linux/include/media/v4l2-dev.h
Hans Verkuil 7f8ecfab7a V4L/DVB (8852): v4l2: use register_chrdev_region instead of register_chrdev
Replace the old register_chrdev with the more flexible register_chrdev_region.

Ensure that the release() is called when the very last chardev usage was
released, and not when the sysfs devices were removed. This should simplify
hotpluggable drivers considerably.

Tested-by: Mike Isely <isely@isely.net>
Tested-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: David Ellingsworth <david@identd.dyndns.org>
Reviewed-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-10-12 09:36:56 -02:00

120 lines
3.3 KiB
C

/*
*
* V 4 L 2 D R I V E R H E L P E R A P I
*
* Moved from videodev2.h
*
* Some commonly needed functions for drivers (v4l2-common.o module)
*/
#ifndef _V4L2_DEV_H
#define _V4L2_DEV_H
#include <linux/poll.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/mutex.h>
#include <linux/videodev2.h>
#define VIDEO_MAJOR 81
/* Minor device allocation */
#define MINOR_VFL_TYPE_GRABBER_MIN 0
#define MINOR_VFL_TYPE_GRABBER_MAX 63
#define MINOR_VFL_TYPE_RADIO_MIN 64
#define MINOR_VFL_TYPE_RADIO_MAX 127
#define MINOR_VFL_TYPE_VTX_MIN 192
#define MINOR_VFL_TYPE_VTX_MAX 223
#define MINOR_VFL_TYPE_VBI_MIN 224
#define MINOR_VFL_TYPE_VBI_MAX 255
#define VFL_TYPE_GRABBER 0
#define VFL_TYPE_VBI 1
#define VFL_TYPE_RADIO 2
#define VFL_TYPE_VTX 3
struct v4l2_ioctl_callbacks;
/*
* Newer version of video_device, handled by videodev2.c
* This version moves redundant code from video device code to
* the common handler
*/
struct video_device
{
/* device ops */
const struct file_operations *fops;
/* sysfs */
struct device dev; /* v4l device */
struct cdev cdev; /* character device */
void (*cdev_release)(struct kobject *kobj);
struct device *parent; /* device parent */
/* device info */
char name[32];
int vfl_type;
int minor;
/* attribute to differentiate multiple indices on one physical device */
int index;
int debug; /* Activates debug level*/
/* Video standard vars */
v4l2_std_id tvnorms; /* Supported tv norms */
v4l2_std_id current_norm; /* Current tvnorm */
/* callbacks */
void (*release)(struct video_device *vfd);
/* ioctl callbacks */
const struct v4l2_ioctl_ops *ioctl_ops;
};
/* dev to video-device */
#define to_video_device(cd) container_of(cd, struct video_device, dev)
/* Register and unregister devices. Note that if video_register_device fails,
the release() callback of the video_device structure is *not* called, so
the caller is responsible for freeing any data. Usually that means that
you call video_device_release() on failure. */
int __must_check video_register_device(struct video_device *vfd, int type, int nr);
int __must_check video_register_device_index(struct video_device *vfd,
int type, int nr, int index);
void video_unregister_device(struct video_device *vfd);
/* helper functions to alloc/release struct video_device, the
latter can also be used for video_device->release(). */
struct video_device * __must_check video_device_alloc(void);
/* this release function frees the vfd pointer */
void video_device_release(struct video_device *vfd);
/* this release function does nothing, use when the video_device is a
static global struct. Note that having a static video_device is
a dubious construction at best. */
void video_device_release_empty(struct video_device *vfd);
/* helper functions to access driver private data. */
static inline void *video_get_drvdata(struct video_device *dev)
{
return dev_get_drvdata(&dev->dev);
}
static inline void video_set_drvdata(struct video_device *dev, void *data)
{
dev_set_drvdata(&dev->dev, data);
}
struct video_device *video_devdata(struct file *file);
/* Combine video_get_drvdata and video_devdata as this is
used very often. */
static inline void *video_drvdata(struct file *file)
{
return video_get_drvdata(video_devdata(file));
}
#endif /* _V4L2_DEV_H */