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 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 66 unsigned long, unsigned long, unsigned long); 67 int (*mmap) (struct file *, struct vm_area_struct *); 68 int (*open) (struct file *); 69 int (*release) (struct file *); 70 }; 71 72 /* 73 * Newer version of video_device, handled by videodev2.c 74 * This version moves redundant code from video device code to 75 * the common handler 76 */ 77 78 struct video_device 79 { 80 #if defined(CONFIG_MEDIA_CONTROLLER) 81 struct media_entity entity; 82 #endif 83 /* device ops */ 84 const struct v4l2_file_operations *fops; 85 86 /* sysfs */ 87 struct device dev; /* v4l device */ 88 struct cdev *cdev; /* character device */ 89 90 /* Set either parent or v4l2_dev if your driver uses v4l2_device */ 91 struct device *parent; /* device parent */ 92 struct v4l2_device *v4l2_dev; /* v4l2_device parent */ 93 94 /* Control handler associated with this device node. May be NULL. */ 95 struct v4l2_ctrl_handler *ctrl_handler; 96 97 /* Priority state. If NULL, then v4l2_dev->prio will be used. */ 98 struct v4l2_prio_state *prio; 99 100 /* device info */ 101 char name[32]; 102 int vfl_type; 103 /* 'minor' is set to -1 if the registration failed */ 104 int minor; 105 u16 num; 106 /* use bitops to set/clear/test flags */ 107 unsigned long flags; 108 /* attribute to differentiate multiple indices on one physical device */ 109 int index; 110 111 /* V4L2 file handles */ 112 spinlock_t fh_lock; /* Lock for all v4l2_fhs */ 113 struct list_head fh_list; /* List of struct v4l2_fh */ 114 115 int debug; /* Activates debug level*/ 116 117 /* Video standard vars */ 118 v4l2_std_id tvnorms; /* Supported tv norms */ 119 v4l2_std_id current_norm; /* Current tvnorm */ 120 121 /* callbacks */ 122 void (*release)(struct video_device *vdev); 123 124 /* ioctl callbacks */ 125 const struct v4l2_ioctl_ops *ioctl_ops; 126 127 /* serialization lock */ 128 struct mutex *lock; 129 }; 130 131 #define media_entity_to_video_device(__e) \ 132 container_of(__e, struct video_device, entity) 133 /* dev to video-device */ 134 #define to_video_device(cd) container_of(cd, struct video_device, dev) 135 136 int __must_check __video_register_device(struct video_device *vdev, int type, 137 int nr, int warn_if_nr_in_use, struct module *owner); 138 139 /* Register video devices. Note that if video_register_device fails, 140 the release() callback of the video_device structure is *not* called, so 141 the caller is responsible for freeing any data. Usually that means that 142 you call video_device_release() on failure. */ 143 static inline int __must_check video_register_device(struct video_device *vdev, 144 int type, int nr) 145 { 146 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 147 } 148 149 /* Same as video_register_device, but no warning is issued if the desired 150 device node number was already in use. */ 151 static inline int __must_check video_register_device_no_warn( 152 struct video_device *vdev, int type, int nr) 153 { 154 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 155 } 156 157 /* Unregister video devices. Will do nothing if vdev == NULL or 158 video_is_registered() returns false. */ 159 void video_unregister_device(struct video_device *vdev); 160 161 /* helper functions to alloc/release struct video_device, the 162 latter can also be used for video_device->release(). */ 163 struct video_device * __must_check video_device_alloc(void); 164 165 /* this release function frees the vdev pointer */ 166 void video_device_release(struct video_device *vdev); 167 168 /* this release function does nothing, use when the video_device is a 169 static global struct. Note that having a static video_device is 170 a dubious construction at best. */ 171 void video_device_release_empty(struct video_device *vdev); 172 173 /* helper functions to access driver private data. */ 174 static inline void *video_get_drvdata(struct video_device *vdev) 175 { 176 return dev_get_drvdata(&vdev->dev); 177 } 178 179 static inline void video_set_drvdata(struct video_device *vdev, void *data) 180 { 181 dev_set_drvdata(&vdev->dev, data); 182 } 183 184 struct video_device *video_devdata(struct file *file); 185 186 /* Combine video_get_drvdata and video_devdata as this is 187 used very often. */ 188 static inline void *video_drvdata(struct file *file) 189 { 190 return video_get_drvdata(video_devdata(file)); 191 } 192 193 static inline const char *video_device_node_name(struct video_device *vdev) 194 { 195 return dev_name(&vdev->dev); 196 } 197 198 static inline int video_is_registered(struct video_device *vdev) 199 { 200 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 201 } 202 203 #endif /* _V4L2_DEV_H */ 204