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 27 struct v4l2_ioctl_callbacks; 28 struct video_device; 29 struct v4l2_device; 30 31 /* Flag to mark the video_device struct as unregistered. 32 Drivers can set this flag if they want to block all future 33 device access. It is set by video_unregister_device. */ 34 #define V4L2_FL_UNREGISTERED (0) 35 36 struct v4l2_file_operations { 37 struct module *owner; 38 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 39 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 40 unsigned int (*poll) (struct file *, struct poll_table_struct *); 41 long (*ioctl) (struct file *, unsigned int, unsigned long); 42 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 43 int (*mmap) (struct file *, struct vm_area_struct *); 44 int (*open) (struct file *); 45 int (*release) (struct file *); 46 }; 47 48 /* 49 * Newer version of video_device, handled by videodev2.c 50 * This version moves redundant code from video device code to 51 * the common handler 52 */ 53 54 struct video_device 55 { 56 /* device ops */ 57 const struct v4l2_file_operations *fops; 58 59 /* sysfs */ 60 struct device dev; /* v4l device */ 61 struct cdev *cdev; /* character device */ 62 63 /* Set either parent or v4l2_dev if your driver uses v4l2_device */ 64 struct device *parent; /* device parent */ 65 struct v4l2_device *v4l2_dev; /* v4l2_device parent */ 66 67 /* device info */ 68 char name[32]; 69 int vfl_type; 70 /* 'minor' is set to -1 if the registration failed */ 71 int minor; 72 u16 num; 73 /* use bitops to set/clear/test flags */ 74 unsigned long flags; 75 /* attribute to differentiate multiple indices on one physical device */ 76 int index; 77 78 int debug; /* Activates debug level*/ 79 80 /* Video standard vars */ 81 v4l2_std_id tvnorms; /* Supported tv norms */ 82 v4l2_std_id current_norm; /* Current tvnorm */ 83 84 /* callbacks */ 85 void (*release)(struct video_device *vdev); 86 87 /* ioctl callbacks */ 88 const struct v4l2_ioctl_ops *ioctl_ops; 89 }; 90 91 /* dev to video-device */ 92 #define to_video_device(cd) container_of(cd, struct video_device, dev) 93 94 /* Register video devices. Note that if video_register_device fails, 95 the release() callback of the video_device structure is *not* called, so 96 the caller is responsible for freeing any data. Usually that means that 97 you call video_device_release() on failure. 98 99 Also note that vdev->minor is set to -1 if the registration failed. */ 100 int __must_check video_register_device(struct video_device *vdev, int type, int nr); 101 int __must_check video_register_device_index(struct video_device *vdev, 102 int type, int nr, int index); 103 104 /* Unregister video devices. Will do nothing if vdev == NULL or 105 vdev->minor < 0. */ 106 void video_unregister_device(struct video_device *vdev); 107 108 /* helper functions to alloc/release struct video_device, the 109 latter can also be used for video_device->release(). */ 110 struct video_device * __must_check video_device_alloc(void); 111 112 /* this release function frees the vdev pointer */ 113 void video_device_release(struct video_device *vdev); 114 115 /* this release function does nothing, use when the video_device is a 116 static global struct. Note that having a static video_device is 117 a dubious construction at best. */ 118 void video_device_release_empty(struct video_device *vdev); 119 120 /* helper functions to access driver private data. */ 121 static inline void *video_get_drvdata(struct video_device *vdev) 122 { 123 return dev_get_drvdata(&vdev->dev); 124 } 125 126 static inline void video_set_drvdata(struct video_device *vdev, void *data) 127 { 128 dev_set_drvdata(&vdev->dev, data); 129 } 130 131 struct video_device *video_devdata(struct file *file); 132 133 /* Combine video_get_drvdata and video_devdata as this is 134 used very often. */ 135 static inline void *video_drvdata(struct file *file) 136 { 137 return video_get_drvdata(video_devdata(file)); 138 } 139 140 static inline int video_is_unregistered(struct video_device *vdev) 141 { 142 return test_bit(V4L2_FL_UNREGISTERED, &vdev->flags); 143 } 144 145 #endif /* _V4L2_DEV_H */ 146