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