(struct video_device *vdev)
> +{
> +	struct stfcamss_video *video = video_get_drvdata(vdev);
> +
> +	media_entity_cleanup(&vdev->entity);
> +
> +	mutex_destroy(&video->q_lock);
> +	mutex_destroy(&video->lock);
> +}
> +
> +int stf_video_register(struct stfcamss_video *video,
> +		       struct v4l2_device *v4l2_dev, const char *name)
> +{
> +	struct video_device *vdev;
> +	struct vb2_queue *q;
> +	struct media_pad *pad = &video->pad;
> +	int ret;
> +
> +	vdev = &video->vdev;
> +
> +	mutex_init(&video->q_lock);
> +
> +	q = &video->vb2_q;
> +	q->drv_priv = video;
> +	q->mem_ops = &vb2_dma_contig_memops;
> +	q->ops = &stf_video_vb2_q_ops;
> +	q->type = video->type;
> +	q->io_modes = VB2_DMABUF | VB2_MMAP | VB2_READ;

VB2_READ support does not generally make sense for uncompressed video since
read() always requires a memcpy, and that makes it very inefficient.

It doesn't hurt though, so it is up to you whether or not you want this.

> +	q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> +	q->buf_struct_size = sizeof(struct stfcamss_buffer);
> +	q->dev = video->stfcamss->dev;
> +	q->lock = &video->q_lock;
> +	q->min_buffers_needed = STFCAMSS_MIN_BUFFERS;
> +	ret = vb2_queue_init(q);
> +	if (ret < 0) {
> +		dev_err(video->stfcamss->dev,
> +			"Failed to init vb2 queue: %d\n", ret);
> +		goto err_vb2_init;
> +	}
> +
> +	pad->flags = MEDIA_PAD_FL_SINK;
> +	ret = media_entity_pads_init(&vdev->entity, 1, pad);
> +	if (ret < 0) {
> +		dev_err(video->stfcamss->dev,
> +			"Failed to init video entity: %d\n", ret);
> +		goto err_vb2_init;
> +	}
> +
> +	mutex_init(&video->lock);
> +
> +	if (video->id == STF_V_LINE_WR) {
> +		video->formats = formats_pix_wr;
> +		video->nformats = ARRAY_SIZE(formats_pix_wr);
> +		video->bpl_alignment = 8;
> +	} else {
> +		video->formats = formats_pix_isp;
> +		video->nformats = ARRAY_SIZE(formats_pix_isp);
> +		video->bpl_alignment = 1;
> +	}
> +
> +	ret = stf_video_init_format(video);
> +	if (ret < 0) {
> +		dev_err(video->stfcamss->dev,
> +			"Failed to init format: %d\n", ret);
> +		goto err_vid_init_format;
> +	}
> +
> +	vdev->fops = &stf_vid_fops;
> +	vdev->ioctl_ops = &stf_vid_ioctl_ops;
> +	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE;
> +	vdev->vfl_dir = VFL_DIR_RX;
> +	vdev->device_caps |= V4L2_CAP_STREAMING | V4L2_CAP_READWRITE;
> +	vdev->release = stf_video_release;
> +	vdev->v4l2_dev = v4l2_dev;
> +	vdev->queue = &video->vb2_q;
> +	vdev->lock = &video->lock;
> +	strscpy(vdev->name, name, sizeof(vdev->name));
> +
> +	ret = video_register_device(vdev, VFL_TYPE_VIDEO, video->id);
> +	if (ret < 0) {
> +		dev_err(video->stfcamss->dev,
> +			"Failed to register video device: %d\n", ret);
> +		goto err_vid_reg;
> +	}
> +
> +	video_set_drvdata(vdev, video);
> +	return 0;
> +
> +err_vid_reg:
> +err_vid_init_format:
> +	media_entity_cleanup(&vdev->entity);
> +	mutex_destroy(&video->lock);
> +err_vb2_init:
