include/media/videobuf-core.h

   1 /*
   2  * generic helper functions for handling video4linux capture buffers
   3  *
   4  * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
   5  *
   6  * Highly based on video-buf written originally by:
   7  * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
   8  * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
   9  * (c) 2006 Ted Walther and John Sokol
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2
  14  */
  15
  16 #include <linux/poll.h>
  17 #ifdef CONFIG_VIDEO_V4L1_COMPAT
  18 #include <linux/videodev.h>
  19 #endif
  20 #include <linux/videodev2.h>
  21
  22 #define UNSET (-1U)
  23
  24
  25 struct videobuf_buffer;
  26 struct videobuf_queue;
  27
  28 /* --------------------------------------------------------------------- */
  29
  30 /*
  31  * A small set of helper functions to manage video4linux buffers.
  32  *
  33  * struct videobuf_buffer holds the data structures used by the helper
  34  * functions, additionally some commonly used fields for v4l buffers
  35  * (width, height, lists, waitqueue) are in there.  That struct should
  36  * be used as first element in the drivers buffer struct.
  37  *
  38  * about the mmap helpers (videobuf_mmap_*):
  39  *
  40  * The mmaper function allows to map any subset of contingous buffers.
  41  * This includes one mmap() call for all buffers (which the original
  42  * video4linux API uses) as well as one mmap() for every single buffer
  43  * (which v4l2 uses).
  44  *
  45  * If there is a valid mapping for a buffer, buffer->baddr/bsize holds
  46  * userspace address + size which can be feeded into the
  47  * videobuf_dma_init_user function listed above.
  48  *
  49  */
  50
  51 struct videobuf_mapping {
  52         unsigned int count;
  53         unsigned long start;
  54         unsigned long end;
  55         struct videobuf_queue *q;
  56 };
  57
  58 enum videobuf_state {
  59         VIDEOBUF_NEEDS_INIT = 0,
  60         VIDEOBUF_PREPARED   = 1,
  61         VIDEOBUF_QUEUED     = 2,
  62         VIDEOBUF_ACTIVE     = 3,
  63         VIDEOBUF_DONE       = 4,
  64         VIDEOBUF_ERROR      = 5,
  65         VIDEOBUF_IDLE       = 6,
  66 };
  67
  68 struct videobuf_buffer {
  69         unsigned int            i;
  70         u32                     magic;
  71
  72         /* info about the buffer */
  73         unsigned int            width;
  74         unsigned int            height;
  75         unsigned int            bytesperline; /* use only if != 0 */
  76         unsigned long           size;
  77         unsigned int            input;
  78         enum v4l2_field         field;
  79         enum videobuf_state     state;
  80         struct list_head        stream;  /* QBUF/DQBUF list */
  81
  82         /* touched by irq handler */
  83         struct list_head        queue;
  84         wait_queue_head_t       done;
  85         unsigned int            field_count;
  86         struct timeval          ts;
  87
  88         /* Memory type */
  89         enum v4l2_memory        memory;
  90
  91         /* buffer size */
  92         size_t                  bsize;
  93
  94         /* buffer offset (mmap + overlay) */
  95         size_t                  boff;
  96
  97         /* buffer addr (userland ptr!) */
  98         unsigned long           baddr;
  99
 100         /* for mmap'ed buffers */
 101         struct videobuf_mapping *map;
 102
 103         /* Private pointer to allow specific methods to store their data */
 104         int                     privsize;
 105         void                    *priv;
 106 };
 107
 108 struct videobuf_queue_ops {
 109         int (*buf_setup)(struct videobuf_queue *q,
 110                          unsigned int *count, unsigned int *size);
 111         int (*buf_prepare)(struct videobuf_queue *q,
 112                            struct videobuf_buffer *vb,
 113                            enum v4l2_field field);
 114         void (*buf_queue)(struct videobuf_queue *q,
 115                           struct videobuf_buffer *vb);
 116         void (*buf_release)(struct videobuf_queue *q,
 117                             struct videobuf_buffer *vb);
 118 };
 119
 120 #define MAGIC_QTYPE_OPS 0x12261003
 121
 122 /* Helper operations - device type dependent */
 123 struct videobuf_qtype_ops {
 124         u32                     magic;
 125
 126         void* (*alloc)          (size_t size);
 127         int (*iolock)           (struct videobuf_queue* q,
 128                                  struct videobuf_buffer *vb,
 129                                  struct v4l2_framebuffer *fbuf);
 130         int (*mmap)             (struct videobuf_queue *q,
 131                                  unsigned int *count,
 132                                  unsigned int *size,
 133                                  enum v4l2_memory memory);
