v4l2-dev.h 6.1 KB

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  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. #include <linux/poll.h>
  12. #include <linux/fs.h>
  13. #include <linux/device.h>
  14. #include <linux/cdev.h>
  15. #include <linux/mutex.h>
  16. #include <linux/videodev2.h>
  17. #include <media/media-entity.h>
  18. #define VIDEO_MAJOR 81
  19. #define VFL_TYPE_GRABBER 0
  20. #define VFL_TYPE_VBI 1
  21. #define VFL_TYPE_RADIO 2
  22. #define VFL_TYPE_SUBDEV 3
  23. #define VFL_TYPE_MAX 4
  24. struct v4l2_ioctl_callbacks;
  25. struct video_device;
  26. struct v4l2_device;
  27. struct v4l2_ctrl_handler;
  28. /* Flag to mark the video_device struct as registered.
  29. Drivers can clear this flag if they want to block all future
  30. device access. It is cleared by video_unregister_device. */
  31. #define V4L2_FL_REGISTERED (0)
  32. /* file->private_data points to struct v4l2_fh */
  33. #define V4L2_FL_USES_V4L2_FH (1)
  34. /* Use the prio field of v4l2_fh for core priority checking */
  35. #define V4L2_FL_USE_FH_PRIO (2)
  36. /* Priority helper functions */
  37. struct v4l2_prio_state {
  38. atomic_t prios[4];
  39. };
  40. void v4l2_prio_init(struct v4l2_prio_state *global);
  41. int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local,
  42. enum v4l2_priority new);
  43. void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local);
  44. void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local);
  45. enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global);
  46. int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local);
  47. struct v4l2_file_operations {
  48. struct module *owner;
  49. ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  50. ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  51. unsigned int (*poll) (struct file *, struct poll_table_struct *);
  52. long (*ioctl) (struct file *, unsigned int, unsigned long);
  53. long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  54. unsigned long (*get_unmapped_area) (struct file *, unsigned long,
  55. unsigned long, unsigned long, unsigned long);
  56. int (*mmap) (struct file *, struct vm_area_struct *);
  57. int (*open) (struct file *);
  58. int (*release) (struct file *);
  59. };
  60. /*
  61. * Newer version of video_device, handled by videodev2.c
  62. * This version moves redundant code from video device code to
  63. * the common handler
  64. */
  65. struct video_device
  66. {
  67. #if defined(CONFIG_MEDIA_CONTROLLER)
  68. struct media_entity entity;
  69. #endif
  70. /* device ops */
  71. const struct v4l2_file_operations *fops;
  72. /* sysfs */
  73. struct device dev; /* v4l device */
  74. struct cdev *cdev; /* character device */
  75. /* Set either parent or v4l2_dev if your driver uses v4l2_device */
  76. struct device *parent; /* device parent */
  77. struct v4l2_device *v4l2_dev; /* v4l2_device parent */
  78. /* Control handler associated with this device node. May be NULL. */
  79. struct v4l2_ctrl_handler *ctrl_handler;
  80. /* Priority state. If NULL, then v4l2_dev->prio will be used. */
  81. struct v4l2_prio_state *prio;
  82. /* device info */
  83. char name[32];
  84. int vfl_type;
  85. /* 'minor' is set to -1 if the registration failed */
  86. int minor;
  87. u16 num;
  88. /* use bitops to set/clear/test flags */
  89. unsigned long flags;
  90. /* attribute to differentiate multiple indices on one physical device */
  91. int index;
  92. /* V4L2 file handles */
  93. spinlock_t fh_lock; /* Lock for all v4l2_fhs */
  94. struct list_head fh_list; /* List of struct v4l2_fh */
  95. int debug; /* Activates debug level*/
  96. /* Video standard vars */
  97. v4l2_std_id tvnorms; /* Supported tv norms */
  98. v4l2_std_id current_norm; /* Current tvnorm */
  99. /* callbacks */
  100. void (*release)(struct video_device *vdev);
  101. /* ioctl callbacks */
  102. const struct v4l2_ioctl_ops *ioctl_ops;
  103. /* serialization lock */
  104. struct mutex *lock;
  105. };
  106. #define media_entity_to_video_device(__e) \
  107. container_of(__e, struct video_device, entity)
  108. /* dev to video-device */
  109. #define to_video_device(cd) container_of(cd, struct video_device, dev)
  110. int __must_check __video_register_device(struct video_device *vdev, int type,
  111. int nr, int warn_if_nr_in_use, struct module *owner);
  112. /* Register video devices. Note that if video_register_device fails,
  113. the release() callback of the video_device structure is *not* called, so
  114. the caller is responsible for freeing any data. Usually that means that
  115. you call video_device_release() on failure. */
  116. static inline int __must_check video_register_device(struct video_device *vdev,
  117. int type, int nr)
  118. {
  119. return __video_register_device(vdev, type, nr, 1, vdev->fops->owner);
  120. }
  121. /* Same as video_register_device, but no warning is issued if the desired
  122. device node number was already in use. */
  123. static inline int __must_check video_register_device_no_warn(
  124. struct video_device *vdev, int type, int nr)
  125. {
  126. return __video_register_device(vdev, type, nr, 0, vdev->fops->owner);
  127. }
  128. /* Unregister video devices. Will do nothing if vdev == NULL or
  129. video_is_registered() returns false. */
  130. void video_unregister_device(struct video_device *vdev);
  131. /* helper functions to alloc/release struct video_device, the
  132. latter can also be used for video_device->release(). */
  133. struct video_device * __must_check video_device_alloc(void);
  134. /* this release function frees the vdev pointer */
  135. void video_device_release(struct video_device *vdev);
  136. /* this release function does nothing, use when the video_device is a
  137. static global struct. Note that having a static video_device is
  138. a dubious construction at best. */
  139. void video_device_release_empty(struct video_device *vdev);
  140. /* helper functions to access driver private data. */
  141. static inline void *video_get_drvdata(struct video_device *vdev)
  142. {
  143. return dev_get_drvdata(&vdev->dev);
  144. }
  145. static inline void video_set_drvdata(struct video_device *vdev, void *data)
  146. {
  147. dev_set_drvdata(&vdev->dev, data);
  148. }
  149. struct video_device *video_devdata(struct file *file);
  150. /* Combine video_get_drvdata and video_devdata as this is
  151. used very often. */
  152. static inline void *video_drvdata(struct file *file)
  153. {
  154. return video_get_drvdata(video_devdata(file));
  155. }
  156. static inline const char *video_device_node_name(struct video_device *vdev)
  157. {
  158. return dev_name(&vdev->dev);
  159. }
  160. static inline int video_is_registered(struct video_device *vdev)
  161. {
  162. return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
  163. }
  164. #endif /* _V4L2_DEV_H */