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_SDR 4 28 #define VFL_TYPE_MAX 5 29 30 /* Is this a receiver, transmitter or mem-to-mem? */ 31 /* Ignored for VFL_TYPE_SUBDEV. */ 32 #define VFL_DIR_RX 0 33 #define VFL_DIR_TX 1 34 #define VFL_DIR_M2M 2 35 36 struct v4l2_ioctl_callbacks; 37 struct video_device; 38 struct v4l2_device; 39 struct v4l2_ctrl_handler; 40 41 /* Flag to mark the video_device struct as registered. 42 Drivers can clear this flag if they want to block all future 43 device access. It is cleared by video_unregister_device. */ 44 #define V4L2_FL_REGISTERED (0) 45 /* file->private_data points to struct v4l2_fh */ 46 #define V4L2_FL_USES_V4L2_FH (1) 47 48 /* Priority helper functions */ 49 50 struct v4l2_prio_state { 51 atomic_t prios[4]; 52 }; 53 54 void v4l2_prio_init(struct v4l2_prio_state *global); 55 int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, 56 enum v4l2_priority new); 57 void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local); 58 void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local); 59 enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global); 60 int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local); 61 62 63 struct v4l2_file_operations { 64 struct module *owner; 65 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 66 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 67 unsigned int (*poll) (struct file *, struct poll_table_struct *); 68 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 69 #ifdef CONFIG_COMPAT 70 long (*compat_ioctl32) (struct file *, unsigned int, unsigned long); 71 #endif 72 unsigned long (*get_unmapped_area) (struct file *, unsigned long, 73 unsigned long, unsigned long, unsigned long); 74 int (*mmap) (struct file *, struct vm_area_struct *); 75 int (*open) (struct file *); 76 int (*release) (struct file *); 77 }; 78 79 /* 80 * Newer version of video_device, handled by videodev2.c 81 * This version moves redundant code from video device code to 82 * the common handler 83 */ 84 85 struct video_device 86 { 87 #if defined(CONFIG_MEDIA_CONTROLLER) 88 struct media_entity entity; 89 struct media_intf_devnode *intf_devnode; 90 struct media_pipeline pipe; 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 /* Internal device debug flags, not for use by drivers */ 129 int dev_debug; 130 131 /* Video standard vars */ 132 v4l2_std_id tvnorms; /* Supported tv norms */ 133 134 /* callbacks */ 135 void (*release)(struct video_device *vdev); 136 137 /* ioctl callbacks */ 138 const struct v4l2_ioctl_ops *ioctl_ops; 139 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); 140 141 /* serialization lock */ 142 DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE); 143 struct mutex *lock; 144 }; 145 146 #define media_entity_to_video_device(__e) \ 147 container_of(__e, struct video_device, entity) 148 /* dev to video-device */ 149 #define to_video_device(cd) container_of(cd, struct video_device, dev) 150 151 int __must_check __video_register_device(struct video_device *vdev, int type, 152 int nr, int warn_if_nr_in_use, struct module *owner); 153 154 /* Register video devices. Note that if video_register_device fails, 155 the release() callback of the video_device structure is *not* called, so 156 the caller is responsible for freeing any data. Usually that means that 157 you call video_device_release() on failure. */ 158 static inline int __must_check video_register_device(struct video_device *vdev, 159 int type, int nr) 160 { 161 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 162 } 163 164 /* Same as video_register_device, but no warning is issued if the desired 165 device node number was already in use. */ 166 static inline int __must_check video_register_device_no_warn( 167 struct video_device *vdev, int type, int nr) 168 { 169 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 170 } 171 172 /* Unregister video devices. Will do nothing if vdev == NULL or 173 video_is_registered() returns false. */ 174 void video_unregister_device(struct video_device *vdev); 175 176 /* helper functions to alloc/release struct video_device, the 177 latter can also be used for video_device->release(). */ 178 struct video_device * __must_check video_device_alloc(void); 179 180 /* this release function frees the vdev pointer */ 181 void video_device_release(struct video_device *vdev); 182 183 /* this release function does nothing, use when the video_device is a 184 static global struct. Note that having a static video_device is 185 a dubious construction at best. */ 186 void video_device_release_empty(struct video_device *vdev); 187 188 /* returns true if cmd is a known V4L2 ioctl */ 189 bool v4l2_is_known_ioctl(unsigned int cmd); 190 191 /* mark that this command shouldn't use core locking */ 192 static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd) 193 { 194 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 195 set_bit(_IOC_NR(cmd), vdev->disable_locking); 196 } 197 198 /* Mark that this command isn't implemented. This must be called before 199 video_device_register. See also the comments in determine_valid_ioctls(). 200 This function allows drivers to provide just one v4l2_ioctl_ops struct, but 201 disable ioctls based on the specific card that is actually found. */ 202 static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd) 203 { 204 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 205 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 206 } 207 208 /* helper functions to access driver private data. */ 209 static inline void *video_get_drvdata(struct video_device *vdev) 210 { 211 return dev_get_drvdata(&vdev->dev); 212 } 213 214 static inline void video_set_drvdata(struct video_device *vdev, void *data) 215 { 216 dev_set_drvdata(&vdev->dev, data); 217 } 218 219 struct video_device *video_devdata(struct file *file); 220 221 /* Combine video_get_drvdata and video_devdata as this is 222 used very often. */ 223 static inline void *video_drvdata(struct file *file) 224 { 225 return video_get_drvdata(video_devdata(file)); 226 } 227 228 static inline const char *video_device_node_name(struct video_device *vdev) 229 { 230 return dev_name(&vdev->dev); 231 } 232 233 static inline int video_is_registered(struct video_device *vdev) 234 { 235 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 236 } 237 238 #endif /* _V4L2_DEV_H */ 239