.. SPDX-License-Identifier: GPL-2.0
-V4L2 File handlers
-------------------
+V4L2 File handles
+-----------------
struct v4l2_fh provides a way to easily keep file handle specific
data that is used by the V4L2 framework.
struct v4l2_fh is allocated as a part of the driver's own file handle
structure and ``file->private_data`` is set to it in the driver's ``open()``
-function by the driver.
+function by the driver. The :c:type:`v4l2_fh` file handle can be retrieved
+from the :c:type:`file` using :c:func:`file_to_v4l2_fh`. Drivers must not
+access ``file->private_data`` directly.
In many cases the struct v4l2_fh will be embedded in a larger
structure. In that case you should call:
int my_release(struct file *file)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct my_fh *my_fh = container_of(fh, struct my_fh, fh);
...
:c:func:`v4l2_fh_init <v4l2_fh_init>`
(:c:type:`fh <v4l2_fh>`, :c:type:`vdev <video_device>`)
-
- Initialise the file handle. This **MUST** be performed in the driver's
:c:type:`v4l2_file_operations`->open() handler.
-
:c:func:`v4l2_fh_add <v4l2_fh_add>`
(:c:type:`fh <v4l2_fh>`)
- Uninitialise the file handle. After uninitialisation the :c:type:`v4l2_fh`
memory can be freed.
+:c:func:`file_to_v4l2_fh <file_to_v4l2_fh>`
+(struct file \*filp)
+
+- Retrieve the :c:type:`v4l2_fh` instance associated with a :c:type:`file`.
If struct v4l2_fh is not embedded, then you can use these helper functions:
int my_release(struct file *file)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct my_fh *my_fh = container_of(fh, struct my_fh, fh);
...
res = vb2_core_poll(q, file, wait);
if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
poll_wait(file, &fh->wait, wait);
if (v4l2_event_pending(fh))
int cx18_v4l2_close(struct file *filp)
{
- struct v4l2_fh *fh = filp->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(filp);
struct cx18_open_id *id = fh2id(fh);
struct cx18 *cx = id->cx;
struct cx18_stream *s = &cx->streams[id->type];
int ivtv_v4l2_close(struct file *filp)
{
- struct v4l2_fh *fh = filp->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(filp);
struct ivtv_open_id *id = fh2id(fh);
struct ivtv *itv = id->itv;
struct ivtv_stream *s = &itv->streams[id->type];
static int allegro_ioctl_streamon(struct file *file, void *priv,
enum v4l2_buf_type type)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct allegro_channel *channel = fh_to_channel(fh);
int err;
static int mtk_jpeg_qbuf(struct file *file, void *priv, struct v4l2_buffer *buf)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct mtk_jpeg_ctx *ctx = mtk_jpeg_fh_to_ctx(priv);
struct vb2_queue *vq;
struct vb2_buffer *vb;
static int tegra_release(struct file *file)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct tegra_ctx *ctx = fh_to_tegra_ctx(fh);
struct tegra_vde *vde = ctx->vde;
static int mxc_jpeg_decoder_cmd(struct file *file, void *priv,
struct v4l2_decoder_cmd *cmd)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct mxc_jpeg_ctx *ctx = mxc_jpeg_fh_to_ctx(fh);
unsigned long flags;
int ret;
static int mxc_jpeg_encoder_cmd(struct file *file, void *priv,
struct v4l2_encoder_cmd *cmd)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct mxc_jpeg_ctx *ctx = mxc_jpeg_fh_to_ctx(fh);
unsigned long flags;
int ret;
static int histo_v4l2_querycap(struct file *file, void *fh,
struct v4l2_capability *cap)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
static int histo_v4l2_enum_format(struct file *file, void *fh,
struct v4l2_fmtdesc *f)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
if (f->index > 0 || f->type != histo->queue.type)
static int histo_v4l2_get_format(struct file *file, void *fh,
struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct vsp1_histogram *histo = vdev_to_histo(vfh->vdev);
struct v4l2_meta_format *meta = &format->fmt.meta;
static int
vsp1_video_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct vsp1_video *video = to_vsp1_video(vfh->vdev);
cap->capabilities = V4L2_CAP_DEVICE_CAPS | V4L2_CAP_STREAMING
static int vsp1_video_enum_format(struct file *file, void *fh,
struct v4l2_fmtdesc *f)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct vsp1_video *video = to_vsp1_video(vfh->vdev);
