drivers/media/test-drivers/vivid/vivid-vid-cap.c
Source file repositories/reference/linux-study-clean/drivers/media/test-drivers/vivid/vivid-vid-cap.c
File Facts
- System
- Linux kernel
- Corpus path
drivers/media/test-drivers/vivid/vivid-vid-cap.c- Extension
.c- Size
- 49683 bytes
- Lines
- 1771
- Domain
- Driver Families
- Bucket
- drivers/media
- Inferred role
- Driver Families: implementation source
- Status
- source implementation candidate
Why This File Exists
Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
- Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
- Allocates kernel memory; connect allocation flags and lifetime to context constraints.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/errno.hlinux/kernel.hlinux/sched.hlinux/vmalloc.hlinux/videodev2.hlinux/prandom.hlinux/v4l2-dv-timings.hmedia/v4l2-common.hmedia/v4l2-event.hmedia/v4l2-dv-timings.hmedia/v4l2-rect.hvivid-core.hvivid-vid-common.hvivid-kthread-cap.hvivid-vid-cap.h
Detected Declarations
function webcam_ival_countfunction vid_cap_queue_setupfunction vid_cap_buf_preparefunction vid_cap_buf_finishfunction vid_cap_buf_queuefunction vid_cap_start_streamingfunction list_for_each_entry_safefunction vid_cap_stop_streamingfunction vid_cap_buf_request_completefunction vivid_update_qualityfunction VIVID_INVALID_SIGNALfunction VIVID_INVALID_SIGNALfunction vivid_get_qualityfunction vivid_get_video_aspectfunction vivid_get_pixel_aspectfunction vivid_update_reduced_fpsfunction vivid_update_format_capfunction vivid_field_capfunction vivid_colorspace_capfunction vivid_xfer_func_capfunction vivid_ycbcr_enc_capfunction vivid_hsv_enc_capfunction vivid_quantization_capfunction vivid_g_fmt_vid_capfunction vivid_try_fmt_vid_capfunction vivid_s_fmt_vid_capfunction vidioc_g_fmt_vid_cap_mplanefunction vidioc_try_fmt_vid_cap_mplanefunction vidioc_s_fmt_vid_cap_mplanefunction vidioc_g_fmt_vid_capfunction vidioc_try_fmt_vid_capfunction vidioc_s_fmt_vid_capfunction vivid_vid_cap_g_selectionfunction vivid_vid_cap_s_selectionfunction vivid_vid_cap_g_pixelaspectfunction vidioc_enum_inputfunction vidioc_g_inputfunction vidioc_s_inputfunction vidioc_enumaudiofunction vidioc_g_audiofunction vidioc_s_audiofunction vivid_video_g_frequencyfunction vivid_video_s_frequencyfunction vivid_video_s_tunerfunction vivid_video_g_tunerfunction vidioc_querystdfunction vivid_vid_cap_s_stdfunction find_aspect_ratio
Annotated Snippet
if (vb2_plane_size(vb, p) < size) {
dprintk(dev, 1, "%s data will not fit into plane %u (%lu < %lu)\n",
__func__, p, vb2_plane_size(vb, p), size);
return -EINVAL;
}
vb2_set_plane_payload(vb, p, size);
vb->planes[p].data_offset = dev->fmt_cap->data_offset[p];
}
return 0;
}
static void vid_cap_buf_finish(struct vb2_buffer *vb)
{
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
struct v4l2_timecode *tc = &vbuf->timecode;
unsigned fps = 25;
unsigned seq = vbuf->sequence;
if (!vivid_is_sdtv_cap(dev))
return;
/*
* Set the timecode. Rarely used, so it is interesting to
* test this.
*/
vbuf->flags |= V4L2_BUF_FLAG_TIMECODE;
if (dev->std_cap[dev->input] & V4L2_STD_525_60)
fps = 30;
tc->type = (fps == 30) ? V4L2_TC_TYPE_30FPS : V4L2_TC_TYPE_25FPS;
tc->flags = 0;
tc->frames = seq % fps;
tc->seconds = (seq / fps) % 60;
tc->minutes = (seq / (60 * fps)) % 60;
tc->hours = (seq / (60 * 60 * fps)) % 24;
}
static void vid_cap_buf_queue(struct vb2_buffer *vb)
{
struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
struct vivid_buffer *buf = container_of(vbuf, struct vivid_buffer, vb);
dprintk(dev, 1, "%s\n", __func__);
spin_lock(&dev->slock);
list_add_tail(&buf->list, &dev->vid_cap_active);
spin_unlock(&dev->slock);
}
static int vid_cap_start_streaming(struct vb2_queue *vq, unsigned count)
{
struct vivid_dev *dev = vb2_get_drv_priv(vq);
unsigned i;
int err;
dev->vid_cap_seq_count = 0;
dprintk(dev, 1, "%s\n", __func__);
for (i = 0; i < MAX_VID_CAP_BUFFERS; i++)
dev->must_blank[i] = tpg_g_perc_fill(&dev->tpg) < 100;
if (dev->start_streaming_error) {
dev->start_streaming_error = false;
err = -EINVAL;
} else {
err = vivid_start_generating_vid_cap(dev, &dev->vid_cap_streaming);
}
if (err) {
struct vivid_buffer *buf, *tmp;
list_for_each_entry_safe(buf, tmp, &dev->vid_cap_active, list) {
list_del(&buf->list);
vb2_buffer_done(&buf->vb.vb2_buf,
VB2_BUF_STATE_QUEUED);
}
}
return err;
}
/* abort streaming and wait for last buffer */
static void vid_cap_stop_streaming(struct vb2_queue *vq)
{
struct vivid_dev *dev = vb2_get_drv_priv(vq);
dprintk(dev, 1, "%s\n", __func__);
vivid_stop_generating_vid_cap(dev, &dev->vid_cap_streaming);
}
static void vid_cap_buf_request_complete(struct vb2_buffer *vb)
Annotation
- Immediate include surface: `linux/errno.h`, `linux/kernel.h`, `linux/sched.h`, `linux/vmalloc.h`, `linux/videodev2.h`, `linux/prandom.h`, `linux/v4l2-dv-timings.h`, `media/v4l2-common.h`.
- Detected declarations: `function webcam_ival_count`, `function vid_cap_queue_setup`, `function vid_cap_buf_prepare`, `function vid_cap_buf_finish`, `function vid_cap_buf_queue`, `function vid_cap_start_streaming`, `function list_for_each_entry_safe`, `function vid_cap_stop_streaming`, `function vid_cap_buf_request_complete`, `function vivid_update_quality`.
- Atlas domain: Driver Families / drivers/media.
- Implementation status: source implementation candidate.
- Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
- IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.