1/*
2 * Media device node
3 *
4 * Copyright (C) 2010 Nokia Corporation
5 *
6 * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
7 *	     Sakari Ailus <sakari.ailus@iki.fi>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
21 *
22 * --
23 *
24 * Common functions for media-related drivers to register and unregister media
25 * device nodes.
26 */
27
28#ifndef _MEDIA_DEVNODE_H
29#define _MEDIA_DEVNODE_H
30
31#include <linux/poll.h>
32#include <linux/fs.h>
33#include <linux/device.h>
34#include <linux/cdev.h>
35
36/*
37 * Flag to mark the media_devnode struct as registered. Drivers must not touch
38 * this flag directly, it will be set and cleared by media_devnode_register and
39 * media_devnode_unregister.
40 */
41#define MEDIA_FLAG_REGISTERED	0
42
43struct media_file_operations {
44	struct module *owner;
45	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
46	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
47	unsigned int (*poll) (struct file *, struct poll_table_struct *);
48	long (*ioctl) (struct file *, unsigned int, unsigned long);
49	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
50	int (*open) (struct file *);
51	int (*release) (struct file *);
52};
53
54/**
55 * struct media_devnode - Media device node
56 * @parent:	parent device
57 * @minor:	device node minor number
58 * @flags:	flags, combination of the MEDIA_FLAG_* constants
59 *
60 * This structure represents a media-related device node.
61 *
62 * The @parent is a physical device. It must be set by core or device drivers
63 * before registering the node.
64 */
65struct media_devnode {
66	/* device ops */
67	const struct media_file_operations *fops;
68
69	/* sysfs */
70	struct device dev;		/* media device */
71	struct cdev cdev;		/* character device */
72	struct device *parent;		/* device parent */
73
74	/* device info */
75	int minor;
76	unsigned long flags;		/* Use bitops to access flags */
77
78	/* callbacks */
79	void (*release)(struct media_devnode *mdev);
80};
81
82/* dev to media_devnode */
83#define to_media_devnode(cd) container_of(cd, struct media_devnode, dev)
84
85int __must_check media_devnode_register(struct media_devnode *mdev,
86					struct module *owner);
87void media_devnode_unregister(struct media_devnode *mdev);
88
89static inline struct media_devnode *media_devnode_data(struct file *filp)
90{
91	return filp->private_data;
92}
93
94static inline int media_devnode_is_registered(struct media_devnode *mdev)
95{
96	return test_bit(MEDIA_FLAG_REGISTERED, &mdev->flags);
97}
98
99#endif /* _MEDIA_DEVNODE_H */
100