path: root/drivers/media/v4l2-core/v4l2-mem2mem.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Memory-to-memory device framework for Video for Linux 2 and videobuf.
 *
 * Helper functions for devices that use videobuf buffers for both their
 * source and destination.
 *
 * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
 * Pawel Osciak, <pawel@osciak.com>
 * Marek Szyprowski, <m.szyprowski@samsung.com>
 */
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>

#include <media/media-device.h>
#include <media/videobuf2-v4l2.h>
#include <media/v4l2-mem2mem.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-device.h>
#include <media/v4l2-fh.h>
#include <media/v4l2-event.h>

MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
MODULE_AUTHOR("Pawel Osciak, <pawel@osciak.com>");
MODULE_LICENSE("GPL");

static bool debug;
module_param(debug, bool, 0644);

#define dprintk(fmt, arg...)						\
	do {								\
		if (debug)						\
			printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
	} while (0)


/* Instance is already queued on the job_queue */
#define TRANS_QUEUED		(1 << 0)
/* Instance is currently running in hardware */
#define TRANS_RUNNING		(1 << 1)
/* Instance is currently aborting */
#define TRANS_ABORT		(1 << 2)


/* Offset base for buffers on the destination queue - used to distinguish
 * between source and destination buffers when mmapping - they receive the same
 * offsets but for different queues */
#define DST_QUEUE_OFF_BASE	(1 << 30)

enum v4l2_m2m_entity_type {
	MEM2MEM_ENT_TYPE_SOURCE,
	MEM2MEM_ENT_TYPE_SINK,
	MEM2MEM_ENT_TYPE_PROC
};

static const char * const m2m_entity_name[] = {
	"source",
	"sink",
	"proc"
};

/**
 * struct v4l2_m2m_dev - per-device context
 * @source:		&struct media_entity pointer with the source entity
 *			Used only when the M2M device is registered via
 *			v4l2_m2m_unregister_media_controller().
 * @source_pad:		&struct media_pad with the source pad.
 *			Used only when the M2M device is registered via
 *			v4l2_m2m_unregister_media_controller().
 * @sink:		&struct media_entity pointer with the sink entity
 *			Used only when the M2M device is registered via
 *			v4l2_m2m_unregister_media_controller().
 * @sink_pad:		&struct media_pad with the sink pad.
 *			Used only when the M2M device is registered via
 *			v4l2_m2m_unregister_media_controller().
 * @proc:		&struct media_entity pointer with the M2M device itself.
 * @proc_pads:		&struct media_pad with the @proc pads.
 *			Used only when the M2M device is registered via
 *			v4l2_m2m_unregister_media_controller().
 * @intf_devnode:	&struct media_intf devnode pointer with the interface
 *			with controls the M2M device.
 * @curr_ctx:		currently running instance
 * @job_queue:		instances queued to run
 * @job_spinlock:	protects job_queue
 * @job_work:		worker to run queued jobs.
 * @m2m_ops:		driver callbacks
 */
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;

	const struct v4l2_m2m_ops *m2m_ops;
};

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)
{
	struct v4l2_m2m_queue_ctx *q_ctx;

	q_ctx = get_queue_ctx(m2m_ctx, type);
	if (!q_ctx)
		return NULL;

	return &q_ctx->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 <