diff mbox series

[v10,4/8] media: staging: media: starfive: camss: Add video driver

Message ID 20231008085154.6757-5-jack.zhu@starfivetech.com
State Accepted
Commit b7eedc7d2b9465f8c302cfd7749176bae3f1eddd
Headers show
Series Add StarFive Camera Subsystem driver | expand

Commit Message

Jack Zhu Oct. 8, 2023, 8:51 a.m. UTC
Add video driver for StarFive Camera Subsystem.

Signed-off-by: Jack Zhu <jack.zhu@starfivetech.com>
---
 drivers/staging/media/starfive/camss/Makefile |   3 +-
 .../staging/media/starfive/camss/stf-video.c  | 572 ++++++++++++++++++
 .../staging/media/starfive/camss/stf-video.h  | 100 +++
 3 files changed, 674 insertions(+), 1 deletion(-)
 create mode 100644 drivers/staging/media/starfive/camss/stf-video.c
 create mode 100644 drivers/staging/media/starfive/camss/stf-video.h
diff mbox series

Patch

diff --git a/drivers/staging/media/starfive/camss/Makefile b/drivers/staging/media/starfive/camss/Makefile
index 78211e30550f..7d320b9317c8 100644
--- a/drivers/staging/media/starfive/camss/Makefile
+++ b/drivers/staging/media/starfive/camss/Makefile
@@ -4,6 +4,7 @@ 
 #
 
