146 строки
4.2 KiB
C
146 строки
4.2 KiB
C
/*
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*
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* V 4 L 2 D R I V E R H E L P E R A P I
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*
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* Moved from videodev2.h
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*
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* Some commonly needed functions for drivers (v4l2-common.o module)
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*/
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#ifndef _V4L2_DEV_H
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#define _V4L2_DEV_H
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#include <linux/poll.h>
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#include <linux/fs.h>
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#include <linux/device.h>
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#include <linux/cdev.h>
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#include <linux/mutex.h>
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#include <linux/videodev2.h>
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#define VIDEO_MAJOR 81
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#define VFL_TYPE_GRABBER 0
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#define VFL_TYPE_VBI 1
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#define VFL_TYPE_RADIO 2
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#define VFL_TYPE_VTX 3
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#define VFL_TYPE_MAX 4
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struct v4l2_ioctl_callbacks;
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struct video_device;
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struct v4l2_device;
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/* Flag to mark the video_device struct as unregistered.
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Drivers can set this flag if they want to block all future
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device access. It is set by video_unregister_device. */
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#define V4L2_FL_UNREGISTERED (0)
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struct v4l2_file_operations {
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struct module *owner;
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ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
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ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
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unsigned int (*poll) (struct file *, struct poll_table_struct *);
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long (*ioctl) (struct file *, unsigned int, unsigned long);
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long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
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int (*mmap) (struct file *, struct vm_area_struct *);
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int (*open) (struct file *);
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int (*release) (struct file *);
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};
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/*
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* Newer version of video_device, handled by videodev2.c
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* This version moves redundant code from video device code to
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* the common handler
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*/
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struct video_device
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{
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/* device ops */
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const struct v4l2_file_operations *fops;
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/* sysfs */
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struct device dev; /* v4l device */
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struct cdev *cdev; /* character device */
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/* Set either parent or v4l2_dev if your driver uses v4l2_device */
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struct device *parent; /* device parent */
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struct v4l2_device *v4l2_dev; /* v4l2_device parent */
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/* device info */
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char name[32];
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int vfl_type;
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/* 'minor' is set to -1 if the registration failed */
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int minor;
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u16 num;
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/* use bitops to set/clear/test flags */
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unsigned long flags;
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/* attribute to differentiate multiple indices on one physical device */
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int index;
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int debug; /* Activates debug level*/
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/* Video standard vars */
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v4l2_std_id tvnorms; /* Supported tv norms */
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v4l2_std_id current_norm; /* Current tvnorm */
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/* callbacks */
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void (*release)(struct video_device *vdev);
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/* ioctl callbacks */
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const struct v4l2_ioctl_ops *ioctl_ops;
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};
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/* dev to video-device */
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#define to_video_device(cd) container_of(cd, struct video_device, dev)
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/* Register video devices. Note that if video_register_device fails,
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the release() callback of the video_device structure is *not* called, so
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the caller is responsible for freeing any data. Usually that means that
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you call video_device_release() on failure.
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Also note that vdev->minor is set to -1 if the registration failed. */
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int __must_check video_register_device(struct video_device *vdev, int type, int nr);
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int __must_check video_register_device_index(struct video_device *vdev,
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int type, int nr, int index);
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/* Unregister video devices. Will do nothing if vdev == NULL or
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vdev->minor < 0. */
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void video_unregister_device(struct video_device *vdev);
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/* helper functions to alloc/release struct video_device, the
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latter can also be used for video_device->release(). */
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struct video_device * __must_check video_device_alloc(void);
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/* this release function frees the vdev pointer */
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void video_device_release(struct video_device *vdev);
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/* this release function does nothing, use when the video_device is a
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static global struct. Note that having a static video_device is
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a dubious construction at best. */
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void video_device_release_empty(struct video_device *vdev);
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/* helper functions to access driver private data. */
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static inline void *video_get_drvdata(struct video_device *vdev)
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{
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return dev_get_drvdata(&vdev->dev);
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}
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static inline void video_set_drvdata(struct video_device *vdev, void *data)
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{
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dev_set_drvdata(&vdev->dev, data);
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}
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struct video_device *video_devdata(struct file *file);
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/* Combine video_get_drvdata and video_devdata as this is
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used very often. */
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static inline void *video_drvdata(struct file *file)
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{
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return video_get_drvdata(video_devdata(file));
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}
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static inline int video_is_unregistered(struct video_device *vdev)
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{
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return test_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
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}
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#endif /* _V4L2_DEV_H */
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