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 /* If ioctl core locking is in use, then apply that also to all 43 file operations. Don't use this flag in new drivers! */ 44 #define V4L2_FL_LOCK_ALL_FOPS (3) 45 46 /* Priority helper functions */ 47 48 struct v4l2_prio_state { 49 atomic_t prios[4]; 50 }; 51 52 void v4l2_prio_init(struct v4l2_prio_state *global); 53 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, 54 enum v4l2_priority new); 55 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); 56 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); 57 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); 58 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); 59 60 61 struct v4l2_file_operations { 62 struct module *owner; 63 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 64 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 65 unsigned int (*poll) (struct file *, struct poll_table_struct *); 66 long (*ioctl) (struct file *, unsigned int, unsigned long); 67 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 68 #ifdef CONFIG_COMPAT 69 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long); 70 #endif 71 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 72 unsigned long, unsigned long, unsigned long); 73 int (*mmap) (struct file *, struct vm_area_struct *); 74 int (*open) (struct file *); 75 int (*release) (struct file *); 76 }; 77 78 /* 79 * Newer version of video_device, handled by videodev2.c 80 * This version moves redundant code from video device code to 81 * the common handler 82 */ 83 84 struct video_device 85 { 86 #if defined(CONFIG_MEDIA_CONTROLLER) 87 struct media_entity entity; 88 #endif 89 /* device ops */ 90 const struct v4l2_file_operations *fops; 91 92 /* sysfs */ 93 struct device dev; /* v4l device */ 94 struct cdev *cdev; /* character device */ 95 96 /* Set either parent or v4l2_dev if your driver uses v4l2_device */ 97 struct device *parent; /* device parent */ 98 struct v4l2_device *v4l2_dev; /* v4l2_device parent */ 99 100 /* Control handler associated with this device node. May be NULL. */ 101 struct v4l2_ctrl_handler *ctrl_handler; 102 103 /* Priority state. If NULL, then v4l2_dev->prio will be used. */ 104 struct v4l2_prio_state *prio; 105 106 /* device info */ 107 char name[32]; 108 int vfl_type; 109 /* 'minor' is set to -1 if the registration failed */ 110 int minor; 111 u16 num; 112 /* use bitops to set/clear/test flags */ 113 unsigned long flags; 114 /* attribute to differentiate multiple indices on one physical device */ 115 int index; 116 117 /* V4L2 file handles */ 118 spinlock_t fh_lock; /* Lock for all v4l2_fhs */ 119 struct list_head fh_list; /* List of struct v4l2_fh */ 120 121 int debug; /* Activates debug level*/ 122 123 /* Video standard vars */ 124 v4l2_std_id tvnorms; /* Supported tv norms */ 125 v4l2_std_id current_norm; /* Current tvnorm */ 126 127 /* callbacks */ 128 void (*release)(struct video_device *vdev); 129 130 /* ioctl callbacks */ 131 const struct v4l2_ioctl_ops *ioctl_ops; 132 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); 133 134 /* serialization lock */ 135 DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE); 136 struct mutex *lock; 137 }; 138 139 #define media_entity_to_video_device(__e) \ 140 container_of(__e, struct video_device, entity) 141 /* dev to video-device */ 142 #define to_video_device(cd) container_of(cd, struct video_device, dev) 143 144 int __must_check __video_register_device(struct video_device *vdev, int type, 145 int nr, int warn_if_nr_in_use, struct module *owner); 146 147 /* Register video devices. Note that if video_register_device fails, 148 the release() callback of the video_device structure is *not* called, so 149 the caller is responsible for freeing any data. Usually that means that 150 you call video_device_release() on failure. */ 151 static inline int __must_check video_register_device(struct video_device *vdev, 152 int type, int nr) 153 { 154 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 155 } 156 157 /* Same as video_register_device, but no warning is issued if the desired 158 device node number was already in use. */ 159 static inline int __must_check video_register_device_no_warn( 160 struct video_device *vdev, int type, int nr) 161 { 162 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 163 } 164 165 /* Unregister video devices. Will do nothing if vdev == NULL or 166 video_is_registered() returns false. */ 167 void video_unregister_device(struct video_device *vdev); 168 169 /* helper functions to alloc/release struct video_device, the 170 latter can also be used for video_device->release(). */ 171 struct video_device * __must_check video_device_alloc(void); 172 173 /* this release function frees the vdev pointer */ 174 void video_device_release(struct video_device *vdev); 175 176 /* this release function does nothing, use when the video_device is a 177 static global struct. Note that having a static video_device is 178 a dubious construction at best. */ 179 void video_device_release_empty(struct video_device *vdev); 180 181 /* returns true if cmd is a known V4L2 ioctl */ 182 bool v4l2_is_known_ioctl(unsigned int cmd); 183 184 /* mark that this command shouldn't use core locking */ 185 static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd) 186 { 187 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 188 set_bit(_IOC_NR(cmd), vdev->disable_locking); 189 } 190 191 /* Mark that this command isn't implemented. This must be called before 192 video_device_register. See also the comments in determine_valid_ioctls(). 193 This function allows drivers to provide just one v4l2_ioctl_ops struct, but 194 disable ioctls based on the specific card that is actually found. */ 195 static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd) 196 { 197 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 198 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 199 } 200 201 /* helper functions to access driver private data. */ 202 static inline void *video_get_drvdata(struct video_device *vdev) 203 { 204 return dev_get_drvdata(&vdev->dev); 205 } 206 207 static inline void video_set_drvdata(struct video_device *vdev, void *data) 208 { 209 dev_set_drvdata(&vdev->dev, data); 210 } 211 212 struct video_device *video_devdata(struct file *file); 213 214 /* Combine video_get_drvdata and video_devdata as this is 215 used very often. */ 216 static inline void *video_drvdata(struct file *file) 217 { 218 return video_get_drvdata(video_devdata(file)); 219 } 220 221 static inline const char *video_device_node_name(struct video_device *vdev) 222 { 223 return dev_name(&vdev->dev); 224 } 225 226 static inline int video_is_registered(struct video_device *vdev) 227 { 228 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 229 } 230 231 #endif /* _V4L2_DEV_H */ 232