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 #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         struct videobuf_queue *q;
  54 };
  55
  56 enum videobuf_state {
  57         VIDEOBUF_NEEDS_INIT = 0,
  58         VIDEOBUF_PREPARED   = 1,
  59         VIDEOBUF_QUEUED     = 2,
  60         VIDEOBUF_ACTIVE     = 3,
  61         VIDEOBUF_DONE       = 4,
  62         VIDEOBUF_ERROR      = 5,
  63         VIDEOBUF_IDLE       = 6,
  64 };
  65
  66 struct videobuf_buffer {
  67         unsigned int            i;
  68         u32                     magic;
  69
  70         /* info about the buffer */
  71         unsigned int            width;
  72         unsigned int            height;
  73         unsigned int            bytesperline; /* use only if != 0 */
  74         unsigned long           size;
  75         unsigned int            input;
  76         enum v4l2_field         field;
  77         enum videobuf_state     state;
  78         struct list_head        stream;  /* QBUF/DQBUF list */
  79
  80         /* touched by irq handler */
  81         struct list_head        queue;
  82         wait_queue_head_t       done;
  83         unsigned int            field_count;
  84         struct timeval          ts;
  85
  86         /* Memory type */
  87         enum v4l2_memory        memory;
  88
  89         /* buffer size */
  90         size_t                  bsize;
  91
  92         /* buffer offset (mmap + overlay) */
  93         size_t                  boff;
  94
  95         /* buffer addr (userland ptr!) */
  96         unsigned long           baddr;
  97
  98         /* for mmap'ed buffers */
  99         struct videobuf_mapping *map;
 100
 101         /* Private pointer to allow specific methods to store their data */
 102         int                     privsize;
 103         void                    *priv;
 104 };
 105
 106 struct videobuf_queue_ops {
 107         int (*buf_setup)(struct videobuf_queue *q,
 108                          unsigned int *count, unsigned int *size);
 109         int (*buf_prepare)(struct videobuf_queue *q,
 110                            struct videobuf_buffer *vb,
 111                            enum v4l2_field field);
 112         void (*buf_queue)(struct videobuf_queue *q,
 113                           struct videobuf_buffer *vb);
 114         void (*buf_release)(struct videobuf_queue *q,
 115                             struct videobuf_buffer *vb);
 116 };
 117
 118 #define MAGIC_QTYPE_OPS 0x12261003
 119
 120 /* Helper operations - device type dependent */
 121 struct videobuf_qtype_ops {
 122         u32                     magic;
 123
 124         struct videobuf_buffer *(*alloc_vb)(size_t size);
 125         void *(*vaddr)          (struct videobuf_buffer *buf);
 126         int (*iolock)           (struct videobuf_queue *q,
 127                                  struct videobuf_buffer *vb,
 128                                  struct v4l2_framebuffer *fbuf);
 129         int (*sync)             (struct videobuf_queue *q,
 130                                  struct videobuf_buffer *buf);
 131         int (*mmap_mapper)      (struct videobuf_queue *q,
 132                                  struct videobuf_buffer *buf,
 133                                  struct vm_area_struct *vma);
 134 };
 135
 136 struct videobuf_queue {
 137         struct mutex               vb_lock;
 138         struct mutex               *ext_lock;
 139         spinlock_t                 *irqlock;
 140         struct device              *dev;
 141
 142         wait_queue_head_t          wait; /* wait if queue is empty */
 143
 144         enum v4l2_buf_type         type;
 145         unsigned int               inputs; /* for V4L2_BUF_FLAG_INPUT */
 146         unsigned int               msize;
 147         enum v4l2_field            field;
 148         enum v4l2_field            last;   /* for field=V4L2_FIELD_ALTERNATE */
 149         struct videobuf_buffer     *bufs[VIDEO_MAX_FRAME];
 150         const struct videobuf_queue_ops  *ops;
 151         struct videobuf_qtype_ops  *int_ops;
 152
 153         unsigned int               streaming:1;
 154         unsigned int               reading:1;
 155
 156         /* capture via mmap() + ioctl(QBUF/DQBUF) */
 157         struct list_head           stream;
 158
 159         /* capture via read() */
 160         unsigned int               read_off;
 161         struct videobuf_buffer     *read_buf;
 162
 163         /* driver private data */
 164         void                       *priv_data;
 165 };
 166
 167 static inline void videobuf_queue_lock(struct videobuf_queue *q)
 168 {
 169         if (!q->ext_lock)
 170                 mutex_lock(&q->vb_lock);
 171 }
 172
 173 static inline void videobuf_queue_unlock(struct videobuf_queue *q)
 174 {
 175         if (!q->ext_lock)
 176                 mutex_unlock(&q->vb_lock);
 177 }
 178
 179 int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
 180                 int non_blocking, int intr);
 181 int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
 182                 struct v4l2_framebuffer *fbuf);
 183
 184 struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q);
 185
 186 /* Used on videobuf-dvb */
 187 void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
 188                               struct videobuf_buffer *buf);
 189
 190 void videobuf_queue_core_init(struct videobuf_queue *q,
 191                          const struct videobuf_queue_ops *ops,
 192                          struct device *dev,
 193                          spinlock_t *irqlock,
 194                          enum v4l2_buf_type type,
 195                          enum v4l2_field field,
 196                          unsigned int msize,
 197                          void *priv,
 198                          struct videobuf_qtype_ops *int_ops,
 199                          struct mutex *ext_lock);
 200 int  videobuf_queue_is_busy(struct videobuf_queue *q);
 201 void videobuf_queue_cancel(struct videobuf_queue *q);
 202
 203 enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
 204 int videobuf_reqbufs(struct videobuf_queue *q,
 205                      struct v4l2_requestbuffers *req);
 206 int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
 207 int videobuf_qbuf(struct videobuf_queue *q,
 208                   struct v4l2_buffer *b);
 209 int videobuf_dqbuf(struct videobuf_queue *q,
 210                    struct v4l2_buffer *b, int nonblocking);
 211 int videobuf_streamon(struct videobuf_queue *q);
 212 int videobuf_streamoff(struct videobuf_queue *q);
 213
 214 void videobuf_stop(struct videobuf_queue *q);
 215
 216 int videobuf_read_start(struct videobuf_queue *q);
 217 void videobuf_read_stop(struct videobuf_queue *q);
 218 ssize_t videobuf_read_stream(struct videobuf_queue *q,
 219                              char __user *data, size_t count, loff_t *ppos,
 220                              int vbihack, int nonblocking);
 221 ssize_t videobuf_read_one(struct videobuf_queue *q,
 222                           char __user *data, size_t count, loff_t *ppos,
 223                           int nonblocking);
 224 unsigned int videobuf_poll_stream(struct file *file,
 225                                   struct videobuf_queue *q,
 226                                   poll_table *wait);
 227
 228 int videobuf_mmap_setup(struct videobuf_queue *q,
 229                         unsigned int bcount, unsigned int bsize,
 230                         enum v4l2_memory memory);
 231 int __videobuf_mmap_setup(struct videobuf_queue *q,
 232                         unsigned int bcount, unsigned int bsize,
 233                         enum v4l2_memory memory);
 234 int videobuf_mmap_free(struct videobuf_queue *q);
 235 int videobuf_mmap_mapper(struct videobuf_queue *q,
 236                          struct vm_area_struct *vma);
 237
 238 #endif