media: via-camera: convert to the vb2 framework

Convert the via-camera to the vb2 framework. With this change this
driver passes all 'v4l2-compliance -s' tests on my OLPC 1.5.

Also tested with the Sugar 'Record' application.

All tests were done under the OLPC official 5.0.8 kernel.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Hans Verkuil 2019-07-28 10:43:41 -04:00 committed by Mauro Carvalho Chehab
parent 4e4f3b99b4
commit 4590c07462
2 changed files with 158 additions and 334 deletions

View file

@ -16,7 +16,7 @@ source "drivers/media/platform/marvell-ccic/Kconfig"
config VIDEO_VIA_CAMERA
tristate "VIAFB camera controller support"
depends on FB_VIA
select VIDEOBUF_DMA_SG
select VIDEOBUF2_DMA_SG
select VIDEO_OV7670
help
Driver support for the integrated camera controller in VIA

View file

@ -21,7 +21,7 @@
#include <media/v4l2-event.h>
#include <media/v4l2-image-sizes.h>
#include <media/i2c/ov7670.h>
#include <media/videobuf-dma-sg.h>
#include <media/videobuf2-dma-sg.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/pm_qos.h>
@ -85,16 +85,11 @@ struct via_camera {
* live in frame buffer memory, so we don't call them "DMA".
*/
unsigned int cb_offsets[3]; /* offsets into fb mem */
u8 __iomem *cb_addrs[3]; /* Kernel-space addresses */
u8 __iomem *cb_addrs[3]; /* Kernel-space addresses */
int n_cap_bufs; /* How many are we using? */
int next_buf;
struct videobuf_queue vb_queue;
struct list_head buffer_queue; /* prot. by reg_lock */
/*
* User tracking.
*/
int users;
struct file *owner;
struct vb2_queue vq;
struct list_head buffer_queue;
u32 sequence;
/*
* Video format information. sensor_format is kept in a form
* that we can use to pass to the sensor. We always run the
@ -107,6 +102,13 @@ struct via_camera {
u32 mbus_code;
};
/* buffer for one video frame */
struct via_buffer {
/* common v4l buffer stuff -- must be first */
struct vb2_v4l2_buffer vbuf;
struct list_head queue;
};
/*
* Yes, this is a hack, but there's only going to be one of these
* on any system we know of.
@ -323,28 +325,15 @@ static irqreturn_t viacam_quick_irq(int irq, void *data)
}
/*
* Find the next videobuf buffer which has somebody waiting on it.
* Find the next buffer which has somebody waiting on it.
*/
static struct videobuf_buffer *viacam_next_buffer(struct via_camera *cam)
static struct via_buffer *viacam_next_buffer(struct via_camera *cam)
{
unsigned long flags;
struct videobuf_buffer *buf = NULL;
spin_lock_irqsave(&cam->viadev->reg_lock, flags);
if (cam->opstate != S_RUNNING)
goto out;
return NULL;
if (list_empty(&cam->buffer_queue))
goto out;
buf = list_entry(cam->buffer_queue.next, struct videobuf_buffer, queue);
if (!waitqueue_active(&buf->done)) {/* Nobody waiting */
buf = NULL;
goto out;
}
list_del(&buf->queue);
buf->state = VIDEOBUF_ACTIVE;
out:
spin_unlock_irqrestore(&cam->viadev->reg_lock, flags);
return buf;
return NULL;
return list_entry(cam->buffer_queue.next, struct via_buffer, queue);
}
/*
@ -352,11 +341,12 @@ static struct videobuf_buffer *viacam_next_buffer(struct via_camera *cam)
*/
static irqreturn_t viacam_irq(int irq, void *data)
{
int bufn;
struct videobuf_buffer *vb;
struct via_camera *cam = data;
struct videobuf_dmabuf *vdma;
struct via_buffer *vb;
int bufn;
struct sg_table *sgt;
mutex_lock(&cam->lock);
/*
* If there is no place to put the data frame, don't bother
* with anything else.
@ -374,12 +364,15 @@ static irqreturn_t viacam_irq(int irq, void *data)
/*
* Copy over the data and let any waiters know.
