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 struct v4l2_ctrl_handler; 31 32 /* Flag to mark the video_device struct as registered. 33 Drivers can clear this flag if they want to block all future 34 device access. It is cleared by video_unregister_device. */ 35 #define V4L2_FL_REGISTERED (0) 36 #define V4L2_FL_USES_V4L2_FH (1) 37 38 struct v4l2_file_operations { 39 struct module *owner; 40 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 41 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 42 unsigned int (*poll) (struct file *, struct poll_table_struct *); 43 long (*ioctl) (struct file *, unsigned int, unsigned long); 44 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 45 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 46 unsigned long, unsigned long, unsigned long); 47 int (*mmap) (struct file *, struct vm_area_struct *); 48 int (*open) (struct file *); 49 int (*release) (struct file *); 50 }; 51 52 /* 53 * Newer version of video_device, handled by videodev2.c 54 * This version moves redundant code from video device code to 55 * the common handler 56 */ 57 58 struct video_device 59 { 60 /* device ops */ 61 const struct v4l2_file_operations *fops; 62 63 /* sysfs */ 64 struct device dev; /* v4l device */ 65 struct cdev *cdev; /* character device */ 66 67 /* Set either parent or v4l2_dev if your driver uses v4l2_device */ 68 struct device *parent; /* device parent */ 69 struct v4l2_device *v4l2_dev; /* v4l2_device parent */ 70 71 /* Control handler associated with this device node. May be NULL. */ 72 struct v4l2_ctrl_handler *ctrl_handler; 73 74 /* device info */ 75 char name[32]; 76 int vfl_type; 77 /* 'minor' is set to -1 if the registration failed */ 78 int minor; 79 u16 num; 80 /* use bitops to set/clear/test flags */ 81 unsigned long flags; 82 /* attribute to differentiate multiple indices on one physical device */ 83 int index; 84 85 /* V4L2 file handles */ 86 spinlock_t fh_lock; /* Lock for all v4l2_fhs */ 87 struct list_head fh_list; /* List of struct v4l2_fh */ 88 89 int debug; /* Activates debug level*/ 90 91 /* Video standard vars */ 92 v4l2_std_id tvnorms; /* Supported tv norms */ 93 v4l2_std_id current_norm; /* Current tvnorm */ 94 95 /* callbacks */ 96 void (*release)(struct video_device *vdev); 97 98 /* ioctl callbacks */ 99 const struct v4l2_ioctl_ops *ioctl_ops; 100 }; 101 102 /* dev to video-device */ 103 #define to_video_device(cd) container_of(cd, struct video_device, dev) 104 105 /* Register video devices. Note that if video_register_device fails, 106 the release() callback of the video_device structure is *not* called, so 107 the caller is responsible for freeing any data. Usually that means that 108 you call video_device_release() on failure. */ 109 int __must_check video_register_device(struct video_device *vdev, int type, int nr); 110 111 /* Same as video_register_device, but no warning is issued if the desired 112 device node number was already in use. */ 113 int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr); 114 115 /* Unregister video devices. Will do nothing if vdev == NULL or 116 video_is_registered() returns false. */ 117 void video_unregister_device(struct video_device *vdev); 118 119 /* helper functions to alloc/release struct video_device, the 120 latter can also be used for video_device->release(). */ 121 struct video_device * __must_check video_device_alloc(void); 122 123 /* this release function frees the vdev pointer */ 124 void video_device_release(struct video_device *vdev); 125 126 /* this release function does nothing, use when the video_device is a 127 static global struct. Note that having a static video_device is 128 a dubious construction at best. */ 129 void video_device_release_empty(struct video_device *vdev); 130 131 /* helper functions to access driver private data. */ 132 static inline void *video_get_drvdata(struct video_device *vdev) 133 { 134 return dev_get_drvdata(&vdev->dev); 135 } 136 137 static inline void video_set_drvdata(struct video_device *vdev, void *data) 138 { 139 dev_set_drvdata(&vdev->dev, data); 140 } 141 142 struct video_device *video_devdata(struct file *file); 143 144 /* Combine video_get_drvdata and video_devdata as this is 145 used very often. */ 146 static inline void *video_drvdata(struct file *file) 147 { 148 return video_get_drvdata(video_devdata(file)); 149 } 150 151 static inline const char *video_device_node_name(struct video_device *vdev) 152 { 153 return dev_name(&vdev->dev); 154 } 155 156 static inline int video_is_registered(struct video_device *vdev) 157 { 158 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 159 } 160 161 #endif /* _V4L2_DEV_H */ 162