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 #ifndef _VIDEOBUF_CORE_H
  17 #define _VIDEOBUF_CORE_H
  18
  19 #include <linux/poll.h>
  20 #ifdef CONFIG_VIDEO_V4L1_COMPAT
  21 #include <linux/videodev.h>
  22 #endif
  23 #include <linux/videodev2.h>
  24
  25 #define UNSET (-1U)
  26
  27
  28 struct videobuf_buffer;
  29 struct videobuf_queue;
  30
  31 /* --------------------------------------------------------------------- */
  32
  33 /*
  34  * A small set of helper functions to manage video4linux buffers.
  35  *
  36  * struct videobuf_buffer holds the data structures used by the helper
  37  * functions, additionally some commonly used fields for v4l buffers
  38  * (width, height, lists, waitqueue) are in there.  That struct should
  39  * be used as first element in the drivers buffer struct.
  40  *
  41  * about the mmap helpers (videobuf_mmap_*):
  42  *
  43  * The mmaper function allows to map any subset of contingous buffers.
  44  * This includes one mmap() call for all buffers (which the original
  45  * video4linux API uses) as well as one mmap() for every single buffer
  46  * (which v4l2 uses).
  47  *
  48  * If there is a valid mapping for a buffer, buffer->baddr/bsize holds
  49  * userspace address + size which can be feeded into the
  50  * videobuf_dma_init_user function listed above.
  51  *
  52  */
  53
  54 struct videobuf_mapping {
  55         unsigned int count;
  56         unsigned long start;
  57         unsigned long end;
  58         struct videobuf_queue *q;
  59 };
  60
  61 enum videobuf_state {
  62         VIDEOBUF_NEEDS_INIT = 0,
  63         VIDEOBUF_PREPARED   = 1,
  64         VIDEOBUF_QUEUED     = 2,
  65         VIDEOBUF_ACTIVE     = 3,
  66         VIDEOBUF_DONE       = 4,
  67         VIDEOBUF_ERROR      = 5,
  68         VIDEOBUF_IDLE       = 6,
  69 };
  70
  71 struct videobuf_buffer {
  72         unsigned int            i;
  73         u32                     magic;
  74
  75         /* info about the buffer */
  76         unsigned int            width;
  77         unsigned int            height;
  78         unsigned int            bytesperline; /* use only if != 0 */
  79         unsigned long           size;
  80         unsigned int            input;
  81         enum v4l2_field         field;
  82         enum videobuf_state     state;
  83         struct list_head        stream;  /* QBUF/DQBUF list */
  84
  85         /* touched by irq handler */
  86         struct list_head        queue;
  87         wait_queue_head_t       done;
  88         unsigned int            field_count;
  89         struct timeval          ts;
  90
  91         /* Memory type */
  92         enum v4l2_memory        memory;
  93
  94         /* buffer size */
  95         size_t                  bsize;
  96
  97         /* buffer offset (mmap + overlay) */
  98         size_t                  boff;
  99
 100         /* buffer addr (userland ptr!) */
 101         unsigned long           baddr;
 102
 103         /* for mmap'ed buffers */
 104         struct videobuf_mapping *map;
 105
 106         /* Private pointer to allow specific methods to store their data */
 107         int                     privsize;
 108         void                    *priv;
 109 };
 110
 111 struct videobuf_queue_ops {
 112         int (*buf_setup)(struct videobuf_queue *q,
 113                          unsigned int *count, unsigned int *size);
 114         int (*buf_prepare)(struct videobuf_queue *q,
 115                            struct videobuf_buffer *vb,
 116                            enum v4l2_field field);
 117         void (*buf_queue)(struct videobuf_queue *q,
 118                           struct videobuf_buffer *vb);
 119         void (*buf_release)(struct videobuf_queue *q,
 120                             struct videobuf_buffer *vb);
 121 };
 122
 123 #define MAGIC_QTYPE_OPS 0x12261003
 124
 125 /* Helper operations - device type dependent */
 126 struct videobuf_qtype_ops {
 127         u32                     magic;
 128
 129         void *(*alloc)          (size_t size);
 130         void *(*vmalloc)        (struct videobuf_buffer *buf);
 131         int (*iolock)           (struct videobuf_queue* q,
 132                                  struct videobuf_buffer *vb,
 133                                  struct v4l2_framebuffer *fbuf);
 134         int (*mmap)             (struct videobuf_queue *q,
 135                                  unsigned int *count,
 136                                  unsigned int *size,
 137                                  enum v4l2_memory memory);
 138         int (*sync)             (struct videobuf_queue* q,
 139                                  struct videobuf_buffer *buf);
 140         int (*video_copy_to_user)(struct videobuf_queue *q,
