videobuf-core.h 6.8 KB

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  1. /* SPDX-License-Identifier: GPL-2.0-only */
  2. /*
  3. * generic helper functions for handling video4linux capture buffers
  4. *
  5. * (c) 2007 Mauro Carvalho Chehab, <[email protected]>
  6. *
  7. * Highly based on video-buf written originally by:
  8. * (c) 2001,02 Gerd Knorr <[email protected]>
  9. * (c) 2006 Mauro Carvalho Chehab, <[email protected]>
  10. * (c) 2006 Ted Walther and John Sokol
  11. */
  12. #ifndef _VIDEOBUF_CORE_H
  13. #define _VIDEOBUF_CORE_H
  14. #include <linux/poll.h>
  15. #include <linux/videodev2.h>
  16. #define UNSET (-1U)
  17. struct videobuf_buffer;
  18. struct videobuf_queue;
  19. /* --------------------------------------------------------------------- */
  20. /*
  21. * A small set of helper functions to manage video4linux buffers.
  22. *
  23. * struct videobuf_buffer holds the data structures used by the helper
  24. * functions, additionally some commonly used fields for v4l buffers
  25. * (width, height, lists, waitqueue) are in there. That struct should
  26. * be used as first element in the drivers buffer struct.
  27. *
  28. * about the mmap helpers (videobuf_mmap_*):
  29. *
  30. * The mmaper function allows to map any subset of contiguous buffers.
  31. * This includes one mmap() call for all buffers (which the original
  32. * video4linux API uses) as well as one mmap() for every single buffer
  33. * (which v4l2 uses).
  34. *
  35. * If there is a valid mapping for a buffer, buffer->baddr/bsize holds
  36. * userspace address + size which can be fed into the
  37. * videobuf_dma_init_user function listed above.
  38. *
  39. */
  40. struct videobuf_mapping {
  41. unsigned int count;
  42. struct videobuf_queue *q;
  43. };
  44. enum videobuf_state {
  45. VIDEOBUF_NEEDS_INIT = 0,
  46. VIDEOBUF_PREPARED = 1,
  47. VIDEOBUF_QUEUED = 2,
  48. VIDEOBUF_ACTIVE = 3,
  49. VIDEOBUF_DONE = 4,
  50. VIDEOBUF_ERROR = 5,
  51. VIDEOBUF_IDLE = 6,
  52. };
  53. struct videobuf_buffer {
  54. unsigned int i;
  55. u32 magic;
  56. /* info about the buffer */
  57. unsigned int width;
  58. unsigned int height;
  59. unsigned int bytesperline; /* use only if != 0 */
  60. unsigned long size;
  61. enum v4l2_field field;
  62. enum videobuf_state state;
  63. struct list_head stream; /* QBUF/DQBUF list */
  64. /* touched by irq handler */
  65. struct list_head queue;
  66. wait_queue_head_t done;
  67. unsigned int field_count;
  68. u64 ts;
  69. /* Memory type */
  70. enum v4l2_memory memory;
  71. /* buffer size */
  72. size_t bsize;
  73. /* buffer offset (mmap + overlay) */
  74. size_t boff;
  75. /* buffer addr (userland ptr!) */
  76. unsigned long baddr;
  77. /* for mmap'ed buffers */
  78. struct videobuf_mapping *map;
  79. /* Private pointer to allow specific methods to store their data */
  80. int privsize;
  81. void *priv;
  82. };
  83. struct videobuf_queue_ops {
  84. int (*buf_setup)(struct videobuf_queue *q,
  85. unsigned int *count, unsigned int *size);
  86. int (*buf_prepare)(struct videobuf_queue *q,
  87. struct videobuf_buffer *vb,
  88. enum v4l2_field field);
  89. void (*buf_queue)(struct videobuf_queue *q,
  90. struct videobuf_buffer *vb);
  91. void (*buf_release)(struct videobuf_queue *q,
  92. struct videobuf_buffer *vb);
  93. };
  94. #define MAGIC_QTYPE_OPS 0x12261003
  95. /* Helper operations - device type dependent */
  96. struct videobuf_qtype_ops {
  97. u32 magic;
  98. struct videobuf_buffer *(*alloc_vb)(size_t size);
  99. void *(*vaddr) (struct videobuf_buffer *buf);
  100. int (*iolock) (struct videobuf_queue *q,
  101. struct videobuf_buffer *vb,
  102. struct v4l2_framebuffer *fbuf);
