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