v4l2-dev.h 4.7 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. #define VIDEO_MAJOR 81
  18. #define VFL_TYPE_GRABBER 0
  19. #define VFL_TYPE_VBI 1
  20. #define VFL_TYPE_RADIO 2
  21. #define VFL_TYPE_MAX 3
  22. struct v4l2_ioctl_callbacks;
  23. struct video_device;
  24. struct v4l2_device;
  25. struct v4l2_ctrl_handler;
  26. /* Flag to mark the video_device struct as registered.
  27. Drivers can clear this flag if they want to block all future
  28. device access. It is cleared by video_unregister_device. */
  29. #define V4L2_FL_REGISTERED (0)
  30. #define V4L2_FL_USES_V4L2_FH (1)
  31. struct v4l2_file_operations {
  32. struct module *owner;
  33. ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
  34. ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
  35. unsigned int (*poll) (struct file *, struct poll_table_struct *);
  36. long (*ioctl) (struct file *, unsigned int, unsigned long);
  37. long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
  38. int (*mmap) (struct file *, struct vm_area_struct *);
  39. int (*open) (struct file *);
  40. int (*release) (struct file *);
  41. };
  42. /*
  43. * Newer version of video_device, handled by videodev2.c
  44. * This version moves redundant code from video device code to
  45. * the common handler
  46. */
  47. struct video_device
  48. {
  49. /* device ops */
  50. const struct v4l2_file_operations *fops;
  51. /* sysfs */
  52. struct device dev; /* v4l device */
  53. struct cdev *cdev; /* character device */
  54. /* Set either parent or v4l2_dev if your driver uses v4l2_device */
  55. struct device *parent; /* device parent */
  56. struct v4l2_device *v4l2_dev; /* v4l2_device parent */
  57. /* Control handler associated with this device node. May be NULL. */
  58. struct v4l2_ctrl_handler *ctrl_handler;
  59. /* device info */
  60. char name[32];
  61. int vfl_type;
  62. /* 'minor' is set to -1 if the registration failed */
  63. int minor;
  64. u16 num;
  65. /* use bitops to set/clear/test flags */
  66. unsigned long flags;
  67. /* attribute to differentiate multiple indices on one physical device */
  68. int index;
  69. /* V4L2 file handles */
  70. spinlock_t fh_lock; /* Lock for all v4l2_fhs */
  71. struct list_head fh_list; /* List of struct v4l2_fh */
  72. int debug; /* Activates debug level*/
  73. /* Video standard vars */
  74. v4l2_std_id tvnorms; /* Supported tv norms */
  75. v4l2_std_id current_norm; /* Current tvnorm */
  76. /* callbacks */
  77. void (*release)(struct video_device *vdev);
  78. /* ioctl callbacks */
  79. const struct v4l2_ioctl_ops *ioctl_ops;
  80. };
  81. /* dev to video-device */
  82. #define to_video_device(cd) container_of(cd, struct video_device, dev)
  83. /* Register video devices. Note that if video_register_device fails,
  84. the release() callback of the video_device structure is *not* called, so
  85. the caller is responsible for freeing any data. Usually that means that
  86. you call video_device_release() on failure. */
  87. int __must_check video_register_device(struct video_device *vdev, int type, int nr);
  88. /* Same as video_register_device, but no warning is issued if the desired
  89. device node number was already in use. */
  90. int __must_check video_register_device_no_warn(struct video_device *vdev, int type, int nr);
  91. /* Unregister video devices. Will do nothing if vdev == NULL or
  92. video_is_registered() returns false. */
  93. void video_unregister_device(struct video_device *vdev);
  94. /* helper functions to alloc/release struct video_device, the
  95. latter can also be used for video_device->release(). */
  96. struct video_device * __must_check video_device_alloc(void);
  97. /* this release function frees the vdev pointer */
  98. void video_device_release(struct video_device *vdev);
  99. /* this release function does nothing, use when the video_device is a
  100. static global struct. Note that having a static video_device is
  101. a dubious construction at best. */
  102. void video_device_release_empty(struct video_device *vdev);
  103. /* helper functions to access driver private data. */
  104. static inline void *video_get_drvdata(struct video_device *vdev)
  105. {
  106. return dev_get_drvdata(&vdev->dev);
  107. }
  108. static inline void video_set_drvdata(struct video_device *vdev, void *data)
  109. {
  110. dev_set_drvdata(&vdev->dev, data);
  111. }
  112. struct video_device *video_devdata(struct file *file);
  113. /* Combine video_get_drvdata and video_devdata as this is
  114. used very often. */
  115. static inline void *video_drvdata(struct file *file)
  116. {
  117. return video_get_drvdata(video_devdata(file));
  118. }
  119. static inline const char *video_device_node_name(struct video_device *vdev)
  120. {
  121. return dev_name(&vdev->dev);
  122. }
  123. static inline int video_is_registered(struct video_device *vdev)
  124. {
  125. return test_bit(V4L2_FL_REGISTERED, &vdev->flags);
  126. }
  127. #endif /* _V4L2_DEV_H */