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 /* device capabilities as used in v4l2_capabilities */ 96 u32 device_caps; 97 98 /* sysfs */ 99 struct device dev; /* v4l device */ 100 struct cdev *cdev; /* character device */ 101 102 struct v4l2_device *v4l2_dev; /* v4l2_device parent */ 103 /* Only set parent if that can't be deduced from v4l2_dev */ 104 struct device *dev_parent; /* device parent */ 105 106 /* Control handler associated with this device node. May be NULL. */ 107 struct v4l2_ctrl_handler *ctrl_handler; 108 109 /* vb2_queue associated with this device node. May be NULL. */ 110 struct vb2_queue *queue; 111 112 /* Priority state. If NULL, then v4l2_dev->prio will be used. */ 113 struct v4l2_prio_state *prio; 114 115 /* device info */ 116 char name[32]; 117 int vfl_type; /* device type */ 118 int vfl_dir; /* receiver, transmitter or m2m */ 119 /* 'minor' is set to -1 if the registration failed */ 120 int minor; 121 u16 num; 122 /* use bitops to set/clear/test flags */ 123 unsigned long flags; 124 /* attribute to differentiate multiple indices on one physical device */ 125 int index; 126 127 /* V4L2 file handles */ 128 spinlock_t fh_lock; /* Lock for all v4l2_fhs */ 129 struct list_head fh_list; /* List of struct v4l2_fh */ 130 131 /* Internal device debug flags, not for use by drivers */ 132 int dev_debug; 133 134 /* Video standard vars */ 135 v4l2_std_id tvnorms; /* Supported tv norms */ 136 137 /* callbacks */ 138 void (*release)(struct video_device *vdev); 139 140 /* ioctl callbacks */ 141 const struct v4l2_ioctl_ops *ioctl_ops; 142 DECLARE_BITMAP(valid_ioctls, BASE_VIDIOC_PRIVATE); 143 144 /* serialization lock */ 145 DECLARE_BITMAP(disable_locking, BASE_VIDIOC_PRIVATE); 146 struct mutex *lock; 147 }; 148 149 #define media_entity_to_video_device(__e) \ 150 container_of(__e, struct video_device, entity) 151 /* dev to video-device */ 152 #define to_video_device(cd) container_of(cd, struct video_device, dev) 153 154 int __must_check __video_register_device(struct video_device *vdev, int type, 155 int nr, int warn_if_nr_in_use, struct module *owner); 156 157 /* Register video devices. Note that if video_register_device fails, 158 the release() callback of the video_device structure is *not* called, so 159 the caller is responsible for freeing any data. Usually that means that 160 you call video_device_release() on failure. */ 161 static inline int __must_check video_register_device(struct video_device *vdev, 162 int type, int nr) 163 { 164 return __video_register_device(vdev, type, nr, 1, vdev->fops->owner); 165 } 166 167 /* Same as video_register_device, but no warning is issued if the desired 168 device node number was already in use. */ 169 static inline int __must_check video_register_device_no_warn( 170 struct video_device *vdev, int type, int nr) 171 { 172 return __video_register_device(vdev, type, nr, 0, vdev->fops->owner); 173 } 174 175 /* Unregister video devices. Will do nothing if vdev == NULL or 176 video_is_registered() returns false. */ 177 void video_unregister_device(struct video_device *vdev); 178 179 /* helper functions to alloc/release struct video_device, the 180 latter can also be used for video_device->release(). */ 181 struct video_device * __must_check video_device_alloc(void); 182 183 /* this release function frees the vdev pointer */ 184 void video_device_release(struct video_device *vdev); 185 186 /* this release function does nothing, use when the video_device is a 187 static global struct. Note that having a static video_device is 188 a dubious construction at best. */ 189 void video_device_release_empty(struct video_device *vdev); 190 191 /* returns true if cmd is a known V4L2 ioctl */ 192 bool v4l2_is_known_ioctl(unsigned int cmd); 193 194 /* mark that this command shouldn't use core locking */ 195 static inline void v4l2_disable_ioctl_locking(struct video_device *vdev, unsigned int cmd) 196 { 197 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 198 set_bit(_IOC_NR(cmd), vdev->disable_locking); 199 } 200 201 /* Mark that this command isn't implemented. This must be called before 202 video_device_register. See also the comments in determine_valid_ioctls(). 203 This function allows drivers to provide just one v4l2_ioctl_ops struct, but 204 disable ioctls based on the specific card that is actually found. */ 205 static inline void v4l2_disable_ioctl(struct video_device *vdev, unsigned int cmd) 206 { 207 if (_IOC_NR(cmd) < BASE_VIDIOC_PRIVATE) 208 set_bit(_IOC_NR(cmd), vdev->valid_ioctls); 209 } 210 211 /* helper functions to access driver private data. */ 212 static inline void *video_get_drvdata(struct video_device *vdev) 213 { 214 return dev_get_drvdata(&vdev->dev); 215 } 216 217 static inline void video_set_drvdata(struct video_device *vdev, void *data) 218 { 219 dev_set_drvdata(&vdev->dev, data); 220 } 221 222 struct video_device *video_devdata(struct file *file); 223 224 /* Combine video_get_drvdata and video_devdata as this is 225 used very often. */ 226 static inline void *video_drvdata(struct file *file) 227 { 228 return video_get_drvdata(video_devdata(file)); 229 } 230 231 static inline const char *video_device_node_name(struct video_device *vdev) 232 { 233 return dev_name(&vdev->dev); 234 } 235 236 static inline int video_is_registered(struct video_device *vdev) 237 { 238 return test_bit(V4L2_FL_REGISTERED, &vdev->flags); 239 } 240 241 #endif /* _V4L2_DEV_H */ 242