*/
vdma = videobuf_to_dma(vb);
viafb_dma_copy_out_sg(cam->cb_offsets[bufn], vdma->sglist, vdma->sglen);
vb->state = VIDEOBUF_DONE;
vb->size = cam->user_format.sizeimage;
wake_up(&vb->done);
sgt = vb2_dma_sg_plane_desc(&vb->vbuf.vb2_buf, 0);
vb->vbuf.vb2_buf.timestamp = ktime_get_ns();
viafb_dma_copy_out_sg(cam->cb_offsets[bufn], sgt->sgl, sgt->nents);
vb->vbuf.sequence = cam->sequence++;
vb->vbuf.field = V4L2_FIELD_NONE;
list_del(&vb->queue);
vb2_buffer_done(&vb->vbuf.vb2_buf, VB2_BUF_STATE_DONE);
done:
mutex_unlock(&cam->lock);
return IRQ_HANDLED;
}
@ -555,7 +548,6 @@ static int viacam_config_controller(struct via_camera *cam)
static void viacam_start_engine(struct via_camera *cam)
{
spin_lock_irq(&cam->viadev->reg_lock);
cam->next_buf = 0;
viacam_write_reg_mask(cam, VCR_CAPINTC, VCR_CI_ENABLE, VCR_CI_ENABLE);
viacam_int_enable(cam);
(void) viacam_read_reg(cam, VCR_CAPINTC); /* Force post */
@ -576,81 +568,117 @@ static void viacam_stop_engine(struct via_camera *cam)
/* --------------------------------------------------------------------------*/
/* Videobuf callback ops */
/* vb2 callback ops */
/*
* buffer_setup. The purpose of this one would appear to be to tell
* videobuf how big a single image is. It's also evidently up to us
* to put some sort of limit on the maximum number of buffers allowed.
*/
static int viacam_vb_buf_setup(struct videobuf_queue *q,
unsigned int *count, unsigned int *size)
static struct via_buffer *vb2_to_via_buffer(struct vb2_buffer *vb)
{
struct via_camera *cam = q->priv_data;
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
*size = cam->user_format.sizeimage;
if (*count == 0 || *count > 6) /* Arbitrary number */
*count = 6;
return 0;
return container_of(vbuf, struct via_buffer, vbuf);
}
/*
* Prepare a buffer.
*/
static int viacam_vb_buf_prepare(struct videobuf_queue *q,
struct videobuf_buffer *vb, enum v4l2_field field)
static void viacam_vb2_queue(struct vb2_buffer *vb)
{
struct via_camera *cam = q->priv_data;
struct via_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
struct via_buffer *via = vb2_to_via_buffer(vb);
vb->size = cam->user_format.sizeimage;
vb->width = cam->user_format.width; /* bytesperline???? */
vb->height = cam->user_format.height;
vb->field = field;
if (vb->state == VIDEOBUF_NEEDS_INIT) {
int ret = videobuf_iolock(q, vb, NULL);
if (ret)
return ret;
list_add_tail(&via->queue, &cam->buffer_queue);
}
static int viacam_vb2_prepare(struct vb2_buffer *vb)
{
struct via_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
if (vb2_plane_size(vb, 0) < cam->user_format.sizeimage) {
cam_dbg(cam,
"Plane size too small (%lu < %u)\n",
vb2_plane_size(vb, 0),
cam->user_format.sizeimage);
return -EINVAL;
}
vb->state = VIDEOBUF_PREPARED;
vb2_set_plane_payload(vb, 0, cam->user_format.sizeimage);
return 0;
}
/*
* We've got a buffer to put data into.
*
* FIXME: check for a running engine and valid buffers?
*/
static void viacam_vb_buf_queue(struct videobuf_queue *q,
struct videobuf_buffer *vb)
static int viacam_vb2_queue_setup(struct vb2_queue *vq,
unsigned int *nbufs,
unsigned int *num_planes, unsigned int sizes[],
struct device *alloc_devs[])
{
struct via_camera *cam = q->priv_data;
struct via_camera *cam = vb2_get_drv_priv(vq);
int size = cam->user_format.sizeimage;
if (*num_planes)
return sizes[0] < size ? -EINVAL : 0;
*num_planes = 1;
sizes[0] = size;
return 0;
}
static int viacam_vb2_start_streaming(struct vb2_queue *vq, unsigned int count)
{
struct via_camera *cam = vb2_get_drv_priv(vq);
struct via_buffer *buf, *tmp;
int ret = 0;
if (cam->opstate != S_IDLE) {
ret = -EBUSY;
goto out;
}
/*
* Note that videobuf holds the lock when it calls
* us, so we need not (indeed, cannot) take it here.
