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 #define __MIN_V4L1
  22 #include <linux/videodev.h>
  23 #endif
  24 #include <linux/videodev2.h>
  25
  26 #define UNSET (-1U)
  27
  28
  29 struct videobuf_buffer;
  30 struct videobuf_queue;
  31
  32 /* --------------------------------------------------------------------- */
  33
  34 /*
  35  * A small set of helper functions to manage video4linux buffers.
  36  *
  37  * struct videobuf_buffer holds the data structures used by the helper
  38  * functions, additionally some commonly used fields for v4l buffers
  39  * (width, height, lists, waitqueue) are in there.  That struct should
  40  * be used as first element in the drivers buffer struct.
  41  *
  42  * about the mmap helpers (videobuf_mmap_*):
  43  *
  44  * The mmaper function allows to map any subset of contingous buffers.
  45  * This includes one mmap() call for all buffers (which the original
  46  * video4linux API uses) as well as one mmap() for every single buffer
  47  * (which v4l2 uses).
  48  *
  49  * If there is a valid mapping for a buffer, buffer->baddr/bsize holds
  50  * userspace address + size which can be feeded into the
  51  * videobuf_dma_init_user function listed above.
  52  *
  53  */
  54
  55 struct videobuf_mapping {
  56         unsigned int count;
  57         unsigned long start;
  58         unsigned long end;
  59         struct videobuf_queue *q;
  60 };
  61
  62 enum videobuf_state {
  63         VIDEOBUF_NEEDS_INIT = 0,
  64         VIDEOBUF_PREPARED   = 1,
  65         VIDEOBUF_QUEUED     = 2,
  66         VIDEOBUF_ACTIVE     = 3,
  67         VIDEOBUF_DONE       = 4,
  68         VIDEOBUF_ERROR      = 5,
  69         VIDEOBUF_IDLE       = 6,
  70 };
  71
  72 struct videobuf_buffer {
  73         unsigned int            i;
  74         u32                     magic;
  75
  76         /* info about the buffer */
  77         unsigned int            width;
  78         unsigned int            height;
  79         unsigned int            bytesperline; /* use only if != 0 */
  80         unsigned long           size;
  81         unsigned int            input;
  82         enum v4l2_field         field;
  83         enum videobuf_state     state;
  84         struct list_head        stream;  /* QBUF/DQBUF list */
  85
  86         /* touched by irq handler */
  87         struct list_head        queue;
  88         wait_queue_head_t       done;
  89         unsigned int            field_count;
  90         struct timeval          ts;
  91
  92         /* Memory type */
  93         enum v4l2_memory        memory;
  94
  95         /* buffer size */
  96         size_t                  bsize;
  97
  98         /* buffer offset (mmap + overlay) */
  99         size_t                  boff;
 100
 101         /* buffer addr (userland ptr!) */
 102         unsigned long           baddr;
 103
 104         /* for mmap'ed buffers */
 105         struct videobuf_mapping *map;
 106
 107         /* Private pointer to allow specific methods to store their data */
 108         int                     privsize;
 109         void                    *priv;
 110 };
 111
 112 struct videobuf_queue_ops {
 113         int (*buf_setup)(struct videobuf_queue *q,
 114                          unsigned int *count, unsigned int *size);
 115         int (*buf_prepare)(struct videobuf_queue *q,
 116                            struct videobuf_buffer *vb,
 117                            enum v4l2_field field);
 118         void (*buf_queue)(struct videobuf_queue *q,
 119                           struct videobuf_buffer *vb);
 120         void (*buf_release)(struct videobuf_queue *q,
 121                             struct videobuf_buffer *vb);
 122 };
 123
 124 #define MAGIC_QTYPE_OPS 0x12261003
 125
 126 /* Helper operations - device type dependent */
 127 struct videobuf_qtype_ops {
 128         u32                     magic;
 129
 130         struct videobuf_buffer *(*alloc)(size_t size);
 131         void *(*vaddr)          (struct videobuf_buffer *buf);
 132         int (*iolock)           (struct videobuf_queue *q,
 133                                  struct videobuf_buffer *vb,
 134                                  struct v4l2_framebuffer *fbuf);
 135         int (*sync)             (struct videobuf_queue *q,
 136                                  struct videobuf_buffer *buf);
