9.8
  +   1ˆl–Ü4ý( ©³( 	Å€fàB¦-ÿÌ„[i¿_†I|¥+ÅÏ -    1/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * V4L2 asynchronous subdevice registration API
 *
 * Copyright (C) 2012-2013, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
 */

#ifndef V4L2_ASYNC_H
#define V4L2_ASYNC_H

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

struct dentry;
struct device;
struct device_node;
struct v4l2_device;
struct v4l2_subdev;
struct v4l2_async_notifier;

/**
 * enum v4l2_async_match_type - type of asynchronous subdevice logic to be used
 *	in order to identify a match
 *
 * @V4L2_ASYNC_MATCH_I2C: Match will check for I2C adapter ID and address
 * @V4L2_ASYNC_MATCH_FWNODE: Match will use firmware node
 *
 * This enum is used by the asynchronous sub-device logic to define the
 * algorithm that will be used to match an asynchronous device.
 */
enum v4l2_async_match_type {
	V4L2_ASYNC_MATCH_I2C,
	V4L2_ASYNC_MATCH_FWNODE,
};

/**
 * struct v4l2_async_subdev - sub-device descriptor, as known to a bridge
 *
 * @match_type:	type of match that will be used
 * @match:	union of per-bus type matching data sets
 * @match.fwnode:
 *		pointer to &struct fwnode_handle to be matched.
 *		Used if @match_type is %V4L2_ASYNC_MATCH_FWNODE.
 * @match.i2c:	embedded struct with I2C parameters to be matched.
 *		Both @match.i2c.adapter_id and @match.i2c.address
 *		should be matched.
 *		Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
 * @match.i2c.adapter_id:
 *		I2C adapter ID to be matched.
 *		Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
 * @match.i2c.address:
 *		I2C address to be matched.
 *		Used if @match_type is %V4L2_ASYNC_MATCH_I2C.
 * @asd_list:	used to add struct v4l2_async_subdev objects to the
 *		master notifier @asd_list
 * @list:	used to link struct v4l2_async_subdev objects, waiting to be
 *		probed, to a notifier->waiting list
 *
 * When this struct is used as a member in a driver specific struct,
 * the driver specific struct shall contain the &struct
 * v4l2_async_subdev as its first member.
 */
struct v4l2_async_subdev {
	enum v4l2_async_match_type match_type;
	union {
		struct fwnode_handle *fwnode;
		struct {
			int adapter_id;
			unsigned short address;
		} i2c;
	} match;

	/* v4l2-async core private: not to be used by drivers */
	struct list_head list;
	struct list_head asd_list;
};

/**
 * struct v4l2_async_notifier_operations - Asynchronous V4L2 notifier operations
 * @bound:	a subdevice driver has successfully probed one of the subdevices
 * @complete:	All subdevices have been probed successfully. The complete
 *		callback is only executed for the root notifier.
 * @unbind:	a subdevice is leaving
 */
struct v4l2_async_notifier_operations {
	int (*bound)(struct v4l2_async_notifier *notifier,
		     struct v4l2_subdev *subdev,
		     struct v4l2_async_subdev *asd);
	int (*complete)(struct v4l2_async_notifier *notifier);
	void (*unbind)(struct v4l2_async_notifier *notifier,
		       struct v4l2_subdev *subdev,
		       struct v4l2_async_subdev *asd);
};

/**
 * struct v4l2_async_notifier - v4l2_device notifier data
 *
 * @ops:	notifier operations
 * @v4l2_dev:	v4l2_device of the root notifier, NULL otherwise
 * @sd:		sub-device that registered the notifier, NULL otherwise
 * @parent:	parent notifier
 * @asd_list:	master list of struct v4l2_async_subdev
 * @waiting:	list of struct v4l2_async_subdev, waiting for their drivers
 * @done:	list of struct v4l2_subdev, already probed
 * @list:	member in a global list of notifiers
 */
struct v4l2_async_notifier {
	const struct v4l2_async_notifier_operations *ops;
	struct v4l2_device *v4l2_dev;
	struct v4l2_subdev *sd;
	struct v4l2_async_notifier *parent;
	struct list_head asd_list;
	struct list_head waiting;
	struct list_head done;
	struct list_head list;
};

/**
 * v4l2_async_debug_init - Initialize debugging tools.
 *
 * @debugfs_dir: pointer to the parent debugfs &struct dentry
 */
void v4l2_async_debug_init(struct dentry *debugfs_dir);

/**
 * v4l2_async_notifier_init - Initialize a notifier.
 *
 * @notifier: pointer to &struct v4l2_async_notifier
 *
 * This function initializes