* Configure things if need be.
*/
vb->state = VIDEOBUF_QUEUED;
list_add_tail(&vb->queue, &cam->buffer_queue);
if (test_bit(CF_CONFIG_NEEDED, &cam->flags)) {
ret = viacam_configure_sensor(cam);
if (ret)
goto out;
ret = viacam_config_controller(cam);
if (ret)
goto out;
}
cam->sequence = 0;
/*
* If the CPU goes into C3, the DMA transfer gets corrupted and
* users start filing unsightly bug reports. Put in a "latency"
* requirement which will keep the CPU out of the deeper sleep
* states.
*/
pm_qos_add_request(&cam->qos_request, PM_QOS_CPU_DMA_LATENCY, 50);
viacam_start_engine(cam);
return 0;
out:
list_for_each_entry_safe(buf, tmp, &cam->buffer_queue, queue) {
list_del(&buf->queue);
vb2_buffer_done(&buf->vbuf.vb2_buf, VB2_BUF_STATE_QUEUED);
}
return ret;
}
/*
* Free a buffer.
*/
static void viacam_vb_buf_release(struct videobuf_queue *q,
struct videobuf_buffer *vb)
static void viacam_vb2_stop_streaming(struct vb2_queue *vq)
{
struct via_camera *cam = q->priv_data;
struct via_camera *cam = vb2_get_drv_priv(vq);
struct via_buffer *buf, *tmp;
videobuf_dma_unmap(&cam->platdev->dev, videobuf_to_dma(vb));
videobuf_dma_free(videobuf_to_dma(vb));
vb->state = VIDEOBUF_NEEDS_INIT;
pm_qos_remove_request(&cam->qos_request);
viacam_stop_engine(cam);
list_for_each_entry_safe(buf, tmp, &cam->buffer_queue, queue) {
list_del(&buf->queue);
vb2_buffer_done(&buf->vbuf.vb2_buf, VB2_BUF_STATE_ERROR);
}
}
static const struct videobuf_queue_ops viacam_vb_ops = {
.buf_setup = viacam_vb_buf_setup,
.buf_prepare = viacam_vb_buf_prepare,
.buf_queue = viacam_vb_buf_queue,
.buf_release = viacam_vb_buf_release,
static const struct vb2_ops viacam_vb2_ops = {
.queue_setup = viacam_vb2_queue_setup,
.buf_queue = viacam_vb2_queue,
.buf_prepare = viacam_vb2_prepare,
.start_streaming = viacam_vb2_start_streaming,
.stop_streaming = viacam_vb2_stop_streaming,
.wait_prepare = vb2_ops_wait_prepare,
.wait_finish = vb2_ops_wait_finish,
};
/* --------------------------------------------------------------------------*/
@ -678,15 +706,7 @@ static int viacam_open(struct file *filp)
}
via_sensor_power_up(cam);
set_bit(CF_CONFIG_NEEDED, &cam->flags);
/*
* Hook into videobuf. Evidently this cannot fail.
*/
videobuf_queue_sg_init(&cam->vb_queue, &viacam_vb_ops,
&cam->platdev->dev, &cam->viadev->reg_lock,
V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FIELD_NONE,
sizeof(struct videobuf_buffer), cam, NULL);
}
(cam->users)++;
out:
mutex_unlock(&cam->lock);
return ret;
@ -698,108 +718,27 @@ static int viacam_release(struct file *filp)
bool last_open;
mutex_lock(&cam->lock);
(cam->users)--;
last_open = v4l2_fh_is_singular_file(filp);
/*
* If the "owner" is closing, shut down any ongoing
* operations.
*/
if (filp == cam->owner) {
videobuf_stop(&cam->vb_queue);
/*
* We don't hold the spinlock here, but, if release()
* is being called by the owner, nobody else will
* be changing the state. And an extra stop would
* not hurt anyway.
*/
if (cam->opstate != S_IDLE)
viacam_stop_engine(cam);
cam->owner = NULL;
}
_vb2_fop_release(filp, NULL);
/*
* Last one out needs to turn out the lights.
