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4.4.0-1128-aws
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media-devnode.h
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/* * Media device node * * Copyright (C) 2010 Nokia Corporation * * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com> * Sakari Ailus <sakari.ailus@iki.fi> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * -- * * Common functions for media-related drivers to register and unregister media * device nodes. */ #ifndef _MEDIA_DEVNODE_H #define _MEDIA_DEVNODE_H #include <linux/poll.h> #include <linux/fs.h> #include <linux/device.h> #include <linux/cdev.h> struct media_device; /* * Flag to mark the media_devnode struct as registered. Drivers must not touch * this flag directly, it will be set and cleared by media_devnode_register and * media_devnode_unregister. */ #define MEDIA_FLAG_REGISTERED 0 struct media_file_operations { struct module *owner; ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); unsigned int (*poll) (struct file *, struct poll_table_struct *); long (*ioctl) (struct file *, unsigned int, unsigned long); long (*compat_ioctl) (struct file *, unsigned int, unsigned long); int (*open) (struct file *); int (*release) (struct file *); }; /** * struct media_devnode - Media device node * @fops: pointer to struct media_file_operations with media device ops * @dev: struct device pointer for the media controller device * @cdev: struct cdev pointer character device * @parent: parent device * @minor: device node minor number * @flags: flags, combination of the MEDIA_FLAG_* constants * @release: release callback called at the end of media_devnode_release() * * This structure represents a media-related device node. * * The @parent is a physical device. It must be set by core or device drivers * before registering the node. */ struct media_devnode { struct media_device *media_dev; /* device ops */ const struct media_file_operations *fops; /* sysfs */ struct device dev; /* media device */ struct cdev cdev; /* character device */ struct device *parent; /* device parent */ /* device info */ int minor; unsigned long flags; /* Use bitops to access flags */ /* callbacks */ void (*release)(struct media_devnode *devnode); }; /* dev to media_devnode */ #define to_media_devnode(cd) container_of(cd, struct media_devnode, dev) int __must_check media_devnode_register(struct media_device *mdev, struct media_devnode *devnode, struct module *owner); /** * media_devnode_unregister_prepare - clear the media device node register bit * @devnode: the device node to prepare for unregister * * This clears the passed device register bit. Future open calls will be met * with errors. Should be called before media_devnode_unregister() to avoid * races with unregister and device file open calls. * * This function can safely be called if the device node has never been * registered or has already been unregistered. */ void media_devnode_unregister_prepare(struct media_devnode *devnode); void media_devnode_unregister(struct media_devnode *devnode); static inline struct media_devnode *media_devnode_data(struct file *filp) { return filp->private_data; } static inline int media_devnode_is_registered(struct media_devnode *devnode) { if (!devnode) return false; return test_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); } #endif /* _MEDIA_DEVNODE_H */