/include/media/v4l2-dev.h

  1/*
  2 *
  3 *	V 4 L 2   D R I V E R   H E L P E R   A P I
  4 *
  5 * Moved from videodev2.h
  6 *
  7 *	Some commonly needed functions for drivers (v4l2-common.o module)
  8 */
  9#ifndef _V4L2_DEV_H
 10#define _V4L2_DEV_H
 11
 12#include <linux/poll.h>
 13#include <linux/fs.h>
 14#include <linux/device.h>
 15#include <linux/cdev.h>
 16#include <linux/mutex.h>
 17#include <linux/videodev2.h>
 18
 19#define VIDEO_MAJOR	81
 20
 21#define VFL_TYPE_GRABBER	0
 22#define VFL_TYPE_VBI		1
 23#define VFL_TYPE_RADIO		2
 24#define VFL_TYPE_VTX		3
 25#define VFL_TYPE_MAX		4
 26
 27struct v4l2_ioctl_callbacks;
 28struct video_device;
 29struct v4l2_device;
 30
 31/* Flag to mark the video_device struct as registered.
 32   Drivers can clear this flag if they want to block all future
 33   device access. It is cleared by video_unregister_device. */
 34#define V4L2_FL_REGISTERED	(0)
 35#define V4L2_FL_USES_V4L2_FH	(1)
 36
 37struct v4l2_file_operations {
 38	struct module *owner;
 39	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
 40	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 41	unsigned int (*poll) (struct file *, struct poll_table_struct *);
 42	long (*ioctl) (struct file *, unsigned int, unsigned long);
 43	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
 44	unsigned long (*get_unmapped_area) (struct file *, unsigned long,
 45				unsigned long, unsigned long, unsigned long);
 46	int (*mmap) (struct file *, struct vm_area_struct *);
 47	int (*open) (struct file *);
 48	int (*release) (struct file *);
 49};
 50
 51/*
 52 * Newer version of video_device, handled by videodev2.c
 53 * 	This version moves redundant code from video device code to
 54 *	the common handler
 55 */
 56
 57struct video_device
 58{
 59	/* device ops */
 60	const struct v4l2_file_operations *fops;
 61
 62	/* sysfs */
 63	struct device dev;		/* v4l device */
 64	struct cdev *cdev;		/* character device */
 65
 66	/* Set either parent or v4l2_dev if your driver uses v4l2_device */
 67	struct device *parent;		/* device parent */
 68	struct v4l2_device *v4l2_dev;	/* v4l2_device parent */
 69
 70	/* device info */
 71	char name[32];
 72	int vfl_type;
 73	/* 'minor' is set to -1 if the registration failed */
 74	int minor;
 75	u16 num;
 76	/* use bitops to set/clear/test flags */
 77	unsigned long flags;
 78	/* attribute to differentiate multiple indices on one physical device */
 79	int index;
 80
 81	/* V4L2 file handles */
 82	spinlock_t		fh_lock; /* Lock for all v4l2_fhs */
 83	struct list_head	fh_list; /* List of struct v4l2_fh */
 84
 85	int debug;			/* Activates debug level*/
 86
 87	/* Video standard vars */
 88	v4l2_std_id tvnorms;		/* Supported tv norms */
 89	v4l2_std_id current_norm;	/* Current tvnorm */
 90
 91	/* callbacks */
 92	void (*release)(struct video_device *vdev);
 93
 94	/* ioctl callbacks */
 95	const struct v4l2_ioctl_ops *ioctl_ops;
 96};
 97
 98/* dev to video-device */
 99#define to_video_device(cd) container_of(cd, struct video_device, dev)
100
101/* Register video devices. Note that if video_register_device fails,
102   the release() callback of the video_device structure is *not* called, so
103   the caller is responsible for freeing any data. Usually that means that
104   you call video_device_release() on failure. */
105int __must_check video_register_device(struct video_device *vdev, int type, int nr);
106
107/* Same as video_register_device, but no warning is issued if the desired
108   device node number was already in use. */
109int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr);
110
111/* Unregister video devices. Will do nothing if vdev == NULL or
112   video_is_registered() returns false. */
113void video_unregister_device(struct video_device *vdev);
114
115/* helper functions to alloc/release struct video_device, the
116   latter can also be used for video_device->release(). */
117struct video_device * __must_check video_device_alloc(void);
118
119/* this release function frees the vdev pointer */
120void video_device_release(struct video_device *vdev);
121
122/* this release function does nothing, use when the video_device is a
123   static global struct. Note that having a static video_device is
124   a dubious construction at best. */
125void video_device_release_empty(struct video_device *vdev);
126
127/* helper functions to access driver private data. */
128static inline void *video_get_drvdata(struct video_device *vdev)
129{
130	return dev_get_drvdata(&vdev->dev);
131}
132
133static inline void video_set_drvdata(struct video_device *vdev, void *data)
134{
135	dev_set_drvdata(&vdev->dev, data);
136}
137
138struct video_device *video_devdata(struct file *file);
139
140/* Combine video_get_drvdata and video_devdata as this is
141   used very often. */
142static inline void *video_drvdata(struct file *file)
143{
144	return video_get_drvdata(video_devdata(file));
145}
146
147static inline const char *video_device_node_name(struct video_device *vdev)
148{
149	return dev_name(&vdev->dev);
150}
151
152static inline int video_is_registered(struct video_device *vdev)
153{
154	return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
155}
156
157#endif /* _V4L2_DEV_H */