*/
if (last_open) {
videobuf_mmap_free(&cam->vb_queue);
via_sensor_power_down(cam);
viafb_release_dma();
}
v4l2_fh_release(filp);
mutex_unlock(&cam->lock);
return 0;
}
/*
* Read a frame from the device.
*/
static ssize_t viacam_read(struct file *filp, char __user *buffer,
size_t len, loff_t *pos)
{
struct via_camera *cam = video_drvdata(filp);
int ret;
mutex_lock(&cam->lock);
/*
* Enforce the V4l2 "only one owner gets to read data" rule.
*/
if (cam->owner && cam->owner != filp) {
ret = -EBUSY;
goto out_unlock;
}
cam->owner = filp;
/*
* Do we need to configure the hardware?
*/
if (test_bit(CF_CONFIG_NEEDED, &cam->flags)) {
ret = viacam_configure_sensor(cam);
if (!ret)
ret = viacam_config_controller(cam);
if (ret)
goto out_unlock;
}
/*
* Fire up the capture engine, then have videobuf do
* the heavy lifting. Someday it would be good to avoid
* stopping and restarting the engine each time.
*/
INIT_LIST_HEAD(&cam->buffer_queue);
viacam_start_engine(cam);
ret = videobuf_read_stream(&cam->vb_queue, buffer, len, pos, 0,
filp->f_flags & O_NONBLOCK);
viacam_stop_engine(cam);
/* videobuf_stop() ?? */
out_unlock:
mutex_unlock(&cam->lock);
return ret;
}
static __poll_t viacam_poll(struct file *filp, struct poll_table_struct *pt)
{
struct via_camera *cam = video_drvdata(filp);
return v4l2_ctrl_poll(filp, pt) | videobuf_poll_stream(filp, &cam->vb_queue, pt);
}
static int viacam_mmap(struct file *filp, struct vm_area_struct *vma)
{
struct via_camera *cam = video_drvdata(filp);
return videobuf_mmap_mapper(&cam->vb_queue, vma);
}
static const struct v4l2_file_operations viacam_fops = {
.owner = THIS_MODULE,
.open = viacam_open,
.release = viacam_release,
.read = viacam_read,
.poll = viacam_poll,
.mmap = viacam_mmap,
.unlocked_ioctl = video_ioctl2,
.read = vb2_fop_read,
.poll = vb2_fop_poll,
.mmap = vb2_fop_mmap,
.unlocked_ioctl = video_ioctl2,
};
/*----------------------------------------------------------------------------*/
@ -926,12 +865,8 @@ static int viacam_try_fmt_vid_cap(struct file *filp, void *priv,
{
struct via_camera *cam = video_drvdata(filp);
struct v4l2_format sfmt;
int ret;
mutex_lock(&cam->lock);
ret = viacam_do_try_fmt(cam, &fmt->fmt.pix, &sfmt.fmt.pix);
mutex_unlock(&cam->lock);
return ret;
return viacam_do_try_fmt(cam, &fmt->fmt.pix, &sfmt.fmt.pix);
}
@ -940,9 +875,7 @@ static int viacam_g_fmt_vid_cap(struct file *filp, void *priv,
{
struct via_camera *cam = video_drvdata(filp);
mutex_lock(&cam->lock);
fmt->fmt.pix = cam->user_format;
mutex_unlock(&cam->lock);
return 0;
}
@ -958,18 +891,15 @@ static int viacam_s_fmt_vid_cap(struct file *filp, void *priv,
* Camera must be idle or we can't mess with the
* video setup.
*/
mutex_lock(&cam->lock);
if (cam->opstate != S_IDLE) {
ret = -EBUSY;
goto out;
}
if (cam->opstate != S_IDLE)
return -EBUSY;
/*
* Let the sensor code look over and tweak the
* requested formatting.
*/
ret = viacam_do_try_fmt(cam, &fmt->fmt.pix, &sfmt.fmt.pix);
if (ret)
goto out;
return ret;
/*
* OK, let's commit to the new format.
*/
@ -979,8 +909,6 @@ static int viacam_s_fmt_vid_cap(struct file *filp, void *priv,
ret = viacam_configure_sensor(cam);
if (!ret)
ret = viacam_config_controller(cam);
out:
mutex_unlock(&cam->lock);
return ret;
}
@ -993,140 +921,22 @@ static int viacam_querycap(struct file *filp, void *priv,
return 0;
}
/*
* Streaming operations - pure videobuf stuff.
