drivers/media/v4l2-core/v4l2-mem2mem.c

Source file repositories/reference/linux-study-clean/drivers/media/v4l2-core/v4l2-mem2mem.c

File Facts

System
Linux kernel
Corpus path
drivers/media/v4l2-core/v4l2-mem2mem.c
Extension
.c
Size
45138 bytes
Lines
1644
Domain
Driver Families
Bucket
drivers/media
Inferred role
Driver Families: exported/initcall integration point
Status
integration 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

struct v4l2_m2m_dev {
	struct v4l2_m2m_ctx	*curr_ctx;
#ifdef CONFIG_MEDIA_CONTROLLER
	struct media_entity	*source;
	struct media_pad	source_pad;
	struct media_entity	sink;
	struct media_pad	sink_pad;
	struct media_entity	proc;
	struct media_pad	proc_pads[2];
	struct media_intf_devnode *intf_devnode;
#endif

	struct list_head	job_queue;
	spinlock_t		job_spinlock;
	struct work_struct	job_work;
	unsigned long		job_queue_flags;

	const struct v4l2_m2m_ops *m2m_ops;

	struct kref kref;
};

static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
						enum v4l2_buf_type type)
{
	if (V4L2_TYPE_IS_OUTPUT(type))
		return &m2m_ctx->out_q_ctx;
	else
		return &m2m_ctx->cap_q_ctx;
}

struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
				       enum v4l2_buf_type type)
{
	return &get_queue_ctx(m2m_ctx, type)->q;
}
EXPORT_SYMBOL(v4l2_m2m_get_vq);

struct vb2_v4l2_buffer *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
{
	struct v4l2_m2m_buffer *b;
	unsigned long flags;

	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);

	if (list_empty(&q_ctx->rdy_queue)) {
		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
		return NULL;
	}

	b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
	return &b->vb;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);

struct vb2_v4l2_buffer *v4l2_m2m_last_buf(struct v4l2_m2m_queue_ctx *q_ctx)
{
	struct v4l2_m2m_buffer *b;
	unsigned long flags;

	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);

	if (list_empty(&q_ctx->rdy_queue)) {
		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
		return NULL;
	}

	b = list_last_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
	return &b->vb;
}
EXPORT_SYMBOL_GPL(v4l2_m2m_last_buf);

struct vb2_v4l2_buffer *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
{
	struct v4l2_m2m_buffer *b;
	unsigned long flags;

	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
	if (list_empty(&q_ctx->rdy_queue)) {
		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
		return NULL;
	}
	b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
	list_del(&b->list);
	q_ctx->num_rdy--;
	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);

	return &b->vb;

Annotation

Implementation Notes