 141                                  char __user *data,
 142                                  size_t count,
 143                                  int nonblocking);
 144         int (*copy_stream)      (struct videobuf_queue *q,
 145                                  char __user *data,
 146                                  size_t count,
 147                                  size_t pos,
 148                                  int vbihack,
 149                                  int nonblocking);
 150         int (*mmap_free)        (struct videobuf_queue *q);
 151         int (*mmap_mapper)      (struct videobuf_queue *q,
 152                                 struct vm_area_struct *vma);
 153 };
 154
 155 struct videobuf_queue {
 156         struct mutex               vb_lock;
 157         spinlock_t                 *irqlock;
 158         struct device              *dev;
 159
 160         wait_queue_head_t          wait; /* wait if queue is empty */
 161
 162         enum v4l2_buf_type         type;
 163         unsigned int               inputs; /* for V4L2_BUF_FLAG_INPUT */
 164         unsigned int               msize;
 165         enum v4l2_field            field;
 166         enum v4l2_field            last;   /* for field=V4L2_FIELD_ALTERNATE */
 167         struct videobuf_buffer     *bufs[VIDEO_MAX_FRAME];
 168         struct videobuf_queue_ops  *ops;
 169         struct videobuf_qtype_ops  *int_ops;
 170
 171         unsigned int               streaming:1;
 172         unsigned int               reading:1;
 173         unsigned int               is_mmapped:1;
 174
 175         /* capture via mmap() + ioctl(QBUF/DQBUF) */
 176         struct list_head           stream;
 177
 178         /* capture via read() */
 179         unsigned int               read_off;
 180         struct videobuf_buffer     *read_buf;
 181
 182         /* driver private data */
 183         void                       *priv_data;
 184 };
 185
 186 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
 187 int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
 188                 struct v4l2_framebuffer *fbuf);
 189
 190 void *videobuf_alloc(struct videobuf_queue* q);
 191
 192 /* Used on videobuf-dvb */
 193 void *videobuf_queue_to_vmalloc (struct videobuf_queue* q,
 194                                  struct videobuf_buffer *buf);
 195
 196 void videobuf_queue_core_init(struct videobuf_queue *q,
 197                          struct videobuf_queue_ops *ops,
 198                          struct device *dev,
 199                          spinlock_t *irqlock,
 200                          enum v4l2_buf_type type,
 201                          enum v4l2_field field,
 202                          unsigned int msize,
 203                          void *priv,
 204                          struct videobuf_qtype_ops *int_ops);
 205 int  videobuf_queue_is_busy(struct videobuf_queue *q);
 206 void videobuf_queue_cancel(struct videobuf_queue *q);
 207
 208 enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
 209 int videobuf_reqbufs(struct videobuf_queue *q,
 210                      struct v4l2_requestbuffers *req);
 211 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
 212 int videobuf_qbuf(struct videobuf_queue *q,
 213                   struct v4l2_buffer *b);
 214 int videobuf_dqbuf(struct videobuf_queue *q,
 215                    struct v4l2_buffer *b, int nonblocking);
 216 #ifdef CONFIG_VIDEO_V4L1_COMPAT
 217 int videobuf_cgmbuf(struct videobuf_queue *q,
 218                     struct video_mbuf *mbuf, int count);
 219 #endif
 220 int videobuf_streamon(struct videobuf_queue *q);
 221 int videobuf_streamoff(struct videobuf_queue *q);
 222
 223 void videobuf_stop(struct videobuf_queue *q);
 224
 225 int videobuf_read_start(struct videobuf_queue *q);
 226 void videobuf_read_stop(struct videobuf_queue *q);
 227 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 228                              char __user *data, size_t count, loff_t *ppos,
 229                              int vbihack, int nonblocking);
 230 ssize_t videobuf_read_one(struct videobuf_queue *q,
 231                           char __user *data, size_t count, loff_t *ppos,
 232                           int nonblocking);
 233 unsigned int videobuf_poll_stream(struct file *file,
 234                                   struct videobuf_queue *q,
 235                                   poll_table *wait);
 236
 237 int videobuf_mmap_setup(struct videobuf_queue *q,
 238                         unsigned int bcount, unsigned int bsize,
 239                         enum v4l2_memory memory);
 240 int videobuf_mmap_free(struct videobuf_queue *q);
 241 int videobuf_mmap_mapper(struct videobuf_queue *q,
 242                          struct vm_area_struct *vma);
 243
 244 #endif