drivers/media/test-drivers/vivid/vivid-meta-out.c

Source file repositories/reference/linux-study-clean/drivers/media/test-drivers/vivid/vivid-meta-out.c

File Facts

System
Linux kernel
Corpus path
drivers/media/test-drivers/vivid/vivid-meta-out.c
Extension
.c
Size
4381 bytes
Lines
171
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.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * vivid-meta-out.c - meta output support functions.
 */

#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/videodev2.h>
#include <media/v4l2-common.h>
#include <linux/usb/video.h>

#include "vivid-core.h"
#include "vivid-kthread-out.h"
#include "vivid-meta-out.h"

static int meta_out_queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
				unsigned int *nplanes, unsigned int sizes[],
				struct device *alloc_devs[])
{
	struct vivid_dev *dev = vb2_get_drv_priv(vq);
	unsigned int size =  sizeof(struct vivid_meta_out_buf);

	if (!vivid_is_webcam(dev))
		return -EINVAL;

	if (*nplanes) {
		if (sizes[0] < size)
			return -EINVAL;
	} else {
		sizes[0] = size;
	}

	*nplanes = 1;
	return 0;
}

static int meta_out_buf_prepare(struct vb2_buffer *vb)
{
	struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
	unsigned int size = sizeof(struct vivid_meta_out_buf);

	dprintk(dev, 1, "%s\n", __func__);

	if (dev->buf_prepare_error) {
		/*
		 * Error injection: test what happens if buf_prepare() returns
		 * an error.
		 */
		dev->buf_prepare_error = false;
		return -EINVAL;
	}
	if (vb2_plane_size(vb, 0) < size) {
		dprintk(dev, 1, "%s data will not fit into plane (%lu < %u)\n",
			__func__, vb2_plane_size(vb, 0), size);
		return -EINVAL;
	}
	vb2_set_plane_payload(vb, 0, size);

	return 0;
}

static void meta_out_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->meta_out_active);
	spin_unlock(&dev->slock);
}

static int meta_out_start_streaming(struct vb2_queue *vq, unsigned int count)
{
	struct vivid_dev *dev = vb2_get_drv_priv(vq);
	int err;

	dprintk(dev, 1, "%s\n", __func__);
	dev->meta_out_seq_count = 0;
	if (dev->start_streaming_error) {
		dev->start_streaming_error = false;
		err = -EINVAL;
	} else {
		err = vivid_start_generating_vid_out(dev,
						     &dev->meta_out_streaming);
	}
	if (err) {
		struct vivid_buffer *buf, *tmp;

Annotation

Implementation Notes