const struct vsp1_format_info *info;
static int
vsp1_video_get_format(struct file *file, void *fh, struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct vsp1_video *video = to_vsp1_video(vfh->vdev);
if (format->type != video->queue.type)
static int
vsp1_video_try_format(struct file *file, void *fh, struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct vsp1_video *video = to_vsp1_video(vfh->vdev);
if (format->type != video->queue.type)
static int
vsp1_video_set_format(struct file *file, void *fh, struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct vsp1_video *video = to_vsp1_video(vfh->vdev);
const struct vsp1_format_info *info;
int ret;
static int
vsp1_video_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct vsp1_video *video = to_vsp1_video(vfh->vdev);
struct media_device *mdev = &video->vsp1->media_dev;
struct vsp1_pipeline *pipe;
static int isp_video_release(struct file *file)
{
struct isp_video *video = video_drvdata(file);
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct isp_video_fh *handle = to_isp_video_fh(vfh);
/* Disable streaming and free the buffers queue resources. */
static int
xvip_dma_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct xvip_dma *dma = to_xvip_dma(vfh->vdev);
cap->capabilities = dma->xdev->v4l2_caps | V4L2_CAP_STREAMING |
static int
xvip_dma_enum_format(struct file *file, void *fh, struct v4l2_fmtdesc *f)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct xvip_dma *dma = to_xvip_dma(vfh->vdev);
if (f->index > 0)
static int
xvip_dma_get_format(struct file *file, void *fh, struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct xvip_dma *dma = to_xvip_dma(vfh->vdev);
format->fmt.pix = dma->format;
static int
xvip_dma_try_format(struct file *file, void *fh, struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct xvip_dma *dma = to_xvip_dma(vfh->vdev);
__xvip_dma_try_format(dma, &format->fmt.pix, NULL);
static int
xvip_dma_set_format(struct file *file, void *fh, struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct xvip_dma *dma = to_xvip_dma(vfh->vdev);
const struct xvip_video_format *info;
static int uvc_meta_v4l2_querycap(struct file *file, void *fh,
struct v4l2_capability *cap)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
struct uvc_video_chain *chain = stream->chain;
static int uvc_meta_v4l2_get_format(struct file *file, void *fh,
struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
struct v4l2_meta_format *fmt = &format->fmt.meta;
static int uvc_meta_v4l2_try_format(struct file *file, void *fh,
struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
struct uvc_device *dev = stream->dev;
struct v4l2_meta_format *fmt = &format->fmt.meta;
static int uvc_meta_v4l2_set_format(struct file *file, void *fh,
struct v4l2_format *format)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
struct v4l2_meta_format *fmt = &format->fmt.meta;
int ret;
static int uvc_meta_v4l2_enum_formats(struct file *file, void *fh,
struct v4l2_fmtdesc *fdesc)
{
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct uvc_streaming *stream = video_get_drvdata(vfh->vdev);
struct uvc_device *dev = stream->dev;
u32 i = fdesc->index;
int v4l2_ctrl_log_status(struct file *file, void *fh)
{
struct video_device *vfd = video_devdata(file);
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) && vfd->v4l2_dev)
v4l2_ctrl_handler_log_status(vfh->ctrl_handler,
*/
__poll_t v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
poll_wait(file, &fh->wait, wait);
if (v4l2_event_pending(fh))
int v4l2_fh_release(struct file *filp)
{
- struct v4l2_fh *fh = filp->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(filp);
if (fh) {
v4l2_fh_del(fh);
rc = v4l2_m2m_poll_for_data(file, m2m_ctx, wait);
if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
poll_wait(file, &fh->wait, wait);
if (v4l2_event_pending(fh))
unsigned long len, unsigned long pgoff,
unsigned long flags)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
unsigned long offset = pgoff << PAGE_SHIFT;
struct vb2_queue *vq;
int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