 starfive-camss-objs += \
-		stf-camss.o
+		stf-camss.o \
+		stf-video.o
 
 obj-$(CONFIG_VIDEO_STARFIVE_CAMSS) += starfive-camss.o
diff --git a/drivers/staging/media/starfive/camss/stf-video.c b/drivers/staging/media/starfive/camss/stf-video.c
new file mode 100644
index 000000000000..0b305f21eb53
--- /dev/null
+++ b/drivers/staging/media/starfive/camss/stf-video.c
@@ -0,0 +1,572 @@ 
+// 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"
+
+/* -----------------------------------------------------------------------------
+ * Helper functions
+ */
+
+static inline struct stfcamss_buffer *
+to_stfcamss_buffer(struct vb2_v4l2_buffer *vbuf)
+{
+	return container_of(vbuf, struct stfcamss_buffer, vb);
+}
+
+static const struct stfcamss_format_info *
+video_g_fi_by_index(struct stfcamss_video *video, int index)
+{
+	if (index >= video->nformats)
+		return NULL;
+
+	return &video->formats[index];
+}
+
+static const struct stfcamss_format_info *
+video_g_fi_by_mcode(struct stfcamss_video *video, u32 mcode)
+{
+	unsigned int i;
+
+	for (i = 0; i < video->nformats; i++) {
+		if (video->formats[i].code == mcode)
+			return &video->formats[i];
+	}
+
+	return NULL;
+}
+
+static const struct stfcamss_format_info *
+video_g_fi_by_pfmt(struct stfcamss_video *video, u32 pixelformat)
+{
+	unsigned int i;
+
+	for (i = 0; i < video->nformats; i++) {
+		if (video->formats[i].pixelformat == pixelformat)
+			return &video->formats[i];
+	}
+
+	return NULL;
+}
+
+static int __video_try_fmt(struct stfcamss_video *video, struct v4l2_format *f)
+{
+	struct v4l2_pix_format *pix = &f->fmt.pix;
+	const struct stfcamss_format_info *fi;
+	u32 width, height;
+	u32 bpl;
+	unsigned int i;
+
+	fi = video_g_fi_by_pfmt(video, pix->pixelformat);
+	if (!fi)
+		fi = &video->formats[0]; /* default format */
+
+	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_NV12,
+		},
+	};
+
+	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;
+	} else {
+		*num_planes = 1;
+		sizes[0] = format->sizeimage;
+	}
+
+	if (!sizes[0]) {
+		dev_dbg(video->stfcamss->dev,
+			"%s: error size is zero.\n", __func__);
+		return -EINVAL;
+	}
+
+	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 = to_stfcamss_buffer(vbuf);
+	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)
+		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_dbg(video->stfcamss->dev,
+			"sizeimage = %u, plane size = %u\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 = to_stfcamss_buffer(vbuf);
+
+	video->ops->queue_buffer(video, buffer);
+}
+
+static int video_get_subdev_format(struct stfcamss_video *video,
+				   struct v4l2_subdev_format *fmt)
+{
+	struct v4l2_subdev *subdev;
+	struct media_pad *pad;
+	struct media_entity *entity;
+	int ret;
+
+	entity = &video->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);
+
+		fmt->pad = pad->index;
+
+		ret = v4l2_subdev_call_state_active(subdev, pad, get_fmt, fmt);
+		if (ret < 0 && ret != -ENOIOCTLCMD)
+			return ret;
+		else if (!ret)
+			break;
+	}
+
+	return 0;
+}
+
+static int stf_video_check_format(struct stfcamss_video *video)
+{
+	struct v4l2_pix_format *pix = &video->active_fmt.fmt.pix;
+	const struct stfcamss_format_info *fi;
+	int ret;
+	struct v4l2_subdev_format sd_fmt = {
+		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
+	};
+
+	ret = video_get_subdev_format(video, &sd_fmt);
+	if (ret < 0)
+		return ret;
+
+	fi = video_g_fi_by_mcode(video, sd_fmt.format.code);
+	if (!fi)
+		return -EINVAL;
+
+	if (pix->pixelformat != fi->pixelformat ||
+	    pix->height != sd_fmt.format.height ||
+	    pix->width != sd_fmt.format.width ||
+	    pix->field != sd_fmt.format.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;
+	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);
+		goto err_ret_buffers;
+	}
+
+	ret = pm_runtime_resume_and_get(video->stfcamss->dev);
+	if (ret < 0) {
+		dev_err(video->stfcamss->dev, "power up failed %d\n", ret);
+		goto err_pipeline_stop;
+	}
+
+	video->ops->start_streaming(video);
+
+	ret = v4l2_subdev_call(video->source_subdev, video, s_stream, true);
+	if (ret) {
+		dev_err(video->stfcamss->dev, "stream on failed\n");
+		goto err_pm_put;
+	}
+
+	return 0;
+
+err_pm_put:
+	pm_runtime_put(video->stfcamss->dev);
+err_pipeline_stop:
+	video_device_pipeline_stop(vdev);
+err_ret_buffers:
+	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;
+
+	video->ops->stop_streaming(video);
+
+	v4l2_subdev_call(video->source_subdev, video, s_stream, false);
+
+	pm_runtime_put(video->stfcamss->dev);
+
+	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, "starfive-camss", sizeof(cap->driver));
+	strscpy(cap->card, "Starfive Camera Subsystem", sizeof(cap->card));
+
+	return 0;
+}
+
+static int video_enum_fmt(struct file *file, void *fh, struct v4l2_fmtdesc *f)
+{
+	struct stfcamss_video *video = video_drvdata(file);
+	const struct stfcamss_format_info *fi;
+
+	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;
+
+		fi = video_g_fi_by_mcode(video, f->mbus_code);
+	} else {
+		fi = video_g_fi_by_index(video, f->index);
+	}
+
+	if (!fi)
+		return -EINVAL;
+
+	f->pixelformat = fi->pixelformat;
+
+	return 0;
+}
+
+static int video_enum_framesizes(struct file *file, void *fh,
+				 struct v4l2_frmsizeenum *fsize)
+{
+	struct stfcamss_video *video = video_drvdata(file);
+	unsigned 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_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_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 int stf_link_validate(struct media_link *link)
+{
+	struct video_device *vdev =
+		media_entity_to_video_device(link->sink->entity);
+	struct stfcamss_video *video = video_get_drvdata(vdev);
+	int ret;
+
+	ret = stf_video_check_format(video);
+
+	return ret;
+}
+
+static const struct media_entity_operations stf_media_ops = {
+	.link_validate = stf_link_validate,
+};
+
+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 = &video->vdev;
+	struct vb2_queue *q;
+	struct media_pad *pad = &video->pad;
+	int ret;
+
+	mutex_init(&video->q_lock);
+	mutex_init(&video->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;
+	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_mutex_destroy;
+	}
+
+	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_mutex_destroy;
+	}
+
+	ret = stf_video_init_format(video);
+	if (ret < 0) {
+		dev_err(video->stfcamss->dev,
+			"Failed to init format: %d\n", ret);
+		goto err_media_cleanup;
+	}
+
+	vdev->fops = &stf_vid_fops;
+	vdev->ioctl_ops = &stf_vid_ioctl_ops;
+	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
+	vdev->entity.ops = &stf_media_ops;
+	vdev->vfl_dir = VFL_DIR_RX;
+	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));
+
+	video_set_drvdata(vdev, video);
+
+	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
+	if (ret < 0) {
+		dev_err(video->stfcamss->dev,
+			"Failed to register video device: %d\n", ret);
+		goto err_media_cleanup;
+	}
+
+	return 0;
+
+err_media_cleanup:
+	media_entity_cleanup(&vdev->entity);
+err_mutex_destroy:
+	mutex_destroy(&video->lock);
+	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/staging/media/starfive/camss/stf-video.h b/drivers/staging/media/starfive/camss/stf-video.h
new file mode 100644
index 000000000000..8052b77e3ad8
--- /dev/null
+++ b/drivers/staging/media/starfive/camss/stf-video.h
@@ -0,0 +1,100 @@ 
+/* 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,
+};
+
+enum stf_capture_type {
+	STF_CAPTURE_RAW = 0,
+	STF_CAPTURE_YUV,
+	STF_CAPTURE_NUM,
+};
+
+struct stfcamss_buffer {
+	struct vb2_v4l2_buffer vb;
+	dma_addr_t addr[2];
+	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;
+	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 v4l2_subdev *source_subdev;
+};
+
+struct stfcamss_video_ops {
+	int (*queue_buffer)(struct stfcamss_video *video,
+			    struct stfcamss_buffer *buf);
+	int (*flush_buffers)(struct stfcamss_video *video,
+			     enum vb2_buffer_state state);
+	void (*start_streaming)(struct stfcamss_video *video);
+	void (*stop_streaming)(struct stfcamss_video *video);
+};
+
+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 */