/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * daedalus-v4l2 — kernel-internal device/state declarations.
 *
 * Shared between daedalus_v4l2_main.c (V4L2 m2m driver) and
 * daedalus_v4l2_chardev.c (kernel↔daemon bridge).  The chardev
 * needs to look up in-flight V4L2 requests by cookie to complete
 * the m2m job when RESP_FRAME arrives — that path lives in
 * daedalus_complete_resp_frame().
 */
#ifndef DAEDALUS_V4L2_MAIN_H
#define DAEDALUS_V4L2_MAIN_H

#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>

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

#include "daedalus_v4l2_proto.h"

/**
 * struct daedalus_dev - top-level device state (singleton for now)
 * @pdev:		owning platform device (synthesised in module_init)
 * @v4l2_dev:		V4L2 device parent for any video_device we register
 * @vdev:		video_device exposed as /dev/videoNN
 * @m2m_dev:		mem2mem device shared by all per-open contexts
 * @m2m_lock:		serialises vb2 queue + v4l2 ioctl ops
 * @inflight:		list of struct daedalus_inflight (REQ_DECODE sent,
 *			RESP_FRAME not yet returned)
 * @inflight_lock:	protects @inflight
 *
 * Singleton per-module instance.  Multi-instance support (one
 * decoder per /dev/videoNN) would require breaking g_daedalus_dev
 * out of daedalus_v4l2_main.c; not needed yet.
 */
struct daedalus_dev {
	struct platform_device		*pdev;
	struct v4l2_device		v4l2_dev;
	struct video_device		vdev;
	struct v4l2_m2m_dev		*m2m_dev;
	struct mutex			m2m_lock;
	struct list_head		inflight;
	struct mutex			inflight_lock;
};

/* Module-wide singleton accessor (chardev needs this for RESP_FRAME). */
struct daedalus_dev *daedalus_get_dev(void);

/**
 * daedalus_complete_resp_frame() - chardev RESP_FRAME completion
 * @cookie:	cookie carried by the matching REQ_DECODE
 * @fr:		RESP_FRAME header from the daemon
 * @pixels:	inline pixel bytes following the header in the
 *		chardev payload (may be NULL if @pixels_len == 0)
 * @pixels_len:	number of inline pixel bytes
 *
 * Called from the chardev write() path on RESP_FRAME.  Looks up
 * the in-flight request, copies inline pixel data into the
 * CAPTURE vb2 buffer if available, then completes both src+dst
 * buffers and finishes the m2m job.  Silently drops responses
 * for unknown cookies (pr_warn_ratelimited).
 */
void daedalus_complete_resp_frame(u32 cookie,
				  const struct daedalus_resp_frame *fr,
				  const u8 *pixels, size_t pixels_len);

#endif /* DAEDALUS_V4L2_MAIN_H */