*/
static int viacam_reqbufs(struct file *filp, void *priv,
struct v4l2_requestbuffers *rb)
{
struct via_camera *cam = video_drvdata(filp);
return videobuf_reqbufs(&cam->vb_queue, rb);
}
static int viacam_querybuf(struct file *filp, void *priv,
struct v4l2_buffer *buf)
{
struct via_camera *cam = video_drvdata(filp);
return videobuf_querybuf(&cam->vb_queue, buf);
}
static int viacam_qbuf(struct file *filp, void *priv, struct v4l2_buffer *buf)
{
struct via_camera *cam = video_drvdata(filp);
return videobuf_qbuf(&cam->vb_queue, buf);
}
static int viacam_dqbuf(struct file *filp, void *priv, struct v4l2_buffer *buf)
{
struct via_camera *cam = video_drvdata(filp);
return videobuf_dqbuf(&cam->vb_queue, buf, filp->f_flags & O_NONBLOCK);
}
static int viacam_streamon(struct file *filp, void *priv, enum v4l2_buf_type t)
{
struct via_camera *cam = video_drvdata(filp);
int ret = 0;
if (t != V4L2_BUF_TYPE_VIDEO_CAPTURE)
return -EINVAL;
mutex_lock(&cam->lock);
if (cam->opstate != S_IDLE) {
ret = -EBUSY;
goto out;
}
/*
* Enforce the V4l2 "only one owner gets to read data" rule.
*/
if (cam->owner && cam->owner != filp) {
ret = -EBUSY;
goto out;
}
cam->owner = filp;
/*
* Configure things if need be.
*/
if (test_bit(CF_CONFIG_NEEDED, &cam->flags)) {
ret = viacam_configure_sensor(cam);
if (ret)
goto out;
ret = viacam_config_controller(cam);
if (ret)
goto out;
}
/*
* If the CPU goes into C3, the DMA transfer gets corrupted and
* users start filing unsightly bug reports. Put in a "latency"
* requirement which will keep the CPU out of the deeper sleep
* states.
*/
pm_qos_add_request(&cam->qos_request, PM_QOS_CPU_DMA_LATENCY, 50);
/*
* Fire things up.
*/
INIT_LIST_HEAD(&cam->buffer_queue);
ret = videobuf_streamon(&cam->vb_queue);
if (!ret)
viacam_start_engine(cam);
out:
mutex_unlock(&cam->lock);
return ret;
}
static int viacam_streamoff(struct file *filp, void *priv, enum v4l2_buf_type t)
{
struct via_camera *cam = video_drvdata(filp);
int ret;
if (t != V4L2_BUF_TYPE_VIDEO_CAPTURE)
return -EINVAL;
mutex_lock(&cam->lock);
if (cam->opstate != S_RUNNING) {
ret = -EINVAL;
goto out;
}
pm_qos_remove_request(&cam->qos_request);
viacam_stop_engine(cam);
/*
* Videobuf will recycle all of the outstanding buffers, but
* we should be sure we don't retain any references to
* any of them.