> +	mutex_destroy(&video->q_lock);
> +	return ret;
> +}
> +
> +void stf_video_unregister(struct stfcamss_video *video)
> +{
> +	vb2_video_unregister_device(&video->vdev);
> +}
> diff --git a/drivers/media/platform/starfive/camss/stf_video.h b/drivers/media/platform/starfive/camss/stf_video.h
> new file mode 100644
> index 000000000000..60323c23a40c
> --- /dev/null
> +++ b/drivers/media/platform/starfive/camss/stf_video.h
> @@ -0,0 +1,92 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * stf_video.h
> + *
> + * StarFive Camera Subsystem - V4L2 device node
> + *
> + * Copyright (C) 2021-2023 StarFive Technology Co., Ltd.
> + */
> +
> +#ifndef STF_VIDEO_H
> +#define STF_VIDEO_H
> +
> +#include <linux/list.h>
> +#include <linux/mutex.h>
> +#include <linux/videodev2.h>
> +#include <media/v4l2-dev.h>
> +#include <media/v4l2-fh.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/videobuf2-v4l2.h>
> +
> +#define STFCAMSS_FRAME_MIN_WIDTH		64
> +#define STFCAMSS_FRAME_MAX_WIDTH		1920
> +#define STFCAMSS_FRAME_MIN_HEIGHT		64
> +#define STFCAMSS_FRAME_MAX_HEIGHT		1080
> +#define STFCAMSS_FRAME_WIDTH_ALIGN_8		8
> +#define STFCAMSS_FRAME_WIDTH_ALIGN_128		128
> +#define STFCAMSS_MIN_BUFFERS			2
> +
> +#define STFCAMSS_MAX_ENTITY_NAME_LEN		27
> +
> +enum stf_v_line_id {
> +	STF_V_LINE_WR = 0,
> +	STF_V_LINE_ISP,
> +	STF_V_LINE_MAX,
> +};
> +
> +struct stfcamss_buffer {
> +	struct vb2_v4l2_buffer vb;
> +	dma_addr_t addr[3];
> +	struct list_head queue;
> +};
> +
> +struct fract {
> +	u8 numerator;
> +	u8 denominator;
> +};
> +
> +/*
> + * struct stfcamss_format_info - ISP media bus format information
> + * @code: V4L2 media bus format code
> + * @pixelformat: V4L2 pixel format FCC identifier
> + * @planes: Number of planes
> + * @vsub: Vertical subsampling (for each plane)
> + * @bpp: Bits per pixel when stored in memory (for each plane)
> + */
> +struct stfcamss_format_info {
> +	u32 code;
> +	u32 pixelformat;
> +	u8 planes;
> +	u8 vsub[3];
> +	u8 bpp;
> +};
> +
> +struct stfcamss_video {
> +	struct stfcamss *stfcamss;
> +	u8 id;
> +	struct vb2_queue vb2_q;
> +	struct video_device vdev;
> +	struct media_pad pad;
> +	struct v4l2_format active_fmt;
> +	enum v4l2_buf_type type;
> +	const struct stfcamss_video_ops *ops;
> +	struct mutex lock;	 /* serialize device access */
> +	struct mutex q_lock;	 /* protects the queue */
> +	unsigned int bpl_alignment;
> +	const struct stfcamss_format_info *formats;
> +	unsigned int nformats;
> +};
> +
> +struct stfcamss_video_ops {
> +	int (*queue_buffer)(struct stfcamss_video *vid,
> +			    struct stfcamss_buffer *buf);
> +	int (*flush_buffers)(struct stfcamss_video *vid,
> +			     enum vb2_buffer_state state);
> +};
> +
> +int stf_video_register(struct stfcamss_video *video,
> +		       struct v4l2_device *v4l2_dev, const char *name);
> +
> +void stf_video_unregister(struct stfcamss_video *video);
> +
> +#endif /* STF_VIDEO_H */

Regards,

	Hans