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 43 struct 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 */ 65 struct 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 85 int __must_check media_devnode_register(struct media_devnode *mdev, 86 struct module *owner); 87 void media_devnode_unregister(struct media_devnode *mdev); 88 89 static inline struct media_devnode *media_devnode_data(struct file *filp) 90 { 91 return filp->private_data; 92 } 93 94 static 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