struct v4l2_requestbuffers *rb)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_reqbufs(file, fh->m2m_ctx, rb);
}
int v4l2_m2m_ioctl_create_bufs(struct file *file, void *priv,
struct v4l2_create_buffers *create)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_create_bufs(file, fh->m2m_ctx, create);
}
int v4l2_m2m_ioctl_remove_bufs(struct file *file, void *priv,
struct v4l2_remove_buffers *remove)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct vb2_queue *q = v4l2_m2m_get_vq(fh->m2m_ctx, remove->type);
if (!q)
int v4l2_m2m_ioctl_querybuf(struct file *file, void *priv,
struct v4l2_buffer *buf)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_querybuf(file, fh->m2m_ctx, buf);
}
int v4l2_m2m_ioctl_qbuf(struct file *file, void *priv,
struct v4l2_buffer *buf)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_qbuf(file, fh->m2m_ctx, buf);
}
int v4l2_m2m_ioctl_dqbuf(struct file *file, void *priv,
struct v4l2_buffer *buf)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_dqbuf(file, fh->m2m_ctx, buf);
}
int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *priv,
struct v4l2_buffer *buf)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_prepare_buf(file, fh->m2m_ctx, buf);
}
int v4l2_m2m_ioctl_expbuf(struct file *file, void *priv,
struct v4l2_exportbuffer *eb)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_expbuf(file, fh->m2m_ctx, eb);
}
int v4l2_m2m_ioctl_streamon(struct file *file, void *priv,
enum v4l2_buf_type type)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_streamon(file, fh->m2m_ctx, type);
}
int v4l2_m2m_ioctl_streamoff(struct file *file, void *priv,
enum v4l2_buf_type type)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_streamoff(file, fh->m2m_ctx, type);
}
int v4l2_m2m_ioctl_encoder_cmd(struct file *file, void *priv,
struct v4l2_encoder_cmd *ec)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_encoder_cmd(file, fh->m2m_ctx, ec);
}
int v4l2_m2m_ioctl_decoder_cmd(struct file *file, void *priv,
struct v4l2_decoder_cmd *dc)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_decoder_cmd(file, fh->m2m_ctx, dc);
}
int v4l2_m2m_ioctl_stateless_decoder_cmd(struct file *file, void *priv,
struct v4l2_decoder_cmd *dc)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct vb2_v4l2_buffer *out_vb, *cap_vb;
struct v4l2_m2m_dev *m2m_dev = fh->m2m_ctx->m2m_dev;
unsigned long flags;
int v4l2_m2m_fop_mmap(struct file *file, struct vm_area_struct *vma)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
return v4l2_m2m_mmap(file, fh->m2m_ctx, vma);
}
__poll_t v4l2_m2m_fop_poll(struct file *file, poll_table *wait)
{
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
struct v4l2_m2m_ctx *m2m_ctx = fh->m2m_ctx;
__poll_t ret;
{
struct video_device *vdev = video_devdata(file);
struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh);
if (sd->internal_ops && sd->internal_ops->close)
{
struct video_device *vdev = video_devdata(file);
struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh);
bool ro_subdev = test_bit(V4L2_FL_SUBDEV_RO_DEVNODE, &vdev->flags);
bool streams_subdev = sd->flags & V4L2_SUBDEV_FL_STREAMS;
if (video_is_registered(vdev)) {
struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
- struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_fh *vfh = file_to_v4l2_fh(file);
struct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh);
struct v4l2_subdev_state *state;
{
struct video_device *vdev = video_devdata(file);
struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
- struct v4l2_fh *fh = file->private_data;
+ struct v4l2_fh *fh = file_to_v4l2_fh(file);
if (!(sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS))
return EPOLLERR;
struct v4l2_m2m_ctx *m2m_ctx;
};
+/**
+ * file_to_v4l2_fh - Return the v4l2_fh associated with a struct file
+ *
+ * @filp: pointer to &struct file
+ *
+ * This function should be used by drivers to retrieve the &struct v4l2_fh
+ * instance pointer stored in the file private_data instead of accessing the
+ * private_data field directly.
+ */
+static inline struct v4l2_fh *file_to_v4l2_fh(struct file *filp)
+{
+ return filp->private_data;
+}
+
/**
* v4l2_fh_init - Initialise the file handle.
*