v4l2-dev.h 3.6 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_VTX 3
  22. #define VFL_TYPE_MAX 4
  23. struct v4l2_ioctl_callbacks;
  24. /* Flag to mark the video_device struct as unregistered.
  25. Drivers can set this flag if they want to block all future
  26. device access. It is set by video_unregister_device. */
  27. #define V4L2_FL_UNREGISTERED (0)
  28. /*
  29. * Newer version of video_device, handled by videodev2.c
  30. * This version moves redundant code from video device code to
  31. * the common handler
  32. */
  33. struct video_device
  34. {
  35. /* device ops */
  36. const struct file_operations *fops;
  37. /* sysfs */
  38. struct device dev; /* v4l device */
  39. struct cdev *cdev; /* character device */
  40. struct device *parent; /* device parent */
  41. /* device info */
  42. char name[32];
  43. int vfl_type;
  44. /* 'minor' is set to -1 if the registration failed */
  45. int minor;
  46. u16 num;
  47. /* use bitops to set/clear/test flags */
  48. unsigned long flags;
  49. /* attribute to differentiate multiple indices on one physical device */
  50. int index;
  51. int debug; /* Activates debug level*/
  52. /* Video standard vars */
  53. v4l2_std_id tvnorms; /* Supported tv norms */
  54. v4l2_std_id current_norm; /* Current tvnorm */
  55. /* callbacks */
  56. void (*release)(struct video_device *vdev);
  57. /* ioctl callbacks */
  58. const struct v4l2_ioctl_ops *ioctl_ops;
  59. };
  60. /* dev to video-device */
  61. #define to_video_device(cd) container_of(cd, struct video_device, dev)
  62. /* Register video devices. Note that if video_register_device fails,
  63. the release() callback of the video_device structure is *not* called, so
  64. the caller is responsible for freeing any data. Usually that means that
  65. you call video_device_release() on failure.
  66. Also note that vdev->minor is set to -1 if the registration failed. */
  67. int __must_check video_register_device(struct video_device *vdev, int type, int nr);
  68. int __must_check video_register_device_index(struct video_device *vdev,
  69. int type, int nr, int index);
  70. /* Unregister video devices. Will do nothing if vdev == NULL or
  71. vdev->minor < 0. */
  72. void video_unregister_device(struct video_device *vdev);
  73. /* helper functions to alloc/release struct video_device, the
  74. latter can also be used for video_device->release(). */
  75. struct video_device * __must_check video_device_alloc(void);
  76. /* this release function frees the vdev pointer */
  77. void video_device_release(struct video_device *vdev);
  78. /* this release function does nothing, use when the video_device is a
  79. static global struct. Note that having a static video_device is
  80. a dubious construction at best. */
  81. void video_device_release_empty(struct video_device *vdev);
  82. /* helper functions to access driver private data. */
  83. static inline void *video_get_drvdata(struct video_device *vdev)
  84. {
  85. return dev_get_drvdata(&vdev->dev);
  86. }
  87. static inline void video_set_drvdata(struct video_device *vdev, void *data)
  88. {
  89. dev_set_drvdata(&vdev->dev, data);
  90. }
  91. struct video_device *video_devdata(struct file *file);
  92. /* Combine video_get_drvdata and video_devdata as this is
  93. used very often. */
  94. static inline void *video_drvdata(struct file *file)
  95. {
  96. return video_get_drvdata(video_devdata(file));
  97. }
  98. static inline int video_is_unregistered(struct video_device *vdev)
  99. {
  100. return test_bit(V4L2_FL_UNREGISTERED, &vdev->flags);
  101. }
  102. #endif /* _V4L2_DEV_H */