 137         int (*mmap_mapper)      (struct videobuf_queue *q,
 138                                 struct vm_area_struct *vma);
 139 };
 140
 141 struct videobuf_queue {
 142         struct mutex               vb_lock;
 143         spinlock_t                 *irqlock;
 144         struct device              *dev;
 145
 146         wait_queue_head_t          wait; /* wait if queue is empty */
 147
 148         enum v4l2_buf_type         type;
 149         unsigned int               inputs; /* for V4L2_BUF_FLAG_INPUT */
 150         unsigned int               msize;
 151         enum v4l2_field            field;
 152         enum v4l2_field            last;   /* for field=V4L2_FIELD_ALTERNATE */
 153         struct videobuf_buffer     *bufs[VIDEO_MAX_FRAME];
 154         const struct videobuf_queue_ops  *ops;
 155         struct videobuf_qtype_ops  *int_ops;
 156
 157         unsigned int               streaming:1;
 158         unsigned int               reading:1;
 159
 160         /* capture via mmap() + ioctl(QBUF/DQBUF) */
 161         struct list_head           stream;
 162
 163         /* capture via read() */
 164         unsigned int               read_off;
 165         struct videobuf_buffer     *read_buf;
 166
 167         /* driver private data */
 168         void                       *priv_data;
 169 };
 170
 171 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
 172 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
 173                 struct v4l2_framebuffer *fbuf);
 174
 175 struct videobuf_buffer *videobuf_alloc(struct videobuf_queue *q);
 176
 177 /* Used on videobuf-dvb */
 178 void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
 179                               struct videobuf_buffer *buf);
 180
 181 void videobuf_queue_core_init(struct videobuf_queue *q,
 182                          const struct videobuf_queue_ops *ops,
 183                          struct device *dev,
 184                          spinlock_t *irqlock,
 185                          enum v4l2_buf_type type,
 186                          enum v4l2_field field,
 187                          unsigned int msize,
 188                          void *priv,
 189                          struct videobuf_qtype_ops *int_ops);
 190 int  videobuf_queue_is_busy(struct videobuf_queue *q);
 191 void videobuf_queue_cancel(struct videobuf_queue *q);
 192
 193 enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
 194 int videobuf_reqbufs(struct videobuf_queue *q,
 195                      struct v4l2_requestbuffers *req);
 196 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
 197 int videobuf_qbuf(struct videobuf_queue *q,
 198                   struct v4l2_buffer *b);
 199 int videobuf_dqbuf(struct videobuf_queue *q,
 200                    struct v4l2_buffer *b, int nonblocking);
 201 #ifdef CONFIG_VIDEO_V4L1_COMPAT
 202 int videobuf_cgmbuf(struct videobuf_queue *q,
 203                     struct video_mbuf *mbuf, int count);
 204 #endif
 205 int videobuf_streamon(struct videobuf_queue *q);
 206 int videobuf_streamoff(struct videobuf_queue *q);
 207
 208 void videobuf_stop(struct videobuf_queue *q);
 209
 210 int videobuf_read_start(struct videobuf_queue *q);
 211 void videobuf_read_stop(struct videobuf_queue *q);
 212 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 213                              char __user *data, size_t count, loff_t *ppos,
 214                              int vbihack, int nonblocking);
 215 ssize_t videobuf_read_one(struct videobuf_queue *q,
 216                           char __user *data, size_t count, loff_t *ppos,
 217                           int nonblocking);
 218 unsigned int videobuf_poll_stream(struct file *file,
 219                                   struct videobuf_queue *q,
 220                                   poll_table *wait);
 221
 222 int videobuf_mmap_setup(struct videobuf_queue *q,
 223                         unsigned int bcount, unsigned int bsize,
 224                         enum v4l2_memory memory);
 225 int __videobuf_mmap_setup(struct videobuf_queue *q,
 226                         unsigned int bcount, unsigned int bsize,
 227                         enum v4l2_memory memory);
 228 int videobuf_mmap_free(struct videobuf_queue *q);
 229 int videobuf_mmap_mapper(struct videobuf_queue *q,
 230                          struct vm_area_struct *vma);
 231
 232 #endif