  103. int (*sync) (struct videobuf_queue *q,
  104. struct videobuf_buffer *buf);
  105. int (*mmap_mapper) (struct videobuf_queue *q,
  106. struct videobuf_buffer *buf,
  107. struct vm_area_struct *vma);
  108. };
  109. struct videobuf_queue {
  110. struct mutex vb_lock;
  111. struct mutex *ext_lock;
  112. spinlock_t *irqlock;
  113. struct device *dev;
  114. wait_queue_head_t wait; /* wait if queue is empty */
  115. enum v4l2_buf_type type;
  116. unsigned int msize;
  117. enum v4l2_field field;
  118. enum v4l2_field last; /* for field=V4L2_FIELD_ALTERNATE */
  119. struct videobuf_buffer *bufs[VIDEO_MAX_FRAME];
  120. const struct videobuf_queue_ops *ops;
  121. struct videobuf_qtype_ops *int_ops;
  122. unsigned int streaming:1;
  123. unsigned int reading:1;
  124. /* capture via mmap() + ioctl(QBUF/DQBUF) */
  125. struct list_head stream;
  126. /* capture via read() */
  127. unsigned int read_off;
  128. struct videobuf_buffer *read_buf;
  129. /* driver private data */
  130. void *priv_data;
  131. };
  132. static inline void videobuf_queue_lock(struct videobuf_queue *q)
  133. {
  134. if (!q->ext_lock)
  135. mutex_lock(&q->vb_lock);
  136. }
  137. static inline void videobuf_queue_unlock(struct videobuf_queue *q)
  138. {
  139. if (!q->ext_lock)
  140. mutex_unlock(&q->vb_lock);
  141. }
  142. int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
  143. int non_blocking, int intr);
  144. int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
  145. struct v4l2_framebuffer *fbuf);
  146. struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q);
  147. /* Used on videobuf-dvb */
  148. void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
  149. struct videobuf_buffer *buf);
  150. void videobuf_queue_core_init(struct videobuf_queue *q,
  151. const struct videobuf_queue_ops *ops,
  152. struct device *dev,
  153. spinlock_t *irqlock,
  154. enum v4l2_buf_type type,
  155. enum v4l2_field field,
  156. unsigned int msize,
  157. void *priv,
  158. struct videobuf_qtype_ops *int_ops,
  159. struct mutex *ext_lock);
  160. int videobuf_queue_is_busy(struct videobuf_queue *q);
  161. void videobuf_queue_cancel(struct videobuf_queue *q);
  162. enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
  163. int videobuf_reqbufs(struct videobuf_queue *q,
  164. struct v4l2_requestbuffers *req);
  165. int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
  166. int videobuf_qbuf(struct videobuf_queue *q,
  167. struct v4l2_buffer *b);
  168. int videobuf_dqbuf(struct videobuf_queue *q,
  169. struct v4l2_buffer *b, int nonblocking);
  170. int videobuf_streamon(struct videobuf_queue *q);
  171. int videobuf_streamoff(struct videobuf_queue *q);
  172. void videobuf_stop(struct videobuf_queue *q);
  173. int videobuf_read_start(struct videobuf_queue *q);
  174. void videobuf_read_stop(struct videobuf_queue *q);
  175. ssize_t videobuf_read_stream(struct videobuf_queue *q,
  176. char __user *data, size_t count, loff_t *ppos,
  177. int vbihack, int nonblocking);
  178. ssize_t videobuf_read_one(struct videobuf_queue *q,
  179. char __user *data, size_t count, loff_t *ppos,
  180. int nonblocking);
  181. __poll_t videobuf_poll_stream(struct file *file,
  182. struct videobuf_queue *q,
  183. poll_table *wait);
  184. int videobuf_mmap_setup(struct videobuf_queue *q,
  185. unsigned int bcount, unsigned int bsize,
  186. enum v4l2_memory memory);
  187. int __videobuf_mmap_setup(struct videobuf_queue *q,
  188. unsigned int bcount, unsigned int bsize,
  189. enum v4l2_memory memory);
  190. int videobuf_mmap_free(struct videobuf_queue *q);
  191. int videobuf_mmap_mapper(struct videobuf_queue *q,
  192. struct vm_area_struct *vma);
  193. #endif