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 /* Is this a receiver, transmitter or mem-to-mem? */ 30 /* Ignored for VFL_TYPE_SUBDEV. */ 31 #define VFL_DIR_RX 0 32 #define VFL_DIR_TX 1 33 #define VFL_DIR_M2M 2 34 35 struct v4l2_ioctl_callbacks; 36 struct video_device; 37 struct v4l2_device; 38 struct v4l2_ctrl_handler; 39 40 /* Flag to mark the video_device struct as registered. 41 Drivers can clear this flag if they want to block all future 42 device access. It is cleared by video_unregister_device. */ 43 #define V4L2_FL_REGISTERED (0) 44 /* file->private_data points to struct v4l2_fh */ 45 #define V4L2_FL_USES_V4L2_FH (1) 46 /* Use the prio field of v4l2_fh for core priority checking */ 47 #define V4L2_FL_USE_FH_PRIO (2) 48 49 /* Priority helper functions */ 50 51 struct v4l2_prio_state { 52 atomic_t prios[4]; 53 }; 54 55 void v4l2_prio_init(struct v4l2_prio_state *global); 56 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, 57 enum v4l2_priority new); 58 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); 59 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); 60 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); 61 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); 62 63 64 struct v4l2_file_operations { 65 struct module *owner; 66 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 67 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 68 unsigned int (*poll) (struct file *, struct poll_table_struct *); 69 long (*ioctl) (struct file *, unsigned int, unsigned long); 70 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 71 #ifdef CONFIG_COMPAT 72 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long); 73 #endif 74 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 75 unsigned long, unsigned long, unsigned long); 76 int (*mmap) (struct file *, struct vm_area_struct *); 77 int (*open) (struct file *); 78 int (*release) (struct file *); 79 }; 80 81 /* 82 * Newer version of video_device, handled by videodev2.c 83 * This version moves redundant code from video device code to 84 * the common handler 85 */ 86 87 struct video_device 88 { 89 #if defined(CONFIG_MEDIA_CONTROLLER) 90 struct media_entity entity; 91 #endif 92 /* device ops */ 93 const struct v4l2_file_operations *fops; 94 95 /* sysfs */ 96 struct device dev; /* v4l device */ 97 struct cdev *cdev; /* character device */ 98 99 struct v4l2_device *v4l2_dev; /* v4l2_device parent */ 100 /* Only set parent if that can't be deduced from v4l2_dev */ 101 struct device *dev_parent; /* device parent */ 102 103 /* Control handler associated with this device node. May be NULL. */ 104 struct v4l2_ctrl_handler *ctrl_handler; 105 106 /* vb2_queue associated with this device node. May be NULL. */ 107 struct vb2_queue *queue; 108 109 /* Priority state. If NULL, then v4l2_dev->prio will be used. */ 110 struct v4l2_prio_state *prio; 111 112 /* device info */ 113 char name[32]; 114 int vfl_type; /* device type */ 115 int vfl_dir; /* receiver, transmitter or m2m */ 116 /* 'minor' is set to -1 if the registration failed */ 117 int minor; 118 u16 num; 119 /* use bitops to set/clear/test flags */ 120 unsigned long flags; 121 /* attribute to differentiate multiple indices on one physical device */ 122 int index; 123 124 /* V4L2 file handles */ 125 spinlock_t fh_lock; /* Lock for all v4l2_fhs */ 126 struct list_head fh_list; /* List of struct v4l2_fh */ 127 128 int debug; /* Activates debug level*/ 129 130 /* Video standard vars */ 131 v4l2_std_id tvnorms; /* Supported tv norms */ 132 133 /* callbacks */ 134 void (*release)(struct video_device *vdev); 135 136 /* ioctl callbacks */ 137 const struct v4l2_ioctl_ops *ioctl_ops; 138 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); 139 140 /* serialization lock */ 141 DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE); 142 struct mutex *lock; 143 }; 144 145 #define media_entity_to_video_device(__e) \ 146 container_of(__e, struct video_device, entity) 147 /* dev to video-device */ 148 #define to_video_device(cd) container_of(cd, struct video_device, dev) 149 150 int __must_check __video_register_device(struct video_device *vdev, int type, 151 int nr, int warn_if_nr_in_use, struct module *owner); 152 153 /* Register video devices. Note that if video_register_device fails, 154 the release() callback of the video_device structure is *not* called, so 155 the caller is responsible for freeing any data. Usually that means that 156 you call video_device_release() on failure. */ 157 static inline int __must_check video_register_device(struct video_device *vdev, 158 int type, int nr) 159 { 160 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 161 } 162 163 /* Same as video_register_device, but no warning is issued if the desired 164 device node number was already in use. */ 165 static inline int __must_check video_register_device_no_warn( 166 struct video_device *vdev, int type, int nr) 167 { 168 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 169 } 170 171 /* Unregister video devices. Will do nothing if vdev == NULL or 172 video_is_registered() returns false. */ 173 void video_unregister_device(struct video_device *vdev); 174 175 /* helper functions to alloc/release struct video_device, the 176 latter can also be used for video_device->release(). */ 177 struct video_device * __must_check video_device_alloc(void); 178 179 /* this release function frees the vdev pointer */ 180 void video_device_release(struct video_device *vdev); 181 182 /* this release function does nothing, use when the video_device is a 183 static global struct. Note that having a static video_device is 184 a dubious construction at best. */ 185 void video_device_release_empty(struct video_device *vdev); 186 187 /* returns true if cmd is a known V4L2 ioctl */ 188 bool v4l2_is_known_ioctl(unsigned int cmd); 189 190 /* mark that this command shouldn't use core locking */ 191 static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd) 192 { 193 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 194 set_bit(_IOC_NR(cmd), vdev->disable_locking); 195 } 196 197 /* Mark that this command isn't implemented. This must be called before 198 video_device_register. See also the comments in determine_valid_ioctls(). 199 This function allows drivers to provide just one v4l2_ioctl_ops struct, but 200 disable ioctls based on the specific card that is actually found. */ 201 static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd) 202 { 203 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 204 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 205 } 206 207 /* helper functions to access driver private data. */ 208 static inline void *video_get_drvdata(struct video_device *vdev) 209 { 210 return dev_get_drvdata(&vdev->dev); 211 } 212 213 static inline void video_set_drvdata(struct video_device *vdev, void *data) 214 { 215 dev_set_drvdata(&vdev->dev, data); 216 } 217 218 struct video_device *video_devdata(struct file *file); 219 220 /* Combine video_get_drvdata and video_devdata as this is 221 used very often. */ 222 static inline void *video_drvdata(struct file *file) 223 { 224 return video_get_drvdata(video_devdata(file)); 225 } 226 227 static inline const char *video_device_node_name(struct video_device *vdev) 228 { 229 return dev_name(&vdev->dev); 230 } 231 232 static inline int video_is_registered(struct video_device *vdev) 233 { 234 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 235 } 236 237 #endif /* _V4L2_DEV_H */ 238