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 #include <media/media-entity.h> 20 21 #define VIDEO_MAJOR 81 22 23 #define VFL_TYPE_GRABBER 0 24 #define VFL_TYPE_VBI 1 25 #define VFL_TYPE_RADIO 2 26 #define VFL_TYPE_SUBDEV 3 27 #define VFL_TYPE_MAX 4 28 29 struct v4l2_ioctl_callbacks; 30 struct video_device; 31 struct v4l2_device; 32 struct v4l2_ctrl_handler; 33 34 /* Flag to mark the video_device struct as registered. 35 Drivers can clear this flag if they want to block all future 36 device access. It is cleared by video_unregister_device. */ 37 #define V4L2_FL_REGISTERED (0) 38 /* file->private_data points to struct v4l2_fh */ 39 #define V4L2_FL_USES_V4L2_FH (1) 40 /* Use the prio field of v4l2_fh for core priority checking */ 41 #define V4L2_FL_USE_FH_PRIO (2) 42 43 /* Priority helper functions */ 44 45 struct v4l2_prio_state { 46 atomic_t prios[4]; 47 }; 48 49 void v4l2_prio_init(struct v4l2_prio_state *global); 50 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, 51 enum v4l2_priority new); 52 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); 53 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); 54 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); 55 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); 56 57 58 struct v4l2_file_operations { 59 struct module *owner; 60 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 61 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 62 unsigned int (*poll) (struct file *, struct poll_table_struct *); 63 long (*ioctl) (struct file *, unsigned int, unsigned long); 64 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 65 int (*mmap) (struct file *, struct vm_area_struct *); 66 int (*open) (struct file *); 67 int (*release) (struct file *); 68 }; 69 70 /* 71 * Newer version of video_device, handled by videodev2.c 72 * This version moves redundant code from video device code to 73 * the common handler 74 */ 75 76 struct video_device 77 { 78 #if defined(CONFIG_MEDIA_CONTROLLER) 79 struct media_entity entity; 80 #endif 81 /* device ops */ 82 const struct v4l2_file_operations *fops; 83 84 /* sysfs */ 85 struct device dev; /* v4l device */ 86 struct cdev *cdev; /* character device */ 87 88 /* Set either parent or v4l2_dev if your driver uses v4l2_device */ 89 struct device *parent; /* device parent */ 90 struct v4l2_device *v4l2_dev; /* v4l2_device parent */ 91 92 /* Control handler associated with this device node. May be NULL. */ 93 struct v4l2_ctrl_handler *ctrl_handler; 94 95 /* Priority state. If NULL, then v4l2_dev->prio will be used. */ 96 struct v4l2_prio_state *prio; 97 98 /* device info */ 99 char name[32]; 100 int vfl_type; 101 /* 'minor' is set to -1 if the registration failed */ 102 int minor; 103 u16 num; 104 /* use bitops to set/clear/test flags */ 105 unsigned long flags; 106 /* attribute to differentiate multiple indices on one physical device */ 107 int index; 108 109 /* V4L2 file handles */ 110 spinlock_t fh_lock; /* Lock for all v4l2_fhs */ 111 struct list_head fh_list; /* List of struct v4l2_fh */ 112 113 int debug; /* Activates debug level*/ 114 115 /* Video standard vars */ 116 v4l2_std_id tvnorms; /* Supported tv norms */ 117 v4l2_std_id current_norm; /* Current tvnorm */ 118 119 /* callbacks */ 120 void (*release)(struct video_device *vdev); 121 122 /* ioctl callbacks */ 123 const struct v4l2_ioctl_ops *ioctl_ops; 124 125 /* serialization lock */ 126 struct mutex *lock; 127 }; 128 129 #define media_entity_to_video_device(entity) \ 130 container_of(entity, struct video_device, entity) 131 /* dev to video-device */ 132 #define to_video_device(cd) container_of(cd, struct video_device, dev) 133 134 int __must_check __video_register_device(struct video_device *vdev, int type, 135 int nr, int warn_if_nr_in_use, struct module *owner); 136 137 /* Register video devices. Note that if video_register_device fails, 138 the release() callback of the video_device structure is *not* called, so 139 the caller is responsible for freeing any data. Usually that means that 140 you call video_device_release() on failure. */ 141 static inline int __must_check video_register_device(struct video_device *vdev, 142 int type, int nr) 143 { 144 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 145 } 146 147 /* Same as video_register_device, but no warning is issued if the desired 148 device node number was already in use. */ 149 static inline int __must_check video_register_device_no_warn( 150 struct video_device *vdev, int type, int nr) 151 { 152 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 153 } 154 155 /* Unregister video devices. Will do nothing if vdev == NULL or 156 video_is_registered() returns false. */ 157 void video_unregister_device(struct video_device *vdev); 158 159 /* helper functions to alloc/release struct video_device, the 160 latter can also be used for video_device->release(). */ 161 struct video_device * __must_check video_device_alloc(void); 162 163 /* this release function frees the vdev pointer */ 164 void video_device_release(struct video_device *vdev); 165 166 /* this release function does nothing, use when the video_device is a 167 static global struct. Note that having a static video_device is 168 a dubious construction at best. */ 169 void video_device_release_empty(struct video_device *vdev); 170 171 /* helper functions to access driver private data. */ 172 static inline void *video_get_drvdata(struct video_device *vdev) 173 { 174 return dev_get_drvdata(&vdev->dev); 175 } 176 177 static inline void video_set_drvdata(struct video_device *vdev, void *data) 178 { 179 dev_set_drvdata(&vdev->dev, data); 180 } 181 182 struct video_device *video_devdata(struct file *file); 183 184 /* Combine video_get_drvdata and video_devdata as this is 185 used very often. */ 186 static inline void *video_drvdata(struct file *file) 187 { 188 return video_get_drvdata(video_devdata(file)); 189 } 190 191 static inline const char *video_device_node_name(struct video_device *vdev) 192 { 193 return dev_name(&vdev->dev); 194 } 195 196 static inline int video_is_registered(struct video_device *vdev) 197 { 198 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 199 } 200 201 #endif /* _V4L2_DEV_H */ 202