*/
ret = videobuf_streamoff(&cam->vb_queue);
INIT_LIST_HEAD(&cam->buffer_queue);
out:
mutex_unlock(&cam->lock);
return ret;
}
/* G/S_PARM */
static int viacam_g_parm(struct file *filp, void *priv,
struct v4l2_streamparm *parm)
{
struct via_camera *cam = video_drvdata(filp);
int ret;
mutex_lock(&cam->lock);
ret = v4l2_g_parm_cap(video_devdata(filp), cam->sensor, parm);
mutex_unlock(&cam->lock);
return ret;
return v4l2_g_parm_cap(video_devdata(filp), cam->sensor, parm);
}
static int viacam_s_parm(struct file *filp, void *priv,
struct v4l2_streamparm *parm)
{
struct via_camera *cam = video_drvdata(filp);
int ret;
mutex_lock(&cam->lock);
ret = v4l2_s_parm_cap(video_devdata(filp), cam->sensor, parm);
mutex_unlock(&cam->lock);
return ret;
return v4l2_s_parm_cap(video_devdata(filp), cam->sensor, parm);
}
static int viacam_enum_framesizes(struct file *filp, void *priv,
@ -1172,9 +982,7 @@ static int viacam_enum_frameintervals(struct file *filp, void *priv,
if (interval->width < QCIF_WIDTH || interval->width > VGA_WIDTH ||
interval->height < QCIF_HEIGHT || interval->height > VGA_HEIGHT)
return -EINVAL;
mutex_lock(&cam->lock);
ret = sensor_call(cam, pad, enum_frame_interval, NULL, &fie);
mutex_unlock(&cam->lock);
if (ret)
return ret;
interval->type = V4L2_FRMIVAL_TYPE_DISCRETE;
@ -1182,8 +990,6 @@ static int viacam_enum_frameintervals(struct file *filp, void *priv,
return 0;
}
static const struct v4l2_ioctl_ops viacam_ioctl_ops = {
.vidioc_enum_input = viacam_enum_input,
.vidioc_g_input = viacam_g_input,
@ -1193,12 +999,15 @@ static const struct v4l2_ioctl_ops viacam_ioctl_ops = {
.vidioc_g_fmt_vid_cap = viacam_g_fmt_vid_cap,
.vidioc_s_fmt_vid_cap = viacam_s_fmt_vid_cap,
.vidioc_querycap = viacam_querycap,
.vidioc_reqbufs = viacam_reqbufs,
.vidioc_querybuf = viacam_querybuf,
.vidioc_qbuf = viacam_qbuf,
.vidioc_dqbuf = viacam_dqbuf,
.vidioc_streamon = viacam_streamon,
.vidioc_streamoff = viacam_streamoff,
.vidioc_reqbufs = vb2_ioctl_reqbufs,
.vidioc_create_bufs = vb2_ioctl_create_bufs,
.vidioc_querybuf = vb2_ioctl_querybuf,
.vidioc_prepare_buf = vb2_ioctl_prepare_buf,
.vidioc_qbuf = vb2_ioctl_qbuf,
.vidioc_dqbuf = vb2_ioctl_dqbuf,
.vidioc_expbuf = vb2_ioctl_expbuf,
.vidioc_streamon = vb2_ioctl_streamon,
.vidioc_streamoff = vb2_ioctl_streamoff,
.vidioc_g_parm = viacam_g_parm,
.vidioc_s_parm = viacam_s_parm,
.vidioc_enum_framesizes = viacam_enum_framesizes,
@ -1242,7 +1051,7 @@ static int viacam_resume(void *priv)
/*
* Make sure the sensor's power state is correct
*/
if (cam->users > 0)
if (!list_empty(&cam->vdev.fh_list))
via_sensor_power_up(cam);
else
via_sensor_power_down(cam);
@ -1327,6 +1136,7 @@ static int viacam_probe(struct platform_device *pdev)
int ret;
struct i2c_adapter *sensor_adapter;
struct viafb_dev *viadev = pdev->dev.platform_data;
struct vb2_queue *vq;
struct i2c_board_info ov7670_info = {
.type = "ov7670",
.addr = 0x42 >> 1,
@ -1370,8 +1180,6 @@ static int viacam_probe(struct platform_device *pdev)
via_cam_info = cam;
cam->platdev = pdev;
cam->viadev = viadev;
cam->users = 0;
cam->owner = NULL;
cam->opstate = S_IDLE;
cam->user_format = cam->sensor_format = viacam_def_pix_format;
mutex_init(&cam->lock);
@ -1432,11 +1240,27 @@ static int viacam_probe(struct platform_device *pdev)
viacam_irq, IRQF_SHARED, "via-camera", cam);
if (ret)
goto out_power_down;
vq = &cam->vq;
vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
vq->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF | VB2_READ;
vq->drv_priv = cam;
vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
vq->buf_struct_size = sizeof(struct via_buffer);
vq->dev = cam->v4l2_dev.dev;
vq->ops = &viacam_vb2_ops;
vq->mem_ops = &vb2_dma_sg_memops;
vq->lock = &cam->lock;
ret = vb2_queue_init(vq);
/*
* Tell V4l2 that we exist.
*/
cam->vdev = viacam_v4l_template;
cam->vdev.v4l2_dev = &cam->v4l2_dev;
cam->vdev.lock = &cam->lock;
cam->vdev.queue = vq;
video_set_drvdata(&cam->vdev, cam);
ret = video_register_device(&cam->vdev, VFL_TYPE_GRABBER, -1);
if (ret)