 134         int (*sync)             (struct videobuf_queue* q,
 135                                  struct videobuf_buffer *buf);
 136         int (*video_copy_to_user)(struct videobuf_queue *q,
 137                                  char __user *data,
 138                                  size_t count,
 139                                  int nonblocking);
 140         int (*copy_stream)      (struct videobuf_queue *q,
 141                                  char __user *data,
 142                                  size_t count,
 143                                  size_t pos,
 144                                  int vbihack,
 145                                  int nonblocking);
 146         int (*mmap_free)        (struct videobuf_queue *q);
 147         int (*mmap_mapper)      (struct videobuf_queue *q,
 148                                 struct vm_area_struct *vma);
 149 };
 150
 151 struct videobuf_queue {
 152         struct mutex               lock;
 153         spinlock_t                 *irqlock;
 154         void                       *dev; /* on pci, points to struct pci_dev */
 155
 156         enum v4l2_buf_type         type;
 157         unsigned int               inputs; /* for V4L2_BUF_FLAG_INPUT */
 158         unsigned int               msize;
 159         enum v4l2_field            field;
 160         enum v4l2_field            last;   /* for field=V4L2_FIELD_ALTERNATE */
 161         struct videobuf_buffer     *bufs[VIDEO_MAX_FRAME];
 162         struct videobuf_queue_ops  *ops;
 163         struct videobuf_qtype_ops  *int_ops;
 164
 165         unsigned int               streaming:1;
 166         unsigned int               reading:1;
 167         unsigned int               is_mmapped:1;
 168
 169         /* capture via mmap() + ioctl(QBUF/DQBUF) */
 170         struct list_head           stream;
 171
 172         /* capture via read() */
 173         unsigned int               read_off;
 174         struct videobuf_buffer     *read_buf;
 175
 176         /* driver private data */
 177         void                       *priv_data;
 178 };
 179
 180 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
 181 int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
 182                 struct v4l2_framebuffer *fbuf);
 183
 184 void *videobuf_alloc(struct videobuf_queue* q);
 185
 186 void videobuf_queue_core_init(struct videobuf_queue *q,
 187                          struct videobuf_queue_ops *ops,
 188                          void *dev,
 189                          spinlock_t *irqlock,
 190                          enum v4l2_buf_type type,
 191                          enum v4l2_field field,
 192                          unsigned int msize,
 193                          void *priv,
 194                          struct videobuf_qtype_ops *int_ops);
 195 int  videobuf_queue_is_busy(struct videobuf_queue *q);
 196 void videobuf_queue_cancel(struct videobuf_queue *q);
 197
 198 enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
 199 int videobuf_reqbufs(struct videobuf_queue *q,
 200                      struct v4l2_requestbuffers *req);
 201 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
 202 int videobuf_qbuf(struct videobuf_queue *q,
 203                   struct v4l2_buffer *b);
 204 int videobuf_dqbuf(struct videobuf_queue *q,
 205                    struct v4l2_buffer *b, int nonblocking);
 206 #ifdef CONFIG_VIDEO_V4L1_COMPAT
 207 int videobuf_cgmbuf(struct videobuf_queue *q,
 208                     struct video_mbuf *mbuf, int count);
 209 #endif
 210 int videobuf_streamon(struct videobuf_queue *q);
 211 int videobuf_streamoff(struct videobuf_queue *q);
 212
 213 void videobuf_stop(struct videobuf_queue *q);
 214
 215 int videobuf_read_start(struct videobuf_queue *q);
 216 void videobuf_read_stop(struct videobuf_queue *q);
 217 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 218                              char __user *data, size_t count, loff_t *ppos,
 219                              int vbihack, int nonblocking);
 220 ssize_t videobuf_read_one(struct videobuf_queue *q,
 221                           char __user *data, size_t count, loff_t *ppos,
 222                           int nonblocking);
 223 unsigned int videobuf_poll_stream(struct file *file,
 224                                   struct videobuf_queue *q,
 225                                   poll_table *wait);
 226
 227 int videobuf_mmap_setup(struct videobuf_queue *q,
 228                         unsigned int bcount, unsigned int bsize,
 229                         enum v4l2_memory memory);
 230 int videobuf_mmap_free(struct videobuf_queue *q);
 231 int videobuf_mmap_mapper(struct videobuf_queue *q,
 232                          struct vm_area_struct *vma);
 233
 234 /* --------------------------------------------------------------------- */
 235
 236 /*
 237  * Local variables:
 238  * c-basic-offset: 8
 239  * End:
 240  */