V4L/DVB (8787): v4l2-dev: cleanups and add video_drvdata helper function

Cleanup v4l2-dev.[ch], add/improve comments and add a new helper
function: video_drvdata() that can get the private driver data from
a file struct.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Hans Verkuil 2008-08-23 07:48:38 -03:00 committed by Mauro Carvalho Chehab
parent 601e9444f2
commit bfa8a273bb
2 changed files with 27 additions and 21 deletions

View File

@ -42,6 +42,7 @@ static ssize_t show_index(struct device *cd,
struct device_attribute *attr, char *buf)
{
struct video_device *vfd = container_of(cd, struct video_device, dev);
return sprintf(buf, "%i\n", vfd->index);
}
@ -49,6 +50,7 @@ static ssize_t show_name(struct device *cd,
struct device_attribute *attr, char *buf)
{
struct video_device *vfd = container_of(cd, struct video_device, dev);
return sprintf(buf, "%.*s\n", (int)sizeof(vfd->name), vfd->name);
}
@ -60,10 +62,7 @@ static struct device_attribute video_device_attrs[] = {
struct video_device *video_device_alloc(void)
{
struct video_device *vfd;
vfd = kzalloc(sizeof(*vfd), GFP_KERNEL);
return vfd;
return kzalloc(sizeof(struct video_device), GFP_KERNEL);
}
EXPORT_SYMBOL(video_device_alloc);
@ -295,7 +294,7 @@ int video_register_device_index(struct video_device *vfd, int type, int nr,
}
/* sysfs class */
memset(&vfd->dev, 0x00, sizeof(vfd->dev));
memset(&vfd->dev, 0, sizeof(vfd->dev));
vfd->dev.class = &video_class;
vfd->dev.devt = MKDEV(VIDEO_MAJOR, vfd->minor);
if (vfd->parent)
@ -312,8 +311,8 @@ int video_register_device_index(struct video_device *vfd, int type, int nr,
fail_minor:
mutex_lock(&videodev_lock);
video_device[vfd->minor] = NULL;
vfd->minor = -1;
mutex_unlock(&videodev_lock);
vfd->minor = -1;
return ret;
}
EXPORT_SYMBOL(video_register_device_index);

View File

@ -9,16 +9,14 @@
#ifndef _V4L2_DEV_H
#define _V4L2_DEV_H
#define OBSOLETE_DEVDATA 1 /* to be removed soon */
#include <linux/poll.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/compiler.h> /* need __user */
#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
@ -71,20 +69,25 @@ struct video_device
const struct v4l2_ioctl_ops *ioctl_ops;
};
/* Class-dev to video-device */
/* dev to video-device */
#define to_video_device(cd) container_of(cd, struct video_device, dev)
/* Version 2 functions */
/* 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 *);
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
later can be used for video_device->release() */
/* 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. */
@ -101,9 +104,13 @@ static inline void video_set_drvdata(struct video_device *dev, void *data)
dev_set_drvdata(&dev->dev, data);
}
#ifdef OBSOLETE_DEVDATA /* to be removed soon */
/* Obsolete stuff - Still needed for radio devices and obsolete drivers */
extern struct video_device* video_devdata(struct file*);
#endif
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 */